DE102022123477A1 - Method for controlling an electric drive of a vehicle, in particular a commercial vehicle, computer program and/or computer-readable medium, control device and vehicle, in particular a commercial vehicle - Google Patents

Abstract

Method (100) for controlling an electric drive (21) of a vehicle (200a), in particular a commercial vehicle (200b), comprising a drive control device (22) and an inverter (23) and set up for regenerative braking (NB), with a friction brake control device (20) comprising friction brake device (19), the method (100) comprising: determining (110) a vehicle reference speed (210) by the friction brake control device (20) taking into account a plurality of detected wheel speeds (211); Determining (120) a target controlled variable (220) by the friction brake control unit (20), taking into account the vehicle reference speed (210); Transmitting (130) the target controlled variable (220) to the drive control unit (22); Determining (140) an actual controlled variable (225) by the inverter (23); Transmitting (150) the target controlled variable (220) to the inverter (23); Determining (160) a control difference (230) based on the target controlled variable (220) and the actual controlled variable (225) by the inverter (23); and rules (170) of the inverter (23) depending on the control difference (230).

Description

The invention relates to a method for controlling an electric drive of a vehicle, in particular a commercial vehicle, comprising a drive control device and an inverter and set up for regenerative braking, with a friction brake device comprising a friction brake control device. The invention also relates to a computer program and/or computer-readable medium, a control device for a vehicle, in particular a commercial vehicle, and a vehicle, in particular a commercial vehicle.

The invention relates in particular to the field of vehicles, in particular commercial vehicles, including trailers, with an electronically controlled braking system (electronic brake system, EBS, or trailer electronic brake system, TEBS) and at least one powered by an electric drive (eDrive) via a central drive and/ or a wheel-specific drive that can be driven electrically, the electric drive being set up for regenerative braking. In other words, the electric drive can be operated as a wear-free continuous brake and enables braking energy to be recovered in the form of electrical energy (recuperation) during deceleration.

A regulation of the friction brake device and the electric drive can contribute to an improvement in driving characteristics and in particular to an improved stability of the vehicle, in particular a commercial vehicle. In order to achieve stability, in certain situations a torque acting on the drivable axles and a slip must be limited, whereby the slip can be a drive and/or braking slip. For this purpose, coordination between the electric drive and the friction brake device is necessary, with the friction brake device according to the prior art monitoring and regulating driving stability, for example through an anti-lock braking system (ABS) and an electronic stability control (ESC), including active roll over protection (ARP) and yaw rate control.

In stability and slip-critical deceleration situations, according to the prior art, the electric drive is deactivated by the friction brake control unit and only friction brakes or the friction brake device are used for control. This is due to the fact that classic continuous braking (so-called retarders) cannot be controlled precisely and dynamically enough due to their dynamics. However, the electric drive has the necessary dynamics and precision, so that the potential in terms of recuperation and, in particular, an improvement in braking performance and stability is currently not being exploited.

If the electric drive is operated with slip control for certain drive and braking cases, close coordination with the friction brake device and its stability control is necessary. It must be ensured that the realized slip values and torques are high enough to achieve recuperation, deceleration when braking and/or propulsion when driving to a desirable extent. At the same time, it must be ensured that the realized slip values and torques are below a stability-critical maximum value in order to ensure sufficient lateral guidance.

The entire slip behavior is strongly dependent on a surface or a coefficient of friction between the surface and the wheel, including a corresponding dynamic change in the surface or the coefficient of friction, as well as the load or static and dynamic axle load distribution. It must also be ensured that torques provided by the electric drive do not lead to a violation and/or exceeding of an intervention condition of a stability control system of the brake system. On the one hand, this affects the absolute level of torque and slip values as well as the change in wheel acceleration over time, since high torque gradients lead to high wheel decelerations and can trigger ABS control.

Slip control by means of the friction brake device, also called the service brake, or by means of one or more electric drives is known from the prior art.

