DE102010021352B4 - Drive device for a motor vehicle - Google Patents

Abstract

Drive device for a motor vehicle, comprising at least two electric machines (EM1 to EM4) driving the vehicle wheels (2, 3, 5, 6) of a vehicle axle (1, 4) and a control device (7) in which a torque calculation unit (14) acts on a driver-side default (MS) a target drive torque (M1 to M4) calculated and a corresponding control signal to the electric machines (EM1 to EM4) passes, the calculated target drive torque (M1 to M4) by means of at least one vehicle dynamics control device (28 to 31) the current driving situation is adaptable, wherein between the torque calculation unit (14) and the electric machines (EM1 to EM4) with the vehicle dynamics control device (28 to 31) signal technically coupled coordination module (17, 18) is connected, in which the desired drive torque (M1 to M4) is adaptable as a function of a driving dynamic parameter transmitted by the driving dynamics control device (28 to 31), and the coordination module (17, 18) for each electric machine (EM1 to EM4) has a processing line (20 to 23) having a number of coordination members (24 to 27), each with different driving dynamics control devices (28 to 31) can be signaled technically coupled, characterized in that one in the signal flow direction first coordination element (24) is a multiplication element, in which a compensation factor (k) determined by the associated vehicle dynamics control device (28) can be multiplied by the desired drive torques (M1 to M4), with which adjustment factor (k) a torque directed about a vehicle vertical axis can be compensated, which results in a straight-ahead driving of the vehicle due to manufacturing and / or component tolerances of the electric machines (EM1 to EM4), and that in the signal flow direction second coordination member (25) of the processing line (20 to 23) with a control device (29 ), which is used to influence the yaw rate or yaw rate of the Kra On the basis of vehicle dynamics parameters, the vehicle torque added to the desired drive torque (M1 to M4) is a moment difference.

Description

The invention relates to a drive device for a motor vehicle according to the preamble of claim 1 and a method for operating the motor vehicle according to claim 11.

Modern motor vehicles are equipped with a variety of driver assistance systems. Examples include slip control, braking and driving stability systems, with the help of which the driver can control his vehicle safely even in critical driving situations.

From the DE 40 11 291 A1 a drive device for a motor vehicle is known, which has both on the front axle and on the rear axle in each case two electric machines, each of which drives a vehicle wheel. The electric machines can be controlled by means of an electronic control device, which determines a target drive torque in response to a driver request. The target drive torque is adjusted as a function of driving dynamics parameters generated in a vehicle dynamics control device, wherein a corresponding control signal is passed to each of the electric machines. Each control intervention of the vehicle dynamics control can make it necessary to adapt the target drive torque generated for the electric machines.

In vehicle production, different vehicle variants, each with different scopes, can be equipped with safety / driving dynamics functions. For this purpose, the central control device of the motor vehicle is technically complex to adapt depending on the desired range of functions.

From the DE 10 2007 017 821 A1 is a generic drive device for a vehicle with single-wheel drive known. The torque input is carried out by the driver, is distributed to the individual wheels and then adjusted by a differential controller to the respective driving situation. Furthermore, the regulation of each individual electric wheel drive components for steering assistance and slip compensation. From the DE 10 2008 053 113 A1 and from the DE 198 26 452 A1 In each case, a drive device is known in which a correction value is generated in order to equalize the different power consumption of two identical drives. By this measure manufacturing tolerances should be compensated. From the DE 41 33 060 C2 a drive arrangement for a motor vehicle is known, in which a yaw moment about the vertical axis of the vehicle is impressed on the vehicle by means of a suitable division of the drive torques on the wheels located on opposite sides of the vehicle longitudinal axis.

The object of the invention is to provide a drive device for a motor vehicle and a method for operating a motor vehicle, in which the electronic control device can be used in a simple manner for varying safety and driving dynamics function ranges of different vehicles.

The object is solved by the features of claim 1 or claim 11. Preferred embodiments of the invention are disclosed in the subclaims.

According to the characterizing part of patent claim 1, a coordination module is connected between the torque calculation unit of the electronic control device, which calculates a drive desired torque for the at least two electric machines, and the electric machines. The coordination module can be signal-technically coupled to the at least one vehicle dynamics control device, so that the control signal directed to the electric machine can be adjusted as a function of a vehicle-dynamics parameter transmitted by the vehicle dynamics control.

