A magnetorheological damping system

Abstract

The present invention relates to the technical field of damping equipment, specifically a magnetorheological damping system, including a magnetorheological damping device and a suspension control module for controlling the magnetorheological damping device, the magnetorheological damping device including a magnetorheological damper, an upper buffer spring and a lower buffer spring distributed up and down, and a self-powered support device driven by the magnetorheological damper to supply power to the magnetorheological damper and support the magnetorheological damper in the upper and lower directions, the magnetorheological damper having a lifting support rod for driving the self-powered support device to supply power, an outer end cover being fixed to the upper end of the lifting support rod, the self-powered support device having a machine base and a generator stored in the machine base that can be driven by the lifting support rod to supply power, the upper buffer spring being sleeved on the periphery of the magnetorheological damper and supported between the outer end cover and the magnetorheological damper, the lower buffer spring being sleeved on the periphery of the magnetorheological damper and supported between the magnetorheological damper and the machine base, and the magnetorheological controllability is better.

Description

Technical Field

[0001] The present invention relates to the technical field of damping equipment, in particular to a magnetorheological damping system. Background Art

[0002] Dampers are widely used in various fields, and magnetorheological dampers are also increasingly used, especially in the suspension systems of various vehicles. The magnetorheological fluid in the magnetorheological damper is a new type of intelligent material that can achieve rapid transformation between liquid and semi-solid states under the action of an external magnetic field. The transformation process is reversible and controllable. Magnetorheological fluid dampers are designed based on the characteristics of magnetorheological fluid and have the advantages of fast response speed, good controllability, low power consumption and relatively simple structure. They are very suitable for application in vehicle suspension systems. There are also many types of magnetorheological dampers currently available.

[0003] For example, Chinese patent application number 201210080180.X discloses a self-energy-collecting, self-sensing magnetorheological damper. This device addresses the existing problem of magnetorheological dampers' over-reliance on external sensors and control power supplies, improving the reliability of magnetorheological vibration reduction devices while reducing their cost and maintenance. The device comprises an outer sleeve, a seal, a damper piston rod, a damper electromagnetic coil, magnetorheological fluid, a power generation unit, and a motion mode conversion unit. These components are mounted within the outer sleeve.

[0004] For example, the Chinese patent application number 201911234358.X discloses a constant temperature control system using a flexible semiconductor group for temperature control, in particular, a magnetorheological damper that can automatically control the constant temperature of magnetorheological fluid. The magnetorheological damper includes a flexible semiconductor group distributed around the outer wall of the outer cylinder of the magnetorheological damper, a temperature sensor inserted into the inner side of the damper on the left end cover of the damper, and an external end controller. The flexible semiconductors are connected in series and connected to the external end controller, and the temperature sensor is connected to the controller.

[0005] The magnetorheological controllability of the magnetorheological fluid in the existing dampers mentioned above during operation is not good enough and cannot meet the precise requirements for the use of magnetorheological functions in harsh driving environments. Summary of the Invention

[0006] The purpose of the present invention is to provide a magnetorheological damping system with better magnetorheological controllability.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions: A magnetorheological damping system includes a magnetorheological damping device and a suspension control module for controlling the magnetorheological damping device, the magnetorheological damping device including a magnetorheological damper, an upper buffer spring and a lower buffer spring distributed vertically on the magnetorheological damper, and a self-powered support device driven by the magnetorheological damper to supply power to the magnetorheological damper and support the magnetorheological damper in the vertical direction, the magnetorheological damper having a lifting support rod for driving the self-powered support device to supply power, an outer end cover being fixed to the upper end of the lifting support rod, the self-powered support device having a base and a generator stored in the base that can be driven by the lifting support rod to supply power, the upper buffer spring being sleeved around the magnetorheological damper and supported between the outer end cover and the magnetorheological damper, and the lower buffer spring being sleeved around the magnetorheological damper and supported between the magnetorheological damper and the base.

[0008] As a preferred embodiment of the present invention, the suspension control module includes a laser sensor, a MOSFET switch and a suspension controller.

