A semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device

Abstract

A semi-active / active suspension teaching experiment platform with a zero-stiffness measuring device comprises an excitation device (7), a guide device (6), a vibration reduction device (5), a semi-active / active switching device (9), a magnetorheological damper, a servo motor, a zero-stiffness structure (4), and a data acquisition system. The data acquisition system comprises a computer (1), a collector (2), and a power amplifier (8). The teaching experiment platform of the present invention utilizes the signals measured by each sensor to determine the damping of the magnetorheological damper and the torque output by the servo motor through a control algorithm; the effectiveness of the control algorithm can be verified through the semi-active / active switching device; and the rationality of the zero-stiffness structure is verified based on the measurement data of the sensors.

Description

Technical Field

[0001] The invention relates to a semi-active / active suspension teaching experiment platform containing a zero-stiffness measuring device, and belongs to the technical field of university teaching experiment equipment. Background Art

[0002] There are many similar suspension teaching experimental platforms in universities today, but most lack zero-stiffness structures and operate in a single mode. These structural deficiencies often lead to instability and limited control accuracy. Furthermore, the single operating mode requires more equipment and space, increasing teaching costs and making research and teaching inconvenient.

[0003] Therefore, there is a need to improve this type of suspension teaching experimental platform. Summary of the Invention

[0004] The purpose of the present invention is to improve the control accuracy and stability of the suspension teaching experiment platform in colleges and universities, and to verify the effectiveness of the control algorithm and the rationality of the zero-stiffness structure through a semi-active / active switching device. A semi-active / active suspension teaching experiment platform with a zero-stiffness measuring device is proposed.

[0005] The technical solution implemented by the present invention is as follows: a semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device, including an excitation device, a guide device, a vibration reduction device, a semi-active / active switching device and a data acquisition system, and also includes a magnetorheological damper, a servo motor and a zero-stiffness structure.

[0006] The magnetorheological damper is installed in the vibration damping device; the servo motor is installed between the driven plate and the reference plate in the guide device; and the zero-rigidity structure is installed between the driven plate and the top plate of the guide device.

[0007] The guide device is installed above the excitation device; the vibration reduction device and the semi-active / active switching device are installed in the guide device; the data acquisition system includes a computer, a collector and a power amplifier, the computer is connected to the acceleration sensor of the zero-stiffness structure, the collector is connected to the displacement sensor, and the power amplifier is respectively connected to the servo motor, the linear motor and the magnetorheological vibration damper.

[0008] The platform uses the signals measured by each sensor to determine the damping of the magnetorheological damper and the torque output by the servo motor, respectively, to verify the rationality of the zero-stiffness structure.

[0009] The zero-stiffness structure consists of a shell, a block, a first coil spring, a second coil spring, a third coil spring, a damper and a force sensor; the shell is a rectangular rigid frame structure, and the block is a cube; in the length direction of the middle part of the inner frame of the shell, the first coil spring and the third coil spring clamp the block in the middle, and the other ends of the first coil spring and the third coil spring respectively press against the two walls of the inner frame of the shell in the length direction; the damper, the second coil spring and the force sensor are installed in parallel between the block and one long side of the inner frame of the shell, and the force sensor is fixed on the inner wall of the shell; under the joint action of the damper and the second coil spring, the block is always in a balanced state relative to the driven plate.

[0010] The excitation device consists of a linear motor, an excitation base plate, a belt, a support rod, an excitation top plate, a screw, a guide rail and a transmission plate; the rectangular excitation base plate and the excitation top plate of the same size are fixed together by four support rods at the four corners; two nuts are installed on the excitation top plate located above, and two screws pass through the nuts in a vertical direction. The upper part of the screw is connected to the transmission plate, and a pulley is installed on the lower part of the screw; a linear motor is vertically installed on the lower part of the excitation top plate; the pulley on the linear motor shaft drives the pulley at the lower part of the screw through a belt; circular guide rails are installed at the four corners of the transmission plate, and the four guide rails pass through the guide rail holes set on the excitation top plate respectively.

