Shock absorber damping adaptive control method and system

Abstract

The application discloses a shock absorber damping self-adaptive control method and system, which comprises the following steps: obtaining the current vehicle mass, and selecting the initial center gap according to the current vehicle mass; continuously collecting the stroke position, motion speed of the piston rod and the vehicle body vertical acceleration, calculating the remaining distance in the stretching direction and the remaining distance in the compression direction according to the stroke position, and identifying the stretching end buffering event or the compression end buffering event in combination with the motion direction of the piston rod; for the corresponding buffering event, calculating the stretching buffering demand value or the compression buffering demand value according to the motion speed when entering the buffering interval, the corresponding direction remaining distance, the current vehicle mass and the vehicle body vertical acceleration; and determining the target center gap according to the two buffering demand values, and adjusting the center gap to the target value. The application can match the end damping of the shock absorber with the vehicle load and the actual impact state, and improve the adaptability of the stroke end buffering and the vehicle riding comfort.

Description

Technical Field

[0001] This application relates to the field of vibration damper control technology, specifically to a vibration damper damping adaptive control method and system. Background Technology

[0002] Vehicle suspension systems typically utilize hydraulic shock absorbers to dissipate vibrational energy between the wheels and the vehicle body, balancing tire contact stability and ride comfort. Existing shock absorbers mainly include passive shock absorbers with fixed damping characteristics, and adjustable or semi-active shock absorbers whose damping force is adjusted via actuators such as electronically controlled valves. With the development of vehicle load variations and chassis electronic control technology, real-time adjustment of damping characteristics based on sensor signals has become an important technological direction.

[0003] However, existing solutions primarily focus on vibration suppression within the normal stroke range. For cushioning near the end of the piston rod's extension or compression stroke, they still rely heavily on buffer pads, fixed throttling channels, graded valve systems, or preset damping parameters. When vehicle weight, impact velocity, and remaining cushioning stroke change, fixed or uniformly set end-of-stroke damping cannot consistently match actual needs: insufficient damping can cause the piston to approach the mechanical limit excessively, resulting in a large impact; excessive damping can lead to an increase in peak vehicle acceleration, affecting ride comfort. Furthermore, some adjustable shock absorbers require manual setting or do not combine piston rod stroke position, movement speed, and vehicle vertical acceleration for real-time judgment and feedback correction of the extension and compression end-of-stroke conditions, making it difficult to balance end-of-stroke protection and ride comfort under different loads and complex road conditions. Therefore, it is necessary to research shock absorber damping control technology capable of identifying end-of-stroke cushioning events and adaptively adjusting the throttling clearance. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this specification provides a method and system for adaptive control of damper damping.

[0005] According to a first aspect of the embodiments of this application, a damper adaptive control method is provided, comprising: Obtain the current vehicle mass and select the initial center clearance based on the current vehicle mass; Continuously collect data on the piston rod's stroke position, movement speed, and the vehicle's vertical acceleration; The remaining distance in the stretching direction and the remaining distance in the compression direction are calculated based on the stroke position. When the piston rod moves in the stretching direction and the remaining distance in the stretching direction is not greater than a preset threshold, it is identified as a stretching end buffer event. When the piston rod moves in the compression direction and the remaining distance in the compression direction is not greater than a preset threshold, it is identified as a compression end buffer event. For the stretching end buffer event, the stretching buffer requirement value is calculated based on the stretching speed when entering the buffer zone, the remaining distance in the stretching direction, the current vehicle mass, and the upward acceleration of the vehicle body; for the compression end buffer event, the compression buffer requirement value is calculated based on the compression speed when entering the buffer zone, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body. The target center gap is determined based on the tensile buffer requirement value and the compression buffer requirement value, and the center gap is adjusted to the target center gap.

[0006] As an optional solution, the stretching buffer requirement value is determined by the sum of the kinetic energy dissipation component and the inertial load component; the kinetic energy dissipation component is calculated based on the current vehicle mass, the stretching speed, and the remaining distance in the stretching direction; the inertial load component is calculated based on the current vehicle mass, the upward acceleration of the vehicle body, and the acceleration weighting coefficient, the acceleration weighting coefficient being obtained through bench calibration; the compression buffer requirement value is determined in the same manner by the compression speed, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body.

[0007] As an optional approach, determining the target center gap based on the stretching buffer demand value and the compression buffer demand value includes: based on the inverse mapping relationship between the center gap and the buffer demand value, converting the stretching buffer demand value and the compression buffer demand value into stretching candidate gaps and compression candidate gaps respectively, with the larger the buffer demand value, the smaller the corresponding candidate gap; both the stretching candidate gap and the compression candidate gap are limited to between the minimum gap and the maximum gap; when the absolute value of the difference between the stretching candidate gap and the compression candidate gap is less than the consistency tolerance, the average value of the two is taken as the target center gap.