[0009] As a preferred embodiment of the present invention, the rotor of the generator is connected to a ball screw nut, the ball screw nut is installed with a ball screw, and the upper end of the ball screw is fixed to the lower end of the lifting support rod.

[0010] As a preferred embodiment of the present invention, an outer mounting sleeve is fixed on the magnetorheological damper.

[0011] As a preferred embodiment of the present invention, the upper buffer spring is located between the outer end cover and the assembled outer sleeve.

[0012] As a preferred embodiment of the present invention, the lower buffer spring is located between the assembly outer sleeve and the machine base.

[0013] As a preference for the present invention, a road excitation generation system is also included.

[0014] As a preferred embodiment of the present invention, the road excitation generation system includes a hydraulic cylinder, a hydraulic valve, a hydraulic station, a laser sensor and an excitation controller controlled by a PID algorithm.

[0015] As a preferred embodiment of the present invention, when a PWM signal is input, the voltage from the suspension controller is +10V, the MOSFET tube switch is turned on, the circuit between the coil in the magnetorheological damper and the generator wire is connected, and the magnetorheological damper is excited by the self-powered support device, so that the damping force of the magnetorheological damper and the stiffness of the magnetorheological damping device increase; when the suspension controller sends a 0V signal to the MOSFET tube, the MOSFET tube will be turned off, the circuit between the coil in the magnetorheological damper and the generator wire is closed, and the self-powered support device will not be used to power the magnetorheological damper.

[0016] Beneficial effects of the present invention: Vibration has a serious negative impact on the safety and health of the driver, and can easily lead to driver fatigue, which is a major factor in a large proportion of car crashes. Physical pain is very common in design driving jobs, especially those that require long and long-distance driving, as well as in the harsh environment of off-road vehicles or mechanical work. In order to reduce the adverse effects on the driver and damage to the vehicle, more and more people have developed suspension technology to reduce vehicle vibration.

[0017] The invention adopts a compact stiffness-controllable magnetorheological damping system with self-powered capability, which ensures that rapid vibration reduction can be achieved while achieving optimal stiffness control without providing external power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the internal three-dimensional structure of one embodiment of the magnetorheological damper in Example 1 after axial section;

[0019] Figure 2 for Figure 1 Schematic diagram of the three-dimensional structure after the coil and sealing rubber sleeve in the middle structure are removed;

[0020] Figure 3 This is a schematic diagram of the complete three-dimensional structure of the magnetorheological damper in Example 1 after the outer sleeve is fixedly assembled on the outer side;

[0021] Figure 4 Schematic diagram of the three-dimensional structure of one embodiment of the magnetorheological damping device in Example 1;

[0022] Figure 5 for Figure 4 A schematic diagram of the three-dimensional structure of the second embodiment after further optimization of the generator drive part structure at the middle structure;

[0023] Figure 6 Schematic diagram of the three-dimensional structure of one implementation scheme of the magnetorheological damping system of Example 2;

[0024] Figure 7 for Figure 6 Schematic diagram of the three-dimensional structure of the machine base after it is cut open. DETAILED DESCRIPTION

[0025] The following specific embodiments are merely explanations of the present invention and are not limitations of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the embodiments as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

