Ultrahigh-resolution piezoelectric controller

Abstract

The utility model discloses an ultrahigh-resolution piezoelectric controller, and relates to an ultrahigh-resolution piezoelectric control technology. In order to solve the problems of limited DAC resolution, slow closed-loop control response speed, large signal noise and drift, multi-DAC superposition error accumulation and the like, the utility model provides a controller circuit board which comprises a power supply unit, a main control unit, a driving unit and a sensing servo unit. The power supply unit provides a stable multi-stage power supply; the master control unit adopts a 32-bit single-chip microcomputer and integrates a DA conversion circuit, an AD conversion circuit and an analog signal input unit. The driving unit amplifies the main control signal and drives the piezoelectric ceramic actuator. The sensing servo unit comprises a signal conditioning circuit and a PID closed-loop control circuit. The utility model also discloses an ultrahigh-resolution piezoelectric controller comprising the circuit board. The piezoelectric driving device is widely applied to the fields of precise motion control, nanoscale positioning, micro-nano manufacturing, acoustic equipment, medical equipment and the like, and high-precision, low-noise and stable piezoelectric driving control is achieved.

Description

Technical Field

[0001] It relates to ultra-high resolution piezoelectric control technology, specifically an ultra-high resolution piezoelectric controller. Background Technology

[0002] In the field of piezoelectric ceramic driving and control, high-resolution piezoelectric controllers are core components for achieving ultra-precision motion control and are widely used in precision engineering, optical alignment, micro-nano manipulation, biomedicine, and semiconductor manufacturing. Traditional piezoelectric controllers primarily rely on the direct output voltage of a digital-to-analog converter (DAC) to drive the piezoelectric ceramic. Their control accuracy is limited by the DAC's resolution, noise, nonlinearity error, and temperature drift. To achieve higher control accuracy, researchers have proposed various improvement schemes, including high-level DACs, feedback closed-loop control, and high-precision signal amplification.

[0003] 1. Current Status of Technological Research

[0004] Currently, research on high-resolution piezoelectric controllers mainly focuses on the following technical approaches:

[0005] (1) High-resolution DAC technology

[0006] Existing piezoelectric control systems typically employ 16-bit or higher-bit DACs (such as 18-bit or 20-bit) to improve control resolution. For example, the AD5791 from Analog Devices is a 20-bit DAC with a minimum resolution of 0.19μV and is widely used in high-precision piezoelectric drive controllers. However, using a single high-bit DAC is costly, and limitations imposed by the DAC itself, such as noise, linearity error, and temperature drift, make it difficult to further improve resolution.

[0007] (2) Closed-loop control + displacement sensing technology

[0008] Modern piezoelectric controllers commonly employ SGS (strain gauge sensors) or Cap (capacitive sensors) feedback for closed-loop control to compensate for the nonlinearity and hysteresis effects of piezoelectric ceramics. For example, the P-725 series nanopositioning platform developed by Physik Instrumente (PI) in Germany achieves sub-nanometer positioning accuracy through capacitive sensor closed-loop feedback. However, relying solely on sensor feedback introduces additional noise, and the response speed of feedback control is limited, failing to fully improve the dynamic resolution of the system.

[0009] (3) Chopper-stabilized amplifier technology

[0010] Some high-precision piezoelectric controllers employ chopper-stabilized amplifiers (such as the ADA4522 and LTC2057) to reduce low-frequency noise and improve voltage output stability. For example, Keysight's nanopositioning controller uses a high-precision, low-noise amplifier, combined with a low-drift power supply and shielding design, to ensure ultra-low noise levels. However, this approach primarily optimizes signal quality and does not directly improve the DAC's resolution.

[0011] (4) Multi-DAC cascade technology

[0012] In recent years, some researchers have attempted to use multi-stage DAC signal superposition technology, which utilizes the addition of two or more DACs with different bit weights to improve the overall system resolution. For example, some laboratories have studied the superposition of a 16-bit DAC and a lower-order DAC to achieve higher resolution voltage output. However, traditional DAC superposition methods face technical bottlenecks such as signal synchronization errors, gain drift, and temperature errors, making it difficult to achieve a resolution of one part per million.

[0013] 2. Technical problems existing in the current technology

[0014] Despite significant progress in improving piezoelectric control accuracy, the following technical bottlenecks still limit the system's ultra-high resolution control capabilities:

[0015] Limited DAC resolution: Even with a 20-bit DAC, its minimum voltage resolution is still insufficient for ultra-high precision applications. Further increasing the DAC bit depth will lead to increased costs and also result in issues such as noise, linearity error, and temperature drift.

[0016] Limited response speed of closed-loop control: Although traditional SGS or Cap sensor feedback can compensate for errors, its bandwidth is limited and cannot meet the requirements of high-speed, high-resolution control.

