Axial eddy current damper vibration control method considering time lag

Abstract

The invention discloses an axial eddy current damper vibration control method considering time lag, and the method comprises the steps: changing a traditional passive energy consumption and vibration reduction mode of an axial eddy current damper through a wireless remote telescoping adjustment device, and enabling the axial eddy current damper to be symmetrically disposed at two sides of a bottom bogie of a straddle type monorail vehicle along a center line of the vehicle; wireless remote active energy consumption vibration reduction is performed on vibration response of the straddle type monorail in the operation process, and a correction method for eliminating the influence on the system control effect caused by time delay is designed for the time delay phenomenon existing between a control instruction and output. The gain feedback matrix of the optimal transverse control force needed by the system and obtained through calculation and analysis of the system in the ideal state is instantaneously corrected to obtain the corrected optimal transverse control force, so that the wireless remote vibration control effect of the system in the presence of time delay is improved by remotely controlling an output device in the eddy current damper, and the system reliability is improved. And the driving comfort and stability are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of traffic vibration reduction control, and more specifically, relates to a vibration control method of an axial eddy current damper taking time lag into consideration. Background Art

[0002] As a type of monorail, straddle-type monorail transportation belongs to a type of urban rail transportation. The straddle-type monorail is a type of rail transportation system that is supported, stabilized and guided by a single track, and the vehicle body uses rubber tires to ride on the track beam. When the near-ground wind with pulsating components bypasses the track beam with a non-streamlined cross-section, vortex shedding and flow separation phenomena are likely to occur, causing the vehicle running on the track beam to be subjected to complex air forces, resulting in a large amplitude lateral vibration response, which will significantly reduce the safety and comfort of vehicle operation. However, due to the limited available space, generally large-volume vibration reduction devices are not convenient to install on straddle-type monorails.

[0003] In the prior art, eddy current dampers usually achieve structural vibration control in a passive form. Through structural design innovation, the magnitude of the damping force can be actively adjusted and controlled according to actual needs. For example, Academician Chen Zhengqing’s paper "New Technology of Permanent Magnet Eddy Current Damping and Its Application in Civil Engineering, China Journal of Highway and Transport, Vol. 33, No. 11, November 2020" discloses axial eddy current dampers. Its three different ball screw eddy current axial dampers can achieve semi-active vibration reduction control by adjusting the current intensity and other methods. Therefore, eddy current dampers can achieve active energy dissipation and vibration reduction of structures through control algorithms and external energy input to cope with extremely changeable environmental changes. With the rapid development of wireless remote communication technology in today's society and the actual demand for intelligent structural vibration reduction, traditional wired structural vibration control can no longer meet the needs of the current rapid development of society. Wireless remote vibration control has become a hot topic in the current industry. Although the use of eddy current dampers for wireless remote vibration control of structures is a new vibration reduction method, there are still technical bottlenecks to be broken through in wireless remote structural vibration control. There is a certain time lag between the issuance of the signal command of the front-end controller and the output of the damping force of the end damper. The real-time performance cannot be effectively guaranteed, which greatly affects the effect of structural vibration control. In severe cases, it will cause system divergence, causing the system to lose stability and balance, causing damage to the structure and the damper itself, and increasing operation and maintenance costs.

[0004] Therefore, for the relatively compact straddle-type monorail, it is urgently necessary to innovate new vibration reduction and energy consumption technologies for straddle-type monorail transportation, and design a vibration control method for axial eddy current dampers taking time lag into consideration, so as to improve the wireless remote vibration reduction control effect of the system in the presence of time lag, effectively suppress the vibration response under various operating conditions, and thus improve driving comfort and safety. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] Based on the defects mentioned in the above background technology, the present invention discloses a vibration control method of an axial eddy current damper taking time lag into consideration, wherein the traditional passive energy dissipation and vibration reduction mode of the axial eddy current damper is changed through a wirelessly controlled telescopic adjustment device, and the axial eddy current damper is symmetrically arranged on the bottom bogie of a straddle-type monorail vehicle along the center line of the vehicle, and wireless remote active energy dissipation and vibration reduction are performed on the vibration response of the straddle-type monorail during operation. In view of the time delay phenomenon between the control command and the output in the wireless remote vibration control system, a correction method for eliminating the influence of the time lag on the system control effect is designed at the control end, and the gain feedback matrix of the optimal lateral control force required by the system obtained by calculation and analysis under the ideal state (without time lag) is instantaneously corrected to obtain the corrected optimal lateral control force, so as to actively change the damping force of the eddy current damper by remotely controlling the output device in the eddy current damper to adapt to the constantly changing control force requirements of the system, and finally realize the active energy dissipation and vibration reduction of the axial eddy current damper, improve the wireless remote vibration control effect of the system in the presence of time lag, and improve the driving comfort and stability.

