Multi-channel controller design method and system for multi-dimensional dynamic vibration absorber

Abstract

The invention discloses a multi-channel controller design method and system for a multi-dimensional dynamic vibration absorber, and belongs to the technical field of vibration control and electronic circuits, and the design method comprises the following steps: 1, building a vibration absorber electromechanical structure model, and obtaining a transformation curve of a first-order inherent frequency along with a point mass position based on the model; 2, designing a vibration absorber structure based on the transformation curve; 3, designing a control circuit, wherein the control circuit is used for controlling the working state of the motor according to the signal of the upper computer; 4, an upper computer control program is programmed, and the control program is used for controlling a motor of the vibration absorber based on the vibration frequency of the high-frequency vibration absorption subsystem assembly of the vibration absorber and the vibration frequency of the high-frequency vibration absorption subsystem assembly, so that the motor reaches a designated frequency absorption position; and step 5, connecting the upper computer with the control circuit to obtain the multi-channel controller of the multi-dimensional dynamic vibration absorber. The technical problem that multiple targets are difficult to be compatible and accurately controlled is solved.

Description

Technical Field

[0001] The present invention belongs to the field of vibration control and electronic circuit technology, and specifically relates to a multi-channel controller design method and system for a multi-dimensional dynamic vibration absorber. Background Art

[0002] Mechanical vibrations can easily lead to reduced performance and reliability of the machine or main structure itself, or affect the performance and reliability of the equipment based on the main structure. Therefore, most of the above mechanical vibrations need to be eliminated or suppressed. Among the many vibration reduction methods, dynamic vibration absorbers have the characteristics of low cost and good effect, so they are widely studied and used. The basic working principle of the dynamic vibration absorber is to attach a sub-oscillation system with mass, damping and stiffness, namely a vibration absorber, to a specific part of the controlled main vibration system. By reasonably selecting the relevant parameters of the vibration absorber, the vibration condition of the main system is changed, and the vibration energy is transferred to the vibration absorber, so that the vibration of the main system is reduced.

[0003] However, in actual application, once the traditional dynamic vibration absorber structure is designed and processed, its characteristic parameters are difficult to adjust in real time. If the vibration frequency of the main system changes due to changes in the environment or the looseness of its own structure, the dynamic vibration absorber will not be able to obtain the ideal vibration reduction effect in time. The vibration noise of the main system will also affect its service life and cause sound pollution to the surrounding environment. Summary of the invention

[0004] The present invention provides a multi-channel controller design method and system for a multi-dimensional dynamic vibration absorber. A vibration absorber fitting frequency model is designed based on a model simulation analysis method, which solves the technical problem that multiple objectives are difficult to control accurately and compatibly, and improves the old vibration absorption and noise reduction control method.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] A multi-channel controller design method for a multi-dimensional dynamic vibration absorber comprises the following steps:

[0007] Step 1: using the finite element method to establish an electromechanical structure model of the vibration absorber, and obtaining a transformation curve of the first-order natural frequency with the point mass position based on the electromechanical structure model of the vibration absorber;

[0008] Step 2: Designing a vibration absorber structure based on the transformation curve;

[0009] Step 3: Design a control circuit, wherein the control circuit is used to control the working state of the motor according to the host computer signal;

[0010] Step 4, compile a host computer control program, wherein the control program is used to control the motor of the high-frequency vibration absorbing subsystem component of the vibration absorber and the motor of the low-frequency vibration absorbing subsystem component of the vibration absorber based on the vibration frequency of the high-frequency vibration absorbing subsystem component of the vibration absorber and the vibration frequency of the low-frequency vibration absorbing subsystem component of the vibration absorber, so that the motor of the high-frequency vibration absorbing subsystem component reaches the specified frequency absorption position;

[0011] Step 5, powering the host computer and the control circuit with different power supplies and connecting them with wires to obtain a multi-channel controller for the multi-dimensional dynamic vibration absorber.

[0012] Furthermore, step 1 includes the following steps:

[0013] The eccentric FRP plate is simulated by beam elements, the mass block is simulated by point mass, and the constraint of the vibration surface on the eccentric FRP plate is simulated by fixed constraints. The characteristic frequency is calculated to obtain the first-order natural frequency. The point mass position is adjusted to obtain the transformation curve of the first-order natural frequency with the point mass position.