[0017] Signal noise and drift issues: While a single high-precision amplifier can reduce low-frequency noise, it cannot completely eliminate the quantization and nonlinearity errors of the DAC, affecting the final control accuracy.

[0018] Accumulated error from multi-DAC stacking: Traditional DAC stacking methods suffer from temperature drift, gain error, and synchronization error among different DACs, making it difficult to achieve a final output accuracy of one part per million. Utility Model Content

[0019] To address the existing technical problems in improving piezoelectric control accuracy, such as limited DAC resolution, limited closed-loop control response speed, excessive signal noise and drift, and the accumulation of errors from multiple DACs, this utility model provides the following technical solution:

[0020] An ultra-high resolution piezoelectric controller circuit board includes:

[0021] The power supply unit is used to receive external DC power and provide a stable multi-stage power output to the circuit board.

[0022] The main control unit includes:

[0023] The main controller, using a 32-bit microcontroller, is responsible for overall signal processing and data control.

[0024] The DA conversion circuit improves the signal resolution to one part per million through an adder circuit and an error compensation algorithm.

[0025] The AD conversion circuit is used to receive signals from the sensing servo unit and perform analog-to-digital conversion.

[0026] The analog signal input unit is used to receive external input signals and transmit them to the main controller for processing.

[0027] The drive unit is used to amplify the control signal output by the main control unit and connect to and drive the piezoelectric ceramic actuator.

[0028] The sensing servo unit includes:

[0029] Signal conditioning circuitry is used to receive and amplify the feedback signal from the SGS / Cap sensor.

[0030] The PID closed-loop control circuit is used to correct errors in the sensor feedback data and transmit it to the main control unit.

[0031] Furthermore, a preferred embodiment is provided in which the power supply is converted to the required operating voltage through a BUCK conversion circuit, a BOOST conversion circuit, and an LLC series resonant circuit, providing a stable multi-stage power output for the circuit board.

[0032] Furthermore, a preferred embodiment is provided, which also includes a data communication interface, including RS232, RS422 and USB interfaces, for enabling data interaction with external devices.

[0033] Furthermore, in a preferred embodiment, the driving unit amplifies the control signal output by the main control unit through a two-stage amplifier circuit, and connects to and drives the piezoelectric ceramic actuator through a piezoelectric drive interface.

[0034] Furthermore, a preferred embodiment is provided in which the DA conversion circuit comprises multiple DACs stacked together.

[0035] Furthermore, a preferred embodiment is provided in which the main controller controls the DA conversion circuit via the SPI bus and performs real-time compensation for the DAC output in conjunction with an error calibration algorithm.

[0036] Furthermore, a preferred embodiment is provided in which the AD conversion circuit adopts a SAR-type 16-bit ADC for high-precision acquisition of displacement data of the piezoelectric ceramic actuator and feedback to the main control unit for closed-loop control.

[0037] Furthermore, a preferred embodiment is provided in which the driving unit employs a two-stage high-voltage amplifier circuit. The first-stage amplifier circuit is used to linearly amplify the control signal, and the second-stage amplifier circuit is used to boost the signal to the driving voltage range required by the piezoelectric ceramic actuator.

[0038] An ultra-high resolution piezoelectric controller, comprising:

[0039] Controller housing, used to house and protect internal circuit components;

[0040] The controller circuit board is disposed inside the controller housing;

[0041] The bottom cover is connected to the controller housing and encapsulates the controller circuit board.

[0042] A mounting bracket is used to install the controller housing and stabilize the internal components.

[0043] Mechanical equipment, wherein the equipment is controlled by the piezoelectric controller for voltage or displacement.

[0044] Compared with the prior art, the advantages of the technical solution provided by this utility model are as follows:

[0045] This solution utilizes DAC superposition technology, employing multi-stage DACs with different bit weights to achieve an output signal resolution of one part per million. Compared to traditional single high-bit DAC solutions (such as 20-bit DACs), this invention can provide higher resolution at a lower cost, while reducing the quantization and nonlinearity errors of the DAC itself and improving output accuracy.

[0046] This solution employs an error calibration and compensation algorithm. By monitoring the DAC output error in real time and making dynamic corrections, it effectively reduces temperature drift, gain error, and nonlinear error. Compared with traditional solutions that rely solely on high-precision DACs, it can reduce the system's dependence on high-end components, thereby improving the overall control accuracy and ensuring output stability, especially during long-term operation.

[0047] This solution designs a precision adder circuit to accurately superimpose the outputs of multiple DACs and uses operational amplifiers and resistor networks for signal conditioning. Compared with existing multi-DAC cascaded solutions, it reduces synchronization errors, ensures linearity of the output signal, and improves the fine control capability of the DAC output voltage, enabling the minimum voltage change to reach the nanovolt level.

