Integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device and method

Abstract

The application discloses a kind of integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device, including linear motion structure part, flexible arm structure part, vibration detection part, vibration excitation part and drive control part.Vibration is generated by exciting base platform by vibration excitation part, experimental platform and base platform are coupled by spring to generate vibration, linear motion structure and experimental platform are coupled by spring to generate vibration, flexible arm structure is installed on linear motion structure to generate vibration, forming rigid-flexible coupling structure.Laser displacement sensor measures vibration detection mark point area, and obtains the vibration information of flexible arm.The application can be used to study the influence of linear guide rail friction, spring stiffness and other factors on rigid-flexible coupling motion of flexible arm system and the corresponding vibration control method.Laser displacement sensor is used for non-contact measurement, with high measurement accuracy, fully collects multi-frequency vibration energy in multiple directions, and considers the influence of structure elasticity on vibration characteristics.

Description

Technical Field

[0001] This invention relates to the field of vibration measurement of rigid-flexible coupled structures, and more specifically, to a non-contact measurement device and method for measuring and controlling the vibration of an integrated multi-branch flexible arm rigid-flexible coupled structure. Background Technology

[0002] Rigid-flexible coupled motion systems are widely used in aerospace, rotating machinery, vehicle engineering, and robotics. These systems involve flexible components exhibiting a wide range of rigid body motions, while simultaneously undergoing elastic deformation due to external excitations. This raises the issue of the coupling between the rigid body motion and elastic deformation of structural components. As rigid-flexible coupled multibody systems become increasingly large and complex, and as their operating speed requirements increase, accurately controlling the system's operation under different constraints, forces, and control conditions has become a major challenge in engineering research and design.

[0003] In the aerospace field, most spacecraft are rigid-flexible coupled systems. Modern spacecraft are typically composed of flexible structures such as beams, plates, and trusses, and also incorporate complex structures like large-span solar panels and robotic arms. Their natural frequencies are low, and their low-frequency vibration modes are easily excited by disturbances. The various vibration effects exhibited during operation can severely impact the stability of the spacecraft. To expand the working range of the robotic arm, it is generally mounted on a mobile base that can move along guide rails. The mobile base has significant flexibility, and due to the inertial forces generated by its rigid body motion, the flexible components will experience substantial vibrations, which will have a significant impact on the end-effector tracking trajectory. Only through coupled analysis of elastic deformation and rigid body motion can high-precision control be achieved.

[0004] Non-contact measurement offers many advantages over traditional contact-based sensor measurements. It does not affect the dynamic performance of the object being measured, does not interfere with its normal operation due to added mass, is non-destructive, and has strong anti-interference capabilities. However, the accuracy of non-contact measurements is generally lower than that of contact measurements. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device and method. It uses a laser displacement sensor for non-contact measurement, which has high measurement accuracy and can achieve complete collection of multi-frequency vibration energy in multiple directions. It also takes into account the influence of structural elasticity on vibration characteristics.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] An integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device includes a linear motion structure, a flexible arm structure, a vibration detection section, a vibration excitation section, and a drive control section.

[0008] The linear motion structure includes a first connecting plate, a connecting spring, a linear guide rail, a slider, a motion base, an experimental platform, an aluminum profile frame, a rigid support, and a second connecting plate. The aluminum profile frame is fixedly connected to the first connecting plate and the experimental platform, the linear guide rail is fixed to the aluminum profile frame, the second connecting plate is connected to the first connecting plate and the experimental platform through the connecting spring, the two sides of the motion base are connected to the slider, and the rigid support is installed parallel to the motion base.

[0009] The flexible arm structure includes a first flexible arm, a second flexible arm, a third flexible arm, a fourth flexible arm, a coupling spring, a first mass block, a magnet, a fifth flexible arm, a second mass block, and a sixth flexible arm. The first, second, third, and fourth flexible arms form an integrated multi-branch flexible arm. The fixed ends of the first, second, and third flexible arms are respectively connected to the fourth flexible arm. Magnets are installed on the free end and upper and lower end faces of the first flexible arm, the upper end face of the second flexible arm, the lower end face of the third flexible arm, and the corresponding end faces of the rigid support and the flexible arms. The relative surfaces of the magnets are of the same polarity. The magnet is also fixed to the rigid support by the magnet bracket and the surface opposite to the magnet at the free end of the first flexible arm is the same polarity. The free end of the second flexible arm is equipped with a first mass block. The free end of the third flexible arm is connected to the second flexible arm by a coupling spring. The two ends of the fourth flexible arm are fixedly connected to the motion base. The fifth and sixth flexible arms form an L-shaped flexible arm. The L-shaped flexible arm is installed on the second connecting plate by a fixed bracket. The fixed end of the fifth flexible arm and the free end of the sixth flexible arm are fixedly connected by a second mass block. The free end of the fifth flexible arm is equipped with a second mass block. The fixed end of the sixth flexible arm is connected to the fixed bracket.