[0011] The guide device includes a guide rail, a transmission plate, a reference plate, a driven plate, a top plate, a first displacement sensor, a second displacement sensor, a first traction device, a second traction device, an acceleration sensor, a first wire, and a second wire. The guide rail in the guide device is provided with a movable plate at the lower and upper middle portions, respectively, which are the transmission plate and the driven plate. The guide rail between the two plates has two coil springs, and the guide rail without the coil springs is fixed to the hole of the reference plate in the middle of the guide rail by an interference fit. The hole of the top plate is also fixed to the guide rail by an interference fit. A fixed zero-stiffness structure is provided above the driven plate, and a fixed acceleration sensor, a second displacement sensor, and a rack are provided below the plate. The second traction device on the second displacement sensor is connected to the top plate by a first wire. A fixed first displacement sensor is provided above the reference plate, and a second wire is connected between the first displacement sensor and the first traction device on the first displacement sensor below the driven plate. The reference plate has a through hole at a position corresponding to the rack, and the rack can move through the through hole when it moves with the driven plate, thereby increasing the movable range of the rack.

[0012] The vibration damping device includes a fourth coil spring and a magnetorheological damper; the fourth coil spring is sleeved on the guide rail between the driven plate and the transmission plate, and the magnetorheological damper is fixed between the reference plate and the driven plate.

[0013] The semi-active / active switching device is installed at a position between the reference plate and the driven plate of the guide device; the semi-active / active switching device includes a servo motor, a gear, a rack, a retaining frame, a first through hole and a second through hole; the retaining frame is vertically installed and fixed on the reference plate, and the servo motor is horizontally installed on the retaining frame; a gear is installed at one end of the servo motor, which engages with the rack installed between the reference plate and the driven plate; the rack passes through the second through hole on the reference plate; the servo motor uses the first through hole at the tail to fix the position with the retaining frame, and the servo motor can move along the retaining frame; the servo motor is moved along the retaining frame to make the gear engage or disengage with the rack, thereby realizing the switching between semi-active and active modes.

[0014] The data acquisition system transmits instructions through a computer, and then a power amplifier amplifies the instruction signal to control the operation of the motor, and finally uses an acquisition card to collect data measured by the sensors; the computer uses the data measured by each sensor to change the damping coefficient of the magnetorheological damper through a corresponding control algorithm.

[0015] The present invention has the following beneficial effects: the teaching experiment platform utilizes the signals measured by various sensors to determine the damping of the magnetorheological damper and the torque output by the servo motor via a control algorithm. A semi-active / active switching device verifies the effectiveness of the control algorithm. The sensor measurement data also verifies the rationality of the zero-stiffness structure. The platform has a compact structure, a small footprint, high control accuracy, and low teaching experiment costs, making it suitable for research and teaching in universities. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0017] Figure 2 A perspective view of the overall structure of the suspension according to the embodiment;

[0018] Figure 3 is a perspective view of an excitation device according to an embodiment;

[0019] Figure 4 A perspective view of a transmission portion in an excitation device according to an embodiment;

[0020] Figure 5 A perspective view of a suspension vibration damping device and a measuring portion of a data acquisition system in an embodiment;

[0021] Figure 6a is a perspective view of a semi-active switching device according to an embodiment;

[0022] Figure 6b is a perspective view of an active switching device according to an embodiment;

[0023] Figure 7 is a three-dimensional diagram of the zero-rigidity structure of an embodiment;

