DE102016223066A1 - A method for traction control of drive wheels of a motor vehicle and traction control device for traction control of drive wheels of a motor vehicle - Google Patents

Abstract

A method is proposed for traction control of drive wheels of a motor vehicle, the motor vehicle having a motor for driving the drive wheels of the motor vehicle, a continuously variable transmission with a limited control range of a transmission (CVT), wherein an input of the transmission is connected to the motor, and drive wheels wherein the drive wheels are connected to an output of the transmission, characterized in that the ratio of the transmission to reduce torque on one or more of the drive wheels is changed such that spinning of one or more of the drive wheels is prevented.

Description

Field of the invention

The invention relates to a method for traction control of drive wheels of a motor vehicle and a traction control device for traction control of drive wheels of a motor vehicle.

State of the art

A variety of methods for traction control of drive wheels of a motor vehicle is known. 2 shows a method for traction control of drive wheels of a motor vehicle according to the prior art. Reference variables from the transverse dynamics controller 5 'are used for setpoint determination in a setpoint determination device 10'. Subsequently, in an operating state determination device 20 ', the operating state of the drive wheels or of the motor vehicle is determined, and based on the reference variables 5', the setpoint values are respectively determined in a PID wheel speed controller 30 'and in a PI quad lock controller 40'. These are split into two values in a torque distribution device 50 ', in braking torque engagement on the drive wheels 60' of the motor vehicle, thereby decelerating the drive wheels and a target engine torque 80 'indicative of the desired output torque of the motor. These values are used to control the brakes and to control the output torque of the motor.

By means of the described method, the drive wheels, in particular during acceleration or during starting, are controlled in such a way that the drive wheels do not spin. Spinning the drive wheels would lead to a reduction in vehicle stability, in particular to a reduction in directional stability. The braking interventions on the drive wheels are typically implemented on a wheel-specific basis.

In continuously variable transmissions, which have a limited control range of the translation, situations may occur in acceleration or starting under unfavorable circumstances, in which the engine control is too slow due to the inertia of the engine to reduce the torque applied to the wheels fast enough. Thus, under unfavorable circumstances, situations may occur in which a reduction or adjustment of the torque to the drive wheels is made too slow, which can lead under very unfavorable circumstances to a wheel spin and a reduction in vehicle stability.

Disclosure of the invention

Advantages of the invention

Embodiments of the present invention may advantageously enable a rapid adjustment of the torque applied to drive wheels of a motor vehicle to a desired torque, thereby substantially preventing the drive wheels from spinning.

According to a first aspect of the invention, a method for traction control of drive wheels of a motor vehicle is proposed, wherein the motor vehicle has a motor for driving the drive wheels of the motor vehicle,
a continuously variable transmission with a limited control range of a ratio (CVT), wherein an input of the transmission is connected to the engine, and drive wheels, wherein the drive wheels are connected to an output of the transmission comprises, wherein the transmission of the transmission to reduce a torque one or more of the drive wheels is changed so that a spin of one or more of the drive wheels is prevented.

One advantage of this is that in a motor vehicle having a continuously variable transmission with a limited control range of a ratio that is interposed between the engine and the drive wheels, a very rapid adjustment of the torque applied to the drive wheels typically allows for a desired torque. In particular, the torque applied to the drive wheels can usually be reduced very quickly. As a result, spinning of the drive wheels is typically substantially prevented. Consequently, there is usually an increased traction and increased vehicle stability, in particular a higher directional stability. In addition, a faster acceleration of the motor vehicle is usually possible.

According to a second aspect of the invention, there is provided a traction control apparatus for traction control of drive wheels of a motor vehicle, the motor vehicle including a motor for driving the drive wheels of the motor vehicle, a continuously variable transmission with a limited control range (CVT), an input of the transmission with the motor Drive wheels, wherein the drive wheels are connected to an output of the transmission, wherein the traction control device for varying the ratio of the transmission to reduce a torque on one or more of the drive wheels such, that a spinning of one or more of the drive wheels is prevented is formed.

