Abstract:
The present invention relates to a lighting or indicating light unit for a vehicle. It also relates to a lighting or indicating system equipped with at least one such light unit. It extends directly to indicating devices, such as vehicle lights but also to other similar products such as reversing radars and other systems.  
     The light unit of the invention includes lighting means and ancillary facility means as known. According to the invention, the light unit incorporates an electronics card, which is connected, on the one hand, to a controller for a multiplexed bus by a harness and, on the other hand, to a source of electrical supply by a harness. It includes an integrated controller, which performs all the functions associated with controlling the lighting means and the ancillary facility means, whatever the type of light unit involved.  
     Among the advantages of the invention is the reduction in the length of the cabling harness of the onboard network and the reduction in the electromagnetic emissions.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a lighting or indicating light unit for a vehicle. It also relates to a lighting or indicating system equipped with at least one such light unit. It extends directly to indicating devices, such as vehicle lights but also to other similar products such as reversing radars and other systems.  
         BACKGROUND OF THE INVENTION  
         [0002]    In the prior art, products for vehicles whose lighting function or indicating function is defined by standards, especially national standards, have already been proposed. Moreover, particularly in the automotive sector, the use of on-board computers has led to the introduction into vehicles of concepts derived from information technology. As a result, the product referred to as a headlamp or the product referred to as an indicating light has taken on a structure which has enabled it to be developed towards an on-board network architecture. Since then, the majority of vehicles have been fitted with a computer connected to various peripherals via an on-board network.  
           [0003]    One example of an on-board network for vehicles is the CAN network. A network of this kind makes it possible, in particular, to reduce the number of conductors along which the signals and supply voltages pass, as regards the signals in particular by time multiplexing the information passing along the bus of the network.  
           [0004]    Given the improvements to the lighting functions and indicating functions, the multiplication of different versions of the same vehicle, versions of the same light unit or versions of the same indicating light having different characteristics, new functions, each linked to lighting or indicating have already been proposed.  
           [0005]    For example, the use of discharge lamps for lighting requires that the orientation of the light unit should be corrected in a dynamic manner in certain configurations so as to prevent drivers approaching the vehicle fitted with them from being dazzled by the lighting power of a light unit of this kind.  
           [0006]    Use has therefore been made of the possibilities of extending the on-board network by adding one or more ancillary facility controllers, in this case, for example, to control one or more motors for correcting the attitude or orientation of the light unit relative to the chassis and/or to the road, each controlling electromechanical devices acting on the orientation of the light beam produced.  
           [0007]    However, to connect each of these ancillary facility controllers to the electromechanical device associated with the light unit, it is necessary to use a harness for connecting the light unit to the network. As a result, the number of conductors in the vehicle increases with each function added to the light unit.  
           [0008]    Since the lengths of these conductors can be significant, this results in an increase in the risk of electromagnetic interference, an increase in the risk associated with cutting wire harnesses for electrical connection when working on the vehicle, and a reduction in the reliability of operation, owing especially to cluttering of the engine compartment.  
           [0009]    Moreover, for each additional function on a particular vehicle, it is necessary to calculate a new wire harness for electrical connection, and management of such a solution becomes prohibitive, especially with the multiplication of available options when purchasing a type of vehicle of the same make.  
           [0010]    Furthermore, over and above questions of aesthetic appearance specific to each motor-vehicle manufacturer, the requirements of two motor-vehicle manufacturers can differ as regards the behaviour of the same lighting or indicating function, forcing the manufacturer of motor-vehicle components to develop a special type of light unit or light for each of them, increasing their design costs.  
           [0011]    The invention provides a remedy to these disadvantages of the prior art. In the text which follows, it will be understood that the functions of lighting and indicating are similar as regards the problem posed and as regards the solution provided by the invention, unless otherwise stated.  
         SUMMARY OF THE INVENTION  
         [0012]    In fact, the said invention relates to a lighting or indicating light unit for a vehicle, of the type comprising a shell containing lighting and/or indicating means and possibly ancillary facility means for implementing ancillary facilities such as light beam adaptation or automatic adjustment of the orientation of the light beam. The light unit of the invention essentially includes, mechanically associated with its shell, an electronics card including:  
           [0013]    a supply connector to an electrical power supply device;  
           [0014]    a standard connector, whatever ancillary facilities are activated on the light unit, the said standard connector being intended to be linked to the multiplexed bus of an on-board network;  
           [0015]    control means for controlling the lighting means and possibly the ancillary facility means, the said control means being connected to the said supply connector and to the said standard connector in such a way as to allow commands and information on the status of the light unit to be exchanged over the multiplexed bus;  
           [0016]    an internal bus connected, on the one hand, to the control means and, on the other hand, to the lighting means and to the ancillary facility means for exchange between them of commands generated by the control means and of information on the status of the light unit.  
