Flexible mechanical arm control device and method based on reciprocating vibration chain elastic base

Abstract

The present invention discloses a flexible mechanical arm control device and method based on a reciprocating vibration chain elastic base, comprising a flexible arm body part, a vibration detection part and a vibration control part, wherein the flexible arm body part comprises three flexible monomers, which are sequentially connected by springs and arranged on a linear guide rail, and under the action of a piston exciter, the three flexible monomers produce reciprocating motion, and the vibration of each flexible beam is detected by a laser displacement sensor and a piezoelectric ceramic sensor, and a piezoelectric ceramic driver and a servo motor are used as actuators for vibration suppression. The device can be used to study the influence of factors such as linear guide friction and spring stiffness on the coupled vibration of the flexible mechanical arm system of the chain elastic base and the corresponding vibration control method.

Description

Technical Field

[0001] The invention relates to the field of vibration control of flexible structures, and in particular to a flexible mechanical arm control device and method based on a reciprocating vibration chain elastic base. Background Art

[0002] Space manipulator technology is an important technology in the field of aerospace. It is an important tool to assist in completing operations such as space docking and target handling. However, the natural frequency of the space manipulator is low, and the low-frequency vibration mode is easily excited by interference. The various vibration effects presented during the operation will seriously affect the stability of the spacecraft. In order to expand the working range of the manipulator, the space manipulator is generally installed on a mobile base, which can move along the guide rail. The vibration generated during the movement will have a significant impact on the end tracking trajectory, and will also have a certain impact on the normal operation of other components; compared with the flexible manipulator with a fixed base, the flexible manipulator under the elastic base has stronger nonlinearity and strong coupling, and its analysis is more complicated, so it is necessary to study it. Summary of the invention

[0003] In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present invention is to provide a flexible robotic arm control device based on an elastic base of a reciprocating vibration chain. The present invention fully considers the influence of spring stiffness and linear guide friction on the vibration characteristics of the flexible beam.

[0004] A secondary object of the present invention is to provide a method for controlling a flexible mechanical arm based on an elastic base of a reciprocating vibration chain.

[0005] The primary purpose of the present invention is to adopt the following technical solutions:

[0006] A flexible mechanical arm control device based on a reciprocating vibration chain elastic base, comprising a flexible arm body part, a vibration detection part and a vibration control part;

[0007] The flexible arm body part includes a piston vibrator, a linear guide, a baffle and three flexible monomers with the same structure. The three flexible monomers are connected in sequence by two springs and are arranged on the linear guide. The baffle is connected to the flexible monomer at the tail end by a spring, and the piston vibrator is connected to the flexible monomer at the head end by a spring. Under the excitation of the piston vibrator, the three flexible monomers generate reciprocating vibrations along the linear guide.

[0008] The vibration detection part is used to detect the vibration signal of the flexible monomer;

[0009] The vibration control part is used for receiving the vibration signal and suppressing the vibration of the flexible monomer.

[0010] Preferably, the flexible monomer includes a guide rail slider, a flexible beam, a support shaft, a servo motor and a planetary reducer;

[0011] The planetary reducer is fixed on the guide rail slider through a bracket, its input end is connected to the servo motor, and its output end is fixed to the support shaft. The guide rail slider is set on a linear guide rail, and a flexible beam is fixed on both sides of the support shaft. The servo motor drives the two flexible beams to swing in the horizontal plane.

[0012] Preferably, the vibration detection part includes a piezoelectric ceramic sensor, a laser displacement sensor, a charge amplifier, a terminal board, a motion control card and a computer;

[0013] The computer is connected to the motion control card, the motion control card is connected to the terminal board, the piezoelectric ceramic sensor is arranged on the flexible beam, the vibration signal is detected and input into the charge amplifier, and the charge amplifier is connected to the terminal board;

[0014] The laser displacement sensor is arranged on one side of the flexible beam, and the vibration signal detected by the laser displacement sensor is input into the computer through the terminal board and the motion control card.