[0048] This solution employs PID closed-loop control based on analog circuits, combined with SGS / Cap sensors for error feedback adjustment, and optimizes signal amplification and conditioning circuits. Compared with existing feedback solutions based on pure digital control, it can provide faster response speed and lower noise, enabling smoother and more precise nanometer-level displacement control in precision motion control applications.

[0049] This solution uses a high-performance 32-bit microcontroller as the main control unit, integrates SPI bus communication, and combines multiple interfaces such as USB, RS232, and RS422 to achieve high-precision digital control of piezoelectric ceramics. Compared with traditional FPGA or DSP solutions, it reduces power consumption and cost while improving the system's flexibility and scalability, making the control system easier to integrate into different application scenarios.

[0050] The power supply unit of this solution adopts a BUCK, BOOST, LLC topology, which optimizes power conversion efficiency and reduces high-frequency noise. Compared with the existing piezoelectric controllers that use linear voltage regulation, the power supply design of this solution reduces the impact of power supply voltage fluctuations on DAC accuracy, ensures the overall stable operation of the system, and improves anti-interference capability, making it suitable for more complex experimental environments.

[0051] It can be widely used in precision motion control, nanoscale positioning, micro-nano manufacturing, acoustic equipment and medical equipment. Attached Figure Description

[0052] Figure 1 A schematic diagram of the overall structure

[0053] Figure 2 Diagram of backend structure

[0054] Figure 3 Schematic diagram of the functional unit structure of the ultra-high resolution controller

[0055] Figure 4 Signal processing flowchart for closed-loop control of ultra-high resolution controller

[0056] Figure 5 Signal processing flowchart for piezoelectric ceramic control board

[0057] Figure 6 Schematic diagram of the power supply structure

[0058] In the diagram: 1 - outer casing; 2 - controller circuit board; 3 - bottom cover; 4 - screw; 100 - power supply unit; 200 - drive unit; 300 - sensor servo unit; 400 - main control unit; 401 - communication circuit; 402 - main controller; 403 - DA conversion circuit; 404 - AD conversion circuit; 405 - analog signal input unit; 406 - DA conversion circuit; 500 - piezoelectric ceramic actuator; 501 - SGS / CAP sensor; and 502 - piezoelectric ceramic drive end. Detailed Implementation

[0059] To make the advantages and benefits of the technical solution provided by this utility model clearer, the technical solution provided by this utility model will now be described in further detail with reference to the accompanying drawings. Specifically:

[0060] Implementation Method 1: This implementation method provides an ultra-high resolution piezoelectric controller circuit board 2, comprising:

[0061] The power supply unit 100 is used to receive external DC power and provide a stable multi-stage power output to the circuit board.

[0062] The main control unit 400 includes:

[0063] The main controller 402, using a 32-bit microcontroller, is responsible for overall signal processing and data control.

[0064] The DA conversion circuit 406403 improves the signal resolution to one part per million through an adder circuit and an error compensation algorithm.

[0065] AD conversion circuit 404 is used to receive signals from sensing servo unit 300 and perform analog-to-digital conversion;

[0066] The analog signal input unit 405 is used to receive external input signals and transmit them to the main controller 402 for processing.

[0067] The drive unit 200 is used to amplify the control signal output by the main control unit 400 and connect to and drive the piezoelectric ceramic actuator 500.

[0068] The sensing servo unit 300 includes:

[0069] The signal conditioning circuit is used to receive and amplify the feedback signal from the SGS / CAP sensor 501.

[0070] The PID closed-loop control circuit is used to correct errors in the sensor feedback data and transmit it to the main control unit 400.

[0071] Implementation Method 2: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method 1. The power supply is converted to the required operating voltage through the BUCK conversion circuit, BOOST conversion circuit and LLC series resonant circuit to provide a stable multi-stage power output for the circuit board.

[0072] Implementation Method 3: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method 1, and also includes a data communication interface, including RS232, RS422 and USB interfaces, for realizing data interaction with external devices.

[0073] Implementation Method 4: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method 1. The drive unit 200 amplifies the control signal output by the main control unit 400 through a two-stage amplifier circuit, and connects to and drives the piezoelectric ceramic actuator 500 through the piezoelectric drive interface.

[0074] Implementation Method 5: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method 1. The DA conversion circuit 406403 includes multiple DACs superimposed.

[0075] Implementation Method Six: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method One. The main controller 402 controls the DA conversion circuit 406 and DA conversion circuit 406403 through the SPI bus and performs real-time compensation for the DAC output in conjunction with an error calibration algorithm.

[0076] Implementation Method Seven: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method One. The AD conversion circuit 404 adopts a SAR-type 16-bit ADC for high-precision acquisition of displacement data of the piezoelectric ceramic actuator 500 and feedback to the main control unit 400 for closed-loop control.

