DE102011106786B4 - Operating element, in particular for an automatic transmission of a motor vehicle - Google Patents

Abstract

Operating element with a key panel with a plurality of keys each having at least one switching element, the operating element having at least one proximity sensor (12) whose sensor signal is used to detect a key defect together with at least one switching signal generated by a switching element (10, 11) in an evaluation unit (13) can be evaluated, characterized in that a proximity sensor (12) is arranged between two switching elements (10, 11) assigned to a button (3, 14), the plausibility of the switching signals of the switching elements (10, 11 ) is verifiable.

Description

The invention relates to a control element, in particular for an automatic transmission of a motor vehicle, with a key control panel with a plurality of keys each having at least one switching element, the control element having at least one proximity sensor whose sensor signal for detecting a key defect together with at least one switching signal generated by a switching element in one Evaluation unit can be evaluated.

Control elements of this type are used in motor vehicles for inputting shift requests in the case of shift-by-wire switching operations, as a result of which conventional control elements such as shift levers are replaced. The proximity sensors of the keys can be implemented redundantly by several digital sensors, e.g. B. microswitches are used.

From the DE 10 2008 015 910 A1 an electrical input key is known which, when actuated, switches several switches at the same time. A possible malfunction can be determined by means of a diagnostic routine. A test signal is generated for this purpose, which is applied to one or more keys and evaluated by a control unit.

There are also electrical input keys are known in which several z. B. three or four digital switches can be used. A specific switching state or a state change is detected based on the switching signals of two of the three or three of the four digital switches, so that the malfunction of an individual digital switch has no effect. However, such conventional electrical input keys with multiple redundant digital proximity sensors also have disadvantages. Due to unavoidable mechanical tolerances, the proximity sensors installed in an input key or a switch input unit have different switching points. If the enter button is moved just far enough that not all of the proximity sensors trigger, the proximity sensor that has not yet triggered will be incorrectly diagnosed as defective. During the service life, wear and tear on the mechanical components can lead to shifts in the switching points of the proximity sensors, which can lead to an increase in the switching point differences between the individual sensors. This can lead to an increase in the number of incorrect diagnoses described for individual proximity sensors.

Conventional controls z. B. internally use four microswitches are comparatively expensive due to the high number of components, and the probability of failure increases with the number of switches. Another disadvantage can be seen in the fact that a defective "stuck" button, which supplies a permanent, constant signal, cannot be detected by an evaluation.

DE 10 2009 036 860 A1 describes a control unit with two buttons, each with a movable button element and a switching element. Each button element has a touch-sensitive input field on its top. When the respective key is actuated, a first switching signal is generated via the respective input field and a second switching signal is generated via the actuated switching element. A computing unit checks the presence of both switching signals, the associated control command being output only if both switching signals are present.

From "Allison Transmissions: Shift Selector, Operation and Code Manual", Indianapolis, Indiana 46206-0894, USA, 2010 - Company publication (URL: http://www.libertus.eu/download.php?id=1574&op=open ) is an electronic gear selector with push buttons for medium and heavy duty transmissions.

The invention is therefore based on the object of specifying an operating element which enables a single failed switching element to be identified and which at the same time has a reduced number of components.

To solve this problem, the invention provides for a control element of the type mentioned that a proximity sensor is arranged between two switching elements assigned to a button, the plausibility of the switching signals of the switching elements being able to be checked using the sensor signal of the proximity sensor.

The invention is based on the finding that a defect in an individual switching element, possibly also a defect in a number of switching elements, can be reliably detected if the operating element has a proximity sensor. The proximity sensor only provides a signal when a user performs an operation, e.g. B. when the user taps the button panel with a finger. This sensor signal supplied by the proximity sensor is evaluated in an evaluation unit together with at least one switching signal generated by a switching element in order to diagnose a button defect that may be present. The evaluation basically corresponds to a comparison process, i.e. if the at least one switching element and the proximity sensor deliver matching signals, it can be concluded that there is no key defect. However, if the switching element and the proximity sensor provide different signals, the button could be defective. A defect can exist, for example, when the proximity sensor has detected an actuation by a user, as a result of which the sensor signal is changed. If, at the same time, the switching element of the key control panel does not supply a switching signal or an unchanged switching signal, the key is defective. Conversely, a defective button could manifest itself in that the switching element permanently signals an actuation, e.g. B. by the signal "key panel pressed" persists, while no key actuation of a user has been detected by the sensor signal of the proximity sensor. In this case, the switching element could "hang" so that it permanently delivers an incorrect switching signal.