[0010] The vibration detection section includes a laser displacement sensor, which is fixed on a rigid bracket and a second connecting plate, and monitors the vibration of the first flexible arm, the second flexible arm and the sixth flexible arm. The laser of the laser displacement sensor is directed at the end face of the first flexible arm, the second flexible arm and the sixth flexible arm.

[0011] The vibration excitation system includes linear bearings, motion springs, support springs, collars, optical shafts, shaft supports, a vibrator, a base platform, a signal generator, a power amplifier, and a base platform. The vibrator is mounted on the base platform and connected to it via a push rod. The shaft support is fixed to the base platform, and the optical shaft is fixed via the shaft support. The collar is fixed to the optical shaft and connected to the base platform via a support spring. The base platform and the experimental platform are coupled via motion springs. Linear bearings are installed on the base platform and the experimental platform, allowing them to move freely in a straight line along the optical shaft. The signal generator emits a vibration signal, which is then transmitted to the vibrator via the power amplifier. The vibrator excites the base platform via the push rod, and the spring coupling causes the experimental platform and the flexible arm to vibrate.

[0012] The drive control section includes a piezoelectric actuator, a piezoelectric amplifier circuit, a terminal board, a motion control card, and a computer. The piezoelectric actuator is located at the fixed end of the first, second, fourth, and sixth flexible arms. The piezoelectric amplifier circuit is connected to the piezoelectric actuator. The laser displacement sensor, piezoelectric amplifier circuit, and motion control card are respectively connected to the terminal board. The computer is connected to the motion control card. The laser displacement sensor collects the vibration signal of the flexible arm and transmits it to the computer through the terminal board and motion control card. The computer generates the corresponding control signal and outputs it to the piezoelectric amplifier circuit through the motion control card and terminal board, thereby controlling the vibration of the flexible arm through the piezoelectric actuator.

[0013] Preferably, the connecting spring has a wire diameter of 3mm, an original length of 80mm, and a stiffness coefficient of 125N / m.

[0014] Preferably, the three rigid supports are installed in parallel on the motion base, with the distance between the upper rigid support and the first connecting plate being 71mm, the distance between the middle rigid support and the upper rigid support being 54mm, and the distance between the lower rigid support and the middle rigid support being 86mm.

[0015] Preferably, the piezoelectric actuator is a piezoelectric ceramic sheet, and there are a total of 16 piezoelectric actuators. Two sheets are installed on the upper and lower end faces of the first flexible arm, the second flexible arm, the fourth flexible arm and the sixth flexible arm, and they are installed symmetrically on both sides.

[0016] Preferably, the piezoelectric actuator is positioned 25mm from the fixed end of the flexible arm. The two piezoelectric actuators located on the same end face are 10mm from both sides of the flexible arm and are symmetrical about the centerline of the width direction of the flexible arm, with an attitude angle of 0°.

[0017] Preferably, the travel distance of the slider is 103 mm.

[0018] Preferably, the vibration excitation part further includes four legs, which are mounted on the base platform.

[0019] Preferably, the excitation position of the vibrator is located at the center of the base platform, and the excitation direction of the top rod is vertical.

[0020] Preferably, the motion control card includes an A / D conversion module, which is used for converting analog signals to digital signals.

[0021] A method for vibration measurement and control of an integrated multi-branch flexible arm with rigid-flexible coupling includes the following steps:

[0022] S1: The signal generator sends a vibration signal, which is amplified by the power amplifier and sent to the exciter. The exciter excites the base platform through the push rod, and the experimental platform and flexible arm vibrate through the spring coupling.

