CN115328340A - Apparatus and method for steering wheel touch detection - Google Patents
Apparatus and method for steering wheel touch detection Download PDFInfo
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- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
- G06F3/0447—Position sensing using the local deformation of sensor cells
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- G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
- G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
- G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
- G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
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- G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
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Abstract
The present disclosure provides an apparatus and method for touch detection of a steering wheel, wherein the steering wheel includes a plurality of touch detection sensors, the method including: generating a plurality of reference signals in one-to-one correspondence with the plurality of preselected frequencies, the number of the plurality of touch detection sensors being the same as the number of the plurality of reference signals; for each of the plurality of reference signals, applying it to a respective one of a plurality of touch detection sensors without temporal overlap, each touch detection sensor modulating its applied reference signal to produce a corresponding modulated signal; detecting a modulation signal generated by each touch detection sensor and demodulating the modulation signal to obtain a touch detection signal of each touch detection sensor under the reference signal; and determining a touch detection state of the steering wheel based on the touch detection signal of each of the plurality of touch detection sensors at each of the plurality of reference signals.
Description
Technical Field
The present invention relates to steering wheel touch detection, and more particularly, to an apparatus and method for steering wheel touch detection.
Background
Currently, the automatic Driving technology is not yet mature, and the assistant Driving technology such as Advanced Driving Assistance System (ADAS) allows the vehicle to be in an automatic Driving state for only a short time, and thus, more and more vehicle manufacturers configure the vehicle with a Hand Off Detection (HOD) function for safety purposes. For example, it is detected whether the driver has both hands off the steering wheel by integrating a capacitive sensor in the steering wheel. However, the HOD function configured for the current vehicle uses a single frequency reference signal, and when the frequency is interfered (e.g., EMC (Electro Magnetic Compatibility)), the sensing result obtained is inaccurate, so that the HOD function cannot achieve the expected effect.
Disclosure of Invention
In view of this, the present disclosure provides a method and an apparatus for detecting a touch on a steering wheel, which implement a time-sharing frequency hopping principle, and use multiple reference signals with different frequencies to perform hands-off detection on a vehicle, thereby avoiding inaccurate or undetectable detection results due to interference of a single-frequency signal.
According to an aspect of the present invention, a method for touch detection of a steering wheel is provided, wherein the steering wheel comprises a plurality of touch detection sensors. The method comprises the following steps: generating a plurality of reference signals in one-to-one correspondence with a plurality of preselected frequencies, wherein the number of the plurality of touch detection sensors is the same as the number of the plurality of reference signals; for each of a plurality of reference signals, applying it to a respective one of a plurality of touch detection sensors without overlapping in time, wherein each touch detection sensor modulates its applied reference signal to produce a corresponding modulated signal; detecting a modulation signal generated by each touch detection sensor in the plurality of touch detection sensors and demodulating the modulation signal to obtain a touch detection signal of each touch detection sensor in the plurality of touch detection sensors under the reference signal; and determining a touch detection state of the steering wheel based on the touch detection signal of each of the plurality of touch detection sensors at each of the plurality of reference signals.
According to another aspect of the present invention, there is provided an apparatus for touch detection of a steering wheel including a plurality of touch detection sensors. The apparatus comprises: a signal generator configured to generate a plurality of reference signals in one-to-one correspondence with the plurality of preselected frequencies and apply, for each of the plurality of reference signals, to a respective one of a plurality of touch detection sensors without temporal overlap, wherein each touch detection sensor modulates the reference signal to which it is applied to produce a corresponding modulated signal, wherein the number of the plurality of touch detection sensors is the same as the number of the plurality of reference signals; a signal detector configured to detect a modulation signal generated by each of the plurality of touch detection sensors and demodulate the modulation signal to obtain a touch detection signal of each of the plurality of touch detection sensors under the reference signal; and a signal processor configured to determine a touch detection state of the steering wheel based on the touch detection signals of the respective touch detection sensors of the plurality of touch detection sensors at the respective reference signals of the plurality of reference signals.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings used in the description of the embodiments will be briefly introduced below. It should be apparent that the drawings in the following description are merely exemplary embodiments of the disclosure and that other drawings may be derived from those drawings by one of ordinary skill in the art without inventive effort.
FIG. 1 schematically illustrates a steering wheel according to an embodiment of the present disclosure;
FIG. 2 schematically illustrates a steering wheel touch detection device according to an embodiment of the present disclosure;
fig. 3 schematically shows the structure of the signal generator in fig. 2;
FIG. 4A schematically illustrates one manner in which the signal generator of FIG. 2 applies reference signals to the various touch detection sensors in the steering wheel;
FIG. 4B schematically illustrates another manner in which the signal generator in FIG. 2 applies reference signals to the various touch detection sensors in the steering wheel;
fig. 5 schematically shows the structure of the signal detector in fig. 2;
fig. 6 schematically illustrates a process in which the signal processor in fig. 2 determines a touch detection state of the steering wheel based on touch detection signals of the respective touch detection sensors at respective ones of a plurality of reference signals;
FIG. 7 schematically illustrates a steering wheel touch detection method according to an embodiment of the present disclosure;
FIG. 8 schematically shows a flowchart of step 740 in FIG. 7; and
fig. 9 schematically illustrates a steering wheel touch detection method according to an embodiment of the present disclosure.
Detailed Description
The present invention will be described in detail below with reference to exemplary embodiments thereof. The invention is not limited to the embodiments described herein, however, which may be embodied in many different forms. The described embodiments are provided only for the sake of completeness and completeness of the disclosure and to fully convey the concept of the invention to those skilled in the art. Features of the various embodiments described may be combined with each other or substituted for each other unless expressly excluded or otherwise excluded in context.
Fig. 1 schematically illustrates a steering wheel according to an embodiment of the present disclosure.
Referring to fig. 1, a steering wheel 100 is a steering wheel of any vehicle (especially an automobile), and during driving of the vehicle, a driver may leave both hands of the steering wheel 100 due to use of an advanced driving assistance system ADAS or other reasons (such as dozing, intoxication, etc.), when the steering wheel 100 is in an hands-off (HO) state.
In order to detect whether the steering wheel 100 is in the hands-off state, the steering wheel 100 is divided into at least one touch detection area, and at least one touch detection sensor is disposed in each touch detection area. For example, fig. 1 shows that the steering wheel 100 is divided into 3 touch detection zones, namely a touch detection zone Z1 covering the front side of the steering wheel, a touch detection zone Z2 covering the back side of the left part of the steering wheel, and a touch detection zone Z3 covering the back side of the right part of the steering wheel, and one touch detection sensor S1, S2, and S3 may be disposed in each touch detection zone. The sensing range of each touch detection sensor is the entire touch detection area to which it belongs, as shown in fig. 1 by shading. The body of each touch detection sensor may be a comb-type electrode integrated inside the steering wheel, which is capable of sensing a capacitance and/or a resistance formed when the driver touches the corresponding touch detection area, and the preset threshold value of the capacitance and/or the resistance may be obtained through experiments or calculations. The term "touching" herein includes the driver touching the steering wheel lightly or holding the steering wheel hard with his hands.
