A rotation locking control system for three inertial groups

Abstract

The present invention relates to the technical field of three-inertial group, and in particular to a rotation locking control system of a three-inertial group, comprising two brushless motor drive chips, two brushed motor drive chips, an outer frame rotary encoder, an inner frame rotary encoder and a processor; the two brushless motor drive chips and the two brushed motor drive chips are connected to the processor, and Hall sensors are connected between the two brushless motor drive chips and the rotating motors and between the two brushed motor drive chips and the locking motors, and all Hall sensors are connected to the processor; the roughing and finishing output channels of the outer frame rotary encoder and the inner frame rotary encoder are connected to the processor. The control system can realize the three-loop closed-loop control of the current loop, position loop and speed loop of the rotating motor and the locking motor, with high control accuracy; at the same time, the unlocking and locking states of the inner platform are judged by the travel switch and the infrared switch, thereby improving safety and stability.

Description

Technical Field

[0001] The invention relates to the technical field of a three-inertia group, and in particular to a rotation locking control system of a three-inertia group. Background Art

[0002] The strapdown inertial group obtains the position information of the aircraft or spacecraft by installing gyroscopes and accelerometers inside it. Among them, the gyroscope is used to sense angular acceleration information, and the accelerometer is used to sense linear acceleration information. However, due to their inherent characteristics, parameters such as zero position of inertial sensitive devices such as gyroscopes and accelerometers will drift over time, resulting in a decrease in measurement accuracy. This requires the strapdown inertial group to be removed from the aircraft or spacecraft at regular intervals and placed on a three-axis turntable for recalibration, which is inconvenient to operate.

[0003] In recent years, China has developed a three-auto strapdown inertial group with the functions of self-calibration, self-detection, and self-alignment. Among them, the self-calibration function can realize the self-rotation calibration of the inertial group inside the aircraft or spacecraft, without the need to disassemble the inertial group, which brings great convenience in practical applications. The self-calibration function mainly relies on the rotation locking system in the three-auto inertial group. The gyroscope and accelerometer are installed on the inner table. During self-calibration, the inner table is first unlocked, and then 360 degrees of free rotation is achieved under the rotation of the inner frame rotation motor and the outer frame rotation motor, thereby realizing the calibration of parameters at each position. After the self-calibration is completed, the inner table is locked and fixed by two locking motors. During the rotation locking process of the inner table, the motor control accuracy of the rotating motor and the locking motor is crucial to the unlocking and locking state of the inner table. Therefore, it is particularly important to provide a high-precision and low-cost three-auto inertial group rotation locking control system. Summary of the invention

[0004] The present invention provides a rotation locking control system of a three-inertia group, which realizes closed-loop control of the current loop, position loop and speed loop of a rotating motor and a locking motor, and has high control accuracy; at the same time, the unlocking and locking states of the inner platform are judged by a travel switch and an infrared switch, thereby improving the safety and stability of unlocking and locking.

[0005] The technical solution adopted by the present invention to solve the technical problem is:

[0006] A rotation locking control system of a three-inertial group, the three-inertial group comprises at least two rotating motors, two locking motors, an inner frame, an outer frame and an inner platform, the rotation locking control system of the three-inertial group comprises two brushless motor drive chips, two brushed motor drive chips, an outer frame rotary encoder, an inner frame rotary encoder and a processor;

[0007] The two brushless motor driver chips are respectively connected to the two rotating motors and drive the two rotating motors to work respectively, so as to realize the rotation of the inner frame and the outer frame; the two brushed motor driver chips are respectively connected to the two locking motors and drive the two locking motors to work respectively, so as to realize the unlocking and locking of the inner platform; the two brushless motor driver chips and the two brushed motor driver chips are all connected to the processor, and Hall sensors are connected between the two brushless motor driver chips and the rotating motors and between the two brushed motor driver chips and the locking motors, and all Hall sensors are connected to the processor to realize the current loop closed-loop control;

[0008] The outer frame rotary encoder is connected to the outer frame and rotates with the outer frame; the inner frame rotary encoder is connected to the inner frame and rotates with the inner frame; the outer frame rotary encoder and the inner frame rotary encoder are both provided with two output channels of rough machining and fine machining, and the two output channels of rough machining and fine machining of the outer frame rotary encoder and the inner frame rotary encoder are both connected to the processor, the processor sends excitation signals to the outer frame rotary encoder and the inner frame rotary encoder respectively, and collects the sine / cosine signals of the two output channels of rough machining and fine machining respectively, obtains the position information and speed information of the outer frame and the inner frame, and realizes closed-loop control of the position loop and the speed loop.