[0014] Further, step 2 includes the following steps:

[0015] Step 2.1, designing a vibration absorbing subsystem: the vibration absorbing subsystem comprises a bracket, a magnet, an eccentric glass fiber reinforced plastic plate and a sound-absorbing vibration absorbing subsystem component, the magnet and the eccentric glass fiber reinforced plastic plate are respectively installed at two ends of the bracket, the two ends of the eccentric glass fiber reinforced plastic plate are at different distances from the central axis of the bracket, and two sound-absorbing vibration absorbing subsystem components are installed on the eccentric glass fiber reinforced plastic plate;

[0016] Step 2.2, design a sound-absorbing and vibration-absorbing subsystem component: the sound-absorbing and vibration-absorbing subsystem component includes a high-frequency vibration-absorbing subsystem component and a low-frequency vibration-absorbing subsystem component, and the two vibration-absorbing subsystem components have the same structure. The high-frequency vibration-absorbing subsystem component includes a motor bracket, an L-shaped connector, a slider, a motor, a guide rail, a coupling and a lead screw, and the lead screw includes a T-type lead screw. The guide rail is installed on an eccentric fiberglass plate, and the slider is slidably installed on the guide rail. The slider is fixedly connected to the horizontal part of the L-shaped connector, one end of the T-type lead screw is installed on the vertical part of the L-shaped connector, and the other end is connected to the power output shaft of the stepper motor through a coupling; the motor on the high-frequency side is installed on the motor bracket;

[0017] Step 2.3, by adjusting the thickness, length and width of the eccentric FRP plate, the transformation curve is approximately evenly distributed on both sides of the design frequency;

[0018] Step 2.4: Select the models of the motor, motor bracket, coupling, lead screw, guide rail, and slider; determine the parameters of the L-type connector.

[0019] Further, in step 3, the designed control circuit includes a host computer, a main control board and a motor drive board connected in sequence;

[0020] Three acceleration sensor chips are designed on the motor drive board. The sensor chip and the single-chip microcomputer chip on the motor drive board communicate through the IIC bus, transfer data to the main control board through RS485, and transfer data to the host computer through USB / Ethernet. The acceleration signal is subjected to spectrum analysis on the host computer to extract the natural frequency.

[0021] Furthermore, the main control board includes multiple digital isolators and signal adapter boards, the digital isolators are used to isolate the 5V and 24V inputs, and the signal adapter board is used to receive control instructions sent by the host computer and send the control instructions to the motor drive board.

[0022] Furthermore, the host computer control program implements the following process:

[0023] S1. Collect the vibration acceleration on the low-frequency side, and obtain the vibration frequency on the low-frequency side according to the vibration acceleration on the low-frequency side; collect the vibration acceleration on the high-frequency side, and obtain the vibration frequency on the high-frequency side according to the vibration acceleration on the high-frequency side;

[0024] S2, extracting the characteristic frequency of the low frequency side from the vibration frequency of the low frequency side; extracting the characteristic frequency of the high frequency side from the vibration frequency of the high frequency side;

[0025] S3, outputting the rotation speed of the motor on the low-frequency side based on the characteristic frequency on the low-frequency side, and outputting the rotation speed of the motor on the high-frequency side based on the characteristic frequency on the high-frequency side;

[0026] S4, according to the length of the low-frequency side mass block from the origin and the speed of the low-frequency side motor, the total movement time of the low-frequency side motor to the specified position is calculated, and the number of low-frequency side pulses is calculated according to the total movement time of the low-frequency side motor to the specified position; according to the length of the high-frequency side mass block from the origin and the speed of the high-frequency side motor, the total movement time of the high-frequency side motor to the specified position is calculated, and the number of high-frequency side pulses is calculated according to the total movement time of the high-frequency side motor to the specified position;

[0027] S5. Control the low-frequency side motor according to the rotational speed of the low-frequency side motor and the number of low-frequency side pulses; control the high-frequency side motor according to the rotational speed of the high-frequency side motor and the number of high-frequency side pulses.

[0028] A multi-channel controller system for a multi-dimensional dynamic vibration absorber, comprising:

[0029] The upper computer is used to send a vibration acceleration acquisition instruction to the main control board through a network interface, and perform spectrum analysis on the acquired vibration acceleration signal to extract the characteristic frequency, determine the motor control instruction according to the characteristic frequency, and then send a generator control instruction to the main control board; the motor control instruction is used to control the rotation speed, direction and number of pulses of the stepper motor to make the motor reach the specified frequency absorption position;

[0030] A main control board, used to realize the forwarding of motor control instructions and relay disconnection, the main control board includes relays, multiple digital isolators and multiple signal adapter boards; the digital isolator is used to isolate 5V and 24V inputs, the signal adapter board is used to receive control instructions sent by the host computer, and send the control instructions to the motor drive board; the multiple signal adapter boards are used to receive and send multi-channel control instructions;

[0031] Motor drive board, used to realize control instruction forwarding and vibration acceleration signal acquisition;

[0032] The stepper motor driver is used to receive the motor control instructions forwarded by the motor drive board, and control the direction, speed and starting time of the motor according to the motor control instructions.

[0033] Furthermore, three MEMS acceleration sensor chips and a linear voltage regulator chip are arranged on the motor drive board; the three MEMS acceleration sensor chips are respectively used to collect the acceleration signal of the low-frequency side of the vibration absorber, the acceleration signal of the high-frequency side of the vibration absorber and the acceleration signal of the motor drive board; the linear voltage regulator chip is used to convert the 24V voltage into a 5V voltage to power the three MEMS acceleration sensor chips.

