WO1998029785A1 - Device in a process system for validating a control signal from a field device - Google Patents

Device in a process system for validating a control signal from a field device Download PDF

Info

Publication number
WO1998029785A1
WO1998029785A1 PCT/US1997/023496 US9723496W WO9829785A1 WO 1998029785 A1 WO1998029785 A1 WO 1998029785A1 US 9723496 W US9723496 W US 9723496W WO 9829785 A1 WO9829785 A1 WO 9829785A1
Authority
WO
WIPO (PCT)
Prior art keywords
learned
control
cycle
variable
information
Prior art date
Application number
PCT/US1997/023496
Other languages
French (fr)
Inventor
Evren Eryurek
Original Assignee
Rosemount Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rosemount Inc. filed Critical Rosemount Inc.
Priority to JP53011198A priority Critical patent/JP4643771B2/en
Priority to EP97953328A priority patent/EP0948759B1/en
Priority to CA002276299A priority patent/CA2276299A1/en
Priority to DE69714606T priority patent/DE69714606T9/en
Publication of WO1998029785A1 publication Critical patent/WO1998029785A1/en

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
    • G05B13/0265—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric the criterion being a learning criterion
    • G05B13/0285—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric the criterion being a learning criterion using neural networks and fuzzy logic
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
    • G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/418—Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS], computer integrated manufacturing [CIM]
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00—Program-control systems
    • G05B2219/20—Pc systems
    • G05B2219/25—Pc structure of the system
    • G05B2219/25428—Field device
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P90/00—Enabling technologies with a potential contribution to greenhouse gas [GHG] emissions mitigation
    • Y02P90/02—Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Definitions

  • the present invention relates to devices which couple to process control loops of the type used in industry. More specifically, the invention relates to validating a control signal from a field device.
  • Process control loops are used in industry to control operation of a process, such as an oil refinery.
  • a transmitter is typically part of the loop and is located in the field to measure and transmit a process variable such as pressure, flow or temperature, for example, to control room equipment.
  • a controller such as a valve controller is also part of the process control loop and controls position of a valve based upon a control signal received over the control loop or generated internally. Other controllers control electric motors or solenoids, for example.
  • the control room equipment is also part of the process control loop such that an operator or computer in the control room is capable of monitoring the process based upon process variables received from transmitters in the field and responsively controlling the process by sending control signals to the appropriate control devices.
  • Another process device which may be part of a control loop, is a portable communicator which is capable of monitoring and transmitting process signals on the process control loop. These are often used to configure devices which form the loop. It is desirable to validate the control signals in the process control system thereby improving the reliability of the entire loop.
  • the prior art has been limited to simple validation techniques, such as monitoring a control signal and sounding an alarm or providing a safety shutdown if the control signal exceeds predefined limits .
  • Another prior art technique is to generate a redundant control signal using the same or a different control algorithm and compare the two control signals . The control signal is invalidated if it differs from the redundant signal.
  • a device in a process control system includes a memory for storing a series of sensed process variables and command outputs representative of a learned process cycle. Comparison circuitry compares recent process information to learned process information stored in the memory and responsively provides a validity output signal.
  • a method in accordance with one aspect of the invention includes learning a cycle of a process to provide learned process information which comprises stored process variables and stored control signals over a time period, measuring a process variable in the process and responsively calculating the control output, storing the process variable in the control output to provide recent process information, and comparing the recent process information to the learned process information and responsively providing a validity output signal.
  • Figure 1 is a simplified diagram showing a process control loop including a transmitter, controller, hand-held communicator and control room.
  • FIG. 2 is a block diagram of a process device in accordance with the present invention.
  • Figure 3 is a simplified block diagram showing steps in accordance with the present invention.
  • Figure 4A shows a learning cycle and
  • Figure 4B shows an operation cycle for two process variables and a control signal.
  • Process variables are typically the primary variables which are being controlled in a process.
  • process variable means any variable which describes the condition of the process such as, for example, pressure, flow, temperature, product level, pH, turbidity, vibration, position, motor current, any other characteristic of the process, etc.
  • Control signal means any signal (other than a process variable) which is used to control the process.
  • control signal means a desired process variable value (i.e.
  • a setpoint such as a desired temperature, pressure, flow, product level, pH or turbidity, etc., which is adjusted by a controller or used to control the process.
  • a control signal means, calibration values, alarms, alarm conditions, the signal which is provided to a control element such as a valve position signal which is provided to a valve actuator, an energy level which is provided to a heating element, a solenoid on/off signal, etc., or any other signal which relates to control of the process.
  • Process devices include any device which forms part of or couples to a process control loop and is used in the control or monitoring of a process.
  • FIG. 1 is a diagram showing an example of a process control system 2 which includes process piping 4 carrying a process fluid and two wire process control loop 6 carrying loop current I.
  • Transmitter 8 controller 10 (which couples to a final control element in the loop such as an actuator, valve, a pump, motor or solenoid), communicator 12, pc 13 and control room 14 are all part of process control loop 6.
  • loop 6 is shown in one configuration and any appropriate process control loop may be used such as a 4-20 mA loop, 2, 3 or 4 wire loop, multi-drop loop and a loop operating in accordance with the HART®, Fieldbus or other digital or analog communication protocol .
  • transmitter 8 senses a process variable such as flow using sensor 16 and transmits the sensed process variable over loop 6.
  • the process variable may be received by controller/valve actuator 10, communicator 12, pc 13 and/or control room equipment 14.
  • Controller 10 is shown coupled to valve 18, and is capable of controlling the process by adjusting valve 18 thereby changing the flow in pipe 4.
  • Controller 10 receives a control input over loop 6 from, for example, control room 14, transmitter 8 or communicator 12 and responsively adjusts valve 18.
  • controller 10 internally generates the control signal based upon process signals received over loop 6.
  • Communicator 12 may be the portable communicator shown in Figure 1 or may be a permanently mounted process unit which monitors the process and performs computations.
  • Process devices include, for example, transmitter 8, controller 10, communicator 12 and control room 14 shown in Figure 1.
  • Another type of process device is a PC, programmable logic unit (PLC) or other computer coupled to the loop using appropriate I/O circuitry to allow monitoring, managing, and/or transmitting on the loop.
  • PLC programmable logic unit
  • FIG. 1 is a block diagram of a process device 40 forming part of loop 6.
  • Device 40 is shown generically and may comprise any of process device 8-14.
  • device 40 comprises pc 13.
  • Control room equipment 14 may comprise, for example, a DCS system implemented with a PLC and controller 10 may also comprise a "smart" motor and pump.
  • Process device 40 includes I/O circuitry 42 coupled to loop 6 at terminals 44. I/O circuitry has preselected input and output impedances known in the art to facilitate appropriate communication from and to device 40.
  • Device 40 includes microprocessor 46, coupled to I/O circuitry 42, memory 48 coupled to microprocessor 46 and clock 50 coupled to microprocessor 46.
  • Microprocessor 46 receives a process signal input 52.
  • Input 52 is intended to signify input of any process signal, and as explained above, the process signal input may be a process variable, or a control signal and may be received from loop 6 using I/O circuitry 42 or may be generated internally within field device 40.
  • Field device 40 is shown with a sensor input channel 54 and a control channel 56. In many instances, a transmitter such as transmitter 8 will exclusively include sensor input channel 54 while a controller such as controller 10 will exclusively include a control channel 56. Other devices on loop 6 such as communicator 12 and control room equipment 14 may not include channels 54 and 56. It is understood that device 40 may contain a plurality of channels to monitor a plurality of process variables and/or control a plurality of control elements as appropriate.
  • Sensor input channel 54 includes sensor 16, sensing a process variable and providing a sensor output to amplifier 58 which has an output which is digitized by analog to digital converter 60.
  • Channel 54 is typically used in transmitters such as transmitter 8.
  • Compensation circuitry 62 compensates the digitized signal and provides a digitized process variable signal to microprocessor 46.
  • control element 18 such as a valve, for example.
  • Control element 18 is coupled to microprocessor 46 through digital to analog converter 64, amplifier 66 and actuator 68.
  • Digital to analog converter 64 digitizes a command output from microprocessor 46 which is amplified by amplifier 66.
  • Actuator 68 controls the control element 18 based upon the output from amplifier 66.
  • actuator 68 is coupled directly to loop 6 and controls a source of pressurized air (not shown) to position control element 18 in response to the current I flowing through loop 6.
  • I/O circuitry 42 provides a power output used to completely power all the circuitry in process device 40 using power received from loop 6.
  • process signal input 52 provides a process signal to microprocessor 46.
  • the process signal may be a process variable from sensor 16, the control output provided to control element 18, or a control signal, process variable or diagnostic signal received over loop 6, or a process signal received or generated by some other means such as another I/O channel.
  • a user I/O circuit 76 is also connected to microprocessor 46 and provides communication between device 40 and a user.
  • User I/O circuit 76 includes, for example, a display for output and a keypad for input.
  • communicator 12 and control room 14 includes I/O circuit 76 which allows a user to monitor and input process signals such as process variables, control signals (setpoints, calibration values, alarms, alarm conditions, etc.)
  • a user may also use circuit 76 in cor.municator 12 or control room 14 to send and receive such process signals between transmitter 8 and controller 10 over loop 6. Further, such circuitry could be directly implemented in transmitter 8, controller 10 or any other process device 40.
  • Microprocessor 46 acts in accordance with instructions stored in memory 48 and provides, in some embodiments, a sensor compensation function 80 and/or a control function 82.
  • microprocessor 46 provides a control signal validation function 84 in accordance with the present invention. The command signal to be validated may be received, for example, through any of the various inputs to microprocessor 46 described above.
  • FIG. 3 is a simplified block diagram 80 of a command validation function in accordance with the present invention performed by microprocessor 46 in response to instructions stored in memory 48 shown in Figure 2.
  • the function is initiated during a repeatable process cycle 82 and enters a process learning cycle 84.
  • Process learning cycle 84 includes block 86 during which process signal(s) are obtained and stored in memory 48 at block 88. More than one process pattern may be obtained and stored in memory 48.
  • Cycle 84 may be performed during commissioning of the process control loop or during manufacturing process (e.g., while the loop is operating) .
  • Control is then passed to block 90 in which a control signal is obtained and stored in memory 48 at block 92.
  • block 94 the current values of the process signal(s) and control signal are obtained.
  • Block 96 is a comparison function in which process cycles which were learned during learning cycle 84 are compared to the current process signal (s) and the current control signal. If the current control signal is wichin boundaries determined based upon the learned process cycle, control is returned to block 82. On the other hand, if the control signal has exceeded the predetermined boundaries, control is passed to block 98 and an error condition is initiated. This error condition is also referred to herein as the validity signal which is generated by microprocessor 46. The validity signal may trigger an error event which is signalled across loop 6 or initiate a special control condition such as an emergency shut down. Furthermore, control is optionally passed to block 100 in which an alternate controller is used to generate the control signal and control the process in real time.
  • Figures 4A and 4B show a control signal C and two process variable signals PVl and PV2 , each plotted versus time, so as to illustrate operation of block diagram 80 of Figure 3.
  • PVl and PV2 may be any of the process variables available in the control system.
  • Figure 4A shows the process cycle during the learning cycle 84 in which process variables PVl and PV2 and control signal C are monitored and stored in memory 48.
  • the process cycle is divided into phases, Phase 1 and Phase 2.
  • information regarding the two process variables is collected and stored such that it will be possible to subsequently identify in which phase the process is currently operating. For example, such information would be the minimum, maximum and rate of change values for PVl and PV2 may be stored along with the minimum, maximum and rate of change for the control signal C for each phase. If there is sufficient memory, data points for the entire phase may be stored.
  • Figure 4B shows a process cycle after the learning period during which time the control signal C experiences an error and illustrates operation of comparison block 96 in Figure 3.
  • PVl and PV2 are monitored to determine "where" in the cycle the process is currently operating, for example, Phase 1 or Phase 2. Then, using a rule based system as an example, if the control signal and the rate of change of the control signal are outside of predetermined percentages of the (learned) stored values, an error is generated. This is shown in Phase 2 of Figure 4B in which the control signal, C, exceeds a predetermined percentage (THRESHOLD). The predetermined percentage is set, for example, during commissioning and stored in memory 48. Microprocessor 48 generates the validity signal error condition shown at block 98 in Figure 3.
  • TRESHOLD predetermined percentage
  • the learning cycle of the present invention can occur over a single process cycle or may be based upon the observance of a number of cycles. Further, the learned values may be selectively updated during subsequent process cycles.
  • the comparison function may be through any appropriate technique including fuzzy logic algorithms, neural networks regression algorithms, other more complex rule based systems, etc. Models for different processes, including thresholds for rule sets, may be stored in memory 48 and selected and optionally optimized over a number of process cycles by a user.
  • process device may include any number or combination of input and control channels and may operate on any number of process signals, alone or in their combination.

