A seat belt active adjustment device and method

Abstract

This invention belongs to the field of vehicle safety technology and discloses an active seat belt adjustment device and method. The device includes a seat belt body; a fatigue detection module disposed on the seat belt body, used to generate physiological motion signals of the driver; a control module used to receive and analyze the physiological motion signals, determine whether the driver is in a fatigued state according to a preset fatigue threshold, and classify it as mild fatigue or severe fatigue; and an execution module including a vibration unit and a tightening unit. The control module is configured to: when mild fatigue is determined, control the vibration unit to execute a first vibration mode; when severe fatigue is determined, simultaneously activate the vibration unit and the tightening unit, with the vibration unit executing a second vibration mode and the tightening unit tightening the seat belt body. This invention can more accurately determine the driver's fatigue state, avoid the errors that may exist in detection based on a single criterion, and effectively reduce the risk of traffic accidents caused by fatigued driving.

Description

Technical Field

[0001] This invention belongs to the field of vehicle safety technology, and specifically relates to an active seat belt adjustment device and method. Background Technology

[0002] Fatigue driving is a major contributing factor to road traffic accidents. When drivers are fatigued, they experience slowed reaction times, decreased attention spans, and reduced operational accuracy, significantly increasing the risk of accidents and seriously endangering the personal and property safety of passengers and other road users. Current fatigue driving monitoring methods largely rely on multi-source devices such as cameras and accelerator / pedal sensors to detect and determine driver fatigue.

[0003] However, existing technologies still have significant drawbacks: while camera-based facial recognition solutions can monitor features such as head posture and eyelid closure, they generally suffer from complex installation structures, high hardware costs, and recognition results are easily affected by environmental factors such as lighting and occlusion. Furthermore, most existing devices only provide a single alarm function; for drivers already in a state of deep fatigue, conventional alarms are insufficient to effectively wake them up, failing to fundamentally reduce the probability of accidents. Summary of the Invention

[0004] To address the above problems, the present invention provides an active seat belt adjustment device, comprising: a seat belt body; a fatigue detection module disposed on the seat belt body, the fatigue detection module being used to acquire the driver's physiological motion state in real time and generate corresponding physiological motion signals; and a control module being used to receive and analyze the physiological motion signals, determine whether the driver is in a fatigue state according to a preset fatigue threshold, and classify the fatigue state into mild fatigue and severe fatigue. The execution module includes a vibration unit and a tightening unit. The control module is configured to: when it is determined that the driver is slightly fatigued, control the vibration unit to start executing the first vibration mode to remind the driver; when it is determined that the driver is severely fatigued, simultaneously activate the vibration unit and the tightening unit, with the vibration unit executing the second vibration mode and the tightening unit tightening the seat belt to restrict the driver's body movement.

[0005] Furthermore, the fatigue detection module includes a pressure sensor, a heart rate sensor, and a motion sensor; The pressure sensor is used to detect changes in the pressure exerted by the seatbelt on the driver's body and to generate a pressure signal; The heart rate sensor is used to generate a heart rate signal based on real-time monitoring of the driver's heart rate; Motion sensors are used to generate motion signals based on the detected movement of the driver's body.

[0006] Furthermore, the fatigue detection module uses flexible low-current communication wire webbing, which is integrated into the webbing of the seat belt body.

[0007] Furthermore, the fatigue detection module and vibration unit are arranged along the length of the webbing, fitting snugly against the driver's chest, abdomen, or shoulders when worn.

[0008] Furthermore, the control module is located under the seat, inside the seat frame, or inside the seat side panel.

[0009] The present invention also provides a vehicle including the above-described active seat belt adjustment device.

[0010] The present invention also provides a method for active adjustment of a seat belt, comprising the following steps: The fatigue detection module acquires the driver's physiological motion state in real time and generates corresponding physiological motion signals; The control module determines whether the driver is fatigued based on the received physiological motion signals and the preset fatigue threshold. If the driver is determined to be fatigued, the fatigue state is further classified as mild fatigue or severe fatigue. If mild fatigue is determined, the control module controls the vibration unit to execute the first vibration mode, which alerts the driver by vibrating the seat belt. If severe fatigue is determined, the control module simultaneously activates the vibration unit and the tightening unit. The vibration unit executes the second vibration mode and controls the retractor to tighten the seat belt, restricting the driver's physical movement.

[0011] Furthermore, the preset fatigue thresholds include pressure change threshold, heart rate threshold, and exercise frequency threshold.

[0012] Furthermore, the frequency, amplitude, and intensity of the second vibration mode are all greater than those of the first vibration mode.

[0013] Furthermore, determining whether the driver is fatigued includes: if any one or more parameters in the physiological motion signal are greater than or less than the corresponding threshold, then the driver is determined to be fatigued.

