Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L7/00—Electrodynamic brake systems for vehicles in general
  • B60L7/22—Dynamic electric resistor braking, combined with dynamic electric regenerative braking
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
  • B60L7/00—Electrodynamic brake systems for vehicles in general
  • B60L7/02—Dynamic electric resistor braking
  • B60L7/06—Dynamic electric resistor braking for vehicles propelled by ac motors
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/60—Other road transportation technologies with climate change mitigation effect
  • Y02T10/72—Electric energy management in electromobility

Definitions

• Electric braking system of a road vehicle with totally electric control.
• the present invention relates to road vehicles. It relates in particular to the braking systems of a road vehicle with electric traction.
• Electric vehicles include vehicles in which the electrical energy necessary for their movement is stored in batteries and vehicles in which electrical energy is produced on board, by a heat engine driving a generator or by a battery. combustible.
• the traction of the vehicle is provided by one or more electrical machines.
• the braking of the vehicle is provided by a conventional mechanical braking system, sometimes with electrical assistance to mechanical braking.
• an electric machine being reversible, it can also be used as an electric generator during the braking phases of the vehicle and in this case it converts the mechanical braking energy into electrical energy that the vehicle must absorb, possibly by thermal dissipation. This mode of operation is often called “electric braking” or “regenerative braking”.
• patent application GB 2 383 567 describes a four-wheeled hybrid series vehicle, each wheel being driven by an electric machine of its own, which takes advantage of this arrangement to reconfigure the functions of control of vehicle dynamics.
• This patent application does not deal with braking but yaw torque to be printed on a vehicle by electric motors.
• Patent GB 2 344 799 which also describes a four-wheeled vehicle of the hybrid series type, each wheel being driven by an electric machine of its own, which more particularly describes an electric braking operation which comes into assistance.
• a conventional mechanical friction brake system is also described.
• the electric machines operate as a generator to ensure a moderate deceleration of the vehicle, to recover as much as possible energy and store it in electrical accumulators, or even to dispel it to lighten the solicitation of mechanical brakes of the vehicle.
• the main braking of a vehicle is in fact ensured by mechanical brakes controlled hydraulically, generally in an assisted manner, and most often now provided with an anti-lock function commonly referred to as "ABS".
• Braking is a key safety feature on a vehicle.
• the mechanical brakes are of significant power, capable of bringing the wheel to the blocking, power clipping being provided by the anti-blocking function, the clipping being related to the limit of adhesion.
• the braking system of a passenger vehicle is generally capable of decelerating the order of 1 "g", where g is the acceleration unit whose value "1" corresponds to Earth's gravity.
• ground connection comprises a pivot to allow to steer the wheel. All mechanical functions of a ground connection are thus integrated into the wheel.
• patent application DE 100 54 368 describes a wheel that incorporates an electric machine, as well as the electronic control means of the electric machine; the possibility of avoiding mechanical brakes, except for the immobilization of the vehicle, is also mentioned.
• the objective of the present invention is to provide reliable electric braking, simplifying the architecture of the ground connections of the vehicles.
• the current The invention proposes practical means for ensuring the service braking function purely electrically, while ensuring a high level of safety.
• the invention proposes an electric braking system for a road vehicle equipped with wheels which are connected in rotation each to at least one rotary electric machine, each rotary electric machine cooperating with a single wheel, an electronic wheel control module driving the one or more electric machines of the same wheel, each electronic wheel control module making it possible selectively to impose on the wheel in question a driving torque determined in amplitude and in sign, so that the wheel in question imposes on the vehicle a driving force or a braking force according to said determined steering torque, the system comprising a central unit for managing the movement of the vehicle, said central unit controlling all the electronic wheel control modules, said central unit having a control mode; vehicle braking operation activated by a vehicle braking control signal having a given amplitude representative of the total braking force desired for said vehicle and in which, in braking mode, irrespective of the amplitude of the brake control signal, said central unit controls all the electronic wheel control modules so that the sum of the longitudinal forces of the set of wheels coming from the rotating electrical machines is a function of said amplitude of the brake control
• none of the wheels of the vehicle comprises a mechanical service brake.