One advantage of this is that in a motor vehicle having a continuously variable transmission with a limited control range of a ratio that is interposed between the engine and the drive wheels, a very rapid adjustment of the torque applied to the drive wheels typically allows for a desired torque. In particular, the torque applied to the drive wheels can usually be reduced very quickly. As a result, spinning of the drive wheels is typically substantially prevented. Consequently, there is usually an increased traction and increased vehicle stability, in particular a higher directional stability. In addition, a faster acceleration of the motor vehicle is usually possible.

Ideas for embodiments of the present invention may be considered, inter alia, as being based on the thoughts and findings described below.

According to one embodiment, the method further comprises the steps of: determining a torque command, wherein the torque command is a desired torque on one or more of the drive wheels; Dividing the torque command into a target engine torque and a target transmission torque, wherein the engine torque command is a desired output torque of the engine, and wherein the transmission target torque is a target output torque of the transmission; Controlling the output torque of the engine to achieve the engine torque specification; and regulating the ratio of the transmission to achieve the transmission torque specification. One advantage of this is that, technically speaking, the torque present at the drive wheels or the drive wheel can usually be adapted to the desired torque specification in a technically simple manner. As a result of the division or splitting of the desired torque input into a desired engine torque input and a desired transmission torque specification, the torque can generally be reduced very rapidly, since the inertia of the transmission is less than the mass inertia of the engine. In addition, as a rule, the output torque of the engine must be reduced less. This usually leads to a more efficient use of the engine or the engine power. Also fuel is usually saved here.

According to one embodiment, a mass moment of inertia of the transmission is further estimated as the output torque of the engine is decreased for different speeds of the engine, taking into account the mass moment of inertia in splitting the torque setpoint into a desired engine torque setpoint and a desired transmission torque setpoint. As a result, the torque setpoint can typically be reached even faster. As a result, the torque on the drive wheels can usually be reduced even faster.

According to one embodiment, the ratio of the transmission to reduce the torque on the drive wheels is reduced such that the speed of the motor is increased. As a result, an even faster reduction of the torque is usually achieved at the drive wheels.

According to one embodiment, a PID controller is used in regulating the output torque of the motor and / or regulating the ratio of the transmission. As a result, typically a particularly rapid adaptation or regulation of the torque applied to the drive wheels or the drive wheel to the torque setpoint can be made. This usually leads to even better directional stability and a faster acceleration of the motor vehicle.

According to one embodiment, the method further comprises the step of: reducing a rotational speed of one or more of the drive wheels by a brake to prevent the spinning of one or more of the drive wheels. By actively braking the rotation of one or more drive wheels, spinning of one or more of the drive wheels can be prevented more effectively, as a rule. This generally increases the vehicle stability, in particular the directional stability of the motor vehicle.

According to one embodiment, the traction control device further comprises torque command means - for determining a torque command, wherein the torque command is a target torque on the drive wheels, and - for dividing the torque command in a target engine torque and a target transmission torque, wherein the target engine torque is a target output torque of the engine, and wherein the transmission target torque is a desired output torque of the transmission. One advantage of this is that, technically speaking, the torque present at the drive wheels or the drive wheel can usually be adapted to the desired torque specification in a technically simple manner. As a result of the division or splitting of the desired torque input into a desired engine torque input and a desired transmission torque specification, the torque can generally be reduced very rapidly, since the mass inertia of the transmission is less than the mass inertia of the transmission Engine. In addition, as a rule, the output torque of the engine must be reduced less. This usually leads to a more efficient use of the engine or the engine power.

According to one embodiment, the traction control device further comprises at least one PID controller for controlling the output torque of the engine to achieve the engine target torque setting and / or to control the ratio of the transmission to achieve the transmission target torque. As a result, typically a particularly rapid adaptation or regulation of the torque applied to the drive wheels or the drive wheel to the torque setpoint can be made. This usually leads to even better directional stability and a faster acceleration of the motor vehicle.

According to one embodiment, the traction control device further comprises a moment of inertia estimating device for estimating the mass moment of inertia of the transmission with a reduction in the output torque of the motor for different speeds of the engine, taking into account the moment of inertia in dividing the torque command by the torque command device into a target engine torque and a desired transmission torque. As a result, the desired torque specification can typically be determined even more precisely. As a result, the torque on the drive wheels can usually be reduced even faster.