[0014] The beneficial effects of this invention are: 1. The fatigue detection module of this invention acquires the driver's physiological motion state and generates corresponding physiological motion signals, enabling a more accurate assessment of the driver's fatigue state and avoiding potential errors associated with detection based on a single criterion. When driver fatigue is detected, the module vibrates to alert the driver and tightens the seatbelt, promptly drawing the driver's attention and restricting the driver's operation in cases of severe fatigue, effectively reducing the risk of traffic accidents caused by fatigued driving.

[0015] 2. This invention integrates the fatigue detection module into the seat belt body, eliminating the need for large-scale vehicle modifications. It is easy to install, relatively low in cost, and easy to promote and apply.

[0016] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description and the drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of an active seatbelt adjustment device according to an embodiment of the present invention is shown; Figure 2 A schematic flowchart of a seatbelt active adjustment method according to an embodiment of the present invention is shown; Figure 3 A detailed flowchart of an active seatbelt adjustment method according to an embodiment of the present invention is shown.

[0019] In the diagram: 1. Seat belt body; 2. Fatigue detection module; 3. Control module; 4. Vibration unit; 5. Tensioning unit; 6. Seat. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., used in this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein.

[0022] This invention provides a seatbelt active adjustment device and method that can accurately detect driver fatigue and take corresponding measures through the seatbelt to remind or restrict the driver's operation when the driver is detected to be in a state of fatigued driving, thereby effectively reducing the risk of traffic accidents caused by fatigued driving.

[0023] An active seatbelt adjustment device according to an embodiment of the present invention is integrated into the driver's seat of a vehicle without modifying the main body structure. It is compatible with a variety of vehicle types, including mainstream passenger cars, commercial vehicles, SUVs, and sedans, and features strong versatility, compact layout, convenient installation, and controllable cost.

[0024] like Figure 1 As shown, a seat belt active adjustment device includes a seat belt body 1, a fatigue detection module 2, a control module 3, and an execution module. The modules are connected by a combination of electrical connection and mechanical fixation to achieve a complete closed loop of signal acquisition, data processing, graded judgment, and active intervention.

[0025] The fatigue detection module 2 is installed on the seat belt body 1. The fatigue detection module 2 is used to acquire the driver's physiological motion state in real time and generate corresponding physiological motion signals, and send the physiological motion signals to the control module 3. The physiological motion signals include pressure signals, heart rate signals and motion signals.

[0026] In this embodiment of the invention, the fatigue detection module 2 is integrated into the seat belt body 1, which eliminates the need for large-scale vehicle modifications, making installation convenient, relatively low-cost, and easy to promote and apply.

[0027] The active seat belt adjustment device of this invention integrates the fatigue detection module 2 completely into the seat belt body 1. It does not rely on the vehicle body structure, does not modify the interior, and does not add complex brackets. The function can be upgraded simply by replacing the seat belt with a sensor. The amount of modification work is minimal. It is suitable for the development of new models and the upgrading of existing models. The threshold for promotion is extremely low.

[0028] Compared to fatigue monitoring solutions such as cameras, steering wheel sensors, and seat sensors, the adjustment device in this invention has a simple structure, fewer parts, and lower sensor costs. It does not require high-precision algorithm chips, maps, networks, or high-precision positioning support, thus reducing the overall vehicle cost. It is especially suitable for cost-sensitive vehicle types such as economy cars, commercial vehicles, and operating vehicles.

[0029] For example, the fatigue detection module 2 is located on the seat belt body 1 near the middle of the driver's body to ensure that the pressure sensor, heart rate sensor and motion sensor can accurately detect the driver's body data.

[0030] When the driver wears the seatbelt body 1 correctly, the fatigue detection module 2 maintains a stable fit with the driver's body, without significant displacement or loss of contact due to vehicle bumps or slight body movements. The fatigue detection module 2 is encapsulated with a flexible thin-film structure with a thickness of no more than 2mm. It is soft and flexible, and can be rolled up and stored inside the retractor synchronously with the webbing without affecting the normal operation of the retractor.

[0031] The fatigue detection module 2 includes a pressure sensor, a heart rate sensor, and a motion sensor. The three types of sensors adopt a coplanar integrated design, share the same flexible circuit board, and have unified power supply and signal output, reducing the number of wires and improving integration and reliability.

[0032] The pressure sensor is used to detect changes in the pressure exerted by the seatbelt body 1 on the driver's body and generate a pressure signal. When the driver is in a normal sitting position, the pressure of the seatbelt on the body is relatively stable; however, when the driver is fatigued, relaxed, or leaning forward, the pressure value detected by the pressure sensor will change significantly.