• braking is provided electrically, that is to say by driving the electric machines in a generator.
• Each wheel has one or more dedicated electrical machines in order to be able to generate a braking force selectively on each wheel, which one could not do with a common electric machine with several wheels, for example the wheels of an axle, because there would be in this case a mechanical transmission and a differential between the wheels. Electrical machines are sized appropriately to impose the highest possible braking force on each wheel.
• the system comprises means for thermally dissipating the electrical energy, capable of absorbing a high electrical power, which for example leads to install an electrical dissipation resistor or cooled effectively, for example by circulating d water, the known electric accumulators not being able to absorb the electric power produced by an emergency braking or not being able to absorb all the electrical energy produced by a long-term braking, except to install a capacity such that the weight of the vehicle would be really prohibitive. It is also possible to adopt other dissipative means, for example a magnetic coupling between a coil and a ferromagnetic piece cooled by circulation of water.
• the invention makes it possible to form an autonomous electrical system isolated from the environment, capable of providing electrical braking of a vehicle in all driving circumstances, and without the exchange of electrical energy with the outside of the vehicle. , therefore also applicable to motor vehicles, application of electric braking systems much more difficult than in the case of vehicles connected to an electrical network such as trains or urban trams.
• control electronics is redundant.
• hardware redundancy is also realized.
• a low-voltage power supply stage for supplying power control and control electronics
• each of these stages has a certain level of redundancy.
• the proposed redundancies for each floor can be used alone, or in combination with another.
• the level of reliability is increased by combining all the proposed redundancies.
• the means for thermally dissipating the electrical energy comprise two electronic dissipation modules and two electrical dissipation resistors in order to always offer a certain deceleration capacity in the event of a failure of a resistor or its control module. .
• the invention proposes an electric braking system of a road vehicle of which at least two wheels are connected in rotation each to at least one rotary electric machine, each rotary electric machine cooperating with a single wheel, an electronic wheel control module controlling the electric machine or machines of the same wheel, each electronic control module for selectively imposing on the wheel in question a driving torque determined in amplitude and in sign, so that the wheel considered imposes on the vehicle a motor force or a braking force according to said determined driving torque, characterized in that it comprises two subsystems connected to a central power line, each of the subsystems comprising:
• a dissipation device powered by an electronic dissipation module powered by an electronic dissipation module.
• each of the wheels is mechanically connected to its or its own rotating electrical machines, each of said subsystems comprising two of said wheels.
• each subsystem groups the vehicle wheels arranged diagonally at opposite corners of the vehicle. It will be seen that this solution offers more safety than the dual hydraulic brake systems commonly used on automobiles.
• the low-voltage power supply stage for supplying control electronics and control of the power elements comprises two independent voltage sources.
• Said low power supply stage voltage comprises a first power supply and at least a second power supply, the first power supply and the second power supply being interconnected by a low voltage electrical line comprising a first section and a second section, said first and second sections being connected by a separation device device galvanically of the two sections in case of undervoltage on one of them, each electronic wheel control module and electronic dissipation module of one of the subsystems being powered by the first section and each electronic control module wheel and electronic module dissipation of the other subsystems being powered by the second section.
• the first power supply is for example constituted by a voltage converter connected to the central power line.
• the electrical energy on this central line can come either from a main source, such as for example a fuel cell, an electrical energy storage device, or real-time recycling energy. There is also a redundancy of energy sources.
• the second power supply consists for example of a low voltage battery, dedicated to this low voltage power supply. Of course, it is possible to use for this second voltage source a second voltage converter also connected to the main line or directly to the storage device.
• the two voltage sources are interconnected by said electrical line comprising said first section and said second section.
• the circulation stage of the brake control signals of the vehicle is built around two sensors mechanically connected, and preferably separately, to a brake control available to a driver, the sensors being operated from totally different way as explained below.
• the system according to the invention comprises, associated with a wheel at least, a mechanical braking device of the wheel controlled solely by a parking brake control.