[0009] A travel switch is installed between the two locking motors and the inner platform body. When the inner platform body is locked in place, the travel switch is turned on. The travel switch is connected to the processor and the switch signal of the travel switch is input to the processor for level judgment after RC filtering, thereby judging the locking status of the inner platform body.

[0010] Both locking motors are equipped with infrared switches, which include an infrared transmitter and an infrared receiver. The infrared transmitter and the infrared receiver are respectively installed at the two ends of the locking motor. A through hole is preset on the locking motor. Every time the locking motor rotates one circle, the signal from the infrared transmitter is transmitted to the infrared receiver through the through hole, and the infrared receiver outputs a pulse signal. The infrared receiver is connected to the processor, and the processor collects the number of pulses output by the infrared receiver. The number of pulses is the number of circles the locking motor rotates, thereby detecting the number of circles the locking motor rotates when locked or unlocked, and judging whether the inner platform is locked in place based on whether the number of circles the locking motor rotates when locked is consistent with the number of circles the locking motor rotates when unlocked.

[0011] The rotation locking control system of the three-auto inertial group further includes an inertial group computer, which is in communication connection with the processor, and the inertial group computer sends control instructions to the processor and receives control state information.

[0012] The inertial computer and the processor communicate via an RS422 serial communication bus, and the interface of the RS422 serial communication bus is electrically isolated via a magnetic coupling isolator.

[0013] The rotation locking control system of the three-inertial group adopts a power supply of 18V to 36V, which is converted into different power supply voltages by a DC / DC converter and respectively used to power various components in the rotation locking control system of the three-inertial group.

[0014] The processor is provided with an A / D converter, and the Hall sensors are connected to the A / D converter on the processor through an RC filtering circuit. The detection signal of the Hall sensor is converted into a digital quantity by the A / D converter on the processor after RC filtering.

[0015] The communication interface between the processor and the two brushless motor drive chips and the two brushed motor drive chips is a PWM interface, and the PWM interface is electrically isolated by a magnetic coupling isolator.

[0016] The processor is connected and communicated with the outer frame rotary encoder and the inner frame rotary encoder through an R / D converter.

[0017] A filter conditioning circuit for filtering and conditioning the sine / cosine signal and an amplification conditioning circuit for amplifying and conditioning the excitation signal are connected between the outer frame rotary encoder and the inner frame rotary encoder and the R / D converter.

[0018] Compared with the prior art, the rotation locking control system of the three-inertial group provided by the present invention has the following advantages: (1) The rotation locking control system of the three-inertial group provided by the present invention realizes closed-loop control of the current loop, position loop, and speed loop of the rotating motor and the locking motor through the arrangement of a brushless motor driver chip, a brush motor driver chip, a Hall sensor, an outer frame rotary encoder, and an inner frame rotary encoder, thereby reducing the influence of the motor control error on the navigation accuracy of the three-inertial group and achieving high control accuracy.

[0019] (2) In the present invention, the unlocking and locking states of the inner platform are judged by the travel switch and the infrared switch, thereby improving the safety and stability of unlocking and locking.

[0020] (3) The present invention combines the use environment of the three-inertial navigation system with electrical isolation of the interfaces between the inertial navigation system computer and the processor, and between the processor and the brushless motor driver chip and the brushed motor driver chip, to prevent interference with analog signals in the system and the inertial sensitive devices of the three-inertial navigation system, thereby improving the motor control accuracy and not causing electromagnetic interference to the navigation accuracy of the inertial navigation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The principle block diagram of the rotation locking control system of the three-inertia group provided by the present invention;

[0022] Figure 2 This is a principle block diagram of the power supply of the rotation locking control system of the three-inertia group provided by the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] The three-inertia group in the present invention includes at least two rotating motors, two locking motors, an inner frame, an outer frame and an inner platform. The two rotating motors drive the inner frame and the outer frame to rotate, and the two locking motors unlock or lock the inner platform. The structure of the three-inertia group is an existing conventional structure and will not be repeated here.

