DE102017204000A1 - Method for anti-lock control of a vehicle and vehicle - Google Patents

Abstract

In a method (B) for anti-lock control of a vehicle (1), during a braking operation, the following steps aba. at least one of the electric motors (4) builds up a recuperation torque (R) on at least one of the wheels until a maximum recuperation torque (Rmax) is reached, b. a braking torque (H) of the hydraulic brake system (2) is built up until a desired slip is reached on this at least one of the wheels, c. the at least one of the electric motors (4) regulates the setpoint slip at this at least one of the wheels and the at least one of the electric motors (4) is adjusted back by an amount to a recuperation moment (R), which in the interval [1/2 maximum recuperation moment; maximum recuperation torque [is and the braking torque (H) of the hydraulic brake system (2) is increased by the same amount, andd. the nominal slip at this at least one of the wheels is stationary controlled by means of the at least one electric motor (4).

Description

The present invention relates to a method for anti-lock control of a vehicle according to claim 1 and claim 6, and a vehicle according to claim 7.

In conventional vehicles, eg. As in cars or trucks, anti-lock braking systems (ABS) are used to provide the driver with the possibility of steering at a high speed out of the way. In hydraulic ABS systems, as soon as a wheel threatens to lock, the pressure of the hydraulic brake fluid is lowered, thereby reducing the force acting on the brake.

In ATZ Elektronik, 6th year, 02/2011, an article presents a simulation of an ABS system in combination with regenerative braking by means of electric drives. In light vehicles with powerful electric motors, the hydraulic braking system can be simplified according to this article and the friction brakes can be omitted.

The present invention is based on the prior art, the object to propose a method for anti-lock control of a vehicle. The anti-skid control should respond faster than is the case with purely hydraulic ABS systems.

The present invention proposes, starting from the above object, a method for anti-lock control of a vehicle with the features of claim 1 and the features of claim 6 before. In addition, the present invention proposes a vehicle according to claim 7. Further advantageous embodiments and developments will become apparent from the dependent claims.

liegt und das Bremsmoment der hydraulischen Bremsanlage wird um den gleichen Betrag erhöht. In einem d. Schritt wird der Sollschlupf an diesem wenigstens einen der Räder mittels des wenigstens einen Elektromotors stationär geregelt. Diese Schritte a bis d laufen in der angegebenen Reihenfolge nacheinander ab.In a method for anti-lock control of a vehicle, wherein the vehicle has a hydraulic brake system, an energy storage device for electrical energy and at least two wheel-individual electric motors on one axis, builds during a braking operation in an a. Step at least one of the electric motors on at least one of the wheels a Rekuperationsmoment up to a maximum Rekuperationsmoment (Rmax) is reached. In a b. Step, a braking torque of the hydraulic brake system is built up to a target slip on the at least one of the wheels is reached. In a c. Step, the at least one of the electric motors regulates the nominal slip at this at least one of the wheels and the at least one of the electric motors is regulated back by an amount to a recuperation moment, which in the interval, $$\begin{array}{l}[1\text{/}2\text{maximum recuperation torque; maximum recuperation moment}[\\ \text{=}[\text{1.2}\text{Rmax; Rmax}[\end{array}$$

is located and the braking torque of the hydraulic brake system is increased by the same amount. In a d. Step, the target slip at this at least one of the wheels by means of the at least one electric motor is controlled stationary. These steps a to d run sequentially in the order given.

The vehicle is preferably a road vehicle, e.g. As a car or commercial vehicle, with hybrid or electric drive. Of course, the vehicle may have more than two electric motors, for example one electric motor per wheel. The vehicle also has an in-vehicle sensor system which serves to sense and evaluate a wheel slip of each wheel. The electrical energy storage is partially charged or not charged. The method is particularly suitable for conventional braking operations (standard braking operations), d. H. Braking during a conventional driving operation in which the increased wheel slip is caused by a less good road condition (eg wet, ice, rolling split).

