Side-opening door motor assistance control method and system and readable storage medium

Abstract

The invention relates to a side-opening door motor assistance control method and system and a readable storage medium. The method comprises the following steps that the real-time rotating speed of a side-opening door motor is detected; querying a preset D-v mapping table based on the real-time rotating speed to obtain a balance duty ratio required for maintaining the real-time rotating speed; wherein the D-v mapping table is obtained through pre-calibration based on the motor and is used for reflecting the relevance between the PWM duty ratio and the rotating speed of the motor; multiplying the balance duty ratio by a preset attenuation coefficient less than 1 to obtain a target duty ratio; and a PID controller is adopted to adjust the actual duty ratio of a PWM signal output to the motor according to the target duty ratio, so that the actual duty ratio approaches the target duty ratio. The method has the advantages that user thrust-motor assistance self-adaptive matching is achieved, and the problem of imbalance of fixed torque output is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile electric power assistance, in particular to a side-hinged door motor power assistance control method and system and a readable storage medium. BACKGROUND

[0002] In automobile applications, the opening and closing experience of side-hinged doors directly affects the convenience of users. Traditional vehicle doors mainly adopt pure mechanical structures, such as a combination of hinges and mechanical limiters to achieve opening, positioning and closing. The limiter of such a structure is usually a metal baffle or a ratchet structure, which can fix the vehicle door at several preset angles (such as 30°, 60°, 90°). Its working process completely depends on the force exerted by the user, and the torque in the entire opening and closing process is provided by the user. The disadvantage of this design is that it is difficult for users with weak strength (such as the elderly or children) to operate the opening and closing of the door, especially in scenarios such as slopes where the gravitational component of the door needs to be overcome. In addition, the pure mechanical structure cannot be linked with electronic systems such as advanced driver assistance systems (ADAS) of the vehicle, limiting its application on intelligent vehicles.

[0003] In order to solve the problem of laborious operation, a mechanical side-hinged door with a spring assistance mechanism has appeared. This scheme integrates a torsional spring or a tension spring in the hinge structure, and uses the pre-tightening force of the spring to offset a part of the gravitational torque of the door itself, thereby reducing the initial pushing force required by the user. However, the defects of this scheme are also very obvious. The metal spring will be fatigued after long-term use, causing changes in its stiffness coefficient and weakening the assistance effect. At the same time, the physical properties of the spring are greatly affected by temperature, for example, in winter low temperature environment, the stiffness of the spring may drift, resulting in insufficient assistance effect. More critically, the assistance curve provided by the spring is fixed and cannot be dynamically adjusted according to the real-time opening angle of the door or the user's intention.

[0004] With the development of automobile electronic technology, an electric power assistance side-hinged door scheme has emerged. The initial electric scheme usually adopts a mode of fixed torque output provided by a DC motor, and its control logic is relatively simple. The electronic control unit (ECU) sends a pulse width modulation signal with a fixed duty cycle to the motor drive module, so that the motor outputs a constant torque to assist the movement of the door. This fixed torque assistance mode cannot adapt to changing actual working conditions. For example, when the vehicle is parked on an uphill road, the fixed assistance may not be sufficient to overcome the gravitational component, resulting in backsliding of the door; while when the user (especially children) only exerts a small force, the fixed motor output may be too large, causing the door to move overshoot, which poses a safety hazard and cannot achieve precise matching with the user's pushing force.

[0005] To achieve more intelligent power-assistance control, the industry has further proposed closed-loop control solutions based on pressure sensors. This solution typically integrates strain gauges or capacitive pressure sensors within the door handle to detect the user's thrust in real time. The analog signal detected by the sensor undergoes analog-to-digital conversion, which is then calculated by the ECU. Combined with control algorithms such as PID, the PWM signal's duty cycle is dynamically adjusted to precisely control the motor's output torque to match the user's intent. While this solution theoretically achieves good power-assistance tracking, the high-precision pressure sensor and its accompanying signal conditioning circuitry (such as amplification and filtering) are expensive, significantly increasing the bill of materials (BOM) by over 30%. Furthermore, sensor performance is susceptible to environmental interference. For example, high humidity can reduce the sensitivity of a capacitive sensor by 30%. Temperature fluctuations can also cause signal drift, requiring complex software algorithms for compensation and calibration, adding to system complexity and uncertainty. Summary of the Invention

[0006] In order to achieve adaptive matching of user thrust and motor assistance and solve the imbalance problem of fixed torque output, the present application provides a side door motor assistance control method, system and readable storage medium.

[0007] In the first aspect, the present application provides a side door motor power assist control method, which adopts the following technical solutions: A side door motor power assist control method includes the following steps: S1. Detect the real-time speed of the side door motor; S2. Based on the real-time speed query preset Dv mapping table, obtain the balance duty cycle required to maintain the real-time speed; wherein the Dv mapping table is pre-calibrated based on the motor to reflect the correlation between the PWM duty cycle and the motor speed; S3. Multiplying the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain a target duty cycle; S4. Using a PID controller, adjust the actual duty cycle of the PWM signal output to the motor according to the target duty cycle, so that the actual duty cycle approaches the target duty cycle.