WO 2013/045584 A1 discloses a slip-controlled braking system for an electrically driven motor vehicle, the friction brakes on the wheels of at least one axle, which are controlled by a friction brake control device, at least one electric machine which is connected to at least one wheel and is controlled by an electric drive control device, means for detecting a deceleration request , in particular a brake pedal with a pedal angle sensor, a wheel slip control device and a torque distribution device. The means or means for detecting a deceleration request is connected to the wheel slip control device, which specifies target braking torques for each wheel in accordance with the deceleration request, the wheel slip control device being connected to a torque distribution device, which is connected to the friction brake control device and the electric drive control device and specifies friction braking requirements for the friction brake control device and generator braking requirements for the electric drive control device in accordance with the target braking torques. Further information relating to driving dynamics is transmitted to the wheel slip control device by a condition observer.

WO 2021/144065 A1 discloses vehicle motion management based on a torque request with a speed limit. The vehicle control should be requested taking slip or wheel speeds into account and not based on a torque request.

An advantage of control via the friction brake device is that the friction brake device has essential information relevant to driving stability and can carry out braking interventions in a coordinated manner (for example with anti-slip control, ASR) on a road with different friction values per wheel (MU split condition or MU split scenario): Holding the spinning wheel at a lower coefficient of friction by means of braking intervention.

In contrast, particularly with wheel-specific drives, control via the electric drive offers the advantage that it can carry out fast and precise speed and/or torque control internally. If the control takes place via the brake system and thus on a separate control unit, this always includes an additional communication path, usually a vehicle bus, for example a CAN BUS, with corresponding dead times and delays.

It is the object of the invention to enrich the prior art and to provide an improved method for controlling an electric drive. An embodiment of the invention can solve the problem of specifying an effective control method for an electric drive, in which the most dynamic control loop possible can be used to control the electric drive.

The task is solved by a method according to claim 1 and the subjects according to the further independent claims. The subclaims indicate preferred developments of the invention.

According to the invention, a method for controlling an electric drive of a vehicle, in particular a commercial vehicle, comprising a drive control device and an inverter and set up for regenerative braking is provided with a friction brake device comprising a friction brake control device. The method has: determining a vehicle reference speed by the friction brake control unit, taking into account a plurality of detected wheel speeds; Determining a target controlled variable by the friction brake control unit, taking into account the vehicle reference speed; Transmitting the target controlled variable to the drive control unit; Determining an actual controlled variable by the inverter; Transmitting the target controlled variable to the inverter; Determining a control difference based on the target controlled variable and the actual controlled variable by the inverter; and regulating the inverter depending on the control difference.

The vehicle, in particular a commercial vehicle, is referred to below as a vehicle. The vehicle includes wheels that can be braked by the electric drive using regenerative braking with a generator braking torque. The wheels can alternatively or additionally be braked with a friction brake torque by the friction brake device. A driver and/or an automated driving function can provide or trigger a braking request, which causes braking of the vehicle, an axle of the vehicle and/or one of the wheels by the electric drive and/or the friction brake device. According to the braking request, the generator braking torque, the friction braking torque or a total braking torque as the sum of the generator braking torque and the friction braking torque can be requested for braking. The electric drive can apply a drive torque to one of the wheels in the case of a wheel-specific drive and/or in the case of a central drive to several wheels of an axle of the vehicle. The drive torque can be requested by a drive request from a driver and/or an automated driving function. The application of a torque to the wheels by the electric drive, i.e. the generator braking torque and/or the drive torque, is subject to regulation according to the method according to the invention.

According to the method, the friction brake control device reads the wheel speeds and uses them to determine the vehicle reference speed, as is known from the prior art. Depending on the situation, the friction brake control unit determines the target controlled variable, for example a permitted slip value and/or a maximum and/or minimum permitted wheel speed. The target controlled variable is determined in such a way that driving stability is guaranteed and, for example, blocking of one of the wheels is reduced and/or avoided.

So that the control of the electric drive takes advantage of the high dynamics and The control quality of the electric drive can take place, the friction brake control unit transmits the target controlled variable to the drive control unit.

The actual controlled variable, i.e. the variable that is to be regulated and adjusted to the target controlled variable, is transmitted from the drive control unit to the inverter.

The inverter applies the torque to the wheel and/or wheels in order to regulate the target controlled variable. It was recognized that the control of the inverter is subject to particularly advantageous dynamics. The inverter can be controlled based on torque or speed in order to correct the control difference or adjust the target controlled variable. For this purpose, the electric drive and in particular the inverter determines the control difference based on which the inverter carries out the control. A control loop, which includes determining the actual controlled variable and the regulation, is therefore carried out entirely by the inverter.