Abstract

A device (40) in a process control system (2) includes a memory (48) for storing a series of sensed process variables and command outputs representative of a learned process cycle. Comparison circuitry (80) compares recent process information to learned process information stored in the memory (48) and responsively provides a validity output signal. A method includes learning a cycle of a process to provide learned process information which comprises stored process variables and stored control signals over a time period, measuring a process variable in the process and responsively calculating the control output, storing the process variable in the control output to provide recent process information, and comparing the recent process information to the learned process information and responsively providing a validity output signal.

Description

DEVICE IN A PROCESS SYSTEM FOR VALIDATING A CONTROL SIGNAL FROM A FIELD DEVICE
BACKGROUND OF THE INVENTION The present invention relates to devices which couple to process control loops of the type used in industry. More specifically, the invention relates to validating a control signal from a field device.
Process control loops are used in industry to control operation of a process, such as an oil refinery. A transmitter is typically part of the loop and is located in the field to measure and transmit a process variable such as pressure, flow or temperature, for example, to control room equipment. A controller such as a valve controller is also part of the process control loop and controls position of a valve based upon a control signal received over the control loop or generated internally. Other controllers control electric motors or solenoids, for example. The control room equipment is also part of the process control loop such that an operator or computer in the control room is capable of monitoring the process based upon process variables received from transmitters in the field and responsively controlling the process by sending control signals to the appropriate control devices. Another process device, which may be part of a control loop, is a portable communicator which is capable of monitoring and transmitting process signals on the process control loop. These are often used to configure devices which form the loop. It is desirable to validate the control signals in the process control system thereby improving the reliability of the entire loop. Typically, the prior art has been limited to simple validation techniques, such as monitoring a control signal and sounding an alarm or providing a safety shutdown if the control signal exceeds predefined limits . Another prior art technique is to generate a redundant control signal using the same or a different control algorithm and compare the two control signals . The control signal is invalidated if it differs from the redundant signal.
SUMMARY OF THE INVENTION
A device in a process control system includes a memory for storing a series of sensed process variables and command outputs representative of a learned process cycle. Comparison circuitry compares recent process information to learned process information stored in the memory and responsively provides a validity output signal. A method in accordance with one aspect of the invention includes learning a cycle of a process to provide learned process information which comprises stored process variables and stored control signals over a time period, measuring a process variable in the process and responsively calculating the control output, storing the process variable in the control output to provide recent process information, and comparing the recent process information to the learned process information and responsively providing a validity output signal. BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a simplified diagram showing a process control loop including a transmitter, controller, hand-held communicator and control room.
Figure 2 is a block diagram of a process device in accordance with the present invention.
Figure 3 is a simplified block diagram showing steps in accordance with the present invention. Figure 4A shows a learning cycle and Figure 4B shows an operation cycle for two process variables and a control signal.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a technique for validating control signals in a process control system to control process variables. Process variables are typically the primary variables which are being controlled in a process. As used herein, process variable means any variable which describes the condition of the process such as, for example, pressure, flow, temperature, product level, pH, turbidity, vibration, position, motor current, any other characteristic of the process, etc. Control signal means any signal (other than a process variable) which is used to control the process. For example, control signal means a desired process variable value (i.e. a setpoint) such as a desired temperature, pressure, flow, product level, pH or turbidity, etc., which is adjusted by a controller or used to control the process. Additionally, a control signal means, calibration values, alarms, alarm conditions, the signal which is provided to a control element such as a valve position signal which is provided to a valve actuator, an energy level which is provided to a heating element, a solenoid on/off signal, etc., or any other signal which relates to control of the process. Process devices include any device which forms part of or couples to a process control loop and is used in the control or monitoring of a process.
Figure 1 is a diagram showing an example of a process control system 2 which includes process piping 4 carrying a process fluid and two wire process control loop 6 carrying loop current I. Transmitter 8, controller 10 (which couples to a final control element in the loop such as an actuator, valve, a pump, motor or solenoid), communicator 12, pc 13 and control room 14 are all part of process control loop 6. It is understood that loop 6 is shown in one configuration and any appropriate process control loop may be used such as a 4-20 mA loop, 2, 3 or 4 wire loop, multi-drop loop and a loop operating in accordance with the HART®, Fieldbus or other digital or analog communication protocol . In operation, transmitter 8 senses a process variable such as flow using sensor 16 and transmits the sensed process variable over loop 6. The process variable may be received by controller/valve actuator 10, communicator 12, pc 13 and/or control room equipment 14. Controller 10 is shown coupled to valve 18, and is capable of controlling the process by adjusting valve 18 thereby changing the flow in pipe 4. Controller 10 receives a control input over loop 6 from, for example, control room 14, transmitter 8 or communicator 12 and responsively adjusts valve 18. In another embodiment, controller 10 internally generates the control signal based upon process signals received over loop 6. Communicator 12 may be the portable communicator shown in Figure 1 or may be a permanently mounted process unit which monitors the process and performs computations. Process devices include, for example, transmitter 8, controller 10, communicator 12 and control room 14 shown in Figure 1. Another type of process device is a PC, programmable logic unit (PLC) or other computer coupled to the loop using appropriate I/O circuitry to allow monitoring, managing, and/or transmitting on the loop.
Any of the process devices 8, 10, 12, 13 or 14 shown in Figure 1 may include control signal validation circuitry in accordance with the present invention. Figure 2 is a block diagram of a process device 40 forming part of loop 6. Device 40 is shown generically and may comprise any of process device 8-14. In one preferred embodiment, device 40 comprises pc 13. Control room equipment 14 may comprise, for example, a DCS system implemented with a PLC and controller 10 may also comprise a "smart" motor and pump. Process device 40 includes I/O circuitry 42 coupled to loop 6 at terminals 44. I/O circuitry has preselected input and output impedances known in the art to facilitate appropriate communication from and to device 40. Device 40 includes microprocessor 46, coupled to I/O circuitry 42, memory 48 coupled to microprocessor 46 and clock 50 coupled to microprocessor 46. Microprocessor 46 receives a process signal input 52. Input 52 is intended to signify input of any process signal, and as explained above, the process signal input may be a process variable, or a control signal and may be received from loop 6 using I/O circuitry 42 or may be generated internally within field device 40. Field device 40 is shown with a sensor input channel 54 and a control channel 56. In many instances, a transmitter such as transmitter 8 will exclusively include sensor input channel 54 while a controller such as controller 10 will exclusively include a control channel 56. Other devices on loop 6 such as communicator 12 and control room equipment 14 may not include channels 54 and 56. It is understood that device 40 may contain a plurality of channels to monitor a plurality of process variables and/or control a plurality of control elements as appropriate.
Sensor input channel 54 includes sensor 16, sensing a process variable and providing a sensor output to amplifier 58 which has an output which is digitized by analog to digital converter 60. Channel 54 is typically used in transmitters such as transmitter 8. Compensation circuitry 62 compensates the digitized signal and provides a digitized process variable signal to microprocessor 46.
When process device 40 operates as a controller such as controller 8, device 40 includes control channel 56 having control element 18 such as a valve, for example. Control element 18 is coupled to microprocessor 46 through digital to analog converter 64, amplifier 66 and actuator 68. Digital to analog converter 64 digitizes a command output from microprocessor 46 which is amplified by amplifier 66. Actuator 68 controls the control element 18 based upon the output from amplifier 66. In one embodiment, actuator 68 is coupled directly to loop 6 and controls a source of pressurized air (not shown) to position control element 18 in response to the current I flowing through loop 6. In one embodiment, I/O circuitry 42 provides a power output used to completely power all the circuitry in process device 40 using power received from loop 6. Typically, field devices such as transmitter 8, or controller 10 are powered from the loop 6 while communicator 12 or control room 14 has a separate power source. As described above, process signal input 52 provides a process signal to microprocessor 46. The process signal may be a process variable from sensor 16, the control output provided to control element 18, or a control signal, process variable or diagnostic signal received over loop 6, or a process signal received or generated by some other means such as another I/O channel. A user I/O circuit 76 is also connected to microprocessor 46 and provides communication between device 40 and a user. User I/O circuit 76 includes, for example, a display for output and a keypad for input. Typically, communicator 12 and control room 14 includes I/O circuit 76 which allows a user to monitor and input process signals such as process variables, control signals (setpoints, calibration values, alarms, alarm conditions, etc.) A user may also use circuit 76 in cor.municator 12 or control room 14 to send and receive such process signals between transmitter 8 and controller 10 over loop 6. Further, such circuitry could be directly implemented in transmitter 8, controller 10 or any other process device 40. Microprocessor 46 acts in accordance with instructions stored in memory 48 and provides, in some embodiments, a sensor compensation function 80 and/or a control function 82. Furthermore, microprocessor 46 provides a control signal validation function 84 in accordance with the present invention. The command signal to be validated may be received, for example, through any of the various inputs to microprocessor 46 described above.
Figure 3 is a simplified block diagram 80 of a command validation function in accordance with the present invention performed by microprocessor 46 in response to instructions stored in memory 48 shown in Figure 2. The function is initiated during a repeatable process cycle 82 and enters a process learning cycle 84. Process learning cycle 84 includes block 86 during which process signal(s) are obtained and stored in memory 48 at block 88. More than one process pattern may be obtained and stored in memory 48. Cycle 84 may be performed during commissioning of the process control loop or during manufacturing process (e.g., while the loop is operating) . Control is then passed to block 90 in which a control signal is obtained and stored in memory 48 at block 92. At block 94, the current values of the process signal(s) and control signal are obtained. Block 96 is a comparison function in which process cycles which were learned during learning cycle 84 are compared to the current process signal (s) and the current control signal. If the current control signal is wichin boundaries determined based upon the learned process cycle, control is returned to block 82. On the other hand, if the control signal has exceeded the predetermined boundaries, control is passed to block 98 and an error condition is initiated. This error condition is also referred to herein as the validity signal which is generated by microprocessor 46. The validity signal may trigger an error event which is signalled across loop 6 or initiate a special control condition such as an emergency shut down. Furthermore, control is optionally passed to block 100 in which an alternate controller is used to generate the control signal and control the process in real time.
Figures 4A and 4B show a control signal C and two process variable signals PVl and PV2 , each plotted versus time, so as to illustrate operation of block diagram 80 of Figure 3. PVl and PV2 may be any of the process variables available in the control system. Figure 4A shows the process cycle during the learning cycle 84 in which process variables PVl and PV2 and control signal C are monitored and stored in memory 48. In this example, the process cycle is divided into phases, Phase 1 and Phase 2. For each phase, information regarding the two process variables is collected and stored such that it will be possible to subsequently identify in which phase the process is currently operating. For example, such information would be the minimum, maximum and rate of change values for PVl and PV2 may be stored along with the minimum, maximum and rate of change for the control signal C for each phase. If there is sufficient memory, data points for the entire phase may be stored.
Figure 4B shows a process cycle after the learning period during which time the control signal C experiences an error and illustrates operation of comparison block 96 in Figure 3. First, PVl and PV2 are monitored to determine "where" in the cycle the process is currently operating, for example, Phase 1 or Phase 2. Then, using a rule based system as an example, if the control signal and the rate of change of the control signal are outside of predetermined percentages of the (learned) stored values, an error is generated. This is shown in Phase 2 of Figure 4B in which the control signal, C, exceeds a predetermined percentage (THRESHOLD). The predetermined percentage is set, for example, during commissioning and stored in memory 48. Microprocessor 48 generates the validity signal error condition shown at block 98 in Figure 3.
The learning cycle of the present invention can occur over a single process cycle or may be based upon the observance of a number of cycles. Further, the learned values may be selectively updated during subsequent process cycles. The comparison function may be through any appropriate technique including fuzzy logic algorithms, neural networks regression algorithms, other more complex rule based systems, etc. Models for different processes, including thresholds for rule sets, may be stored in memory 48 and selected and optionally optimized over a number of process cycles by a user. Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, all of the various functions and circuitry described herein can be implemented in any appropriate circuitry including software, ASICs, fuzzy logic techniques, or even analog implementations. Further, the process device may include any number or combination of input and control channels and may operate on any number of process signals, alone or in their combination.

