Device for anti-interference detection of touch with steering handle

Abstract

The invention relates to a device (1) for the anti-interference detection of a user touching a steering handle (2), comprising at least one touch sensor (11, 12) for touch detection, at least one disturbance variable sensor (21, 22) for disturbance variable acquisition, and an evaluation unit (31), an evaluation unit is connected to the sensors (11, 12, 21, 22) by means of signal technology and is designed to determine a value, which is adjusted in accordance with a disturbance variable, for touch detection on the basis of measured values captured by the sensors (11, 12, 21, 22), at least one disturbance variable sensor (21, 22) being designed in each case for receiving a frequency as a disturbance variable.

Description

[0001] manual:

[0002] The invention relates to a fault detection or anti-interference detection device, which is used for detecting contact with a surface, in particular with the surface of a steering handle of a vehicle.

[0003] A large number of surfaces and steering handles, which are to be detected in contact with them, are known from the prior art.

[0004] These systems for detecting touch are generally based on changes in capacitance or impedance on energized conductors caused by a touch.

[0005] However, the problem here is that the sensor or the measuring path of the sensor which detects the change in capacitance or impedance can also be disturbed, so that the detected measured value and thus the determination of the touch detection can be falsified.

[0006] These disturbing influences or disturbance variables may be, for example, electromagnetic fields, such as those caused by radio signals.

[0007] Therefore, there may be a situation where a touch is detected even though no touch occurs on the steering handle, or conversely, a situation where a touch is not detected even though the user touches the steering handle.

[0008] This is particularly disadvantageous if the impact detection is used for safety functions, which is common in modern vehicles, for example. Thus, for example, in vehicles, hand detection is used for steering handles, which is usually provided for use in autonomous or automated driving.

[0009] It is therefore desirable to improve touch detection and accordingly design it to be more robust and less prone to error.

[0010] For this purpose, various methods are known from the prior art, but some of them still need further improvement.

[0011] The object of the present invention is therefore to overcome the above-mentioned disadvantages and to provide a device by means of which a touch by a user, in particular a touch by a user with a steering handle, can be detected in a substantially undisturbed manner.

[0012] This object is achieved by the combination of features described in patent claim 1 .

[0013] Therefore, according to the present invention, a device for detecting a user's touching of a steering handle in an interference-free manner according to claim 1 is proposed. The device has at least one touch sensor for touch detection, at least one interference variable sensor for interference variable detection, and an evaluation unit. Therefore, at least one touch sensor can also be called a hand detection sensor. For example, the evaluation unit is connected to the sensor in a signal technology manner via one or more measuring circuits, that is, connected to all touch sensors and all interference variable sensors, and the evaluation unit is constructed to determine a value adjusted according to the interference variable based on the measured values ​​collected by the sensor for touch detection. For example, in order to determine the adjustment value, the evaluation unit can subtract the interference variable corresponding to the measured value of the interference variable sensor from the measured value of the touch sensor, and the measured value of the touch sensor corresponds to the sum of the interference variable and the hand-induced signal or the touch-induced signal. In addition to simple subtraction, vector subtraction or other suitable operations can also be used. According to the present invention, at least one interference variable sensor is constructed to receive a frequency as an interference variable. Although the interference variable sensors can each receive a plurality of frequencies as interference variables, it is preferably provided that the interference variable sensors are each designed to receive a predetermined frequency as interference variable or to receive a frequency band as interference variable, a frequency channel being a plurality of frequencies, of which there is a predetermined frequency. In this case, at least one interference variable sensor is in particular designed as an antenna line, and in particular as an open or one-sided open antenna line.

[0014] An advantageous variant of the invention provides a plurality of disturbance variable sensors for receiving a plurality of frequencies as disturbance variables, so that different frequencies or different frequency bands can be detected and different disturbance variables can be taken into account. Preferably, exactly one disturbance variable sensor is provided for each frequency or frequency band. The disturbance variable sensors are thus each designed to receive a respective predetermined frequency as disturbance variable or a predetermined frequency band with a predetermined frequency as disturbance variable. Although the different disturbance variable sensors are preferably each designed to detect a frequency band with a predetermined frequency as disturbance variable, so that the predetermined frequencies to be detected as disturbance variables of the disturbance variable sensors are different, the frequency bands can overlap with one another.

[0015] A variant of the invention further provides that at least one disturbance variable sensor or at least some of the disturbance variable sensors are each designed as an independent antenna structure.

