Locked-rotor current self-protection system of automobile seat motor

Abstract

The invention discloses a locked-rotor current self-protection system of an automobile seat motor, and relates to the technical field of locked-rotor protection of automobile seat motors. Comprising a current sensor module which is used for collecting a working current signal of a motor; the signal conditioning circuit module processes a signal output from the current sensor, amplifies a weak signal based on an amplifier, and removes a high-frequency noise component based on a low-pass filter; and the microcontroller module is used for receiving the digital signal from the signal conditioning circuit and analyzing and processing the data according to a preset program algorithm. According to the method, the locked-rotor state is judged by adopting double indexes based on the current change rate and the absolute value, and compared with a traditional single threshold value method, the method has higher accuracy and reliability; the transient current fluctuation influence caused by high current impact at the starting moment of the motor and other non-locked-rotor factors is avoided, and the false alarm rate is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of automotive seat motor stall protection technology, and more particularly to a stall current self-protection system for automotive seat motors. Background Technology

[0002] With the rapid development of the automotive industry, electric adjustment of car seats has become a standard feature. However, in actual use, various reasons (such as mechanical jamming, obstruction by foreign objects, etc.) may cause the seat motor to stall. If the motor remains stalled for a long time, the excessive current will rapidly increase the temperature, which may not only burn out the motor windings but also cause safety hazards such as fire.

[0003] Traditional solutions often use simple fuses or thermal relays for overcurrent protection, but these have significant drawbacks, as follows:

[0004] ① Mechanical protection elements have fixed operating thresholds and long reset times, making them unable to adapt to dynamically changing load conditions;

[0005] ② It is difficult to distinguish between normal starting current and abnormal stall current, which can easily lead to false triggering (such as transient peaks during ramp start);

[0006] ③ It can only achieve passive power outage and lacks fault diagnosis, status feedback and adaptive adjustment capabilities.

[0007] Therefore, there is an urgent need for a self-protection system for stall current of automotive seat motors to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of existing technologies by proposing a self-protection system for stall current in automotive seat motors.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The locked-rotor current self-protection system for automotive seat motors includes:

[0011] A current sensor module, which is used to acquire the operating current signal of the motor;

[0012] The signal conditioning circuit module processes the signal output from the current sensor, amplifies the weak signal based on an amplifier, and removes high-frequency noise components based on a low-pass filter.

[0013] The microcontroller module receives digital signals from the signal conditioning circuit and analyzes and processes the data according to a preset program algorithm.

[0014] A stall detection algorithm module, which determines whether the motor is stalled based on an established stall detection model;

[0015] The protection execution module, based on the judgment result of the stall judgment algorithm module, if the stall is determined, cuts off the motor power supply line based on the relay; achieves soft shutdown based on the power MOSFET array, gradually reduces the voltage across the motor, reduces current surge impact, and at the same time issues an audible and visual alarm signal based on the alarm component.

[0016] The communication feedback module transmits the motor's operating status information to the vehicle's main controller or instrument panel display.

[0017] Preferably, the current sensor module includes:

[0018] The main sensing unit uses a Hall current sensor to accurately measure the current without contacting the wires;

[0019] The temperature compensation unit uses a thermistor to monitor the sensor's operating temperature in real time and corrects the measurement results based on temperature changes.

[0020] The anti-interference shielding unit uses a metal shielding cover to enclose the sensor.

[0021] Preferably, the main sensing unit accurately measures the current magnitude without contacting the wires, specifically:

[0022] Let the phase current of the motor be I. p Then the Hall sensor output voltage V out with I p They are directly proportional, which can be expressed as:

[0023] V out =k×I p

[0024] Where k is the proportionality coefficient, which is determined by the characteristics of the sensor itself.

[0025] Preferably, the signal conditioning circuit module includes:

[0026] The preamplifier unit amplifies the signal output from the current sensor through a low-noise operational amplifier to bring the signal up to the level required for subsequent processing.