[0026] Example 1, as Figure 1-5 As shown, a magnetorheological damper comprises an outer cylinder 1, an inner cylinder 2 arranged in the outer cylinder 1, an upper end cover 3 covering the upper end port of the outer cylinder 1, a lower end cover 4 covering the lower end port of the outer cylinder 1, and a lifting support rod 5 extending up and down and passing through the upper end cover 3 and the lower end cover 4 at the same time. The cylinder, the end cover, and the lifting support rod 5 are made of conventional stainless steel metal. The axial directions of the cylinder, the end cover, and the lifting support rod 5 are all in the up and down direction, that is, they are upright. After the lifting support rod 5 passes through the upper end cover 3 and the lower end cover 4, it moves up and down relative to the upper end cover 3 and the lower end cover 4 during operation. In order to enable the lifting support rod 5 to pass through the center of the upper end cover 3 and the lower end cover 4 and move up and down smoothly, while ensuring the sealing performance, a sealing ring is provided on the upper end cover 3 and the lower end cover 4. The upper end cover 3 and the lower end cover 4 are flat and have a hole that passes through the center and can be used for the lifting support rod 5 to pass through. Therefore, it is preferred to provide a sealing ring m in the hole in the center of the upper end cover 3 and the lower end cover 4 for the lifting support rod 5 to pass through. It is also preferred to provide a sealing ring m between the outer cylinder 1 and the upper end cover 3 and the lower end cover 4 in the radial direction. An annular groove can be provided on the outer side wall of the end cover for the sealing ring to be embedded. In a further solution, the inner cylinder 2 is against the upper end cover 3 and the lower end cover 4, and the outer cylinder 1, the inner cylinder 2, the upper end cover 3 and the lower end cover 4 surround an outer chamber a1 capable of accommodating magnetorheological fluid, and the inner cylinder 2, the lifting support rod 5, the upper end cover 3 and the lower end cover 4 surround an inner chamber a2 capable of accommodating magnetorheological fluid, and the outer chamber a1 and the inner chamber a2 are connected at the upper side and at the lower side. The outer chamber a1 and the inner chamber a2 are two connected cylindrical storage spaces, and the magnetorheological fluid will be accommodated in the outer chamber a1 and the inner chamber a2;

[0027] Furthermore, a coil 20 is wound around the inner cylinder 2, and a driving piston 50 is mounted on the lifting support rod 5, which can be lifted and lowered in the inner chamber a2 to drive the flow of magnetorheological fluid. In accordance with this design, which is also a key design point of the present application, the driving piston 50 can be fixed to the lifting support rod 5 in an existing manner. The driving piston 50 as a whole should also be a cylindrical structure, but in terms of size, the upper and lower length dimensions of the driving piston 50 are smaller than the inner chamber a2, but the radial dimension of the driving piston 50 should be equal to or as consistent as possible with the radial dimension of the inner chamber a2, so that the driving piston 50 is just filled in the inner chamber a2 in the radial direction. It can also be understood that the cross-sectional size and shape of the inner chamber are as consistent as possible with the cross-sectional size and shape of the driving piston 50. The purpose of this is that when the driving piston 50 follows the lifting support rod 5 to lift and lower, the driving piston 50 can better promote the flow of magnetorheological fluid to perform buffering. A damping effect is achieved. For example, when the magnetorheological damper is used on the suspension system of a vehicle, up and down bumps cause the lifting support rod 5 to move up and down. Specifically, if it moves downward, the lifting support rod 5 moves downward with the driving piston 50, and the lower surface of the driving piston 50 will press down the magnetorheological fluid below the driving piston 50 in the inner chamber a2 to move. The outer chamber a1 and the inner chamber a2 are connected up and down, so the magnetorheological fluid pressed down in the inner chamber a2 will flow from the inner chamber a2 to the outer chamber a1 on the lower side, and the magnetorheological fluid on the upper side of the outer chamber a1 will flow from the connecting position at the upper end into the inner chamber a2 for filling, thereby forming an internal circulation flowing up and down, ensuring that the lifting support rod 5 is better buffered during the up and down movement, and also allowing the suspension system to better provide buffering for the vehicle.

[0028] Preferably, the driving piston 50 includes a rigid piston main body sleeve 51 fixedly sleeved on the lifting support rod 5 and a sealing rubber sleeve 52 embedded on the outer wall of the rigid piston main body sleeve 51 and capable of resting on the inner wall of the inner cylinder 2. The rigid piston main body sleeve 51 can adopt a steel cylindrical structure and an annular embedding groove is provided in the middle part of the upper and lower directions of the outer wall of the rigid piston main body sleeve 51. The purpose of the embedding groove is to enable the sealing rubber sleeve 52 to be embedded in the outer wall of the rigid piston main body sleeve 51. The sealing rubber sleeve 52 can be a rubber or silicone rubber sleeve, so that The purpose of this is to better move up and down and seal. The sealing here refers to the upper and lower sealing of the driving piston in the inner chamber. The radial dimension of the driving piston 50 can be slightly smaller than the radial dimension of the inner chamber a2. The difference between the two should be controlled within 1 mm as much as possible. The sealing rubber sleeve 52 also adopts a cylindrical sleeve. After the sealing rubber sleeve 52 is embedded in the embedding groove, the outer wall of the sealing rubber sleeve 52 needs to protrude slightly from the rigid piston main sleeve 51 in the radial direction and be able to fit tightly against the inner wall of the inner cylinder 2. This can well allow the driving piston 50 to be filled in the inner chamber and move up and down smoothly and drive the magnetorheological fluid.

