Commercial vehicle steering wheel system integrated with driver state monitoring function and vehicle

Abstract

The invention relates to the field of driver state monitoring, in particular to a commercial vehicle steering wheel system integrated with a driver state monitoring function and a vehicle, and the system comprises photoelectric sensors which are embedded in a rim of a steering wheel body in a surrounding array mode; an induction electrode of the capacitance induction detection module is a heating wire integrated in the steering wheel body, and the control unit is configured to drive the heating wire to execute a heating function in a first time period in a time division multiplexing mode and work as a capacitance induction electrode in a second time period so as to detect capacitance signal change caused by hand holding of a driver; receiving a physiological signal and a capacitance signal; performing data fusion analysis on the physiological signal and the capacitance signal to cooperatively judge a hand-off state and a body state of the driver; and generating and outputting a corresponding alarm signal or a vehicle control instruction based on the result of the cooperative judgment. The system is upgraded from passive monitoring to active early warning and intervention.

Description

Technical Field

[0001] This application relates to the field of driver condition monitoring technology, specifically to a commercial vehicle steering wheel system and vehicle that integrates driver condition monitoring functions. Background Technology

[0002] In the commercial vehicle sector, prolonged driving can easily lead to driver fatigue, distraction, and even sudden health problems, which are among the main causes of traffic accidents. Therefore, real-time monitoring and timely intervention of drivers' physical condition and driving behavior have become a key technological direction for improving road safety.

[0003] Currently, several technological solutions have been developed to address this issue. The first generation of solutions primarily relies on capacitive sensing-based hand-off-steering-wheel detection systems. These systems determine whether the driver has removed their hands by detecting changes in capacitance on the steering wheel. However, this approach is susceptible to capacitance interference from external conductors near the steering wheel, leading to a high false alarm rate. To monitor the driver's physiological state, a second generation of solutions has emerged, involving the installation of independent contact or non-contact physiological monitoring devices within the vehicle's cockpit, such as independent heart rate detection contacts on the edge of the steering wheel horn cover. However, this requires the driver to consciously place their hands above specific contact points for measurement, severely interfering with normal driving and failing to achieve real-time, unobtrusive monitoring.

[0004] Therefore, there is an urgent need in this field for an integrated steering wheel system that can simultaneously and reliably monitor the driver's hands-off state and physical state without being noticed, and can make intelligent decisions and coordinate with the whole vehicle based on multi-dimensional information. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a commercial vehicle steering wheel system and vehicle that integrates driver status monitoring functionality.

[0006] In a first aspect, the present invention provides a commercial vehicle steering wheel system integrating driver status monitoring function, including a steering wheel body, a detection part and a control unit. The detection part includes a capacitive sensing detection module and multiple photoelectric sensors. The control unit is electrically connected to the photoelectric sensors and the capacitive sensing detection module. The photoelectric sensors are embedded in the rim of the steering wheel body in a surrounding array and are used to detect physiological signals, including heart rate and pulse signals, by means of reflective photoelectric principle when the driver holds the steering wheel. The sensing electrode of the capacitance sensing detection module is a heating wire integrated in the steering wheel body. The control unit is connected to the heating wire through the heating drive circuit and the capacitance detection circuit, respectively. The control unit is configured to drive the heating wire in a time-division multiplexing manner, specifically including: dividing a control cycle into a first time period and a second time period; during the first time period, the control unit controls the heating drive circuit to apply a heating voltage to the heating wire and disconnects the capacitance detection circuit; during the second time period, the control unit controls the heating drive circuit to stop heating and connects the capacitance detection circuit to sample and detect the capacitance signal of the heating wire. The control unit is also configured to: receive physiological signals and capacitance signals; perform data fusion analysis on the physiological signals and capacitance signals to collaboratively determine the driver's hands-off state and physical state; and generate and output corresponding alarm signals or vehicle control commands based on the results of the collaborative determination.

[0007] By integrating the capacitive sensing module, photoelectric sensor, and control unit into the steering wheel body, a multi-functional integrated design is achieved, reducing system complexity and cost. The photoelectric sensor and capacitive sensing module can monitor the driver's physical and hand-off states in real time, ensuring timely detection of abnormalities during driving. Through data fusion analysis, the system collaboratively judges the driver's hand-off and physical states, improving the accuracy and reliability of monitoring. Based on the collaborative judgment results, corresponding warning signals or vehicle control commands are generated and output to promptly remind the driver or take necessary control measures, improving driving safety.

[0008] The system employs reflective photoelectric principles to detect heart rate and pulse signals, improving the accuracy and reliability of the detection. The heating wire combines heating and capacitive sensing functions, and time-division multiplexing technology enhances system integration and resource utilization.

[0009] As a preferred embodiment of the technical solution of the present invention, the heating wire is divided into multiple independent capacitive sensing sections in terms of electrical connection; The capacitance detection circuit includes a multiplexer and a capacitance sensing unit. The input terminal of the multiplexer is connected to each capacitive sensing section, the output terminal of the multiplexer is connected to the sensing input terminal of the capacitive sensing unit, and the channel selection terminal of the multiplexer is controlled by the control unit. The control unit is configured to: During the first time period, the control multiplexer disconnects all channels so that the heating drive circuit can simultaneously apply heating voltage to all capacitive sensing sections. During the second time period, by controlling the multiplexer, each capacitance sensing segment is switched to be connected to the capacitance sensing unit in turn according to a preset sequence, thereby detecting the capacitance signal change of each capacitance sensing segment respectively. The control unit identifies the driver's grip pattern based on capacitance signals detected from different capacitance sensing zones. The heating wire is electrically divided into multiple independent capacitance sensing zones. The control unit determines the driver's hand position based on the capacitance signals from different sensing zones, improving the accuracy and flexibility of hand-off detection.

[0010] As a preferred embodiment of the technical solution of the present invention, the output terminal of the heating drive circuit is directly connected in parallel to all capacitive sensing sections; The control unit is further configured to: During the first time period, while enabling the heating drive circuit, the multiplexer is controlled to enter a high-impedance state or a shutdown state to physically isolate the heating drive circuit from the capacitance sensing unit; during the second time period, after disabling the heating drive circuit, the multiplexer is then controlled to perform channel switching and capacitance signal detection.

