1. A multi-flexible-arm vibration control device capable of moving and rotating is characterized by comprising a moving platform part, a rotating platform part, a control part and a detection part;

the moving platform part comprises a moving beam, the moving beam is arranged on the moving platform, and a moving motor is connected with the moving platform through a moving elastic joint to drive the moving platform to move;

the rotating platform part is connected with the moving platform part and comprises a rotating beam, the rotating beam is arranged on the rotating platform, and a rotating motor is connected with the rotating platform through a rotating elastic joint and controls the rotation of the rotating platform;

the detection part is used for detecting vibration signals of the flexible beam and the rotating beam;

and the control part is used for receiving the vibration signals and processing the vibration signals to obtain control signals of the flexible beam and the rotating beam.

2. The vibration control device with multiple flexible arms as claimed in claim 1, wherein the movable elastic joint comprises a ball screw, a pulling rod, a guide rail and an extension spring, the movable platform slides on the guide rail, the moving motor drives the ball screw to rotate, the rotation of the ball screw drives the pulling rod to move, the pulling rod is connected with the movable platform through the extension spring, and the movable platform is driven to move on the guide rail.

3. The multi-flexure arm vibration control device of claim 1, wherein the sensing portion includes an acceleration sensor disposed at a free end of the turning beam and the traveling beam and a piezo ceramic sensor disposed at a fixed end of the turning beam and the traveling beam.

4. The multi-flexure arm vibration control device according to claim 3, wherein the control section includes a piezoelectric ceramic actuator, a charge amplifier, a terminal block, a motion control card, a piezoelectric driver, a servo motor driver, and a computer, the piezoelectric ceramic actuator is disposed at the fixed ends of the moving beam and the rotating beam, the vibration signal is transmitted to the computer through the charge amplifier, the terminal block, and the motion control card, and then the computer calculates a control amount, transmits the control signal to the piezoelectric ceramic actuator through the piezoelectric driver, and transmits to the servo motor through the servo motor driver, thereby suppressing vibration.

5. A multi-flexible-arm vibration control device as claimed in any of claims 1 to 4, wherein the rotary elastic joint is a torsion spring mechanism.

6. The multi-flexure arm vibration control device of claim 5, where the torsion spring mechanism includes a torsion spring coupling, two symmetrically mounted bearings, a sleeve, a joint output shaft, and two oppositely mounted torsion springs;

the structure is as follows: the sleeve is connected with the output shaft of the rotating motor through the speed reducer, the sleeve supports the joint output shaft through two symmetrical bearings, the joint output shaft is connected with the rotating platform through the torsion spring coupler, and the joint output shaft is connected with the sleeve through two reversely mounted torsion springs.

7. The multiple flexible arm vibration control device of claim 6, wherein the sleeve and the joint output shaft are perforated with holes or notches.

8. The multiple flexure arm vibration control device of any one of claims 6 or 7 wherein the transfer beam and the turning beam are each comprised of two flexible beams.

9. The multi-flexure arm vibration control device of claim 8, wherein four piezo ceramic actuators are provided per flexure beam, two on each side, symmetrically arranged, in the same attitude as the flexure beams.

10. A control method for a multi-flexible-arm vibration control apparatus according to any one of claims 1 to 9, comprising:

the first step is as follows: the computer transmits the control signal to the two motors through the motion control card to excite the four flexible beams;

the second step is that: respectively detecting the vibration of the flexible beam by using a piezoelectric ceramic sensor and an acceleration sensor to obtain corresponding measurement signals;

the third step: amplifying the vibration signal of the piezoelectric ceramic sensor acquired in the step two through a charge amplifier, transmitting the vibration signal through a terminal board, converting an analog signal into a digital signal through a motion control card, and inputting the digital signal into a computer; meanwhile, a vibration signal detected by the acceleration sensor is input to the motion control card, and an analog signal is converted into a digital signal through an A/D conversion module in the motion control card and then is input into a computer;

the fourth step: the computer processes the received vibration signals and calculates the control quantity transmitted to the rotating motor of the moving motor and the piezoelectric ceramic actuators on the four beams in real time;

the fifth step: the computer transmits the control quantity to the motion control card, the motion control card transmits the control quantity to the piezoelectric ceramic actuators of the four beams through the terminal board and the piezoelectric drivers, and the analog signal transmits the control quantity to the two motors through the terminal board and the servo motor drivers.

Background

With the rapid development of aerospace technology, flexible structures are widely used in the field of aviation. The flexible structure has the advantages of light dead weight, low energy consumption, small volume and the like, and is widely applied to solar sailboards and space manipulators. The defect is that the vibration is easy to excite and is easy to be influenced by disturbance.