It should be noted that the number of touch detection areas in the steering wheel 100 and the number of touch detection sensors in each touch detection area shown in fig. 1 are merely examples, and the steering wheel 100 may be divided into any number of touch detection areas, and a plurality of touch detection sensors may also be redundantly provided in each touch detection area, and the plurality of touch detection sensors may detect in parallel the capacitance and/or resistance formed when the driver touches the corresponding touch detection area, in order to improve detection reliability.
For ease of understanding, the following description will be made with an example in which three touch detection areas Z1, Z2, Z3 shown in fig. 1 and one touch detection sensor S1, S2, S3 is arranged in each touch detection area.
Fig. 2 schematically illustrates a structure of a steering wheel touch detection apparatus 200 according to an embodiment of the present disclosure.
The steering wheel touch detection apparatus 200 may be located outside the steering wheel 100 or inside the steering wheel 100. As shown in fig. 2, the steering wheel touch detecting apparatus 200 includes a signal generator 210, a signal detector 220, and a signal processor 230.
The signal generator 210 may employ a dedicated signal generator chip or a set register. For example, a reference signal of a predetermined frequency range may be generated using a dedicated signal generator chip, for example, a sine wave, a rectangular wave, and a square wave of a frequency range within 0.1Hz to 20MHz may be generated, a low distortion sine wave, a triangular wave, a rectangular wave of from 0.001Hz to 300kHz may be generated, or a sine wave, a triangular wave, or the like of a frequency up to 37.5MHz may be generated. For example, in the case of using a register to generate the reference signal, its output waveform and frequency can be controlled by software.
The signal generator 210 generates a plurality of reference signals, which are the same as the number of touch detection sensors, in time division, i.e., at different times (this is the case where one touch detection sensor is arranged in each touch detection area as shown in fig. 1, and when each touch detection area contains a plurality of touch detection sensors, a plurality of reference signals, which are the same as the number of touch detection sensors in the touch detection area, are generated for each touch detection area), which correspond one-to-one to a plurality of preselected frequencies, respectively. For example, reference signals W1, W2, W3 are generated at preselected frequencies F1, F2, F3, respectively, the waveforms of which include, but are not limited to, sine waves, rectangular waves, triangular waves, and the like. For each reference signal W1, W2, W3, the signal generator 210 applies it to three touch detection sensors S1, S2, S3 in the touch detection zones Z1, Z2, Z3 without overlapping in time. The manner of applying the reference signals W1, W2, W3 includes, but is not limited to, the two manners shown in fig. 4.
Each touch detection sensor S1, S2, S3 modulates its applied reference signal W1, W2, W3 to generate a corresponding modulation signal M SiWj Where i is an integer between 1 and the number of touch detection sensors and j is an integer between 1 and the number of preselected frequencies/reference signals. For each touch detection sensor S1, S2, S3, a touch sensing signal is generated upon sensing a capacitance or resistance formed by the driver touching the corresponding touch detection area Z1, Z2, Z3, at which time the modulation signal M SiWj (i =1-3, j = 1-3) corresponds to the superposition of the reference signals W1, W2, W3 and the touch detection signal. On the contrary, for each of the touch detection sensors S1, S2, S3, if the capacitance or resistance formed by the driver touching the touch detection areas Z1, Z2, Z3 is not sensed, the modulation signal M generated thereby SiWj No touch sensing signal is included.
Produced by touch-detecting sensors S1, S2, S3Generating a modulated signal M SiWj Will be detected by the signal detector 220 (e.g., via a wireless or wired communication line), and the signal detector 220 may modulate the signal M SiWj Demodulated to obtain touch detection signals generated by the respective touch detection sensors S1, S2, S3 under the respective reference signals W1, W2, W3. If the touch detection sensor senses the capacitance and/or resistance formed by the driver touching the corresponding touch detection area, the modulation signal M is modulated SiWj The demodulated touch detection signal will include the capacitance and/or resistance.
Modulated signal M is modulated by signal detector 220 SiWj The touch detection signal resulting from the demodulation will be processed by the signal processor 230. The signal processor 230 determines the touch detection state of the corresponding touch detection sensor based on the capacitance and/or resistance indicated by the touch detection signal, thereby determining the touch detection state of the steering wheel 100. The touch detection state includes at least an hands-off state HO or a hands-free state Non-HO.
In addition, the steering wheel touch detecting apparatus 200 may further include a wireless communication module (not shown in the drawings) for supporting the signal generator 210 to transmit the reference signal to each touch detection sensor and the signal detector 220 to receive the modulation signal from each touch detection sensor.
It should be noted that, although the signal generator 210, the signal detector 220 and the signal processor 230 are shown as components inside the steering wheel touch detection apparatus 200 in fig. 2, one or more of them may be an external device having an equivalent function. For example, the signal processor 230 may be an external device, such as a micro control unit MCU having calculation and processing functions, a system on a chip, or a central processing unit CPU, etc., which is communicatively connected with the signal generator 210 and the signal detector 220 through a data interface of the steering wheel touch detection apparatus 200.
Fig. 3 schematically illustrates the structure of the signal generator 210 in fig. 2.
Referring to fig. 3, the signal generator 210 includes a frequency selection unit 211, a signal generation unit 212, and a sensor selection unit 213. The frequency selection unit 211 is configured to select a plurality of pre-selected frequencies from a range of frequencies, such as F1, F2, F3. The signal generating unit 212 is used for sequentially generating a plurality of reference signals, such as the reference signals W1, W2, W3, corresponding to a plurality of preselected frequencies. The sensor selection unit 213 is used to sequentially select the respective touch detection sensors to which the reference signal is to be applied, such as the aforementioned touch detection sensors S1, S2, S3.
Fig. 4A schematically illustrates one way in which the signal generator in fig. 2 applies reference signals to the various touch detection sensors in the steering wheel.
The time for the steering wheel touch detection apparatus 100 to complete one touch detection on the steering wheel is set to one detection period (for example, about 10 ms), and in each detection period, the signal generator 210 completes one application of the respective reference signals to the respective touch detection sensors in the touch detection area without overlapping in time.
Referring to fig. 4A, each of the respective touch detection sensors is sequentially selected by the frequency selection unit 211 in the signal generator 210, and for the selected touch detection sensor (e.g., S1), a plurality of reference signals corresponding to a plurality of preselected frequencies one-to-one are sequentially generated and applied by the signal generation unit 212 in the signal generator 210.
