DE102018130051B4 - Control device for a vehicle - Google Patents

Abstract

Control device (12) for a vehicle (10) with at least one motor (30) for driving wheels (44), to which control device (12) a first signal (M_D) and a second signal (ω ') can be fed, which first signal (M_D) characterizes a desired torque and which second signal (ω ') characterizes the angular acceleration of the wheels, which control device (12) is set up to output a third signal (M_S) which is a setpoint value for a torque of the at least one motor ( 30), which control device (12) is designed to determine a transient area (85; 85A, 85B, 85C) as a function of the second signal (ω ') in which transient area (85; 85A, 85B, 85C) a change from a pulling mode (83) to a pushing mode (81) or a change from a pushing mode (81) to a pulling mode (83) is expected, which control device (12) is designed to send the third signal (M_S) influence if that corresponds to the third signal (M_S) prechende torque in the transient area (85; 85A, 85B, 85C) to reduce the jerking during such a change in the transient area (85; 85A, 85B, 85C), which control device is designed to control the transient area (85; 85A, 85B, 85C) with a lower limit (TA_LOW) and an upper limit (TA_HIGH), and which control device is set up to set both the lower limit (TA_LOW) and the upper limit (TA_HIGH) of the transient range (85; 85A, 85B, 85C ) to change depending on the second signal (ω ').

Description

The invention relates to a control device for a vehicle, in particular for a vehicle with at least one motor for driving wheels.

In modern engine control units, the accelerator pedal position is viewed as the torque requested by the driver and used as a reference variable. In addition to the torque requested by the driver, further requirements are placed on the engine management system by the transmission, auxiliary consumers, cruise control, driver assistance systems or operating conditions such as idling and catalyst temperature. All requirements are bundled in the torque requirement and used as an input variable for the torque structure. The torque structure coordinates and prioritizes the various requirements depending on the operating state of the combustion engine and converts them into target torques. In the torque conversion, these setpoint torques are converted, for example, as a reference variable for the relative air mass, the combustion air ratio lambda, the ignition angle and the cylinder suppression. In the case of electric motors or hybrid drives, too, a torque requested by the driver can serve as the basis for engine control.

The DE 20 2011 104 781 U1 shows a device for operating a drive unit of a motor vehicle, wherein a target torque for driving the drive unit is determined as a function of a torque requested by the driver and an idling control torque is included in the driver's request torque to determine the target torque and a driveability filter is used for torque smoothing

The DE 43 21 333 A1 shows a device for controlling a drive unit of a vehicle, in which during the transition from the overrun phase to the traction phase, the execution of the driver's request to adjust the engine power is delayed, with vibrations and jerking in the transition from overrun to traction operation are avoided. The driver's request is specified via the position of an accelerator pedal and detected via a measuring device. A wheel speed of the driven wheel is detected. A frictional connection is detected based on the wheel speed of a driven wheel and the engine speed.

The DE 11 2008 001 208 T5 shows a control device for a vehicle drive unit with a target output torque setting device for setting a target output torque of the vehicle drive unit.

The DE 10 2004 005 728 A1 shows a device for controlling an output unit of a vehicle. The DE 10 2012 004 432 A1 shows a device for driver evaluation. The DE 10 2008 041 693 A1 shows a method for driving a hybrid vehicle during a load change.

It is an object of the invention to provide a new control device for a vehicle.

This object is achieved by the subject matter of claim 1.

A control device for a vehicle with at least one motor for driving wheels is a first signal M_D and a second signal ω 'can be supplied, which first signal M_D characterizes a desired torque and which second signal ω 'characterizes the angular acceleration of the wheels. The control device is designed to output a third signal, which is a setpoint value for a torque of the at least one motor, and the control device is designed to determine a transient range as a function of the second signal ω ′, in which transient range a A change from a pulling operation to a pushing operation or a change from a pushing operation to a pulling operation is expected at the third signal M_S to influence if that's the third signal M_S corresponding torque reaches the transient range in order to reduce the jerking during such a change in the transient range.