[0034] Furthermore, the host computer and the main control board communicate via USB and Ethernet.

[0035] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0036] The design method provided by the present invention realizes the precise vibration absorption effect of different vibration frequencies with multiple channels, high precision and multiple targets, thereby increasing the service life of the transformer equipment and meeting the use requirements.

[0037] The controller designed in the present invention can realize accurate identification and efficient vibration absorption for different vibration frequencies of different transformer casings, accurately adjust the characteristic frequency parameters of the vibration absorber through high-frequency and low-frequency modes, control the frequency accuracy of vibration absorption within 1 Hz, achieve the best vibration absorption and noise reduction effect, and realize efficient use of the noise reduction performance of the dynamic vibration absorber.

[0038] The present invention provides a multi-channel controller system for a multi-dimensional dynamic vibration absorber, which comprehensively uses serial ports, Ethernet, and the Internet to obtain vibration signals of multiple vibration reduction and noise reduction devices themselves and the dynamic vibration absorbers installed thereon, performs spectrum analysis, extracts characteristic parameters, and then sends stepper motor control instructions to accurately adjust the structural parameters of the dynamic vibration absorber and change the natural frequency of the vibration absorber, so as to solve the main problem of the difficulty in coordinated control of the vibration absorption frequency of the multi-dimensional adjustable vibration absorption structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1Calculate a finite element model for the natural frequencies of a cantilever beam under moving mass loads;

[0040] Figure 2 The mechanical structure of the present invention;

[0041] Figure 3 The structure of the motor assembly;

[0042] Figure 4 It is the overall structure diagram of the control system;

[0043] Figure 5 This is the RS485 network diagram;

[0044] Figure 6 This is the frequency acquisition circuit diagram;

[0045] Figure 7 This is the forward and reverse potential operation diagram of the motor;

[0046] Figure 8 Scan communication function code for the serial port;

[0047] Fig. 9 It is the motor control function code;

[0048] Fig.10 It is the frequency analysis function code;

[0049] Fig.11 This is the control flow chart of the template vibration absorber by the host computer;

[0050] Fig.12 This is a schematic diagram of the host computer operation interface.

[0051] In the attached figure: 1- bracket, 2- magnet, 3- eccentric fiberglass plate, 4- stepper motor assembly, 41- motor bracket, 43- L-shaped connector, 44- stepper motor, 45- guide rail, 46- coupling, 47- T-type screw rod. DETAILED DESCRIPTION

[0052] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0053] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] A multi-channel controller design method for a multi-dimensional dynamic vibration absorber, the specific design steps are as follows:

[0055] Step 1: Modeling the frequency characteristics of multiple adjustable vibration absorbing structures based on motor control;

[0056] Step 2: frequency-adjustable vibration absorption coordinated control system;

[0057] Step 3: Control circuit design based on motor control;

[0058] Step 4: Set up the upper computer software operating environment;

[0059] Step 5: Combine multiple vibration absorption frequency control systems to test the vibration absorption effect.

[0060] In step 1, a vibration absorption effect analysis method is provided, which uses a cantilever beam under the center of mass of a moving mass block to construct a dynamic vibration absorber model with a changing end mass position, such as Figure 1 As shown, the natural frequency of the vibration absorber at different mass block positions can be quickly obtained.

[0061] According to the analysis results of step 1, step 2 designs a frequency-dividable structure for the frequency-adjustable vibration-absorbing subsystem. The vibration-absorbing subsystem specifically includes a bracket 1, a magnet 2, an eccentric glass fiber reinforced plastic plate 3, a sound-absorbing vibration-absorbing subsystem component, and the like. Figure 2 A magnet 2 is fixed on one side of the bracket 1, and an eccentric glass fiber reinforced plastic plate 3 is fixed on the other side. The distances between the two ends of the eccentric glass fiber reinforced plastic plate 3 and the central axis of the bracket 1 are different. Two sound-absorbing and vibration-absorbing subsystem components 4 are installed on the eccentric glass fiber reinforced plastic plate 3, which are a high-frequency vibration-absorbing subsystem component and a low-frequency vibration-absorbing subsystem component. The two vibration-absorbing subsystem components have the same structure and are located on both sides of the axis of the bracket.

[0062] Specifically, Figure 3 As shown, the sound-absorbing and vibration-absorbing subsystem assembly is composed of a motor bracket 41, an L-shaped connector 43, a slider, a counterweight mass block, a stepper motor 44, a guide rail 45, a coupling 46, a lead screw and other components; the lead screw includes a T-type lead screw 47.

[0063] The guide rail 45 is mounted on the glass fiber reinforced plastic 3, the slider is slidably mounted on the guide rail 45, the slider is fixedly connected to the horizontal portion of the L-shaped connector 43, one end of the T-type screw rod 47 is mounted on the vertical portion of the L-shaped connector 43, and the other end is connected to the power output shaft of the stepper motor 44 through the coupling 46. The stepper motor 44 is mounted on the motor bracket 41.