As shown in fig. 4A, one detection period may be divided into 3 sub-periods according to the number of touch detection sensors. In the sub-period 1, the sensor selection unit 213 selects the touch detection sensor S1, and for S1, W2, W3 with frequencies F1, F2, and F3, respectively, are sequentially applied. In response, the touch detection sensor S1 will sequentially generate modulation signals M corresponding to frequencies F1, F2, and F3 S1W1 、M S1W2 And M S1W3 . In the sub-period 2, the sensor selection unit 213 selects the touch detection sensor S2, and for S2, W1, W2, W3 with frequencies F1, F2, and F3, respectively, are sequentially applied. In response, the touch detection sensor S2 will sequentially generate modulation signals M corresponding to frequencies F1, F2, and F3 S2W1 、M S2W2 And M S2W3 . In the sub-period 3, the sensor selection unit 213 selects the touch detection sensor S3, and for S3, W1, W2, W3 with frequencies F1, F2, and F3, respectively, are sequentially applied.In response, the touch detection sensor S3 will sequentially generate modulation signals M corresponding to frequencies F1, F2, and F3 S3W1 、M S3W2 And M S3W3 。
Thus, during one detection period, each touch detection sensor S1, S2, S3 generates a total of 9 modulation signals, i.e., M SiWj (i＝1～3，j＝1～3)。
Fig. 4B schematically illustrates another manner in which the signal generator 210 in fig. 2 applies reference signals to the respective touch detection sensors in the steering wheel.
Referring to fig. 4B, the frequency selection unit 211 in the signal generator 210 sequentially selects each of the plurality of preselected frequencies, and for the selected preselected frequency (e.g., F1), the signal generation unit 212 in the signal generator 210 generates a reference signal (e.g., W1) corresponding thereto, and for the generated reference signal (e.g., W1), the sensor selection unit 213 in the signal generator 210 sequentially applies it to the respective touch detection sensors.
As shown in fig. 4B, one detection period may also be divided into 3 sub-periods according to the number of preselected frequencies. In the sub-period 1, the frequency selection unit 211 selects the preselection frequency F1, the signal generation unit 212 generates the reference signal W1 corresponding to the preselection frequency F1, and the sensor selection unit 213 sequentially applies it to the touch detection sensors S1, S2, S3 for the generated W1. In response, the touch detection sensors S1, S2, S3 will sequentially generate modulation signals M corresponding to the frequency F1 S1W1 、M S2W1 And M S3W1 . In the sub-period 2, the frequency selection unit 211 selects the preselection frequency F2, the signal generation unit 212 generates the reference signal W2 corresponding to the preselection frequency F2, and the sensor selection unit 213 sequentially applies it to the touch detection sensors S1, S2, S3 for the generated W2. In response, the touch detection sensors S1, S2, S3 will sequentially generate a modulation signal M corresponding to the frequency F2 S1W2 、M S2W2 And M S3W2 . In sub-period 3, frequency selecting unit 211 selects preselection frequency F3, signal generating unit 212 generates reference signal W3 corresponding to preselection frequency F2, and for generated W3, transmitsThe sensor selection unit 213 sequentially applies it to the touch detection sensors S1, S2, S3. In response, the touch detection sensors S1, S2, S3 will sequentially generate a modulation signal M corresponding to frequency F3 S1W3 、M S2W3 And M S3W3 。
Thus, as in fig. 4A, each of the touch detection sensors S1, S2, S3 generates a total of 9 modulation signals, i.e., M, in one detection cycle SiWj (i＝1～3，j＝1～3)。
Fig. 5 schematically shows the structure of the signal detector in fig. 2.
The signal detector 220 includes a signal receiving unit 221 and an IQ demodulation unit 222. The signal receiving unit 221 may receive the modulation signal M generated by each of the touch detection sensors S1, S2, S3 SiWj (i＝1，j＝1～3)。
IQ demodulation unit 222 modulates signal M SiWj IQ demodulation is performed to obtain a capacitance value C sensed by the touch detection sensor Si when a reference signal Wj with a frequency Fj is applied to the touch detection sensor Si SiWj And/or resistance value R SiWj Wherein the capacitance value C SiWj Resistance R as Q component of IQ demodulation SiWj As the I component of IQ demodulation, the influence caused by parasitic resistance can be removed, and the capacitance and/or resistance change caused by touch can be measured more accurately, thereby realizing more accurate steering wheel touch detection.
As previously mentioned, the touch detection sensors S1, S2, S3 together generate 9 modulation signals M SiWj (i =1 to 3, j =1 to 3), and IQ demodulating section 222 individually applies 9 modulated signals M to the modulated signals M SiWj (i =1 to 3, j =1 to 3) IQ demodulation was performed, and 9 sets of capacitance values C were obtained SiWj And/or resistance value R SiWj (i =1 to 3, j =1 to 3) comprising: capacitance values C sensed by the touch detection sensor S1 under the respective reference signals W1, W2, W3 S1W1 、C S1W2 、C S1W3 And/or resistance value R S1W1 、R S1W2 、R S1W3 Capacitance value C sensed by the touch detection sensor S2 under each reference W1, W2, W3 S2W1 、C S2W2 、C S2W3 And/or resistance value R S2W1 、R S2W2 、R S2W3 And a capacitance value C sensed by the touch detection sensor S3 under the reference signals W1, W2, W3 S3W1 、C S3W2 、C S3W3 And/or resistance value R S3W1 、R S3W2 、R S3W3 。
These capacitance values C SiWj And/or resistance value R SiWj Is processed by the signal processor 230 to determine the touch detection state sensed by each touch detection sensor, and thus, the touch detection state of the steering wheel.
Fig. 6 schematically illustrates a process in which the signal processor 230 in fig. 2 determines a touch detection state of the steering wheel based on touch detection signals of the respective touch detection sensors at respective reference signals of the plurality of reference signals.
Referring to fig. 6, at 610, for each touch detection sensor S1, S2, S3 of the plurality of touch detection sensors, the signal processor 230 determines a touch detection state of the touch detection sensor at the respective reference signal W1, W2, W3 based on a touch detection signal of the touch detection sensor at the respective reference signal W1, W2, W3. Specifically, the signal processor 230 is based on the capacitance value C demodulated by the signal detector 220 SiWj And resistance value R SiWj To determine the touch detection state of the touch detection sensor under the respective reference signals W1, W2, W3. Preset thresholds that have been determined experimentally or by calculation to establish the capacitance and resistance that are formed when the driver touches the steering wheel may be set to C and R, respectively. When the driver touches the steering wheel, the hand of the driver is equivalent to one pole of the capacitor, the area of the plate electrode of the capacitor is increased, the capacitance value is increased, and the resistance value is reduced when the driver is equivalent to the resistance connected in parallel.
In one example, the signal processor 230 is based only on the capacitance value C in the touch detection signal SiWj The touch detection state of the touch detection sensor under each of the reference signals W1, W2, W3 is determined.
