DE4011850A1 - Automatically clutch of motor vehicle - using processor program for engagement following automatic determination of clutch biting point - Google Patents

Abstract

The automatic clutch is operated in response to the vehicle dynamics, e.g. starting, retarding, braking, reversing, etc. The actual point at which the clutch bites is determined when the clutch is engaged with the vehicle stopped and the engine running. The normal waiting point of the clutch is then determined by backing off until a minimum transmission drag is obtained. The engagement point is automatically updated as the clutch wears. The other parameters monitored include throttle setting, engine speed, transmission slip, etc. The clutch operation is controlled by a processor. ADVANTAGE - Improved transmission and driving control.

Description

The invention relates to a method for controlling a effective between a prime mover and a transmission automated friction clutch for at least one of the Operating conditions, such as starting, switching, driving, accelerating braking, reversing, parking or the like, or of transitions between individual operating states.

Furthermore, the invention relates to a device for Implementation of the procedure for controlling an automated Friction clutch.

The invention also relates to a regulation for the Transmission torque of a clutch between an engine and a gearbox in connection with the invention Process used and with the Einrich invention tion can be generated.

The present invention was based on the object Procedure and a device of the type mentioned above create with which with optimal driving comfort a consumption  favorable driving and / or optimal accelerations, gentle driving and long service life of the vehicle, especially the clutch can be achieved.

The invention was also the object of providing a regulation based on negligible dead time, that is, within the working period in each case Consideration of the operating parameters for the regulation of the Provides transmission torque of a clutch.

This is done according to a method variant of the invention achieved in that at least for the starting process Control engagement point of the clutch depending on an inner Torque measurement carried out half of the drive train and / or an angle measurement can be determined by the coupling from a disengaged position and with the Gear and stationary vehicle at a defined speed is closed up to a position where a Moment initiated, but this moment is less than the one that would move the vehicle and one at Reaching a certain moment and / or a certain one Angle corresponding value, e.g. B. the way or location of the dome actuation, determined and fed to a memory, whereupon the clutch at least partially opened again up to a defined waiting position at which the clutch does not have a moment or only a very slight drag moment transmits.  

According to another process variant of the invention, at least for the starting process, a control point of intervention Coupling depending on a gradient determination rotatable components of the drive train determined by the Clutch from a disengaged position and not engaged gear and stationary vehicle with defined Speed up to a position is closed at which drives the transmission input shaft, but remains below the engine idle speed, and a at Reaching a certain state, like a certain one gradient value occurring and a status dependent dependent value, such as the path or location of the clutch actuation, determined and fed to a memory, whereupon the Clutch, at least partially, is opened again in a waiting position in which the clutch has no or only one transmits very low drag torque.

The aforementioned waiting position can also be the fully disengaged one Correspond to the condition of the coupling. It can also be activated system that is hydraulically and / or pneumatically trained can be pending pressure instead of the path or location of the Clutch actuation or in addition to this route or location are determined and recorded in the memory.

Further advantageous measures and further training of the The inventive method result from claims 2  and 4 to 64, with some of these measures or further training solutions on their own or at least in connection with the The preamble of the independent claims is inventive.

To carry out a method for controlling an automati Fixed friction clutch can be particularly advantageous Wise a facility that at least some of the Switching, measuring and control devices listed below and at least one electronic unit with at least a computer and memory for processing and storage the state variables or Impulses and to control or regulate some of them Facilities has:

• a) a precaution to record the engine speed to Example in the form of a teeth on the flywheel sensing sensor
• b) a precaution to determine the transmission speed
• c) a measure to measure the clutch actuation path, for example in the form of a clutch actuation path tion member, such as a hydraulic slave cylinder, sensing potentiometer,
• d) a measure of the position of the force fabric feeder, for example in the form of a die  Throttle valve determining potentiometer
• e) a precaution to detect the accelerator pedal position in Form, for example, one that can be influenced via the accelerator pedal Potentiometers
• f) a device for determining the idle position of the Fuel supply device
• g) a precaution to detect the gear position Idle and gear detection
• h) a precautionary measure for switching intent recognition in the form of Example of one provided on the gear shift lever Sensors
• i) a device for detecting the throttle valve end position
• j) a temperature measuring device, whereby the electronics can at least be controlled
• k) a clutch actuator, such as a hydraulic cal donor and receiver device
• l) a drive device for changing the throttle flap position

Furthermore, it may be appropriate if the device for Execution of the method of detection of the direction of rotation or Roll direction detection includes, for. B. according to claims 67 to 72. Such recognition is advantageous for the conditions stuck if the gear selected and the direction of roll of the driver not match. This is e.g. B. the case with one Motor vehicle that - with first gear engaged - uphill  stands, and moves downhill, i.e. rolls back. This detection can take place by means of a sensor. By recognizing such cases cannot do this appropriate controller response can be avoided. This can e.g. B. happen in that in the aforementioned case determined gearbox speed receives a negative sign, so that the control of the necessary for this operating state state of engagement of the clutch and thus the required Chen slip speed is correct. Without direction detection the slip speed may be calculated incorrectly becomes what is an improper control behavior and thus engaging behavior of the clutch would also result.

The task of regulating the transmissible moment one Coupling is according to the invention by the following features solved:

• a) as the difference between the engine speed and the transmission speed an actual slip is determined;
• b) a processor periodically asks input parameters, such as Clutch travel, throttle position (load), engine tempe rature and / or gear position, from and determined under Query stored maps a target slip and characteristic control factors;
• c) from the difference between the target slip and the actual slip is in a rule controlled by the control factors stretch formed a manipulated variable for the clutch travel.

The invention differs from the prior art Technology than the clutch depending on the operating condition the engine is operated with a slip. So you can the transmission of engine vibrations to the drive train largely turn off. It is also an optimization of the Driving behavior possible.

Further developments of the invention are in subclaims 75 to 88 specified.

Referring to Figs. 1 to 15, the invention is closer tert erläu. It shows

Fig. 1 shows the schematic structure of a vehicle drive bes with a device according to the invention.

Fig. 2 shows the schematic structure of a hydraulic adjustment device, which is used in the device of FIG. 1.

