Radio telescope main reflecting surface actuator control device of optical fiber interface

Abstract

The invention discloses a radio telescope main reflecting surface actuator control device of an optical fiber interface. The control and optical communication board card is communicated with the motor driving board card through a CAN (Controller Area Network) bus; the control and optical communication board card is provided with an optical fiber communication module which is responsible for analyzing an optical fiber communication protocol; the control and optical communication board card is further used for controlling the electromagnetic valve so as to control interconnection of hydraulic media between the permanent magnet synchronous motor pump and the hydraulic cylinder. The motor driving board card is responsible for driving the permanent magnet synchronous servo motor pump; the control and optical communication board card is further used for collecting feedback signals of the magnetostriction displacement sensor, the control and optical communication board card compares the motion instruction with the collected feedback signals of the magnetostriction displacement sensor, and the rotating speed needing to be achieved by the permanent magnet synchronous servo motor pump is obtained after internal operation. And the rotating speed instruction is sent to a motor driving module through a CAN bus, and the motor driving module drives a permanent magnet synchronous servo motor pump to rotate forwards and backwards according to the instruction, so that a hydraulic cylinder extends out or compresses.

Description

Technical Field

[0001] The invention relates to the technical field of radio telescopes, in particular to a radio telescope main reflection surface actuator control device with an optical fiber interface. Background Art

[0002] A radio telescope is a device for collecting and detecting radio signals. The aperture and surface accuracy of its main reflector directly affect the observation effect. The Five-hundred-meter Aperture Spherical Radio Telescope, referred to as FAST, is the largest single-aperture radio telescope in the world today. FAST is mainly composed of an active reflector system, a feed support system, a receiver and a terminal system. The active reflector system consists of a ground anchor, a ring beam, a cable net, a pull-down cable, an actuator and a main reflector. Actuators are deformation driving devices for the main reflector of the telescope. There are a total of 2,225 actuators distributed below the main reflector. The actuator drives the main reflector to rotate through contraction, thereby completing the overall deformation of the main reflector.

[0003] The actuator currently used by the FAST telescope uses an industrial general-purpose frequency converter as a control device, and requires an external fiber optic module to communicate with the main reflector control system. Due to the non-customized design, it has the disadvantages of large size and poor reliability. The actuator communicates with the control system through optical fiber Profibus. Optical fiber Profibus is generally implemented using Profibus dedicated ASIC chips in conjunction with OLM (optical link module). This method requires writing complex software to interact with dedicated ASIC chips. The networking method can only be linear topology, star topology and ring topology, and cannot implement bus topology like the electrical signal Profibus network.

[0004] In addition, the electromechanical actuator composed of a motor and a harmonic reducer in the prior art has the disadvantages of low precision and resonance risk of the stepper motor. If damage occurs, the control device needs to be replaced as a whole, and the maintenance cost is high. The communication part is implemented using a complex Profibus ASIC chip, and the software interface is complex. The existing actuator also uses a high-voltage AC servo motor plus a plunger pump solution, but its motor driver directly uses an industrial frequency converter, which is not conducive to miniaturization of the control device. Summary of the invention

[0005] The invention provides a radio telescope main reflection surface actuator control device with an optical fiber interface, aiming to overcome the problems of large volume and low reliability caused by the use of a general industrial frequency converter and a stepping motor pump in the existing actuator.

[0006] In a first aspect, a radio telescope main reflector actuator control device with an optical fiber interface is provided, comprising: a motor drive board, a control and optical communication board, a permanent magnet synchronous servo motor pump, a solenoid valve, and a magnetostrictive displacement sensor;