According to a development of the invention, it can be provided that each key is assigned a proximity sensor. For example, each key could have a conventional, mechanical switching element and, in addition, a proximity sensor. In this variant, an operating process by a user can be recognized with a high spatial resolution.

In the operating element according to the invention, it is particularly preferred that a switching element is designed as a microswitch or as a safety mat or as a non-contact switch. A non-contact switch can be designed, for example, as a digital switch with a Hall sensor.

Particularly reliable information from the control element according to the invention results when the proximity sensor is an inductive or capacitive proximity sensor. Both configurations allow reliable detection of an operating process by a user, in that an approaching finger or hand can be recognized.

In order to ensure reliable operation of the control element and the motor vehicle, it can be provided that the evaluation unit is designed to output an error signal when a button defect is detected, which error signal can preferably be stored in an error memory. The error memory can be read out during maintenance so that the defective switching element or the button panel can be replaced. The error memory can also be used to make this error accessible to other systems or components of the motor vehicle, so that their functions are not influenced by an existing defect in a switching element. If a key panel has, for example, two switching elements and the proximity sensor, the evaluation unit in the error memory z. B. store the information that a specific switching element has a defect.

In the operating element according to the invention, it is particularly preferred that the sensor signal generated by the proximity sensor is an analog signal. As a result, the approach of a user's finger can be continuously detected, so that a specific action can be triggered depending on a detected proximity.

According to a development of the invention, it can be provided that the control element according to the invention has an illumination element that can be controlled as a function of the sensor signal. The intensity of the lighting, i.e. the brightness, can be controlled depending on the size of the sensor signal. For example, the brightness can be increased as you get closer to the button panel.

In addition, the invention relates to an automatic transmission. The automatic transmission according to the invention includes a control element of the type described.

In addition, the invention relates to a motor vehicle. The motor vehicle according to the invention includes an automatic transmission with an operating element of the type described.

• 1 ein erfindungsgemäßes Bedienelement;
• 2 einen Schnitt durch das in 1 gezeigte Bedienelement entlang der Linie II - II; und
• 3A - 3C eine Taste des Bedienfelds während der Betätigung.

The invention is explained below using an exemplary embodiment with reference to the drawings. The drawings are schematic representations and show:

• 1 a control element according to the invention;
• 2 a cut through the in 1 control shown along the line II - II; and
• 3A - 3C a button on the control panel during operation.

This in 1 The control element 1 shown comprises a key panel 2 with a plurality of keys 3. The control element 1 is provided for an automatic transmission of a motor vehicle in order to select a particular gear or a parking position.

2 shows a section through the in 1 Control element 1 shown along the line II - II cut. The button 3 consists of a spring-loaded button cover 4 which is acted upon by a compression spring 5 . In other configurations, several compression springs 5 can be provided. The key cover 4 has an outwardly protruding edge 6 which is supported on the underside 7 of a key body 8 . the bag The keyboard cover 4 is vertically movably arranged in the key body 8 which is arranged on a circuit board 9 . When operated by a user who presses down the key top 4 with his finger, the compression spring 5 is compressed and the key top 4 is displaced toward the circuit board 9 .

Inside the button 3 are switching elements 10, 11, which have a specific feel. A specific haptic perception is thus conveyed to the user, which he can grasp through his sense of touch. Similarly, the switching elements 10, 11 have a specific acoustic behavior, so that the user can recognize a switching operation. A specific acoustic switching noise is thus generated by the switching elements 10, 11 designed as microswitches.

The key 3 also includes a proximity sensor 12, which is designed as an inductive proximity sensor and detects whether there is an object in the area above the key cover 4, in particular a finger or a hand of a user. The proximity sensor 12 generates an analog sensor signal which is thus a measure of the distance between the object and the proximity sensor 12 . The switching elements 10, 11 generate digital switching signals, ie the "on" signal is generated when the key top 4 is pressed down by the user and the "off" signal is generated after the key top 4 is released again. When released, the key cover 4 is returned to the in. position by the energy stored in the compression spring 5 2 shown initial state moves.

The two digital switching signals of the switching elements 10, 11 and the analog signal of the proximity sensor 12 are fed to an evaluation unit 13, shown schematically, which is connected to the microswitches and the proximity sensor 12 via lines, not shown. The evaluation unit 13 evaluates the switching signals and the signal from the proximity sensor 12 . If both switching elements 10, 11 supply the signal "on" and at the same time the proximity sensor 12 has detected an object in the vicinity of the key cover 4, it is assumed that an actuation by a user is taking place. In this case, a function assigned to button 3 is triggered, for example, a specific speed level is selected.

