DE2939556A1 - CONTROL CIRCUIT FOR AN AUTOMATIC TRANSMISSION - Google Patents

Description

description

Summary ;

A circuit for controlling the shifting operations of an automatic transmission for a motor vehicle is specified. at you monitor a monitoring circuit (123) which simultaneously fulfills control functions and which are transmitted to it as input signals Shift commands that the driver of the vehicle has given by setting the range selector lever (108), which defines the limits of the switching range. The monitoring group also receives the required gear ratio or the command signal corresponding to the target transmission ratio, which either comes from a switching point computer (121) or a manually operable selector lever for the gear to be set of the manual transmission is provided. If the monitoring circuit determines that the actual value transmission ratio signal differs from the setpoint transmission ratio signal, the mode of operation is "monitored" interrupted, and a command signal is issued by which a switching process is initiated. This command signal is used to activate certain circuits (125, 126), the output signals of which are in turn used in a distribution circuit (124) and the time course of the switching process and thus its quality. In this way a controlled gear change is obtained. One of output derived from the power transmission of the vehicle

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signal (105) is used together with the control circuits that determine the timing of the switching process. After the switching process has been completed, the previously activated circuits are released again, and the monitoring circuit returns to the operating mode "Monitoring", in which the setpoint transmission ratio is compared with the actual value transmission ratio will. By activating certain circuits for each controlled change in the gear ratio and then releases again, they can also be used when the gear ratio is subsequently changed and this leads to a very cost-effective compromise between the total number of circuits required in the circuit and the complexity and performance of the logic circuits actually used.

Significant efforts have long been made in the design of automatic transmissions for automobiles undertaken to optimize the quality of a shift or a change in the gear ratio. One within Shifting carried out for too short a time results in the vehicle being accelerated or decelerated rapidly. This leads to noticeable jerks, which are perceived as uncomfortable. If, on the other hand, the switching process is via a pulled away too long, the friction elements

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of the transmission is excessively worn, and this type of shifting process is also perceived as uncomfortable. In general, one obtains an optimal quality of the switching process when its duration is somewhere between the Time periods are as outlined above for the too short switching process and the too long switching process. A comprehensive treatment of this problem can be found in an article by F. J. Winchell and W. D. Route entitled "Ratio Changing the Passenger Car Automatic Transmission" which as Chapter 10 in the SAE publication "Design Practices - Passenger Car Automatic Transmissions", 1973, was published. In FIGS. 21 and 25 this one The article shows in detail how the speed, torque and control pressures change when that Transmission upshifted or downshifted in a non-positive manner will.

Considerable research efforts have already been made to effectively control the switching process itself. These went in the first direction to improve the quality of the switching process by using a closed loop Control system, taking a torque signal is used to control the change in gear ratio when upshifting. Details of the feedback loop, in which a torque transducer is used, and the logical or digital signals are suitable for this

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in US Pat. No. 4,031,782. The control circuit disclosed there as the starting point for the further development was later improved so that in addition to the control of the upshifting process, a control is also available of the downshift process, in which a double slip occurs. This improved arrangement is shown in U.S. Patent 41 02 222 disclosed.

Further efforts have been made to control the shifting process in automatic transmissions to improve even further based on the two patents cited above. The most obvious way to do this would be of course, the one to combine the circuits described in these two patents so that the corresponding Control circuit consists of two sub-units, which are exclusively responsible for the upshift and the downshift are. However, this leads to the fact that one has a large number of circuits which are practically identical in structure but only for a given upshift or a predetermined downshift can be used. Considerable efforts have therefore been made to an optimal compromise between the number of redundant circuits and the increase in logical complexity to achieve, which occurs when the number of circuits is reduced.

The present invention is therefore intended to provide a circuit

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to control the shifting processes of an automatic transmission, which works with good efficiency, can be manufactured at low cost and which has a variety of gear ratios both when upshifting as well as when downshifting.

Another important object of the present invention is a new and unobvious method of control of shifting processes in automatic transmissions, in which the ratio actually set in each case is compared with the desired translation. In this comparison, there is a difference between the actual transmission ratio and the target transmission ratio is determined, the comparison is interrupted while at the same time a corresponding gear change is carried out; after its conclusion, the comparison is then resumed .

The present invention is also intended to provide a circuit for controlling the shifting of an automatic transmission which is very simple and is characterized by great economic efficiency. To do this will be Circuits of the circuit are then addressed and activated when they are needed to control a switching process will; then the addressing of these circuits is then terminated and thus also their activation, and the Circuit then takes the comparison between the actual translation

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ratio and target transmission ratio again.

A circuit according to the invention for controlling the shifting processes of an automatic operation can be used for controlling shifting processes in an automatic transmission having a plurality of gear ratios, which connects a drive motor and a power transmission operating mechanically on a load. The circuit contains a switching point calculator to which input information is applied. The latter includes information about the target torque and at least one output-side operating parameter of the automatic transmission, such as the torque transmitted by the power transmission. The shift point calculator generates an output signal which characterizes the target transmission ratio of the transmission. The output signal of the shift point calculator is applied to a monitoring circuit which at the same time fulfills control functions and compares this output signal with a status signal which is assigned to the actual transmission ratio of the transmission. Is different, the status signal Istübersetzungsverhältnissignal ie from the desired transmission ratio signal which is provided from the switching point computer, the Uberwachungskreis interrupts the comparison of these Signa le and addresses and activates certain circuits wel che be used by switching operation for this type. At the same time, the monitoring circuit generates control signals, which

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be transferred to the automatic transmission to make the desired gear change. To the monitoring group a control circuit for the quality of the switching process is also connected. This specifies the quality of the switching process The control circuit sends signals to the monitoring circuit, which ensure precise control of the switching process. In addition, it provides the control circuit that specifies the quality and timing of the switching process Signals ready to indicate that the shift has been completed. These latter signals cause then that the monitoring circuit again makes the comparison between the target transmission ratio signal and the actual transmission ratio signal records. A transducer works with the output shaft of the automatic gearbox together which one is assigned to the torque or other output-side operating parameters of the gearbox Output signal generated, which then controls the timing of the switching circuit and the Switching point calculator is transferred.

Viewed from a different angle, the invention provides a method for controlling gear changes an automatic transmission, which drives a load via a drive shaft connected to its output. This process includes the following process steps: Generating a first signal that corresponds to the one demanded by the transmission Torque is assigned, and generating a two-

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th signal that is assigned to at least one output-side parameter of the automatic transmission, e.g. the transmitted torque, and then processing the first and second signals to a further signal which the Is assigned to the target gear ratio of the transmission. A comparison is made between the desired gear ratio signal and carried out a further signal which is assigned to the actual transmission ratio. Will make a difference is determined between the target transmission ratio signal and the actual transmission ratio signal, the Comparison is interrupted and a gear change is initiated. After the gear change has been completed is, the comparison between the target transmission ratio signal and the actual transmission ratio signal is resumed .

The invention is explained in more detail below using an exemplary embodiment with reference to the accompanying drawings explained. In this show:

1: a schematic representation of an automatic gearbox with several gear ratios, in which the invention can be used;

FIG. 2: a simplified block diagram of a control circuit for the automatic transmission according to FIG

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in connection with input units for the control underlying input variables and in Connection to a transducer which provides feedback signals;

FIG. 3 shows a somewhat more detailed block diagram of the control circuit shown in FIG. 2;

FIG. 4: a block diagram of a switching point calculator of the type shown in FIGS. 2 and 3 reproduced control circuit, in which the function of individual circuits is entered in Boolean notation is;

Fig. 5: a graphic representation of the shaft speed as a function of the target torque, on the basis of which the Work of the control circuit according to FIGS. 3 and 4 will be explained;

6: a block diagram of a monitoring circuit of the Control circuit according to FIGS. 2 and 3, with the function of individual circuits in Boolean ' shear notation is given;

7 is a block diagram of a control circuit for an upshift operation; again being the function individual circuits in Boolean notation

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is specified;

8: a graphic representation of the torque curve as a function of time in an upshift;

9: a graphic representation of a plurality of signals of the control circuit for the automatic transmission as a function of the time for the switching process shown in FIG. 8;

FIG. 10: a block diagram of a further section of the control circuit shown in FIG. 7 for a Upshift which completes a control loop;

11: a more detailed circuit diagram of some computing circuits of the control circuit shown in FIG. 7 for an upshift, in turn the function of some circuits in Boolean notation is specified;

12: a circuit diagram of a distribution circuit of the control circuit according to FIG. 3, the function of individual circuits again being given in Boolean notation is;

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13: a schematic block diagram of a control circuit for a downshift;

14: a table showing the generation of various control signals of the control circuit shown in FIG is entered for three different operating conditions of the automatic transmission; and

15: a circuit diagram of a computing circuit which, together with the control circuit according to FIG Table according to FIG. 14 laid down circuit program can ensure.

First, the essential features of an automatic transmission are repeated with reference to FIG. 1, which of one there not reproduced control circuit is operated forth. Fig. 1 shows, in simplified form, an automatic transmission like that in Fig. 1 of US-PS 37 44 348 is described in more detail. The automatic transmission has an input shaft 50 that is frictional is connected to a hydraulic torque converter 51. The latter drives through planetary gear sets 52 and an output shaft 54. The transmission has a plurality of devices working on the principle of frictional engagement through which the various gear ratios of the transmission can be set. Which also includes a first front clutch 55, a second rear clutch 56, a first brake 57, and a second brake 58.