[0008] As an optional approach, when the absolute value of the difference between the candidate tension gap and the candidate compression gap is not less than the consistency tolerance: for each candidate gap, based on the current vehicle mass, the speed when entering the buffer zone, and the damping characteristics corresponding to the candidate gap, calculate the stroke length required to decelerate the piston rod to zero in both the tension and compression directions as the remaining safety distance; select the candidate gap that satisfies the preset safety distance lower limit in the direction where the minimum value of the remaining safety distance is located as the target center gap; when both candidate gaps satisfy the safety distance lower limit in this direction, select the one with the larger value.

[0009] As an optional approach, after each stretching end buffer event or compression end buffer event, the maximum vertical acceleration peak of the vehicle body, the minimum measured distance between the piston rod and the corresponding end of the stroke, and the time required for the vehicle body to recover stability are recorded as buffer effect feedback. The correction direction is determined based on the buffer effect feedback, and the target center clearance is updated according to the correction direction.

[0010] As an optional solution, the rule for determining the correction direction is as follows: when the minimum measured distance is less than the preset lower limit of the safety distance, or when the duration of the piston end face approaching the corresponding stroke limit exceeds the preset upper limit of the contact time, the correction direction is to reduce the center gap; when the minimum measured distance is not less than the lower limit of the safety distance and the peak value of the maximum vertical acceleration of the vehicle body exceeds the comfort acceleration limit, or when the time required for the vehicle body to recover stability exceeds the comfort recovery time limit, the correction direction is to increase the center gap.

[0011] As an optional approach, the target center gap is updated according to the correction direction only when the same type of buffer events for a consecutive preset number of times produce the same correction direction; the adjustment amount of each update does not exceed the preset single-step maximum adjustment amount; no adjustment is performed when the absolute value of the difference between the target center gap and the current actual center gap is less than the preset adjustment dead zone.

[0012] As an optional approach, the timing for controlling the execution of the adjustment action is one of the following: the vehicle is stationary; the vehicle is traveling at low speed in a straight line; the piston rod is in the middle stroke region where both the remaining distance in the stretching direction and the remaining distance in the compression direction are greater than the corresponding preset threshold.

[0013] As an optional solution, the step of selecting the initial center clearance based on the current vehicle weight includes: reading the static stroke position of the piston rod when the vehicle is stationary, taking the difference between the static stroke position and the pre-calibrated no-load static position as the static offset, determining the load level based on the static offset and the preset offset step size, and selecting the initial center clearance from the pre-calibrated clearance parameter table based on the load level; the higher the load level, the smaller the initial center clearance.

[0014] According to a second aspect of the embodiments of this application, a damper damping adaptive control system is also provided, comprising: The mass acquisition and initial gap determination module is used to acquire the current vehicle mass and select the initial center gap based on the current vehicle mass. The status acquisition module is used to continuously acquire the piston rod's stroke position, movement speed, and vehicle body vertical acceleration; The buffer event identification module is used to calculate the remaining distance in the stretching direction and the remaining distance in the compression direction based on the stroke position; when the piston rod moves in the stretching direction and the remaining distance in the stretching direction is not greater than a preset threshold, it is identified as a stretching end buffer event; when the piston rod moves in the compression direction and the remaining distance in the compression direction is not greater than a preset threshold, it is identified as a compression end buffer event. The buffer demand calculation module is used to calculate the stretching buffer demand value based on the stretching speed when entering the buffer zone, the remaining distance in the stretching direction, the current vehicle mass, and the upward acceleration of the vehicle body for the stretching end buffering event; and to calculate the compression buffer demand value based on the compression speed when entering the buffer zone, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body for the compression end buffering event. The center gap control module is used to determine the target center gap based on the tensile buffer demand value and the compression buffer demand value, and adjust the center gap to the target center gap.

[0015] This application uses the piston rod stroke position, movement speed, and vehicle vertical acceleration as state criteria. After identifying the end-of-stroke buffering event of the stretching or compression stroke, it calculates the buffering requirement by combining the current vehicle mass, speed upon entering the buffer zone, remaining stroke, and vehicle inertial load. This requirement is then converted into a target value for the composite piston center clearance. A stepper motor drives a conical adjusting needle to move axially, achieving adaptive adjustment of the end-of-stroke throttling area. This control method matches the center clearance with the vehicle load, road impact level, and actual piston rod movement state, creating suitable oil flow resistance within the remaining stroke. This reduces the impact risk when the piston approaches the mechanical limit, while avoiding an increase in peak vehicle acceleration due to excessive damping. Through buffering effect feedback, continuous event judgment, and adjustment dead zone control, the target clearance can be stably corrected, reducing frequent adjustments and damping abrupt changes. This improves the shock absorber's end-of-stroke buffering adaptability, operational safety, and vehicle ride comfort under different loads and complex road conditions. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this specification and, together with the description, serve to explain the principles of this specification.

[0017] Figure 1 This is a schematic diagram of an application scenario in one embodiment of this application.

[0018] Figure 2 This is a flowchart of an adaptive control method for damper damping in one embodiment of this application.

[0019] Figure 3 This is a flowchart of adjusting the center gap in one embodiment of this application.

