DE10135747B4 - Method and device for the electronic control of an automatic powershift transmission - Google Patents

Abstract

Method for the electronic control of an automatic powershift transmission of a motor vehicle during a gear change, whereby suitable status data (actual data) of the drive unit and the vehicle are recorded for the gear change and nominal values for regulators and control values for actuators are formed from this actual data, characterized by the following features : - From the actual data, target values for an optimal gear change are calculated; - These optimal target values are checked to see whether they can be achieved with the existing actual data; if these calculated optimal setpoints can be achieved, they are passed on to the precontrol and controller; - If these calculated optimal setpoints cannot be realized with the existing actual data, realizable substitute setpoints are selected which are close to the calculated setpoints, so that a gear change close to the optimal gear change is possible, after which these substitute setpoints on the pilot control and controller to get redirected.

Description

The invention relates to a method and apparatus for the electronic control of an automatic powershift transmission according to the respective preambles of the independent claims.

Automatic powershift transmissions are used in motor vehicles, especially in trucks and passenger cars, wherein a gear change takes place automatically by an electronic control. The electronic control are several parameters for this purpose, eg. B. status data of the drive unit and other driving data, such. B. Throttle d. H. Gas or accelerator pedal position, program data or the speeds transmitted at the input and output of the transmission. Based on this data then activates the electronic control, for example, via regulators, the individual actuators z. B. on the clutches of the transmission, which are necessary for the gear change.

From the DE-A1 44 42 991 is a method for controlling and regulating one of a drive unit, for. Example, an internal combustion engine-driven automatic transmission with an electronic control unit, in which are controlled due to input variables in a gear change, ie generally a change in the transmission ratio, via electromagnetic actuators clutches or brakes of the automatic transmission. In this case, two clutches are used, wherein a faulty engagement of the second clutch is detected when the transmission input speed during a load transfer phase exceeds a threshold. In such a case, the sequence control is aborted and a control phase of the first disconnecting clutch is started.

From the DE-A1 198 56 326 Also, a method for controlling an engine-driven automatic transmission is described, again two clutches are used and the electronic control via electromagnetic valves controls the pressure curve of the first and the second clutch during the switching operation. Within the individual circuit phases, in particular the Lastübernahme-, the Gradienteinstell-, the sliding, the Gradientabbau- and the closing phase, an engine intervention takes place, wherein an engine torque signal and / or a characteristic determining this is transmitted from the control unit to an engine control unit of the engine.

In the prior art, therefore, a gear change takes place by an electronic control, which controls the various actuators for setting individual sizes substantially without causal coupling. This concerns z. As the engine controller, the converter clutch controller and the switching sequence control, etc. The electronic control includes several controllers, which thus operate without direct coupling. For some operating points, it may happen that the controllers work with conflicting targets, which of course can adversely affect the shift quality.

The invention has for its object to adjust the state data of the drive train coordinated during a gear change and thereby optimally implement the driver's request.

This object is achieved for a method by the features of claim 1, for a device by the features of claim 9.

Accordingly, from the current state and driving data, i. H. the actual data, setpoints for this data are calculated, at which the gear change is to take place. These setpoints are then checked to see if they can be realized for a gear change. If these optimum setpoints are realizable, they are forwarded to the feedforward control and the controllers. If, however, the setpoint values can not be realized in this way or can only be implemented with a lower switching quality, the replacement setpoint values closest to and attainable from these setpoint values are forwarded to the controllers.

Preferably, the actual rotational speed of the engine, the actual rotational speed at the transmission input and the actual rotational speed at the transmission output, as well as a signal for the actual gear and the target gear and as an expression of the driver's request, the position of the accelerator pedal are entered as the state data of the drive train , From these data are then calculated in a setpoint generator, the corresponding setpoints for the speed of the drive unit, for the speed at the input and at the output of the transmission, with which an optimal gear change is possible.

