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

Abstract

The application relates to a side-opening door motor assisting control method, a system and a readable storage medium. The method comprises the following steps: detecting the real-time rotating speed of a side-opening door motor; querying a preset D-v mapping table based on the real-time rotating speed to obtain a balance duty cycle required for maintaining the real-time rotating speed; wherein the D-v mapping table is obtained by pre-calibration based on the motor and is used for reflecting the correlation between the PWM duty cycle and the motor rotating speed; multiplying the balance duty cycle by a preset attenuation coefficient smaller than 1 to obtain a target duty cycle; and adopting a PID controller 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. The application has the effect of realizing user thrust-motor assisting adaptive matching and solving the imbalance problem of fixed torque output.

Description

Technical Field

[0001] This application relates to the field of electric power steering for automobiles, and in particular to a side-opening door motor power steering control method, system, and readable storage medium. Background Technology

[0002] In automotive applications, the opening and closing experience of side-opening doors directly impacts user convenience. Traditional car doors primarily employ purely mechanical structures, such as a combination of hinges and mechanical limiters to achieve opening, positioning, and closing. These limiters are typically metal baffles or ratchet mechanisms, fixing the door at preset angles (e.g., 30°, 60°, 90°). The entire process relies on the force applied by the user; the torque throughout the opening and closing process is provided by the user. The drawback of this design is that opening and closing the door is difficult for users with less strength (e.g., the elderly or children), especially in scenarios requiring overcoming the weight of the door, such as on slopes. Furthermore, purely mechanical structures cannot integrate with advanced driver assistance systems (ADAS) and other electronic systems, limiting their application in intelligent vehicles.

[0003] To address the aforementioned issue of cumbersome operation, a mechanical side-opening door with a spring-assisted mechanism has emerged. This solution integrates a torsion spring or tension spring into the hinge structure, utilizing the spring's preload to offset some of the door's own gravitational torque, thereby reducing the initial pushing force required by the user. However, this solution also has significant drawbacks. Metal springs experience fatigue after prolonged use, leading to changes in their stiffness coefficient and a weakening of the assist effect. Furthermore, the physical properties of springs are greatly affected by temperature; for example, in low-temperature winter conditions, spring stiffness may drift, resulting in insufficient assist. More importantly, the assist curve provided by the spring is fixed and cannot be dynamically adjusted based on the real-time opening angle of the door or the user's intention.

[0004] With the development of automotive electronics technology, electric power-assisted side-opening door solutions have emerged. Early electric solutions typically used a DC motor to provide a fixed torque output. Their control logic was relatively simple: the electronic control unit (ECU) sent a pulse-width modulation signal with a fixed duty cycle to the motor drive module, causing the motor to output a constant torque to assist the door's movement. This fixed-torque assistance method cannot adapt to varying real-world conditions. For example, when the vehicle is parked on an uphill slope, the fixed assistance may be insufficient to overcome the component of gravity, causing the door to slide back; while when the user (especially a child) applies only a small force, the fixed motor output may be too large, causing the door to overshoot, posing a safety hazard, and failing to achieve precise matching between the user's pushing force and the door's movement.

[0005] To achieve more intelligent power assist control, the industry has further proposed a closed-loop control scheme based on pressure sensors. This scheme typically integrates strain gauges or capacitive pressure sensors inside the door handle to detect the user's thrust in real time. The analog signal detected by the sensor is converted from analog to digital and then calculated by the ECU. Combined with control algorithms such as PID, the duty cycle of the PWM signal is dynamically adjusted to precisely control the torque output of the motor to match the user's intention. Although this scheme can theoretically achieve good power assist following effect, high-precision pressure sensors and their supporting signal conditioning circuits (such as amplification and filtering circuits) are expensive, significantly increasing the bill of materials cost, for example, by more than 30%. Moreover, the performance of the sensor is easily affected by environmental factors. For example, in a high-humidity environment, the sensitivity of a capacitive sensor may decrease by 30%; temperature changes may also cause signal drift, requiring complex software algorithms for compensation and calibration, increasing the complexity and uncertainty of the system. Summary of the Invention

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

[0007] Firstly, this application provides a side-opening door motor assist control method, which adopts the following technical solution:

[0008] A side-opening door motor assist control method includes the following steps:

[0009] S1. Detect the real-time speed of the side door motor;

[0010] S2. Based on the real-time speed, query the preset Dv mapping table to obtain the balance duty cycle required to maintain the real-time speed; wherein, the Dv mapping table is obtained based on the motor through pre-calibration and is used to reflect the correlation between the PWM duty cycle and the motor speed;

[0011] S3. Multiply the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain the target duty cycle;

[0012] S4. Using a PID controller, the actual duty cycle of the PWM signal output to the motor is adjusted according to the target duty cycle, so that the actual duty cycle approaches the target duty cycle.