[0077] Implementation Method 8: This implementation method further defines the ultra-high resolution piezoelectric controller circuit board 2 provided in Implementation Method 1. The drive unit 200 adopts a two-stage high-voltage amplifier circuit. The first stage amplifier circuit is used to linearly amplify the control signal, and the second stage amplifier circuit is used to boost the signal to the driving voltage range required by the piezoelectric ceramic actuator 500.

[0078] Implementation Method Nine: This implementation method provides an ultra-high resolution piezoelectric controller, including:

[0079] Controller housing 1, used to house and protect internal circuit components;

[0080] The controller circuit board 2 provided in Embodiment 1 is disposed inside the controller housing 1;

[0081] The bottom cover 3 is connected to the controller housing 1 and encapsulates the controller circuit board 2;

[0082] A mounting bracket is used to install the controller housing 1 and stabilize the internal components.

[0083] Specifically, the structure is as follows:

[0084] 1. Overall structure of the circuit board

[0085] The ultra-high resolution piezoelectric controller circuit board 2 is located inside the controller housing 1. Its core components include a power supply unit 100, a main control unit 400, a drive unit 200, and a sensing servo unit 300, which are electrically connected to achieve signal interaction between the units. The circuit board is fixed in the controller housing 1 with a plug-in design and is secured at the bottom with studs to ensure structural stability and meet electromagnetic compatibility requirements.

[0086] 2. Power supply unit 100

[0087] The power supply unit 100 provides a stable multi-stage power output to the entire controller circuit board 2. Its input is DC 20V~30V, and it adopts a BUCK, BOOST and LLC series resonant topology internally. The specific structure is as follows:

[0088] BUCK conversion circuit: Steps down the input voltage to the low-voltage regulated power supply (+5V) required by the main control unit 400.

[0089] BOOST conversion circuit: used to boost voltage to provide the high voltage power supply (±HV) required by drive unit 200.

[0090] LLC series resonant circuit: used to reduce high-frequency noise in switching power supplies, improve conversion efficiency, and reduce interference with analog signals.

[0091] Output voltage: ±HV (high voltage drive), ±15V (operational amplifier circuit), +5V (main control unit 400).

[0092] 3. Main control unit 400

[0093] The main control unit 400 is the core of the control system, including the main controller 402, DA conversion circuit 406, DA conversion circuit 403, AD conversion circuit 404, and analog signal input unit 405. Its structure and operation are as follows:

[0094] Main controller 402: It adopts a 32-bit microcontroller with built-in USB 2.0, RS232 and RS422 communication interfaces, and controls the DAC and ADC through the SPI bus.

[0095] DA conversion circuit 406 (403): It consists of multiple DACs stacked together, and uses a high-precision adder circuit to fuse the outputs of multiple DACs to achieve an ultra-high resolution signal output of one-millionth.

[0096] AD conversion circuit 404: Uses a 16-bit SAR type ADC to acquire sensor feedback signals and drive voltage data.

[0097] Analog signal input unit 405: Used to receive external input signals and convert them into a format that can be processed by the main control unit 400.

[0098] 4. Drive unit 200

[0099] The drive unit 200 is responsible for amplifying the ultra-high resolution signal output by the main control unit 400 and applying it to the piezoelectric ceramic actuator 500. Its structure includes:

[0100] The first-stage amplifier circuit uses a low-noise operational amplifier to linearly amplify the control signal output by the main control unit 400.

[0101] The second-stage high-voltage amplifier circuit uses a high-voltage operational amplifier to boost the signal to the driving voltage range required by the piezoelectric ceramic actuator 500.

[0102] Output port: Connects to the piezoelectric ceramic actuator 500 via cable to provide high-precision displacement control.

[0103] 5. Sensor Servo Unit 300

[0104] The sensor servo unit 300 is used to acquire feedback signals in real time and adjust drive signals to achieve closed-loop control. Its specific structure is as follows:

[0105] SGS / CAP sensor 501: Used to detect the displacement or strain of piezoelectric ceramics and output analog signals.

[0106] Signal conditioning circuit: amplifies, filters, and shapes the sensor output signal to improve signal quality.

[0107] PID closed-loop control circuit:

[0108] The error between the feedback signal and the target signal is calculated, and the error is corrected through proportional, integral, and differential operations.

[0109] The error signal is input to the main control unit 400, and the DAC outputs the corrected control signal to adjust the driving voltage of the piezoelectric ceramic and realize closed-loop control.

[0110] 6. Data communication interface

[0111] The controller circuit board 2 integrates multiple data communication interfaces to enable external devices to access and control the device.

[0112] USB 2.0 interface: Supports high-speed data transfer and facilitates interaction with computers.

[0113] RS232 / RS422 interface: used for remote serial communication to achieve device linkage control.

