FR2843341A1 - Distributed control of steering and braking of vehicles, uses central control unit which can take over some of the functions of various local systems in the event of failure, and uses dual redundancy braking system - Google Patents

Abstract

The control system has a central unit providing a high-level management function for the braking, steering, engine control and parking-aid systems. The steering system can also be controlled from the central unit. The braking system uses a double redundant system. The systems communicate over a bus, timed by a synchronization bus.

Description

The present invention relates to a distributed control system for a

  electric steering and braking device, in particular at

  decoupled control, in particular for motor vehicles.

  For some time, the concept of an integral or comprehensive control system for motor vehicles has become more and more common in the automotive industry. This integral control of the vehicle involves the incorporation into the vehicle of many and varied electronic systems dedicated to detecting driving conditions and controlling the various functions.

of the vehicle.

  Some of these systems already exist or will be present on the market

  in the years to come. These include, for example, satellite navigation systems (GPS), driver assistance systems (cruise control with distance control, collision avoidance, parking assistance) or stability and stability control systems. vehicle traction (ABS, ESP, TRAXXAR, 15 ASR).

  In the near future, these systems will also have an ideal complement for vehicle control: control systems with decoupled control or "X-by-wire", such as electric braking systems, controlled suspensions or columns of electric steering. With this type of 20 systems it will be possible to control the functions of the vehicle with more

  precision and take into account a higher number of parameters.

  We will then be able to offer the user of the vehicle services

  improved in terms of safety, road handling and comfort.

  In order to achieve these objectives, it will nevertheless be necessary to meet increased requirements in terms of reliability and security, but also in terms of the system development process. In particular, systems designed typically independently will have to be interacted in order to ensure all the functions of the vehicle with a very high degree of reliability. These requirements are particularly present in the design of distributed control systems in which a function is

  distributed to different electronic controllers.

  The present invention relates to a control system and a function

  control system for a motor vehicle. This system as well as the control algorithm exposed in the present description can be applied to a global control or vehicle supervision system. In order to describe the present invention, examples will be used concerning its preferred solution, a vehicle equipped with braking and steering systems with decoupled control transmission, and control functions.

  stability, traction and driving assistance.

  In known "by-wire" steering systems, the actions of the driver on the steering wheel are first detected by a sensor.

  They are then interpreted and modulated, according to the information on the state of the vehicle in order to improve the dynamic behavior of the latter. These actions are finally translated into commands and sent to actuators responsible for steering the wheels. These systems can also reconstitute the torque 15 which would be transmitted to the steering column and return this value to the actuator of the steering column, thereby recreating the sensation

  driving force felt by the driver.

  As for electric braking systems, it is the travel or force of the brake pedal that is detected by a sensor. Depending on the signal from the sensor, a control system emits

  brake controls that are routed to the brake actuators.

  These act on the cylinders of the hydraulic circuit which are located near the wheels (electro-hydraulic systems) or directly on the brake pads (electromechanical systems) providing the desired braking force.

  This type of system has the advantage of being able to be integrated into electronic traction control systems since the electrical signals coming from the steering wheel or the brake pedal can be easily used by various control functions. However, the 30 conventional by-wire steering and braking systems have

  rarely used on the same vehicle in the past.

  J The so-called redundant or safe electrical systems for steering or braking offer the coupling of a "by-wire" type system and a parallel, hydraulic or mechanical auxiliary system, dedicated to safety functions and capable of acting on the actuators steering or brakes. These 5 systems are therefore capable of transmitting a command even if an electrical fault in the "by-wire" system occurs. In this case, the redundant mechanical or hydraulic system covers the functions of

  braking and steering and controls the actuators.

  The purely electric secure steering systems are based on an alternately closed and open loop control system generally consisting of two electronic controllers in parallel. Each controller transmits signals to one of two actuators which act on a single steering axis, thereby creating two similar but independent control subsystems. During a normal operating cycle, only one of the two systems controls the steering, but the

  two controllers monitor each other. In the event of a failure of one of the systems, the non-faulty system switches off the faulty system and assumes control of management. This principle, called the "watch dog" function, is also applied to purely electrically controlled braking systems.

  In the case of distributed control systems, the emergency functions activated by electronic controllers in the event of failure of one of the systems of the distributed network are generally designed independently of the other systems which form the network. These backup solutions are intended to resolve only the faults of the single failed system and do not seek to respond to the faults from the system point of view

global vehicle.