           [0017]    The invention relates to a lighting and/or indicating system for a vehicle including at least one lighting and/or indicating light unit incorporating an electronics card or controller, which is connected by a standard connector to the harness of the multiplexed bus of an on-board lighting and/or indicating control network. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    Other characteristics and advantages of the present invention will be better understood with the aid of the description and the attached drawings, in which:  
         [0019]    [0019]FIG. 1 illustrates an exemplary embodiment of a lighting control system in accordance with the prior art;  
         [0020]    [0020]FIG. 2 illustrates another exemplary embodiment of a lighting control system in accordance with the prior art;  
         [0021]    [0021]FIG. 3 represents a diagram illustrating the means of the invention to allow the development of a platform on four levels;  
         [0022]    [0022]FIG. 4 is a block diagram of a light unit in accordance with one embodiment of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    [0023]FIG. 1 shows a computer  1  on board a vehicle, which is connected to different loads by a network, which has been represented schematically in the rectangle  2 .  
         [0024]    The on-board network  2  includes a bus controller  3 , which carries connectors on harnesses, such as the harness  4  leading towards other peripherals, and the harness  5  leading towards a peripheral  6 , and the harness  10  leading towards a lighting controller  9  and an ancillary facility controller  8 .  
         [0025]    The two controllers  8  and  9  can be arranged in the compartment for the engine of the vehicle (not shown) and are connected to the two light units via four harness elements, the harness elements  13  coming from a part  8 L and  14  coming from a part  8 R of the controller  8  and the harness elements  15  and  16  coming from the controller  9  respectively.  
         [0026]    Each controller has means for activating the left-hand light unit, such as the light unit  17 , or the right-hand light unit, such as the light unit  18 .  
         [0027]    In FIG. 1, the control means activated directly by the controllers  8  and  9  have been shown only on the light unit  17 .  
         [0028]    In the case of a vehicle fitted with a discharge lamp, the light unit also includes customary filament lamps, which are put into operation with the aid of a series of controlled switches  24 , and they also include a ballast, which is an electronic circuit that allows the discharge lamp connected to it to be put into operation, kept alight and monitored.  
         [0029]    To this end, the lighting controller  9  is connected by the harness  15  to appropriate inputs of the light unit  21  and the various control signals, which are decoded and implemented in the modules  24  and  26 .  
         [0030]    The outputs of the modules  24  and  26  are connected to the conventional filament lamps by the point  25  and to the discharge lamp by the point  27  respectively.  
         [0031]    Finally, the use of a discharge lamp in a motor-vehicle headlamp requires that there be a means of adjusting the orientation of the light unit as a function of the instantaneous position of the vehicle on the road. In fact, discharge lamps produce a high-intensity luminous flux. The driver of a vehicle approaching a vehicle fitted with a discharge lamp may be dazzled, and accidents must be avoided by preventing the upper part of the lighting light beam from reaching the level of the face of drivers of oncoming vehicles.  
         [0032]    The means of control  28  of an orientation control motor  29  is connected by a connector  19  to a harness  13  issuing from the part L of the attitude controller  8 . The attitude controller receives information from the onboard computer  1 , such that a program stored in the controller  28  is executed so as to allow the upward excursion of the light beam to be reduced when the vehicle performs an oscillating motion linked to the chaotic variation in conditions on the road.  
         [0033]    Finally, the light unit incorporates diagnostic functions  22 , which are connected to a means  23  for using diagnostic information on the on-board network, this requiring an additional connection on the multiplexed bus.  
         [0034]    The right-hand light unit  18  is identical and will not be described further.  
         [0035]    In the example of the prior art in FIG. 1, it will be appreciated that the connection harnesses between the computers  8  and  9  and the light units  17  and  18  will be multiplied as soon as the number of ancillary facilities is increased.  