[0025] The three-auto inertial group rotation locking control system provided by the present invention includes two brushless motor drive chips, two brush motor drive chips, an outer frame rotary encoder, an inner frame rotary encoder, a travel switch, an infrared switch, a processor and an inertial group computer, such as Figure 1 shown.

[0026] In this embodiment, the processor is a digital signal processor (DSP) or a microcontroller (MCU) with a PWM output interface, such as the domestically produced 32-bit digital signal processor AVP32F335BA176S. The processor has a maximum main frequency of 150MHz, a power consumption of no more than 400mW, 18 pulse width modulation (PWM) outputs, 6 event capture inputs, and a 16-channel 12-bit analog-to-digital (A / D) converter, and can communicate with peripherals through a 16-bit or 32-bit external bus (XINTF) and 3 asynchronous serial communication buses (UART).

[0027] In this embodiment, the two brushless motor driver chips are respectively connected to the two rotating motors and drive the two rotating motors to work respectively. Specifically, the two brushless motor driver chips are existing domestic brushless motor driver chips, which integrate 6 MOS tubes, with a maximum continuous drive current of 3A, output three-phase drive signals, drive the two rotating motors, and realize the rotation of the inner frame and the outer frame. The two brushed motor driver chips are respectively connected to the two locking motors and drive the two locking motors to work respectively. Specifically, the two brushed motor driver chips are existing domestic brushed motor driver chips, which integrate H-bridge drive MOS tubes, with a maximum continuous drive current of 4A, output two-phase drive signals, drive the two locking motors, and realize the unlocking and locking of the inner platform. The two brushless motor driver chips and the two brushed motor driver chips are connected to the processor; Hall sensors are connected between the two brushless motor driver chips and the rotating motor, and between the two brushed motor driver chips and the locking motor. Since the brushless motor driver chips are three-phase driven, there are four Hall sensors on the two brushless motor driver chips, and two Hall sensors on the two brushed motor driver chips. The six Hall sensors are connected to the processor; the processor sends motor drive signals to the two brushless motor driver chips and the two brushed motor driver chips respectively, and the two brushless motor driver chips and the two brushed motor driver chips drive the rotating motor and the locking motor to work according to the motor drive signals. At the same time, the processor receives the motor drive current measured by the Hall sensor (including the drive current of the rotating motor and the drive current of the locking motor) to realize the current loop closed-loop control. Specifically, an A / D converter is provided on the processor, and the Hall sensors are connected to the A / D converter on the processor through an RC filter circuit. The detection signal of the Hall sensor is converted into a digital quantity by the A / D converter on the processor after RC filtering. Since the motor drive signal output by the processor in the rotation locking control system is a high-current frequency signal, it is a very large source of electromagnetic interference. In order to prevent the electromagnetic interference from being transmitted to other devices, especially the precision inertial devices in the inertial group, it is necessary to electrically isolate the communication interface between the processor and the two brushless motor driver chips and the two brushed motor driver chips. Specifically, the communication interface between the processor and the two brushless motor driver chips and the two brushed motor driver chips is electrically isolated by a magnetic coupling isolator. Furthermore, the communication interface between the processor and the two brushless motor driver chips and the two brushed motor driver chips is a PWM interface.

[0028] In this embodiment, the outer frame rotary encoder is connected to the outer frame and rotates with the outer frame; the inner frame rotary encoder is connected to the inner frame and rotates with the inner frame, and both the outer frame rotary encoder and the inner frame rotary encoder are provided with two output channels of roughing and finishing, and the two output channels of roughing and finishing of the outer frame rotary encoder and the inner frame rotary encoder are connected and communicated with the processor through a rotary digital converter (R / D converter), and the processor sends excitation signals to the outer frame rotary encoder and the inner frame rotary encoder respectively through the R / D converter, and respectively collects the sine / cosine signals of the two output channels of roughing and finishing (i.e., the inner frame roughing output channel, the inner frame finishing output channel, the outer frame roughing output channel, and the outer frame finishing output channel), and the R / D converter decodes the sine / cosine signals, obtains the position information and speed information of the outer frame and the inner frame, and realizes the closed-loop control of the position loop and the speed loop. Specifically, all R / D converters are connected to the processor through a parallel bus. Preferably, a filter conditioning circuit for filtering and conditioning the sine / cosine signal and an amplification conditioning circuit for amplifying and conditioning the excitation signal are connected between the outer frame rotary encoder and the inner frame rotary encoder and the R / D converter.