[0020] Figure 4 This is a schematic block diagram of an adaptive damping control system for a shock absorber according to this application.

[0021] Figure 5 This is a structural diagram of an electronic device according to one embodiment of this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The shock absorber involved in this embodiment is a hydraulic shock absorber equipped with a compound piston, installed in the vehicle suspension system. The compound piston contains a plunger with an axial channel at its center. A tapered adjusting pin is installed within the channel, forming an annular central gap between the outer wall of the adjusting pin and the inner wall of the channel. An external adjusting handle is connected to the adjusting pin via a stepper motor and a transmission rod. The stepper motor rotates, causing the adjusting pin to move axially, changing the width of the central gap. When the piston rod reaches the end of its stroke, the plunger undergoes relative displacement with respect to the piston body. Oil in one side of the plunger's oil chamber is forced to flow through the central gap to the other side. The smaller the cross-sectional area of ​​the gap, the greater the flow resistance and the greater the damping force. The controller uses an onboard embedded microcontroller with a control cycle configurable, for example, 5ms. Required sensors include a displacement sensor mounted on the piston rod and a vertical acceleration sensor fixed to the vehicle body, both standard configurations in the vehicle suspension field.

[0024] Please see Figure 1 , Figure 1 This is a schematic diagram of an application scenario in one embodiment of this application. As shown in the figure, the hydraulic shock absorber is installed between the vehicle body and the wheels. A displacement sensor is installed at the piston rod, and a vertical acceleration sensor is installed at the vehicle body. Both sensors collect the piston rod stroke position and the vehicle body vertical acceleration, respectively, and send them to the controller. The controller determines the target center clearance based on the collected signals and sends an adjustment command to the stepper motor. The stepper motor drives the conical adjustment needle to move axially via the adjustment handle and transmission rod, thereby changing the center clearance between the outer wall of the adjustment needle and the inner wall of the axial channel of the plunger. When the piston rod enters the buffer zone at the end of its stroke, the plunger is displaced relative to the compound piston, and the oil flows from one oil chamber to the other oil chamber through the center clearance. When the center clearance decreases, the oil flow resistance and the end-buffer damping force increase; when the center clearance increases, the oil flow resistance and the end-buffer damping force decrease accordingly.

[0025] The implementation process of the method described in this application will be explained in detail below with reference to specific embodiments.

[0026] Please see Figure 2 , Figure 2 This is a flowchart of an adaptive control method for damper damping in one embodiment of this application, such as... Figure 2 As shown, the method includes steps 101-105: Step 101: Obtain the current vehicle mass and select the initial center clearance based on the current vehicle mass.

[0027] According to embodiments of this disclosure, after the vehicle starts but before entering driving mode, the controller acquires the current vehicle mass. In one implementation, the current vehicle mass is determined based on the load force signal or airbag pressure signal output by the load sensor, according to a pre-calibrated correspondence. In another implementation, when the vehicle is not equipped with the aforementioned sensor, the mass is indirectly determined by the static stroke position of the piston rod: the controller reads the static stroke position output by the displacement sensor when the vehicle is stationary on a level road surface, and calculates the difference between this static stroke position and a pre-calibrated no-load static position to obtain the static offset. The no-load static position is measured and calibrated in an no-load state at the time of vehicle manufacturing and stored in the controller's non-volatile memory. The load level is determined based on the static offset and a preset offset step size. ; in The current static stroke position is read in real time by the displacement sensor. The positive direction of the piston rod's static stroke position is uniformly defined as the direction in which the static offset increases when the vehicle load increases; unit: mm. This is the unloaded static position, measured and calibrated under unloaded conditions at the factory when the vehicle leaves the factory, in mm; The offset step size is in mm and is obtained through step-by-step loading calibration on the test bench. For example, it can be configured to 3 mm. This is the load class number. The higher the load class, the greater the corresponding vehicle mass.

[0028] The controller selects the initial center clearance from a pre-calibrated clearance parameter table based on the load level. This clearance parameter table is established during the bench calibration phase. For each load level, using standard road surface excitation as input, the center clearance is gradually adjusted, and the damping effect is recorded. When the peak deceleration at the piston rod end is within the comfort range and the piston end face does not contact the mechanical hard limit, the corresponding clearance value is written into the corresponding entry for that load level. Higher load levels require smaller initial center clearances, resulting in a corresponding increase in damping force at the end of the stroke when the vehicle mass is large. For example, the initial center clearances for load levels 1 to 5 can be configured as 0.40mm, 0.32mm, 0.25mm, 0.20mm, and 0.16mm, respectively.

[0029] Step 102: Continuously acquire the piston rod's stroke position, movement speed, and vehicle vertical acceleration. During vehicle operation, the controller continuously acquires three signals at a fixed control cycle: stroke position... Directly output from the displacement sensor, unit: mm; motion speed The vertical acceleration of the vehicle body is obtained by first-order differential and low-pass filtering of the stroke position signal, with units of m / s. Positive values ​​represent the extension direction and negative values ​​represent the compression direction. The signal is obtained by bandpass filtering from the accelerometer output, with units of m / s². Positive values ​​represent upward movement and negative values ​​represent downward movement. These three signals are used throughout all subsequent control steps and are updated in each control cycle.

