SYSTEM FOR CONTROLLING A NUMBER OF AUTOMOTIVE ELECTRICAL DEVICES

Abstract: A system for controlling a number of electric devices (14, 15, 17, 18, 28, 28'; 19) on a car (1), particularly those fitted to the vehicle door (2, 2', 3, 3') and comprising at least a window regulator (18), a door lock device (17), a manual control push-button device (14) and a device (15) for electrically controlling an external rearview mirror (16); which devices (14, 15, 17, 18, 28, 28'; 19) comprise at least an electric operating member (24), and which system comprises at least a central processing unit (5) and at least a cable (7, 7', 8, 8') for electrically connecting the central processing unit (5) to the devices (14, 15, 17, 18, 28, 28'; 19); a single electric connecting cable (7, 7', 8, 8') being provided for the devices (14, 15, 17, 18) on each door (2, 2', 3, 3'), and comprising a first wire (10) for supplying positive electrical power, a second wire (11) for transmitting information signals, and a third ground wire (12); which information signals are transmitted over the aforementioned second wire (11) in asynchronous, serial manner; and which devices (14, 15, 17, 18, 28, 28'; 19) comprise a specific electronic control block (27) comprising at least a first integrated circuit (23) for supplying electrical power for operating the aforementioned member (24), and a second integrated circuit (25) for processing information signals relative to operation of the same.

Description: SYSTEM FOR CONTROLLING A NUMBER OF AUTOMOTIVE ELECTRICAL DEVICES TECHNICAL FIELD The present invention relates to a system for controlling a number of automotive electrical devices, particularly those fitted to car doors, such as window regulators, door locking devices, external rearview mirror actuating devices and push-button control devices for manually regulating the above devices. BACKGROUND ART The wiring system currently employed for controlling the above electrical devices comprises a number of cables, each controlling a specific device. Such a system obviously involves numerous drawbacks, such as: complex routing of cable bundles; numerous electrical connections; fault finding difficulties; and complex system testing during and/or after assembly to the vehicle. DISCLOSURE OF INVENTION It is an object of the present invention to provide a system for controlling a number of automotive electrical devices, designed to overcome the above drawbacks, i.e. which is fairly straightforward to produce and assemble; provides for troublefree fault finding and a high degree of reliability; and is cheap to both produce and assemble. Further objects and advantages of the system according to the present invention will be revealed in the following description. According to the present invention, there is provided a system for controlling a number of automotive electrical devices, said devices comprising at least an electric operating member, and said system comprising at least a central processing unit and at least a cable for electrically connecting said central processing unit to said devices; characterised by the fact that said devices comprise a specific electronic control block. BRIEF DESCRIPTION OF DRAWINGS A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which: Fig.l shows a schematic top view of a car featuring the control system according to the present invention; Fig.2 shows a schematic side view of a front door on the Fig.l vehicle; Fig.3 shows a schematic side view of an electrical device on the Fig.2 door. BEST MODE FOR CARRYING OUT THE INVENTION Number 1 in Fig.l indicates a car having two front doors 2, 2' and two rear doors 3, 3' shown in the open position. Close to the dashpanel 4, there is housed a central processing unit 5 comprising a microprocessor 6 from which originate respective cables 7, 7' , 8 and 8' , each comprising a first positive supply wire 10, a second wire 11 for transmitting information signals, and a third ground wire 12. Cables 7 and 7' are connected respectively to front doors 2 and 2', and cables 8 and 8' to rear doors 3 and 3'. As shown in Fig.2 relative to cable 7 on door 2, respective branches of each said cable provide for connecting a manual push-button control device 14, a device 15 for electrically controlling external rearview mirror 16, a door lock device 17, and a window regulating device 18. Each of said devices, shown schematically and numbered 19 in Fig.3, presents a connecting block 20 with three connectors for respective connection to a similar terminal block branch connecting the three wires 10, 11 and 12 of cable 7. The connectors of said block 20 are connected to an electronic block 27 comprising a printed circuit 22 to which are connected a first integrated circuit 23 for electrically supplying the actuating member 24 (e.g. d.c. motor) of device 19, and a second integrated circuit 25 for processing information signals relative to operation of said actuating member 24. Said integrated circuits 23 and 25 may conveniently comprise specific logic circuits or a microprocessor, solid-state switches, etc., and may form overcurrent or overvoltage protection circuits, control and diagnostic circuits, etc. In the case of manual push-button control device 14, which involves no power actuation, said first integrated circuit 23 will be absent, whereas device 15 for electrically controlling external rearview mirror 16 will present more than one actuating member 24, for controlling the various electrical actuating members governing positioning of the mirror reflecting surface, positioning of the mirror body in relation to the door, and supply to the reflecting surface heating members. In the case of cables 8 and 8' on doors 3 and 3' , the connection to device 15 electrically controlling external rearview mirror 16 is obviously dispensed with. Cable 8' is also connected, via branches 26 and 26', to respective devices 28 and 28', similar to device 19 in Fig.3, for locking and releasing luggage compartment 30 and fuel filler box lid 31 of vehicle 1. By means of the control system according to the present invention, the various control signals determined, for example by manual push-button control devices 14 are sent via wire 11 to central processing unit 5. This accordingly controls the respective devices on doors 2, 2', 3, 3' and devices 28, 28', which decode the incoming signals via respective integrated circuits 25 and, via respective integrated circuits 23, provide for controlling power supply for actual operation (regulating the window in the case of device 18, operating the door lock member in the case of device 17, positioning and/or heating the mirror in the case of device 15). Data is transmitted between central processing unit 5 and the various devices in asynchronous serial manner, the information units being coded by modulating the duration of a pulse the amplitude of which is constantly equal to the difference in potential of wires 10 and 12, and is conveniently transmitted at low speed, about 1-10 K bit/sec, which in no way interferes with priority safety operation of processing unit 5 and, at the same time, presents device operating response times comparable with or less than the minimum delay discernible by the human eye (about 75 msec). INDUSTRIAL APPLICABILITY The advantages of the system according to the present invention will be clear from the foregoing description. Firstly, it provides for connecting central processing unit 5 to the various electrical devices on car 1 by means of a single three-wire cable, by virtue of specific logic block 27 which, applied to each device, provides for transmitting and receiving the signal over wire 11 according to the protocol, for processing the information signals relative to operation of the device, and controlling power supply for actual operation of the same. Moreover, the switches controlling device 14 are affected solely by low information signal currents instead of those of the power circuit. This provides for considerably simplifying assembly and improving the reliability of the connection system, by drastically reducing the number of device .connecting cables and connections. Moreover, the electronic logic block on each device provides for fault diagnosis, thus improving driving safety, by informing the driver immediately of any operating faults, and also reducing repair time by indicating the type of fault involved. All of which obviously provides for simplifying both on- and off-line testing. Providing each device with a specific monolithic integrated circuit comprising logic circuits enables changes to be made to the type of operation of each device, by simply changing the specific integrated circuit and the resident program on central processing unit 5. To those skilled in the art it will be clear that changes may be made to the embodiment described and illustrated herein without, however, departing from the scope of the present invention. For example, changes may be made to the number and location of the devices shown by way of example herein (e.g. each door may also feature an electric locking and/or unlocking device), as well as to the circuit configurations also shown by way of example (e.g. a different number of cables may be used for connecting central processing unit 5 to the various devices).