These setpoint values are fed to a setpoint tester, which checks whether these setpoint values can be realized by means of the actuators for a motor intervention and an actuation of the converter and shift clutches. If these setpoints can be realized, they are forwarded directly to the pilot control and the controllers. However, if these setpoint values can not be realized, the setpoint tester determines substitute setpoint values.

The substitute setpoints that can be replaced as substitutes can be B. in terms of the square deviation of the difference of the respective tested Setpoint and the unchecked setpoint are optimally calculated to the original setpoints.

The entire controller calculates a coordinated setting intervention for the individual actuators, in particular for a motor intervention and for influencing the clutches, from the tested realizable setpoint values. The controllers that complement the controlled control action work here in a way in which individual control differences z. B. in the engine intervention to influence its speed and the speed of the converter clutch and the output speed are controlled by engaging all manipulated variables, without affecting the other control differences are significantly affected.

Such control is preferably based on a kinetic model of the transmission.

A special role comes in a solution according to the invention to the engine intervention. The transmission control can call the engine both a torque reduction and an increase in torque in order to optimize the respective shift quality.

With such a total control, the shift quality is generally improved. Likewise, the shift quality is often poor circuits, eg. B. coasting down, improved. Furthermore, the implementation of the driver's request is optimized in the vehicle movement. The tuning of the gearbox is hereby significantly simplified because the controller no longer work against each other by the calculation of consistent setpoints.

Further embodiments of the invention will become apparent from the dependent claims.

The invention is explained in more detail in an embodiment with reference to the single figure, in which a block diagram for an apparatus for electronically controlling an automatic powershift transmission according to the invention is shown.

An electronic control 1 for an automatic powershift transmission has in sequence a setpoint generator 2 , a setpoint checker 3 and a pilot control 4 on that a motor controller 5 , a converter clutch controller 6 and a shift sequencer 7 controls.

The setpoint generator 2 state data is entered, namely the actual speed of the motor n is / mot the actual speed at the input of the gearbox n is / t the actual speed at the transmission output n is / ab , furthermore, the actual gear i _istgang , the target gear i _{target gear} and a signal DKI for the accelerator pedal position. The signal DKI corresponds to the driver's request and indicates whether it wants to accelerate, keep the speed or decelerate.

These input data for the setpoint generator are used in this unchecked setpoint values for the engine speed n soll_ungepr / mot for the speed at the input of the gearbox n soll_ungepr / t and for the speed at the output of the transmission M soll_ungepr / ab calculated, with which an optimal gear change with optimum shift quality is determined.

These unchecked, inherently optimal setpoints become the set point tester 3 supplied, which checks whether these setpoints can be realized by means of the actuators for the engine, for the torque converter and clutches. If this is the case, then these tested setpoints n soll_gepr / mot . n soll_gepr / t and M soll_gepr / ab to the feedforward control 4 forwarded.

If the unchecked setpoint values for an optimal gear change can not be realized, then the setpoint tester determines substitute setpoint values that can be implemented as substitutes, which are close to the original setpoint values and optimal for these. This is done z. For example, in the context of a calculation of the quadratic deviation Σ _l (setpoint _checked - setpoint _unchecked ) ² for each setpoint.

In the feedforward control 4 From the tested, realizable setpoint values, a coordinated control intervention for the engine and the converter and clutch clutches is calculated. The feedforward control 4 gives a tested setpoint n soll_gepr / mot for the motor controller, a tested setpoint n soll_gepr / t for the converter clutch controller 6 and a tested setpoint M soll_gepr / ab for the shift sequencing controller 7 further. The regulators 5 . 6 and 7 , which supplement the controlled control action, operate in a manner in which individual control differences in the engine speed, the speed at the input or at the output of the transmission are compensated by engaging all manipulated variables without the other control differences are significantly affected.

In this way it is ensured that the individual regulators act only in the same direction, d. H. in the sense that the switching process is optimized; it is not possible for individual controllers to work against each other.

