DE102006042355A1 - Bridging method for speed differential between engine and drive train for vehicle, involves controlling starting clutch electro-hydraulically, with which target engine speed is generated by electronic control - Google Patents

Abstract

The method involves controlling the starting clutch electro-hydraulically with which a target engine speed is generated by an electronic control as a function of the respective driving conditions. The former basic function of a transition function between the former desired speed of the driving side and the former speed of the driving side of the clutch is near the quasi constant of the command from the driver. The another basic function of transition function between former speed of the driving side and a desired speed of the driving side of the clutch is appropriate to the power requirement.

Description

The The present invention relates to a method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch, according to the preamble of claim 1

at a motor vehicle, comprising a transmission with a starting clutch, the starting clutch must start or after a power interruption bridge the speed difference between engine and driveline.

in this connection may not exceed the maximum allowed thermal load of the starting clutch due to the power loss Slipping clutch not exceeded become.

at Vehicles equipped with a gearbox with a hydrodynamic torque converter equipped are, the starting process is taken over by the converter and accordingly the traction requirement of the vehicle, the engine torque and the engine speed changed. For vehicles equipped with a gearbox with a starting clutch are equipped instead of a hydrodynamic torque converter, must over the control of the clutch as a speed converter ensured be that sufficient traction or driving performance for the starting process to disposal stands.

From the DE 102 30 774 A1 the Applicant is a control system for a starting switching element of an automated transmission or automatic transmission for a motor vehicle is known, wherein the starting switching element in a normal operation of the transmission via an electronic transmission control unit electro-hydraulically or electro-pneumatically actuated, and wherein the starting switching element in case of failure of the electronic Getriebesteuegergerä tes in an emergency operation of the transmission is hydraulically or pneumatically actuated. In this case, the starting switching element, in particular for controlling a starting operation of the motor vehicle in case of failure of the electronic transmission control unit in emergency operation of the transmission via an electrically controllable emergency operation switching valve actuated, which is assigned to the hydraulic or pneumatic actuator of the starting switching element and can be controlled by a gearbox independent electronic control module.

Furthermore, from the DE 199 43 334 A1 the applicant a method for controlling an electro-hydraulically controlled clutch or brake of a transmission known in the context of the clutch or brake is controlled with a model-based compensation pressure regulator using an observer, the compensation pressure control loop includes a non-linear compensation element, the inverse model of the controlled system of clutch or brake, and wherein the observer estimates clutch control disturbances based on a powertrain model according to a state estimation method.

From the DE 39 37 976 A1 a method for controlling a clutch is known, which is arranged within a drive train between a input and an output shaft, wherein in the drive train, a sensor device for detecting a rotational speed difference Δω is provided with a control device, which is determined in dependence on the determined by the sensor means controlled variable the manipulated variable y to be supplied to the clutch, which influences the rotational speed difference Δn, wherein the control device has a comparator unit in which an actual value x of the rotational speed difference Δω determined in the drive train behind the clutch is compared with a predetermined fixed limit value W _const , and wherein upon reaching or Exceeding the limit value W _const the rotational speed difference Δω is limited by changing the manipulated variable y of the clutch to the limit value W _const .

As part of the DE 103 05 180 A1 The Applicant is a method for controlling and regulating a desired course of a time-varying signal of a system, in particular a signal transmission control, known between a defined start time and a defined end point. In the event that the method is applied to a system "clutch device", in particular to a torque converter lockup clutch of a drive train, the setpoint generation for a target speed curve of a drive side of a clutch device in consideration of itself during a closing phase, an opening phase or a slip control phase of the clutch device is possibly changing Boundary conditions or operating parameters of a drive train. Here, when closing a clutch device at least at the beginning of the closing phase, a theoretical closing time and an actual speed curve of the drive side is generated such that the target speed curve of the drive side and an actual speed curve of the output side have at least approximately the same gradients and speeds in an actual closing time of the clutch device.