[0013] By adopting the above technical solution, the real-time speed of the side-opening door motor is detected, and the balance duty cycle required to maintain the speed is obtained by querying a preset Dv mapping table based on the speed. The Dv mapping table is established through motor pre-calibration to reflect the correlation between PWM duty cycle and speed. Then, the balance duty cycle is multiplied by a preset attenuation coefficient of less than 1 to obtain the target duty cycle. The PID controller adjusts 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. This realizes the dynamic adaptive adjustment of the motor assist output, reduces the user's initial force threshold, and maintains stable speed under different load conditions.

[0014] The pre-calibrated Dv mapping table increments the PWM duty cycle in steps under no-load conditions and records stable speeds to form data pairs. By fitting and storing the correlation, it supports real-time querying to compensate for motor characteristic deviations, improving the robustness of the control algorithm to external disturbances and reducing sensor dependence.

[0015] A preset attenuation coefficient is used to balance the duty cycle to generate the target duty cycle. Overshoot of the motor output is avoided by progressively adjusting the PWM signal, and the assist torque is reduced synchronously when the user decelerates, improving the system's responsiveness to user intentions. The PID controller calculates the error between the target duty cycle and the actual duty cycle and applies proportional-integral-derivative control to achieve closed-loop feedback to track the target value, shortening the speed following delay and automatically compensating for torque requirements in scenarios involving slopes or obstacles.

[0016] Optionally, the real-time rotational speed is detected by a Hall sensor mounted on the shaft of the side-opening door motor.

[0017] Optionally, S1 includes the following steps:

[0018] S101. Acquire the motion acceleration signal of the side-opening door at a sampling rate of not less than 100Hz using a MEMS accelerometer installed on the side-opening door;

[0019] S102. Perform zero-bias calibration on the motion acceleration signal to deduct the gravity component;

[0020] S103. Integrate the calibrated motion acceleration signal and perform high-pass filtering on the integration result to obtain the real-time rotational speed.

[0021] By adopting the above technical solution, a MEMS accelerometer installed on the side-opening door collects motion acceleration signals at a sampling rate of not less than 100Hz. The signal is zero-biased to deduct the gravity component, and the calibrated signal is integrated and high-pass filtered to obtain the real-time rotational speed. This realizes acceleration-based rotational speed estimation, reduces dependence on external encoders, and maintains the accuracy of rotational speed calculation under vibration interference environment.

[0022] The acquisition of motion acceleration signals employs a high sampling rate to capture transient changes. Zero-bias calibration eliminates the influence of static gravity, and high-pass filtering is applied to the integration results to suppress low-frequency drift, thereby enhancing the stability of speed estimation and adapting to attitude deviations under slope conditions.

[0023] Optionally, step S1 estimates the real-time rotational speed based on the motor's back electromotive force, and step S1 includes the following sub-steps:

[0024] S111. Measure the terminal voltage across the motor during the period when the PWM signal is off;

[0025] 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;

[0026] S113. Subtract the IR voltage drop from the terminal voltage to obtain the back electromotive force voltage;

[0027] S114. Perform low-pass filtering on the back EMF voltage, and calculate the real-time rotational speed based on the filtered back EMF voltage and the preset motor back EMF constant.

[0028] By adopting the above technical solution, sensorless speed detection is achieved, reducing system hardware complexity and maintaining estimation accuracy under low-speed conditions. Specifically, the measurement terminal voltage is limited to the PWM off period to avoid switching noise interference. The IR voltage drop is calculated through real-time current sampling and subtracted from the terminal voltage, separating the back EMF component and compensating for the influence of resistor voltage drop, thus improving the accuracy of back EMF extraction and adapting to current fluctuation scenarios. A low-pass filter is applied to the back EMF voltage to suppress high-frequency noise, and the speed is calculated based on the ratio of the filtered voltage to the back EMF constant, enhancing signal stability, supporting real-time speed tracking, and reducing the impact of environmental interference on the control algorithm.

[0029] Optionally, the pre-calibration step of the Dv mapping table includes:

[0030] S21. Under no-load conditions of the motor, the PWM duty cycle is increased from the initial value by a preset step size, and the motor speed after stabilization is measured and recorded for each duty cycle to form multiple sets of duty cycle-speed data pairs;

[0031] S22. Perform data fitting on the multiple sets of duty cycle-speed data pairs;

[0032] S23. Store the fitted functional relationship or discrete data points to generate the Dv mapping table.