[0024] In the figure, 1 is a computer; 2 is an acquisition card; 3 is a wire; 4 is a zero-stiffness structure; 5 is a vibration reduction structure; 6 is a guide device; 7 is an excitation device; 8 is a power amplifier; 9 is a semi-active / active switching device; 401 is a housing; 402 is a block; 403 is a first coil spring; 404 is a damper; 405 is a force sensor; 406 is a second coil spring; 407 is a third coil spring; 501 is a fourth coil spring; 502 is a magnetorheological damper; 601 is a guide rail; 602 is a transmission plate; 603 is a reference plate; 604 is a driven plate Block; 605 is the top plate; 606 is the first displacement sensor; 607 is the first traction device; 608 is the first line; 609 is the second displacement sensor; 610 is the second traction device; 611 is the acceleration sensor; 612 is the second line; 701 is the linear motor; 702 is the excitation base plate; 703 is the belt; 704 is the support rod; 705 is the excitation top plate; 706 is the screw; 707 is the screw hole; 901 is the servo motor; 902 is the gear; 903 is the rack; 904 is the first through hole; 905 is the retaining frame; 906 is the second through hole. DETAILED DESCRIPTION

[0025] The specific embodiments of the present invention are as follows Figure 1 shown.

[0026] This embodiment provides a semi-active / active suspension teaching experiment platform with a zero-stiffness measurement device, which includes an excitation device 7, a guide device 6, a vibration reduction device 5, a semi-active / active switching device 9 and a data acquisition system.

[0027] The excitation device 7 provides excitation.

[0028] Guide device 6: controls the directional movement of the plate and carries the corresponding components.

[0029] Vibration damping device 5: buffers energy and accelerates vibration attenuation.

[0030] Semi-active / active switching device 9: switches the working mode.

[0031] Data acquisition system: controls system operation and data acquisition.

[0032] This embodiment further includes a magnetorheological damper 502 , a servo motor 901 and a zero-stiffness structure 4 .

[0033] The magnetorheological damper 502 is installed in the vibration damping device 5; the servo motor 901 is installed between the driven plate 604 and the reference plate 603 in the guide device 6; the zero-stiffness structure 4 is installed between the driven plate 604 and the top plate 605 of the guide device 6; the guide device 6 is installed above the excitation device 7; the vibration damping device 5 and the semi-active / active switching device 9 are installed in the guide device 5; the data acquisition system includes a computer 1, a collector 2 and a power amplifier 8, the computer 1 is connected to the acceleration sensor 611 of the zero-stiffness structure 4, the collector 2 is connected to the first displacement sensor 606, and the power amplifier 8 is respectively connected to the servo motor 901, the linear motor 701 and the magnetorheological damper 502.

[0034] The platform uses the signals measured by the sensors to respectively determine the damping of the magnetorheological damper 502 and the torque output by the servo motor 901 , thereby verifying the rationality of the zero-stiffness structure 4 .

[0035] like Figure 2 、 3 As shown in , 4, 6a and 6b, when the servo motor 901 is moved along the retaining frame 905 so that the gear 902 and the rack 903 are in a disengaged state, it is a semi-active mode; on the contrary, when the gear 902 and the rack 903 are in an engaged state, it is an active mode.

[0036] Computer 1 issues a command, which is amplified by power amplifier 8 and transmitted to linear motor 701. After receiving the electrical signal, linear motor 701 drives screw 706 to rotate via belt 703. Since screw 706 is threadedly connected to two screw holes 707 in the middle of transmission plate 602, linear motor 701 drives screw 706 to rotate while also driving transmission plate 602 to move. Driven plate 604 and zero-stiffness structure 4 also move with transmission plate 602 through excitation transmitted by coil spring 501. Under this working condition, coil spring 501 is very prone to vibration, causing the state of driven plate 604 to be extremely unstable. At this moment, computer 1 uses the electrical signals collected by various sensors to change the damping coefficient of magnetorheological damper, absorbing the energy of vibration of coil spring 501 in the shortest possible time through optimal variable damping force, thereby accelerating the attenuation rate of vibration of coil spring 501.