[0029] Through the setting of brushless motor driver chip, brushed motor driver chip, Hall sensor, outer frame rotary encoder and inner frame rotary encoder, combined with the PID control algorithm set on the processor, the three-loop closed-loop control of the current loop, position loop and speed loop of the rotating motor and the locking motor can be achieved, reducing the influence of the motor control error on the navigation accuracy of the three-inertial group, and the control accuracy is relatively high.

[0030] In this embodiment, a travel switch is installed between the two locking motors and the inner platform. When the inner platform is locked in place, the travel switch is turned on. The travel switch is connected to the processor and the switch signal of the travel switch is input to the processor for level judgment after RC filtering, so as to judge whether the inner platform is locked in place. Specifically, an RC filter circuit and a level converter are connected between the travel switch and the processor.

[0031] Since the stability of the inner platform after locking directly affects the navigation accuracy of the inertial group, the unlocking and locking control of the inner platform must be very precise. In order to further ensure that the inner platform is locked in place, infrared switches are installed on both locking motors in this embodiment. The infrared switch includes an infrared transmitter and an infrared receiver. The infrared transmitter and the infrared receiver are respectively installed at the two ends of the locking motor. A through hole is preset on the locking motor. Every time the locking motor rotates one circle, the signal of the infrared transmitter is transmitted to the infrared receiver through the through hole. The infrared receiver will output a pulse signal. The infrared receiver is connected to the processor. The processor collects the number of pulses output by the infrared receiver. The number of pulses is the number of circles of the locking motor, thereby detecting the number of circles of the locking motor when locked or unlocked. If the number of circles of the locking motor when locked is consistent with the number of circles of the locking motor when unlocked, it is considered that the inner platform is locked in place, and accurate control of the locking state is achieved. Since the pulse signal is relatively weak and susceptible to electromagnetic interference, a signal amplification circuit is connected between the infrared receiving end of the infrared switch and the processor. The signal amplification circuit amplifies the signal through a triode and then transmits it to the processor for pulse number collection. Specifically, the processor counts the received pulse signal through a level converter.

[0032] In this embodiment, the inertial group computer is connected to the processor for communication, and the inertial group computer sends control instructions to the processor and receives control state information. Specifically, the inertial group computer and the processor communicate via an RS422 serial communication bus (RS422 transceiver), and the interface of the RS422 serial communication bus is electrically isolated via a magnetic coupling isolator.

[0033] The rotation locking control system of the three-inertial group adopts a power supply of 18V to 36V. The power supply is converted into different power supply voltages through a DC / DC converter and used to power various components in the rotation locking control system of the three-inertial group. The power supply design principle block diagram is shown in the figure. Figure 2As shown. Specifically, the power supply is nominally 24V, and the isolated DC / DC converter converts the 24V into a 12V power supply to power the control part (processor, R / D converter, A / D converter, level converter, etc.), while the power drive part (brushless motor drive chip and brushed motor drive chip) is directly powered by 24V. In this way, the power supply of the control part can be distinguished from the power supply of the power drive part, and electrical isolation can be achieved to avoid electromagnetic interference of the power drive part to the processor, resolver signal, current loop signal, etc. Specifically, the 12V power supply of the control part is converted into a 5V power supply for the R / D converter, a 3.3V power supply for the processor, a 1.8V power supply for the processor interface (i.e., the interface connecting the processor with the R / D converter, RS422 transceiver, PWM, Hall sensor, etc.) and a 5V power supply for the control interface (i.e., the chip interface such as RS422 transceiver and magnetic coupling isolator).