[0008] By adopting the above technical solution, the real-time speed of the side door motor is detected, and the preset Dv mapping table is queried based on the speed to obtain the balanced duty cycle required to maintain the speed, wherein the Dv mapping table is established through motor pre-calibration to reflect the relationship between the PWM duty cycle and the speed, and then the balanced duty cycle is multiplied by a preset attenuation coefficient less than 1 to obtain the target duty cycle, and a PID controller is used to adjust the actual duty cycle of the PWM signal output to the motor according to the target duty cycle, so that the actual duty cycle approaches the target duty cycle, thereby realizing dynamic adaptive adjustment of the motor power output, reducing the user's initial force threshold and maintaining speed stability under different load conditions.

[0009] The pre-calibrated DV mapping table increases the PWM duty cycle in steps under no-load conditions and records the stable speed to form data pairs. By fitting and storing the association relationship, it supports real-time query to compensate for the motor characteristic deviation, improves the robustness of the control algorithm to external interference and reduces sensor dependence.

[0010] A preset attenuation coefficient is applied to balance the duty cycle to generate the target duty cycle. This progressively adjusts the PWM signal to avoid motor output overshoot and simultaneously reduces assist torque as the user decelerates, improving the system's responsiveness to user intent. A PID controller calculates the error between the target and actual duty cycles and applies proportional-integral-derivative adjustments, achieving closed-loop feedback to track the target value. This reduces speed tracking delay and automatically compensates for torque demands on slopes or around obstacles.

[0011] Optionally, the real-time rotation speed is detected by a Hall sensor installed on the rotating shaft of the side door motor.

[0012] Optionally, the S1 includes the following steps: S101. The MEMS accelerometer mounted on the side door is used to collect the motion acceleration signal of the side door at a sampling rate of not less than 100 Hz; S102. Performing zero-bias calibration on the motion acceleration signal to deduct the gravity component; S103. Perform an integration operation on the calibrated motion acceleration signal and perform high-pass filtering on the integration result to obtain the real-time rotation speed.

[0013] By adopting the above technical solution, the motion acceleration signal is collected at a sampling rate of not less than 100 Hz by a MEMS accelerometer installed on the side door. The signal is zero-bias calibrated to deduct the gravity component, and the calibrated signal is integrated and high-pass filtered to obtain the real-time speed. This realizes acceleration-based speed estimation, reduces dependence on external encoders, and maintains speed calculation accuracy in vibration interference environments.

[0014] A high sampling rate is used to collect motion acceleration signals to capture transient changes. The influence of static gravity is eliminated through zero-bias calibration, and high-pass filtering is applied to the integration result to suppress low-frequency drift, thereby enhancing the stability of speed estimation and adapting to attitude deviations under slope conditions.

[0015] Optionally, the step S1 estimates the real-time rotation speed based on the motor back electromotive force, and the step S1 includes the following sub-steps: S111. During the PWM signal off period, measuring the terminal voltage across the motor; S112. Measure the real-time current flowing through the motor, and calculate the IR voltage drop based on the real-time current I and the preset motor winding resistance R; S113. Subtracting the IR voltage drop from the terminal voltage to obtain a back electromotive force voltage; S114. Perform low-pass filtering on the back electromotive force voltage, and calculate the real-time rotational speed based on the filtered back electromotive force voltage and a preset motor back electromotive force constant.

[0016] By adopting the above technical solution, speed detection without external sensors is achieved, reducing system hardware complexity and maintaining estimation accuracy under low-speed conditions. The terminal voltage is measured only during the PWM off period to avoid switching noise interference. The IR drop is calculated through real-time current sampling and subtracted from the terminal voltage, separating the back EMF component and compensating for the effects of the IR drop. This improves the accuracy of back EMF extraction and adapts to current fluctuations. Low-pass filtering is applied to the back EMF voltage to suppress high-frequency noise. Speed ​​is calculated based on the proportional relationship between the filtered voltage and the back EMF constant, enhancing signal stability and supporting real-time speed tracking, reducing the impact of environmental interference on the control algorithm.

[0017] Optionally, the pre-calibration step of the Dv mapping table includes: S21. With the motor unloaded, increase the PWM duty cycle from its initial value by a preset step size, and measure and record the motor's stable speed at each duty cycle, generating multiple duty cycle-speed data pairs. S22. Performing data fitting on the plurality of duty cycle-speed data pairs; S23. Store the functional relationship or discrete data points formed by fitting to generate the Dv mapping table.