In recent years, active control of vibration of flexible structures has become a major and hot topic of research in the world today. The acceleration sensor has light weight, easy installation and wider frequency band, and the active damping of the system can be increased in a wider frequency band range by utilizing the feedback control of the acceleration sensor, so that the robustness of the system is enhanced. Since the application of the acceleration sensor introduces a large amount of high-frequency noise signals into the system, the filtering process is performed. The piezoelectric ceramic material has the advantages of fast response, wide frequency band, good linearity, easy processing and the like, and is particularly suitable for the vibration control application of flexible structures such as flexible beams and the like.

Elastic joints are widely used in the field of robotics. The elastic joint can simplify the force control of the mechanical arm and play a key role under the condition of strict force control requirements. Because the elastic joint has low rigidity, low natural frequency and small damping, large-amplitude vibration is easy to generate and is difficult to automatically attenuate, especially under the condition of no air damping in vacuum.

When the flexible mechanical arm is combined with an elastic joint, the system will be less rigid, the natural frequency will be lower and vibration control will be more difficult.

Disclosure of Invention

In order to overcome the problem that the vibration control of the flexible mechanical arm combined with the elastic joint is difficult, the invention mainly aims to provide a movable and rotatable multi-flexible-arm vibration control device, which simulates the structure of the flexible mechanical arm combined with the elastic joint and performs vibration experiment and control.

It is a secondary object of the present invention to provide a method of controlling a multi-flexible-arm vibration control apparatus that moves and rotates.

The invention adopts the following technical scheme:

a multi-flexible-arm vibration control device capable of moving and rotating comprises a moving platform part, a rotating platform part, a control part and a detection part;

the moving platform part comprises a moving beam, the moving beam is arranged on the moving platform, and a moving motor is connected with the moving platform through a moving elastic joint to drive the moving platform to move;

the rotating platform part is connected with the moving platform part and comprises a rotating beam, the rotating beam is arranged on the rotating platform, and a rotating motor is connected with the rotating platform through a rotating elastic joint and controls the rotation of the rotating platform;

the detection part is used for detecting vibration signals of the flexible beam and the rotating beam;

and the control part is used for receiving the vibration signals and processing the vibration signals to obtain control signals of the flexible beam and the rotating beam.

Furthermore, the movable elastic joint comprises a ball screw, a pull rod, a guide rail and an extension spring, the movable platform slides on the guide rail, the movable motor drives the ball screw to rotate, the ball screw rotates to drive the pull rod to move, and the pull rod is connected with the movable platform through the extension spring to drive the movable platform to move on the guide rail.

Further, the detection part comprises an acceleration sensor and a piezoelectric ceramic sensor, the acceleration sensor is arranged at the free ends of the rotating beam and the movable beam, and the piezoelectric ceramic sensor is arranged at the fixed ends of the rotating beam and the movable beam.

Further, the control part comprises a piezoelectric ceramic actuator, a charge amplifier, a terminal board, a motion control card, a piezoelectric driver, a servo motor driver and a computer, wherein the piezoelectric ceramic actuator is arranged at the fixed ends of the movable beam and the rotating beam, vibration signals are transmitted to the computer through the charge amplifier, the terminal board and the motion control card, then the computer calculates control quantity, the control signals are transmitted to the piezoelectric ceramic actuator through the piezoelectric driver and transmitted to the servo motor through the servo motor driver, and therefore vibration is restrained.

Furthermore, the rotary elastic joint is a torsion spring mechanism.

Further, the torsion spring mechanism comprises a torsion spring coupler, two bearings which are symmetrically arranged, a sleeve, a joint output shaft and two torsion springs which are reversely arranged;

the structure is as follows: the sleeve is connected with the output shaft of the rotating motor through the speed reducer, the sleeve supports the joint output shaft through two symmetrical bearings, the joint output shaft is connected with the rotating platform through the torsion spring coupler, and the joint output shaft is connected with the sleeve through two reversely mounted torsion springs.

Further, holes or notches are formed in the sleeve and the joint output shaft.

Furthermore, the movable beam and the rotating beam are both composed of two flexible beams.

Furthermore, each flexible beam is provided with four piezoelectric ceramic actuators, each flexible beam is provided with two piezoelectric ceramic actuators, each piezoelectric ceramic actuator is symmetrically arranged, and the posture of each piezoelectric ceramic actuator is the same as that of the flexible beam.