[0033] By adopting the above technical solution, a quantitative correlation between PWM duty cycle and speed is established, supporting 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 a stable speed is recorded. By forming data pairs to capture motor response characteristics, the calibration process is standardized, and the impact of environmental factors on data acquisition is reduced. The data pairs are fitted to generate functional relationships or discrete points. By minimizing the fitting residuals, the mapping accuracy is improved, enhancing the reliability of the query results and maintaining correlation accuracy under nonlinear motor models. The fitted function or data points are stored to form a Dv mapping table. Interpolation queries are supported through discrete or continuous representations, reducing the computational load in real-time control and maintaining the stability of speed-duty cycle matching under different operating conditions.

[0034] Optionally, the data fitting uses the least squares method.

[0035] Optionally, the preset attenuation coefficient k can be in the range of 0.5. <k<0.8。

[0036] Optionally, a safety protection step is also included: when the real-time speed exceeds a preset maximum speed threshold, the output of the PWM signal to the motor is stopped.

[0037] Secondly, the side-opening door motor assist control system provided in this application adopts the following technical solution:

[0038] A side-opening door motor assist control system includes:

[0039] The speed detection module is used to detect the real-time rotational speed of the side-opening door motor;

[0040] A storage module is used to store a preset Dv mapping table, wherein the Dv mapping table is used to reflect the correlation between PWM duty cycle and motor speed;

[0041] The control unit, electrically connected to the speed detection module and the storage module, is configured to:

[0042] Based on the real-time rotational speed detected by the speed detection module, the Dv mapping table is queried to obtain the balance duty cycle;

[0043] Multiply the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain the target duty cycle;

[0044] The motor drive module is electrically connected to the control unit. The motor drive module is equipped with a PID controller, which 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.

[0045] Thirdly, this application provides a computer-readable storage medium that adopts the following technical solution:

[0046] A computer-readable storage medium storing a computer program that can be loaded by a processor and executed as described above.

[0047] The storage medium stores at least one instruction, at least one program, a code set, or an instruction set, wherein 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 the following:

[0048] The above describes the motor assist control method for side-opening doors.

[0049] In summary, this application includes at least one of the following beneficial technical effects:

[0050] 1. This system significantly reduces the physical force required to open and close car doors, reducing the required force from over 15N to 5N or less, which is equivalent to a 67% reduction in force, making it easier for children and the elderly to use car doors.

[0051] 2. Unlike systems with fixed torque output, this solution uses a Hall sensor to detect the user's pushing intention (i.e., speed) and dynamically adjusts the motor's assistance accordingly. The system has an extremely low response latency of approximately 38ms, ensuring instantaneous assistance. Furthermore, the system can integrate other sensors to automatically compensate for the effects of environmental factors, such as vehicle tilting on inclines.

[0052] 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 the power when the door is moving too fast. Attached Figure Description

[0053] Figure 1 A flowchart illustrating a side-opening door motor assist control method according to an embodiment of the present invention is shown.

[0054] Figure 2 A flowchart illustrating sub-step S1 in one embodiment of the present invention is shown.

[0055] Figure 3 A flowchart illustrating sub-step S1 in another embodiment of the present invention is shown.

[0056] Figure 4 A flowchart illustrating sub-step S2 in one embodiment of the present invention is shown. Detailed Implementation

[0057] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application.

[0058] In the following description, numerous specific details are set forth for purposes of explanation in order to provide a thorough understanding of the inventive concept. As part of this specification, some of the accompanying drawings of this disclosure are block diagrams illustrating structures and devices to avoid complicating the disclosed principles. For clarity, not all features of the actual embodiment need to be described. Furthermore, the language used in this disclosure has been primarily chosen for readability and instructional purposes and may not have been chosen to define or limit the subject matter of the invention, thus requiring the necessary claims to determine such inventive subject matter. References to “an embodiment” or “an embodiment” in this disclosure mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment, and multiple references to “an embodiment” or “an embodiment” should not be construed as necessarily referring to the same embodiment.

[0059] Unless explicitly defined, the terms “a,” “an,” and “the” are not intended to refer to a singular entity, but rather to include a general category whose specific examples can be used for illustration. Therefore, the use of the terms “a” or “an” can mean any number of at least one, including “a,” “one or more,” “at least one,” and “one or more.” The term “or” means any of the options and any combination of the options, including all options unless explicitly indicated that the options are 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 items in the list. The phrase does not require all items listed unless explicitly defined as such.

