DE10316438B4 - Method and transmission control for determining a target gear in an automated transmission - Google Patents

Abstract

A method is proposed for determining a target gear in an automated transmission in a drive train of a vehicle, in which the currently engaged gear is maintained in an operating situation in which the vehicle speed cannot be reliably determined. Furthermore, a transmission control for an automated transmission, in particular for carrying out the method, is proposed which, in an operating situation in which the vehicle speed cannot be reliably determined, the currently engaged gear is maintained.

Description

The present invention relates to a transmission controller and method for determining a target gear in an automated transmission in a powertrain of a vehicle.

Vehicles with an automated clutch or an automated transmission in the drive train are known from automotive engineering. In particular, in the automated transmission, the gear selection and the gear change can be carried out independently. However, it has been shown that in case of failure of the transmission or incorrectly transmitted wheel speeds secure target gear calculation may not take place under certain circumstances.

Therefore, z. B. be provided that the output stages of the transmission actuators are switched off, so a so-called shut-down (shutdown) is performed. The so-called shut-down can be triggered at any time in any gear position. To cancel the shutdown, it is necessary that the ignition must be switched off in the meantime and the resulting error is filtered out accordingly. If the causing error is still active, the vehicle can not be moved in this case with gear engaged. Accordingly, thereby the availability and safety in the operation of the vehicle is limited.

• a) beruhend auf den Betriebszustand des Fahrzuges repräsentierender Information, Erzeugen einer Ansteuerungsvorgabe für die automatisierte Kupplungsanordnung und/oder die automatisierte Getriebeanordnung, um diese in einen Stellzustand zu bringen oder in diesem zu halten,
• b) beruhend auf den Betriebszustand des Fahrzeugs repräsentierender Information, Überprüfen, ob eine Übergang oder/und Ansteuervorgabe entsprechend der Art des Übergangs der automatisierten Kupplungsanordnung und/oder der automatisierten Getriebeanordnung in einen Stellzustand zulässig ist,
• c) dann, wenn gemäß Maßnahme a) eine Ansteuervorgabe zum Erhalt des Stellzustand erzeugt wird und gemäß Maßnahme b) ein Übergang und/oder eine der Ansteuervorgabe entsprechend der Art des Übergangs in diesen Stellzustand nicht zulässig ist, Ergreifen einer Sicherheitsmaßnahme.

The DE 199 47 025 A1 discloses a method for driving a drive system of a vehicle, which drive system comprises an automated clutch arrangement and / or an automated transmission arrangement and a drive device for controlling the automated clutch arrangement and / or the automated transmission arrangement according to an operating state of the vehicle, and comprises the following measures:

• a) based on the operating state of the vehicle representative information representing generating a drive specification for the automated clutch assembly and / or the automated transmission assembly to bring this in a state of adjustment or in this,
• b) based on the information representing the operating state of the vehicle, checking whether a transition and / or control input according to the type of transition of the automated clutch assembly and / or the automated transmission assembly is allowed in a control state,
• c) if, in accordance with measure a), a control input is generated to obtain the control state and, according to measure b), a transition and / or one of the control command according to the type of transition to this control state is not permissible, taking a safety measure.

The DE 197 49 681 A1 discloses a motor vehicle having an apparatus for automated operation of a transmission and / or a torque transmission system such as a clutch. The DE 195 27 414 A1 discloses a method for monitoring a shifting sequence in an automated transmission. In order to detect error states, it is proposed in a solution to compare the actual translation profile with a desired translation profile. In another solution, the course of the differential speed on the upcoming switching element is considered. It is also possible to evaluate the gradient of the differential speed at the coming switching element. It is also possible to monitor the gradient of the transmission input speed. Furthermore, in a further solution, a comparison of the gradient of the transmission output speed is provided. As a result of the comparison, a transmission ratio is maintained or brought about in a predetermined safety state. In the US 4,635,508 a method is disclosed in which a faulty speed signal of the engaged gear is maintained.

Accordingly, it is the object of the present invention to propose a transmission control and a method for determining a target gear in an automated transmission in a drive train of a vehicle, by which the vehicle availability and the vehicle safety is increased.

This object can be achieved procedurally by a method for determining a target gear in an automated transmission in a drive train of a vehicle in which in an operating situation in which the vehicle speed can not be reliably determined, the currently engaged gear is maintained.

Thus, if the vehicle speed can no longer be determined with appropriate safety by the transmission control or the like, the current gear which is engaged in the transmission is correspondingly frozen. This means that a gear change in this case is not possible.

According to the invention, however, the energization of the output stages of the gear actuators is preferably maintained, so as to be able to complete a started circuit still safe.

As part of a development of the invention may, for. B. be provided that the frozen current gear is maintained until z. B. the driver moves the gear selector lever to the neutral position. In a neutral gear request then the frozen gear can be taken out again, since the transmission is in this case in the neutral position and thus can not occur safety-critical situations.

If z. B. the gear selector lever is brought back into the driving position or drive position and the driver operates the accelerator pedal, in particular over a predetermined limit, can be provided according to a development of the present invention, that then a gear is engaged in which a Overspeeding the engine is avoided even at high speeds. This can be z. B. be achieved by choosing the 4th or 5th gear as the gear.

When the gear selector z. B. in the R position (backward) is brought, can be provided according to another embodiment of the invention that the neutral gear is engaged; because it can not be ruled out that the vehicle is moving forward at high speed.

It is particularly advantageous that the method according to the invention can be used for almost every transmission system that enables automatic gear selection.

The object underlying the invention can also be achieved by a transmission control for an automated transmission, in particular for carrying out the method, wherein in an operating situation in which the vehicle speed can not be reliably determined, the currently engaged gear is maintained.

Further advantages and advantageous embodiments will become apparent from the dependent claims.

Furthermore, the invention relates to a method, an apparatus and their use for operating a motor vehicle.

According to 1 indicates a vehicle 1 a drive unit 2 such as a motor or an internal combustion engine. Furthermore, in the drive train of the vehicle 1 a torque transmission system 3 and a gearbox 4 arranged. In this embodiment, the torque transmission system 3 arranged in the power flow between the engine and transmission, wherein a drive torque of the engine via the torque transmission system 3 to the gearbox 4 and from the transmission 4 on the output side to an output shaft 5 and to a downstream axis 6 as well as to the wheels 6a is transmitted.

The torque transmission system 3 is as a clutch, such as. Example, as a friction clutch, multi-plate clutch, magnetic powder clutch or torque converter lock-up clutch, configured, wherein the clutch may be a self-adjusting or a wear-compensating coupling. The gear 4 is an uninterruptible gearbox (USG). According to the inventive concept, the transmission can also be an automated transmission (ASG), which can be switched automatically by means of at least one actuator. As an automated manual transmission is further to be understood an automated transmission, which is connected to a traction interruption and in which the switching operation of the transmission ratio is controlled by at least one actuator.

Furthermore, as USG also find an automatic transmission use, wherein an automatic transmission, a transmission is substantially without interruption of traction in the switching operations and which is usually constructed by planetary gear stages.

Furthermore, a continuously variable transmission, such as conical-pulley transmission can be used. The automatic transmission can also be equipped with a torque transmission system arranged on the output side 3 , be designed as a clutch or a friction clutch. The torque transmission system 3 can continue to be designed as a starting clutch and / or reversible clutch for reversing the direction of rotation and / or safety clutch with a selectively controllable transmissible torque. The torque transmission system 3 may be a dry friction clutch or a wet friction clutch, for example, running in a fluid. It can also be a torque converter.

The torque transmission system 3 has a drive side 7 and an output side 8th on, with a torque from the drive side 7 on the output side 8th is transferred by z. B. the clutch disc 3a by means of the pressure plate 3b , the plate spring 3c and the release bearing 3e as well as the flywheel 3d is charged with force. To this admission, the release lever 20 by means of an actuating device, for. As an actuator operated.

The activation of the torque transmission system 3 takes place by means of a control unit 13 , such as B. a control unit, which the control electronics 13a and the actor 13b may include. In another advantageous embodiment, the actuator 13b and the control electronics 13a also in two different units, such. As housings, be arranged.

