CN110737210B - Two-dimensional fast-swinging mirror physical simulation system driven by piezoelectric ceramics - Google Patents
Two-dimensional fast-swinging mirror physical simulation system driven by piezoelectric ceramics Download PDFInfo
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Abstract
A piezoelectric ceramic driven two-dimensional fast-swinging mirror physical simulation system belongs to the field of photoelectric telescope fast-swinging mirror system model identification and servo control, and mainly comprises a piezoelectric ceramic power simulation module, an AD acquisition circuit, a fast-swinging mirror mathematical model simulation module and a DA output module. The simulation of the physical characteristics and the power of the piezoelectric ceramic actuator is realized by building a piezoelectric ceramic power simulation module, voltages at two ends of the piezoelectric ceramic power simulation module are collected through an AD (analog-digital) collection circuit and are used as the input of a two-dimensional fast oscillating mirror and a piezoelectric ceramic hysteresis characteristic data model, the expansion amount of the piezoelectric ceramic actuator is obtained by utilizing the model to calculate, the expansion amount is converted into a voltage signal amount of a simulation resistance strain type displacement sensor (SGS), the voltage signal amount is output through a DA (digital-analog) output module, the output of the simulation expansion amount is collected by a fast oscillating mirror controller, and therefore closed-loop control simulation is completed. The invention realizes the closed-loop debugging of the closed-loop control link and the control algorithm of the controller, and shortens the time for formal joint debugging.
Description
Technical Field
The invention belongs to the field of photoelectric telescope fast oscillating mirror system model identification and servo control, and particularly relates to a two-dimensional fast oscillating mirror physical simulation system of a piezoelectric ceramic driving element.
Background
For photoelectric telescopes with high-precision tracking requirements, such as astronomical telescopes, laser tracking systems and the like, in order to improve the tracking precision, the photoelectric telescopes adopt a multi-stage tracking mode to improve the tracking precision, wherein the last stage tracking system mainly adopts a two-dimensional fast-swinging mirror system. The two-dimensional fast oscillating mirror has the characteristics of high oscillating speed and high positioning precision. At present, a fast oscillating mirror driving element is mainly made of piezoelectric ceramics and a voice coil motor, a resistance strain type displacement sensor (SGS) and a capacitance displacement sensor are adopted to carry out piezoelectric ceramic deformation and fast oscillating mirror oscillation measurement, and closed-loop control is adopted to realize fast and accurate positioning.
In order to realize the rotation of the mirror surface of the two-dimensional fast oscillating mirror around any axis on the plane and simplify the driving structure, the motion of the two-dimensional fast oscillating mirror is generally decomposed into the synthesis of the rotation around the X axis and the Y axis. The driving capability of a single piezoelectric ceramic driver is limited, and the two-dimensional fast oscillating mirror usually adopts a multipoint parallel differential driving structure, such as a 4-point parallel driving structure which is uniformly distributed at 90 degrees in a plane. The influence of temperature drift and the like on the system is effectively reduced by a multipoint parallel differential driving mode, and the deflection control of the two-dimensional fast oscillating mirror is realized by controlling the expansion amount of the piezoelectric driver. The displacement of the piezoelectric ceramic actuator is limited, and the expansion amount of the piezoelectric ceramic actuator is amplified through the flexible hinge, so that the oscillating amount of the two-dimensional fast oscillating mirror reaches the design requirement. And a resistance strain type displacement sensor is arranged at one end of the piezoelectric ceramic actuator and used for testing the strain amount of the piezoelectric actuator, and then the oscillating amount of the fast oscillating mirror is obtained through calculation. The swing amount of the fast oscillating mirror can be directly measured through a capacitance sensor according to requirements. The two-dimensional fast oscillating mirror is mainly composed as shown in figure 1.
The piezoelectric ceramic utilizes the inverse piezoelectric effect to generate displacement under the action of an external electric field, and has the characteristics of nonlinearity, hysteresis, creep deformation and the like due to a complex action mechanism, so that the inverse piezoelectric strain and the external electric field strength are in a nonlinear relation, wherein the hysteresis nonlinearity has the greatest influence, and the piezoelectric ceramic is a difficult problem which needs to be solved urgently in the control academic field of the piezoelectric ceramic at present.
The piezoelectric ceramic mathematical models commonly used at present include a Bouc-Wen model, a Duhem model and the like. Duhem model is a hysteresis model in the form of a differential equation obtained by a scientist p. The model has the characteristics that the mathematical formula is clear, and various hysteresis characteristics can be accurately expressed by adjusting various model parameters in the expression. The model is a dynamic hysteresis model, and is suitable for the characteristics of the dynamic hysteresis of a piezoelectric ceramic actuator system. The Duhem model parameters are obtained by system identification. The model dynamics are functionally changed by changing the model parameters. The Duhem model is available from the open literature.