[0037] like Figure 2 、 6aAs shown in Figure 6b, the rack 903 is fixed below the driven plate 604. When the servo motor 901 is moved horizontally along the retaining frame 905 to engage the gear 902 and the rack 903, it is in the active mode. The computer 1 issues a command, and the power amplifier 8 amplifies the electrical signal and transmits it to the servo motor 901. After receiving the command, the servo motor 901 accurately and effectively controls the speed and torque of the gear 902 to drive the rack 903 to move. The position of the driven plate 604 also changes with the movement of the rack 903. A second through hole 906 is provided in the plate 603 at a position corresponding to the rack 903. When the rack 903 drives the driven plate 604 to move, the rack 903 can pass through the through hole 906 and move up and down, thereby increasing the movable range of the rack 903. In this working mode, the excitation is directly and accurately controlled by the servo motor 901, and the coil spring 501 has little effect on the working condition of the driven plate 604. Therefore, under this working condition, the magnetorheological damper no longer needs to provide a highly controllable variable damping force. At this time, the magnetorheological damper is a common damper.

[0038] like Figure 1 and 2 As shown in the figure, when the platform is in active or semi-active mode, if the magnetorheological shock absorber does not comply with the above working form to provide a highly controllable variable damping force, it means that the control algorithm of the semi-active or active mode of the platform is defective, otherwise it is effective.

[0039] like Figure 2 and 5 As shown, when the platform is working, the first traction device 607 and the second traction device 610 on the two first displacement sensors 606 and the second displacement sensor 609 automatically rotate to straighten the wound wire; since the reference plate 603 is fixed, when the driven plate 604 is stimulated, only the second displacement sensor 609 of the two displacement sensors moves, and the first traction device 607 and the second traction device 610 also rotate with the movement of the second displacement sensor 609; the lengths of the first wire 608 and the second wire 612 wound around the traction device also change accordingly; the computer 1 calculates the length changes of the first wire 608 and the second wire 612 through the number of rotations and the circumference of the first traction device 607 and the second traction device 610, thereby obtaining the absolute displacement of the driven plate 604 and the object 402, and the acceleration sensor 611 records the acceleration of the driven plate 604.

[0040] Such as Figure 2 、 7As shown, when the block 402 moves with the driven plate 604, under the action of the zero-stiffness structure 4, the block 402 is always in a balanced state relative to the driven plate 604 at any time; when the zero-stiffness structure 4 moves with the driven plate 604, the force sensor 405 records the magnitude of the force on the block 402 according to the deformation of the coil spring 406, and immediately transmits the obtained data to the computer 1 via the acquisition card 2. At the same time, the computer 1 obtains the theoretical value of the absolute displacement of the block 402 according to Hooke's law, and compares this absolute displacement data with the data measured by the first displacement sensor 606 and the second displacement sensor 609. If the data deviation is small, it means that the zero-stiffness structure is reasonable and effective, otherwise it is invalid.

[0041] During operation, this embodiment utilizes the signals measured by each sensor to determine the damping of the magnetorheological damper and the torque output by the servo motor through a control algorithm. A semi-active / active switching mechanism verifies the effectiveness of the control algorithm. The sensor data also verifies the rationality of the zero-stiffness structure. This platform features a compact structure, a small footprint, high control accuracy, and low-cost teaching experiments, making it suitable for research and teaching at universities.

Claims

1. A semi-active / active suspension teaching experiment platform with a zero-stiffness measurement device, comprising an excitation device, a guide device, a vibration reduction device, a semi-active / active switching device, and a data acquisition system, characterized in that: The platform also includes a magnetorheological damper, a servo motor and a zero-stiffness structure; the magnetorheological damper is installed in the vibration damping device; the servo motor is installed between the driven plate and the reference plate in the guide device; the zero-stiffness structure is installed between the driven plate and the top plate of the guide device; the guide device is installed above the excitation device; the vibration damping device and the semi-active / active switching device are installed in the guide device; the data acquisition system includes a computer, a collector and a power amplifier, the computer is connected to the acceleration sensor of the zero-stiffness structure, the collector is connected to the displacement sensor, and the power amplifier is respectively connected to the servo motor, the linear motor and the magnetorheological damper; The zero-stiffness structure consists of a shell, a block, a first coil spring, a second coil spring, a third coil spring, a damper and a force sensor; the shell is a rectangular rigid frame structure, and the block is a cube; in the length direction of the middle part of the inner frame of the shell, the first coil spring and the third coil spring clamp the block in the middle, and the other ends of the first coil spring and the third coil spring respectively press against the two walls of the inner frame of the shell in the length direction; the damper, the second coil spring and the force sensor are installed in parallel between the block and one long side of the inner frame of the shell, and the force sensor is fixed on the inner wall of the shell; under the joint action of the damper and the second coil spring, the block is always in a balanced state relative to the driven plate.

