A method for adaptive compensation of overturning moment of combined bearing for motor home

Abstract

The application discloses a kind of motor home combined bearing anti-overturning torque self-adapting compensation method, belong to motor home combined bearing anti-overturning torque compensation technical field.This method collects the real-time pressure value of each measuring point of distributed pressure sensing array in motor home combined bearing, and each real-time pressure value and bearing structure parameter are input to compensation control unit;According to the spatial distribution characteristics of each real-time pressure value, the direction and amplitude of the overturning torque of the bearing end face are calculated, and the rolling body eccentric load factor under the action of overturning torque is extracted;During the process of applying reverse compensation force, the real-time pressure value of each measuring point is continuously collected and the rolling body eccentric load factor is updated, and the driving voltage of piezoelectric micro-displacement actuator is dynamically adjusted according to the updated eccentric load factor;When the updated rolling body eccentric load factor is lower than the hysteresis eccentric load threshold, gradually reduce the driving voltage until the actuator resets.The scheme applies and adjusts the reverse compensation force according to the real-time eccentric load state, reduces the rolling body eccentric load degree under the action of overturning torque.

Description

Technical Field

[0001] This invention relates to the field of anti-overturning moment compensation technology for RV composite bearings, specifically an adaptive compensation method for anti-overturning moment of RV composite bearings. Background Technology

[0002] During the driving and parking of a motorhome, the combined bearings, in addition to bearing axial and radial loads, are also subjected to overturning moments caused by vehicle roll, road lateral slope, onboard equipment offset, and sharp turns. Overturning moments cause uneven circumferential pressure distribution on the bearing end faces, resulting in some rolling elements bearing excessively high contact loads while others experience significantly reduced loads. This leads to uneven loading and localized stress concentration on the rolling elements, accelerating localized rolling element fatigue and causing uneven end face wear. Existing anti-overturning methods mainly rely on increasing the bearing cross-sectional dimensions, using higher-strength materials, increasing preload, or installing mechanical limiting structures. These methods cannot actively adjust when the overturning moment changes; they can only allow for a margin based on the maximum load during the design phase, increasing the bearing weight and volume. Compensation methods using hydraulic or electromagnetic actuators suffer from response lag, insufficient control precision, and difficulty in applying continuously adjustable axial compensation forces to localized areas. Another method, which indirectly determines uneven loading by monitoring bearing vibration or temperature, struggles to obtain accurate spatial distribution of the overturning moment direction and amplitude, easily leading to biased selection of compensation areas or mismatched compensation amplitudes. Some solutions, by pre-measuring the static overturning moment and setting fixed compensation shims, can only adapt to a single working condition. When the RV's driving conditions change, the compensation amount cannot follow suit. Centralized force sensors or the arrangement of a few measuring points cannot obtain a complete circumferential pressure distribution, making it impossible to determine the local area corresponding to the direction of the overturning moment. Existing compensation methods lack a smooth exit mechanism after the degree of off-center loading decreases; rapid actuator retraction may cause pressure redistribution shocks, or overcompensation and oscillation may occur during the compensation process due to fixed adjustment step sizes. A method is needed that can identify the direction and amplitude of the overturning moment based on the real-time spatial pressure distribution on the bearing end face, apply a reverse axial compensation force to the off-center loading area, and dynamically adjust the compensation intensity. This would overcome the problems of untimely compensation, inaccurate area positioning, and unstable exit process of existing passive structures and indirect monitoring methods under changing overturning moment conditions. Summary of the Invention

[0003] An adaptive compensation method for overturning moment of a combined bearing for RVs is provided. This method acquires the real-time spatial pressure distribution on the bearing end face using a distributed pressure sensor array. The direction and amplitude of the overturning moment are calculated from the pressure distribution, and the rolling element off-center load factor is extracted. Based on the rolling element off-center load factor, the application area and initial amplitude of the reverse compensation force are determined. A piezoelectric micro-displacement actuator lifts the thrust ring along the bearing axis to apply the reverse compensation force. During the compensation process, the drive voltage is adjusted according to the real-time updated rolling element off-center load factor. After the off-center load condition is restored, the drive voltage is gradually reduced until the actuator is reset. This allows the combined bearing to adaptively compensate according to the actual off-center load degree under changing overturning moment conditions.

[0004] To achieve the above objectives, the present invention provides the following technical solution: The present invention provides an adaptive compensation method for anti-overturning moment of a combined bearing for RVs, comprising: collecting real-time pressure values ​​at each measuring point of a distributed pressure sensing array in the combined bearing for RVs, and inputting each real-time pressure value and bearing structural parameters to a compensation control unit; calculating the direction and amplitude of the overturning moment on the bearing end face based on the spatial distribution characteristics of each real-time pressure value, and extracting the rolling element off-center loading factor under the action of the overturning moment; when the off-center loading degree represented by the rolling element off-center loading factor exceeds a preset off-center loading threshold, mapping the application area and initial amplitude of the reverse compensation force by the rolling element off-center loading factor; activating the piezoelectric micro-displacement actuator in the corresponding area according to the application area, and the actuator lifting the thrust ring along the bearing axis to apply the reverse compensation force to the bearing end face; during the application of the reverse compensation force, continuously collecting real-time pressure values ​​at each measuring point and updating the rolling element off-center loading factor, and dynamically adjusting the driving voltage of the piezoelectric micro-displacement actuator according to the updated rolling element off-center loading factor; when the updated rolling element off-center loading factor is lower than the hysteresis off-center loading threshold, gradually reducing the driving voltage until the actuator is reset. This method, through real-time pressure distribution identification and reverse compensation force closed-loop adjustment, can adaptively adjust the compensation effect according to the overturning moment change, reduce the rolling element eccentricity, and improve the operational stability and service life of the RV combined bearing under overturning conditions.

[0005] Preferably, the real-time pressure values ​​of each measuring point in the distributed pressure sensor array of the RV composite bearing are collected, and the real-time pressure values ​​and bearing structural parameters are input to the compensation control unit. Specifically, this includes: connecting the output signals of the sensitive elements of each measuring point in the distributed pressure sensor array to a multi-channel signal conditioning circuit, filtering and amplifying them, and then converting them into digital pressure values ​​through an analog-to-digital converter; obtaining the rolling element pitch circle diameter, rolling element diameter, and number of rolling elements of the composite bearing to form a bearing structural parameter vector; aligning the digital pressure values ​​of each measuring point with the bearing structural parameter vector according to the acquisition time to form a structured input data frame, so as to ensure that the pressure data and structural parameters are input synchronously and improve the consistency of subsequent overturning moment calculation.