It was recognized that a control of the electric drive distributed between the electric drive and the friction brake device can be provided in order to regulate the inverter of the electric drive in the shortest and most dynamic control loop possible. This ensures that in the case of deviating actual controlled variables of the wheels of the vehicle, with a wheel-specific drive, the target controlled variable can be regulated directly by the electric drive and in particular by the inverter. The inverter then carries out the regulation. The drive control unit and/or the friction brake control unit are therefore unnecessary in the control loop. Communication between the inverter and the drive control unit and/or the friction brake control unit is therefore unnecessary for controlling the inverter, which leads to an improvement in the dynamics of the control. For centrally driven axles, the friction brake device can monitor the implementation of the desired wheel or side-specific target controlled variable and have a stability-ensuring effect through braking interventions. Because the friction brake device determines the permissible target control variables depending on the driving situation, i.e. the vehicle reference speed and the wheel speeds that flow into the vehicle reference speed, driving stability is guaranteed as much as possible at all times. At the same time, the high control quality and dynamics of an internal control of the electric drive or the inverter are optimally utilized.

Preferably, the target controlled variable includes a target speed and the actual controlled variable includes an actual speed. The control difference to be adjusted is therefore a speed difference. In this case, the inverter can be controlled based on speed. Alternatively or additionally, the target controlled variable includes a target slip and the actual controlled variable includes an actual slip. The control difference to be adjusted is therefore a slip difference. For this purpose, the vehicle reference speed can be transmitted to the inverter, which can be used by the inverter to carry out speed-based control of the slip. In this case, the inverter can be controlled based on torque, with optional restrictions on the speed of the inverter and/or a driven wheel being taken into account.

The regulation is preferably carried out in such a way that a wheel is subjected to a total braking torque. This makes it possible, for example in an MU split scenario, to set a braking torque and/or a speed reduction on a wheel on a road with a comparatively high coefficient of friction.

The regulation is preferably carried out in such a way that a drive torque is achieved. This makes it possible, for example, in an MU split scenario, to regulate a targeted reduction of the drive torque on a wheel on a road with a comparatively low coefficient of friction in order to be able to regulate the transferable torque on a wheel on a road with a comparatively high coefficient of friction.

The method preferably comprises: determining a coefficient of friction between a wheel of the vehicle, in particular a commercial vehicle, and a road surface by means of the electric drive; wherein the wheel speed and/or a torque is controlled taking the coefficient of friction into account. The coefficient of friction can, for example, be carried out using the method for estimating the coefficient of friction described in German patent application 10 2022 114 084.9 dated June 3, 2022, which has not yet been published at the time of registration, in that the electric drive applies an excitation torque to a wheel. The regulation can take into account the coefficient of friction between a wheel and the road and possibly different coefficients of friction between different wheels and road sections to ensure the stability of the vehicle. The coefficient of friction can, for example, limit the slip on a wheel.

Preferably, the determination of the control difference and/or the control is carried out on an individual wheel and/or axle-related basis. For this purpose, the actual controlled variable can also be determined on an individual wheel basis and/or, in the case of a central drive, on an axle-related basis. Axis-related control can be implemented particularly effectively if the electric drive is used is set up to drive an axle of the vehicle. Wheel-specific control enables different wheels to be subjected to different torques and thus different target control variables to be adjusted. This means that control can also be carried out reliably and precisely in an MU split scenario. The vehicle can include several inverters in order, for example, to apply a torque individually to several axles and/or several wheels. The method described here can be carried out for each of the inverters so that a torque and/or a speed of each of the axles and/or each of the wheels can be regulated effectively and with high dynamics.

Preferably, the drive control device transmits first gradient information to the friction brake control device, with the determination of the target controlled variable taking the first gradient information into account. In addition to the communication of speed and/or slip limits to be maintained by the target controlled variable, the exchange of torque and/or speed gradients to be maintained, i.e. general target controlled variable gradients as first gradient information, is also possible, for example the permissible change in torque/speed per time. In addition to information about a stationary available torque, the drive control unit also provides information about the convertible gradients, which can take into account possible influences on the service life of an energy storage device and/or a mechanical transmission. The friction brake control unit can take the first gradient information into account in the strategy for selecting and controlling the friction brake device.