Claims

WHAT IS CLAIMED IS:
1. A method for validating a control output from a field device in a process, the method comprising: learning a cycle of the process to provide a learned process information, the learned process information comprising stored process variables and stored control outputs over a specific time period; measuring a current process variable in the process and calculating the current control output for the process as a function of the current process variable to provide current process information; and comparing the current process information to the learned process information and providing a validity signal.
2. The method of claim 1 wherein the steps are performed in the field device.
3. The method of claim 1 wherein the process variable is measured at a first location and the control output is calculated at a second location and the comparing is performed at the second location.
4. The method of claim 1 wherein process variable measured in a first location, the control output calculated at a second location and the comparing is performed at a third location.
5. The method of claim 1 wherein the learned process information is modeled in a fuzzy logic algorithm.
6. The method of claim 1 wherein the learned process information is modeled by a neural network.
7. The method of claim ΓÇó 1 wherein the learned process information is modeled by a regression algorithm.
8. A two-wire device of the type used in the process control industry, comprising: a process variable input receiving a process variable; a control circuit for calculating a control output as a function of the sensed process variable and a setpoint; a memory for storing a series of sensed process variables and command outputs representative of a learned process cycle; an output circuit for formatting the control output onto the two wires; and a validation circuit which compares the learned process cycle to the sensed process variable and command output to responsively provide a validation signal representative of a state of the control output .
9. The device of claim 8 including a compensation circuit compensating the process variable.
10. The device of claim 8 wherein the learned process cycle is modeled in a fuzzy logic algorithm.
11. The device of claim 8 wherein the learned process cycle is modeled by a neural network.
12. The device of claim 8 wherein the learned process cycle is modeled by a regression algorithm.
13. The device of claim 8 wherein the process variable input comprises a sensor for sensing a process variable.
14. The device of claim 8 wherein the device is wholly powered through the two-wire loop.
15. The device of claim 8 wherein the device comprises a transmitter.
PCT/US1997/023496 1996-12-31 1997-12-29 Device in a process system for validating a control signal from a field device WO1998029785A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP53011198A JP4643771B2 (en) 1996-12-31 1997-12-29 Method and apparatus for verifying the validity of control signals from field devices
EP97953328A EP0948759B1 (en) 1996-12-31 1997-12-29 Device in a process system for validating a control signal from a field device
CA002276299A CA2276299A1 (en) 1996-12-31 1997-12-29 Device in a process system for validating a control signal from a field device
DE69714606T DE69714606T9 (en) 1996-12-31 1997-12-29 DEVICE FOR CHECKING A CONTROL SIGNAL COMING FROM A PLANT IN A PROCESS CONTROL

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US3412596P 1996-12-31 1996-12-31
US60/034,125 1996-12-31

Publications (1)

Publication Number Publication Date
WO1998029785A1 true WO1998029785A1 (en) 1998-07-09

Family

ID=21874466

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1997/023496 WO1998029785A1 (en) 1996-12-31 1997-12-29 Device in a process system for validating a control signal from a field device

Country Status (7)

Country Link
US (1) US6047220A (en)
EP (1) EP0948759B1 (en)
JP (1) JP4643771B2 (en)
CN (1) CN1138193C (en)
CA (1) CA2276299A1 (en)
DE (1) DE69714606T9 (en)
WO (1) WO1998029785A1 (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19835416A1 (en) * 1998-08-05 2000-02-17 Siemens Ag Process and device for commissioning plants in the basic materials industry
WO2003050479A1 (en) * 2001-12-12 2003-06-19 Endress + Hauser Gmbh + Co.Kg Electronic field device with a sensor unit for process measurement
WO2005052881A2 (en) * 2003-11-21 2005-06-09 Rosemount Inc. Process device with supervisory overlayer
US7098798B2 (en) 2003-08-07 2006-08-29 Rosemount Inc. Process device with loop override
US7280048B2 (en) 2003-08-07 2007-10-09 Rosemount Inc. Process control loop current verification
US7464721B2 (en) 2004-06-14 2008-12-16 Rosemount Inc. Process equipment validation
US9020768B2 (en) 2011-08-16 2015-04-28 Rosemount Inc. Two-wire process control loop current diagnostics
US20170093533A1 (en) 2015-09-30 2017-03-30 Rosemount Inc. Process variable transmitter with self-learning loop diagnostics