[0006] Preferably, when calculating the direction and amplitude of the overturning moment on the bearing end face based on the spatial distribution characteristics of each real-time pressure value, and extracting the rolling element off-center load factor under the action of the overturning moment, the real-time pressure values ​​of each measuring point are expanded according to the circumferential angle of their respective locations to form a spatial pressure distribution sequence. The spatial pressure distribution sequence is weighted and summed to obtain the resultant force direction angle of the overturning moment. The pressure values ​​of the measuring points within a set angle range on both sides of the resultant force direction angle are accumulated and divided by the sum of the pressure values ​​of all measuring points to obtain the directional load concentration. The directional load concentration is multiplied by the resultant force amplitude of the overturning moment and then divided by the rated dynamic load of the bearing to obtain the rolling element off-center load factor. This rolling element off-center load factor can reflect the degree of uneven loading of the rolling element under the action of the overturning moment, providing a basis for subsequent compensation area and amplitude.

[0007] Preferably, when the off-center load factor, representing the degree of off-center load, exceeds a preset off-center load threshold, the off-center load factor is mapped to the application area and initial amplitude of the reverse compensation force. The off-center load factor is then subtracted from the preset off-center load threshold to obtain the off-center load excess. The off-center load excess is divided by the historical peak value of the off-center load factor to obtain the off-center load overshoot ratio. Based on the quadrant where the overturning moment direction angle is located, a sector-shaped compensation area corresponding to the actuator group is divided on the bearing end face. The off-center load overshoot ratio is mapped to the compensation force amplitude coefficient of the sector-shaped compensation area. The compensation force amplitude coefficient is multiplied by the rated output force of the actuator to obtain the initial amplitude of the reverse compensation force. The sector-shaped compensation area corresponding to the reverse overturning moment direction angle is used as the application area of ​​the reverse compensation force. Thus, the magnitude and location of the compensation force are quantitatively determined according to the degree of off-center load, avoiding insufficient or excessive compensation.

[0008] Preferably, the piezoelectric micro-displacement actuator corresponding to the application area is activated. When the actuator lifts the thrust ring along the bearing axial direction to apply a reverse compensating force to the bearing end face, a target piezoelectric actuator group corresponding to the position code of the application area is selected from the actuator array, and a pre-start voltage is applied to the target piezoelectric actuator group. After the pre-start voltage is maintained for a set stable duration, the driving voltage is gradually increased to the target voltage value corresponding to the initial amplitude, causing the piezoelectric stack to extend axially. The extended piezoelectric stack pushes the push rod, transmitting the linear displacement of the push rod to the corresponding arc segment of the thrust ring, which then applies an axial thrust force to the bearing end face. This pre-start and gradual voltage increase method avoids instantaneous impact on the actuator and improves the smoothness of the compensating force application.

[0009] Preferably, during the application of the reverse compensation force, real-time pressure values ​​at each measuring point are continuously collected and the rolling element off-center load factor is updated. When dynamically adjusting the drive voltage of the piezoelectric micro-displacement actuator according to the updated rolling element off-center load factor, the real-time pressure values ​​at each measuring point are collected again according to a fixed sampling period, and the updated rolling element off-center load factor for the current period is calculated. The updated rolling element off-center load factor is compared with the rolling element off-center load factor of the previous period. If the updated rolling element off-center load factor is greater than that of the previous period, the drive voltage is increased by the first step value to increase the reverse compensation force. If the updated rolling element off-center load factor is less than that of the previous period but still higher than the hysteresis off-center load threshold, the drive voltage is kept unchanged by the second step value, where the second step value is less than the first step value. This achieves closed-loop tracking of the off-center load state, which can increase compensation when the off-center load intensifies and maintain stability when the off-center load eases, avoiding frequent fluctuations.

[0010] Preferably, when the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold, the drive voltage is gradually reduced until the actuator resets. During this process, the updated rolling element off-center load factor is compared with the hysteresis off-center load threshold. If the updated rolling element off-center load factor remains lower than the hysteresis off-center load threshold for three consecutive sampling cycles, the actuator reset phase begins. During the actuator reset phase, the current drive voltage is gradually reduced according to a set decreasing step size. After each reduction, a sampling cycle is waited, and the rolling element off-center load factor is reread. If the reread rolling element off-center load factor exceeds the hysteresis off-center load threshold again, the reduction is terminated, and the current drive voltage is maintained. If the reread rolling element off-center load factor remains lower than the hysteresis off-center load threshold, the reduction continues until the drive voltage returns to zero, and the actuator is fully reset. This hysteresis judgment and gradual reset process avoids premature termination of compensation due to instantaneous pressure fluctuations, ensuring system stability.

[0011] As a technical solution of the present invention, in the weighted summation, the real-time pressure value of each measuring point is assigned the sine and cosine values ​​of the circumferential angle of its location as weighting coefficients, and after summing, the off-center load azimuth angle is obtained by four-quadrant arctangent operation; the off-center load azimuth angle represents the circumferential azimuth of the pressure concentration on the bearing end face, rather than the direction of the overturning moment vector.

[0012] As a technical solution of the present invention, the angle range set on both sides of the resultant force direction angle is a sector interval with the resultant force direction angle as the center and the angle of expansion as 60°. When the pressure values ​​of the measuring points in the sector interval are accumulated, they are weighted according to the cosine value of the angle between the measuring point angle and the resultant force direction angle, so as to more centrally reflect the main area of ​​action of the overturning moment.

[0013] As a technical solution of the present invention, when the three consecutive sampling cycles are all below the hysteresis off-center load threshold, the current driving voltage is locked and two additional sampling cycles are maintained before entering the actuator reset stage to confirm that the off-center load state is stable, and to further suppress false reset caused by instantaneous disturbances.

[0014] This invention obtains the rolling element off-center load factor through real-time data acquisition and spatial pressure analysis, and applies an axial reverse compensation force to the thrust ring using a piezoelectric micro-displacement actuator. During the compensation process, the drive voltage is adjusted in a closed loop, so that the compensation area, compensation amplitude, and exit timing are adaptively determined according to the actual off-center load state. It features fast response speed, high compensation accuracy, and strong anti-interference ability, and is suitable for off-center load suppression of combined bearings under complex overturning conditions during RV operation.