[0007] The control and optical communication board and the motor drive board use the CAN bus for communication; the control and optical communication board is designed with a fiber optic communication module, which is responsible for parsing the fiber optic communication protocol; the control and optical communication board is also used to control the solenoid valve to control the hydraulic medium interconnection between the permanent magnet synchronous motor pump and the hydraulic cylinder; the motor drive board is responsible for driving the permanent magnet synchronous servo motor pump; the control and optical communication board is also used to collect the feedback signal of the magnetostrictive displacement sensor. The control and optical communication board compares the motion instruction with the collected feedback signal of the magnetostrictive sensor, and after internal calculation, the speed that the permanent magnet synchronous servo motor pump needs to reach is obtained, and the speed instruction is sent to the motor drive module through the internal CAN bus. The motor drive module drives the permanent magnet synchronous servo motor pump to perform forward and reverse motion according to the instruction to further drive the hydraulic cylinder to extend or compress.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the control and optical communication board includes a DSP chip, a single-fiber bidirectional optical module and a Profibus-to-serial port chip; the DSP chip serves as a control core, receives optical signals from the main reflector control system through the single-fiber bidirectional optical module, and the Profibus-to-serial port chip converts optical signals between the single-fiber bidirectional optical module and the DSP chip, thereby realizing Profibus communication between the DSP chip and the actuator reflector control system.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the control and optical communication board also includes an optical signal receiving inverter; the input end of the optical signal receiving inverter is connected to the receiving end of the single-fiber bidirectional optical module, and the output end of the optical signal receiving inverter is connected to the receiving data signal RX end of the Profibus to serial port chip; the optical signal receiving inverter is used to convert the high level output by the optical module into a valid data low level recognized by the serial port.

[0010] In combination with the first aspect, in certain implementations of the first aspect, the control and optical communication board also includes an inverter and an AND gate; the inverter and the AND gate are arranged in a transmission path between the single-fiber bidirectional optical module and the Profibus-to-serial port chip; the transmit data signal TX end of the Profibus-to-serial port chip is connected to the input end of the inverter; the two input ends of the AND gate are respectively connected to the transmit enable DE end of the Profibus-to-serial port chip and the output end of the inverter; the output end of the AND gate is connected to the transmit end of the single-fiber bidirectional optical module.

[0011] In combination with the first aspect, in certain implementations of the first aspect, when no data is sent, the sending enable DE terminal signal is at a low level; at this time, regardless of whether the signal output by the sending data signal TX terminal is at a high level or a low level, the output of the AND gate is at a low level, and the single-fiber bidirectional optical module does not send an optical signal to the optical fiber path under the condition of a low level input, and does not occupy the optical path. At this time, other control devices in the optical path use the optical fiber network to communicate normally.

[0012] In combination with the first aspect, in certain implementations of the first aspect, when the DE end signal is at a high level, the high and low changes of the sending data signal TX end of the Profibus to serial port chip are inverted by the inverter and transmitted to the single-fiber bidirectional optical module to complete normal optical fiber data transmission.

[0013] In combination with the first aspect, in certain implementations of the first aspect, the control and optical communication board also includes a 422 chip and a CAN chip; the DSP chip receives the displacement signal of the actuator magnetostrictive sensor through the 422 chip; after the DSP chip performs a position closed-loop operation in combination with the comprehensive optical fiber instructions and the collected signals, it sends the motor speed instruction to the motor drive module through the CAN chip to drive the motor to move, thereby completing the position closed-loop control of the actuator.

[0014] In combination with the first aspect, in certain implementations of the first aspect, the control and optical communication board also includes a solenoid valve drive module and a current sensor; the DSP chip completes the switch control of the solenoid valve through the solenoid valve drive module under the action of the optical fiber instruction; the DSP chip collects the coil current of the solenoid valve through the current sensor to complete the diagnostic function of the solenoid valve.

[0015] In combination with the first aspect, in certain implementations of the first aspect, the control and optical communication board also includes a DC / DC power supply and an LDO chip; the DC / DC power supply and the LDO chip are used to provide main control power supply for various devices inside the control and optical communication board.

[0016] In a second aspect, a radio telescope is provided, comprising a radio telescope main reflecting surface actuator control device with an optical fiber interface as described in any one of the implementations of the first aspect.