[0007] (II) Technical solution

[0008] The present invention discloses a vibration control method for an axial eddy current damper considering time lag, wherein the axial eddy current damper is symmetrically arranged on the left and right sides of a bogie at the bottom of the vehicle along the cross-section center line of a straddle-type monorail vehicle, one end of the axial eddy current damper is fixed on the bogie, and the other end is fixed on the bottom of the straddle-type monorail vehicle, and the angle between the axial eddy current damper and the horizontal plane is θ, and a plurality of wireless remote telescopic adjustment devices are arranged on the circumference of a ball screw of the axial eddy current damper, a permanent magnet is fixed on the wireless remote telescopic adjustment device, and the wireless remote telescopic adjustment device can wirelessly receive a control instruction issued by a remote control end to adjust the distance between the permanent magnet and a conductor tube in the radial direction; the remote control end can execute the vibration control method for the axial eddy current damper considering time lag:

[0009] Step 1: Real-time acquisition of the lateral velocity v(t) and acceleration a(t) of the straddle-type monorail vehicle during operation;

[0010] Step 2: Determine whether the acceleration a(t)>a0 is established, where a0 is a preset acceleration threshold. If so, execute the next step. If not, at this time, the acceleration a(t)≤a0, and no control instruction is issued to the wireless remote telescopic adjustment device;

[0011] Step 3: Establish the state equation of the vehicle system Where S(t) is the state vector of the vehicle system, including the vehicle lateral velocity v(t), is the state vector derivative of the vehicle system, including the lateral acceleration of the vehicle a(t), A is the system characteristic matrix, which can be obtained according to the mass, damping and stiffness of the vehicle, U(t) is the lateral control force required by the system, B is the action position matrix of the control force, which can be obtained according to the action position coordinates of the output damping force of the damper, F(t) is the environmental interference, and D is the position matrix of the environmental interference, all of which are measured by sensors;

[0012] Step 4: Considering the existence of system time lag, the optimal lateral control force U″(t) is calculated by the optimal control algorithm;

[0013] Step 4.1: Solve the state equations through the embedded optimal control algorithm to obtain the control force gain matrices G1 and G2. The optimal lateral control force is expressed as Among them, G1 and G2 are the gain matrices of velocity and acceleration respectively. Considering the existence of system time delay, in order to correct the influence of time delay, the optimal lateral control force is expressed as Where Δt s is the time lag of speed feedback, is the time lag of acceleration feedback. In order to compensate for the influence of time lag on the control system, the controller instantly corrects the feedback gains G1 and G2. The optimal lateral control force is expressed as: Where G1′ and G2′ are respectively the corrected feedback gains;

[0014] Step 4.2: The essence of the time lag in the system is the lag in the phase of the velocity and acceleration gain feedback. In the time-delay system, the phase of the velocity and acceleration feedback lags by ωΔt respectively. s ,ωΔt s , where ω is the natural frequency of the vehicle system. According to the phase difference, the speed feedback matrix is ​​decomposed into G1′S(t)cos(ωΔt s )、-G1′S(t)sin(ωΔt s ) / ω, decomposing the acceleration feedback matrix into In order to make the actual control system equivalent to the ideal control system, that is, the time-delay system is equivalent to the time-delay-free system, the following equation needs to be satisfied:

[0015]

[0016] Step 4.3: Consider that the stiffness and damping of the two systems must be consistent, that is The speed and acceleration control force matrices G1′ and G2′ required by the time-delay system are calculated, and the optimal lateral control force for the final active correction is obtained.