Families Citing this family (101)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6017143A (en) 1996-03-28 2000-01-25 Rosemount Inc. Device in a process system for detecting events
US6654697B1 (en) 1996-03-28 2003-11-25 Rosemount Inc. Flow measurement with diagnostics
US7949495B2 (en) 1996-03-28 2011-05-24 Rosemount, Inc. Process variable transmitter with diagnostics
US6539267B1 (en) * 1996-03-28 2003-03-25 Rosemount Inc. Device in a process system for determining statistical parameter
US7630861B2 (en) * 1996-03-28 2009-12-08 Rosemount Inc. Dedicated process diagnostic device
US8290721B2 (en) 1996-03-28 2012-10-16 Rosemount Inc. Flow measurement diagnostics
US7146230B2 (en) * 1996-08-23 2006-12-05 Fieldbus Foundation Integrated fieldbus data server architecture
US6424872B1 (en) 1996-08-23 2002-07-23 Fieldbus Foundation Block oriented control system
US20040194101A1 (en) * 1997-08-21 2004-09-30 Glanzer David A. Flexible function blocks
US6601005B1 (en) 1996-11-07 2003-07-29 Rosemount Inc. Process device diagnostics using process variable sensor signal
US6519546B1 (en) 1996-11-07 2003-02-11 Rosemount Inc. Auto correcting temperature transmitter with resistance based sensor
US6449574B1 (en) 1996-11-07 2002-09-10 Micro Motion, Inc. Resistance based process control device diagnostics
US6754601B1 (en) 1996-11-07 2004-06-22 Rosemount Inc. Diagnostics for resistive elements of process devices
US6434504B1 (en) 1996-11-07 2002-08-13 Rosemount Inc. Resistance based process control device diagnostics
DE19827430C2 (en) * 1997-07-22 2001-07-12 Siemens Ag Monitoring procedure for the detection of infinite loops and blocked processes in a computer system
US6999824B2 (en) * 1997-08-21 2006-02-14 Fieldbus Foundation System and method for implementing safety instrumented systems in a fieldbus architecture
JP4611517B2 (en) * 1997-10-13 2011-01-12 ローズマウント インコーポレイテッド Fluid process equipment
US6615149B1 (en) 1998-12-10 2003-09-02 Rosemount Inc. Spectral diagnostics in a magnetic flow meter
US6611775B1 (en) 1998-12-10 2003-08-26 Rosemount Inc. Electrode leakage diagnostics in a magnetic flow meter
US6356191B1 (en) 1999-06-17 2002-03-12 Rosemount Inc. Error compensation for a process fluid temperature transmitter
US7010459B2 (en) * 1999-06-25 2006-03-07 Rosemount Inc. Process device diagnostics using process variable sensor signal
AU5780300A (en) 1999-07-01 2001-01-22 Rosemount Inc. Low power two-wire self validating temperature transmitter
US6505517B1 (en) 1999-07-23 2003-01-14 Rosemount Inc. High accuracy signal processing for magnetic flowmeter
US6701274B1 (en) 1999-08-27 2004-03-02 Rosemount Inc. Prediction of error magnitude in a pressure transmitter
US6556145B1 (en) 1999-09-24 2003-04-29 Rosemount Inc. Two-wire fluid temperature transmitter with thermocouple diagnostics
GB0007065D0 (en) * 2000-03-23 2000-05-10 Simsci Limited Process monitoring and control using self-validating sensors
US20050240286A1 (en) * 2000-06-21 2005-10-27 Glanzer David A Block-oriented control system on high speed ethernet
US6735484B1 (en) 2000-09-20 2004-05-11 Fargo Electronics, Inc. Printer with a process diagnostics system for detecting events
US6701665B1 (en) * 2000-10-23 2004-03-09 Phytech Ltd. Remote phytomonitoring
US6898585B2 (en) * 2001-02-02 2005-05-24 University Of Illinois Fuzzy logic method for adaptively evaluating the validity of sensor data
US20020166423A1 (en) * 2001-02-20 2002-11-14 Mueller Co. Cutting apparatus for generating threads for pipe nipples
US7389204B2 (en) * 2001-03-01 2008-06-17 Fisher-Rosemount Systems, Inc. Data presentation system for abnormal situation prevention in a process plant
US7720727B2 (en) 2001-03-01 2010-05-18 Fisher-Rosemount Systems, Inc. Economic calculations in process control system
US8073967B2 (en) 2002-04-15 2011-12-06 Fisher-Rosemount Systems, Inc. Web services-based communications for use with process control systems
WO2002091117A2 (en) 2001-05-04 2002-11-14 Invensys Systems, Inc. Process control loop analysis system
US6629059B2 (en) 2001-05-14 2003-09-30 Fisher-Rosemount Systems, Inc. Hand held diagnostic and communication device with automatic bus detection
US6859755B2 (en) * 2001-05-14 2005-02-22 Rosemount Inc. Diagnostics for industrial process control and measurement systems
US7054694B2 (en) * 2001-05-30 2006-05-30 Yokogawa Electric Corporation Process control system
US7107176B2 (en) * 2001-06-25 2006-09-12 Invensys Systems, Inc. Sensor fusion using self evaluating process sensors
US6772036B2 (en) 2001-08-30 2004-08-03 Fisher-Rosemount Systems, Inc. Control system using process model
FI20011742A (en) * 2001-08-31 2003-03-01 Metso Field Systems Oy A method and system for analyzing the performance of an industrial process control circuit
GB0122681D0 (en) * 2001-09-20 2001-11-14 Mead Corp Packaging systems apparatus and method therefor
AT411068B (en) * 2001-11-13 2003-09-25 Voest Alpine Ind Anlagen METHOD FOR PRODUCING A METAL MELT IN A LODGE TECHNICAL PLANT
JP3711976B2 (en) * 2002-12-04 2005-11-02 トヨタ自動車株式会社 Conformity value generation device, conformity procedure control program, and conformity value generation program
CA2522755A1 (en) 2003-04-16 2004-11-04 Drexel University Acoustic blood analyzer for assessing blood properties
US7523667B2 (en) * 2003-12-23 2009-04-28 Rosemount Inc. Diagnostics of impulse piping in an industrial process
US7676287B2 (en) * 2004-03-03 2010-03-09 Fisher-Rosemount Systems, Inc. Configuration system and method for abnormal situation prevention in a process plant
US7079984B2 (en) * 2004-03-03 2006-07-18 Fisher-Rosemount Systems, Inc. Abnormal situation prevention in a process plant
US7536274B2 (en) * 2004-05-28 2009-05-19 Fisher-Rosemount Systems, Inc. System and method for detecting an abnormal situation associated with a heater
US20050267709A1 (en) * 2004-05-28 2005-12-01 Fisher-Rosemount Systems, Inc. System and method for detecting an abnormal situation associated with a heater
CA2567139A1 (en) 2004-06-12 2005-12-29 Fisher-Rosemount Systems, Inc. System and method for detecting an abnormal situation associated with a process gain of a control loop
GB0415951D0 (en) * 2004-07-16 2004-08-18 Meadwestvaco Packaging Systems A method for identifying abnormal operation of a machine and an apparatus therefor