[0030] Step 103: Calculate the remaining distance in the stretching direction and the remaining distance in the compression direction based on the stroke position, and identify the end-of-stretch buffer event and the end-of-compression buffer event. The remaining distance in the stretching direction and the remaining distance in the compression direction are calculated based on the stroke position; when the piston rod moves in the stretching direction and the remaining distance in the stretching direction is not greater than a preset threshold, it is identified as an end-of-stretch buffer event; when the piston rod moves in the compression direction and the remaining distance in the compression direction is not greater than a preset threshold, it is identified as an end-of-compression buffer event.

[0031] In some embodiments, the controller calculates the remaining distance in both directions based on the current stroke position. The remaining distance in the tension direction refers to the distance between the current position of the piston rod and the end position of the tension stroke, while the remaining distance in the compression direction refers to the distance between the current position of the piston rod and the end position of the compression stroke. The end positions of the tension and compression strokes are calibrated and determined during installation, corresponding to the stroke positions when the upper end face of the piston just contacts the buffer pad and when the lower end face of the piston just contacts the bottom of the vibration damper, respectively. Specifically, the remaining distance in the tension direction is equal to the end position of the tension stroke minus the current stroke position, and the remaining distance in the compression direction is equal to the current stroke position minus the end position of the compression stroke; both are positive values ​​and are in mm.

[0032] The preset thresholds are set as the initial thresholds between the buffer zones on the tension and compression sides, i.e., the distance thresholds for entering the end buffer zone. These thresholds depend on the effective working stroke length of the plunger and are calibrated by measuring the remaining distance at which the plunger begins to produce significant buffer damping on a test bench; for example, they can be configured to 25mm.

[0033] When the piston rod's movement speed is positive (moving in the stretching direction) and the remaining distance in the stretching direction is not greater than the preset threshold, the controller identifies it as a stretching end-buffering event; when the movement speed is negative (moving in the compression direction) and the remaining distance in the compression direction is not greater than the preset threshold, it is identified as a compression end-buffering event. For small vibrations of the piston rod in the middle region of its normal stroke, where the remaining distances in both directions are greater than the preset threshold, the controller does not trigger any end-buffering event identification. The stretching function pin and the compression function pin, along with their corresponding function springs, independently control the oil circuit's on / off state within this range.

[0034] Step 104: Calculate the stretching buffer demand value and the compression buffer demand value for the end-buffer event. Specifically, for each detected stretching end-buffer event, the controller records the instantaneous velocity of the piston rod entering the buffer zone (i.e., when the remaining distance in the stretching direction first drops to the preset threshold) as the stretching velocity. At the same time, read the remaining distance in the stretching direction. The equivalent sprung mass corresponding to the current vehicle weight and the upward acceleration of the vehicle at this time (That is, the positive part of the vertical acceleration of the vehicle body).

[0035] Among them, the stretching buffer requirement value Determined by the sum of the kinetic energy dissipation component and the inertial load component: ; in The equivalent sprung mass, in kg, is obtained by subtracting the unsprung mass from the current total vehicle mass. The stretching velocity when entering the buffer zone, in m / s; This is the remaining distance in the stretching direction at this point, in meters (mm is converted to meters during calculation). This is the upward acceleration of the vehicle body at this moment, expressed in m / s². For acceleration weighting coefficients, The physical meaning is force, with the unit N. The first term on the right side of the equation is the average force required to dissipate the current kinetic energy of the piston rod over the remaining distance, and the second term is the contribution of the additional inertial force when the car body is still accelerating upwards.

[0036] In one embodiment, the acceleration weighting coefficient The calibration was determined through bench testing, specifically by applying excitations of different frequencies and amplitudes to the bench, and taking measurements for each set of excitations. Calculate the buffer requirement value one by one from 0.1 to 1.0 with a step size of 0.1, and compare the results. The time required for the vehicle body to recover stability after setting the required gap value is selected, and the time with the shortest recovery time is chosen. This is used as a calibration value. Its value ranges from 0.3 to 0.8 and is related to the shock absorber mounting angle and the suspension lever ratio.

[0037] In one embodiment, for each identified compression end buffer event, the controller calculates the compression buffer demand value using the same structure. : ; in This represents the absolute value of the compression velocity when entering the buffer zone. This is the remaining distance in the compression direction at this point. This is the absolute value of the downward acceleration of the vehicle body at this moment; the meanings of the other parameters are the same as above.

[0038] As an example, let =400kg, =0.6m / s, =0.025m, =2.0m / s², =0.5, then: Term 1 = 400 × 0.36 / (2 × 0.025) = 2880 N; Term 2 = 0.5 × 400 × 2.0 = 400 N; =3280N.