[0114] Independent SPI channel: used for DAC / ADC data transmission, improving signal synchronization accuracy and reducing data transmission conflicts.

[0115] 7. Error Compensation and Calibration Mechanism

[0116] To improve system stability and long-term accuracy, this solution provides error compensation and calibration mechanisms:

[0117] Real-time error compensation algorithm: The main control unit 400 detects the deviation between the DAC output and the target signal and corrects it in real time.

[0118] EEPROM stores calibration data: It stores the DAC's error compensation parameters to ensure that high-precision output is maintained after the system restarts.

[0119] Temperature compensation circuit: Reduces the impact of ambient temperature changes on DAC / ADC accuracy.

[0120] 8. Mechanically fixed structure

[0121] The controller circuit board 2 adopts a modular design and can be installed inside the housing 1. The specific mechanical structure is as follows:

[0122] Plug-in design: The circuit board can be inserted into a fixed position via a guide rail, which facilitates maintenance and replacement.

[0123] Stud fixing: The bottom has a screw hole, which can be fixed by screw 4 to prevent the circuit board from loosening.

[0124] Heat sink design: The high-voltage amplifier circuit on the drive unit 200 is equipped with a heat sink to improve heat dissipation efficiency and ensure long-term stable operation.

[0125] In the workplace, specifically:

[0126] 1. Power supply

[0127] The power supply unit 100 of this system adopts switching power supply technology, combined with BUCK, BOOST and LLC topologies, to convert the externally input DC voltage into the operating voltage required by each functional module, ensuring the stability and high efficiency of the system.

[0128] Input voltage: DC 20V~30V

[0129] Conversion method:

[0130] The BUCK switching circuit provides the low-voltage regulated power required by the main control unit 400.

[0131] The BOOST converter circuit boosts the voltage to meet the high-voltage drive requirements.

[0132] LLC series resonant circuits reduce power supply noise and improve conversion efficiency.

[0133] Output voltage:

[0134] ±HV (high voltage power supply) is used for drive unit 200

[0135] ±15V supplies power to the analog signal processing circuit.

[0136] 5V supply to the main control unit 400

[0137] 2. Main control unit 400 signal processing

[0138] The main control unit 400 is the core of this system, responsible for controlling the DAC output, acquiring sensor data, performing error calibration, and making precise adjustments through a closed-loop algorithm.

[0139] Main controller 402: Employs a 32-bit microcontroller with integrated SPI bus communication module.

[0140] Digital-to-analog conversion (DA):

[0141] 16-bit DAC with SPI interface

[0142] Stacking multiple DACs (DAC406) to improve resolution

[0143] Analog-to-Digital Conversion (AD):

[0144] A SAR-type 16-bit ADC is used for real-time acquisition of piezoelectric ceramic displacement data and drive signals.

[0145] Data communication:

[0146] RS232, RS422, and USB interfaces enable data exchange with external devices.

[0147] 3. Signal output of the DAC superposition circuit

[0148] This invention employs a dual DAC superposition + high-precision addition circuit method to improve the resolution to one millionth.

[0149] DAC1: Provides the main output voltage and performs coarse adjustment.

[0150] DAC2: Provides fine-tuning signals via a voltage divider network.

[0151] Adder circuit:

[0152] Composed of a high-precision operational amplifier and a resistor network

[0153] By calculating weights, the output voltage of DAC2 is superimposed on DAC1 to improve signal resolution.

[0154] After employing an error compensation algorithm, temperature drift and synchronization errors are eliminated.

[0155] 4. Sensor Servo Unit 300 Signal Acquisition

[0156] This invention uses an SGS / CAP sensor 501 for feedback control to achieve high-precision closed-loop control.

[0157] Sensor type:

[0158] SGS sensors for strain detection

[0159] Cap sensors are used for displacement detection.

[0160] Signal conditioning:

[0161] The sensor signal is amplified by the conditioning and amplification circuit.

[0162] The input is sent to the AD conversion circuit 404 and fed back to the main control unit 400.

[0163] Error calibration:

[0164] By combining error compensation algorithms, sensor drift is corrected, and signal accuracy is improved.

[0165] 5. Amplified output of drive unit 200

[0166] The drive unit 200 of this invention achieves precise driving of piezoelectric ceramics through two-stage amplification and is further optimized by combining closed-loop control.

[0167] First level of magnification:

[0168] A low-noise operational amplifier is used to linearly amplify the output signal of the main control unit 400.

[0169] Second level of magnification:

[0170] A high-voltage amplifier is used to amplify the signal to the voltage range required to drive the piezoelectric ceramic.

[0171] Final output:

[0172] The amplified signal is applied to the piezoelectric ceramic driver 502 to achieve high-resolution control.