For example, for the touch detection sensor S1, the capacitance value C is sensed under the reference signal W1, which is demodulated by the signal detector 220 S1W1 . A capacitance value C S1W1 Comparing with a preset capacitance threshold value C if the capacitance value C is larger than the preset capacitance threshold value C S1W1 At or above C, i.e. C S1W1 If the capacitance value C is larger than or equal to C, determining that the touch detection state of the touch detection sensor S1 under the reference signal W1 is a hand-off state, and otherwise, if the capacitance value C is larger than or equal to C, determining that the touch detection state of the touch detection sensor S1 under the reference signal W1 is a hand-off state S1W1 Less than C, i.e. C S1W1 If so, the touch detection state of the touch detection sensor S1 under the reference signal W1 is determined to be the hands-off state. Similarly, the capacitance values C of the touch detection sensor S1 under the reference signal W2 are respectively set S1W2 Capacitance value C under reference signal W3 S1W3 In comparison with the capacitance preset threshold C, it can be determined that the touch detection state of the touch detection sensor S1 under the reference signals W2, W3 is the hands-off state or the hands-off state. Similarly, for the touch detection sensors S2 and S3, the capacitance value C to be sensed under the reference signals W1, W2, W3 S2W1 、C S2W2 、C S2W3 、C S3W1 、C S3W2 、C S3W3 Compared with the capacitance preset threshold C, it can be determined that the touch detection states of the touch detection sensors S2 and S3 under the reference signals W2, W3 are an unopened state or an unopened state.
In another example, the signal processor 230 is based only on the resistance value R in the touch detection signal SiWj The touch detection state of the touch detection sensor under each of the reference signals W1, W2, W3 is determined.
And using a capacitance value C SiWj Similarly, the resistance value R can be compared SiWj The touch detection state of each touch detection sensor under each reference signal W1, W2, W3 is determined with the resistance preset threshold R. When R is SiWj When R is less than or equal to R, determining that the touch detection state of the touch detection sensor under the corresponding reference signal is not in the hands-off state, and when R is less than or equal to R, determining that the touch detection state of the touch detection sensor under the corresponding reference signal is in the hands-off state SiWj And when R is greater than R, determining that the touch detection state of the touch detection sensor under the corresponding reference signal is an out-of-hand state.
In yet another example, the signal processor 230 is based on a capacitance value C in the touch detection signal SiWj And resistance value R SiWj Both determine the touch detection state of the touch detection sensor under the respective reference signals W1, W2, W3.
For example, for touchA detection sensor S1 for detecting the capacitance C S1W1 With a predetermined threshold value C of capacitance and a resistance value R S1W1 Is compared to a predetermined resistance threshold R. When C is present S1W1 Not less than C and R S1W1 When the touch detection state of the touch detection sensor S1 under the reference signal W1 is not larger than R, determining that the touch detection state is not away from the hand; when C is present S1W1 < C and R S1W1 When R is greater than R, determining that the touch detection state of the touch detection sensor S2 under the reference signal W1 is a hands-off state; when C is present S1W1 Not less than C and R S1W1 > R or when C S1W1 < C and R S1W1 When R or more, the touch detection state of the touch detection sensor S1 in the reference signal W1 cannot be determined. Similarly, for the touch detection sensors S2, S3, the capacitance value C sensed under the reference signals W1, W2, W3 is compared SiWj (i =2 to 3,j =1 to 3) with a capacitance preset threshold value C, and compares resistance values R sensed under the reference signals W1, W2, W3 SiWj (i =2 to 3, j =1 to 3) and the resistance preset threshold value R, the touch detection state of the touch detection sensors S2, S3 at the respective reference signals W2, W3 can be determined.
At 620, for each of the touch detection sensors S1, S2, S3, the signal processor 230 determines a touch detection state of the touch detection sensor S1, S2, S3 based on the touch detection state of the touch detection sensor at the respective reference signal W1, W2, W3.
The signal processor 230 determines the touch detection state of the touch detection sensor at each reference signal according to the following rule: (1) Determining that the touch detection state of the touch detection sensor is the hands-off state under the condition that the touch detection states of the touch detection sensor under the reference signals W1, W2 and W3 are the hands-off states; (2) Determining that the touch detection state of the touch detection sensor is the hand-not-leaving state under the condition that the touch detection states of the touch detection sensor under the reference signals W1, W2 and W3 are the hand-not-leaving states; and (3) in the case that the touch detection states of the touch detection sensors under the respective reference signals W1, W2, W3 are not consistent, marking the frequencies of at least a part of the respective reference signals as interfered frequencies. Incidentally, the touch detection state of the touch detection sensor may also be set to the touch detection state reflected by the majority of the plurality of reference signals according to a minority majority-compliant principle.
For example, the touch detection states of the respective touch detection sensors S1, S2, and S3 at the respective sensors W1, W2, and W3 obtained at 610 may be as shown in table 1.
[ TABLE 1 ]
According to table 1, the touch detection states of the respective touch detection sensors S1, S2 and S3 under the respective reference signals W1, W2 and W3 are all off-hand states HO, which indicates that none of the touch detection sensors S1, S2 and S3 senses the capacitance and/or resistance formed by the driver touching the corresponding touch detection area.
In this case, it is determined that the touch detection states of the touch detection sensors S1, S2, and S3 are all the hands-off states.
For another example, the touch detection states of the respective touch detection sensors S1, S2, S3 at the respective sensors W1, W2, W3 obtained at 610 may be as shown in table 2.
[ TABLE 2 ]
According to table 2, the touch detection states of the touch detection sensors S1, S3 at the respective reference signals W1, W2, W3 are hands-off states HO, which means that no touch detection sensor S1, S3 senses the capacitance and/or resistance formed by the driver touching the respective touch detection area Z1, Z3 at any reference signal of a preselected frequency. The touch detection state of the touch detection sensor S2 in each of the reference signals W1, W2, W3 is the hands-off state Non-HO, which indicates that the touch detection sensor S2 senses the capacitance and/or resistance formed by the driver touching the corresponding touch detection area Z2 in any reference signal of a preselected frequency.
In this case, the touch detection state of the touch detection sensors S1, S3 is determined to be the hands-off state, and the touch detection state of the touch detection sensor S2 is determined to be the hands-off-free state.
For another example, the touch detection states of the respective touch detection sensors S1, S2, S3 at the respective sensors W1, W2, W3 obtained at 610 may be as shown in table 3.
[ TABLE 3 ]
According to table 3, if the touch detection states of the touch detection sensor S1 under the reference signals W1, W2, and W3 are all the hands-off states HO, it is determined that the touch detection state of the touch detection sensor S1 is the hands-off state HO. If the touch detection states of the touch detection sensor S3 under the reference signals W1, W2, and W3 are all the hands-off state Non-HO, it is determined that the touch detection state of the touch detection sensor S3 is the hands-off state Non-HO. The touch detection state of the touch detection sensor S2 under the reference signals W1 and W3 is the hands-off state HO, and the touch detection state under the reference signal W2 is the hands-off state Non-HO, which indicates that the sensing results of the touch detection sensor S2 for the reference signals with different frequencies are inconsistent, and the touch detection state of the touch detection sensor S2 cannot be determined, because: since the position of the driver's hand relative to the steering wheel 100 is almost constant at the same time or within an extremely short period of time (e.g., one detection cycle, about 10 ms), the resulting touch detection state should be the same for the same touch detection sensor regardless of which reference signal of a preselected frequency is applied thereto. If the touch detection state obtained when a certain preselected frequency is applied is different from the touch detection state obtained when other preselected frequencies are applied, it may be because the preselected frequency or other preselected frequencies are disturbed.