[0015] The technical effects and advantages provided by the present invention in the above technical solution are as follows: A distributed pressure sensor array is used to acquire real-time pressure values ​​at various measuring points on the bearing end face. Combined with bearing structural parameters, this forms a structured input. Based on the spatial distribution of pressure values ​​at each measuring point, the resultant force direction angle, resultant force amplitude, and rolling element off-center load factor of the overturning moment are calculated. Unlike conventional methods that rely on overall vibration or temperature to indirectly determine off-center load, the distributed pressure sensor array directly reflects the pressure change along the circumferential direction on the bearing end face. It can determine the direction of the overturning moment and the degree of off-center load based on the location and extent of pressure concentration, reducing misjudgments of the compensation area caused by indirect estimation. When the rolling element off-center load factor exceeds a preset off-center load threshold, the application area and initial amplitude of the reverse compensation force are mapped from the rolling element off-center load factor. This causes the reverse compensation force to act on the fan-shaped compensation area corresponding to the direction of the overturning moment. The initial amplitude is determined based on the off-center load overshoot ratio and the rated output force of the actuator. This directly generates an axial reaction force on the high-pressure side when off-center load occurs, reducing the concentration of rolling element contact load on that side. The actuator is a piezoelectric micro-displacement actuator that lifts the corresponding arc segment of the thrust ring along the bearing axial direction, applying an axial thrust force to the bearing end face. Piezoelectric micro-displacement actuators offer fast response and high displacement resolution, enabling them to apply continuously adjustable compensation forces to localized areas when the off-center load changes. This avoids the response lag and insufficient local adjustment capabilities of hydraulic or electromagnetic compensation methods. During the application of the reverse compensation force, real-time pressure values ​​at each measuring point are continuously collected, and the rolling element off-center load factor is updated. Based on the comparison between the updated rolling element off-center load factor and the previous cycle, the drive voltage is adjusted according to the first or second step value. This closed-loop adjustment method allows the compensation force to change in real time with the off-center load condition. When the off-center load increases, the reverse compensation force increases; when the off-center load decreases but remains above the hysteresis off-center load threshold, the voltage remains stable, reducing overcompensation and oscillation. When the updated rolling element off-center load factor remains below the hysteresis off-center load threshold for three consecutive sampling cycles, a reset phase is initiated. The drive voltage is gradually reduced, and the rolling element off-center load factor is reread after each reduction. If the rolling element off-center load factor exceeds the hysteresis off-center load threshold again, the reduction stops, and the current drive voltage is maintained. If it remains below the hysteresis off-center load threshold, the reduction continues until the actuator resets. This reset strategy exits compensation in a step-by-step manner after the off-center load is restored, avoiding the pressure redistribution impact caused by the rapid withdrawal of the actuator. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0017] Figure 1 This is a flowchart of an adaptive compensation method for anti-overturning moment of a combined bearing for RVs. Figure 2This is a flowchart of distributed pressure signal conditioning and structured input data frame generation; Figure 3 It is a curve showing the real-time digital pressure value change at the measuring points of a distributed pressure sensor array; Figure 4 This is a curve showing the relationship between the off-center load factor of the rolling elements of the combined bearing and the driving voltage over time. Figure 5 It is the curve showing the gradual decrease of the drive voltage during the actuator reset phase and the change of the rolling element off-center load factor. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] See Figure 1 This invention provides an adaptive compensation method for overturning moment of a combined bearing for RVs, comprising: Step S1, collecting real-time pressure values ​​at each measuring point of the distributed pressure sensor array in the combined bearing for RVs, and inputting each real-time pressure value and bearing structural parameters as inputs to the compensation control unit; Step S2, calculating the direction and amplitude of the overturning moment on the bearing end face based on the spatial distribution characteristics of each real-time pressure value, and extracting the rolling element off-center loading factor under the action of the overturning moment; Step S3, when the off-center loading degree represented by the rolling element off-center loading factor exceeds a preset off-center loading threshold, the rolling element off-center loading factor... Step S4: Map the application area and initial amplitude of the reverse compensation force; Step S5: Start the piezoelectric micro-displacement actuator corresponding to the application area, and the actuator lifts the thrust ring along the bearing axis to apply the reverse compensation force to the bearing end face; Step S6: During the application of the reverse compensation force, continuously collect the real-time pressure value of each measuring point and update the rolling element off-center load factor, and dynamically adjust the driving voltage of the piezoelectric micro-displacement actuator according to the updated rolling element off-center load factor; Step S7: When the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold, gradually reduce the driving voltage until the actuator is reset.

[0020] In specific implementation, please refer to Figure 2The output signals of the sensitive elements at each measuring point in the distributed pressure sensor array are connected to a multi-channel signal conditioning circuit. The multi-channel signal conditioning circuit contains the same number of signal conditioning channels as the number of measuring points, with each channel corresponding to one measuring point. Each signal conditioning channel consists of a cascaded second-order active low-pass filter and an instrumentation amplifier. The cutoff frequency of the second-order active low-pass filter is set to 100Hz to filter out high-frequency interference signals introduced by vibrations during vehicle operation. The gain of the instrumentation amplifier is determined based on the full-scale output signal amplitude of the sensitive element and the input range of the analog-to-digital converter (ADC). The gain of the instrumentation amplifier is set through an adjustable resistor, ensuring that the amplitude of the instrumentation amplifier's output signal does not exceed the upper limit of the ADC's input range and is not lower than 50% of the lower limit of the ADC's input range. The filtered and amplified analog signal is converted into a digital pressure value by the ADC, which uses a 16-bit resolution, 1kHz sampling rate successive approximation ADC. The digital output of the ADC is the raw count value, which is then converted into the actual pressure value using the sensitive element calibration data. The calibration data for the sensing element includes a zero-point offset count and a sensitivity coefficient. The zero-point offset count is the count value output by the analog-to-digital converter when the sensing element has zero pressure input. The sensitivity coefficient is the change in the count value caused by each unit pressure change in the sensing element. Subtracting the zero-point offset count value from the original count value and multiplying it by the sensitivity coefficient yields the digital pressure value, which is measured in Newtons (N).

[0021] Obtain the rolling element pitch circle diameter, rolling element diameter, and number of rolling elements for the combined bearing, and construct a bearing structural parameter vector. The rolling element pitch circle diameter is the diameter of the circle containing the centers of all rolling elements in the combined bearing; the rolling element diameter is the outer diameter of a single rolling element; and the number of rolling elements is the total number of rolling elements in the combined bearing. The rolling element pitch circle diameter and rolling element diameter are obtained from the dimensions indicated on the bearing design drawings, and the number of rolling elements is obtained from the bearing assembly records. The bearing structural parameter vector is stored in triplicate form, with the first element being the rolling element pitch circle diameter, the second element being the rolling element diameter, and the third element being the number of rolling elements.

[0022] The digital pressure values ​​at each measuring point are aligned with the bearing structural parameter vector according to the acquisition time to form a structured input data frame. Within one acquisition cycle, the acquisition controller starts the analog-to-digital converter at a fixed sampling period to read the digital pressure values ​​of all measuring points, and simultaneously reads the system clock value as a timestamp. The digital pressure values ​​of each measuring point are arranged into a pressure value sequence according to the ascending order of the measuring point number. Then, the pressure value sequence, the bearing structural parameter vector, and the timestamp are combined to form the structured input data frame. The structured input data frame is represented by a structure containing a timestamp field, a measuring point number list field, a digital pressure value list field, and a bearing structural parameter vector field. The timestamp field is the millisecond-level system clock value corresponding to the acquisition time. The measuring point number list field is a list of integers starting from 1 and increasing. The digital pressure value list field contains digital pressure values ​​that correspond one-to-one with the measuring point number list. The bearing structural parameter vector field is a triple consisting of the rolling element pitch circle diameter, the rolling element diameter, and the number of rolling elements. The structured input data frame serves as the input data for subsequent calculations of the overturning moment direction and amplitude.

