EP0575907A1

EP0575907A1 - A system for the reception and transmission of information between fixed and mobile stations

Info

Publication number: EP0575907A1
Application number: EP93109767A
Authority: EP
Inventors: Angelo Cacciotti
Original assignee: Magneti Marelli Rete SpA
Current assignee: Denso Manufacturing Italia SpA
Priority date: 1992-06-26
Filing date: 1993-06-18
Publication date: 1993-12-29
Also published as: ITRM920490A1; ITRM920490A0; IT1254595B

Abstract

The invention relates to a system for the transmission and reception of information to motorists between a plurality of transmitter stations and a plurality of receiver stations installed on motor vehicles and a plurality of sensor devices disposed along the road network for detecting information on ambient and climatic road conditions; each transmitter station comprises: a sensor circuit module, a processor circuit module for managing and processing all the information which it receives and for generating coded output signals, a communication circuit module for bidirectional management of coded signals coming from the processor circuit module and from a control unit and a further plurality of transmitter stations installed along the road network, a transmitter circuit module, and a supply circuit module; each said plurality of receiver stations comprises: a radio frequency circuit module, a logic circuit module for recognising codes and decoding received input information from the said circuit module, a silencing circuit module, an audio circuit module such as to activate sound circuit means and a signalling circuit module.

Description

The present invention relates to a system for the reception and transmission of information between a plurality of transmitting stations installed or otherwise located along a road network, motorway or normal road way, and a plurality of receiving stations installed on motor vehicles.
The development of traffic and transport, the higher speeds and consequent expansion of the road network all underline the problem of road safety.
Numerous devices are commercially available, which, in particular, solve part of the above indicated problem. In fact, road improvements and current signalling of hazard points do not guarantee complete, or sufficient, safety. In the known devices the radiating system of current transmitters, being omnidirectional, does not, especially on motorways, allow discrimination between the carriageway involved in the hazard situation.
The object of the present invention is therefore that of eliminating the disadvantage just mentioned and of providing a system for the reception and transmission of information, with transmission from transmitting stations of coded signals relating to events or to particular road conditions and with a reception which takes place at a distance of about 300 metres from the critical point.
Another object of the present invention is that of providing a plurality of transmitting stations in which the road condition, environmental and climatic information detected in a given locality can be transferred upstream of the transmitting stations to other transmitting stations to alert motorists before their arrival at the critical zone.
Another object of the present invention is that of passing the detected information to a control unit which can send commands and/or information to selectable transmitting stations.
The invention, which is set out in the claims, solves the problems of providing a system for the reception and transmission of information to motorists between fixed and mobile stations, and from the general point of view, is characterised by the fact that it comprises a sensor circuit module connected by a bidirectional connection to sensor devices to supply them and to detect parameters characteristic of the information and subsequently compare the said parameters with predetermined reference levels, providing at their output an information signal identified by means of logic states; a processor circuit module for managing, recognising, selecting, generating and processing all the information which it receives at its input, and for generating at its output one or more coded signals identified by a ten bit word containing all the information relating to the event to be signalled or to the command to be executed in accordance with the information coming from the said sensor circuit module; a communication circuit module, constituted by a micro processor, for bidirectional management of messages identified by the said coded signals coming from the processor circuit module, and via a bidirectional connection from a control unit and from a further plurality of transmitting stations installed along the road network; the said communication circuit module receiving at its input from the said sensor circuit module a signal identified by means of logic states; a transmitting circuit module, constituted by an amplitude modulation section and a frequency modulation section receiving at its inputs the said coded signals relating to the events to be signalled from the said processor circuit module and an audio signal from the said communication circuit module; a stabilised-voltage supply circuit module for supplying each circuit module of the transmitting station; a control unit connected to each transmitting station; and in that each of said plurality of receiving stations comprises: a radio frequency circuit module with automatic gain control, for receiving and recovering the information from an antenna; a logic circuit module provided with appropriate firmware for code recognition and decoding of information received at its input from the said circuit module and for outputting respectively at one output, commands for selection and timing/activation, and at another output commands for selection, timing/activation and memory control; a silencing circuit module which outputs to the said logic circuit module a deactivation command for blocking out information coming from the said circuit module in such a way that the said receiving station cannot provide any information after the vehicle has passed beyond predetermined positions relative to the signalled event; an audio circuit module operable to receive at its input the information coming from the circuit module and the commands for selection, timing/activation and memorisation from the logic circuit module in such a way as to activate a sound circuit means; a signalling circuit module receiving at its input from the said logic circuit module the said commands signals for selection and timing/activation for visual representation of the detected information; the said transmitting stations, the said receiving stations and the said control unit being logically managed by dedicated firmware.
The invention is explained in more detail hereinafter with the aid of the drawings which represent a purely exemplary and non-limitative embodiment thereof, in which:

Figure 1 illustrates a block diagram of a transmitter station of the invention;
Figure 2 is a block diagram of a receiver station of the invention;
Figure 3 is a block diagram of a processor circuit module belonging to the transmitter station of Figure 1;
Figure 4 is a block diagram of a supply circuit module belonging to the transmitter station of Figure 1;
Figure 5 is a block diagram of a RF circuit module belonging to the receiver station of Figure 2;
Figure 6 is a block diagram of a logic circuit module belonging to the receiver station of Figure 2; and
Figure 7 is a block diagram of an audio circuit module belonging to the receiver station of Figure 2.

With reference to the attached drawings, and in particular to Figures 1 and 2, the system subject of the invention, for the reception and transmission of information to motorists between fixed and mobile stations principally provides a plurality of transmitter stations T installed or otherwise located along a road network with a radius of action of 300 metres, and a plurality of mobile receiver stations installed in motor vehicles and a plurality of sensor devices S disposed along the road network for detection information on the ambient and climatic road conditions.
In particular,as is shown in Figure 1, each transmitter station T, logically managed with dedicated firmware, comprises a sensor circuit module MS which is connected by a bidirectional connection 1 to the said sensor devices S. The said sensor circuit module MS has the purpose both of supplying the sensor devices S and of detecting the characteristic parameters of the information, and subsequently, comparing the said parameters with predetermined reference levels, providing at an output 2 an information signal identified by logic states, for example an on/off signal relating to snow, ice etc.
The reference ME indicates a processor circuit module which serves the function of guaranteeing a correct interface and correct execution of the following functions: code generation, code selection, road condition type selection, sensor management, audio message priority selection, network code management, commands from a control unit, and RF module selection.
In fact the said module ME manages, recognises, selects, generates and processes all the information which it receives at the input 2 and generates both at its output 3 and its output 6 one or more coded signals identified by a ten bit word containing all the information relating to the event to be signalled or to the command to be executed in correspondence with the information coming from the said sensor circuit module MS.

In particular the information signal identified by ten bits relative to the event to be signalled is structured according to the following configuration:

b0=low
b1=high
b2=	high=normal road	low=motorway
b3=	high=direction II	low=direction I
b4=low
b5=	high = network messages	low=normal

and the bits from b6 to b9 determine the intrinsic coded content of the information according to the following table:

b6	b7	b8	b9		Codes
low	low	low	low	road works	1
high	low	low	low	wind	2
low	high	low	low	vehicles slowing	3
high	high	low	low	accident or tailback	4
low	low	high	low	fog	5
high	low	high	low	ice		6
low	high	high	low	pedestrian crossing	7
high	high	high	low	vehicle with a siren	8
low	low	low	high	barrier		9
high	low	low	high	general danger	10
low	high	low	high	direction selection I	11
high	high	low	high	direction selection II	12
low	low	high	high	end of audio message	13
high	low	high	high	beginning of audio message	14
low	high	high	high	not allocated	15
high	high	high	high	not allocated	16