  Unreinforced "by-wire" systems can have faults that can lead to loss of control when a fault in the electrical network occurs. This fault can come from a fault in one of the sensors, a fault in the electrical network or a failure of the communication controller. Secured systems with dual controllers (with reinforced system and chain of custody) are also susceptible to this type of failure. Safety systems reinforced with a second type of control transmission, hydraulic or mechanical, often result in congestion of the vehicle systems and involve the implementation of an intricate mechanical and electronic architecture. In addition, the security system comes into action only on a fault in the "by-wire" system that it reinforces, the call to this security system by other vehicle systems

then being impossible.

  Likewise, in most distributed control systems, a subsystem on the network cannot generally use functionality driven by another subsystem. The security of the distributed system is then weakened because the control system has a limited response capacity vis-à-vis the different types of failures (or combinations of failures) that may occur during use of the system.

  In recent distributed systems, when a failure of one of

  elements of the distributed network is noted, certain functions of the vehicle can be sheltered in isolation by the control system which controls them, but this sheltering does not take into account the state of the other systems.

  In contrast to conventional design processes, this

  The invention addresses the safety aspects of the vehicle from the point of view of the overall system. The control system presented in the present description tolerates various failures of its subsystems while ensuring the braking and steering functions of the vehicle.

  The invention proposes an emergency control function which makes it possible to shelter the vehicle in a secure manner when a degradation of its functions represents a significant risk for the driver. It uses the concept of distributed control in which the laws of regulation and

  control are shared by different electronic controllers.

  In this description, we will only describe the implementation of this

  control system in a motor vehicle without detailing the architecture s

  electric or communication. In the same way, the technical characteristics of the elements integrated in the vehicle will only be described in detail when this description is essential for understanding the

present invention.

  According to the invention, the distributed control system for an electric steering device and a braking device, in particular, with decoupled control, in particular for motor vehicles, is characterized in that it comprises: i. a central control unit containing a management function io high level, plus the basic braking functions, ABS, ESP, (TRAXXAR), ASR, MSR, ACC, Anticollision, Parking aid, Guidance system, Level monitoring energy, ii. an Electrical Management controller containing the high-level management and basic management functions, 15 iii. an Electric Brake controller with redundant (double) control chain containing the basic braking functions,

ABS, ESP; (TRAXXAR)

  iv. a Steering Actuator controller, c. four Brake Actuator controllers for each of the four wheels of the vehicle containing the High Level Management function, vi. a communication bus, vii. a synchronous bus, in which - the Electric Steering, Electric Braking, Central Unit, Steering Actuator and Brake Actuator controllers exchange messages by the synchronous bus, the messages circulating by this bus being dedicated to controlling the steering functions, braking and stability of the vehicle, the central unit communicates with engine and gearbox controllers via the communication bus and sends commands to open the throttle valve to the engine and downshifts to the gearbox speed from the functions it contains: ESP (TRAXXAR), ASR, ACC, Anticollision, - basic control loops are established between the Electric Steering and Electric Brake controllers and their respective actuators, to control the steering and braking, - and a dynamic control loop is established between the basic control loops and the functions responsible for controlling the trajectory and vehicle traction, the

  system being adapted to activate vehicle emergency control functions.

  According to a feature of the invention, the controllers are adapted to calculate braking and steering controls for the wheels as a function, respectively, of the depressing stroke of the pedal and of the angle of the steering wheel, the values thus calculated being sent to the corresponding actuators which apply them to the wheels, through the brake pads or pinions / racks of the steering axle, the actuators are adapted to measure the value of the braking force or of the displacement of the steering axis actually applied and to send them back to the synchronous bus and the dynamic control loop is suitable for modulating the braking and steering controls according to the instantaneous driving conditions of the vehicle (trajectory, grip conditions) performed by the functions responsible for controlling the dynamic behavior of the vehicle, such as ESP, ABS or Anticollision. According to another characteristic of the invention, in the case of braking controlled by the ACC, the basic control loop is established between the ACC, the brake controller and the brake actuators, the ACC function communicates with the engine controllers and the gearbox, the ACC is adapted to calculate a braking force and an opening of the motorized intake throttle of the engine according to information on the environment coming from the radar system (relative distance and speed of target) and the state of the engine and gearbox, the braking force requested by the ACC being sent to the brake controller, the latter being suitable for transferring the commands of the braking forces which will correspond to the force calculated by the ACC when the brake pedal is not depressed or the force calculated by the pedal node when the driver

press the brake pedal.