[0011] As a preferred embodiment of the technical solution of the present invention, the capacitance sensing unit is a charge amplifier circuit based on switched capacitor technology, including an operational amplifier, a feedback capacitor, a first analog switch, a second analog switch and a third analog switch; The non-inverting input of the operational amplifier is grounded, the inverting input of the operational amplifier is connected to the output of the multiplexer through the second analog switch, and the output of the operational amplifier is connected to one end of the feedback capacitor. The other end of the feedback capacitor is connected to the inverting input of the operational amplifier; The output of the multiplexer is connected to a reference voltage source via the first analog switch; The third analog switch is connected in parallel across the feedback capacitor as a reset switch.

[0012] As a preferred embodiment of the technical solution of the present invention, the control unit is configured to perform the following capacitance detection steps for each capacitance sensing segment during the second time period: SS0 controls the multiplexer to select the current capacitance sensing segment to be detected; SS1. Control the first analog switch to close, apply the reference voltage to the output of the multiplexer, thereby charging the induced capacitor formed between the currently selected capacitor sensing section and ground; SS2. Control the first analog switch to open and control the second analog switch to close, transferring the charge stored on the sensing capacitor to the feedback capacitor of the operational amplifier; the operational amplifier outputs a voltage signal proportional to the change in the sensing capacitor; SS3. Control the third analog switch to close to reset the charge on the feedback capacitor; SS4. Read the output voltage signal of the operational amplifier; SS5. Disconnect the second and third analog switches to prepare for detecting the next section.

[0013] As a preferred embodiment of the technical solution of the present invention, the control unit is configured to process the voltage signal to determine the basic hand state through the following process: a. Perform analog-to-digital conversion and digital filtering on the voltage signal output by the operational amplifier to obtain a real-time digital quantity; b. Calculate the difference ΔD between the real-time digital quantity and a preset reference digital quantity; c. Continuously compare the difference ΔD with a preset hand grip judgment threshold; d. If the current state is hand off, and ΔD is greater than the hand grip judgment threshold for more than the first stabilization time, then the basic hand state is determined to be hand grip. e. If the current state is hand-held, and the time for which ΔD is continuously less than or equal to the hand-held judgment threshold exceeds the second stabilization time, then the basic hand state is determined to be hand-off; The second stabilization time is longer than the first stabilization time.

[0014] As a preferred embodiment of the technical solution of the present invention, the control unit is further configured to perform data fusion analysis based on the basic hand state and physiological signals, specifically including: If the basic hand state is determined to be a gripping state, the analysis of the physiological signals is initiated. If the analyzed heart rate or pulse data exceeds the normal threshold range, the driver's physical state is determined to be abnormal. If the basic hand status is determined to be a hands-off state, a timer is started; if the hands-off state continues for more than a preset safe time threshold, it is determined to be a prolonged hands-off state; the driver is analyzed based on physiological signals to determine whether he is still in the seat; if it is confirmed that the driver is still in the seat, it is finally determined to be a dangerous driving state.

[0015] By fusing and analyzing capacitive and physiological signals, the system collaboratively assesses the driver's hands-off state and physical condition, improving the accuracy and reliability of the judgment. Different levels of alarm signals and vehicle control commands are generated based on different states, ensuring appropriate measures are taken in various situations to improve driving safety. The judgment logic for normal hands-off state, abnormal physical condition, and dangerous driving state is clearly defined, ensuring the system can accurately identify various situations and respond accordingly.

[0016] As a preferred embodiment of the technical solution of the present invention, the control unit is further configured to execute hierarchical alarms: When it is determined that the driver's physical condition is abnormal, a first-level alarm signal is generated. The first-level alarm signal includes displaying a warning message on the steering wheel display screen and issuing a first-level audible reminder. When a dangerous driving condition is determined, a secondary warning signal and a vehicle control command are generated. The secondary warning signal includes stronger visual and audible warnings, and the vehicle control command is used to perform operations such as limiting the power of the vehicle or turning on the hazard warning lights via the vehicle CAN bus.

[0017] As a preferred embodiment of the present invention, the system further includes a display screen embedded in the horn cover of the steering wheel body; The control unit is further configured to send the heart rate and pulse information parsed from the physiological signals, as well as the result status information of the collaborative judgment, to the display screen for real-time display. The control unit includes an embedded processor that supports two-wire Ethernet and CAN bus communication; The system is connected to the in-vehicle intelligent cockpit system via a two-wire Ethernet connection for transmitting display data; and is connected to the vehicle controller via the CAN bus for transmitting alarm signals and vehicle control commands.

[0018] The display screen embedded in the steering wheel horn cover can display the driver's heart rate, pulse information, and collaborative judgment results in real time, allowing the driver to intuitively understand their own status. The control unit supports two-wire Ethernet and CAN bus communication. It connects to the in-vehicle intelligent cockpit system via two-wire Ethernet for transmitting display data; and connects to the vehicle controller via CAN bus for transmitting alarm signals and vehicle control commands, ensuring the system's integration and scalability.

[0019] As a preferred embodiment of the present invention, the steering wheel body includes a frame, a foam layer covering the frame, and an outermost covering layer; a light-transmitting cover is provided between the sensing window of the photoelectric sensor and the inner surface of the covering layer, and an electromagnetic shielding layer formed by metal vacuum coating is provided around the photoelectric sensor.

[0020] The steering wheel body comprises a frame, a foam layer, and a covering layer. A light-transmitting cover is positioned between the sensing window of the photoelectric sensor and the inner surface of the covering layer. This rational structural design ensures that the sensor's signal transmission is not interfered with. An electromagnetic shielding layer formed by vacuum-deposited metal is placed around the photoelectric sensor, improving the sensor's anti-interference capability and ensuring the stability and accuracy of the detection signal.

[0021] The light-transmitting cover is a 0.3mm thick plexiglass plate; the photoelectric sensor uses a green LED light source, and the signal processing circuit of the photoelectric sensor includes a preamplifier for amplifying weak reflected signals.

[0022] A 0.3mm thick acrylic sheet is used as the light-transmitting cover to ensure effective light penetration while minimizing signal attenuation. A green LED light source is employed because human blood absorbs green light extensively, improving the clarity of signal feedback. The signal processing circuit includes a preamplifier to amplify weak reflected signals, improving the signal-to-noise ratio and ensuring detection accuracy.

[0023] As a preferred embodiment of the present invention, the wheel rim of the steering wheel body frame has multiple mounting grooves pre-set. The photoelectric sensor is fixed in the mounting groove by a snap-fit ​​structure, and electrical interconnection and signal transmission are achieved through a flexible circuit board pre-laid in the mounting groove.