[0033] For example, the pressure sensor is a flexible thin-film pressure sensor with a detection area of ​​not less than 20 cm². 2 It can continuously and in real-time collect the restraining pressure of the seat belt webbing on the driver's torso, with a detection range covering 50N to 800N, meeting the pressure detection needs of drivers of different body types and sitting postures. The pressure values ​​collected by the pressure sensor reflect the driver's sitting posture stability, the degree of forward lean, and the degree of torso relaxation. When the driver is awake, the sitting posture is relatively stable, and the pressure value fluctuates little; when the driver enters a state of fatigue, the torso muscles relax, the head leans forward, and the body tilts, and the pressure sensor can quickly capture characteristics such as sudden pressure changes, pressure shifts, and continuous pressure drops.

[0034] Heart rate sensors are used to generate heart rate signals based on real-time monitoring of the driver's heart rate. When a driver is fatigued, their heart rate may change abnormally, such as slowing down or becoming irregular. By monitoring heart rate, the driver's fatigue level can be determined more accurately.

[0035] For example, the heart rate sensor is an optical flexible heart rate monitoring sensor that uses the principle of reflective photoelectric detection. It monitors changes in the pulsation of microvessels on the driver's skin by emitting infrared light and receiving reflected light signals, thereby calculating the real-time heart rate. The heart rate sensor does not need to directly contact the skin and can achieve stable detection through clothing, making it suitable for all-season wear. The detection range is 30 to 200 beats per minute, with a resolution of 1 beat per minute, and it can accurately identify fatigue-related abnormalities such as bradycardia, tachycardia, and heart rhythm fluctuations.

[0036] Motion sensors are used to generate motion signals based on detected driver body movements. During normal driving, drivers make certain body movements to operate the vehicle; however, when driving while fatigued, these body movements decrease or become irregular. Motion sensors can capture these subtle changes, providing a basis for fatigue detection.

[0037] For example, a motion sensor is a six-axis inertial measurement unit that integrates a three-axis accelerometer and a three-axis gyroscope. It can detect minute body movements, torso swing amplitude, movement frequency, and movement regularity. Under normal driving conditions, drivers produce regular movements due to steering, road condition responses, and body adjustments. In a fatigued state, movements significantly decrease, their amplitude diminishes, and their regularity disappears; drivers may even remain still for extended periods. Motion sensors can capture low-frequency movement changes from 0.1Hz to 10Hz and are highly sensitive to the decline in physical activity caused by fatigue.

[0038] The fatigue detection module 2 of this invention collects the driver's physiological and motor state through the coordinated use of a pressure sensor, a heart rate sensor, and a motion sensor to construct a multi-dimensional fatigue judgment model. This fundamentally solves the problems of large detection errors, susceptibility to environmental interference, and high false trigger rates associated with traditional single-sensor detection. The pressure sensor reflects posture stability, the heart rate sensor reflects physiological arousal level, and the motion sensor reflects body activity. These three types of signals complement and verify each other, enabling a comprehensive judgment of physiological and behavioral characteristics and significantly improving the accuracy of fatigue recognition.

[0039] Compared to existing camera-based fatigue detection systems, the fatigue detection module 2 in this embodiment of the invention is completely unaffected by environmental factors such as lighting, occlusion, sunglasses, viewing angle, and nighttime driving. It requires no complex calibration or algorithm training and can operate stably in scenarios such as strong light, backlight, tunnels, and underground parking garages. Furthermore, the sensor is integrated inside the seatbelt, eliminating the need for additional cameras, displays, or other equipment inside the vehicle. This saves space, does not affect the interior aesthetics, and does not interfere with the driver's vision, thus overcoming the shortcomings of traditional visual monitoring systems, such as complex installation, high cost, and poor versatility.

[0040] For example, the fatigue detection module 2 uses a flexible low-current communication wire webbing, which is integrated into the webbing of the seat belt body 1 and arranged to fit the driver's body area. The communication wire and the webbing are woven synchronously, which does not affect the strength and curling performance of the webbing, and does not produce protrusions, burrs or foreign objects, thus ensuring the driver's wearing comfort.

[0041] This invention adopts an integrated design of flexible sensor and webbing. The sensor can bend and roll freely with the seat belt, adapting to different car models, different seat structures, and drivers of different body types. It eliminates the need for separate molds for different car models, greatly reducing engineering adaptation costs and providing strong vehicle compatibility.

[0042] The control module 3 is electrically connected to the fatigue detection module 2. It is used to receive and analyze physiological motion signals, determine whether the driver is in a fatigued state according to the preset fatigue threshold, and classify the fatigue state into mild fatigue and severe fatigue.

[0043] For example, when the detected pressure, heart rate, and motion signals exceed or fall below the corresponding thresholds, the control module 3 determines that the driver is in a state of fatigued driving.

[0044] The execution module is electrically connected to the control module 3 and includes a vibration unit 4 and a tightening unit 5. The control module 3 is configured to: when it is determined that the driver is slightly fatigued, control the vibration unit 4 to start executing the first vibration mode to remind the driver; when it is determined that the driver is severely fatigued, simultaneously start the vibration unit 4 and the tightening unit 5, the vibration unit 4 executes the second vibration mode, and the tightening unit 5 tightens the seat belt to restrict the driver's body movement.