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The clutch 55 is always engaged, if there is any torque transmission through the transmission according to FIG. 1 it is asked for. To set the first gear ratio, a conductor 113 is provided with an electrical signal applied and thereby a valve V1 is energized, whereby the brake 58 is then applied. This is about the planetary gear set 52 exerted a reaction torque on the planetary gear set 53, and thus an output-side is obtained Torque on the output shaft 54. The brake is used to set the second gear ratio 57 created. This is done using an electrical signal applied to conductor 114 through which a valve V2 is energized, while at the same time the brake 58 is relieved. This gives a reaction torque against the ring gear of the planetary gear set 53, and in this way the second gear ratio is set. Around To set the third gear ratio, the brake 57 is released and a conductor 115 is connected to a applied electrical signal through which a valve V3 is energized. This engages the clutch 56. This then enables a direct torque transmission via the Planetary gear sets set, which corresponds to the third gear ratio. So you can change the gear ratios of the gearbox by changing the excitation of the three valves V1, V2 and V3 by corresponding controls electrical signals and thus controls the application of the brake 58 or 57 and the engagement of the clutch 56.

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A control circuit will now be described in its basic features with reference to FIG. 2, which control circuit provides electrical signals by which the valves V1, V2 and V3 are controlled.

Fig. 2 shows a closed circuit in the form of a block diagram Loop-forming control circuit which controls the electrical signals on conductors 113, 114 and 115 provides by which the hydraulic solenoid valves no longer shown in detail in FIG. 2 are actuated which belong to the automatic transmission designated as a whole by 101 in FIG. 2. Through appropriate Excitation of these valves can be a desired gear ratio adjust the gearbox. The automatic transmission 101 has a driven input shaft 102, which with is connected to a motor not shown. The mechanically driving output shaft of the gearbox is than on the drive wheels of a vehicle operating drive shaft 103 reproduced. On the drive shaft 103 is a transducer 104 arranged. This generates two output signals, namely on a conductor 105 to the transmitted torque associated drive signal and on a conductor 106 a signal associated with the speed of the drive shaft 103. It understands that only a single line is shown in the drawing for the various signal lines, in In practice, however, two electrical conductors can be used for signal transmission in order to assign a certain parameter

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to be able to transmit an ordered signal in the form of a potential difference. A corresponding transducer is in U.S. Patent 4,100,794. The control circuit receives further input signals. This includes an input signal, which contains information about the selected driving range of the automatic transmission. This input signal reaches the control circuit via a conductor 107, which is designated as a whole by 100 in FIG. 2, and is provided by a range selector switch 108. This selector switch is usually on or in the neighborhood of the steering column of the with the automatic Gear provided vehicle arranged and can optionally be moved into one of the positions shown in the drawing parking (P), reversing (R), neutral position (N), normal driving mode (D), switching through only up to to second gear (2) and exclusive use of first gear (1).

The control circuit 100 also receives a target torque signal via a conductor. This signal is the one under consideration here Embodiment derived using a potentiometer 111 from the position of the throttle valve. The movable wiper of the potentiometer 111 is mechanical with the movable throttle valve of the designated 112 Carburetor of the vehicle shown connected. It goes without saying that the wiper of the potentiometer 111

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can also couple directly to the accelerator pedal of the vehicle or can provide another suitable arrangement to a provide a signal on the conductor that corresponds to the target torque. Instead, you can use the target torque signal can also be derived from the pressure changes in the intake manifold of the internal combustion engine.

The control circuit 100 receives further input signals via a conductor 116 than input variables to be taken into account in the control, which are provided by a control and monitoring circuit 117 for the internal combustion engine. This additional information for the control can be stored information, for example signals stored in the form of a table or a measured value matrix, which contain information about how to drive most economically under given operating conditions. Other input signals can also be used as output variables for the control, e.g. a signal which corresponds to the percentages of the various components of the exhaust gases from the internal combustion engine, or a signal which is assigned to a target value for the fuel / air ratio of the ignitable mixture supplied to the internal combustion engine or any other operating parameter of interest.

The control circuit 100 processes these input signals and, depending on them, generates

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terminals connected to conductors 113, 114 and 115 individual, individual exit ignaü.e, through which individual, individual Actuating devices of the automatic transmission, e.g. the solenoid valves already mentioned above, the desired change in the gear ratio bring about. The operation of such solenoid valves to control the movement of the on-coming and off-going The person skilled in the art is familiar with the friction body of such an automatic transmission. Therefore only needs the Operation of the control circuit to be described, which for applying the conductors 113 to 115 with the required Activation signals are used. This is sufficient to understand the successive sub-steps in one Switching process off.

As can be seen from Fig. 2, the control circuit 100 has three major sub-units: one, the coordination worrisome and the other control circuits monitoring main control circuit 118, a control circuit 119, which for the temporal progression of a switching process and thus responsible for its quality, and a switching point calculator 121.

The switching point computer 121 receives signals on the input side, which provide it with information about the target torque, the The operating state of the internal combustion engine, the speed of the drive shaft 103 and the selected driving range are conveyed

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(the latter with the interposition of the main control circuit 118). In a very simplified way, one could say that the main steering committee 118 processes the signals transmitted to it on the input side in such a way that it is in the form of output signals "says" the transmission ratio with which the transmission should work under the conditions encountered. Of the Main control circuit 118 knows the transmission ratio present in each case of the transmission from the past. If the main control circuit 118 determines that the transmission is momentary The present transmission ratio (actual transmission ratio) differs from the desired transmission ratio (target transmission ratio) differs, he interrupts his work in the way he "supervises" monitors the signals present on the input side, and causes the control circuit 119, which for the temporal Is responsible for the course of a switching process, is triggered and begins to process a switching cycle. Of the The switching process is then under the control of the control circuit 119 and with the assistance of the main control circuit 118 completely settled, with activation signals being selected for the required time periods the conductor 113 to 115 receives so as to accomplish the change in the gear ratio.

If the switching process is finished, this is indicated by a corresponding Completion signal displayed, which is transmitted back from the control circuit 119 to the main control circuit 118

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will. The main control circuit 118 then takes its previous one Mode of operation again, in which he constantly monitors the target transmission ratio signal, thus ensuring is that this corresponds to the actual transmission ratio of the transmission.

After expounding these basic properties, the one closed loop control circuit 100 will now be described in detail thereof.

FIG. 3 shows the larger sub-units of the control circuit 100 enclosed in dashed lines in FIG. 2. In addition, FIG. 3 shows a coupling circuit 120 which serves to eliminate interference signals caused by contact bouncing in the drive range selector switch. This circuit is not a subunit of the control circuit 100, which is of greater importance, it can be implemented by a conventional electronic buffer memory circuit and prevents - as mentioned - that short interference pulses or a plurality of control signals are generated from a single, usually mechanical input signal. For example, it can happen that the driver unintentionally moves the lever of the driving range selector switch back and forth with a small amplitude when he moves this lever from the neutral position N to the driving position D. Otherwise, a plurality of trigger pulses could arise. However, since the coupling circuit 120 is provided, which the consequences of a

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eliminates such contact bounce, it is ensured that only a single digital command signal is provided which indicates the mechanical actuation of the range selector switch. The coupling circuit 120, a Monitoring circuit 123 and a distribution circuit 124 all belong to that represented in FIG. 1 by a single box Main control circuit 118. The monitoring circuit 123 and the distribution circuit 124 are both digitally operating, circuits performing predetermined logic functions.

As can be seen from Fig. 3, the switching point calculator 121 receives a plurality of logical, digital signals from the coupling circuit 120. The switching point calculator 121 is a special type of implementation of a command unit for setting a desired gear ratio and generates a command signal when subjected to appropriate information signals on the input side Change in the transmission ratio, which can also be referred to as the target transmission ratio signal.

In the more detailed description of the In various circuits of the control circuit 100, different signals are taken from Bezua shown in the drawing are identified by combinations of letters and numbers. Enter the appropriate letter combinations in the English language, a reference to the type of each

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occasional signal, which makes the drawing easier to read. Where in the following we speak of such signals for the first time is, it is briefly explained in brackets by which abbreviation of English-language terms the respective letter combination comes about. In general, logical, digital signals have either the value logical "1" or can assume logical "0", the first letter L (_logic). As usual, there are also inverted signals marked by overlining (negation).

As can be seen from FIG. 3, the switching point computer 121 receives four from the coupling circuit 120 Conductor four logical signals L1, L2, LD (drive; normal Forward drive) and LR (reverse). Above The switching point computer 121 also has a conductor 110 a signal which is assigned to the throttle position, and via conductors 106 and 122 a signal which the Speed of the drive shaft 103 is assigned.

At the output of the switching point computer 121, two logic signals LA and LB are obtained, which together form a command signal to perform a specific gear change. The individual ladder to transfer the logical Signals are not provided with separate reference symbols in FIG. 3, since this makes the drawing clearer would suffer without providing additional information. The logic signals LA and LB

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hold the information about the target transmission ratio and are together - as I said - as a command signal for the View the setting of the gear ratio.

As can also be seen from FIG. 3, the monitoring circuit receives 123 also has a plurality of input signals. Below are the settings for the gear ratio predetermined command signals LA and LB, as well as a signal LD, which is from the range selector switch the coupling circuit 120 is provided. At the exit of the Monitoring circuit 123 one receives on the one hand start signals, which initiate a switching process, and status signals, which are assigned to the currently set transmission ratio of the gearbox. The start signals to initiate of a switching process are as two logical signals LUS-R (upshift reset; starting an upshift cycle) and LDS-R (downshift reset; starting a downshift process). The letter R is intended to generally indicate that a Switching process, which consists of partial steps that together form a cycle and carried out one after the other, is initiated will. This initiation of the switching process affects other subunits of the control circuit 100, in particular a distribution circuit 124 and either a control circuit 125 for upshifting or a control circuit 126 for the downshift. The start signal for an upshift LUS-R is applied to both the upshift control circuit 125 and the distribution circuit 124.

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The start signal for a Downpchnlten LDS-R is on the other hand given to both the downshift control circuit 126 and the distribution circuit 124. The status signals LC and LD, which are the currently set transmission ratio characterize, both are given to the distribution circuit 124, while the control circuit 125 for the upshift additionally with the status signal LC and the control circuit 126 for the downshift additionally with the Status signal LD is applied.

