WO2004046585A1

WO2004046585A1 - Gearbox device with a switching device

Info

Publication number: WO2004046585A1
Application number: PCT/DE2003/003754
Authority: WO
Inventors: Klaus Henneberger; Martin Zimmermann; Peter BÜHRLE
Original assignee: Luk Lamellen Und Kupplungsbau Beteiligungs Kg
Priority date: 2002-11-16
Filing date: 2003-11-13
Publication date: 2004-06-03
Also published as: DE10393280B4; DE10393280D2; AU2003291936A1

Abstract

The invention relates to a gearbox device especially a gearbox for a motor vehicle comprising a drive-by-wire operating device and a method for operating said gearbox device . Sensors detect the position of a selector aid, said sensors transmit the signals thereof via a data bus to a control device and the chosen selector position is determined in the control device by means of identification logic.

Description

Gear device with switching device

The invention relates to a transmission device and a method for operating a transmission device according to claims 1 and 24.

Transmission devices - especially for the automotive sector - have undergone a major change in the past decades. The transmission devices were originally manual transmissions that were shifted with a selector lever. It was advantageous for the driver that the position and / or inclination of the selector lever provided information about the gear engaged. The selected position of the selector lever - and thus the selected gear or a middle position - was and can be read in many cases, for example, on the top of the gear lever knob as a selector image. In some cases, the orientation for the aisles was made even easier by guiding the selector lever in a guide that was visible to the driver - a kind of backdrop (eg in an H-shape).

Due to the mechanical coupling of the selector lever, the selection of the selector lever position and gear engaged was always given in the case of the type of gearbox cited at the beginning.

The introduction of automated manual transmissions - or generally the transmission without a mechanical connection from the selector lever to the actual transmission - gave, at least in part, responsibility for the appropriate gear and the right time for shifting to a control system. In order for a control to be able to operate, at least in part "independently", there must be no compulsory mechanics between the driver's intention to choose and the actual shifting process positively driven mechanics are transferred directly to the clutch and the transmission, whereby an optimal shifting process would then be rather accidental. In the case of an automated manual transmission, the desired gear is communicated to a control system by means of a selection aid, for example in the form of a selector lever. If the right moment for changing gears has now come in accordance with a predetermined pattern in the control system, the control system automatically opens the clutch, changes the gear and closes the clutch again. That is why there is no clutch pedal in such vehicles. With this technology, the driver is only connected to the transmission via electrical / electronic signals, which is also referred to as drive-by-wire.

Although automated manual transmissions and drive-by-wire technology increase driving comfort and also reduce the vehicle's fuel consumption, considerable efforts must be made with regard to security of choice, since electrical / electronic connections of the dialing aid to a transmission device are necessary possibly more prone to failure than mechanical connections.

With the drive-by-wire, there is no inevitable position of the dialing aid for a certain gear or a driving mode or a neutral position (Advantageous additional measures - such as Shift Lock - can prevent the selector lever position from being changed when "Ignition OFF") By means of suitable facial expressions, however, the position of the dialing aid can be structured as if there was a direct, geometric connection between the dialing aid and the selected gear, ie a dialing aid for a fifth gear is first pivoted to the right and then upwards The fifth gear of the drive-by-wire does not actually have to be arranged in this position, so that the well-chosen image of the historically grown and intuitively used H-gear (or with 5 or 6 forward gears, an extended H-gear) can be retained without being tied to the gearbox conditions (actual position of the gears). In the non-automated manual transmission, the selection aid is also in a locked position due to its mechanical coupling to the transmission when the gear is engaged. If no gear is engaged, the dialing aid can be moved relatively easily in the dialing lane (apart from a possible reverse gear lock). However, springs acting on the dialing aid cause the dialing aid to spring back into a central position whenever the gear is not engaged.

With the drive-by-wire, the dialing aid must only be put into a dialing position for the selection of a specific switching situation. Once the desired switching status has been recognized by the electrical system / electronics, it is no longer necessary to leave the dialing aid in the dialing position. For this reason, in a gear device operated in drive-by-wire, the dialing aid may spring back into a central position immediately after the dialing process. This middle position is also called "stable position". In some cases, automated transmissions also have dialing patterns with several "stable positions". In connection with the description of the figures, this will be discussed in detail here.