[0045] The frequency, amplitude, and intensity of the second vibration mode are all greater than those of the first vibration mode.

[0046] For example, the seat belt body 1 is used to restrain the driver during vehicle operation. The seat belt body 1 is a three-point seat belt structure and also serves as the mounting carrier for the fatigue detection module 2 and the execution module. The webbing is woven from high-molecular polyester fibers and possesses sufficient tensile strength, flexibility, and durability.

[0047] The seat belt body 1 includes a webbing, a retractor, a latch, a buckle, an upper fixing point, and a lower fixing point. The seat 6 is the driver's seat 6, which includes a seat cushion, a backrest, a headrest, and a seat frame.

[0048] The retractor is fixedly installed on the lower left or right side of the backrest of seat 6, or inside the interior panel of the B-pillar of the vehicle, corresponding to the outer side of the backrest of seat 6.

[0049] The upper fixing point is located at the upper shoulder height of the seat back of seat 6 or on the upper part of the vehicle's B-pillar, allowing the webbing to extend upwards and change direction; the lower fixing point is located below the outer side of the seat cushion of seat 6 or on the vehicle floor, used to fix the lower end of the webbing. The buckle is fixedly installed on the outer edge of the seat cushion of seat 6, located next to the driver's hip.

[0050] The fatigue detection module 2 and vibration unit 4 are arranged along the length of the webbing and fit snugly against the driver's chest, abdomen or shoulders when worn; the control module 3 is located under the seat 6, inside the seat 6 frame or inside the seat 6 side panel, in a position that is easy to wire and maintain, and does not intrude on the driving and riding space.

[0051] The retractor housing is rigidly fixed to the lower outer side of the seat back of seat 6, or to the inner sheet metal location of the vehicle's B-pillar, ensuring a secure and stable installation. One end of the webbing is fixed to the internal retractor spool, and the other end extends downwards, passes through the guide ring at the upper fixing point, passes through the locking tongue, and is fixed to the lower fixing point. The upper fixing point is installed at the upper shoulder height of the seat back of seat 6, or at the upper part of the B-pillar; the height is slightly adjustable to accommodate drivers of different heights. The lower fixing point is fixed to the lower outer side of the seat cushion of seat 6 or to the floor sheet metal, ensuring that the tensile strength meets regulatory requirements. The latch is fixedly installed on the outer edge of the seat cushion of seat 6, located next to the driver's buttocks; the locking tongue and latch can be quickly inserted and removed to engage, forming a complete constraint circuit after engagement.

[0052] The tightening unit 5 is connected to the reel of the reel and is used to drive the reel to rotate forward to actively tighten the webbing and rotate in reverse to loosen the webbing; the vibration unit 4 is fixed on the surface of the webbing or inside the webbing and fits the driver's body synchronously with the webbing.

[0053] The fatigue detection module 2 is electrically connected to the control module 3 via a flexible wiring harness; the control module 3 is electrically connected to the tightening unit 5 and the vibration unit 4; the control module 3 is connected to the vehicle controller via the vehicle body wiring harness.

[0054] The retractor is fixed to the outside of the seat back or the seat frame of the seat 6, and the buckle is installed on the outside of the seat cushion of the seat 6; the fatigue detection module 2 and the vibration unit 4 are integrated into the seat belt webbing, and the tightening unit 5 is connected to the retractor. The webbing fits the driver's body when worn.

[0055] For example, control module 3 uses a vehicle-grade ECU controller, which includes a power management unit, signal acquisition unit, data processing unit, drive output unit, and communication unit, meeting automotive-grade vibration, high and low temperature, and electromagnetic compatibility requirements. Control module 3 is fixedly installed in the space under the driver's seat 6, or inside the seat 6 frame or side panel, without intruding into the passenger compartment or affecting the seat 6's adjustment function. The controller housing has a waterproof and dustproof structure with a protection level of no less than IP6K, adapting to the humid, dusty, and oily environment inside the vehicle. The controller is connected to fatigue detection module 2 and the execution module via hard wiring harnesses, and also connects to the vehicle controller, instrument unit, and alarm system via a CAN / LIN bus, reporting fatigue status to the entire vehicle and triggering linked actions such as instrument light warnings and voice prompts.

[0056] For example, vibration unit 4 is a flat, miniature vibration motor encapsulated in a flexible housing and fixed to the seatbelt webbing near the driver's shoulder or chest. The output shaft of the vibration motor is equipped with an eccentric wheel, and vibrations of different intensities and frequencies are achieved by controlling the power supply parameters. Vibration unit 4 adopts a low-power design, with an operating current of no more than 200mA, which will not cause a load impact on the vehicle's power system.