[0060] In side-opening door applications, the user's experience and safety when opening and closing the door are directly affected by the degree of matching between the motor output and the door's movement. Traditional purely mechanical or fixed-torque electric assist methods are difficult to consider various operating conditions such as different door weights, slopes, ambient temperatures, and hinge friction variations. Therefore, this application discloses a side-opening door motor assist control method, referring to... Figure 1 This includes the following steps S1-S4.

[0061] S1. Detect the real-time speed of the side-opening door motor.

[0062] In the embodiments of this application, the side-opening door motor is an electric drive unit that provides power assist output for the side-opening door mechanism of a vehicle. It typically includes a motor body, a reduction gear 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. The reduction gear transmission mechanism can be a gear set, a worm gear, or a synchronous belt 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 auxiliary torque while the user applies external force. This motor unit, together with the door hinge assembly, limiter assembly, and seals, constitutes the door opening and closing actuator. The motor drive signal is generated by the control unit and applied through the motor drive module. Duty cycle modulation is used to adjust the average voltage and output capacity of the motor to achieve power assist control during the door rotation process.

[0063] There is a deterministic kinematic relationship between the motor speed and the door rotation determined by the transmission mechanism. Through the reducer and mechanical coupling components, the angular velocity of the motor shaft is mapped to the angular velocity or equivalent linear velocity of the door under a fixed transmission ratio and a given kinematic chain. The two follow each other and are monotonically consistent.

[0064] In one embodiment, the real-time rotational speed of the side-opening door motor can be directly detected by a Hall sensor mounted on the motor shaft. The Hall device counts the passing events of the rotor magnetic poles, and the control unit calculates the current rotational speed based on the pulse count and the duration of the counting window. It is suitable for the entire speed range from low to medium speed, has a simple structure, fast response, and is not sensitive to switching noise.

[0065] In another embodiment, refer to Figure 2 S1 includes the following steps S101-S103.

[0066] S101. Acquire the motion acceleration signal of the side-opening door using a MEMS accelerometer installed on the side-opening door at a sampling rate of not less than 100Hz.

[0067] S102. Perform zero-bias calibration on the motion acceleration signal to deduct the gravity component.

[0068] S103. Integrate the calibrated motion acceleration signal and perform high-pass filtering on the integration result to obtain the real-time rotational speed.

[0069] For example, a three-axis MEMS accelerometer is installed on the side-opening door trim panel near the door's center of mass. The device's sensitivity and range are selected based on the vehicle model, and the sampling rate is set to 200Hz. After power-on, 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 bias in a stationary state, which are used as zero bias calibration parameters for subsequent operation. To reduce the impact of vehicle engine vibration and road surface micro-vibrations, the acquisition end applies amplitude limiting and median denoising to the raw data at the hardware or drive layer to ensure that the acceleration data entering the algorithm link is within the usable dynamic range and that glitches are controlled.

[0070] During the door opening process, the control unit performs attitude compensation on the triaxial acceleration after zero-bias calibration according to the preset door coordinate system, and extracts the component consistent with the door rotation tangential direction as the integral input. To avoid cumulative velocity estimation offset caused by low-frequency drift, the integration stage uses a first-order numerical integration implemented at a fixed point. The integration result enters a digital high-pass filter for drift suppression. The filter adopts a second-order structure with a cutoff frequency on the order of 0.1Hz, and the group delay is controlled within several sampling periods. The door tangential velocity obtained by the above processing is converted into the real-time rotational speed of the motor shaft under the fixed transmission ratio of the transmission chain and the geometric constraints of the mechanism.

[0071] In another implementation, refer to Figure 3 S1 estimates the real-time rotational speed based on the back electromotive force of the motor, and S1 includes the following sub-steps S111-S114.

[0072] S111. Measure the terminal voltage across the motor during the period when the PWM signal is off.

[0073] 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.

[0074] S113. Subtract the IR voltage drop from the terminal voltage to obtain the back electromotive force voltage.

[0075] S114. Perform low-pass filtering on the back EMF voltage, and calculate the real-time rotational speed based on the filtered back EMF voltage and the preset motor back EMF constant.