Fig. 3 is a block diagram of the electronic control,

Fig. 4 shows a modified block diagram of the electro-African control,

Fig. 5 shows waveforms for explaining the rotation payer averaging,

Fig. 6 is a diagram of a speed-dependent integrator,

Fig. 7 is a diagram of an absolute value investigator

Fig. 8 is a block diagram of the parameter-dependent control of a transformer,

Fig. 9 is a block diagram of a P-element,

Fig. 10 is a block diagram of an I-member,

Fig. 11 is a block diagram of a D-element,

Fig. 12 waveforms for explaining a Anfahrvor gear,

Fig. 13 waveforms for the control response at a load jump,

Fig. 14 waveforms for a switching operation and

Fig. 15 is a simplified data flow for data analysis by the processor.

The device illustrated in FIG. 1 1 for the drive of a motor vehicle comprises a motor 2, which is non-positively connected via a clutch 3 and the transmission 4. The transmission 4 is connected to the drive wheels 6 of the motor vehicle via a drive train 5 . The friction clutch 3 can be engaged and disengaged via an actuating mechanism 7 , which can include a release bearing and a fork acting thereon. The actuating mechanism 7 is actuated via an actuator in the form of a hydraulic cylinder 8 . The cylinder 8 is connected via a line 9 to a hydraulic adjusting device, such as a hydraulic actuator 10 , which is shown in the basic structure in FIG. 2.

To regulate the frictional engagement of the clutch 3 , an electronic unit 11 is provided, which comprises at least one processor or computer and processes the sizes required for controlling the clutch 3 to regulate a corresponding clutch engagement via the hydraulic actuator 10 .

From the electronic unit 11 , the sizes of the speed of the engine 2 , the speed of the transmission input shaft 12 , the position of the cylinder 8 and the position of the throttle valve 13 (and, if necessary, other engine parameters such as operating temperature, air temperature, exhaust gas, fuel) are detected.

The electronics unit 11 is explained in connection with the block diagram shown in FIG. 3.

The engine speed is determined by a sensor 14 which, for example, scans the teeth 15 of the starter ring gear provided on the flywheel of the engine 2 .

The transmission speed is determined by a sensor 16 which scans the teeth 17 of a gearwheel provided on the transmission input shaft 12 .

The position of the fuel supply device or the throttle valve 13 is determined by a sensor, such as a potentiometer 18 .

The accelerator or accelerator pedal 19 is not mechanically coupled to the fuel supply device 13 in the present exemplary embodiment, but via an actuating device, such as a control circuit 20 which is controlled by the electronics unit 11 and has an electric servomotor.

A precaution 22 is provided on the gear lever 21 for gear detection, which may additionally include a shift intention detection.

By integrating into the provision 22 intent shift detection, the electronic unit 11 is reported whether you actually move the shift lever 21 in the direction where the next logically following gear lies. If the lever is moved in the wrong direction, this must have no influence on the electronics unit 11 , that is, the clutch 3 is only opened when the shift lever 21 is actuated in the right direction. An actuation of the shift lever 21 in a non-logical direction is therefore not recognized by the electronics unit 11 as an intention to shift.

To determine the clutch actuation path or the clutch engagement state, provision is made for displacement measurement (displacement transducer), for example a potentiometer 23 , which detects the path or position of the piston of the actuator 8 and reports a corresponding electrical quantity to the electronics unit 11 .

Instead of detecting the path or the position of a clutch actuation by means of the pressure present in the hydraulic actuation system, the pressure could be determined and processed accordingly by the electronic unit 11 . For this purpose, only a pressure meter would be required instead of the displacement sensor 23 , the z. B. detects the pressure in the hydraulic actuator 8 and converts it into a corresponding size, which is reported to the electronic unit 11 . For many applications, it can also be advantageous if both a displacement measurement and a pressure measurement are carried out, the pressure measurement being able to be used in a particularly advantageous manner for regulating the slip in the clutch, since for this adjustment only very small distances are used in some cases be covered by the actuator.

The hydraulic adjusting device 10 shown schematically in FIG. 2 has a hydraulic pump 26 which can be driven by an electric motor 25 and which is connected to an oil reservoir 27 and can act on the hydraulic cylinder 8 via a valve block 28 . An electromagnetically operated 3/3 control valve 29 with a return spring is integrated in the valve block 28 and can be controlled by the electronic unit 11 . The control valve 29 acts as a volume-proportional valve, which means that the valve slide is displaced depending on the size reported by the electronic unit, as a result of which the flow cross section is varied accordingly. As an alternative, a volume-proportional 4/4 valve or a control valve that is controlled by pulse width modulation could also be used.

Provided between the pump 26 and the control valve 29 is a filter 30 , a check valve 31 , a pressure switch 32 which switches the motor 25 on and off as required, and a pressure accumulator 33 .

The pressure accumulator can be dimensioned in such a way that when the motor vehicle is started up, at least an initial disengagement without energy supply is possible, so that no special motor 25 is then required for the pump 26 . During the operation of the internal combustion engine 2 , the memory 33 can be supplied via a pump driven by the internal combustion engine, such as that operated by the power steering.

The operation of the unit 1 according to FIGS. 1 and 2 will now be described in more detail below.

When starting the internal combustion engine 2 , that is to say when the motor vehicle is at a standstill, as soon as the ignition contact is closed, the control valve 29 is actuated such that the clutch 3 is initially completely disengaged by the energy of the pressure medium available in the pressure accumulator 33 via the hydraulic cylinder 8 . As soon as the engine 2 is started and rotates at idle speed, that is to say no gear is engaged, the clutch 3 is closed from its disengaged position at a defined speed to a position at which the transmission input shaft 12 is driven but below the engine idle speed remains, and a certain gradient, such as, for example, speed gradient or angular acceleration gradient, is reported by the sensor 16 to the electronic unit 11 . On the basis of the measured gradient, the engagement path of the clutch 3 covered until this gradient was determined can be corrected in order to obtain a control intervention point. This control intervention point corresponds to the position of the actuation path of the friction clutch 3 up to which a rapid engagement process takes place. When this control point of engagement in the direction of engagement of clutch 3 is exceeded, a controlled engagement occurs. The detection of the control point is required in order to largely eliminate the influence of the manufacturing tolerances and thus to achieve an optimal clutch actuation for each motor vehicle. On the basis of the gradient course up to the limit gradient, the engagement path of the clutch 3 covered up to this limit gradient can be corrected in such a way that, with a flat course of the gradient increase, a greater correction takes place in the clutch 3 disengaging device than with a steep course of the gradient increase. A flat course of the gradient increase can be attributed, for example, to a clutch disc with a larger axial stroke, so that the control engagement point begins or is reached earlier when the clutch is engaged than in the case of a disc with little side runout.