  In the control system according to the invention, the top management function

  level is suitable for detecting the various failures of the controllers, lo and for triggering the emergency functions according to the origin of the failure.

  According to another particular feature, the control system according to the invention is adapted to activate at least one of the following emergency functions i. Emergency braking, corresponding to a failure of the Electric Brake controller (responsible for interpreting the driver's wishes) 15 which is corrected by developing and applying a maximum braking force controlled by the ACC function and taking charge braking by the central unit, ii. Braking ACC failure, corresponding to a failure of the ACC function which is corrected by the development and application of an average braking force controlled by the Electric Brake controller or, in the presence of a failure thereof, by the central unit; iii. Emergency Control, corresponding to a serious failure of the braking system, when the latter is unable to satisfy the braking function of the vehicle, which is corrected by

sheltering the vehicle.

  Other features and advantages of the invention will become apparent

in the description below.

  In the accompanying drawings, given by way of nonlimiting examples.

  FIG. 1 is a diagram of the architecture of the control system, FIG. 2a diagrammatically represents the basic regulation loop of the steering system, FIG. 2b diagrammatically represents the basic regulation loop of the braking system, - Figure 2c schematically shows the dynamic loops for regulating the steering and braking systems, - Figure 3 shows the flowchart of the high-level management system

  level of the system according to the invention.

  The invention relates to an electronic control system dedicated to the management and dynamic control of the vehicle and an emergency control function of the vehicle. The system manages the vehicle functions which mainly use the braking and steering systems and, in a

  to a lesser extent, transmission and engine control systems.

  Figure 1 shows the example of a preferred embodiment of

  the architecture of the control system. This diagram represents a typical placement of the different control functions in a distributed architecture.

  To implement the control system described in this document, it is of course possible to place the functions in the electronic controllers 20 which can be fitted to the vehicle in a different way without departing from the spirit of the present invention. These different placements can then be considered

  as part of the present invention.

  The vehicle of the preferred solution is equipped with electromechanical steering and braking systems with electric control transmission. The steering system is also reinforced by a mechanical * or hydraulic safety system, developed according to the corresponding state of the art, which allows the driver to control the steering when

  the electromechanical system is faulty.

  In this preferred embodiment, the electric braking system has a double control system (two sensors, two control units, two messaging systems) working in parallel which makes it possible to check the consistency.

  information produced by this system.

  The vehicle is equipped with at least the following functions: basic braking, ABS, ESP, (TRAXXAR), ASR, MSR, ACC, Anticollision, Parking assistance, Guidance system, Energy level monitoring, developed according to the rules of art. It is understood that the vehicle is also equipped with all the sensors, actuators and other organs (such as radars, sonars, infrared sensors, accelerometers, inclinometers, force sensors, etc.)

  necessary for the operation of these functions.

  The management of these functions is ensured by another function called High Level Management which contains the operating logic of the overall system, including io the management of failures, as they will be described more in detail.

detail later.

  The central unit communicates, on the one hand, with the steering, braking, brake actuators and the steering column actuator units by the fault tolerant TTP / C communication bus. This first network includes the functions that make

  mainly using the vehicle's braking and steering systems.

  On the other hand, the same central unit communicates with the engine and gearbox control units via the CAN communication bus. This second network allows the transmission of data and 20 commands between the systems which can call on the engine or the gearbox (ESP, ACC, ASR, Anticollision) and the associated controllers. It also includes other vehicle functions such as, for example, the

  satellite guidance or cockpit control.

  The operation and architecture of the two communication buses 25 TTP / C and CAN are not within the scope of the present invention and will not be

therefore not more fully described.

  In the nominal operating mode, the steering and

  braking are controlled first by the driver. At the request of the driver, the vehicle speed can also be controlled by the automatic driving function, ACC.

  In the first case, two separate basic control loops are established for the braking system (see Figure 2a) and for the steering (see

  Figure 2b). The controllers calculate braking and steering controls as a function of, respectively, the depressing stroke of the pedal and the angle of the steering wheel. These values are sent to the corresponding actuators which apply them to the wheels, through the brake pads or the pinions / racks of the steering axle.

  The actuators finally measure the values of the braking force or the displacement of the steering axis actually applied and return them to the

TTP / C bus.