If a braking process is initiated, it is first braked with at least one of the electric motors, that is, a recuperation torque is built up until the Rmax or the maximum recuperation power is reached (brake blending). The at least one electric motor is thus operated regeneratively. Of course, in each case a Rekuperationsmoment be established with both of the at least two electric motors until the Rmax each individual electric motor is reached. If the vehicle has more than two electric motors, a recuperation torque can be set up with more than two or with all the electric motors until the Rmax of each individual electric motor is reached. The recuperation torque of each individual electric motor corresponds to the braking torque that can be provided by each individual electric motor. The controlling and regulating the at least two electric motors and also the hydraulic brake system by means of conventional on-board systems. For example, the vehicle may have at least one control unit which, starting from the wheel slip, actuates the hydraulic brake system and the electric motors.

If the braking torque provided by the at least one electric motor is insufficient, the hydraulic brake system is added. The braking torque of the hydraulic brake system is increased until a desired slip is achieved on at least one of the wheels. The slip is preferably determined and evaluated individually by means of the commercially available vehicle sensors for each wheel. The nominal slip represents a threshold, which is stored for example in a database and z. B. varies depending on the type of vehicle or vehicle type, z. For example, the nominal slip for a car may be different than for a commercial vehicle. The nominal slip is, for example, a slip of a wheel at a height where it has no negative effects on the driving behavior and on the reaction of the vehicle.

By means of the vehicle's own sensor technology, therefore, the slip of the respective wheels and thus also of the at least one wheel is measured and evaluated. Based on this, the braking torque is controlled. The nominal slip on the at least one of the wheels is adjusted by means of the at least one electric motor. This means that the recuperation torque provided by the electric motor and the hydraulic braking torque are controlled in a corresponding manner. In order to subsequently be able to control the setpoint slip in a stationary manner, it is necessary for the recuperation moment provided by the at least one electric motor to be previously regulated back by an amount to a value that is determined in the interval [1/2 Rmax; Rmax [lies. For example, the recuperation torque provided by the at least one electric motor can be 1/2 Rmax, 2/3 Rmax or another suitable value in the interval [1/2 Rmax; Rmax [exhibit. Only the value Rmax is excluded. The provided braking torque of the hydraulic brake system is increased by the same amount in the same step. This back regulation of the at least one electric motor serves the purpose that the at least one electric motor can regulate the braking torque provided by it, which corresponds to the recuperation torque, in the positive and negative directions by the selected value. If the braking torque required on the at least one of the wheels due to the wheel slippage drops below a predetermined threshold, the braking torque of the hydraulic brake system is lowered by an amount and at the same time the recuperation torque of the at least one electric motor is increased by the same amount. If the braking torque required on the at least one of the wheels due to the wheel slippage increases above a predetermined threshold, the braking torque of the hydraulic brake system is increased by an amount and at the same time the recuperation torque of the at least one electric motor is lowered by the same amount. These processes can alternate several times in succession in a driving operation of the vehicle. Thus, the recuperation torque provided by the at least one electric motor, which corresponds to the braking torque of the electric motor, moves permanently in a range in which a regulation of the same in the positive and negative directions is always possible.

The desired slip can then be controlled by the stationary stationary at least one electric motor. That is, the actual slip occurring on the at least one of the wheels shows only minimal deviations around the value of the desired slip. The at least one electric motor adapts its provided recuperation torque in order to fix the nominal slip in a stationary manner. Depending on the amount of slip actually occurring at the at least one of the wheels, the at least one electric motor provides less or more recuperation torque. The braking torque of the hydraulic brake system, however, remains constant during stationary control. If the actually occurring slip on the at least one of the wheels is higher than the setpoint slip, the at least one electric motor reduces its provided recuperation torque. If the actually occurring slip on the at least one of the wheels is lower than the setpoint slip, the at least one electric motor increases its provided recuperation torque.

An advantage of this method is that by the interaction of the hydraulic brake system and the at least one electric motor for braking the at least one wheel blocking of the hydraulic brake system can be prevented. The presented method has a shorter reaction time than conventional anti-skid control methods using an ABS block. In addition, by using the at least one electric motor for recuperation energy can be recovered, whereby the vehicle is more energy efficient than a conventional vehicle with hybrid or electric drive.

According to one embodiment, when the coefficient of friction changes in comparison to a starting time during the braking process, steps c and d again take place. The friction coefficient may change, for example, due to a changed road condition. For example, the road may be slippery at one point, such as wet film or ice, and not elsewhere. If these two points happen during the braking process, the braking process must be adjusted. The starting time is in this case the time at which the braking process is initiated.