[0173] 6. Closed-loop control and error compensation

[0174] To further improve system stability, this solution combines analog PID control circuits with real-time error compensation algorithms to achieve precise closed-loop control.

[0175] PID closed-loop control:

[0176] Input: Feedback signal from SGS / CAP sensor 501

[0177] Processing: The error signal is corrected using PID calculation.

[0178] Output: The corrected signal is input to the drive unit 200 to adjust the driving voltage of the piezoelectric ceramic.

[0179] Error compensation algorithm:

[0180] Correct DAC output error by combining real-time calibration data.

[0181] Improve overall system accuracy by matching compensation tables.

[0182] 7. System Operation and Optimization

[0183] During system operation, this solution provides efficient data processing and optimization mechanisms to ensure long-term stable operation of the system.

[0184] SPI independent channel control: reduces data transmission conflicts and improves signal synchronization accuracy.

[0185] Low-noise power supply design: Reduce power supply noise and improve DAC stability through capacitor filtering.

[0186] High-precision temperature compensation: Reduces the impact of ambient temperature changes on control accuracy.

[0187] This invention employs a combination of hardware optimization and software algorithms to improve system stability and scalability while ensuring high precision. It can be widely applied in high-precision control fields such as high-precision nano-positioning, optical alignment, biological micro-manipulation, and semiconductor manufacturing.

[0188] Implementation Method 10: This implementation method provides a mechanical device, which is controlled by a piezoelectric controller provided in Implementation Method 9 for voltage or displacement control.

[0189] Implementation Method Eleven: Combination Figure 1-6 This embodiment describes the technical solution provided above in further detail through specific examples. Specifically:

[0190] This utility model provides the following technical solution:

[0191] An ultra-high resolution controller implemented with superimposed DACs, specifically comprising:

[0192] Controller housing 1, piezoelectric ceramic control board 2, bottom cover 3, studs 4, etc. Figure 1 and Figure 2 As shown

[0193] The ultra-high resolution controller circuit board 2 is located inside the controller housing 1.

[0194] The controller housing consists of a housing 1 and a bottom cover 3 that fit together to form an internal accommodating space.

[0195] The outer casing 1 has an opening on one side, providing a power supply interface and a power switch.

[0196] The outer casing 1 has an opening on the other side, providing a communication interface, an input signal interface, and an output signal interface.

[0197] The ultra-high resolution controller consists of a power supply unit 100, a drive unit 200, a sensing servo unit 300, and a main control unit 400. By improving the addition circuit and optimizing the algorithm, the resolution is increased to one millionth.

[0198] The output terminal of the power supply unit 100 is connected to the input terminal of the drive unit 200, the input terminal of the sensing servo unit 300, and the input terminal of the main control unit 400, respectively.

[0199] The input terminal of the drive unit 200 is connected to the output terminal of the power supply unit 100, the output terminal of the DA conversion circuit of the main control unit 400, and the output terminal of the sensing servo unit 300, respectively.

[0200] The output terminal of the drive unit 200 is connected to the input terminal of the piezoelectric ceramic 500;

[0201] The input terminal of the sensing servo unit 300 is connected to the output terminal of the power supply unit 100, the output terminal of the DA conversion circuit of the main control unit 400, and the output terminal of the SGS / Cap sensor 501 on the piezoelectric ceramic actuator 500, respectively.

[0202] The output terminal of the sensing servo unit 300 is connected to the input terminal of the AD conversion circuit of the main control unit 400 and the input terminal of the drive unit 200, respectively.

[0203] The main control unit 400 includes a communication circuit 401, a main controller 402, a DA conversion circuit 403, an AD conversion circuit 404, and an analog signal input unit 405, wherein 403 is composed of superimposed DACs 406;

[0204] The output terminals of the DA conversion circuit 403 and the analog signal input unit 405 are respectively connected to the input terminals of the sensing servo unit 300 and the driving unit 200.

[0205] The power supply unit 100 uses switching power supply technology, utilizing BUCK, BOOST, and LLC topologies to convert the external DC voltage into the operating voltage required by the drive unit 200, the sensing servo unit 300, and the main control unit 400.

[0206] In detail, the main control unit 400 uses a 32-bit microcontroller as the core controller 402. It utilizes a 16-bit DAC chip with an SPI bus, in conjunction with a high-precision operational amplifier circuit 403, to generate drive control signals. Circuit 403 is composed of superimposed DACs 406, which improves the resolution to one millionth. Simultaneously, a 16-bit SAR-type ADC chip with an SPI bus is used to construct an AD conversion circuit 404 to acquire displacement data of the piezoelectric ceramic and output voltage data of the drive unit. Furthermore, the microcontroller's own I / O ports implement input or output trigger functions, enabling interaction with external sensors. The microcontroller also integrates a full-speed USB 2.0 controller and a UART controller, and through a level conversion chip, it can communicate with external devices via RS232, RS422, and USB buses.

