Automobile seat anti-pinch control method based on double hall sensors

Abstract

The application provides a kind of based on double hall sensor's car seat anti-pinch control method, it is related to the technical field of car seat.Based on double hall sensor's car seat anti-pinch control method, it includes the following steps: real-time acquisition seat drive motor operating current and two hall sensor signals;The motor current signal collected is filtered;Call the reference current value corresponding to the current motor speed;Based on the filtered current value, calculate the current rate of change, calculate the hall frequency rate of change based on two hall signals, and identify the motor rotation direction;The current rate of change and the hall frequency rate of change are compared with dynamic threshold;When the current rate of change and the hall frequency rate of change exceed their corresponding dynamic threshold at the same time, and the motor is identified to be in the driving direction, it is determined that an anti-pinch event occurs;After determining anti-pinch, control the motor to execute stop or reverse action.The technical effect of improving the anti-pinch effect of car seat is achieved.

Description

Technical Field

[0001] This invention relates to the field of automotive seat technology, and more specifically, to an anti-pinch control method for automotive seats based on dual Hall effect sensors. Background Technology

[0002] With the increasing demands for intelligent and comfortable vehicles, anti-pinch functionality in electric seats has become a standard feature in high-end models. The measured anti-pinch force of existing seat products exceeds 120N. This excessively high anti-pinch force threshold not only reduces the user experience but also implies that the obstacle would be under significant pressure in the event of actual pinching.

[0003] Existing anti-pinch algorithms generally suffer from false triggering issues. For example, when the vehicle is traveling on a bumpy road, the user is actively leaning against the backrest, or there is interference from the motor's own ripple noise, the system may misjudge it as a pinching event and execute a reverse action, affecting the normal use of the function and user trust. Summary of the Invention

[0004] The purpose of this invention is to provide a car seat anti-pinch control method based on dual Hall sensors, so as to alleviate the technical problem of poor anti-pinch effect of car seats in the prior art.

[0005] In a first aspect, embodiments of the present invention provide a method for preventing pinching of automotive seats based on dual Hall effect sensors, comprising the following steps: S1: Real-time acquisition of the operating current of the seat drive motor and signals from two Hall sensors; S2: Filter the acquired motor current signal; S3: Calls the reference current value corresponding to the current motor speed; S4: Calculate the current change rate based on the filtered current value, calculate the Hall frequency change rate based on the two Hall signals, and identify the motor rotation direction; S5: Compare the rate of change of current and the rate of change of Hall frequency with the dynamic threshold; S6: When the rate of change of current and the rate of change of Hall frequency both exceed their corresponding dynamic thresholds, and the motor is detected to be in the driving direction, an anti-pinch event is determined to have occurred. S7: After determining that an anti-pinch event has occurred, control the motor to perform a stop or reverse action.

[0006] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein, in step S1 above, the power supply voltage and ambient temperature of the seat drive motor are collected in real time, and an environmental compensation coefficient is obtained by querying a pre-stored voltage and temperature two-dimensional correction table based on the power supply voltage and ambient temperature.

[0007] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein, in step S5, the rate of change of current and the rate of change of Hall frequency are compared with a dynamic threshold adjusted by an environmental compensation coefficient.

[0008] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein, in step S4, the phase difference between the two output signals of the two Hall sensors is used to determine whether the motor is in a forward drive, reverse drive, or inertial coasting state.

[0009] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein, in step S2, the acquired motor current signal is subjected to sliding window filtering processing.

[0010] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the window size N of the sliding window filtering is 10 to 20 sampling points.

[0011] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the physical anti-pinch force threshold corresponding to the above-mentioned anti-pinch event is not greater than 100N.

[0012] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein the above-mentioned car seat anti-pinch control method based on dual Hall sensors further includes a self-learning update module, which updates the new current data to the reference curve when the number of stable motor operation cycles reaches a preset value.

[0013] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein when the collected current value continuously exceeds the current reference curve threshold, new current data is updated to the reference curve.

[0014] In conjunction with the first aspect, the present invention provides a possible implementation of the first aspect, wherein, in step S3 above, the reference current value corresponding to the current motor speed is called after self-learning update.

[0015] Beneficial effects: This invention provides a method for anti-pinch control of automotive seats based on dual Hall sensors, comprising the following steps: S1: Real-time acquisition of the operating current of the seat drive motor and signals from two Hall sensors; S2: Filtering the acquired motor current signal; S3: Calling a reference current value corresponding to the current motor speed; S4: Calculating the current change rate based on the filtered current value, calculating the Hall frequency change rate based on the two Hall signals, and identifying the motor rotation direction; S5: Comparing the current change rate and the Hall frequency change rate with dynamic thresholds; S6: When the current change rate and the Hall frequency change rate simultaneously exceed their corresponding dynamic thresholds, and the motor is identified as being in the driving direction, an anti-pinch event is determined to have occurred; S7: After determining that an anti-pinch event has occurred, controlling the motor to perform a stop or reverse action.

