A method for detecting when a steering wheel is removed from hands, a storage medium, and an electronic device.

Abstract

This application provides a steering wheel hands-off detection method, storage medium, and electronic device, including: monitoring the capacitance value of a heating coil installed on the steering wheel; calculating the capacitance value change curve of the heating coil based on the capacitance value; and determining whether the driver's hands have left the steering wheel based on the capacitance value change curve. This application's solution achieves cost reduction and structural simplification through integrated reuse of the heating coil. Furthermore, the mechanical performance and service life of the original heating coil are superior to traditional mechanical pressure sensors, and the capacitance value monitoring is performed in real time, providing immediacy. Additionally, since this application's solution does not require additional components, it will not affect the internal structure and tactile feel of the current steering wheel.

Description

Technical Field

[0001] This application relates to the field of intelligent vehicle steering wheel hands-off detection technology, specifically to a steering wheel hands-off detection method, storage medium, and electronic device. Background Technology

[0002] Hands-Off Detection (HOD) is a key technology in Advanced Driver Assistance Systems (ADAS) and autonomous driving functions. It determines whether the driver is holding the steering wheel to ensure timely takeover of vehicle control when necessary. Currently, hands-off detection technology mainly includes the following solutions:

[0003] Capacitive sensor solution: This solution detects the driver's hand approaching or touching the steering wheel by embedding a capacitive sensor array within the steering wheel. This solution has the following main problems: high cost, requiring additional capacitive sensors and increasing hardware costs; and the capacitive sensor array needs to be integrated under the steering wheel surface, affecting the steering wheel's aesthetics and tactile feel.

[0004] Pressure sensor solution: A mechanical pressure sensor is installed in the steering wheel grip area to determine hand position based on pressure signals. This solution has the following main problems: the mechanical sensor needs to evenly cover the circumference of the steering wheel, leading to complex wiring; the mechanical pressure sensor is prone to sensitivity decrease due to aging or fatigue; it cannot distinguish grip strength, and a light touch may be misinterpreted as a valid grip, affecting safety.

[0005] Torque sensor-assisted solution: This solution uses torque fluctuations in the electric power steering system to determine whether the driver has intervened. This solution has the following main problems: it requires the driver to actively apply torque to trigger the detection, making it impossible to determine the driver's hands-off status in real time; additionally, it may generate interference signals when the vehicle is bumpy or when the lane-keeping assist function is activated.

[0006] Therefore, there is still room for improvement in the existing steering wheel hands-off detection technology. Summary of the Invention

[0007] The technical problem to be solved by this application is that existing steering wheel hands-off detection technologies suffer from high hardware costs, limited installation, insufficient reliability, and untimely response. Therefore, this application provides a steering wheel hands-off detection method, storage medium, and electronic device.

[0008] Firstly, the technical solution of this application provides a method for detecting when a steering wheel is removed from hands, including: Monitor the capacitance value of the heating coil installed on the steering wheel; Calculate the capacitance change curve of the heating coil based on the capacitance value of the heating coil; The driver's hands are determined based on the capacitance change curve of the heating coil.

[0009] In some solutions, the method for detecting whether the driver's hands have left the steering wheel, which involves determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil, includes: If the capacitance value change curve indicates that the capacitance value is rising, the rising rate reaches a first threshold, and the rising duration reaches a preset time threshold, then it is determined that the driver's hand is in contact with the steering wheel.

[0010] In some solutions, the method for detecting whether the driver's hands have left the steering wheel, which involves determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil, includes: If the capacitance value change curve indicates that the capacitance value is decreasing, the rate of decrease reaches a second threshold, and the duration of decrease reaches a preset time threshold, then it is determined that the driver's hands have left the steering wheel.

[0011] In some solutions, the method for detecting whether the driver's hands have left the steering wheel, which involves determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil, further includes: Monitor the steering wheel temperature and adaptively adjust the values ​​of the first threshold and the second threshold based on the steering wheel temperature.