According to the invention, therefore, in the torque calculation unit "static", ie independent of the current driving situation, a desired drive torque is calculated for each electric machine. Subsequently, the statically calculated desired drive torque in the downstream coordination module is adapted driving dynamics. Changes in the functional scope of the driving dynamics control interventions are therefore made in the coordination module, without any structural changes in the static torque calculation unit. In the event that the vehicle dynamics control device associated with the coordination module is not included in the vehicle equipment, the control signal determined in the torque calculation unit is forwarded unprocessed to the electric machine.

The coordination module has a separate processing line for each electric machine, in which a number of coordination elements are connected. These can each be signal-technically coupled with different driving dynamics control devices, such as a slip control system, a braking system and / or a driving stability system.

For a simple signal processing, it is preferable if the coordination elements in each processing strand of the coordination module are connected in series in a signal line. The different driving dynamics control interventions can therefore be in a predetermined order Consideration in the adaptation of the guided to the respective electric machine control signal.

The drive device has at least two electric machines which each drive a vehicle wheel or a vehicle axle. However, the invention is also executable in a four-wheel drive, in which each vehicle wheel is assigned as an individual wheel each having an electric machine. In this case, four processing lines are led to the electric machines. Each of the four processing strands can preferably have an identical configuration of coordination elements.

However, the equipped with the total of four processing lines coordination module can also be used in less four electric machines. In this case, the processing lines not required for the signal processing are shut down.

As a coordination element for the signal processing, an addition element can be used in which a torque value determined by the associated vehicle dynamics control device is added to the control signal, that is to say the desired drive torque. Alternatively, the coordination member may be a multiplier in which a factor determined by the associated vehicle dynamics control means may be multiplied by the control signal.

For a reliable driving dynamics control, the calculation sequence in the adaptation of the control signal in the signal flow direction of great importance. Against this background, according to the invention, a first coordination element of the respective processing line in the signal flow direction can be coupled to a first control device, which determines its own adjustment factor on the basis of vehicle dynamics parameters for each electric machine. With the adjustment factor, a torque formed around a vehicle vertical axis can be compensated for, which results from the manufacturing and / or component tolerances of the electric machines during a straight-ahead travel of the vehicle.

A subsequent second coordination member according to the invention is coupled to a control device with which a yaw angle or a yaw rate of the motor vehicle can be influenced during cornering. The control device can determine a moment difference on the basis of vehicle dynamics parameters, which is added to the control signal in the second coordination element.

A third coordination element in the signal flow direction may be coupled to a brake control device. This determines to control a vehicle deceleration a torque difference that can be added to the control signal in the third coordination element. With the aid of the brake control device, the total deceleration of the motor vehicle from deceleration components of the friction brakes and the electric machines operating as generators can be combined during braking.

A subsequent fourth coordination element may be coupled to a further control device, which determines a torque difference for controlling a motor drag torque or for traction control, which torque can be added to the control signal in the fourth coordination element.

If the drive device has at least two electric machines in each case for the front axle and for the rear axle drive, the torque calculation unit can have a torque distribution module. By means of the torque distribution module, the vehicle drive torque can be divided into a desired torque for the rear axle and a desired torque for the front axle. Preferably, a load impact damping unit can be connected between the torque distribution module and the coordination module, which processes the rear axle and / or the front axle drive torques for damping load impacts when a load shock hazard is detected.

Hereinafter, an embodiment of the invention with reference to the accompanying figures will be described.

Show it:

1 in a rough schematic view of a drive device of a motor vehicle; and

2 the electronic control device of the motor vehicle in a simplified block diagram.

In the 1 is shown in a schematic representation of the drive system of an electric vehicle, which is provided with an all-wheel drive. At the front vehicle axle 1 two electric machines EM1, EM2 are arranged, which via a gear stage, not shown, the front left and right vehicle wheels 2 and 3 drive. The same applies to the rear axle of the vehicle 4 two electric machines EM3, EM4 arranged, each the left and right rear wheels 5 . 6 drive. Like from the 1 As can be seen, the electric machines are used as individual wheel drives.

That in the 1 shown motor vehicle has to control the electric machines EM1 to EM4 a central electronic control device 7 on, according to the 1 via a pedal module 8th recorded a driver request. Depending on the detected driver request and as a function of detected driving dynamics parameters calculated by the controller 7 Target drive torques M ₁ to M ₄ , which are passed as control signals to the electric machines EM1 to EM4.