[0023] See Figure 3 In the figure, the horizontal axis represents the timestamp in milliseconds, ranging from 0 to 500 milliseconds, and the vertical axis represents the digital pressure value in Newtons, ranging from approximately 60 to 145 Newtons. The figure shows the curves of the digital pressure values ​​of four measuring points numbered 1, 2, 3, and 4 in the distributed pressure sensor array changing over time, represented by blue, orange, green, and red, respectively.

[0024] The digital pressure value at measuring point 1 is generally in the highest range, with a large fluctuation range, periodically changing between approximately 105 Newtons and 140 Newtons, showing obvious periodic oscillation characteristics, reflecting that the force at this measuring point is subject to strong dynamic influences. The digital pressure value at measuring point 2 is between 95 Newtons and 120 Newtons, with a similar fluctuation trend to measuring point 1 but a smaller amplitude. The digital pressure value at measuring point 3 is the lowest, fluctuating between approximately 60 Newtons and 95 Newtons, and the fluctuation frequency is similar to that of the other measuring points. The digital pressure value at measuring point 4 is between 70 Newtons and 110 Newtons, with a fluctuation trend similar to measuring points 2 and 3, but the overall value is higher.

[0025] The digital pressure values ​​at all four measuring points exhibited periodic fluctuations and a certain phase difference in the waveforms, indicating that the bearing end face circumferential angles at each measuring point were different, resulting in spatial non-uniformity in the dynamic distribution of pressure values ​​over time. This pressure signal was processed by a second-order active low-pass filter in a multi-channel signal conditioning circuit, effectively filtering out high-frequency vibration interference and ensuring accurate pressure value acquisition.

[0026] In practical implementation, the real-time pressure values ​​of each measuring point in the distributed pressure sensor array are unfolded according to the circumferential angle position of each measuring point on the end face of the combined bearing, forming a spatial pressure distribution sequence. Each element in the spatial pressure distribution sequence corresponds to a measuring point, and the element content includes the circumferential angle position of the measuring point and the real-time pressure value. The circumferential angle position of the measuring point is established in a polar coordinate system with the center of the end face of the combined bearing as the pole and the preset zero-degree reference line as the polar axis. The circumferential angle position of the measuring point is the angle between the line connecting the measuring point and the center of the end face of the combined bearing and the preset zero-degree reference line, with the angle unit being degrees. Based on the circumferential angle position and real-time pressure value of each measuring point in the spatial pressure distribution sequence, the resultant force direction angle and resultant force amplitude of the overturning moment are calculated.

[0027] When calculating the resultant force direction angle and resultant force amplitude of the overturning moment, a weighted summation is performed on the spatial pressure distribution sequence. During the weighted summation, the real-time pressure value at each measuring point is assigned the sine value of its circumferential angle position as a sine weighting coefficient, and simultaneously, the cosine value of its circumferential angle position as a cosine weighting coefficient. The real-time pressure value at each measuring point is multiplied by the sine value of its circumferential angle position, and the products of all measuring points are summed to obtain the sine weighted sum component. The real-time pressure value at each measuring point is multiplied by the cosine value of its circumferential angle position, and the products of all measuring points are summed to obtain the cosine weighted sum component.

[0028] The resultant force direction angle of the overturning moment is obtained by performing an arctangent operation on the ratio of the sine weighted sum component to the cosine weighted sum component. When the cosine weighted sum component is greater than zero, the resultant force direction angle of the overturning moment is equal to the angle value obtained by performing an arctangent operation on the ratio of the sine weighted sum component to the cosine weighted sum component. When the cosine weighted sum component is less than zero and the sine weighted sum component is greater than or equal to zero, the resultant force direction angle of the overturning moment is equal to the angle value obtained by performing an arctangent operation on the ratio of the sine weighted sum component to the cosine weighted sum component plus 180 degrees. When the cosine weighted sum component is less than zero and the sine weighted sum component is less than zero, the resultant force direction angle of the overturning moment is equal to the angle value obtained by performing an arctangent operation on the ratio of the sine weighted sum component to the cosine weighted sum component minus 180 degrees. The range of the resultant force direction angle of the overturning moment is -180 degrees to 180 degrees.

[0029] The resultant amplitude of the overturning moment is equal to the square root of the sum of the squares of the sine weighted sum component and the squares of the cosine weighted sum component. The unit of the resultant amplitude of the overturning moment is Newton.

[0030] The real-time pressure values ​​at measuring points within a set angle range on both sides of the resultant force direction angle of the overturning moment are accumulated, and then the accumulated result is divided by the sum of the real-time pressure values ​​at all measuring points to obtain the directional load concentration. The set angle range is a sector interval with an angle of 60 degrees centered on the resultant force direction angle of the overturning moment. For the calculation of directional load concentration, the angle is extended by 30 degrees clockwise and 30 degrees counterclockwise from the resultant force direction angle of the overturning moment to obtain the lower and upper boundaries of the angle. The lower boundary of the angle is equal to the resultant force direction angle of the overturning moment minus 30 degrees, and the upper boundary of the angle is equal to the resultant force direction angle of the overturning moment plus 30 degrees. When the lower boundary of the angle is less than -180 degrees, 360 degrees is added to the lower boundary of the angle; when the upper boundary of the angle is greater than 180 degrees, 360 degrees is subtracted from the upper boundary of the angle. This maps the sector interval to the measuring point angle range of -180 degrees to 180 degrees. The real-time pressure values ​​of all measuring points within the sector interval of the spatial pressure distribution sequence are accumulated. During accumulation, the real-time pressure value of each measuring point is weighted according to the cosine of the angle between the circumferential angle of the measuring point and the direction angle of the resultant force of the overturning moment. The angle is the absolute value of the angular difference between the circumferential angle of the measuring point and the direction angle of the resultant force of the overturning moment, ranging from 0 to 180 degrees. The weighted accumulation result is divided by the sum of all real-time pressure values ​​of all measuring points to obtain the directional load concentration, which ranges from 0 to 1.

[0031] The rolling element off-center loading factor is calculated using the following formula:

[0032] in, This represents the dimensionless rolling element off-center loading factor. The directional load concentration is obtained by dividing the aforementioned weighted sum by the sum of the real-time pressure values ​​at all measuring points. The value of the directional load concentration ranges from 0 to 1 (dimensionless). The magnitude of the resultant force representing the pressure distribution is obtained by adding the squares of the sine weighted sum component and the squares of the cosine weighted sum component, and then taking the square root. The dimension is Newton (N); This represents the rated dynamic load of the bearing, measured in Newtons (N). It is the rated load value that the rolling elements can withstand under specified conditions, as given in the product manual of the combined bearing, and is a constant greater than 0. It is a dimensionless quantity used for direct comparison with the preset off-center load threshold and the hysteresis off-center load threshold.