It should be understood that some of the possible features and advantages of the invention are described herein with reference to different embodiments. A person skilled in the art will recognize that the features can be suitably combined, adapted or replaced in order to arrive at further embodiments of the invention.

list of figures

• 1 zeigt eine Ausführungsform der erfindungsgemäßen Antriebsschlupfregelungsvorrichtung; und
• 2 zeigt eine Antriebsschlupfregelungsvorrichtung gemäß dem Stand der Technik.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the drawings nor the description are to be construed as limiting the invention.

• 1 shows an embodiment of the traction control device according to the invention; and
• 2 shows a traction control device according to the prior art.

The figures are only schematic and not to scale. Like reference numerals designate the same or equivalent features in the figures.

Embodiments of the invention

1 shows an embodiment of the traction control device according to the invention for traction control of drive wheels in a motor vehicle.

The motor vehicle has a motor for driving the drive wheels of the motor vehicle. The number of drive wheels may be two, three, four, five or more than five. The motor or the output of the motor is connected to a continuously variable transmission with a limited control range of a translation. The translation of the transmission is thus regulated or changeable only a limited range.

The continuously variable transmission is a so-called continuously variable transmission (CVT). The output of the gearbox is connected to the drive wheels.

The motor vehicle has a traction control device which, when accelerating and / or starting, ensures that the wheels or drive wheels do not essentially spin. Wheel spin is prevented when there is wheel slip of about 10% to 20%. At this value, the coefficient of adhesion on dry roads is at its maximum. That is, the circumferential forces transmitted from the drive wheels reach their maximum at this value of wheel slip.

In the process become leaders 5 from a transverse dynamics controller in a setpoint determination or setpoint determination device 10 entered. The setpoint determination or setpoint determination device 10 determines the setpoints of the lateral dynamics. In addition, in an operating condition determination device 20 a determination of the operating state of the drive wheels or of the motor vehicle is performed. The resulting values become a PID wheel speed controller 30 or a PI cross-lock controller 40 supplied or entered into this.

The two results or outputs of the PID wheel speed controller 30 and the PI cross-lock controller 40 become in a torque distribution device 50 input, which is a distribution or division into a braking torque intervention 60 on one or more of the drive wheels, and in a torque to be applied by the motor to the drive wheels, divides. The torque to be applied to the drive wheels by the motor is the torque command 75 ,

The torque setpoint 75 is through a coordinator facility 70 split or split into two values. The coordinator facility 70 shares the torque command 75 in a motor setpoint torque 80 and a transmission target torque 90 on. The motor setpoint torque 80 is the desired torque (setpoint torque) at the output of the motor, ie at the input of the gearbox. The transmission torque specification 90 is the target output torque (target torque) of the transmission, ie the torque applied to the wheels. According to the motor setpoint torque 80 and the torque command 75 now the rotational speed of the motor is controlled, in particular reduced, and the ratio of the continuously variable transmission changed.

In contrast to the prior art, therefore, not only the torque or the output torque of the engine is changed in the present inventive method for changing the torque of the drive wheels, in particular reduced, but it is simultaneously changed the ratio of the continuously variable transmission.

The motor has a relatively high mass inertia or a relatively high mass moment of inertia. Thus, the output torque of the engine can be changed only slowly. By changing the ratio of the continuously variable transmission (and simultaneously changing the output torque of the engine), the output torque of the transmission is rapidly reduced. Consequently, the torque applied to the drive wheels or the drive wheel, is rapidly reduced, whereby the torque applied to the wheels quickly to the desired value (torque command 75 ) can be adjusted or regulated.

As a result, spinning of the drive wheels is substantially reduced or even prevented.

The traction control device may include a mass moment of inertia estimating device for estimating the mass moment of inertia of the transmission as the output torque of the motor is reduced for different speeds of rotation of the motor. The moment of inertia becomes when dividing the torque setpoint 75 by the torque setpointing means into a motor setpoint torque 80 and a transmission target torque 90 considered. The moment of inertia-estimating device may estimate or calculate the mass moments of inertia of the transmission depending on the reduction of the output torque of the engine at different speeds of the engine. This estimate serves as the basis for the amount of transmission torque specification 90 ,

The torque target setting device may be the torque distribution device 50 and the coordinator facility 70 include. The torque distribution device 50 and the coordinator facility 70 may constitute the torque command means.