A control method based on a multi-flexible-arm vibration control device comprises the following steps:

the first step is as follows: the computer transmits the control signal to the two motors through the motion control card to excite the four flexible beams;

the second step is that: respectively detecting the vibration of the flexible beam by using a piezoelectric ceramic sensor and an acceleration sensor to obtain corresponding measurement signals;

the third step: amplifying the vibration signal of the piezoelectric ceramic sensor acquired in the step two through a charge amplifier, transmitting the vibration signal through a terminal board, converting an analog signal into a digital signal through a motion control card, and inputting the digital signal into a computer; meanwhile, a vibration signal detected by the acceleration sensor is input to the motion control card, and an analog signal is converted into a digital signal through an A/D conversion module in the motion control card and then is input into a computer;

the fourth step: the computer processes the received vibration signals and calculates the control quantity transmitted to the moving motor, the rotating motor and the piezoelectric ceramic actuators on the four beams in real time;

the fifth step: the computer transmits the control quantity to the motion control card, the motion control card transmits the control quantity to the piezoelectric ceramic actuators of the four beams through the terminal board and the piezoelectric drivers, and the analog signal transmits the control quantity to the two motors through the terminal board and the servo motor drivers.

The invention has the beneficial effects that:

1. the invention provides a good vibration control device for researching specific vibration control problems. Such as: the method can conveniently research how to effectively and actively control the vibration of the flexible mechanical arm with the elastic joint, research the optimal moving track which enables the system to vibrate minimally, and research the influence of the rigidity and the pretightening force of the spring in the elastic joint on the vibration control difficulty.

2. The invention has a large amount of rigid-flexible coupling and spring coupling, and provides hardware conditions for researching a system with a large amount of rigid-flexible coupling and spring coupling.

3. The structure is flexible to change, for example, the tail end of the flexible arm can be selected to increase the tail end quality, an acceleration sensor can also be selected to be installed, and nothing is needed, so that the application scene of the invention is increased.

4. The invention uses the method of combining the piezoelectric ceramic piece detection and the acceleration sensor detection to detect and compare the vibration of the flexible beam, thereby being beneficial to improving the detection precision.

5. The invention fully considers the problems of assembly, disassembly and maintenance during design. The installation is simple, and the part all can be dismantled and change.

Drawings

FIG. 1 is a schematic diagram of the construction of the multi-flexible arm vibration control device of the present invention;

FIG. 2 is a front view of the present invention;

FIG. 3 is a left side view of the present invention;

FIG. 4 is a top view of the present invention;

fig. 5 is a structural view of the interior of the sleeve of the torsion spring mechanism.

FIG. 6 is an isometric view of a torsion spring;

fig. 7 is a vibration control flow block diagram of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the present invention is not limited to these examples.

Examples

As shown in fig. 1 to 6, a multi-flexible-arm vibration control apparatus that moves and rotates, the entire apparatus being mounted on a stand 1. Comprises a moving platform part, a rotating platform part, a control part and a detection part.

The moving platform part comprises a moving beam 14 which is mounted on the moving platform 3, the moving platform 3 being freely slidable on the guide rails 2. The moving motor 18 is connected with the moving platform through a moving elastic joint to drive the moving platform to move and further drive the moving beam to move. The movable elastic joint comprises a ball screw, a pull rod guide rail and an extension spring, the movable platform is arranged on the guide rail and moves on the guide rail, the movable motor 18 drives the ball screw 15 to rotate through the coupler 17, the ball screw converts rotary motion into movement of the pull rod through transmission threads, and the rotary motion of the ball screw 15 can be converted into movement of the pull rod 16. The shift lever 16 is connected with the mobile platform 3 through one end of two extension springs 5, and the other end of the two extension springs is connected with the base of the mobile platform. The movement of the shift lever 16 will move the movable platform 3 on the guide rail 2.

Further, the extension springs 5 are arranged on two sides of the pulling rod 16, and the two extension springs 5 are in a tension pre-tightening state. The moving driving force transmitted from the slider can be transmitted to the moving beam 14.

The rotary platform part is arranged above the movable platform part. The device comprises a rotating beam 11, wherein the rotating beam is arranged on a rotating platform 10, a rotating motor 4 is connected with the rotating platform 10 through a torsion spring mechanism 12, and the torsion spring mechanism 12 is called as a rotating elastic joint.

As shown in fig. 5, further, the torsion spring mechanism 12 includes a coupler 28, two bearings 31 symmetrically installed, a sleeve 26, a sleeve lower end cover 25, a sleeve upper end cover 27, a joint output shaft 30, and two torsion springs 32 and 33 installed in opposite directions.