In the described embodiment, only the stated actual and setpoint values are used; it is of course possible to use other or additional values. Decisive is the setpoint check in the setpoint checker 3 whether the setpoint values can be realized or whether new realizable substitute setpoint values have to be calculated.

LIST OF REFERENCE NUMBERS

1

Electronic control

2

Setpoint generator

3

Setpoint Examiner

4

feedforward

5

motor controller

6

TCC regulator

7

Shifting sequence control knob

n is / mot

Actual rotational speed of the engine

n is / t

Actual speed at the input of the gearbox

n is / ab

Actual speed at the output of the gearbox

I _{'m going}

Signal for the current gear

i _{target gear}

Signal for the target gear

DKI

Signal for accelerator pedal or throttle position

n soll_ungepr / mot

Target speed of the engine for optimum gear change

n soll_ungepr / t

Target speed at the input of the transmission for optimum gear change

M soll_ungepr / ab

Target speed at the output of the transmission for optimum gear change

n soll_gepr / mot

Target speed of the engine for realizable gear change

n soll_gepr / t

Target speed at the input of the gearbox for realizable gear changes

M soll_gepr / ab

Target turning count at the output of the gearbox for realizable gear changes

Claims (10)

Method for the electronic control of an automatic powershift transmission of a motor vehicle during a gear change, wherein for the gear change suitable state data (actual data) of the drive unit and the vehicle detected and formed from these actual data set values for controllers and manipulated variables for actuators, characterized by the following features : From the actual data setpoints for an optimal gear change are calculated; - These optimal setpoints are checked to see if they are feasible with the existing actual data; if these calculated optimal setpoint can be realized, they are forwarded to feedforward control and controller; - If these calculated optimal setpoints are not feasible with the existing actual data, viable replacement setpoints are chosen that are close to the calculated setpoints, so that a gear change near the optimal gear change is possible, after which these replacement setpoints to feedforward control and regulator to get redirected. A method according to claim 1, characterized in that as replacement setpoint values are selected, which are located between the actual data and the checked optimum setpoints. Method according to Claim 1 or 2, characterized in that the substitute setpoint values are calculated by an approximation calculation, preferably in the sense of a quadratic deviation between the actual data and the checked optimum setpoint values. Method according to one of the preceding claims, characterized in that control differences of individual controlled variables are corrected over all control variables. A method according to claim 4, characterized in that the control differences are adjusted so that control differences for other setpoints are not significantly affected. Method according to one of the preceding claims, characterized in that the actual speed of the drive unit, the actual speed at the input of the transmission, the actual speed at the output of the transmission and the accelerator pedal or throttle position are selected as actual data. A method according to claim 6, characterized in that are chosen at the output of the transmission as set values the target rotational speed of the engine, the target rotational speed at the input of the transmission and the target rotation speed. Method according to one of the preceding claims, characterized in that the realizable setpoint values are used for controlling the drive unit, for controlling clutches and for switching sequence control. Device for the electronic control of an automatic power transmission of a motor vehicle driven by a drive unit during a gear change, whereby state data (actual data) of the drive unit and of the vehicle suitable for the gear change is detected and made from these Data manipulated variables for controllers and actuators are formed, characterized by the following features: - A setpoint generator ( 2 ), which from the actual data optimal setpoints ( n soll_ungepr / mot . n soll_ungepr / t . M soll_ungepr / ab ) is calculated; - a set point checker ( 3 ), in which the setpoint generator ( 1 ) are checked to see whether they can be implemented in the present actual data, or in the event that the calculated optimal setpoint values are not realizable, determine replacement setpoint values which are close to the calculated optimum setpoint values, and these realizable setpoint values forwarded and - a pilot control ( 4 ), which calculates controlled control interventions. Apparatus according to claim 9, characterized in that the feedforward control ( 4 ) Calculates regulatory interventions according to a kinetic model of the transmission.

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