As already stated, a drive-by-wire can be unsafe if countermeasures are omitted. For the safety of the so-called e-drive, at least one transmitter is often attached in the lower area of the dialing aid - for example a selector lever - which activates sensors when the dialing aid approaches a dialing position. Such a sensor is located near a selected position. If a sensor has now been activated, it signals this activation to a controller via a line. By activating the sensor, the controller is informed that a certain selector position has been assumed. The encoder described is often a permanent magnet arranged on the underside of a selector lever. The sensors that respond to a permanent magnet in a reliable form are Hall sensors

If one sensor is used for each possible selector position, there is an unambiguous assignment to a desired gear for each selector position Neutral position, a driving mode, a "stable position" or another situation possible.

If a controller is designed accordingly, it can store a signal from a sensor once received until another signal from another sensor arrives. If a control - as described - is not required for a dial position permanently, which is why a springing back of the dialing aid into a "stable position" after "tapping" the desired dial position, but still maintaining the desired gear or comparable.

The information about a selected position or a possibly activated Hall sensor is often provided by means of a digital, serial line. Since the CAN bus of a motor vehicle is a serial line, the CAN bus is also often used for the transmission of information from the Hall sensors. In some cases, transmission of the serial information from the selector lever to the control unit is also used via a simple serial protocol. There are two wires on a serial line or a serial data bus. One wire gives the so-called clock signal, while the other line is high or low depending on the clock signal and the information to be transmitted.

These sensors discussed so far represent a main position detection for the dialing aid. If one of these sensors failed, the controller might not register if the selector lever was moved, for example to shift into a gear. In order to never allow such an information gap to arise, redundancy position recordings are used in drive-by-wire.

With this redundancy position detection, further sensors (possibly also Hall sensors) are positioned near the sensors of the main position detection. Since the sensors of the redundancy position detection in the prior art are operated by means of analog technology and the analog components have tolerances, only a limited number of these sensors are circuit-technical. niche to be clearly identified. By a suitable combination of the sensors of the main position detection and the redundancy position detection, however, at least a clear identification of dial position groups is nevertheless possible. The relationships between this identification logic will be discussed later in the description of the figures.

As already stated, there are sensors that are serial, and some that are connected to the control device in an analog manner. It is disadvantageous that a limited number of selector lever positions can be clearly monitored with this described technology. It is therefore an object of the invention to find a transmission device and a method for operating the transmission device which increases the reliability of the selection of the transmission device.

According to the invention, a gear device - in particular a gear device for motor vehicles - is equipped with a dialing aid, the dialing aid being brought into a desired dialing position when dialing, which according to a dialing pattern, that is to say a pattern of the arrangement of gears, neutral positions, “stable Positions "and driving modes, are arranged. Furthermore, this transmission device has a main position detection for each selector position and a redundancy position detection for at least one single selector position. A sensor system for the main and the redundancy position detection - consisting of a multiplicity of sensors and the associated wiring - supplies the digital signals of both the main position detection and the redundancy position detection. According to the invention, the transmission device is also equipped with a control device which communicates with the main position detection and the redundancy Po via a data bus sition acquisition is connected. It is therefore advantageous that instead of a serial and analog connection of the sensors - as in the prior art - only a single data line is required for the sensors, and this one data line has a higher value, a higher value because of its digital nature Represents functionality and greater stability. As already stated, the control unit has to process digital signals. However, this does not mean that the control unit as a whole has a digital structure. It can therefore be advantageous if the control unit is only partially digital, because then intelligent analog technology can also be accommodated in the control unit.

In a further advantageous embodiment of the invention, the signal of the redundancy position detection is designed as a serial signal. For example, serial signals have the advantage that, in contrast to parallel signals, they only need two signal wires. The clock signal is sent there on a first signal wire, while the actual bit information is sent on the other signal wire.

In the case of parallel signal lines, the technical effort - in particular the wiring effort - is considerably higher. Here, for example, eight signal wires alone are required for the transmission of a bit.