In this case, frequencies of the plurality of reference signals that reflect a portion of the reference signals that differ from the touch detection state reflected by the majority of the reference signals may be labeled as interfered frequencies according to a minority majority-compliant principle. With respect to table 3, the touch detection state reflected by the reference signal W2 is different from W1 and W3, and the frequency F2 of the reference signal W2 can be labeled as a disturbed frequency. Incidentally, the touch detection state of the touch detection sensor may also be set to the touch detection state reflected by the majority of the plurality of reference signals according to a minority majority-compliant principle.
It should be noted that the case of table 3 is merely an example, and it is more likely that once a certain preselected frequency is interfered, the touch detection state determined via the reference signal of the interfered frequency may reflect a touch detection state different from the touch detection state determined via the reference signals of other frequencies, regardless of which touch detection sensor.
At 630, a touch detection state of the steering wheel is determined based on the touch detection state of each of the plurality of touch detection sensors.
The signal processor 230 determines the touch detection state of the steering wheel 100 according to the following rule: (1) In a case where it is determined at 620 that the touch detection states of the respective touch detection sensors are the hands-off state, determining that the touch detection state of the steering wheel is the hands-off state; (2) Determining the touch detection state of the steering wheel 100 as an unhooked state in case that the touch detection states of the respective touch detection sensors are determined as the unhooked state at 620, or in case that the touch detection state of at least one touch detection sensor is determined as the unhooked state and the touch detection states of the other touch detection sensors are determined as the unhooked state at 620; (3) When at least one interfered frequency is marked at 620, the touch detection state of the steering wheel cannot be determined, and the marked interfered frequency is fed back to the signal generator. As an alternative to (3) here, also (4): when at least one disturbed frequency is marked at 620, then for each touch detection sensor, the most numerous touch detection states presented by the touch detection sensor are selected as the touch detection states of the touch detection sensor, subject to a minority majority-compliant principle. Further, in this case, when a plurality of touch detection sensors are arranged in each touch detection area, the state of the touch detection area in which the plurality of touch detection sensors are located may be determined according to the touch detection states of the plurality of touch detection sensors, and then the touch detection state of the steering wheel may be finally determined according to the touch detection state of each touch detection area.
Thus, at the end of one detection period, the steering wheel touch detection apparatus 200 may determine that the touch detection state of the steering wheel is the hands-off state, or the touch detection state of the steering wheel cannot be determined.
On this basis, the steering wheel touch detection apparatus 200 may continuously perform a plurality of detection cycles on the steering wheel, and if the time for detecting that the steering wheel is in the hands-off state exceeds a preset hands-off threshold, for example, the time for detecting that the steering wheel is in the hands-off state is detected within 500 detection cycles (each detection cycle being 10ms, i.e., 5 seconds), an alarm message is issued to remind the driver that the hands-off time has been too long, which may cause a safety accident to occur.
As previously described, the signal processor 230 feeds back the marked interfered frequency to the signal generator 210, and once the interfered frequency is fed back by the signal generator 210, the frequency selection unit 211 in the signal generator 210 may replace the interfered frequency with a new frequency that is not used in a predetermined period (e.g., a certain number of detection cycles, such as the last 3, 5, 10 detection cycles, etc., to which the present disclosure is not limited) in a new detection cycle to update the preselected frequency. For example, with table 3, once the signal processor marks the frequency F2 as an interfered frequency at 620, the frequency selection unit 211 selects a new frequency F4 that has not been used for a predetermined period of time instead of the interfered frequency F2 in a new detection period, and the signal generation unit 212 generates updated reference signals W1, W4, W3 corresponding one-to-one to the updated pre-selected frequencies F1, F4, F3. Then, the signal processor 230 determines the touch detection state of the steering wheel 100 based on the touch detection signals generated by the respective touch detection sensors at the respective updated reference signals W1, W4, W3.
Further, as another example, even if no frequency was marked as a disturbed frequency in the last detection period, one or more of the preselected frequencies F1, F2, and F3 may be replaced with one or more new frequencies that were not used for a predetermined period of time in a new detection period, such as updating the preselected frequencies F1, F2, and F3 to F1, F4, and F5 in the new detection period, where F4 and F5 are different frequencies from F1, F2, and F3. In this way, the reliability of the touch detection state can be improved.
According to the steering wheel touch detection device disclosed by the embodiment of the disclosure, the time-sharing frequency hopping principle is adopted, the reference signals of different frequencies are applied to the touch detection sensors in the steering wheel, and the touch detection state of the steering wheel is determined based on the touch detection states sensed by the touch detection sensors under the reference signals of the frequencies, so that the reliability of the touch detection of the steering wheel is improved, and the safety in the vehicle driving process is favorably enhanced. Meanwhile, by marking the interfered frequency and replacing the interfered frequency with a new frequency that is not used for a predetermined period of time, it is possible to reduce interference caused to the detection of the touch detection sensor caused by, for example, electromagnetic compatibility EMC.
The steering wheel touch detection apparatus 200 according to the embodiment of the present disclosure is described above with reference to fig. 2 to 6, and a steering wheel touch detection method performed by the steering wheel touch detection apparatus is described below with reference to fig. 7 to 9. Since some steps or processes have been set forth above in detail, the same or similar contents will be omitted below in order to avoid repetition.
Fig. 7 schematically illustrates a flow chart of a steering wheel touch detection method 700 according to an embodiment of the present disclosure, which may be performed by the steering wheel touch detection apparatus 200 described above within one detection period.
Referring to fig. 7, a method 700 for steering wheel touch detection according to an embodiment of the present disclosure includes steps 710-740, where the steering wheel includes a plurality of touch detection sensors. Wherein the touch detection sensors may be simultaneously located in one touch detection area, or may be respectively located in different touch detection areas
In step 710, a plurality of reference signals are generated in one-to-one correspondence with a plurality of preselected frequencies, wherein the number of the plurality of touch detection sensors is the same as the number of the plurality of reference signals. For example, reference signals having frequencies F1, F2, and F3 are generated, and the waveforms of the reference signals may be sine waves, rectangular waves, triangular waves, or the like.
In step 720, for each of the plurality of reference signals, it is applied to each of the plurality of touch detection sensors without overlapping in time. This means that reference signals having different frequencies are applied to the respective touch detection sensors in a time-sharing manner, including, but not limited to, the two manners that have been described above in connection with fig. 4A and 4B. Each touch detection sensor modulates the reference signal to which it is applied to generate a corresponding modulated signal.