Furthermore, the said bits from b6 to b9 can determine up to 16 configurations of codes relating to events to be signalled.
As is shown in Figure 1, MC indicates a communication circuit module which serves an interface function, with a bidirectional connection 4, between the location of a particular transmitter station T and other stations T or the said control unit UC. In fact, detected information can be passed back upstream from station to station, in such a way as to alert motorists before their arrival at the critical zone. Moreover, information can be sent back to the control unit UC where it can be processed so as to allow retransmission of targeted information, for example directed to particular transmitter stations T.
The said module MC is constituted by a microprocessor (not shown in the Figure) which serves to manage bidirectionally both the information identified by the said coded signals, that is to say the said codes, coming from the processor circuit module ME, and the audio messages coming from the said control unit UC by means of the said bidirectional connection 4 from the control unit UC. Upon commencement of an audio message from the control unit UC the module MC sends, to the module ME, a command signal such that it can process the code 14 and send it via the output 6 to a transmitter circuit module MT. The said module ME, after sending the code 14 , interrupts the sending of other codes. When the audio message from the control unit UC finishes, the module MC sends an end-of-message signal to the module ME which returns to its normal function after having transmitted the code 13.
The said communication circuit module MC receives, at its input 5, from the said sensor circuit module MS, a signal identified by means of logic states which indicate that a certain sensor device S is activated.
The said transmitter circuit module MT is constituted by an amplitude modulation section and a frequency modulation section which receives, at input 6, the said coded signals relating to the event to be signalled from the said processor circuit module ME and at input 7 the audio message from the said communication circuit module MC.
Still referring to Figure 1, there is shown a supply circuit module MA that provides a stabilised voltage for supplying each circuit module MS, ME, MT, MC of the transmitter station T.
By way of further detail, the block diagram of the processor circuit module ME is shown in Figure 3.
The said module ME comprises a code generation module MG for generation of coded signals identified by the codes. The said module MG receives an input 12 from a message selector module MSM for selecting the code to be transmitted, an input 13 from a transmission selector module MST for selecting among three states corresponding to activation for amplitude modulation, frequency modulation, and a cyclic alternation of amplitude modulation and frequency modulation, and an input 14 from a road network selector module MSV for selecting the road network relevant to the vehicle to be alerted such that MG generates a code corresponding to the type of road network on which the transmitter station T is installed.
The directionality characteristic is, in fact, activated only on motorways and on high speed roads, for example bypasses, whilst it is not indicated for normal roads for example on provincial roads. In this particular case, in correspondence with the inputs of this road network,a transmitter station T is installed in a suitable position such as to transmit the direction or reference codes 11 or 12.
In Figure 4 there is shown a block diagram of the supply circuit module MA. The said module MA comprises a battery B which can be interfaced with solar panels PS and/or with a mains supply RA at 220V .
A voltage regulator is indicated RT, and serves to stabilise the output voltage at a fixed value, the output of the voltage regulator being connected to the respective modules MS, MC and ME, whilst RT is connected serially to a switching and control device DC connected to the input of the said transmitter module MT for sending a transmission interruption signal when the signal falls below a predetermined threshold.
According to the invention, the said system for transmission and reception of information, as already mentioned, includes a plurality of receiver stations R installed on motor vehicles. The said receiver stations R are logically managed with dedicated firmware.
As is shown in particular in Figure 2, each station R comprises a radio frequency circuit module RF, with automatic gain control, for recovering information received from an antenna A. In particular, as is shown in Figure 5, the said RF module is constituted by an AM/FM receiver, a squaring circuit SQ for recovering the signal, and a circuit CP for control of the carrier level.
The said module RF is connected to a logic circuit module ML which is provided with appropriate firmware for recognition of the codes and decoding the information received at input 8 from the said circuit module RF. The module ML outputs respectively from its output 9 selection and timing/activation commands and, from output 10, selection, timing/activation and memory control commands.
As is shown in Figure 6 the module ML comprises a decoder D for recognising, selecting and decoding information coming from the said circuit module RF. In fact, at its input 8 arrives decoded information recovered by the squaring circuit SQ, and in particular from the circuit CP via connection 8A, the signal identifying the level of the carrier. The level of the carrier goes directly to the decoder D for analysis; if the level exceeds a preset value signal handling is enabled, otherwise though detecting a code, signal handling does not take place. In this way intermittent signalling due to momentary weakening of the radiated field is avoided.
The said decoder D is connected bidirectionally to a directionality circuit module MD constituted by a memory for motorway direction as determined by information from the corresponding sensor devices S. The said decoder D provides an activation signal at its output 19 for a timer module CT.
Still in Figure 2, the reference TM indicates a silencing circuit module which outputs on line 18, to the logic circuit module ML, in particular to the decoder D, Figure 6, a deactivation command for blocking out the information coming from the said RF circuit module in such a way that the said receiver station R cannot provide any information after the vehicle has passed beyond predetermined positions relative to the signalled event.
Reference AM shows an audio circuit module operable to receive on input line 11 information coming from the RF circuit module and the commands for selection, timing/activation and memory control from the logic circuit module ML on input line 10, in particular coming from the decoder D in such a way as to activate sound circuit means CS.
The said audio module AM comprises, as is shown in Figure 7, a synthesizer SI which receives on input line 10 from the decoder D the code relating to the address and the message to be emitted. The said module AM further includes a data memory M which is connected to the said synthesizer SI, and in which the audio messages to be transmitted are pre-stored. The synthesizer SI is serially connected at its output with a low pass filter FP, an amplifier A1, and a loud speaker A2. Moreover, between the said synthesizer SI and said low pass filter there is connected a voice decoder DEC receiving on input line 11 the audio message coming from the said RF circuit module.
Still in Figure 2, the reference SM indicates a signalling circuit module which receives on input line 9 from the said logic circuit module ML, the said selection and timing/activation command signals for the visual representation of the received information.
The invention thus conceived is susceptible of numerous modifications and variations all lying within the ambit of the inventive concept. Moreover, all the details can be replaced by technically equivalent elements.
In practice modifications and/or improvements lying however within the ambit of the following claims are obviously possible.