[0016] In this case, the independent antenna structure can be an electrically conductive structure which is mounted on a printed circuit board or etched on a printed circuit board and which has a predetermined length and / or a length adapted to a predetermined frequency to be received as a disturbance variable. The printed circuit board is preferably a printed circuit board on which the evaluation unit is also arranged, so that the independent antenna structure can be constructed on the evaluation unit in a cost-effective and space-saving manner and integrated with the evaluation unit in a common structural unit. Furthermore, the antenna structure can have a predetermined course, for example a meandering course, which can be optimized for the reception of a predetermined frequency of the antenna structure. In general, for antennas, the structure can be open on one side, i.e. one side of the electrically conductive structure is not electrically connected to other components.

[0017] However, similar to the alternative embodiments mentioned below, a switch element for disconnecting the conductive structure may also be provided in the antenna structure.

[0018] Another variant of the separate antenna arrangement, which can also be used in combination with the separate antenna arrangement, provides that at least one disturbance variable sensor or at least one independent disturbance variable sensor is formed integrally by a disconnectable electrical line of an electronic component which is or can be integrated into the steering handle. The electronic component can be in particular a further sensor, further in particular a temperature sensor, which can be integrated into the steering handle anyway, for example, in order to control a heater of the steering handle.

[0019] Electronic components or other sensors, in particular temperature sensors, can also be connected to the evaluation unit via signal technology, for example via one or more measuring circuits, so that the evaluation unit can, on the one hand, detect and / or evaluate measured values ​​of other sensors / temperature sensors and, on the other hand, detect and / or evaluate measured values ​​of interference variable sensors formed by disconnectable electrical lines.

[0020] It can also be provided that the disconnectable electrical line extends at least in sections over the grip area of ​​the steering handle or the steering wheel rim, so that the line is not located behind the airbag or other shielding elements, but extends outwards to the steering wheel rim and is shielded to a lesser extent from interference or interference frequencies.

[0021] In conjunction with the disconnectable electrical line, the device further comprises at least one switching element, by means of which the disconnectable electrical line can be disconnected in such a way that the line is open on one side and / or has a predetermined length and / or a length adapted to the frequency to be received as a disturbance variable. To this end, the at least one switching element can be controlled by the evaluation unit. Furthermore, the evaluation unit can also be connected to or disconnected from the disconnectable electrical line via the switching element.

[0022] For operation of the electronic component, the electronic component can be connected to a supply voltage or a voltage source and / or a ground via a disconnectable electrical line, and for operation or use as a disturbance variable sensor, the line can be disconnected from the supply voltage or a voltage source and / or the ground via at least one switching element and can be switched in a potential-free manner. Thus, the supply voltage and / or the ground can be disconnected from the disconnectable electrical line, so that it can be used as a disturbance variable sensor.

[0023] The disconnectable electrical line can also be divided into a plurality of sections, which can be disconnected from each other by further switching elements, so that each section can be used as a disturbance variable sensor or a plurality of sections can be used together as a disturbance variable sensor. In particular, each section can be designed with a length adapted thereto or a course adapted thereto to receive a predetermined frequency as a disturbance variable or a predetermined frequency band with a frequency as a disturbance variable. Each section can then be connected to the evaluation unit or the measuring circuit of the evaluation unit by means of signal technology.

[0024] The evaluation unit is therefore designed to actuate at least one switching element to disconnect at least one disturbance variable sensor before recording and evaluating the measured values ​​of the at least one disturbance variable sensor. After recording the measured values, the disconnectable electrical line is preferably immediately reconnected to the supply voltage and / or ground.

[0025] The evaluation unit can also be designed to acquire the measured values ​​of the sensors in parallel in time. For this purpose, the evaluation unit can be connected to or have a plurality of measuring circuits or measuring ICs, wherein, for example, one measuring IC is assigned to each sensor. However, due to the large number of measuring ICs, this leads to an increased installation space requirement and increased costs. Therefore, as an alternative, it is provided that the evaluation unit can be designed to acquire the measured values ​​of the sensors sequentially in time, i.e. successively. For this purpose, the evaluation unit can be connected to or have a single measuring IC or just one measuring IC, i.e. a measuring circuit, which accordingly successively acquires the measured values ​​of the sensors. However, in order to ensure that disturbances present when acquiring the measured values ​​of the at least one touch sensor can be correctly acquired by the at least one disturbance variable sensor, it is provided that the evaluation unit is also designed to acquire the measured values ​​of the at least one disturbance variable sensor immediately in time after acquiring the measured values ​​of the at least one touch sensor.

[0026] If a plurality of touch sensors are provided, it can also be provided that the measured values ​​of a single touch sensor are respectively acquired first and then the measured values ​​of one, all or a plurality of disturbance variable sensors are acquired successively.

[0027] One aspect of the invention also relates to a steering handle in which the device according to the invention is integrated or connected, or to a system comprising a steering handle and the device according to the invention.