US7181654B2 (en) * 2004-09-17 2007-02-20 Fisher-Rosemount Systems, Inc. System and method for detecting an abnormal situation associated with a reactor
US7222049B2 (en) * 2005-03-11 2007-05-22 Rosemount, Inc. User-viewable relative diagnostic output
JP5049956B2 (en) * 2005-04-04 2012-10-17 フィッシャー−ローズマウント システムズ，インコーポレイテッド Statistical processing methods used to detect abnormal situations
US8112565B2 (en) * 2005-06-08 2012-02-07 Fisher-Rosemount Systems, Inc. Multi-protocol field device interface with automatic bus detection
US7835295B2 (en) * 2005-07-19 2010-11-16 Rosemount Inc. Interface module with power over Ethernet function
US20070068225A1 (en) 2005-09-29 2007-03-29 Brown Gregory C Leak detector for process valve
US7489977B2 (en) * 2005-12-20 2009-02-10 Fieldbus Foundation System and method for implementing time synchronization monitoring and detection in a safety instrumented system
US8676357B2 (en) * 2005-12-20 2014-03-18 Fieldbus Foundation System and method for implementing an extended safety instrumented system
DE102006004582B4 (en) * 2006-02-01 2010-08-19 Siemens Ag Procedure for diagnosing clogging of a pulse line in a pressure transmitter and pressure transmitter
US8032234B2 (en) * 2006-05-16 2011-10-04 Rosemount Inc. Diagnostics in process control and monitoring systems
CN101501469B (en) * 2006-07-20 2011-04-27 西门子公司 Method for the diagnosis of a blockage of an impulse line in a pressure measurement transducer, and pressure measurement transducer
US7657399B2 (en) * 2006-07-25 2010-02-02 Fisher-Rosemount Systems, Inc. Methods and systems for detecting deviation of a process variable from expected values
US8606544B2 (en) 2006-07-25 2013-12-10 Fisher-Rosemount Systems, Inc. Methods and systems for detecting deviation of a process variable from expected values
US8145358B2 (en) * 2006-07-25 2012-03-27 Fisher-Rosemount Systems, Inc. Method and system for detecting abnormal operation of a level regulatory control loop
US7912676B2 (en) * 2006-07-25 2011-03-22 Fisher-Rosemount Systems, Inc. Method and system for detecting abnormal operation in a process plant
US7953501B2 (en) 2006-09-25 2011-05-31 Fisher-Rosemount Systems, Inc. Industrial process control loop monitor
US8788070B2 (en) * 2006-09-26 2014-07-22 Rosemount Inc. Automatic field device service adviser
EP2392982B1 (en) * 2006-09-28 2015-03-25 Fisher-Rosemount Systems, Inc. Abnormal situation prevention in a heat exchanger
US8014880B2 (en) * 2006-09-29 2011-09-06 Fisher-Rosemount Systems, Inc. On-line multivariate analysis in a distributed process control system
WO2008042290A2 (en) 2006-09-29 2008-04-10 Rosemount Inc. Magnetic flowmeter with verification
US20080188972A1 (en) * 2006-10-11 2008-08-07 Fisher-Rosemount Systems, Inc. Method and System for Detecting Faults in a Process Plant
US8032340B2 (en) 2007-01-04 2011-10-04 Fisher-Rosemount Systems, Inc. Method and system for modeling a process variable in a process plant
US8032341B2 (en) * 2007-01-04 2011-10-04 Fisher-Rosemount Systems, Inc. Modeling a process using a composite model comprising a plurality of regression models
US7827006B2 (en) * 2007-01-31 2010-11-02 Fisher-Rosemount Systems, Inc. Heat exchanger fouling detection
US7539593B2 (en) 2007-04-27 2009-05-26 Invensys Systems, Inc. Self-validated measurement systems
WO2009014658A1 (en) * 2007-07-20 2009-01-29 Rosemount Inc. Pressure diagnostic for rotary equipment
US7770459B2 (en) * 2007-07-20 2010-08-10 Rosemount Inc. Differential pressure diagnostic for process fluid pulsations
US8898036B2 (en) 2007-08-06 2014-11-25 Rosemount Inc. Process variable transmitter with acceleration sensor
US8301676B2 (en) 2007-08-23 2012-10-30 Fisher-Rosemount Systems, Inc. Field device with capability of calculating digital filter coefficients
US7702401B2 (en) 2007-09-05 2010-04-20 Fisher-Rosemount Systems, Inc. System for preserving and displaying process control data associated with an abnormal situation
US7590511B2 (en) * 2007-09-25 2009-09-15 Rosemount Inc. Field device for digital process control loop diagnostics
US8265794B2 (en) * 2007-10-01 2012-09-11 Westlock Controls Corporation Knowledge based valve control method
US8055479B2 (en) 2007-10-10 2011-11-08 Fisher-Rosemount Systems, Inc. Simplified algorithm for abnormal situation prevention in load following applications including plugged line diagnostics in a dynamic process
US8185902B2 (en) * 2007-10-31 2012-05-22 International Business Machines Corporation Method, system and computer program for distributing a plurality of jobs to a plurality of computers
US20090133027A1 (en) * 2007-11-21 2009-05-21 Gunning Mark B Systems and Methods for Project Management Task Prioritization
US20090302588A1 (en) * 2008-06-05 2009-12-10 Autoliv Asp, Inc. Systems and methods for airbag tether release
CN101739019B (en) * 2008-11-23 2011-10-12 三科电器有限公司 Method and equipment to debug the system controlled volume by the host computer
US7921734B2 (en) * 2009-05-12 2011-04-12 Rosemount Inc. System to detect poor process ground connections
US8682630B2 (en) * 2009-06-15 2014-03-25 International Business Machines Corporation Managing component coupling in an object-centric process implementation
US9207670B2 (en) 2011-03-21 2015-12-08 Rosemount Inc. Degrading sensor detection implemented within a transmitter
US9927788B2 (en) 2011-05-19 2018-03-27 Fisher-Rosemount Systems, Inc. Software lockout coordination between a process control system and an asset management system
US9052240B2 (en) 2012-06-29 2015-06-09 Rosemount Inc. Industrial process temperature transmitter with sensor stress diagnostics
US9207129B2 (en) 2012-09-27 2015-12-08 Rosemount Inc. Process variable transmitter with EMF detection and correction
US9602122B2 (en) 2012-09-28 2017-03-21 Rosemount Inc. Process variable measurement noise diagnostic
US9798302B2 (en) * 2013-02-27 2017-10-24 Rockwell Automation Technologies, Inc. Recognition-based industrial automation control with redundant system input support
EP3207386B1 (en) * 2014-12-17 2018-09-12 Siemens Aktiengesellschaft Checking a functional module of an automation system
DE102016116378B4 (en) 2016-09-01 2018-04-12 Abb Schweiz Ag Method for checking the operability of transmitters
US10915084B2 (en) 2018-03-12 2021-02-09 Rosemount Inc. Field device switch monitor
US11821951B2 (en) 2021-09-29 2023-11-21 Rosemount Inc. Field device switch monitoring