[0012] In some solutions, the method for detecting whether the driver's hands have left the steering wheel, after determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil, further includes: If the driver's hand is in contact with the steering wheel is determined based on the capacitance value change curve of the heating coil, then wavelet decomposition is performed on the monitored capacitance value of the heating coil. Based on the results of the wavelet decomposition, it is determined whether the driver's contact with the steering wheel is a valid grip signal; If the driver's contact with the steering wheel is not a valid grip signal, a warning signal will be issued.

[0013] In some solutions, the method for detecting steering wheel hand-off involves a wavelet decomposition with six layers. The step of determining whether the driver's contact with the steering wheel constitutes a valid grip signal based on the wavelet decomposition results includes: Calculate the energy of the fourth level detail coefficients Ed4, the fifth level detail coefficients Ed5, and the sixth level detail coefficients Ed6 of the wavelet decomposition results; When Ed4 / Ed5∈[0.8,1.2] and Ed5>3×Ed6, it is determined to be a valid hold signal.

[0014] In some solutions, the method for detecting whether the driver's hands have left the steering wheel, after determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil, further includes: If the driver's hand leaves the steering wheel based on the capacitance change curve of the heating coil, a warning signal is issued to remind the driver.

[0015] Secondly, the present application provides a computer-readable storage medium storing program information, wherein a computer reads the program information and executes the steps of the steering wheel off-hand detection method described in any one of the first aspects.

[0016] Thirdly, the present application provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the steering wheel off-hand detection method as described in any of the first aspects.

[0017] Fourthly, the present application provides an electronic device, including a memory, a processor, and a computer program stored in the memory. The electronic device is disposed in the gear shift of a vehicle, and the processor executes the computer program to implement the steps of the steering wheel off-hand detection method as described in any of the first aspects.

[0018] The technical solution provided in this application has the following technical effects compared with the prior art: The steering wheel hands-off detection method, storage medium, and electronic device provided in this application directly utilize the existing heating coil on the steering wheel as a capacitance sensor. By monitoring the capacitance value of the heating coil, the capacitance change curve is calculated, and the driver's hand is determined to have left the steering wheel based on this curve. This application's solution reduces costs and simplifies the structure through integrated reuse of the heating coil. Furthermore, the mechanical performance and lifespan of the existing heating coil are superior to traditional mechanical pressure sensors, and the capacitance monitoring is real-time, providing instantaneous detection. Additionally, since this application's solution requires no additional components, it does not affect the internal structure or tactile feel of the existing steering wheel. Attached Figure Description

[0019] Figure 1 This is a flowchart of a steering wheel hands-off detection method according to one embodiment of this application; Figure 2 This is a flowchart illustrating, in one embodiment of this application, a method for determining whether the driver's hand has left the steering wheel based on the capacitance change curve of the heating coil; Figure 3 This is a schematic diagram of the capacitance change curve of the heating coil described in one embodiment of this application when the driver's hand touches the steering wheel; Figure 4 This is a schematic diagram of the steering wheel hands-off detection circuit according to one embodiment of this application; Figure 5This is a schematic diagram of the hardware connections of an electronic device that performs the steering wheel off-hand detection method according to an embodiment of this application. Detailed Implementation

[0020] The specific embodiments of this application will be further described below with reference to the accompanying drawings.

[0021] It is readily understood that, based on the technical solution of this application, various structural and implementation methods can be interchanged by those skilled in the art without altering the essential spirit of this application. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this application and should not be considered as the entirety of this application or as limitations or restrictions on the technical solution of the application.

[0022] This embodiment provides a steering wheel hands-off detection method, applied in a control device, preferably disposed in a shift knob, the method comprising: S100: Monitors the capacitance value of the heating coil installed on the steering wheel.