[0076] In one specific embodiment, using the aforementioned vehicle and operating condition settings, the control unit employs a sampling strategy synchronized with the PWM carrier to estimate the motor's back EMF. Within each PWM cycle, after the high-side and low-side power devices are turned off and enter the non-drive time slot, the control unit sets a blanking time of approximately 4 μs to attenuate switching transition spikes and loop ringing. Subsequently, within a sampling window of approximately 8 μs, the terminal voltages at both ends of the motor are acquired through a differential analog-to-digital converter channel. To reduce the impact of instantaneous noise from a single sampling, the control unit performs a moving average over thirty-two consecutive PWM cycles and configures an RC buffer and common-mode clamping circuit in the hardware to improve measurement stability under large common-mode conditions.

[0077] To obtain the resistance voltage drop, the motor current is synchronously acquired via a sampling resistor installed at the low end of the circuit, in conjunction with a current sensing 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 with its baseline value and temperature coefficient during mass production calibration. During operation, compensation is performed based on temperature sensor readings to calculate the current resistance voltage drop. Taking typical data from this embodiment at 25°C as an example, the motor current is approximately 0.58A, the temperature-compensated winding resistance is approximately 1.87Ω, and the corresponding resistance voltage drop is approximately 1.59V.

[0078] The control unit subtracts the resistor voltage drop from the terminal voltage to obtain the back electromotive force (EMF) voltage. Continuing the example above, the terminal voltage, after moving average, is approximately 7.8V, so the back EMF voltage is approximately 6.21V. To suppress slow drift and high-frequency noise caused by low-frequency vibrations and electromagnetic interference in the vehicle body, the back EMF voltage enters a digital low-pass filter link. The filter adopts a second-order structure, and its parameters are determined during the calibration phase to keep the group delay within a few 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 rotational speed of the motor shaft based on the motor back EMF constant obtained from mass production calibration.

[0079] S2. Based on the real-time speed, query the preset Dv mapping table to obtain the balance duty cycle required to maintain the real-time speed; wherein, the Dv mapping table is obtained based on the motor through pre-calibration and is used to reflect the correlation between the PWM duty cycle and the motor speed.

[0080] In the embodiments of this application, the Dv mapping table is a database of correspondences between duty cycles and steady-state speeds established for the target motor and its associated drive, power supply, and transmission mechanisms. Its content can be a set of discrete data points or a functional relationship stored as fitting parameters. The purpose of pre-calibration is to absorb the nonlinearity and batch differences of the motor and mechanism offline, making the lookup results during operation closer to the actual device characteristics. Specifically, factors such as the motor's back electromotive force constant, winding resistance, brush-grip contact or brushless commutation strategy, driver modulation and dead zone, transmission mechanism friction and backlash, door load and seal condition, bus voltage, and ambient temperature all collectively determine the steady-state speed achievable by the motor at a given duty cycle. By completing pre-calibration under representative conditions, the combined effects of these factors can be solidified into data, allowing online control to perform only table lookups and necessary interpolation and limiting processing, thereby maintaining a stable reference correlation even when power supply and environmental conditions experience normal fluctuations.

[0081] Balanced duty cycle refers to 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 change significantly, the motor speed will remain stable without a continuous acceleration or deceleration trend. The balanced duty cycle is derived from a lookup or reverse index of the real-time speed in a mapping table, reflecting 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.

[0082] Adjusting the duty cycle regulates the speed because it directly determines the amplitude of the equivalent average voltage and equivalent phase voltage applied to the motor by the driver, thereby altering the electromagnetic torque generated by the motor and its achievable steady-state speed. At a low duty cycle, the effective drive applied to the motor is insufficient, limiting the motor's output torque and achievable speed. Increasing the duty cycle increases the equivalent drive, prompting the motor to overcome friction and damping under load and increase its speed until a new steady-state point is reached. For both DC motors and brushless motors, although the specific electrical implementations differ, the modulation effect of the duty cycle on the effective drive amplitude and average energy injection is consistent. Therefore, continuous adjustment of the duty cycle allows for continuous and controllable speed regulation.

[0083] Specifically, refer to Figure 4 The precalibration steps of the Dv mapping table include S21-S23.

[0084] S21. Under no-load conditions, the PWM duty cycle is increased from the initial value by a preset step size, and the motor speed after stabilization is measured and recorded for each duty cycle to form multiple sets of duty cycle-speed data pairs.

[0085] S22. Perform data fitting on the multiple sets of duty cycle-speed data pairs.

[0086] S23. Store the fitted functional relationship or discrete data points to generate the Dv mapping table.

[0087] In one specific embodiment, using the aforementioned vehicle model and environmental conditions, the side-opening door motor was decoupled to an unloaded state on a test bench, while the bus voltage, ambient temperature, and drive carrier frequency remained constant. The control unit set the duty cycle to increase incrementally from an initial value, with a fixed step size, and recorded the steady-state speed after the speed stabilized at each duty cycle. Taking a duty cycle step size of 2% as an example, 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), (45%, 20.0 rpm).