• – dann, wenn ein Kupplungseinrückbefehl ausgegeben ist, Bezug nehmen auf eine frühere Kupplungseinrückzeit;
• – Vorsehen einer Drucküberwachungseinrichtung für den Kupplungseinrück-Fluiddruck, die so beschaffen ist, dass sie ein Einrücksignal, das die Kupplungseinrückung als Funktion des Kupplungseinrück-Fluiddrucks angibt, und ein Ausrücksignal, das die Kupplungsausrückung als Funktion des Kupplungseinrück-Fluiddrucks angibt, liefert und
• – Angeben einer Kupplungseinrückung, je nachdem, ob zuerst die Drucküberwachungseinrichtung das Einrücksignal liefert oder zuerst die frühere Kupplungseinrückzeit überschritten ist.

From the DE 10 2005 022 295 A1 A method is known for indicating a clutch engagement after the issuance of a clutch engagement command, wherein the clutch engagement command is controlling the clutch engagement fluid pressure in one Clutch control chamber, the method comprising:

• When a clutch engagement command is issued, refer to an earlier clutch engagement time;
• Providing a clutch engagement fluid pressure monitoring means arranged to provide an engagement signal indicative of clutch engagement as a function of clutch engagement fluid pressure and a release signal indicative of clutch disengagement as a function of clutch engagement fluid pressure;
• - Specifying a clutch engagement, depending on whether first the pressure monitoring device delivers the engagement signal or first the previous clutch engagement time is exceeded.

Of the The present invention is based on the object, a method to bridge the Speed difference between the engine and the driveline for a vehicle, to provide a transmission with a starting clutch, which a comfortable start with consideration of the driver's request guaranteed.

The inventive method should even under a variety of conditions, e.g. on slopes, at high / low temperatures, with / without trailer, comfortably displayed be; In addition, should be in the vote of the components of the drive train and thus also the starting clutch optimization criteria such as driving performance, Fuel consumption, emission and ride comfort are taken into account.

These The object is solved by the features of claim 1. Further Embodiments of the invention and advantages are apparent from the dependent claims.

Therefore is a method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission proposed with a starting clutch, wherein the actuation of the starting clutch is electro-hydraulic, in which by means of an electronic control in dependence a target engine speed is generated by the respective driving situation, the above a speed control and / or speed control in a target pressure for the Control of the starting clutch is converted. This target pressure serves the current control of a hydraulic pressure regulator, wherein the pressure regulator and the hydraulic downstream of the pressure regulator a corresponding actuation pressure for the Provide starting clutch.

According to the invention Setpoint generation includes two basic functions, where the first basic function a transfer function between the actual / desired Drehzahi the drive side and the engine speed and the actual speed of the output side of the clutch is "quasi" constant driver request, and wherein the second basic function is a transfer function between the Actual / target speed of the drive side and a target speed of the Drive side according to the power requirement from a driver's request is and at a significant change the power request is activated, whereby, when the driver through a significant change the accelerator pedal value indicates the desire more or less drive power to get this, the transmission side is supported by the first basic function is canceled and the second basic function is executed. When the target speed is reached according to the power requirement, is transferred to the first basic function, in the case of a homogeneous transition between the previous actual / target speed of the drive side and the synchronization point is realized.

By the inventive leadership of the engine speed will, independent of any driveline vibrations of the output side, a homogeneous Target engine speed curve and thus ensures a comfortable start.

prerequisite for the Speed control and thus for the setpoint generation according to the invention is that the clutch is engaged.

in the Frame of an advantageous variant of the method according to the invention is the form of the first basic function or the transition function between the Actual / target speed of the drive side and the actual speed of the output side the coupling decisive influenced by available speed levels and speed gradients, wherein the previous gradient of the actual / target speed of the drive side was added and adjusted in sync point with the gradient of the output side is, d. h., approaches it tangentially or at an acute angle.

According to the invention Time, speed level and speed gradient of the synchronization point based on the current driving situation, preferably on the Accelerator pedal value, the actual / target speed curve of the output side and the drive side and physical limits, such as the minimum and the maximum possible Engine speed estimated.

In this case, a theoretical closing time (synchronization point) of the clutch is determined, as a function of which a desired rotational speed profile of the drive side of the clutch is generated in such a way that the desired rotational speed profile of the drive side and an actual rotational speed curve of the output side in one act have at least approximately the same gradients and rotational speeds of the clutch closing time of the clutch.

By this procedure is ensured that the rotational speed of the drive side of the clutch, d. H. in the present Fall the engine speed just before the actual closing time the clutch harmoniously to the speed of the output side of the clutch brought and is adjusted, so that advantageously only small, additional personnel to close the clutch and the final Compensation of the speed difference between the drive side and the Output side of the coupling are required; this leads too much comfortable startup procedures.