The control unit 13 can the control and power electronics for controlling the drive motor 12 of the actor 13b contain. This can be advantageously achieved, for example, that the system as a single space, the space for the actuator 13b needed with electronics. The actor 13b consists of the drive motor 12 , such as B. an electric motor, wherein the electric motor 12 via a transmission, such. As a worm gear, a spur gear, a crank gear or a threaded spindle gear, on a master cylinder 11 acts. This effect on the master cylinder 11 can be done directly or via a linkage.

Movement of the initial part of the actuator 13b , such as B. the master cylinder piston 11a , comes with a clutch travel sensor 14 detected, which detects the position or position or the speed or the acceleration of a large, which is proportional to the position or engagement position or the speed or acceleration of the clutch. The master cylinder 11 is via a pressure medium line 9 , such as B. a hydraulic line, with the slave cylinder 10 connected. The starting element 10a the slave cylinder is with the release means 20 , z. B. a release lever, operatively connected, so that a movement of the output part 10a the slave cylinder 10 causes the release means 20 also moved or tilted to that of the clutch 3 to control transmissible torque.

The actor 13b for controlling the transmittable torque of the torque transmission system 3 can be druckmittelbetätigbar, ie, it may have a Druckmittelgeber- and slave cylinder. The pressure medium may be, for example, a hydraulic fluid or a pneumatic medium. The actuation of the Druckmittelgeberzylinders can be done by an electric motor, wherein the drive element as 12 provided electric motor can be controlled electronically. The drive element 12 of the actor 13b may be in addition to an electric motor drive element and another, for example, pressure-medium-actuated drive element. Furthermore, magnetic actuators can be used to adjust a position of an element.

In a friction clutch, the control of the transmittable torque takes place in that the contact pressure of the friction linings of the clutch disc between the flywheel 3d and the printing plate 3b targeted. About the position of the release 20 , such as As a release fork or a Zentralausrückers, the application of force to the pressure plate 3b respectively the friction linings are selectively controlled, the pressure plate 3b can be moved between two end positions and set and fixed as desired. The one end position corresponds to a fully engaged clutch position and the other end position of a fully disengaged clutch position. To control a transmittable torque, which is, for example, less than the momentarily applied engine torque, for example, a position of the pressure plate 3b be driven, which lies in an intermediate region between the two end positions. The coupling can by means of targeted activation of the release 20 be fixed in this position. However, it is also possible to control transmittable clutch torques which are defined above the currently pending engine torques. In such a case, the currently pending engine torques can be transmitted, wherein the torque irregularities in the drive train are damped and / or isolated in the form of, for example, torque peaks.

For controlling the torque transmission system 3 Furthermore, sensors are used which at least temporarily monitor the relevant quantities of the entire system and supply the control variables necessary for the state variables, signals and measured values which are processed by the control unit, wherein a signal connection to other electronic units, such as to an engine electronics or electronics of a Antilock braking system (ABS) or traction control (ASR) can be provided and can exist. The sensors detect, for example, speeds, such as wheel speeds, engine speeds, the position of the load lever, the throttle position, the gear position of the transmission, a shift intent and other vehicle-specific characteristics.

The 1 shows that a throttle sensor 15 , an engine speed sensor 16 and a tachometer sensor 17 Can be used and readings or information to the control unit 13 hand off. The electronics unit, such as. B. a computer unit, the control electronics 13a processes the system inputs and gives control signals to the actuator 13b further.

The transmission is as z. B. stepped change gear, wherein the gear ratios by means of a shift lever 18 be changed or the gearbox by means of this lever 18 is operated or operated. Furthermore, on the shift lever 18 of the manual transmission at least one sensor 19b arranged, which detects the shift intention and / or the gear position and to the control unit 13 forwards. The sensor 19a is hinged to the transmission and detects the current gear position and / or a shift intention. The shift intent detection using at least one of the two sensors 19a . 19b can be done by the sensor is a force sensor, which on the shift lever 18 acting force detected. Furthermore, however, the sensor can also be configured as a displacement or position sensor, wherein the control unit recognizes a switching intent from the time change of the position signal.

The control unit 13 is at least temporarily in signal communication with all sensors and evaluates the sensor signals and system input variables in such a way that depending on the current operating point, the control unit control or regulation commands to the at least one actuator 13b outputs. The drive motor 12 of the actor 13b , z. As an electric motor, receives from the control unit, which controls the clutch actuation, a manipulated variable in response to measured values and / or system input variables and / or signals of the connected sensors. This is in the control unit 13 a control program implemented as hardware and / or software that evaluates the incoming signals and calculates or determines the output variables based on comparisons and / or functions and / or maps.

The control unit 13 Advantageously, it has implemented or is in signal communication with at least one of these units, a torque determination unit, a gear position determination unit, a slip determination unit, and / or an operating condition determination unit. These units can be implemented by control programs as hardware and / or as software, so that by means of the incoming sensor signals the torque of the drive unit 2 of the vehicle 1 , the gear position of the gearbox 4 as well as the slip, which in the area of the torque transmission system 3 prevails and the current operating state of the vehicle 1 can be determined. The gear position determination unit determines based on the signals of the sensors 19a and 19b the currently engaged gear. Here are the sensors 19a . 19b on the shift lever and / or on internal gear actuating means, such as a central shift shaft or shift rod, hinged and detect these, for example, the location and / or speed of these components. Furthermore, a load lever sensor 31 at the load lever 30 , such as B. on an accelerator pedal, which detects the load lever position. Another sensor 32 can act as an idle switch, ie when the load lever is actuated 30 or accelerator pedal is this idle switch 32 switched on and with the load lever not actuated 30 it is off, so that can be detected by this digital information, whether the load lever 30 is pressed. The load lever sensor 31 detects the degree of operation of the load lever 30 ,

The 1 shows next to the load lever 30 and the associated sensors, a brake actuator 40 for actuating the service brake or the parking brake, such. As a brake pedal, a hand brake lever or a hand or foot operated actuator of the parking brake. At least one sensor 41 is on the actuator 40 arranged and monitors its operation. The sensor 41 is for example as a digital sensor, such. B. as a switch, designed, which detects that the brake actuator 40 is pressed or not operated. With the sensor 41 can a signaling device, such. As a brake light, are in signal communication, which signals that the brake is actuated. This can be done both for the service brake and for the parking brake. The sensor 41 However, it can also be designed as an analog sensor, wherein such a sensor, such as a potentiometer, the degree of actuation of the brake actuator 41 determined. This sensor can also be in signal connection with a signaling device.

Hereinafter, a possible embodiment of the invention presented here will be described, in which a model-based compensation, in particular in geared motors or the like, is provided.

It has been shown that in particular in an automated manual transmission (ASG), the geared motors such. As selector and switching motors are controlled in different modes, for example, position or speed controlled. The z. For example, control schemes performed in an off-line mode are usually based on simple physical models of the gearmotors and actuators. These Models are verified by simulations and measurements. In particular, studies on a test bench and on the vehicles have shown, however, that a changed track behavior can lead to loss of comfort and in unfavorable cases even to malfunction or failure of the gear actuator. Possible causes for route changes are z. B. production-related fluctuations in the engine characteristics in new condition of the vehicle. Furthermore, causes can also be wear and aging of the motors over the entire service life or even temporarily occurring temperature influences.

It is possible that temperature-induced changes in the route in the control software of the automated manual transmission via a z. B. experimentally determined static compensation can be considered. However, a temperature-dependent adaptation of the controller parameters does not take place.

In order to realize a systematic and comprehensive consideration of all possible route changes, for example, the adaptation of the controller parameters and / or the compensation of the route changes can be provided. Both procedures, however, require suitable route models and a method that can be implemented in the control software for identifying the route changes in the online mode.