  In the case of braking controlled by the ACC, the base control loop is established between the ACC, the brake controller and the actuators of the

  brakes. The ACC function also communicates with engine and gearbox controllers. ACC calculates a braking force and an opening of the motorized engine intake throttle based on environmental information from the radar system (distance and relative speed of the target) and the state of the engine and of the gearbox.

  The braking force requested by ACC is sent to the brake controller. The latter then transfers the commands for the braking forces which will correspond to the force calculated by ACC when the brake pedal is not depressed or to the force calculated by the pedal node when the client 20 presses the brake pedal.

  The nominal operating mode finally contains a dynamic control loop established above the two basic loops described above (see Figure 2c). This loop consists of a modulation of the braking and steering controls according to the instantaneous driving conditions of the vehicle (trajectory, grip conditions) carried out by the functions responsible for controlling the dynamic behavior of the vehicle,

  like ESP, ABS or Anticollision.

  We will now explain the management of failures.

  The High Level Management function (see Figure 3) supervises the overall behavior of the system and decides on the activation of the various functions according to the operating state of the vehicle. It is installed in It all the controllers associated with the subsystems equipping the vehicle so

  to ensure a uniform overall behavior of the vehicle.

  High-level management detects the various failures of its subsystems and triggers the emergency functions depending on the origin of the 5 failure. The failures managed by this function can come from the different subsystems equipping the vehicle (Central Unit, Electric Steering, Electric Brake, Steering Actuator, Brake Actuators)

  or functions managed locally by these subsystems.

  The ESP (TRAXXAR), ABS, ASR, MSR functions can integrate their own degraded modes, without these being perceived by the driver.

  These degraded modes are managed internally by said functions and are not within the scope of the present invention. Furthermore, these modes do not interfere with failure management conceived from a global point of view which is the

central point of the invention.

  Electric brake controller failure: safety function

"Emergency Braking".

  The entry conditions for failure of the Electric Brake controller are

the following.

  (1) the TTP communication controller does not receive a message from either of the two dual control systems when required; (2) an internal error in the Electric Brake controller occurs, such as a sensor failure, for example; (3) the two double control systems calculate forces of

braking too different.

  In this case, the ACC function defines a maximum braking force which the actuators apply once to the wheels ignoring any braking force coming from the Electric Brake controller. Thereafter, it is the central unit which defines and sends to the actuators the braking force to be applied.

  using the ABS and basic braking functions it contains.

  Incidentally, the ACC function can send a signal to the passenger compartment controller in order to light a specific warning lamp to warn the driver of

  failure of the Electric Brake.

  If in this mode a new failure of the ABS and braking functions

  base of the central unit or actuators is detected, before the 5 Electric Brake controller is restored, the system enters the "Emergency Control" mode, described below.

  The system only returns to nominal operating mode if all

  the subsystems are functioning properly again.

  ACC function failure: "Braking 10 ACC failure" safety function.

  The ACC entry failure conditions are as follows. (1) the TTP communication controller does not receive a message from the function when required; (2) an internal error in the function takes place, such as a calculation error or a braking force outside the field of application, for example. This failure mode is only taken into account if the ACC function is activated by the driver and if the driver does not apply the brake pedal. 20 In this case, the Electric Brake controller sends medium braking force commands (instead of the braking force from ACC) to the actuators which apply them to the wheels to warn the driver of the ACC system failure. . Incidentally, the Electric Brake controller can send a signal to the passenger compartment controller in order to light a specific warning lamp to warn the driver of the failure and

of the ACC system standby.

  If in this mode a failure of the Electric Brake controller is detected, the central unit defines the braking force to be applied using the ABS and basic braking functions it contains. In the event of failure of the ABS and basic braking functions of the central unit or in the event of failure

  actuators, the system enters "Emergency Control" mode, described below.

  The system only returns to nominal operating mode if all

  the subsystems are functioning properly again.

  The Emergency Control function is activated when the braking system is unable to satisfy the braking commands requested by the various control functions. This condition is validated by one of the following events: (1) the conditions for entering "Emergency Control" mode

  described above are satisfied.

  (2) The values of the forces actually applied by the actuators differ too much from the set braking forces commanded by the Electric Brake controller or by the central unit; (3) The actuators emit an alarm signal indicating that the electrical energy level, informed by the energy level monitoring system, has dropped below

  of a limit threshold reducing their braking capacities critically.