Claims

A system for the transmission and reception of information to motorists between fixed and mobile stations, comprising a plurality of transmitter stations (T) installed or otherwise located along a road network, a plurality of mobile receiver stations (R) installed on vehicles and a plurality of sensor devices (S) disposed along the road network to detect information on the ambient and climatic road conditions, characterised in that each said transmitter station T comprises:
- a sensor circuit module (MS) connected by a bidirectional connection (1) to the said sensor devices (S) to supply them and to detect parameters characteristic of the information and subsequently compare the said parameters with predetermined reference levels, providing at its output (2) an information signal identified by logic states;

- a processor circuit module (ME) for managing, recognising, selecting, generating and processing all the information received at its input (2), and for generating at its output (3) one or more coded signals identified by a ten bit word containing all the information relating to the event to be signalled or to the command to be executed in accordance with the information coming from the said sensor circuit module (MS);

- a communication circuit module (MC) constituted by a microprocessor, for bidirectional management of messages identified by the said coded signals coming from the processor circuit module (ME), and via a bidirectional connection (4) from a control unit (UC) and from a further plurality of transmitter stations (T) installed along the road network; the said communication circuit module (MC) receiving at its input (5) from the said sensor circuit module (MS) a signal identified by logic states;

- a transmitter circuit module (MT) constituted by an amplitude modulation section and a frequency modulation section receiving at its input (6) the said coded signals relating to the events to be signalled by the said processor circuit module (ME) and at an input (7) an audio signal from the said communication circuit module (MC);

- a stabilised-voltage supply circuit module (MA) for supplying each circuit module (MS), (ME), (MT), (MC) of the transmitter station (T);
a control unit (UC) connected to each transmitter station (T);
and in that each said plurality of receiver stations (R) comprises:

- a radio frequency circuit module (RF) with automatic gain control, for recovering the information received from an antenna (A);

- a logic circuit module (ML) provided with appropriate firmware for code recognition and decoding of information received at input (8) from the said circuit module (RF), and for outputting respectively at one output (9) selection and timing/activation commands, and from another output (10) selection, timing/activation and memory control commands;