The sleeve 26 is coupled to the output shaft of the rotating motor 4 via a speed reducer 6, and the sleeve 26 supports a joint output shaft 30 via a bearing 31. The joint output shaft 30 is connected to the rotating platform 10. Two torsion springs connect the sleeve 26 and the joint output shaft 30. The sleeve 26 transmits the torque from the rotating motor 4 to the joint output shaft 30 through the two torsion springs. Thus, the connection between the rotary motor and the rotary beam is not rigid but elastic. This elastic connection is called a rotational elastic joint.

The installation process of the torsion spring mechanism is as follows:

the sleeve 26 and the sleeve lower end cover 25 are fixed by screws. The sleeve 26 is slotted and the output shaft 30 is slotted to facilitate mounting, dismounting and pre-tightening of the torsion springs 32, 33.

During installation, the tapered roller bearing is first placed into the sleeve 26 in the proper orientation, and then a torsion spring 32 is inserted into the proper slot of the sleeve 26 in the proper attitude. The selection of the slot is determined by the pre-tightening force of the torsion springs 31 and 32. The flat key mounted joint output shaft 30 is then placed into the socket, with the torsion spring 32 snapped into the notch of the joint output shaft 30. And then inserting one end of the torsion spring 33 into the slotted hole of the sleeve, forcibly rotating the joint output shaft 30, rotating the notch of the joint output shaft 30 to the short end of the torsion spring 33, and moving the torsion spring 33 to the buckling part along the notch to be clamped. Then the other bearing 31, the end cover adjusting ring 29 and the torsion spring upper end cover 27 are sequentially installed and fastened by screws. Finally, the sleeve lower end cover 25 and the output shaft of the speed reducer 6 are fixed by screws, and the sleeve 26 is mounted on the sleeve lower end cover 25 and fixed by screws. Thus, the torsion spring mechanism 12 is installed.

The number of the movable beams 14 and the rotating beams 11 is two, and the movable beams are both composed of flexible beams, the two movable beams are fixed through a movable beam clamp 13, and the included angle is 180 degrees.

The two rotating beams 11 are fixed through a rotating beam clamp, and the included angle is 180 degrees.

Among them, the flexible beam is a flexible material, and easily generates vibration which lasts for a long time and is difficult to naturally attenuate. The flexible beam is made of intelligent materials, and the piezoelectric ceramic actuator 9 and the piezoelectric ceramic sensor 8 are simultaneously adhered to the beam. The tail end of the flexible beam is provided with a small hole, and the acceleration sensor 7 can be installed, the tail end mass can also be installed, or nothing can be installed.

The two travelling beams 14 are all the same size, 800mm long, 140mm wide and 2mm thick. The distance between the piezoelectric ceramic driver and the fixed end of the flexible beam is 20mm, the distance between the two piezoelectric ceramic actuators on one surface is 60mm, and the distance between the end surface of the piezoelectric ceramic sensor and the end surface of the piezoelectric ceramic actuator is 20 mm.

The two rotary beams 11 are the same in size, 800mm in length, 100mm in width and 2mm in thickness. The distance between the piezoelectric ceramic driver and the fixed end of the flexible beam is 20mm, the distance between the two piezoelectric ceramic actuators on one surface is 20mm, and the distance between the end surface of the piezoelectric ceramic sensor and the end surface of the piezoelectric ceramic actuator is 20 mm.

The detection part comprises an acceleration sensor 7 and a piezoelectric ceramic sensor 8, wherein a small round hole is formed in the tail end of each flexible beam, the tail end mass or acceleration sensor 7 can be installed, and one acceleration sensor is installed on each flexible beam. Each flexible beam is provided with a piece of piezoelectric ceramic sensor and is arranged at the transverse center line position of the flexible beam.

The vibration signal of the piezoelectric ceramic sensor 8 is amplified by a charge amplifier 19, and is transmitted by a terminal board 21, and an analog signal is converted into a digital signal by an A/D conversion module inside a motion control card 24 and is input into a computer 23; meanwhile, the vibration signal detected by the acceleration sensor 7 is input to the motion control card 24, and the analog signal is converted into a digital signal by an a/D conversion module inside the motion control card 24 and input to the computer 23.

The control part comprises piezoelectric ceramic actuators which are symmetrically arranged, and two piezoelectric ceramic actuators are adhered to each surface. The postures of the piezoceramic actuator 9 and the piezoceramic sensor 8 are the same as those of the flexible beam.

The rotation motor will control the rotation of the rotary beam 11. The output shaft of the rotating motor is connected with the input shaft of the speed reducer, the output shaft of the speed reducer is connected with the sleeve of the torsion spring mechanism, and the output shaft of the sleeve is connected with the rotating platform.