[0024] The steering wheel's frame rim has multiple pre-set mounting grooves. Photoelectric sensors are fixed within these grooves using a snap-fit ​​mechanism, and electrical interconnection and signal transmission are achieved via a flexible circuit board, ensuring the accuracy and stability of sensor installation. This guarantees stable and reliable signal transmission without affecting the driving experience.

[0025] As a preferred embodiment of the technical solution of this invention, the control unit also transmits the driver's physiological state data, the hand-off status judgment result, and system alarm information to the cloud monitoring platform via the vehicle-mounted T-box communication module. This transmission of the driver's physiological state data, hand-off status judgment result, and system alarm information to the cloud monitoring platform via the vehicle-mounted T-box communication module enables remote monitoring and data analysis, facilitating fleet management and safety supervision.

[0026] Secondly, the present invention also provides a vehicle including the steering wheel system described in the first aspect. Integrating the steering wheel system into the vehicle not only improves the vehicle's safety and intelligence level, but also provides important support for autonomous driving and driver assistance systems, thereby enhancing the overall driving experience.

[0027] As can be seen from the above technical solutions, this application has the following advantages: It combines photoelectric physiological monitoring with capacitive hand-off detection, and through data fusion, effectively distinguishes between dangerous and normal hand-offs, significantly reducing the false alarm rate of single capacitive detection. By reusing the heating wire as the capacitive sensing electrode, the internal structure of the steering wheel is greatly simplified, saving space and cost, and improving system reliability and production assembly efficiency. The control unit performs fusion analysis based on multi-source information and outputs control commands, upgrading the system from passive monitoring to active early warning and intervention, laying a solid foundation for improving the active safety of commercial vehicles. Attached Figure Description

[0028] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 A block diagram of a system provided in an embodiment of the present invention.

[0030] Figure 2 This is a schematic diagram of the sensor installation and layout. Detailed Implementation

[0031] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0033] like Figure 1 As shown, this embodiment of the invention provides a commercial vehicle steering wheel system with integrated driver status monitoring function, including a steering wheel body, a detection part, and a control unit. The detection part includes a capacitive sensing detection module and multiple photoelectric sensors. The control unit is electrically connected to the photoelectric sensors and the capacitive sensing detection module. The photoelectric sensors are embedded in the rim of the steering wheel body in a surrounding array and are used to detect physiological signals, including heart rate and pulse signals, through reflective photoelectric principle when the driver holds the steering wheel. The sensing electrode of the capacitance sensing detection module is a heating wire integrated in the steering wheel body. The control unit is connected to the heating wire through the heating drive circuit and the capacitance detection circuit, respectively. The control unit is configured to drive the heating wire in a time-division multiplexing manner, specifically including: dividing a control cycle into a first time period and a second time period; during the first time period, the control unit controls the heating drive circuit to apply a heating voltage to the heating wire and disconnects the capacitance detection circuit; during the second time period, the control unit controls the heating drive circuit to stop heating and connects the capacitance detection circuit to sample and detect the capacitance signal of the heating wire. The control unit is also configured to: receive physiological signals and capacitance signals; perform data fusion analysis on the physiological signals and capacitance signals to collaboratively determine the driver's hands-off state and physical state; and generate and output corresponding alarm signals or vehicle control commands based on the results of the collaborative determination.

[0034] The commercial vehicle steering wheel system provided in this embodiment is suitable for commercial vehicles such as heavy-duty trucks and large buses. It can monitor the driver's status in real time and ensure driving safety. The specific structure and working method are as follows: The steering wheel body is made of a high-strength alloy frame. There are 18 sensor mounting holes (8mm in diameter and 5mm in depth) on the inner side of the frame rim. The holes are distributed in a ring along the rim, with a spacing of 20mm between adjacent holes. The frame is wrapped with a 30mm thick polyurethane foam layer, and the foam layer is covered with a black genuine leather covering layer. The frame rim is also pre-set with 3 grooves with a width of 5mm and a depth of 3mm for laying flexible circuit boards.

[0035] The photoelectric sensor uses a TI dedicated bio-front-end analog detection chip (model ADS1292) and is equipped with a 520nm green LED light source. Each sensor measures 6mm×6mm×4mm. A 10μm thick copper-nickel alloy shielding layer is applied around the sensor using a vacuum coating process to enhance its electromagnetic interference resistance. After the sensor is embedded in the pre-set holes in the foam layer, a 4mm×4mm light-transmitting hole is opened at the corresponding position in the leather covering layer. A 0.3mm thick acrylic plate is installed inside the light-transmitting hole. The acrylic plate is fixed to the foam layer by ABS plastic clips, ensuring that the distance between the sensor and the steering wheel surface (including the leather layer) is controlled at 1.5mm.

[0036] The heating wire is a 0.5mm diameter nickel-chromium alloy heating wire. The heating wire is spirally wound along the rim of the steering wheel and twisted with embroidery thread (silver-plated copper wire, 0.1mm diameter) inside the heating wire to form a bus. The two ends of the heating wire are connected to the heating drive interface of the control unit through terminals, and at the same time, they are connected to the capacitance detection interface of the control unit as capacitance sensing electrodes.

[0037] The control unit uses a 32-bit embedded processor (model GD32F450ZET6), which has a built-in LCD driver controller and integrates a 100Mbps Ethernet controller and a CAN 2.0B controller. The control unit hardware circuit also includes a 5V / 3.3V power supply module, an AD conversion module and a signal filtering circuit. The control unit is encapsulated in an aluminum housing with dimensions of 50mm×40mm×15mm and is installed in the cavity behind the horn cover of the steering wheel body.

[0038] The display module uses a 5-inch TFT LCD screen, embedded in the center of the steering wheel horn cover; the button input module has 6 mechanical buttons (corresponding to page up / down, cruise control, answering / hanging up phone calls, volume up / down, confirmation, and mute respectively), which are installed on the multi-function button area on both sides of the steering wheel. Each button is connected in series with a resistor with an accuracy of ±1% (resistance values ​​of 1kΩ, 2.2kΩ, 3.3kΩ, 4.7kΩ, 5.1kΩ, and 6.8kΩ respectively) to form a resistance-to-voltage conversion circuit.