The friction coefficient is directly related to the wheel slip detected on the at least one wheel. For example, the wheel slip of the at least one wheel is higher in wet or icy slippery roads than in dry roads. The wheel slip does not change as desired during the braking operation by the changed friction coefficient continuously over a period of time due to the braking operation, but has a jump at the time when the friction coefficient changes.

When the coefficient of friction is changed and thus when there is a change in slip, the at least one of the electric motors regulates the nominal slip at this at least one of the wheels and the at least one of the electric motors is regulated back by an amount to a recuperation torque which, in the interval,
[1/2 Rmax; Rmax [
is and the braking torque is increased by the same amount (step c). In the d. Step, the target slip is fixed at this at least one of the wheels stationary. This is done in the manner already described above.

According to a further embodiment, in step c, the at least one of the electric motors is regulated back by an amount to a recuperation moment, which corresponds to 1/2 maximum recuperation torque. The recuperation moment is therefore 1/2 Rmax. It is advantageous here that a regulation of the recuperation torque, which corresponds to the braking torque of the at least one electric motor, can take place uniformly in both the positive and negative directions.

According to another embodiment, steps a, c and d are performed by each of the electric motors of the vehicle. If the vehicle, as described here, has a wheel-individual electric drive on an axle for each of the wheels, then both electric motors carry out the steps a, c and d. If the vehicle has a wheel-specific electric drive on two axles for each of the wheels, all the electric motors carry out the steps a, c and d. This means that the described method can run on any individually driven wheel. All electric motors of a vehicle thus cooperate in a braking process. Each electric motor can provide a different recuperation torque from the other electric motors. Alternatively, each electric motor can provide an equal recuperation moment.

In a method for anti-lock control of a vehicle, wherein the vehicle has a hydraulic brake system, an energy storage device for electrical energy and at least two wheel-individual electric motors on one axis, builds during a braking operation of at least one of the electric motors a Rekuperationsmoment on at least one of the wheels until a value is reached is, which in the interval,
[1/2 maximum recuperation torque; maximum recuperation torque [lies (step a '). At the same time, a braking torque of the hydraulic brake system is built up until a desired slip is reached on this at least one of the wheels (step b '). The at least one of the electric motors controls a target slip at at least one of the wheels stationary from a predetermined slip threshold value (step d ').

The vehicle here is the same as that already described in the previous description and has the same systems. The method is particularly suitable for danger braking operations. A danger braking process is, for example, an emergency braking process in which a maximum negative acceleration or a maximum braking torque must be applied as quickly as possible in order to avoid a collision, for example. Due to the high braking moments required in a short period of time in a danger braking process, the wheel slip on the at least one wheel is particularly high, so that the anti-skid control is unavoidable.

Both the recuperation torque of the at least one electric motor and the braking torque of the hydraulic brake system are set up at the same time as soon as the braking process is initiated. This is determined for example by means of conventional on-board sensors. The recuperation torque increases until it reaches a value which in the interval [1/2 Rmax; Rmax [lies. Preferably, the value is 1/2 Rmax. Of course, a higher value, for. B. 2/3 Rmax or 4/5 Rmax possible. The braking torque of the hydraulic brake system continues to increase until the setpoint slip reaches a slip threshold value. The slip threshold is in this case a predetermined slip of the at least one wheel whose value is, for example, close to the nominal slip. This slip threshold may be stored, for example, in a vehicle equipped with a memory controller of the vehicle. Is the Has reached slip threshold, controls the at least one electric motor, the target slip stationary, while the braking torque of the hydraulic brake system remains constant. The stationary control has already been described in the previous description.

The advantage here is that even with emergency braking the ABS control has a shorter reaction time than conventional ABS systems that use an ABS block. The illustrated method is complementary to the method described in the previous description, so that a vehicle can utilize anti-skid control in both conventional braking and danger braking operations.