After the control intervention point has been determined, the clutch is restored fully open.

As soon as the driver engages the first, possibly the second or the reverse gear, the clutch 3 is closed via the hydraulic adjusting device 10 from the fully open state at high speed to the control intervention point. If the driver now actuates the accelerator pedal 19 , a speed dependent on the position of the throttle valve 13 can be determined from a map stored in the processor of the electronic unit 11 and a starting speed can be formed by adding the current idle speed. This starting speed is set via the throttle valve 13 actuating control device 20 . The controlled closing of the clutch 3 now takes place in such a way that the starting speed remains practically constant over the entire engagement path at a defined accelerator pedal position. The speed at which the engine 2 outputs the maximum torque for a predetermined throttle valve position can be stored as the optimum speed for starting. By closing the friction clutch 3 in this way , a smooth, even start-up is made possible with an optimal torque, with the engine virtually being stalled.

By taking the idle speed into account when determining The start-up speed can affect the weather Influences are taken into account as the idle speed at Example depends on the cooling water temperature.

The controlled closing of the clutch 3 can take place until a desired slip speed has been reached or until the torque that can be transmitted by the clutch 3 speaks at least approximately exactly to the torque output by the engine 2 . As an alternative, the clutch 3 could also be closed completely.

When starting attempts in gears other than those provided for this purpose, the clutch 3 remains open and the throttle valve 13 can be kept in the closed state by the control device 20 in order to prevent the engine from accelerating unintentionally.

The device 1 according to the invention is designed such that there is always a certain slip between the engine 2 and the transmission 3 , at least in the speed ranges of the engine in which gear rattling or a booming of the body can occur. This slip eliminates the vibrations with ignition frequency superimposed on the engine speed in vehicles with internal combustion engines. The amplitude of these torsional vibrations is load-dependent, which is why it is advisable to change the slip speed depending on the load of the engine. The slip speed can be of the order of 10 to 100 revolutions per minute. The defined by the clutch 3 slip acts as a low-pass filter and keeps the prescribed vibrations of the part of the drive train located behind the clutch in the torque flow away from the vehicle.

For the slip control, the speed of the motor 2 and the transmission input shaft 12 are accessed via the sensors 14 and 16 , and the differential speed is determined therefrom in the processor of the electronic unit 11 . This determined differential speed is compared with a target slip speed stored in the processor of the electronic unit 11 for the currently prevailing operating state of the motor vehicle and, based on the result obtained, the actual clutch path or actual contact pressure of the clutch is brought to a target clutch path or target contact pressure, which brings the Frictional engagement of the clutch 3 is changed in order to achieve the target slip speed. The target slip speeds assigned to a specific operating state of the motor vehicle can be stored in the form of a 3D matrix of speed, load or accelerator pedal position and gearbox in the memory of the computer of the electronic unit 11 . The target slip speeds can, however, also be stored in a table-like manner, punctiform or as a function, the individual table values being able to be assigned to a speed range, for example of 100 revolutions. In this case, a table can be stored for each ratio of the transmission or a basic table can be stored, the values of which are adjusted according to the gear engaged via a correction factor. A direction of rotation or roll direction detection can also be provided. Such detection can e.g. B. take place by means of at least one sensor 35 which emits corresponding information to the electronic unit 11 . The sensor 35 can be integrated in an ABS system. Instead of the sensor 35 , the sensor 16 could also be designed such that it not only detects the transmission speed, but also the transmission rotation direction. Such a direction sensor makes it possible to recognize those cases in which the selected gear and the direction of roll do not match. This is e.g. B. the case of an uphill motor vehicle that moves downhill when the first gear is engaged. Incorrect control reactions of the electronic unit 11 can be avoided by using a direction sensor. In cases in which the direction of roll and the gear selected do not match, the gearbox speed detected by sensor 16 is given a negative sign, so that the slip speed is calculated correctly.

The slip control works principally as a torque limiter during its operation. Due to the fact that a predetermined slip speed is used, i.e. a predetermined slip speed is set by the control loop, there is practically an equal torque in the clutch between the driving torque of the motor 2 and the slip torque of the clutch 3, whereby the power consumed by the slip plus the power delivered to the gearbox corresponds to the engine power. The slipping moment is the moment that can be transferred to the vehicle for driving or accelerating. A gas surge can now suddenly give more torque from the engine 2 , which accelerates and increases in speed. This has the consequence that the clutch 3 regulates more in the direction of engagement. This is done in that the occurring higher / lower speed difference between motor 2 and gear 4 is recognized by the control circuit and, as a result, a higher / lower contact force is set in clutch 3 .

In some vehicles it is not necessary to drive with slip for rattling or roaring reasons, i.e. vibration isolation for the high-frequency engine vibrations caused by the firing order. If you drive in an area that is not critical for rattling and roaring, the clutch 3 can be fully closed. By closing the clutch, there is no longer any wear, but also no torque-limiting operation. According to the invention, the torque that can be transmitted by the clutch 3 is to be adjusted to a value in these non-critical areas that is the same or only slightly greater than the torque of the engine 2 . Since this engagement point of the clutch 2 can only be determined with a very high effort by means of a torque measurement, this engagement point is determined in the device according to the invention via a speed measurement. For this purpose, the clutch 3 is opened a little via the control at certain time intervals, namely until a slight slip is detected, for example in the order of 5 to 10 revolutions per minute, and then moves the clutch 3 back up to an engagement point. where no more slip is detected. This process can be carried out at a constant frequency. This method guarantees that speed equality between engine 2 and transmission input shaft 12 and practically identical torque between the torque output by engine 2 and transmission torque of clutch 3 can be adjusted. With constant driving, that is, with practically constant accelerator pedal position, the scanning of the point of engagement, in which there is practically the same torque, can be carried out with a relatively low sampling frequency. It is different if there are sudden jumps in torque, which means that the accelerator pedal is suddenly depressed or released. With such sudden torque jumps, the sampling rate must be increased considerably. For this purpose, the sampling rate can be changed as a function of the speed at which the accelerator pedal 19 or the throttle valve 13 is moved. The latter can be done by means of a potentiometer 34 which determines the position of the accelerator pedal 19 .