Preferably, the drive control device receives second gradient information from the friction brake control device, and the control takes place taking second gradient information into account. The friction brake control unit sends permitted gradients of the target controlled variable as the second gradient information to the drive control unit, which, if adhered to, is always such that the wheel deceleration is always such that, for example, a tendency for the wheel to lock is avoided, i.e. the wheel deceleration is below an ABS threshold and therefore no ABS is triggered. The drive control unit receives the second gradient information and ensures that the gradients are maintained for all torque requirements placed on the electric drive, for example by the driver and/or through an automated driving function such as electronic braking system, EBS, cruise control CC, and adaptive cruise control, ACC.

According to a further aspect of the invention, a computer program and/or computer-readable medium is provided. The computer program and/or computer-readable medium comprises instructions which, when the program or instructions are executed by a computer, cause the computer to carry out the method described here and/or the steps of the method described here. The computer program and/or computer-readable medium may include instructions to carry out steps of the method described as optional and/or advantageous in order to achieve a corresponding technical effect.

According to a further aspect of the invention, a vehicle, in particular a commercial vehicle, is provided. The vehicle, in particular commercial vehicle, comprises an electric drive comprising a drive control device and an inverter and set up for regenerative braking, and a friction brake device comprising a friction brake control device, the drive control device and the friction brake control device being connected in terms of information technology, and the vehicle, in particular commercial vehicle, being set up to do so. carry out the procedure described above. This means that the control takes place on various electronic control units (ECU), namely the drive control unit and the friction brake control unit. Alternatively, the friction brake control device and the drive control device are comprised by a central control device and are formed by different sections, for example software modules. The vehicle can be set up to carry out steps of the method described as optional and/or advantageous in order to achieve a corresponding technical effect.

• 1 eine schematische Darstellung einer Übersicht eines Fahrzeugs, insbesondere Nutzfahrzeugs, gemäß einer Ausführungsform der Erfindung;und
• 2 eine schematische Darstellung eines Ablaufschemas eines Verfahrens gemäß einer Ausführungsform der Erfindung.

Further advantages and features of the invention as well as their technical effects result from the figures and the description of the preferred embodiments shown in the figures. Show it

• 1 a schematic representation of an overview of a vehicle, in particular a commercial vehicle, according to an embodiment of the invention; and
• 2 a schematic representation of a flow chart of a method according to an embodiment of the invention.

1 shows a schematic representation of an overview of a vehicle 200a, in particular commercial vehicle 200b, according to an embodiment of the invention. The vehicle 200a, in particular commercial vehicle 200b, is referred to below as vehicle 200a, 200b. The vehicle 200a, 200b is a land vehicle and, for example, a truck car, a bus, a trailer and/or a multi-part vehicle.

The vehicle 200a, 200b is set up to do this with reference to 2 to carry out the procedure 100 described. The vehicle 200a, 200b in the in 1 Embodiment shown has an electric drive 21 comprising a drive control device 22 and an inverter 23 and set up for regenerative braking NB. Furthermore, the vehicle 200a, 200b has a friction brake device 19 comprising a friction brake control device 20. The drive control unit 22 and the friction brake control unit 20 are connected to one another in terms of information technology, for example through a data bus, in order to exchange information, as illustrated schematically with the arrows between the drive control unit 22 and the friction brake control unit 20.

The electric drive 21 is set up for regenerative braking NB. The electric drive 21 can generate a generator braking torque 25, which can lead to a deceleration of the vehicle 200a, 200b. The electric drive 21 can change, in particular reduce and increase, the generator braking torque 25. The electric drive 21 can generate a drive torque 321 for driving and/or accelerating a wheel 305. For this purpose, the drive control device 22 receives and sends a corresponding control signal 229 to the inverter 23. The inverter 23 includes power electronics in order to regulate the electric drive 21 in accordance with the control signal 229.

The friction brake device 19 is an electrical brake system 43 or an electronically controlled brake system and can apply a friction brake torque 41. In an embodiment not shown, the friction brake device 19 is a pneumatic and/or hydraulic brake system.