[0057] The tightening unit 5 includes a seatbelt drive motor, a reduction gear mechanism, a clutch mechanism, and a reel transmission mechanism, all integrated within the retractor and rigidly connected to it. The tightening motor is a DC brushed motor or a stepper motor, capable of forward tightening and reverse release. Torque is amplified through the gear set to ensure stable and controllable tightening force. The clutch disconnects the motor from the reel in a non-interventional state, allowing the seatbelt to maintain its normal free stretching and rewinding functions. Upon receiving a tightening command, the clutch engages, transmitting motor power to the reel for active tightening.

[0058] When the active seat belt adjustment device of this embodiment detects driver fatigue, the execution module can promptly attract the driver's attention by vibrating to remind him and tightening the seat belt body 1. In cases of severe fatigue, it can also restrict the driver's operation, effectively reducing the risk of traffic accidents caused by fatigued driving.

[0059] This invention also provides a vehicle including the aforementioned active seatbelt adjustment device. All electronic components of the active seatbelt adjustment device are integrated under the seatbelt body 1 webbing, retractor, or seat 6, without occupying vehicle passenger compartment space, affecting the seat 6's fore-aft, height, and backrest adjustment functions, or affecting the normal extension, locking, and retraction functions of the seatbelt. In a non-fatigue intervention state, the seatbelt is completely identical to a regular seatbelt, without changing the driver's usage habits.

[0060] Based on the aforementioned active seatbelt adjustment device, such as Figure 2 and Figure 3 As shown, this embodiment of the invention also provides a seatbelt active adjustment method, including the following steps: S0. The active seatbelt adjustment device performs a self-test procedure and driver baseline calibration, as follows: After the vehicle is powered on, the active seatbelt adjustment device enters the power-on self-test process. Control module 3 sequentially checks the status of the pressure sensor, heart rate sensor, motion sensor, vibration unit 4, and tensioning unit 5 to determine whether the circuit is open or short-circuited, whether the sensor output is normal, and whether the actuator is responding. If the self-test passes without fault indication, it enters normal operating mode; if an abnormality is detected during the self-test, the controller records the fault code and sends a fault signal to the entire vehicle via the bus. The instrument panel illuminates the fault indicator light, and the system enters safety protection mode, where it does not perform active tensioning action and only maintains the conventional seatbelt function.

[0061] After the self-test is completed, the driver baseline calibration stage begins. The calibration process requires no manual operation and is completed automatically within a certain period of time (e.g., 3 minutes) after the driver has fastened the seatbelt unit 1 and is driving normally. The purpose of calibration is to establish personalized baseline parameters for the current driver, avoid misjudgments caused by differences in body shape, sitting posture, and wearing habits, and improve detection accuracy.

[0062] Pressure reference calibration: Collect the stable pressure value of the seat belt body 1 on the driver's torso within a set time (e.g., 3 minutes), record it as the normal sitting posture reference pressure P0, and set the normal fluctuation range of ±20% based on this, that is, the pressure is between 0.8P0 and 1.2P0 as the normal state; the pressure fluctuation range exceeds ±20% but does not exceed ±30% to be judged as mild fatigue; the pressure fluctuation exceeds ±30% to be judged as severe fatigue.

[0063] Heart rate baseline calibration: The driver's heart rate is continuously collected under quiet driving conditions. The average heart rate during the stable period is taken as the baseline heart rate HR0, and the normal working range is set to 60 to 100 beats per minute. When the heart rate is below 50 beats per minute or above 120 beats per minute, it is judged as severe fatigue. When the heart rate is outside the normal range but does not reach the danger threshold, it is judged as mild fatigue.

[0064] Movement frequency benchmark calibration: Collect the driver's body movement frequency under normal driving conditions, and set 5 to 15 large-amplitude movements per minute as the normal range; when the movement frequency drops to less than 3 times per minute, it is judged as severe fatigue; when the movement frequency is between 3 and 5 times, it is judged as mild fatigue.

[0065] After calibration is completed, the reference parameters are stored in a temporary storage area and remain valid within the current driving cycle. They are automatically cleared after the vehicle is powered off and recalibrated the next time it is powered on, ensuring that each driving cycle matches the current driver's state.

[0066] This invention features automatic calibration upon power-on, which can automatically generate personalized benchmark parameters based on different drivers' body types, sitting postures, heart rates, and exercise habits. There is no need to manually adjust the thresholds. It can adaptively match drivers of all ages, including the elderly, adults, men, women, and drivers of all heights and weights, avoiding misjudgments or omissions due to differences in body type.

[0067] S1. After completing the self-test and driver baseline calibration, the fatigue detection module 2 acquires the driver's physiological motion state in real time and generates corresponding physiological motion signals, and sends the physiological motion signals to the control module 3.