By determining the transient range as a function of the angular acceleration, the change between pushing operation and pulling operation can be better predicted. On the one hand, this enables a better reduction of the jerking in the transient area, and a false assumption that the vehicle is in the transient area can be avoided. This enables greater dynamics outside the transient area.

According to a preferred embodiment, the control device is designed to shift the transient area relative to a first transient area, which is assigned to an angular acceleration of zero, depending on the sign of the angular acceleration in different directions. If the angular acceleration is positive, the transient area is shifted in a different direction than if the angular acceleration is negative. This allows the transient range to be specified as a function of the torque balance.

According to a preferred embodiment, the control device is set up to shift the transient range with the same sign of the second signal ω ′, the greater the shift The amount of angular acceleration. The transient area thus follows the amount of the angular acceleration. This enables a qualitatively good prediction of the transient area.

According to a preferred embodiment, the control device is designed to generate the third signal M_S to influence by the gradient of the third signal M_S is limited in the transient area to a first maximum gradient applicable to the transient area. The limitation of the torque gradient reduces an excessive increase in the torque in the transient area and thereby reduces the jerking.

According to a preferred embodiment, the first maximum gradient is dependent on the first signal M_D . This dependency allows the first maximum gradient within the transient range as a function of the first signal M_D can be specified.

According to a preferred embodiment, the control device is designed to limit the gradient of the third signal outside of the transient area to a second maximum gradient that applies outside of the transient area, which second maximum gradient is at least in areas greater than the first maximum gradient in order to To enable greater acceleration than in the transient area. It is also advantageous to limit the target torque gradient outside the transient range in order to suppress vibrations. However, this limitation can be significantly more generous than within the transient range, so a higher dynamic is possible.

According to a preferred embodiment, the control device is designed to determine a setpoint value for the torque as a function of the first signal in a first step, and to change the setpoint value at least regionally as a function of the transient range, in particular to reduce its change.

The control device is designed to provide a transient range with a lower limit and an upper limit. By providing the two limits, the transient range can be clearly defined. For example, the limits can be specified as corresponding values, or a first point of the transient region can be defined and the lower and upper limits can be defined as the distance from this first point.

The control device is set up to change both the lower limit and the upper limit of the transient range as a function of the second signal ω '. This enables a precise definition of the transient area.

According to a preferred embodiment, the control device is designed not to change the distance between the lower limit and the upper limit of the transient range in the event of a shift. This facilitates the calculations within the transient area. However, if the required distance is physically widened at certain angular accelerations, this can also be mapped.

According to a preferred embodiment, the control device is designed to influence the third signal in a first step as a function of the first signal M_D Calculate a first intermediate value for the change in the target torque and, in a second step, determine a second intermediate value by multiplying the first intermediate value by a factor or by reducing the first intermediate value by a predetermined value, and then the third signal M_S to be determined depending on the second intermediate value. These calculations can reduce the change, and this can reduce the jerk in the transient area.

• 1 in schematischer Darstellung ein Fahrzeug mit einer Drehmomentübertragungsvorrichtung zwischen einer Antriebsseite und einer Abtriebsseite,

Further details and advantageous developments of the invention emerge from the exemplary embodiments described below and shown in the drawings, which are in no way to be understood as a restriction of the invention, as well as from the dependent claims. It goes without saying that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination, but also in other combinations or on their own, without departing from the scope of the present invention. It shows:

• 1 a schematic representation of a vehicle with a torque transmission device between a drive side and an output side,

• 2 a diagram with curves for the target torque, the output speed, the input speed and the longitudinal acceleration of the vehicle,
• 3 a diagram with three transient areas for three vehicle states,
• 4th in a schematic representation a control device for the vehicle of 1 ,
• 5 a flow chart for a shift of the Transient range as a function of the angular acceleration,
• 6th a flowchart with a further exemplary embodiment for a shift of the transient region as a function of the angular acceleration, and
• 7th a flowchart with a general target torque gradient limitation and an additional target torque gradient limitation in the transient area.

1 shows a vehicle 10 in a schematic representation.