In step 730, for each of the plurality of reference signals, the modulated signal generated by each of the plurality of touch detection sensors is detected and demodulated to obtain a touch detection signal for each of the plurality of touch detection sensors at the reference signal. As an example of this step, IQ demodulation may be performed on the modulated signals by using an IQ demodulation technique, and each obtained touch detection signal includes a capacitance value and/or a resistance value sensed by the touch detection sensor, where the capacitance value is used as a Q component of the IQ demodulation, and the resistance value is used as an I component of the IQ demodulation, so that an influence caused by a parasitic resistance may be removed, and a change in capacitance and/or resistance due to a touch may be measured more accurately, thereby achieving more accurate steering wheel touch detection.
In step 740, a touch detection state of the steering wheel is determined based on the touch detection signal of each of the plurality of touch detection sensors at each of the plurality of reference signals. As an example of this step, the touch detection state of the steering wheel may be determined based on the capacitance value and/or the resistance value obtained by IQ demodulation in step 730, which will be described in detail in fig. 8.
Fig. 8 schematically shows a flowchart of step 740 in fig. 7.
Referring to fig. 8, step 740 includes three substeps 810-830.
In sub-step 810, for each touch detection sensor of the plurality of touch detection sensors, a touch detection state of the touch detection sensor at a respective reference signal of the plurality of reference signals is determined based on the touch detection signal of the touch detection sensor at the respective reference signal. As an example of this sub-step, one or both of the capacitance value and/or the resistance value indicated by the touch detection signal of the touch detection sensor at each reference signal may be compared with the corresponding predetermined capacitance threshold value C and/or resistance threshold value R, respectively, to determine the touch detection state of the touch detection sensor at each reference signal.
In sub-step 820, for each touch detection sensor of the plurality of touch detection sensors, a touch detection state of the touch detection sensor is determined based on a touch detection state of the touch detection sensor at the respective reference signal. In this sub-step, the touch detection state of the touch detection sensor is determined according to the following rule: (1) Determining that the touch detection state of the touch detection sensor is the hands-off state under the condition that the touch detection states of the touch detection sensor under the reference signals are the hands-off states; (2) Determining that the touch detection state of the touch detection sensor is the hand-not-leaving state under the condition that the touch detection state of the touch detection sensor under each reference signal is the hand-not-leaving state; and (3) in the case where the touch detection states of the touch detection sensors under the respective reference signals are not consistent, failing to determine the touch detection state of the touch detection sensor, while, according to a minority-compliant principle, marking a frequency of the plurality of reference signals reflecting a portion of the reference signals different from the touch detection states reflected by the majority of reference signals as an interfered frequency. Incidentally, the touch detection state of the touch detection sensor may also be set to a touch detection state reflected by most of the plurality of reference signals according to a minority-majority-compliant principle.
In sub-step 830, a touch detection state of the steering wheel is determined based on the touch detection state of each of the plurality of touch detection sensors. In this sub-step, the touch detection state of the steering wheel 100 is determined according to the following rule: (1) In a case where it is determined in sub-step 820 that the touch detection states of the respective touch detection sensors are the hands-off state, determining that the touch detection state of the steering wheel is the hands-off state; (2) Determining the touch detection state of the steering wheel 100 as the hands-off-free state in a case where it is determined in sub-step 820 that the touch detection states of the respective touch detection sensors are the hands-off-free state, or in a case where it is determined in sub-step 820 that the touch detection state of at least one touch detection sensor is the hands-off-free state and the touch detection states of the other touch detection sensors are the hands-off-free state; (3) In the case where at least one disturbed frequency is marked in sub-step 820, the touch detection state of the steering wheel cannot be determined. As an alternative to (3) here, also (4): when at least one disturbed frequency is marked in sub-step 820, then for each touch detection sensor, the most numerous touch detection states presented by the touch detection sensor are selected as the touch detection states of the touch detection sensor, according to a minority majority-compliant principle. Further, in this case, when a plurality of touch detection sensors are arranged in each touch detection area, the state of the touch detection area in which the plurality of touch detection sensors are located may be determined according to the touch detection states of the plurality of touch detection sensors, and then the touch detection state of the steering wheel may be finally determined according to the touch detection state of each touch detection area.
The above sub-steps 810-830 are similar to the processes 610-630 of determining the touch detection state of the steering wheel based on the touch detection signal of each touch detection sensor under each reference signal of the plurality of reference signals by the signal processor 230 in the steering wheel touch detection device 200 shown in fig. 6, and since the processes have been described in detail in the foregoing by taking table 1, table 2, and table 3 as examples, the details are not repeated here.
Fig. 9 is a schematic flow chart diagram schematically illustrating a steering wheel touch detection method 900 performed by the steering wheel touch detection apparatus 200 described above in a plurality of detection cycles according to an embodiment of the present disclosure.
In step 910, the number of detection cycles is set to k, and the method 900 starts with k = 1.
In step 920, the method 700 described above is executed in the first detection period to determine the touch detection state of the steering wheel in the detection period.
In step 930, it is determined whether at least one frequency is marked as an interfered frequency in step 920. As one case, if at least one frequency is marked as an interfered frequency in step 920, the process proceeds to step 940.
In step 940, the plurality of preselected frequencies are updated by replacing the interfered frequency with a new frequency that has not been used for a predetermined period of time (e.g., a number of detection cycles). For example, when the frequency F2 is marked as an interfered frequency in step 920, a new frequency F4 that has not been used for a predetermined period of time is used instead of F2, and the updated preselected frequencies are F1, F2, and F4. Then, proceed to step 950.
In step 950, the number of detection cycles k is increased by 1, i.e., the next detection cycle is entered.
Returning to step 930, as another case, if no frequency is marked as an interfered frequency in step 920, the process proceeds to step 960.
In step 960, it is determined whether the time that the steering wheel is in the hands-off state exceeds a preset hands-off threshold, for example, 5 seconds, and if each detection period is 10ms, it corresponds to 500 detection periods. For example, if the results of step 920 are all in the hands-off state in 500 consecutive detection cycles, it is determined that the time that the steering wheel is in the hands-off state has reached the preset hands-off threshold. In this case, an alarm message is issued. If the time that the steering wheel is in the hands-off state does not exceed the preset hands-off threshold, the process proceeds to step 950, where the number of detection cycles is k and is increased by 1, and the next detection cycle is entered.
And repeating the steps 920 to 960 until whether the time of the steering wheel in the hands-off state exceeds a preset hands-off threshold value, and sending an alarm message to remind a driver that the hands-off time is too long, which may cause a safety accident.
Although the description above has been made with the steering wheel including three touch detection areas and one touch detection sensor per detection area, it should be understood that the steering wheel touch detection method of the embodiments of the present disclosure is not limited thereto.