[0039] After the vehicle starts, the control unit supplies power to the photoelectric sensor. The green LED light source emits light that penetrates the plexiglass plate and the dermis, illuminating the driver's hand skin. Blood flow causes changes in the skin's absorption rate of light, and the reflected light is received by the sensor and converted into an analog electrical signal. After being amplified and filtered inside the sensor, the signal is transmitted to the control unit. At the same time, the heating wire operates in a time-sharing manner under the control of the control unit. During the heating period, it heats the steering wheel, and during the power-off period, it acts as a capacitance sensing electrode, detecting changes in capacitance with ground and transmitting the signal to the control unit. When the button is operated, the series resistor in the button changes the voltage division of the circuit, and the control unit collects the voltage division signal through the AD module.

[0040] The control unit performs AD conversion on the analog signals transmitted by the photoelectric sensor, extracts heart rate and pulse signals through a digital filtering algorithm, and combines the data collected by the respiratory rate detection chip (model MAX30102) to obtain the driver's heart rate (normal range 60-100 beats / minute), blood pressure (normal range 90 / 60-140 / 90 mmHg), and respiratory rate (normal range 12-20 breaths / minute). After AD conversion on the heating wire capacitor signal, it is compared with the preset reference capacitance value (approximately 20pF when there is no hand contact). When the real-time capacitance value increment exceeds 5pF and lasts for 50ms, it is determined that the driver is holding the steering wheel. The button voltage signal is converted into a digital AD value (e.g., the AD value is 800±20 when the "volume up" button is pressed), and compared with the button AD value lookup table preset by the control unit (pre-stored in Flash memory, the preset AD value for the "volume up" button is 800) to determine the button command.

[0041] The control unit transmits the analyzed driver's physical status data to the display screen, showing heart rate, blood pressure, respiratory rate, and hand-off status in real time (displaying "hands in" or "hands off"). It communicates with the vehicle's instrument system via dual-wire Ethernet to obtain instrument information such as vehicle speed and engine speed, and displays it synchronously on the screen. When a heart rate >100 beats / minute or <60 beats / minute, or blood pressure >140 / 90 mmHg or <90 / 60 mmHg is detected, the control unit generates an alarm signal. The alarm signal is transmitted to the vehicle controller via the CAN bus, and a local alarm is triggered simultaneously. The control unit accesses the smart cockpit via the smart cockpit protocol, and displays the driver's status data synchronously on the in-vehicle central control screen.

[0042] In some embodiments, the heating wire is electrically divided into multiple independent capacitive sensing sections; The capacitance detection circuit includes a multiplexer and a capacitance sensing unit. The input terminal of the multiplexer is connected to each capacitive sensing section, the output terminal of the multiplexer is connected to the sensing input terminal of the capacitive sensing unit, and the channel selection terminal of the multiplexer is controlled by the control unit. The control unit is configured to: During the first time period, the control multiplexer disconnects all channels so that the heating drive circuit can simultaneously apply heating voltage to all capacitive sensing sections. During the second time period, by controlling the multiplexer, each capacitance sensing segment is switched to be connected to the capacitance sensing unit in turn according to a preset sequence, thereby detecting the capacitance signal change of each capacitance sensing segment respectively. The control unit identifies the driver's grip pattern based on capacitance signals detected from different capacitance sensing zones. The heating wire is electrically divided into multiple independent capacitance sensing zones. The control unit determines the driver's hand position based on the capacitance signals from different sensing zones, improving the accuracy and flexibility of hand-off detection.

[0043] The heating wire in commercial vehicle steering wheels is typically not a single, continuous resistance wire running from front to back. Instead, it uses a "serpentine" or "loop-like" routing pattern, evenly distributed across the entire circumference of the steering wheel rim to ensure uniform heating. To enable zoned detection, this continuous heating wire can be electrically divided into several independent segments during the design and manufacturing process. For example, a typical solution is to divide it into four zones: the left zone (corresponding to the 9 o'clock position), the upper zone (corresponding to the 12 o'clock position), the right zone (corresponding to the 3 o'clock position), and the lower zone (corresponding to the 6 o'clock position). Each zone is electrically independent and has its own lead wire.

[0044] Multiplexer: The control unit is connected to a multiplexer. This electronic switch sequentially connects the control unit's capacitance detection circuit to each heating wire section.

[0045] Scan detection: The control unit repeatedly "interrogates" each partition at an extremely high speed (e.g., hundreds of times per second).

[0046] The control unit contains a precise timer that divides time into very short basic periods (e.g., a 10-millisecond period), and further divides it into two time slots: First time period (heating period, e.g., 8ms): Control Action: The control unit activates the heating drive circuit, applying a heating voltage (such as 12V DC) to the heating wire. Simultaneously, it disconnects from the capacitance detection circuit or puts it into a high-resistance state to prevent the powerful heating current from burning out the delicate detection chip.

[0047] Objective: During this period, the heating wire, acting as a purely resistive element, efficiently generates heat. Due to thermal inertia, brief power outages will not cause the driver to feel temperature fluctuations.

[0048] Second time period (detection period, e.g., 2ms): Control Action: The control unit cuts off the heating drive circuit, stopping the power supply. Then, it connects the capacitor detection circuit to the multiplexer to begin the aforementioned scanning detection of each partition.

[0049] Objective: At this point, the heating wire acts as a clean capacitive sensing electrode, no longer affected by heating noise, allowing for accurate measurement of its capacitance to ground.

[0050] Correspondingly, the output of the heating drive circuit is directly connected in parallel to all capacitive sensing sections; The control unit is further configured to: During the first time period, while enabling the heating drive circuit, the multiplexer is controlled to enter a high-impedance state or a shutdown state to physically isolate the heating drive circuit from the capacitance sensing unit; during the second time period, after disabling the heating drive circuit, the multiplexer is then controlled to perform channel switching and capacitance signal detection.

[0051] In this embodiment of the invention, the capacitance sensing unit is a charge amplifier circuit based on switched capacitor technology, including an operational amplifier, a feedback capacitor, a first analog switch, a second analog switch, and a third analog switch; The non-inverting input of the operational amplifier is grounded, the inverting input of the operational amplifier is connected to the output of the multiplexer through the second analog switch, and the output of the operational amplifier is connected to one end of the feedback capacitor. The other end of the feedback capacitor is connected to the inverting input of the operational amplifier; The output of the multiplexer is connected to a reference voltage source via the first analog switch; The third analog switch is connected in parallel across the feedback capacitor as a reset switch.