A drive side 21st is via a torque transfer device 24 with one output side 22nd connected. The drive side 21st has an engine 30th , which can also be referred to as a torque source. The motor 30th is an example of a drive shaft 32 with a drive-side gear 34 the torque transmitting device 24 connected. The output side 22nd has a gear on the output side 40 , which is an example of an output shaft 42 with wheels 44 is in operative connection. The wheels 44 are exemplary on one axis 46 arranged.

The torque transmission device 24 who exemplified the gears 34 , 40 has, has game. In common drive trains of vehicles 10 are usually one or more torque-transmitting devices 24 provided with play, for example gear with fixed or variable translation or coupling elements between torque sources, such as side shafts or two-mass flywheels.

• - Steigung der Fahrbahn
• - Luftwiderstand
• - Bremsmoment

On the drive side, the torque is generated in particular by the motor 30th specified, whereby torque is also generated as a result of friction. On the output side, for example, the following conditions play a role for the resulting torque:

• - slope of the road
• - air resistance
• - braking torque

The direction of rotation of the gear 34 is by an arrow 35 marked, and the direction of rotation of the gear 40 by an arrow 41 . The gear 34 is driving on the gear 40 on, and this is the case when that's due to the engine 30th generated torque is greater than the torque acting on the output side. There is a torque transfer from the gear 34 on the gear 40 . One speaks of a train operation in which the engine 30th the vehicle 10 pulls.

If the driver releases the accelerator pedal, the engine torque drops 30th . If this is the torque on the drive side 21st is lower than on the output side 22nd , it comes in a first step to an empty play in the torque transmission device 24 where the teeth of the gears 34 , 40 be turned over. During this shifting process, there is little or no torque transmission between the drive side 21st and the output side 22nd . The gear 40 in this case rotates faster than the gearwheel 34 , and the gears 34 , 40 lie against each other on the other flanks of the teeth. This is known as coasting, and the engine 30th is - with a force-fit coupling - through the output side 22nd towed or driven.

Whether a vehicle 10 works in pulling or pushing operation depends on the torque ratio between the drive side 21st and the output side 22nd from. The transition between pulling and pushing is known as the transfer area.

2 shows at a transition from a thrust range 81 via a transfer area 82 to a train area 83 the target torque over time 84 , the output speed 86 on the output side 22nd , the speed on the input side 88 and the resulting longitudinal acceleration 94 of the vehicle 10 .

The transient area 85 denotes a torque range in which a transition takes place from the thrust range to the pull range or vice versa. The target torque 84 is located in the thrust area below the transient area 85 , and the accelerator pedal is not depressed, for example. At a time 96 if the driver presses the accelerator pedal, this increases the engine torque 30th desired. The target torque 84 increases and enters the transient area 85 . In the transient area 85 the target torque increases 84 in the exemplary embodiment with a constant slope until it reaches the upper limit of the transient range 85 got. Then the target torque increases 84 with a larger slope.

The output speed 86 decreases in the thrust range 81 as the vehicle 10 in the exemplary embodiment not, or only slightly, by the engine 30th is driven. The drive speed 88 decreases with the output speed 86 . At the time 90 the vehicle arrives 10 in the transfer area 82 , and there is little or no power transmission through the torque transfer device 24 instead of. The vehicle 10 slows down further, ie the output speed 86 continues to sink. The drive speed 88 on the other hand increases because the engine 30th due to the increased target torque 84 the actual torque and thus also the speed 88 elevated. In the transfer area 82 are the speeds 86 , 88 not coupled because of the play of the gears 34 and 40 via the torque transfer device 24 there is little or no torque transmission. At the time 92 the teeth of the gears are placed 34 , 40 on the opposite flanks to each other, and due to the different speeds 86 , 88 it comes at the time 92 the synchronization leads to a surcharge, which on the one hand leads to a reduction in the speed of the engine 30th and on the other hand to an increase in the output-side speed 86 leads. Depending on the strength of the impact of the teeth of the gears 34 , 40 there is a noise development and a jolt of the vehicle noticeable by the driver. This can also lead to annoying noises. The line 94 shows the longitudinal acceleration, i.e. the derivative of the vehicle speed 10 . Until then 90 there is a negative longitudinal acceleration 94 before since the vehicle by the engine 30th is braked. Between the points in time 90 and 92 there is no influence from the motor on the output side 30th , and, for example, there is no longitudinal acceleration. At the time 92 occurs when the gears hit 34 , 40 a positive acceleration, followed by a negative acceleration, followed by a longitudinal acceleration 94 into a straight line with a constant slope. The oscillation of the longitudinal acceleration 94 after the point in time 92 is perceived as negative by the driver, and about limiting or reducing the slope of the target torque 84 in the transfer area 82 can the oscillation of the longitudinal acceleration 94 after the point in time 92 be reduced.