[0029] The above is an introduction to the basic buffering function of the magnetorheological damper. The following is a special design of the application of magnetorheological fluid in the damper, specifically:

[0030] The coil 20 includes two or more sets of windings 201 spaced apart from each other, and the windings 201 are wound around the outer wall of the inner cylinder 2. As described in the prior art, when the coils of the existing magnetorheological fluid damper are supported by electricity, a magnetic field of corresponding size will be generated, and the magnetorheological fluid will exhibit different stiffness under the action of the magnetic field. The stronger the magnetic field, the stronger the stiffness of the magnetorheological fluid, which can control the stiffness of the magnetorheological fluid damper. These coils receive electrical energy provided by other components, thereby changing the stiffness of the magnetorheological fluid to meet the requirements of changing the buffering performance. Of course, the magnetorheological fluid damper can operate normally without receiving electrical energy. At this time, the magnetorheological fluid has the effect of an ordinary oil damping fluid.

[0031] Furthermore, an annular winding groove 2011 for the winding 201 is formed on the outer wall of the inner cylinder 2. The thickness of the winding 201, that is, the radial dimension, is ensured to be able to fit into the annular winding groove 2011.

[0032] Furthermore, the outer wall of the inner cylinder 2 includes an upper straight guide section 21, an intermediate buffer section 22 and a lower straight guide section 23 connected in sequence from top to bottom, and at least a portion of the intermediate buffer section 22 protrudes radially from the upper straight guide section 21 and the lower straight guide section 23 to form a buffer protrusion 2012. It is necessary to ensure here that there is a gap for upward and downward flow between the buffer protrusion 2012 and the inner wall of the outer cylinder 1 to ensure that the magnetorheological fluid can flow up and down, that is, the radial gap between the buffer protrusion 2012 and the inner wall of the outer cylinder 1 is smaller than the radial gap between the upper straight guide section 21 and the inner wall of the outer cylinder 1. Of course, the radial gap between the buffer protrusion 2012 and the inner wall of the outer cylinder 1 is also smaller than the radial gap between the lower straight guide section 23 and the inner wall of the outer cylinder 1, that is, the middle buffer section 22 is more protruding in the radial direction, which will cause buffering of the magnetorheological fluid itself on the path of the upward and downward flow process, for example, when the vehicle is severely shaken and suddenly pressed down to produce an impact, it prevents the magnetorheological fluid from flowing rapidly and not being well buffered.

[0033] Preferably, there are two or more buffer protrusions 2012 that are spaced apart and annular in shape, and the portion between two adjacent buffer protrusions 2012 forms the annular winding groove 2011. Four buffer protrusions 2012 can be provided, and then there are three annular winding grooves 2011.

[0034] Preferably, an upper guide hole b1 is provided on the upper side of the inner cylinder 2 for conducting communication between the outer chamber a1 and the inner chamber a2 on the upper side, and a lower guide hole b2 is provided on the lower side of the inner cylinder 2 for conducting communication between the outer chamber a1 and the inner chamber a2 on the lower side. This is mainly provided for the circulation of magnetorheological fluid in the inner chamber a2 and the outer chamber a1. It is designed to be in the upper and lower positions as much as possible, and can be opened on the upper straight guide section and the lower straight guide section to ensure that the area of ​​internal magnetorheological fluid flow is larger, and it is also beneficial that the range of magnetorheological fluid that can act on the magnetic field during the magnetorheological process will be wider.