         [0036]    It will also be noted that each connection harness  13  to  16  can have a not inconsiderable length relative to electromagnetic activity damaging to the vehicle&#39;s environment.  
         [0037]    [0037]FIG. 2 shows another example of a control system  30  for two light units in accordance with the prior art, in which the ancillary facility controller  8  and the lighting controller  9  of the example described above have been integrated into a single controller  31  linked to the two light units, one on the left and one on the right, by separate connection harnesses due to the fact that the two light units are relatively far apart when mounted on a vehicle.  
         [0038]    Either the central unit or the orientation-control controller is therefore eliminated, and the cost of the overall system is reduced thanks to the reduction in the cost of the levelling orientation function, which has been transferred to the integrated controller  31 .  
         [0039]    In FIG. 2, the same elements as those in FIG. 1 bear the same reference numeral and are not described further.  
         [0040]    The control system  30  essentially includes three parts, which are formed by the controller  31  and two electronics cards, the electronics card  33  being arranged near to the left-hand light unit and the electronics card  34  being arranged near to the right-hand light unit. The control system  30  overall is connected by a first connection harness  32  to the network  2  and by two connection harnesses to the two light units, one on the right and one on the left.  
         [0041]    The integrated controller  31  simultaneously performs the function of controlling the lighting proper (switching on, control, switching off) and the function of controlling orientation, especially in the case of a xenon lamp.  
         [0042]    The controller  31  is connected by a first harness  35  to the appropriate inputs of the left-hand light unit  33  and by a harness  36  to the appropriate inputs of the right-hand light unit  34 .  
         [0043]    Electrical earth distribution is accomplished from the controller  31  with the aid of a conductor  37 , which is routed separately to the light units  33  and  34 , the rest of the supply to which is performed separately.  
         [0044]    In the previous exemplary embodiment, shown in FIG. 2, four conductors are necessary to perform the lighting control function. The four wires are connected directly to a lighting control circuit  40 , which features two outputs  44  and  45  respectively for switching on or off two lamps, allocated respectively to dipped-beam operation and passing-light operation.  
         [0045]    The same group of four inputs is connected respectively to a control module  41 , which performs the function of electronic control of a xenon lamp, which is connected by the terminal  46  and of a controller  42 , which is connected by its output terminal  47  to a long-range driving lamp.  
         [0046]    The electronics card  33  can furthermore include a terminal for connection to members for controlling the orientation of the light beam, such as the device  38 . The signal received from the terminal is transmitted to an information input with a single conductor, which is connected to the controller  39 , which allows automatic orientation of the light unit to be performed by means of an electric motor connected to the output terminal  43 .  
         [0047]    In the previous exemplary embodiment, shown in FIG. 2, the controller  31  is arranged close to the dash-board, in the passenger compartment of the vehicle, while the light units  33  and  34  are arranged in the engine compartment, close to the headlamps. The controller  31  has a structure set by masking an integrated circuit and it is adapted to a specific type of light unit.  
         [0048]    According to the invention, in contrast, the system for controlling the light units is completely integrated into each light unit in such a way that the number and length of the connection harnesses are reduced so as to improve reliability of operation.  
         [0049]    To this end, each light unit thus includes an electronics card, on which is mounted an integrated controller including both means for controlling lighting means and means for controlling ancillary facility means. The lighting means and the ancillary facility means, or only some of them, are installed on a given light unit. However, the integrated controller of the electronics card of each light unit is perfectly capable of controlling any of them. In the rest of the description, a distinction will not always be made between the electronics card and the integrated controller which it carries, in the knowledge that, depending on the implementation of the invention, one or more integrated circuits are necessary and that, if a number of them are necessary, it is not absolutely essential to employ a support of the printed-circuit type, it being possible, for example, to make direct use of the body of the light unit, which is coated locally with an insulated metallic substrate.  
         [0050]    One advantage of the invention is that it allows the development of a range of light units over time or allows a choice of ancillary facility options, in particular, or a choice of various ancillary facility designs prompted by innovations in future vehicles. Thus the invention allows the development of a light unit based on a multi-level platform principle, as will be explained with the aid of FIG. 3.  
         [0051]    [0051]FIG. 3 shows a platform with four levels A to D, each level corresponding to a development in a range of lighting and/or ancillary facilities offered.  