An adaptation of the controller parameters can, for. B. implemented when the control design is implemented in the control software and is performed in online mode. However, a sufficient capacity in terms of storage, the term or the like. In the controller used is required. A second possibility may be that the controller parameters are calculated for different route behavior in offline mode and then in the control software z. B. stored in predetermined maps. In addition, all force specifications defined in the control software must be suitably adapted. In order to avoid this, according to the invention presented here, a model-based strategy for compensating route changes can be provided, in the application of which the controller parameters and force specifications implemented in the control software do not have to be adapted in an advantageous manner.

In the context of the invention presented here, a model-based compensation strategy is proposed, in particular for gearmotors and for actuators, with which an identified track change with respect to a reference model can be compensated without the parameters and specifications implemented in the software having to be adapted. A corresponding flow chart of the compensation strategy according to the invention is shown in FIG 2 shown schematically. There, the arrangement of identification and compensation in a corresponding control circuit is indicated.

This compensation strategy includes a distinction between temporarily occurring temperature-related route changes and long-term changes in the route behavior that are dependent on the operation and the hardware. It is conceivable that further suitable aspects are taken into account in the strategy according to the invention. For example, in the strategy according to the invention, an adaptation of the compensation to a changed path behavior, a limitation of the compensation and / or a storage of the long-term changes in route can be taken into account.

It is particularly advantageous in the compensation strategy according to the invention presented here that these are based on simple parametric models of the gearmotors and / or the actuators. Taking into account predetermined boundary conditions, the model parameters can preferably be selected in online mode during a gear change, for example during a gear change. B. in position-controlled operation of the geared motors identified. For z. B. be implemented in the control software, a suitable parameter estimation method. For the identification of the compensated and, for example limited to the maximum battery voltage voltages U _k and the measured gear engine speeds n can be used. It is also possible that other parameters and sizes are taken into account.

The deviations of the identified model parameters from the parameters of the reference models can theoretically be used for the derivation of a complete, especially dynamic compensation strategy. Due to the simple track models, the dead times in the detection of engine speeds or the like. However, a partial static compensation of the route changes may be useful.

A possible static compensation strategy may preferably comprise the following steps, which are shown schematically in FIG 3 are shown, with the individual steps with 1 to 6 are numbered.

After a successful identification, the new model parameters can be used to create a new system gain k in a first step 1 be calculated, cf. 3 ,

In a second step 2 is the system gain k with the already implemented in the control software temperature compensation 7 suitably corrected, which before the limitation of the position controller voltages U _R , which are used as control variables, to the maximum battery voltage and the conversion to z. B. PWM sizes (pulse width modulation sizes) takes place. The correction carried out has the task of separating the long-term path changes from the temperature-dependent and temporarily occurring changes and the temperature compensation 7 containing uncertainties. A possible uncertainty can z. B. in that the compensation is based on the transmission temperature, which is calculated in the control software with a temperature model. The temperature conditions on the gearmotors may not be known. From a control point of view, the temperature compensation can thus only take over the function of a pilot control, but with the failure of the identification, at least within a certain frame, temperature-induced changes in the route can be compensated.

The filtering performed in a third step of the inventive compensation strategy 3 The distance gain K ₁ is used to weight new gain values and thus determines the adaptation speed of the compensation to a changed track behavior, preferably using a first-order discrete filter. However, it is also possible to use other filters for filtering in the inventive compensation strategy. The filter constant can be z. B. be constant or be given as a function of other boundary conditions. For example, the temperature, its change or the like can be used as a boundary condition.

The filtered gain value K ₂ can then be limited to a defined range of values, which in a fourth step 4 is carried out. Thus, aspects such as the robustness of the control or the protection of the actuators and geared motors can be suitably taken into account. The robustness of the control can z. B. be affected if the dynamics of the route is increased; this means that the system is more sensitive to disturbances and at the same time the compensation of the system is increased, which corresponds to an additional excitation of the system.

The initialization from the executed limit 4 resulting compensation gain K _c can preferably be done once after start-up with the path gain K _{r of} the reference model. The normally changing compensation gain during operation may be within a fifth step 5 z. B. in the state "ignition off" are preferably stored in the so-called EEPROM. This stored value can be z. B. be used as the starting value at the next state "ignition on". Changes in temperature occurring between the states "ignition off" and "ignition on" can then be caused by the temperature compensation 7 be compensated. In order to take into account the uncertainties in the temperature compensation can also be provided options in which preferably the gain value is stored only in the state "ignition off" when the transmission temperature is within a defined range and / or a certain, dependent on the value of the filter constant number successfully performed identifications. Other possibilities for taking into account the uncertainties in the temperature compensation are also conceivable.

In a last step 6 the strategy of the invention may, for. B. the actual static compensation of the position controller voltage U _{R are} performed. The compensated voltage U _c can result from the product of U _R and the ratio K _R / K _c .

In order to further improve the strategy according to the invention, provision can be made for further suitable steps to be integrated into the strategy according to the invention or for another arbitrary combination of said steps to be provided.

The compensation strategy presented here can preferably be used in all vehicles which have an automated manual transmission (ASG). It is also conceivable that the present strategy will be used on vehicles with other transmissions.

It is particularly advantageous in the strategy presented here that the compensation can be combined with a suitable adaptation of the controller parameters. It is also conceivable for the adaptation of the controller parameters or the like to be carried out independently of the compensation carried out.

Hereinafter, a further embodiment of the invention presented here will be described, in which a possible strategy for the detection, for. B. a shift finger break in a switching actuator or the like., Is proposed.

It has been shown that z. B. at a fraction of the dialing of an automatic transmission (ASG), the transmission control can still measure Wählinkremente, although the shift finger in the transmission can not move in the direction of selection. Thus, it is possible that possibly wrong gears are inserted. In particular, if the first gear and the reverse gear are arranged side by side, then in a desired change from gear 1 to R without selecting movement again 1st gear can be engaged and then the vehicle will be moved in the wrong direction. This should be avoided at all costs.

Accordingly, in the context of an embodiment of the present invention, a detection capability is proposed to z. B. to detect a fraction of Wählaktorik or even a total failure of the dialing. This can z. B. after a gear change, preferably first in the RL direction (right-left direction) the lane width are felt. If z. B. in this scan, the corresponding lane walls are found or detected, a break or misconduct of Wählaktorik can be excluded. For example, it can be provided that the clutch is not closed until at least one stop in the RL direction has been found. Thus, however, it may happen that the torque to be transmitted is delayed on the drive train, which under certain circumstances can lead to a route of the engine. To prevent this, preferably, the structure of the engine torque can be delayed according to the structure of the clutch torque. By the inventive detection of a z. B. broken Wählaktorik can be excluded in particular that the vehicle anfährt in an undesirable direction, because falsely z. B. a forward gear instead of the reverse gear or vice versa has been inserted. This inventive detection or detection of a malfunction of the Schaltaktorik can be used preferably in automated manual transmissions but also in other transmissions.

Hereinafter, a further embodiment of the invention presented here will be described, in which a plausibility of the direction of movement z. B. is proposed by electric motors based on the Bestromungsrichtung.

It has been shown that, due to an increased contact resistance, for example due to moisture at the plug contacts, it can affect the voltage level of a directional and / or frequency signal. This can be z. B. lead to it that an incorrect direction of movement can be interpreted.

For detecting the direction of rotation in the geared motors z. B. from each switching and / or dial motor preferably be provided depending on a frequency and a direction signal. The frequency signal can then be evaluated as a function of the direction signal preferably via an up / down counter directly on the microcontroller.

• – Kurzschluss Masse
• – Kurzschluss Plus/Kabelbruch
• – High-Pegel (ca. 8 Volt)
• – Low-Pegel (ca. 4 Volt)

For example, each signal may preferably provide four different states of information:

• - short circuit ground
• - Short circuit plus / cable break
• - high level (about 8 volts)
• - low level (about 4 volts)

It is possible that a short circuit of the signals z. B. a Hall sensor is detected immediately. A plausible but wrong signal, z. B. by an altered contact resistance on a plug or the like., Can not be detected in this case directly on the voltage level. In order to recognize this error as well, provision can be made, for example, for a parallel model to be used. Similar to a PT1 element or the like, the parallel model can compare the energization with the changed position accordingly.