In one embodiment of a method for anti-lock control of a vehicle, wherein the vehicle has a hydraulic brake system, an energy store for electrical energy and at least two wheel-individual electric motors on one axis, a first of the at least two electric motors is regenerative during a braking process with fully charged energy storage for electrical energy and a second of the at least two electric motors actively operated. The actively driven electric motor uses more energy than the regenerative electric motor provides. The vehicle here is the same vehicle already described in the previous description and has the same systems. The method is particularly suitable for standard braking operations.

At the beginning of the braking process, the regeneratively operated electric motor builds up a recuperation torque on at least one of the wheels until a value is reached which, in the interval,
[1/2 maximum recuperation torque; maximum recuperation torque [lies (step a '). For example, the recuperation torque can be 1/2 Rmax, 2/3 Rmax, 4/5 Rmax, or another suitable value in the interval [1/2 Rmax; Rmax [exhibit. The actively operated electric motor of the at least two electric motors builds up a drive torque simultaneously or with a short time offset until a drive torque threshold is reached. At the same time, the hydraulic brake system builds up a braking torque until a desired slip is achieved at this at least one of the wheels, wherein the braking torque is higher by an amount corresponding to the amount of the drive torque (step b '). The regeneratively operated electric motor then controls a target slip at at least one of the wheels stationary (step d ') after reaching a predetermined slip threshold value, and at the same time the actively operated electric motor provides its drive torque corresponding to the recuperation torque of the regeneratively operated electric motor when the predetermined slip threshold value is reached.

This procedure takes place in the same vehicle as the previously described method, but with fully charged electrical energy storage. If the energy store is completely charged, no further energy can be recuperated by means of the electric motors. In order to be able to carry out the method for anti-skid control nevertheless, this method is adapted. The first of the at least two electric motors is regeneratively operated, i. H. he recuperates energy. The second of the at least two electric motors, however, is actively operated, d. H. he uses energy to power the vehicle. If the vehicle has more than two electric motors, several of these electric motors can be actively operated and, for example, only one of the electric motors regenerative.

It is necessary to avoid a positive energy balance, so that the electrical energy storage is not overloaded and / or damages. The drive torque provided by the actively operated electric motor is to be selected as low as possible, so that braking with the regeneratively operated electric motor is possible. The drive torque threshold should thus be as low as possible and can be chosen differently for each vehicle type. This means that the drive torque threshold is predefined and stored, for example, in a database. It is necessary that more energy be used by the actively driven electric motor than provided by the regeneratively driven electric motor.

The hydraulic brake system performs the previously described method step b ', but due to the fact that the actively driven electric motor drives the vehicle to provide a higher braking torque available, as in the previously described braking operation at partially charged or non-charged electrical energy storage. The braking torque provided by the hydraulic brake system must have at least an amount which corresponds to the drive torque provided by the actively operated electric motor. In other words, the hydraulic brake system brakes both the vehicle regularly and the additionally provided by the actively driven electric motor drive torque. The steady-state control of the setpoint slip proceeds exactly as described in the previous description.

It is advantageous that the proposed method for anti-lock control can be used both in partially charged or non-charged electrical energy storage as well as fully charged electrical energy storage.

A vehicle has a hydraulic brake system, an energy store for electrical energy and at least two wheel-individual electric motors on an axle that can drive the wheels of this axle. The vehicle also has an in-vehicle sensor system which serves to sense and evaluate a wheel slip of each wheel. The control and regulation of the at least two electric motors and also the hydraulic brake system by means of conventional on-board systems. For example, the vehicle may have at least one control unit which, starting from the wheel slip, actuates the hydraulic brake system and the electric motors. The vehicle is adapted to perform a method for anti-lock control both in a conventional braking operation and in a danger braking operation, which have already been described in the previous description.

• 1 eine schematische Darstellung eines Fahrzeugs, das ein Verfahren zur Antiblockierregelung ausführen kann, nach einem Ausführungsbeispiel,
• 2 einen Graph, der die Momentenverläufe über die Zeit schematisch darstellt nach einem Ausführungsbeispiel,
• 3 einen Graph, der die Momentenverläufe über die Zeit schematisch darstellt nach einem weiteren Ausführungsbeispiel, und
• 4 einen Graph, der die Momentenverläufe über die Zeit schematisch darstellt nach einem weiteren Ausführungsbeispiel.