The control and power supply of the electric machines EM1 to EM4 via power electronics units 9 , For this is every power electronics 9 in signal communication with the electronic control device 7 as well as via supply lines 10 with an accumulator 11 Connection. The accumulator 11 is via a battery control device 13 also from the electronic control device 7 driven.

In the 2 is a block diagram of the signal processing in the electronic control device 7 illustrated. Consequently, the electronic control device 7 a moment calculation unit 14 on. In the moment calculation unit 14 First, a target vehicle drive torque is determined based on the driver's default. The target vehicle drive torque is in a torque distribution unit 15 in a desired torque M _VA for the front axle 1 and in a desired torque M _HA for the rear axle 4 divided up. The two setpoint moments M _VA and M _HA become a filter block 16 passed, which has a low-pass filter and a load impact attenuation member. By way of example, the low-pass filter can be a proportional-time element whose time response is such that a driver-side input-jump function can be smoothed. The low-pass filter is followed in the signal flow direction by the load-beat attenuator. This can impose a reduced moment gradient on the respective nominal moment M _HA and M _{VA in case of} a load impact hazard in order to dampen a load impact.

The so-modulated setpoint moments M _HA and M _VA are in torque distribution blocks 19 halved in a first and second target moment M ₁ , M ₂ for the electric machines EM1 and EM2. Accordingly, the drive torque M _HA for the rear axle 4 halved to the same large desired torques M ₃ and M ₄ .

The corresponding control signals M ₁ to M ₄ are in coordination modules 17 . 18 directed. The structure of the two coordination modules 17 . 18 is equal. This is the assignment of the coordination module 17 in each case two processing strands connected in parallel to each other 20 . 21 and the coordination module 18 also two processing lines each 22 . 23 on. The processing lines 20 to 23 are equipped with mutually parallel partial lines, in each of which the coordination elements 24 to 26 are connected in series. Each of these coordination links 24 to 27 is signal technology with different vehicle dynamics control devices 28 to 31 coupled.

Thus, the first coordination elements in the signal flow direction 24 the coordination modules 17 . 18 with the first control device 28 coupled. On the basis of driving dynamics parameters, such as a yaw rate detected by sensor technology, an acceleration or a rotational speed, this determines a matching factor k for each electric machine. With this adjustment factor k, a directed to a vehicle vertical axis moment can be bleached, resulting in a straight-ahead due to manufacturing and / or component tolerances of the electric machines EM1 and EM2 of the front axle 1 and / or the electric machines EM3 and EM4 at the rear axle 4 results. On the basis of the calculated adjustment factor k, the respective control signal M ₁ to M ₄ can therefore be adapted accordingly so that a torque difference resulting from manufacturing and / or component tolerances is compensated for without the driver having to counter-steer when driving straight ahead. To carry out this calculation step, the first coordination elements 24 executed as multipliers.

The second coordinators 25 the coordination modules 17 . 18 are with a second control device 29 coupled, with the aid of the yaw angle or the yaw rate of the motor vehicle can be influenced. For this purpose, determines the control device 29 for each of the electric machines EM1 to EM4, a moment difference occurring in the respective second coordination elements 25 the associated control signal M ₁ to M ₄ can be added.

In the following third coordination elements 26 can also be added to the guided to the electric machines target torque M ₁ to M ₄ , a torque difference, which from a brake control device 30 is determined. With the aid of the brake control device, the deceleration component of the friction brakes and the deceleration component of the electric machines EM1 to EM4 which can be operated as a generator are determined during a braking process and a torque difference is determined correspondingly in the third coordination elements 26 the respective control signal M ₁ to M ₄ is added.

The following fourth coordination links 27 are in contrast with a control device 31 connected, with the help of a motor drag torque or a drive slip can be monitored. That is, in the control device 31 for each of the four electric machines EM1 to EM4 a moment difference is determined and in the corresponding fourth coordination elements 27 is added to the respective control signal M ₁ to M ₄ .

The through the first to fourth coordination links 24 to 27 Guided control signals M ₁ to M ₄ are then from the two coordination modules 17 . 18 to the power electronics components 9 the electric machines EM1 to EM4 forwarded.