In a rapid change in the ratio of the transmission, the torque applied to the drive wheel (s) is rapidly reduced by the continuous mechanical connection of the transmission to the engine. At the same time, this leads to an increase in the speed of the motor, since less load is applied to this.

When changing the gear ratio, the reduction of the transmission is made even smaller / smaller or further reduced.

Dependent on the motor setpoint torque 80 and the gear setpoint torque 90 the gear ratio is changed.

The interventions of the traction control in the engine and in the transmission, that is, the distribution of the torque target specification 75 in a motor setpoint torque 80 and a transmission target torque 90 , depend on the particular vehicle or engine. This is taken into account accordingly in the calculation or regulation.

The splitting of the torque setpoint 75 in a motor setpoint torque 80 and a transmission target torque 90 may be performed by a torque target setting means of the traction control device. The traction control device may include one or more PID controllers. The PID controllers are designed to control the output torque of the motor and / or to control the transmission ratio.

Finally, it should be noted that terms such as "comprising," "comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude. Reference signs in the claims are not to be considered as limiting.

Claims (10)

A method for traction control of drive wheels of a motor vehicle, wherein the motor vehicle a motor for driving the drive wheels of the motor vehicle, a continuously variable transmission with a limited control range of a ratio (CVT), wherein an input of the transmission is connected to the engine, and drive wheels, wherein the drive wheels are connected to an output of the transmission, characterized characterized in that the gear ratio for reducing a torque on one or more of the drive wheels is changed such that spinning of one or more of the drive wheels is prevented. Method according to Claim 1 , further comprising the steps of: determining a torque command (75), wherein the torque command (75) is a desired torque on one or more of the drive wheels; Dividing the torque command (75) into a target engine torque (80) and a desired transmission torque (90), wherein the target engine torque (80) is a desired output torque of the engine, and wherein the desired transmission torque (90) is a desired output torque of the transmission; Controlling the output torque of the engine to achieve the engine torque specification (80); and regulating the ratio of the transmission to achieve the transmission torque setpoint (90). Method according to Claim 1 or 2 and further, estimating a moment of inertia of the transmission as the output torque of the motor is reduced for different speeds of the motor, taking into account the mass moment of inertia in splitting the torque command (75) into a target engine torque (80) and a desired transmission torque (90). Method according to one of the preceding claims, wherein the ratio of the transmission to reduce the torque on the drive wheels is reduced so that the rotational speed of the motor is increased. Method according to one of the preceding claims, wherein a PID controller is used in the regulation of the output torque of the motor and / or the rules of the transmission ratio. Method according to one of the preceding claims, further comprising the following step: Reducing a rotational speed of one or more of the drive wheels by a brake to prevent the spinning of one or more of the drive wheels. A traction control device for traction control of drive wheels of a motor vehicle, wherein the motor vehicle is a motor for driving the drive wheels of the motor vehicle, a continuously variable transmission with a limited control range of a ratio (CVT), wherein an input of the transmission is connected to the engine, and Driving wheels, wherein the drive wheels are connected to an output of the transmission, includes, wherein the traction control device is configured to vary the ratio of the transmission to reduce torque on one or more of the drive wheels to prevent spinning of one or more of the drive wheels. Traction control device according to Claim 7 further comprising torque command means - for determining a torque command (75), said torque command (75) being a target torque at said drive wheels, and - dividing said torque command (75) into a target engine torque (80) and a target transmission torque (90) wherein the engine torque command (80) is a desired output torque of the engine, and wherein the transmission command torque (90) is a desired output torque of the transmission. Traction control device according to Claim 7 or 8th and further comprising at least one PID controller for controlling the output torque of the engine to achieve the engine setpoint torque (80) and / or for controlling the ratio of the transmission to achieve the transmission setpoint torque (90). Traction control device according to one of Claims 7 - 9 further comprising an inertia moment estimator for estimating the mass moment of inertia of the transmission as the output torque of the engine is reduced for different speeds of the engine, the mass moment of inertia in dividing the torque command (75) by the torque command input into a desired engine torque (80) and a desired transmission torque (90). is taken into account.

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