[0035] In addition, in order to better install and use the magnetorheological damper, an outer sleeve 11 is fixed on the outer wall of the outer cylinder 1. The outer sleeve 11 can be made of steel and can be installed on the outer wall of the outer cylinder 1.

[0036] The outer sleeve 11 is provided with an annular step for supporting the spring. An upward annular step and a downward annular step can be formed on the upper and lower sides of the outer sleeve 11, respectively, so that both the upper and lower sides can be used to support the spring, thereby cooperating with the spring to form a better damping structure.

[0037] The following describes a magnetorheological damping device, including the aforementioned magnetorheological damper. The lower end of the lifting support rod 5 in the magnetorheological damper is connected to a generator 82 that is driven by the rod and provides electrical energy. This creates a self-powered magnetorheological damping system. The vertical linear motion of the lifting support rod 5 serves as the power source for the generator, which is connected to the coil windings in the damper via wires to provide electrical energy and form a variable magnetic field, thereby varying the stiffness of the magnetorheological fluid. The lifting support rod 5 and the generator 82 can be connected using an existing transmission connection structure that converts linear motion into circular motion, so that the vertical linear motion of the lifting support rod 5 is converted into the circular motion of the generator rotor.

[0038] Here are two implementation methods:

[0039] 1. The first structure is relatively simple, but more practical, that is, the rotor z of the generator 82 is directly connected and fixed with a ball screw nut 831 at the upper end, and the axial direction of the ball screw nut 831 is in the up and down direction. The ball screw nut 831 is installed with a ball screw 832, and the ball screw 832 is upright in the up and down direction and a part of it is inside the ball screw nut 831, so that the ball screw 832 can drive the ball screw nut 831 to rotate when it moves up and down, and further the upper end of the ball screw 832 is fixed to the lower end of the lifting support rod 5, so that a complete transmission power generation mode can be realized, and the lifting support rod 5 can drive the ball screw 832 to move up and down when it moves up and down, and the ball screw The up and down movement of 832 can drive the ball screw nut 831 and the rotor z of the generator 82 to rotate, thereby generating electricity. The generator 82 can be connected to the coil end in the damper through the corresponding wire. Because of the need to thread the wires, the lead holes on the damper can be sealed to prevent or reduce the leakage of the damping fluid. In this way, a generator is used with its axis in the up and down directions, and its rotor axis is also in the up and down directions. The ball screw nut 831 is fixed at the upper part of the center of the rotor z. In this way, the lifting support rod 5, the ball screw 832, the ball screw nut 831 and the generator 82 are one-to-one corresponding to each other and the axes are consistent. It is a simple and effective implementation method.

[0040] 2. The second method is a further optimization of the first method, that is, the upper end of the ball screw 832 is still fixed to the lower end of the lifting support rod 5, and the lower part of the ball screw 832 is also installed in the ball screw nut 831. The difference is that the ball screw nut 831 and the rotor z are also connected, but not directly. Instead, a horizontal central gear c1 is fixed to the lower end of the ball screw nut 831, and more than two generators 82, preferably three, are used. They are arranged around the central gear c1 in a circular array. A driving gear c2 is fixed to the upper end of the rotor z of each generator 82. Each driving gear c2 is meshed with the central gear c1 and is horizontal, and drives the rotor z at the same time. The driving gears c2 are arranged in a circular array on the central gear c1. When the ball screw nut 831 is driven to rotate, the central gear c1 acts as a central gear transmission medium, causing the driving gears c2 to rotate accordingly. Consequently, the rotors rotate to generate electricity for their corresponding generators. This allows the damper to be equipped with three different coils, each forming its own winding. For example, three coils form three independent windings, and the three generators are each connected to a single winding via different wires, forming three independent power generation connections. This allows the damper's three windings to generate electricity simultaneously, resulting in better synchronization and stability, and reduced feedback lag. In the first embodiment, there are also three windings, but because it is a single generator, the three windings are wound from the same coil wire, resulting in a certain lag in power transmission. More importantly, if one generator fails, magnetorheological applications cannot be implemented. Three generators effectively avoid this problem, allowing operation even if one generator fails, resulting in greater safety and reliability.