If the signal of the redundancy position detection is transmitted as a serial signal, the signal of the main position detection does not necessarily also have to be transmitted as a serial signal. However, it is advantageous if the signal of the main position detection is also transmitted as a serial signal, because this not only limits the hardware expenditure, but components that are used in the redundancy position detection can also be used for the main position detection.

A dialing aid does not necessarily have to be designed as a selector lever within the scope of the invention, as is usually found in the motor vehicle sector. A gear device that is operated in the drive-by-wire does not require a selector lever, as is otherwise required with manual transmissions. In the context of the invention, a selector lever merely represents a signal generator. Depending on the position of the selector lever, a gear in question, a neutral position or a driving mode - such as sporty driving behavior - is selected. In a further advantageous embodiment of the invention, the selection aid is designed as a selection wheel. The selector wheel can be designed as a rotary knob that has a marking arrow. Depending on the position of the marking arrow on a fixed scale, a gear or equivalent is selected. In contrast to a selector lever, a dialing aid, which is designed as a selector wheel, only allows a sequential selection of the selector positions. In the context of the invention, sequential selection is to be understood to mean that it is only possible to go from one selection position to the next and that a selection position cannot be skipped.

In a further embodiment of the invention, the dialing aid consists of an arrangement of keys, which is to be referred to as a keypad. Such a keypad can consist of a row of keys, or can also be formed from an arrangement - similar to the dial pattern of the H circuit. The keys on a keypad can be designed to either snap in or as tip contacts. It is only important in the context of the invention that the keypad is constructed mechanically, electrically or electronically in such a way that only one key can be actuated at a time. With a keypad, you can choose as you would with a selector lever, which means that there is no prescribed sequence of dialing positions when dialing, but you can also skip individual gears. A direct change from a higher forward gear to reverse gear should, however, be prevented by suitable structural measures.

The redundancy position detection significantly increases the security of dialing. In this context, dialing security is not only to be understood as the moment of the driver's dialing, but also the maintenance of the gear unit's dialing position. Every system that is to be further protected requires more effort. This is why a redundancy position detection is associated with a technical effort. For cost reasons, therefore, only a limited number of dial positions can be provided with redundancy position detection. In an out design of the invention, only the reverse gear is provided with a redundancy position detection. In a further embodiment of the invention, it can be a forward gear group or just a single forward gear. However, not only gears (forward or reverse gears) can be monitored, but also one or more "stable positions" of the dialing aid. Dialing pictures sometimes also have switch positions (for example labeled "A / M"). Such a changeover position allows a changeover - for example for the forward gear group - from automatic driving mode to manual driving mode. In manual driving, you could shift up or down, for example by tapping a selector lever. However, a switch position can also be used to switch between moderate driving dynamics and sporty driving behavior of the motor vehicle. Therefore, a switch position is also an important selection position, which should be monitored for safety reasons.

In a further advantageous embodiment of the invention, at least one “stable position” is provided for the dialing aid. A “stable position” in the sense of the invention is a position for the dialing aid in which there are no tasks or intentions on the part of the dialing aid to the control device of the transmission device - be signaled. All other required selection positions can be located around a "stable position". If there are several "stable positions" in a selection screen, these "stable positions" are connected to each other via a neutral lane. Around each of these "stable positions" is a sensible one Grouping of the other dial positions arranged.

In another advantageous embodiment of the invention, a neutral position is provided in the dialing image - and above all in the sensors of the position detection. With this neutral position, an actively engaged gear - be it a forward: - or a reverse gear - is selected.

If only a single neutral position is arranged in the dialing picture, this can be very advantageous. With only one neutral position in the dialing screen (see further above) the selection positions are arranged around this neutral position. This is advantageous insofar as the driver always knows without looking where he can find the dialing aid with his hand and in which direction - with knowledge of the dialing image - he has to move a dialing aid in order to set a certain dialing position. It is also advantageous that when selecting a certain dialing position, there is never a need to drive over other dialing positions.

In one embodiment of the “stable position”, this is equipped with a reset mechanism for the dialing aid. This reset mechanism causes the dialing aid to return to the “stable position” after being released by the driver after a dialing process. The resetting mechanism can consist of a suitable arrangement of springs and / or of a correspondingly shaped catch, where a spring - in connection with a catch means - can - at least partially - reduce its tension.