[0052] The control unit is configured to perform the following capacitance detection steps for each of the capacitance sensing segments during the second time period: SS0 controls the multiplexer to select the current capacitance sensing segment to be detected; SS1. Control the first analog switch to close, apply the reference voltage to the output of the multiplexer, thereby charging the induced capacitance formed between the currently selected capacitive sensing section and ground; when the driver's hand approaches or grips the steering wheel, it acts as a ground conductor, forming an additional capacitance with the capacitive sensing section. Chand This additional capacitance, along with the inherent parasitic capacitance to ground, Cparasitic They are connected in parallel to form an induced capacitor. Cs Charging refers to charging the inductive capacitor. Cs conduct.

[0053] SS2. Control the first analog switch to open and control the second analog switch to close, transferring the charge stored on the sensing capacitor to the feedback capacitor of the operational amplifier; the operational amplifier outputs a voltage signal proportional to the change in the sensing capacitor; SS3. Control the third analog switch to close to reset the charge on the feedback capacitor; SS4. Read the output voltage signal of the operational amplifier; SS5. Disconnect the second and third analog switches to prepare for detecting the next section.

[0054] The working sequence is as follows: Reset phase: The control unit closes and then opens the third analog switch. The first and second analog switches remain open. The charge on the feedback capacitor is cleared, causing the output Vout to return to zero.

[0055] Sampling and charging phase: The control unit controls the first analog switch to close, and the second and third analog switches to open. The reference voltage Vref output by the reference voltage source charges the inductive capacitor Cs through the first analog switch, so that the stored charge Q = Cs × Vref. The inductive capacitor is a capacitor formed between a heating wire (as an electrode) and the driver's hand (as a ground conductor). Charge transfer and amplification stage: The control unit closes the second analog switch, while the first and third analog switches open. The charge stored in the measured induced capacitor Cs is transferred entirely to the feedback capacitor Cf through the second analog switch. Due to the virtual short characteristic of the operational amplifier, the inverting input remains at ground potential; therefore, the output voltage Vout will change to -Q / Cf = -(Cs / Cf) × Vref.

[0056] Output reading: After the charge transfer phase ends, the control unit reads the operational amplifier's output voltage Vout. When a hand approaches, causing the sensing capacitance Cs to increase by ΔC, the change in output voltage is ΔVout = -(ΔC / Cf) × Vref. This voltage change is sampled by the subsequent ADC to determine the hand's state.

[0057] In this embodiment of the invention, the control unit is configured to process the voltage signal to determine the basic hand state through the following process: a. Perform analog-to-digital conversion and digital filtering on the voltage signal output by the operational amplifier to obtain a real-time digital quantity; b. Calculate the difference ΔD between the real-time digital quantity and a preset reference digital quantity; c. Continuously compare the difference ΔD with a preset hand grip judgment threshold; d. If the current state is hand off, and ΔD is greater than the hand grip judgment threshold for more than the first stabilization time, then the basic hand state is determined to be hand grip. e. If the current state is hand-held, and the time for which ΔD is continuously less than or equal to the hand-held judgment threshold exceeds the second stabilization time, then the basic hand state is determined to be hand-off; The second stabilization time is longer than the first stabilization time.

[0058] The control unit is further configured to perform data fusion analysis based on the basic hand state and physiological signals, specifically including: If the basic hand state is determined to be a gripping state, the analysis of the physiological signals is initiated. If the analyzed heart rate or pulse data exceeds the normal threshold range, the driver's physical state is determined to be abnormal. If the basic hand status is determined to be a hands-off state, a timer is started; if the hands-off state continues for more than a preset safe time threshold, it is determined to be a prolonged hands-off state; the driver is analyzed based on physiological signals to determine whether he is still in the seat; if it is confirmed that the driver is still in the seat, it is finally determined to be a dangerous driving state.

[0059] By fusing and analyzing capacitive and physiological signals, the system collaboratively determines the driver's hands-off state and physical condition, improving the accuracy and reliability of the assessment. Different levels of warning signals and vehicle control commands are generated based on different states, ensuring appropriate measures are taken in various situations to improve driving safety. The system clearly defines the judgment logic for normal hands-off state, abnormal physical condition, and dangerous driving state, ensuring that the system can accurately identify various situations and respond accordingly.

[0060] In some embodiments, the control unit is also configured to perform tiered alarms: When it is determined that the driver's physical condition is abnormal, a first-level alarm signal is generated. The first-level alarm signal includes displaying a warning message on the steering wheel display screen and issuing a first-level audible reminder. When a dangerous driving condition is determined, a secondary warning signal and a vehicle control command are generated. The secondary warning signal includes stronger visual and audible warnings, and the vehicle control command is used to perform operations such as limiting the power of the vehicle or turning on the hazard warning lights via the vehicle CAN bus.

[0061] In some embodiments, the steering wheel body includes a frame, a foam layer covering the frame, and an outermost covering layer; a light-transmitting cover is provided between the sensing window of the photoelectric sensor and the inner surface of the covering layer, and an electromagnetic shielding layer formed by metal vacuum coating is provided around the photoelectric sensor.

[0062] The light-transmitting cover is a 0.3mm thick plexiglass plate; the photoelectric sensor uses a green LED light source, and the signal processing circuit of the photoelectric sensor includes a preamplifier for amplifying weak reflected signals.

[0063] In some embodiments, the control unit's decision logic based on the capacitance signal includes: Phase 1: Conditional Triggering and Initial Judgment (Perception Layer) The capacitor signal remains abnormal (first condition): The control unit continuously receives signals from the capacitive sensing module. When the signal changes from a hand-on to a hand-off state, an internal timer starts counting. This timer continues for a preset safe time threshold. This threshold is set based on ergonomics and relevant regulations, such as 3 or 5 seconds. This process initially filters out dangerous behaviors such as prolonged hand-off from the steering wheel.

[0064] Phase Two: Context Confirmation and Misjudgment Elimination (Decision-Making Level) Physiological signals confirm the driver's presence (second condition): During the same time period when the capacitor signal times out, the control unit analyzes the data from the photoelectric physiological monitoring sensor in parallel. The logic for confirming presence involves not simply detecting the presence or absence of a signal, but rather making an intelligent judgment. The driver is determined to be still in their seat if the following conditions are met: The photoelectric sensor detected a regular pulse wave consistent with human characteristics and was able to calculate a heart rate within a reasonable range (e.g., 50-120 beats per minute). This directly proves that the driver's hand is in contact with the sensor area and that their body is in the seat.

[0065] The photoelectric sensor did not detect a valid pulse wave (invalid signal), but the system (e.g., by fusing information from the seat pressure sensor, door signal, seatbelt signal, etc.) determined that the driver had not left the vehicle. In this case, the invalid physiological signal meant that the driver's hands were not in the correct grip position, which is consistent with the hand-off state.