The respective location, that is to say the respective engagement position of the clutch 3 , at which the control has found a point at which no slip or only a very small slip occurs, can also be found together with the throttle valve position assigned to this point in the memory of the computer the electronic unit 11 are held. In the event of sudden changes in torque, the new throttle valve position and the stored values can be used to immediately determine where the new slip point or torque equilibrium point is.

The values recorded by the electronic unit 11 , at which no slip or only a very small slip occurs, are newly recorded or corrected when deviations occur, that is to say that the system is designed to be intelligent or capable of learning. Such deviations can e.g. B. occur due to a change in the coefficient of friction or in the contact pressure, whereby the control point at which no slip or only a very small slip occurs is shifted ben. The engagement of the clutch 3 detected for this control point can also be determined by pressure detection, e.g. B. in the hydraulic cylinder 8 to be replaced. This engagement position can also be defined by means of a force measurement.

In connection with FIGS. 3 and 5 to 15, a possible design and operation of the electronics unit 11 will now be described.

Input variables for the electronics unit 11 are the motor tooth impulses of the teeth 15 of the flywheel, which are detected by a sensor 14 and formed in an interface 124 . The frequency of the engine tooth pulses is therefore proportional to the speed of the crankshaft. The pulses of the sensor 16 for the transmission speed are formed in an interface 125 . The frequency of these gear tooth pulses is proportional to the speed of the gear input shaft.

The signals from the displacement sensor 23 for the clutch position are formed in an interface 126 . The values of the sensor 18 for the position of the throttle valve are formed in an interface 127 . The gear detection 22 provides digital values for the gear engaged and, if applicable, for the intention to shift when the gear lever is actuated. These values are processed in an interface 128 .

The motor tooth impulses and the gear tooth impulses must each be converted into speed-proportional analog quantities. For this purpose, clock pulses from an oscillator 129 are used which operate at a high frequency. In detail, the voltage-proportional voltage values are provided in each case by means of a monoflop, in particular a counter 130 or 131 which can be preset and an integrator 132 or 133 .

Fig. 5 shows the pulse shapes that occur. In the first row, the clock pulses To of the oscillator 129 are shown, which occur with constant high frequency. The second row shows the motor tooth pulses Mz , the frequency of which is proportional to the motor speed. The number of teeth 15 on the engine flywheel has the value Zn . The presettable counter 130 is programmed to a pulse number Dm . He counts an equal number Dm of clock pulses as motor clock pulses MT for each motor tooth pulse Mz . Each time the overflow occurs, the output is switched so that it maintains speed-proportional analog voltages. The output of the motor counter M is shown in the next row. The pulse duty factor T of these pulses is proportional to the engine speed.

The following lines each show the transmission tooth pulses Gz , the transmission clock pulses GT counted in the transmission counter and the pulses occurring at the output of the transmission counter G , the pulse duty factor of which is proportional to the transmission speed. The number of teeth 17 has the value Zg . The gear counter is preprogrammed to the value Dg .

The following relationships apply:

Um = K × Dm × Zm
Ug = K × Dg × Zg ,

where K is a proportionality factor. When one of the preset value for the motor counter Dm = K × Zg and the default value for the Ge gear counter Dg = K × cm selected, so you can have the abovementioned Who te To Normie temperatures for the engine speed and Ug for the transmission speed. The output pulses of the motor counter and the gear counter are integrated in integrators 132 and 133 . These are compared with one another in a comparator, so that a value or a voltage for the speed difference or the actual slip of the clutch is obtained at the output of the comparator 134 .

To dampen the ignition-specific speed fluctuations in the engine speed and to shorten the time required to determine the engine speed, a speed-dependent integrator is used as integrator 132 according to FIG. 6. Fig. 6 shows the input from the output voltage of the motor counter with the duty cycle T. A switch 135 is switched by the input pulses. The two integrators each have a resistor 136 with the value R ₁ or 138 with the value R ₂ and a capacitor 137 with the value C ₁ or 139 with the value C ₂. The integration times are then:

t ₁ = R ₁ × C ₁ or t ₂ = R ₂ × 1 / T × C ₂.

If the switch 135 is closed by the output pulses from the motor counter, the dynamic resistance increases with a decreasing duty cycle, that is to say a lower speed. This leads to an extension of the integration time at low speeds.

The absolute value of the slip is formed in a switching stage 135 . Details of this switching stage 135 are shown in FIG. 7. The incoming slip-proportional voltage is compared in a comparator 140 with the zero value. If the voltage is greater than zero, the position of the switch 141 remains unchanged so that the positive slip voltage is passed through unchanged. On the other hand, if the comparator detects a voltage value below the zero value, the switch 141 is switched over and the voltage inverted in an inverter 142 is passed.

The slip values and the other input values are available in analog form and must be combined with setpoints and other control values. These setpoints and control values must be changed depending on the operation. These values are determined and made available by means of a processor 143 , which contains a programmable arithmetic unit and an address memory as a map memory. The map memory contains characteristic curves or maps for the slip, which are stored as a function of the load, depending on the respective transmission position and, if appropriate, depending on other engine parameters such as engine temperature, engine speed and the like. The map memory contains values for the target slip and also control factors. The meaning of these values and their processing is explained below.

The processor 143 controls a multiplexer 124 and an A / D converter 145 so that the various parameters can be processed in a staggered manner. The analog values of the engine speed, the transmission speed, the clutch position, the throttle valve position and the like are converted into digital values which enable control of memory addresses of the address memory within the processor 143 . The queried memory values of the stored map are output as target slip values and converted into analog values in a D / A converter 146 . The actual slip from the switching stage 139 and the setpoint slip from the converter 146 are compared with one another in a comparator 147 and result in a differential slip value, which is then processed in controlled systems.

The corresponding controlled system comprises a P branch 148 and an I branch 149 . The characteristic curve or the gain of each controlled system can be controlled as a function of parameters, as is explained in principle in the circuit diagram in FIG. 8. Fig. 8 shows a resistor 150 and a switch 151. The switch 151 is controlled by the output pulses of a timer 152 and closed in time with these timer pulses. The duty cycle of the timer is controlled by digital manipulated values 153 . The duty cycle of the timer 152 thus determines the closing time of the switch 151 . The effective value of the resistor 150 is changed in accordance with this closing time. This parameter-dependent resistance is shown below by symbol 154 .