In the transmission device according to the invention, it is important that the sensors for the main position detection and the redundancy position detection function reliably. A possible sensor would be electrical resistance. This electrical resistance could be influenced by a relative movement of the dialing aid to a base and thereby allow a dependent current to pass through (resistance as a potentiometer, for example). Depending on this current, electronics could determine whether a sensor is reporting a selector position or not. In a further embodiment of the invention, the sensor consists of an electrical switch. An electrical switch can be designed as a break contact or as a make contact, but it can also have a blocking and a forward direction, for example as in the case of a transistor. In a further embodiment of the sensor, it is designed as an electrical / electronic circuit. This can be accomplished, for example, by designing the sensor as a tilt switch, reed contact or otherwise. In a preferred embodiment of the invention, the sensor is a Hall sensor educated. Hall sensors have the advantage that they can be operated very small, very reliably and very easily.

A sensor, for example a Hall sensor, supplies an analog, constant current and / or voltage level when an electrical source is present, which can be influenced by an applied, external magnetic field. In order to convert this information into digital information, an electronic circuit is required which can convert the level states into a bit pattern, that is, digital information. According to the invention, the sensors of the main and redundancy position detection are connected to a control device via a data bus. Preset codes are used for the control-related, logical detection of sensors or signals of the control device. These codes have a predetermined bit pattern. If one bit or several bits deviate from these preset codes, the controller can recognize that a corresponding sensor has failed. If the control device contains corresponding error-detecting codes, it can even determine the error and the location of the error. Error-correcting codes in the control device can even be used to carry out signal “repairs”. In order to be able to differentiate sensors in the main position detection and sensors in the redundancy position detection in terms of control technology, the data transfer between the sensor and the control device can be arranged by means of a channel coding.

The present invention also represents a method, because a desired selection position is selected by means of a selection aid, sensors of the main position detection and sensors of the redundancy position detection each deliver a signal, which their statements are compared with one another in a control unit, and if the statements are identical This selection position is confirmed for and in the control device.

A specific dialing position can be selected by means of a dialing aid by tapping the same. Is the dialing aid for example around a selector lever, a short tap, for example on a plus symbol, is sufficient to either move from standstill to first gear or to move from a second to a third gear. Dialing by tapping can also be used for different driving directions. It is advantageous here if a dialing aid automatically returns to a "stable position" after tapping.

Tapping a dialing aid as a dialing form can also be done in conjunction with touch sensors and non-latching buttons. Another form of dialing is by turning a dial. This dialing represents a sequential dialing. A sequential dialing means that the arrangement of dialing positions can only be carried out in a fixed prescribed sequence.

In an advantageous embodiment of the invention, to increase the security of choice of the transmission device according to the invention, the control unit continuously checks whether the information about the current selector position has changed. If the dialing aid is, for example, a dialing aid that snaps into the dialing position, the sensors of the main and the redundancy position detection can deliver a continuous signal. If this control signal is permanently queried by the control device, information about the current dial position is available at all times. But even if the dialing aid is non-latching and the dialing aid is not locked in the dialing position, the sensors can influence, for example, memory areas of the control device through their brief activation during the dialing process. If the signals from the sensors remain constant in the subsequent time and if they correspond to the bit pattern of a "stable position", the control system can assume that the current selector positions have not changed. Querying signals from the sensors that are only briefly during the dialing activated, can therefore be checked continuously because the signal from the sensors has been stored in memory areas of the control device. If you want to keep the monitoring effort for the current dial position as low as possible, you can only check the information about the dial position periodically. A periodic check in connection with digital signals, in contrast to the permanent check, is countersigned in that in the case of a permanent check after the query of a specific bit pattern or a memory area, the check of a bit pattern or a memory area is continued without delay. However, it is also conceivable within the scope of the invention that the signal is processed in an event-controlled manner. In this case, a level change (ie a change in the current / voltage value) of the signal would serve as the event trigger.