[0018] By employing the above technical solution, a quantitative relationship between PWM duty cycle and speed is established, enabling real-time querying to compensate for motor characteristic deviations and adapt to load changes. Under no-load conditions, the PWM duty cycle is incrementally increased and the stable speed is recorded. This captures the motor response characteristics by forming data pairs, standardizing the calibration process and reducing the impact of environmental factors on data acquisition. The data pairs are fitted to generate functional relationships or discrete points. Minimizing the fitting residual improves mapping accuracy, enhances the reliability of query results, and maintains association accuracy under nonlinear motor models. The fitted functions or data points are stored to form a Dv mapping table, supporting interpolation queries through discrete or continuous representations. This reduces the computational load in real-time control and maintains the stability of speed-duty cycle matching under different operating conditions.

[0019] Optionally, the data fitting adopts the least squares method.

[0020] Optionally, the preset attenuation coefficient k is in the range of 0.5 <k<0.8。

[0021] Optionally, a safety protection step is also included: when the real-time rotation speed exceeds a preset maximum rotation speed threshold, the output of the PWM signal to the motor is stopped.

[0022] In the second aspect, the present application provides a side door motor power-assisted control system, which adopts the following technical solutions: A side door motor power-assistance control system, comprising: Speed ​​detection module, used to detect the real-time speed of the side door motor; A storage module, configured to store a preset Dv mapping table, wherein the Dv mapping table is configured to reflect the correlation between the PWM duty cycle and the motor speed; A control unit is electrically connected to the speed detection module and the storage module, and is configured to: Based on the real-time rotation speed detected by the speed detection module, querying the Dv mapping table to obtain a balanced duty cycle; Multiplying the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain a target duty cycle; A motor drive module is electrically connected to the control unit, and the motor drive module is configured with a PID controller for adjusting the actual duty cycle of the PWM signal output to the motor according to the target duty cycle so that the actual duty cycle approaches the target duty cycle.

[0023] In a third aspect, the present application provides a computer-readable storage medium, which adopts the following technical solution: A computer-readable storage medium stores a computer program that can be loaded by a processor and execute the above method.

[0024] The storage medium stores at least one instruction, at least one program, a code set, or an instruction set, and the at least one instruction, the at least one program, the code set, or the instruction set is loaded and executed by the processor to implement: Such as the side door motor power assist control method mentioned above.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The system significantly reduces the physical force required to open and close the door, reducing the required force from more than 15N to 5N or less, equivalent to a 67% reduction in force, making it easier for children and the elderly to use the door.

[0026] 2. Unlike systems with fixed torque output, this solution uses a Hall effect sensor to detect the user's intention (i.e., speed) to push the door, dynamically adjusting the motor's assist. This system has an extremely low response latency of approximately 38ms, ensuring instantaneous assist. Furthermore, the system can integrate other sensors to automatically compensate for environmental factors, such as the vehicle's tilt on a slope.

[0027] 3. This solution also provides safety features, such as an anti-pinch function that reverses the motor when an obstacle is detected, and an overspeed protection function that cuts off power when the door speed is too fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A flowchart of a side door motor assist control method according to an embodiment of the present invention is shown.

[0029] Figure 2 FIG. 4 is a flow chart illustrating sub-step S1 in an embodiment of the present invention.

[0030] Figure 3 FIG. 4 is a flow chart illustrating sub-step S1 in another embodiment of the present invention.

[0031] Figure 4 FIG. 4 is a flow chart illustrating the S2 sub-step in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The present application will be further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0033] In the following description, for the purpose of explanation, many specific details are set forth in order to provide a thorough understanding of the inventive concepts. Some of the figures in the drawings of the present disclosure, which are part of this specification, represent structures and devices in block diagram form to avoid making the disclosed principles complicated and obscure. For the sake of clarity, not all features of an actual implementation are necessarily described. In addition, the language used in this disclosure has been selected primarily for readability and instructional purposes and may not have been selected to delineate or limit the subject matter of the invention, thereby resorting to the necessary claims to determine such inventive subject matter. References in this disclosure to "one embodiment" or "an embodiment" mean that the specific features, structures or characteristics described in conjunction with that embodiment are included in at least one embodiment, and multiple references to "one embodiment" or "an embodiment" should not be understood to necessarily all refer to the same embodiment.

[0034] Unless expressly limited, the terms "a", "an" and "the" are not intended to refer to a singular entity, but rather to include a general class of which a specific example may be used for illustration. Thus, the use of the term "a" or "an" may mean any number of at least one, including "one", "one or more", "at least one", and "one or more than one". The term "or" means any of the alternatives and any combination of the alternatives, including all, unless the alternatives are expressly indicated to be mutually exclusive. The phrase "at least one of" when combined with a list of items refers to a single item in the list or any combination of the items in the list. The phrase does not require all of the listed items unless expressly limited to that.