With reference to the figures explained below, embodiments and details of the invention are described in more detail. Show it:

• 1 1 is a schematic representation of a vehicle that can perform a method for anti-skid control, according to an embodiment,
• 2 4 is a graph which schematically illustrates the torque curves over time according to an exemplary embodiment,
• 3 a graph showing the torque curves over time schematically according to another embodiment, and
• 4 a graph showing the torque curves over time schematically according to another embodiment.

1 shows a schematic representation of a vehicle 1 that's a procedure B for anti-lock control can perform according to one embodiment. The vehicle 1 has on each wheel a wheel-individual drive, by an electric motor 4 is formed on. The vehicle 1 also has a hydraulic brake system 2 on. This hydraulic brake system 2 can slow down each wheel. Furthermore, the vehicle 1 a control unit 3 and an electrical energy storage 6 on. Every electric motor 4 is with the electrical energy storage 6 by means of one line each 7 connected. The control unit 3 is with the electric motors 4 and with the hydraulic brake system 2 connected so that a data exchange 5 can take place. In addition, the vehicle points 1 a conventional on-board sensor, which is not shown here, and which serves to detect a wheel slip of each individual wheel.

The control unit 3 can the hydraulic brake system 2 as well as the electric motors 4 to control and regulate. In addition, the controller receives 3 the sensor data of the sensor system, not shown here, which detects the wheel slip. The electric motors 4 are designed in such a way that they can be operated both regeneratively and actively. In a regenerative operation every electric motor recuperates 4 Energy. In an active operation, every electric motor provides 4 Energy ready for a drive torque for the vehicle 1 provide. Be the electric motors 4 operated regeneratively, they provide a Rekuperationsmoment ready, which a braking torque of the respective electric motor 4 equivalent. The hydraulic brake system 2 however, can only provide braking torque.

If during a braking process the sensed wheel slip on the wheels or on only one of the wheels is too high, so that there is a blockage of the respective wheel or all wheels, it is necessary to use a method for anti-skid control. This process is illustrated in the following figures 2 to 4 described in more detail.

2 shows a graph schematically illustrating the torque curves over time according to an embodiment. It shows the torque curves of a conventional braking process with partially charged electrical energy storage, while a method B is executed for anti-skid control. In the illustrated coordinate system, the moments are plotted over time. Shown is both the braking torque H , which is provided by the hydraulic brake system, as well as the Rekuperationsmoment R provided by at least one of the electric motors. Furthermore, two specific values are plotted, Rmax, ie a maximum recuperation moment, and 1/2 Rmax, ie a half maximum recuperation moment. The illustrated braking process is divided into seven phases.

In a first phase I that the step a corresponds, at least one of the electric motors builds a Rekuperationsmoment R on at least one of the wheels, until a maximum Rekuperationsmoment Rmax is reached. In a second phase II that the step b corresponds, the hydraulic brake system builds a braking torque H on, until a desired slip on the at least one of the wheels is reached. The nominal slip is in this case a value of the slip, in which the slip of the wheel has no negative impact on a driving behavior of the vehicle. Meanwhile, the recuperation moment R of the at least one electric motor at the maximum recuperation torque Rmax kept constant.

In a third phase III that the step c corresponds, the at least one electric motor at the at least one of the wheels controls the desired slip. At the same time the recuperation moment becomes R of the electric motor to a value that corresponds to 1/2 Rmax. The hydraulic braking torque H increases in the same period by the amount by the recuperation moment R is lowered. In a fourth phase IV that one step d corresponds, remains the hydraulic braking torque H constant at a value and the nominal slip of the at least one wheel is controlled by the stationary electric motor. This means that the electric motor tries the recuperation moment R on the value 1 / 2 Rmax to keep. If the measured slip on the at least one wheel exceeds the desired setpoint slip, the electric motor lowers its recuperation torque R by a small amount. If the actually measured slip at the at least one wheel falls below the setpoint slip, then the at least one electric motor raises its recuperation moment by a small value. The recuperation moment R so fluctuates around the value 1 / 2 Rmax during this fourth phase IV ,