• – Pulsweitenmodulations-Signal (PWM-Signal) ist hinsichtlich seiner Verdrahtung vertauscht;
• – die Magnete oder der Poltopf des Motors ist bei der Fertigung vertauscht worden;
• – der verwendete Hallsensor ist defekt, welches aus dem Richtungssignal generiert wird;
• – die Übergangswiderstände sind zu hoch z. B. bei verwendeten Steckkontakten;

As part of an advantageous embodiment of the present invention can be provided, this so-called parallel model is extended by a further error detection. In particular, this advanced model should be improved in terms of its speed for detecting possible errors. This can z. B. be provided that in a de-energized, stationary engine preferably a plausibility of the starting current is provided with the direction signal. It will checks whether the received direction signal after a certain time T with corresponding rotational movement X for a predetermined time does not match the predetermined Bestromungsrichtung. If this case, z. B. the power amplifier are turned off. Possible causes of error can be z. For example:

• - Pulse width modulation signal (PWM signal) is reversed in terms of its wiring;
• - The magnets or the pole pot of the engine has been reversed during manufacture;
• - The used Hall sensor is defective, which is generated from the direction signal;
• - The contact resistance is too high z. B. when used plug contacts;

Furthermore, in addition to the already mentioned applications with a frequency and a direction signal, other applications may be provided which are used in motors with a plurality of sensors, in particular Hall sensors or the like, ie with different frequency signals. In these applications, the direction can be determined from the order of the frequency levels, such. B. brushless motors.

For these applications monitoring can be done as follows; starting from a standby, stationary motor, a plausibility check of the starting current with the Hall signals is carried out. It is checked whether the next received sensor edge does not match the predetermined Bestromungsrichtung. If this is the case, the output stage can also be switched off.

The cause may be in addition to a falsified level or frequency level and a defective sensor, in particular Hall sensor. Due to the very fast error detection according to the invention, under certain circumstances it may be possible to dispense with the otherwise additional short circuit monitoring in an advantageous manner.

It is also possible that the above-mentioned and also other measures for checking the plausibility of the movement direction are combined with one another as desired in order to further improve the method according to the invention.

A further embodiment of the invention presented here will be described below, in which a possible strategy is preferably proposed for freezing the current gear in case of uncertainties regarding the determination of the vehicle speed.

It has been shown that in case of failure of the transmission or incorrectly transmitted wheel speeds safe target gear calculation can no longer take place. Therefore, z. B. be provided that the output stages of the transmission actuators are switched off, so a so-called shut-down (shutdown) is performed.

The so-called shut-down can be triggered at any time in any gear position. For a cancellation of the shut-downs z. B. be provided that the ignition must be switched off in the meantime and the causative error is filtered out accordingly. If the causing error is still active, the vehicle can not be moved in this case with gear engaged. Accordingly, thereby the availability and safety in the operation of the vehicle is limited.

Accordingly, the present invention has for its object to propose a suitable strategy, which is to replace the scheduled shut-down and thus increases vehicle availability and vehicle safety.

This can be achieved in accordance with an advantageous development of the present invention in that if the vehicle speed can no longer be determined with corresponding safety, the current gear engaged in the transmission is correspondingly frozen; this means that a gear change is not possible in this case. The energization of the output stages of the gearbox actuators can preferably be maintained in order to be able to conclude a circuit that has been started safely.

It can, for. B. be provided that the frozen current gear is maintained until the driver moves the gear selector lever to the neutral position. In a neutral gear request then the frozen gear can be taken out again, since the transmission is in this case in the neutral position.

If z. B. the gear selector lever is returned to the drive position and a driver by operating z. B. the accelerator pedal can be seen over a predetermined threshold value can be provided according to a development of the present invention, that then a gear is engaged, in which overspeeding of the engine is avoided even at high speeds. This can be z. B. be achieved by choosing the 4th or 5th gear as the gear.

When the gear selector z. B. in the R position (backward) is brought, it can be provided according to another embodiment of the invention that the neutral gear is engaged, because it can not be ruled out that the vehicle is moving at high speed forward.

It is particularly advantageous that the solution presented here according to the invention can be used for almost any system that is responsible for automatic gear selection.

Hereinafter, a further embodiment of the invention presented here will be described, in which a method for storing z. B. the transmission number is proposed in the transmission control unit to determine a subsequent replacement of this component can.

Usually, the transmission control unit (SG) is mounted in a gearbox to the transmission; then the transmission parameters, such. As the Gangendlagen, the lanes, the lane width, the sync thresholds or the like. Learned in a corresponding transmission test and stored in the transmission control unit in a non-volatile memory. After the successful learning process, the transmission and the transmission control unit form a fixed pair or unit, which can not be easily separated from each other later. An identification of this pairing or unit does not take place.

There is now the possibility that of these pairings subsequently z. B. the gearbox control units are exchanged, which is also referred to as a cross exchange, without the transmission parameters of the new transmission are learned again. In this case the gearbox will be operated with wrong parameters. There is a risk that increased wear and thus premature gear damage may occur.

Since each gear is provided with its own serial number or the like, it can be read from the test bench or from the assembly line. In the method according to the invention z. B. be provided that the serial number is preferably written by means of a diagnostic command in the transmission control unit and stored there. In this way it can be determined by comparing the stored serial number in the transmission control unit and in the transmission, whether the transmission / transmission ECU pairing belongs to each other or is correct or whether an exchange has taken place. Thus, it can be avoided with the inventive method, the transmission / transmission ECU pairings are operated with the wrong transmission parameters and thus possible transmission damage can be avoided.

In the following, another embodiment of the invention presented here will be described in which an identification, in particular an online identification, for models of the geared motors, in particular with a robust error detection of the incremental path measurement, is proposed.

It is known that in the event of a failure or a fault in the incremental path measurement of the gear actuator, a movement can be detected by the parallel models of the gearmotors (select / shift) implemented in the control software. Thus, a difference between measured and modeled increments can be made possible. If this difference is exceeded by a certain threshold, errors in the incremental displacement measurement can be detected. In order to ensure the robustness of the models or the manufacturing spread, the operating temperature and the service life of the gearmotors, it may be advantageous to enable an online identification of the path behavior of the gearmotors.

According to the invention presented here it can be provided that preferably by means of a suitable software measure an online identification for the already implemented models, eg. As an ASG geared motor, a sufficient quality of the error detection for the Inkrementalwegmessung is guaranteed. It can be provided that during the switching and dialing operations, in particular in position-controlled mode, the signals of the input voltage and / or the speed of the geared motors is used to identify the track behavior of the engine in the online state. This solution is in 4 represented in the manner of a signal flow diagram of the transmission control. Other approaches are also possible to provide suitable on-line identification of the geared motor models.

The discrete motor model of the geared motors is preferably composed of a PT1 element and an I element. In this case, the input voltage u _k-1 and the motor speed N _{k-1 of} a position controller interrupt are previously detected and used as input variables of the PT1 model. The currently modeled engine speed n _k can be converted in the integrator (I element) into corresponding motor increments x _k .

The result for the PT1 element is: _nk = A * _nk-1 + B * _uk-1

For the I-term (integrator) the following equation results: x _k = x _k-1 + K * T _A * n _k

If the parameter K (I-term) is represented as a constant ratio between the angle of rotation of the motor and the motor increments, the parameters A and B of the PT1 model can e.g. B. not be constant. They may change due to manufacturing dispersion, operating temperature, engine life, or the like.

That is, in order to realize a robust modeling, the parameters A and B should be appropriately identified during operation in the vehicle. In this case, the identification method of the so-called least-square method can be used. There are in the position-controlled state, the engine speed n and the motor voltage u in each position controller interrupt, z. 5 ms, and the multiplied values are added according to the following equations:

In the aforementioned equations, the number N of the sum depends on the duration of the position-controlled mode during a shift. As a result, the number N corresponds to the number of position controller interrupts within the position controlled mode during a gear change.