[0088] During the data fitting phase, the control unit performs piecewise linear fitting with monotonic constraints on the above data to ensure that the duty cycle-speed relationship remains monotonically increasing across the entire range, facilitating linear interpolation retrieval during runtime. In cases where local relationships need to be represented parametrically, least-squares linear fitting can be performed on adjacent data segments. For example, within the interval [28%, 37%], based on the two representative points (28%, 10.0) and (37%, 15.0), a local slope of approximately [missing value] can be obtained. This corresponds to an approximate linear relationship within the interval. The same method can be used to obtain segmented parameters in other intervals, ensuring the continuity of speed at the connection points of each segment. For vehicle models with higher requirements for smoothness, monotonic spline fitting can also be used to reduce abrupt slope changes while maintaining monotonicity.

[0089] During the storage generation phase, if a discrete point approach is used, the control unit writes the filtered and denoised duty cycle-speed data pairs into non-volatile memory in ascending duty cycle order, carrying version numbers, power supply and environmental identifiers for interval positioning and linear interpolation during online queries. If a function-based approach is used, the control unit stores the fitting parameters and effective interval boundaries for each segment, and performs a reverse lookup based on the real-time speed during runtime. After locating the corresponding interval, it calculates the balanced duty cycle matching that speed. Using a discrete table online lookup example, when the real-time speed is 12 rpm, the control unit locates adjacent data points (10 rpm, 28%) and (15 rpm, 37%) in the table, and obtains the corresponding duty cycle of approximately 31.6% through linear interpolation.

[0090] S3. Multiply the balanced duty ratio by a preset attenuation coefficient k less than 1 to obtain the target duty ratio. The value range of the preset attenuation coefficient k is 0.5 < k < 0.8.

[0091] The preset attenuation coefficient is used to perform amplitude constraint on the balanced duty ratio obtained by querying the mapping table, so that the motor only provides assistance and does not form excessive self-driving under typical working conditions. The balanced duty ratio is the reference driving amount corresponding to maintaining the current real-time speed on the premise that the calibration and operating conditions are the same or similar. This reference does not introduce the limitation of the assistance strategy on user dominance. The product obtained by multiplying by the preset attenuation coefficient is used as the target duty ratio, which is a bounded scaling of the reference driving amount based on the assistance strategy, making the output direction more biased towards the interval dominated by the user's thrust, and at the same time reserving a margin for abnormal disturbances and protection. That is to say, the difference between the target duty ratio and the balanced duty ratio is that the former reflects the expected driving intensity under the assistance strategy, and the latter reflects the reference demand of the motor-mechanism when maintaining the current speed point. Numerically, the two satisfy the constraint relationship that the target duty ratio is less than the balanced duty ratio.

[0092] In a specific embodiment, using the aforementioned vehicle, environment and transmission parameters, when the real-time speed is 12 rpm, the control unit queries the balanced duty ratio from the mapping table as 31.6%. Select the attenuation coefficient k = 0.70 according to the preset range 0.5 < k < 0.8, then the target duty ratio is 31.6% × 0.70 = 22.12%. Under the same vehicle and environment, when the real-time speed is 8 rpm, the balanced duty ratio queried from the mapping table is about 24%. If the attenuation coefficient k = 0.65 is selected, the target duty ratio is 24% × 0.65 = 15.6%. The above numerical examples are all based on the same vehicle model and the same working condition, reflecting the amplitude adjustment of the reference driving amount in a consistent manner through the attenuation coefficient at different speed points to obtain the target duty ratio consistent with the assistance strategy.

[0093] S4. Use a PID controller to adjust the actual duty ratio of the PWM signal output to the motor according to the target duty ratio, so that the actual duty ratio approaches the target duty ratio.

[0094] In the embodiment of the present application, S4 is used to perform closed-loop correction on the PWM modulation channel through the PID controller built in the control unit on the premise that the target duty ratio has been determined, so that the actual duty ratio output to the motor quickly and stably approaches the target duty ratio in time.

[0095] Specifically, the error is given by the difference between the target duty ratio and the actual duty ratio: . When the actual duty ratio is low, e > 0 will push the output up; vice versa.

[0096] The controller output is the superposition of three parts: The proportional term handles the current deviation, the integral term eliminates the steady-state deviation, and the derivative term suppresses overshoot caused by rapid changes.