         [0052]    One advantage of the invention is to enable the computer and the network to remain strictly identical for the entire platform, with only certain elements of the controller integrated into the light unit being changed, in particular simply by programming, depending on the new ancillary facilities that are added from level to level.  
         [0053]    At level A of the platform, the network controller  50  actuates or activates a harness  51  for connection to the multiplexed bus of the vehicle in such a way as to exchange commands and status information of the light unit addressed on the multiplexed bus with the on-board computer of the vehicle (not shown). The electronics card  53  or  54  is fitted with a controller (not shown) which participates in this communication via a standard connector, whatever the lighting functions or ancillary facilities activated in the light unit. Moreover, the electronics card  53  or  54  is connected to the electrical supply network of the vehicle by a supply connector (not shown) by a second harness  52 . The electronics cards are associated with the light units on the left (card  53 ) and on the right (card  54 ) in such a way as to produce a set  61  of lighting functions and ancillary facilities determined according to the level within the platform envisaged.  
         [0054]    Halogen-type lamps and simple manual adjustment of the orientation of the light unit are provided in the equipment of a light unit at level A of the platform.  
         [0055]    At level B of the platform, the electronics card  55  associated with the left-hand light unit and the electronics card  56  associated with the right-hand light unit are each provided with the same integrated controller as the cards  53  and  54  of the light units of level A of the platform. In the same way, the harnesses  51  and  52  and the bus controller  50  are retained for all the levels of the platform. The advantage of the invention—standardising a significant number of components of a lighting system—will therefore be appreciated. The majority of the control means can be kept on the electronics card, and they are merely validated by the entry of a level identifier (A to D) into the platform, such that, merely by programming the integrated controller, only the lighting functions and the ancillary facilities authorised at the level under consideration are activated.  
         [0056]    In a light unit at level B of the platform, the beam produced by the headlamps can be adapted in accordance with the technology of discharge lamps, as well as an ancillary facility for the dynamic orientation of the light unit accomplished as described with the aid of FIG. 2.  
         [0057]    At level C of the platform, the technology of discharge lamps has been integrated into a dual-function light unit, and ancillary facilities for adapting the lower part of the lighting beam in accordance with technologies for lighting on bends, as known to the person skilled in the art. The electronics cards  57  and  58  are substantially identical to the electronics card  55  and  56  at level B. However, the lighting functions and the ancillary facilities available in implementation  63  are more extensive than those in the implementation  62  at level B.  
         [0058]    In this case, the ancillary facilities that enable the dual function of the discharge-lamp type and the adapting of the bottom part of the light beam to be achieved are integrated directly onto the cards  57  (left-hand light unit) or  58  (right-hand light unit).  
         [0059]    At level D of the platform, AFS corrections, also referred to as “intelligent lighting” corrections of the bottom part of the lighting beam of the discharge-lamp type are provided, as are dynamic orientation functions, which have already been described. Ancillary facilities linked to electro-optical accessories such as a LIDAR or an infrared lighting system are added.  
         [0060]    According to the invention, most of the necessary means for the implementation of the various ancillary facilities do not change over the entire platform.  
         [0061]    By virtue of this fact, the problem posed at the beginning of the present description has been solved, having, on the one hand, shortened the length of the harness and, on the other hand, eliminated the multiplication of controllers in the prior art.  
         [0062]    Moreover, there is now available a technology that makes it possible to keep only a single electronic control card, which develops according to the requirements of a range or of a platform.  
         [0063]    In the case of a system having a function for lighting on bends, when the device is fixed in an angular position it is possible to use a sensor that indicates to the lighting controller that the orientation motor is locked in an angular position, the controller issuing at that moment an additional command to an orientation motor for setting the optical system to an anti-dazzle position.  
         [0064]    This function of locking the beam at a non-dazzling level can be implemented without the need for the reception of a command coming from outside the light unit, and in particular without overloading either the network or the computer partly on board the vehicle.  
         [0065]    Finally, it will be noted that all the ancillary facilities and means for implementing these ancillary facilities that are integrated with an electronics card integrated with the light unit share the same supply line (via the lighting controller) and the same means of electrical protection as the rest of the lighting control system.  
         [0066]    In one prior art system, the on-board network furthermore includes a diagnostic line specifically for this purpose. According to the invention, the diagnostic line having been eliminated, the bus also exchanges diagnostic data, and the controller for the bus of the on-board network manages both the exchange of data linked to the use of the lighting controller and ancillary facility controller and the exchange of diagnostic data.  