[0033] The rolling element off-center loading factor is obtained through the above calculation. The rolling element off-center loading factor is used as a quantitative value of the degree of off-center loading of the rolling element under the action of overturning moment, and is used for subsequent comparison with the preset off-center loading threshold.

[0034] In practice, when the off-center load factor, representing the degree of off-center load, exceeds the preset off-center load threshold, the off-center load factor is subtracted from the preset off-center load threshold to obtain the off-center load excess. The preset off-center load threshold is stored in the controller and is preset based on the maximum allowable off-center load of the combined bearing. The specific value of the preset off-center load threshold is determined based on the design load conditions and allowable vibration level of the combined bearing. The off-center load excess is a positive real number; the larger the off-center load excess, the greater the current off-center load exceeds the allowable level.

[0035] The historical peak value of the rolling element load factor is continuously recorded and updated by the controller. Each time the controller receives a new rolling element load factor, it compares the new factor with the currently stored historical peak value. If the new factor is greater than the currently stored historical peak value, the controller updates the historical peak value to the new factor. If the new factor is less than or equal to the currently stored historical peak value, the controller keeps the historical peak value unchanged.

[0036] The off-center overshoot ratio is obtained by dividing the excess off-center load by the historical peak value of the rolling element off-center load factor. The off-center overshoot ratio is calculated using the following formula:

[0037] in, This represents the off-center load overshoot ratio. The value of the off-center load overshoot ratio is a real number greater than or equal to 0. When the off-center load overshoot ratio is 0, it means that the current off-center load level has just reached the preset off-center load threshold. The larger the off-center load overshoot ratio, the larger the relative proportion of the current off-center load level exceeding the preset off-center load threshold. This represents the rolling element off-center loading factor calculated in the current sampling period. The value of the rolling element off-center loading factor is calculated from the real-time pressure value of the distributed pressure sensor array. This indicates the preset off-center load threshold, which is the maximum allowable rolling element off-center load factor value for the combined bearing. The preset off-center load threshold is a constant greater than 0. This represents the historical peak value of the rolling element bias factor. The historical peak value of the rolling element bias factor is the maximum rolling element bias factor value that has occurred since the system started, stored in the controller. The historical peak value of the rolling element bias factor is a constant greater than 0.

[0038] Based on the quadrant of the overturning moment direction angle, sector-shaped compensation zones corresponding to the actuator groups are divided on the bearing end face. Multiple sector-shaped compensation zones are pre-divided on the bearing end face, each corresponding to a set of piezoelectric micro-displacement actuators. The sector-shaped compensation zones are evenly divided along the circumference, centered on the bearing end face center, and each sector-shaped compensation zone has a position code. The value of the overturning moment direction angle is obtained through a weighted summation of the spatial pressure distribution sequence. The quadrant of the overturning moment direction angle is determined as follows: when the overturning moment direction angle is within the range of 0 to 90 degrees, it is in the first quadrant; when it is within the range of 90 to 180 degrees, it is in the second quadrant; when it is within the range of -180 to -90 degrees, it is in the third quadrant; and when it is within the range of -90 to 0 degrees, it is in the fourth quadrant. The quadrant in which the overturning moment direction angle is located is used to determine the location range of the sector compensation zone corresponding to the direction of the off-center load source.

[0039] The off-center overshoot ratio is mapped to the compensation force amplitude coefficient of the sector compensation zone. The relationship between the compensation force amplitude coefficient and the off-center overshoot ratio is determined by a pre-stored mapping relationship within the controller. This mapping relationship is linear, and the compensation force amplitude coefficient is equal to the off-center overshoot ratio multiplied by the compensation gain coefficient. The compensation gain coefficient is a constant between 0.85 and 0.95, set based on the force transmission efficiency of the piezoelectric micro-displacement actuator within the sector compensation zone. When the off-center overshoot ratio increases, the compensation force amplitude coefficient increases accordingly; when the off-center overshoot ratio decreases, the compensation force amplitude coefficient decreases accordingly.

[0040] Multiplying the compensation force amplitude coefficient by the actuator's rated output force yields the initial amplitude of the reverse compensation force. The actuator's rated output force is the maximum axial thrust output by a single piezoelectric micro-displacement actuator under rated drive voltage. The rated output force is obtained from the product specifications of the piezoelectric micro-displacement actuator, and its unit is Newtons. The initial amplitude of the reverse compensation force serves as the initial value of the target compensation force that the piezoelectric micro-displacement actuator needs to output.

[0041] The sector-shaped compensation area corresponding to the opposite direction angle of the overturning moment is used as the application area of ​​the reverse compensation force. The opposite direction angle of the overturning moment is the overturning moment direction angle plus 180 degrees. If the overturning moment direction angle plus 180 degrees is greater than 180 degrees, then 360 degrees is subtracted from the opposite direction angle to obtain the reverse direction angle. The sector-shaped compensation area into which the reverse direction angle falls is the application area of ​​the reverse compensation force. The reverse direction angle and the overturning moment direction angle are symmetrical about the center of the bearing end face, and the sector-shaped compensation area corresponding to the reverse direction angle and the sector-shaped compensation area corresponding to the overturning moment direction angle are diagonally distributed along the center of the bearing end face.

[0042] When the piezoelectric micro-displacement actuator in the corresponding area is activated according to the application area, the target piezoelectric actuator group corresponding to the position code of the application area is selected from the actuator array. The actuator array consists of multiple piezoelectric micro-displacement actuators, each with a unique position code, which corresponds one-to-one with the position code of the sector compensation area. The controller generates an actuator selection signal based on the position code of the application area of ​​the reverse compensation force. The actuator selection signal is output to the target piezoelectric actuator group through the drive channel corresponding to the position code, putting the target piezoelectric actuator group into a ready-to-drive state.

[0043] A pre-start voltage is applied to the target piezoelectric actuator assembly. The pre-start voltage is the initial drive voltage at which the piezoelectric micro-displacement actuator begins to generate axial displacement. The pre-start voltage is determined based on the actuation characteristics of the piezoelectric micro-displacement actuator and is set to 10% of the rated drive voltage of the piezoelectric micro-displacement actuator. The pre-start voltage is maintained for a set stabilization time, which is pre-stored in the controller and is 0.5 seconds. Maintaining the pre-start voltage for this stabilization time allows the piezoelectric stack inside the piezoelectric micro-displacement actuator to be fully charged and enter a steady-state elongation state.

[0044] After the pre-start voltage is maintained at a set stable duration, the drive voltage is gradually increased to the target voltage value corresponding to the initial amplitude. The target voltage value is determined based on the initial amplitude of the reverse compensation force using the force-voltage characteristic curve of the piezoelectric micro-displacement actuator. This force-voltage characteristic curve is provided by the piezoelectric micro-displacement actuator manufacturer and stored in the controller. Starting from the pre-start voltage, the drive voltage gradually increases according to a pre-set voltage rise slope until the drive voltage reaches the target voltage value. During this gradual increase in drive voltage, the piezoelectric stack gradually elongates axially, with the elongation proportional to the increment of the drive voltage.