[0017] After obtaining the optimal lateral control force U″(t), the axial eddy current damper is controlled by the wireless remote telescopic adjustment device to perform active vibration reduction.

[0018] Preferably, the sensor used to collect the lateral velocity v(t) and acceleration a(t) in step 1 includes an acceleration sensor and a velocity sensor. The sensor wirelessly sends the collected lateral velocity v(t) and acceleration a(t) data to the remote control end. The remote control end can save and analyze the data to perform subsequent judgment and calculation analysis steps, and can control the wireless remote telescopic adjustment device to actively adjust the damping force.

[0019] Preferably, the acceleration sensor and the speed sensor are installed at two ends of the top of the straddle-type monorail body, and the remote control terminal is installed in the driving cab of the straddle-type monorail.

[0020] Preferably, the method further comprises the following steps 5:

[0021] Step 5: According to the established route of straddle-type monorail transportation, determine the turning radius of the route where the current vehicle is located; when the turning radius R ≥ 1000m, the damping force of the axial eddy current damper provides the optimal lateral control force U″(t) of the vehicle system, and according to the structural characteristics of the vehicle and the spatial arrangement of the axial eddy current damper, the relationship between the output damping force and the optimal lateral control force U″(t) is as follows:

[0022]

[0023] Among them, f c is the axial damping force of a single axial eddy current damper, r is the inner radius of the conductor tube, d is the lead of the rolling resistance screw, ρ is the number of permanent magnet poles, A m is the projected area of ​​a single permanent magnet on the conductor tube, σ is the magnetic permeability of the conductor tube, B re is the residual magnetic flux density, t1 is the thickness of the permanent magnet, t2 is the distance between the permanent magnet and the conductor, t3 is the thickness of the conductor tube, and t2 is the controllable variable to be determined;

[0024] When the turning radius R is less than 1000m, the damping force of the axial eddy current damper provides the lateral control force U(t) and centrifugal force of the vehicle system and satisfies:

[0025]

[0026] Where M is the mass of the straddle-type monorail vehicle, v 车 is the running speed of the vehicle. The distance t2 between the permanent magnet and the conductor tube as a controllable variable is obtained according to the above formula.

[0027] Preferably, the method further comprises the following steps 6:

[0028] Step 6: According to the newly calculated distance t2 between the permanent magnet and the conductor tube in step 5, the wireless remote telescopic adjustment device is controlled to drive the permanent magnet to approach the conductor tube radially, so that the extension length of the wireless remote telescopic adjustment device is Δ=t2'-t2, where t2' is the original distance between the permanent magnet and the conductor tube when the wireless remote telescopic adjustment device is in the initial passive state, and the optimal lateral control force required by the system is provided in real time to perform active balance control.

[0029] Preferably, steps 1-6 are executed cyclically according to a preset period.

[0030] (III) Beneficial effects

[0031] 1. The present invention adopts an axial eddy current damper to replace the traditional viscous oil damper for active energy dissipation and vibration reduction of straddle-type monorail vehicles, which completely solves the oil leakage problem, prolongs the service life of the damper, and reduces the operation and maintenance cost. In addition, because the damper has a narrow installation space below the straddle-type monorail, the structural design of the axial eddy current damper is improved, and the permanent magnet is designed to be height-adjustable through a wireless remote telescopic adjustment device, so that the size of the damping force can be actively changed in real time by wireless remote control, and active control force output is achieved, thereby improving the scope of the system's vibration control capability and the active adaptability to extreme situations.

[0032] 2. The present invention considers the influence of time lag on vibration control according to actual conditions in the active control algorithm of the controller, proposes a time lag correction method, solves the corrected velocity and acceleration feedback gain matrix, and obtains the effective optimal lateral control force. In this way, the controller can issue relevant instructions to remotely control the damper to output the corresponding damping force, thereby achieving effective control of the vibration response and avoiding poor control effect due to the existence of system time lag, or even causing system divergence and instability.