[0023] In this step, the capacitance value of the steering wheel heating coil is collected in real time. The heating coil is usually made of metal wire. When the driver's hand touches or approaches the steering wheel, capacitive coupling is formed between the coil and the hand due to the influence of the human body's dielectric constant, causing the capacitance value to change.

[0024] The steering wheel originally contained a heating coil for heating. The heating coil was made of an alloy material with high conductivity and good heat resistance, such as a nickel-chromium alloy. This material not only effectively heats the steering wheel but also ensures the sensitivity and accuracy of capacitance detection.

[0025] A capacitance sensor, such as an LCR capacitance tester, is used to monitor the capacitance value of the heating coil. The capacitance sensor is integrated into the gearshift and electrically connected to the heating coil via a wire. When the heating coil is working, it is energized, and the LCR capacitance tester can measure its capacitance value. In situations with high ambient temperatures where steering wheel heating is not required, this application controls the heating coil to intermittently switch on and off according to a set cycle. This ensures that the LCR capacitance tester accurately monitors the capacitance value and prevents the detection signal from failing due to high impedance when the heating coil is not in heating mode.

[0026] S200: Calculate the capacitance change curve of the heating coil based on the capacitance value of the heating coil.

[0027] In this step, based on continuously monitored capacitance values, signal processing techniques such as filtering and noise reduction are used to plot a curve showing the change of capacitance value over time. This curve reflects the dynamic trend of capacitance change and may include characteristics such as amplitude, slope, and fluctuation frequency.

[0028] S300: Determine whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil.

[0029] The controller is responsible for receiving capacitance data, analyzing capacitance change curves, and determining whether a driver's hand has left the steering wheel. The controller also communicates with the alarm module and other vehicle systems. The core technical principle of this embodiment is to use the capacitance change of the existing heating coil inside the steering wheel to detect whether the driver's hand has left the steering wheel. When the driver grips the steering wheel, their hand is close to the heating coil, forming an additional capacitance between the human body and the heating coil, causing an increase in the total capacitance of the entire circuit. That is, the heating coil can be considered as one electrode, the driver's hand as another electrode, and together with the leather layer of the steering wheel, they constitute a variable capacitor. When the driver's hand is on the wheel: a capacitance path is formed between the coil, the leather layer, and the hand, and the total capacitance value detected by the system increases significantly. When the driver's hand leaves the wheel: this additional capacitance formed by the human body disappears, and the capacitance value detected by the system returns to its baseline value. Therefore, by monitoring the change in capacitance value in real time, it is possible to accurately determine whether the driver has left the wheel.

[0030] The above-described solution in this embodiment directly utilizes the existing heating coil on the steering wheel as a capacitance sensor. It calculates the capacitance change curve of the heating coil by monitoring its capacitance value, and determines whether the driver's hand has left the steering wheel based on this curve. This solution reduces costs and simplifies the structure by integrating and reusing the heating coil. Furthermore, the mechanical performance and lifespan of the existing heating coil are superior to traditional mechanical pressure sensors, and the capacitance monitoring is real-time, providing instantaneous monitoring. Additionally, since this solution requires no additional components, it does not affect the internal structure or tactile feel of the existing steering wheel.

[0031] In actual measurement, the difference between the baseline value and the detected value can be used to determine whether a hand is on the steering wheel. That is, the controller records the reference capacitance value of the heating coil in the "handless state" at the factory or during startup, and then determines a capacitance change threshold based on the results of calibration tests. When the detected capacitance value continuously exceeds the threshold for a certain period of time, it is determined that the hand is on the steering wheel; otherwise, it is determined that the hand is off the steering wheel.

[0032] Preferably, in this embodiment of the application, the driver's hands are determined to be on the steering wheel in the following manner: Figure 2 As shown, it includes: S301: If the capacitance value change curve indicates that the capacitance value is rising, the rising rate reaches a first threshold and the rising duration reaches a preset time threshold, then it is determined that the driver's hand is in contact with the steering wheel.