[0045] An elongated piezoelectric stack pushes a push rod, which is fixedly connected to the piezoelectric stack. As the piezoelectric stack elongates, it pushes the push rod to move axially, transmitting the linear displacement of the push rod to the corresponding arc segment of the thrust ring. The thrust ring has a ring structure, and the corresponding arc segment of the thrust ring is the circular arc segment adjacent to the target piezoelectric actuator assembly. The corresponding arc segment of the thrust ring applies an axial thrust force to the bearing end face. The axial thrust force is related to the elongation of the piezoelectric stack and acts as a counter-compensating force on the combined bearing end face.

[0046] In practice, during the application of the reverse compensation force, the controller re-acquires the real-time pressure values ​​of each measuring point in the distributed pressure sensor array according to a fixed sampling period. The fixed sampling period is pre-stored inside the controller and is 10 milliseconds. When each fixed sampling period arrives, the controller initiates a sampling process of the distributed pressure sensor array. The output signals of the sensitive elements at each measuring point are filtered and amplified by a multi-channel signal conditioning circuit and then converted into digital pressure values ​​by an analog-to-digital converter.

[0047] The controller recalculates the rolling element off-center load factor for the current cycle based on the newly acquired digital pressure values ​​from each measuring point, following the calculation process for the rolling element off-center load factor. The calculation process for the updated rolling element off-center load factor includes: expanding the digital pressure values ​​from each measuring point according to the circumferential angle of the measuring point to form a spatial pressure distribution sequence; performing a weighted summation on the spatial pressure distribution sequence to obtain the resultant force direction angle and resultant force amplitude of the overturning moment; performing a cosine-weighted summation of the pressure values ​​from the measuring points within a set angle range on both sides of the resultant force direction angle and dividing by the sum of all measuring point pressure values ​​to obtain the directional load concentration; multiplying the directional load concentration by the resultant force amplitude of the overturning moment and then dividing by the bearing's rated dynamic load to obtain the updated rolling element off-center load factor.

[0048] The updated rolling element load factor is compared with the rolling element load factor of the previous cycle. The rolling element load factor of the previous cycle is the value of the rolling element load factor stored in the rolling element load factor storage unit by the controller at the end of the previous sampling cycle. The rolling element load factor storage unit is a random access memory buffer inside the controller. After each calculation of a new rolling element load factor, the controller writes the new rolling element load factor into the rolling element load factor storage unit, overwriting the original value in the rolling element load factor storage unit, so that the rolling element load factor storage unit always retains the rolling element load factor corresponding to the most recent sampling cycle.

[0049] If the updated rolling element off-center loading factor is greater than that of the previous cycle, it indicates that the degree of off-center loading on the combined bearing end face is increasing. The controller increases the drive voltage of the piezoelectric micro-displacement actuator by the first step value. The first step value is pre-stored in the controller and is set to 5% of the rated drive voltage of the piezoelectric micro-displacement actuator. The rated drive voltage of the piezoelectric micro-displacement actuator is obtained from the product technical specifications of the piezoelectric micro-displacement actuator. The controller reads the current drive voltage value, adds the first step value to the current drive voltage value to obtain the new drive voltage value, and applies the new drive voltage value to the target piezoelectric actuator group. After the drive voltage increases, the axial elongation of the piezoelectric stack in the target piezoelectric actuator group increases, the linear displacement of the push rod increases, the axial thrust applied to the combined bearing end face by the corresponding arc segment of the thrust ring increases, and the reverse compensation force increases.

[0050] If the updated rolling element off-center load factor is less than that of the previous cycle and is still higher than the hysteresis off-center load threshold, it indicates that the off-center load on the combined bearing end face has decreased but has not yet fallen below the threshold for canceling compensation. The hysteresis off-center load threshold is pre-stored in the controller. The hysteresis off-center load threshold is the rolling element off-center load factor value that is less than the preset off-center load threshold. The hysteresis off-center load threshold is used to prevent the reverse compensation force from frequently switching under a single boundary condition. The controller keeps the drive voltage constant according to the second step value. The second step value is pre-stored in the controller and is set to 1% of the rated drive voltage of the piezoelectric micro-displacement actuator. The second step value is less than the first step value. While keeping the drive voltage constant, the controller sets the drive voltage adjustment amount to the product of the second step value and 0. The drive voltage adjustment amount is zero, the current drive voltage value remains unchanged, the elongation of the piezoelectric stack remains unchanged, the axial thrust applied to the combined bearing end face by the corresponding arc segment of the thrust ring remains unchanged, and the reverse compensation force is maintained at the current level.

[0051] After the comparison is completed, the controller enters the next fixed sampling cycle and repeats the process of real-time pressure value acquisition, rolling element off-center load factor calculation, rolling element off-center load factor comparison, and drive voltage adjustment.

[0052] See Figure 4 In the graph, the horizontal axis represents time in milliseconds, the left vertical axis represents the driving voltage in volts, and the right vertical axis represents the rolling element off-center load factor. The blue curve in the graph is the driving voltage variation curve of the piezoelectric micro-displacement actuator, and the red curve is the rolling element off-center load factor variation curve calculated in real time.

[0053] Starting from 0 milliseconds, the drive voltage curve rises rapidly in fixed steps, reaching the maximum rated drive voltage of 100 volts at approximately 50 milliseconds and remaining constant. This reflects the process of the actuator's pre-start voltage gradually increasing to the target drive voltage, which is consistent with the description in the above embodiment of the drive voltage gradually increasing from the pre-start voltage to the target voltage.

[0054] The rolling element off-center load factor curve remains at a low level before the driving voltage reaches its maximum value. As the driving voltage approaches and reaches its maximum value, the rolling element off-center load factor rises rapidly, peaking at approximately 1.5 at about 150 milliseconds, indicating a significant increase in the off-center load on the combined bearing end face during this stage. Subsequently, the rolling element off-center load factor gradually decreases, stabilizing after 300 milliseconds and remaining below 0.4. This shows that the continuous effect of the reverse compensation force significantly reduces the off-center load, and does not exceed the hysteresis off-center load threshold. This demonstrates that the controller dynamically adjusts the driving voltage based on the updated rolling element off-center load factor, thereby achieving real-time compensation.

[0055] In practice, the controller compares the updated rolling element off-center load factor with the hysteresis off-center load threshold. The updated rolling element off-center load factor is recalculated based on the real-time pressure values ​​at each measuring point of the distributed pressure sensor array within the current sampling period. The hysteresis off-center load threshold is pre-stored in the controller and is a threshold value for the rolling element off-center load factor that is less than the preset off-center load threshold. The value of the hysteresis off-center load threshold is determined based on the allowable residual off-center load level of the combined bearing and the reset conditions of the piezoelectric micro-displacement actuator. When the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold, it indicates that the reverse compensation force has reduced the off-center load on the end face of the combined bearing to a level where compensation can be withdrawn. However, the updated rolling element off-center load factor must remain below the hysteresis off-center load threshold for a certain number of sampling periods before entering the actuator reset stage to avoid erroneous resets caused by instantaneous pressure fluctuations.