The electric drive 21 and the friction brake device 19 can be operated and controlled separately and/or together.

The vehicle 200a, 200b according to 1 has several wheels 305. The wheels 305 are arranged on a roadway 315. A total braking torque 320 conveyed by the roadway 315 and caused by the electric drive 21 and the friction brake device 19 can act on the wheels 305. The total braking torque 320 is the sum of the generator braking torque 25 and the friction braking torque 41. The wheel 305 can also be subjected to the drive torque 321. The electric drive 21 can be set up as a so-called central drive to apply the generator braking torque 320 and/or the drive torque 321 to several wheels 305 of an axle (not shown). The electric drive 21 is in the in 1 Embodiment shown is set up to apply the generator braking torque 320 and/or the drive torque 321 individually to each wheel, whereby 1 only schematically illustrates the braking of a wheel 305.

Contact between the wheel 305 and the road 315 is characterized by a coefficient of friction MU. The electric drive 21 can be set up to carry out the method for estimating the coefficient of friction described in German patent application 10 2022 114 084.9 dated June 3, 2022, which has not yet been published at the time of registration. For this purpose, the electric drive can be set up to apply a predetermined excitation torque to the wheel 305, the excitation torque being applied to the wheel 305 periodically at a frequency; and from this to determine a change in slip depending on the excitation torque, the determination of the change in slip taking the frequency into account.

There may be different coefficients of friction MU between different wheels 305 and the road 315 (MU split scenario). The MU split scenario can be caused by different moments on the wheels 305, by different conditions of the road 315 and/or by a different load on the wheels 305.

The vehicle 200a, 200b has an energy storage device 260. The energy storage device 260 is set up to store and provide electrical energy 262. For this purpose, the energy storage device 260 is connected to the electric drive 21. The energy storage device 260 includes a plurality of battery cells and a battery controller (not shown). The energy storage device 260 has a charge state 261, which can be increased by regenerative braking NB and decreased by a drive.

The drive control device 22 and the friction brake control device 20 each have a processor, not shown, for processing information and a memory, not shown, for storing information. Information processed and/or stored in the drive control unit 22 and the friction brake control unit 20 is in 1 shown schematically as a box with a dashed line.

The friction brake control device 20 is set up to detect wheel speeds 211 of the wheels. The friction brake control unit 20 is equipped with one or several speed sensors, not shown. Based on the wheel speeds 211, the friction brake control unit 20 determines a vehicle reference speed 210 and determines a target controlled variable 220, taking into account the vehicle reference speed 210 and the wheel speeds 211. The drive control unit 22 sends a first gradient information 240 to the friction brake control unit 22 in order to determine the target controlled variable 220 to be determined taking into account the first gradient information 240. The first gradient information 240 includes the information at which rate of change an actual controlled variable 225 can be adjusted to the target controlled variable 220, taking into account the circumstances affecting the electric drive 21.

The friction brake control unit 20 transmits the target controlled variable 220 to the drive control unit 22.

The inverter 23 determines the actual controlled variable 225. A high-resolution resolver signal from the inverter 23 can be used. The inverter 23 can create control information 228 relating to the actual controlled variable 225 and transmit it to the drive control unit 22.

The drive control device 22 transmits the target controlled variable 220 to the inverter 23. Based on the target controlled variable 220 and the actual controlled variable 225, the inverter determines the control difference 230, for example by forming a difference between the target controlled variable 220 and the actual controlled variable 225.

The inverter 23 is regulated depending on the control difference 230. The inverter 23 regulates and limits slip, for example, by limiting all torque requirements placed on it in an internal speed/torque control and thus ensuring that the target controlled variable 220 is regulated. This creates a control loop in the inverter 23, whereby the actual controlled variable 225 is recorded and the control difference 230 is determined and corrected. The drive control device 22 receives a second gradient information 241 from the friction brake control device 22 in order to use the second gradient information 241 when controlling 170 of the inverter 23 to be taken into account. The second gradient information 241 includes the information at which rate of change the actual controlled variable 225 can be adjusted to the target controlled variable 220, taking into account the circumstances affecting the friction brake device 19 and/or wheel and/or vehicle dynamics.