3 shows the transient range for three different vehicle states 10 .

In condition 101 drives the vehicle 10 exemplary in the plane, and there is no braking. The transient area 85A in which the torque transmission device 24 is shifted is, for example, in the range -5 Nm to 25 Nm.

In the area 102 drives the vehicle 10 for example downhill, or it travels with a strong tailwind. This increases the torque on the output side. Since the transient range depends on the equilibrium between the drive torque and the output torque, the transient range is shifted by one value ΔM102 up. The changed transient area is with 85B and in the exemplary embodiment are both the lower limit and the upper limit of the transient range 85B about the value ΔM102 postponed.

In condition 103 of the vehicle 10 drives the vehicle 10 for example uphill, or braking takes place on the output side. This reduces the torque on the output side by one value ΔM102 causes and the transient area 85C is corresponding to the transient area 85A about the value ΔM102 moved down.

Taking into account the shift in the transient area depending on the condition of the vehicle 10 is advantageous because, for example, in the state 102 with an increase in the target torque from -10 Nm to 0 Nm, the torque transmission device does not transition, and it is therefore possible to drive with high load change dynamics in this area. On the other hand, the area would 85A apply to all states of the vehicle, the slope of the target torque would be limited in the situation described.

In the exemplary embodiment, the transient areas 85A , 85B , 85C a constant width of 30 Nm. The width can, however, also be dependent on the displacement or the torque on the output side and, if necessary, also dependent on further parameters such as the current gear of a transmission or the selected driving program (eg sporty or normal).

4th shows a control device 12th for the vehicle 10 from 1 .

The control device 12th is a first signal M_D via a signal line 74 can be supplied, which characterizes a desired torque. The first signal is an example M_D from an accelerator pedal 73 generated, but it can also (alternatively or exclusively) be generated by a control of an autonomous vehicle.

The control device 12th is a second signal ω 'via a signal line 72 can be supplied, which second signal ω 'the angular acceleration of the wheels 44 characterized. An angular acceleration sensor is used for this 71 in the area of the axis 46 intended. As the angular acceleration of the wheels 44 The characterizing signal, the change in speed over time can also be used. The sensor 71 can alternatively be designed as a rotation angle sensor, and the angular acceleration can be determined by deriving the signal from the rotation angle sensor twice.

The control device 12th determined as a function of the first signal M_D and a third signal from the second signal ω ' M_S , and this is through M_S : = f ( M_D , ω ') clarifies. The third signal M_S is via a signal line 75 to a 'control device 14th issued that the engine 30th depending on the third signal M_S drives to depending on the third signal M_S to generate a corresponding torque. The control device 12th and the control device 14th can collectively be referred to as motor control.

5 FIG. 11 shows a flow chart with a routine for adjusting the transient area 85 . The routine starts in S110 , and there is a jump to S112 . In S112 becomes a value for the angular acceleration α = ω '= dω / dt. and then in S114 the torque ΔM is calculated by multiplying the angular acceleration ω 'by a constant CONST. The angular acceleration is proportional to the speed gradient. In S116 the lower value TA_LOW of the transient area is then calculated by adding the value ΔM to a basic value TA_LOW_0, and the upper value TA_HIGH of the transient area 85 is calculated by adding the value ΔM to the base value TA_HIGH_0. This has the effect of shifting the transient area 85 has taken place and the routine becomes in S118 completed.