The steering wheel touch detection method of the embodiments of the present disclosure may be applied to a case where at least one touch detection area is included for a steering wheel and each detection area includes a plurality of touch detection sensors, and in this case, for the plurality of touch detection sensors in each touch detection area, a touch detection state of the touch detection area, that is, whether the touch detection area is in a hands-off state or a hands-off state, may be determined using the steering wheel touch detection method of the embodiments of the present disclosure. That is, a plurality of reference signals having the same number of touch detection sensors in the touch detection area and different pre-selected frequencies respectively are applied to the plurality of touch detection sensors in the touch detection area; then, determining a touch detection state of the touch detection area based on the touch detection signal of each of the plurality of touch detection sensors within the touch detection area at each of the plurality of reference signals; then, the touch detection state of the steering wheel is determined based on the detection result of each touch detection area, which may be performed according to the following rule: (1) When the touch detection states of all the touch detection areas are in the hands-off state, determining that the touch detection state of the steering wheel is in the hands-off state; (2) When the states of all the touch detection areas are in the hand-not-off state, or when the state of at least one touch detection area is in the hand-not-off state and the touch detection states of other touch detection areas are in the hand-off state, determining that the touch detection state of the steering wheel is in the hand-not-off state; (3) In the case where the touch detection state of the at least one touch detection area cannot be determined because the at least one frequency is marked as the interfered frequency, it is considered that the touch detection state of the steering wheel cannot be determined, in which case the marked interfered frequency may be updated using a new frequency that has not been used for a predetermined period of time as previously described, and the next detection cycle may be performed using the updated preselected frequency; as an alternative to (3) herein, it may also be considered that (4) when at least one frequency is marked as a disturbed frequency, a most numerous touch detection state presented by each touch detection sensor may be selected as the touch detection state of the touch detection sensor according to a minority majority-compliant principle. Further, in this case, when a plurality of touch detection sensors are arranged in each touch detection area, the state of the touch detection area in which the plurality of touch detection sensors are located may be determined according to the touch detection states of the plurality of touch detection sensors, and then the touch detection state of the steering wheel may be finally determined according to the touch detection state of each touch detection area.
Further, in the case where a plurality of touch detection areas each including a plurality of touch detection sensors are provided, the number of touch detection sensors in each touch detection area may be the same or different. In the case where the number of touch detection sensors in each touch detection area is the same, the same preselected frequency may be applied to each touch detection area. In the case where the number of touch detection sensors in each touch detection area is different, a different frequency may be applied to each touch detection area.
As described above, according to the steering wheel touch detection method of the embodiment of the present disclosure, by applying reference signals of different frequencies to respective touch detection sensors in a steering wheel without overlapping in time by using a time-division frequency hopping technique, and determining a touch detection state of the steering wheel based on touch detection states sensed by the respective touch detection sensors at the respective reference signals of the respective frequencies, reliability of touch detection of the steering wheel is improved. Meanwhile, by marking the interfered frequency and excluding the interfered frequency in the detection process, the adverse effect of EMC on the touch detection result can be reduced. Moreover, the alarm message is sent out when the time of judging the hands-off state exceeds the preset hands-off threshold value, so that safety accidents are favorably avoided, and the HOD function can play an expected effect.
The exemplary embodiments of the present disclosure described in detail above are merely illustrative, and not restrictive. It will be appreciated by those skilled in the art that various modifications and combinations of these embodiments or features thereof may be made without departing from the principles and spirit of the disclosure, and that such modifications are intended to be within the scope of the disclosure.
Claims (19)
1. A method for steering wheel touch detection, wherein the steering wheel includes a plurality of touch detection sensors, the method comprising:
generating a plurality of reference signals in one-to-one correspondence with a plurality of preselected frequencies, wherein the number of the plurality of touch detection sensors is the same as the number of the plurality of reference signals;
for each of the plurality of reference signals,
applying them to respective ones of the plurality of touch detection sensors without overlapping in time, wherein each touch detection sensor modulates its applied reference signal to produce a corresponding modulated signal; and
detecting a modulation signal generated by each of the plurality of touch detection sensors and demodulating the modulation signal to obtain a touch detection signal of each of the plurality of touch detection sensors under the reference signal; and
determining a touch detection state of the steering wheel based on the touch detection signal of each of the plurality of touch detection sensors at each of the plurality of reference signals.
2. The method of claim 1, wherein determining the touch detection state of the steering wheel comprises:
for each touch detection sensor of the plurality of touch detection sensors, determining a touch detection state of the touch detection sensor at a respective reference signal of the plurality of reference signals based on a touch detection signal of the touch detection sensor at the respective reference signal;
for each touch detection sensor of the plurality of touch detection sensors, determining a touch detection state of the touch detection sensor based on a touch detection state of the touch detection sensor at the respective reference signal; and
determining a touch detection state of the steering wheel based on a touch detection state of each of the plurality of touch detection sensors.
3. The method of claim 2, wherein the first and second light sources are selected from the group consisting of,
wherein the touch detection state includes at least an out-of-hand state, and
wherein the touch detection state of the steering wheel is determined to be a hands-off state in a case where the touch detection states of the plurality of touch detection sensors are all hands-off states.
4. The method of claim 3, wherein determining, for each of the plurality of touch detection sensors, a touch detection state of the touch detection sensor based on the touch detection signal of the touch detection sensor at a respective one of the plurality of reference signals comprises:
determining that the touch detection state of the touch detection sensor is an out-of-hand state under the condition that the touch detection states of the touch detection sensor under the reference signals are all out-of-hand states;
determining that the touch detection state of the touch detection sensor is the hand-not-off state under the condition that the touch detection states of the touch detection sensor under the reference signals are the hand-not-off states; and
and in the case that the touch detection states of the touch detection sensors under the reference signals are inconsistent, marking the frequency of at least one part of the reference signals as an interfered frequency.
5. The method of claim 4, further comprising:
updating the plurality of preselected frequencies by replacing the interfered frequency with a new frequency that has not been used for a predetermined period of time, if the frequency of at least a portion of the plurality of reference signals is marked as an interfered frequency; and
generating a plurality of updated reference signals in one-to-one correspondence with the plurality of updated preselected frequencies, and determining a touch detection state of the steering wheel based on the plurality of updated reference signals.
6. The method of claim 4, further comprising:
updating the plurality of preselected frequencies by replacing one or more of the plurality of preselected frequencies with a new frequency that has not been used for a predetermined period of time if it is determined that the touch detection state of the touch detection sensor is an out-of-hand state or an out-of-hand state; and
generating a plurality of updated reference signals in one-to-one correspondence with the plurality of updated preselected frequencies, and determining a touch detection state of the steering wheel based on the plurality of updated reference signals.
7. The method of claim 2, wherein the touch detection signals comprise capacitance values and/or resistance values, wherein detecting and demodulating the modulated signals generated by each of the plurality of touch detection sensors to obtain the touch detection signals of each of the plurality of touch detection sensors at the reference signal comprises:
performing IQ demodulation on the modulation signal to obtain a capacitance value and/or a resistance value sensed by each touch detection sensor in the plurality of touch detection sensors.
8. The method of claim 6, wherein determining a touch detection state of the touch detection sensor at each of the plurality of reference signals based on the touch detection signal of the touch detection sensor at the respective reference signal comprises:
comparing the capacitance value and/or the resistance value of the touch detection sensor under each reference signal with a preset threshold value to determine a touch detection state of the touch detection sensor under each reference signal.