[0023] S2: The laser displacement sensor collects the vibration signal of the flexible arm and transmits it to the computer through the terminal block and motion control card;

[0024] S3: The computer generates the corresponding control signal and outputs the control signal to the piezoelectric amplifier circuit through the motion control card and terminal board, and controls the vibration of each flexible arm through the piezoelectric actuator.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0026] 1. This invention uses a laser displacement sensor for non-contact measurement, avoiding some drawbacks of traditional contact measurement methods, such as additional effects, sensitivity to noise, and low measurement accuracy; the laser displacement sensor uses laser triangulation, which is suitable for high-precision, short-distance measurement.

[0027] 2. Typical environmental vibrations are multi-frequency and multi-directional. Unlike traditional methods that rely on a single cantilever beam for vibration energy harvesting in a single direction, this invention employs an integrated multi-branch flexible arm structure and an L-shaped flexible arm structure to achieve complete harvesting of multi-frequency vibration energy in multiple directions.

[0028] 3. This invention employs flexible arm branches with different structures, which allows for a more comprehensive study of the vibration characteristics of multi-branch flexible arms.

[0029] 4. The linear motion structure of this invention has a large displacement stroke, and a spring is added to the coupling structure. 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. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device.

[0031] Figure 2 This is a front view of an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device.

[0032] Figure 3 This is a schematic diagram of the structure of the multi-branch flexible arm of the integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device.

[0033] Figure 4 This is a schematic diagram of the structure of an L-shaped flexible arm for an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device.

[0034] Figure 5 This is a schematic diagram of the exciter structure of an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device.

[0035] Figure 6 This is a control flowchart for an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device.

[0036] Explanation of icon numbers:

[0037] 1-First connecting plate; 2-Connecting spring; 3-Linear guide rail; 4-Slider; 5-Motion base; 6-First flexible arm; 7-Second flexible arm; 8-Third flexible arm; 9-Fourth flexible arm; 10-Linear bearing; 11-Motion spring; 12-Support spring; 13-Collar; 14-Optical axis; 15-Shaft support; 16-Feet; 17-Vibrator; 18-Base platform; 19-Signal generator; 20-Power amplifier; 21-Base platform; 22-Experimental platform; 23-Aluminum profile frame; 24-Coupled spring; 25-First mass block; 26-Magnet; 27-Rigid bracket; 28-Laser displacement sensor; 29-Second connecting plate; 30-Fifth flexible arm; 31-Second mass block; 32-Sixth flexible arm; 33-Piezoelectric actuator; 34-Piezoelectric amplifier circuit; 35-Terminal board; 36-Motion control card; 37-Computer. Detailed Implementation

[0038] The integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device and method of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0039] This invention discloses an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device. The device includes a linear motion structure, a flexible arm structure, a vibration detection section, a vibration excitation section, and a drive control section. This invention employs a laser displacement sensor for non-contact measurement, achieving high measurement accuracy and complete collection of multi-frequency vibration energy in multiple directions, while also considering the influence of structural elasticity on vibration characteristics.

[0040] Please see Figure 1 and Figure 2The linear motion structure includes a first connecting plate 1, a connecting spring 2, a linear guide rail 3, a slider 4, a motion base 5, an experimental platform 22, an aluminum profile frame 23, rigid supports 27, and a second connecting plate 29. The main body of the linear motion structure is composed of the motion base 5 and the second connecting plate 29 connected together. The aluminum profile frame 23 is fixedly connected to the experimental platform 22 and the first connecting plate 1 via angle brackets. The linear guide rail 3 is fixedly connected to the aluminum profile frame 23 with screws. The two sides of the motion base 5 are symmetrically connected to two sliders 4 via screws, ensuring the stability of the motion base 5's movement on the linear guide rail 3. Three rigid supports 27 are installed parallel to each other on the motion base 5 with screws. The upper second connecting plate 29 is connected to the first connecting plate 1 via a connecting spring 2, and the lower second connecting plate 29 is connected to the experimental platform 22 via a connecting spring 2, allowing the main body of the linear motion structure to perform coupled motion along the linear guide rail 3 in the vertical direction.

[0041] Please see Figure 1 In this embodiment, the entire test platform is assembled from aluminum profiles and plates with a length of 480mm. The experimental platform 22 is a 600mm×600mm×10mm aluminum plate, connected to the profile with screws, and each connection of the profile is fixed with angle iron. The first connecting plate 1 is a 600mm×200mm×10mm aluminum plate, and the rigid support 27 is a 225×40×4mm stainless steel plate. The distance between the upper rigid support 27 and the first connecting plate is 71mm, the distance between the middle rigid support 27 and the upper rigid support 27 is 54mm, and the distance between the lower rigid support 27 and the middle rigid support 27 is 86mm. The maximum size of the main body of the linear motion structure is 304mm×380mm. The connecting spring 2 has a wire diameter of 3mm, an original length of 80mm, and a stiffness coefficient of 125N / m. The stroke of the slider 4 is 103mm.