[0056] The controller is equipped with an off-center load status counter, which counts the number of sampling periods in which the updated rolling element off-center load factor is continuously below the hysteresis off-center load threshold. When the updated rolling element off-center load factor falls below the hysteresis off-center load threshold, the value of the off-center load status counter is incremented by 1; when the updated rolling element off-center load factor returns to above or equal to the hysteresis off-center load threshold, the value of the off-center load status counter is reset to zero and the accumulation restarts. The initial value of the off-center load status counter is 0, and the off-center load status counter is stored in the controller's data register.

[0057] If the updated rolling element off-center load factor remains below the hysteresis off-center load threshold for three consecutive sampling cycles (i.e., the off-center load state counter reaches 3), the current drive voltage is locked and maintained for an additional two sampling cycles to confirm that the off-center load state is stable. Locking the current drive voltage means that the controller stops executing the automatic adjustment cycle of the drive voltage, keeping the current drive voltage value applied to the target piezoelectric actuator group constant. During the locking period, the output value of the drive voltage is not changed according to the change in the rolling element off-center load factor. The duration of the two additional sampling cycles is the sum of the durations of two fixed sampling cycles (10 milliseconds). During the two additional sampling cycles, the controller continues to collect real-time pressure values ​​at each measuring point and calculates the updated rolling element off-center load factor. The controller also continuously compares the updated rolling element off-center load factor with the hysteresis off-center load threshold. If the updated rolling element off-center load factor remains below the hysteresis off-center load threshold during the two additional sampling cycles, the off-center load state is confirmed to be stable, and the controller enters the actuator reset phase. If the rolling element off-center load factor is higher than or equal to the hysteresis off-center load threshold during the two additional sampling periods, the current drive voltage lockout is released, and the reverse compensation force dynamic adjustment process is re-entered.

[0058] After confirming the off-center load condition is stable, the actuator reset phase begins. During the actuator reset phase, the controller gradually reduces the current drive voltage in increments of a set decreasing step size. This set decreasing step size is pre-stored in the controller and is set to 3% of the rated drive voltage of the piezoelectric micro-displacement actuator. The rated drive voltage of the piezoelectric micro-displacement actuator is obtained from the product's technical specifications. The decreasing step size is set to ensure a slow reduction in the output force of the piezoelectric micro-displacement actuator, preventing abrupt changes in the pressure redistribution on the combined bearing end face caused by the sudden removal of the reverse compensation force.

[0059] The controller reads the current drive voltage value, subtracts the set decrease step size from the current drive voltage value to obtain the reduced drive voltage value, and applies the reduced drive voltage value to the target piezoelectric actuator assembly. After each step of reducing the drive voltage, the controller waits for one sampling cycle, with the duration of one sampling cycle being 10 milliseconds. During the waiting period of one sampling cycle, the elongation of the piezoelectric stack gradually shortens according to the decrease in drive voltage, the linear displacement of the push rod decreases, and the axial thrust applied to the end face of the combined bearing by the corresponding arc segment of the thrust ring decreases.

[0060] After waiting for the end of a sampling cycle, the controller re-acquires the real-time pressure values ​​at each measuring point and recalculates the rolling element off-center load factor, obtaining the re-read rolling element off-center load factor. The controller then compares the re-read rolling element off-center load factor with the hysteresis off-center load threshold.

[0061] If the rereading rolling element off-center load factor exceeds the hysteresis off-center load threshold again, the reduction of the drive voltage is terminated and the current drive voltage is maintained. Terminating the reduction of the drive voltage means that the controller stops continuing to execute the drive voltage reduction operation with decreasing steps, and keeps the current drive voltage value constant. Maintaining the current drive voltage means that the drive voltage is no longer reduced in subsequent sampling cycles, but the rolling element off-center load factor is still continuously monitored. When the rereading rolling element off-center load factor is lower than the hysteresis off-center load threshold again for three consecutive sampling cycles, the actuator reset phase is restarted and the step-by-step reduction of the drive voltage continues.

[0062] If the rereading rolling element off-center load factor remains below the hysteresis off-center load threshold, the drive voltage continues to decrease, and the next level of decreasing drive voltage reduction operation is executed. This process of reducing drive voltage, waiting for one sampling cycle, rereading the rolling element off-center load factor, and comparing it with the hysteresis off-center load threshold is repeated until the drive voltage returns to zero. After the drive voltage returns to zero, the piezoelectric stack of the piezoelectric micro-displacement actuator is completely retracted, the push rod returns to its initial position, the corresponding arc segment of the thrust ring no longer applies axial thrust to the end face of the combined bearing, the reverse compensation force is completely canceled, and the actuator is fully reset.

[0063] See Figure 5In the graph, the horizontal axis represents time in milliseconds, the left side of the vertical axis represents the driving voltage in volts, and the right side of the vertical axis represents the rolling element off-center load factor. The curves in the graph include the driving voltage (blue solid line), the rolling element off-center load factor (red solid line), and the hysteresis off-center load threshold (green dashed line).

[0064] Over time, the drive voltage gradually decreases in steps, from an initial 100 volts to approximately 30 volts. This reflects the process during the actuator reset phase where the controller progressively reduces the drive voltage in stages according to a set decreasing step size (approximately 3% of the rated drive voltage). The gradual decrease in drive voltage corresponds to a decrease in the axial thrust of the piezoelectric micro-displacement actuator, and the reverse compensation force exerted by the push rod and thrust ring on the combined bearing end face gradually disappears.

[0065] The rolling element off-center load factor curve exhibits periodic fluctuations throughout the time range, with the numerical fluctuations generally between 0.20 and 0.50. The overall trend of the rolling element off-center load factor is inversely correlated with the decrease in drive voltage. During the decrease in drive voltage, the rolling element off-center load factor is mostly below the hysteresis off-center load threshold (approximately 0.40) indicated by the green dashed line, which meets the judgment condition for entering the actuator reset stage when "the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold" as described in the above embodiment.

[0066] During the decrease of the drive voltage, although the rolling element off-center load factor fluctuated, it remained below the hysteresis off-center load threshold, indicating that the reverse compensation force effectively suppressed the off-center load on the combined bearing end face, and the degree of off-center load was within the range where compensation could be withdrawn. The figure does not show the drive voltage holding and additional maintenance phases, but the step-like decrease of the drive voltage and the fluctuation trend of the rolling element off-center load factor demonstrate the process by which the controller dynamically adjusts the drive voltage based on the off-center load state counter and the hysteresis threshold to achieve a slow reset of the actuator.