[0028] In addition, one aspect of the invention relates to a method for determining a control value for touch detection by means of the device according to the invention. According to the method, measured values ​​of at least one touch sensor are acquired, in particular immediately after the acquisition of measured values ​​of at least one disturbance variable sensor. The control value is then determined as a function of the measured values ​​of the sensors, i.e. the measured values ​​of the touch sensor and the disturbance variable sensor. The control value or values ​​can be determined by subtracting the measured values ​​of the disturbance variable sensor from the measured values ​​of the touch sensor, in particular by vectorial subtraction.

[0029] As long as it is technically feasible and not contradictory, the features disclosed above can be combined as needed.

[0030] Further advantageous embodiments of the invention are described in the dependent claims or are explained in more detail below together with the description of the preferred embodiments of the invention with reference to the accompanying drawings.

[0031] Figure 1 Showing the system consisting of the steering handle and the device;

[0032] Figure 2 A flow chart for detecting measured values ​​of a sensor is shown.

[0033] Figure 1 The illustration shows a system consisting of a steering handle 2 and a device 1 according to the invention. Figure 2 A method for determining a control value by means of the device 1 according to the invention is shown, for example Figure 1 Here, according to Figure 2 The method is shown based on a flow chart.

[0034] Figure 1 The device 1 in this case comprises two touch sensors 11, 12, two disturbance variable sensors 21, 22, and an evaluation module 30, which are integrated into the steering handle 2. All sensors 11, 12, 21, 22 are connected to the evaluation module 30 or to a measuring circuit 32 of the evaluation module 30 and, via the measuring circuit 32, to an evaluation unit 31 of the evaluation module 30. Although the evaluation unit 31 and the measuring circuit 32 are shown as two components, they can alternatively also be formed integrally by one component.

[0035] In this case, the two touch sensors 11 , 12 are each connected via a filter element 33 , while the two disturbance variable sensors 21 , 22 are connected to the measuring circuit 32 without a filter element or directly.

[0036] The measuring circuit 32 can be provided as a measuring IC (integrated circuit), which provides an input terminal for each sensor 11, 12, 21, 22 accordingly, but here it cannot evaluate the sensors 11, 12, 21, 22 simultaneously, but can only evaluate them successively, that is, in sequence, so that the measuring circuit 32 can switch the input terminals or evaluate the input terminals successively.

[0037] It is provided that the first disturbance variable sensor 21 is designed as a separate antenna structure. In order to reduce installation space and costs, the antenna structure or the first disturbance variable sensor 21 is designed as an electrically conductive structure 23, which is mounted on a printed circuit board of the evaluation module 30. In this case, the electrically conductive structure 23 is adapted in terms of its length to the specific frequency to be received as a disturbance variable.

[0038] Since the measuring circuit 32 and the evaluation unit 31 of the evaluation module 30 are also arranged as ICs on a printed circuit board, the evaluation module 30 can be provided as a compact unit.

[0039] Furthermore, a second disturbance variable sensor 22 is provided, which is formed integrally from a disconnectable electrical line 24, which also serves as a supply line for an electronic component 3 arranged in the steering handle 2. The electronic component 3 is here a temperature sensor for the heater of the steering handle 2, which is connected to a voltage source 4 and to ground 5 via a supply line.

[0040] Since the power supply line of the electronic component 3 is to be used as an open antenna line for receiving a predetermined frequency as a disturbance variable, two switch elements 41, 42 are provided in this example, wherein the first switch element 41 is used to separate the disconnectable electrical line 24 from the voltage source 4, and the second switch element 42 is used to separate the disconnectable electrical line 24 from the ground line 5, i.e., disconnect them. It is provided that the switch elements 41, 42 are arranged and the power supply line is separated in such a way that the second disconnectable electrical line 24 forming the disturbance variable sensor 22 has a predetermined length and is accordingly suitable for receiving a predetermined frequency.

[0041] However, the two disturbance variable sensors 21 , 22 are each adapted to two different predetermined frequencies as disturbance variables and can therefore correspondingly take into account different disturbance frequencies or disturbance variables.

[0042] In order to determine the adjustment value, the evaluation unit 31 of the evaluation module 30 is connected to the measuring circuit 32 so that the measured values ​​of the sensors 11, 12, 21, 22 acquired by the measuring circuit 32 are transmitted to the evaluation unit 31. Before acquiring the measured values, the evaluation unit 31 controls the switching elements 41, 42 so that the disconnectable electrical line 24 can be used as a disturbance variable sensor 22. After acquiring the measured values ​​of the disturbance variable sensor 22, the switching elements 41, 42 can be actuated to reconnect the temperature sensor 3 to the voltage source 4 and the ground line 5.

