WO2009047111A2

WO2009047111A2 - Dynamic stop i n a parallel hybrid

Info

Publication number: WO2009047111A2
Application number: PCT/EP2008/062660
Authority: WO
Inventors: Frank Steuernagel; Jens-Werner Falkenstein; Christian Muehlbauer
Original assignee: Robert Bosch Gmbh
Priority date: 2007-10-05
Filing date: 2008-09-23
Publication date: 2009-04-16
Also published as: WO2009047111A3; DE102007047589A1

Abstract

The invention relates to a method for deactivating the internal combustion engine of a parallel hybrid drive comprising the internal combustion engine, an electric motor and a controllable disconnect clutch, which connects the internal combustion engine to the electric motor. The method comprises the steps: detection of a decoupling signal; and, when said decoupling signal is detected: changing the speed control by blocking control of the internal combustion engine speed depending on the driver's wishes and bringing the speed of the internal combustion engine to a speed that corresponds to a torque transmission of the internal combustion engine of essentially zero. Once control of the internal combustion engine speed depending on the driver's wishes has been blocked, the disconnect clutch is opened. The invention also relates to a corresponding controller.

Description

description

title

Dynamic stop with parallel hybrid

State of the art

The invention is based on a control method for a parallel hybrid drive. A parallel hybrid drive has the same structure as a conventional power train of an internal combustion engine drive, but in addition there is an electric motor and a clutch between the transmission and the internal combustion engine, which can separate the engine from the drive train. The internal combustion engine and the electric motor are thus connected in series, wherein a separating clutch controls whether a torque that was generated by the internal combustion engine, is passed via the electric motor to the output.

A control method involving torque coordination, i. the division of torque generation, provide, generate in severe rule changes, especially when completely switching off the engine, an unpleasant driving behavior, which manifests itself as Ruckein.

It is therefore an object of the invention to provide a motor controller for a parallel hybrid, which makes the switching off of an internal combustion engine of a parallel hybrid drive more pleasant.

Disclosure of the invention

The invention enables the shutdown of an internal combustion engine of a parallel hybrid drive, without affecting the driving behavior unpleasant. Furthermore, an existing torque coordination structure may be used, which is provided for example in the form of a combined engine control. This allows stopping the internal combustion engine while driving, ie the transition to the complete electric drive, without this being noticeable to the driver. The concept underlying the invention consists in initially setting the separating clutch between the internal combustion engine and the electric motor load-free, in order then to open the separating clutch. Since the separating clutch is load-free, ie the entire drive torque is generated by the downstream electric motor, the driving behavior of the internal combustion engine has no influence on the driving behavior, so that the drive torque generated by the internal combustion engine does not influence the driving behavior during the switch-off. For this purpose, the torque limits of the internal combustion engine or the SoIl- generating torque of the internal combustion engine are set so that the side of the clutch facing the engine is synchronous with the side facing the electric motor, so that the clutch no torque of the engine in transmits the subsequent drive train. For this purpose, the speed of the internal combustion engine and / or its torque can be controlled as a controlled variable. A signal corresponding to the driver's request, for example a signal originating from the accelerator pedal, will completely pass on the driver's desired signal to the electric motor, wherein the internal combustion engine receives signals which are designed to provide the disconnect clutch without load. Preferably, the engine control receives a signal according to which the internal combustion engine is no longer available as a drive unit. The control, which carries out the torque coordination, thus ignores the internal combustion engine and no longer uses it to generate the torque, but merely forwards the driver's wish to the electric motor. This can be done, for example, that the driver request signal is redirected accordingly and the signal path to the engine is blocked.

Thus, after the engine no longer generates torque, the electric motor generates the full drive torque and the driver's request is not forwarded to the engine or its control, but to the electric motor, the disconnect clutch is opened. Since the clutch does not transmit any torque when it is being opened (after all, it is unloaded due to the engine control), the drive train is not influenced or excited by the opening of the clutch.

After the clutch has been opened, the engine is stopped. Alternatively, the internal combustion engine can also be stopped during or shortly before opening the separating clutch. This depends on the behavior of the internal combustion engine during the stop phase, since it can be designed in such a way that, in spite of connection to the electric motor, the internal combustion engine does not significantly influence the drive.

