Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/17—Using electrical or electronic regulation means to control braking
  • B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/17—Using electrical or electronic regulation means to control braking
  • B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
  • B60T8/17555—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve specially adapted for enhancing driver or passenger comfort, e.g. soft intervention or pre-actuation strategies
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T2270/00—Further aspects of brake control systems not otherwise provided for
  • B60T2270/60—Regenerative braking
  • B60T2270/602—ABS features related thereto
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T2270/00—Further aspects of brake control systems not otherwise provided for
  • B60T2270/60—Regenerative braking
  • B60T2270/613—ESP features related thereto

Definitions

• the invention relates to a method for controlling a Radbremsschlupfes and a Radbremsschlupfregelsystem for a vehicle with an electric drive and a computer program.
• the vehicle dynamics control may be an anti-lock braking system (ABS), an electronic stability program (ESP), an ESC (Electronic Stability Control) or a traction control system (TCS).
• ABS anti-lock braking system
• ESP electronic stability program
• ESC Electronic Stability Control
• TCS traction control system
• the vehicle dynamics control then takes place only via a friction brake.
• a friction brake can produce a high friction brake torque.
• the friction brake does not have sufficient dynamics to adapt to a fast or sudden variable road friction coefficient.
• this means that the vehicle dynamics control can no longer keep a wheel slip in a stable range. This suffers a stability of the vehicle regarding the driving behavior. This means that the vehicle may possibly break out of a lane, which entails an increased accident risk.
• Another disadvantage is that by the operation of the friction brake it has an increased abrasion, which has an increased amount of harmful fine dust result.
• the object is achieved by means of a method for controlling a Radbremsschlupfes according to independent claim 1, by means of a Radbremsschlupfregelsystem according to independent claim 7 and by means of a computer program according to independent claim 10th
• the inventive method for controlling a Radbremsschlupfes includes the idea that when a vehicle dynamics control is active, this is performed not only by means of a friction brake, but also with the aid of the electric drive.
• the electric drive signals and friction brake signals generated by means of the slip control device in this case correspond in particular to desired values or target values.
• the electric drive generates an electric drive torque, which can be positive or negative, wherein the electric drive comprises an electric motor.
• a positive electric drive torque causes a drive of the wheel.
• a negative electric drive torque causes a braking of the wheel.
• the electric motor is operated as a generator.
• a negative electric drive torque is also referred to below as a regenerative braking torque.
• the total braking torque required for slip control thus results as the sum of the electric drive torque and the friction brake torque, wherein the rapid, but in amplitude relatively small torque changes are generated by the electric drive and the remaining braking torque generated by the friction brake.
• the friction brake generates a basic brake torque to which the electric drive torque is modulated.
• a slip control by means of the friction brake and the electric drive is performed, which is why the slip control can also be referred to as a cooperative slip control.
• the electric drive can change its generated electric drive torque quickly and this quickly adjustable, but limited in size torque ideally supplements the slower controllable, but larger braking torque of the friction brake.
• the vehicle dynamics control can advantageously be adjusted to rapidly changing vehicle situations, in particular if a road friction coefficient changes.
• an electric motor can be provided per wheel of a vehicle. This means that each wheel is individually can be driven or braked by means of an electric motor.
• the vehicle has only one electric motor per axle, in which case a drive or a braking of the wheels takes place in particular by means of a differential gear.
• the vehicle axle may for example also have double wheels.
• the vehicle can not only include an electric drive, but for example, in addition, a gasoline or a diesel engine. Such vehicles are commonly referred to as hybrid vehicles.
• an electric drive speed signal is measured and evaluated by means of an evaluation device connected to the slip control device.
• the evaluation device can also be integrated into the slip control device.
• An electric drive speed signal can be generated in particular by means of an electric motor angle sensor, for example an electric motor position sensor, which is arranged, for example, in the electric motor for an internal magnetic field control.
• an electric motor speed which corresponds to a wheel speed of the wheel connected to the electric motor, can be measured faster and more precisely than in conventional slip control systems.