[0097] This control process uses the target duty cycle as the reference input and the actual duty cycle obtained by timing capture or equivalent measurement as the feedback. By periodically calculating the difference between the two and updating the PWM comparison register or modulation depth, it compensates for inherent non-ideal factors in the drive channel, including dead time of switching devices, rising and falling edge delays, gate drive asymmetry, counting clock quantization errors, and equivalent duty cycle offsets caused by load disturbances. At the implementation level, the control unit performs PID calculations with a fixed control cycle. The control cycle is asynchronous with the PWM carrier but is an integer multiple thereof to ensure relative stability of sampling and modulation. To avoid ringing and glitches affecting the duty cycle measurement, the actual duty cycle is obtained using a combination of hardware capture and multi-cycle moving average. Before updating, amplitude limiting and ramp constraints are applied to ensure continuous duty cycle changes and meet the mechanical constraints of the motor and mechanism.

[0098] In one specific embodiment, using the same vehicle model and operating conditions as described above, the PWM carrier frequency is set to 10kHz, with a single cycle of 100μs. The control unit executes the output based on the target duty cycle of 22.12% obtained in the previous steps, corresponding to a single-cycle high-level time of approximately 22.12μs. Due to the dead time of the power devices and the gate drive delay, the actual duty cycle measured by the hardware in the initial few cycles is approximately 21.5%, which deviates from the target by approximately 0.62%. The PID controller completes 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, converging to around 22.1% after several control cycles. The steady-state fluctuation is limited to within ±0.15% through integral and derivative suppression.

[0099] In another specific embodiment, using the same vehicle and environment, the target duty cycle is 15.6%, corresponding to a single-cycle high-level time of approximately 15.6 μs. When starting the vehicle at low temperatures, changes in the driving characteristics of the power devices lead to a relatively larger effective dead time, with the initial captured actual duty cycle being approximately 14.1%. After detecting a continuous deviation, the control unit uses the proportional and integral components of the PID controller to gradually increase the comparison value while maintaining the set duty cycle ramp limit and upper and lower limit constraints to avoid motor noise and mechanical shock caused by sudden changes. After several control cycles, the actual duty cycle stabilizes within the range of 15.5% to 15.7%, meeting the target duty cycle tracking accuracy requirements.

[0100] Furthermore, the side-opening door motor assist control method also includes a safety protection step: when the real-time speed exceeds the preset maximum speed threshold, the output of the PWM signal to the motor is stopped.

[0101] In one specific embodiment, under the same vehicle model and environmental conditions, the control unit sets a maximum speed threshold for overspeed protection. This threshold is determined through mass production calibration and stored in non-volatile memory. For example, in this vehicle model, the maximum speed threshold is set to... The system uses the real-time rotational speed after low-pass filtering as input and configures a minimum hold time to suppress instantaneous glitches. During a rapid opening of a side door, influenced by external disturbances, the real-time rotational speed rises to 23.4 rpm within a short period and remains above the threshold for 25 ms. The control unit determines this as an overspeed event, immediately clears the PWM channel's compare register, and disables the drive enable, effectively stopping the output of the PWM signal to the motor. To ensure electromagnetic compatibility and mechanical safety, this stopping action is completed within one PWM cycle, with a corresponding delay of no more than 100 μs when the carrier frequency is 10 kHz. After stopping, the motor phase is placed in a driveless state, and the door naturally decelerates under the action of mechanical damping and load. The control unit continuously monitors the rotational speed and records the event timestamp and peak value.

[0102] The implementation principle of this application embodiment is as follows:

[0103] In one specific embodiment, when a user quickly pushes the door, causing a brief increase in the current rotational speed, the control unit obtains a higher balanced duty cycle from the Dv mapping table based on the rotational speed and updates the target duty cycle accordingly. Under the constraints of the target duty cycle change (upper and lower limits and slope limits), the PWM modulation depth is increased, and the motor output assistance increases accordingly, keeping the door acceleration process continuous and controllable, and avoiding overshoot and noise caused by instantaneous disturbances.

[0104] When the user reduces the applied force, causing the current rotational speed to decrease, the balance duty cycle obtained from the mapping query decreases accordingly, and the target duty cycle is adjusted downwards. The PWM modulation depth gradually decreases at a predetermined slope, the motor switches from providing high assistance to providing low resistance, and the door speed smoothly drops back to match the user's door-pushing speed, thereby reducing mechanical shock and improving comfort.