- a silencing circuit module (TM) which outputs (18) to the said logic circuit module (MY), a deactivation command for blocking out information coming from the said circuit module (RF) in such a way that the said receiver station (R) cannot provide any information after the vehicle has passed beyond predetermined positions relative to the signalled event;

- an audio circuit module (AM) operable to receive at its input (11) information coming from the circuit module (RF) and the commands for selection, timing/activation and memory control from the logic circuit module (ML) in such a way as to activate sound circuit means (CS);

- a signalling circuit module (SM) receiving at input (9), from the said logic circuit module (ML), the said selection and timing/activation command signals for the visual representation of the received information;

- the said transmitter stations (T), the said receiver stations (R) and the said control unit (UC) being logically managed with dedicated firmware.
A system according to Claim 1, characterised in that the said information signal identified by ten bits relating to the event to be signalled is structured according to the following configuration: b0=low b1=high b2= high=normal road low=motorway b3 = high=direction II low=direction I b4=low b5 = high = network messages low=normal

and the bits from b6 to b9 determine the intrinsic coded content of the information according to the following table: b6 b7 b8 b9 Codes low low low low road works 1 high low low low wind 2 low high low low vehicles slowing 3 high high low low accident or tailback 4 low low high low fog 5 high low high low ice 6 low high high low pedestrian crossing 7 high high high low vehicle with a siren 8 low low low high barrier 9 high low low high general danger 10 low high low high direction selection I 11 high high low high direction selection II 12 low low high high end of audio message 13 high low high high beginning of audio message 14 low high high high not allocated 15 high high high high not allocated 16
A system according to Claim 1, characterised in that the said bits from b6 to b9 can determine up to 16 code configurations relating to events to be signalled.
A system according to Claim 1, characterised in that the said processor circuit module (ME) comprises:
- a code generation module (MG) for the generation of coded signals identified by codes, which receives an input (12) from a message selector module (MSM) for selecting the code to transmit, an input (13) from a transmission selector module (MST) for selecting among three states corresponding to activation for amplitude modulation, frequency modulation, and cyclic alternation of amplitude modulation and frequency modulation, and an input (14) from a road network selector (MSV) for selecting the road network relevant to the vehicle to be alerted according to the type of road on which the transmitter station (T) is installed.
A system according to Claim 1, characterised in that the said supply circuit module (MA) comprises:
- a battery (B) that can be interfaced with solar panels (PS) and/or a mains network (RA);

- a voltage regulator (RT) for stabilising the output voltage at a fixed value;

- a switching and control device (DC) connected at its input to the said transmitter module (MT) for interrupting the transmission when the signal falls below a predetermined threshold.
A system according to Claim 1, characterised in that the said circuit module (RF) is constituted by a receiver (AM/FM), a squaring circuit (SQ) for recovery of the signal, and a circuit (CP) for controlling the level of the carrier.
A system according to Claim 1, characterised in that the said logic circuit module (ML) comprises:
- a decoder (D) for recognising, selecting and decoding the information coming from the said circuit module (RF), the decoder being connected bidirectionally to a directionality circuit module (MD) constituted by a memory for motorway direction as determined by information from the corresponding sensor devices (S); the said decoder (D) providing at output (19) an activation signal for a timer module (CT).
A system according to Claim 1, characterised in that the said audio circuit module (AM) comprises:
- a synthesizer (SI) to the input (10) of which is supplied the code relating to the address and message to be emitted;

- a data memory (M) connected to the said synthesizer (SI) and in which the audio messages to be transmitted are pre-stored; the said synthesizer (SI) being serially connected at its output with a low pass filter (FP), an amplifier (A1), and a loud speaker (A2); a voice decoder (DEC) being connected between the said synthesizer (SI) and the said low pass filter and receiving at its input (11) the audio message coming from the said circuit module (RF).
A system for transmission and reception of information between fixed and mobile stations according to the preceding claims and as described and illustrated with reference to the figures of the attached drawings and for the indicated objects.