DE102020214659A1 - Method for vibration damping of a torque of a drive train, drive system for a vehicle and vehicle - Google Patents

Abstract

The present invention relates to a method for vibration damping of a torque of a drive train, as well as a drive system, which is set up in particular for carrying out the method, and a motor vehicle with a drive system according to the invention.

Description

The present invention relates to a method for vibration damping of a torque of a drive train according to claim 1, a drive system for a vehicle according to claim 2, and a vehicle according to claim 5.

Method for vibration damping of an engine torque are, for example, from DE102016200006A1 and the DE102012224294A1 known. It is proposed that the vibration damping should take place by filtering the output speed of the electric motor.

Although usable methods for vibration damping of a torque of a drive train are described here, there is still a need for improvement here.

Accordingly, the object of the present invention is to propose an improved method for vibration damping of a torque of a drive train, in particular to propose an alternative to the known methods.

1. I) Bestimmen einer Verdrehung des Antriebsstrangs aus einem Vergleich aus einer von dem Drehzahlsensor des Elektromotors detektierten Motordrehzahl und einer von dem Drehzahlsensor des Fahrzeugrades detektierten Raddrehzahl als ein Wert für die berechnete oder geschätzte Verdrehung des Antriebsstrangs in der ersten Berechnungseinrichtung;
2. II) Zuführen des Wertes der Verdrehung des Antriebsstrangs dem Hochpassfilter und Ausgabe eines Hochfrequenzwerts der Verdrehung des Antriebsstrangs aus dem Hochpassfilter an den Controller;
3. III) Bestimmung eines Wertes für ein Kompensationsdrehmoment zur Dämpfung von Schwingungen durch den Controller und Ausgabe des Wertes für ein Kompensationsdrehmoment zur Dämpfung von Schwingungen an die zweite Berechnungseinrichtung;
4. IV) Abfragen eines Wertes für ein Motor-Solldrehmoment der Einrichtung zur Bestimmung des Solldrehmoments des Elektromotors und Ausgabe Wertes für ein Motor-Solldrehmoment an die zweite Berechnungseinrichtung;
5. V) Bestimmen eines Wertes eines kompensierten Motor-Solldrehmoments von der zweiten Berechnungseinrichtung und Ausgabe des Wertes eines kompensierten Motor-Solldrehmoments an das Motorsteuergerät.

According to the invention, this object is achieved by a method according to claim 1, according to which a method for vibration damping of a torque of a drive train is provided, the drive train having an electric motor with a speed sensor and an engine control unit, a damping control device, a device for determining the target torque of the electric motor and at least one Vehicle wheel comprising a speed sensor, wherein the damping control device comprises a first calculation device, a high-pass filter, a controller and a second calculation device, the following method steps being carried out:

1. I) determining a torsion of the drive train from a comparison of an engine speed detected by the speed sensor of the electric motor and a wheel speed detected by the speed sensor of the vehicle wheel as a value for the calculated or estimated torsion of the drive train in the first calculation device;
2. ii) inputting the value of the drive train twist to the high pass filter and outputting a high frequency value of the drive train twist from the high pass filter to the controller;
3. III) the controller determining a value for a compensating torque for damping vibrations and outputting the value for a compensating torque for damping vibrations to the second calculation means;
4. IV) interrogating a value for a target motor torque from the device for determining the target torque of the electric motor and outputting a value for a target motor torque to the second calculation device;
5. V) determining a value of a compensated target engine torque from the second calculation means and outputting the value of a compensated target engine torque to the engine controller.

The target torque is adjusted so as not to induce any shaft vibration. The in-phase component of the shaft vibrations is removed by modifying the motor's target torque and ensuring that the motor does not induce resonance on the shaft.

In particular, this results in an electric drive train with reduced friction and possibilities for using components with lower weight and lower costs for the electric drive train.

In particular, it is intended to dampen the vibrations caused by the inertia and stiffness of the powertrain after a sudden change in torque demand by modulating the engine torque. In particular, the vibrations should be dampened in a certain frequency range between 10Hz and 30Hz to avoid excessive vibrations.

Further advantageous refinements of the proposed invention result in particular from the features of the dependent claims. The objects or features of the various claims can in principle be combined with one another as desired.