[0068] For example, once the driver fastens the seatbelt unit 1, the fatigue detection module 2 (pressure / heart rate / motion sensor) begins to collect the driver's body pressure, heart rate, and motion status in real time, and transmits the signals to the control module 3 (ECU controller). S2, the control module 3 determines whether the driver is in a fatigued state based on the received physiological motion signals and the preset fatigue threshold. If the driver is determined to be in a fatigued state, the fatigue state is further divided into mild fatigue or severe fatigue. If the driver is determined to be in a normal driving state, the vibration unit 4 and the tightening unit 5 are controlled to be in the off state.

[0069] The preset fatigue thresholds include pressure change thresholds, heart rate thresholds, and exercise frequency thresholds. For example, when a driver is in a normal driving state, the pressure change range is set to ±20% of the normal sitting pressure value, the normal heart rate range is 60-100 beats / minute, and the normal exercise frequency range is 5-15 large-amplitude body movements per minute. Simultaneously, criteria for judging severe fatigue are set, such as pressure change exceeding 30%, heart rate below 50 beats / minute or above 120 beats / minute, and exercise frequency below 3 times per minute, which are considered severe fatigue; those between the normal range and severe fatigue are considered mild fatigue.

[0070] Determining whether a driver is fatigued includes: if any one or more parameters in the physiological motion signal are greater than or less than the corresponding threshold, then the driver is determined to be fatigued, and further classified into mild fatigue and severe fatigue based on the physiological motion signal.

[0071] After receiving the physiological motion signal, the control module 3 performs multi-level filtering processing, including mean filtering, sliding window filtering, outlier removal, and trend judgment, to ensure signal stability and reliability.

[0072] Pressure signal processing includes: the controller acquires pressure signals at a sampling frequency of 10Hz, takes an average value every second, and filters out instantaneous impact interference. If a single pressure surge occurs but recovers to the reference range within 1 second, it is determined to be an interference signal and fatigue assessment is not performed; if the pressure deviates from the reference range for more than 2 seconds, it is determined to be a valid change in sitting posture.

[0073] Heart rate signal processing includes: applying a moving average filter to the heart rate signal with a window length of 5 seconds to filter motion artifacts and signal fluctuations caused by turbulence. The controller also judges the trend of heart rate changes; if the heart rate slowly decreases or increases within 10 seconds, it is judged as a change in physiological trend; if it jumps instantaneously, it is judged as interference.

[0074] Motion signal processing: The motion sensor fuses acceleration and angular velocity to obtain the frequency and amplitude of body movements, filters out vehicle vibration frequencies (usually higher than 10Hz), and retains only the low-frequency body movement signals of the driver, thereby improving the accuracy of motion recognition.

[0075] The embodiments of this invention employ signal processing strategies such as filtering algorithms, trend judgment, and outlier removal, which can effectively filter out interference signals such as road bumps, vehicle vibration, and body fine-tuning, and only respond to the actual fatigue state. The false trigger rate is extremely low, and it will not interfere unnecessarily during normal driving, thereby improving driving continuity and comfort.

[0076] The filtered and stable signal is sent to the controller's judgment unit, compared with a preset threshold, and then enters the fatigue level determination process.

[0077] For example, a normal driving condition is determined when the following conditions are met: the pressure value is within ±20% of the reference pressure P0; the heart rate is within 60 to 100 beats per minute; the body movement frequency is 5 to 15 times per minute; and all parameters remain stable without any continuous deviation trend.

[0078] At this time, the controller does not trigger any intervention, and both vibration unit 4 and tightening unit 5 are in sleep mode to collect signals at the set period. Under normal conditions, the sampling period is 3 minutes, that is, a set of signals is collected and judged every 3 minutes, reducing power consumption and reducing frequent calculations.

[0079] For example, mild fatigue is defined as meeting any of the following conditions, but not reaching the severe fatigue threshold: pressure fluctuation exceeds ±20% of the baseline, but does not exceed ±30%; heart rate is below 60 beats / minute or above 100 beats / minute, but above 50 beats / minute and below 120 beats / minute; body movement frequency drops to 3-5 times per minute; a single parameter shows a mild abnormality, while the other parameters remain basically normal.

[0080] Mild fatigue indicates decreased driver alertness, muscle relaxation, and reduced attention, but has not yet manifested as drowsiness, slow reaction, or other dangerous conditions. In such cases, a gentle reminder should be given.

[0081] For example, a severe fatigue state is immediately determined if any of the following conditions are met: pressure fluctuations exceed ±30% of the baseline, indicating significant forward leaning and severe loss of posture control; heart rate is below 50 beats / minute or above 120 beats / minute, indicating an abnormal physiological state; body movement frequency is below 3 times per minute, with no obvious movement for a long time, approaching a state of drowsiness; mild fatigue persists for more than a set time (such as 30 seconds) without recovery, and is automatically upgraded to severe fatigue.