[0015] Preferably, the vibration control part includes a piezoelectric ceramic driver, a servo motor driver and a piezoelectric amplifier circuit. The computer obtains an active control signal based on the detection information of the laser displacement sensor and the piezoelectric ceramic sensor, and inputs the active control signal into the piezoelectric amplifier circuit and the servo motor driver in turn through the motion control card and the terminal board, thereby further driving the servo motor and the piezoelectric ceramic driver to suppress vibration.

[0016] Preferably, the number of the piezoelectric ceramic sensors is 6, one of which is pasted on each flexible beam, specifically on the center line in the width direction of the flexible beam, 80 mm away from the fixed end, with an attitude angle of 0° and pasted on one side.

[0017] Preferably, the number of the piezoelectric ceramic drivers is 24, with four pieces on each flexible beam, which are respectively pasted on both sides of the center line in the width direction of the flexible beam, 25 mm away from the fixed end, with an attitude angle of 0° and double-sided pasting, 2 pieces on each side, to suppress residual vibration of the flexible beam.

[0018] Preferably, the number of the laser displacement sensors is 6, which are respectively fixed on the experimental table through laser displacement sensor brackets and are located on one side of the flexible beam.

[0019] Preferably, the bottom of the support shaft is a disc-shaped base.

[0020] The secondary purpose of the present invention is to adopt the following technical solution:

[0021] A control method for a flexible mechanical arm control device comprises the following steps:

[0022] Step 1: Start the piston vibrator to stimulate the flexible robotic arm system based on the chain elastic base to vibrate;

[0023] Step 2: Use piezoelectric ceramic sensors and laser displacement sensors to detect the vibration information of the flexible beam and obtain corresponding vibration measurement signals;

[0024] Step 3: The vibration signal detected by the piezoelectric ceramic sensor in the second step is transmitted to the charge amplifier for amplification, and the amplified signal is transmitted to the motion control card through the terminal board, and then converted into a digital signal by the A / D conversion module of the motion control card and transmitted to the computer; the vibration signal detected by the laser displacement sensor is transmitted to the computer through the motion control card via the terminal board;

[0025] Step 4: Based on the vibration information obtained in the third step, the computer runs the corresponding vibration control algorithm, calculates the corresponding control amount of the servo motor and the piezoelectric ceramic driver, transmits the control amount of the servo motor to the servo motor driver through the motion control card via the terminal board, and the servo motor driver drives the servo motor to rotate accordingly; the control amount of the piezoelectric ceramic driver is converted into an analog signal through the D / A conversion module inside the motion control card, and the analog signal passes through the terminal board and is amplified by the piezoelectric amplifier circuit, and then drives the piezoelectric ceramic driver to suppress the vibration of the flexible beam;

[0026] Step 5: By changing the control parameters, conducting repeated tests, and obtaining multiple experimental results, the vibration characteristics and control effects of the flexible robotic arm based on the elastic base of the reciprocating vibration chain are obtained.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] (1) The present invention adopts reasonable structural design and uses springs to connect various bases together to form a coupled elastic base. The flexible beam is installed on each elastic base through a clamping plate and can reciprocate with the base to form a structure of a reciprocating vibration chain elastic base. The vibration characteristics of a space robot with a similar structure can be studied.

[0029] (2) The present invention uses a piston-type pneumatic vibrator as a vibration exciter to simulate the vibration generated by the space robot arm during operation.

[0030] (3) The present invention uses a servo motor combined with a piezoelectric ceramic driver as an actuator for suppressing the vibration of the flexible beam, which can effectively eliminate the influence of factors such as structural gaps on the control and quickly suppress large-amplitude vibrations and small-amplitude residual vibrations.

[0031] (4) The present invention adds a tension spring to the structure, and the length and stiffness of the spring can be freely adjusted, taking into account the influence of structural elasticity on the vibration characteristics of the system.