The control circuit 125 for the upshift receives in addition to the Status signal LC via the conductor 105 a signal corresponding to the torque in the power transmission and in turn provides when the upshift start signal is applied LUS-R two control signals for the distribution circuit 124 ready. One of these control signals is used for control of the engaging friction body. This signal is shown in the drawing with LUS-N (upshift-on; control of the engaging friction element when shifting up). The other of these control signals is used to control the disengaging friction element; this signal is indicated in the drawing with LUS-F (upshift-off; control of the disengaging friction body when Upshift). These two signals will be channeled via the distribution circuit 124 in a suitable manner so that two of the three are connected to the output of the distribution circuit 124 connected conductors 113, 114 and 115 the-

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COPY

those suitable signals received, which one to the controlled Performing the switching process is required. The distribution circuit 124 is also with the two status signals LC and LD acted upon, and also with the one switching process initiating start signals LUS-R or LDS-R, which are emitted by the monitoring circuit 123.

Similarly, control circuit receives 126 for the downshift the status signal LD, the start signal LDS-R of interest to him, the speed signal present on the conductor 106 and the torque signal on conductor 105. The control circuit 126 generates two of these signals Signals LDS-F (downs; hift-off_; control of the disengaging Friction body when downshifting) and LDS-N (downshift-on; Control of the engaging body when downshifting), which are given to the distribution circuit 124 and are channeled via these so that on two of the three conductors 113, 114 and 115 that signal combination is provided, which are needed to control the disengaging and engaging friction bodies when downshifting .

At the end of a complete switching process, which in turn consists of a sequence of sub-steps, becomes an end indicating this from the control circuit 125 for the upshift or from the control circuit 126 for the downshift Final signal sent to the monitoring circuit 123

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give. More specifically, the control circuit 125 provides a completion signal LUS-O (upshift-over; upshift process ended) ready for the monitoring circuit 123 when an upshift is completed, and the control circuit 126 transmits the monitoring circuit 123 a termination signal LDS-O (downshift-over; downshift process terminated) when a downshift process is finished, which ibid? is from a There is a sequence of several sub-steps.

In the foregoing brief description of FIG. 3, many simplifications have been made over a practical one Control circuit made. For example, both the control circuit for the upshift and the control circuit for downshifting, both computing circuits, each forming a closed loop, and a reaction torque computing circuit have which the control circuit 47 representing a closed loop or the reaction torque computing circuit 60 of FIG. 5 of US Pat. No. 4,031,782. However, these simplifications make it easier understanding how the control circuit works and are also useful when looking at the individual subunits will be described in more detail below.

4 shows the essential parts of the switching point calculator 121. An input terminal of the switching point calculator 121 is connected to the conductor 110, on which the target rotation

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torque signal is available, a second input terminal is connected to the Connected conductor 122, on which the signal associated with the speed of the drive shaft 103 is, via a conductor 131 a first logical signal List (first; first) is then received when the first gear ratio in the gearbox, that is, the first rank is set. A second logic signal L2nd (second) provided when the second gear ratio is set in the transmission. The other input signals are reference signals formed by voltage levels, each of which designates a specific target torque value or target speed value. For example, it says on one Conductor 133 a reference signal with a specified voltage level, which characterizes 85% of the maximum target torque, which can be characterized by the throttle position signal present on conductor 110. This Setpoint torque signal is in a waveform circuit 134, e.g. a filter, processed so that a smoothed target torque signal is obtained on a conductor 135. You get thus at the output of a comparator 136 on a conductor 137 a logic signal LDT (detent; kick-down position) , which is always present when the target torque exceeds 85% of the maximum available torque. This A signal is very often received when the driver depresses the accelerator pedal all the way to the floor in order to accelerate quickly of the vehicle.

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The switching point calculator 121 contains three function generators 140, 141 and 142, which are also linked to the one on the ladder 135 standing target torque signal are applied and a correspondingly modified one on conductors 143, 144 and 145 provide an analog output signal. The signals on conductors 142-145 are all analog signals. These signals emitted by the function generators are compared in further comparators 146, 147 and 148 with that of the Speed of the drive shaft 103 associated signal compared, which is fed via the conductor 122 and a conductor 150 will. The digital output signals of the comparators 146 to 148 are shown in FIG. There corresponds the output of comparator 146 on conductor 151 a curve 152. That provided on conductor 153 The output of the comparator 147 is represented by a dashed curve 154, and the output of the comparator 148 on the conductor 155 corresponds to the curve 156 of FIG. 5. As from the lettering of FIG. 5 can be seen, the ordinate corresponds to the revolution of the drive shaft 103 in revolutions per minute, while the throttle valve position (given in% of the maximum flow rate position) as a measure of the desired target torque is plotted on the abscissa. It goes without saying that one can also use a different measure for the setpoint torque Can use variable, for example the pressure in the intake line of the internal combustion engine, without the curves 152, 154 and 156 needed to modify.

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As can be seen from FIG. 4, the switching point calculator has
121 three more comparators 157, 158 and 159, of which
each is acted upon by the speed signal present on conductor 150. The comparator 157 additionally receives a reference signal in the form of a voltage via a conductor 160
predetermined size, which is assigned to a speed of 350 rpm; the comparator 158 additionally receives a reference signal via a conductor 161 in the form of a voltage level which is assigned to a speed of 1800 rpm; and the comparator 159 receives an additional one via a conductor 162
Reference signal in the form of a voltage level which is assigned to a speed of the drive shaft 103 of 3450 rpm.

The output signal of the comparator 157 is applied via a conductor 163 to an input terminal of a computing circuit 164; the output signal of the comparator 158 is applied to a further input of the computing circuit 164 via a conductor 165. The output of the comparator 159 is applied to one of the input terminals via a conductor 166
of a computing circuit 167, which additionally receives the signals List and L2nd via the conductors 131 and 132
is, which indicate that the first or the
second gear is engaged. In addition, the computing circuits 164 and 167 receive the information provided via the conductor 137
Output signal LDT of comparator 136; and the computing circuit 167 is additionally acted upon by the output signal of the comparator 147 via the conductor 153.

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Another computing circuit 168 receives the logic signals List and L2nd and the output signal of the comparator 146. Another computing circuit 170 receives the logical signal List on conductor 131 and the output signal via conductor 155 of the comparator 148. The output signals of the computing circuits 164 and 170 are applied to the R and S input terminals a flip-flop 171 given. Its output terminal Q is connected to a conductor 172 on which the digital Sianal LA is provided, which - as can be seen from Fig. 3, one of the output signals of the switching point computer 121 represents.

The outputs of the other two arithmetic circuits 167 and 168 are connected to the R or S input terminal of a further flip-flop 173, the output terminal Q of which is connected to a conductor 174 is connected, on which the command signal LB is issued by the switching point computer 121.

Inside the boxes, which stand for the various arithmetic circuits 164, 167, 168 and 170, are certain mathematical ones Operations given in Boolean notation. It will be understood that a variety of different circuits can be used to perform the mathematical calculations to be carried out, which are entered in the individual boxes. Under a computing circle, one should be digital here working circuit are understood, which are in the rectangular box of a computing circle in Boolean

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Notation can perform specified math operations.

Fig. 6 shows details of the monitoring circuit 123, the in Fig. 3 is shown only schematically. As can be seen from Fig. 6, there are input terminals of the monitoring circuit 123 is applied via the conductors 172 and 174 with the command signals LA and LB, which are the target transmission ratio to be set characterize. On the output side, the signals LC and LD are provided on conductors 180 and 181, which characterize the gear ratio currently set in the gearbox. Furthermore is provided by the monitoring circuit 123 reproduced in FIG. 6 a start signal ready either on a conductor 182 or on a conductor 183, namely the start signal LUS-R for the Upshifting or the start signal LDS-R for downshifting, Via a conductor 184, the monitoring circuit 123 is connected to the termination signal when switching up LUS-O and applied via a conductor 185 with the termination signal for the downshift LDS-O, and thus learns when a Switching process is complete.

The monitoring circuit receives via the conductors 172 and 174 123 on the input side thus the command signals LA and LB, which indicate the change in the transmission ratio to be carried out or show the desired gear ratio. The LA signal on conductor 172 becomes

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applied directly to one input terminal of a NAND gate 187 via a conductor 186; the same signal arrives with the interposition of an inverter 188 to an input terminal of a further NAND gate 190. This NAND gate 190 also receives a feedback signal via a conductor 191, with which via a conductor 192 also another NAND gate 193 is applied. The NAND element 190 receives a feedback signal LD via conductors 194 and 195. A further feedback signal is fed via a conductor 196 to the last input terminal of the NAND gate 190. That The output signal of the NAND gate 190 is via a delay stage 197 headed. This is a delay stage in which only falling edges of a pulse can be delayed, while leading, rising edges of a pulse are practically without delay walk through. The delayed signal emitted by the delay stage 197 arrives at the S input terminal of a Flip-flops 198. The NAND gate 187 receives a feedback signal via a conductor 200; its output signal passes through a further delay stage 201 which is similar to the delay stage 197 only falling edges of a pulse delayed. The output of the delay stage 201 is applied to the R input terminal of flip-flop 198. The output signals received at the output terminals Q and Q. of the flip-flop 198 are denoted by A and Ä ~ in order to carry out the signal processing in the following circuits to be able to describe the monitoring circuit more easily.

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The logic signal A comes from the output terminal Q des Flip-flops 198 via a conductor 202 to an input terminal of a NAND element 203 and via a conductor 204 one of the input terminals of a computing circuit 205 and via a conductor 206 to one of the input terminals of another Arithmetic cycle 2O7. These computing circuits ultimately provide the start signals for a switching process on conductor 182 the start signal LUS-R and on conductor 183 the start signal LDS-R. The digital output signal A of the flip-flop 198 reaches one of the input terminals of a NAND element 210 via a conductor 208 and also over a conductor 211 to one of the input terminals of the NAND gate 193. The NAND gate 203 receives next to that on the conductor 202 pending digital signal A via conductor 185, the termination signal indicating the end of a downshift process LDS-O. The output signal of the NAND gate 203 comes to the R input terminal of a flip-flop 212, the output terminal of which Q is connected to conductor 180, which is one of the outputs of monitoring circuit 123. on the conductor 180 is referenced above

Sianal
Figure 3 dealt with ¹ JiC. The output terminal Q of the flip-flop 212 also provides the feedback signal to which the NAND gates 190 and 193 are applied via the conductor 191. This feedback signal is also given to the two computing circuits 205 and 207. In addition to the signal A transmitted via the conductor 208, the NAND element 210 also receives the signal provided via the conductor 184.