[0042] Please see Figure 1 and Figure 2 The flexible arm structure includes a first flexible arm 6, a second flexible arm 7, a third flexible arm 8, a fourth flexible arm 9, a coupling spring 24, a first mass block 25, a magnet 26, a fifth flexible arm 30, a second mass block 31, and a sixth flexible arm 32. The main body of the flexible arm structure is composed of the first flexible arm 6, the second flexible arm 7, the third flexible arm 8, and the fourth flexible arm 9.

[0043] Please see Figure 1 and Figure 3The fixed ends of the first flexible arm 6, the second flexible arm 7, and the third flexible arm 8 are welded to the fourth flexible arm 9, forming an integrated multi-branch flexible arm structure. Magnets 26 are mounted on the free end and both upper and lower end faces of the first flexible arm 6. The magnets 26 are fixed to the middle rigid support 27 by magnet brackets, and their surfaces are homogeneous with the surfaces of the magnets 26 at the free end of the first flexible arm 6. A first mass block 25 is mounted on the free end of the second flexible arm 7, and a magnet 26 is mounted on its upper end face. The free end of the third flexible arm 8 is connected to the second flexible arm 7 via a coupling spring 24, and a magnet 26 is mounted on its lower end face. The four flexible arms 9 are fixed to the motion base 5 at both ends by screws. Magnets 26 are mounted on the corresponding end faces of the rigid support 27 and the flexible arms, and the surfaces of the magnets 26 are homogeneous.

[0044] The end magnets 26 of the first flexible arm 16 are symmetrically located on both end faces 16 of the first flexible arm, and are magnetically coupled to the two magnets 26 on the upper rigid support 27 and the middle rigid support 27, while also limiting the movement of the flexible arm. The free end magnet 26 of the first flexible arm 16 is magnetically coupled to the magnet 26 on the fixed support of the middle rigid support 27, and is subjected to a variable magnetic force during vibration. The first flexible arm is made of an aluminum plate of 245×40×2mm, the second flexible arm 7 is made of an aluminum plate of 230×40×2mm, and the third flexible arm 8 is made of an aluminum plate of 215×40×2mm. A first mass block 25 is installed on the second flexible arm 7. The second flexible arm 7 and the third flexible arm 8 are connected by a linear coupling spring 24 to form a double cantilever beam structure, and two pairs of magnets are installed to make the flexible arm structure nonlinear.

[0045] Please see Figure 1 and Figure 4 The fifth flexible arm 30 and the sixth flexible arm 32 form an L-shaped flexible arm for collecting energy from vibrations in different environmental directions. The L-shaped flexible arm is mounted on the second connecting plate 29 via a fixed bracket. The fixed end of the fifth flexible arm 30 and the free end of the sixth flexible arm 32 are fixedly connected by a second mass block. The second mass block 31 is mounted on the free end of the fifth flexible arm 30, and the fixed end of the sixth flexible arm 32 is connected to the fixed bracket.

[0046] Please see Figure 1 and Figure 2The vibration detection section includes laser displacement sensors 28. The main body of the vibration detection section consists of three laser displacement sensors 28, which are fixed to the upper rigid support 27, the lower rigid support 27, and the upper second connecting plate 29 by brackets, respectively, to monitor the vibration of the first flexible arm 6, the second flexible arm 7, and the sixth flexible arm 32. The vibration detection section can adjust the detection area of ​​the flexible arm by adjusting the position of the brackets relative to the rigid support 27 and the second connecting plate 29, and can adapt to vibration detection within the sensor range by adjusting the relative positional relationship between the laser displacement sensors 28 and the brackets. The laser of the laser displacement sensor 28 should be directly facing the end face of the flexible arm, so that the laser is at the center of the flexible arm structure.

[0047] The laser displacement sensor 28 can accurately measure the position and displacement of an object without contact. It employs laser triangulation, a method generally suitable for high-precision, short-distance measurements. The laser emitter projects a visible red laser beam onto the surface of a flexible arm through a lens. The laser beam scattered by the flexible arm passes through a receiver lens and is received by an internal CCD linear camera. Depending on the distance, the CCD linear camera can capture this light spot at different angles. Based on this angle and the known distance between the laser and the camera, a digital signal processor calculates the distance between the sensor and the object being measured.