• the parking brake device is controlled by an electric actuator controlled by a brake control unit which can be activated only under a longitudinal speed threshold of the vehicle, said threshold being for example less than 10 km / h.
• the invention also extends to a vehicle equipped with an electric braking system according to what is described herein.
• Figure 1 shows schematically a braking system of a four-wheeled vehicle, producing electrical energy on board
• FIG. 2 is a diagram showing the level of power organized to present a certain material redundancy
• Figure 3 shows the low voltage power supply level of the various control electronics
• Figure 4 shows the level of the control lines between the control electronics of the different elements and the central unit.
• IArD- wheels are denoted IA V GP our the left front wheel, IA V D for the right front wheel, iarg F or the left rear wheel and casualty F or the rear right wheel.
• Each wheel is equipped with an electric machine that is mechanically coupled to it.
• the electrical machines ⁇ AvG ' ⁇ AvD' ⁇ ArG e * ⁇ ArD- we will not take again the indices specifically designating the position of the wheel 1 or the electric machine 2 in the vehicle when it does not bring nothing to the clarity of the presentation.
• the electrical traction machines 2 are three-phase synchronous machines, equipped with a resolver-type angular position sensor and are controlled by the electronic wheel control modules 23 to which they are connected by power lines 21.
• the electronic modules wheel steering 23 are designed to drive the electric machines in torque. As a result, the electrical machines can be used as motor and generator.
• Each of the rear wheels IArG e * ⁇ ArD es1 further equipped with a mechanical braking device 71 of the wheel controlled by an electric actuator 7 controlled by a brake control unit.
• an electric machine mechanically coupled to the wheel. Note, however, that it will be advantageous to install a relatively large gear ratio, for example at least equal to 10 and preferably even greater than 15, so that the electric machine is not too bulky.
• An electric machine can be installed coaxially with the wheel, the mechanical connection being provided by an epicyclic gear train to provide the necessary reduction. It is also possible to adopt a configuration of the type described in patent application EP 0878332, preferably by adding a mechanical reduction stage.
• One can also choose to have several electrical machines whose couples add up. In this case, an electronic wheel module can drive several electrical machines in parallel installed in the same wheel. Regarding the installation of several electrical machines in a wheel, see for example the patent application WO 2003/065546 and the patent application FR 2776966.
• the invention is illustrated in an application to a vehicle ensuring the production of electrical energy on board.
• a fuel cell 4 delivering an electric current on a central electrical line 40.
• any other power supply means can be used, such as batteries.
• an electrical energy storage device constituted in this example by a bank of super capacitors 5, connected to the central electrical line 40 by an electronic recovery module 50.
• an electrical dissipation resistor 6 preferably dipped in a coolant discharging heat to an exchanger (not shown), constituting an energy absorbing device adapted to absorb the electrical energy produced by all the electrical machines during braking.
• the dissipation resistor 6 is connected to the central electrical line 40 by an electronic dissipation module 60.
• a central unit 3 manages various functions, including the electric traction system of the vehicle.
• the central unit 3 communicates with all the electronic wheel control modules 23 as well as with the electronic recovery module 50 via the electrical lines 30A (CAN bus).
• the central unit 3 also communicates with an acceleration control 33 via an electric line 30E, with a braking command 32 (service brakes) via an electric line 30F, and with a control 31 selecting the forward or reverse gear via a 30C power line. This makes it possible to take into account driver's intentions.
• the central unit 3 also dialogs with a longitudinal acceleration sensor 34 via a power line 3OD.
• the electronic recovery module 50 communicates with the electronic dissipation module 60 via an electrical line 30B.
• the central unit 3 manages the longitudinal movement of the vehicle. Said central unit 3 controls all the electronic wheel control modules 23.
• the central unit 3 has a vehicle braking operating mode activated by a vehicle braking control signal having a given amplitude representative of the total force desired braking effect for said vehicle. In braking mode, whatever the amplitude of the braking control signal, said central unit 3 controls all the electronic wheel control modules 23 so that the sum of the longitudinal forces of the set of wheels 1 from rotating electrical machines is a function of said amplitude of the brake control signal. In other words, there is no mechanical service brake; the electric braking system described here is the service brake of the vehicle.