[0064] In step 3, the motor control circuit is composed of a USB serial communication module, a single-chip microcomputer, a motor drive circuit, and an Ethernet monitoring circuit. Since the controlled object is based on the goal of motor control, the motor control circuit is designed first. The stepper motor requires a special duty cycle mode. By energizing one or more phases of the motor stator, the current flowing in the coil generates a magnetic field, and the rotor aligns with the magnetic field to realize the conversion of electrical energy into kinetic energy. In the actual use of stepper motor drivers, subdivision fractions are often used to control the size of the micro-step drive. The subdivision technology of stepper motors is essentially an electronic damping technology. Its main purpose is to weaken or eliminate the low-frequency vibration of stepper motors. Improving the operation accuracy of the motor is only a by-product of the subdivision technology. Subdivision is that the stepper motor driver divides each pulse emitted by the upper device into a coefficient of pulses according to the subdivision coefficient set by the stepper motor driver. After subdivision, the actual step angle of the motor during operation is a fraction of the basic step angle. The motor control circuit is as follows Figure 4 The host computer and the main control board communicate via USB and Ethernet, as shown in Figure 5 The entire design process is implemented on the domestic software LiChuang EDA.

[0065] Specifically, in step 3, the collection of low-frequency vibration signals is realized, a MEMS acceleration sensor chip is installed on the motor drive board, the sensor chip and the single-chip microcomputer chip on the motor drive board communicate through the IIC bus, the data is transmitted to the main control board through RS485, and further transmitted to the host computer through USB / Ethernet (Enternet), the acceleration signal is spectrally analyzed on the host computer, and the natural frequency is extracted.

[0066] The motor control circuit receives the control signal sent by the upper level, and controls the direction, speed and starting time of the motor according to the control signal.

[0067] In step 4, the software operating platform of the host computer is built. The host computer software should have functions such as serial port scanning, communication, multi-channel, adjustable precision parameters, vibration frequency acquisition and display, and frequency effect acquisition and display after vibration absorption, and use Fourier transform to perform spectrum analysis on the collected data, extract characteristic frequencies, and feed back the processing results to the single-chip microcomputer;

[0068] In step 5, the control system circuit is designed based on the unique driving method of the stepper motor. Figure 5 As shown, the control system circuit consists of three parts: the host computer, the main control board and the motor drive board. The host computer software is the human-computer interaction interface, the main control board implements functions such as command forwarding and relay disconnection, and the motor drive board implements functions such as motor drive and acceleration test;

[0069] In step 5, a control algorithm is implemented, which simultaneously detects the vibration of the vibration absorber structure and the vibration of the motor drive plate, performs spectrum analysis on the vibration time domain signal, extracts the natural frequency and structural vibration spectrum distribution, controls the stepper motor to make structural adjustments, and implements a motor mass block control algorithm with adaptive frequency changes.

[0070] Example 1

[0071] Reference Figure 1 , a multi-channel controller design method for a multi-dimensional dynamic vibration absorber has the function of detecting the vibration frequency of the main system and the adjustable characteristic parameters of the system itself. When multiple frequencies of the controlled main vibration system are clear, an efficient control system is constructed so that the multi-vibrator frequency is accurately matched with the main vibration system and the characteristic parameters of the system are accurately adjustable. The specific steps are as follows:

[0072] Step 1: Use the finite element method to establish the electromechanical structure model of the vibration absorber and calculate the natural frequency of the electromechanical structure of the vibration absorber. The model diagram is shown in Figure 1 . Use beam elements to simulate the eccentric FRP plate, use point mass to simulate the mass block, and use fixed constraints to simulate the constraints of the vibration surface on the eccentric FRP plate. Perform characteristic frequency calculations to obtain the first-order natural frequency. Change the point mass position to obtain the transformation curve of the first-order natural frequency with the point mass position (hereinafter referred to as the transformation curve). Perform structural design based on the calculation results of the natural frequency.

[0073] Specifically, for Figure 1 Finite element model for calculating the natural frequency of a cantilever beam under moving mass load. The differential equation for its bending free vibration is:

[0074]

[0075] Where ρ is the mass per unit length of the beam; E is the elastic modulus of the FRP plate material; I is the principal moment of inertia of the cross-sectional centroid of the beam; m j is the mass of the fiberglass plate in the jth concentrated area, x j is the coordinate of the jth concentrated mass; δ is the δ function; y = y(x, t) is the lateral displacement of the beam;

[0076] set up

[0077]

[0078] l is the length of the FRP plate, ω is the vibration frequency, and t is the time;

[0079] Substituting into formula (1), we get

[0080]

[0081] In the formula

[0082]

[0083] Among them, α j is an intermediate variable;

[0084] Take the Laplace transform of both ends of (3)

[0085]

[0086] Taking the Laplace inverse transform on both ends of the above equation, we get

[0087]

[0088] In the formula, u(ξ-ξ j ) is the unit step function

[0089]

[0090] Formula (7) is a Krylov function, and we have

[0091]

[0092] Each Y(ξ j )(j=1,2,...n) is unknown and can be determined as follows: First, let’s discuss the case where j=1.