If switching element 10 supplies the “on” signal and switching element 11 supplies the “off” signal, one of the two switching elements 10, 11 could be defective. In this state, however, it is not clear which of the two switching elements 10, 11 is defective, because both the signal supplied by the switching element 10 and the signal supplied by the switching element 11 could be based on a defect. Therefore, the sensor signal of the proximity sensor 12 is also taken into account. If the proximity sensor 12 has detected that an object, ie a finger or a hand of the user, is in the area monitored by the proximity sensor 12, it can be concluded that the “Off” signal from the switching element 11 is based on a defect.

Conversely, if the sensor signal from the proximity sensor provides the information that there is no object above the key, it can be concluded that the “On” signal provided by the switching element 10 is based on a defect. The plausibility of the switching signals of the switching elements 10, 11 can thus be checked by means of the sensor signal of the proximity sensor.

The invention is not limited to the exemplary embodiment shown; other variants are also conceivable in which a button has three or four microswitches. In addition, other switching elements are possible instead of a microswitch, in particular a digital switching element with a Hall sensor.

the 3A until 3C show the behavior of a key 14 when it is actuated. Button 14 is analogous to that in 2 shown button 3 constructed, that is, it includes two switching elements and a proximity sensor inside. In addition, the key 14 has an illumination element 15 which, in the exemplary embodiment shown, is designed as a peripheral edge that can be illuminated. Other designs are also conceivable in which the lighting element shows a letter, a symbol or the like when switched on.

As long as a user's hand 16 stays a certain distance from the button 3, no action is triggered, this state is in 3A shown.

Then the hand 16 further approaches the key 14 until the finger touches the key 14, this state is in 3B shown. It is essential that the user touches the key cover but has not yet pressed it down, so that the switching elements have not yet generated a switching signal. However, the proximity sensor arranged inside the button 14 has already detected the hand 16, so that the analog sensor signal generated by the proximity sensor has reached or exceeded a specific value. After detecting an object, the lighting element 15 is switched on by the evaluation unit or a control unit, see above that the user touching the button 14 is conveyed optically. The brightness of the lighting element 15 can be controlled steplessly, and the lighting element 15 is controlled as a function of the analog signal from the proximity sensor 12 . If the object, in particular a user's finger, is still at a certain distance from the button 14, the button 14 will only be illuminated dimly, which in 3B is indicated by the hatching. As the button 14 gets closer, the brightness increases, and the brightness is therefore a measure of the distance of the object from the button 14.

In 3C shows the state after the user has operated it. When it is actuated, the key cover is pressed down, whereby switching signals of the switching elements inside the key are generated. In addition, the signal from the proximity sensor verifies that there is actually an object on the key 14 . After actuation, the lighting element 15 is switched on completely, i.e. the lighting element 15 emits the maximum brightness, which is 3C is represented symbolically by the narrow hatching.

This "staging", in which the approach to the button is communicated to the user by lighting control, can also be used for user guidance. If a switching process is not possible in a specific situation, for example if the user has not applied the brake or if the speed is too high, the lighting element 15 is not switched on during the approach. The user thus recognizes that a certain function is currently not available.

Claims (10)

Operating element with a key panel with a plurality of keys each having at least one switching element, the operating element having at least one proximity sensor (12) whose sensor signal is used to detect a key defect together with at least one switching signal generated by a switching element (10, 11) in an evaluation unit (13) can be evaluated, characterized in that a proximity sensor (12) is arranged between two switching elements (10, 11) assigned to a button (3, 14), the plausibility of the switching signals of the switching elements (10, 11 ) is verifiable. control after claim 1 , characterized in that each key (3, 14) is assigned a proximity sensor (12). control after claim 1 or 2 , characterized in that a switching element (10, 11) is designed as a microswitch or as a safety mat or as a non-contact switch. control after claim 3 , characterized in that designed as a non-contact switch switching element (10, 11) is a Hall sensor. Operating element according to one of the preceding claims, characterized in that the proximity sensor (12) is an inductive or capacitive proximity sensor. Operating element according to one of the preceding claims, characterized in that the evaluation unit (13) is designed to output an error signal which can be stored in an error memory when a key defect is detected. Operating element according to one of the preceding claims, characterized in that the sensor signal is an analogue signal. Control element according to one of the preceding claims, characterized in that it has a lighting element (15) which can be controlled as a function of the sensor signal. Automatic transmission, comprising a control element according to one of patent claims 1 until 8th . Motor vehicle comprising an automatic transmission Claim 9 .

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