Claims

1. A rotation locking control system of a three-inertial group, the three-inertial group comprising at least two rotating motors, two locking motors, an inner frame, an outer frame and an inner platform, characterized in that: The rotation locking control system of the three-inertia group includes two brushless motor drive chips, two brushed motor drive chips, an outer frame rotary encoder, an inner frame rotary encoder and a processor; The two brushless motor driver chips are respectively connected to the two rotating motors and drive the two rotating motors to work respectively, so as to realize the rotation of the inner frame and the outer frame; the two brushed motor driver chips are respectively connected to the two locking motors and drive the two locking motors to work respectively, so as to realize the unlocking and locking of the inner platform; the two brushless motor driver chips and the two brushed motor driver chips are all connected to the processor, and Hall sensors are connected between the two brushless motor driver chips and the rotating motors and between the two brushed motor driver chips and the locking motors, and all Hall sensors are connected to the processor to realize the current loop closed-loop control; The outer frame rotary encoder is connected to the outer frame and rotates with the outer frame; the inner frame rotary encoder is connected to the inner frame and rotates with the inner frame; the outer frame rotary encoder and the inner frame rotary encoder are both provided with two output channels of roughing and finishing, and the two output channels of roughing and finishing of the outer frame rotary encoder and the inner frame rotary encoder are both connected to the processor, the processor sends excitation signals to the outer frame rotary encoder and the inner frame rotary encoder respectively, and collects the sine / cosine signals of the two output channels of roughing and finishing respectively, obtains the position information and speed information of the outer frame and the inner frame, and realizes the closed-loop control of the position loop and the speed loop; A travel switch is installed between the two locking motors and the inner platform body. When the inner platform body is locked in place, the travel switch is turned on. The travel switch is connected to the processor and the switch signal of the travel switch is input to the processor for level judgment after RC filtering, thereby judging the locking status of the inner platform body.

2. The rotation locking control system of the three-inertial group according to claim 1 is characterized in that: Both locking motors are equipped with infrared switches, which include an infrared transmitter and an infrared receiver. The infrared transmitter and the infrared receiver are respectively installed at the two ends of the locking motor. A through hole is preset on the locking motor. Every time the locking motor rotates one circle, the signal from the infrared transmitter is transmitted to the infrared receiver through the through hole, and the infrared receiver outputs a pulse signal. The infrared receiver is connected to the processor, and the processor collects the number of pulses output by the infrared receiver. The number of pulses is the number of circles the locking motor rotates, thereby detecting the number of circles the locking motor rotates when locked or unlocked, and judging whether the inner platform is locked in place based on whether the number of circles the locking motor rotates when locked is consistent with the number of circles the locking motor rotates when unlocked.

3. The rotation locking control system of the three-inertial group according to claim 1 is characterized in that: The rotation locking control system of the three-auto inertial group further includes an inertial group computer, which is in communication connection with the processor, and the inertial group computer sends control instructions to the processor and receives control state information.

4. The rotation locking control system of the three-inertial group according to claim 3 is characterized by: The inertial computer and the processor communicate via an RS422 serial communication bus, and the interface of the RS422 serial communication bus is electrically isolated via a magnetic coupling isolator.

5. The rotation locking control system of the three-inertial group according to claim 1 is characterized by: The rotation locking control system of the three-inertial group adopts a power supply of 18V to 36V, which is converted into different power supply voltages by a DC / DC converter and respectively used to power various components in the rotation locking control system of the three-inertial group.

6. The rotation locking control system of the three-inertial group according to claim 1 is characterized by: The processor is provided with an A / D converter, and the Hall sensors are connected to the A / D converter on the processor through an RC filtering circuit. The detection signal of the Hall sensor is converted into a digital quantity by the A / D converter on the processor after RC filtering.

7. The rotation locking control system of the three-inertial group according to claim 1 is characterized by: The communication interface between the processor and the two brushless motor drive chips and the two brushed motor drive chips is a PWM interface, and the PWM interface is electrically isolated by a magnetic coupling isolator.

8. The rotation locking control system of the three-inertial group according to claim 1 is characterized by: The processor is connected and communicated with the outer frame rotary encoder and the inner frame rotary encoder through an R / D converter.

9. The rotation locking control system of the three-inertial group according to claim 8 is characterized in that: A filter conditioning circuit for filtering and conditioning the sine / cosine signal and an amplification conditioning circuit for amplifying and conditioning the excitation signal are connected between the outer frame rotary encoder and the inner frame rotary encoder and the R / D converter.

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