• a highly dynamic control of the electric drive torque is at least partially way is executed in the electric drive control device.
• the electric drive control device detects and evaluates in particular an electric drive speed.
• the electric drive control device comprises a magnetic field control for the electric motor.
• a friction braking torque is set smaller than an electric drive torque when a generating by means of the electric drive torque regenerative braking torque is greater than a loadable on a roadway
• a distance or an air gap between a brake shoe and a brake disk of the friction brake is set to zero. This means that the brake shoe on the brake disc just grinds so that no friction braking effect is achieved. The friction brake is not in its rest position.
• the friction brake can be activated directly and without time delay, for example when the road friction coefficient changes.
• it can further be provided to at least partially convert electrical energy formed by the electric drive into thermal energy when the electric drive torque is formed as a regenerative braking torque.
• the kinetic energy generated during braking as electrical energy is at least partially supplied to an electrical resistance, in particular a braking resistor, for example a controlled braking resistor, which then converts it into thermal energy in the form of heat.
• This thermal energy can be dissipated for example by cooling or used as useful heat for other functions, such as a passenger compartment heating.
• the proportion of the electrical energy generated during braking which is not converted into thermal energy, in particular, is fed back into an electrical energy store, so that this electrical energy can be made available to electrical consumers at later times.
• it can also be provided in particular to supply at least part of this portion directly to one or more electrical consumers.
• a reactive power can be generated in the electric motor without the electric drive torque changing.
• the additional electrical power loss generated thereby is led away with the engine cooling and thus the windings in the electric motor act as an integrated braking resistor.
• the computer program according to the invention can be stored, for example, in a firmware, wherein the firmware can be implemented in particular in the slip control device.
• the firmware is partly implemented in the slip control device and partly in the electric drive control device.
• Fig. 1 is a schematic arrangement of an inventive
• FIG. 2 shows two graphs which show a behavior of the method according to the invention in a driving situation with a varying road friction coefficient.
• a wheel 1 of a vehicle (not shown) is connected to an electric drive 2 by means of a mechanical connection 3.
• the vehicle may be, for example, a passenger car, a truck or a motorcycle.
• the electric drive 2 comprises an electric motor (not shown).
• the electric drive 2 may also comprise a plurality of electric motors, so that each wheel of the vehicle can be individually driven or braked by means of an electric drive.
• the electric motor 2 drives an axle of the vehicle via a differential gear.
• the axle may comprise double wheels.
• the electric drive 2 can either drive the wheel 1 or, if the electric motor is operated as a generator, generate a regenerative braking torque, so that the wheel is braked.
• the electric drive 2 further comprises an electric motor angle sensor 4 which generates an electric motor drive signal 5, the electric motor drive signal 5 corresponding to an electric motor position signal or electric motor speed signal.
• the electric motor drive signal 5 or the Electric motor position signal is transmitted to an electric drive control device 6.
• An evaluation device 7, which measures and evaluates the electric motor drive signal 5, is integrated in the electric drive control device 6.
• the evaluated electric motor drive signal 5 corresponds to an electric motor speed signal 8, which is transmitted to a slip control device 9. Thus, an electric motor speed can be measured.
• the wheel 1 can also be braked by means of a friction brake 10, which encompasses a friction brake actuator 11.
• the friction brake 10 is controlled by a friction brake controller 12.
• the friction brake control device 12 is also designed to transmit friction brake state signals 13 to the slip control device 9.
• friction brake state signals 13 may correspond to a brake pressure, brake application force, brake torque, or a brake temperature.
• the friction brake 10 is formed as a hydraulic friction brake. In an embodiment of the invention, not shown, the friction brake 10 may be formed in particular as an electromechanical friction brake.
• the slip control device 9 detects a brake signal 14.
• the brake signal 14 can be calculated in particular from signals corresponding to a brake pedal actuation, a vehicle speed, a steering angle, a yaw rate and / or a lateral acceleration.