[0048] Please see Figure 1 and Figure 5 The vibration excitation system includes a linear bearing 10, a motion spring 11, a support spring 12, a collar 13, an optical axis 14, a shaft support 15, a support leg 16, a vibrator 17, a base platform 18, a signal generator 19, a power amplifier 20, and a base platform 21. The vibrator 17 is mounted on the base platform 18 with screws, ensuring its excitation position is centered on the base platform 21. The vibrator 17 is connected to the base platform 21 via a push rod, with the push rod's excitation direction being vertical. The shaft support 15 is fixed to the base platform 18 with screws. The optical axis 14 is fixed via the shaft support 15, and the collar 13 is fixed to the optical axis. The collar 13 is connected to the base platform 21 via the support spring 12. The base platform 21 and the experimental platform 22 are coupled via the motion spring 11. Linear bearings 10 are installed on the base platform 21 and the experimental platform 22, allowing the platform to move freely in a straight line along the optical axis 14.

[0049] The signal generation module includes a signal generator 19 and a power amplifier 20. The signal generator 19 emits signals corresponding to different vibrations, which are amplified by the power amplifier 20 and sent to the exciter 17. The exciter 17 excites the base platform 21 through the exciter push rod. Through the action of spring coupling, the experimental platform 22 and the flexible arm structure generate vibrations at different frequencies. By sending different excitation signals to the exciter 17, the phase of the sinusoidal signal of the exciter 17's vibration is different, causing the experimental platform 22 and the flexible arm structure to generate different forms of modal vibration.

[0050] Please see Figure 1 and Figure 2 The drive control section includes a piezoelectric actuator 33, a piezoelectric amplifier circuit 34, a terminal board 35, a motion control card 36, and a computer 37. The piezoelectric actuator 33 is mounted on the fixed ends of the first flexible arm 6, the second flexible arm 7, the fourth flexible arm 9, and the sixth flexible arm 32. The piezoelectric amplifier circuit 34 is connected to the piezoelectric actuator 33. The laser displacement sensor 28, the piezoelectric amplifier circuit 34, and the motion control card 36 are respectively connected to the terminal board 35. The computer 37 is connected to the motion control card 36. The laser displacement sensor 28 collects the vibration signals of the flexible arms and transmits them through the terminal board 35. The A / D conversion module of the motion control card 36 converts the signals into digital signals, which are then transmitted to the computer 37. The computer collects the vibration signal of the flexible arm through the laser displacement sensor 28, 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 36, and outputs it to the piezoelectric amplifier circuit 34 through the terminal board 35. After the piezoelectric amplifier circuit 34 amplifies the analog signal, the piezoelectric actuator 33 controls the vibration of the flexible arm.

[0051] In this embodiment, the two linear guides 3 of the linear motion structure are LM rolling guides from THK, model SHS25C2SS. The exciter 17 is a 4824 type electric modal exciter manufactured by HBK, with a rated force (sine peak / random RMS) of 100 / 70 N, a maximum rated stroke of 25.4 mm, a maximum speed (sine peak / random RMS) of 1.5 / 1.5 m / s, and a maximum acceleration (sine peak / random RMS) of 432 / 305 m / s². 2 The rated current is 5.5A, the suspension stiffness is 4N / mm, the effective moving mass is 0.23kg, the main resonance frequency is >6000Hz, the frequency range is DC-5000Hz, the external dimensions are 226mm×220mm×241.5, and the output method is to transmit the force from the top rod of the exciter 17 to the base platform 21.

[0052] The power amplifier 20 uses a 50WD1000 power amplifier from AR Corporation (USA), operating at a frequency of DC-1000MHz. The laser displacement sensor 28 is a Keyence product, model IL-065, with a reference distance of 65mm and a measurement distance of 55 to 105mm. The light source is a red semiconductor laser with a wavelength of 655nm; the measurement linearity is ±0.1%FS, the repeatability is 2μm, and the sampling period is 0.33 / 1 / 2 / 5ms (4 levels of variable). The flexible arm can be made of aluminum plate, which has a Poisson's ratio of 0.3, a density of 2700kg / m3, and a Young's modulus of 70Gpa.