[0093]

[0094] When ξ=ξ1, we have

[0095] Y(ξ)=Y(0)S(βξ1)+Y'(0)T(βξ1)+Y”U(βξ1)+Y”’(0)V(βξ1) (10)

[0096] Introducing operator symbols

[0097]

[0098] Then formula (9) can be rewritten as

[0099]

[0100] When one end is fixed and the other end is free, according to Y(0)=Y′(0)=0 and Y(1)=Y′(1)=0, the frequency equation is:

[0101]

[0102] In particular, when there is only one concentrated mass at the free end of the beam, we take i = 1, ξ1 = 1, and then we get

[0103]

[0104] 1+chβcosβ=αβ(chβsinβ-shβcosβ) (13);

[0105] High frequency side frequency range (100-200) Hz

[0106] When the high-frequency side mass block is l1 away from the origin, Substituting (13) into the solution, the β is β1; from (4), we can get ω1 is the high frequency;

[0107] For the automatic control system, the input is the extracted characteristic frequency, and the output is the rotation speed of the stepper motor. Assume that the Laplace transform of the input characteristic frequency on the high-frequency side is R1(s), the Laplace transform of the output speed is N1(s), and the transfer function is

[0108] According to the final value theorem, Input a unit step response and observe the system adjustment time t s1 (5% error band), we get Therefore, G1(S) can be obtained;

[0109] The distance between the high-frequency side mass block and the origin is l1, the speed of the high-frequency side motor is N1, and the time required for the high-frequency side motor to move to the specified position is Among them, R1 is the high-frequency characteristic frequency after extraction and transformation;

[0110] Assume the starting time is t0, then the total movement time of the high-frequency side motor to the specified position is T 高频 =t0+t1;

[0111] T高频 Enter the host computer,

[0112] Low frequency side frequency range (0-100) Hz

[0113] When the distance between the low-frequency side mass block and the origin is l2, we can substitute (13) to obtain β2; from (4), we can obtain ω2 is the low frequency;

[0114] For the automatic control system, the input is the extracted characteristic frequency and the output is the rotation speed of the stepper motor.

[0115] Assume that the Laplace transform of the input characteristic frequency on the high-frequency side is R2(s), the Laplace transform of the output speed is N2(s), and the transfer function is

[0116] According to the final value theorem,

[0117]

[0118] Input a unit step response and observe the system adjustment time t s1 (5% error band), we get Therefore, G2(S) can be obtained; the distance between the mass block and the origin is l2, the motor speed is N2, and the time required for the motor to move to the specified position is Among them, R2 is the low-frequency characteristic frequency after extraction and transformation;

[0119] Assume the starting time is t0, then the total movement time for the motor to move to the specified position is T 低频 =t0+t2;

[0120] T 低频 Enter the host computer, The number of pulses is sent to the main control board, which calculates and sends it to the motor driver board, which controls the running status of the motor.

[0121] Step 2, structural design. According to the analysis results of step 1, this step first designs the frequency-dividable structure of the adjustable frequency vibration absorbing subsystem. The adjustable frequency vibration absorbing subsystem includes a bracket 1, a magnet 2, an eccentric glass fiber reinforced plastic plate 3, a sound-absorbing vibration absorbing subsystem component, etc. Figure 2As shown. A magnet 2 is fixed on one side of the bracket 1, and an eccentric glass fiber reinforced plastic plate 3 is fixed on the other side. The distances between the two ends of the eccentric glass fiber reinforced plastic plate 3 and the central axis of the bracket 1 are different. Two sound-absorbing and vibration-absorbing subsystem components 4 are installed on the eccentric glass fiber reinforced plastic plate 3, which are respectively a high-frequency vibration-absorbing subsystem component and a low-frequency vibration-absorbing subsystem component. The two vibration-absorbing subsystem components have the same structure and are respectively located on both sides of the axis of the bracket. The sound-absorbing and vibration-absorbing subsystem component 4 includes a motor bracket 41, an L-shaped connector 43, a slider, a counterweight mass block, a stepper motor 44, a guide rail 45, a coupling 46, a lead screw and other components; the lead screw includes a T-type lead screw 47. In this embodiment, the stepper motor and its mounting seat constitute a mass block.

[0122] The guide rail 45 is mounted on the eccentric glass fiber reinforced plastic plate 3, the slider is slidably mounted on the guide rail 45, the slider is fixedly connected to the horizontal portion of the L-shaped connector 43, one end of the T-shaped screw rod 47 is mounted on the vertical portion of the L-shaped connector 43, and the other end is connected to the power output shaft of the stepper motor 44 through the coupling 46. The stepper motor 44 is mounted on the motor bracket 41.