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set the final signal for an upshift LUS-O, The output signal of the NAND gate 210 is applied to the S input terminal of the flip-flop 212 given. The initial cycle Q of the flip-flop 212 is via the conductor 200, which represents a feedback path, with the associated an input terminal of the NAND gate 187 is connected. the The output signals provided by the flip-flop 212 are thus the signals LC and LC, which have already been dealt with.

As can be seen from the lower part of FIG. 6, the signal LB present on conductor 174 is applied directly to one input terminal of NAND gate 193; Via an inverter 215, it also reaches one of the input terminals of a further NAND element 216, the other input terminal of which has the output signal LD on conductor 181, which is fed as a feedback signal via a conductor 217 '. The other input signals for the NAND element 193 are the signal LD provided via the conductor 194 , the signal LC transmitted via the conductors 191 and 192 and the signal A present on the conductor 211. The output signal of the NAND element passes through a delay stage 217 , which in turn only delays the falling edges of a pulse, to the R input terminal of a flip-flop 218. The output signal of the NAND element 216 reaches the S- similarly via a delay stage 220, which also only delays the falling edges of a pulse. Input terminal of the

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Flip-flops 218. At output Q of flip-flop 218 receives a logic signal B, which reaches an input terminal of a NAND gate 222 via a conductor 221 and via a conductor 223 to an input terminal of the computing circuit 205 and similarly to an input terminal of the computing circuit 207 reached. The standing on the conductor 223 logic signal B also arrives on the conductor 196 on the associated input terminal of the NAND gate 190. The signal B obtained at the output Q of the flip-flop 218 arrives via a conductor 224 to an input terminal of a NAND gate 225, which via the conductor 184 to its other The LUS-O signal is applied to the input terminal. The output of the NAND gate 225 is connected to the S input terminal a flip-flop 226, the R input terminal of which is connected to the output of the NAND gate 222. The exit Q of flip-flop 226 provides signal LD on conductor 181. This signal also arrives via conductor 217 ' to the second input terminal of the NAND element 216 and via a conductor 227 to other input terminals of the computing circuits 205 and 207. The output terminal Q of the flip-flop provides a signal LD, which via the conductor 194 to one of the input terminals of the NAND gate 193 and via the conductor 195 to one of the input terminals of the NAND gate 190 is given.

The monitoring circuit 123 reproduced in FIG. 6 receives thus on the input side the required translation ratio

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ratio associated command signals LA and LB (via conductors 172 and 174); further input signals for the monitoring circuit are the termination signals LUS-O and LDS-O on conductors 184 and 185. Generated on the output side the monitoring circuit 123 a status signal LC corresponding to the actually set transmission ratio and LD, which stands on the ladders 180 and 181, as well as a Start signal for the upshift LUS-R on the ladder 182 and a start signal for the downshift LDS-R on the ladder 183. In the upper left corner of FIG. 6 a table is shown which shows the signals at the outputs Q and Q. at each of the flip-flops 198, 212, 218 and 226 for a given set of logical input signals at the S- and R input terminal.

Fig. 7 shows the most important components of the control circuit 125 for the upshift, more precisely that part the control circuit 125 in which the reaction torque is calculated. About mutual connection and cooperation to be able to better understand the circuit parts shown in FIG. 7 during the description the circuit itself and then the mode of operation of the control circuit 125 is explained with reference to FIG. In Fig. 8 a curve is designated by 228 as a whole, which shows the change over time of the torque signal present on the conductor 105 through a full upshift reproduces away.

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In FIG. 9 below, the partial representations 9A to 9L show the temporal course of signals in the circuit shown in FIG. 7 correlated to the temporal course of the curve 228 above. Various points in time are shown on the time axis shown immediately below the curve 228 which will be referred to in more detail later, _{denoted by t o} to t _7. Various points 230 to 237 on the curve 228 reproducing the time profile of the torque correspond to these points in time.

The circuit shown in Fig. 7 has four input signals already described above, namely that which is present on conductor 105 and assigned to the actual torque Signal, the signal LD present on conductor 180, which is part of the signal formed by the two signals LC and LD Represents status signal, and the upshift start signal LUS-R supplied via conductor 182. about a Conductor 250 are also PWM signals (p_ulse width modulated signals; pulse-width-modulated signals), which will be explained in more detail later with reference to FIG. 10 will. For the moment it may suffice that these pulse-width-modulated signals represent an alternating signal and have a duty cycle of 50% when the automatic transmission is operated with a constant transmission ratio will. The duty cycle of the pulse-width-modulated signals, on the other hand, is changed when either upshifted

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switched or downshifted.

There are also four output signals in FIG. An output signal LT-LOW (t.orque-low; Signal for low torque transmission), through which a control circuit designed as an open loop 249 is activated for upshifting whenever a switching cycle is started, i.e. when a start signal LUS-R is received on the input-side conductor 182 and at the same time the torque signal present on the conductor 105 has such a level that is below one given limit, e.g. less than 34 Nm (25 foot / pounds). Under these conditions, the on The signal LT-Low, which is connected to the conductor 251 and indicates that it is working at low torques, indicates that the control circuit is working 249 initiated, and this for the various sub-steps of a switching process in chronological order in the same way, so that you normally get an uncontrolled switching process. So you need then no closed loop control if the torque level for stable operation with good efficiency is too small.

On an output-side conductor 252 there is a further logic signal, which is designated with L ¹ CL ". This is a control signal for resetting the steepness of a ramp signal, which at time t, -

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of Fig. 8 is provided and the steepness of a ramp-shaped Resets the reference signal which is the basis for that part of the torque curve designated by 228 forms, which between the times tj- and t, of Fig. 8 is located. On conductors 253 and 254, the control signals LUS-F and LUS-N for the disengaged and the friction bodies to be brought into engagement provided in the controlled planetary gear. After explaining this most important Parts of the control circuit 125 shown in FIG. 7 will now also be described in detail.

The torque signal on conductor 105 is sent to a storage circuit 255, which is used to store the minimum torque. The signal on conductor 105 is also applied to an integrator 256 and a comparator 263. The integrator 256 is also acted upon by the upshift start signal LUS-R and receives a clock signal from a clock generator 257 over a period of time which in FIG. 8 corresponds to the period between times t_ and t ₁ , so the integrator 256 works and then provides a signal on conductor 258 after time t- and later over the entire switching process, which signal corresponds to the averaged torque level. The memory circuit 255 is designed so that it is constantly overwritten as long as the level of the signal applied to it decreases, and that it stores ("holds") the minimum value of the input signal, even after the

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Input signal has started to grow. This stored, assigned to the minimum torque value in the past Signal is pending on conductor 260. The clock

257 is preset in such a way that during the period between times t_ and t .. of FIG An activation signal is applied to the integrator 256 and, after this period of time has elapsed, to one with its output connected conductor 261 provides a delayed start signal for the upshift. This delayed upshift start signal is designated in the drawing with LUS-R *.

In the control circuit 125 there are four comparators 262 to 265 provided, which are interconnected in the manner shown and the signals just described above to one Process a large number of trigger and control signals. Specifically, comparator 262 is on line with that

258 applied averaged torque signal and also receives a reference signal in via a conductor 266 Form of a voltage which corresponds to a predetermined minimum torque level. In a preferred embodiment this value is set to be 34 Nm (25 foot / pounds). The comparator 262 sets on one with its output connected conductor 267 a logic signal Cp-LOW ready, which indicates whether in the power transmission a sufficiently large torque is available to control a closed loop To be able to complete the switching process. To be there

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293955B

The signal on the conductor 251 indicating that the torque in the power transmission is too low is reached at the end of the torque averaging interval between the times t _Q and t. 8 is provided whenever the averaged torque value is not at or above the predetermined reference value, which corresponds to 34 Nm.

Of the remaining comparators, a first, namely 265, is used to generate a first trigger signal C ₁ . This trigger signal is only used when upshifting from first to second gear. The comparator 265 thus serves to "tell" the upshift control circuit that the corresponding control valve should be prepared for the brief response time required during an upshift from first to second gear. For this purpose, the first comparator 265 provides the first _{trigger signal labeled C 1} on a conductor 270, which leads to a further computing circuit 271. The first trigger signal is also applied to the S input terminal of a flip-flop 273 via a conductor 272. The operation of the entire system in a closed loop is initiated either by a second trigger signal, which is provided by the second comparator 264 on a conductor 274, or by a return signal C "(turn around; signal indicating that the slope of the Curve 228 has changed again after passing through a minimum), which is generated by the comparator 263 on a line connected to its output

03 0 016/0785

ter 275 is provided. The comparator 265 provides the first trigger signal on the conductors 270 and 272 at approximately the point in time at which the value of the torque signal drops to 80% of the averaged torque. This point in time is denoted _{by t 2 in FIG. 8.} The second comparator 264 is set so that it provides the second trigger signal on the conductor 274 when the averaged torque level drops even further, namely to 60% of the averaged torque level. This point in time is denoted by t in FIG. Comparator 264 provides return signal C on conductor 275 when the average torque signal has reached its minimum and then increased again to a point where the average torque signal is 27 Nm (20 foot / pounds) greater than that minimum signal value. The corresponding point in time is indicated by t in FIG. and corresponds to point 234 of curve 228.