[0041] Of course, in the design of this self-powered magnetorheological damping device, the automatic system control is carried out on the line of the conductor, and the on-off switching of the conductor can realize the on-off switching of the self-power supply, because sometimes the magnetorheological effect is not needed. It is turned on when it is needed, and when it is not needed, even if the lifting support rod 5 moves up and down to generate electricity, magnetorheological flow will not be generated. This more practical work requirement can be controlled. But overall, the design of the damping structure of the present application is safer and more stable, and the magnetorheological effect will also be more stable and reliable. It can also power itself without the need for external power input, which is very convenient and effective.

[0042] The magnetorheological damper and magnetorheological damping device of this embodiment can be applied to the magnetorheological damping system in Example 2, making the use of the magnetorheological damping system in the vehicle safer and more reliable, and enhancing the vehicle's operating stability and service life.

[0043] A more specific embodiment of the magnetorheological damping device may include the aforementioned magnetorheological damper, upper and lower buffer springs 71 and 72 disposed vertically therewith, a self-powered support device driven by the magnetorheological damper to supply power to the magnetorheological damper and to support the magnetorheological damper in the vertical direction, and the magnetorheological damper having a lifting support rod 5 for driving the self-powered support device to supply power. Implementation details are further described in Example 2.

[0044] Example 2, as Figure 6-7 As shown, a magnetorheological damping system is provided. As mentioned above, the magnetorheological damping system of this embodiment can adopt the damper and damping device in Example 1, but is not limited to the damper and damping device in Example 1.

[0045] Specifically, the system includes a magnetorheological damping device and a suspension control module for controlling the magnetorheological damping device. The magnetorheological damping device includes a magnetorheological damper, an upper buffer spring 71 and a lower buffer spring 72 distributed vertically on the magnetorheological damper, and a self-powered support device driven by the magnetorheological damper to supply power to the magnetorheological damper and support the magnetorheological damper in the vertical direction. The magnetorheological damper has a lifting support rod 5 for driving the self-powered support device to supply power. The upper end of the lifting support rod 5 is fixed with an outer end cover 73. The self-powered support device has a base 81 and a generator 82 stored in the base 81 that can be driven by the lifting support rod 5 to supply power. The upper buffer spring 71 is sleeved on the periphery of the magnetorheological damper and supported between the outer end cover 73 and the magnetorheological damper. The lower buffer spring 72 is sleeved on the periphery of the magnetorheological damper and supported between the magnetorheological damper and the base 81. The outer end cap 73 is connected to the structure of the vehicle chassis and will float up and down. Through the combination of two springs and a damper, a more controllable damping structure is formed. During vehicle vibration, the direct action of the spring and the more precise damping control of the damper can achieve a safer and more reliable damping effect for the vehicle. In addition, the existence of an autonomous power supply structure can form a better magnetorheological operation. The base 81 can adopt a conventional steel chassis or frame structure, and the generator 82 can be installed and fixed in the base 81. In order to ensure the springs are mounted and abutted, the lower part of the outer end cap 73 should be provided with a downward annular step structure for the upper end of the upper buffer spring 71 to be mounted, and the upper part of the base 81 should be provided with an upward annular step structure for the lower end of the lower buffer spring 72 to be mounted. A corresponding step portion should be provided on the outer peripheral portion of the middle of the magnetorheological damper for the upper and lower buffer springs to be mounted and abutted.

[0046] Furthermore, the rotor of the generator 82 is connected to a ball screw nut 831, and the ball screw nut 831 is installed with a ball screw 832. The upper end of the ball screw 832 is fixed to the lower end of the lifting support rod 5. Here, the connection can be made by referring to the two implementation methods of Example 1.