[0053] The piezoelectric actuator 33 is a product of ChipTomorrow Technology Co., Ltd., model NAC2228, with geometric dimensions of 50mm × 7.8mm × 1.3mm, a weight of 4g, a stiffness of 0.0019N / μm, a resonant frequency of 180Hz, a maximum driving voltage of ±100V, a displacement of ±1000μm, and an output force of 1.90N. The piezoelectric actuator 33 is a piezoelectric ceramic plate; there are 16 piezoelectric actuators in total. Two are mounted on the upper and lower end faces of the first flexible arm 6, the second flexible arm 7, the fourth flexible arm 9, and the sixth flexible arm 32, symmetrically mounted on both sides. The piezoelectric actuators 33 are installed 25mm from the fixed end of the flexible arm. The two piezoelectric actuators 33 located on the same end face are 10mm from each side of the flexible arm and symmetrical about the centerline of the flexible arm's width direction, with an attitude angle of 0°.

[0054] The piezoelectric amplifier circuit 34 uses the APEX-PA241DW model, developed by South China University of Technology. Its amplification factor reaches 52 times, amplifying -5V to +5V to -260V to +260V. The motion control card 36 is a Googol GUC-800-TPV-M23-L2-F8G model, providing 8 controllable axes and analog input and output ranging from -10V to +10V. The selected computer 37 has a Pentium G620 2.6GHz CPU, 4GB of memory, and a PCI interface on the motherboard, allowing for the installation of the motion control card.

[0055] Please see Figure 6 The present invention also discloses an integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control method, applied to the above-mentioned integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device, comprising the following steps:

[0056] S1: The signal generator 19 sends a vibration signal, which is amplified by the power amplifier 20 and sent to the exciter 17. The exciter 17 excites the base platform 21 through the exciter top rod, and the experimental platform 2 and the flexible arm structure generate vibrations of different frequencies through the spring coupling.

[0057] S2: During the vibration of the flexible arm structure, three laser displacement sensors 28 measure the vibration detection area on the flexible arm, collect vibration signals, and send them to the computer 25.

[0058] S3: The computer collects the vibration signal of the flexible arm through the laser displacement sensor 28, 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 36, outputs it to the piezoelectric amplifier circuit 34 through the terminal board 35, amplifies the analog signal through the piezoelectric amplifier circuit 34, and controls the vibration of the flexible arm through the piezoelectric actuator 33.

[0059] Finally, by changing the control parameters and conducting repeated experiments, multiple experimental results were obtained to determine the vibration characteristics and control effect of the integrated multi-branch flexible robotic arm.

[0060] In summary, the present invention has the following advantages and beneficial effects:

[0061] 1. This invention uses a laser displacement sensor for non-contact measurement, avoiding some drawbacks of traditional contact measurement methods, such as additional effects, sensitivity to noise, and low measurement accuracy; the laser displacement sensor uses laser triangulation, which is suitable for high-precision, short-distance measurement.

[0062] 2. Typical environmental vibrations are multi-frequency and multi-directional. Unlike traditional methods that rely on a single cantilever beam for vibration energy harvesting in a single direction, this invention employs an integrated multi-branch flexible arm structure and an L-shaped flexible arm structure to achieve complete harvesting of multi-frequency vibration energy in multiple directions.

[0063] 3. This invention employs flexible arm branches with different structures, which allows for a more comprehensive study of the vibration characteristics of multi-branch flexible arms.

[0064] 4. The linear motion structure of this invention has a large displacement stroke, and a spring is added to the coupling structure. 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.

[0065] The above description is a detailed description of the preferred embodiments of the present invention. However, the embodiments are not intended to limit the scope of the patent application of the present invention. All equivalent changes or modifications made under the technical spirit disclosed in the present invention should fall within the patent scope covered by the present invention.