[0027] The multi-stage filtering unit includes a combination of various types of filters such as low-pass filters, band-pass filters, and notch filters. The low-pass filter is used to remove high-frequency noise components and improve the signal-to-noise ratio of the signal. The band-pass filter allows useful signals within a specific frequency range to pass through while suppressing other irrelevant frequency components. The notch filter is used to specifically eliminate noise at specific frequency points, such as power frequency interference, making the final analog signal smoother and more stable.

[0028] The analog-to-digital conversion unit, based on the ADC chip, converts the conditioned analog signal into a digital signal for the MCU to perform calculations and processing.

[0029] The reference voltage source unit provides a reference voltage as a standard reference for ADC conversion, ensuring consistency between different batches of devices and stability under different operating conditions.

[0030] Preferably, the microcontroller module includes:

[0031] The central processing unit receives digital signals from the signal conditioning circuit based on a microcontroller chip, analyzes and processes the data according to a preset program algorithm, makes timely decisions, and issues instructions to the protection execution module.

[0032] The program storage and loading unit is used to store application code and configuration parameters;

[0033] The clock management unit provides a time reference signal to ensure timing synchronization of the entire system.

[0034] Preferably, the stall detection algorithm module includes:

[0035] The data acquisition and preprocessing unit performs smoothing filtering and DC component removal operations on the digital signal from the ADC to remove random fluctuations and offsets.

[0036] The feature extraction and analysis unit extracts feature parameters that can characterize the stall state based on the characteristic curves of motor operation and historical statistical data. By analyzing the feature parameters, a stall identification model is constructed.

[0037] The threshold setting dynamic adjustment unit dynamically adjusts the various threshold indicators for stall detection according to different working conditions.

[0038] The logic decision-making unit combines the collected data and the preset rule base, and uses fuzzy logic reasoning or neural network algorithms to make a comprehensive judgment; when the preset conditions are met, it issues a blocking warning signal; if blocking is confirmed to have occurred, it initiates protective measures.

[0039] Preferably, the stall detection algorithm module detects that the motor current rises sharply within a short period of time, exceeding a set threshold I. th1 And it remains above another lower threshold I.th2 The time exceeded the scheduled duration T h When this occurs, it is determined that the motor is stalled; the details are as follows:

[0040] if And I>I th1 If so, the pre-alarm procedure will be activated;

[0041] If I>I is further satisfied th2 And the duration t>T h If so, the stalled state is confirmed;

[0042] Where ΔI represents the current increment, Δt is the corresponding time interval, and S r This is the threshold for the rate of current rise.

[0043] Preferably, the protection execution module includes:

[0044] When the power cut-off control unit confirms that the motor is in a stalled state, it immediately triggers the relay drive circuit to disconnect the main power supply line of the motor and prevents the continued supply of electrical energy to the motor.

[0045] The soft-shutdown buffer unit, based on an H-bridge drive circuit composed of a power MOSFET array, realizes the soft-shutdown function; by gradually reducing the PWM duty cycle, the voltage across the motor is reduced, thus reducing current surge impact.

[0046] An alarm indication output unit includes a visual alarm and an audible alarm; when a stall fault is detected, a warning is issued based on the visual alarm and the audible alarm.

[0047] The fault-locking memory unit records stall events and related parameters, and stores them in memory.

[0048] Preferably, the communication feedback module includes:

[0049] Protocol stack implementation unit, supporting CAN bus and LIN bus;

[0050] The command receiving and parsing unit listens for command frames on the bus, parses control instructions from the upper-level control system, and returns the execution results to the sender.

[0051] The data analysis and storage unit collects and saves operational data samples within a set time period, forming a database file.

[0052] Preferably, the self-protection method of the system includes the following steps:

[0053] S1: Initialization. After the system is powered on, the MCU first performs initialization settings, and each functional module is in standby mode, waiting for the motor start signal to arrive.

[0054] S2: Operation monitoring. When a valid motor start command is received, the current sensor starts to collect motor current data in real time. After being processed by the signal conditioning circuit, the data is sent to the MCU for analysis.

[0055] S3: The MCU continuously monitors the current changes according to the stall condition judgment algorithm. As long as the stall condition is not met, the motor is allowed to run normally, and the current working parameters are periodically reported to other systems for reference through the communication feedback module.