The inverter 22 can be operated speed-based for speed control (speed mode). The inverter 220 receives a target speed 221 or a target speed as the target controlled variable 220. The actual controlled variable 225 is an actual speed and can be determined by the inverter 23 itself, for example using the analog resolver signal of the electric drive 21. The inverter 23 regulates the target speed as a target controlled variable 220. This control does not take place on the drive control unit 22, so no further data transmission via, for example, a CAN BUS is required. This results in a fast and comparatively “small” control loop with few components. Alternatively, the inverter 23 can be controlled based on torque (torque mode). The inverter 23 regulates the target torque as the target controlled variable 220 to the actual torque as the actual controlled variable 225. At the same time, it is possible to transmit a permitted upper or lower speed limit to the inverter 23 in torque mode. In this case, the inverter 23 additionally ensures that these speed limits are not exceeded/undershot by internally transmitting the actual speed based on the resolver signal and the limit, for example determined by the friction brake control unit 20 and forwarded to the inverter 23 by the drive control unit 21 , compares.

The target controlled variable 220 is a target speed 221 and the actual controlled variable 225 is an actual speed 226. This is in the in 1 embodiment shown is particularly effective. This means that a comparatively dynamic and efficient control loop can be implemented by the electric drive 21. Alternatively, the target controlled variable 220 is a target slip 222 and the actual controlled variable 225 is an actual slip 227.

The determination 160 of the control difference 230 and the regulation 170 is carried out on a wheel-specific or axle-related basis (not shown).

2 shows a schematic representation of a flowchart of a method 100 according to an embodiment of the invention. In particular shows 2 a method 100 for controlling an electric drive 21 of a vehicle 200a, in particular commercial vehicle 200b, comprising a drive control device 22 and an inverter 23 and set up for regenerative braking NB, with a friction brake device 19 comprising a friction brake control device 20. Such a vehicle 200a, in particular commercial vehicle 200b, is in Referred to below as vehicle 200a, 200b. The vehicle 200a, 200b is related to 1 described in more detail.

The procedure 100 according to 2 has a determination 110 of a vehicle reference speed 210 by the friction brake control unit 20 taking into account a plurality of detected wheel speeds 211.

A target controlled variable 220 is determined 120 by the friction brake control unit 20, taking into account the vehicle reference speed 210.

The target controlled variable 220 comprises a target speed 221 and the actual controlled variable 225 comprises an actual speed 226, and/or the target controlled variable 220 comprises a target slip 222 and the actual controlled variable 225 comprises an actual slip 227

The target controlled variable 220 is transmitted 130 to the drive control unit 22.

An actual controlled variable 225 is determined 140 by the inverter 23 and the target controlled variable 220 is transmitted 150 to the inverter 23.

A control difference 230 is determined 160 based on the target controlled variable 220 and the actual controlled variable 225 by the inverter 23.

A coefficient of friction MU is determined 165 between a wheel 305 of the vehicle 200a, in particular commercial vehicle 200b, and a roadway 315 by the electric drive 21.

The inverter 23 is controlled 170 depending on the control difference 230. The control 170 takes place in such a way that a wheel 305 is subjected to a total braking torque 320 or a drive torque 321. The regulation 170 of the wheel speed 211 and/or a torque 320, 321 takes place taking into account the coefficient of friction MU.

The determination 160 of the control difference 230 and/or the regulation 170 can be carried out on a wheel-specific and/or axle-related basis.

Those skilled in the art will recognize that steps of method 100 may be performed in a different order than in the embodiment 2 described. For example, the transmission 150 of the target controlled variable 220 to the inverter 23 can be carried out directly after the transmission 130 of the target controlled variable 220 to the drive control unit 21. The determination 140 of the actual controlled variable 225 and the control 170 of the inverter 23 are advantageously carried out repeatedly in a control loop.

During operation, switching between the options mentioned in the prior art, such as control solely by the friction brake device 19 and/or the electric drive 21 and the method 100 described above with distributed control, is conceivable. This can be done depending on the driving situation and the drive concept. In the case of a drive with a central drive in an MU split scenario, the control can be carried out completely via the friction brake device 19 with parallel braking intervention, while in the case of braking on a homogeneous road with sole use of the electric drive 21, the method 100 described above can be used. This allows switching of the methods, for example taking into account a coefficient of friction estimate.