[0082] Severe fatigue indicates that the driver is in a dangerous driving state, with a significant decrease in reaction speed, which may lead to operational errors at any time, requiring the activation of strong intervention strategies.

[0083] S3. If mild fatigue is determined, the control module 3 controls the vibration unit 4 to execute the first vibration mode, which reminds the driver by vibrating the seat belt.

[0084] In the first vibration mode, the vibration intensity and frequency of the vibration unit 4 can be adjusted according to the degree of fatigue. For example, a lower intensity and frequency vibration can be used when there is mild fatigue.

[0085] For example, every 3 minutes, the fatigue detection module 2 acquires the driver's physiological movement state and generates corresponding physiological movement signals, which are then sent to the control module 3. If the driver is determined to be in a state of mild fatigue, the control module 3 activates the vibration unit 4 to execute the first vibration mode to remind the driver.

[0086] For example, when mild fatigue is detected, the controller immediately starts the vibration unit 4 and executes the first vibration mode: the vibration frequency is 30-60Hz, the vibration amplitude is low, and the drive duty cycle is 20%-40%; the vibration mode is intermittent vibration, vibrating for 2 seconds and pausing for 3 seconds, and then repeating in a loop.

[0087] The first vibration mode provides gentle vibrations that will not startle the driver, only alerting them through physical touch without interfering with normal driving operations. During the first vibration mode, the sampling period is reduced from 3 minutes to 1 minute, increasing the monitoring frequency and closely tracking changes in the driver's state. If the driver returns to a normal state during intervention, the vibration immediately stops, and the system returns to normal monitoring mode.

[0088] S4. If severe fatigue is determined, the control module 3 simultaneously controls the vibration unit 4 and the tightening unit 5 to start. The vibration unit 4 executes the second vibration mode and controls the seat belt body 1 of the tightening unit 5 to restrict the driver's physical activity and ensure that the driver cannot perform dangerous operations for a short period of time until the driver regains consciousness.

[0089] For example, if it is determined that the driver is mildly fatigued, the detection interval is reduced and physiological motion signals are collected every 1 minute. If it is determined that the driver is severely fatigued, the control module 3 simultaneously activates the vibration unit 4 and the tightening unit 5. The vibration unit 4 executes the second vibration mode and emits a stronger vibration to remind the driver. The tightening unit 5 tightens the seat belt body 1 to restrict the driver's operation.

[0090] When severe fatigue is detected, the controller simultaneously activates vibration unit 4 and tightening unit 5 to execute the highest level of safety intervention: Vibration unit 4 switches to the second vibration mode: frequency 80-120Hz, amplitude greatly increased, duty cycle 60%-100%, continuous strong vibration, and significantly improved alert intensity; Tightening unit 5 action: The tightening motor drives the roller to rotate in the forward direction, tightening the webbing at a constant speed. The tightening force is controlled between 50N and 150N, which ensures effective restraint and stimulation without causing excessive restraint or discomfort. The tightening action is maintained until the driver's state returns to normal.

[0091] Active tightening can forcibly wake the driver from a physical restraint perspective, while restricting dangerous postures such as leaning forward or to the side, preventing dangerous behaviors such as steering wheel control failure and braking delay due to fatigue. The tightening process is equipped with stall protection, overcurrent protection, and overload protection. When the webbing tightening force exceeds the upper limit, the motor automatically stops to prevent injury to the driver.

[0092] This invention classifies fatigue into three levels: normal, mild fatigue, and severe fatigue. Differentiated intervention strategies are implemented based on the degree of danger to avoid the discomfort and resistance caused by "one-size-fits-all" reminders, and truly achieve the design goal of "gentle awakening, mandatory intervention, and safety first".

[0093] For mild fatigue, low-intensity, low-frequency intermittent vibration is used as a reminder, which does not affect driving operations or cause fright. It only enhances the driver's alertness through tactile cues, conforming to daily driving habits. For severe fatigue, a dual intervention of strong vibration and active tightening is activated, forcibly waking the driver from both tactile stimulation and physical restraint, while restricting dangerous sitting postures and reducing the probability of accidents. This tiered intervention mechanism ensures the effectiveness of fatigue reminders while maximizing the driving experience, solving the problems of traditional alarm devices having a single reminder method, being ineffective against deep fatigue, and easily causing resentment.

[0094] Vibration intensity, frequency, and duty cycle can all be adjusted according to fatigue level. Tightening force and tightening speed can be calibrated through controller software, which can flexibly adapt to drivers of different ages and tolerance levels, achieving personalized intervention for each individual and significantly improving system acceptability and practicality.