If there is an inequality in the signals between the main position detection and the redundancy position detection, then a motor vehicle with a transmission device according to the invention - or with the method according to the invention for operating this transmission device - must have measures which pose a danger or emergency situation Prevent people. In one embodiment of the invention, if the signals are not identical, an emergency drive program of the transmission is activated. This emergency driving program provides, for example, that the vehicle can still drive to the edge of the road at reduced speed.

The emergency driving program can, for example, be designed in such a way that the driving mode valid in the control device - for example “D” - is maintained until the vehicle comes below a defined driving speed - for example 20 km / h the control device then forcibly selects the zero position, ie the gear selected. In addition, the driver can also be warned about the incomplete function of his transmission until the vehicle comes to a standstill the control device, for example, are shifted to higher engine speeds. The otherwise unusual, high-speed engine noise would then cause the driver be warned and informed. An optical (lamp) or an acoustic (buzzer) warming device can also draw attention to the defect. In another embodiment of the warning device, the shift quality of the transmission device can also be significantly reduced, so that the driver is also warned and he visits the workshop as soon as possible.

In another embodiment of the invention, if the statements of the signals are not identical, an emergency braking program for the transmission is activated. This emergency braking program is intended to prevent a crisis situation for people from developing in the last few meters.

The invention will be explained in more detail below with reference to the figures. Show it:

Figure 1 shows a sensor arrangement from the prior art;

Figure 2 is a voltage-current diagram for Figure 1;

3 shows an identification logic with a tristable dialing aid;

FIG. 4 dialing picture with a monostable dialing aid;

FIG. 5 shows identification logic with a monostable dialing aid; FIG. 6 shows a diagram of an identification logic with only a digital connection to a control device,

Figure 7 is a dialing diagram.

FIG. 1 shows an analog sensor arrangement 1 from the prior art. The sensors 2, 3 and 4 are arranged in parallel in a branched circuit. The equivalent circuit diagram of the sensor 2 in this embodiment consists of a resistor. The equivalent circuit diagrams of sensors 3 and 4 consist of a resistor and a switch. The switches and the resistors can be formed by so-called Hall sensors. Depending on the magnetic influence, the sensors are more or less electrically conductive and thus resistors or even switches. The sensor 2 reacts, for example, to the D position (= forward gears) of a selector lever. Sensor 3 is activated accordingly in the N position (N = neutral position) and sensor 4 in the R position (corresponds to reverse gear). The sensors are activated by magnets arranged on the articulated end of the selector lever (not shown here).

The battery voltage U _ßa t is present between the measuring points 5 and 8. The battery voltage is unfortunately not constant in practice and can fluctuate between 8 and 16 volts at a nominal voltage of 12 volts. The voltage ΔU can be tapped between the measuring points 6 and 7. The voltage ΔU is influenced by the sensors 2, 3, 4, which ultimately also affects the current I. The defined resistance R ₂ can then be used to tap a voltage on it which is dependent on the selection position.

2 shows the current I and the associated voltage as a function of the selector lever position - from FIG. 1 - as a diagram. Line 9 results when a short circuit has occurred in sensor arrangement 1. In this case, the current I is limited and constant by the resistor Ri and is independent of the voltage present. In the event of a cable break, characteristic curve 10 occurs. Due to the high contact resistance at the break point, there is only a minimal, voltage-independent current I.

If the analog sensors function properly and their wiring is used, depending on the N, R and D selection position, voltage and current values are accordingly within the N, R and D areas. Line 11 represents an approximate dividing line between the N and R ranges, and line 12 represents an approximate dividing line between the R and D ranges. For this reason, there are only three, clearly separable, analog assignments. This small number of assignments is - as already in the general part of the application - a disadvantage in the prior art. For this reason, this analog solution has so far only been used for the redundancy position detection of the selector lever (or the dialing aid).

FIG. 3 shows identification logic according to the prior art for dial positions, the dial aid (not shown here) (here a selector lever) having three so-called “stable positions” at points SP1, SP2 and SP3. The “stable positions” have the effect that the dialing aid - without human intervention - is always moved to the nearest "stable position". The dialing aid is therefore provided with a reset mechanism. The connecting lines of the points SP1, SP2, SP3, the line going beyond the point SP1 to the left and the vertical Lines standing at point SP1 represent a dialing image. The sensor arrangement 1 is connected to a control device 15 via a digital signal line 13 and an analog signal line 14. The sensors 17 (shown as empty boxes) are sensors for the main position detection of the Dialing aid and deliver a digital signal. The sensors 18 (shown as filled boxes) are d sensors for redundancy position detection and deliver an analog signal.