2. A semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device according to claim 1, characterized in that: The excitation device consists of a linear motor, an excitation base plate, a belt, a support rod, an excitation top plate, a screw, a guide rail and a transmission plate; the rectangular excitation base plate and the excitation top plate of the same size are fixed together by four support rods at the four corners; two nuts are installed on the excitation top plate located above, and two screws pass through the nuts in a vertical direction. The upper part of the screw is connected to the transmission plate, and a pulley is installed on the lower part of the screw; a linear motor is vertically installed on the lower part of the excitation top plate; the pulley on the linear motor shaft drives the pulley at the lower part of the screw through a belt; circular guide rails are installed at the four corners of the transmission plate, and the four guide rails pass through the guide rail holes set on the excitation top plate respectively.

3. The semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device according to claim 1, characterized in that: The guide device includes a guide rail, a transmission plate, a reference plate, a driven plate, a top plate, a first displacement sensor, a second displacement sensor, a first traction device, a second traction device, an acceleration sensor, a first wire, and a second wire. The guide rail in the guide device is provided with a movable plate at the lower and upper middle portions, respectively, which are the transmission plate and the driven plate. The guide rail between the two plates has two coil springs, and the guide rail without the coil springs is fixed to the hole of the reference plate in the middle of the guide rail by an interference fit. The hole of the top plate is also fixed to the guide rail by an interference fit. A fixed zero-stiffness structure is provided above the driven plate, and a fixed acceleration sensor, a second displacement sensor, and a rack are provided below the plate. The second traction device on the second displacement sensor is connected to the top plate by a first wire. A fixed first displacement sensor is provided above the reference plate, and a second wire is connected between the first displacement sensor and the first traction device on the first displacement sensor below the driven plate. The reference plate has a through hole at a position corresponding to the rack, and the rack can move through the through hole when it moves with the driven plate, thereby increasing the movable range of the rack.

4. The semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device according to claim 1, characterized in that: The vibration damping device includes a fourth coil spring and a magnetorheological damper; the fourth coil spring is sleeved on the guide rail between the driven plate and the transmission plate, and the magnetorheological damper is fixed between the reference plate and the driven plate.

5. The semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device according to claim 1, characterized in that: The semi-active / active switching device is installed at a position between the reference plate and the driven plate of the guide device; the semi-active / active switching device includes a servo motor, a gear, a rack, a retaining frame, a first through hole and a second through hole; the retaining frame is vertically installed and fixed on the reference plate, and the servo motor is horizontally installed on the retaining frame; a gear is installed at one end of the servo motor, which engages with the rack installed between the reference plate and the driven plate; the rack passes through the second through hole on the reference plate; the servo motor uses the first through hole at the tail to fix the position with the retaining frame, and the servo motor can move along the retaining frame; the servo motor is moved horizontally by the retaining frame, so that the gear and the rack engage or disengage, thereby realizing the switching between semi-active and active modes.

6. The semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device according to claim 1, characterized in that: The data acquisition system transmits instructions through a computer, and then a power amplifier amplifies the instruction signal to control the operation of the motor, and finally uses an acquisition card to collect data measured by the sensors; the computer uses the data measured by each sensor to change the damping coefficient of the magnetorheological damper through a corresponding control algorithm.

7. The semi-active / active suspension teaching experimental platform with a zero-stiffness measurement device according to claim 1, characterized in that: The platform uses the signals measured by the sensors to determine the damping of the magnetorheological damper and the torque output by the servo motor, respectively, to verify the rationality of the zero-stiffness structure.

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