[0056] S4: Stalled rotor detection and response. When an abnormal current condition that meets the stalled rotor condition is detected during operation, the MCU immediately enters the emergency handling process; the control and protection execution module cuts off the motor power supply and implements a soft shutdown strategy.

[0057] S5: Activate the audible and visual alarm device to remind the driver to pay attention to safety; record the traffic jam incident and upload it to the superior monitoring system through the communication feedback module;

[0058] S6: After eliminating the cause of the stall, the driver can send a reset signal to the system through the operating interface; upon receiving the reset command, the MCU re-evaluates the motor status, and after confirming that there are no errors, restores normal power supply, allowing the motor to return to a runnable state.

[0059] The beneficial effects of this invention are as follows:

[0060] 1. This invention uses a dual index based on the rate of change of current and the absolute value to determine the stall state, which has higher accuracy and reliability compared with the traditional single threshold method.

[0061] 2. This invention avoids the impact of high current surges during motor startup and transient current fluctuations caused by other non-stall factors, effectively reducing the false alarm rate.

[0062] 3. This invention combines hard power-off protection with soft shutdown technology, and gradually reduces the motor voltage through the power MOSFET array, thereby reducing the impact of current surges on the motor and extending the motor's service life. Attached Figure Description

[0063] Figure 1 This is a flowchart of the self-protection method of the stall current self-protection system for automotive seat motors proposed in this invention;

[0064] Figure 2 This is a framework diagram of the stall current self-protection system for the automotive seat motor proposed in this invention. Detailed Implementation

[0065] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0066] Example 1:

[0067] The locked-rotor current self-protection system for automotive seat motors includes:

[0068] A current sensor module, which is used to acquire the operating current signal of the motor;

[0069] The signal conditioning circuit module processes the signal output from the current sensor, amplifies the weak signal based on an amplifier, and removes high-frequency noise components based on a low-pass filter.

[0070] The microcontroller module receives digital signals from the signal conditioning circuit and analyzes and processes the data according to a preset program algorithm.

[0071] A stall detection algorithm module, which determines whether the motor is stalled based on an established stall detection model;

[0072] The protection execution module, based on the judgment result of the stall judgment algorithm module, if the stall is determined, cuts off the motor power supply line based on the relay; achieves soft shutdown based on the power MOSFET array, gradually reduces the voltage across the motor, reduces current surge impact, and at the same time issues an audible and visual alarm signal based on the alarm component.

[0073] The communication feedback module transmits the motor's operating status information to the vehicle's main controller or instrument panel display.

[0074] The current sensor module includes:

[0075] The main sensing unit employs a high-precision Hall current sensor, which, based on the principle of electromagnetic induction, can accurately measure the current magnitude without contacting the wires; let the motor phase current be I. p Then the Hall sensor output voltage V out with I p They are directly proportional, which can be expressed as:

[0076] V out =k×I p

[0077] Where k is the proportionality coefficient, which is determined by the characteristics of the sensor itself; by reasonably selecting the sensor parameters, we can ensure that accurate current measurement values ​​can be obtained within the range of normal motor operation and possible stall.

[0078] The temperature compensation unit uses a thermistor to monitor the sensor's operating temperature in real time and corrects the measurement results based on temperature changes to improve the stability of measurement accuracy.

[0079] The anti-interference shielding unit uses a metal shielding cover to enclose the sensor. In addition, filter capacitors can be added to the circuit to further suppress the influence of high-frequency noise.

[0080] The signal conditioning circuit module includes:

[0081] The preamplifier unit amplifies the signal output from the current sensor through a low-noise operational amplifier to bring the signal up to the level required for subsequent processing.

[0082] The multi-stage filtering unit includes a combination of various types of filters such as low-pass filters, band-pass filters, and notch filters. The low-pass filter is used to remove high-frequency noise components and improve the signal-to-noise ratio of the signal. The band-pass filter allows useful signals within a specific frequency range to pass through while suppressing other irrelevant frequency components. The notch filter is used to specifically eliminate noise at specific frequency points, such as power frequency interference, making the final analog signal smoother and more stable.