For example, it can be provided that at the end of the position-controlled switching and selecting operation, the calculated intermediate variables are used to determine the parameters A and B of the PT1 element. The following equations can be used for this:

Hereinafter, the sequence of the proposed identification will be described according to a development of the present invention. In order to be able to control the process in a targeted manner and to monitor it, you can different states of identification are defined. The individual states during an identification can be traversed in the so-called hand-shake procedure, which in 5 , which shows a corresponding table with the defined states.

The associated state sequences of the identification strategy according to the invention are in 6 with corresponding transition conditions of the states in a further table, which in 7 is shown. It is possible that other states, state sequences and also transition conditions are used or suitably combined with one another in order to further improve the identification strategy according to the invention.

Hereinafter, a further embodiment of the present invention will be described, in which a method for estimating the current strength in particular in ASG geared motors z. B. with a software-based observer or the like. Is proposed.

It has been shown that the on-board network is stressed in particular by high current peaks of the ASG geared motors during a shift such that it can possibly lead to a recognizable flickering of the headlights, the tacho lighting or the like. It was determined that there is no hardware-side current measurement of the gear motors and therefore no current limit can be performed.

According to the present invention, it can be provided that the currents of the ASG geared motors are preferably suitably estimated by a software-related observer and that, as a result, a software-side current limitation can also be carried out. It is possible that the observer identifies the track behavior of the geared motors and z. B. the requested current over the determined line parameters, the applied voltage and / or the measured engine speed estimates appropriate.

n

= Motordrehzahl

a, b

= Motorparameter

u

= Motorspannung sind.

In this case, the path behavior of the geared motors can be represented with the aid of a PT ₁ model with variable parameters, which corresponds to the following equation 1. With regard to the equation of motion of a DC motor, the parameters a and b can be identified during a gear change in the position-controlled state: ṅ = a · n + b · u Eq. 1 in which

n

= Engine speed

a, b

= Motor parameter

u

= Motor voltage.

R

= Ankerwiderstand [Ω]

l

= Stromstärke [A]

k_Φ

= Motorkonstante [Vs]

ω

= Motordrehzahl [ 1 / s]

Jω . = k_Φ·l Gl. 3

J

= Motorträgheit

ω .

= Motorbeschleunigung

kann durch Umformung, Gleichsetzung und einem Koeffizientenvergleich mit der Gleichung 1 über die Parameter a und b auf die physikalischen Parameter geschlossen werden.With the general equations of a DC motor neglecting the inductance, the following equations result: U = R * 1 + k _Φ * ω Eq. 2

R

= Anchor resistance [Ω]

l

= Current [A]

k _Φ

= Motor constant [Vs]

ω

= Engine speed [1 / s]

Jω. = k _Φ · l Eq. 3

J

= Motor inertia

ω.

= Engine acceleration

can be concluded by transformation, equation and a coefficient comparison with the equation 1 on the parameters a and b on the physical parameters.

Assuming that the engine inertia J is predetermined, only two unknowns result for the aforementioned system of equations, namely the armature resistance R and the motor constant k. In this way, the physical parameters can be determined via the identified parameters a and b by solving the equations. The following equations result:

Thus, it is now possible to estimate the current intensity I using the method according to the invention with the known magnitudes of the motor voltage U and the motor speed n. In this way, the current peaks can be detected accordingly and a correspondingly heavy load on the electrical system can be compensated, so that no flickering may occur in headlights or tacho lighting.

Another possible identification strategy, especially in ASG geared actuators, is proposed.

The position determination of the shift finger within the transmission shift pattern can be done via the Inkrementalwegmessung in the gearbox actuators. The changes of the rotor positions are recorded. A new rotor position can be calculated via the rotor position at the previous time and the current change. The actuators have magnetic pole pairs whose field can be detected contactlessly via Hall sensors. The evaluation electronics can z. B. at each pole change generate a change of the count signal and a signal indicating the direction of rotation of the rotor. For example, in the case of a failure of the evaluation electronics in the control unit and / or a failure of the Hall sensors on the motors no counting pulses can be received. The controller can then no longer determine the position of the shift finger. It is also possible that z. B. induced by the EMV pulses on the signal line or that the electronic evaluation system sporadically sparsely. This can also lead to malfunction in the controller.

In order to recognize the above-mentioned errors as early as possible, a modeling of the ASG geared actuators can be implemented. These possible models can z. B. from the motor voltages determine the expected speeds and rotor positions and thus compare the modeled sizes with those of Inkrementalwegmessung accordingly. For example, during the switching and dialing operations, the measured motor increments are compared with the modeled increments. If the difference of the two magnitudes exceeds a predetermined threshold, an error of the incremental displacement measurement may be assumed. The confidence measure is set to 1 (Guess) and a neutral reference travel is requested, which sets the confidence measure back to 2 (Coarse) on successful comparison. at detected error can be made an entry in the error memory. It is possible that the proposed error strategy is suitably modeled to further improve error detection.

During measurements in the climatic chamber, it has been shown that the models of the geared motors, especially at very low temperatures, eg. B. at about -30 ° C, too inaccurate. Error detection may occur at these temperatures, although objectively there was no incremental measurement error. The reason for this may be the change in the path behavior of the transmission reactor in the event of temperature changes. The previous model can not be set to this because the model parameters are constant.

The same effect occurs when using geared motors that are at the limit of manufacturing tolerances because the determination of model parameters based on a standard geared motor is performed under normal operating conditions. This results in the requirement that the model parameters have to be adapted to the actual and existing path behavior of the transmission actuator. In this way, a long-term robust error detection of the incremental path measurement can be realized.

It has been found that the online identification described above for the fulfillment of the aforementioned requirements is particularly advantageous. A corresponding signal flow diagram of the transmission control for an online identification of the transmission actuator is already in 4 shown. In 4 the position of the identification in the signal flow plan of the incremental displacement measurement is shown. Only when no error detection is present, the geared motors is detected during the shift and select operations, the engine speed _n and the motor voltages _u and each after a completed circuit, the identified model parameters in the PT ₁ element of the model are adjusted accordingly. This is done independently of each other both the shift and the selector motor. It follows that the in 4 shown online identification for both the dial and the switch actuator is used.

In the implementation of the proposed strategy, a time window may preferably be provided in the identification. An identification can be carried out on the one hand, if a steady excitation of the system, ie an energization of the motors, and on the other hand, the identification can be carried out when the movement of the gear actuator runs freely in the shift gate. Therefore, the identification should be limited in time during a circuit because z. B. during synchronization takes place no free-running movement of the motors and thus the result of an identification could be falsified. Thus, the provision of a time window in the identification is particularly advantageous. It is also possible to implement the implementation in other ways.

In 8th For example, a dialing operation of a 5-2 circuit is shown. In 9 is the complete switching movement during the 5-2 circuit shown. The individual switching states can be clearly seen: Take out the gear (Z_Schalt = 0) Select in neutral range (Z_switch = 1) Synchronize (Z_Schalt = 2) Resting position (Z_Schalt = 4) Resting area reached (Z_Schalt = 6) Keys in the hallway (Z_Schalt = 8)

In case of possible errors, the states sync problem (3) and single track problem (5) can also occur.

In switching state 1, the free-running selection movement of the selector motor takes place within the neutral track, while the switching movement takes place in the direction of neutral path switching state 0 and switching state = 1. The motors should be in the position-controlled mode (SelMode = 4 and ShfMode = 4). In this area, the identification and the modeling of the transmission actuators can take place. Also, the bias of the switching motor at about 2 to 4 V shows no influence on the identification parameters. Since the motors are also not in position-controlled mode, the identification can not be started.

The identification process can be provided, for example, as shown in FIG 5 is shown in a table. In order to ensure a regulated process of identification, it may be necessary to use a Introduce status for identification. This uniquely identifies the individual states of identification and appropriately controls the sequence ( 5 ).

6 now shows the possible processes during an identification strategy according to the invention in the form of a state representation. The possible entry conditions for the individual states are in a 10 described table. The initial state is generally state 0 (no identification allowed). If the status is set to 0, the identification can be deactivated. It is conceivable that the identification of the switching and selection motor is activated separately. This makes it possible to deactivate identification in circuits that do not require dialing.