[0039] Step 105: Determine the target center gap based on the tensile buffer demand value and the compression buffer demand value, and adjust the center gap to the target center gap.

[0040] Specifically, such as Figure 3 As shown, Figure 3 This is a flowchart of adjusting the center gap in one embodiment of this application. In step 201, the target center gap is determined based on the tensile buffer demand value and the compression buffer demand value.

[0041] In some embodiments, the relationship between the center clearance and the damping force is based on the laminar flow damping characteristics of oil passing through the annular gap; that is, the smaller the gap width, the greater the flow resistance, and the damping force is approximately inversely proportional to the cube of the gap width. Accordingly, the controller, based on the inverse mapping relationship between the center clearance and the buffer demand value, converts the tensile buffer demand value and the compressive buffer demand value into corresponding candidate gaps, respectively. The larger the buffer demand value, the smaller the corresponding candidate gap. The specific mapping relationship is as follows: ; in Candidate gap, unit: mm; The maximum clearance, in mm, is determined by the maximum permissible distance between the adjusting pin and the channel wall. For reference demand value, in N, the buffer demand value obtained by actual measurement under standard road excitation conditions of unloaded vehicles during the bench calibration stage is used as the value. This represents the current buffer requirement, in N units.

[0042] Will Substituting into the above formula, we obtain the candidate gap for stretching. ,Will Substituting the values ​​yields the candidate gap for compression. Both are limited to the minimum gap. With maximum gap The minimum clearance is determined by the safe fit clearance between the adjusting pin and the channel wall, for example... =0.10mm; maximum gap for example =0.45mm.

[0043] Continuing with the example above, let's assume... =1500N, =0.45mm, then the candidate gap for stretching is... =0.45×(1500 / 3280)^(1 / 3)=0.45×0.773=0.348mm.

[0044] When the absolute value of the difference between the stretching candidate gap and the compression candidate gap is less than the consistency tolerance (e.g., configurable to 0.02 mm), the arithmetic mean of the two is taken as the target center gap. The consistency tolerance is determined based on the positioning accuracy of the stepper motor drive mechanism and is taken as 1.5 times the accuracy value.

[0045] In one embodiment, when the absolute value of the difference between the candidate tension gap and the candidate compression gap is not less than the consistency tolerance, the optimal value needs to be selected from the two candidate values. For each candidate gap, the controller calculates the minimum stroke length required to decelerate the piston rod to zero in both the tension and compression directions, based on the current vehicle mass, the speed upon entering the buffer zone, and the damping characteristics corresponding to that candidate gap. This length is the remaining safety distance. ; in The absolute value of the velocity when entering the buffer zone, in m / s; For candidate gaps, in meters (mm will be converted to meters during calculation); The damping coefficient of the plunger structure is expressed in N·m²·s. It is determined by the dynamic viscosity of the oil, the effective axial length of the gap, and the inner diameter of the plunger. It is obtained by reverse calculation through actual measurement of the damping force on the test bench. The smaller the remaining safety distance, the stronger the braking capacity under that gap.

[0046] Specifically, Based on the dynamic viscosity of oil (Unit: Pa·s), effective axial length of center clearance (Unit: m) and plunger inner diameter (Unit: m) are jointly determined, and the specific relationship is as follows: (Based on the derivation of the annular gap laminar flow damping theory), the damping force-velocity curves were back-calculated through bench testing. The value is taken as a fixed constant, for example, under conditions of oil viscosity of 40 cSt, effective length of 20 mm, and plunger inner diameter of 8 mm. N / m.

[0047] In one embodiment, four values ​​are obtained after calculating the remaining safety distances in the tensile and compressive directions for two candidate gaps. The selection rule is as follows: first, determine the direction of the minimum value among the four remaining safety distances (the direction closer to the end of the stroke), and select the candidate gap that meets the preset lower limit of the safety distance in this direction as the target center gap. The lower limit of the safety distance (e.g., configurable to 5 mm) is calibrated on the test bench based on the criterion that the piston end face does not contact the hard limit. When both candidate gaps meet the lower limit of the safety distance in this direction, the larger value is selected as the target center gap. A larger gap corresponds to a gentler damping force gradient, and the instantaneous pressure change amplitude of the oil when passing through the center gap is relatively small.

[0048] In some embodiments, the system also includes buffer effect feedback and target center gap correction. Specifically, after each stretch end buffer event or compression end buffer event, the controller records the following feedback indicators during the event as buffer effect feedback: the maximum peak value of the vehicle body vertical acceleration (the maximum absolute value of acceleration during the event); the minimum measured distance between the piston rod and the end of the corresponding stroke (the minimum remaining distance output by the displacement sensor during the event); and the time required for the vehicle body to recover stability (the time interval from when the piston rod speed drops to zero until the vehicle body vertical acceleration remains below the steady-state determination threshold, which can be configured as 0.3 m / s² for example).