[0033] In practical applications, the capacitance value of the heating coil is acquired at 0.1-second intervals. The acquired capacitance signal is converted into a digital signal by an analog-to-digital converter and transmitted to the controller. The controller filters the capacitance data to eliminate the influence of environmental noise and sensor noise, resulting in a stable capacitance change curve.

[0034] like Figure 3 As shown, when the driver grips the steering wheel, their hand approaches the heating coil, causing the capacitance value to rise. The capacitance change curve indicates that when the rate of increase in capacitance value reaches a first threshold (e.g., +5% / 0.1s) and continues for at least ten detection cycles, it is determined that the driver is performing the operation of gripping the steering wheel.

[0035] S302: If the capacitance value change curve indicates that the capacitance value is decreasing, the rate of decrease reaches the second threshold, and the duration of decrease reaches the preset time threshold, then it is determined that the driver's hand is off the steering wheel.

[0036] When the driver's hands leave the steering wheel, the effect of the proximity of the hands is removed, and the capacitance value gradually decreases. The capacitance value change curve represents the decrease in capacitance value. When the rate of decrease reaches a second threshold (e.g., -5% / 0.1s) and continues for at least ten detection cycles, it is determined that the driver has removed their hands.

[0037] Figure 3 A schematic diagram is provided showing the capacitance change curves when the driver holds the steering wheel with one or both hands at different positions. The capacitance value circled in red increases, and both the duration and rate of increase meet the judgment criteria, corresponding to the driver's hand holding the steering wheel. When the driver's hands complete the holding action or completely remove them from the steering wheel, the detected capacitance value tends to stabilize.

[0038] This application's solution effectively filters out misjudgments caused by accidental triggering scenarios such as bumps and slight steering wheel touches by using a dual determination of the rate of change in capacitance value and duration.

[0039] Furthermore, in the above scheme, determining whether the driver's hand has left the steering wheel based on the capacitance change curve of the heating coil further includes: monitoring the steering wheel temperature and adaptively adjusting the values ​​of the first threshold and the second threshold according to the steering wheel temperature. Specifically, an NTC temperature sensor (installed on the inner side of the steering wheel rim) can be used to monitor the steering wheel temperature. By monitoring the steering wheel temperature in real time, the first and second thresholds can be dynamically adjusted to counteract the interference of temperature changes on the accuracy of capacitance detection.

[0040] In practical applications, the steering wheel temperature can be divided into multiple intervals, with a preset threshold adjustment coefficient for each interval. The original threshold is then corrected using this coefficient. In addition to adjusting the thresholds, the capacitance reference value can be simultaneously corrected based on the temperature, establishing a temperature-reference value calibration curve. Before the vehicle leaves the factory, the ungripped capacitance values ​​of the heating coil at different temperatures are tested using high and low temperature tests, generating a calibration database. Based on the current temperature, the corresponding reference value is retrieved from the database to replace the initial calibration, further eliminating the influence of temperature drift. This solution, employing the above adaptive threshold adjustment, achieves higher detection accuracy.

[0041] Preferably, after determining whether the driver's hand has left the steering wheel based on the capacitance change curve of the heating coil, the method further includes: S3011: If it is determined from the capacitance value change curve of the heating coil that the driver's hand is in contact with the steering wheel, then the monitored capacitance value of the heating coil is decomposed by wavelet decomposition. S3012: Determine whether the driver's contact with the steering wheel is a valid grip signal based on the wavelet decomposition result; specifically, this includes: calculating the energy of the fourth level detail coefficient Ed4, the energy of the fifth level detail coefficient Ed5, and the energy of the sixth level detail coefficient Ed6 of the wavelet decomposition result; when Ed4 / Ed5∈[0.8, 1.2] and Ed5>3×Ed6, it is determined to be a valid grip signal.

[0042] S3013: If the driver's contact with the steering wheel is not a valid grip signal, a warning signal is issued.

