Anti-snaking shock absorber with adjustable rigidity and damping and control method of anti-snaking shock absorber

Abstract

The invention belongs to the technical field of rail transit, and provides an anti-snaking shock absorber with adjustable rigidity and damping and a control method thereof, and the main scheme is as follows: firstly, detecting a displacement signal of the anti-snaking shock absorber; secondly, processing the displacement signal to obtain vibration displacement frequency domain characteristics and displacement time domain characteristics of the shock absorber; then, according to a processing result, judging the type of the snaking motion of the vehicle and whether the vehicle passes through the curve; and finally, the opening degree of the variable inertia channel is changed by adjusting the opening degree of the electromagnetic proportional valve according to the judgment result, then the rigidity of the hydraulic rubber node is changed, the rigidity of the anti-snaking shock absorber is adjusted, the valve opening pressure of the corresponding inverse proportional overflow valve is adjusted according to the judgment result, and the damping of the anti-snaking shock absorber is adjusted. According to the anti-snaking shock absorber, the working conditions of primary snaking, secondary snaking instability and curve passing of a vehicle can be considered at the same time, and the rigidity and damping of the anti-snaking shock absorber under the working conditions can be adjusted respectively.

Description

Technical Field

[0001] The present invention relates to the technical field of rail transit, and particularly to an anti - hunting shock absorber with adjustable stiffness and damping and its control method. Background Art

[0002] During the high - speed operation of high - speed rail trains, if the section where the high - speed train runs is not smooth, and high - speed trains generally run at high speeds. Therefore, during the high - speed operation of high - speed rail trains, the unevenness of the running section will cause the high - speed train to run unevenly, resulting in poor passenger riding comfort. Therefore, shock absorbers can be installed in high - speed rail trains to reduce the vibration and impact between trains, suppress the nodding and shaking movements of high - speed trains, and then improve the running stability of high - speed trains and enhance the passenger riding comfort.

[0003] Regarding the adjustable stiffness and damping of shock absorbers: The stiffness of a shock absorber is generally composed of the stiffness generated by the compression of internal oil and the stiffness of rubber nodes at both ends. Currently, most variable - stiffness shock absorbers change the stiffness of the shock absorber by changing the stiffness of the oil, such as the magnetorheological method or through valve system control. The disadvantage of the above methods is that: the damping force of the shock absorber is also generated by the oil. Therefore, when adjusting the stiffness of the shock absorber, the damping will be adjusted simultaneously, and separate adjustment cannot be achieved.

[0004] Regarding the control of the stiffness and damping of shock absorbers: The current mainstream solution is to collect the lateral acceleration signal of the train body and the lateral acceleration signal at the end of the bogie. Because when a high - speed train experiences a first - order hunting instability, the train body will experience large - amplitude low - frequency lateral shaking, and at this time, the lateral acceleration signal of the train body has obvious 1 - 2 Hz harmonics; when a high - speed train experiences a second - order hunting instability, the bogie will experience large - amplitude higher - frequency lateral shaking and shaking of the head, and at this time, the lateral acceleration at the end of the bogie will have obvious 5 - 10 Hz harmonics. And when a high - speed train experiences a first - order hunting instability, it is hoped that the anti - hunting shock absorber exhibits the characteristics of small stiffness and large damping. When a high - speed train experiences a second - order hunting instability, it is hoped that the anti - hunting shock absorber exhibits the characteristics of large stiffness and large damping. The disadvantage of this control method is that at least two acceleration sensors need to be added and connected to the shock absorber controller, and the layout is complex and the cost is relatively high. Summary of the Invention

[0005] The purpose of the present invention is to provide an anti - hunting shock absorber with adjustable stiffness and damping and its control method, which can separately adjust the stiffness and damping of the anti - hunting shock absorber, and can take into account the conditions of the vehicle experiencing first - order hunting motion, second - order hunting motion instability, and passing through curves.