[0033] 3. The present invention establishes a functional relationship between the damping force of the axial damper and various core parameters, and realizes precise adjustment and control of the damping force of the damper based on different working conditions on the turning radius, providing the system with accurate and stable control force output, thereby improving driving comfort and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments:

[0035] Figure 1 A flow chart of a vibration control method for an axial eddy current damper taking time lag into consideration according to the present invention;

[0036] Figure 2The figure is a schematic diagram of the overall arrangement of the axial eddy current damper of the present invention installed on a straddle-type monorail transportation; wherein (a) is a front view and (b) is a side view;

[0037] Figure 3 for Figure 2 Schematic diagram of the structure of the mid-axial eddy current damper. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0039] In order not to affect the normal operation of straddle-type monorail traffic and effectively suppress vibration, such as Figure 2 As shown, the present invention arranges the axial eddy current damper symmetrically on the left and right sides of the bogie at the bottom of the vehicle along the cross-section center line of the straddle-type monorail vehicle, one end of the axial eddy current damper is fixed on the bogie, and the other end is fixed to the bottom of the straddle-type monorail vehicle, and the angle between the axial eddy current damper and the horizontal plane is θ.

[0040] like Figure 3 As shown, the axial eddy current damper of the present invention is specifically an improvement on the inner rotating tube type axial eddy current damper of Academician Chen Zhengqing. Of course, the axial eddy current damper can also be an outer rotating tube type or disc type axial eddy current damper. The inner part of the axial eddy current damper mainly includes the outermost back iron cylinder, which is mainly used to ensure the magnetic field strength and magnetic conductivity and prevent magnetic leakage. The conductor round tube is fixed on the inner side of the back iron cylinder, which is mainly a carrier for generating eddy currents and used for heat dissipation. The ball screw in the center mainly converts the axial linear motion of the damper screw into rotation around the screw, and significantly amplifies the axial speed, so that the energy consumption density is significantly improved. Several wireless remote telescopic adjustment devices are arranged on the circumference of the ball screw. The wireless remote telescopic adjustment device can receive the control of its axial length adjustment command issued by the remote control end to adjust the distance t2 in the radial direction and complete the command output. A permanent magnet is fixed on each wireless remote telescopic adjustment device to provide the magnetic field required for the operation of the axial eddy current damper. Wireless speed sensors and acceleration sensors are respectively installed at the top ends of the straddle-type monorail vehicle body, which can collect the vehicle's lateral speed v(t) and acceleration data a(t) in real time and transmit them wirelessly to the remote control terminal.

[0041] It is worth mentioning that the reason why the present invention adopts a wireless remote telescopic adjustment device with wireless communication and telescopic control functions to control the distance t2 between the permanent magnet and the conductor tube is mainly to reduce the overall volume of the damper as much as possible while maintaining controllability, so that it can be installed on the lower bogie of the straddle-type monorail transportation, and can also actively suppress the vibration of the upper car body when the vehicle is operating normally.

[0042] The present invention takes an inner rotating tube type axial eddy current damper as an example to illustrate the working principle of the damper: when the spacing between the permanent magnet and the conductor tube is adjusted, the axial eddy current damper is driven to move repeatedly in the axial direction under the action of the vibration of the straddle-type monorail vehicle, and the axial movement is converted into rotation through the action of the ball screw, driving the permanent magnet on the ball screw to make rapid circular motion, so that the conductor tube produces a motion of cutting magnetic flux lines, and an eddy current effect is generated in the conductor. Due to the resistance of the conductor, the vibration energy is dissipated through the resistance effect, and at the same time, a damping force opposite to the movement direction is generated to suppress the vibration response and improve the stability and comfort of vehicle operation.

[0043] like Figure 1 As shown, based on the hardware improvement of adding a wireless remote telescopic adjustment device at the permanent magnet of the above-mentioned axial eddy current damper, the vibration control method of the axial eddy current damper considering time lag of the present invention can be executed by a remote control terminal, comprising the following steps:

[0044] Step 1: Real-time acquisition of the lateral velocity v(t) and acceleration a(t) of the straddle-type monorail vehicle during operation;

[0045] In another embodiment, the sensor for collecting the lateral velocity v(t) and the acceleration a(t) includes the above Figure 2 The acceleration sensor and speed sensor shown in the figure, the sensor with wireless communication function wirelessly sends the collected lateral speed v(t) and acceleration a(t) data to the remote control terminal, and the remote control terminal can save and analyze the data to perform subsequent judgment and calculation analysis steps, and can control the wireless remote telescopic adjustment device to actively adjust the damping force. In addition, the remote control terminal can be preferably set in the cab of the straddle-type monorail.