[0043] The above scheme analyzes the capacitance change curve using wavelet decomposition to distinguish between valid grip signals and invalid interference signals (such as fingertip touch, foreign object scraping, steering wheel vibration, etc.), further reducing the false judgment rate and improving the system's detection reliability. The principle is that the capacitance change from valid grip is a low-frequency steady-state signal, while invalid interference is a high-frequency transient signal. Wavelet decomposition can accurately extract this difference feature through multi-scale frequency domain analysis. When the system determines that the driver's hand is in contact with the steering wheel based on basic logic, it triggers the wavelet decomposition process, extracting capacitance data (10 collection points, 0.1-second interval) for a certain period before the trigger determination time, forming the capacitance change sub-curve to be analyzed. The DB4 wavelet is selected as the decomposition basis function, which can effectively separate low-frequency steady-state signals from high-frequency interference signals and is adapted to the signal characteristics of the in-vehicle environment. A 6-level wavelet decomposition is performed on the capacitance change sub-curve to obtain 6 levels of approximation coefficients A1. A6 (for low-frequency signals) and 6 layers of detail D1 D6 (corresponding to high-frequency signals). The energy of the detail factor reflects the fluctuation intensity of the signal within the corresponding frequency range. The energy calculation formula is: ; This represents the energy of the detail coefficients at the k-th layer; This represents the i-th data point of the detail coefficient at the k-th level, and n represents the number of data points for the detail coefficient.

[0044] Among them, the fourth layer of detail coefficients mainly corresponds to low-to-mid frequency interference (such as capacitance fluctuations caused by slight hand tremors); the fifth layer of detail coefficients mainly corresponds to the steady-state characteristic frequency of effective grip; and the sixth layer of detail coefficients mainly corresponds to high-frequency noise (such as electromagnetic interference and steering wheel vibration). When Ed4 / Ed5∈[0.8, 1.2], it indicates that the energy of low-to-mid frequency fluctuations is comparable to that of the steady-state characteristic of grip, which is consistent with the signal characteristics of stable hand contact with the steering wheel; if the ratio is too large, it indicates severe hand tremors (ineffective grip); if the ratio is too small, it indicates that the signal is too flat (possibly due to slow contact with foreign objects). Ed5>3×Ed6 indicates that the steady-state characteristic energy of effective grip is much greater than the energy of high-frequency noise, ruling out false triggering caused by factors such as electromagnetic interference and vibration.

[0045] Furthermore, the above solution also includes issuing a warning signal to remind the driver if the driver's hand leaves the steering wheel based on the capacitance change curve of the heating coil. This solution can remind the driver through audible alarms (such as a buzzer) and visual cues (such as flashing LED indicators on the steering wheel). Simultaneously, the system can be linked to the vehicle's automated driving assistance functions, such as Lane Keeping Assist System (LKAS), to ensure vehicle driving safety.

[0046] The reliability of the solutions in the above embodiments of this application was verified through experiments. The environmental test conditions were as follows: Temperature range: -40℃~105℃ (Incubator model: Weiss WK11-340); Humidity range: 20%~95%RH (refer to IEC 60068-2-30); Data acquisition equipment: Keysight 34461A digital multimeter; Real-time signal analysis: NI PXIe-5171R high-speed acquisition card; Statistical methods: False positive rate calculation: Number of false alarms / Total number of samples (sample size N=10) 5 ); Delay time measurement: the time difference from when the hand leaves the steering wheel to when the system outputs a signal (laser displacement sensor calibration).

[0047] The results are as follows: (1) Reliability: Extreme environment test: At a low temperature of -30℃ (heating wire resistance drift rate ±15%) and a high temperature of 85℃, the false detection rate is <0.5%, while the false detection rate of capacitive sensors reaches 5%-8% (test standard: ISO 11452-2).