In an advantageous embodiment of the invention, it can be provided that a drive train comprises an electric motor with a speed sensor and an engine control unit, a damping control device, a device for determining the target torque of the engine and at least one vehicle wheel with a speed sensor, with a damping control device being provided, comprising a first calculation means, a high-pass filter, a controller and a second calculation means.

The device for determining the setpoint torque can be an accelerator pedal, in particular if only one electric motor is provided. Can also be advantageous Arrangement according to the invention comprise several electric motors in order to obtain a better average speed of the vehicle wheels.

In a further advantageous embodiment of the invention, it can be provided that the damping control device is set up to carry out the method according to the method described above. The drive train is set up particularly advantageously in a motor vehicle.

• 1 eine schematische Darstellung einer Dämpfungsregelungseinrichtung zur Durchführung des erfindungsgemäßen Verfahrens;
• 2 ein erfindungsgemäßes Antriebssystem mit einem Antriebsstrang für ein Fahrzeug;
• 3 ein erfindungsgemäßes Kraftfahrzeug.

Further features and advantages of the present invention become clear from the following description of preferred exemplary embodiments with reference to the attached figures. show in it

• 1 a schematic representation of a damping control device for carrying out the method according to the invention;
• 2 a drive system according to the invention with a drive train for a vehicle;
• 3 a motor vehicle according to the invention.

1

Elektromotor

2

Dämpfungsregelungseinrichtung

3

Einrichtung zur Bestimmung des Solldrehmoments (Gaspedal)

4

Rad

11

Drehzahlsensor / Motordrehzahl

12

Motorsteuergerät

13

Getriebe

14

Welle

21

erste Berechnungseinrichtung, insbesondere Addiereinrichtung

22

Hochpassfilter

23

Controller

24

zweite Berechnungseinrichtung, insbesondere Addiereinrichtung

25

Wert für die geschätzte oder berechnete Verdrehung des Antriebsstrangs

26

Hochfrequenzwert der Verdrehung des Antriebsstrangs

27

Wert für ein Kompensationsdrehmoment zur Dämpfung von Schwingungen

28

Solldrehmomentwert

29

Wert für ein kompensiertes Motor-Solldrehmoment

41

Drehzahlsensor / Raddrehzahl

The following reference symbols are used in the figures:

1

electric motor

2

damping control device

3

Device for determining the target torque (accelerator pedal)

4

wheel

11

Speed sensor / engine speed

12

engine control unit

13

transmission

14

Wave

21

first calculation device, in particular adding device

22

high pass filter

23

controllers

24

second calculation device, in particular adding device

25

Estimated or calculated drive train twist value

26

High frequency value of drive train twist

27

Value for a compensation torque to dampen vibrations

28

target torque value

29

Value for a compensated motor target torque

41

Speed sensor / wheel speed

First up 3 referenced.

A vehicle, in particular a motor vehicle, includes, among other things, a drive system.

The propulsion system for the vehicle includes, as in 2 shown schematically, essentially a drive train, a damping control device 2 and a device 3 for determining the target torque.

The drive train essentially comprises an electric motor 1 and a vehicle wheel 4. If necessary, the drive train can also comprise a transmission 13 and/or a shaft 14. The vehicle wheel 4 is preferably driven by the electric motor 1, in particular via the intermediate transmission 13 and/or the shaft 14.

The drive system preferably also includes a speed sensor 11 for determining the speed of the electric motor 1 and an engine control unit 12 for controlling the electric motor 1. The drive system also includes a vehicle wheel 4 with a speed sensor 41.

However, it does not necessarily have to be the wheel from which the speed is detected.

A torque of the electric motor 1 , which is to be transmitted to the vehicle wheel 4 , is requested via the device 3 for determining the target torque of the motor. Ultimately, this requirement comes from the driver of the vehicle who wants to accelerate the vehicle. A target torque value 28 is transmitted by the device 3 for determining the target torque.

In particular, when there is a sudden change in the torque requirement, for example when starting from a standstill, problems, or at least restrictions in comfort, can result from unwanted vibrations in the drive train. The problem arises in particular from the vibration of the drive train due to the low transmission rigidity (possibly shaft + gearbox) of the electric drive train. The electric drive train usually has no coupling or joint to dampen the vibrations.