In a fifth phase V changes due to the further movement of the vehicle during the braking suddenly the friction coefficient of the road. This change in the coefficient of friction also changes the slip of the at least one wheel. This sudden change requires the recuperation moment R be readjusted. This initially increases by a certain amount, so that the value is briefly above 1/2 Rmax in proximity Rmax lies. The hydraulic braking torque H however, remains constant. In a sixth phase VI that the step c corresponds, the recuperation moment R the electric motor back to 1/2 Rmax. At the same time the braking torque H the hydraulic brake system increased by the same amount to the recuperation of the moment R is back regulated. The hydraulic braking torque H So get on. In a seventh phase VII that the step d corresponds, the target slip at the at least one wheel is in turn controlled stationary by means of the at least one electric motor. The hydraulic braking torque H stay constant. The regulation takes place exclusively via the recuperation moment R of the at least one electric motor.

Changes so during a braking process, the road surface and thus the friction coefficient, which also changes the slip of the wheels, the hydraulic brake system and the at least one electric motor through steps c and d again. If a friction coefficient change occurs several times during a braking process, these steps are also run through several times.

Advantageous in this method B is that the slip control alone by the at least one electric motor and its Rekuperationsmoment R he follows. The at least one electric motor can react in a shorter period of time than the hydraulic brake system with the hydraulic braking torque H , In addition, by the Rekuperationsmoment R Energy recovered, which can be stored in the electrical energy storage. A vehicle equipped in this way is therefore more energy efficient. The procedure shown here B is particularly suitable for conventional braking operations in a partially charged electrical energy storage of the vehicle. In a hazard braking operation, the procedure that is in 3 is shown, however, particularly advantageous.

3 shows a graph which schematically illustrates the torque curves over time according to a further embodiment. Shown is a method B 'to an anti-skid control in a danger braking operation at partially charged electrical energy storage. In a danger braking process, it is important in the shortest possible time to apply a maximum braking torque, so that the vehicle comes to a complete halt. At the same time it is necessary to keep the vehicle controllable. The anti-skid control method B 'preferably has three phases in a danger braking operation I . II and III on.

In the first phase I becomes the recuperation moment R of the electric motor increases to 1/2 Rmax as soon as the danger braking process is initiated. At the same time the braking torque H the hydraulic brake system increases. In a second phase II becomes the braking torque H the hydraulic brake system further increased. At the same time the recuperation moment R of the electric motor kept constant at 1/2 Rmax. The braking torque H the hydraulic brake system is increased until a desired slip of the at least one wheel is reached.

In a third phase III becomes the hydraulic braking torque H kept constant. This happens as soon as the nominal slip on the at least one wheel is reached. From this point on, the recuperation moment becomes R the at least one electric motor used to control the target slip stationary. This stationary rules is done just like in 2 described.

The procedure B this in 3 shown is running at a partially charged electrical energy storage. In a fully charged energy storage and a conventional braking process, however, the process B to 4 executed.

4 shows a graph illustrating the torque curves over time schematically, according to another embodiment. Shown is a method B "for anti-skid control in a conventional braking operation and fully charged electrical energy storage. The illustrated method B "has four phases I , II, III . IV on. In a first phase I becomes the recuperation moment R of the electric motor increases. At the same time the braking torque H the hydraulic brake system increases. Both moments H and R show the same course here. In a second phase II become the hydraulic braking torque H and the recuperation moment R further increased. The recuperation moment R is further increased until it is determined that the electrical energy storage can absorb any more energy. From this point on, another electric motor is switched on, which is actively operated. The actively operated electric motor uses energy to z. B. a drive torque A provide. The drive torque A will be in this third phase III increased until a drive torque threshold Alim is reached. The further electric motor thus uses energy from the electrical energy storage, so that this electrical energy storage can again absorb energy generated by the Rekuperationsmoment R provided. In this third phase III increases the hydraulic braking torque H even further. The recuperation moment R On the other hand, it increases less strongly, until finally 1/2 Rmax is reached.

In a fourth phase IV becomes the hydraulic braking torque H kept constant. The recuperation moment R however, it is used to control the target slip of at least one wheel stationary. The drive torque A will be in this fourth phase IV used, however, to use enough energy from the electrical energy storage, so that the Rekuperationsmoment R can perform the stationary control. It should be noted that the hydraulic braking torque H by the amount must be higher, by the drive torque A provided. The hydraulic brake system must namely perform both the actual braking and the provided drive torque H decelerate.