[0066] If the capacitor signal times out and the physiological signal also disappears completely (and other signals indicate that the driver may have left the seat), the system may determine that it is a normal hand-off (e.g., the driver gets out of the car after parking) and will not trigger a level 2 alarm.

[0067] Phase 3: State Determination and Instruction Generation (Decision-Making Level) Dangerous driving condition assessment: The control unit will ultimately determine a dangerous driving state only if both the first and second conditions are met simultaneously. The logic for this determination is: the driver is in the vehicle but has not been holding the steering wheel for an extended period. This usually indicates that the driver may be in an extremely dangerous state, such as being distracted, fatigued, or experiencing a sudden health problem, requiring immediate system intervention.

[0068] Generate secondary alarm signals and vehicle control commands: Level 2 alarm signal: The control unit generates a specific set of signal codes. Simultaneously, the control unit prepares to send a predefined control message via the CAN bus.

[0069] Phase Four: System Execution and Vehicle Intervention (Execution Layer) Command sending and execution: Alarm escalation: A red, flashing warning icon and text pop up on the steering wheel display. A rapid, loud alarm sounds through the car audio system.

[0070] Active vehicle intervention (via vehicle interaction unit): It sends a command to the engine control unit to limit the engine torque output, preventing the vehicle from accelerating or even slowing down.

[0071] If the vehicle is equipped with adaptive cruise control or lane keeping assist, the system will send instructions to these modules to trigger auxiliary functions such as emergency lane keeping or automatic emergency braking, attempting to safely keep the vehicle within its lane.

[0072] The hazard warning lights (double flashers) will automatically turn on to alert vehicles behind and around to take evasive action.

[0073] The T-box sends dangerous driving alerts and vehicle location information to the cloud monitoring center, which then intervenes manually (such as calling the driver) or coordinates rescue efforts.

[0074] In some embodiments, the system also includes a display screen embedded in the horn cover of the steering wheel body; The control unit is further configured to send the heart rate and pulse information parsed from the physiological signals, as well as the result status information of the collaborative judgment, to the display screen for real-time display. The control unit includes an embedded processor that supports two-wire Ethernet and CAN bus communication; The system is connected to the in-vehicle intelligent cockpit system via a two-wire Ethernet connection for transmitting display data; and is connected to the vehicle controller via the CAN bus for transmitting alarm signals and vehicle control commands.

[0075] The embedded display provides drivers with intuitive, real-time information feedback without requiring them to look away from the center console or instrument panel, enhancing both convenience and safety. The hybrid network of two-wire Ethernet and CAN bus leverages the strengths of each: Ethernet handles the high-speed transmission of large amounts of data (such as graphics and video) required by the display, while the CAN bus ensures reliable transmission of critical control and alarm commands. This architecture achieves an optimal balance between data bandwidth and real-time reliability.

[0076] In some embodiments, the wheel rim of the steering wheel body frame has multiple mounting grooves. The photoelectric sensor is fixed in the mounting groove by a snap-fit ​​structure, and electrical interconnection and signal transmission are achieved through a flexible circuit board pre-laid in the mounting groove.

[0077] Pre-set grooves and snap-fit ​​fasteners ensure the accuracy and consistency of the installation positions of multiple sensors, guaranteeing uniform detection results. Flexible circuit boards replace traditional wiring harnesses, solving the problems of messy wiring and easy cross-interference among multiple sensors. The layout is neat and reliable, reducing failures caused by wiring harness issues and lowering assembly complexity.

[0078] In some embodiments, the control unit also sends the driver's physiological state data, hands-off status judgment results, and system alarm information to the cloud monitoring platform via the in-vehicle T-box communication module. Uploading data to the cloud platform via the T-box facilitates remote real-time monitoring, historical data review, and driver behavior analysis by fleet administrators, providing strong data support for realizing digital fleet management and preventive safety dispatching, and greatly expanding the application value and commercial prospects of the system.

[0079] In embodiments of the present invention, such as Figure 2 As shown, 18 photoelectric sensors 100 are distributed in a ring along the inner side of the steering wheel rim, covering a 360° range. The sensor detection distance is 1-3mm, which can cover all hand positions where the driver normally grips the steering wheel, including: Grip the steering wheel with both hands at the 3 o'clock and 9 o'clock positions (palms against the outside of the wheel rim, fingers wrapped around the wheel rim); Grasp the 6 o'clock or 12 o'clock position with one hand (press your fingers on the inside of the rim); Gently grasp the rim with both hands (fingers lightly touching the surface of the rim); Only excluding cases where both hands are completely off the steering wheel, or where a special gripping method is used, such as using tools (like tweezers) to pick up the wheel rim, are excluded. In such cases, the sensors cannot detect human physiological signals, and the control unit determines that the hands are off the steering wheel.

[0080] During the processing of the steering wheel foam layer, a special tooling is used to ensure that the depth of the sensor mounting holes is consistent. After the sensor is embedded in the hole, a 1.5mm thick silicone pad is placed at the bottom of the sensor, and the distance between the top of the sensor and the surface of the foam layer is adjusted to 3mm. The thickness of the leather covering layer is controlled at 1.5mm, and the final distance between the sensor and the steering wheel surface (including the leather layer) is 1.5mm. After installation, a special testing device is used to test the installation distance of each sensor to ensure that the distance deviation of all sensors is ≤0.2mm, so as to avoid weak detection signals due to excessive distance (>2mm) or sensor damage due to excessive distance (<1mm).

[0081] Each of the 18 photoelectric sensors is equipped with an independent power supply circuit. Each photoelectric sensor is powered by a separate linear regulator with an input voltage of 12V (taken from the vehicle power supply), an output voltage of 5V, and an output current of 50mA. Each regulator has a 1A resettable fuse connected in series at the input terminal and a 100μF electrolytic capacitor and a 0.1μF ceramic capacitor connected in parallel at the output terminal to suppress power supply ripple. The independent power supply circuit is integrated into the housing of the control unit via a PCB board. The PCB board is connected to the photoelectric sensors via a flexible circuit board to ensure that the power supply of each sensor is not interfered with by other components and to avoid detection signal distortion caused by power supply fluctuations.