[0017] Compared with the prior art, the solution provided by the present invention includes at least the following beneficial technical effects:

[0018] The present invention adopts a single-fiber bidirectional optical module and cooperates with a gate circuit to form a simple optical fiber Profibus network topology communication circuit. The circuit is simple and has strong secondary development capabilities. The present invention adopts a modular design and is divided into a control module and a drive module. Both are customized and developed to adapt to the actuator. The structure is compact. The control module and the drive module are installed in a plug-in manner, which is easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the principle block diagram of the actuator control device.

[0020] Figure 2 This is the structural diagram of the actuator control device.

[0021] Figure 3 This is the principle block diagram of the control module. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The FAST radio telescope includes a main reflector control system and 2225 actuators. The main reflector control system is connected to the 2225 actuators in a bus mode through an optical fiber path, and the optical fiber Profibus protocol is used to control the motion trajectory of each actuator. The present invention provides an actuator control device, whose main function is to control the hydraulic cylinder of the actuator to complete the telescopic movement according to the instructions in the optical fiber bus. The overall framework is shown in FIG. Figure 1 .

[0024] The actuator control device includes a filter plus power factor correction module (EMI+PFC), an ACDC power supply module, a motor drive board, a control and optical communication board, a permanent magnet synchronous servo motor pump, a solenoid valve, a pressure temperature sensor, and a magnetostrictive displacement sensor. The appearance of the above control device is as follows Figure 2 As shown, 1 is the ACDC power module; 2 is the permanent magnet synchronous servo motor pump; 3 is the solenoid valve assembly; 4 is the motor drive board; 5 is the control and optical communication board; 6 is the motherboard, which is responsible for connecting the power module, motor drive board, control and optical communication board.

[0025] The ACDC power supply is responsible for converting 220V AC power supply into 24V DC voltage for use by internal modules. The control and optical communication board is designed with a fiber optic communication module, which is responsible for parsing the fiber optic communication protocol. The control and optical communication board is also used to collect feedback signals from magnetostrictive displacement sensors, collect feedback signals from pressure and temperature sensors, and control solenoid valves. The motor drive board is responsible for driving the permanent magnet synchronous servo motor pump to perform forward and reverse motion. The control and optical communication board and the motor drive board are connected through an interconnect motherboard, and the two use the CAN bus for communication.

[0026] After the control and optical communication board receives the motion command sent by the main reflector control system through the optical fiber bus, it controls the solenoid valve to open through the valve drive signal to interconnect the hydraulic medium between the permanent magnet synchronous motor pump and the hydraulic cylinder. The control and optical communication board compares the motion command with the feedback signal of the collected magnetostrictive sensor, and after internal calculation, it obtains the speed that the permanent magnet synchronous servo motor pump needs to reach, and sends the speed command to the motor drive module through the internal CAN bus. The motor drive module drives the permanent magnet synchronous servo motor pump to rotate according to the command. Then the permanent magnet synchronous servo motor pump is driven to rotate forward or reverse to further drive the hydraulic cylinder to extend or compress.

[0027] The principle of control and optical communication board is as follows Figure 3 As shown. The control and optical communication board may include a DSP chip U3, a single-fiber bidirectional optical module U6, and a Profibus to serial port chip U8. The DSP chip U3 serves as the control core, and receives optical signals from the main reflector control system through the single-fiber bidirectional optical module U6. The Profibus to serial port chip U8 can convert optical signals between the single-fiber bidirectional optical module U6 and the DSP chip U3, thereby realizing the Profibus communication between the DSP chip U3 and the actuator reflector control system. The control and optical communication board may also include a DC / DC power supply U1 and an LDO chip U2. The DC / DC power supply U1 and the LDO chip U2 are used to provide main control power supply for various devices inside the control and optical communication board.