In addition, in an error detection of Inkrementalwegmessung by the model of the geared motors identification z. B. be canceled. In state 2, the speeds and motor voltages are detected and the intermediate sizes of the identification calculated. In state 3, the intermediate quantities determined in state 2 are used to calculate the model parameters (A, B). If the calculated model parameters are in a plausible range (see 10 ), the identification status z. B. be set to 5. Thus, the identification can be completed successfully and the identified model parameters can be advantageously used further.

In 11 is shown a possible identification strategy in the dialing during a 2-3-circuit. When the target gear is changed, the identification is activated (SelState = 1). If the switching state is set to switch / select (Z_switch = 1), the identification can be started. The motor voltages as well as the engine speeds are read in and the intermediate quantities are calculated. When the free-running selection movement is completed (Z_Schalt = 2), parameters A (SelldA) and parameter B (SelldB) can be determined. Thereafter, the identification z. B. deactivated (SelState = 0).

• 1. Anzahl der Messdaten sind zu gering; die Zwischengrößen werden über die Motorspannung und Motordrehzahl eingelesenen Wertepaare von z. B. berechnet. Wenn die Anzahl der Messdaten nicht ausreichend ist, kann eine sichere Identifikation nicht gewährleistet werden. Daher kann vorzugsweise kontrolliert werden, ob sich die Anzahl über einer vorgegebenen Schwelle befindet. Diese Schwelle kann erfahrungsgemäß z. B. auf 10 Wertepaare festgesetzt werden. Es sind auch andere Werte für die Schwelle möglich. Wenn die Anzahl nach einer Schaltung kleiner als 10 ist, werden keine neuen Parameter identifiziert. Die Modellparameter können dann ihre alten Werte behalten. Die Identifikation kann z. B. abgebrochen werden und die Parameter werden damit nicht aktualisiert (SelState = 4). In 12 ist eine Messung am Prüfstand dargestellt, bei der die Anzahl der Messdaten zu gering sind und somit keine Identifikation durchgeführt wird. Hierbei wird ein Abbruch der Identifikation provoziert, indem die Anzahl der zu messenden Wertepaare (SelHwN, SelHwUk) erhöht wird (Mindestanzahl = 20 Wertepaare). Dabei kann es bei dieser Schaltung zu einem Abbruch der Identifikation kommen, da die Anzahl der Wertepaare (während SelState = 2) gleich 12 ist. Somit gilt der SelState auf dem Wert 4 (entspricht Fehler in der Identifikation). Dabei können die Parameter konstant bleiben und den bereits ermittelten Wert behalten und nicht aktualisiert werden.
• 2. Ein Überlauf der Zwischengrößen; die Zwischengrößen errechnen sich durch eine Summierung von Messwerten. Daher kann die Gefahr bestehen, dass die Zwischengrößen überlaufen. Um einen Überlauf zu erkennen, kann vor jeder Summierung z. B. kontrolliert werden, ob der Wertebereich überschritten wird. Erst wenn der Wertebereich nicht überschritten wird, kann z. B. die Summierung durchgeführt werden. Ansonsten kann die Summierung abgebrochen und die bereits berechneten Werte der Zwischengröße verwendet werden, um die aktuellen Modellparameter noch zu ermitteln. In diesem Fall werden die Parameter nicht aktualisiert. In 13 ist eine derartige Messung am Prüfstand dargestellt. Sie zeigt einen Überlauf der Zwischengrößen während einer Identifikation. Wenn die Anzahl der Messdaten aber ausreichend ist, kann vorgesehen sein, dass nach dem Abbruch der Identifikation dennoch mit den bereits berechneten Summationsgrößen neue Parameter berechnet werden (ShfState = 5).

In the context of an advantageous development of the invention, additional strategies can be provided. For example, the correctness of an identification can be checked. The prerequisite for calculating the parameters is z. B. the correct determination of the intermediate sizes. In order to ensure this, it may be necessary to perform some safety measures before a parameter calculation, with safety measures being mentioned below by way of example, the list of the following safety measures not being conclusive:

• 1. Number of measurement data is too low; the intermediate variables are read in via the motor voltage and motor speed value pairs of z. B. calculated. If the number of measurement data is insufficient, reliable identification can not be guaranteed. Therefore, it can be preferably checked whether the number is above a predetermined threshold. This threshold can be experienced z. B. be set to 10 value pairs. Other values for the threshold are also possible. If the number after a circuit is less than 10, no new parameters are identified. The model parameters can then retain their old values. The identification can z. For example, the parameters are not updated (SelState = 4). In 12 a measurement is shown on the test bench, where the number of measurement data is too small and thus no identification is performed. In this case, a demolition of the identification is provoked by the number of value pairs to be measured (SelHwN, SelHwUk) is increased (minimum number = 20 value pairs). In this case, it can lead to an abort of the identification in this circuit, since the number of value pairs (while SelState = 2) is equal to 12. Thus, the SelState is valid at the value 4 (corresponds to error in the identification). The parameters can remain constant and retain the already determined value and can not be updated.
• 2. An overflow of intermediate sizes; the intermediate quantities are calculated by summing measured values. Therefore, there may be a risk that the intermediate sizes overflow. To detect an overflow, before each summation z. For example, you can check whether the value range is exceeded. Only when the value range is not exceeded, z. B. the summation can be performed. Otherwise, the summation can be aborted and the already calculated values of the intermediate size can be used to determine the current model parameters. In this case, the parameters are not updated. In 13 Such a measurement is shown on the test bench. It shows an overflow of intermediate sizes during an identification. However, if the number of measurement data is sufficient, it can be provided that after the abortion of the identification new parameters are nevertheless calculated with the already calculated summation variables (ShfState = 5).

It is also possible that other than the two aforementioned safety measures are used in the strategy according to the invention.

• 1. Nach der ersten erfolgreichen Identifikation können die Modellparameter aus den identifizierten Parameter übernommen werden, d. h. P_mod = P_ident;
• 2. Das Modell zur Fehlererkennung der Inkrementalwegmessung ist jedoch noch deaktiviert;
• 3. Nach jeder erfolgreichen Identifikation können die Modellparameter nach der Gleichung 3.1 gefiltert werden;
• 4. Z. B. nach drei erfolgreichen Identifikationen kann das Modell zur Fehlererkennung aktiviert werden.

With regard to an initialization can be provided that the model parameters z. B. after the condition "ignition-one" can be redetermined. This means that they are not stored in the state "ignition off" in the EEProm (electronic memory). This is because the parameters are in the "ignition off" state, e.g. B. when the vehicle is parked overnight, can significantly change that in the state "ignition-on" these can not be used for fault detection. The following initialization routine can therefore preferably be run through:

• 1. After the first successful identification, the model parameters can be taken from the identified parameters, ie P _mod = P _ident ;
• 2. The model for error detection of the incremental path measurement is still deactivated;
• 3. After each successful identification the model parameters can be filtered according to equation 3.1;
• 4. For example, after three successful identifications, the model can be activated for error detection.

This means that the model z. For example, after each "Ignition On" state, it may pass through a dead time of three successful identifications until the parameters have settled to reliable levels. Only then can the model and thus the error detection of the incremental path measurement be activated. It is also conceivable that other initialization routines or any combinations of other possible routines can be used.

The already mentioned under 3. in the aforementioned initialization routine filtering z. B. due to the robustness of the identified model parameters, the models of the switching and Wählaktorik be performed only after three successfully performed identifications. Since there is a slight variance with respect to the identified parameters, it may be advantageous to weight the newly identified parameters with those of the previously identified parameters. In this case, a distinction can be made between model parameters P _mod and identification parameters P _ident . The identification parameters are determined after each shift with the calculation routine. The model parameters are the parameters that can be used for the implemented models of the switch and select actuators. These can be z. For example, calculate only after each successful identification as follows: P _Mod = P _mod × 2/3 + P _Ident × 1/3 Eq. 3.1

This means that the parameters already used in the model z. B. to 2/3 and the newly determined after a circuit parameters are preferably taken over to 1/3 to calculate the current model parameters.