[0123] By changing the thickness, length, width and other structural parameters of the eccentric glass fiber reinforced plastic plate 3, the transformation curve is approximately evenly distributed on both sides of the design frequency.

[0124] Carry out detailed structural design and select standard parts, including: stepper motor 44, motor bracket 41, coupling 46, connecting screw, guide rail slider, etc.; design non-standard parts, including: L-shaped connector 43, eccentric fiberglass plate 3 and fixing bracket, such as Figure 2 , Figure 3 shown.

[0125] Assemble each component in the specified position and sequence, and use a vibration test analyzer to perform a natural frequency test to verify the rationality of the structural design and make structural adjustments for unreasonable situations.

[0126] Step 3, the specific circuit functions include building a motor control circuit such as Figure 4 As shown, the motor forward and reverse potential operation is as follows Figure 7 As shown, the host computer communication circuit is as follows Figure 5 shown.

[0127] The control process of the motor forward and reverse potential operation is as follows: the main control chip sets the frequency and duty cycle to control the speed of motor 1; the main control chip sets the high and low levels of the two pins to control the direction of motor 1;

[0128] Specifically, the control system logic control part uses a 3.3V power supply, which is derived from the 5V power supply of the USB. 24V is used to power the stepper motor driver boards of all vibration absorbers. The 5V and 24V inputs are isolated by a digital isolator, so that even if the stepper motor driver board is damaged by component breakdown, it will not cause damage to the main control board; 24V is controlled by 4 relays, and 4 24V power supplies are separated. Only one relay is turned on at the same time, thereby reducing energy consumption requirements; on the stepper motor driver board, 24V is converted to 5V through a linear voltage regulator chip, and 5V is converted to 3.3V. 5V is used to power the main control chip, motor driver, etc., 3.3V is used to power the acceleration sensor chip, and 24V itself is used to power the stepper motor driver chip and the stepper motor brake.

[0129] Specifically, frequency acquisition requires the establishment of a vibration signal acquisition circuit with the LIS331HHTR acceleration sensor as the core. The frequency acquisition circuit is as follows: Figure 6 The frequency acquisition circuit uses the LIS331HHTR chip, and its SCL pin and SDAA pin are connected to the main control chip.

[0130] The working principle of the circuit is as follows: the chip is mounted on the STC15W408AS microcontroller through IIC communication. There are two signals related to the IIC bus: the serial clock line (SCL) and the serial data acquisition line (SDA). The latter is a bidirectional line used to send data to and receive data from the interface. Both lines are connected to Vdd_IO through pull-up resistors embedded inside the LIS331HH.

[0131] Step 4: Build a host computer software development platform based on visual studio, using C# as the development language.

[0132] In order to meet the needs of this invention, the host computer software should have functions such as serial port scanning communication, multi-channel, adjustable precision parameters, vibration frequency acquisition and display, and frequency effect acquisition and display after vibration absorption, and use Fourier transform to analyze the spectrum of the collected frequency data, extract the characteristic frequency, and feed back the processing results to the microcontroller. The serial port scanning communication function code is as follows: Figure 8 As shown; the motor control function code is as follows Fig. 9 As shown: z forward and reverse state; m speed control; d rotation time; r rotation state (start and stop); frequency analysis function code as shown Fig.10 As shown, it includes: performing Fourier transform on acceleration data; assuming here that there is a method FFT() that implements Fourier transform; extracting frequency components (for example, only taking the positive frequency part); the assumed Fourier transform method requires the use of an FFT library or implementation in actual applications 1 reference; / / This should be the implementation of FFT.

[0133] Step 5: Power each submodule and control circuit with different power supplies and connect them with wires, and build a control circuit to realize the control of the template vibration absorber by the upper computer interface. The specific control process is as follows: Fig.11 shown.

[0134] Specifically, the host computer sends an acceleration acquisition instruction to the main control board through the network interface. The acceleration acquisition instruction contains two parts: the address code and the command code. The address code indicates which main control board or driver board controls the acceleration sensor to collect the acceleration signal. After the host computer obtains the relevant data, it performs spectrum analysis on the data, extracts characteristic parameters, and then issues a generator control instruction to control the speed, direction and number of pulses of the stepper motor so that the motor reaches the specified frequency absorption position.

[0135] Similarly, the host computer can manually adjust the motor control parameter accuracy on the host computer interface during the frequency fitting process, such as rotation time, rotation speed, forward and reverse, start and stop, etc. to find the corresponding frequency, and feedback the vibration absorption effect through the current vibration parameters. The host computer operation interface is as follows: Fig.12 shown.

[0136] Example 2

[0137] A control system for a multi-dimensional dynamic vibration absorber comprises a host computer, a main control board, a motor drive board and a stepper motor driver which are connected in sequence.