[0083] The analog-to-digital converter (ADC) unit, based on an ADC chip, converts the conditioned analog signal into a digital signal for the MCU to perform calculations and processing.

[0084] The reference voltage source unit provides a reference voltage as a standard reference for ADC conversion, ensuring consistency between different batches of devices and stability under different operating conditions.

[0085] The microcontroller module includes:

[0086] The central processing unit receives digital signals from the signal conditioning circuit based on a microcontroller chip and analyzes and processes the data according to a preset program algorithm. It integrates peripheral resources, such as timers and serial communication interfaces, to facilitate interaction and communication with other modules and to implement the system's control logic. By quickly executing the stall judgment algorithm, it makes timely decisions and issues instructions to the protection execution module.

[0087] The program storage and loading unit is used to store application code and configuration parameters;

[0088] The clock management unit provides a time reference signal to ensure timing synchronization of the entire system.

[0089] The stall detection algorithm module includes:

[0090] The data acquisition and preprocessing unit performs smoothing filtering and DC component removal operations on the digital signal from the ADC to remove random fluctuations and offsets.

[0091] The feature extraction and analysis unit extracts feature parameters that can characterize the stall state based on the characteristic curves of motor operation and historical statistical data. By analyzing the feature parameters, a stall identification model is constructed.

[0092] The threshold setting dynamic adjustment unit dynamically adjusts the various threshold indicators for stall detection according to different operating conditions (such as load size, speed, etc.). For example, it allows a large current surge at startup without triggering a false alarm, while strictly controlling the upper limit of the current during stable operation to ensure timely detection of potential stall risks.

[0093] The logic decision-making unit combines the collected data and the preset rule base, and uses fuzzy logic reasoning or neural network algorithms to make a comprehensive judgment; when the preset conditions are met, it issues a stall warning signal; if stalling is confirmed, it activates protection measures; and at the same time, it records detailed fault information.

[0094] The stall detection algorithm module detects when the motor current rises sharply within a short period of time, exceeding a set threshold I. th1 And it remains above another lower threshold I. th2 The time exceeded the scheduled duration T h When this occurs, it is determined that the motor is stalled. Specifically:

[0095] if And I>I th1 If so, the pre-alarm procedure will be activated;

[0096] If I>I is further satisfied th2 And the duration t>T h If so, the stalled state is confirmed;

[0097] Where ΔI represents the current increment, Δt is the corresponding time interval, and S r This is the threshold for the rate of current rise.

[0098] The protection execution module includes:

[0099] When the power cut-off control unit confirms that the motor is in a stalled state, it immediately triggers the relay drive circuit to disconnect the main power supply line of the motor and prevents the continued supply of electrical energy to the motor.

[0100] The soft-shutdown buffer unit, based on an H-bridge drive circuit composed of a power MOSFET array, realizes the soft-shutdown function; by gradually reducing the PWM duty cycle, the voltage across the motor is reduced, thus reducing current surge impact.

[0101] The alarm indication output unit includes visual alarms (such as LED lights) and audible alarms (such as buzzers); when a stall fault is detected, the driver is warned to pay attention to safety based on the visual and audible alarms.

[0102] The fault-locking memory unit records stall events and related parameters, and stores them in memory.

[0103] The communication feedback module includes:

[0104] The protocol stack implementation unit supports multiple vehicle network protocols, such as CAN bus and LIN bus, so as to seamlessly integrate with other vehicle electronic devices;

[0105] The command receiving and parsing unit listens to command frames on the bus, parses control instructions from the upper-level control system (such as starting / stopping the motor, querying status, resetting fault codes, etc.), and returns the execution results to the sender.

[0106] The data analysis and storage unit collects and saves operational data samples within a set time period, forming a database file.

[0107] The self-protection method of the system includes the following steps:

[0108] S1: Initialization. After the system is powered on, the MCU first performs initialization settings, and each functional module is in standby mode, waiting for the motor start signal to arrive.

[0109] S2: Operation monitoring. When a valid motor start command is received, the current sensor starts to collect motor current data in real time. After being processed by the signal conditioning circuit, the data is sent to the MCU for analysis.