[0035] In the side-opening door application scenario, the user's experience and safety of opening and closing the door are directly affected by the degree of matching between the motor output and the door body's motion state. Traditional purely mechanical or fixed-torque electric assist methods are difficult to take into account different door body weights, slopes, ambient temperatures, hinge friction changes and other working conditions. To this end, the present application discloses a side-opening door motor assist control method, referring to Figure 1 , including the following steps S1-S4.

[0036] S1. Detect the real-time speed of the side door motor.

[0037] In an embodiment of the present application, the side door motor is an electric drive unit that provides power output for the vehicle side door mechanism, and generally includes a motor body, a reduction transmission mechanism, a mechanical coupling component connected to the door body, and an electrical interface connected to the control unit. The motor body can be a DC motor or a brushless motor, and the reduction transmission mechanism can be in the form of a gear set, a worm gear, or a synchronous pulley, etc. The mechanical coupling component is used to transmit the rotation of the motor output shaft to the rotation axis of the door body or a connection part that forms a fixed kinematic relationship with it, so as to output an auxiliary torque while the user applies external force. The motor unit usually constitutes an actuator for opening and closing the door together with a door hinge assembly, a limiter assembly, and a seal, wherein the drive signal of the motor is generated by the control unit and applied through the motor drive module, and the duty cycle modulation is used to adjust the average voltage and output capacity of the motor to achieve power control of the door body rotation process.

[0038] There's a deterministic kinematic relationship between motor speed and door rotation, defined by the transmission mechanism. Through the reducer and mechanical coupling components, the motor shaft's angular velocity, under a fixed transmission ratio and a defined kinematic chain, is mapped to the door's angular velocity or equivalent linear velocity, resulting in a monotonically aligned and coordinated movement.

[0039] In one embodiment, the real-time speed of the side-door motor can be directly detected by a Hall effect sensor mounted on the motor shaft. The Hall effect device counts the passage of the rotor magnetic poles, and a control unit converts the pulse count and the duration of the counting window into the current speed. This design is applicable to all speeds, from low to medium, and features a simple structure, fast response, and insensitivity to switching noise.

[0040] In another embodiment, referring to Figure 2 , said S1 includes the following steps S101-S103.

[0041] S101. The motion acceleration signal of the side-opening door is collected at a sampling rate of not less than 100 Hz by using a MEMS accelerometer installed on the side-opening door.

[0042] S102. Perform zero-bias calibration on the motion acceleration signal to deduct the gravity component.

[0043] S103. Perform an integration operation on the calibrated motion acceleration signal, and perform high-pass filtering on the integration result to obtain the real-time rotation speed.

[0044] For example, a three-axis MEMS accelerometer is installed on the side door interior panel near the door's center of mass. The device sensitivity and range are selected according to the vehicle model, and the sampling rate is set to 200Hz. After power is applied, the control unit collects raw acceleration data within a 1.5s time window when the door is closed and stationary, calculates the three-axis average value, and obtains the gravity direction and zero offset in the static posture, which are used as zero offset calibration parameters in the subsequent operation stage. To reduce the impact of vehicle engine vibration and road micro-vibration, the acquisition end applies limiting and median denoising to the raw data at the hardware or driver level to ensure that the acceleration data entering the algorithm chain is within the available dynamic range and the burrs are controlled.

[0045] During the door opening process, the control unit applies attitude compensation to the three-axis acceleration after zero-bias calibration according to the preset door coordinate system, extracting the component consistent with the tangential direction of the door's rotation as the integral input. To avoid cumulative offset in velocity estimation caused by low-frequency drift, the integral stage uses a first-order numerical integration implemented at a fixed point. The integral result is passed through a digital high-pass filter for drift suppression. The filter adopts a second-order structure with a cutoff frequency of the order of 0.1 Hz and group delay controlled within a number of sampling periods. The door's tangential velocity obtained through this processing is converted to the real-time speed of the motor shaft within the fixed transmission ratio of the drive train and the geometric constraints of the mechanism.

[0046] In yet another implementation, referring to Figure 3 , the S1 estimates the real-time rotation speed based on the motor back electromotive force, and the S1 includes the following sub-steps S111-S114.

[0047] S111. During the off period of the PWM signal, measure the terminal voltage across the motor.

[0048] S112. Measure the real-time current flowing through the motor, and calculate the IR voltage drop based on the real-time current I and the preset motor winding resistance R.

[0049] S113. Subtract the IR voltage drop from the terminal voltage to obtain a back electromotive force voltage.

[0050] S114. Perform low-pass filtering on the back electromotive force voltage, and calculate the real-time rotational speed based on the filtered back electromotive force voltage and a preset motor back electromotive force constant.