In FIG. 3, the area of the sensor arrangement 1 is divided into three areas D, N, and A / M or D, which are symbolically surrounded by dash-dotted lines. It can be clearly seen that the area R (for reverse gear) and the area N (for neutral position) are provided with sensors of the main as well as sensors of the redundancy position detection. In the area A / M or D (A = automatic shifting; M = manual shifting; D = drive = forward driving range) there is SP1 for the "stable position", "higher gear" (= plus sign) for the selector position the selection position "a lower gear" (= minus sign) and a changeover position 16 only one digital sensor of the main position detection. To what extent here redundant sensor used depends on the respective security needs or the respective country-specific security regulations. If a sensor of the main position detection failed in the area A / M or D, the control device would not know whether the dialing aid is "on the way" to one of the dialing positions of this area or whether the sensor of the "stable position" SP1 has failed or whether a sensor in the other selector positions has failed. This uncertainty arises because no signal from a sensor can mean that the driver has not selected a dial position or that the sensor has failed. However, if the driver does not change the dialing aid at all and the dialing aid is moved to position SP1 by the reset mechanism and there is no signal from the sensor in question, only the driver can notice the failure of the sensor by observing a possibly changed behavior of the vehicle. On the other hand, it is easier for the driver to determine if one of the sensors in the "+", "-" and "A / M" selector positions should have failed. The absence of a desired selector position is immediately noticeable In the "A / M" area, for example for cost reasons, redundant sensors are dispensed with, so the driver can still continue his journey by intervening. If, for example, the "-" sensor fails in "manual mode" and a high speed, the driver cannot "downshift", but he can reduce the speed by "tapping" the "automatic mode".

FIG. 4 shows a dialing picture - similar to FIG. 3 - in which there is only one “stable position” SP1 for the dialing aid. The dialing aid is therefore “monostable”. In FIG. 3, the dialing aid is to a certain extent “tri-stable” due to the stable points SP2 and SP3. The advantage of a monostable dialing aid is that the driver, by simply feeling his dialing aid (without looking), knows how he knows it of the dialing picture - the dialing aid must move in order to achieve a desired dialing position. The dial picture can either be placed on the dial of a dialing aid or in a clear place for the driver's orientation.

Essentially, the same can be said in FIG. 5 as in FIG. 3. FIG. 5 represents the state of the art and represents one of several possible identification logics for a monostable dialing aid. In contrast to FIG. 3, position SP1 is not here more monitored with a sensor. Position SP1 is only supported mechanically by a reset mechanism. On the other hand, the selection positions "+" and "-" are additionally secured by sensors for the redundancy position detection. These sensors for redundancy position detection are designed analogously. There are a total of four analog, redundant sensors. Monitoring the position SP1 and the selected position "A / M" cannot be accomplished with analog technology. This is a disadvantage in the prior art.

According to FIG. 6, the essential difference between the invention and the prior art is emphasized. By connecting the sensor arrangement 1 to the control device 15 by means of a digital signal line - that is to say by means of a data bus - an almost arbitrary number of sensors for the main and the redundancy position detection as well as almost any identification logic can be realized. This means that every selector position - i.e. every gear position, the changeover position, the neutral position and every stable position - can be clearly recorded in terms of control technology.

With the help of FIG. 7, further considerations regarding the identification logic are to be presented. FIG. 7 is based on the dial pattern and the sensor arrangement of FIGS. 4 and 5. The identification logic here provides that both sensors must always have addressed a dialing position so that the desired dialing position is also accepted by the control device. The control device then controls the switching process via actuators. According to the table (FIG. 7), the future dialing state is then specified as a function of the dialing aid movement and the dialing state currently valid in the control unit ("dialing state" in the context of the present invention denotes the dialing position stored in the control unit). So if you come from "R" and press the dialing aid movement from the "stable position" (= large dot) "to the right", you get to "N" (top left in the table). This makes it possible, for example, to shift into forward gear in reverse by touching "+".