[0032] (5) The present invention uses a laser displacement sensor combined with a piezoelectric ceramic sensor to detect vibration, which is beneficial to improving the detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 It is a schematic diagram of the structure of the flexible robotic arm on the elastic base;

[0035] Figure 3 yes Figure 1 The main view of

[0036] Figure 4 yes Figure 1 A top view of

[0037] Figure 5 yes Figure 1 Right view of;

[0038] Figure 6 It is a flow chart of the vibration control process of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0040] Example

[0041] like Figure 1-Figure 5 As shown, a flexible mechanical arm control device based on a reciprocating vibration chain elastic base includes a flexible arm body part, a vibration detection part and a vibration control part;

[0042] The flexible arm body includes three flexible monomers with the same structure, which are connected in sequence by two springs 12, and a baffle is connected to the flexible monomer at the tail end by a spring, and a piston exciter is connected to the flexible monomer at the head end by a spring. A base 15, a linear guide 13 and a baffle 2 are installed on a test bench 1, and a piston exciter 14 is connected to the base 15 through a mounting hole at the bottom, so as to ensure that the vibration excitation generated by it is concentrated on the piston output end, so that the elastic base generates reciprocating vibration along the linear guide 13;

[0043] Each flexible monomer includes a guide rail slider 22, a bracket 3, a servo motor 8, a planetary reducer 23, a support shaft 24, a torsion spring 25, a bearing 26, a bearing cover 4, a gasket 27, a nut 28, a flexible beam 11 and a clamping plate 7;

[0044] The planetary reducer 23 is fixed to the guide rail slider 22 through the bracket 3, and its input end is connected to the servo motor 8, and the output end is fixed to the support shaft 24 with a disc-shaped base at the bottom through a threaded hole; a circular baffle is arranged on the support shaft 24, on which a bearing 26 can be placed, and the upper end of the bearing 26 is locked by a nut 28 and a gasket 27; the outer ring of the bearing is connected to the bearing cover 4 and fixed by bolts, and the other side of the bearing cover is connected to the flexible beam 11 through a clamping plate 7; mounting holes are reserved on the disc-shaped base of the support shaft 24 and the bearing cover 4 to install elastic components such as torsion springs 25 or other rigid components, so that the servo motor 8 can drive the flexible beam 11 to swing in the horizontal plane; the above components constitute a monomer of the flexible mechanical arm body part of the chain elastic base, and a total of three identical monomers are installed on the linear guide 13 end to end through four springs 12, and the head end is connected to the piston exciter 14, and the tail end is fixed to the baffle 2, which can generate reciprocating vibration along the linear guide under the excitation of the piston exciter 14 and excite the coupled vibration of the flexible beam 11.

[0045] like Figure 2 As shown, each flexible monomer includes two flexible beams. The device has a total of six flexible beams with the same structural material. Three flexible monomers are placed in parallel on the linear guide rail at a distance.

[0046] ——The vibration detection part is used to detect the vibration signal of the flexible monomer, specifically including:

[0047] Piezoelectric ceramic sensor 10, laser displacement sensor bracket 5, laser displacement sensor 6, charge amplifier 16, terminal board 19, motion control card 20 and computer 21;

[0048] The piezoelectric ceramic sensor 10 collects the vibration signal of the flexible beam 11 and amplifies it through the charge amplifier 16, then transmits it to the A / D conversion module of the motion control card 20 through the terminal board 19 to convert it into a digital signal, and finally transmits it to the computer 21; the laser displacement sensor 6 is installed on the laser displacement sensor bracket 5, which collects the vibration signal of the flexible beam 11 and transmits it through the terminal board 19, and then converts it into a digital signal by the A / D conversion module of the motion control card 20 and transmits it to the computer 21.

[0049] The number of the piezoelectric ceramic sensors is 6, one of which is pasted on each flexible beam, specifically on the center line of the flexible beam in the width direction, 80 mm away from the fixed end, with an attitude angle of 0° and pasted on one side.

[0050] The number of the laser displacement sensors is 6, which are fixed on the experimental table through laser displacement sensor brackets and are located on the same side of the flexible beam to detect the vibration of the middle part of the flexible beam.