[0051] In one specific embodiment, following the aforementioned vehicle and operating condition settings, the control unit estimates the motor back EMF using a sampling strategy synchronized with the PWM carrier. Within each PWM cycle, after the high-side and low-side power devices are turned off and enter the non-driven time slot, the control unit sets a blanking time of approximately 4μs to attenuate switching transition spikes and loop ringing. The terminal voltage across the motor is then acquired via the differential analog-to-digital conversion channel within a sampling window of approximately 8μs. To reduce the impact of transient noise from a single sampling, the control unit performs a sliding average over 32 consecutive PWM cycles and configures an RC buffer and common-mode clamp circuit on the hardware side to improve measurement stability under high common-mode conditions.

[0052] To obtain the resistance voltage drop, the motor current is synchronously collected through a sampling resistor installed at the low end of the loop in conjunction with a current detection amplifier. The sampling time is aligned with the terminal voltage sampling window to avoid estimation errors caused by sudden changes in the freewheeling path. The winding resistance is recorded during mass production calibration, and its baseline value and temperature coefficient are recorded. During operation, it is compensated based on the temperature sensor reading to calculate the current resistance voltage drop. Taking the typical data of this embodiment at 25°C as an example, the motor current is approximately 0.58A, the winding resistance is approximately 1.87Ω after temperature compensation, and the corresponding resistance voltage drop is approximately 1.59V.

[0053] The control unit subtracts the resistor voltage drop from the terminal voltage to obtain the back EMF voltage. Continuing with the above example, the terminal voltage is approximately 7.8V after sliding average, and the back EMF voltage is approximately 6.21V. In order to suppress the slow drift and high-frequency noise caused by low-frequency vibration and electromagnetic interference of the vehicle body, the back EMF voltage enters the digital low-pass filter link. The filter adopts a second-order structure and its parameters are determined in the calibration stage so that the group delay is controlled within several PWM cycles without affecting the response of subsequent control. After the filter output stabilizes, the control unit converts the back EMF voltage into the real-time speed of the motor shaft based on the motor back EMF constant obtained by mass production calibration.

[0054] S2. Based on the real-time speed, a preset Dv mapping table is queried to obtain a balanced duty cycle required to maintain the real-time speed; wherein the Dv mapping table is pre-calibrated based on the motor to reflect the correlation between the PWM duty cycle and the motor speed.

[0055] In an embodiment of the present application, the Dv mapping table is a database of correspondences between duty cycle and steady-state speed established for a target motor and its associated drive, power supply, and transmission mechanism. Its contents can be a set of discrete data points or a functional relationship stored in the form of fitted parameters. The purpose of pre-calibration is to absorb nonlinearities and batch variations in the motor and mechanism in an offline manner, so that the table lookup results during operation are closer to the actual device characteristics. Specifically, factors such as the motor's back-electromotive force constant, winding resistance, brush holder contact or brushless commutation strategy, driver modulation and deadband, transmission mechanism friction and backlash, door load and seal status, bus voltage, and ambient temperature all jointly determine the steady-state speed that the motor can achieve at a certain duty cycle. By completing pre-calibration under representative conditions, the combined effects of these factors can be solidified into data, allowing online control to only require table lookup and necessary interpolation and limiting processing, thereby maintaining a stable baseline correlation even when the power supply and environment undergo normal fluctuations.

[0056] The equilibrium duty cycle is the baseline duty cycle required to maintain the current real-time speed under given hardware and environmental conditions. When the system is near this duty cycle and external disturbances do not significantly change, the motor speed will remain stable without a continuous acceleration or deceleration trend. The equilibrium duty cycle is derived from a lookup or reverse index of the real-time speed in a mapping table and reflects the drive strength required to achieve a dynamic balance between the motor's internal electromagnetic drive and the load and losses at that speed point.

[0057] Adjusting the duty cycle can regulate speed because it directly determines the equivalent average voltage and equivalent phase voltage amplitude applied by the driver to the motor, thereby changing the electromagnetic torque generated by the motor and the achievable steady-state speed. When the duty cycle is low, the effective drive applied to the motor is small, limiting the motor's output torque and achievable speed. Increasing the duty cycle increases the equivalent drive, forcing the motor to overcome friction and damping under load and increase speed until a new steady-state point is reached. For DC motors and brushless motors, although the specific electrical implementations are different, the duty cycle modulates the effective drive amplitude and average energy injection in the same way. Therefore, continuous adjustment of the duty cycle enables continuous and controllable speed regulation.

[0058] Specifically, refer to Figure 4 , the pre-calibration step of the Dv mapping table includes S21-S23.

[0059] S21. Under no-load conditions, increase the PWM duty cycle from an initial value by a preset step size, and measure and record the stable motor speed at each duty cycle to form multiple duty cycle-speed data pairs.

[0060] S22. Perform data fitting on the multiple sets of duty cycle-speed data pairs.

[0061] S23. Store the functional relationship or discrete data points formed by fitting to generate the Dv mapping table.