[0082] The control unit has a built-in DC offset correction module, which is implemented based on the DAC module inside the processor. During the photoelectric sensor signal acquisition process, the correction module acquires the DC offset signal caused by the refraction of the plexiglass plate once every 500ms, outputs a reverse compensation voltage through the DAC module, and superimposes it on the analog signal output by the sensor. For example, when the offset voltage is detected to be 0.2V, the DAC module outputs a compensation voltage of -0.2V to cancel the signal offset caused by refraction. After correction, the signal-to-noise ratio of the signal acquired by the photoelectric sensor is improved to more than 40dB, ensuring that the accuracy of heart rate and pulse signal resolution is ≥95%.

[0083] Two red LED beads are selected and installed on the multi-function button area on both sides of the steering wheel. The LED beads are connected to the GPIOA0 and GPIOA1 interfaces of the control unit through a 1kΩ current-limiting resistor. The working voltage is 3.3V and the luminous intensity is 500mcd.

[0084] A piezoelectric buzzer is selected and installed in the cavity behind the steering wheel horn cover. It is driven by an NPN transistor, and the base of the transistor is connected to the GPIOB0 interface of the control unit through a 1kΩ resistor.

[0085] When the control unit detects that the increase in the heating wire capacitance is less than 5pF for 1 second via the capacitance sensing module, it determines that the hand has left the steering wheel. At this time, the control unit controls the output of the GPIOA0 and GPIOA1 interfaces to be high, and the red LED bead flashes at a frequency of 1Hz. At the same time, the control unit controls the output of the GPIOB0 interface to be high, the transistor is turned on, and the buzzer emits a "beep" sound at a frequency of 1kHz, once every 2 seconds, each lasting 0.5 seconds. When the capacitance increase is detected to recover to more than 5pF and last for 0.5 seconds, the alarm stops.

[0086] When the heart rate is >110 beats / minute or <50 beats / minute, blood pressure is >150 / 100 mmHg or <80 / 50 mmHg, and respiratory rate is >25 breaths / minute or <10 breaths / minute, the driver's physical condition is deemed abnormal. The red LED light will flash at a frequency of 2Hz, and the buzzer will sound continuously at a frequency of 1.5kHz. At the same time, a red warning pop-up window will appear on the display screen, showing the message "Abnormal heart rate, please rest immediately" and other prompts. The alarm will stop when the driver's physical condition returns to normal.

[0087] The heating temperature is set via the up / down page keys and the confirmation key on the input module. The setting range is 30-50℃, with a step size of 1℃. For example, a short press of the up page key increases the displayed temperature from 30℃ to 31℃, a short press of the down page key decreases the temperature, and pressing the confirmation key saves the set temperature. An NTC thermistor is connected in series in the middle of the heating wire. The thermistor is connected to the AD module of the control unit through a voltage divider circuit. The thermistor's resistance changes with temperature. The control unit collects the divided voltage and, combined with the thermistor resistance-temperature lookup table, calculates the real-time temperature of the heating wire. The detection frequency is 1Hz.

[0088] The control unit uses a PID control algorithm to adjust the working state of the heating wire: When the real-time temperature is less than the set temperature -3℃, the heating wire is controlled to operate at 100% duty cycle (12V full voltage heating). When the real-time temperature is between -3℃ and -1℃ from the set temperature, heat with a 50% duty cycle. When the real-time temperature is between -1℃ and +1℃ from the set temperature, heating is performed at a 20% duty cycle to maintain a stable temperature. When the real-time temperature exceeds the set temperature +5℃, the heating element will be powered off and heating will stop. At the same time, the display screen will show the message "Temperature too high, heating has stopped". When the real-time temperature drops to the set temperature +1℃, heating with a 20% duty cycle is restored. During temperature control, the display screen shows the set temperature and the real-time temperature in real time, ensuring that the driver is aware of the heating status.

[0089] After the vehicle-mounted T-box communication module accesses the Internet via the 4G network, it establishes a long TCP connection with the cloud monitoring platform. The control unit communicates with the T-box using the Modbus protocol with a communication baud rate of 115200bps, 8 data bits, 1 stop bit, and no parity.

[0090] After receiving the data, the cloud monitoring platform performs the following processing: Regular data and alarm data are stored in a MySQL database. The database uses a master-slave backup architecture to ensure that the data is not lost and the data retention period is 1 year. The platform displays a real-time list of vehicles, driver status, and alarm information on its web interface. It supports querying historical data by VIN code and time range, and generates reports such as heart rate trend charts and blood pressure change curves. When alarm data is received, the platform sends an alarm SMS to the fleet administrator's mobile phone via the SMS gateway (content: "Vehicle VIN: LZWADAGA6KB000001, time: 2024-05-20 15:42:10, alarm type: abnormal heart rate, current heart rate: 120 beats / minute, please handle it in time"), and pushes an alarm notification to the platform APP at the same time.

[0091] This invention also provides a vehicle including the steering wheel system described in the above embodiments. In this embodiment, the steering wheel system is connected to the vehicle steering system via a steering column, the steering column being model TZ520-001. The steering wheel and steering column are connected by a spline connection, and the tightening torque is... The steering wheel horn cover is linked to the vehicle horn system; pressing the horn cover triggers the vehicle horn.

[0092] The steering wheel system control unit is powered by the 12V power supply in the vehicle's cab; the control unit's CAN interface is connected to the vehicle's chassis CAN bus; the Ethernet interface is connected to the vehicle's smart cockpit Ethernet; the on-board T-box module is connected to the steering wheel system control unit via UART, and the T-box is also connected to the vehicle's GPS module to upload vehicle location information to the cloud platform.

[0093] When the steering wheel system detects an abnormal physical condition of the driver and generates a level 2 alarm signal, the vehicle controller receives the signal, controls the engine torque limit, activates the vehicle retarder to reduce the vehicle speed, and displays a "Please stop and rest immediately" message on the vehicle instrument panel. The cruise control button on the steering wheel system is linked to the vehicle's cruise control system. When the cruise control button is pressed, the vehicle's ECU controls the engine speed to maintain the vehicle's current speed. When the brake is applied or the cancel button is pressed, the cruise control is deactivated. The steering wheel system display receives vehicle instrument information via Ethernet and displays it in separate areas from the driver's status data. It also supports switching the display interface via the "confirm" button.