Preferably, as in the DE 103 05 180 A1 described the Applicant, the disclosure content is also intended to be the subject of this description, the target speed curve of the drive side of the clutch via a configurable transition function as a vectorized course generated depending on a current state of the system and a relation between a defined starting point and a defined Endpoint is formed. Here, the defined starting point is defined as a function of the actual state of the system to start the transition function; the end point is estimated as a function of the actual state of the system or applied as a function of the actual state of the system.

Of the defined starting point is the time as well as the actual / target speed and the Gradient of the actual / desired speed curve clearly defined; of the End point (i.e., the sync point) is the one by the estimated end time, the estimated speed at the end time as well as by the expected gradient of the desired speed curve for End time clearly defined.

in this connection results in the relation between the starting point and the end point essentially by the gradient of the desired speed curve in the defined Starting point and in the defined end point, the position of the starting point and the end point and by a reference gradient, wherein the Reference gradient essentially the slope of the distance between corresponds to the starting point and the end point.

Of further consists of the vectorized course of the desired speed curve from at least three vectors, viz a start vector, a transition vector and an end vector between the starting point and the end point form a polygon, wherein the starting point of the start vector the defined starting point and the end point of the end vector coincides with the defined endpoint; the starting point of the transition vector corresponds to the end point of the start vector and the end point of the transition vector corresponds to the starting point of the end vector.

The Orientation of the start vector corresponds approximately to the gradient of the actual speed curve to the starting point, wherein the orientation of the final vector approximates the predetermined gradient of the desired speed curve in the endpoint corresponds, this gradient depending on an actual state of the system is estimated or applied. The Gradients of the start vector and the end vector are dependent the current state of the system adaptable.

Of Furthermore, it is provided that the time components of the start vector, the end vector and the transition vector on the vectorized curve of the desired speed curve in each case depending a current state of the system are determined, the Determination of time shares based on empirically determined characteristics or maps. The characteristic curves each correspond with each other Applied speed curves the drive side or the engine speed and the output side of the Clutch for certain driver strategies or different Accelerator pedal values.

If the sync point changes, becomes the transition function adapted according to the new synchronization point. This is advantageous Way an adaptation of the target engine speed to different, changeable Driving situations given. Furthermore, it is provided that the thermal Load of the starting clutch in the setpoint generation by a Modification of the synchronization point is taken into account; in this Case, the synchronous speed is modified accordingly.

in the Frame of the transfer function between the drive side actual / desired rotational speed (i.e., the engine) and the target rotational speed of the drive side according to a driver's request is a target speed according to the invention generated according to the driving situation and the driver's request, where as input value for the generation of the target speed preferably the driver's request expressed by the Accelerator pedal value is used.

Becomes a significant change the performance requirement expressed by a change the driver's request and thus a significant accelerator pedal change or target speed change - detected, this is the target engine speed Controlled by the current value transferred to the target value, preferably the Target speed is controlled such that the target speed with a preferably flat gradient is achieved.

As soon as the target engine speed has reached the target value, according to the invention again on the transition function between input and output side (i.e., the first basic function) become. By the immediate reaction to a significant change the power requirement in the form of the conversion of the target engine speed is achieved that enough Drive power can be built up before the clutch is closed becomes.

If while the execution the first basic function, i. the leadership of the drive speed to the output speed the driver's request changes, i.e., when the driver Gas is, according to the invention in the second basic function, where the target engine speed is converted from the current value to the target value.

to support or optimization of the speed control or the speed control can over it In addition, an engine torque intervention and an engine idle speed increase be issued. Thereby can very steep speed gradients are avoided, provided according to the invention may be that a threshold for the speed gradient is not exceeded becomes.

The The invention will be explained in more detail below by way of example with reference to the attached figures.

It demonstrate:

1 a flow chart illustrating the essential steps of the method according to the invention and

2 a diagram showing the time course of the actual engine speed, the target engine speed and the actual output speed according to the invention.