• a parking brake control 35 The actuator 7 of the mechanical wheel brake device is controlled via an electric line 30H only by this parking brake control 35, and absolutely not by the braking command 32.
• said parking brake control unit can not be activated. that under a longitudinal speed threshold of the vehicle rather low, for example less than 10 km / h.
• the central unit 3 orders the electronic wheel control modules 23 to power the electrical machines 2 by drawing the electric power on the central electrical line 40. This is supplied by the fuel cell 4 and / or the bank of super capacitors 5, according to the state of charge thereof and under the control of the unit 3.
• the vehicle is moving forward. Electrical machines 2 convert electrical energy into mechanical traction energy. The power used depends in particular on the position of the acceleration control 33.
• the central unit 3 When the driver actuates the brake pedal 32, the central unit 3 goes into braking mode. From the action of the driver on the brake pedal 32, the central unit 3 calculates a value of the brake control signal. Whatever the amplitude of the signal of brake control, said central unit 3 controls all of the electronic wheel control modules 23 so that the sum of the longitudinal forces of the set of wheels 1 is proportional to said amplitude of the brake control signal. The rotating electrical machines 2 then transform mechanical rotation energy into electrical energy.
• the latter distributes the braking energy so as to recharge the bank of super capacitors 5 and / or controls the electronic dissipation module. 60 so as to dissipate the energy in the electrical dissipation resistor 6.
• the power of the storage means can be limited, that is to say that the charging speed of the storage means can for example correspond to a light braking as is commonly expected from a heat engine (this which is called the "engine brake"). Beyond this braking level, the electrical power produced is then directed towards the dissipation means.
• the electrical dissipation resistor 6 is dimensioned and cooled so that all the electrical energy produced in emergency braking maneuvers, the most violent, can to be dissipated. In fact, it is advisable to size the chain formed by the rotary electrical machines 2, the electronic wheel control modules 23, the central electrical line 40, the electronic dissipation module 60 and the electrical dissipation resistor 6 according to similar criteria. severity than what is applied to mechanical braking systems.
• the set of rotary electrical machines 2 is capable of producing peak power of more than 500 kW per ton of vehicle, and preferably all of the electrical dissipation resistors 6 form an absorption device. power of more than 500 kW per tonne of vehicle.
• the power per ton of vehicle is about 350 kW and it is about 500 kW at 160 km / h.
• each of these electrical dissipation resistors 6A and 6B is preferably of greater than 250 kW power and the set of rotary electrical machines 2 is capable of producing peak power of more than 500 kW, all per ton of vehicle.
• the central unit 3 orders the electronic wheel control modules 23 to reverse the operation of the rotating electrical machines 2, including in case of braking.
• each wheel 1 having its own rotary electrical machine 2 thus has a speed sensor of each wheel rotation. It is from this that we construct a device for controlling the sliding of each wheel in which, in braking mode, the steering torque of a wheel is decreased when the sliding control device detects a sliding of the wheel. wheel considered.
• the derivative of the rotational speed signal of each wheel can be calculated in real time, thus obtaining a signal representative of P acceleration / deceleration of each wheel and comparing it with a signal giving the actual acceleration / deceleration of the vehicle if the we have an appropriate sensor. It is the longitudinal acceleration sensor 34 already introduced above, or it is the fact of a processing of several signals for estimating the actual acceleration / deceleration of the vehicle. Therefore, the central unit 3 can order the electronic wheel control modules 23 to reduce the wheel drive torque (selectively wheel) when the slip control device detects a sliding of the wheel in question. Note that this torque reduction can be controlled directly by the electronic wheel modules, which can react in real time to the speed and acceleration measured at the wheel, the central unit for example transmitting instructions for maximum speed and speed. acceleration to respect.
• the following description illustrates a particular, non-limiting example, to build a system with sufficient hardware redundancy to ensure a very high level of safety to the vehicle braking system.
• the electric braking system comprises two subsystems (A and B) connected to the central electrical line 40, each of the subsystems comprises two wheels each connected in rotation to at least one machine. rotating electric 2 of its own.