[0062] In one specific embodiment, using the aforementioned vehicle model and environmental conditions, the side door motor was decoupled and placed in an unloaded state on a test bench. The bus voltage, ambient temperature, and drive carrier frequency were maintained constant. A control unit set the duty cycle to increase from an initial value in fixed increments. At each duty cycle, the steady-state speed was recorded after the speed stabilized. For an example with a 2% duty cycle increment, several duty cycle-speed data pairs were obtained: (20%, 5.0 rpm), (22%, 6.2 rpm), (24%, 7.5 rpm), (26%, 8.7 rpm), (28%, 10.0 rpm), (30%, 11.2 rpm), (32%, 12.5 rpm), (34%, 13.8 rpm), (36%, 15.0 rpm), (38%, 16.2 rpm), (40%, 17.5 rpm), (42%, 18.7 rpm), and (45%, 20.0 rpm).

[0063] During the data fitting phase, the control unit performs piecewise linear fitting of the above data with monotonic constraints to ensure that the duty cycle-speed relationship remains monotonically increasing in the entire domain, which facilitates linear interpolation retrieval during operation. In cases where local relationships need to be expressed in parameter form, least squares straight line fitting can be performed on adjacent data segments. For example, in the interval [28%, 37%], based on the two end representative points (28%, 10.0) and (37%, 15.0), the local slope can be obtained to be approximately , the approximate linear relationship corresponding to this interval The same method can be used to obtain segment parameters for other intervals, ensuring velocity continuity at the junctions between segments. For vehicles with higher requirements for smoothness, monotonic spline fitting can also be used to maintain monotonicity while reducing sudden slope changes.

[0064] During the storage generation phase, if a discrete point method is used, the control unit writes the filtered and denoised duty cycle-speed data pairs into non-volatile memory in ascending order of duty cycle, and carries the version number, power supply, and environmental identifiers for interval positioning and linear interpolation during online query. If a function form is used, the control unit stores the fitting parameters and valid interval boundaries of each segment, and performs a reverse query based on the real-time speed during runtime. After locating the corresponding interval, it calculates the balanced duty cycle that matches the speed. Taking the example of an online query of a discrete table, when the real-time speed is 12rpm, the control unit locates the adjacent data points (10rpm, 28%) and (15rpm, 37%) in the table, and obtains the corresponding duty cycle of approximately 31.6% by linear interpolation.

[0065] S3. Multiply the balance duty cycle by a preset attenuation coefficient k less than 1 to obtain the target duty cycle. The preset attenuation coefficient k ranges from 0.5 <k<0.8。

[0066] The preset attenuation coefficient is used to impose an amplitude constraint on the balanced duty cycle obtained by querying the mapping table, so that the motor only provides power assistance under typical working conditions without excessive self-drive. The balanced duty cycle is a benchmark drive quantity corresponding to the current real-time speed, under the premise that the calibration is consistent with or close to the operating conditions. This benchmark does not introduce any restrictions on the user's dominance of the power assistance strategy. The product obtained by multiplying by the preset attenuation coefficient is used as the target duty cycle. This is a bounded scaling of the benchmark drive quantity based on the power assistance strategy, which makes the output point more biased towards the user's thrust-dominated range, while reserving a margin for abnormal disturbances and protection. In other words, the difference between the target duty cycle and the balanced duty cycle is that the former reflects the expected drive strength under the power assistance strategy, while the latter reflects the benchmark requirement of the motor-mechanism when maintaining the current speed point. The two numerically satisfy the constraint relationship that the target duty cycle is less than the balanced duty cycle.

[0067] In a specific embodiment, using the aforementioned vehicle, environment and transmission parameters, the control unit obtains a balanced duty cycle of 31.6% from the mapping table when the real-time speed is 12 rpm. <k<0.8选择衰减系数k=0.70,则目标占空比为31.6%×0.70=22.12%。在相同车辆与环境下,当实时转速为8rpm时,映射表查询平衡占空比约为24%,若选取衰减系数k=0.65,则目标占空比为24%×0.65=15.6%。上述数值示例均以同一车型与同一工况为前提,体现了在不同速度点上通过衰减系数对基准驱动量进行一致方式的幅度调整,获得与助力策略相一致的目标占空比。

[0068] S4. Using a PID controller, adjust the actual duty cycle of the PWM signal output to the motor according to the target duty cycle, so that the actual duty cycle approaches the target duty cycle.

[0069] In an embodiment of the present application, S4 is used to perform closed-loop correction on the PWM modulation channel through the PID controller built into the control unit, under the premise that the target duty cycle has been determined, so that the actual duty cycle output to the motor approaches the target duty cycle quickly and stably in time.

[0070] Specifically, the error is given by the difference between the target duty cycle and the actual duty cycle: When the actual duty cycle is low, e>0 will push the output up, and vice versa.

[0071] The controller output is a superposition of three parts: Among them, the proportional term processes the current deviation, the integral term eliminates the steady-state deviation, and the differential term suppresses the overshoot caused by rapid changes.