[0207] When the operating mode is closed-loop control, the SGS feedback signal of the SGS / Cap sensor 501 is processed by the signal conditioning and amplification circuit inside the sensing servo unit 300 and compared with the drive control signal. The error between the two is processed by PID closed-loop to generate the final drive control signal. The final drive control signal can be directly connected to the input of the drive unit 200 by controlling the analog switch through the main control unit 400. The drive control signal is amplified by two stages inside the drive unit 200 and the amplified result is output to the piezoelectric ceramic.

[0208] The power supply unit 100 uses switching power supply technology and utilizes BUCK, BOOST and LLC topologies to convert the DC voltage from the external power supply into the voltage required by the drive unit 200, the sensing servo unit 300 and the main control unit 400.

[0209] Specifically, the sensing servo unit 300 employs a PID control circuit based on analog circuitry to achieve precise and stable control of the piezoelectric ceramic. For example... Figure 4 As shown, this circuit performs proportional, integral, and derivative adjustments on the deviation between the drive control signal output by the DA converter circuit 403 and the SGS / Cap sensor 501. The adjusted output signal then serves as the final drive control signal, connected to the input of the drive unit 200, achieving precise closed-loop control of the piezoelectric ceramic. This control strategy is not only low-cost but also has a fast response speed.

[0210] Specific implementation of high and ultra-high resolution

[0211] Through precise error matching, the performance of each DAC unit 406 is highly consistent. The output of the DA conversion circuit 403 is composed of the superposition of DACs 406. By superimposing the DACs, the resolution is improved to one millionth. Subsequently, the drive control signal is amplified in two stages inside the drive unit 200 and then output to the piezoelectric ceramic for driving.

[0212] Meanwhile, by optimizing the circuit design, synchronization errors and signal interference were minimized, thereby improving the overall stability and reliability of the system. Furthermore, advanced calibration techniques were used to fine-tune the DAC units. Since slight differences inevitably exist in the output of each DAC, stemming from factors such as nonlinear errors during manufacturing and temperature variations, these minute errors tend to cancel each other out when multiple DAC outputs are combined, thus improving the overall output accuracy and further enhancing resolution.

[0213] Using capacitors to connect critical pins, such as power and ground, helps eliminate high-frequency noise and fluctuations caused by the power supply. This is because capacitors act as low-pass filters, helping to stabilize the DAC's power supply and thus reducing output errors.

[0214] Each DAC connects to the controller via an SPI interface, allowing independent control of each DAC's output. Using independent SPI channels reduces communication conflicts and latency, improving the reliability of signal transmission.

[0215] Operational amplifiers (op-amps) are used for signal amplification and buffering. By setting feedback loops and gain configurations, the amplification factor of a signal can be adjusted while maintaining signal stability and low noise. Each op-amp processes signals from two different DACs. By precisely amplifying and adjusting these signals, the op-amps improve the dynamic range of the signal and adjust the output level to better suit the needs of subsequent circuitry.

[0216] To achieve an ultra-high resolution of one-millionth of a resolution with two DACs, a sophisticated adder circuit was designed. Combined with appropriate calibration and control algorithms, the outputs of the two DACs are superimposed, and a finely tuned adder circuit is used to sum their outputs to obtain even higher resolution. Their outputs are superimposed using operational amplifiers, and a suitable resistor network ensures that the output voltage of each DAC contributes a different number of significant bits. DAC1 provides the primary output voltage, and DAC2 provides the secondary output voltage through a voltage divider network. The total output voltage is a weighted sum of the output voltages of the two DACs.

[0217] The software algorithms mainly include: a DAC output calculation module, a real-time calibration and error compensation module, a DAC setting module, and an output voltage measurement and error calculation module.

[0218] DAC Output Calculation Module: The main task of this module is to calculate the output values ​​of the two DACs to achieve the target voltage. Since DAC1 is used for coarse tuning and DAC2 for fine tuning, the ideal output values ​​of both DACs need to be calculated. DAC1 provides the main voltage output, while DAC2 performs fine-tuning through a scaling factor, providing more precise voltage control.

[0219] Real-time calibration and error compensation module: Used for real-time calibration of the DAC output and error compensation. It reads the actual output voltage and adjusts the DAC's input value according to the error. The DAC's input value is adjusted using pre-measured calibration data to compensate for the DAC's nonlinearity error and other systematic errors. The calibration data can be obtained by measuring the actual output voltage at a known input voltage during manufacturing or calibration.

[0220] The combination of hardware design and software algorithms, especially through superimposed DAC output and error calibration compensation, achieves an ultra-high resolution of up to one part per million. The minimum change in total output voltage can reach the nanovolt level, making it extremely sensitive to minute voltage changes and able to capture very small voltage fluctuations and details. This high-resolution output is suitable for precision measurement and control fields, such as high-precision power supplies, precision instruments, and testing equipment.