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5089984A (en) * 1989-05-15 1992-02-18 Allen-Bradley Company, Inc. Adaptive alarm controller changes multiple inputs to industrial controller in order for state word to conform with stored state word
WO1994025933A1 (en) * 1993-04-30 1994-11-10 Pavilion Technologies, Inc. Method and apparatus for determining the sensitivity of inputs to a neural network on output parameters
EP0624847A1 (en) * 1993-05-12 1994-11-17 Laboratoires D'electronique Philips S.A.S. Device and method to generate an approximating function
US5386373A (en) * 1993-08-05 1995-01-31 Pavilion Technologies, Inc. Virtual continuous emission monitoring system with sensor validation
US5511004A (en) * 1992-06-03 1996-04-23 Thomson-Csf Diagnostic method for an evolutionary process
DE19502499A1 (en) * 1995-01-27 1996-08-01 Pepperl & Fuchs ASI-slaves control and activation bus-system

Family Cites Families (103)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US29383A (en) * 1860-07-31 Improvement in preserving food
NL135953C (en) 1960-12-02
US3096434A (en) * 1961-11-28 1963-07-02 Daniel Orifice Fitting Company Multiple integration flow computer
US3404264A (en) * 1965-07-19 1968-10-01 American Meter Co Telemetering system for determining rate of flow
US3701280A (en) * 1970-03-18 1972-10-31 Daniel Ind Inc Method and apparatus for determining the supercompressibility factor of natural gas
USRE29383E (en) 1974-01-10 1977-09-06 Process Systems, Inc. Digital fluid flow rate measurement or control system
US4058975A (en) * 1975-12-08 1977-11-22 General Electric Company Gas turbine temperature sensor validation apparatus and method
US4099413A (en) * 1976-06-25 1978-07-11 Yokogawa Electric Works, Ltd. Thermal noise thermometer
US4337516A (en) * 1980-06-26 1982-06-29 United Technologies Corporation Sensor fault detection by activity monitoring
EP0122622B1 (en) * 1983-04-13 1987-07-08 Omron Tateisi Electronics Co. Electronic thermometer
US4530234A (en) * 1983-06-30 1985-07-23 Mobil Oil Corporation Method and system for measuring properties of fluids
JPH0619666B2 (en) * 1983-06-30 1994-03-16 富士通株式会社 Failure diagnosis processing method
US4707796A (en) * 1983-10-19 1987-11-17 Calabro Salvatore R Reliability and maintainability indicator
JPS60210193A (en) * 1984-04-02 1985-10-22 Mitsubishi Electric Corp Operation system of variable frequency power source
US4517468A (en) * 1984-04-30 1985-05-14 Westinghouse Electric Corp. Diagnostic system and method
US4649515A (en) * 1984-04-30 1987-03-10 Westinghouse Electric Corp. Methods and apparatus for system fault diagnosis and control
US4644479A (en) * 1984-07-31 1987-02-17 Westinghouse Electric Corp. Diagnostic apparatus
US4642782A (en) * 1984-07-31 1987-02-10 Westinghouse Electric Corp. Rule based diagnostic system with dynamic alteration capability
JPH0734162B2 (en) * 1985-02-06 1995-04-12 株式会社日立製作所 Analogical control method
US5179540A (en) * 1985-11-08 1993-01-12 Harris Corporation Programmable chip enable logic function
US5005142A (en) * 1987-01-30 1991-04-02 Westinghouse Electric Corp. Smart sensor system for diagnostic monitoring
WO1988007678A2 (en) * 1987-04-02 1988-10-06 Eftag Entstaubungs- Und Fördertechnik Ag Circuit arrangement for evaluating a signal produced by a semiconductor sensor
US4873655A (en) * 1987-08-21 1989-10-10 Board Of Regents, The University Of Texas System Sensor conditioning method and apparatus
US4907167A (en) * 1987-09-30 1990-03-06 E. I. Du Pont De Nemours And Company Process control system with action logging
US4831564A (en) * 1987-10-22 1989-05-16 Suga Test Instruments Co., Ltd. Apparatus for estimating and displaying remainder of lifetime of xenon lamps
US5274572A (en) * 1987-12-02 1993-12-28 Schlumberger Technology Corporation Method and apparatus for knowledge-based signal monitoring and analysis
US5193143A (en) * 1988-01-12 1993-03-09 Honeywell Inc. Problem state monitoring
US5488697A (en) * 1988-01-12 1996-01-30 Honeywell Inc. Problem state monitoring system
US4924418A (en) * 1988-02-10 1990-05-08 Dickey-John Corporation Universal monitor
US5032525A (en) * 1988-03-31 1991-07-16 United States Of America As Represented By The Secretary Of The Air Force Qualitative process automation for autoclave cure of composite parts
JPH0774961B2 (en) * 1988-04-07 1995-08-09 株式会社日立製作所 Auto tuning PID controller
US4964125A (en) * 1988-08-19 1990-10-16 Hughes Aircraft Company Method and apparatus for diagnosing faults
US5197328A (en) * 1988-08-25 1993-03-30 Fisher Controls International, Inc. Diagnostic apparatus and method for fluid control valves
US5099436A (en) * 1988-11-03 1992-03-24 Allied-Signal Inc. Methods and apparatus for performing system fault diagnosis
EP0369489A3 (en) * 1988-11-18 1991-11-27 Omron Corporation Sensor controller system
JP2714091B2 (en) * 1989-01-09 1998-02-16 株式会社日立製作所 Field instrument
US5098197A (en) * 1989-01-30 1992-03-24 The United States Of America As Represented By The United States Department Of Energy Optical Johnson noise thermometry
US5081598A (en) * 1989-02-21 1992-01-14 Westinghouse Electric Corp. Method for associating text in automatic diagnostic system to produce recommended actions automatically
JPH0692914B2 (en) * 1989-04-14 1994-11-16 株式会社日立製作所 Equipment / facility condition diagnosis system
US4934196A (en) * 1989-06-02 1990-06-19 Micro Motion, Inc. Coriolis mass flow rate meter having a substantially increased noise immunity
US5293585A (en) * 1989-08-31 1994-03-08 Kabushiki Kaisha Toshiba Industrial expert system
JPH0397009A (en) * 1989-09-11 1991-04-23 Toshiba Corp Change rate alarm device for process control system
JP2656637B2 (en) * 1989-11-22 1997-09-24 株式会社日立製作所 Process control system and power plant process control system
JPH03166601A (en) * 1989-11-27 1991-07-18 Hitachi Ltd Symbolizing device and process controller and control supporting device using the symbolizing device
CA2031765C (en) * 1989-12-08 1996-02-20 Masahide Nomura Method and system for performing control conforming with characteristics of controlled system
US5111531A (en) * 1990-01-08 1992-05-05 Automation Technology, Inc. Process control using neural network
US5235527A (en) * 1990-02-09 1993-08-10 Toyota Jidosha Kabushiki Kaisha Method for diagnosing abnormality of sensor
US5134574A (en) * 1990-02-27 1992-07-28 The Foxboro Company Performance control apparatus and method in a processing plant
US5122976A (en) * 1990-03-12 1992-06-16 Westinghouse Electric Corp. Method and apparatus for remotely controlling sensor processing algorithms to expert sensor diagnoses
US5053815A (en) * 1990-04-09 1991-10-01 Eastman Kodak Company Reproduction apparatus having real time statistical process control
DE69121789T2 (en) * 1990-06-04 1997-04-03 Hitachi Ltd Control device for controlling a controlled system and control method therefor