It is advantageous here that the method B "can also be used for anti-skid control when the electrical energy store is completely charged. Due to the stationary control of the nominal slip by means of the electric motor, the anti-skid control has a shorter reaction time than a conventional anti-skid control with an ABS block.

LIST OF REFERENCE NUMBERS

1

vehicle

2

hydraulic brake system

3

control unit

4

electric motor

5

data exchange

6

electrical energy storage

7

management

A

drive torque

Alim

Driving torque threshold

B

Method for anti-skid control

B '

Method for anti-skid control

B "

Method for anti-skid control

H

hydraulic braking torque

R

recuperation

Rmax

maximum recuperation moment

a

a. step

b

b. step

c

c. step

d

d. step

I

Phase 1

II

Phase 2

III

Phase 3

IV

Phase 4

V

Phase 5

VI

Phase 6

VII

Phase 7

Claims (7)

Method (B) for anti-lock control of a vehicle (1), wherein the vehicle (1) has a hydraulic brake system (2), an energy store (6) for electrical energy and at least two wheel-individual electric motors (4) on one axle, characterized in that during a braking operation a. at least one of the electric motors (4) builds up a recuperation torque (R) on at least one of the wheels until a maximum recuperation torque (Rmax) is reached, b. a braking torque (H) of the hydraulic brake system (2) is built up until a desired slip is reached at this at least one of the wheels, c. the at least one of the electric motors (4) adjusts the setpoint slip on this at least one of the wheels and the at least one of the electric motors (4) is adjusted back by an amount to a recuperation moment (R) which in the interval [1/2 maximum recuperation moment; maximum recuperation torque [is and the braking torque (H) of the hydraulic brake system (2) is increased by the same amount, d. the setpoint slip is fixedly controlled at this at least one of the wheels by means of the at least one electric motor (4). Method (B) according to Claim 1 , characterized in that at a compared to a start time modified friction coefficient during the braking process, the steps c and d run again. Method (B) according to one of the preceding claims, characterized in that in step c, the at least one of the electric motors (4) is back-regulated by an amount to a recuperation torque (R) which corresponds to 1/2 maximum recuperation torque. Method (B) according to one of the preceding claims, characterized in that the steps a, c and d of each of the electric motors (4) of the vehicle (1) are performed. Method (B ') for anti-lock control of a vehicle (1), wherein the vehicle (1) has a hydraulic brake system (2), an energy store (6) for electrical energy and at least two wheel-individual electric motors (4) on one axle, characterized that during a braking process a '. at least one of the electric motors (4) builds up a recuperation torque (R) on at least one of the wheels until a value is reached which in the interval [1/2 maximum regeneration torque; maximum recuperation moment [lies, b '. at the same time a braking torque (H) of the hydraulic brake system (2) is built up to a target slip is reached at this at least one of the wheels, d '. the at least one electric motor (4) controls a setpoint slip on at least one of the wheels in a stationary manner upon reaching a predetermined slip threshold value. Method (B ") for anti-lock control of a vehicle (1) according to Claim 5 , characterized in that during a braking process with fully charged energy store (6) for electrical energy, a first of the at least two electric motors (4) regenerative and a second of at least two electric motors (4) is actively operated, wherein the actively operated electric motor (4) uses more energy than the regeneratively operated electric motor (4) provides, wherein - the regeneratively operated electric motor (4) performs step a ', - the actively operated electric motor (4) of the at least two electric motors (4) builds up a drive torque (A) Drive torque threshold (Alim) is reached - the hydraulic brake system (2) performs step b ', wherein the braking torque (H) is higher by an amount corresponding to the amount of the drive torque (A), - the regenerative electric motor (4) step d 'performs, and - at the same time the actively operated electric motor (4) from reaching the predetermined slip threshold its drive motor ent (A) corresponding to the Rekuperationsmoment (R) of the regeneratively driven electric motor (E) provides. Vehicle (1) having a hydraulic brake system (2), an energy store (6) for electrical energy and at least two wheel-individual electric motors (4) on one axle, characterized in that the vehicle has a method (B; B '; B "). ) after one of the Claims 1 to 4 , and after one of Claims 5 to 6 performs.

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