  In this case, the ACC function requests a closure of the intake throttle valve 20 and downshifts of successive reports to the gearbox.

  to brake the vehicle as quickly as possible using the engine brake.

  No braking force is requested by the Electric Brake controller or by the central unit. In order not to disturb the stability of the vehicle, the actuators therefore open the brake shoes, in the event that the pads 25 are defective.

  At the same time, the direction controller uses information from the front, rear and side obstacle sensors of the ACC, collision avoidance and parking assistance functions, to: (1) decide which side of the road is most suitable and determine the 30 trajectory for folding the vehicle onto said side of the road as a function of fixed obstacles and instantaneous traffic conditions;

  (2) send the necessary commands to the actuator of the steering axis in order to automatically steer the vehicle towards said side of the road along the chosen path.

  If the electromechanical steering system is in degraded mode (the steering axis then being actuated by the mechanical or hydraulic safety system) the direction controller sends a signal to the passenger compartment controller in order to display a message indicating to the driver what he must

  check the trajectory of the vehicle.

  Incidentally, the ACC function can send signals to the passenger compartment controller in order to turn on the hazard warning lights and to turn on a specific warning light signaling to the driver that an emergency stop is in progress. These signals can also be used, for example, to send a radio distress message indicating the position of the vehicle, according to information from the navigation system, to an assistance center.

or determined relief.

  Once the vehicle has come to a complete stop, the central unit requests the engine controller to stop the engine and the vehicle to stop. This immobilization results in the issuance of a command 20 to engage the parking brake mechanism and another command to engage a gear (first, reverse or "Drive") to the gearbox. . Actions allowing the signaling of the vehicle stopping can remain active until a limit threshold of the energy level is reached. The system only returns to nominal operating mode if all

  the subsystems are functioning properly again.

  We will now explain the advantages of the control system according to the invention. The inter-system design approach used for the development of the control system and the back-up functions which are the subject of the present invention makes it possible to cope with the possible failures of the components and controlled organs which participate in the functions. steering and braking] 5 of the vehicle. This approach breaks with the methods typically used in the development of systems and laws for controlling

electronic systems.

  The functions presented in this description are distributed functions, shared by several functions or subsystems. The independent control system of the electronic architecture and the placement of control functions in this architecture, which facilitates the adaptation of

  solutions exposed in this description to other distinct architectures.

  This type of solution also makes it possible to weight in an innovative way (depending on the state of the overall vehicle) the safety constraints to which the control elements and the organs of the steering systems

and braking will be subject.

  Another advantage of the invention lies in the fact that, during its implementation, existing systems and the signals produced by these systems can be used. Indeed, the invention is based on an exploitation of the functionalities inherent in the components of the system. The components and their functionalities can therefore be designed beforehand and independently by different developers, as is the case with ABS, ESP, (TRAXXAR), etc. However, to achieve the integration of the independently developed components, it is necessary to define the operating system, that is to say, the macroscopic behavior of the system, in a global manner. Then, it is necessary to establish an arbitration between the tasks of control and regulation carried out individually by each of the components. These 25 supervision and arbitration operations are carried out in the present

  invention by the high-level Management automaton described above.

  As it was established above, the high-level management automaton is installed in all the controllers associated with the subsystems equipping the vehicle in order to ensure a homogeneous overall behavior of the vehicle. Indeed, since the functioning of the subsystems depends on the macroscopic states defined by the same automaton, it can be affirmed that all the elements participating in the steering and braking functions are found in

  one and the same state at the same time.

  The integration approach that has just been described further promotes the reuse, by other applications or other systems, of the various components used in the present invention.

  The examples used for the description of the present invention,

  relate to the preferred solution for its implementation. This preferred embodiment is a motor vehicle equipped with electromechanical steering and braking systems with 1o electric control transmission. The steering system has a redundant mechanical or hydraulic safety system, developed according to the rules of the art. The braking system has redundancy by double control chain (double pedal sensor, double control logic, two messaging) which

operate in parallel.

  The preferred solution vehicle is equipped with at least the

  basic braking functions, ABS, ESP (TRAXXAR), ASR, MSR, ACC, Anticollision, Parking aid, Guidance system, Energy level monitoring, the description of which is not within the purview of the present invention. It is understood that the vehicle is also equipped with all the sensors, actuators, and other organs (such as radars, sonars, infrared sensors,

  accelerometers, inclinometers, force sensors, etc.) In the following paragraphs, the main components of the control system which participate in the control functions will be described in detail.

  forming the subject of the present invention.