[0138] Among them, a multi-dimensional dynamic vibration absorber includes a plurality of vibration absorbing subsystems;

[0139] The host computer software is a human-computer interaction interface. The host computer sends vibration acceleration acquisition instructions to the main control board through the network interface, performs spectrum analysis on the acquired vibration acceleration signal, extracts the characteristic frequency, determines the motor control instruction based on the characteristic frequency, and then sends the generator control instruction to the main control board; among them, the motor control instruction is used to control the speed, direction and number of pulses of the stepper motor, so that the motor reaches the specified frequency absorption position. The host computer and the main control board communicate using USB and Ethernet;

[0140] The main control board is used to realize functions such as forwarding control instructions and switching on and off relays. The main control board includes relays, 4 digital isolators and 8 signal adapter boards. The 4 digital isolators can isolate the 4-way 5V and 24V inputs. The signal adapter board is used to receive control instructions sent by the host computer and send the control instructions to the motor drive board. The 8 signal adapter boards can receive and send 8-way control instructions.

[0141] The motor driver board is used to realize functions such as control instruction forwarding and vibration acceleration testing. The motor driver board includes: 3 MEMS acceleration sensor chips and a linear voltage regulator chip;

[0142] The three MEMS acceleration sensor chips are used to collect the acceleration signal of the low-frequency side of the vibration absorber, the acceleration signal of the high-frequency side of the vibration absorber and the acceleration signal of the motor drive board respectively;

[0143] The linear voltage regulator chip is used to convert the 24V voltage into 5V voltage to power the three MEMS acceleration sensor chips.

[0144] The stepper motor driver receives the control instructions forwarded by the motor drive board and controls the direction, speed and start-up time of the motor according to the control instructions.

[0145] The present invention provides a novel dynamic vibration absorption control system based on vibration monitoring. By detecting the vibration natural frequency of the vibration absorber and the frequency spectrum distribution of the vibration source on the surface of the structure, a stepper motor is used to change the position of the mass block and the natural frequency of the vibration absorber, thereby achieving efficient control of the noise radiation of the power equipment.

[0146] The above contents are only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A multi-channel controller design method for a multi-dimensional dynamic vibration absorber, characterized in that: The following steps are involved: Step 1: using the finite element method to establish an electromechanical structure model of the vibration absorber, and obtaining a transformation curve of the first-order natural frequency with the point mass position based on the electromechanical structure model of the vibration absorber; Step 2: Designing a vibration absorber structure based on the transformation curve; Step 3: Design a control circuit, wherein the control circuit is used to control the working state of the motor according to the host computer signal; Step 4, compile a host computer control program, wherein the control program is used to control the motor of the high-frequency vibration absorbing subsystem component of the vibration absorber and the motor of the low-frequency vibration absorbing subsystem component of the vibration absorber based on the vibration frequency of the high-frequency vibration absorbing subsystem component of the vibration absorber and the vibration frequency of the low-frequency vibration absorbing subsystem component of the vibration absorber, so that the motor of the high-frequency vibration absorbing subsystem component reaches the specified frequency absorption position; Step 5, powering the host computer and the control circuit with different power supplies and connecting them with wires to obtain a multi-channel controller for the multi-dimensional dynamic vibration absorber.

2. The method for designing a multi-channel controller for a multi-dimensional dynamic vibration absorber according to claim 1, characterized in that: The step 1 comprises the following steps: The eccentric FRP plate is simulated by beam elements, the mass block is simulated by point mass, and the constraint of the vibration surface on the eccentric FRP plate is simulated by fixed constraints. The characteristic frequency is calculated to obtain the first-order natural frequency. The point mass position is adjusted to obtain the transformation curve of the first-order natural frequency with the point mass position.

3. The method for designing a multi-channel controller for a multi-dimensional dynamic vibration absorber according to claim 1, characterized in that: The step 2 comprises the following steps: Step 2.1, designing a vibration absorbing subsystem: the vibration absorbing subsystem comprises a bracket (1), a magnet (2), an eccentric glass fiber reinforced plastic plate (3) and a sound-absorbing vibration absorbing subsystem component, wherein the magnet (2) and the eccentric glass fiber reinforced plastic plate (3) are respectively mounted at two ends of the bracket (1), the two ends of the eccentric glass fiber reinforced plastic plate (3) are at different distances from the central axis of the bracket (1), and two sound-absorbing vibration absorbing subsystem components (4) are mounted on the eccentric glass fiber reinforced plastic plate (3); Step 2.2, designing a sound-absorbing and vibration-absorbing subsystem component (4): the sound-absorbing and vibration-absorbing subsystem component (4) includes a high-frequency vibration-absorbing subsystem component and a low-frequency vibration-absorbing subsystem component, and the two vibration-absorbing subsystem components have the same structure. The high-frequency vibration-absorbing subsystem component includes a motor bracket (41), an L-shaped connector (43), a slider, a motor, a guide rail (45), a coupling (46) and a lead screw, and the lead screw includes a T-shaped lead screw (47). The guide rail (45) is installed on the eccentric glass fiber reinforced plastic plate (3), and the slider is slidably installed on the guide rail (45). The slider is fixedly connected to the horizontal part of the L-shaped connector (43), one end of the T-shaped lead screw (47) is installed on the vertical part of the L-shaped connector (43), and the other end is connected to the power output shaft of the stepping motor (44) through the coupling (46); the motor on the high-frequency side is installed on the motor bracket (41); Step 2.3, by adjusting the thickness, length and width of the eccentric glass fiber reinforced plastic plate (3), the transformation curve is approximately evenly distributed on both sides of the design frequency; Step 2.4, select the models of the motor, motor bracket (41), coupling (46), lead screw, guide rail (45), and slider; and determine the parameters of the L-type connector (43).