[0067] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A method for adaptive compensation of overturning moment of a combined bearing for motorhomes, characterized in that, include: Collect real-time pressure values ​​at each measuring point of the distributed pressure sensor array in the combined bearing for RVs, and input each real-time pressure value and bearing structural parameters into the compensation control unit; Based on the spatial distribution characteristics of each real-time pressure value, the direction and amplitude of the overturning moment on the bearing end face are calculated, and the rolling element off-center loading factor under the action of the overturning moment is extracted. When the degree of off-center loading represented by the rolling element off-center loading factor exceeds the preset off-center loading threshold, the application area and initial amplitude of the reverse compensation force are mapped by the rolling element off-center loading factor. The piezoelectric micro-displacement actuator in the corresponding area is activated according to the application area. The actuator lifts the thrust ring along the bearing axis and applies a reverse compensation force to the bearing end face. During the application of the reverse compensation force, the real-time pressure values ​​of each measuring point are continuously collected and the rolling element off-center loading factor is updated. The driving voltage of the piezoelectric micro-displacement actuator is dynamically adjusted according to the updated rolling element off-center loading factor. When the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold, the drive voltage is gradually reduced until the actuator is reset.

2. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 1, characterized in that, The system collects real-time pressure values ​​from various measuring points in the distributed pressure sensor array of the combined bearing for RVs, and inputs these real-time pressure values ​​along with the bearing structural parameters into the compensation control unit. Specifically, this includes: The output signals of the sensitive elements at each measuring point in the distributed pressure sensor array are connected to a multi-channel signal conditioning circuit, and after filtering and amplification, they are converted into digital pressure values ​​by an analog-to-digital converter. Obtain the rolling element pitch circle diameter, rolling element diameter, and number of rolling elements of the combined bearing to form a bearing structural parameter vector; Align the digital pressure values ​​at each measuring point with the bearing structural parameter vector according to the acquisition time to form a structured input data frame.

3. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 1, characterized in that, Based on the spatial distribution characteristics of each real-time pressure value, the direction and amplitude of the overturning moment on the bearing end face are calculated, and the rolling element off-center loading factor under the action of the overturning moment is extracted, specifically including: The real-time pressure values ​​at each measuring point are expanded according to the circumference angle of the circle to form a spatial pressure distribution sequence. The resultant force direction angle of the overturning moment is obtained by weighted summation of the spatial pressure distribution sequence. The pressure values ​​of the measuring points within the set angle range on both sides of the resultant force direction angle are summed and divided by the sum of the pressure values ​​of all measuring points to obtain the directional load concentration. Multiply the directional load concentration by the resultant amplitude of the overturning moment, and then divide by the rated dynamic load of the bearing to obtain the rolling element eccentric load factor.

4. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 1, characterized in that, When the off-center loading factor, representing the degree of off-center loading, exceeds the preset off-center loading threshold, the off-center loading factor maps the application area and initial amplitude of the reverse compensation force, specifically including: Subtract the rolling element off-center load factor from the preset off-center load threshold to obtain the off-center load excess. Divide the off-center load excess by the historical peak value of the rolling element off-center load factor to obtain the off-center load overshoot ratio. Based on the quadrant where the overturning moment direction angle is located, a sector-shaped compensation area corresponding to the actuator group is divided on the bearing end face, and the off-center overshoot ratio is mapped to the compensation force amplitude coefficient of the sector-shaped compensation area. Multiply the compensation force amplitude coefficient by the rated output force of the actuator to obtain the initial amplitude of the reverse compensation force, and take the sector-shaped compensation area corresponding to the reverse overturning moment direction angle as the application area of ​​the reverse compensation force.

5. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 1, characterized in that, The piezoelectric micro-displacement actuator in the corresponding area is activated according to the application area. The actuator lifts the thrust ring along the bearing axis and applies a reverse compensation force to the bearing end face, specifically including: Based on the position code of the application area, the target piezoelectric actuator group corresponding to the position code is selected from the actuator array, and a pre-start voltage is applied to the target piezoelectric actuator group; After the pre-start voltage is maintained for a set stable period of time, the driving voltage is gradually increased to the target voltage value corresponding to the initial amplitude, causing the piezoelectric stack to extend axially. The extended piezoelectric stack pushes the push rod, which transmits the linear displacement of the push rod to the corresponding arc segment of the thrust ring. This arc segment of the thrust ring applies an axial thrust to the bearing end face.

6. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 1, characterized in that, During the application of the reverse compensation force, the real-time pressure values ​​at each measuring point are continuously collected and the rolling element off-center loading factor is updated. The drive voltage of the piezoelectric micro-displacement actuator is dynamically adjusted according to the updated rolling element off-center loading factor, specifically including: The real-time pressure values ​​of each measuring point are re-acquired according to a fixed sampling period, and the updated rolling element off-center load factor for the current period is calculated. The updated rolling element off-center load factor is then compared with the rolling element off-center load factor of the previous period. If the updated rolling element off-center loading factor is greater than the rolling element off-center loading factor of the previous cycle, the driving voltage is increased by the first step value to increase the reverse compensation force. If the updated rolling element off-center load factor is less than the rolling element off-center load factor of the previous cycle but is still higher than the hysteresis off-center load threshold, then the drive voltage is kept constant according to the second step value, where the second step value is less than the first step value.

7. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 1, characterized in that, When the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold, the drive voltage is gradually reduced until the actuator is reset, specifically including: The updated rolling element off-center load factor is compared with the hysteresis off-center load threshold. If the updated rolling element off-center load factor is lower than the hysteresis off-center load threshold for three consecutive sampling periods, the actuator reset phase is initiated. During the actuator reset phase, the current drive voltage is gradually reduced step by step according to the set decreasing step size. After each reduction step, wait for one sampling cycle and reread the rolling element off-center load factor. If the rereading rolling element off-center load factor exceeds the hysteresis off-center load threshold again, the reduction will stop and the current drive voltage will be maintained; if the rereading rolling element off-center load factor remains below the hysteresis off-center load threshold, the reduction will continue until the drive voltage returns to zero and the actuator is fully reset.

8. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 3, characterized in that, In the weighted summation, the real-time pressure value of each measuring point is assigned the sine and cosine values ​​of its circumferential angle as weighting coefficients. After summing, the off-center load azimuth angle is obtained by arctangent calculation in four quadrants. The off-center load azimuth angle represents the circumferential azimuth of the pressure concentration on the bearing end face, rather than the direction of the overturning moment vector.

9. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 3, characterized in that, The angle range set on both sides of the resultant force direction angle is a sector interval with a subtended angle of 60° centered on the resultant force direction angle, and the pressure values ​​of the measuring points within this sector interval are weighted according to the cosine value of the angle between the measuring point angle and the resultant force direction angle.

10. The adaptive compensation method for anti-overturning moment of a combined bearing for a motorhome according to claim 7, characterized in that, When the voltage is below the hysteresis off-center load threshold for three consecutive sampling cycles, the current drive voltage is locked and maintained for two additional sampling cycles before entering the actuator reset phase to confirm that the off-center load state is stable.

Images