FIG. 9 shows the circuit diagram of a P-controller with parameter-dependent resistor 154 , FIG. 10 shows the circuit diagram of an I-controller with parameter-dependent resistor 154 , FIG. 11 shows the circuit diagram of a D-controller with parameter-dependent resistor 154 . The parameters are represented by the manipulated values 153 and each change the characteristic curve of the controlled system concerned. These control values or parameters are queried in each case by the processor 143 in the characteristic diagram and, if necessary, fed to the P branch 148 and the I branch 149 after processing, so that the differential slip value is processed in a parameter-dependent manner. The converted components of the differential slip value who added the in an adder 155 and after amplification in an output stage 156 as a manipulated variable in the actuator 10 for adjusting the clutch. In Fig. 3 is a P- are branches 148 and an I-branch 149 shown for the slip control. If necessary, the control can also contain a D branch and / or other control branches.

The control parts described are for the slip control of the Clutch required. You determine the respective position of the coupling according to the target slip.

In other driving conditions, direct control of the clutch travel regardless of the slip is desired. This applies to starting and switching operations. A parameter-dependent control branch 157 is provided for this. For gear changes or other special operating conditions that are recognized by the processor in the workflow, setpoint values for the clutch position are provided via a D / A converter 158 and compared in a comparator 159 with the actual value of the clutch position. The difference value is generally processed in branch 157 and fed into the actuator 10 in the manner described above. If necessary, you can also use a parameter-controlled control path for a negative feedback in order to exclude vibrations of the control.

Through the interface 128 to the gear position and the visual recognition is Schaltab via an output stage 161, a throttle flap Enver Stel lung driven 162, which adjusts the throttle valve in the closed position during a gear shift operation to obtain a by rotating the motor excluded.

In summary, the input variables are provided analogously and processed within the processor 143 after conversion into digital variables. The output values of the processor, which are stored and possibly processed in the map, are in turn converted to analog values and are available on the one hand as setpoints for slip or for the clutch travel and on the other hand as control parameters for setting the individual control branches. With this design, an analog control with changeable control characteristics is possible in order to optimally adapt the control in the different operating states. The individual characteristic maps are controlled on the basis of the input values of the control. Thus, based on a shift intention detection, the control is switched from the slip control to the displacement control of the clutch. In slip control mode, the stored characteristic curves can be switched depending on the gear and / or load. The working period of the processor 143 is 5 ms, so that a current change in the setpoints and control variables is possible during driving. The position control takes place when starting off, shifting or when a programmed maximum speed of the transmission input shaft is exceeded.

The interface 128 with the gear recognition and the shift intent recognition enables a change of the respective control processes. When driving, depending on the position of the throttle valve and since with the desired acceleration, the target starting speed of the engine is determined, which is kept constant by the control by appropriate speed determination while changing the slip value. The idle speed is also taken into account. Starting is only possible in 1st, 2nd or reverse gear. When starting attempts in other gears, the clutch remains open, so that starting is not possible due to the control of processor 143 . During the switching process itself, the throttle valve is closed and only opened again when the clutch is engaged. The respective speed at which the clutch and the throttle valve is adjusted when starting is limited by the branch 160 in order to avoid excessive reactions.

The slip target is typically 50 to 100 µm rotations per minute. However, other setpoints can also be found in the map be saved. In the high speed range when the speed swan The engine is low or above the resonance frequencies of the chassis and the body can be with a zero slip be driven. Working below the idle speed above control in start-up mode. Above the specified speed the clutch is fully closed and works without slippage.

The behavior of the control will now be explained with reference to FIGS. 12 to 14 for different driving conditions. Fig. 12 shows the operation of the control when starting for partial load. The position D of the throttle valve is entered in the figure below. The position D of the throttle valve indicates the desired acceleration and thus the load. The control sets the required clutch travel K according to a setpoint for the engine speed n _M. In the picture above, the engine speed n _M and the gear speed n _{G are} shown. You can clearly see the steady increase in the transmission speed n _G and thus the smooth starting behavior of the vehicle.

Fig. 13 shows the behavior of the control in a load step without switching gear. The load jump goes from 0 to 100%, as can be seen from the picture below for the throttle valve position D. The slip control applies.

Fig. 14 shows in accordance with a control characteristic for a To shift from second to third gear under full load. Here, the throttle valve is automatically closed (at D ₂) when the intention to switch (≃ at D ₁) and after the gear shift (from D ₃) is opened again slowly until the full load value D ₄ is reached to prevent the engine from over-revving. The clutch is switched to position control during the switching process. You can also see the even course during the switching process.

When the engine is switched off, the Mo the clutch is fully closed and the corresponding Coupling distance measured. This value is in the Kenn field memory and is therefore the basic value for the scheme is available.

The saved values can be determined with the current values compared values and stored in the maps be saved. So it is possible to save the memory values current operating condition, especially wear and tear stood to adjust.

Fig. 4 shows a modified embodiment of the control. Input variables for the electronics unit 11 (in FIG. 1) are the motor tooth pulses of the teeth 15 of the flywheel, which are detected by a sensor 14 and formed in an interface 124 . The frequency of the motor tooth pulses is proportional to the speed of the crankshaft. The pulses of the sensor 16 for the transmission speed are formed in an interface 125 . The frequency of these gear tooth pulses is proportional to the speed of the gear input shaft.

The signals from the displacement sensor 23 for the clutch position are formed in an interface 126 . The values of the sensor 18 for the position of the throttle valve are formed in an interface 127 . The gear detection 22 supplies digital values for the gear engaged and, if applicable, for the intention to shift when the gear lever is actuated. These values are processed in an interface 128 .

The time intervals between two successive engine and transmission pulses are measured in counters 130 and 131, respectively. For this purpose, clock pulses from an oscillator 129 are used which operate at a high frequency. The counter readings are read by the processor 143 , they are inversely proportional to the speed. The processor 143 controls a multiplexer 144 and an A / D converter 145 , so that the various parameters can be processed in a staggered manner. The clutch position, the throttle valve position and the like are converted into digital values.

The processor 143 contains an address memory as a map memory. The map memory contains characteristic curves or maps for the slip, which are load-dependent, dependent on the respective gearbox position and possibly dependent on other engine parameters. The map memory contains values for the target slip and also control factors.

The processor 143 calculates the engine speed and the transmission speed from the counter readings of the counters 130 and 131 and from this the actual slip. The actual slip and the target slip from the map are compared in the arithmetic unit of the processor 143 and result in a differential slip value, which is further processed arithmetically. A P branch and an I branch are simulated and calculated in processor 143 by known arithmetic methods. If necessary, the calculation can also contain a D branch and / or other control branches.