The various steps, ie Step 1: load-free provision of the clutch by controlling the internal combustion engine, Step 2: Notify the engine control that the Combustion engine is no longer available and that the driver is only to pass on to the electric motor, Step 3: opening the clutch and Step 4: stopping the engine, can also be combined with each other in time. Preferably, steps 2-4 are performed during the same time interval. Preferably, the engine speed is kept constant via idle control to prevent the engine from howling when the disconnect clutch is opened or opened. In addition, for the internal combustion engine when opening or after opening the clutch a predetermined change in speed can be controlled, for example, reducing the speed in the form of a ramp.

The internal combustion engine may also be shut off as preparations are made to open the disconnect clutch to account for a time delay of the internal combustion engine that is between the actual input and the response of the internal combustion engine and for the duration wear, which passes during the shutdown of the internal combustion engine. The internal combustion engine is switched off by appropriate signals to the engine control system, for example, reduces the speed, reduces the degree of leadership and / or adapts the firing angle to a lower speed and a lower torque.

The method according to the invention thus comprises the control of three different components: the torque control, which controls the torque of the internal combustion engine and the electric motor, the disconnect clutch and the control of the internal combustion engine. First, a signal is detected, according to which the engine is to be turned off, and this can be automatically generated by another controller or by a driver by corresponding operation of a button. First, the separating clutch is driven load-free, so that the torque control, i. the torque coordination, receives a signal, according to which a differential torque of zero is set at the separating clutch. Then, the torque control is switched to 100% electric operation by the torque control receives a corresponding switching signal. From this switching driver command signals are no longer passed to the engine control, but only to the electric motor control, since only the electric motor participates in the torque generation. Then, the separating clutch is opened, wherein the separating clutch receives an opening signal in this step. The opening signal may be a corresponding signal edge or signal level.

After the opening or during the opening of the separating clutch of the internal combustion engine is switched off, this being provided by the engine control receives a shutdown signal. The shutdown signal may be a single, particular signal or can be provided by appropriate ignition angle, speed or filling level signals, for example, by a specification degree of filling = zero or a default speed = zero.

After the internal combustion engine is switched off, the disconnect clutch remains open and the torque or engine control is completely provided for the electric motor. In particular, the driver request signal is completely forwarded to the electric motor and the control of the electric motor is adjusted so that the electric motor generates the entire setpoint torque.

Brief description of the drawings

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

Show it

Figure 1 is a schematic diagram of a parallel hybrid drive, and Figure 2 is a block diagram of an embodiment of the circuit according to the invention

Embodiments of the invention

1 shows a schematic diagram of a parallel hybrid drive is shown. A parallel hybrid drive comprises an internal combustion engine 10, which is connected via a separating clutch 20 to an electric motor 30. The electric motor is followed by a transmission 40 which is connected to the output 50, i. connected to the wheels of a vehicle. The torque component generated by the engine 10, if provided, therefore passes through the disconnect clutch 20, the electric motor 30, the transmission 40, and is thus transmitted to the wheels 50. The torque generated by the electric motor 30 passes through the transmission to be transmitted to the wheels 50. The electric motor 30 is thus located between the output 50 and the internal combustion engine 10. In contrast to the internal combustion engine 10, the electric motor 30 can be switched by switching off the excitation in a passive state by the electric motor neither receives a torque nor gives a and only the transmission of mechanical power between separating clutch 20 (or internal combustion engine 10) and the output 50 is used.

FIG. 2 shows a circuit structure according to the invention with a motor control 100, which has a torque distribution or moment coordination 102 and a separation control 104 includes. The engine controller receives an input signal from a driver request input 106 and has two outputs, a first engine output connected to the engine or its controller 110, and an e-machine output via which an e-machine 130 can be controlled. The combustion engine output and the E engine output are connected to the torque split 102. The torque distribution 102 further receives a driver request signal from the driving request input 106. The driver request can be controlled by another controller or by the accelerator pedal.

The torque controller 102 may provide signals to the engine controller 100 and the E-machine controller 130 in the form of logic levels. Alternatively, the torque control 102 may include an output stage device with which the internal combustion engine and the electric machine can be directly controlled. Similarly, disconnect controller 104 may provide logic or high power drive signals to transmission 140 and disconnect clutch 120. Both the connection between the separation control 104 and the transmission 140 or the disconnect clutch 120 and the connections between the torque control 102 and the combustion engine 110 and the electric motor 130 may be provided by means of output ports. Furthermore, level converters and / or output stages can be used to supply the connected devices with suitable electrical power.