4. The method for designing a multi-channel controller for a multi-dimensional dynamic vibration absorber according to claim 1, characterized in that: In step 3, the designed control circuit includes a host computer, a main control board and a motor drive board connected in sequence; Three acceleration sensor chips are designed on the motor drive board. The sensor chip and the single-chip microcomputer chip on the motor drive board communicate through the IIC bus, transfer data to the main control board through RS485, and transfer data to the host computer through USB / Ethernet. The acceleration signal is subjected to spectrum analysis on the host computer to extract the natural frequency.

5. The method for designing a multi-channel controller for a multi-dimensional dynamic vibration absorber according to claim 4, characterized in that: The main control board includes multiple digital isolators and a signal adapter board. The digital isolators are used to isolate the 5V and 24V inputs, and the signal adapter board is used to receive control instructions sent by the host computer and send the control instructions to the motor drive board.

6. The method for designing a multi-channel controller for a multi-dimensional dynamic vibration absorber according to claim 1, characterized in that: The host computer control program implements the following process: S1. Collect the vibration acceleration on the low-frequency side, and obtain the vibration frequency on the low-frequency side according to the vibration acceleration on the low-frequency side; collect the vibration acceleration on the high-frequency side, and obtain the vibration frequency on the high-frequency side according to the vibration acceleration on the high-frequency side; S2, extracting the characteristic frequency of the low frequency side from the vibration frequency of the low frequency side; extracting the characteristic frequency of the high frequency side from the vibration frequency of the high frequency side; S3, outputting the rotation speed of the motor on the low-frequency side based on the characteristic frequency on the low-frequency side, and outputting the rotation speed of the motor on the high-frequency side based on the characteristic frequency on the high-frequency side; S4, calculating the total movement time of the low-frequency side motor to the specified position according to the length of the low-frequency side mass block from the origin and the speed of the low-frequency side motor, and calculating the number of low-frequency side pulses according to the total movement time of the low-frequency side motor to the specified position; The total movement time of the high-frequency side motor to the specified position is calculated according to the length of the high-frequency side mass block from the origin and the speed of the high-frequency side motor, and the number of high-frequency side pulses is calculated according to the total movement time of the high-frequency side motor to the specified position; S5. Control the low-frequency side motor according to the rotational speed of the low-frequency side motor and the number of low-frequency side pulses; control the high-frequency side motor according to the rotational speed of the high-frequency side motor and the number of high-frequency side pulses.

7. A multi-channel controller system for a multi-dimensional dynamic vibration absorber, characterized in that: include: The upper computer is used to send a vibration acceleration acquisition instruction to the main control board through a network interface, and perform spectrum analysis on the acquired vibration acceleration signal to extract the characteristic frequency, determine the motor control instruction according to the characteristic frequency, and then send a generator control instruction to the main control board; the motor control instruction is used to control the rotation speed, direction and number of pulses of the stepper motor to make the motor reach the specified frequency absorption position; A main control board, used to realize the forwarding of motor control instructions and relay disconnection, the main control board includes relays, multiple digital isolators and multiple signal adapter boards; the digital isolator is used to isolate 5V and 24V inputs, the signal adapter board is used to receive control instructions sent by the host computer, and send the control instructions to the motor drive board; the multiple signal adapter boards are used to receive and send multi-channel control instructions; Motor drive board, used to realize control instruction forwarding and vibration acceleration signal acquisition; The stepper motor driver is used to receive the motor control instructions forwarded by the motor drive board, and control the direction, speed and starting time of the motor according to the motor control instructions.

8. The multi-channel controller system of a multi-dimensional dynamic vibration absorber according to claim 7, characterized in that: Three MEMS acceleration sensor chips and a linear voltage regulator chip are arranged on the motor drive board; the three MEMS acceleration sensor chips are respectively used to collect the acceleration signal of the low-frequency side of the vibration absorber, the acceleration signal of the high-frequency side of the vibration absorber and the acceleration signal of the motor drive board; the linear voltage regulator chip is used to convert the 24V voltage into a 5V voltage to power the three MEMS acceleration sensor chips.

9. The multi-channel controller system of a multi-dimensional dynamic vibration absorber according to claim 7, characterized in that: The host computer and the main control board communicate using USB and Ethernet.

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