[0028] Since the optical signal in the optical fiber represents a high level and the rest of the time is a low level, and the traditional serial port protocol is a high level during idle time, in order to realize optical fiber networking, a dedicated circuit needs to be designed to convert the level. Figure 3 As shown, the control and optical communication board can also include an optical signal receiving inverter U4. The optical signal receiving inverter U4 is arranged in the receiving path between the single-fiber bidirectional optical module U6 and the Profibus to serial port chip U8. That is to say, the input end of the optical signal receiving inverter U4 is connected to the receiving end of the single-fiber bidirectional optical module U6, and the output end of the optical signal receiving inverter U4 is connected to the receiving data signal RX end of the Profibus to serial port chip U8. The optical signal receiving inverter U4 is used to convert the high level output by the optical module into a valid data low level recognized by the serial port.

[0029] In order to ensure that the optical module is in a non-luminous state when no data is sent and does not occupy the optical fiber path, Figure 3As shown, the control and optical communication board can also include an inverter U5 and an AND gate U14. The inverter U5 and the AND gate U14 are arranged in the transmission path between the single-fiber bidirectional optical module U6 and the Profibus to serial port chip U8. The transmission data signal TX end of the Profibus to serial port chip U8 is connected to the input end of the inverter U5. The two input ends of the AND gate U14 are respectively connected to the transmission enable DE end of the Profibus to serial port chip U8 and the output end of the inverter U5. The output end of the AND gate U14 is connected to the transmission end of the single-fiber bidirectional optical module U6.

[0030] When there is no data to be sent, the signal at the transmission enable DE end is at a low level. At this time, regardless of whether the signal outputted from the transmission data signal TX end is at a high level or a low level, the output of the AND gate U14 is at a low level. When the single-fiber bidirectional optical module U6 is at a low level input, it does not send an optical signal to the optical fiber path and does not occupy the optical path. At this time, other control devices in the optical path can use the optical fiber network communication normally.

[0031] When the DE terminal signal is at a high level, the high and low changes of the sending data signal TX terminal of the Profibus to serial port chip U8 can be inverted by the inverter U5 and then transmitted to the single-fiber bidirectional optical module U6 to complete normal optical fiber data transmission.

[0032] The control and optical communication board can also include a 422 chip U11 and a CAN chip U12. The DSP chip U3 receives the displacement signal of the actuator magnetostrictive sensor through the 422 chip U11. Combining the integrated optical fiber instructions and the collected signals, the DSP chip performs a position closed-loop operation and sends the motor speed instruction to the motor drive module through the CAN chip U12 to drive the motor to move, thereby completing the position closed-loop control of the actuator.

[0033] In order to realize the manual control function of the actuator, the control and optical communication board can also include a solenoid valve drive module U10 and a current sensor U13. The DSP chip can complete the switch control of the solenoid valve through the solenoid valve drive module U10 under the action of the optical fiber instruction. The DSP chip can collect the coil current of the solenoid valve through the current sensor U13 to complete the diagnosis function of the solenoid valve.

[0034] In summary, the present invention adopts a single-fiber bidirectional optical module and a Profibus to serial port chip combination design, designs a dedicated circuit, cancels the OLM, realizes the optical fiber Profibus network topology communication, and the communication circuit is simple and easy to carry out secondary development. In the scheme provided by the present invention, the electrical part is a dedicated circuit and adopts a modular design. It is divided into a power supply module, a control and optical communication board, and a motor drive board. The structure is compact, and each functional module is easy to disassemble and assemble, which can realize the miniaturization of the actuator control device. When a fault occurs, only the faulty board needs to be replaced separately, and the maintenance cost is low.

[0035] Although the present invention is disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims of the present invention.