• the slip control device 9 generates in dependence on the detected brake signal 14 an electric drive signal 15 and a friction brake signal 16.
• the electric drive signal 15 is transmitted to the electric drive control device 6.
• the friction brake signal 16 is transmitted to the friction brake control device 12.
• the friction brake control device 12 will generate a Reibungsbremsaktuatorsignal 17 depending on the friction brake signal 16 and transmit it to the friction brake 10.
• the friction brake 10 will operate the friction brake actuator 11 depending on the friction brake actuator signal 17.
• the friction brake actuator 11 generates a friction braking torque that brakes the wheel 1.
• the electric drive control device 6 will generate an electric drive control signal 18 as a function of the transmitted electric drive signal 15 and transmit the electric drive control signal 18 to the electric drive 2 for controlling the electric drive 2.
• the electric drive 2 will generate an electric drive torque in accordance with the electric drive control signal 18.
• the wheel is driven or braked.
• the generated electric drive torque is also referred to as a regenerative braking torque.
• the slip control device 9 generates the electric drive signal 15 and the friction brake signal 16 such that a predetermined slip value of the wheel 1 can be adjusted. That is, the resulting total braking torque from the proportion of the friction braking torque generated by the friction brake 10 and the electric drive torque generated by the electric drive 2 does not cause the wheel 1 to rotate slower than a predetermined slip value known by the slip control device 9, and this slip torque value is chosen in particular so that a vehicle stability and a braking effect are optimal.
• the slip control device 9 evaluates the electric motor speed signal 8 transmitted by the evaluation device 7 for slip control.
• the electric drive control device 6 is connected to an electrical resistance 19, which is connected to a storage device 20 for storing thermal energy.
• the electrical resistor 19 may, for example, a braking resistor, in particular a regulated
• Braking resistor be.
• the electrical resistor 19 and / or the memory device 20 is / are integrated in the electric drive control device 6.
• the electric drive 2 comprises the electrical resistor 19. This advantageously makes it possible that electrical energy generated by means of the electric drive 2 can be converted into thermal energy.
• the memory device 20 it is possible to store the thermal energy converted by means of the electrical resistor 19 in order to then make it available for heating, for example at a later time, to a passenger compartment.
• FIG. 2 shows two graphs which explain in more detail the behavior of an exemplary embodiment of the wheel brake slip control system according to the invention or of the method according to the invention in a driving situation with a varying road friction coefficient.
• velocity is plotted over time, with arbitrary units chosen for the axes. Plotted are the vehicle speed V v , a target wheel speed V t and a wheel speed V w .
• the individual torques T are plotted over the time t, whereby arbitrary units are also selected here.
• a driver brake request torque T d is plotted.
• This torque T d is the total braking torque predefined by the driver on the basis of his brake pedal actuation, which however may not be completely transferable to the road as a braking effect, in particular if the roadway is wet or icy.
• this driver brake request torque T d flows into the calculation of the brake signal 14.
• an electric drive torque T 9 a friction brake torque Tf
• the total brake torque T t resulting from the electric drive torque T 9 and friction brake torque T f .
• the driver depresses the brake pedal.
• the signal T d rises rapidly to a value which is not completely transferable to the road as a braking effect.
• the slip control device 9 will thus generate an electric drive signal 15 such that the electric drive control device 6 by means of a corresponding electric drive control signal 18 controls the electric drive such that the electric motor of the electric drive 2 operates as a generator, so that a regenerative braking torque T 9 is generated.
• the electric drive signal 15 corresponds to a desired value.
• the regulation of the electric drive 2 itself is carried out by means of the electric drive control device 6.
• the slip control device 9 will also generate a friction brake signal 16 so that the friction brake control device 12 generates a corresponding friction brake actuator signal 17 and transmits it to the friction brake 10 for actuating the friction brake actuator 11.
• the friction brake torque T f increases with respect to the regenerative friction brake circuit
• the friction brake signal 16 corresponds to a desired value.