[0048] Long-term durability: After 100,000 grip cycles, the detection sensitivity decreases by less than 3%, which is better than pressure sensors (typical attenuation rate >10%). (2) Real-time performance and compatibility optimization Real-time performance verification: In a lane keeping scenario at 60km / h, the average response delay of this invention is 35ms (test equipment: DSPACE SCALEXIO), while the average delay of the torque sensor-assisted solution is 200ms.

[0049] Compatibility verification: Successfully connected to the CAN bus of a certain vehicle model (baud rate 500kbps), communication error rate <10. -6 .

[0050] (3) User experience Effect Description: No visible sensors are needed on the steering wheel surface, maintaining the original tactile feel and aesthetics. User Survey Data: In a blind test with 100 participants, 92% felt that the steering wheel grip of this invention was no different from that of a regular steering wheel, while the satisfaction rate for the capacitive solution was only 65% ​​(due to the unevenness of the surface).

[0051] Comparative tests show that, under the same functional requirements, the solution of this invention reduces costs by approximately 95% compared to capacitive sensors. Production line modification costs are reduced by more than 80% (no need to add steering wheel molds or wiring processes).

[0052] This application provides a computer-readable storage medium storing program information. After reading the program information, the computer executes the steps of the steering wheel off-hand detection method described in any of the above embodiments.

[0053] This application provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps of the steering wheel off-hand detection method described in any of the above embodiments.

[0054] like Figure 4 The diagram shown is a circuit diagram of a steering wheel hands-off detection method according to an embodiment of this application. It includes the following functional modules: (1) Power module 5Vinm power supply (NCV33269DTRK5.0G): Responsible for converting the vehicle's 12V battery voltage to 5V to power the core components of the system; 3.3V LDO (NCV33260DTRK3.3G): Converts 5V to 3.3V to power low-voltage devices such as MCUs, ensuring power supply stability.

[0055] (2) Core control module: MCU (S32K116) Used for all data processing and logical decisions: Input interface: Receives button input (can be used for system settings) and the capacitance value of the steering wheel heating coil (via HOD module); Output interfaces: control RGB LEDs (status indicator lights) and OLED display (display system status); Core functions: Execute algorithms such as capacitance data acquisition, filtering, wavelet decomposition, effective grip determination, and temperature adaptive threshold adjustment.

[0056] (3) HOD module + 74HC125 HOD module (Hand-On-Detection): This is the steering wheel hands-off detection module, which is electrically connected to the steering wheel heating coil and internally contains the device responsible for collecting data on the heating coil capacitance. 74HC125: Level conversion chip, responsible for converting the signal output from the HOD module into an MCU-compatible level, realizing signal adaptation between the sensor and the MCU.

[0057] (4) Auxiliary system linkage ADAS (Advanced Driver Assistance System): Communicates with the MCU via the TJA1044 interface (a commonly used in-vehicle communication interface), receives the hands-off judgment result, and links functions such as lane keeping assist (LKAS) and adaptive cruise control (ACC); Assistance system + OLED display: OLED is used to display system status (such as valid grip, hand-off warning), and the assistance system is the functional extension carrier of ADAS.

[0058] This application embodiment also provides an electronic device, which is disposed in the vehicle's column shifter, such as... Figure 5As shown, the electronic device includes at least one processor 51 and at least one memory 52. ​​The at least one memory 52 stores program information. After reading the program information, the at least one processor 51 executes the steering wheel hands-off detection method described in any of the above method embodiments. The device may further include an input device 53 and an output device 54. The processor 51, memory 52, input device 53, and output device 54 can be communicatively connected. The memory 52, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The processor 51 executes various functional applications and data processing by running the non-volatile software programs, instructions, and modules stored in the memory 52, thereby implementing the steering wheel hands-off detection method provided in any of the above embodiments. The memory 52 may include a program storage area and a data storage area. The program storage area may store the operating system and at least one application program required for a function; the data storage area may store data created based on the use of the steering wheel hands-off detection method, etc. Furthermore, memory 52 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 52 may optionally include memory remotely located relative to processor 51, and these remote memories may be connected via a network to the apparatus performing the hands-off steering wheel detection method. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof. Input device 53 may receive user clicks and generate signal inputs related to user settings and function control of the hands-off steering wheel detection method. Output device 54 may include a display device such as a display screen. When the one or more modules are stored in memory 52 and are executed by the one or more processors 51, the hands-off steering wheel detection method in any of the above method embodiments is performed.