In the control shown in FIG. 4, no analog control loops are required, since this scheme is simulated by running the processor a Programmab 143rd The program flow of the processor 143 can be carried out according to the flow chart of FIG. 15. One recognizes in this flow chart the provision of the input variables controlled by the multiplexer 144, such as speed, clutch position, throttle valve position, gear detection and the like. In a first branching stage 171 , the engine speed is queried and compared with a minimum value that occurs below the idling speed when the engine is switched off. If the speed falls below this minimum value, the clutch is switched on completely after program part 173 and the zero point of the clutch travel is determined. This zero point of the coupling path is stored in the map. Based on the design values of the clutch, this zero point of the clutch path results in the clutch disengagement point, after which the clutch path is controlled.

In the next branch 174 , an existing switching intention is checked. If there is an intention to shift, the clutch is completely disengaged after the program part 185 so that the transmission can be shifted. If there is no intention to shift or if the transmission is shifted into the desired gear, a check is made after branch 175 whether the neutral gear or neutral is engaged. In first gear and / or in reverse gear as well as at a transmission speed below half a minimum value, a control for starting takes place after branching 176 . When the throttle valve is open, the start-up process is finally triggered after branching 177 . Otherwise, the gripping point is determined according to the branch 175 during each program run after the program part 179 , as is the idling speed and the clutch is completely disengaged again.

Branch 176 , on the other hand, leads to program part 180 , after which the desired slip of the clutch is controlled. Finally, after branching 177 in program part 181 , disengagement takes place up to the gripping point. In program part 182 , the weight parameters for the rule stretch are provided.

The replication of the control branches by a program sequence calculates the input values of the control branches and a product a factor from the map memory. The different product values are added. A damping branch is formed by a difference between those calculated in successive calculation periods realized. The calculation period should be about 3 ms.

The processor 143 carries out the above-mentioned calculations and outputs the output values to an output stage 183 , which controls the actuator 10 to control the clutch. The output stage can contain a D / A converter. There may also be a pulse generator with a controlled duty cycle.

Claims (89)