[0016] Specifically, the car seat anti-pinch control method based on dual Hall sensors controls the car seat. The two Hall sensors can identify the forward and reverse directions of the motor, thereby effectively distinguishing between normal motor drive, inertial gliding and mechanical rebound, fundamentally solving the problem of false triggering, effectively distinguishing between real clamping and non-clamping conditions such as road bumps, user active pressure, and motor ripple noise, and eliminating false anti-pinch actions. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific 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 from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram illustrating the principle of the anti-pinch control method for car seats based on dual Hall sensors provided in an embodiment of the present invention. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0022] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0023] The present invention will now be described in further detail with reference to specific embodiments and accompanying drawings.

[0024] See Figure 1 As shown, this embodiment provides a car seat anti-pinch control method based on dual Hall sensors, including the following steps: S1: Real-time acquisition of the operating current of the seat drive motor and signals from two Hall sensors; S2: Filtering the acquired motor current signal; S3: Calling the reference current value corresponding to the current motor speed; S4: Calculating the current change rate based on the filtered current value, calculating the Hall frequency change rate based on the two Hall signals, and identifying the motor rotation direction; S5: Comparing the current change rate and Hall frequency change rate with dynamic thresholds; S6: When the current change rate and Hall frequency change rate simultaneously exceed their corresponding dynamic thresholds, and the motor is identified as being in the driving direction, an anti-pinch event is determined to have occurred; S7: After determining that an anti-pinch event has occurred, controlling the motor to perform a stop or reverse action.

[0025] Specifically, the car seat anti-pinch control method based on dual Hall sensors controls the car seat. The two Hall sensors can identify the forward and reverse directions of the motor, thereby effectively distinguishing between normal motor drive, inertial gliding and mechanical rebound, fundamentally solving the problem of false triggering, effectively distinguishing between real clamping and non-clamping conditions such as road bumps, user active pressure, and motor ripple noise, and eliminating false anti-pinch actions.

[0026] In step S1, the power supply voltage and ambient temperature of the seat drive motor are collected in real time. Based on the power supply voltage and ambient temperature, a pre-stored two-dimensional voltage and temperature correction table is queried to obtain the environmental compensation coefficient.

[0027] In step S5, the rate of change of current and the rate of change of Hall frequency are compared with the dynamic threshold adjusted by the environmental compensation coefficient.

[0028] In step S4, the phase difference between the two output signals of the two Hall sensors is used to determine whether the motor is in a forward drive, reverse drive, or inertial coasting state.

[0029] In step S2, the acquired motor current signal is subjected to sliding window filtering.

[0030] In this case, the window size N of the sliding window filter is 10 to 20 sampling points.

[0031] Among them, the physical anti-pinch force threshold corresponding to the anti-pinch event is no greater than 100N.

[0032] Among them, the car seat anti-pinch control method based on dual Hall sensors also includes a self-learning update module, which updates the new current data to the reference curve when the number of stable motor operation cycles reaches a preset value.

[0033] Specifically, when the collected current value continuously exceeds the current reference curve threshold, new current data is updated to the reference curve.

[0034] Specifically, here's an example of a self-learning process: Assume the system is set to trigger a self-learning update every 100 complete seat backrest adjustment cycles. At the end of the 100th cycle, the system extracts the current data from the stable operation phase of this cycle, filters and averages it to generate a new temporary reference curve. This curve is then weighted and fused with the stored historical reference curves (e.g., the new data has a 30% weight) to form an updated reference curve, which is then written back to storage. This process allows the system to slowly track long-term changes in motor performance.

[0035] In step S3, the reference current value corresponding to the current motor speed is called and updated through self-learning.

[0036] Specifically, the system acquires motor current in real time through a high-precision ADC, sampling at 20kHz with 12-bit resolution; it also uses two Hall sensors to accurately capture motor speed, position, and direction of rotation at 1kHz; it employs sliding window filtering to suppress noise in the current information and uses a two-dimensional correction table to compensate for environmental variables such as voltage and temperature in real time; the system has self-learning capabilities, dynamically updating the current reference curve for normal operation, and using a dual judgment based on the rate of change of current and the rate of change of Hall sensors to accurately identify clamping events; once clamping is detected, the system can control the motor to stop or reverse within 40ms.

[0037] It should be noted that one Hall signal is used to determine the motor's normal speed and position calculations, while the other is specifically used to identify the motor's rotation direction. By comparing the phase difference between the two Hall signals, it can be clearly determined whether the motor is in an active drive state, an inertial rotation state after power failure, or a reverse rotation caused by the mechanism's rebound. This information can distinguish between "actual clamping causing stall" and "mechanical rebound / inertia," thereby preventing false clamping actions and solving the problem of accumulated deviations caused by changes in mechanical clearance after long-term operation.