[0051] The vibration control part is used to receive the vibration signal and suppress the vibration of the flexible monomer, including a piezoelectric ceramic driver 9, a servo motor 8, a servo motor driver 18, a piezoelectric amplifier circuit 17, a terminal board 19, a motion control card 20 and a computer 21;

[0052] The computer controls the servo motor as follows: the servo motor is initially powered off to prevent the flexible beam from rotating in the horizontal plane; after receiving the vibration signal of the flexible beam collected by the piezoelectric ceramic sensor and the laser displacement sensor, the computer runs the corresponding vibration control algorithm to generate the corresponding vibration control signal, which is converted into an analog signal by the D / A conversion module of the motion control card and transmitted to the servo motor driver by the terminal board. The servo motor driver drives the servo motor to rotate accordingly according to the position control method or the speed control method, so as to realize the rapid control of the large amplitude vibration of the flexible beam;

[0053] Computer control process of piezoelectric ceramic driver: The computer collects the vibration signal of the flexible beam through the piezoelectric ceramic sensor and the laser displacement sensor, runs the corresponding vibration control algorithm to generate the corresponding vibration control signal, converts it into an analog signal through the D / A conversion module of the motion control card, transmits it to the piezoelectric amplifier circuit through the terminal board, amplifies the analog signal through the piezoelectric amplifier circuit, and outputs it to the piezoelectric ceramic driver to control the residual vibration of the flexible beam.

[0054] The number of the piezoelectric ceramic drivers is 24, with four pieces on each flexible beam, which are respectively pasted on both sides of the center line of the flexible beam in the width direction, 25 mm away from the fixed end, with an attitude angle of 0° and double-sided pasting, 2 pieces on each side, to suppress the residual vibration of the flexible beam.

[0055] This embodiment can use a servo motor to drive the flexible beam to swing through a planetary reducer to suppress the large-amplitude vibration of the flexible beam. At the same time, a piezoelectric ceramic driver can be used to suppress the residual vibration of the flexible beam, thereby achieving fast and efficient control of the coupled vibration of the flexible mechanical arm of the chain elastic base.

[0056] The length and stiffness parameters of the springs between the piston exciter and the elastic base, between the elastic base and the elastic base, and between the elastic base and the baffle can be freely adjusted to detect the influence of different spring lengths and stiffness factors on the coupled vibration characteristics of the chain elastic base system.

[0057] like Figure 6 As shown, the control process of this device is:

[0058] Step 1: Start the piston vibrator to stimulate the flexible robotic arm system based on the chain elastic base to vibrate;

[0059] Step 2: Use piezoelectric ceramic sensors and laser displacement sensors to detect the vibration information of the flexible beam and obtain corresponding vibration measurement signals;

[0060] Step 3: The vibration signal detected by the piezoelectric ceramic sensor in the second step is transmitted to the charge amplifier for amplification, and the amplified signal is transmitted to the motion control card through the terminal board, and then converted into a digital signal by the A / D conversion module of the motion control card and transmitted to the computer; the vibration signal detected by the laser displacement sensor is transmitted to the computer through the motion control card via the terminal board;

[0061] Step 4: Based on the vibration information obtained in the third step, the computer runs the corresponding vibration control algorithm, calculates the corresponding control amount of the servo motor and the piezoelectric ceramic driver, transmits the control amount of the servo motor to the servo motor driver through the motion control card via the terminal board, and the servo motor driver drives the servo motor to rotate accordingly; the control amount of the piezoelectric ceramic driver is converted into an analog signal through the D / A conversion module inside the motion control card, and the analog signal passes through the terminal board and is amplified by the piezoelectric amplifier circuit, and then drives the piezoelectric ceramic driver to suppress the vibration of the flexible beam;

[0062] Step 5: By changing the control parameters, conducting repeated tests, and obtaining multiple experimental results, the vibration characteristics and control effects of the flexible robotic arm based on the elastic base of the reciprocating vibration chain are obtained.

[0063] Figure 1 The dotted lines in the figure indicate the connection relationship between the various devices, and the direction arrows indicate the transmission direction of the detection and control signal flow.