[0059] As needed, the above technical solutions can be combined to achieve the best technical effect.

[0060] The above are merely the principles and preferred embodiments of this application. It should be noted that, for those skilled in the art, several other modifications can be made based on the principles of this application, and these modifications should also be considered within the scope of protection of this application.

Claims

1. A method for detecting when a steering wheel is removed from the hands, characterized in that, include: Monitor the capacitance value of the heating coil installed on the steering wheel; Calculate the capacitance change curve of the heating coil based on the capacitance value of the heating coil; The driver's hands are determined based on the capacitance change curve of the heating coil.

2. The method for detecting steering wheel removal from hands according to claim 1, characterized in that, The step of determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil includes: If the capacitance value change curve indicates that the capacitance value is rising, the rising rate reaches a first threshold, and the rising duration reaches a preset time threshold, then it is determined that the driver's hand is in contact with the steering wheel.

3. The steering wheel removal detection method according to claim 2, characterized in that, The step of determining whether the driver's hands have left the steering wheel based on the capacitance change curve of the heating coil includes: If the capacitance value change curve indicates that the capacitance value is decreasing, the rate of decrease reaches a second threshold, and the duration of decrease reaches a preset time threshold, then it is determined that the driver's hands have left the steering wheel.

4. The steering wheel removal detection method according to claim 2 or 3, characterized in that, The method of determining whether the driver's hand has left the steering wheel based on the capacitance change curve of the heating coil further includes: Monitor the steering wheel temperature and adaptively adjust the values ​​of the first threshold and the second threshold based on the steering wheel temperature.

5. The steering wheel removal detection method according to claim 4, characterized in that, After determining whether the driver's hand has left the steering wheel based on the capacitance change curve of the heating coil, the method further includes: If the driver's hand is in contact with the steering wheel is determined based on the capacitance value change curve of the heating coil, then wavelet decomposition is performed on the monitored capacitance value of the heating coil. Based on the results of the wavelet decomposition, it is determined whether the driver's contact with the steering wheel is a valid grip signal; If the driver's contact with the steering wheel is not a valid grip signal, a warning signal will be issued.

6. The method for detecting steering wheel removal from hands according to claim 5, characterized in that, The wavelet decomposition has 6 levels. Determining whether the driver's contact with the steering wheel constitutes a valid grip signal based on the wavelet decomposition results includes: Calculate the energy of the fourth level detail coefficients Ed4, the fifth level detail coefficients Ed5, and the sixth level detail coefficients Ed6 of the wavelet decomposition results; When Ed4 / Ed5∈[0.8,1.2] and Ed5>3×Ed6, it is determined to be a valid hold signal.

7. The method for detecting steering wheel removal from hands according to claim 4, characterized in that, After determining whether the driver's hand has left the steering wheel based on the capacitance change curve of the heating coil, the method further includes: If the driver's hand leaves the steering wheel based on the capacitance change curve of the heating coil, a warning signal is issued to remind the driver.

8. A computer-readable storage medium, characterized in that, The storage medium stores program information, and after the computer reads the program information, it executes the steps of the steering wheel off-hand detection method according to any one of claims 1-7.

9. A computer program product, characterized in that, The method includes a computer program / instruction, characterized in that, when executed by a processor, the computer program / instruction implements the steps of the steering wheel off-hand detection method according to any one of claims 1-7.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The electronic device is disposed in the vehicle's gearshift, and the processor executes the computer program to implement the steps of the steering wheel off-hand detection method according to any one of claims 1-7.

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