[0038] In addition, after the system is powered on, it loads a preset reference current curve from storage. After each seat adjustment is completed, the system will evaluate the current data of this operation. If the preset learning conditions are met (such as a threshold for the number of stable operations), the new current data will be smoothly updated to the reference curve and written back to storage. This mechanism enables the system to adapt to long-term drift such as motor efficiency decay and lubrication changes.

[0039] Specifically, when using the dual-Hall sensor-based anti-pinch control method for car seats, after the car seat system is powered on, the anti-pinch control ECU first performs hardware initialization, then reads the pre-stored self-learning reference current curve and two-dimensional correction table data from storage to complete system parameter preparation. Then, real-time signal acquisition and processing are performed. During the operation of the seat adjustment motor, the system samples the motor phase current at a frequency of 20kHz and the dual-Hall sensor signal at a frequency of 1kHz. Simultaneously, the power supply voltage and ambient temperature are periodically read. The raw current signal is first filtered through a sliding window (e.g., window size N=15) to suppress high-frequency switching noise, obtaining a smooth current value and its instantaneous fluctuation value i. The dual-Hall signal is parsed to extract the motor's real-time speed and key direction indicators. Environmental compensation and dynamic reference are obtained. Based on the currently detected voltage value (e.g., 12.5V) and temperature value (e.g., 25°C), the two-dimensional correction table is consulted, and a compensation coefficient K is obtained through bilinear interpolation. comp Simultaneously, based on the current motor operating speed, the corresponding normal no-load / load current reference value I at that speed point is obtained from the self-learning reference current curve. baseThen, anti-pinch judgment and execution are performed, calculating the rate of change of the current after filtering relative to the reference value ΔI / Δt, and the rate of change of the current Hall frequency ΔF. hall / Δt, the compensation coefficient K comp Applied to a preset anti-pinch force-rate of change mapping threshold, a dynamic judgment threshold is obtained under the current working condition. This threshold is only determined when ΔI / Δt and ΔF... hall The system determines that a real clamping has occurred only when both / Δt and the motor drive PWM exceed their respective dynamic thresholds, and the Hall direction signal indicates that the motor is in a driving state rather than an inertial or rebounding state. Once the determination is made, the motor control module immediately acts, cutting off the motor drive PWM within 40ms and applying a short reverse pulse to cause the seat to move in the opposite direction to release the clamped object.

[0040] It should be noted that the Hall change rate refers to the fact that the anti-pinch function will only be triggered when the change rates of both Halls reach the anti-pinch trigger threshold, thereby avoiding the risk of false anti-pinch judgment and improving detection accuracy.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them. 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 or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preventing pinching of car seats based on dual Hall effect sensors, characterized in that, Includes the following steps: S1: Real-time acquisition of the operating current of the seat drive motor and signals from two Hall sensors; S2: Filter the acquired motor current signal; S3: Calls the reference current value corresponding to the current motor speed; S4: Calculate the current change rate based on the filtered current value, calculate the Hall frequency change rate based on the two Hall signals, and identify the motor rotation direction; S5: Compare the rate of change of current and the rate of change of Hall frequency with the dynamic threshold; S6: When the rate of change of current and the rate of change of Hall frequency both exceed their corresponding dynamic thresholds, and the motor is detected to be in the driving direction, an anti-pinch event is determined to have occurred. S7: After determining that an anti-pinch event has occurred, control the motor to perform a stop or reverse action.

2. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 1, characterized in that, In step S1, the power supply voltage and ambient temperature of the seat drive motor are collected in real time. Based on the power supply voltage and ambient temperature, the pre-stored voltage and temperature two-dimensional correction table is queried to obtain the environmental compensation coefficient.

3. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 2, characterized in that, In step S5, the rate of change of current and the rate of change of Hall frequency are compared with the dynamic threshold adjusted by the environmental compensation coefficient.

4. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 1, characterized in that, In step S4, the phase difference between the two output signals of the two Hall sensors is used to determine whether the motor is in forward drive, reverse drive, or inertial coasting state.

5. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 1, characterized in that, In step S2, the acquired motor current signal is subjected to sliding window filtering.

6. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 5, characterized in that, The window size N of the sliding window filter is 10 to 20 sampling points.

7. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 1, characterized in that, The physical anti-pinch force threshold corresponding to the anti-pinch event is no greater than 100N.

8. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 1, characterized in that, It also includes a self-learning update module, which updates the new current data to the reference curve when the number of stable operation cycles of the motor reaches a preset value.

9. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 8, characterized in that, When the collected current value continuously exceeds the current reference curve threshold, the new current data is updated to the reference curve.

10. The automotive seat anti-pinch control method based on dual Hall sensors according to claim 9, characterized in that, In step S3, the self-learned updated reference current value corresponding to the current motor speed is called.

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