To verify the robustness of the model in terms of track changes due to temperature differences, circuits can be performed in a climate chamber at temperatures of -30 ° C to 105 ° C. It has been shown that with identical switching cycles, the average model parameters A and B are taken for switching and selection actuators at different temperatures. The scatters regarding the individual identifications amount to about 5-8%. The result of the averaged model parameters is in 14 shown. It can be seen that only by an inventive online identification of the geared motors and a suitable adaptation of the engine models, the error detection of Inkrementalwegmessung can be kept robust in an advantageous manner.

In 15 a special situation is presented which represents the identification and modeling strategy after a reset. After a reset, the model parameters are reset to 0 and the model is deactivated. This can reduce the uncertainties of the track behavior with respect to the modeling after a reset. After three successful identifications, the model can then be reactivated. The values of the identified model parameters were also included in the output of the long-term measurement in order to provide long-term observation and diagnosis.

Overall, it has been shown that the online identification of the actuator models enables a robust error detection of the incremental energy measurement, since an identification of the system behavior is performed during operation. Thus, line changes due to temperature influences, service life and production spread of the geared motors are suitably taken into account. It is possible that an adaptation of the position controller is additionally performed via the identified behavior of the route. In this way, an optimal control behavior is to be realized. The compensation scheme for the position controller also uses the identified parameters of the geared actuator to compensate for the changes in the path by changing the position controller voltage.

In summary, it can be stated that the developed online identification for the gear actuators makes it possible to adapt the models due to changes in the track behavior. This ensures long-term adaptation and sufficient robustness of the models.

A further embodiment of the invention presented here will be described below, in which a further possible modeling of the ASG gearbox actuators is proposed.

About the actuators, the DC motors of the gear actuators can move the shift finger in the backdrop. The speed and positions are measured by means of Hall sensors directly on the motors. The gear actuator shows with respect to the armature voltage and the engine speed PT ₁ behavior when the shift finger moves in the shift gate freewheeling. With regard to the motor position, the motors show a so-called IT ₁ behavior. This means that a series connection of a PT ₁ element and an integrator is provided. This is also in 16 shown. There, the track behavior of the geared actuators is suitably modeled.

The equations for the in 16 Motor model shown are as follows:

wobei

ω_m:

Drehgeschwindigkeit Motor

n:

Motordrehzahl der Getriebemotoren [1/min]

x:

Motorposition [Inkremente]

N_puls:

Anzahl der Motorinkremente pro Umdrehung

Due to the negligible inductance L _a (L _a / R _a ~ 0.0008), the term formed in equation 1.1 can be set equal to zero. The neglect of the inductance can also be performed during the actual controller design. A continuous state representation can be given by the following equation:

in which

ω _m:

Rotational speed motor

n:

Motor speed of geared motors [1 / min]

x:

Motor position [increments]

N _pulse :

Number of motor increments per revolution

⇒ = a_k·n + b_k·U_a Gl. 1.7 ẋ = K·n Gl. 1.8 A continuous equation of motion can then be as follows:

⇒ = a _k * n + b _k * U _a Eq. 1.7 ẋ = K · n Eq. 1.8

A:

Modellparameter für die Dynamik der Strecke

B:

Modellparameter für die Streckenverstärkung

T_A:

Abtastzeit (5 ms)

K:

Umrechnungsfaktor zwischen Motordrehzahl und Motorinkremente = N_puls/60

n:

Motordrehzahl (k: aktueller Interrupt, k – 1: Lageregler-Interrupt zuvor)

x:

Motorinkremente (k: aktueller Interrupt, k – 1: Lageregler-Interrupt zuvor)

A discrete representation of the equation of motion 1.7 or 1.8 shows the already mentioned equations: n _k = A * n _k-1 + B * u _k-1 Eq. 1.9 x _k = x _k-1 + K * T _A * n _k Eq. 1.10 in which

A:

Model parameters for the dynamics of the track

B:

Model parameter for the track gain

T _A :

Sampling time (5 ms)

K:

Conversion factor between motor speed and motor increments = N _pulse / 60

n:

Motor speed (k: current interrupt, k - 1: position controller interrupt before)

x:

Motor increments (k: current interrupt, k - 1: position controller interrupt before)

The dynamic system behavior can, for. B. are represented by the parameter A, while the parameter B, the gain of the system is displayed. The conversion of the engine speeds into increments can be done by an integrator or the like (equation 1.6). It can be a constant conversion factor K between the number of increments per revolution and a constant sampling time of z. B. 5 ms (reading the measured data). In 17 By way of example, discrete modules of the equations of motion 1.5 and 1.6 are shown graphically.

k:

diskreter Zeitpunkt

n:

Drehzahl

u:

Eingangsspannung

z:

Störungssignal (weißes Rauschen)

Hereinafter, an identification of a first-order system (least-square method) will be described. A simple and easy to implement identification method is the so-called least-square (LS) method. A special case may be the least squares method for a first order system. The following equations result: n _u (k) = A * n _u (k-1) + B * u (k-1) Eq. 2.11 n (k) = n _u (k) + z (k) Eq. 2.2

k:

discrete time

n:

rotation speed

u:

input voltage

z:

Noise signal (white noise)

• 1. Aufsummieren von Zwischengrößen; während der Schalt- und Wählvorgänge können zu diskreten Abtastzeiten (Lageregler-Interrupt von etwa 5 ms) die Motorspannung und die Motordrehzahl von Schalt- und Wählmotor eingelesen werden. Mit diesen Werten können folgende Zwischengrößen berechnet werden, wobei die nachfolgenden Gleichungen teilweise vorher verwendet worden sind:
  
  
• 2. Es kann eine Berechnung von Modellparametern vorgesehen sein; wenn die Berechnung der Zwischengröße nach der freilaufenden Bewegung des Schalt- und Wählvorganges abgeschlossen ist, können die Parameter A und B durch die bereits erwähnten Gleichungen bevorzugt berechnet werden;
  
• 3. Es kann eine Modellierung der Getriebemotoren vorgesehen sein; das Modell der Motoren kann sich vorzugsweise aus einem PT₁-Glied und einem Integrator zusammensetzen. Die aktuelle Motordrehzahl kann sich dann aus der Motordrehzahl und der Motorspannung eines Interrupts von z. B. 5 ms berechnen. Dazu können die bereits erwähnten Gleichungen verwendet werden: n_k = A·n_k-1 + B·u_k-1 Gl. 2.10 x_k = x_k-1 + K·T_A·n_k Gl. 2.11

K:

Umrechnungsfaktor (Motor-Aktorik-Übersetzung)

TA:

Abtastzeit (Lagereglerinterrupt; 5 ms)

nk:

modellierte Motordrehzahl

xk:

modellierte Motorinkremente

This difference equation 2.1 may consist of a continuous delay z. B. a PT ₁ member and a holding member zeroth order arise. This is in 18 indicated graphically, wherein a holding member is used with discrete sampling. The output of the delay element n _u can preferably be provided with a fault z according to equation 2.2. This disorder z can the uncertainties of the system, such. As friction or the like., And the signal processing, for. As measurement noise or the like., Represent. The parameters A and B of the above equation of motion 2.1 can be identified as follows:

• 1. Sum up of intermediate sizes; During the switching and selection processes, the motor voltage and the motor speed of the switching and selection motor can be read in at discrete sampling times (position controller interrupt of approximately 5 ms). The following intermediate variables can be calculated with these values, with the following equations having been used in part:
  
  
• 2. It may be provided a calculation of model parameters; when the calculation of the intermediate quantity has been completed after the free-running movement of the switching and selecting operation, the parameters A and B can be preferably calculated by the already mentioned equations;
  
• 3. It can be provided a modeling of the geared motors; The model of the motors may preferably be composed of a PT ₁ element and an integrator. The current engine speed can then be calculated from the engine speed and the motor voltage of an interrupt of z. For example, calculate 5 ms. The already mentioned equations can be used for this: n _k = A * n _k-1 + B * u _k-1 Eq. 2.10 x _k = x _k-1 + K * T _A * n _k Eq. 2.11

K:

Conversion factor (motor-actuator translation)

TA:

Sampling time (position controller interruption, 5 ms)

nk:

modeled engine speed

xk:

modeled engine increments

The aforementioned identification strategy can be checked by a simulation. During the simulation, a position-controlled process is carried out. The output voltages and motor speeds can be used for identification. The identified parameters can be used in a model of geared motors. In another simulation, it is possible to compare the real and modeled engine speeds and positions to verify the accuracy of the identification. The identification can be done in the discrete representation while the simulation is performed with continuous parameters. Therefore, it is necessary to convert the identified parameters into the continuous representation. The real parameters are used in the model via motor characteristics and data specification.