• the left front wheel and the right rear wheel, or more exactly the rotary electrical machines 2 and the electronic wheel control modules 23 associated therewith form the subsystem B.
• Each subsystem comprises an electrical dissipation resistor 6A, respectively 6B, each powered by an electronic dissipation module 6OA , respectively 6OB.
• the rotating electric machines 2 integrated wheels form a system that naturally has redundancy since each of the wheels has its own electric machine .
• the control electronics of these machines, namely the electronic wheel control modules 23, also form a system which has a material redundancy since each of these electrical machines 2 has its own control electronics.
• each of the rotary electrical machines 2 provides electrical power line 40 with electrical energy via the electronic wheel control modules 23.
• This energy can be stored in accumulators such as the super bench. capacitors 5 or be dissipated by the electrical power resistors 6A and 6B.
• the electrical resistance 6 is a crucial element for the operational safety.
• the electric power line 40 is a crucial element for the operational safety of the braking system of the vehicle by all-electric means. Different failure scenarios are discussed below.
• FIG 2 there is recognized the main source of electrical energy which, in this embodiment, is a fuel cell 4. It also shows the battery for storing electrical energy which, in this exemplary embodiment, is a bank of super capacitors 5 and its electronic recovery module 50.
• the low voltage power supply of the various electronic modules is provided on the one hand by a voltage converter 41 to convert the voltage available on the power line 40 low voltage (for example 12 volts) used to power the various control electronics, and secondly by a battery 42 such as a battery conventionally used on a vehicle voltage of 12 volts continuous.
• the braking system is organized in two subsystems, namely the system A grouping the right front wheel and the left rear wheel and the system B grouping the left front wheel and right rear wheel.
• the subsystem A is connected to the power line 40 via an overcurrent protection device 4 IA.
• the subsystem B is connected to the power line 40 via an overcurrent protection device 4 IB.
• Each of the subsystems therefore has its own dissipation resistor 6A, 6B and each has its own control electronics 6OA, 6OB.
• a power line section 4OA is connected to the electronic wheel control module 23 associated with the left rear wheel, to the electronic wheel control module 23 associated with the right front wheel and finally to the module 6OA dissipation electronics associated with the dissipation resistor 6A.
• Each of the electronic wheel control modules 23 is able to manage by itself the operation in electric braking. In this way, in case of damage on the power line 40 causing a break between the connection points of the circuit breakers 41 A and 4 IB, there remain two subsystems independent of each other, the systems A and B, each capable of providing electrical braking of the vehicle. Each of these subsystems has its own electrical dissipation resistor. So we have a hardware redundancy of the power stage.
• the power stage may have other damage than a failure on the power line 40.
• the section of the power line 4OA leading to the electronic dissipation module 6OA is interrupted.
• the dissipation resistor 6A is off.
• the electric power produced by the subsystem A in electric braking can pass through the section of the uninterrupted power line 4OA and, via the circuit breaker 4 IA, back on the power line 40 and be routed, via the line of power 4OB, to the electrical dissipation resistor 6B.
• the electrical dissipation resistor 6B therefore becomes common, in this case, to the subsystem A and the subsystem B.
• the braking capacity of the electric braking system remains large, sufficient to provide emergency braking.
• each of the electrical dissipation resistors 6 is immersed in a hydraulic cooling circuit.
• the energy produced by the electric braking is sufficient to bring the cooling fluid to a boil.
• the vaporized fluid is immediately replaced by liquid phase cooling fluid, which licks the resistor again and the system continues to have a certain capacity to evacuate calories.
• the cooling system has a certain thermal inertia. The applicant's experiments have shown that, even in this case, the electric braking system remains much more powerful and effective than a cross-hydraulic braking system such as those currently used on motor vehicles.
• the electrical resistance of dissipation 6A remains available for the rotary electric machine 2 associated with the right front wheel when it operates as a generator while the electrical resistance of dissipation 6B is available for the subsystem B and for the rotary electric machine 2 associated with the left rear wheel, that is to say one of the rotating electrical machines 2 of the subsystem A.