1. A method for controlling an automatic friction clutch effective between a drive machine and a transmission for at least one of the operating states such as starting, switching, driving, accelerating, braking, reversing, parking or the like, or of transitions between individual operating states, characterized in that that at least for the starting process, a control point of engagement of the clutch depending on a torque carried out within the drive train and / or an angle measurement can be determined by the clutch from a disengaged position and with the gear engaged and the vehicle stationary at a defined speed to a position , at which a moment is initiated, but this moment is less than that by which the vehicle would be moved, and a corresponding value when a certain torque and / or a certain angle is reached, e.g. B. the location of the clutch actuation, determined and fed to a memory, whereupon the clutch is at least partially opened again (waiting position). 2. The method according to claim 1, characterized in that the angle measurement between an input and an output element of one of the clutch components, such as the friction linings and the hub of the clutch disc. 3. Method of controlling one between a drive measure machine and a transmission effective automated Rei Exercise clutch for at least one of the operating states like starting, switching, driving, accelerating, braking Reversing, parking, etc. or of transitions between individual operating conditions, characterized in that a control intervention point at least for the starting process the clutch depending on a gradient determination can be determined on rotatable components of the drive train is by removing the clutch from a disengaged position and when the gear is not engaged (and the vehicle is stationary) at a defined speed to a position is closed, in which the transmission input shaft driven, but below engine idle speed remains, and one when a certain state is reached, like a certain speed, existing gradient value and a condition-dependent value, such as the location of the dome actuation, determined and fed to a memory , whereupon the clutch at least partially again is opened (waiting position).   4. The method according to claim 3, characterized in that the determined clutch operating location for determining the Control intervention point according to the determined Gradient is corrected. 5. The method according to any one of claims 1 to 4, characterized characterized in that the closing of the clutch in Dependency of changing gear from the control room position up to the control intervention point with a defined speed and from the rule grip point depending on the accelerator pedal position regulated closing of the clutch so that the Engine speed to one of the respective accelerator pedal positions assigned target rotation stored in a memory number is settled. 6. The method according to claim 5, characterized in that the engine speed is at least substantially constant is held. 7. The method according to claim 5 or 6, characterized in that that the engine speed from a stored map is derived that the respective throttle valves Settings corresponding target engine speeds that the correspond to the maximum engine torque.   8. The method according to any one of the preceding claims, characterized in that the current engine temperature dependent engine idling speed depending on the engaged neutral gear and the closed throttle flap determined and one of the corresponding Temperature associated difference amount is increased. 9. The method according to claim 8, characterized in that the starting speed depending on an inserted one Ganges, the throttle open and reaching of the predetermined, increased speed value the start-up gear is released, the engagement of the clutch is controllable from the control intervention point. 10. The method according to claim 3 or following, characterized records that the gradient from the speed, like the Speed of the transmission input shaft is determined. 11. The method according to claim 3 or the following, characterized records that the gradient consists of an angular acceleration (from an angular velocity measurement) is determined. 12. The method according to claim 3 or following, characterized characterized that a gradient from a moment build-up is determined.   13. The method according to any one of claims 3 or the following, characterized in that the gradient is dependent the throughput time of a certain speed range and determined when the upper speed range is reached becomes. 14. The method according to any one of claims 1 to 13, characterized characterized in that the clutch depending on Control intervention point opened by a constant path becomes. 15. The method according to any one of claims 1 to 14, characterized characterized in that the clutch depending on Control intervention point opened by the maximum disengagement distance becomes. 16. The method according to at least one of the preceding Claims, characterized in that the rule handle point the farther from the point that closed the its state of the clutch (zero point) is removed, depending flatter (slower) the gradient gradient increase is. 17. The method according to any one of the preceding claims, characterized in that depending on the quietest motor is closed, the clutch (zero lung).   18. The method according to claim 17, characterized in that the coupling path corresponding to the zero position in one Memory is held. 19. Method according to at least one of the preceding Claims, characterized in that depending of the engine start the clutch by the maximum release opened away, at least until the rule is determined handle point closed, a corresponding Value fed to a memory and the clutch up to Waiting position is opened again. 20. Procedure in particular according to at least one of the above outgoing claims, characterized in that at least the determined gearbox and / or engine speed using a filter, in particular a "low pass filter" is smoothed. 21. The method according to claim 20, characterized in that the filter is a so-called "moving" or "flying" filter is. 22. The method in particular according to one of the preceding Claims, characterized in that during the Driving operation at least over parts of the speed range a slip in the clutch is regulated.   23. The method according to claim 22, characterized in that a (slight) slip is permanently adjusted. 24. The method according to claim 22 or 23, characterized in net that the slip is changeable. 25. The method according to claim 24, characterized in that the slip can be changed depending on the engine speed is. 26. The method according to any one of claims 22 to 25, characterized characterized in that the slip depending on the transmitted moment is changeable. 27. The method according to any one of claims 22 to 26, characterized characterized in that the slip depending on the Throttle valve is changeable. 28. The method according to any one of claims 22 to 27, characterized characterized in that the slip can be regulated depending on the gear is. 29. The method according to any one of claims 22 to 28, characterized characterized in that the slip on each one Operating state of the vehicle, such as the engine, the Coupling or throttle valve or the like, assigned change the target slip stored in a memory  is cash. 30. The method according to any one of claims 22 to 29, characterized characterized in that the change in slip in the form a map, a table or a characteristic curve is saved. 31. The method according to any one of claims 22 to 30, characterized characterized that increase depending on one slip the clutch is (further) closed. 32. The method according to any one of claims 22 to 31, characterized characterized in that depending on one is reduced the slip (further) is opened. 33. Method according to at least one of the preceding Claims, characterized in that the slip through Change in the contact pressure of the clutch is changeable. 34. Method in particular according to one of the preceding Claims, characterized in that during the Driving operation at least over sections of the speed limit range of the engine that is transferable from the clutch Moment depending on operating parameters such as the Accelerator pedal position is adjusted to a value that is as equal as possible to the engine torque (Equal moment).   35. The method according to any one of the preceding claims, characterized in that at a found Slip the transmissible torque of the clutch (like Clutch travel, clutch contact pressure or the like) is changeable until the slip is at least approximately is eliminated (equal torque). 36. Method according to at least one of the preceding Claims, in particular claim 34, characterized net that at least approximately the same moment between the input and output side of the clutch existing operating parameters, such as accelerator pedal position, Clutch travel, clutch pressure or the like in be held in memory. 37. Method according to one of the preceding claims, characterized in that the parameters at which the Slip becomes practically "zero" in the form of a map or a characteristic curve can be saved. 38. The method according to any one of claims 34 to 36, characterized characterized in that at least at approximate moments the coupling at certain intervals (slightly) is opened until a (slightly) Slip is detected, then the clutch again is closed wide until at least a smaller one  (no) slip is detected. 39. The method in particular according to claim 38, characterized characterized in that the time intervals depending on the Operating states of the engine or the force vehicle are changeable. 40. The method in particular according to claim 39, thereby characterized in that at practically constant torque ver run in the drive train, like constant engine load, the Time intervals are larger than for torque changes, especially sudden changes in torque. 41. The method according to any one of claims 38 to 40, characterized characterized in that the time intervals depend on the speed at which the accelerator pedal position is changed. 42. The method according to any one of claims 1 to 41, characterized characterized in that the determined and stored Information, such as rule intervention point, Zero point, waiting position, slip, torque equilibrium points of view or the like due to each new determined information are updated. 43. The method in particular according to claim 42, characterized records that the most recently determined information  with the corresponding information stored is compared and in the event of a deviation from this is exchanged. 44. The method according to claim 42 or 43, characterized net that the last determined information with the stored corresponding information compared and a plausibility check is carried out. 45. The method according to any one of the preceding claims, characterized in that determined from several Information values of the same kind are averaged and saved. 46. The method according to any one of the preceding claims, characterized in that the particular one Accelerator pedal position assigned and saved engine speed at least for the starting process depending the engine temperature is corrected. 47. Method according to one of the preceding claims, characterized in that the idle speed is determined with the clutch open at idle or in gear Gear and / or clutch engaged at idle and each time the accelerator pedal is not operated. 48. Method in particular according to one of the preceding  Claims, characterized in that depending a sudden load change, such as transition from train to The clutch opens quickly for a short time (around an adhesion phase in the zero crossing of the slip to prevent). 49. The method in particular according to claim 48, characterized characterized that the speed of the load change due to the speed of change of the accelerator pedal position and / or the engine speed change detected becomes. 50. The method according to claim 49, characterized in that the clutch first up to the control intervention point is opened and with the accelerator pedal still partially depressed on the intervention corresponding to the accelerator pedal position point is closed again. 51. The method according to claim 48 or the following, thereby characterized in that the overrun and when not operated accelerator pedal the clutch to the control intervention point opens. 52. Method according to one of the preceding claims, characterized in that starting only in the first Gear and / or in second gear and in reverse gear is possible.   53. Method in particular according to at least one of the above going claims, characterized in that the Gear shifting the fuel supply while driving direction is returned to the idle position, without the driver taking his foot off the accelerator needs, continue to open the clutch and after success The clutch closes again when the gear is changed and the fuel supply device back to that of the position corresponding to the respective accelerator pedal position opens. 54. Method according to at least one of the preceding Claims, characterized in that due to the determined and stored waymarks, such as zero point, Control intervention point, waiting position, the state of wear the friction clutch is monitored and when a Limit this is displayed. 55. Method according to at least one of the preceding Claims, characterized in that the due to a Slippage of energy generated in the friction clutch is determined and when a limit value is exceeded a message is issued and / or the clutch engagement status is changed. 56. The method according to claim 55, characterized in that  if the limit is exceeded, the clutch for Reduction of the friction energy with defined speed closed or open becomes. 57. The method according to claim 55, characterized in that an automatic gear change when the limit value is reached sel recommended or automatically with automated gearbox tig takes place, for example in the next lower gear. 58. The method according to any one of claims 55 to 57, characterized characterized in that to determine the in the clutch occurring friction energy the product of slip and transmitted moment is integrated over time. 59. The method according to claim 58, characterized in that the determined friction energy in defined time intervals which is reduced by a cooling constant. 60. Method for controlling an automated slip clutch tion for or during switching, in particular according to one of the preceding claims, such as Claim 53, characterized in that depending after actuating the gear lever, the clutch is opened after Engaging the aisle the defined controlled closing the clutch is initiated by depending on the Position of the accelerator pedal the speed of engagement  process is adjustable. 61. The method according to claim 60, characterized in that depending on the speed of the engagement process the fuel supply is regulated. 62. Method in particular according to one of claims 1 to 61, characterized in that as an actuator a hydraulic, quantity-controlling for the clutch Proportional valve (like 4/3 or 3/3-way valve) is provided. 63. The method according to any one of claims 60 to 62, characterized characterized in that as a clutch actuator a hydraulic, proportional to volume, in terms of servo valve integrating the clutch position is provided. 64. Method, in particular according to one of the preceding Claims such as claim 60 or the following characterized that the clutch for switching only is disengaged when the gear lever is in one direction is loaded or moved, the load or Movement of the lever from the engaged gear position in the next or preceding gear position corresponds.   65. Device for performing the method according to claim 64, characterized in that the signal to open the Coupling of the clutch actuation is fed in Dependency of the gear engaged (gear recognition direction) and depending on the actuation or Loading the gear lever in one direction of the next fol current or preceding gear stage (gear shiftab view detection). 66. Device for performing the method for controlling an automated friction clutch, in particular according to one of the preceding claims, characterized by at least some of the switching, measuring and regulating devices listed below, and electronic unit with at least computer and memory, with which at least one is connected