In the exemplary embodiment, both the upper value TA_HIGH and the lower value TA_LOW are shifted. It is equally possible to use the transient area 85 by defining a point and moving this point accordingly. The transient area 85 can then be defined by a corresponding area around the point.

mit

M:

auf den Körper einwirkendes Drehmoment

J:

Trägheitsmoment des Körpers

α:

Winkelbeschleunigung des Körpers

The physical relationship between the angular acceleration and the torque results from the formula for a rotatably mounted body $$\text{M.}=\text{J}\cdot \mathrm{\alpha }$$

With

M:

torque acting on the body

J:

Moment of inertia of the body

α:

Angular acceleration of the body

Regardless of whether a torque is caused by an incline in the roadway or by braking or some other mechanical action, this leads to a change in the angular acceleration of the body. The torques acting on the drive train and on the drive train can thus be determined from the change in the angular acceleration.

6th shows a further embodiment for the calculation of the shift of the transient area 85 . In the steps S120 , S122 and S124 the shift .DELTA.M is calculated, as already done for the steps S110 , S112 and S114 from 5 was explained. The calculation of the lower limit TA_LOW and the upper limit TA_HIGH of the transient area 85 takes place in S126 with the help of a respectively assigned function TA_LOW_F (ΔM, G) or T_HIGH_F (ΔM, G). The two functions each have a dependency on the calculated value ΔM and preferably also on the currently engaged gear G. The functions can be applied to the vehicle 10 can be adjusted and allow further effects that may occur in certain areas to be taken into account.

The routine ends in S128.

7th shows an example of a routine for limiting the target torque in the transient range 85 . In a simplified embodiment, the routine contains load impact damping and a torque gradient limitation in the transient range. Other aspects such as the load and torque requirements by the secondary consumers are not taken into account.

In S130 the routine begins and there is a jump to S132 . In S132 become the values M_D determined for the driver's torque request and the current time t. Then in S134 the sign VZ of the change between the desired torque M_D and the old target torque M_OLD is calculated by dividing the difference by the amount of the difference. The target torque M_S is the first step on the torque request M_D set.

In S136 it is checked whether the absolute value of the slope of the target torque is greater than a limit value M_GRAD_MAX. If YES ("Y"), there is a jump to S138 , and the target torque M_S is calculated by multiplying the limit value M_GRAD_MAX with the sign VZ and the time difference (t - t_OLD) in such a way that it has a generally maximum permissible gradient M_GRAD_MAX, which can be selected depending on the respective driving mode. This is a basic function of the load shock absorption function of the motor control. Then there is a jump to S140 . If the result is in S136 Is NO ("N"), the slope is in the permissible range and a jump is made to S140 .

In S140 it is checked whether the old set speed value M_OLD or the current set speed value M_S in the transient area 85 or whether the old set speed value M_OLD is the same as the current set speed value M_S opposite side is located so that the transient area 85 is crossed. If NO, is the slope of the target torque with respect to the transient area 85 uncritical, and there is a jump to S146 . If YES, in S142 a check of the absolute value of the slope of the target torque as in step S136 , with one for the transient area 85 suitable limit value M_GRAD_MAX_TA is used, which is usually smaller than the general limit value M_GRAD_MAX of S138 . With a stronger target torque gradient in the transient area, the transfer area is traversed more quickly, and a more powerful acceleration can be continued more quickly. This is positive for a sporty driving mode. On the other hand, the stronger gradient of the setpoint torque results in a stronger jerk in the synchronization, and a lower maximum gradient of the setpoint torque is advantageous for a comfortable driving mode. If the absolute value of the slope is too large ("Y"), there is a jump to S144 , otherwise ("N") there is a jump to S146 .

In S144 the target torque becomes accordingly S138 increased, but using the gradient value M_GRAD_MAX_TA. The gradient is therefore also in the transient range 85 in a permissible range. Then there is a jump to S146 .