[0046] Step 2: Determine whether the acceleration a(t)>a0 is established, where a0 is a preset acceleration threshold. If so, execute the next step. If not, at this time, the acceleration a(t)≤a0, indicating that the vibration response of the vehicle system is small, and no control command will be issued to the wireless remote telescopic adjustment device.

[0047] In another embodiment, when the acceleration a(t)≤a0, the eddy current damper only plays a passive control function, and the controller will not send a control command to the conductor tube height adjustment device, and the system vibration response is suppressed by generating a damping effect to improve the running stability and comfort. When the acceleration a(t)>a0, it means that the vibration response of the current vehicle system is large, and the damping force required by the system to suppress vibration is large. At this time, the passive effect of the eddy current damper can no longer meet the vibration reduction energy consumption requirements. At this time, the controller needs to remotely send a control command to the wireless remote telescopic adjustment device to actively suppress vibration.

[0048] Step 3: Establish the state equation of the vehicle system Where S(t) is the state vector of the vehicle system, including the vehicle lateral velocity v(t), is the state vector derivative of the vehicle system, including the vehicle's lateral acceleration a(t), A is the system characteristic matrix, which can be obtained based on the vehicle's mass, damping, and stiffness, U(t) is the lateral control force required by the system, B is the action position matrix of the control force, which can be obtained based on the action position coordinates of the damping force output by the damper, F(t) is the environmental interference, and D is the position matrix of the environmental interference, all of which are measured by sensors.

[0049] Step 4: Consider the existence of system time lag and calculate the optimal lateral control force U″(t) through the optimal control algorithm.

[0050] In another embodiment, in order to obtain the optimal active lateral control force in consideration of the time delay of the wireless communication system, step 4 specifically includes:

[0051] Step 4.1: Solve the state equations through the embedded optimal control algorithm to obtain the control force gain matrices G1 and G2. The optimal lateral control force is expressed as Among them, G1 and G2 are the gain matrices of velocity and acceleration respectively. Considering the existence of system time delay, in order to correct the influence of time delay, the optimal lateral control force is expressed as Where Δt s is the time lag of speed feedback, is the time lag of acceleration feedback. In order to compensate for the influence of time lag on the control system, the controller instantly corrects the feedback gains G1 and G2. The optimal lateral control force is expressed as: Where G1′ and G2′ are the corrected feedback gains respectively.

[0052] Step 4.2: The essence of the time lag in the system is the lag in the phase of the velocity and acceleration gain feedback. In the time-delay system, the phase of the velocity and acceleration feedback lags by ωΔt respectively. s ,ωΔt s, where ω is the natural frequency of the vehicle system. According to the phase difference, the speed feedback matrix is ​​decomposed into G1′S(t)cos(ωΔt s )、-G1′S(t)sin(ωΔt s ) / ω, decomposing the acceleration feedback matrix into In order to make the actual control system equivalent to the ideal control system, that is, the time-delay system is equivalent to the time-delay-free system, the following equation needs to be satisfied:

[0053]

[0054] Step 4.3: Consider that the stiffness and damping of the two systems must be consistent, that is The speed and acceleration control force matrices G1′ and G2′ required by the time-delay system are calculated, and the optimal lateral control force for the final active correction is obtained.

[0055] After obtaining the optimal lateral control force U″(t) based on step 4, the remote control end can control the damping force of the axial eddy current damper through the wireless remote telescopic adjustment device to perform active vibration reduction. The specific adjustment method refers to the subsequent steps 5-6.