• a) a measure for detecting the engine speed, for example in the form of a sensor scanning the teeth on the flywheel
• b) a precaution to determine the transmission speed
• c) a measure for measuring the clutch actuation path, for example in the form of a path of the clutch actuator, such as a hydraulic slave cylinder, sensing potentiometer
• d) a provision for detecting the position of the fuel supply device, for example in the form of a potentiometer which determines the throttle valve position
• e) a precaution for detecting the accelerator pedal position in the form of, for example, a potentiometer that can be influenced by the accelerator pedal
• f) a device for determining the idle position of the fuel supply device
• g) a precaution to detect the transmission position with idle and gear detection
• h) a precautionary measure for switching intent recognition in the form of, for example, a sensor provided on the gear shift lever.
• i) a device for detecting the throttle valve end position
• j) a temperature measuring device,

whereby the electronics can at least be controlled

• k) a clutch actuator, such as a hydraulic transmitter and slave device
• l) a drive device for changing the throttle valve position.

67. Institution for carrying out the method according to a of the preceding claims, characterized in that it includes detection of the direction of rotation.   68. Device according to claim 67, characterized in that the direction of rotation detection with the transmission input shaft cooperates. 69. Device according to claim 67, characterized in that the detection of the direction of rotation with an intermediate gear shaft le or transmission output shaft interacts. 70. Establishment for carrying out the procedure according to at least one of the preceding claims 1 to 69, characterized in that it detects a roll direction tion includes. 71. Device according to one of claims 67 to 70, characterized characterized that the direction of rotation detection and Roll direction detection form a unit. 72. Device according to one of claims 66 to 71, characterized characterized in that it additionally comprises an ABS system, that is used for roll direction detection. 73. Regulation for the transmission torque of a clutch between an engine and a transmission, in particular for carrying out a method according to one of claims 1 to 64, characterized by the following features:

• a) an actual slip is determined as the difference between the engine speed and the transmission speed;
• b) a processor periodically queries input parameters such as clutch travel, throttle valve position (load), engine temperature and / or gearbox position and determines a target slip and characteristic control factors by querying stored characteristic maps;
• c) a manipulated variable for the clutch travel is formed from the difference between the desired slip and the actual slip in a controlled system controlled by the control factors.

74. Regulation for the transmission torque of a clutch between an engine and a transmission, characterized by the following features:

• a) an actual slip is determined as the difference between the engine speed and the transmission speed;
• b) a processor periodically queries input parameters such as clutch travel, throttle valve position (load), engine temperature and / or gearbox position and determines a clutch target travel and characteristic control factors when a load change condition occurs;
• c) The clutch path setpoint and the clutch path actual value are compared with one another and a manipulated variable for the clutch path is formed.

75. Regulation according to claim 72 or 74, characterized net that for speed measurement of the engine and / or gear bes the respective tooth impulses a presettable Counters provide high frequency clock pulses in this presettable counter are counted and that the Output pulses of the presettable counter have duty cycle proportional to the speed. 76. Regulation according to claim 75, characterized in that the respective preset value of the counter for the motor clock pulses and the counter for the transmission clock pulses taking into account the number of teeth in the sense a standardization of the speed values can be selected. 77. Regulation according to claim 75 or 76, characterized in that the output pulses of the respective presettable counter in a speed-dependent integrator ( Fig. 5) are integrated to form a speed-proportional analog voltage. 78. Regulation according to claim 77, characterized in that the integrator in series two RC links and between the same one through the output pulses of the previous  adjustable counter controlled electronic switch includes. 79. Regulation according to claim 78, characterized in that to form the absolute value of the actual slip Inverter, a switch for switching between the actual Slip values and the inverter output and one Comparator for controlling the switch includes. 80. Regulation according to one of claims 76 to 79, characterized characterized in that the output values of the integrators in compare a comparator for the formation of an actual slip will be. 81. Regulation according to one of claims 73 to 80, characterized characterized in that the analog input variables each converted into digital values in an A / D converter, the as input variables for querying the maps serve. 82. Regulation according to claim 81, characterized in that the processor for staggered polling and processing device of the values comprises a multiplexer. 83. Regulation according to one of claims 73 to 82, characterized characterized that the output variables of the processor each in a D / A converter in analog values for target  Slip, target clutch travel and control parameters being transformed. 84. Regulation according to claim 82 or 83, characterized net that from the actual values and target values each in a control value is determined using a comparator. 85. Regulation according to one of claims 81 to 84, characterized characterized that each control loop for processing of an actuating value contains an electronic switch, by pulses with controlled duty cycle according to the respective map value and the desired control characteristic is controllable. 86. Regulation according to one of claims 73 to 85, characterized characterized in that a sensor for detecting a Switching intent is provided, the closing of the Throttle valve and the regulation of the clutch travel causes. 87. Regulation according to one of claims 73 to 86, characterized characterized that the path control for the clutch path a feedback branch to limit the adjustment speed includes. 88. Regulation according to one of claims 73 to 87, characterized characterized in that in the engine shutdown phase  complete engagement of the clutch the zero point for the Coupling travel determined and stored in the map becomes.