An adaptive programming stage 276 for controlling the gain and slope of a ramp signal in the in The part of the control circuit 125 shown in FIG. 10 is connected to the averaged torque signal via the conductor 258 (cf. 9C) and applied to the LC status signal via conductor 180. The programming stage 276 poses on a ladder 277 ready a first analog voltage signal, through which the slope of a ramp voltage of the shown in Fig. 10, forming a closed loop

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29395B6

Control circuit is controlled for the duration of a controlled switching process; on a ladder 278 represents the programming level 276 ready a second analog voltage signal, through which the gain control in the closed Loop is controlled accordingly. The corresponding circuit connections will be more detailed later described. Their basic work can also be understood from FIG. 6 of US Pat. No. 4,031,782. In this In the figure, an adaptive computing circuit 93 generates an analog voltage signal for controlling the steepness of a ramp a conductor 92, while an analog voltage signal for gain control is present on a conductor 94. The adaptive computing circuit 93 also generates an upshift signal there, as is also described in more detail for the present application.

Returning to the upshift control circuit 125 illustrated in FIG. 7 of the present application, one can see that the signal on conductor 267 indicating low torque operation is applied to one of the Input terminals of a NOR gate 280 reaches the other input terminal via a common conductor 281 with the on the conductor 261 standing delayed start signal is applied for a switching process. The output of the NOR gate 280 is connected to the S input of a flip-flop 282, which also has the on the common conductor 281 standing delayed start signal for

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receives the switching process. The signal obtained at the Q output of flip-flop 281 is the au the conductor 251 ^c standing signal LT-LOW, and this signal is at the same time via a conductor 283 to three arithmetic circuits 284, 285 and optionally 286th

Another computing circuit 287 is applied to the model shown in Fig. 9B delayed start signal for a shift operation, receives via the conductor 275, the reproduced in Fig. 91 return signal C_ _A and the second trigger signal shown over the conductor 274 in Fig. 9H. The output of the computing circuit 287 is connected to the S input of a flip-flop 288. The R input of the latter receives the delayed start signal on conductor 281 for an upshift. The flip-flop 288 provides the logic signal LCL at its output Q, which signal is applied to one of the inputs of the computing circuit 284. An output signal LCL is obtained on a conductor 290 at the output Q of the flip-flop 288, which output signal LCL is used in the control circuit section of FIG. 10 which forms a closed loop. The signal LCL emitted by the flip-flop 288 is sent as one of the input signals to the computing circuit 284, which at the same time ^{receives the low torque signal LT-LOW via the conductor 283 and a feedback signal L 1} RR via a conductor 292, which is sent from a differentiating circuit 291 is provided. The computing circuit 284 puts the signal L ¹ CL on the line at its output.

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ter 252 ready and this signal is shown in Figure 9L.

As already explained above, the first trigger signal on conductor 272 and shown in FIG. 90 is applied to the S input of flip-flop 27 3. The R input of the flip-flop 273 receives a delayed signal via a delay stage 293, its output Q provides the signal LRR (ramp reset; signal for resetting the ramp slope) at time t, - of FIG The signal for resetting the ramp inclination has the shape of a step curve, as is indicated in FIG. 7 by curve 294. The differentiating circuit 291 is used to produce a sharp pulse from this signal, which is shown in FIG. 7 at 295 and is also drawn in FIG. 9K. The resetting of the ramp generator arranged in the control circuit part contained in FIG. 10 is controlled by this pulse.

The computing circuit 285 receives in addition to the delayed start signal on the conductor 281 for an upshift process also via the conductor 283 the signal LT-LOW provided by the flip-flop 282, which means that working under lower Indicates torque transmission. The computing circuit 285 also receives an output from the computing circuit 268 via a conductor 296 Feedback signal. On the output side, the computing circuit 285 generates the control signal for the disengaging friction body.

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which is on the conductor 253 and is labeled LUS-F.

The computing circuit 271 also receives the feedback signal provided by the computing circuit 268 via the conductor 296 and is via the conductor 270 with the first trigger signal provided by the first comparator 265, via a Conductor 297 with the trigger signal provided by the computing circuit 284 for working in a closed loop (see. Fig. 9L) and via a conductor 298 with the delayed start signal shown in Fig. 9B for initiating a Switching process applied. This delayed start signal is shown in the manner shown in the drawing also given directly to the arithmetic circuit 268. The output signal LFF of the computing circuit 271 is both on the following Arithmetic circuit 268 as well as the delay stage 293 given. In addition to the input signals just described, the computing circuit receives 268 via a conductor 300 the status signal LC as a further input signal. The pulse-width-modulated signal PWM is applied via the conductor 250 the arithmetic circuit 268 and given to the last arithmetic circuit 286. The pulse width modulated signal PWM is from the a closed loop control circuit portion shown in Fig. 10 and later is provided will be described in more detail.

In the part of the upshift shown in FIG.

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Control circuit 125, the two output signals Q ₁ and Q _{2 of} the computing circuit 268 are given directly to the last computing circuit 286. In addition, the output signal Q _{1 is applied} as a feedback signal via the conductor 296 to one input terminal of the computing circuit 271. The signal LT-LOW provided by the flip-flop, which indicates that the system is working at low torque values, is sent via the conductor 283 to one of the inputs of the computing circuit 286; the other input signals for the computing circuit 286 have already been described above. According to a predetermined combination, which is specified in detail in FIG. 11, the computing circuit 286 generates the signal LUS-N from its input signals on the output side, which controls the engaging friction element of a clutch or a brake of the automatic gearbox and which is provided on the conductor 254 will.

In Fig. 10 that is part of the upshift control circuit 125 reproduced, which represents a circuit part that closes a loop. This part of the circuit represents a termination of the upshift on conductor 184 indicating termination signal LUS-O ready and generates the pulse-width-modulated signal on conductor 25O PWM to which the part of the control circuit 125 shown in FIG. 7 is acted upon. As can be seen from FIG is, this part of the circuit receives the torque signal on conductor 105 as input signals.

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the analog voltage signals for controlling the ramp slope and the gain control, which are on the conductors 277 and 278 and from the programming stage 276 of Fig. 7 can be provided. The signal LCL provided at the output Q of the flip-flop is transmitted via the conductor 290 as well such as the delayed upshift start signal LUS-R on conductor 281 and that on conductor 180 standing status signal LC.

The torque signal on conductor 105 is given to a storage circuit 303 and to a summing circuit 304. The memory circuit 303 is designed so that the memory content continuously reflects the torque level Signal follows, which is assigned to the current torque in the power transmission. As well as via ladder 290 the signal LCL is provided, but the memory part of the memory circuit 303 is activated, so that the then present Value for the torque is saved. Upon receipt of the logic signal LCL on conductor 219, this becomes Stored value stored and given on a conductor 305 to an input terminal of the summing circuit 304. That The logic signal LCL on conductor 290 is also applied to a ramp generator 306. This works at Receiving the analog voltage on conductor 277 such that it has a ramped voltage on a conductor 307 provides. This increasing voltage is used to reduce the increasing torque during controlled production.

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on switching between times t 1 - and t _g of FIG. 8 to control. This ramp signal is applied to a further input of the summing circuit 304 and also reaches an input of a clock generator 308. The clock generator 308 is also acted upon by the analog ramp control signal on the conductor 277 at a further input. Since the inclination of the Rairpen signal is predetermined by the charging time, which in turn depends on the components inside the ramp generator 306, the clock generator 308 outputs the final signal for an upshift operation LUS-O on the conductor 184 when the level of the ramp-shaped signal increases the conductor 307 becomes greater than the voltage level of the other analog control voltage. The corresponding point in time is _{denoted by t 7 in} FIG.

An analog / digital converter 310 receives the analog control voltage for the gain control and via the conductor 278 via conductor 281 the delayed start signal for an upshift operation. This analog / digital converter generates From the analog voltage obtained, a digital combination of output signals, which are transmitted to conductors 311 to 314 and designated LGO, LG1, LG2, LG3 are. This combination of four digital signals allows 16 different values for the gain control to adjust. These digital signals are then provided when the delayed Start signal from the value logical "1" to the value logical

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"O" drops, which occurs at time t .. of the switching cycle of the Case is. These signals are in turn given to input terminals of an amplification control circuit 315, which via a Conductor 316 is acted upon at the same time with the output signal of the summing circuit 304. You can see that on one conductor 317 connected to the output of gain control loop 315 will receive an analog gain control signal which depends on both the gain control voltage and the ramp set voltage. The expert in the field of closed loop controls it will be understood that the analog gain control voltage on conductor 278 is decreased when corresponding signals are present on conductor 105 for higher torque values; This way the stability of the closed loop control ensured. For lower torque levels, on the other hand, the gain is turned up, and you can keep tracking errors in the system very small. The output of gain control loop 315 is always output via the conductor 317 to a frequency compensation network 318, which is always activated when he receives a status signal LC via the conductor 180. This Network can thus be made to do so when switching up work differently from first to second than on any other upshift. Such a thing Upshifting from first to second gear is indicated by the fact that there is a signal on conductor 180 the value logic "0" is present, which is only when switching up

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from first to second gear is present while the signal otherwise always has the value logical "1" on the conductor 180. The output of the frequency compensation network 318 is given to an input of a further summing circuit 320, which via a conductor 321 at the same time a signal from a zero point setting circuit 322. The logic signal LC on conductor 180 is also sent to the zero point setting circuit 322 given, and part of this signal, which is caused by the setting of an adjustable component is specified in the zero point setting circuit, it is sent via the conductor 321 to the summing circuit 320. The output signal of summing circuit 320 is an analog signal and is provided on conductor 323. It is used for Control of the duty cycle of an AC voltage output signal from a pulse width modulator 324 the conductor 250 connected to its output is provided.