[0056] Step 5: According to the established route of straddle-type monorail transportation, determine the turning radius of the route where the current vehicle is located. When the turning radius R ≥ 1000m, the damping force of the axial eddy current damper provides the optimal lateral control force U″(t) of the vehicle system. According to the structural characteristics of the vehicle and the spatial arrangement of the axial eddy current damper, the relationship between the output damping force and the optimal lateral control force U″(t) is as follows:

[0057]

[0058] Among them, f c is the axial damping force of a single axial eddy current damper, r is the inner radius of the conductor tube, d is the lead of the rolling resistance screw, ρ is the number of permanent magnet poles, A m is the projected area of ​​a single permanent magnet on the conductor tube, σ is the magnetic permeability of the conductor tube, B re is the residual magnetic flux density, t1 is the thickness of the permanent magnet, t2 is the distance between the permanent magnet and the conductor, t3 is the thickness of the conductor tube, v(t) is the lateral speed of the vehicle, θ is the angle between the axial damper and the horizontal plane, and t2 is the controllable variable to be determined;

[0059] When the turning radius R is less than 1000m, the damping force of the axial eddy current damper provides the lateral control force U(t) and centrifugal force of the vehicle system and satisfies:

[0060]

[0061] Where M is the mass of the straddle-type monorail vehicle, v 车 is the running speed of the vehicle. The distance t2 between the permanent magnet and the conductor tube as a controllable variable is obtained according to the above formula.

[0062] In another embodiment, it can be seen that the turning radius threshold of 1 km in step 5 is a threshold preset according to the line layout of the monorail. When the turning radius R ≥ 1000m, the system determines that the line that the current vehicle passes is a straight line, and the influence of the vehicle centrifugal force on the driving comfort can be ignored. Considering the spatial arrangement of the axial eddy current damper, the optimal lateral control force required by the system is provided by the lateral component of the damping force of the two eddy current dampers. In the process of the eddy current damper playing a passive control role to provide structural additional damping, the wireless remote telescopic adjustment device on one side of the permanent magnet is remotely controlled to actively adjust the spacing t2 between the permanent magnet and the conductor tube, and change the magnitude of the eddy current output damping force to meet the needs of system vibration control. When the turning radius R < 1000m, the influence of the line turning radius on the ride comfort needs to be considered at this time. The balance of the optimal lateral control force required by the system and the centrifugal force of the vehicle is provided by the lateral component of the damping force of the two eddy current dampers, that is, the damping force is adjusted by remotely controlling the spacing t2 between the permanent magnet and the conductor tube to meet the needs of system vibration control.

[0063] Step 6: According to the newly calculated distance t2 between the permanent magnet and the conductor tube in step 5, the wireless remote telescopic adjustment device is controlled to drive the permanent magnet to approach the conductor tube radially, so that the extension length of the wireless remote telescopic adjustment device is Δ=t2'-t2, where t2' is the original distance between the permanent magnet and the conductor tube when the wireless remote telescopic adjustment device is in the initial passive state, and the optimal lateral control force required by the system is provided in real time to perform active balance control.

[0064] In another embodiment, see Figure 1 It can be seen that steps 1-6 can be executed cyclically according to the preset period, and the remote controller actively adjusts the distance between the permanent magnet and the conductor tube through the output signal, and specifically adjusts the extension length of the wireless remote telescopic adjustment device to Δ=t 2原间距 -t 2新间距 =t2'-t2, where t2' is the original spacing between the permanent magnet and the conductor tube when the wireless remote telescopic adjustment device is in the initial passive state (the elongation length Δ is 0 at this time), so that the permanent magnet is radially close to the conductor tube to increase and control the damping force, so as to provide the optimal lateral control force required by the system in real time, suppress the vibration response of the vehicle system in various situations, and improve driving stability and comfort.

[0065] It can be seen that the present invention changes the traditional passive energy dissipation and vibration reduction mode of the axial eddy current damper through a wireless remote telescopic adjustment device that can be wirelessly controlled, and arranges the axial eddy current damper symmetrically on the bottom bogie of the straddle-type monorail vehicle along the center line of the vehicle, and performs wireless remote active energy dissipation and vibration reduction on the vibration response of the straddle-type monorail during operation. In addition, in the wireless remote vibration control system, the time delay between the control command and the output, that is, the time delay includes the sensor data acquisition time Δt1, the controller calculation and analysis time Δt2, the output device response time Δt3 and the wireless remote transmission time Δt4, all of which constitute The main reason for the total time lag Δt of the system is that a correction method is designed at the control end to eliminate the influence of time lag on the control effect of the system. The gain feedback matrix of the optimal lateral control force required by the system obtained by calculation and analysis under the ideal state (without time lag) is instantly corrected to obtain the corrected optimal lateral control force, and the output device in the eddy current damper is remotely controlled to actively change the damping force of the eddy current damper to adapt to the changing control force requirements of the system, and finally realize the active energy dissipation and vibration reduction of the axial eddy current damper, improve the wireless remote vibration control effect of the system in the presence of time lag, and improve driving comfort and stability.