  The electric steering controller is responsible for calculating the steering angle of the wheels as a function of the angle of the steering wheel required by the driver and for sending the value of the steering wheel to the actuator.

setpoint deflection.

  This value corresponds to the customer's request in nominal mode when the latter turns the steering wheel or to the steering angle calculated by the Electric Steering controller when the emergency control function is activated. The steering axis actuator controller is responsible for three main tasks: applying the displacement corresponding to the set point deflection (from the Electric Steering controller) to the steering axis by actuating the pinion system ò measure the steering actually applied; ò calculate the difference between the deflection applied and the deflection of

  setpoint and send this information back to the TTP / C bus.

  io It is thanks to these values that faults in the electromechanical steering system can be detected and that the mechanical or hydraulic safety system is activated, as described above. The ACC and anti-collision (Central Unit) functions are responsible for calculating: A braking force when braking without customer request is required; ò an opening of the intake throttle when an acceleration

  (ACC function only) or vehicle deceleration is required.

  To calculate these values, the functions use the data concerning the distance and the speed of a target which they obtain thanks to the sensors linked directly to the controller (radars, sonars). The data produced by these 25 sensors is used by the ACC function and by the Electrical Direction controller to execute the emergency control function, as set out above. These same data are used to detect certain faults in the ACC function enabling the function described above to be activated. The basic braking function (Electric brake controller and central unit) is responsible for calculating a braking force according to the depressing of the brake pedal by the driver and sending to the actuators

set braking forces.

  These forces correspond to the braking force dd calculated by the function

  basic braking when the driver depresses the brake pedal or at the braking force calculated by the ACC or Anticollision functions when the brake pedal is not depressed.

  The redundancy of the Electric Brake controller makes it possible to carry out diagnostics on the consistency of the calculated braking force and to check the operating status of the controller. This information, plus information 10 concerning the state of the basic braking and ACC functions of the central unit,

  are used to activate the function described above.

  The brake actuator controllers have limited intelligence. They are responsible for three main tasks: * apply the corresponding wheel to the set braking force 15 (either from the Electric Brake controller or from the central unit) by tightening the jaws of the brake pads Measuring the braking force actually applied ; * calculate the difference between the applied force and the force of

  set braking and send this information back to bus 20 TTP / C.

  It is thanks to these values that actuator faults can be partially detected and that the emergency control function can be

  triggered, as described above.

  The central unit communicates with the controllers of the internal combustion engine and of the gearbox through the CAN communication bus. It is through this network that the central unit receives data from these two controllers in order to use them for calculations.

  of some of the functions it contains.

  The present invention does not use the properties of the controller of the

  CAN network for setting up security functions.

  Communication between controllers regarding

  steering and braking is carried out on the TTP / C communication bus. The controller of this bus synchronizes the sending and receiving of data and provides information on the availability (status) of the data produced by each controller.

  This information is also used to detect certain failures of the components of the overall system and to activate the functions.

  described above.

Claims (10)