In S146 the newly determined and possibly limited target torque becomes M_S output ("OUTPUT M_S"), and the values M_OLD and t_OLD are saved for the next calculation. The routine in S148 completed.

A wide variety of variations and modifications are of course possible within the scope of the present invention.

In the transient area, for example, instead of limiting the gradient, the desired torque can be set in a first step M_D corresponding slope can be calculated, and this slope can then be reduced by a predetermined factor or by a predetermined value. This procedure can also be coupled with the limitation.

Claims (10)

Control device (12) for a vehicle (10) with at least one motor (30) for driving wheels (44), to which control device (12) a first signal (M_D) and a second signal (ω ') can be fed, which first signal (M_D) characterizes a desired torque and which second signal (ω ') characterizes the angular acceleration of the wheels, which control device (12) is set up to output a third signal (M_S) which is a setpoint value for a torque of the at least one motor ( 30), which control device (12) is designed to determine a transient range (85; 85A, 85B, 85C) as a function of the second signal (ω ') in which transient range (85; 85A, 85B, 85C) a change from a pulling operation (83) to a pushing operation (81) or a change from a pushing operation (81) to a pulling operation (83) is expected, which control device (12) is designed to send the third signal (M_S) influence if that corresponds to the third signal (M_S) Prechende torque in the transient area (85; 85A, 85B, 85C) to reduce the jerking during such a change in the transient area (85; 85A, 85B, 85C), which control device is designed to control the transient area (85; 85A, 85B, 85C) with a lower limit (TA_LOW) and an upper limit (TA_HIGH), and which control device is set up to both the lower limit (TA_LOW) and the upper limit (TA_HIGH) of the transient area (85; 85A, 85B, 85C ) to change depending on the second signal (ω '). Control device (12) after Claim 1 , which is designed to move the transient area (85; 85A, 85B, 85C) relative to a first transient area (85; 85A, 85B, 85C) which is assigned to an angular acceleration of approximately zero, depending on the sign of the angular acceleration to move in different directions. Control device according to Claim 1 or 2 which is set up to shift the transient area (85; 85A, 85B, 85C) with the same sign of the second signal (ω '), the greater the amount of angular acceleration. Control device (12) according to one of the preceding claims, which is designed to influence the third signal (M_S) by setting the gradient of the third signal (M_S) in the transient range (85; 85A, 85B, 85C) to one for the Transient area (85; 85A, 85B, 85C) applicable first maximum gradient (M_GRAD_MAX_TA) is limited. Control device (12) after Claim 4 , at which the first maximum gradient (M_GRAD_MAX_TA) depends on the first signal (M_D). Control device (12) after Claim 4 or 5 which is designed to convert the gradient of the third signal (M_S) outside of the transient area (85; 85A, 85B, 85C) to a second maximum gradient (M_GRAD_MAX) applicable outside of the transient area (85; 85A, 85B, 85C) to limit which second maximum gradient (M_GRAD_MAX) is at least in some areas greater than the first maximum gradient (M_GRAD_MAX_TA) in order to enable greater acceleration outside the transient area (85; 85A, 85B, 85C) than in the transient area. Control device (12) according to one of the preceding claims, which is designed to determine a desired value (M_S) for the torque as a function of the first signal (M_D) in a first step, and which is designed to depend on the transient range to change the setpoint (M_S) at least in areas. Control device (12) after Claim 7 which is designed to reduce the change in the setpoint (M_S) at least in some areas as a function of the transient area. Control device (12) according to one of the preceding claims, which is designed not to change the distance between the lower limit (TA_LOW) and the upper limit (TA_HIGH) of the transient range (85; 85A, 85B, 85C) in the event of a shift . Control device (12) according to one of the preceding claims, which is designed to influence the third signal (M_S) in a first step depending on the first signal (M_D) to calculate a first intermediate value for the change in the target torque and in a second step determine a second intermediate value by multiplying the first intermediate value by a factor or by reducing the first intermediate value by a predetermined value, and then determining the third signal (M_S) as a function of the second intermediate value.

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