[0105] When the user stops applying force, causing the current speed to continuously decrease to near the stationary range, the target duty cycle gradually approaches a low value according to the set decay and limiting strategy. The actual duty cycle of the PWM channel decreases in a short time until it stops driving. At this time, the gate naturally stops under the action of mechanical damping and load. If abnormal changes in speed or current are detected, the safety and protection logic will take priority to handle the situation, ensuring the predictability of the shutdown process and human-machine safety.

[0106] This application also discloses a side-opening door motor assist control system, including a speed detection module, a storage module, a control unit, and a motor drive module.

[0107] The speed detection module is used to detect the real-time rotational speed of the side-opening door motor.

[0108] The storage module is used to store a preset Dv mapping table, wherein the Dv mapping table is used to reflect the correlation between PWM duty cycle and motor speed.

[0109] The control unit, electrically connected to the speed detection module and the storage module, is configured to:

[0110] Based on the real-time rotational speed detected by the speed detection module, the Dv mapping table is queried to obtain the balance duty cycle;

[0111] The target duty cycle is obtained by multiplying the balanced duty cycle by a preset attenuation coefficient less than 1.

[0112] The motor drive module is electrically connected to the control unit. The motor drive module is equipped with a PID controller, which 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.

[0113] It should be understood that the sequence number of each step in the above embodiments does not imply 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.

[0114] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, which, when executed by a processor, implements the side-opening door motor assist control method of the above embodiment.

[0115] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. This computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments of this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can 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), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0116] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to 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.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A method for controlling the motor assist of a side-opening door, characterized in that, Includes the following steps: S1. Detect the real-time speed of the side door motor; S2. Based on the real-time speed, query the preset Dv mapping table to obtain the balance duty cycle required to maintain the real-time speed; wherein, the Dv mapping table is obtained based on the motor through pre-calibration and is used to reflect the correlation between the PWM duty cycle and the motor speed; S3. Multiply the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain the target duty cycle; S4. Using a PID controller, the actual duty cycle of the PWM signal output to the motor is adjusted according to the target duty cycle, so that the actual duty cycle approaches the target duty cycle.

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

3. The side-opening door motor assist control method according to claim 1, characterized in that, S1 includes the following steps: S101. Acquire the motion acceleration signal of the side-opening door at a sampling rate of not less than 100Hz using a MEMS accelerometer installed on the side-opening door; S102. Perform zero-bias calibration on the motion acceleration signal to deduct the gravity component; S103. Integrate the calibrated motion acceleration signal and perform high-pass filtering on the integration result to obtain the real-time rotational speed.

4. The side-opening door motor assist control method according to claim 1, characterized in that, S1 estimates the real-time rotational speed based on the motor's back electromotive force, and S1 includes the following sub-steps: S111. Measure the terminal voltage across the motor during the period when the PWM signal is off; 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. Subtract the IR voltage drop from the terminal voltage to obtain the back electromotive force voltage; S114. Perform low-pass filtering on the back EMF voltage, and calculate the real-time rotational speed based on the filtered back EMF voltage and the preset motor back EMF constant.

5. The side-opening door motor assist control method according to claim 1, characterized in that, The pre-calibration steps of the Dv mapping table include: S21. Under no-load conditions of the motor, the PWM duty cycle is increased from the initial value by a preset step size, and the motor speed after stabilization is measured and recorded for each duty cycle to form multiple sets of duty cycle-speed data pairs; S22. Perform data fitting on the multiple sets of duty cycle-speed data pairs; S23. Store the fitted functional relationship or discrete data points to generate the Dv mapping table.

6. The side-opening door motor assist control method according to claim 5, characterized in that, The data fitting was performed using the least squares method.

7. The side-opening door motor assist control method according to claim 1, characterized in that, The preset attenuation coefficient k has a value range of 0.

5. <k<0.8。 8. The side-opening door motor assist control method according to claim 1, characterized in that, It also includes a safety protection step: when the real-time speed exceeds the preset maximum speed threshold, the output of the PWM signal to the motor is stopped.

9. A side-opening door motor assist control system, characterized in that, include: The speed detection module is used to detect the real-time rotational speed of the side-opening door motor; A storage module is used to store a preset Dv mapping table, wherein the Dv mapping table is used to reflect the correlation between PWM duty cycle and motor speed; The control unit, electrically connected to the speed detection module and the storage module, is configured to: Based on the real-time rotational speed detected by the speed detection module, the Dv mapping table is queried to obtain the balance duty cycle; Multiply the balanced duty cycle by a preset attenuation coefficient less than 1 to obtain the target duty cycle; The motor drive module is electrically connected to the control unit. The motor drive module is equipped with a PID controller, which 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.

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

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