US5167009A (en) * 1990-08-03 1992-11-24 E. I. Du Pont De Nemours & Co. (Inc.) On-line process control neural network using data pointers
US5282261A (en) * 1990-08-03 1994-01-25 E. I. Du Pont De Nemours And Co., Inc. Neural network process measurement and control
US5142612A (en) * 1990-08-03 1992-08-25 E. I. Du Pont De Nemours & Co. (Inc.) Computer neural network supervisory process control system and method
US5224203A (en) * 1990-08-03 1993-06-29 E. I. Du Pont De Nemours & Co., Inc. On-line process control neural network using data pointers
US5197114A (en) * 1990-08-03 1993-03-23 E. I. Du Pont De Nemours & Co., Inc. Computer neural network regulatory process control system and method
US5121467A (en) * 1990-08-03 1992-06-09 E.I. Du Pont De Nemours & Co., Inc. Neural network/expert system process control system and method
US5212765A (en) * 1990-08-03 1993-05-18 E. I. Du Pont De Nemours & Co., Inc. On-line training neural network system for process control
US5175678A (en) * 1990-08-15 1992-12-29 Elsag International B.V. Method and procedure for neural control of dynamic processes
US5821498A (en) * 1990-08-15 1998-10-13 Valmet Corporation Method for heating of a roll and a heatable roll
US5130936A (en) * 1990-09-14 1992-07-14 Arinc Research Corporation Method and apparatus for diagnostic testing including a neural network for determining testing sufficiency
ES2112853T3 (en) * 1990-10-10 1998-04-16 Honeywell Inc IDENTIFICATION OF PROCESS SYSTEMS.
US5367612A (en) * 1990-10-30 1994-11-22 Science Applications International Corporation Neurocontrolled adaptive process control system
US5265031A (en) * 1990-11-26 1993-11-23 Praxair Technology, Inc. Diagnostic gas monitoring process utilizing an expert system
US5214582C1 (en) * 1991-01-30 2001-06-26 Edge Diagnostic Systems Interactive diagnostic system for an automobile vehicle and method
ATE178418T1 (en) * 1991-02-05 1999-04-15 Storage Technology Corp MAINTENANCE DEVICE AND PROCEDURE ACTIVED BY KNOWLEDGE-BASED MACHINE
US5357449A (en) * 1991-04-26 1994-10-18 Texas Instruments Incorporated Combining estimates using fuzzy sets
US5671335A (en) * 1991-05-23 1997-09-23 Allen-Bradley Company, Inc. Process optimization using a neural network
US5317520A (en) * 1991-07-01 1994-05-31 Moore Industries International Inc. Computerized remote resistance measurement system with fault detection
US5414645A (en) * 1991-10-25 1995-05-09 Mazda Motor Corporation Method of fault diagnosis in an apparatus having sensors
US5327357A (en) * 1991-12-03 1994-07-05 Praxair Technology, Inc. Method of decarburizing molten metal in the refining of steel using neural networks
WO1993012410A1 (en) * 1991-12-13 1993-06-24 Honeywell Inc. Piezoresistive silicon pressure sensor design
US5365423A (en) * 1992-01-08 1994-11-15 Rockwell International Corporation Control system for distributed sensors and actuators
US5282131A (en) * 1992-01-21 1994-01-25 Brown And Root Industrial Services, Inc. Control system for controlling a pulp washing system using a neural network controller
US5349541A (en) * 1992-01-23 1994-09-20 Electric Power Research Institute, Inc. Method and apparatus utilizing neural networks to predict a specified signal value within a multi-element system
EP0565761B1 (en) * 1992-04-15 1997-07-09 Mita Industrial Co. Ltd. An image forming apparatus provided with self-diagnosis system
GB9208704D0 (en) * 1992-04-22 1992-06-10 Foxboro Ltd Improvements in and relating to sensor units
JP3100757B2 (en) * 1992-06-02 2000-10-23 三菱電機株式会社 Monitoring and diagnostic equipment
CA2097558C (en) * 1992-06-16 2001-08-21 William B. Kilgore Directly connected display of process control system in an open systems windows environment
JPH064789A (en) * 1992-06-22 1994-01-14 Hitachi Ltd Method and device for monitoring abnormality of equipment
US5384699A (en) * 1992-08-24 1995-01-24 Associated Universities, Inc. Preventive maintenance system for the photomultiplier detector blocks of pet scanners
US5477444A (en) * 1992-09-14 1995-12-19 Bhat; Naveen V. Control system using an adaptive neural network for target and path optimization for a multivariable, nonlinear process
US5228780A (en) * 1992-10-30 1993-07-20 Martin Marietta Energy Systems, Inc. Dual-mode self-validating resistance/Johnson noise thermometer system
JPH06187030A (en) * 1992-12-17 1994-07-08 Hitachi Ltd Control system abnormality diagnostic method and display method by time-sequential model
US5486996A (en) * 1993-01-22 1996-01-23 Honeywell Inc. Parameterized neurocontrollers
US5394341A (en) * 1993-03-25 1995-02-28 Ford Motor Company Apparatus for detecting the failure of a sensor
DE4416317B4 (en) * 1993-05-17 2004-10-21 Siemens Ag Method and control device for controlling a material processing process
US5361628A (en) * 1993-08-02 1994-11-08 Ford Motor Company System and method for processing test measurements collected from an internal combustion engine for diagnostic purposes
US5539638A (en) * 1993-08-05 1996-07-23 Pavilion Technologies, Inc. Virtual emissions monitor for automobile
US5404064A (en) * 1993-09-02 1995-04-04 The United States Of America As Represented By The Secretary Of The Navy Low-frequency electrostrictive ceramic plate voltage sensor
US5489831A (en) * 1993-09-16 1996-02-06 Honeywell Inc. Pulse width modulating motor controller
US5408406A (en) * 1993-10-07 1995-04-18 Honeywell Inc. Neural net based disturbance predictor for model predictive control
JPH07160661A (en) * 1993-12-02 1995-06-23 Hitachi Ltd Automatic teacher data extraction method for neural network, neural network system using the same and plant operation supporting device
JP2893233B2 (en) * 1993-12-09 1999-05-17 株式会社ユニシアジェックス Diagnostic device for in-cylinder pressure sensor
US5440478A (en) * 1994-02-22 1995-08-08 Mercer Forge Company Process control method for improving manufacturing operations
US5483387A (en) * 1994-07-22 1996-01-09 Honeywell, Inc. High pass optical filter
US5704011A (en) * 1994-11-01 1997-12-30 The Foxboro Company Method and apparatus for providing multivariable nonlinear control
US5600148A (en) * 1994-12-30 1997-02-04 Honeywell Inc. Low power infrared scene projector array and method of manufacture
US5572420A (en) * 1995-04-03 1996-11-05 Honeywell Inc. Method of optimal controller design for multivariable predictive control utilizing range control
GB2301901B (en) * 1995-06-05 1999-04-07 Nippon Denso Co Apparatus and method for diagnosing degradation or malfunction of oxygen sensor
US5672975A (en) * 1995-06-07 1997-09-30 Rosemount Inc. Two-wire level transmitter
US5561599A (en) * 1995-06-14 1996-10-01 Honeywell Inc. Method of incorporating independent feedforward control in a multivariable predictive controller
CA2165400C (en) * 1995-12-15 1999-04-20 Jean Serodes Method of predicting residual chlorine in water supply systems