[0006] To solve its technical problems, the present invention adopts the following technical solutions: On the one hand, the present invention provides an anti - hunting shock absorber with adjustable stiffness and damping, including an anti - hunting shock absorber body; One end of the outside of the anti-rolling damper body is a hydraulic rubber node, and the other end is a traditional passive rubber node. There are two hydraulic chambers inside the hydraulic rubber node, and the two hydraulic chambers are connected by a variable inertia channel. An electromagnetic proportional valve is arranged on the above-mentioned hydraulic rubber node. Laser reflection sheets, laser displacement sensors, controllers and two inverse proportional overflow valves are arranged on the outside of the anti-rolling damper body; The said laser displacement sensor is used to detect the displacement signal of the anti-rolling damper, and after reading the displacement signal through the laser reflection sheet, it transmits the signal to the controller; The said controller is used to process the displacement signal after receiving it, obtain the frequency-domain characteristics of the vibration displacement of the damper and the time-domain characteristics of the damper displacement, and judge the type of snake movement of the vehicle and whether it passes through a curve according to the processing results. According to the judgment results, by adjusting the opening of the electromagnetic proportional valve to change the opening of the variable inertia channel, and then changing the stiffness of the hydraulic rubber node to adjust the stiffness of the anti-rolling damper; and adjusting the opening pressure of the corresponding inverse proportional overflow valve according to the judgment results to adjust the damping of the anti-rolling damper.

[0007] As a further optimization, the displacement signal of the anti-rolling damper is the tensile signal or compression signal of the anti-rolling damper.

[0008] As a further optimization, after receiving the displacement signal, the controller processes it to obtain the frequency-domain characteristics of the vibration displacement of the damper and the time-domain characteristics of the damper displacement, and judges the type of snake movement of the vehicle and whether it passes through a curve according to the processing results, including: Performing frequency-domain calculation on the displacement signal, and judging whether the vehicle has a primary snake movement, a secondary snake movement or passes through a curve according to the frequency calculation result of the frequency-domain calculation; Performing time-domain calculation on the displacement signal, and judging whether the vehicle has a snake movement according to the amplitude calculation result of the time-domain calculation; When the type of snake movement of the vehicle judged according to the frequency calculation result and the amplitude calculation result is the same, or the vehicle passes through the curve, the controller works.

[0009] As a further optimization, the performing frequency-domain calculation on the displacement signal and judging whether the vehicle has a primary snake movement, a secondary snake movement or passes through a curve according to the frequency calculation result of the frequency-domain calculation means: Performing low-pass filtering on the displacement signal and performing Fourier transform to obtain a power spectrum curve, and describing the power distribution of the displacement signal in the frequency domain through the power spectrum curve; Smoothing the power spectrum curve and obtaining the maximum value in the smoothed power spectrum curve, which is used to represent the main frequency of the vehicle's snake movement and the main frequency when passing through the curve; Based on the main frequency of the vehicle's hunting motion and the main frequency when passing through a curve, it is determined whether the vehicle has a primary hunting motion, a secondary hunting motion, or passes through a curve.

[0010] As a further optimization, when the vehicle does not have a hunting motion, the frequency corresponding to the maximum value in the power spectrum is not taken as the main frequency of the hunting motion at this time.

[0011] As a further optimization, after obtaining the maximum value in the power spectrum curve after smoothing processing, calculate the energy concentration rate of the displacement signal; The calculation of the energy concentration rate of the displacement signal refers to: specifying the vibration main frequency as the center frequency and the frequency bandwidth power range with an offset of 0.5 Hz to obtain the energy concentration rate of the displacement signal; After obtaining the energy concentration rate of the displacement signal, set the first limit value according to the energy concentration rate of the acceleration signal at the general measurement points of the hunting motion. If it is judged that the peak frequency of the shock absorber displacement signal corresponds to the general vehicle hunting frequency and the energy concentration rate reaches above the first limit value, it indicates that the vehicle has a hunting motion or is passing through a curve.

[0012] As a further optimization, when detecting the displacement signal of the anti-hunting shock absorber, the displacement signal is collected in the form of an analysis window.

[0013] As a further optimization, the time-domain calculation of the displacement signal and the judgment of whether the vehicle has a primary hunting motion, a secondary hunting motion, or passes through a curve according to the amplitude calculation result of the time-domain calculation refer to: Collect the displacement signal when the vehicle starts running, and calculate the average value of the extreme values within a 5s window as the second limit value and record this limit value; If in the analysis window, the extreme value corresponding to the amplitude of the displacement signal is much larger than the second limit value, it indicates that the vehicle has a hunting motion.