9. The method of claim 1, wherein generating a plurality of reference signals in one-to-one correspondence with a plurality of preselected frequencies and applying, for each of the plurality of reference signals, to each of the plurality of touch detection sensors without overlapping in time comprises:
sequentially selecting each of the plurality of touch detection sensors; and
for a selected touch detection sensor, a plurality of reference signals corresponding one-to-one to a plurality of preselected frequencies are sequentially generated and applied.
10. The method of claim 1, wherein generating a plurality of reference signals in one-to-one correspondence with a plurality of preselected frequencies and applying, for each of the plurality of reference signals, to each of the plurality of touch detection sensors without overlapping in time comprises:
sequentially selecting each of the plurality of preselected frequencies and generating a reference signal corresponding to the preselected frequency; and
for the generated reference signal, it is sequentially applied to each of the plurality of touch detection sensors.
11. An apparatus for steering wheel touch detection, the steering wheel including a plurality of touch detection sensors, the apparatus comprising:
a signal generator configured to generate a plurality of reference signals in one-to-one correspondence with a plurality of preselected frequencies and apply, for each of the plurality of reference signals, to a respective one of the plurality of touch detection sensors without temporal overlap, wherein each touch detection sensor modulates the reference signal to which it is applied to produce a corresponding modulated signal, wherein the number of the plurality of touch detection sensors is the same as the number of the plurality of reference signals;
a signal detector configured to detect a modulated signal generated by each of the plurality of touch detection sensors and demodulate the modulated signal to obtain a touch detection signal of each of the plurality of touch detection sensors at the reference signal; and
a signal processor configured to determine a touch detection state of the steering wheel based on touch detection signals of respective ones of the plurality of touch detection sensors at respective ones of the plurality of reference signals.
12. The apparatus of claim 11, wherein the signal processor determines the touch detection state of the steering wheel by:
for each touch detection sensor of the plurality of touch detection sensors, determining a touch detection state of the touch detection sensor at a respective reference signal of the plurality of reference signals based on a touch detection signal of the touch detection sensor at the respective reference signal;
for each touch detection sensor of the plurality of touch detection sensors, determining a touch detection state of the touch detection sensor based on a touch detection state of the touch detection sensor at the respective reference signal; and
determining a touch detection state of the steering wheel based on a touch detection state of each of the plurality of touch detection sensors.
13. The apparatus as set forth in claim 12, wherein,
wherein the touch detection state includes at least an out-of-hand state, and
the signal processor determines that the touch detection state of the steering wheel is the hands-off state when the touch detection states of the plurality of touch detection sensors are all the hands-off states.
14. The device of claim 13, wherein, for each of the plurality of touch detection sensors, the signal processor:
determining that the touch detection state of the touch detection sensor is an out-of-hand state under the condition that the touch detection states of the touch detection sensor under the reference signals are all out-of-hand states;
determining that the touch detection state of the touch detection sensor is the hand-not-off state under the condition that the touch detection states of the touch detection sensor under the reference signals are the hand-not-off states; and
and in the case that the touch detection states of the touch detection sensors under the reference signals are inconsistent, marking the frequency of at least one part of the reference signals as an interfered frequency.
15. The apparatus of claim 14, wherein,
the signal generator is further configured to:
updating the plurality of preselected frequencies by replacing the interfered frequency with a new frequency that has not been used for a predetermined period of time, if the signal processor marks the frequencies of at least a portion of the plurality of reference signals as interfered frequencies; and
generating a plurality of updated reference signals in one-to-one correspondence with the plurality of updated preselected frequencies;
the signal processor is further configured to determine a touch detection state of the steering wheel based on the updated plurality of reference signals.
16. The apparatus of claim 14, wherein,
the signal generator is further configured to:
updating the plurality of preselected frequencies by replacing one or more of the plurality of preselected frequencies with a new frequency that has not been used for a predetermined period of time if the signal processor determines that the touch detection state of the touch detection sensor is an out-of-hand state or an unused out-of-hand state; and
generating a plurality of updated reference signals in one-to-one correspondence with the plurality of updated preselected frequencies;
the signal processor is further configured to determine a touch detection state of the steering wheel based on the updated plurality of reference signals.
17. The apparatus as set forth in claim 12, wherein,
wherein the touch detection signal includes a capacitance value and/or a resistance value,
wherein the signal detector comprises an IQ demodulation unit configured to IQ demodulate the modulated signal to obtain the sensed capacitance and/or resistance values of each of the plurality of touch detection sensors.
18. The apparatus of claim 16, wherein the signal processor is configured to determine the touch detection state of the touch detection sensor at each reference signal by comparing the capacitance and/or resistance values of the touch detection sensor at each reference signal to a preset threshold.
19. The apparatus of claim 11, wherein the signal generator comprises:
a frequency selection unit configured to select the plurality of preselected frequencies;
a signal generation unit configured to sequentially generate a plurality of reference signals in one-to-one correspondence with a plurality of preselected frequencies; and
a sensor selection unit configured to sequentially select each of the plurality of touch detection sensors to which the plurality of reference signals are to be applied.
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| PCT/CN2022/091916 WO2022237761A1 (en) | 2021-05-10 | 2022-05-10 | Touch detection device and method for steering wheel |
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| CN101638072B (en) * | 2009-08-25 | 2011-06-08 | 武汉理工大学 | Device and method for monitoring and early warning of driving without hands |
| US8548667B2 (en) * | 2011-12-15 | 2013-10-01 | Steering Solutions Ip Holding Corporation | Hands on steering wheel detect in lane centering operation |
| US9552069B2 (en) * | 2014-07-11 | 2017-01-24 | Microsoft Technology Licensing, Llc | 3D gesture recognition |
| EP3601002B1 (en) * | 2017-03-20 | 2024-03-20 | Neonode Inc. | Touch sensor systems and methods for vehicles |
| US10589664B2 (en) * | 2017-09-11 | 2020-03-17 | Stanislav D. Kashchenko | System and method for automatically activating turn indicators in a vehicle |
| CN111811829B (en) * | 2020-06-18 | 2022-10-28 | 深圳市周立功单片机有限公司 | Steering wheel hands-off detection device and method |
| CN111741264A (en) * | 2020-06-22 | 2020-10-02 | 漳州龙文维克信息技术有限公司 | Vehicle-mounted terminal and internet-based driving monitoring method |
| CN112684507B (en) * | 2020-12-17 | 2024-06-04 | 广州立功科技股份有限公司 | Automobile steering wheel hand-off detection system and method |
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2021
- 2021-05-10 CN CN202110505480.7A patent/CN115328340A/en active Pending
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2022
- 2022-05-10 WO PCT/CN2022/091916 patent/WO2022237761A1/en active Application Filing
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| Publication number | Publication date |
|---|---|
| WO2022237761A1 (en) | 2022-11-17 |
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