For example: selector motor

• R _a = 0.45 Ω
• C _m = 0.025 Vs
• J _m = 1.16 × 10 ^-5 kg / m ²
• d _friction = 0.8 · 10 ^-4 Nms

The continuous representation is as follows: Real parameters a _k = -91.8 b _k = 3472.2 Identified parameters a _k = -91.8 b _k = 3472.2

In 19 is a simulated step response of a real system and a system with identified parameters A, B shown. The PT ₁ behavior can be reproduced exactly. In one implementation, however, it should be noted that on the one hand the integer arithmetic must be used and on the other hand, the real system in the vehicle should not have an exact PT ₁ behavior. When simulating in 19 is the step response of a real plus sign and a modeled system marked zero.

The simulation shows that this identification method of a PT ₁ system has a very high accuracy with simple programming.

In summary, it can be stated that the online identification for the gearbox actuators is particularly advantageous if an adaptation is additionally provided. The track behavior of the ASG actuators shows a PT ₁ behavior with respect to the armature voltage as an input quantity and the engine speed as an output variable during free-running movement within the shifting gate.

Hereinafter, a method for detecting errors in the incremental measurement is preferably explained during the key and / or during the rest position in a gear.

Preferably during a right-left keying in the hallway and during the rest position in the hallway, errors in the incremental path measurement can lead to the insertion of a hallway. These errors can z. B. by drift, a failure or the like.

An object of the present invention is to propose a method which in particular recognizes these errors and carries out corresponding countermeasures.

Accordingly, it can be provided according to the invention that the selection movement is preferably subjected to a plausibility check by a control operation in the drive program during the right-left key and / or the standstill is checked during the rest position, ie during the standstill of the actuator. In this case, preferably, the speed signals of the selector motor determined by the incremental displacement measurement can be compared with those of an already existing motor model. If z. B. the entry condition for the keys is met, it can be checked whether the measured speed exceeds a certain threshold. If this is the case, the sign of the measured speed and the modeled speed can be compared. Preferably, one counter can be incremented per interrupt. After a certain number of interrupts and no previous error detection, the check can be terminated, for example, because by driving at the stop a speed reduction of the engine takes place. If z. For example, if a dial move to the right is measured during the right-left key, but the model is awaiting a left-hand dial move, the confidence measure may be immediately reset to initiate a neutral reference run for verification or the like.

Furthermore, it can be provided that during the rest position in the corridor, the actuator without energization should not move excessively. It can be checked during this switching state, whether the measured speed exceeds a certain threshold absolute. If this case occurs and the calculated speed gives no movement, z. B. the degree of confidence can be reduced and also in the next circuit a neutral reference travel or the like can be performed.

In 20 is shown a strategy in the form of a flowchart in which, during a selection or switching movement of the gear actuators z. B. in an automated transmission (ASG) a failure or drift of Inkrementalwegmessung is detected. Meanwhile, the expected engine speeds and engine increments are calculated using a model. The activation of the model can be dependent on predetermined entry conditions, which z. B. be supplied by the function control. As entry conditions may be preferred for a dialing z. B. the switching state (SZ) = 1 and / or the position control mode (LM) = 4 (position controlled) can be used. It is also conceivable that other suitable entry conditions are used. The implemented strategy starts with the detection of the motor voltage. When the onset conditions shift state = 1 and position controller mode = 4 are present, the motor speed and motor increments are calculated, thus detecting the detection of drift or failure of the incremental displacement measurement. In parallel, the motor increments can be used for this detection.

In 21 a strategy according to the invention is shown in the form of a flow chart, which is based on the models of the selection and switching actuators. An essential difference to the aforementioned strategy is that the activation of the models with respect to the switching states is extended and the fault strategies are adapted to the individual switching states.

According to an advantageous embodiment of the invention, the extension may preferably be that during the key in the corridor and during the rest position in the corridor, ie at standstill of the actuator, also the model is activated in the selection direction. The expected speeds can be calculated in order to compare them with the measured speeds.

When keys in the corridor z. B. the switching state (SZ) = 8 and the position controller mode (LM) ≥ 3 are selected, which corresponds to a position-controlled and speed-controlled state. In the rest position in transition, the switching state SZ = 6 and the position controller mode (LM) = 1 can be selected.

The following explains the detection of direction reversal in the direction of selection while the key is in progress.

This error strategy can be activated when the keys are requested in the corridor. Then the switching state (SZ) = 8 and the position controller mode (LM) ≥ 3 can be selected. This strategy is in the form of a flow chart in 22 shown.

The detection of an implausible movement during the rest position in the corridor is explained below. This fault strategy can be activated when the rest position is reached in the corridor. In this case, the actuator can be force-free at a standstill. The switching state (SZ) can have the value 6 and the position controller mode (LM) can have the value 1. This implausible motion detection strategy is in the form of a flowchart in FIG 23 shown.

The aforementioned values in the strategies, in particular with regard to the switching state (SZ) and the position controller mode (LM), can also assume any other values.

Preferably, the proposed strategies may be used on vehicles with an automated manual transmission (ASG), a parallel shift transmission (PSG) or the like.

The claims filed with the application are formulation proposals without prejudice to the achievement of further patent protection. The Applicant reserves the right to claim further feature combinations previously disclosed only in the description and / or drawings.

Relationships used in subclaims indicate the further development of the subject of the main claim by the features of the respective subclaim; they should not be construed as a waiver of obtaining independent, objective protection for the feature combinations of the dependent claims.

Since the subject-matter of the subclaims can form separate and independent inventions with regard to the prior art on the priority date, the Applicant reserves the right to make them the subject of independent claims or statements of division. They may further contain independent inventions having an independent of the subjects of the preceding sub-claims design.

The embodiments are not to be understood as limiting the invention. Rather, numerous modifications and variations are possible within the scope of the present disclosure, in particular those variants, elements and combinations and / or materials, for example, by combination or modification of individual in conjunction with those described in the general description and embodiments and the claims and in The features or elements or method steps contained in the drawings for the expert with regard to the solution of the problem can be removed and lead by combinable features to a new subject or to new process steps or process steps, even if they concern manufacturing, testing and working procedures.

Claims (6)

Method for determining a target gear in an automated transmission in a drive train of a vehicle, in which in an operating situation in which a vehicle speed can not be reliably determined, the currently engaged gear is maintained, characterized in that in this operating situation, the energization of each output stage of the gear actuators is maintained until a started shift is completed or the current gear is maintained until a neutral position of the transmission is requested. A method according to claim 2, characterized in that the neutral request by a driver by moving a gear selector lever is carried out in the neutral position. A method according to claim 2, characterized in that when the gear selector lever is moved to a driving position and the accelerator pedal is operated over a predetermined threshold, a determined target gear is engaged. A method according to claim 3, characterized in that is selected as the target gear of the 4th or 5th gear. A method according to claim 2, characterized in that when the gear selector lever is moved to the R position, the neutral gear is maintained. Transmission control for an automated transmission in which in an operating situation in which the vehicle speed is not determined safely, the currently engaged gear is maintained, characterized in that in this operating situation, the energization of each output stage of the gear actuators is maintained until a started circuit is terminated or the current gear is maintained until a neutral position of the transmission is requested.

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