• One 6B of the electrical resistors dissipation will receive a higher electrical power than the other 6A. The operation is not optimal but we are therefore in a configuration less penalizing for the slowing capacity of the vehicle than that exposed in the previous paragraph.
• the dissipation power of the electrical dissipation resistors 6A and 6B depends on the proper operation of the cooling system. Indeed, they are immersed in a heat transfer fluid.
• Figure 3 schematically shows the cooling circuit. We see that it includes 2 pumps 8A and 8B and 2 radiators 8OA and 80B. The 2 pumps 8A and
• Each of these electric motors is driven by its own control electronics 82A and 82B.
• the radiators 80A and 80B are connected in parallel, and equipped with valves 83 which make it possible to isolate each of the radiators selectively in case of leakage to one of them.
• the pump assembly and pump actuation motor is dimensioned so that if one of the pumps is out of order, the other pump is able to ensure a sufficient flow of the heat transfer fluid despite the fact that the other pump is no longer functional.
• a line 43 provides the interconnection between the voltage converter 41 and the battery 42.
• This line 43 comprises a first section 43 A and a second section 43B, as well as a galvanic separation device 430 of the two sections in case of under-voltage. tension on one of them.
• Some elements are connected to the first section 43A, each via an overcurrent protection device 434A.
• one of the motors 8 IA is connected to the first section 43A via its control electronics 82A.
• the other of the motors 8 IB is connected to the second section 43B via its control electronics 82B.
• the control electronics of the subsystem A namely the electronic wheel control module 23 associated with the rotary electric machine 2 of the right front wheel, the electronic wheel control module 23 associated with the rotary electric machine 2 of the left rear wheel and the electronic dissipation module 6OA of the dissipation resistor 6A are connected to the second section 43B while the same electronics of the subsystem B are connected to the first section 43A.
• the electronic recovery module 50 associated with the bank of super capacitors 5 is connected to the first section 43A only. Note that this type of dual connection could also be used for all electronics, including electronic wheel control modules 23.
• the galvanic isolation device 430 interrupts the interconnection between the voltage converter 41 and the battery 42 and that- It can continue to supply the control electronics associated with the subsystem A and the central unit as well as one of the two pumps of the hydraulic cooling circuit with low voltage. Conversely, if there was a significant fault on the battery side 42, the galvanic isolation device 430 can interrupt the interconnection and the voltage converter 41 can continue to supply the subsystem B, the unit central and one of the pumps of the hydraulic cooling circuit. It can therefore be seen that the architecture described makes it possible to maintain the operation of one of the two subsystems A or B and therefore half of the braking power of the vehicle is still available.
• the system according to the invention comprises a central unit 3 which controls all the electronic wheel control modules 23.
• the system according to the invention comprises a braking control 32 at the disposal of a said control being mechanically connected to at least a first sensor C1 delivering a brake control signal of the vehicle having a given amplitude representative of the total braking force desired for the vehicle, and a second sensor C2 delivering a brake control signal of the vehicle having a given amplitude representative of the total braking force desired for the vehicle.
• the sensor C1 is supplied with low voltage electrical energy by the central unit 3. It delivers the control signal to the central unit 3 and the latter only receives the braking control signal from the sensor C 1 to create the signals. overall control of the braking of the vehicle of a first level.
• the second sensor C2 is powered by the electronic wheel control modules 23 associated with each of the electrical machines. Said second sensor C2 delivers its control signal to each of the electronic wheel control modules 23.
• a diode 230 is located in the connection line between each of the control electronics 23 and the sensor C2.
• an appropriate circuit 231 monitors the presence of voltage on each of the four supply lines, in order to send a fault signal in the event of failure of one of the four power supplies. It will be seen in the following paragraph that the sensor C2 is directly associated with the wheel control electronics 23 and only with the wheel control electronics 23.
• the low voltage power supply stage comprises a first power supply and at least a second power supply, the first power supply and the second power supply being interconnected by an electrical line 43 comprising a first section 43A and a second power supply.