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5089984A (en) * 1989-05-15 1992-02-18 Allen-Bradley Company, Inc. Adaptive alarm controller changes multiple inputs to industrial controller in order for state word to conform with stored state word
US5511004A (en) * 1992-06-03 1996-04-23 Thomson-Csf Diagnostic method for an evolutionary process
WO1994025933A1 (en) * 1993-04-30 1994-11-10 Pavilion Technologies, Inc. Method and apparatus for determining the sensitivity of inputs to a neural network on output parameters
EP0624847A1 (en) * 1993-05-12 1994-11-17 Laboratoires D'electronique Philips S.A.S. Device and method to generate an approximating function
US5386373A (en) * 1993-08-05 1995-01-31 Pavilion Technologies, Inc. Virtual continuous emission monitoring system with sensor validation
US5548528A (en) * 1993-08-05 1996-08-20 Pavilion Technologies Virtual continuous emission monitoring system
DE19502499A1 (en) * 1995-01-27 1996-08-01 Pepperl & Fuchs ASI-slaves control and activation bus-system

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19835416A1 (en) * 1998-08-05 2000-02-17 Siemens Ag Process and device for commissioning plants in the basic materials industry
WO2003050479A1 (en) * 2001-12-12 2003-06-19 Endress + Hauser Gmbh + Co.Kg Electronic field device with a sensor unit for process measurement
US7098798B2 (en) 2003-08-07 2006-08-29 Rosemount Inc. Process device with loop override
US7280048B2 (en) 2003-08-07 2007-10-09 Rosemount Inc. Process control loop current verification
WO2005052881A2 (en) * 2003-11-21 2005-06-09 Rosemount Inc. Process device with supervisory overlayer
WO2005052881A3 (en) * 2003-11-21 2006-02-02 Rosemount Inc Process device with supervisory overlayer
CN102339059A (en) * 2003-11-21 2012-02-01 罗斯蒙德公司 Process device used to monitor or control operation of an industrial process
US8180466B2 (en) 2003-11-21 2012-05-15 Rosemount Inc. Process device with supervisory overlayer
US7464721B2 (en) 2004-06-14 2008-12-16 Rosemount Inc. Process equipment validation
US9020768B2 (en) 2011-08-16 2015-04-28 Rosemount Inc. Two-wire process control loop current diagnostics
US20170093533A1 (en) 2015-09-30 2017-03-30 Rosemount Inc. Process variable transmitter with self-learning loop diagnostics
US10367612B2 (en) 2015-09-30 2019-07-30 Rosemount Inc. Process variable transmitter with self-learning loop diagnostics

Also Published As

Publication number Publication date
US6047220A (en) 2000-04-04
JP2001507834A (en) 2001-06-12
EP0948759A1 (en) 1999-10-13
DE69714606D1 (en) 2002-09-12
CA2276299A1 (en) 1998-07-09
DE69714606T2 (en) 2003-04-10
CN1242845A (en) 2000-01-26
DE69714606T9 (en) 2004-09-09
CN1138193C (en) 2004-02-11
EP0948759B1 (en) 2002-08-07
JP4643771B2 (en) 2011-03-02

Similar Documents

Publication Publication Date Title
US6047220A (en) Device in a process system for validating a control signal from a field device
US6119047A (en) Transmitter with software for determining when to initiate diagnostics
US6539267B1 (en) Device in a process system for determining statistical parameter
CA2066743C (en) Field-mounted control unit
US7018800B2 (en) Process device with quiescent current diagnostics
US7630861B2 (en) Dedicated process diagnostic device
US20070010900A1 (en) Diagnostics in industrial process control system
EP1803041B1 (en) Process device with diagnostic annunciation
EP2150861B1 (en) Industrial field device with reduced power consumption
US10761524B2 (en) Wireless adapter with process diagnostics
US8788070B2 (en) Automatic field device service adviser
JP2007501980A5 (en)

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 97181171.7

Country of ref document: CN

AK Designated states

Kind code of ref document: A1

Designated state(s): BR CA CN JP SG

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 1997953328

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 1998 530111

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2276299

Country of ref document: CA

Ref document number: 2276299

Country of ref document: CA

Kind code of ref document: A

WWP Wipo information: published in national office

Ref document number: 1997953328

Country of ref document: EP

WWG Wipo information: grant in national office

Ref document number: 1997953328

Country of ref document: EP