Reference symbols (part of the description):

19

Friction brake device

20

Friction brake control unit

21

electric drive

22

Drive control unit

23

Inverters

25

Generator braking torque

41

Friction braking torque

43

electric braking system

100

Proceedings

110

Determine a vehicle reference speed

120

Determining a target controlled variable

130

Transmission of the target controlled variable

140

Determining an actual controlled variable

150

Transmission of the target controlled variable

160

Determining a control difference

165

Determining a coefficient of friction

170

Rules of the inverter

200a

vehicle

200b

Commercial vehicle

210

Vehicle reference speed

211

Wheel speed

220

Target controlled variable

221

Target speed

222

Target slip

225

Actual controlled variable

226

Is speed

227

Actual slip

228

Rules information

229

control signal

230

Rule difference

250

Control unit

251

processor

252

Storage

260

Energy storage device

261

charging status

262

electrical power

305

wheel

315

roadway

320

Total braking torque

321

Drive torque

NB

Regenerative braking

MU

Friction coefficient

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2013045584 A1 [0008]
• WO 2021144065 A1 [0009]

Claims (10)

Method (100) for controlling an electric drive (21) of a vehicle (200a), in particular a commercial vehicle (200b), comprising a drive control device (22) and an inverter (23) and set up for regenerative braking (NB), with a friction brake control device (20) comprising friction brake device (19), the method (100) comprising: - Determining (110) a vehicle reference speed (210) by the friction brake control device (20), taking into account a plurality of detected wheel speeds (211); - Determining (120) a target controlled variable (220) by the friction brake control unit (20), taking into account the vehicle reference speed (210); - Transmit (130) the target controlled variable (220) to the drive control unit (22); - Determination (140) of an actual controlled variable (225) by the inverter (23) - Transmit (150) the target controlled variable (220) to the inverter (23); - Determining (160) a control difference (230) based on the target controlled variable (220) and the actual controlled variable (225) by the inverter (23); and - Rules (170) of the inverter (23) depending on the control difference (230). Procedure according to Claim 1 , wherein the target controlled variable (220) comprises a target speed (221) and the actual controlled variable (225) comprises an actual speed (226), and / or the target controlled variable (220) comprises a target slip (222) and the actual controlled variable (225) comprises an actual slip (227). Procedure according to Claim 1 or 2 , whereby the regulation (170) takes place in such a way that a wheel (305) is subjected to a total braking torque (320). Method according to one of the preceding claims, wherein the control (170) takes place in such a way that a drive torque (321) is achieved. Method according to one of the preceding claims, wherein the method (100) comprises: - Determining (165) a coefficient of friction (MU) between a wheel (305) of the vehicle (200a), in particular commercial vehicle (200b), and a roadway (315) by the electric drive (21); and where - the control (170) of the wheel speed (211) and/or a torque (320, 321) takes place taking into account the coefficient of friction (MU). Method according to one of the preceding claims, wherein the determination (160) of the control difference (230) and/or the control (170) is carried out individually for each wheel and/or in relation to the axle. Method according to one of the preceding claims, wherein the drive control device (22) transmits first gradient information (240) to the friction brake control device (22), the determination (120) of the target controlled variable (220) taking into account the first gradient information (240). Method according to one of the preceding claims, wherein the drive control device (22) receives a second gradient information (241) from the friction brake control device (22), and wherein the control (170) takes place taking into account a second gradient information (241). Computer program and/or computer-readable medium, comprising commands which, when the program or commands are executed by a computer, cause the computer to carry out the method (100) and/or the steps of the method (100) according to one of Claims 1 until 8th to carry out Vehicle (200a), in particular commercial vehicle (200b), comprising an electric drive (21) comprising a drive control device (22) and an inverter (23) and set up for regenerative braking (NB), and a friction brake device (19) comprising a friction brake control device (20) , wherein the drive control device (22) and the friction brake control device (20) are connected in terms of information technology, and wherein the vehicle (200a), in particular commercial vehicle (200b), is set up to carry out the method according to one of Claims 1 until 8th to carry out.

Images