Claims: CLAIMS 1) - A system for controlling a number of electrical devices (14, 15, 17, 18, 28, 28'; 19) on a vehicle (1), said devices (14, 15, 17, 18, 28, 28'; 19) comprising at least an electric operating member (24), and said system comprising at least a central processing unit (5) and at least a cable (7, 7', 8, 8') for electrically connecting said central processing unit (5) to said devices (14, 15, 17, 18, 28, 28'; 19); characterised by the fact that said devices (14, 15, 17, 18, 28, 28'; 19) comprise a specific electronic control block (27). 2) - A system as claimed in Claim 1, characterised by the fact that said electronic block (27) comprises at least an integrated circuit. 3) - A system as claimed in Claim 2, characterised by the fact that said electronic block (27) comprises at least a first integrated circuit (23) for supplying electrical power for operating said member (24), and at least a second integrated circuit (25) for processing information signals relative to operation of said member (24). 4) - A system as claimed in Claim 2 or 3, characterised by the fact that said electronic block (27) comprises logic circuits. 5) - A system as claimed in one of the foregoing Claims, characterised by the fact that said electric connecting cable (7, 7*, 8, 8') comprises a first wire (10) for supplying positive electrical power, a second wire (11) for transmitting information signals, and a third ground wire (12). 6) - A system as claimed in Claim 5, characterised by the fact that said central processing unit (5) comprises at least a microprocessor (6), and that said information signals are transmitted over said second wire (11) in asynchronous, serial manner. 7) - A system as claimed in one of the foregoing Claims, characterised by the fact that it comprises one said cable (7, 7', 8, 8' ) for electrically connecting at least the devices (14, 15, 17, 18) on one door (2, 2', 3, 3') of said vehicle (1). 8) - A system as claimed in Claim 7, characterised by the fact that said devices on said door (2, 2 3, 3') comprise at least a window regulator (18), a door locking device (17) and a manual control push-button device (14). 9) - A system as claimed in Claim 8, characterised by the fact that said devices on said door (2, 2 1 ) also comprise a device (15) for electrically controlling an external rearview mirror (16). 10) - A system as claimed in Claim 9, characterised by the fact that said device (15) for electrically controlling said external rearview mirror (16) comprises electric actuating members (24) for positioning the reflecting surface of said rearview mirror (16), and/or positioning the body of said rearview mirror (16) in relation to said door (2, 2* ) , and/or members for heating said reflecting surface. 11) - A system as claimed in one of the foregoing Claims, characterised by the fact that said electric connecting cable (8' ) also connects said central processing unit (5) to a first device (28) for locking and releasing the luggage compartment (30) of said vehicle (1), and to a second device (28' ) for locking and releasing the fuel filler box lid (31) on said vehicle (1). 12) - A system as claimed in one of the foregoing Claims, characterised by the fact that said specific electronic control blocks (27) comprise means • for diagnosing and/or indicating faults on said respective electrical device (19). 13) - A car (1), characterised by the fact that it comprises a system for controlling a number of devices (14, 15, 17, 18, 28, 28'; 19) comprising at least an electric operating member (24), as claimed in one of the foregoing Claims. 14) - A system for controlling a number of automotive electric devices, and relative vehicle featuring said system, substantially as described and illustrated herein with reference to the accompanying drawings.

Inventors: BOERO GIUSEPPE, BRUSASCO ENZO, MURARI BRUNO, STORTI SANDRO, BOERO, GIUSEPPE, BRUSASCO, ENZO, MURARI, BRUNO, STORTI, SANDRO
Applicants: ROLTRA MORSE SPA, SGS THOMSON MICROELECTRONICS, ROLTRA-MORSE S.P.A., SGS-THOMSON MICROELECTRONICS S.R.L.
Application year: 1990
Main classification: B60R16
IPC codes: B60R16