[0014] As a further optimization, When the controller judges the type of the vehicle's hunting motion and whether it passes through a curve according to the processing result, and sends current signals to the electromagnetic proportional valve and the inverse proportional overflow valve to make the anti-hunting shock absorber exhibit corresponding stiffness and damping characteristics; The statement that the anti-hunting shock absorber exhibits corresponding stiffness and damping characteristics by sending current signals to the electromagnetic proportional valve and the inverse proportional overflow valve refers to: If it is judged that the vehicle has a primary hunting motion, increase the current of the electromagnetic proportional valve to change its state from normally closed to open, thereby increasing the opening of the variable inertia channel and making the rubber node have the characteristic of small stiffness. For the normally closed inverse proportional overflow valve, it is not energized to keep its characteristic of large damping; If it is determined that the vehicle undergoes secondary hunting motion, the normally closed electromagnetic proportional valve is de-energized, enabling the rubber node to maintain the characteristic of high stiffness. For the normally closed inverse proportional overflow valve, it is also de-energized to maintain the characteristic of high damping. If it is determined that the vehicle enters or exits a curve, the current of the electromagnetic proportional valve is increased to change it from the normally closed state to the open state, thereby increasing the opening of the variable inertia channel, enabling the rubber node to have the characteristic of low stiffness, and increasing the current of the inverse proportional overflow valve to endow it with the characteristic of low damping.

[0015] On the other hand, the present invention also provides a control method for a hunting vibration damper with adjustable stiffness and damping, which is applied to the hunting vibration damper with adjustable stiffness and damping, and includes the following steps: Detect the displacement signal of the hunting vibration damper; Process the displacement signal to obtain the frequency-domain characteristics of the vibration displacement of the damper and the time-domain characteristics of the damper displacement; Judge the type of hunting motion of the vehicle and whether it passes through a curve according to the processing result; According to the judgment result, adjust the opening of the electromagnetic proportional valve to change the opening of the variable inertia channel, and then change the stiffness of the hydraulic rubber node to adjust the stiffness of the hunting vibration damper, and adjust the opening pressure of the corresponding inverse proportional overflow valve according to the judgment result to adjust the damping of the hunting vibration damper.

[0016] The beneficial effects of the present invention are as follows: On the one hand, by installing an inverse proportional overflow valve on the damper body to control the damping of the damper, and replacing the rubber nodes at both ends of the damper with hydraulic rubber nodes, it is possible to make two hydraulic chambers be connected in parallel with the rubber structure, and the hydraulic chambers are connected through a variable inertia channel. By setting an electromagnetic proportional valve to change the opening of the inertia channel, the stiffness of the rubber node is changed, thereby changing the stiffness of the damper. At the same time, the present invention can also complete the damping of the damper through the opening control of the set inverse proportional overflow valve.