If a sensor fails (permanently inactive, ie permanently zero) of the selector positions "+", "-", "A / M" and "R", it may be possible to start in the wrong direction without taking appropriate countermeasures. An example: the Dialing aid is in position "R" and this is also recognized accordingly by the control device. Now there is a failure of a sensor of the "+" dial position. The driver then moves the dial aid in the "+" direction and expects the control device and the associated actuators to engage a forward gear. However, since only one of the "+" sensors responds, the software or the hardware logic of the control device remains in the "old" selection state. This means that - contrary to the driver's request - the direction of travel is reversed.

In another critical situation, the dialing aid is located in an intermediate area between SP1 and N. Depending on the mechanical design of the dialing aid, there is an area in which only one of the N sensors responds. In this area, the software normally remains in the old dialing state. If the second N sensor is now erroneously active, i.e. permanently ONE, then "N" is recognized in this position and the gear is selected. This means that the propulsion of the vehicle is interrupted.

The problems of the identification logic are also made clear by a further example: If, for example, a dialing aid is moved from the "stable position" to "R", the sensors of the dialing positions "SP1", "N", "R", "N" and "SP1" are scanned one after the other. That is, depending on the operating speed of the dialing aid and "recognition speed" of the dialing states, the control device can recognize "R" or "N".

Several solutions are therefore proposed according to the invention from the aforementioned problems of the identification logic: if, for example, the dialing state “R” is active and only a “+” or “-“ or “A / M” is present, then “N” is activated in the control device , If, on the other hand, the selection state "A" or "M" is active and only an "R" signal is present, then "N" is activated in the control device. Furthermore, the selection state "N" is already activated when only an "N" sensor responds. This last-mentioned measure always activates the selection state “N” in the control device in normal operation in the intermediate range between “SP1” and “N” selection position, if only an “N” sensor responds.

For safety reasons - for example by tapping "+", i.e. at least engaging the first gear, or even shifting up in the forward gears - the two assigned sensors should always send a signal. shaft of the vehicle can be switched according to the invention in the presence of an "A" or "M" dialing state, even then based on a dialing pulse at "+" or "-" or "A / M", if these Selector positions only respond to one sensor.

After selecting the "R" position, the dialing aid would spring back over to the "N" position when springing back into "SP1". Depending on the defined, required response time of the two sensors, "R" could be activated immediately after activating the dialing state the selection state "N" (ie gear selection) takes place. One could never drive in reverse. Therefore, it is proposed according to the invention that before one or both activated "N" sensors are recognized by the control device, at least one of the sensors of the " Stable position "(here SP1) have been recognized this can also be expanded to include the sensors from the "+", "-" or "A / M" range.

Against this background, it also becomes clear that the uniqueness of the signals from the sensors is of great importance. In an advantageous embodiment of the invention, the sensors are therefore designed as switches, which can be arranged either in parallel or in series. In order to debounce the signals in time, the information is read out three times at intervals of 10 milliseconds. For redundancy of the sensors / switches, there is also a temporal redundancy.

Claims

claims

1. Transmission device - in particular for a motor vehicle - with a drive-by-wire operating device and with - a selection aid, which serves to select a selection position - for example a gear, a neutral position or a driving mode - according to a selection screen; a main position detection for each selector position; a redundancy position detection for at least one dial position; a sensor system for the main and the redundancy position detections, which consists of a plurality of sensors; a digital signal of the main position detection; a digital signal of the redundancy position detection and - a control device that is connected to the main

Position detection and the redundancy position detection is connected.

2. Gear device in particular according to claim 1, characterized in that the control device is at least partially digital.

3. Gear device in particular according to claim 1 or 2, characterized in that the signal of the redundancy position detection represents a serial signal.

4. Gear device in particular according to claim 1. to 3, characterized in that the signal of the main position detection is a serial signal.

5. Gear device in particular according to one of claims 1 to 4, characterized in that the selection aid is designed as a selector lever.