[0095] Existing driver fatigue devices only provide alerts, such as audible and visual alarms and voice prompts. These alerts are often ineffective for drivers who are deeply fatigued, have slowed reaction times, or are near drowsy, and thus cannot prevent accidents. This invention activates the active seatbelt tightening function in a state of severe fatigue, forcibly waking the driver through physical restraint and limiting dangerous postures such as leaning forward, tilting, or slipping, allowing the driver to maintain a basic control posture and significantly improving vehicle driving safety.

[0096] S5. When the control module 3 determines that the driver has returned to normal driving state based on the received physiological motion signal and the preset fatigue threshold, it controls the vibration unit 4 and the tightening unit 5 to close, the vibration unit 4 stops vibrating, and the seat belt body 1 returns to the normal restraint state.

[0097] During the intervention, signals are continuously collected in real time. Once the driver is determined to have returned to normal driving status after multiple consecutive samplings (e.g., 3 consecutive samplings), the vibration unit 4 immediately stops vibrating; the tightening unit 5 controls the motor to reverse and slowly releases the webbing, so that the seat belt returns to normal restraint force and the retractor returns to its normal free extension and retraction function; the normal monitoring mode is returned and the sampling cycle is restored to 3 minutes.

[0098] If the driver is unable to return to normal after prolonged intervention, the controller sends the highest level fatigue alarm signal to the entire vehicle via the CAN bus, triggering an instrument panel audible and visual alarm and a voice reminder to prompt the driver to stop and rest immediately.

[0099] In any fault condition, the active intervention function of this invention will be automatically cut off, so that the seat belt returns to its original passive restraint state. The core safety function of the seat belt will not be affected by electronic system failure, which is in line with the functional safety design concept of automobiles and ensures that the vehicle has basic safety protection under any working conditions.

[0100] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A seat belt active adjustment device, characterized by, include: Seat belt body (1); A fatigue detection module (2) is installed on the seat belt body (1). The fatigue detection module (2) is used to acquire the driver's physiological motion state in real time and generate corresponding physiological motion signals. The control module (3) is used to receive and analyze physiological motion signals, determine whether the driver is in a state of fatigue according to the preset fatigue threshold, and classify the fatigue state into mild fatigue and severe fatigue. The execution module includes a vibration unit (4) and a tightening unit (5). The control module (3) is configured to: when the driver is slightly fatigued, control the vibration unit (4) to start executing the first vibration mode to remind the driver; when the driver is severely fatigued, simultaneously start the vibration unit (4) and the tightening unit (5), the vibration unit (4) executes the second vibration mode, and the tightening unit tightens the seat belt body (1) to restrict the driver's body movement.

2. The active seat belt adjustment device of claim 1, wherein, The fatigue detection module (2) includes a pressure sensor, a heart rate sensor, and a motion sensor; The pressure sensor is used to detect the pressure change of the seat belt body (1) on the driver's body and generate a pressure signal; The heart rate sensor is used to generate a heart rate signal based on real-time monitoring of the driver's heart rate; The motion sensor is used to generate motion signals based on the detected motion state of the driver's body.

3. The seat belt active adjustment device of claim 1, wherein, The fatigue detection module (2) is made of flexible low-current communication wire and integrated into the webbing of the seat belt body (1).

4. The seat belt active adjustment device of claim 1, wherein The fatigue detection module (2) and the vibration unit (4) are arranged along the length of the webbing and fit snugly against the driver's chest, abdomen or shoulders when worn.

5. The seat belt active adjustment device of claim 1, wherein, The control module (3) is located below the seat (6), inside the seat (6) frame, or inside the seat (6) side panel.

6. A vehicle characterized by comprising: Includes the active seatbelt adjustment device as described in any one of claims 1-5.

7. A method of active seat belt adjustment, characterized in that Includes the following steps: The fatigue detection module (2) acquires the driver's physiological motion state in real time and generates corresponding physiological motion signals; The control module (3) determines whether the driver is in a state of fatigue based on the received physiological motion signals and the preset fatigue threshold. If the driver is determined to be in a state of fatigue, the fatigue state is further divided into mild fatigue or severe fatigue. If mild fatigue is determined, the control module (3) controls the vibration unit (4) to execute the first vibration mode, which reminds the driver by vibrating the seat belt; If severe fatigue is determined, the control module (3) simultaneously controls the vibration unit (4) and the tightening unit (5) to start. The vibration unit (4) executes the second vibration mode and controls the retractor to tighten the seat belt, restricting the driver's physical activity.

8. The seat belt active adjustment method of claim 7, wherein, The preset fatigue thresholds include pressure change threshold, heart rate threshold, and exercise frequency threshold.

9. The seat belt active adjustment method of claim 7, wherein, The frequency, amplitude, and intensity of the second vibration mode are all greater than those of the first vibration mode.

10. The method of active seat belt adjustment according to any one of claims 7-9, characterized in that, Determining whether a driver is fatigued includes: if any one or more parameters in the physiological motion signal are greater than or less than the corresponding threshold, then the driver is determined to be fatigued.

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