[0094] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A commercial vehicle steering wheel system integrating driver status monitoring function, characterized in that, The system includes a steering wheel body, a detection component, and a control unit. The detection component includes a capacitive sensing detection module and multiple photoelectric sensors. The control unit is electrically connected to the photoelectric sensors and the capacitive sensing detection module. The photoelectric sensors are embedded in the rim of the steering wheel body in a surrounding array and are used to detect physiological signals, including heart rate and pulse signals, by means of reflective photoelectric principle when the driver holds the steering wheel. The sensing electrode of the capacitance sensing detection module is a heating wire integrated into the steering wheel body. The control unit is connected to the heating wire through a heating drive circuit and a capacitance detection circuit. The control unit is configured to drive the heating wire in a time-division multiplexing manner, specifically including: dividing a control cycle into a first time period and a second time period; during the first time period, the control unit controls the heating drive circuit to apply a heating voltage to the heating wire and disconnects the capacitance detection circuit; during the second time period, the control unit controls the heating drive circuit to stop heating and connects the capacitance detection circuit to sample and detect the capacitance signal of the heating wire. The control unit is also configured to: receive physiological signals and capacitance signals; perform data fusion analysis on the physiological signals and capacitance signals to collaboratively determine the driver's hands-off state and physical state; and generate and output corresponding alarm signals or vehicle control commands based on the results of the collaborative determination.

2. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 1, characterized in that, The heating wire is divided into multiple independent capacitive sensing sections in terms of electrical connection; The capacitance detection circuit includes a multiplexer and a capacitance sensing unit. The input terminal of the multiplexer is connected to each capacitive sensing section, the output terminal of the multiplexer is connected to the sensing input terminal of the capacitive sensing unit, and the channel selection terminal of the multiplexer is controlled by the control unit. The control unit is configured to: During the first time period, the control multiplexer disconnects all channels so that the heating drive circuit can simultaneously apply heating voltage to all capacitive sensing sections. During the second time period, by controlling the multiplexer, each capacitance sensing segment is switched to be connected to the capacitance sensing unit in turn according to a preset sequence, thereby detecting the capacitance signal change of each capacitance sensing segment respectively. The control unit identifies the driver's grip pattern based on the capacitance signals detected from different capacitance sensing segments.

3. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 2, characterized in that, The output of the heating drive circuit is directly connected in parallel to all capacitive sensing sections; The control unit is further configured to: During the first time period, while enabling the heating drive circuit, the multiplexer is controlled to enter a high-impedance state or a shutdown state to physically isolate the heating drive circuit from the capacitance sensing unit; during the second time period, after disabling the heating drive circuit, the multiplexer is then controlled to perform channel switching and capacitance signal detection.

4. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 3, characterized in that, The capacitance sensing unit is a charge amplifier circuit based on switched capacitor technology, including an operational amplifier, a feedback capacitor, a first analog switch, a second analog switch, and a third analog switch. The non-inverting input of the operational amplifier is grounded, the inverting input of the operational amplifier is connected to the output of the multiplexer through the second analog switch, and the output of the operational amplifier is connected to one end of the feedback capacitor. The other end of the feedback capacitor is connected to the inverting input of the operational amplifier; The output of the multiplexer is connected to a reference voltage source via the first analog switch; The third analog switch is connected in parallel across the feedback capacitor as a reset switch.

5. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 4, characterized in that, The control unit is configured to perform the following capacitance detection steps for each of the capacitance sensing segments during the second time period: SS0 controls the multiplexer to select the current capacitance sensing segment to be detected; SS1. Control the first analog switch to close, apply the reference voltage to the output of the multiplexer, thereby charging the induced capacitor formed between the currently selected capacitor sensing section and ground; SS2. Control the first analog switch to open and control the second analog switch to close, transferring the charge stored on the sensing capacitor to the feedback capacitor of the operational amplifier; the operational amplifier outputs a voltage signal proportional to the change in the sensing capacitor; SS3. Control the third analog switch to close to reset the charge on the feedback capacitor; SS4. Read the output voltage signal of the operational amplifier; SS5. Disconnect the second and third analog switches to prepare for detecting the next section.

6. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 5, characterized in that, The control unit is configured to process voltage signals to determine the basic hand state through the following process: a. Perform analog-to-digital conversion and digital filtering on the voltage signal output by the operational amplifier to obtain a real-time digital quantity; b. Calculate the difference ΔD between the real-time digital quantity and a preset reference digital quantity; c. Continuously compare the difference ΔD with a preset hand grip judgment threshold; d. If the current state is hand off, and ΔD is greater than the hand grip judgment threshold for more than the first stabilization time, then the basic hand state is determined to be hand grip. e. If the current state is hand-held, and the time for which ΔD is continuously less than or equal to the hand-held judgment threshold exceeds the second stabilization time, then the basic hand state is determined to be hand-off; The second stabilization time is longer than the first stabilization time.

7. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 6, characterized in that, The control unit is further configured to perform data fusion analysis based on the basic hand state and physiological signals, specifically including: If the basic hand state is determined to be a gripping state, the analysis of the physiological signals is initiated. If the analyzed heart rate or pulse data exceeds the normal threshold range, the driver's physical state is determined to be abnormal. If the basic hand status is determined to be a hands-off state, a timer is started; if the hands-off state continues for more than a preset safe time threshold, it is determined to be a prolonged hands-off state; the driver is analyzed based on physiological signals to determine whether he is still in the seat; if it is confirmed that the driver is still in the seat, it is finally determined to be a dangerous driving state.

8. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 7, characterized in that, The control unit is also configured to execute tiered alarms: When it is determined that the driver's physical condition is abnormal, a first-level alarm signal is generated. The first-level alarm signal includes displaying a warning message on the steering wheel display screen and issuing a first-level audible reminder. When a dangerous driving condition is determined, a secondary warning signal and a vehicle control command are generated. The secondary warning signal includes stronger visual and audible warnings, and the vehicle control command is used to perform operations such as limiting the power of the vehicle or turning on the hazard warning lights via the vehicle CAN bus.

9. The commercial vehicle steering wheel system with integrated driver status monitoring function according to claim 8, characterized in that, The system also includes a display screen embedded in the horn cover of the steering wheel body; The control unit is further configured to send the heart rate and pulse information parsed from the physiological signals, as well as the result status information of the collaborative judgment, to the display screen for real-time display. The control unit includes an embedded processor that supports two-wire Ethernet and CAN bus communication; The system is connected to the in-vehicle intelligent cockpit system via a two-wire Ethernet connection for transmitting display data; and is connected to the vehicle controller via the CAN bus for transmitting alarm signals and vehicle control commands.

10. A vehicle, characterized in that, Including the steering wheel system as described in any one of claims 1-9.

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