[0064] The material of the flexible beam is epoxy resin sheet, with geometric dimensions of 600mm×100mm×2mm, Poisson's ratio of epoxy resin is 0.33, and density is 1980kg / m 3 , Young’s modulus is 26.3Gpa.

[0065] The linear guide adopts the original linear guide of Hiwin, model HG25, and its corresponding guide slider adopts the matching slider, model HGH25CA.

[0066] The piston vibrator uses the FP-40-M model piston pneumatic exciter, and the spring uses a compression spring with a stiffness of 1000N / mm. The total length is 225mm, and the spring is made of high-quality manganese steel.

[0067] The servo motor is a Mitsubishi product, model HC-KFS13, with a power of 100W, a maximum speed of 3000r / min, and a resolution of 40,000 pulses / rev. The servo motor driver is a Mitsubishi driver model MR-J2S-10A. The planetary reducer is a German Neugart reducer, model PLFN-64, with a reduction ratio of 64:1.

[0068] The laser displacement sensor is a product of Keyence Corporation, model IL-100, and the measurement base is 100mm.

[0069] The piezoelectric ceramic sensor and piezoelectric ceramic driver are products of Core Tomorrow Technology Co., Ltd., model NAC2228, with geometric dimensions of 50mm×7.8mm×1.3mm, weight of 4g, stiffness of 0.0019N / μm, resonant frequency of 180Hz, maximum drive voltage of ±100V, displacement of ±1000μm, and output of 1.90N. The charge amplifier is the YE5851 charge amplifier of Jiangsu Lianneng Electronics Co., Ltd., with an input range of charge ±103Pc, an output range of ±10VP / 5mA, and an overall size of 50mm×32mm×100mm.

[0070] The piezoelectric amplifier circuit is composed of voltage amplifiers such as APEX-PA241DW or APEX-PA240CX, which were developed by South China University of Technology. The amplification factor can reach 52 times, that is, -5V~+5V is amplified to -260V~+260V.

[0071] The motion control card uses the DMC-2x00 digital motion controller produced by the American GALIL company, which provides a standard PCI bus interface; the CPU model of the computer selected is Pentium G620 2.6GHz, the memory is 4G, and there is a PCI slot in the motherboard, which can be used to install the motion control card.

[0072] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A flexible mechanical arm control device based on a reciprocating vibration chain elastic base, characterized in that: It includes a flexible arm body part, a vibration detection part and a vibration control part; The flexible arm body part includes a piston vibrator, a linear guide, a baffle and three flexible monomers with the same structure. The three flexible monomers are connected in sequence by two springs and are arranged on the linear guide. The baffle is connected to the flexible monomer at the tail end by a spring, and the piston vibrator is connected to the flexible monomer at the head end by a spring. Under the excitation of the piston vibrator, the three flexible monomers generate reciprocating vibrations along the linear guide. The vibration detection part is used to detect the vibration signal of the flexible monomer; The vibration control part is used to receive the vibration signal and suppress the vibration of the flexible monomer; The flexible monomer includes a guide rail slider, a flexible beam, a support shaft, a servo motor, a planetary reducer, a bracket, a torsion spring, a bearing, a bearing cover, a gasket, a nut and a clamping plate; The planetary reducer is fixed to the guide rail slider through a bracket, and its input end is connected to the servo motor, and the output end is fixed to the support shaft with a disc-shaped base at the bottom through a threaded hole; the guide rail slider is arranged on the linear guide rail, and a flexible beam is fixed on both sides of the support shaft, and the servo motor drives the two flexible beams to swing in the horizontal plane; a circular baffle is arranged on the support shaft to place the bearing, and the upper end of the bearing is locked by a nut and a gasket; the outer ring of the bearing is connected to the bearing cover and fixed by bolts, and the other side of the bearing cover is connected to the flexible beam through a clamping plate; mounting holes are reserved on the disc-shaped base and the bearing cover of the support shaft to install torsion spring elastic components or other rigid components, so that the servo motor can drive the flexible beam to swing in the horizontal plane; the above components constitute a monomer of the flexible mechanical arm body part of the chain elastic base, and a total of three identical monomers are installed on the linear guide rail end to end through four springs, and the head end is connected to the piston exciter, and the tail end is fixed to the baffle, which can generate reciprocating vibration along the linear guide rail and excite the coupled vibration of the flexible beam under the excitation of the piston exciter; Each flexible monomer includes two flexible beams. The device has a total of six flexible beams made of the same structural material. Three flexible monomers are placed in parallel on a linear guide rail at an interval.