• section 43B said first and second sections being connected by a galvanic separation device 430 of the two sections capable of interrupting the interconnection on command, in case of undervoltage on one of them.
• Said first sensor C1 is powered by the same section as the central unit 3 and said second sensor C2 is powered by both a wheel control electronics 23 of one (A) subsystems and by a control electronics wheel 23 of the other (B) subsystems via a pair of diodes insulating said power supplies.
• the central unit 3 is interconnected with each of the electronic wheel control modules 23 and with the electronic recovery module 50 via a CAN ® bus (Control Area Network, designated by the reference 30A) allowing the transfer of control orders in computer form.
• the central unit 3 is responsible for the appropriate software to be able to take into account all the desirable parameters in order to develop a braking command signal which is sent to the different electronics driving the machines according to the protocols required to travel on the CAN bus 30A.
• Each of the modules Electronic wheel steering 23 further receives directly analogue signals delivered by the sensor C2, this time via analog lines 300.
• command lines 3OB connect the electronic module of recovery
• the electronic dissipation modules 6OA and 6OB retain the possibility of dissipating the braking power which rises on the power line 40 in an autonomous manner, without receiving a command on the line 30B (the principle of subsets A and B remains fully operational for braking but without the possibility of storing energy since in the latter case, the electronic module 50 recovery is out of service.
• the control of the electrical machines 2 is provided directly by an electronic wheel control module 23 particular to each of the electrical machines 2.
• the latter is responsible for the appropriate software to control each electric machine in torque according to the received control signals.
• Each electronic wheel control module 23 receives braking control signals on the one hand on the bus 30A and on the other hand on the analog line 300 delivering the signal of the sensor C2.
• Each electronic wheel control module 23 can therefore compare at any time the control signal delivered on the bus 30A and the control signal delivered by the analog line 300 and, within a certain tolerance, for example of the order of 10 at 20% according to experimental determinations, give priority to the braking control signal from the bus 30A. This is the normal operating mode.
• the braking command signal sent by the bus 30A was much lower than the brake control signal from directly analog C2 sensor, priority can be given to the control signal from the sensor C2 to ensure the safety of braking operation of the vehicle.
• the proposed architecture performs a different operation of the signals delivered by each of the sensors C1 and C2.
• the sensor C1 is associated with the central unit 3 and makes it possible to calculate a global first level braking signal.
• the control signal delivered by the sensor C2 is directly delivered by analog means by lines appropriate to the electronic wheel control modules 23. Overall consistency is ensured by comparing the signal conflicts.
• This type of brake control is taken into account by the central unit 3, more precisely by the software implanted in the central unit 3, and is routed to the control electronics 23 of each of the machines by the CAN bus 30A.
• This can provide braking safety even in the event of breakage of the brake pedal.
• this can ensure a braking operation safety in case of rupture of the 2 sensors or failure of the attachment of the 2 brake sensors C2 and C2. If only the mechanical connection of one of the 2 sensors C1 or C2 or one of the two sensors is defective, of course the safety of operation in braking is ensured as explained in the previous paragraph. But in this case, one can for example allow the end of the trip and, after stopping the vehicle, prohibit restarting.
• the hardware redundancy that has just been exposed is preferably used in combination with a software redundancy, advantageously both for the software loaded in the central unit 3 and those loaded in the electronic control modules. In this way, a high degree of safety of the vehicle braking system is achieved by a completely electric way.

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)
• Regulating Braking Force (AREA)
• Arrangement And Driving Of Transmission Devices (AREA)
• Braking Systems And Boosters (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=38110051

Family Applications (1)

Country Status (4)

Families Citing this family (20)

Family Cites Families (16)

• 2007
  • 2007-03-20 JP JP2009500859A patent/JP2009531008A/ja not_active Withdrawn
  • 2007-03-20 US US12/293,945 patent/US8246120B2/en not_active Expired - Fee Related
  • 2007-03-20 EP EP07727137A patent/EP2001700A1/de not_active Withdrawn
  • 2007-03-20 WO PCT/EP2007/052660 patent/WO2007107576A1/fr active Application Filing

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events