The photoelectric telescope belongs to a developed product and is difficult to form and produce. In the process of developing the two-dimensional fast oscillating mirror, the general steps are that the fast oscillating mirror is assembled and then a model parameter test is carried out, a control system is debugged based on the parameter, and the development work is completed when the control precision reaches the design. Meanwhile, in practical engineering application, a large amount of work cannot be carried out in the early stage of debugging of the fast oscillating mirror control system due to overlong processes of the processing, assembling and debugging periods of the structural components, and the later time is seriously insufficient, so that the system period is influenced, and the problem that the research and engineering research system of the fast oscillating mirror control model is very unfavorable is solved.
Disclosure of Invention
The invention aims to provide a piezoelectric ceramic driven two-dimensional fast oscillating mirror physical simulation system, which realizes the simulation of physical characteristics and power of a piezoelectric ceramic actuator by building a piezoelectric ceramic equivalent simulation circuit, acquires the voltage at two ends of the piezoelectric ceramic equivalent simulation circuit through an AD acquisition card to be used as the input of a two-dimensional fast oscillating mirror and piezoelectric ceramic hysteresis characteristic data model, calculates the expansion and contraction quantity of the piezoelectric ceramic actuator by utilizing the model, converts the expansion and contraction quantity into the voltage signal quantity of a simulation resistance strain type displacement sensor (SGS), and outputs the voltage signal quantity through a high-precision DA output circuit. The output of the analog telescopic quantity is acquired by the fast swing mirror controller through an SGS acquisition circuit, and closed-loop control simulation is formed.
The technical scheme adopted by the invention for solving the technical problem is as follows:
a two-dimensional fast-swinging mirror physical simulation system of a piezoelectric ceramic driving element comprises: fast pendulum mirror controller, piezoceramics driver and resistance strain type displacement sensor, this simulation system includes: the device comprises a piezoelectric ceramic power simulation module, an AD acquisition circuit, a fast swing mirror mathematical simulation module and a DA output module; the fast oscillating mirror controller sends out control signals, is driven by a piezoelectric ceramic driver, realizes the simulation of the capacitance and the power of a piezoelectric ceramic actuator by building a piezoelectric ceramic power simulation module, collects the voltages at two ends of the piezoelectric ceramic power simulation module through an AD acquisition circuit, utilizes the fast oscillating mirror mathematical simulation module to pass through the voltage calculation to obtain the expansion amount of the piezoelectric ceramic actuator, converts the expansion amount into the voltage signal amount of an artificial resistance strain type displacement sensor, outputs the voltage signal amount through a DA output module, outputs the expansion amount through a processing circuit of the artificial resistance strain type displacement sensor, and finally collects the expansion amount through the fast oscillating mirror controller, thereby completing the simulation of closed-loop control.
Preferably, the piezoelectric ceramic power simulation module is connected with the piezoelectric ceramic driver, the piezoelectric ceramic power simulation module is composed of a large-capacity capacitor, a high-power resistor and an inductor, the piezoelectric ceramic is simulated by adopting a composite circuit mode, the large-capacity capacitor is connected with the high-power resistor in series, and then the inductor, the bypass capacitor and the resistor are connected in parallel.
Preferably, the AD acquisition circuit consists of a 16-bit AD acquisition card, outputs 0-5V, and is adjusted to 0-20 mV through a precision attenuator.
Preferably, the mathematical simulation model of the fast oscillating mirror comprises: a second-order linear model of the fast oscillating mirror and a piezoelectric ceramic Dehum model; the second-order linear model of the fast oscillating mirror needs to be established in advance, the real fast oscillating mirror is used for carrying out system identification and test on model parameters, an input signal is identified to be a voltage signal in a frequency modulation sine form, and simulation of the fast oscillating mirror driven by different piezoelectric ceramics is realized.
Preferably, the DA output module generates a voltage signal output of the simulated resistance strain gauge displacement sensor in a simulation manner, and the conversion relationship needs to be calibrated in advance.
Preferably, the DA output module is designed with low noise, and the low temperature drift component and the circuit board signal and power supply isolation wiring measure are selected.
The invention has the beneficial effects that: the piezoelectric ceramic driven two-dimensional fast oscillating mirror physical simulation system provided by the invention realizes piezoelectric ceramic driven two-dimensional fast oscillating mirror closed-loop simulation by adopting a physical simulation and mathematical model combined simulation mode, and has important significance for closed-loop joint test and test of a fast oscillating mirror controller, piezoelectric ceramic hysteresis nonlinear modeling, model parameter identification and relation research work of model parameters and fast oscillating mirror performance.