[0049] In one embodiment, the controller determines the correction direction based on the buffering effect feedback, where the determination rule falls into two categories: In the first scenario, when the minimum measured distance is less than the preset lower limit of the safety distance, or when the duration of the proximity between the piston end face and the corresponding stroke limit (a buffer pad on the stretching side and the bottom of the damping cylinder on the compression side) exceeds the preset upper limit of the contact time (e.g., configurable to 50ms, with the calibration based on not generating metal impact noise), the correction direction is to reduce the center clearance. This scenario indicates that the damping force generated by the current clearance is insufficient to sufficiently attenuate the piston rod speed within the remaining stroke.

[0050] In the second scenario, when the minimum measured distance is not less than the lower limit of the safety distance (i.e., the safety distance meets the requirements), but the peak vertical acceleration of the vehicle exceeds the comfort acceleration limit, or the time required for the vehicle to recover stability exceeds the comfort recovery time limit, the correction direction is to increase the center clearance. The comfort acceleration limit is determined based on the upper limit of human tolerance to transient impacts, for example, it can be configured as 8 m / s²; the comfort recovery time limit is determined based on 2 to 3 oscillation cycles of the suspension system's natural frequency, for example, it can be configured as 0.8 s. This scenario indicates that an excessively small clearance leads to excessive damping force, resulting in excessively rapid vehicle deceleration or slow oscillation decay.

[0051] In one embodiment, when updating the target center gap according to the correction direction, an anti-frequent adjustment mechanism is set. The controller only performs an update when a series of similar buffer events (both being stretch end buffer events or both being compression end buffer events) produce the same correction direction judgment result after a preset number of consecutive events (e.g., configurable to 3 times). If the consecutive events produce judgments with opposite directions or no need for correction, the counter is reset and re-accumulated. The adjustment amount of each update does not exceed the preset maximum single-step adjustment amount (e.g., configurable to 0.03 mm) to prevent drastic changes in damping characteristics caused by a single adjustment. When the absolute value of the difference between the target center gap and the current actual center gap is less than the preset adjustment dead zone (e.g., configurable to 0.01 mm), the position of the adjustment handle remains unchanged and no physical action is performed. The adjustment dead zone is determined based on the minimum resolvable displacement of the stepper motor drive mechanism, and is taken as 1.2 to 1.5 times the gap change value corresponding to this displacement.

[0052] For example, when the correction direction is determined to be reducing the center gap, the correction amount is... Calculated as follows: Input data is the current actual center clearance. (Unit: mm, from stepper motor position feedback) Minimum measured distance (Unit: mm, from displacement sensor records) Lower limit of safe distance (Unit: mm, preset value) Current vehicle speed (Unit: km / h, from wheel speed sensor).

[0053] Specifically, if The correction amount is ,in This is the distance deviation-gap correction factor (dimensionless, bench calibration value is 0.005). The speed influence coefficient (unit: s / m, bench calibration value: 0.001) is used. The maximum adjustment amount per step is 0.03mm, and the vehicle speed term is used to provide additional correction weight during high-speed impacts.

[0054] If the correction direction is determined to be increasing the center gap and the maximum acceleration peak value Exceeding the comfort acceleration limit The correction amount is ,in The acceleration overshoot-clearance correction factor (the bench calibration value is 0.02).

[0055] Correction amount The updated target center gap value is superimposed on the current target center gap and sent to the stepper motor for execution.

[0056] In step 202, the control adjustment handle adjusts the center gap to the target center gap. In one embodiment, the controller controls the adjustment handle to perform the adjustment action when one of the following conditions is met: the vehicle is stationary; the vehicle is traveling at low speed in a straight line (vehicle speed is below a speed threshold and the steering angle is zero, the speed threshold can be configured as 20 km / h); the piston rod is in the middle stroke region where both the remaining distance in the stretching direction and the remaining distance in the compression direction are greater than the corresponding preset threshold. When the plunger is generating damping force through the center gap (i.e., the piston rod is in the end buffer zone), the controller does not issue an adjustment command to avoid a sudden change in damping force. Specifically, the controller sends a pulse command to the stepper motor, which drives the adjustment needle to move axially via the transmission rod until the position feedback signal indicates that the center gap has reached the target center gap.

[0057] In one implementation, the controller stores the final target center clearance, determined after feedback correction, in non-volatile memory, indexed by the current load level and the road impact level. The road impact level is based on the statistical average of the piston rod velocity when entering the buffer zone in the most recent buffer events (e.g., the last 5 events). With preset speed step size Sure: ; in Unit: m / s The speed range is calibrated based on the statistical speed range of different road surface types at the test site; for example, it can be configured to 0.2 m / s. This is the road impact level sequence number. When the vehicle is again under the same load level and the difference between the road impact level and the level already recorded in the storage does not exceed one level, the controller directly calls the stored gap value as the initial center gap, and can continue to correct it based on new buffer events.

[0058] Optionally, if a record in storage is not updated for more than a preset driving mileage (e.g., 500km) consecutively, it is marked as expired, and when it is called again, it will fall back to the base value in the gap parameter table.