[0017] On the other hand, a laser displacement sensor is additionally installed on the anti-hunting damper of the present invention, which can identify the stretching or compression signal of the anti-hunting damper itself and use it as a displacement signal. Since the anti-hunting damper is installed between the bogie and the car body, the relative motion characteristics of the two can be significantly reflected. At the same time, when the vehicle passes through a curve, an angle gradually forms between the car body and the bogie. At this time, the anti-hunting damper will also be greatly stretched or compressed. Therefore, the present invention processes the displacement signal to obtain the frequency-domain characteristics of the vibration displacement of the damper and the time-domain characteristics of the damper displacement, and judges the type of hunting motion of the vehicle and whether it passes through a curve according to the processing results. Then, according to the judgment results, the opening degree of the electromagnetic proportional valve is adjusted to change the opening degree of the variable inertia channel, thereby changing the stiffness of the hydraulic rubber node to adjust the stiffness of the anti-hunting damper, and the opening pressure of the corresponding inverse proportional overflow valve is adjusted according to the judgment results to adjust the damping of the anti-hunting damper. Therefore, the working conditions of the vehicle during primary hunting motion, secondary hunting motion instability, and passing through a curve can be taken into account. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the composition structure of the anti-hunting damper with adjustable stiffness and damping in Embodiment 1 of the present invention; Figure 2 It is a time-domain diagram of the displacement of the anti-hunting damper when the vehicle has primary hunting in Embodiment 1 of the present invention; Figure 3 It is a frequency-domain diagram of the displacement of the anti-hunting damper when the vehicle has primary hunting in Embodiment 1 of the present invention; Figure 4 It is a time-domain diagram of the displacement of the anti-hunting damper when the vehicle has secondary hunting in Embodiment 1 of the present invention; Figure 5 It is a frequency-domain diagram of the displacement of the anti-hunting damper when the vehicle has secondary hunting in Embodiment 1 of the present invention; Figure 6 It is a time-domain diagram of the displacement of the outer anti-hunting damper when the vehicle passes through a curve in Embodiment 1 of the present invention; Figure 7 It is a time-domain diagram of the displacement of the inner anti-hunting damper when the vehicle passes through a curve in Embodiment 1 of the present invention; Figure 8 It is a displacement power spectrum curve of the anti-hunting damper when the vehicle has secondary hunting in Embodiment 1 of the present invention; Figure 9 It is a schematic diagram comparing the displacement amplitudes of the anti-hunting damper under the primary hunting condition and the normal condition of the vehicle in Embodiment 1 of the present invention; Figure 10 It is a schematic diagram comparing the displacement amplitudes of the anti-hunting damper under the secondary hunting condition and the normal condition of the vehicle in Embodiment 1 of the present invention; Figure 11Schematic diagram for comparing the smoothing process of the anti-hunting damper displacement curve under the curve condition and normal condition of the vehicle in Embodiment 1 of the present invention; Figure 12 Schematic diagram for comparing the smoothing process of the anti-hunting damper displacement curve under the curve condition and the first hunting condition of the vehicle in Embodiment 1 of the present invention; Figure 13 Schematic diagram for comparing the smoothing process of the anti-hunting damper displacement curve under the curve condition and the second hunting condition of the vehicle in Embodiment 1 of the present invention; Figure 14 Schematic diagram for the smoothing process of the anti-hunting damper displacement curve when the vehicle passes through the curve condition in Embodiment 1 of the present invention; Figure 15 Flow chart of the control method for the anti-hunting damper with adjustable stiffness and damping in Embodiment 2 of the present invention. Detailed implementation manners

[0019] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0020] Embodiment 1

[0021] Refer to Figure 1 , the anti-hunting damper with adjustable stiffness and damping provided in this embodiment includes an anti-hunting damper body. In addition, One end of the outer side of the anti-hunting damper body is a hydraulic rubber node, and the other end is a traditional passive rubber node. There are two hydraulic chambers inside the hydraulic rubber node, and the two hydraulic chambers are connected by a variable inertia channel. An electromagnetic proportional valve is provided on the above-mentioned hydraulic rubber node. Laser reflection sheets, laser displacement sensors, controllers and two inverse proportional overflow valves are arranged on the outer side of the anti-hunting damper body. In this embodiment, the two inverse proportional overflow valves are a compression stroke inverse proportional overflow valve and a tension stroke inverse proportional overflow valve respectively; The laser displacement sensor is used to detect the displacement signal of the anti-hunting damper, and after reading the displacement signal through the laser reflection sheet, it transmits the displacement signal to the controller; The controller is configured to process the displacement signal upon receipt, obtain the frequency-domain characteristics of the vibration displacement of the shock absorber and the time-domain characteristics of the displacement of the shock absorber, and determine the type of hunting motion of the vehicle and whether it passes through a curve based on the processing results. Then, according to the determination results, it adjusts the opening degree of the electromagnetic proportional valve to change the opening degree of the variable inertia channel, thereby changing the stiffness of the hydraulic rubber node to adjust the stiffness of the anti-hunting shock absorber, and adjusts the opening pressure of the corresponding inverse proportional overflow valve according to the determination results to adjust the damping of the anti-hunting shock absorber.

[0022] In the above device, the electromagnetic proportional valve is installed on the hydraulic node of the shock absorber. The opening degree of the electromagnetic proportional valve is adjusted by changing the current. It is in a normally closed state when powered off, so that the node still has stiffness characteristics. The inverse proportional overflow valve is installed on the shock absorber body, and the number is two. It can control the damping force of the tensile stroke and the compression stroke respectively. It is in a normally closed state when powered off, so that the shock absorber still has damping characteristics. The characteristic of the inverse proportional overflow valve is that as the current increases, the opening pressure will decrease, so that the shock absorber reaches the unloading point earlier, thereby reducing the unloading damping force of the shock absorber. The electromagnetic proportional valve and the two inverse proportional overflow valves are both connected to the controller through a wire harness and are controlled by the controller. The laser displacement sensor is installed on the controller and reads the displacement signal of the shock absorber in real time through the laser reflection sheet installed on the shock absorber.