Claims

1. A radio telescope main reflector actuator control device with an optical fiber interface, characterized in that: include: Motor drive board, control and optical communication board, permanent magnet synchronous servo motor pump, solenoid valve, magnetostrictive displacement sensor; The control and optical communication board and the motor drive board use the CAN bus for communication; the control and optical communication board is designed with a fiber optic communication module, which is responsible for parsing the fiber optic communication protocol; the control and optical communication board is also used to control the solenoid valve to control the hydraulic medium interconnection between the permanent magnet synchronous motor pump and the hydraulic cylinder; the motor drive board is responsible for driving the permanent magnet synchronous servo motor pump; the control and optical communication board is also used to collect the feedback signal of the magnetostrictive displacement sensor. The control and optical communication board compares the motion instruction with the collected feedback signal of the magnetostrictive sensor, and after internal calculation, the speed that the permanent magnet synchronous servo motor pump needs to reach is obtained, and the speed instruction is sent to the motor drive module through the internal CAN bus. The motor drive module drives the permanent magnet synchronous servo motor pump to perform forward and reverse motion according to the instruction to further drive the hydraulic cylinder to extend or compress.

2. The device according to claim 1, characterized in that The control and optical communication board includes a DSP chip, a single-fiber bidirectional optical module and a Profibus-to-serial port chip; the DSP chip serves as the control core and receives optical signals from the main reflector control system through the single-fiber bidirectional optical module, and the Profibus-to-serial port chip converts optical signals between the single-fiber bidirectional optical module and the DSP chip, thereby realizing Profibus communication between the DSP chip and the actuator reflector control system.

3. The device according to claim 2, characterized in that The control and optical communication board also includes an optical signal receiving inverter; the input end of the optical signal receiving inverter is connected to the receiving end of the single-fiber bidirectional optical module, and the output end of the optical signal receiving inverter is connected to the receiving data signal RX end of the Profibus to serial port chip; the optical signal receiving inverter is used to convert the high level output by the optical module into a valid data low level recognized by the serial port.

4. The device according to claim 2, characterized in that The control and optical communication board also includes an inverter and an AND gate; the inverter and the AND gate are arranged in a transmission path between the single-fiber bidirectional optical module and the Profibus to serial port chip; the transmission data signal TX end of the Profibus to serial port chip is connected to the input end of the inverter; the two input ends of the AND gate are respectively connected to the transmission enable DE end of the Profibus to serial port chip and the output end of the inverter; the output end of the AND gate is connected to the transmission end of the single-fiber bidirectional optical module.

5. The device according to claim 4, characterized in that When there is no data to be sent, the signal at the DE end is at a low level; at this time, no matter whether the signal outputted by the TX end of the data signal is at a high level or a low level, the output of the AND gate is at a low level. When the single-fiber bidirectional optical module is at a low level input, it does not send optical signals to the optical fiber path and does not occupy the optical path. At this time, other control devices in the optical path use the optical fiber network for communication normally.

6. The device according to claim 4, characterized in that When the DE end signal is at a high level, the high and low changes of the TX end of the Profibus-to-serial port chip's sending data signal are inverted by the inverter and then transmitted to the single-fiber bidirectional optical module to complete normal optical fiber data transmission.

7. The device according to claim 2, characterized in that The control and optical communication board also includes a 422 chip and a CAN chip; the DSP chip receives the displacement signal of the actuator magnetostrictive sensor through the 422 chip; after combining the integrated optical fiber instructions and the collected signals, the DSP chip performs a position closed-loop operation, and then sends the motor speed instruction to the motor drive module through the CAN chip to drive the motor to move, thereby completing the position closed-loop control of the actuator.

8. The device according to claim 2, characterized in that The control and optical communication board also includes a solenoid valve drive module and a current sensor; the DSP chip completes the switch control of the solenoid valve through the solenoid valve drive module under the action of the optical fiber instruction; the DSP chip collects the coil current of the solenoid valve through the current sensor to complete the diagnosis function of the solenoid valve.

9. The device according to claim 2, characterized in that The control and optical communication board also includes a DC / DC power supply and an LDO chip; the DC / DC power supply and the LDO chip are used to provide main control power supply for various devices inside the control and optical communication board.

10. A radio telescope, characterized in that: The radio telescope comprises a radio telescope main reflecting surface actuator control device of the optical fiber interface according to any one of claims 1 to 9.

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