[0221] Through meticulous error matching, high performance consistency is ensured for each DAC unit, which is fundamental to achieving the ideal superposition effect. Simultaneously, optimized circuit design minimizes synchronization errors and signal interference, thereby improving the overall stability and reliability of the system. Furthermore, advanced calibration techniques are employed to fine-tune the DAC units, further enhancing output accuracy.

[0222] In signal processing, sophisticated algorithms were employed to precisely process signals from the two DACs, ensuring the linearity and continuity of the output signals, which is crucial for achieving ultra-high resolution. These processing algorithms not only optimize the performance of individual DACs but also achieve results exceeding the performance of a single device by intelligently combining the outputs of the two DACs. The combined application of these technologies and measures enabled the final controller to achieve a precision of one part in a million during full-stroke operation.

[0223] The beneficial effects of this utility model are as follows:

[0224] By superimposing DACs, the overall output noise level can be reduced by averaging the random errors of individual DACs. This is important in signal processing because lower noise means more accurate data reading and processing.

[0225] By reducing the errors and noise interference introduced by a single DAC, and achieving ultra-high resolution control of the superimposed DAC (one-millionth of a resolution) based on algorithms and adding circuits, and by using operational amplifiers to provide signal amplification, filtering, and other processing functions, the controller achieves high-resolution output control.

[0226] The above description of the technical solution provided by this utility model through several specific embodiments is intended to highlight the advantages and benefits of the technical solution provided by this utility model. However, the above-described specific embodiments are not intended to limit this utility model. Any reasonable modifications and improvements to this utility model, combinations of embodiments, and equivalent substitutions based on the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An ultrahigh resolution piezoelectric controller circuit board, characterized by, It comprises: a power supply unit for receiving external DC power supply and providing stable multi-level power output for the circuit board; a main control unit comprising: a main controller using a 32-bit single-chip microcomputer, responsible for overall signal processing and data control; a DA conversion circuit, which improves the signal resolution to one part in a million through an addition circuit and an error compensation algorithm; an AD conversion circuit for receiving signals from the sensing servo unit and performing analog-to-digital conversion; an analog signal input unit for receiving external input signals and transmitting them to the main controller for processing; a drive unit for amplifying the control signals output by the main control unit and connecting and driving the piezoelectric ceramic actuator; a sensing servo unit comprising: a signal conditioning circuit for receiving and amplifying the feedback signals of the SGS / Cap sensor; a PID closed-loop control circuit for error correction of the sensor feedback data and transmission to the main control unit.

2. An ultrahigh resolution piezoelectric controller circuit board according to claim 1, wherein, The power supply source converts the required operating voltage through a BUCK conversion circuit, a BOOST conversion circuit, and an LLC series resonance circuit to provide stable multi-level power output for the circuit board.

3. An ultrahigh resolution piezoelectric controller circuit board according to claim 1, wherein, It also includes a data communication interface, including RS232, RS422, and USB interfaces, for data interaction with external devices.

4. The ultrahigh-resolution piezoelectric controller circuit board of claim 1, wherein, The drive unit amplifies the control signals output by the main control unit through a two-stage amplification circuit and connects and drives the piezoelectric ceramic actuator through a piezoelectric drive interface.

5. The ultrahigh-resolution piezoelectric controller circuit board of claim 1, wherein, The DA conversion circuit includes multiple DACs stacked.

6. An ultrahigh resolution piezoelectric controller circuit board according to claim 1, wherein, The main controller controls the DA conversion circuit through an SPI bus and combines error calibration algorithms to perform real-time compensation on DAC output.

7. An ultrahigh resolution piezoelectric controller circuit board according to claim 1, wherein, The AD conversion circuit uses a SAR-type 16-bit ADC for high-precision collection of piezoelectric ceramic actuator displacement data and feedback to the main control unit for closed-loop control.

8. An ultrahigh resolution piezoelectric controller circuit board according to claim 1, wherein, The drive unit uses a two-stage high-voltage amplification circuit, with the first-stage amplification circuit for linear amplification of control signals and the second-stage amplification circuit for boosting the signal to the required drive voltage range of the piezoelectric ceramic actuator.

9. An ultrahigh resolution piezoelectric controller characterized by, It comprises: a controller housing for accommodating and protecting internal circuit components; the controller circuit board of claim 1 is arranged inside the controller housing; a bottom cover connected to the controller housing to package the controller circuit board; a fixed support for mounting the controller housing and stabilizing the internal components.

10. Mechanical device, characterized in that The device is controlled by the piezoelectric controller of claim 9 for voltage or displacement control.

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