After the disconnect clutch 120 has been opened, the transmission 140 is driven by the disconnect controller 104 according to the driver's request and the operating parameters of the electric machine. The control of the transmission 140 thus takes into account only the driver's request and the operating parameters or properties of the electric motor and any operating parameters of the internal combustion engine after the opening of the clutch 120.

The engine control or the torque distribution and the separation control can be provided in individual modules which are interconnected via interfaces. The modules themselves can be implemented by hardware, software or a combination thereof. In particular, the respective functions may be implemented by means of a microprocessor or a CPU processing software and data, the software preferably being stored in a non-volatile memory and the data being input or output data associated with the respective signals. Preferably, the separation control, the torque control are provided as software modules that run on the same microprocessor. To control the transmission 140, the separating clutch 120, the electric motor 130 and the internal combustion engine 110, interfaces, in particular power interfaces, can be provided. The driver The desired signal is preferably time-discrete sampled and converted into discrete-value signals to allow processing by a microprocessor.

Claims

claims

1. A method for deactivating the internal combustion engine (10) of a parallel hybrid drive, the internal combustion engine (10), an electric motor (30), and a controllable separating clutch (20), the internal combustion engine (10) with the electric motor (30 ) connects, with the steps:

Detecting a decoupling signal; and, upon detecting the decoupling signal, changing the torque control by inhibiting engine speed control responsive to a driver request and driving the internal combustion engine to a speed corresponding to a torque transfer from the engine to the disconnect clutch (20) of substantially zero; and, after that

Control of the engine torque was blocked depending on a driver's request, opening the clutch.

2. The method of claim 1, wherein the internal combustion engine (10) after, or shortly before the opening of the separating clutch (20) is turned off.

3. The method of claim 1 or 2, wherein the separating clutch (20) is opened after the internal combustion engine (10) is driven such that substantially all of the torque to a on the electric motor (30) following output (50) GE - is generated by the electric motor (30) is generated and substantially no torque, which is passed to the output (50) from the internal combustion engine (10).

4. A method according to any one of the preceding claims, wherein the blocking, propulsion, opening and stopping of the internal combustion engine (10) is carried out substantially simultaneously.

5. The method of claim 1, wherein the internal combustion engine (10) after, during or shortly before the opening of the separating clutch (20) is controlled to a constant speed.

6. The method according to any one of the preceding claims, wherein the separating clutch (20) is opened when the internal combustion engine (10) has been controlled to a speed, which leads to a torque transfer from the internal combustion engine (10) to the separating clutch (20) of substantially zero.

7. The method according to any one of the preceding claims, wherein when the torque transfer from the internal combustion engine (10) to the separating clutch (20) is substantially zero, a torque controller (100) is signaled that the internal combustion engine (10) is deactivated, and if the torque control has been signaled that the internal combustion engine (10) is deactivated, the torque control outputs a driver request signal corresponding to the driver request only to the electric motor (30) or to an electric motor control, and the internal combustion engine (10) or a

Engine control does not receive a driver request signal.

8. A torque split controller (100) in a parallel hybrid drive including an electric motor and an internal combustion engine having a lock configured to inhibit the delivery of a driver request signal to an engine controller from the input of an engine deactivation signal is to release the delivery of a driver request signal to an engine controller prior to inputting the engine deactivation signal, wherein the controller is further configured to deliver the driver request signal to an electric motor controller irrespective of occurrence of an engine deactivation signal and a disconnect clutch upon occurrence of an engine deactivation signal Opening signal.

9. Control according to claim 8 with an input for receiving the driver command signal, an output for delivering an electric motor drive signal, an output to

Outputting an engine drive signal and an output for outputting a disconnect clutch drive signal.

10. The controller of claim 9, further configured to receive a torque carry signal indicative of the value of the torque applied by the engine to the engine

Disconnect coupling or vice versa is transmitted; is arranged to detect, based on a comparison with a threshold value, whether the torque transmission is below the threshold value, and is set up to output a disconnect clutch drive signal upon detection of an undershooting of the threshold value.