[0023] During the application process, the displacement signal of the laser displacement sensor is identified through the laser reflection sheet, and filtering and Fourier transform processing are performed. When it is recognized that the main vibration frequency is in the low-frequency region, the shock absorber is adjusted to achieve the characteristics of small stiffness and large damping; when it is recognized that the main vibration frequency is in the high-frequency region, the shock absorber is adjusted to achieve the characteristics of large stiffness and large damping; when it is recognized that the time-domain signal of the displacement shows a large increase or decrease in amplitude, the shock absorber is adjusted to achieve the characteristics of small stiffness and small damping.

[0024] See Figures 2 - 7 As can be seen, when the vehicle has a primary hunting motion, the car body shows a large-amplitude lateral tilting motion relative to the bogie. At this time, the acceleration signal of the lateral motion of the car body is generally collected for judgment. When the vehicle has a secondary hunting motion, the bogie shows a large-amplitude yawing and lateral movement relative to the car body. At this time, the lateral acceleration signal at the end of the bogie is generally collected for judgment. The anti-hunting shock absorber is installed between the car body and the bogie, and its displacement signal can directly reflect the relative motion between the car body and the bogie. This signal will have an obvious main frequency during both the primary and secondary hunting of the vehicle, and the vibration amplitude will also be greater than the normal amplitude. When passing through a curve, this displacement signal will show an obvious slope, and the amplitude will also increase significantly. Now, the analysis window duration is set to 5 s, and the analysis window sliding interval is 1 s. The displacement signal of the shock absorber is calculated in real time, so as to adjust the stiffness and damping characteristics of the shock absorber in real time. The following will make judgments from the frequency-domain curve and the time-domain curve of the vibration displacement signal of the shock absorber respectively.

[0025] First, for the vibration displacement frequency domain characteristics of the shock absorber: The anti-rolling shock absorber is installed between the car body and the bogie. Its main function is to dissipate the energy of the relative movement between the car body and the bogie. Therefore, when the vehicle undergoes hunting motion, there will also be obvious peak values and frequency concentration phenomena in the displacement frequency domain curve of the shock absorber. Since the primary and secondary hunting frequencies of the vehicle are both below 10 Hz, first perform a 10 Hz low-pass filtering process on the displacement signal of the anti-rolling shock absorber. After filtering, perform Fourier transform on it, and take the power spectrum curve after Fourier transform. See Figure 8 , the power spectrum describes the power distribution of the signal in the frequency domain, representing the power density at each frequency point. The area under the power spectrum density curve is numerically equal to the total power of the signal. Therefore, it can clearly describe the main frequency range of the anti-rolling shock absorber dissipating the energy of the relative movement between the car body and the bogie. At this time, taking the maximum value in the power spectrum can represent the main hunting frequency of the vehicle.

[0026] Generally, the main frequency of the primary hunting motion of the vehicle is between 1 and 2 Hz, and the main frequency of the secondary hunting motion is above 3 Hz. There is no overlapping part between the two, which is relatively easy to judge. At the same time, when the vehicle enters a curve, there is an obvious slope in the displacement signal of the shock absorber. According to the principle of Fourier transform, "sine wave decomposition of the signal", it can be known that the period of this signal is very large at this time. Therefore, after performing the same processing on this signal, the main frequency will be much less than 1 Hz. So it is feasible to identify the hunting type of the vehicle and whether it enters the curve according to the power spectrum.

[0027] When there is no hunting phenomenon in the vehicle system, the vibration frequency distribution of the collected signal is relatively wide, but there are still extreme values. At this time, it cannot be considered that the frequency corresponding to the extreme value in the power spectrum is the hunting frequency. The concept of Power Concentration Ratio (PCR) can be introduced to measure the concentration degree of vibration energy around the specified frequency, which can be expressed as: , In the formula, and correspond to the upper and lower limits of the vibration frequency range respectively, is the upper limit of the analysis frequency, is the power spectrum density function.

[0028] It should be noted that by calculating the energy concentration ratio of the shock absorber displacement signal, specifying the main vibration frequency as the center frequency and the frequency bandwidth range with an offset of 0.5 Hz, the energy concentration ratio of the shock absorber displacement signal can be obtained. Set the first limit value according to the energy concentration ratio of the acceleration signal of the general hunting motion measurement point. When it is judged that the peak frequency of the shock absorber displacement signal corresponds to the general hunting frequency of the vehicle and the energy concentration ratio reaches above the first limit value, the vehicle undergoes hunting motion or is passing through a curve.