The damping control device 2 is provided to reduce undesired vibrations of the drive train. In particular, it is provided that the vibrations caused by the inertia and rigidity of the drive train after a Sudden change in torque demand caused by engine torque modulation. In particular, the vibrations should be dampened in a certain frequency range between 10Hz and 30Hz to avoid excessive vibrations.

The damping control device 2 essentially comprises a first calculation device 21, a high-pass filter 22, a controller 23 and a second calculation device 24.

In the 1 a schematic of the control and signal flow of the drive train, in particular of the damping control device 2, is described.

In a first method step, an engine speed and a wheel speed are compared with one another in first calculation device 21 . The engine speed is detected by the speed sensor 11 of the electric motor 1. The wheel speed is detected by the speed sensor 41 of the wheel 4. The result of this comparison is a value for the estimated or calculated twisting speed, which is also known as an estimated or calculated twisting 25 of the drive train can be referred to as the difference between engine speed and wheel speed.

The estimated or calculated torsion 25 of the drive train is supplied to the high-pass filter 22 in a next method step. The high-pass filter 22 filters out correspondingly low frequencies from the twisting of the drive train signal 25 and feeds the remaining high frequencies to the controller 23 as a high-frequency value 26 of the twisting of the drive train.

In a subsequent method step, the controller 23 determines a value 27 for a compensation torque for damping vibrations.

In a next method step, the compensation torque 27 for damping vibrations and the originally desired engine torque 28, which is detected by the device 3 for determining the desired torque, are summed in the second calculation device 24 and sent to the engine control unit 12 as a value 29 for a compensated engine Desired torque derived.

The above-mentioned data/signals for the values are transmitted between the components in an appropriate form, in particular analog or digital.

Features and details that are described in connection with a method also apply in connection with the device according to the invention and vice versa, so that the disclosure of the individual aspects of the invention is or can always be referred to reciprocally. In addition, an optionally described method according to the invention can be carried out with the device according to the invention.

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited 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.

Patent Literature Cited

• DE 102016200006 A1 [0002]
• DE 102012224294 A1 [0002]

Claims (5)

Method for vibration damping of a torque of a drive train, the drive train being part of a drive system, the drive train comprising an electric motor (1) and a vehicle wheel (4), the drive system also having a speed sensor (11) for detecting the speed of the electric motor (1) and a motor control unit (12) for controlling the electric motor (1), the drive system also comprising a damping control device (2) and a device (3) for determining the target torque of the electric motor, the damping control device (2) having a first calculation device (21 ), a high-pass filter (22), a controller (23) and a second calculation device (24), characterized by the following method steps: I) determining a torsion of the drive train from a comparison of one of the speed sensor (11) of the electric motor (1) detected engine speed and one of the speed sensor (41) of the driving wheel speed detected as a value (25) for the calculated torsion of the drive train in the first calculation device (21); ii) supplying the value (25) of the drive train twist to the high pass filter (22) and outputting a high frequency value (26) of the drive train twist from the high pass filter (22) to the controller (23); III) the controller (23) determining a value (27) for a compensating torque for damping vibrations and outputting the value (27) for a compensating torque for damping vibrations to the second calculation means (24); IV) querying a value (28) for a target motor torque from the device (3) for determining the target torque of the electric motor (1) and outputting a value (28) for a target motor torque to the second calculation device (24); V) determining a value (29) of a compensated target engine torque by the second calculation device (24) and outputting the value (29) of a compensated target engine torque to the engine control unit (12). Drive system for a motor vehicle, comprising a drive train with an electric motor (1) and a vehicle wheel (4), the drive system also having a device (3) for determining the target torque of the electric motor, a speed sensor (11) for determining the speed of the electric motor and a Motor control unit (12) for controlling the electric motor, and a damping control device (2), characterized by a damping control device (2), comprising a first calculation device (21), a high-pass filter (22), a controller (23) and a second calculation device (24 ). drive system claim 2 , characterized in that the damping control device (2) for carrying out the method according to claim 1 is set up. Propulsion system according to one of claims 2 or 3 , characterized in that a gear 13 and / or a shaft 14 between the vehicle wheel 4 and the electric motor 1 is arranged. Motor vehicle comprising a drive system according to at least one of claims 2 until 4 .

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