[0047] Similarly, as a preference, an assembly outer sleeve 11 is fixed to the magnetorheological damper. Furthermore, the upper buffer spring 71 is located between the outer end cover 73 and the assembly outer sleeve 11, and the lower buffer spring 72 is located between the assembly outer sleeve 11 and the base 81. Therefore, the upper and lower sides of the assembly outer sleeve 11 need to form upward and downward annular steps, respectively, to facilitate the lower end of the upper buffer spring 71 to be downwardly sheathed against the upper side of the assembly outer sleeve 11, and the upper end of the lower buffer spring 72 to be upwardly sheathed against the lower side of the assembly outer sleeve 11.

[0048] Furthermore, the system's control design includes the following: the suspension control module includes a laser sensor, a MOSFET switch, and a suspension controller, all of which can be existing electronic devices. The MOSFET switch can be installed in the circuit connecting the generator's wires to the electrical coil in the damper.

[0049] Furthermore, it also includes a road excitation generation system, which includes a hydraulic cylinder, a hydraulic valve, a hydraulic station, a laser sensor and an excitation controller controlled by a PID algorithm, all of which can use existing road excitation generation system modules.

[0050] The specific application of the magnetorheological damping system of this application in the control aspect is as follows:

[0051] First, in order to achieve the vibration reduction effect of the vehicle under different road conditions, the present invention provides a system that can control a self-powered compact stiffness-controllable magnetorheological damper, ensuring that the effect of rapid vibration reduction can be achieved without providing an external power supply while achieving the best stiffness control effect.

[0052] To control a self-powered, compact, and stiffness-controlled magnetorheological damper system, a quarter-car test system, widely used to evaluate the ride comfort of vehicle suspensions, can be used. This test system consists of a vehicle body, suspension system, controller, and road excitation generation system. The road excitation generation system includes a hydraulic cylinder, hydraulic valve, hydraulic station, laser sensor, and an excitation controller controlled using a PID algorithm. The suspension control system comprises two laser sensors, MOSFET switches, and an actual suspension controller. The laser sensors measure the displacement of the sprung mass and the travel of the magnetorheological damper. The MOSFET switches, controlled by the suspension controller, control the operating mode of the self-powered circuit. The MOSFET switches are located in the circuit connecting the generator and the damper coil. Control components other than the MOSFET switches are typically installed within the vehicle body, typically within the control modules for other vehicle functions.

[0053] The circuit then has two operating modes. When a PWM signal is input, the voltage from the suspension controller is +10V, and the MOSFET switch is turned on, thereby conducting the circuit between the magnetorheological damper's coil and the self-powered generator. In this case, the magnetorheological damper is excited by the self-powered energy, resulting in an increase in the damping force and device stiffness. When the suspension controller sends a 0V signal to the MOSFET tube, the MOSFET tube will be turned off and the circuit will be closed. In this case, the self-powered energy will not be used to power the magnetorheological damper, and there will be no magnetorheological stiffness change effect. That is, when the PWM signal is input, the voltage from the suspension controller is +10V, the MOSFET tube switch is turned on, the circuit between the coil in the magnetorheological damper and the generator wire is connected, and the magnetorheological damper is excited by the self-powered support device, so that the damping force of the magnetorheological damper and the stiffness of the magnetorheological damper increase; when the suspension controller sends a 0V signal to the MOSFET tube, the MOSFET tube will be turned off, the circuit between the coil in the magnetorheological damper and the generator wire is closed, and the self-powered support device will not be used to power the magnetorheological damper.

[0054] The transmissibility of the vehicle suspension was determined by exciting a quarter-car test bench with swept-frequency harmonic excitation at frequencies between 0.5 and 2.75 Hz. Four types of suspensions were tested: three passive suspensions powered by constant external currents of 0 A, 1.2 A, and 2 A, and a self-powered suspension using self-generated power. Comparative frequency analysis revealed that the transmissibility of the self-powered suspension was significantly lower than that of the passive 0 A suspension within the 0.5-2.1 Hz excitation frequency range. Furthermore, within the 2.1-2.75 Hz excitation frequency range, the passive 0 A suspension was lower than the transmissibility of the self-powered, passive 1.2 A, and passive 2 A suspensions. Passive refers to the use of externally supplied power, rather than self-generated power. From the above experiments, it can be seen that at low frequencies, such as when the frequency is less than 2.1 Hz, it is more effective to change the stiffness of the magnetorheological device without the need for current. There is no need for self-power supply or external current input. At this time, no power supply conditions are required. When the frequency exceeds 2.1 Hz, the effect of current input to the damper will be better, so it is advisable to turn on the circuit for magnetorheological device. In the system of this application, it is necessary to turn on the switch for self-power supply under high-frequency vibration.