Claims (11)

Drive device for a motor vehicle, with at least two, the vehicle wheels ( 2 . 3 . 5 . 6 ) of a vehicle axle ( 1 . 4 ) driving electrical machines (EM1 to EM4) and a control device ( 7 ) in which a moment calculation unit ( 14 ) to a driver-side specification (M _S ) calculates a desired drive torque (M ₁ to M ₄ ) and a corresponding control signal to the electric machines (EM1 to EM4) passes, wherein the calculated target drive torque (M ₁ to M ₄ ) by means of at least a vehicle dynamics control device ( 28 to 31 ) is adaptable to the current driving situation, wherein between the torque calculation unit ( 14 ) and the electric machines (EM1 to EM4) with the driving dynamics control device ( 28 to 31 ) signaling-coupled coordination module ( 17 . 18 ) is switched, in which the desired drive torque (M ₁ to M ₄ ) in dependence on a of the vehicle dynamics control device ( 28 to 31 ) is adaptable and the coordination module ( 17 . 18 ) for each electric machine (EM1 to EM4) a processing strand ( 20 to 23 ) having a number of coordination members ( 24 to 27 ), each with different vehicle dynamics control devices ( 28 to 31 ) can be signal-technically coupled, characterized in that a first coordination element in the signal flow direction ( 24 ) is a multiplier in which a vehicle dynamics control device ( 28 ) compensated factor (k) with the desired drive torque (M ₁ to M ₄ ) can be multiplied, with which adjustment factor (k) a directed to a vehicle vertical axis torque is compensated, resulting in a straight-ahead driving of the vehicle due to manufacturing and / or Component tolerances of the electrical machines (EM1 to EM4) yields, and that in the signal flow direction second coordination member ( 25 ) of the processing strand ( 20 to 23 ) with a control device ( 29 ) can be coupled, which adds to the desired drive torque (M ₁ to M ₄ ) a torque difference to influence the yaw rate or the yaw rate of the motor vehicle on the basis of vehicle dynamics parameters. Drive device according to claim 1, characterized in that the coordination members ( 24 to 27 ) of the processing strand ( 20 to 23 ) of the coordination module ( 17 . 18 ) in one between the torque calculation unit ( 14 ) and the electric machine (EM1 to EM4) extending signal line are connected in series. Drive device according to claim 1 or 2, characterized in that each vehicle wheel ( 2 . 3 . 5 . 6 ) is associated with an electric machine (EM1 to EM4). Drive device according to claim 3, characterized in that the coordination module ( 17 . 18 ) for each electric machine (EM1 to EM4) identical processing lines ( 20 to 23 ) having. Drive device according to one of the preceding claims, characterized in that the coordination member ( 25 to 27 ) is an addition member, in which one of the associated driving dynamics control device ( 29 to 31 ) determined torque value is added to the desired drive torque (M ₁ to M ₄ ). Drive device according to one of the preceding claims, characterized in that a third in the signal flow direction coordination member ( 26 ) of the processing strand ( 20 to 23 ) with a brake control device ( 30 ), which determines a moment difference for controlling a vehicle deceleration, which in the third coordination element ( 26 ) can be added to the desired drive torque (M ₁ to M ₄ ). Drive device according to one of the preceding claims, characterized in that a fourth in the signal flow direction coordination member ( 27 ) of the processing strand ( 20 to 23 ) with a control device ( 31 ), which determines a torque difference for controlling an engine drag torque or traction control, which in the fourth coordination element ( 27 ) can be added to the desired drive torque (M ₁ to M ₄ ). Drive device according to one of the preceding claims, characterized in that the torque calculation unit ( 14 ) a torque distribution module ( 15 ), by means of which a vehicle drive torque (M _S ) in each case a drive torque (M _VA , M _HA ) for the rear axle ( 4 ) and for the front axle ( 1 ) is divisible. Drive device according to claim 8, characterized in that the Hinterachs- and Vorderachs drive torques (M _VA , M _HA ) to a filter module ( 16 ) are feasible, in which at a torque jump, the respective drive torque (M _VA , M _HA ) is smoothed and / or at Lastschlag- risk the Hinterachs- and / or Vorderachsantriebsmomente (M _VA , M _HA ) are processed to dampen load impacts. Drive device according to claim 8 or 9, characterized in that the Hinterachs- and Vorderachs drive torques (M _VA , M _HA ) in one Torque distributor module ( 19 ) are divided into the desired drive torques (M ₁ to M ₄ ) for the electric machine (EM1 to EM4). Method for operating a motor vehicle with a device according to one of the preceding claims.

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