[0072] This control process uses the target duty cycle as a reference input and the actual duty cycle obtained through timing capture or equivalent measurement as feedback. By periodically calculating the difference between the two and updating the PWM comparator register or modulation depth, it compensates for inherent non-idealities in the drive channel, including switching device deadband, rising and falling edge delays, gate drive asymmetry, count clock quantization error, and equivalent duty cycle offset caused by load disturbances. At the implementation level, the control unit performs PID calculations with a fixed control period. The control period is asynchronous with the PWM carrier but an integer multiple of it to ensure relative sampling and modulation stability. To prevent ringing and glitches from affecting duty cycle measurement, the actual duty cycle is acquired using a combination of hardware capture and multi-cycle sliding average. Limiting and ramping constraints are applied before updating to ensure continuous duty cycle variation and meet the mechanical constraints of the motor and mechanism.

[0073] In a specific embodiment, the same vehicle model and operating conditions as above are used, with the PWM carrier frequency set to 10kHz and a single cycle of 100μs. The control unit executes the output based on the target duty cycle of 22.12% obtained in the previous step, and the corresponding single-cycle high-level time is approximately 22.12μs. Due to the dead time and gate drive delay of the power device, the actual duty cycle captured and measured by the hardware is approximately 21.5% in the initial several cycles, which deviates from the target by approximately 0.62%. The PID controller completes the error calculation and output update within one control cycle, increases the PWM comparison value, and increases the actual duty cycle in the next control cycle. After several control cycles, it converges to around 22.1%. The steady-state fluctuation is limited to ±0.15% through the integral link and differential suppression.

[0074] In another specific embodiment, still taking the same vehicle and environment as before, the target duty cycle is 15.6%, corresponding to a single-cycle high-level time of approximately 15.6μs. When starting the vehicle at low temperatures, the driving characteristics of the power device change, resulting in a relative increase in the effective dead time, and the actual duty cycle initially captured is approximately 14.1%. After detecting a continuous deviation, the control unit drives the comparison value to gradually increase through the proportional and integral links of the PID, while maintaining the set duty cycle ramp limit and upper and lower limit constraints to avoid motor noise and mechanism impact caused by jumps. After several control cycles, the actual duty cycle stabilizes in the range of 15.5% to 15.7%, meeting the target duty cycle tracking accuracy requirements.

[0075] Furthermore, the side door motor power assist control method also includes a safety protection step: when the real-time speed exceeds a preset maximum speed threshold, the output PWM signal to the motor is stopped.

[0076] In a specific embodiment, based on the same vehicle model and environmental conditions, the control unit sets a maximum speed threshold for overspeed protection. The threshold is given by mass production calibration and stored in non-volatile memory. For example, on this vehicle model, the maximum speed threshold is set to The judgment uses the real-time speed after low-pass filtering as input, and configures a minimum hold time to suppress instantaneous glitch triggering. During a rapid opening of a side door, affected by external disturbances, the real-time speed rose to 23.4 rpm in a short period of time and continuously exceeded the threshold for 25ms. The control unit determined this as an overspeed event, immediately cleared the comparison register of the PWM channel and turned off the drive enable, which is equivalent to stopping the output of the PWM signal to the motor. To ensure electromagnetic compatibility and mechanical safety, this stop action is completed within one PWM cycle, and the corresponding delay does not exceed 100 μs when the carrier is 10 kHz. After stopping, the motor phase ends are placed in an undriven state, and the door body naturally decelerates under the action of the mechanism damping and load. The control unit continuously monitors the speed and records the event timestamp and peak value.

[0077] The implementation principles of the embodiments of this application are as follows: In one specific embodiment, when a user pushes the door quickly, causing the current speed to briefly increase, the control unit obtains a higher equilibrium duty cycle from the DV mapping table based on the speed and updates the target duty cycle accordingly. Within the constraints of the target duty cycle (upper and lower limits and slope limits), the PWM modulation depth is increased, and the motor output power increases accordingly, maintaining a continuous and controllable door acceleration process and avoiding overshoot and noise caused by transient disturbances.

[0078] As the user reduces force, lowering the current speed, the balanced duty cycle obtained from the mapping query decreases accordingly, and the target duty cycle is adjusted downward accordingly. The PWM modulation depth gradually decreases at a predetermined slope, and the motor transitions from providing high assist to providing less resistance. The door speed smoothly decreases to match the user's push speed, minimizing mechanical impact and improving comfort.

[0079] When the user stops applying force, causing the current speed to continue decreasing to a near-stationary range, the target duty cycle gradually approaches a low value according to the set attenuation and limiting strategies. The actual duty cycle of the PWM channel decreases quickly until the door stops. At this point, the door stops naturally due to the effects of the mechanism's damping and load. If any abnormal changes in speed or current are detected, the safety and protection logic takes precedence, ensuring the predictability of the stop process and ensuring human and machine safety.