[0059] In some embodiments, each time the vehicle starts, the controller reads the current static travel position and compares it with the static travel position stored at the last time the vehicle stopped. When the difference between the two exceeds the load change determination threshold (e.g., configurable to 2 mm), it indicates that the load conditions have changed between the two drives (e.g., loading and unloading of goods or changes in the number of occupants). The controller then re-determines the load level and updates the initial center clearance according to the aforementioned steps, while resetting the road impact level to the initial state to avoid mismatch caused by using the clearance parameters accumulated from the previous drive.

[0060] The aforementioned adaptive control method uses the piston rod stroke position, motion speed, and vehicle vertical acceleration as state inputs. Through a processing path involving buffer event identification, buffer demand value quantification, target clearance mapping, buffer effect feedback correction, and operating condition parameter storage, the adjustment result is applied to the physical dimension of the plunger center clearance. Changes in the center clearance directly affect the oil flow resistance between the upper and lower chambers of the plunger, thereby altering the buffer damping force at the end of the stroke. Without altering the original structure of the compound piston, plunger, functional pin, functional spring, and buffer pad, automatic control of the external adjustment handle position allows the shock absorber to achieve end-of-stroke buffer damping characteristics matching the current state under different vehicle weights, road impacts, and both tensile and compressive extreme operating conditions.

[0061] Please see Figure 4 , Figure 4 This is a schematic block diagram of an adaptive damping control system for a vibration damper according to this application. Figure 4 As shown, the system includes: The mass acquisition and initial gap determination module is used to acquire the current vehicle mass and select the initial center gap based on the current vehicle mass. The status acquisition module is used to continuously acquire the piston rod's stroke position, movement speed, and vehicle body vertical acceleration; The buffer event identification module is used to calculate the remaining distance in the stretching direction and the remaining distance in the compression direction based on the stroke position; when the piston rod moves in the stretching direction and the remaining distance in the stretching direction is not greater than a preset threshold, it is identified as a stretching end buffer event; when the piston rod moves in the compression direction and the remaining distance in the compression direction is not greater than a preset threshold, it is identified as a compression end buffer event. The buffer demand calculation module is used to calculate the stretching buffer demand value based on the stretching speed when entering the buffer zone, the remaining distance in the stretching direction, the current vehicle mass, and the upward acceleration of the vehicle body for the stretching end buffering event; and to calculate the compression buffer demand value based on the compression speed when entering the buffer zone, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body for the compression end buffering event. The center gap control module is used to determine the target center gap based on the tensile buffer demand value and the compression buffer demand value, and adjust the center gap to the target center gap.

[0062] The implementation process of the functions and roles of each module in the above system is detailed in the implementation process of the corresponding steps in the above method, and will not be repeated here.

[0063] Based on the same concept as the above method, this application proposes an electronic device, see [link to previous application]. Figure 5 As shown, it includes: a processor 5001 and a machine-readable storage medium 5002, the machine-readable storage medium 5002 storing machine-executable instructions that can be executed by the processor 5001; the processor 5001 is used to execute the machine-executable instructions to implement the damper damping adaptive control method disclosed in the above example of this application.

[0064] Based on the same concept as the methods described above, this application also provides a machine-readable storage medium storing a plurality of computer instructions. When executed by a processor, these computer instructions can implement the shock absorber damping adaptive control method disclosed in the examples above. The machine-readable storage medium can be any electronic, magnetic, optical, or other physical storage device, and can contain or store information such as executable instructions, data, etc.

[0065] Based on the same application concept as the above method, this application embodiment also provides a computer program product, which includes a computer program that, when executed by a processor, implements the shock absorber damping adaptive control method disclosed in the above examples of this application.

[0066] In the above embodiments, the descriptions of each embodiment have different focuses. Parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. The above descriptions are merely preferred embodiments of this application and explanations of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above technical features, but should also cover other technical solutions formed by arbitrary combinations of the above technical features or their equivalent features without departing from the inventive concept.

Claims

1. A damper damping adaptive control method, characterized in that, include: Obtain the current vehicle mass and select the initial center clearance based on the current vehicle mass; Continuously collect data on the piston rod's stroke position, movement speed, and the vehicle's vertical acceleration; The remaining distance in the stretching direction and the remaining distance in the compression direction are calculated based on the stroke position; when the piston rod moves in the stretching direction and the remaining distance in the stretching direction is not greater than a preset threshold, it is identified as a stretching end buffer event; When the piston rod moves in the compression direction and the remaining distance in the compression direction is not greater than a preset threshold, it is identified as a compression end buffer event; For the stretching end buffer event, the stretching buffer requirement value is calculated based on the stretching speed when entering the buffer zone, the remaining distance in the stretching direction, the current vehicle mass, and the upward acceleration of the vehicle body; for the compression end buffer event, the compression buffer requirement value is calculated based on the compression speed when entering the buffer zone, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body. The target center gap is determined based on the tensile buffer requirement value and the compression buffer requirement value, and the center gap is adjusted to the target center gap.