[0043] Figure 2 The method for determining the adjustment value is exemplified. The method comprises the following steps:

[0044] AStart

[0045] B collects the measured values ​​of all touch sensors 11 and 12

[0046] (Collect the measurement value of the i-th touch sensor)

[0047] C Have all touch sensors been read or their measurements collected? No → proceed to step D; Yes → proceed to step E

[0048] D. Increase counter i or collect the measurement value of the next touch sensor 11, 12.

[0049] E Is there a disturbance variable sensor 21 constructed as an independent antenna structure on the circuit board? No → continue to step G; Yes → continue to step F

[0050] F. Acquisition of measured values ​​of disturbance variable sensor 21 constructed as a separate antenna structure on the printed circuit board

[0051] G Is there (at least) one disturbance variable sensor 22 which is integrally formed of a disconnectable electrical line 24? No → continue with step M; Yes → continue with step H

[0052] H Are there switch elements 41, 42 for disconnecting the electrical line 24? No → proceed to step J; Yes → proceed to step I

[0053] I controls the switching elements 41 , 42 , thereby disconnecting the line 24 .

[0054] J. Detection of measured values ​​of disturbance variable sensor 22, which is composed entirely of disconnectable electrical lines 24.

[0055] K Are there switch elements 41, 42 for disconnecting the electrical line 24? No → proceed to step M; Yes → proceed to step L

[0056] L activates the switching elements 41 , 42 , so that the line 24 is connected to the voltage source 4 and the ground 5 .

[0057] M determines the adjustment value by subtracting the measured values ​​of the interference sensors 21 , 22 from the measured values ​​of the touch sensors 11 , 12 .

[0058] N Waiting for updated measurement request / waiting for next measurement slot.

Claims

1. A device (1) for detecting, with anti-interference, a user touching a steering handle (2), A device having at least one touch sensor (11, 12) for touch detection, at least one disturbance variable sensor (21, 22) for disturbance variable acquisition, and an evaluation unit (31), the evaluation unit being connected to the sensors (11, 12, 21, 22) via signal technology and being configured to determine a value adjusted according to the disturbance variable based on the measured values ​​acquired by the sensors (11, 12, 21, 22) for touch detection, in, The at least one disturbance variable sensor (21, 22) is each designed to receive a frequency as a disturbance variable.

2. The device according to claim 1, A plurality of disturbance variable sensors (21, 22) are provided for receiving a plurality of frequencies as disturbance variables, wherein: Each of the disturbance variable sensors is designed to receive a respective predetermined frequency as a disturbance variable or to receive a predetermined frequency band having a predetermined frequency as a disturbance variable.

3. The device according to claim 1 or 2, in, At least one disturbance variable sensor (21) is designed as a separate antenna structure.

4. Device according to the preceding claim, in, The independent antenna structure is a conductive structure (23) which is mounted on or etched on a printed circuit board and has a predetermined length and / or a length adapted to a predetermined frequency to be received as a disturbance variable.

5. The device according to any one of the preceding claims, in, At least one disturbance variable sensor (22) is formed integrally by a disconnectable electrical line (24) of an electronic component (3) integrated in the steering handle (2).

6. Device according to the preceding claim, Also included is at least one switching element (41, 42), by which the disconnectable electrical line (24) can be disconnected in such a way that the line (24) is open-circuited on one side and has a predetermined length and / or a length adapted to the frequency to be received as a disturbance variable.

7. Device according to the preceding claim, in, In order to operate the electronic component (3), the electronic component (3) is connected to a voltage source (4) and / or a ground line (5) via a disconnectable electrical line (24), and in order to operate as a disturbance variable sensor (22), the line (24) can be separated from the voltage source (4) and / or the ground line (5) by the at least one switching element (41, 42) and switched in a potential-free manner.

8. Device according to any one of the two preceding claims, in, The evaluation unit (31) is designed to actuate the at least one switching element (41, 42) to disconnect the at least one disturbance variable sensor (22) before recording and evaluating a measured value of the at least one disturbance variable sensor (22).

9. The device according to any one of the preceding claims, in, The evaluation unit (31) is designed to acquire the measured values ​​of the sensors (11, 12, 21, 22) in parallel in time. or among them, The evaluation unit (31) is designed to detect the measured values ​​of the sensors (11, 12, 21, 22) sequentially in time and to detect the measured values ​​of the at least one disturbance variable sensor (21, 22) immediately after detecting the measured values ​​of the at least one touch sensor (11, 12).

10. A method for determining a setting value for touch detection by means of a device (1) according to any one of the preceding claims, in, collecting a measurement value of the at least one touch sensor (11, 12), wherein a measured value of the at least one disturbance variable sensor (21, 22) is acquired, And wherein the adjustment value for touch detection is determined by the measurement value of the sensor (11, 12, 21, 22).

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