[0066] It is worth mentioning that, compared with the prior art, the present invention has the following innovative features:

[0067] 1. The present invention innovatively installs the axial eddy current damper symmetrically on the left and right sides of the bottom bogie of the straddle-type monorail vehicle, which does not occupy the extra space of the vehicle body, does not require modification of the prototype vehicle body structure, and is convenient for inspection and maintenance.

[0068] 2. The present invention innovatively designs the internal structure of the axial eddy current damper, and arranges a wireless remote telescopic adjustment device under one side of the permanent magnet, which can freely control the tiny distance between the permanent magnet and the conductor tube, change the magnetic field strength, and establish the relationship between the output damping force of the axial eddy current damper and the movement displacement of the permanent magnet, which can provide timely and accurate output damping force size for wireless remote control of the vehicle system.

[0069] 3. The present invention innovatively establishes a wireless remote active control method for state feedback of a straddle-type monorail vehicle taking time lag into consideration. By wirelessly monitoring the lateral velocity and acceleration of the running vehicle, the motion state of the vehicle system is analyzed, and the system time lag problem is corrected to eliminate the influence of time lag on the system control effect, thereby providing effective optimal lateral control force in a timely manner.

[0070] 4. The present invention fully considers the centrifugal force existing when the vehicle runs through a small curve radius line, and further improves the riding comfort and stability of the passengers by modeling the axial eddy current damper and balancing the output damping force.

[0071] Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vibration control method for an axial eddy current damper considering time lag, characterized in that: The axial eddy current damper is symmetrically arranged on the left and right sides of the bogie at the bottom of the vehicle along the center line of the cross-section of the straddle-type monorail vehicle, one end of the axial eddy current damper is fixed on the bogie, and the other end is fixed on the bottom of the straddle-type monorail vehicle, and the angle between the axial eddy current damper and the horizontal plane is θ, and a plurality of wireless remote telescopic adjustment devices are arranged on the circumference of the ball screw of the axial eddy current damper, and a permanent magnet is fixed on the wireless remote telescopic adjustment device, and the wireless remote telescopic adjustment device can wirelessly receive a control instruction issued by a remote control end to adjust the distance between the permanent magnet and the conductor tube in the radial direction; The remote control terminal is capable of executing the axial eddy current damper vibration control method considering time lag: Step 1: Real-time acquisition of the lateral velocity v(t) and acceleration a(t) of the straddle-type monorail vehicle during operation; Step 2: Determine whether the acceleration a(t)>a0 is established, where a0 is a preset acceleration threshold. If so, execute the next step. If not, at this time, the acceleration a(t)≤a0, and no control instruction is issued to the wireless remote telescopic adjustment device; Step 3: Establish the state equation of the vehicle system Where S(t) is the state vector of the vehicle system, including the vehicle lateral velocity v(t), is the state vector derivative of the vehicle system, including the lateral acceleration of the vehicle a(t), A is the system characteristic matrix, which can be obtained according to the mass, damping and stiffness of the vehicle, U(t) is the lateral control force required by the system, B is the action position matrix of the control force, which can be obtained according to the action position coordinates of the output damping force of the damper, F(t) is the environmental interference, and D is the position matrix of the environmental interference, all of which are measured by sensors; Step 4: Considering the existence of system time lag, the optimal lateral control force U″(t) is calculated by the optimal control algorithm; Step 4.1: Solve the state equations through the embedded optimal control algorithm to obtain the control force gain matrices G1 and G2. The optimal lateral control force is expressed as Among them, G1 and G2 are the gain matrices of velocity and acceleration respectively. Considering the existence of system time delay, in order to correct the influence of time delay, the optimal lateral control force is expressed as Where Δt s is the time lag of speed feedback, Δt s is the time lag of acceleration feedback. In order to compensate for the influence of time lag on the control system, the controller instantly corrects the feedback gains G1 and G2. The optimal lateral control force is expressed as: Where G1′ and G2′ are respectively the corrected feedback gains; Step 4.2: The essence of the time lag in the system is the lag in the phase of the velocity and acceleration gain feedback. In the time-delay system, the phase of the velocity and acceleration feedback lags by ωΔt respectively. s ,ωΔt s , where ω is the natural frequency of the vehicle system. According to the phase difference, the speed feedback matrix is ​​decomposed into G1′S(t)cos(ωΔt s )、-G1′S(t)sin(ωΔt s ) / ω, decomposing the acceleration feedback matrix into In order to make the actual control system equivalent to the ideal control system, that is, the time-delay system is equivalent to the time-delay-free system, the following equation needs to be satisfied: Step 4.3: Consider that the stiffness and damping of the two systems must be consistent, that is The speed and acceleration control force matrices G1′ and G2′ required by the time-delay system are calculated, and the optimal lateral control force for the final active correction is obtained. After obtaining the optimal lateral control force U″(t), the axial eddy current damper is controlled by the wireless remote telescopic adjustment device to perform active vibration reduction.