Claims

1. An integrated multi-branch flexible arm rigid-flexible coupling vibration measurement and control device, characterized in that, The device comprises a linear motion structure part, a flexible arm structure part, a vibration detection part, a vibration excitation part and a driving control part. The linear motion structure part comprises a first connecting plate, connecting springs, a linear guide rail, a sliding block, a motion base, an experimental platform, an aluminum profile frame, a rigid support and a second connecting plate. The flexible arm structure part comprises a first flexible arm, a second flexible arm, a third flexible arm, a fourth flexible arm, coupling springs, a first mass block, magnets, a fifth flexible arm, a second mass block and a sixth flexible arm. The vibration detection part comprises a laser displacement sensor. The vibration excitation part comprises a linear bearing, motion springs, support springs, a shaft ring, an optical axis, a shaft support, an exciter, a base platform, a signal generator, a power amplifier and a base platform. The signal generator sends a vibration signal, which is sent to the exciter through the power amplifier. The exciter excites the base platform through the top rod, and the experimental platform and the flexible arm generate vibration through the spring coupling effect. The driving control part comprises piezoelectric actuators, piezoelectric amplification circuits, terminal plates, motion control cards and computers, the piezoelectric actuators are arranged at fixed ends of the first flexible arm, the second flexible arm, the fourth flexible arm and the sixth flexible arm, the piezoelectric amplification circuits are connected with the piezoelectric actuators, the laser displacement sensors, the piezoelectric amplification circuits and the motion control cards are connected with the terminal plates respectively, and the computers are connected with the motion control cards; the laser displacement sensors collect vibration signals of the flexible arms and transmit the vibration signals to the computers through the terminal plates and the motion control cards, the computers generate corresponding control signals and output the control signals to the piezoelectric amplification circuits through the motion control cards and the terminal plates, and the vibration of the flexible arms is controlled through the piezoelectric actuators.

2. The integrated multi-branched flexible arm rigid-flexible coupling vibration measurement and control device according to claim 1, characterized in that, The wire diameter of the connecting spring is 3 mm, the original length is 80 mm, and the stiffness coefficient is 125 N / m.

3. The integrated multi-branched flexible arm rigid-flexible coupling vibration measurement and control device according to claim 1, characterized in that, The three rigid supports are installed in parallel on the motion base, the distance between the upper rigid support and the first connecting plate is 71 mm, the distance between the middle rigid support and the upper rigid support is 54 mm, and the distance between the lower rigid support and the middle rigid support is 86 mm.

4. The integrated multi-branched flexible arm rigid-flexible coupling vibration measurement and control device according to claim 1, characterized in that, The piezoelectric actuators are piezoelectric ceramic sheets, there are 16 piezoelectric actuators in total, 2 piezoelectric actuators are installed on the upper and lower end faces of each of the first flexible arm, the second flexible arm, the fourth flexible arm and the sixth flexible arm, and the two piezoelectric actuators are symmetrically installed on both sides.

5. The integrated multi-branched flexible arm rigid-flexible coupling vibration measurement and control device according to claim 4, characterized in that, The piezoelectric actuators are arranged at positions 25 mm away from the fixed ends of the flexible arms, the two piezoelectric actuators on the same end face are respectively 10 mm away from the two sides of the flexible arm and are symmetric about the width direction center line of the flexible arm, and the attitude angle is 0°.

6. The integrated multi-link flexible arm rigid-flexible coupling vibration measurement and control device of claim 1, wherein, The movement stroke of the slider is 103 mm.

7. The integrated multi-link flexible arm rigid-flexible coupling vibration measurement and control device of claim 1, wherein, The vibration excitation part further comprises four supporting legs, and the four supporting legs are installed on the base platform.

8. The integrated multi-link flexible arm rigid-flexible coupling vibration measurement and control device of claim 1, wherein, The excitation position of the exciter is located at the center of the base platform, and the excitation direction of the top rod is the vertical direction.

9. The integrated multi-link flexible arm rigid-flexible coupling vibration measurement and control device of claim 1, wherein, The motion control card comprises an A / D conversion module, and the A / D conversion module is used for conversion between analog signals and digital signals.

10. A method for measuring and controlling the vibration of a rigid-flexible coupling of an integrated multi-branch flexible arm, applied to the device for measuring and controlling the vibration of a rigid-flexible coupling of an integrated multi-branch flexible arm according to any one of claims 1 to 9, characterized in that, The method comprises the following steps: S1: the signal generator sends a vibration signal, the vibration signal is amplified by a power amplifier and then sent to an exciter, the exciter excites the base platform through a top rod, and the experimental platform and the flexible arms are vibrated through the coupling effect of the spring; S2: a laser displacement sensor collects vibration signals of the flexible arms and transmits the vibration signals to a computer through terminal plates and motion control cards; S3: the computer generates corresponding control signals and outputs the control signals to piezoelectric amplification circuits through motion control cards and terminal plates, and the vibration of each flexible arm is controlled through piezoelectric actuators.

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