The housing of the reducer is mounted on the moving platform 3. Therefore, the speed reducer, the rotating motor, the torsion spring mechanism, the rotating platform and the rotating beam can move along with the movement of the moving platform.

The rotary motor 18 and the moving motor 4 are servo motors.

And a vibration control section for measuring the vibration signal and the vibration suppression. The vibration signal is first measured by the piezo ceramic sensor 8 or the acceleration sensor. The vibration signal is transmitted to the computer 23 through the charge amplifier 19, the terminal board 21 and the motion control card 24. The computer then calculates the control amount according to the control law, and transmits the control signal to the piezoelectric ceramic actuator 9 via the piezoelectric driver 20 and to the servo motor via the servo motor driver 22, thereby suppressing vibration.

As shown in fig. 7, a method for controlling a multi-flexible-arm vibration control device includes the following steps:

the first step is as follows: the computer transmits the control signal to the two motors through the motion control card to enable the four flexible arms to vibrate, or external interference can be added to enable the flexible mechanical arms to vibrate.

The second step is that: respectively detecting the vibration of the multiple movable flexible beams by using a piezoelectric ceramic sensor and an acceleration sensor to obtain corresponding measurement signals;

the third step: amplifying the vibration signal of the piezoelectric ceramic sensor acquired in the step two through a charge amplifier, transmitting the vibration signal through a terminal board, converting an analog signal into a digital signal through an A/D conversion module in a motion control card, and inputting the digital signal into a computer; meanwhile, a vibration signal detected by the acceleration sensor is input to the motion control card, and an analog signal is converted into a digital signal through an A/D conversion module in the motion control card and then is input into a computer;

the fourth step: the computer processes the received vibration signals, such as band-pass filtering or low-pass filtering, and calculates the control quantity transmitted to the rotating motor of the moving motor and the piezoelectric ceramic actuators on the four beams in real time by using algorithms such as a nonlinear control algorithm or an intelligent control algorithm.

The fifth step: the computer transmits the control quantity to the motion control card. The motion control card is internally provided with a D/A conversion module which converts a digital control signal from a computer into an analog signal. And the piezoelectric ceramic actuator is transmitted to the four beams through a terminal board and a piezoelectric driver. The analog signal is transmitted to the two motors through the terminal board and the servo motor driver.

And a sixth step: parameters were varied and multiple experiments were performed.

In this embodiment, the flexible beam is made of epoxy resin. Elastic modulus E of epoxy resin_p34.64Gpa, and the density ρ 1840kg/m³。

The piezoelectric ceramic sensor is made of piezoelectric ceramic materials, and the geometric dimension of the piezoelectric ceramic sensor is 40mm multiplied by 10mm multiplied by 1 mm; the piezoelectric ceramic actuator is made of piezoelectric ceramic materials, and the geometric dimension of the piezoelectric ceramic actuator is 60mm multiplied by 20mm multiplied by 1 mm; the elastic modulus of the piezoelectric ceramic material is Epe-63 GPa, and d 31-166 pm/V.

The acceleration sensor is a capacitive sensor with the model number 8310B2 of Kistler company, the nominal sensitivity of the sensor is 1000mV/g, and the measurement frequency range is 0-250 Hz.

The lead screw guide rail is a KK86 module of a silver module in Taiwan, the total length is 840mm, and the track length is 740 mm;

the servo motor is made of Mitsubishi corporation, the model is HC-KFS13, the power is 100W, the maximum rotating speed is 3000r/min, and the resolution is 40000 pulses/revolution. The servo motor driver is a Mitsubishi driver with the model number of MR-J2S-10A. The planet speed reducer is a German Neugart speed reducer, the model of the planet speed reducer is PLFN-64, and the reduction ratio is 64: 1.

The motion control card selects DMC-2x00 digital motion controller produced by GALIL corporation in America, and provides standard PCI bus interface; the CPU model of the selected computer is Pentium G6202.6 GHz. And the memory 4G is provided with a PCI slot in the mainboard and can be provided with a motion control card. The display adopts a large display area VA249 HE.

The piezoelectric driver can be composed of parts such as piezoelectric amplifiers with the models of APEX-PA241DW or APEX-PA240CX, and the like, and the development unit is the university of southern China, and the device and the method are applied by the applicant and named as space sailboard bending and torsional mode vibration simulation active control device and method, and are described in detail in the patent with the application number of 200810027186.4. The amplification factor can reach 52 times, namely, the amplification factor is from-5V to +5V to-260V.

The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.