         [0067]    The lighting control system of the invention does not require any particular electrical protection of the bus itself because the light unit includes a function for the electrical protection of the supply of the light unit itself.  
         [0068]    According to another aspect of the invention, the novel lighting control system of the invention also leads to changes in the definition of lighting systems for vehicles.  
         [0069]    In fact, in addition to the current specifications of style, photometry, and thermal and electrical stresses to which the design of a lighting or indicating system has to respond, the invention makes it possible to add a means of characterising the behaviour of the lighting or indicating functions and of the associated ancillary facilities.  
         [0070]    This behaviour can be controlled with the aid of a behaviour controller (not shown), which is integrated into the lighting control system. For example, the lighting function for cornering can have different behaviours, smooth or abrupt.  
         [0071]    According to another aspect of the invention, the coordination between the right-hand and left-hand functions of the light units can be linear, non-linear or complex.  
         [0072]    In one embodiment, the control of lighting is anticipated at the level of the lighting control system by using information available on the network, such as the speed of the vehicle, the acceleration of the vehicle or navigation instructions.  
         [0073]    To this end, the parameters used for anticipation are entered in an anticipation controller, which produces an anticipated lighting control value, such as the switching on or off of a lamp, the increasing or reduction of the luminous flux produced by one of the lamps, and/or a function command of the AFS or intelligent lighting type, and/or a command to change the orientation of the light beam.  
         [0074]    In one embodiment of the invention, the lighting control system of the invention includes means that allow the lighting or indicating performance and the technical signature of the light unit or light to be specified.  
         [0075]    In fact, depending on the style of the vehicle that a motor-vehicle manufacturer wants to design, the operating parameters of the lighting or indicating system and of the various ancillary facilities associated with them within the scope of the present invention can be determined in registers read during at least one parameterisation stage of the functioning of the lighting control system of the invention so as to give consistency of behaviour between the various components of the vehicle, this consistency determining the desired character of the vehicle and/or of the manufacturer&#39;s mark.  
         [0076]    To this end, the electronics card of the light unit of the invention includes a means which selects a class of performance for the light unit and its ancillary facilities, such as the lighting range, the speed of response of the dynamic orientation of the light unit, etc as a function of a signature which is loaded when the vehicle is started.  
         [0077]    According to another aspect of the invention, the electronics card of each light unit is provided with means that allow the lighting means and/or the ancillary facility means to be connected and disconnected or allow one parameter of their operation to be controlled and, possibly, with means for carrying out diagnostics on the operating status of the said lighting means and of the said ancillary facility means.  
         [0078]    According to another aspect of the invention, the electronics card of the light unit of the invention includes a means for implementing the connection of the light unit to the multiplexed bus of the vehicle in such a way as to ensure periodic communication between the light unit and the vehicle.  
         [0079]    During this periodic communication, control commands coming from the on-board computer that communicates over the multiplexed bus and reaching the light unit are introduced, as is information on the status of the light unit, in particular of the lighting means and of the various ancillary facility means mentioned above. As a result, the on-board computer continuously monitors the status of the lighting system, the commands being notified to it.  
         [0080]    It is thus possible to automatically carry out diagnostics and to take appropriate measures as a function of critical situations, particularly when situations involving failure are detected, in which it is possible to put a light unit, a lamp of a light unit or an ancillary facility means of the light unit in a downgraded operating mode.  
         [0081]    According to another aspect of the invention, the lighting control system can include a module for regulating the supply energy. To this end, the electrical supply cable of the light unit is connected to the output of a supply regulator. The supply regulator makes it possible to reduce the variations in the direct supply voltage within a range of variation that protects the filament lamps, both incandescent and halogen lamps, arranged in the light units, thereby optimising their life.  
         [0082]    According to another aspect of the invention, the general electrical energy supply system of the vehicle no longer receives significant surges in current demand from the lighting system. In fact, the integrated controller of the electronics card of the light unit of the invention includes a module for sequencing the switching on of the various loads included in a light unit, in such a way that the different loads are supplied according to schemes that make it possible to optimise the smoothing of the inrush currents.  
         [0083]    According to another aspect of the invention, the source of electrical energy supply of the vehicle can be at different voltages for the same type of light unit.  