[0110] S3: The MCU continuously monitors the current changes according to the stall condition judgment algorithm. As long as the stall condition is not met, the motor is allowed to run normally, and the current working parameters are periodically reported to other systems for reference through the communication feedback module.

[0111] S4: Stalled rotor detection and response. When an abnormal current condition that meets the stalled rotor condition is detected during operation, the MCU immediately enters the emergency handling process; the control and protection execution module cuts off the motor power supply and implements a soft shutdown strategy.

[0112] S5: Activate the audible and visual alarm device to remind the driver to pay attention to safety; record the traffic jam incident and upload it to the superior monitoring system through the communication feedback module;

[0113] S6: After eliminating the cause of the stall, the driver can send a reset signal to the system through the operating interface; upon receiving the reset command, the MCU re-evaluates the motor status, and after confirming that there are no errors, restores normal power supply, allowing the motor to return to a runnable state.

[0114] The following components can be used in this solution:

[0115]

[0116] This invention uses a dual indicator based on the rate of change and absolute value of current to determine the stall state, which has higher accuracy and reliability compared to the traditional single threshold method; it avoids the impact of high current surge at the moment of motor start-up and other short-term current fluctuations caused by non-stall factors, effectively reducing the false alarm rate.

[0117] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A self-protection system for stall current of an automotive seat motor, characterized in that, include: A current sensor module, which is used to acquire the operating current signal of the motor; The signal conditioning circuit module processes the signal output from the current sensor, amplifies the weak signal based on an amplifier, and removes high-frequency noise components based on a low-pass filter. The microcontroller module receives digital signals from the signal conditioning circuit and analyzes and processes the data according to a preset program algorithm. A stall detection algorithm module, which determines whether the motor is stalled based on an established stall detection model; The protection execution module, based on the judgment result of the stall judgment algorithm module, if the stall is determined, cuts off the motor power supply line based on the relay; achieves soft shutdown based on the power MOSFET array, gradually reduces the voltage across the motor, reduces current surge impact, and at the same time issues an audible and visual alarm signal based on the alarm component. The communication feedback module transmits the motor's operating status information to the vehicle's main controller or instrument panel display.

2. The self-protection system for stall current of an automotive seat motor according to claim 1, characterized in that, The current sensor module includes: The main sensing unit uses a Hall current sensor to accurately measure the current without contacting the wires; The temperature compensation unit uses a thermistor to monitor the sensor's operating temperature in real time and corrects the measurement results based on temperature changes. The anti-interference shielding unit uses a metal shielding cover to enclose the sensor.

3. The self-protection system for stall current of the automotive seat motor according to claim 2, characterized in that, The main sensing unit accurately measures the current magnitude without contacting the wires, specifically: Let the phase current of the motor be I. p Then the Hall sensor output voltage V out with I p They are directly proportional, which can be expressed as: In out =k×I p Where k is the proportionality coefficient, which is determined by the characteristics of the sensor itself.

4. The self-protection system for stall current of the automotive seat motor according to claim 1, characterized in that, The signal conditioning circuit module includes: The preamplifier unit amplifies the signal output from the current sensor through a low-noise operational amplifier to bring the signal up to the level required for subsequent processing. The multi-stage filtering unit includes a combination of various types of filters such as low-pass filters, band-pass filters, and notch filters. The low-pass filter is used to remove high-frequency noise components and improve the signal-to-noise ratio of the signal. The band-pass filter allows useful signals within a specific frequency range to pass through while suppressing other irrelevant frequency components. The notch filter is used to specifically eliminate noise at specific frequency points, such as power frequency interference, making the final analog signal smoother and more stable. The analog-to-digital conversion unit, based on the ADC chip, converts the conditioned analog signal into a digital signal for the MCU to perform calculations and processing. The reference voltage source unit provides a reference voltage as a standard reference for ADC conversion, ensuring consistency between different batches of devices and stability under different operating conditions.