[0029] In addition, regarding the time-domain characteristics of the vibration displacement of the shock absorber: When the vehicle experiences primary or secondary hunting or passes through a curve, abnormal relative movement will occur between the car body and the bogie. As one of the most important suspension components connecting the car body and the bogie, the displacement characteristics of the anti-hunting shock absorber will also exhibit abnormal amplitude vibrations.

[0030] See Figure 9 and Figure 10 For the primary and secondary hunting conditions: Since the controller signal of this shock absorber is collected in the form of an analysis window, the displacement data of the anti-hunting shock absorber can be collected when the vehicle starts running, and the average value of the extreme values within a 5s window can be calculated as the second limit value, and this limit value is recorded. When the vehicle undergoes hunting movement, the amplitude of the displacement signal will increase significantly. Therefore, in the analysis window where hunting movement occurs, the extreme value will be much larger than the previously calculated second limit value. Thus, it can be determined that the vehicle is undergoing hunting movement. By combining the previous calculation of the frequency-domain characteristics of the shock absorber vibration displacement, the current hunting movement type of the vehicle can be judged. Only when both the frequency-domain and time-domain judgments exceed the specified limit values, the shock absorber controller will operate to adjust the stiffness and damping characteristics of the shock absorber.

[0031] In the actual application process, for the curve condition: The data in the analysis window is processed by locally weighted scatterplot smoothing (LOWESS), and appropriate smoothing parameters are selected. The smoothing calculation results are as Figures 11 - 14 shown.

[0032] By selecting appropriate smoothing parameters to smooth the normal condition, hunting condition, and curve passing condition, it can be seen that the processing results of the normal condition and the hunting condition are approximately a straight line, while the smoothing result of the curve passing condition has an obvious slope. Differentiating the smoothing result can obtain its change rate. Since it is necessary to ensure that the shock absorber has small stiffness and small damping characteristics when the vehicle enters and exits the curve, when the vehicle is already in the curve, that is, at about 8 - 12s in the figure, it is still necessary to maintain the original stiffness and damping characteristics of the shock absorber. Therefore, when the change rate is greater than the normal value, the shock absorber can be adjusted, and when the curve change rate returns to near the normal value at about 8 - 12s in the figure, the original stiffness and damping characteristics of the shock absorber are restored. Similarly, by combining the previous calculation of the frequency-domain characteristics of the shock absorber vibration displacement, it is judged whether the current vehicle enters or exits the curve. Only when both the frequency-domain and time-domain judgments exceed the specified limit values, the shock absorber controller will operate to adjust the stiffness and damping characteristics of the shock absorber.

[0033] In summary, the control of the stiffness and damping of the shock absorber is based on the comprehensive judgment of the time-domain and frequency-domain signals of the shock absorber displacement, and both the time-domain and frequency-domain judgment conditions need to be satisfied simultaneously for control.

[0034] It should be noted that the stiffness and damping of the shock absorber are adjusted according to the above judgment of the current state of the vehicle. When the controller determines the type of hunting motion of the vehicle and whether it passes through a curve based on the processing result, and sends a current signal to the electromagnetic proportional valve and the inverse proportional overflow valve, the hunting shock absorber exhibits corresponding stiffness and damping characteristics; here, the opening degree of the valve system can be changed by the magnitude of the current, so as to realize the adjustment of stiffness and damping. By adopting a feedback adjustment method, when the vehicle has a hunting motion, the magnitude of the current is corrected in real time through the analysis window, so as to adjust the stiffness and damping to appropriate values. When the vehicle enters and exits a curve, the stiffness and damping values are reduced, and the original stiffness and damping values are restored when entering the interior of the curve and returning to a straight line.