Referring to 1 At the beginning of the method according to the invention, it is checked whether there is a driving condition-dependent request for a setpoint for the engine speed. If this is not the case, then the desired drive speed of the clutch is set equal to the current actual drive speed of the clutch or the actual engine speed. If there is a drive-state-dependent request for a setpoint for the engine speed, then the system moves to the first basic function, in which a homogeneous transition between the previous actual / desired rotational speed of the drive side and the synchronization point (drive rotational speed equal to output rotational speed) is realized.

According to the invention is checked, whether the setpoint generation is to be ended, which is the case can, if the target drive speed or the actual drive speed the clutch comes to rest on the actual output speed, wherein in this case, the target drive speed of the clutch is equal to the current actual output speed of the clutch is set.

During the execution the setpoint generation according to the first Basic function is checked whether a significant change the power request or a driver request is present. If the driver through a significant change the accelerator pedal value indicates the desire more or less drive power This is supported on the transmission side by using the transfer function with the target, the input speed of the clutch and the output speed to merge the clutch, is canceled and the second basic function is executed, in which the target engine speed from the current value by means of a homogeneous, continuous course in the target value accordingly the service request is transferred.

If the second basic function is completed, i. if the target value is appropriate the performance requirement is reached, the first basic function is in the case of a homogeneous transition between the previous actual / target speed of the drive side and the synchronization point (Input speed equal to output speed) is realized.

In 2 the time profiles of the actual engine speed, the target engine speed and the actual output speed in the implementation of the method according to the invention are shown.

in this connection At the beginning of the procedure, the engine speed corresponds to any one Value; At time t_0, the setpoint generation according to the invention started. Here, in the context of the first basic function, a homogeneous transition between the previous actual / target speed of the drive side, d. H. the engine speed and the synchronization point are realized, wherein the form of the transition function between Starting point and end point decisive influenced by existing speed levels and speed gradients is and where the previous gradient of the actual / target speed of the Drive side recorded and in sync point with the gradient the output side is adjusted, d. h., this tangential, d. H. approaching at an acute angle.

According to the invention is, as already explained, the synchronization point based on the current driving situation, preferably on the accelerator pedal value, the actual / target speed curve of the output side and the drive side and physical limits such as the minimum / maximum Engine speed estimated.

The course of the target engine speed up to the synchronization point without an additional power requirement on the part of the driver is until synchronous point t_3 'represented by curve A; in the figure, the curve representing the course of the actual output speed is denoted by D. In the example shown, during the execution of the first basic function at time t_1, a significant change in the power requirement - expressed by a change in the driver's request and thus a significant accelerator pedal change or target speed change - is detected, so that the second basic function is entered.

in this connection is the target engine speed (curve B) of the current value in the Target value by means of a homogeneous, continuous course according to Performance request transferred. The Target speed n_z is generated according to the driving situation, where the input value preferably the accelerator pedal value is used. in the figure, the curve representing the course of the actual engine speed, denoted by C.

As soon as the target engine speed has reached the target speed n_z, the invention returns to the first basic function. This is done in 2 at time t_2. At time t_3, the synchronization point is reached and the setpoint generation according to the invention is terminated.

The execution the method according to the invention is not limited to a starting clutch of a transmission; much more For each frictional switching element, the method can be dependent on the constructional conditions and the respective application become.

t_0

time the beginning of setpoint generation

t_1

time a significant change the performance requirement

t_2

time of reaching the target speed

t_3

time of reaching the sync point

t_3 '

time of reaching the sync point without a significant change the performance requirement

N_Z

Target speed

A

course the target engine speed to the synchronization point without a significant performance requirement

B

course the target engine speed from the current value to the target value at significant performance requirement

C

course the actual engine speed

D

course the actual output speed

Claims (16)