According to the invention, a hardware interface, a data model and a resistance strain type displacement sensor signal for measuring the deformation of the piezoelectric ceramic actuator are carried out on the two-dimensional fast oscillating mirror driven by the piezoelectric ceramic actuator through physical simulation, and the simulation and the modeling are carried out. The established simulation equipment is directly connected with the fast oscillating mirror controller and the driver to form a closed loop, so that the fast oscillating mirror control system can debug and test the closed loop interface, signals and the preliminary control model through the physical simulation model, and then is in butt joint with the real fast oscillating mirror after the test is finished, thereby improving the debugging efficiency and shortening the debugging time. Meanwhile, the piezoelectric ceramic actuator model is established in a mathematical mode, so that model parameters can be modified and adjusted very conveniently, and systematic and regular model research work can be developed.
Drawings
FIG. 1 is a schematic diagram of a 4-channel piezoelectric ceramic driven two-dimensional fast-oscillating mirror.
FIG. 2 is a schematic diagram of a two-dimensional fast-swinging mirror physical simulation system of a piezoelectric ceramic driving element according to the present invention.
FIG. 3 is a schematic diagram of a mathematical simulation module of the fast oscillating mirror of the present invention.
Fig. 4 is a schematic diagram of a high-precision DA output module simulating an SGS bridge output according to the present invention.
Detailed Description
The invention discloses a piezoelectric ceramic driven two-dimensional fast oscillating mirror physical simulation system, which is shown in figure 2. The device mainly comprises a piezoelectric ceramic power simulation module, an AD acquisition circuit, a fast swing mirror mathematical model simulation module and a DA output module.
The fast oscillating mirror controller sends out control signals, is driven by a piezoelectric ceramic driver, realizes the simulation of the capacitance and the power of a piezoelectric ceramic actuator by building a piezoelectric ceramic power simulation module, collects the voltages at two ends of the piezoelectric ceramic power simulation module through an AD acquisition circuit, utilizes the fast oscillating mirror mathematical simulation module to pass through the voltage calculation to obtain the expansion amount of the piezoelectric ceramic actuator, converts the expansion amount into the voltage signal amount of an artificial resistance strain type displacement sensor, outputs the voltage signal amount through a DA output module, outputs the expansion amount through a processing circuit of the artificial resistance strain type displacement sensor, and finally collects the expansion amount through the fast oscillating mirror controller, thereby completing the simulation of closed-loop control.
The piezoelectric ceramic driver is connected with the piezoelectric ceramic power simulation module, the piezoelectric ceramic power simulation module simulates the capacitive characteristics of piezoelectric ceramic, and meanwhile, the high-power resistor is used for simulating the power consumption of the piezoelectric ceramic, so that the simulation of inductance and bypass resistance-capacitance characteristics is increased. The electrical characteristic of the piezoelectric ceramic is represented by a capacitance characteristic, and the piezoelectric ceramic is generally equivalent to a capacitor in the modeling and simulation process. In fact, however, the conversion process of the piezoelectric ceramic from electric energy to mechanical energy is very complex, so the method adopts a composite circuit mode to simulate the piezoelectric ceramic, and adopts a mode of connecting a large-capacity capacitor in series with a large-power resistor and then connecting an inductor in parallel with a bypass capacitor and the resistor. The specific type selection of each component needs to be selected according to specific parameters of the simulation piezoelectric ceramics.
And two ends of the piezoelectric ceramic power simulation module are connected with the AD acquisition circuit. The AD acquisition circuit is used for acquiring the voltage of the output circuit of the piezoelectric ceramic driver in real time, the resolution ratio is 16 bits or more, and the sampling frequency is not lower than 25 kHz. The shelf product of a PCI bus or a PCIe bus can be selected, an AD acquisition circuit is integrated into a computer operated by a fast swing mirror mathematical model simulation module, and a PCI1716 acquisition card of Taiwan Shanhua company in China can be selected.
AD acquisition circuit is connected with quick pendulum mirror mathematical simulation model, quick pendulum mirror mathematical simulation model includes: a second-order linear model of the fast oscillating mirror and a piezoelectric ceramic Dehum model; as shown in fig. 3, the second-order linear model of the fast oscillating mirror needs to be established in advance, and the real fast oscillating mirror is used to perform system identification and test on the model parameters, so as to ensure that the motion characteristics of the established simulation model are consistent with the characteristics of the real two-dimensional fast oscillating mirror, which means that the frequency spectrum of the input signal must cover the frequency spectrum of the process. And identifying that the input signal is a voltage signal in a frequency modulation sine form, and realizing the simulation of different piezoelectric ceramic driven fast oscillating mirrors. The fast oscillating mirror mathematical simulation model acquires voltage values at two ends of the piezoelectric ceramic power simulation module in real time through the AD acquisition circuit, inputs the voltage values into a fast oscillating mirror second-order linear model and a piezoelectric ceramic Dehum model which are established in the piezoelectric ceramic power simulation module in advance, and calculates to obtain the expansion amount of the piezoelectric ceramic actuator simulation model.