[0035] Specifically, the statement that the hunting shock absorber exhibits corresponding stiffness and damping characteristics by sending a current signal to the electromagnetic proportional valve and the inverse proportional overflow valve means that: If it is judged that the vehicle has a single hunting motion, the current of the electromagnetic proportional valve is increased, so that it changes from the normally closed state to the open state, thereby increasing the opening degree of the variable inertia channel, making the rubber node have the characteristic of small stiffness. For the normally closed inverse proportional overflow valve, there is no need to energize it, so that it can continue to maintain the characteristic of large damping; If it is judged that the vehicle has a double hunting motion, there is no need to energize the normally closed electromagnetic proportional valve, so that the rubber node can continue to maintain the characteristic of large stiffness. For the normally closed inverse proportional overflow valve, there is also no need to energize it, so that it can continue to maintain the characteristic of large damping; If it is judged that the vehicle enters or exits a curve, the current of the electromagnetic proportional valve is increased, so that it changes from the normally closed state to the open state, thereby increasing the opening degree of the variable inertia channel, making the rubber node have the characteristic of small stiffness, and the current of the inverse proportional overflow valve is increased, thereby reducing the opening pressure of the valve, making the shock absorber unload earlier and having the characteristic of small damping.

[0036] Embodiment 2

[0037] Based on Embodiment 1, this embodiment provides a control method for a hunting shock absorber with adjustable stiffness and damping. The flowchart is shown in Figure 15 , and the method includes the following steps: S1. Detect the displacement signal of the hunting shock absorber; S2. Process the displacement signal to obtain the frequency-domain characteristics of the shock absorber vibration displacement and the time-domain characteristics of the shock absorber displacement; S3. Determine the type of hunting motion of the vehicle and whether it passes through a curve according to the processing result; S4. According to the judgment result, adjust the opening degree of the electromagnetic proportional valve to change the opening degree of the variable inertia passage, thereby changing the stiffness of the hydraulic rubber node, so as to adjust the stiffness of the anti-hunting damper, and adjust the opening pressure of the corresponding inverse proportional overflow valve according to the judgment result to adjust the damping of the anti-hunting damper.

[0038] According to the description of Embodiment 1, it can be known that the application scenario and implementation principle of this embodiment are the same as those of Embodiment 1, so they will not be elaborated here.

[0039] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hunting vibration damper with adjustable stiffness and damping, comprising a hunting vibration damper body, characterized in that: One end of the outer side of the hunting vibration damper body is a hydraulic rubber node, and the other end is a traditional passive rubber node. There are two hydraulic chambers inside the hydraulic rubber node, and the two hydraulic chambers are connected by a variable inertia channel. An electromagnetic proportional valve is arranged on the above-mentioned hydraulic rubber node. Laser reflection sheets, laser displacement sensors, controllers and two inverse proportional overflow valves are arranged on the outer side of the hunting vibration damper body; The laser displacement sensor is used to detect the displacement signal of the hunting vibration damper, and after reading the displacement signal through the laser reflection sheet, it transmits the displacement signal to the controller; The controller is used to process the displacement signal after receiving it, obtain the frequency domain characteristics of the vibration displacement of the damper and the time domain characteristics of the damper displacement, and judge the type of hunting motion of the vehicle and whether it passes through a curve according to the processing results. According to the judgment results, by adjusting the opening degree of the electromagnetic proportional valve to change the opening degree of the variable inertia channel, and then changing the stiffness of the hydraulic rubber node to adjust the stiffness of the hunting vibration damper, and adjusting the opening pressure of the corresponding inverse proportional overflow valve according to the judgment results to adjust the damping of the hunting vibration damper.

2. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 1, characterized in that, The displacement signal of the hunting vibration damper is a tensile signal or a compression signal of the hunting vibration damper.

3. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 1, characterized in that After receiving the displacement signal, the controller processes it to obtain the frequency domain characteristics of the vibration displacement of the damper and the time domain characteristics of the damper displacement, and judges the type of hunting motion of the vehicle and whether it passes through a curve according to the processing results, including: Performing frequency domain calculation on the displacement signal, and judging whether the vehicle has a primary hunting motion, a secondary hunting motion or passes through a curve according to the frequency calculation result of the frequency domain calculation; Performing time domain calculation on the displacement signal, and judging whether the vehicle has a hunting motion according to the amplitude calculation result of the time domain calculation; When the type of hunting motion of the vehicle judged according to the frequency calculation result and the amplitude calculation result is the same, or the vehicle passes through a curve, the controller works.

4. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 3, characterized in that, The performing frequency domain calculation on the displacement signal and judging whether the vehicle has a primary hunting motion, a secondary hunting motion or passes through a curve according to the frequency calculation result of the frequency domain calculation means: Performing low-pass filtering on the displacement signal and performing Fourier transform to obtain a power spectrum curve, and describing the power distribution of the displacement signal in the frequency domain through the power spectrum curve; Smoothing the power spectrum curve and obtaining the maximum value in the smoothed power spectrum curve, which is used to represent the main frequency of the vehicle's hunting motion and the main frequency when passing through a curve; Judging whether the vehicle has a primary hunting motion, a secondary hunting motion or passes through a curve based on the main frequency of the vehicle's hunting motion and the main frequency when passing through a curve.

5. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 4, characterized in that, When the vehicle does not have a hunting motion, the frequency corresponding to the maximum value in the power spectrum is not taken as the main frequency of the hunting motion at this time.

6. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 5, characterized in that, After obtaining the maximum value in the smoothed power spectrum curve, calculate the energy concentration rate of the displacement signal; The calculating the energy concentration rate of the displacement signal means: specifying the vibration main frequency as the center frequency and the frequency bandwidth power range with an offset of 0.5 Hz to obtain the energy concentration rate of the displacement signal; After obtaining the energy concentration rate of the displacement signal, set the first limit value according to the energy concentration rate of the acceleration signal of the general measuring point in the snake-like motion. If it is judged that the peak frequency of the shock absorber displacement signal corresponds to the general vehicle snake-like frequency and the energy concentration rate reaches above the first limit value, it indicates that the vehicle has a snake-like motion or is passing through a curve.

7. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 6, characterized in that, When detecting the displacement signal of the anti-snake vibration damper, the displacement signal is collected in the form of an analysis window.

8. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 7, characterized in that, The statement that the displacement signal is calculated in the time domain and whether the vehicle has a primary snake-like motion, a secondary snake-like motion or passes through a curve is judged according to the amplitude calculation result of the time domain calculation means: Collect the displacement signal when the vehicle starts to run, and calculate the average value of the extreme values within a 5s window as the second limit value, and record this limit value; If in the analysis window, the extreme value corresponding to the amplitude of the displacement signal is much larger than the second limit value, it indicates that the vehicle has a snake-like motion.

9. The anti-hunting shock absorber with adjustable stiffness and damping according to claim 3, characterized in that, When the controller judges the type of the snake-like motion of the vehicle and whether it passes through a curve according to the processing result, and sends current signals to the electromagnetic proportional valve and the inverse proportional overflow valve to make the anti-snake vibration damper exhibit corresponding stiffness and damping characteristics; The statement that the anti-snake vibration damper exhibits corresponding stiffness and damping characteristics by sending current signals to the electromagnetic proportional valve and the inverse proportional overflow valve means: If it is judged that the vehicle has a primary snake-like motion, increase the current of the electromagnetic proportional valve to change it from the normally closed state to the open state, thereby increasing the opening of the variable inertia channel and making the rubber node have the characteristic of small stiffness. The normally closed inverse proportional overflow valve is not energized to keep its characteristic of large damping; If it is judged that the vehicle has a secondary snake-like motion, the normally closed electromagnetic proportional valve is not energized to keep the rubber node with the characteristic of large stiffness, and the normally closed inverse proportional overflow valve is also not energized to keep its characteristic of large damping; If it is judged that the vehicle enters or exits a curve, increase the current of the electromagnetic proportional valve to change it from the normally closed state to the open state, thereby increasing the opening of the variable inertia channel and making the rubber node have the characteristic of small stiffness, and increase the current of the inverse proportional overflow valve to make it have the characteristic of small damping.

10. A control method for a hunting vibration damper with adjustable stiffness and damping, which is applied to the hunting vibration damper with adjustable stiffness and damping according to any one of claims 1-9, characterized in that, It includes the following steps: Detect the displacement signal of the anti-snake vibration damper; Process the displacement signal to obtain the frequency domain characteristics of the vibration displacement of the shock absorber and the time domain characteristics of the shock absorber displacement; Judge the type of the snake-like motion of the vehicle and whether it passes through a curve according to the processing result; According to the judgment result, adjust the opening of the electromagnetic proportional valve to change the opening of the variable inertia channel, and then change the stiffness of the hydraulic rubber node to adjust the stiffness of the anti-snake vibration damper, and adjust the opening pressure of the corresponding inverse proportional overflow valve according to the judgment result to adjust the damping of the anti-snake vibration damper.

Images