A method for bridging the speed difference between the engine and the drive train for a vehicle, comprising a transmission with a starting clutch, wherein the activation of the starting clutch is electro-hydraulic, in which by means of an electronic control depending on the particular driving situation, a target engine speed is generated via a Speed control and / or speed control is converted into a desired pressure for the activation of the starting clutch, characterized in that the setpoint generation comprises two basic functions, wherein the first basic function is a transfer function between the actual / target speed of the drive side and the actual speed of the output side of the Clutch is quasi-constant driver's request, and wherein the second basic function is a transfer function between the actual / target rotational speed of the drive side and a target rotational speed of the drive side of the clutch according to the power requirement of a driving is desired and is activated upon a significant change in the power demand, wherein if the driver indicates a greater or lesser propulsive power through a significant change in the accelerator pedal value, the transmission side is assisted by aborting the first basic function and performing the second basic function is, and wherein when the target speed is reached in accordance with the power requirement, is transferred to the first basic function in which a homogeneous transition between the previous actual / target rotational speed of the drive side and the synchronization point is realized. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 1, characterized in that the shape of the first basic function or the transition function between the actual / target speed of the drive side and the actual speed the output side of the clutch of existing speed levels and speed gradients is affected, the previous gradient the actual / target speed of the drive side is recorded and in the synchronization point is adjusted with the gradient of the output side, d. h., yourself the tangential, d. H. approaching at an acute angle, where time, speed level and speed gradient of the synchronization point based on the current one Driving situation, in particular on the accelerator pedal value, the actual / target speed curve the output side and the drive side and physical limits estimated becomes. A method for bridging the speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 2, characterized in that as minimum physical and the maximum possible engine speed be be taken into account. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to one of the preceding claims characterized in that in the first basic function a theoretical Closing time of the Detected coupling and an actual speed curve of the drive side and output side of the clutch is detected, depending on generates a desired speed profile of the drive side of the clutch so is that the target speed curve of the drive side and an actual speed curve the output side in an actual Closing time at least approximately close to the coupling have the same gradients and speeds. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 4, characterized in that the desired speed curve of the drive side the clutch over a parameterizable transition function is generated as a vectorized history, depending on a current state of the system and a relation between formed a defined starting point and a defined endpoint is, with the defined starting point depending on the actual state of System to start the transition function is defined and the endpoint is dependent on the actual state of the Systems estimated or depending the actual state of the system is applied. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 5, characterized in that the defined starting point is determined by the time the speed and gradient of the speed curve is defined, and that the endpoint through the estimated end time, the estimated speed at the end time and by the expected gradient of the desired speed curve clearly defined at the time of the end. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 6, characterized in that the relation between the starting point and the endpoint through the gradients of the desired speed curve in the defined starting point and in the defined end point, through which Location of the starting point and the end point and by a reference gradient yields, wherein the reference gradient substantially the slope corresponds to the distance between the starting point and the end point. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 5, 6 or 7, characterized in that the vectorized course the desired speed curve of at least three vectors, namely a Start vector, a transition vector and an end vector exists between the start point and the end point form a polygon, wherein the starting point of the start vector the defined starting point, the end point of the end vector with coincides with the defined end point, the starting point of the transition vector the End point of the start vector and the end point of the transition vector the starting point corresponds to the end vector, and that the orientation of the start vector nearly corresponds to the gradient of the actual speed curve to the starting point, wherein the orientation of the end vector to the gradient of the desired speed curve in the end time corresponds, depending on an actual state of the system or applied. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 5, 6, 7 or 8, characterized in that the time components of the starting vector, the end vector and the transition vector at the vectorized course of the desired speed curve respectively dependent on a current state of the system are determined, the Determination of time shares based on empirically determined characteristics or maps, which respectively correspond with each other Applied speed curves the drive side or the engine speed and the output side of the Clutch for certain driver strategies or different Represent accelerator pedal values. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to one of the preceding Claims, characterized in that, when the sync point changes, the first basic function is adjusted according to the new synchronization point. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to one of the preceding Claims, characterized in that the thermal load of the clutch taken into account in the setpoint generation by a modification of the synchronization point becomes. Method for bridging the speed difference between the engine and the driveline for a vehicle comprising a transmission with a starting clutch according to one of the preceding claims, characterized in that in the context of the second basic function or the transfer function between the actual / target rotational speed of the drive side and the target rotational speed of the drive side of the clutch, according to a driver's request, a target speed is generated according to the driving situation and the driver's request. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 12, characterized in that as an input value for the generation of the target speed the driver's request expressed by the accelerator pedal value is used. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 12 or 13, characterized in that the target engine speed of controlled current value is transferred to the target value. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to claim 14, characterized in that the target speed is controlled in such a way that the target speed with the lowest possible gradient is reached. Method for bridging the Speed difference between the engine and the driveline for a vehicle, comprising a transmission with a starting clutch according to one of the preceding Claims, characterized in that to support or optimize the Speed control or the speed control, an engine torque intervention or an engine idle speed increase is issued.