5. The self-protection system for stall current of an automotive seat motor according to claim 1, characterized in that, The microcontroller module includes: The central processing unit receives digital signals from the signal conditioning circuit based on a microcontroller chip, analyzes and processes the data according to a preset program algorithm, makes timely decisions, and issues instructions to the protection execution module. The program storage and loading unit is used to store application code and configuration parameters; The clock management unit provides a time reference signal to ensure timing synchronization of the entire system.

6. The self-protection system for stall current of an automotive seat motor according to claim 1, characterized in that, The stall detection algorithm module includes: The data acquisition and preprocessing unit performs smoothing filtering and DC component removal operations on the digital signal from the ADC to remove random fluctuations and offsets. The feature extraction and analysis unit extracts feature parameters that can characterize the stall state based on the characteristic curves of motor operation and historical statistical data. By analyzing the feature parameters, a stall identification model is constructed. The threshold setting dynamic adjustment unit dynamically adjusts the various threshold indicators for stall detection according to different working conditions. The logic decision-making unit combines the collected data and the preset rule base, and uses fuzzy logic reasoning or neural network algorithms to make a comprehensive judgment; when the preset conditions are met, it issues a blocking warning signal; if blocking is confirmed to have occurred, it initiates protective measures.

7. The self-protection system for stall current of an automotive seat motor according to claim 6, characterized in that, The stall detection algorithm module detects a sharp increase in motor current exceeding a set threshold I within a short period of time. th1 And it remains above another lower threshold I. th2 The time exceeded the scheduled duration T h When this occurs, it is determined that the motor is stalled; the details are as follows: if And I>I th1 If so, the pre-alarm procedure will be activated; If I>I is further satisfied th2 And the duration t>T h If so, the stalled state is confirmed; Where ΔI represents the current increment, Δt is the corresponding time interval, and S r This is the threshold for the rate of current rise.

8. The self-protection system for stall current of an automotive seat motor according to claim 1, characterized in that, The protection execution module includes: When the power cut-off control unit confirms that the motor is in a stalled state, it immediately triggers the relay drive circuit to disconnect the main power supply line of the motor and prevents the continued supply of electrical energy to the motor. The soft-shutdown buffer unit, based on an H-bridge drive circuit composed of a power MOSFET array, realizes the soft-shutdown function; by gradually reducing the PWM duty cycle, the voltage across the motor is reduced, thus reducing current surge impact. An alarm indication output unit includes a visual alarm and an audible alarm; when a stall fault is detected, a warning is issued based on the visual alarm and the audible alarm. The fault-locking memory unit records stall events and related parameters, and stores them in memory.

9. The self-protection system for stall current of an automotive seat motor according to claim 1, characterized in that, The communication feedback module includes: Protocol stack implementation unit, supporting CAN bus and LIN bus; The command receiving and parsing unit listens for command frames on the bus, parses control instructions from the upper-level control system, and returns the execution results to the sender. The data analysis and storage unit collects and saves operational data samples within a set time period, forming a database file.

10. The self-protection system for stall current of an automotive seat motor according to claim 9, characterized in that, The self-protection method of the system includes the following steps: S1: Initialization. After the system is powered on, the MCU first performs initialization settings, and each functional module is in standby mode, waiting for the motor start signal to arrive. S2: Operation monitoring. When a valid motor start command is received, the current sensor starts to collect motor current data in real time. After being processed by the signal conditioning circuit, the data is sent to the MCU for analysis. S3: The MCU continuously monitors the current changes according to the stall condition judgment algorithm. As long as the stall condition is not met, the motor is allowed to run normally, and the current working parameters are periodically reported to other systems for reference through the communication feedback module. S4: Stalled rotor detection and response. When an abnormal current condition that meets the stalled rotor condition is detected during operation, the MCU immediately enters the emergency handling process. The control and protection execution module cuts off the motor power supply and implements a soft shutdown strategy; S5: Activate the audible and visual alarm device to remind the driver to pay attention to safety; record the traffic jam incident and upload it to the superior monitoring system through the communication feedback module; S6: After eliminating the cause of the stall, the driver can send a reset signal to the system through the operating interface; upon receiving the reset command, the MCU re-evaluates the motor status, and after confirming that there are no errors, restores normal power supply, allowing the motor to return to a runnable state.

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