2. The flexible robotic arm control device according to claim 1, characterized in that: The vibration detection part includes a piezoelectric ceramic sensor, a laser displacement sensor, a charge amplifier, a terminal board, a motion control card and a computer; The computer is connected to the motion control card, the motion control card is connected to the terminal board, the piezoelectric ceramic sensor is arranged on the flexible beam, the vibration signal is detected and input into the charge amplifier, and the charge amplifier is connected to the terminal board; The laser displacement sensor is arranged on one side of the flexible beam, and the vibration signal detected by the laser displacement sensor is input into the computer through the terminal board and the motion control card.

3. The flexible robotic arm control device according to claim 2, characterized in that: The vibration control part includes a piezoelectric ceramic driver, a servo motor driver and a piezoelectric amplifier circuit. The computer obtains an active control signal based on the detection information of the laser displacement sensor and the piezoelectric ceramic sensor, and inputs the active control signal into the piezoelectric amplifier circuit and the servo motor driver through the motion control card and the terminal board in turn, further driving the servo motor and the piezoelectric ceramic driver to suppress vibration.

4. The flexible robotic arm control device according to claim 2, characterized in that: The number of the piezoelectric ceramic sensors is 6, one of which is pasted on each flexible beam, specifically on the center line of the flexible beam in the width direction, 80 mm away from the fixed end, with an attitude angle of 0° and pasted on one side.

5. The flexible robotic arm control device according to claim 3, characterized in that: The number of the piezoelectric ceramic drivers is 24, with four pieces on each flexible beam, which are respectively pasted on both sides of the center line of the flexible beam in the width direction, 25 mm away from the fixed end, with an attitude angle of 0° and double-sided pasting, 2 pieces on each side, to suppress the residual vibration of the flexible beam.

6. The flexible robotic arm control device according to claim 1, characterized in that: The number of the laser displacement sensors is 6, which are fixed on the experimental table through laser displacement sensor brackets and are located on one side of the flexible beam.

7. A control method for a flexible robotic arm control device according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: Start the piston vibrator to stimulate the flexible robotic arm system based on the chain elastic base to vibrate; Step 2: Use piezoelectric ceramic sensors and laser displacement sensors to detect the vibration information of the flexible beam and obtain corresponding vibration measurement signals; Step 3: The vibration signal detected by the piezoelectric ceramic sensor in the second step is transmitted to the charge amplifier for amplification, and the amplified signal is transmitted to the motion control card through the terminal board, and then converted into a digital signal by the A / D conversion module of the motion control card and transmitted to the computer; the vibration signal detected by the laser displacement sensor is transmitted to the computer through the motion control card via the terminal board; Step 4: Based on the vibration information obtained in the third step, the computer runs the corresponding vibration control algorithm, calculates the corresponding control amount of the servo motor and the piezoelectric ceramic driver, transmits the control amount of the servo motor to the servo motor driver through the motion control card via the terminal board, and the servo motor driver drives the servo motor to rotate accordingly; the control amount of the piezoelectric ceramic driver is converted into an analog signal through the D / A conversion module inside the motion control card, and the analog signal passes through the terminal board and is amplified by the piezoelectric amplifier circuit, and then drives the piezoelectric ceramic driver to suppress the vibration of the flexible beam; Step 5: By changing the control parameters, conducting repeated tests, and obtaining multiple experimental results, the vibration characteristics and control effects of the flexible robotic arm based on the elastic base of the reciprocating vibration chain are obtained.

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