Fig. 11 shows details of the circuitry of the computing circuits 271, 268 and 286, which are shown in Fig. 7 only as a box. Even in Boolean notation, they are mathematical Operations specified which are carried out in arithmetic logic circuits 271 and 286. Because the corresponding Expression for arithmetic circuit 268 is more complicated, the circuit details are for two connected together Flip-flops of this arithmetic cycle are explicitly reproduced. From the circuit diagram shown in Fig. 11 is the

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Type of processing of the input signal for generation of the LUS-N signal, which is used to control the engaging friction body.

Fig. 12 shows details of the distribution circuit 124, carried out mathematical operations are indicated again in Boole ¹ shear listing in individual computing circuits of this distribution circuit. The distribution circuit 124 was only indicated as a single block in FIG. 3. The same letter combinations are used to designate the signals as in FIG. 3 and the other figures, so that it can be seen from where these signals are provided.

As can be seen from FIG. 12, the distribution circuit 124 has computing circuits 330 and 331 and 332 which receive as input signals: the status signals LC and LD; the switching operation start signals (LUS-R or LDS-R), which initiate the operation of the circuit either for an upshift or for a downshift, and the appropriate signal pair LUS-F and LUS-N or LDS-F and LDS-N for Controlling the on-going and off-going friction bodies depending on whether the shift is controlling an upshift or a downshift. After processing in the computing circuits 330, 331 and 332, signals LB3, LB2, LC2 are obtained at the output of the same, which are given to one of the inputs of further computing circuits 333, 334 and 335.

030016/0785

These computing circuits are additionally supplied with the signals LR and LN, which are provided by the drive range selector switch and indicate that reverse gear or idle (neutral position) is set. The output signals of the computing circuits 333, 334, 335 are labeled L'B3, L'B2, L'C2 and are given to the associated conductors 113, 114 and 115 after amplification. For a shifting process under consideration, a signal is present on two of these three conductors 113 to 115, and the engaging and disengaging friction bodies are controlled by this signal combination.

Each of the computing circuits 333 to 335 receives a third input signal from a delay stage 336. The latter is only used to delay a signal LLU which is provided by a computing circuit 337. The three output signals of the computing circuits 330 to 332 are in turn applied to the latter. The signal processing in the computing circuit 337 according to the local Boolean notation and the delay of the signal LLU received at the output of this computing circuit in the delay stage 336 for generating the corresponding delayed signal L ¹ LU before the last-mentioned signal is fed to the computing circuits 333 to 335 is used to that the control circuit prevents locking of the automatic transmission, which could be caused by one friction body engaging prematurely before the other friction body has been disengaged.

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The work described above should now be carried out Control circuit for an automatic gearbox will be explained on the basis of an upshift process:

It is assumed that the engine of the motor vehicle, which is equipped with the automatic transmission 101, has started, that the transmission is in first gear and that the driving range selector switch is in position D (normal driving mode). It is also assumed that a higher torque is required from the driver than is currently provided on the drive shaft 103 on the output side. A corresponding target torque signal is provided in accordance with the position of the wiper of the potentiometer 111 shown in FIG. 2. The shift point computer 121 (see FIG. 3) now generates a signal LA or LB, respectively, at its two output terminals, which has the value logic "0" and thus indicates that first gear is engaged in the transmission. Before an upshift is now requested, the monitoring circuit 123 generates status signals LC and LD at its outputs, which also have the logical value "O ^{: |} The signal on conductor 113 also has the value of logic "1" and ensures that valve V1 is energized, while the signals on conductors 114 and 115 are low at this point in time immediately before the throttle valve position

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development signal, i.e. the target torque signal on the conductor 110 indicates that with regard to the momentarily present torque on the drive shaft 103, which has a The actual torque signal present on conductor 105 makes an upshift necessary.

If the switching point calculator 121 determines that a switching process is to be carried out, the target transmission ratio command signal LA, LB changes in such a way that the signal LA becomes high, that is to say assumes the value "1", while the signal LB remains low. This change in signal is also detected by the monitoring circuit 123, which compares the target transmission ratio with the actual transmission ratio by comparing the signals LA, LB with the signals LC and LD. Under the conditions considered here, the monitoring circuit determines that an upshift from first to second gear is to be carried out. This takes place in that the monitoring circuit 123 provides the signal LUS-R, which is shown in FIG. 9A and _{begins at time t Q} of FIG. This means that the signal LUS-R goes low from its normally high level "1" at time t _Q of FIG. As can be seen from FIG. 7, the upshift start signal LUS-R passes via the conductor 182 to the upshift control circuit 125 and there starts both the integrator and the clock generator 257. The integrator 256 now calculates the mean torque averaged over the period between

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see the times t _o and t. and stores the mean value obtained after the averaging interval. The averaging interval is specified by the clock generator 257. The LC signal on conductor 180, which, as evidenced by FIG. 7, is also fed to control circuit 125, indicates that an upshift from first to second gear and not an upshift from second to third gear is to be performed. In the latter case, the signal LC on conductor 1CO would have the value logic "1 ^1:. The combination of the upshift start signal on conductor 182 and the status signal on conductor 180 thus not only indicates that an upshift operation should be initiated , but also shows which sequence of sub-steps is to be carried out during the upshift process.

At the end of the torque averaging interval, that is to say at time t. At this point in time, the averaged torque signal on conductor 258 becomes a constant which represents the average torque transmitted in the drive connection immediately before a shift is initiated. The delayed start signal LUS-R *, which is obtained at the time t ₁ at the output of the clock generator 257, is also applied to one of the input terminals of the computing circuit 285. So you immediately have a signal level on the line.

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- (\ Q -

ter 253, which controls the disengaging friction body. Consequently the transmitted torque begins to decrease in the drive shaft 103, as can be seen from FIG. 8 is.

At time t_ the torque is in the drive shaft dropped to 80% of that value, which on average was immediately existed before the switching process was initiated. To this At this point in time, the output signal of the first comparator 265 drops to a low value, and the first is thus obtained Trigger signal shown in Fig. 9G. This trigger signal arrives at the computing circuits 271 and 268 last arithmetic circuit 286 of the arithmetic circuit chain and indicates to this that a LUS-M signal is to begin, so that the assigned The control valve can begin filling the hydraulic servomotor assigned to the engaging friction body, as required for a shift from first to second gear. This is done faster than with one Shifting from second to third gear. Assuming that a normal switching process continues, at which the value of the torque at time t ~ 80% of the mean value transmitted before the start of the switching process Torque is, the torque transmitted by the drive shaft continues to drop and reaches a in Fig. 8 with t-, designated time a value of 60% of the initial value. At this point in time, comparator 264 provides the second trigger signal on conductor 274.

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As can be seen from FIG. 9H, the output signal of the second comparator 264 goes from the value "1" to the value "0" at this point in time. The second trigger signal is now processed in the computing circuit 287, in the flip-flop 288 and in the computing circuit 284, and the signal L ¹ CL, which is shown in FIG. 9L and which closes the control loop, is obtained on the conductor 252, i.e. it ensures that the control circuit works in a closed loop. If the torque drop is so small that no output signal is received at the second comparator 264, there is no closing of a control loop up to time t. At this time, a return signal is provided by the comparator 263, which is shown in FIG. 91 and indicates that the minimum torque has been passed. The output of comparator 263 is more precisely provided when the torque signal has passed its minimum value and then increased again to a value which is approximately 27 Nm (20 foot-pounds) above the value of the minimum. At time t _& of FIG. 8, this is from drive shaft 103

transmitted torque increased again to a value,

of
which corresponds to about 80% 'of the mean torque transmitted before the start of the switching process. This torque value was last available at the point in time at which the comparator 265 provided the first trigger signal; correspondingly, the first trigger signal is ended at time t ₅ , ie the output of the comparator 265 goes back to the value "1". In this way, the ramp generator 306 of FIG.

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reset, ie a very rapid increase in the output signal of this ramp generator is obtained, which is shown in dashed lines in FIG. Correspondingly, at time t _5, a jump in the corresponding curve at time te is observed, while this curve rose steadily between times t 1 and tr of FIG. 8.

It should be emphasized that the above-described sequence of signals provided by the comparators 265, 264 and 263 only is then obtained when the averaged torque signal is present Initiation of a switching process is above a predetermined reference value, which is preferred in the case of the one considered here Embodiment is 34 Nm (25 foot-pounds). A torque value that is below this reference value indicates that control of the shift using a closed loop is not necessary is. The existence of such an operating state can be recognized by the fact that the comparator 262 on the conductor 267 a corresponding signal C_-LOW is provided. As shown in dashed lines in FIG. 9F, remains the output signal of the comparator 262 is always low in this case, and one then obtains at the output of the Flip-flops 282 on conductor 283 a signal which blocks computing circuit 284. This then prevents that on an output signal is provided to the conductor 252, which signals the transition of the control circuit to the closed loop initiates some work. Instead, the sign

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level on the conductor 251 to ensure that the control circuit 24 9, which is only shown schematically in FIG. 7, is the open loop ig works, is activated. In this way you get a conventionally programmed switching process, consisting of chronologically successive individual steps instead of a lock-loop control of the switching precedence.

The programming stage 276 shown in FIG. 7 for the gain control and the control of the steepness of the signal emitted by the ramp generator 306 generates those analog signals which are required by the closed-loop circuit part according to FIG. The pulse-width-modulated signals PWM provided on conductor 250 in FIG. 10 are then generated from these signals, as has already been described above. They are used to regulate the torque level between times t ^ and t _fi of FIG. In this way, it is possible to ensure that the torque actually present runs very close to the ramp signal which is shown in FIG. 8 by a dashed curve. At time t _g , which corresponds to point 236 of curve 22P, the engaging friction body or the engaging clutch is fully engaged. This means that there is no longer any further increase in the output torque, and the torque value becomes essentially constant, as is shown by that part of the curve which lies between the times t _fi and t ₇ . Select

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rend this time remains, the control circuit but continues in the operation of "control ^11, is so that a certain degree of security mark HAT Bie operation" control "is as long as not fully completed until the in Fig. IO wiedergege- beneji clock 3o8 the Afoschlußsignal LUS-O provided This is the case at time t, which indicates the end of a switching process or a complete switching cycle for the control circuit.