• the actual regulation of the friction brake 10 is carried out by means of the friction brake control device 12
• the road friction coefficient abruptly decreases to a value which is limited to the transmission of brake allowed forces that are significantly smaller than the driver's braking torque T d .
• the electric drive torque T d of the electric drive 2 is now reduced very quickly and the electric motor 2 even acts as a drive to counteract the slower reducing and for this road friction too large friction brake torque T f and thus reduce a tendency to lock the wheel 1 and the wheel to rapid achievement of the optimum total braking torque T t and vehicle stability required wheel speed V t to accelerate.
• the friction braking torque T f is reduced somewhat further to a value which in any case precludes locking of the wheel 1 due to the currently acting road friction coefficient.
• the electric drive torque T 9 of the electric motor is increased again in the opposite direction to the decrease of the friction brake torque T f .
• the friction brake torque Tf thus represents a basic braking torque to which the electric drive torque T 9 is modulated, which can be adapted very quickly to the slip behavior of the wheel 1 and advantageously allows a highly dynamic fine correction of the total braking torque T t .
• the wheel runs with the slip value which is optimal for the stability of the vehicle and for the length of the braking path.
• the optimal brake slip requires only a very limited total braking torque T t , which can even be generated almost exclusively by means of the electric drive torque T 9 , so that a negligible friction braking torque T f can be generated.
• T t total braking torque
• T f negligible friction braking torque
• the electric motor drive control device 6 performs an integrated electric motor speed control in an inverter (not shown), which receives its target speed from the brake control / vehicle dynamics control and carries out the highly dynamic torque control in the case of slip control demand itself.
• the electric drive 2 can very quickly change the drive or regenerative braking torque generated by it - thus can even act on the braked wheel driving, if this is advantageous for the setting of the wheel slip - and this quickly controllable, but in size limited torque which is modulated slower controllable, but magnitude larger braking torque of the friction brake, in particular the following advantages arise, especially if the electric drive 2 for an internal magnetic field control has at least one engine position sensor, as this engine speed and thus the wheel speed can be measured faster and more precise than in conventional Slip control systems:
• the driving dynamics control functions (ABS, ESC, TCS) can realize a much more precise slip control, which improves both the friction coefficient utilization and thus the braking distance as well as the ride comfort and dynamic chassis load.
• the friction brake can be designed for smaller dynamic demand and thus manufactured more cost-effectively.
• the friction brake is designed as a hydraulic friction brake, its modulation frequency be reduced for the brake pressure control, which has an advantageous effect on pedal reaction and noise.
• the friction brake is designed as an electromechanical brake, its design can be more focused on reducing manufacturing costs and power loss optimization and less on the otherwise critical dynamic requirements.
• the electromechanical brake can also be designed as an electromechanical wheel brake, in particular a front wheel brake, with a 12 V operating voltage.
• Improved driving dynamics functionality such as reduced braking distance, reduced pedal vibration and reduced noise during slip control operations.
• the computer program can be stored and executed in particular in a vehicle dynamics control device, in particular in an ABS / VSC ("Vehicle Stability Control") control device.
• the invention provides a wheel brake slip control system and a method for controlling a wheel brake. Slippage ready, which combine the respective advantages of a friction brake and an electric drive with each other, so that any respective disadvantages can be compensated or overcome in a synergetic manner.

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• Engineering & Computer Science (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Regulating Braking Force (AREA)

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• 2010
  • 2010-03-19 DE DE102010003076A patent/DE102010003076A1/de active Pending
  • 2010-07-09 EP EP10732692A patent/EP2462013A1/de not_active Withdrawn
  • 2010-07-09 CN CN201080034739.4A patent/CN102574511B/zh active Active
  • 2010-07-09 US US13/388,456 patent/US8577531B2/en active Active
  • 2010-07-09 KR KR1020127005732A patent/KR20120054033A/ko not_active Application Discontinuation
  • 2010-07-09 WO PCT/EP2010/059890 patent/WO2011015422A1/de active Application Filing

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