         [0084]    Thus, if it is desired to adapt the lighting control system of the invention to a 42-volt source of supply, while the lighting control system is designed for supply at 12 volts throughout, the electronics card of the light unit of the invention is fitted with a dc-dc converter that converts the new voltage of 42 volts into a voltage of 12 volts due to the fact that the entirety of the control formed by the electronics card of the light unit of the invention comprises a single electrical supply cable.  
         [0085]    [0085]FIG. 4 shows an embodiment of a light unit according to the invention. The light unit  70  includes a first connector  71 , which is connected to the electrical energy supply harness of the vehicle. It includes a second standard connector  72  connected to the multiplexed bus of the on-board network as described above.  
         [0086]    In a variant, the network features a bus that has a third connector  73 , which is assigned to the driving of the network.  
         [0087]    The light unit  70  furthermore incorporates a controller  74 , which includes electronic components for carrying out the control of the lighting functions and of the ancillary facilities, complemented if necessary by appropriately dimensioned power components (MOS transistors, motor drivers etc . . . ), which are connected within the light unit  70  in such a way that the lighting functions and the ancillary facilities described by way of example with the aid of FIG. 3 are assured.  
         [0088]    The integrated controller  74  includes a module  75  for managing the electrical supply, which is connected directly to the supply connector  71 .  
         [0089]    The module  75  for controlling the supply makes it possible, in particular, to perform the functions of regulation and sequencing of switching on that have been described above. The various components of the light unit are supplied directly via this control module. The controller  74  furthermore includes an input module  76 , which is connected to the network via the standard bus connector  72 .  
         [0090]    The controller  74  furthermore includes a module  77  for driving electric motors, which are employed for the various ancillary facilities mentioned above, such as automatic adjustment of orientation.  
         [0091]    The controller  74  optionally includes a module  78  for controlling the network, which makes it possible to exploit the information output from the bus via the connector  73  described above.  
         [0092]    The controller  74  includes a central unit  79 , which communicates with memories and the various modules which have already been described.  
         [0093]    The controller  74  includes a switching module  80 , which makes it possible to set the various electrical loads associated with the light unit  70 , such as the loads  84 ,  87  or  93 , to the supply voltage controlled by the module  75  of the controller  74 .  
         [0094]    To this end, the supply switching module  80  of the controller  74  has an output port which is connected to power conductors  83  within the light unit. The conductors  83  are connected to all  84  of the lamps, which are subjected to controlled switching.  
         [0095]    Moreover, the conductors  83  are connected to the various electronic power-control circuits, such as the electronic control circuits or ballast  87 , by a conductor  85 .  
         [0096]    The conductors  83  are also connected by internal conductors  86  to all the lamps  93  mounted on the outside of the light unit  70 , which are controlled directly by the switching module  80 .  
         [0097]    The controller  74  furthermore includes a bus driver module  81 , which features an access port to a bus  88  within the light unit of the invention. The bus  88  allows commands and status information to be exchanged with the various ancillary facilities and ancillary facility modules of the headlamp.  
         [0098]    In particular, the bus  88  can be connected to a module for command and control of the ballast  87 , to a module for controlling an opto-electronic sensor  89 , to a module for controlling an actuator  90 , to a module for controlling functions for controlling the orientation of the light beams on bends, and for controlling an actuator  91  for adapting the bottom of the light beam produced by the light unit in accordance with the AFS or intelligent lighting functionalities.  
         [0099]    In a variant in which additional electronic functions are added at the front of the vehicle, the bus  88  is also connected to a module  92  for command and control of status, which manages these additional functions.  
         [0100]    Finally, the light unit  70  incorporates a plurality of sensors  94  for the status of the light unit and essentially sensors for the failure of the various actuators  90 ,  91 ,  89  of the light unit  70 . The controller  74  incorporates a module  96  for processing information on the status of the light unit  70  produced by the sensors for the status of the light unit  70 . The information is transmitted by the sensors  94  to the module  96  for processing status information via lines  95 , depending on circumstances, or is processed locally by the controller  74  or indeed returned, after appropriate formatting, to the on-board network for processing by the vehicle&#39;s on-board computer. In particular, the module  96  includes means for placing all or some of the lighting functions and/or of the ancillary facilities in a downgraded mode when a corresponding state of failure has been detected.