Now that the operation of the control circuit for an upshift has been described, that should also be done Operation of the control circuit when downshifting will be considered. It has been found to be useful that To divide the duration of the shutdown process into three basic sub-intervals. The first sub-interval to be considered is the time it takes for the motor's drive shaft to accelerate to the new speed after the load has been reduced at the beginning of the shutdown process. This acceleration time is denoted by ta (time, acceleration; Acceleration time) in the present description and in FIGS. 13 and 15 designated. It will also a certain period of time is required to withdraw the pressure medium from the piston of that servomotor, which the disengaging friction body is assigned. This time is called te (emptying; pressure relief time). The third The period of time is that which is required to fill the servomotor for the engaging friction body. This time-

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span is denoted by tf (filling; filling time). These However, the periods of time all change to a small extent as a function of the speed and the transmitted torque at the point in time at which the downshift process is initiated. In addition, these periods of time depend on it from which gear was engaged in the transmission and which gear is to be set in the transmission. These three different Time spans are therefore used in an outgoing invoice, according to many of three working methods the downshift is to be controlled. These three ways of working are also referred to below as Case 1, Case 2 and Case 3 designated.

The first mode of operation is used when the initial calculation shows that the filling time tf is greater than the sum of the acceleration time ta and the pressure relief time te. In this case, a delay time td (delay) must then be introduced into the algorithm which the control circuit operates. If the filling time is so long, the pressure medium can be supplied to the servomotor for the engaging friction body then begin as soon as the downshift start signal is provided. Against it you cannot start the pressure relief of the servomotor for the disengaging friction body immediately, because the pressure relief time te is a much shorter time. That would mean that there would be too long a period of time between them Time obtained at which the disengaging friction body is free

03 0 016/0785

comes, and the time at which about the engaging Friction body can be transmitted again torque. It is therefore necessary to set the delay time td at the beginning of the Introduce switching process and let it pass before the pressure relief of the servomotor assigned to the disengaging friction body can begin. It can thus be seen that in the first mode of operation, the desired delay time td is equal to the filling time tf minus the sum of the pressure relief time te and the acceleration time is ta.

In the second mode of operation, the filling time tf is less than the sum of the pressure relief time te and the acceleration time ta. To ensure proper timing under these circumstances, the pressurization of the servomotor for the engaging friction body is slightly delayed by the delay time td. In this way ensures that between the pressure relief of the servomotor for the disengaging friction body and the full Engaging the engaging friction body is the correct amount of time. The desired delay time td for the Mode of operation 2 is equal to the sum of the acceleration time ta and the pressure relief time te minus the filling time tf for the servomotor of the engaging friction body.

The third possible case with a controlled downshift is that the acceleration time ta is equal to or less than that is the sum of the filling time tf and the pressure

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load time te. It is therefore only necessary to postpone the start of the filling time by the delay time td. at In this third mode of operation, the delay time td is then the difference between the acceleration time ta and the Filling time tf calculated. Fig. 13 shows a circuit which generates the corresponding auxiliary control signals which Control the start of the filling time and the pressure relief time accordingly.

As can be seen from FIG. 13, the electrical torque signal on conductor 105 reaches a special one formed memory circuit 340, the memory content of which follows the applied torque signal] until the The LDS-R switch-off start signal is applied to the storage circuit. At this point in time the will be found The signal is finally stored and continuously provided as an output signal on a conductor 341. In a similar way it is a specially designed storage circuit 342 is supplied with the speed signal on conductor 106, and the content of the memory circuit 342 is tracked to this signal until a downshift start signal LDS-R is obtained. Then the currently present value of the speed signal is stored and thereafter continuously on a output-side conductor 343 provided. The stored speed signal 343 is applied to a circuit 344 given, which takes into account the inertia of the drive motor. If the circuit 344 receives the status signal LD (LD

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has the value "Γ when downshifting from third to second gear and the value" O "when downshifting from second into first gear), then the circuit 344 on an output-side conductor 345 will do this according to the inertia The modified signal provided by the drive motor- This Signal is applied to the non-inverting input of each of two summing circuits 346 and 347.

The torque present on the input-side conductor 1Ο5 The signal is also applied to the inverting input terminal of a comparator 348. Its non-inverting input terminal receives the torque signal stored by storage circuit 34Ο, but by a predetermined factor which can be set on a potentiometer 349 or an equivalent component. At the one considered here Embodiment, the potentiometer 349 is adjusted so that the comparator 348 is approximately 65% of the Input of the potentiometer 34 9 receives the given signal. The comparator 348 can thus monitor the torque drop and then generates an output signal when the instantaneous torque signal applied to its inverting input terminal has dropped to a value that is 65% of the stored torque value provided on conductor 341 amounts to. When this state occurs, a torque drop signal LTD (torque drop), which is given to one of the three inputs of a clock generator 350. Do you work in the

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First and second mode of operation (see. Above), the clock generator 35O receives the shutdown start signal as a further input signal LDS-R. The stored signal on the conductor 341 is continuously sent to the input terminal via a conductor 351 a gate circuit 3 52 given, which then allows this signal to pass when it is from the clock generator 350 Receives open signal. The output of the gate circuit 352 is via a conductor 353 to the non-inverting input terminal a first comparator 354 and connected to the non-inverting input terminal of a further comparator 355. The stored torque signal on conductor 341 is also sent to a computing circuit 356, which provides an output signal that corresponds to the filling time tf required by the servomotor for the engaging friction body. The output signal of the computing circuit 356 is applied to the inverting input terminal of the summing circuit 346. Similarly, the signal on the conductor 341 is also applied to a computing circuit 357 and generates a signal at its output Signal which is the sum of the filling time tf and the pressure relief time te for the servomotors of the two to be moved Friction body corresponds. The output of computing circuit 357 becomes the inverting input terminal of the summing circuit 347 supplied. The computing circuits 356 and 357 are both activated on receipt of a status signal LD, the only has the value "1" when downshifting from third to second gear. The output of the summing circuit 346 reaches both the inverting input

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output terminal of the comparator 354 as well as the input of an inverter 358. The comparator 354 generates a signal LTIII at its output, which signal is shown in FIG Circuit part is used to generate the signal LDS-N. On the other hand, at the output of inverter 358 in the third case received the signal LIII. This signal is fed to clock 350 only.

The output of the other summing circuit 34 7 passes via a computing circuit 361, which calculates the absolute value of the signal, and via an inverter 362 to the inverting input terminal of the comparator 355. The output signal of the summing circuit 34 7 also goes directly to a buffer memory 363, at its output the Ll / II signal is provided. From the above description of modes of operation 1 to 3 it can be seen how the input signal combinations shown in FIG. 13 are used to generate the logical output signals. These logical output signals either have the value "1" or ¹¹ O ", depending on the conditions under which one is working, ie which of the three cases explained above is present. This can be seen from the first six rows of the table shown in FIG Direct application of logical combination rules then gives the last two rows of the table shown in FIG. 14, which represent the control signals LDS-F and LDS-N for the disengaging and the engaging friction body when downshifting.

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use circuits other than those shown in Fig. 13 to make the torque signal and the speed signal so to process that one activation signals for the controlled movement of the engaging and the disengaging friction body for a specific downshift.

15 schematically shows an embodiment of a circuit part for further processing of the logic signals provided on the output side in the circuit part according to FIG. The circuit part calculates from these input signals reproduced in the first six lines of FIG according to FIG. 15, the activation signals for the disengaging and engaging friction bodies. The one shown in FIG Circuit part is particularly suitable for use in case 3 described above, i.e. when the total acceleration time ta is greater than or equal to the sum of the filling time tf and the pressure relief time te this sum is. In the circuit part shown in FIG concrete values are given for the various digital modules and flip-flops. With that, the A person skilled in the art can easily implement such a circuit.

In the claims, the term "connected" refers to a direct voltage connection between two components understand, which ensures a practically vanishing DC resistance between these components. U.N-

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The term "coupled" should be understood to mean that there is a functional relationship between two components, further components can be arranged between these components.

O2UU16 / 0785

L e r s e i t e

Claims (21)