[0055] Therefore, it is concluded that if the excitation frequency is less than 2.1Hz, a passive input of 0V and a current of 0A are used; if the excitation frequency is greater than 2.1Hz, a self-powered mode is used. Therefore, the system of this embodiment can change the power supply mode of the stiffness-controlled magnetorheological damper according to the degree of road bumps. When the bump frequency is less than 2.1Hz, the suspension controller will turn off the MOSFET tube, and the self-powered function of the stiffness-controlled magnetorheological damper will be turned off; when the bump frequency is greater than 2.1Hz, the suspension controller will turn on the MOSFET tube, and the self-powered function of the stiffness-controlled magnetorheological damper will be turned on. Therefore, the control system of this application contains a suspension controller and a MOSFET tube, so that the stiffness-controlled magnetorheological damper can achieve a better vibration reduction method for road vibrations of different frequencies. Moreover, the STFT control strategy adopted in the control system realizes the comparison of the vibration transmission rate of self-powered and passively powered at different frequencies, achieving the purpose of finding the frequency threshold.

[0056] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A magnetorheological damping system, characterized in that: The invention relates to a magnetorheological damping device and a suspension control module for controlling the magnetorheological damping device, wherein the magnetorheological damping device comprises a magnetorheological damper, an upper buffer spring (71) and a lower buffer spring (72) distributed vertically on the magnetorheological damper, a self-powered support device driven by the magnetorheological damper and capable of supplying power to the magnetorheological damper and supporting the magnetorheological damper in the vertical direction, the magnetorheological damper having a lifting support rod (5) for driving the self-powered support device to supply power, and the lifting support rod (5) for driving the self-powered support device to supply power. An outer end cover (73) is fixed to the upper end of the lowering support rod (5); the self-powered support device has a base (81) and a generator (82) stored in the base (81) that can be driven and powered by the lifting support rod (5); the upper buffer spring (71) is sleeved on the periphery of the magnetorheological damper and supported between the outer end cover (73) and the magnetorheological damper; the lower buffer spring (72) is sleeved on the periphery of the magnetorheological damper and supported between the magnetorheological damper and the base (81); The suspension control module includes a laser sensor, a MOSFET switch and a suspension controller; The rotor of the generator (82) is connected to a ball screw nut (831), the ball screw nut (831) is mounted with a ball screw (832), and the upper end of the ball screw (832) is fixed to the lower end of the lifting support rod (5); An outer shaft sleeve (11) is fixed on the magnetorheological damper; The upper buffer spring (71) is located between the outer end cover (73) and the outer shaft sleeve (11); The lower buffer spring (72) is located between the assembly outer sleeve (11) and the machine base (81).

2. A magnetorheological damping system according to claim 1, characterized in that: Also included is a road excitation generation system.

3. The magnetorheological damping system according to claim 2, characterized in that: The road excitation generation system includes a hydraulic cylinder, a hydraulic valve, a hydraulic station, a laser sensor and an excitation controller controlled by a PID algorithm.

4. The magnetorheological damping system according to claim 1, characterized in that: When the PWM signal is input, the voltage from the suspension controller is +10V, the MOSFET tube switch is turned on, the circuit between the coil in the magnetorheological damper and the generator wire is connected, and the magnetorheological damper is excited by the self-powered support device, so that the damping force of the magnetorheological damper and the stiffness of the magnetorheological damper increase; when the suspension controller sends a 0V signal to the MOSFET tube, the MOSFET tube will be turned off, the circuit between the coil in the magnetorheological damper and the generator wire is closed, and the self-powered support device will not be used to power the magnetorheological damper.

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