2. The method according to claim 1, characterized in that, The required value for stretching buffer is determined by the sum of the kinetic energy dissipation component and the inertial load component; the kinetic energy dissipation component is calculated based on the current vehicle mass, the stretching speed, and the remaining distance in the stretching direction. The inertial load component is calculated based on the current vehicle mass, the upward acceleration of the vehicle body, and the acceleration weighting coefficient, which is obtained through bench calibration. The compression buffer requirement value is determined in the same way by the compression speed, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body.

3. The method according to claim 1, characterized in that, The step of determining the target center gap based on the stretching buffer demand value and the compression buffer demand value includes: based on the inverse mapping relationship between the center gap and the buffer demand value, converting the stretching buffer demand value and the compression buffer demand value into stretching candidate gaps and compression candidate gaps respectively, wherein the larger the buffer demand value, the smaller the corresponding candidate gap; both the stretching candidate gap and the compression candidate gap are limited to between the minimum gap and the maximum gap; when the absolute value of the difference between the stretching candidate gap and the compression candidate gap is less than the consistency tolerance, the average value of the two is taken as the target center gap.

4. The method according to claim 3, characterized in that, When the absolute value of the difference between the stretching candidate gap and the compression candidate gap is not less than the consistency tolerance: for each candidate gap, based on the current vehicle mass, the speed when entering the buffer zone and the damping characteristics corresponding to the candidate gap, calculate the stroke length required to decelerate the piston rod to zero in the stretching direction and the compression direction respectively as the remaining safety distance; The candidate gap that satisfies the preset lower limit of the safety distance in the direction of the minimum value of the remaining safety distance is selected as the target center gap; when both candidate gaps satisfy the lower limit of the safety distance in this direction, the one with the larger value is selected.

5. The method according to claim 1, characterized in that, After each stretching end buffer event or compression end buffer event, the maximum vertical acceleration peak of the vehicle body, the minimum measured distance between the piston rod and the end of the corresponding stroke, and the time required for the vehicle body to recover stability are recorded as buffer effect feedback. The correction direction is determined based on the buffer effect feedback, and the target center clearance is updated according to the correction direction.

6. The method according to claim 5, characterized in that, The correction direction is determined as follows: when the minimum measured distance is less than the preset lower limit of safety distance, or when the duration of the piston end face approaching the corresponding stroke limit exceeds the preset upper limit of contact time, the correction direction is to reduce the center gap; when the minimum measured distance is not less than the lower limit of safety distance and the peak value of the maximum vertical acceleration of the vehicle body exceeds the comfort acceleration limit, or when the time required for the vehicle body to recover stability exceeds the comfort recovery time limit, the correction direction is to increase the center gap.

7. The method according to claim 5, characterized in that, The target center gap is updated according to the correction direction only when the same type of buffer event is determined to have the same correction direction after a preset number of consecutive events; the adjustment amount of each update does not exceed the preset single-step maximum adjustment amount; no adjustment is performed when the absolute value of the difference between the target center gap and the current actual center gap is less than the preset adjustment dead zone.

8. The method according to claim 7, characterized in that, The timing for executing the adjustment action is one of the following: the vehicle is stopped; the vehicle is traveling at low speed in a straight line; the piston rod is in the middle stroke region where both the remaining distance in the stretching direction and the remaining distance in the compression direction are greater than the corresponding preset threshold.

9. The method according to claim 1, characterized in that, The step of selecting the initial center clearance based on the current vehicle weight includes: reading the static stroke position of the piston rod when the vehicle is stationary, taking the difference between the static stroke position and the pre-calibrated no-load static position as the static offset, determining the load level based on the static offset and the preset offset step size, and selecting the initial center clearance from the pre-calibrated clearance parameter table based on the load level; the higher the load level, the smaller the initial center clearance.

10. A damper damping adaptive control system, characterized in that, include: The mass acquisition and initial gap determination module is used to acquire the current vehicle mass and select the initial center gap based on the current vehicle mass. The status acquisition module is used to continuously acquire the piston rod's stroke position, movement speed, and vehicle body vertical acceleration; The buffer event identification module is used to calculate the remaining distance in the stretching direction and the remaining distance in the compression direction based on the stroke position; when the piston rod moves in the stretching direction and the remaining distance in the stretching direction is not greater than a preset threshold, it is identified as a stretching end buffer event; when the piston rod moves in the compression direction and the remaining distance in the compression direction is not greater than a preset threshold, it is identified as a compression end buffer event. The buffer demand calculation module is used to calculate the stretching buffer demand value based on the stretching speed when entering the buffer zone, the remaining distance in the stretching direction, the current vehicle mass, and the upward acceleration of the vehicle body for the stretching end buffering event; and to calculate the compression buffer demand value based on the compression speed when entering the buffer zone, the remaining distance in the compression direction, the current vehicle mass, and the downward acceleration of the vehicle body for the compression end buffering event. The center gap control module is used to determine the target center gap based on the tensile buffer demand value and the compression buffer demand value, and adjust the center gap to the target center gap.

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