6. Gear device in particular according to one of claims 1 to 4, characterized in that the selection aid is designed as a selector wheel.

7. Gear device in particular according to one of claims 1 to 4, characterized in that the dialing aid is designed as a key field.

8. Gear device in particular according to one of claims 1 to 7, characterized in that a reverse gear is provided with a redundancy position detection.

9. Gear device in particular according to one of claims 1 to 8, characterized in that a forward gear group is provided with a redundancy position detection.

10. Transmission device in particular according to one of claims 1 to 9, characterized in that a single forward gear is provided with a redundancy position detection.

11. Gear device in particular according to one of claims 1 to 10, characterized in that a neutral position is provided with a redundancy position detection.

12. Transmission device in particular according to one of claims 1 to 11, characterized in that a switch position - with which one can switch from automatic driving mode to manual driving mode for the forward gear group - is provided with a redundancy position detection.

13. Gear device in particular according to one of claims 1 to 12, characterized in that one to three "stable positions", preferential however, only a "stable position" is arranged in the dialing picture for the dialing aid.

14. Gear device in particular according to claim 13, characterized in that a reset mechanism for the selection aid is arranged for at least one “stable position”.

15. Gear device in particular according to one of claims 1 to 14, characterized in that at least one sensor is designed as an electrical resistor.

16. Gear device in particular according to one of claims 1 to 15, characterized in that at least one sensor is designed as an electrical switch.

17. Transmission device in particular according to one of claims 1 to 16, characterized in that at least one sensor is designed as an electrical / electronic circuit.

18. Gear device in particular according to one of claims 1 to 17, characterized in that at least one sensor is designed as a Hall sensor.

19. Gear device in particular according to one of claims 1 to 18, characterized in that the sensor is assigned an electronic circuit which can form digital information from a signal from the sensor.

20. Gear device in particular according to claim 19, characterized in that in the data transfer between the sensors and the

Control device preset codes are available.

21. Gear device in particular according to claim 19 or 20, characterized in that the digital information of the control device contains error-detecting codes.

22. Gear device in particular according to one of claims 19 to 21, characterized in that the digital information of the control device contains error-correcting codes.

23. Gear device in particular according to one of claims 19 to 22, characterized in that the digital data transfer between the sensor and the control device is accomplished by means of a channel coding.

24. A method for operating a transmission device according to at least one of claims 1 to 23.

25. Method in particular for increasing the security of choice in a transmission device according to claim 24, which is operated in the drive-by-wire method, with the following features:

- According to the spatial position on the dialing picture, the desired dialing position is selected using the dialing aid;

- A sensor of the main position detection delivers a first signal from the current selection position; - A sensor of the redundancy position detection delivers a second signal in at least one selected position;

- The signals of the main position detection and the redundancy position detection are compared with one another in the control device; - If an equality of the statements is prescribed and also given for a selector position, this selector position is confirmed in the control device.

26. The method in particular according to one of claims 24 or 25, characterized in that the dialing is carried out by tapping the dialing aid in the direction of the desired dialing position on the dialing image.

27. The method in particular according to claim 26, characterized in that it can be shifted up or down by n gears by tapping the dialing aid n times - preferably tapping twice in the forward driving group.

28. The method in particular according to one of claims 26 to 27, characterized in that the dialing aid is automatically reset to a “stable position” after being tapped.

29. The method in particular according to one of claims 24 or 25, characterized in that the selection is carried out by rotating a selector wheel or by means of a rectilinear pivoting movement of a shift lever in the direction of the desired selector position on the selector screen.

30. The method in particular according to one of claims 24 to 29, characterized in that the control device permanently checks whether the information about the current dial position has changed.

31. The method in particular according to one of claims 24 to 29, characterized in that the control device periodically checks whether the information about the current dial position has changed.

32. The method in particular according to one of claims 24 to 31, characterized in that in the event of an inequality in the statements of the signals of the main position detection and the redundancy position detection, an emergency drive program for the transmission is activated.

3. The method in particular according to one of claims 24 to 31, characterized in that, if the statements of the signals of the main position detection and the redundancy position detection are not identical, an emergency braking program for the transmission is activated