2. The vibration control method of the axial eddy current damper considering time lag according to claim 1, characterized in that: The sensors used to collect the lateral velocity v(t) and acceleration a(t) in step 1 include an acceleration sensor and a velocity sensor. The sensors wirelessly send the collected lateral velocity v(t) and acceleration a(t) data to the remote control end. The remote control end can save and analyze the data to perform subsequent judgment and calculation analysis steps, and can control the wireless remote telescopic adjustment device to actively adjust the damping force.

3. The vibration control method of the axial eddy current damper considering time lag according to claim 2, characterized in that: The acceleration sensor and the speed sensor are installed at two ends of the top of the straddle-type monorail vehicle body, and the remote control terminal is installed in the driving cab of the straddle-type monorail.

4. The vibration control method of an axial eddy current damper considering time lag according to claim 1, characterized in that: Also includes the following step 5: Step 5: According to the established route of straddle-type monorail transportation, determine the turning radius of the route where the current vehicle is located; when the turning radius R ≥ 1000m, the damping force of the axial eddy current damper provides the optimal lateral control force U″(t) of the vehicle system, and according to the structural characteristics of the vehicle and the spatial arrangement of the axial eddy current damper, the relationship between the output damping force and the optimal lateral control force U″(t) is as follows: Among them, f c is the axial damping force of a single axial eddy current damper, r is the inner radius of the conductor tube, d is the lead of the rolling resistance screw, ρ is the number of permanent magnet poles, A m is the projected area of ​​a single permanent magnet on the conductor tube, σ is the magnetic permeability of the conductor tube, B re is the residual magnetic flux density, t1 is the thickness of the permanent magnet, t2 is the distance between the permanent magnet and the conductor, t3 is the thickness of the conductor tube, and t2 is the controllable variable to be determined; When the turning radius R is less than 1000m, the damping force of the axial eddy current damper provides the lateral control force U(t) and centrifugal force of the vehicle system and satisfies: Where M is the mass of the straddle-type monorail vehicle, v 车 is the running speed of the vehicle. The distance t2 between the permanent magnet and the conductor tube as a controllable variable is obtained according to the above formula.

5. The vibration control method of the axial eddy current damper considering time lag according to claim 4, characterized in that: Also includes the following step 6: Step 6: According to the newly calculated distance t2 between the permanent magnet and the conductor tube in step 5, the wireless remote telescopic adjustment device is controlled to drive the permanent magnet to approach the conductor tube radially, so that the extension length of the wireless remote telescopic adjustment device is Δ=t2'-t2, where t2' is the original distance between the permanent magnet and the conductor tube when the wireless remote telescopic adjustment device is in the initial passive state, and the optimal lateral control force required by the system is provided in real time to perform active balance control.

6. The active energy dissipation vibration reduction method based on eddy current damper according to claim 5 is characterized in that: The steps 1-6 are executed cyclically according to a preset period.

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