[0080] An embodiment of the present application also discloses a side door motor power-assistance control system, including a speed detection module, a storage module, a control unit and a motor drive module.

[0081] The speed detection module is used to detect the real-time speed of the side door motor.

[0082] The storage module is used to store a preset Dv mapping table, wherein the Dv mapping table is used to reflect the correlation between the PWM duty cycle and the motor speed.

[0083] A control unit is electrically connected to the speed detection module and the storage module, and is configured to: Based on the real-time rotation speed detected by the speed detection module, querying the Dv mapping table to obtain a balanced duty cycle; The balanced duty cycle is multiplied by a preset attenuation coefficient less than 1 to obtain a target duty cycle.

[0084] A motor drive module is electrically connected to the control unit, and the motor drive module is configured with a PID controller for adjusting the actual duty cycle of the PWM signal output to the motor according to the target duty cycle so that the actual duty cycle approaches the target duty cycle.

[0085] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0086] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the side door motor power assist control method of the above embodiment is implemented.

[0087] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments of this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct RAMbus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM).

[0088] Those skilled in the art will clearly understand that for the sake of convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0089] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A side door motor power assist control method, characterized in that: The following steps are involved: S1. Detect the real-time speed of the side door motor; S2. Based on the real-time speed query preset Dv mapping table, obtain the balance duty cycle required to maintain the real-time speed; wherein the Dv mapping table is pre-calibrated based on the motor to reflect the correlation between the PWM duty cycle and the motor speed; S3. Multiplying the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain a target duty cycle; S4. Using a PID controller, adjust the actual duty cycle of the PWM signal output to the motor according to the target duty cycle, so that the actual duty cycle approaches the target duty cycle.

2. The side door motor power assist control method according to claim 1, characterized in that: The real-time rotation speed is detected by a Hall sensor installed on the rotating shaft of the side door motor.

3. The side door motor power assist control method according to claim 1, characterized in that: Said S1 comprises the following steps: S101. The MEMS accelerometer mounted on the side door is used to collect the motion acceleration signal of the side door at a sampling rate of not less than 100 Hz; S102. Performing zero-bias calibration on the motion acceleration signal to deduct the gravity component; S103. Perform an integration operation on the calibrated motion acceleration signal and perform high-pass filtering on the integration result to obtain the real-time rotation speed.

4. The side door motor power assist control method according to claim 1, characterized in that: The step S1 estimates the real-time speed based on the motor back electromotive force, and the step S1 includes the following sub-steps: S111. During the PWM signal off period, measuring the terminal voltage across the motor; S112. Measure the real-time current flowing through the motor, and calculate the IR voltage drop based on the real-time current I and the preset motor winding resistance R; S113. Subtracting the IR voltage drop from the terminal voltage to obtain a back electromotive force voltage; S114. Perform low-pass filtering on the back electromotive force voltage, and calculate the real-time rotational speed based on the filtered back electromotive force voltage and a preset motor back electromotive force constant.

5. The side door motor power assist control method according to claim 1, characterized in that: The pre-calibration step of the Dv mapping table includes: S21. With the motor unloaded, increase the PWM duty cycle from its initial value by a preset step size, and measure and record the motor's stable speed at each duty cycle, generating multiple duty cycle-speed data pairs. S22. Performing data fitting on the plurality of duty cycle-speed data pairs; S23. Store the functional relationship or discrete data points formed by fitting to generate the Dv mapping table.

6. The side door motor power assist control method according to claim 5, characterized in that: The data were fitted using the least squares method.

7. The side door motor power assist control method according to claim 1, characterized in that: The preset attenuation coefficient k is in the range of 0.5 <k<0.8。 8. The side door motor power assist control method according to claim 1, characterized in that: The method further includes a safety protection step: when the real-time rotation speed exceeds a preset maximum rotation speed threshold, the output of the PWM signal to the motor is stopped.

9. A side door motor power assist control system, characterized in that: include: Speed ​​detection module, used to detect the real-time speed of the side door motor; A storage module, configured to store a preset Dv mapping table, wherein the Dv mapping table is configured to reflect the correlation between the PWM duty cycle and the motor speed; A control unit is electrically connected to the speed detection module and the storage module, and is configured to: Based on the real-time rotation speed detected by the speed detection module, querying the Dv mapping table to obtain a balanced duty cycle; Multiplying the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain a target duty cycle; A motor drive module is electrically connected to the control unit, and the motor drive module is configured with a PID controller for adjusting the actual duty cycle of the PWM signal output to the motor according to the target duty cycle so that the actual duty cycle approaches the target duty cycle.

10. A computer-readable storage medium, characterized in that The storage medium stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set are loaded and executed by the processor to implement: the side door motor power assistance control method as described in any one of claims 1 to 8.

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