  1. Distributed control system for an electrical steering device and braking device, in particular with decoupled control, in particular for motor vehicles, characterized in that it comprises: 5 i. a central control unit containing a high level management function, plus the basic braking functions, ABS, ESP, (TRAXXAR), ASR, MSR, ACC, Anticollision, Parking assistance, Guidance system, Energy level monitoring , ii. an Electrical Management controller containing the 10 High-level management and Basic management functions, iii. an Electric Brake controller with redundant control chain (double) containing the basic braking functions, ABS, ESP, (TRAXXAR), iv. a Steering Actuator controller, c. four Brake Actuator controllers for each of the four wheels of the vehicle containing the High Level Management function, vi. a communication bus, vii. a synchronous bus, in which - the Electric Steering, Electric Braking, Central Unit, Steering Actuator and Brake Actuator controllers exchange messages by the synchronous bus, the messages circulating by this bus being dedicated to controlling the steering functions, braking and stability of the vehicle, the central unit communicates with engine and gearbox controllers via the communication bus and sends commands to open the throttle valve to the engine and downshifts to the gearbox speed from the functions 30 it contains: ESP (TRAXXAR), ASR, ACC, Anticollision, - basic control loops are established between the Electric Steering and Electric Brake controllers and their respective actuators, to control the steering and braking , - and a dynamic control loop is established between the 5 basic regulation loops and the functions responsible for   vehicle trajectory and traction control, the system being adapted to activate vehicle emergency control functions.   o0 2. Control system according to claim 1, characterized in that the controllers are adapted to calculate braking and steering controls for the wheels as a function, respectively, of the depressing stroke of the pedal and of the angle of the steering wheel direction, the values thus calculated being sent to the corresponding actuators which apply them to the 5 wheels, through the brake pads or pinions / racks of the steering axle in that the actuators are suitable for measuring the values of the braking force or the displacement of the steering axis actually applied and to send them back to the synchronous bus and in that the dynamic control loop is adapted to effect modulation of the braking and steering commands according to the conditions of instantaneous driving of the vehicle (trajectory, grip conditions) carried out by the functions responsible for controlling the dynamic behavior of the vehicle cule,   such as ESP, ABS or Anticollision.   3. Control system according to one of claims 1 or 2,   characterized in that in the case of braking controlled by the ACC, the basic control loop is established between the ACC, the brake controller and the brake actuators, the ACC function communicates with the engine controllers and the gearbox, the ACC is adapted to calculate a braking force and an opening of the motorized intake throttle of the engine as a function of information on the environment coming from the radar system (relative distance and speed of the target) and the state of the engine and of the gearbox, the braking force requested by the ACC being sent to the brake controller, the latter being adapted to transfer the commands of the braking forces which will correspond to the force calculated by l 'ACC when the brake pedal is not depressed or at the force calculated by the pedal node when the driver presses the brake pedal.   4. Control system according to one of claims 1 to 3,   characterized in that the high level management function is suitable for detecting the various failures of the controllers and for triggering the emergency functions depending on the origin of the failure.   5. Control system according to one of claims 1 to 4,   characterized in that it is adapted to activate at least one of the following emergency functions: i. Emergency braking, corresponding to a failure of the Electric Brake controller (responsible for interpreting the driver's wishes) which is corrected by developing and applying a maximum braking force controlled by the ACC function and taking charge of the central unit braking, 20 ii. Braking ACC failure, corresponding to a failure of the ACC function which is corrected by the development and application of an average braking force controlled by the Electric Brake controller or, in the presence of a failure thereof, by central unity; iii. Emergency Control, corresponding to a serious failure of the   braking system, when this is not able to satisfy the vehicle's braking function, which is corrected by making the vehicle safe.   6. Control system according to claim 5, characterized in that the failure entry conditions of the Electric Brake controller are as follows: (1) the TTP communication controller does not receive a message from one of the two systems of the double check when required; (2) an internal error in the Electric Brake controller occurs, such as a sensor failure, for example; (3) both systems of double control calculate forces of braking too different.   7. Control system according to one of claims 5 or 6,   characterized in that the failure conditions for the ACC 10 function are as follows: (1) the TTP communication controller does not receive a message from the function when required; (2) an internal function error occurs, such as a calculation error   or a braking force outside the field of application.   8. Control system according to one of claims 5 to 7,   characterized in that the "Emergency Control" function is activated when the braking system is unable to satisfy the braking commands requested by the various control functions, this condition 20 being validated by one of the events following: (1) the conditions for entering "Emergency Control" mode are satisfied; (2) the values of the forces actually applied by the actuators differ too much from the set braking forces commanded by the Electric Brake controller or by the central unit; (3) the actuators emit an alarm signal indicating that the electrical energy level, informed by the energy level monitoring system, has dropped from a limit threshold reducing their   braking capabilities critically.   9. Control system according to one of claims 5 to 8, characterized in that said emergency functions are adapted to allow:   i. restarting (restarting) of the faulty element or member while ensuring the maneuverability and slowing down of the vehicle; ii. the rehabilitation of the vehicle's braking function in a secure manner only when the systems participating in said function work properly.   10. Control system according to one of claims 5 to 9, characterized in that said Emergency Control function is adapted to allow:   i. stopping the vehicle using the engine brake; ii. the automatic conduction of the vehicle or the indications necessary for the driver to guide the car himself towards the side of the road; iii. the algorithm deciding the best trajectory to follow to achieve said automatic driving; iv. reporting the emergency stop to the driver; v. reporting of the emergency stop and the position of the car to the specified assistance or rescue centers; vi. stopping the engine and immobilizing the vehicle once reached the latter stopped completely. 20