Control circuit for an automatic transmission 1.) Circuit for controlling the switching processes of an automatic Transmission, which is arranged between a drive motor and a drive shaft, characterized by a) a gear change command circuit (121) associated with the working conditions of the transmission assigned input signals, including at least one driving range selection signal is acted upon and provides gear change command signals (LA, LB) as a function of these; b) a monitoring circuit (123) which carries out logical functions and which uses the gear change command signals (LA, LB) and driving range selection signals (LD) is applied; and c) a distribution circuit (124) which carries out logical functions and which is supplied with start signals (LUS-R or LDS-R) for initiating a switching process, which are provided by the monitoring circuit (123) with 0 3 00 16 / 07RR ORIGINAL INSPECTED Driving range selection signals (LR, LD) and activation signals (LUS-N, LUS-F or LDS-N, LDS-F) that control the timing of the switching process are applied and provides control signals at separate outputs (113, 114, 115) with which separate actuating devices (V1, V2, V3) are applied to set the desired gear ratio serve in the automatic transmission (101). 2. Circuit according to claim 1, characterized in that the gear change command circuit has a shift point computer (121) having a signal at a first input terminal (11O) which changes depending on the desired torque, at a second input terminal with drive range selection signals (L1, L2, LD, LR) and a signal is applied to a third input terminal (122), which changes depending on the speed of the drive shaft (103), the gear change command signals (LA, LB) are provided by the switching point computer (121). 3. A circuit according to claim 1, characterized in that the gear change command circuit (121) is a manually operable A gear selector (e.g. 108) to provide a first associated with a desired gear ratio Input signal and a second input signal (from 120) to which the information about the 030016/0785 desired driving range. 4. A circuit according to claim 1, characterized by a
Control circuit (125) for the upshift, which with the upshift initiating start signal (LUS-R) of the
Uberwachungskreises (123) is applied and the
Activation signals (LUS-N and LUS-F) for the upshifting to the distribution circuit (124) and which after the end of the
Switching process, a termination signal (LUS-O) is transmitted to the monitoring circuit (123) when the various successive substeps of an upshifting process
are finished. 5. A circuit according to claim 1, characterized in that
a control circuit (126) for switching down operations with the start signal provided by the monitoring circuit (123)
(LDS-R) is applied for a downshift and the distribution circuit (124) the timing
activation signals (LDS-F and LDS-N) prescribing a downshift process and a termination signal (LDS-O) sent back to the monitoring circuit (123) when the various partial steps in downshifting have been completed in succession. 6. Circuit for controlling the switching processes of an automatic transmission, which is between a drive motor 030016/0785 and a drive shaft, characterized by a gear change command unit (122) connected to the Input signals assigned to the operating conditions of the transmission, including at least one driving range selection signal is acted upon and generates gear change command signals as a function of these signals; through a Logical functions performing monitoring circuit (123) with the gear change signals and with driving range selection signals is acted upon; by a logical function performing distribution circuit (124) with Start signals for initiating a switching process, which are provided by the monitoring circuit, with driving range selection signals, with a status signal that characterizes the currently set transmission ratio and is acted upon with the timing of the switching process controlling activation signals and on separate Outputs provides control signals with which separate actuating devices are applied to the Serve setting the desired gear ratio in the automatic transmission; by a control circuit (125) for upshifting with the start signals and status signals provided by the monitoring circuit is acted upon and the activation signals that determine the quality of the switching process are sent to the distribution circuit and a termination signal is sent to the monitoring circuit transferred back if the sub-steps run through one after the other during an upshift 030016/0785 " ^b " have expired completely; and by a control circuit (126) for downshifting the start signals and status signals provided by the monitoring circuit is acted upon and provides the activation signals determining the switching process to the distribution circuit and a termination signal is transmitted to the monitoring circuit when the partial steps carried out one after the other are fully unwound during a downshift. 7. A circuit according to claim 6, characterized in that the gear change command unit has a shift point computer (121) to which a first input signal is applied at a first input (110), which is changes depending on the target torque, at a second input (from 120) with information about the selected Driving range containing input signals is applied and at a third input (122) with a third The input signal is applied, which changes depending on the speed of the drive shaft, and which provides the gear change command signals. 8. A circuit according to claim 6, characterized in that the gear change command unit is a manual gear selector (e.g. 108) to provide a first input signal associated with the desired gear ratio and receive a second input signal assigned to the selected driving range. 03C016 / 0785 - 6 - 9. Circuit for controlling the switching processes of an automatic transmission, which is between a drive motor and a drive shaft is arranged, characterized by a switching point computer (121), which is connected to a first, from Input signal that depends on the target torque, a second input signal that depends on the selected travel range and is acted upon by a third input signal, which is dependent on the speed of the drive shaft changes, and which calculates the gear change command signals in response to these input signals; through a Logical functions performing monitoring circuit (123), which with the gear change command signals and with driving range selection signals is acted upon; by a distribution circuit (124) performing logical functions, which with the start signals provided by the monitoring circuit to initiate a switching process, driving range selection signals, a status signal reflecting the currently set transmission ratio and is acted upon with the timing of the switching process predetermined activation signals and on separate Outputs provides control signals with which separate actuating devices are applied to the Serve setting a desired gear ratio in the automatic transmission; by a control circuit (125) for upshifts to which the start signals initiating a shift and the status signal are applied, which are from the monitoring circuit 030016/0785 are provided, and which to the distribution circuit the activation signals controlling the course of the switching process provides and returns a termination signal to the monitoring circuit, if the successively The partial steps carried out in an upshift process are fully processed; and by one Control circuit (126) for the downshift, which the start signals initiating the shifting process and the status signal receives from the monitoring circuit and to the distribution circuit that the timing of a shutdown process emits controlling activation signals and transmits a termination signal to the monitoring circuit when the sub-steps carried out one after the other in a downshift process have been completely processed. 10. Shift for controlling the shifts of an automatic transmission having multiple gear ratios, which is arranged between a drive motor and a drive shaft, characterized by a Switching point computer (121) to which signals are applied on the input side, which information pertaining to the Target torque (110) and at least one piece of information about an output parameter (speed or torque) of the automatic transmission, and which provides an output signal (LA, LB) which corresponds to the desired gear ratio is assigned; and through a monitoring function that fulfills control functions 030016/0785 circuit (118) to which the output signal of the switching point calculator is applied, this output signal with a Status signal compares which is assigned to the currently present transmission ratio and the Comparison of these two signals interrupts and at the same time initiates a switching process when the status signal from the command signal provided by the shift point calculator and assigned to the desired transmission ratio differentiates, and which provides activation signals that influence the automatic transmission so that the desired gear change is made. 11. Circuit according to claim 10, characterized by a control circuit (119) for the timing of the switching process, which is coupled to the monitoring circuit and sends signals to it, which enables precise control ensure the gear change, and which serves to inform the monitoring circuit the end of a gear change display, so that the Uberwachungskreis again the comparison between the desired target transmission ratio corresponding signal and the signal assigned to the current actual transmission ratio. 12. A circuit according to claim 11, characterized by a transducer (104), which by the automatic Gear-driven drive shaft is assigned and one of the output parameters (speed and / or torque) 030016/0785 of the transmission generated signal assigned to the control circuit (119) for controlling the timing a switching process and the switching point computer (121) is transferred. 13. Circuit for controlling gear changes in an automatic transmission with multiple gear ratios, which is driven by a drive motor and works on a power transmission, via which one to be driven Load is acted upon by drive torque, characterized by a switching point calculator (121), which is acted upon on the input side with information signals, including a signal for the target torque, and which on the output side provides a command signal assigned to the desired target transmission ratio; by a sensor (104) which is coupled to the power transmission and provides a signal at its output, which changes depending on the torque transmitted in the power transmission; and by a control circuit (118, 119) which is connected to the switching point computer and the sensor, which are used for this is used to monitor the target transmission ratio signal and a difference of the same from the actual transmission ratio signal determine and initiate a gear change if such a difference is detected, and to interrupt the monitoring function during such a gear change while it is a resumption - 10 - 030016/0785 The monitoring function is effective when the gear change is complete. 14. A circuit according to claim 13, characterized in that the output signal of the sensor (104) is the torque in the Power transmission is assigned. 15. Method for controlling a switching process in an automatic Transmission with a plurality of gear ratios, which is used to transmit torque from a Drive motor is used on a drive shaft, characterized by the following process steps: Generating a first signal (on 110) corresponding to the desired torque demanded from the automatic transmission is assigned, and generating a second signal (to 105 or 106), which at least one output-side Parameters of the automatic transmission is assigned; Processing of the first and second signal (in Switching point calculator 121) for generating a signal which corresponds to the desired target transmission ratio of the Gearbox corresponds to; Compare this setpoint transmission ratio signal (in monitoring circuit 118) with a signal which is assigned to the actual transmission ratio of the transmission; Interrupt the comparison between the target gear ratio signal and the actual gear ratio signal, as well as a difference is determined between these two signals, 030016/0785 - 11 - Activation of the control circuits responsible for the gear change to be carried out for upshifting or downshifting, which provide activation signals that control the timing of the switching process, and Controlling (using circuit 119) the particular gear change to be made using the activated circles and using a signal which is assigned to the torque in the power transmission is; and deactivation of the control circuits that dictate the timing of the switching process after completion Sequence of the desired gear change and resumption of the comparison between the target transmission ratio signal and the actual gear ratio signal. 16. The method according to claim 15, characterized by the following further method steps: Determine whether the torque signal measured on the output side is above a specified level, initiate a gear change using a closed loop control (with normal circuitry) when the torque signal is above the predetermined level, and initiating the successive steps of one Shift gears with an open control loop (circuit 249) when the torque signal is below the specified Level. 17. Method of controlling gear change in one of several 030016/0785 - 12 - Automatic transmission having gear ratios, which is connected to the drive engine of a motor vehicle is connected, characterized by the following process steps: Generation of a setpoint translation ratio signal using input information, to which information about the selected driving area and a Heard information about the target torque; Compare the setpoint transmission ratio signal with an actual value transmission ratio signal and generating a shift start signal when the actual value gear ratio signal differs from the setpoint transmission ratio signal; Enable circuits for the upshift or downshift, thereby closing a path for providing shift control signals so that control of a shift is obtained; and using the switching process start signal, the status signal and the switching process control signals, which are received via the route specified above to perform the gear change in the automatic transmission. 18. The method according to claim 17, characterized in that the input information also includes information about an operating parameter of the motor vehicle drive (from 119). - 13 030016/0785 19. The method according to claim 17, characterized in that the input information includes signals which from Driver of the motor vehicle are transmitted manually. 20. A method of controlling a gear change in an automatic Gearbox which is coupled to the drive motor of a motor vehicle, characterized by the the following process steps: Generating (in 121) a gear change command signal using input information, to which belongs: Information about the selected driving range, information about the target torque and information about the speed the drive shaft connected to the gearbox; Processing (in 118) the gear change command signal together with additional information about the selected travel range for generating a switching process start signal and a gear ratio status signal; Activating circuits for upshifting or downshifting, whereby a distribution path is closed, via which switching process control signals are provided, which ensure the setting of the target transmission ratio; and using (in 118 and 119) the shift start signal, des Status signals and the switching process control signals, which via the activated distribution path be obtained, to carry out that gear change in the automatic transmission, which for setting 030016/0785 len of the target transmission ratio is necessary. 21. The method according to claim 20, characterized in that a termination signal (LUS-O or LDS-O) in the activated branching channel indicating the end of a switching process is generated when the partial steps carried out one after the other when changing a gear are complete are completed, and that the completion signal indicating the end of the switching process is used to reset the gear ratio status signal. 030016/0 785