The fast swing mirror mathematical model simulation module operates in a high-performance computer, such as an OptiPlex5050 commercial computer of dell corporation, which can be selected from high-performance commercial computers or industrial control computers. The mathematical model is run using specially developed software whose front panel supports software-related operations and parameter configuration. The software development adopts VS2012 development environment compilation of Microsoft corporation of America and adopts C # language development.
And the fast swing mirror mathematical simulation model is connected with the DA output module. The fast oscillating mirror mathematical simulation model obtains an output voltage value by the stretching amount of the piezoelectric ceramic actuator according to simulation transformation dimensions of the SGS sensor, the voltage value is simulated by a 20-bit high-precision low-noise DA output module to generate an SGS bridge voltage signal, the SGS bridge voltage signal is collected by an SGS processing circuit, the output value of the fast oscillating mirror mathematical simulation model is converted into a simulated SGS output voltage signal, and the simulated SGS output voltage signal is sent to a fast oscillating mirror controller to realize closed-loop control simulation.
The DA output module core device selects a 20-bit digital-to-analog conversion chip AD5971 in the United states. And the DA output module is inserted into a computer slot operated by the fast swing mirror mathematical model simulation module and is communicated with a computer by adopting a PCIe bus. An AD8676 chip is adopted to supply power to the AD 5971. As shown in FIG. 4, the AD5971 outputs 0-5V, is adjusted to 0-20 mV by a precision attenuator, and then is output after passing through a low-pass filter and an AD8675 voltage stabilizing circuit in sequence. In order to reduce noise interference, the high-precision DA output module needs to be specially designed with low noise, and the low-noise design comprises measures of selecting low-temperature drift components, isolating and wiring circuit board signals and power supply and the like.
Claims (6)
1. A piezoelectric ceramic driven two-dimensional fast-swinging mirror physical simulation system comprises: fast pendulum mirror controller, piezoceramics driver and resistance strain type displacement sensor, its characterized in that, this simulation system includes: the device comprises a piezoelectric ceramic power simulation module, an AD acquisition circuit, a fast swing mirror mathematical simulation module and a DA output module; the fast oscillating mirror controller sends a control signal, is driven by a piezoelectric ceramic driver, realizes the simulation of the capacitance and the power of a piezoelectric ceramic actuator by building a piezoelectric ceramic power simulation module, collects the voltages at two ends of the piezoelectric ceramic power simulation module through an AD acquisition circuit, obtains the expansion amount of the piezoelectric ceramic actuator through the voltage calculation by using a fast oscillating mirror mathematical simulation module, converts the expansion amount into the voltage signal amount of an artificial resistance strain type displacement sensor, outputs the voltage signal amount through a DA output module, outputs the analog expansion amount through a processing circuit of the artificial resistance strain type displacement sensor, and finally collects the voltage signal amount by the fast oscillating mirror controller, thereby completing the closed-loop control simulation; the piezoelectric ceramic power simulation module is connected with the piezoelectric ceramic driver, consists of a capacitor, a resistor and an inductor, and is realized by simulating piezoelectric ceramic in a composite circuit mode, connecting the capacitor with the resistor in series and then connecting the inductor with a bypass capacitor and the resistor in parallel.
2. The piezoceramic-driven two-dimensional fast oscillating mirror physical simulation system according to claim 1, wherein the AD acquisition circuit consists of 16-bit or more AD acquisition cards, and the sampling frequency is not lower than 25 kHz.
3. The piezoceramic-driven two-dimensional fast-swinging mirror physical simulation system according to claim 1, wherein the fast-swinging mirror mathematical simulation module comprises: a second-order linear model of the fast oscillating mirror and a piezoelectric ceramic Dehum model; the second-order linear model of the fast oscillating mirror needs to be established in advance, the real fast oscillating mirror is used for carrying out system identification and test on model parameters, an input signal is identified to be a voltage signal in a frequency modulation sine form, and simulation of the fast oscillating mirror driven by different piezoelectric ceramics is realized.
4. The piezoceramic-driven two-dimensional fast oscillating mirror physical simulation system according to claim 1, wherein the DA output module simulates voltage signal output of a simulation resistance strain type displacement sensor, and conversion relation needs to be calibrated in advance.
5. The system of claim 1, wherein the low noise design of the DA output module comprises selecting low temperature drift components and circuit board signal and power supply isolation wiring measures.
6. The piezoceramic-driven two-dimensional fast oscillating mirror physical simulation system according to claim 1, wherein the output voltage of the DA output module is 0-5V and is adjusted to 0-20 mV through a precision attenuator.
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