A kind of control device and method of de-racing system

Abstract

A derotation system control device and method, the method comprising: calculating the angle θ that the derotation encoder needs to operate dp , the angle θ dp That is, the position to which the derotation encoder needs to move during derotation; the derotation system receives the limit signals of the forward limit and reverse limit and the feedback value of the derotation platform to calculate the position and speed that the derotation platform needs to move in various situations, and control the derotation platform to perform corresponding movements. The scheme of the present invention adopts the method of installing Hall limit switches at both ends, comprehensively judging the limit logic of the derotation system according to the derotation angle value measured by the high-precision encoder feedback original on the derotation platform, and adopts a method combining segmented limit offset processing with segmented fast switching area control, which can unify the initial position, limit position and limit processing method of multiple derotation system cameras, and realize program unification, and at the same time realize fast area switching of the derotation system with limit.

Description

Technical Field

[0001] The present invention relates to the field of de-racing control, and in particular to a de-racing system control device and method. Background Art

[0002] The derotation system of a large-field prime focus horizon telescope is generally installed on the prime focus of the large-field horizon telescope, and is mainly responsible for the image rotation caused by the rotation of the earth when the large-field telescope is exposed for a long time. A large-field camera is generally installed on the derotation platform, and a dimming and focusing component is generally installed on the camera. An encoder is installed on the derotation platform, and the derotation platform is driven by a motor, so there are generally many cables on the derotation system. When the derotation system rotates, the cables installed on the components of the derotation system will rotate with it. If there is no photoelectric slip ring to convert the cable signal, the derotation mechanism cannot rotate infinitely, because infinite rotation will cause the rotation of the cables on the derotation mechanism, and in severe cases, the cable rotation will cause the cable to break. If the derotation platform is infinitely rotated by adding a photoelectric slip ring, but if a photoelectric slip ring is added to the derotation system to convert the signal, the weight of each system at the prime focus will be too heavy, which may cause the imaging optical path to deviate. At the same time, it is expensive and the structure is complex.

[0003] According to the tracking principle of astronomical horizon telescope, when the telescope works in the whole sky, the position of the de-rotation platform on the telescope and the position of the camera on the de-rotation platform are as follows: Figure 1 As shown in the figure, if the horizontal position of the camera when installed is taken as the starting point and this starting point is taken as the 0 point, the range of rotation of the derotation mechanism is about -180°~180°. In order to ensure that the derotation mechanism can work in the whole sky without breaking the cable, the derotation mechanism is generally allowed to operate between -A°~A°, where A>180°. The method of adding a multi-turn limit encoder can also record the limit absolute position value, but adding an absolute encoder will cause the limit cost to be too high and the mechanical structure to be complicated. Summary of the invention

[0004] In view of the technical defects and technical drawbacks in the prior art, the embodiments of the present invention provide a control device and method for a de-racing system that overcomes the above problems or at least partially solves the above problems. The specific scheme is as follows:

[0005] As a first aspect of the present invention, a de-rotation system control device is provided, the device comprising: a de-rotation platform, a position calculation module and a motion control module;

[0006] The position calculation module is used to calculate the angle θ that the derotation encoder needs to run dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation;

[0007] The motion control module is used to receive the limit signals of the forward limit and the reverse limit through the de-rotation system and the feedback value of the de-rotation platform is θ df , in order to calculate the position and speed at which the de-racing platform needs to move in various situations, and control the de-racing platform to move accordingly.

[0008] Furthermore, the derotation platform includes a derotation motor rotor, a derotation motor stator, a derotation encoder, a derotation encoder reading head, a limit switch 1, a limit switch 2, a limit connection block, a limit switch 1 sensing component and a limit switch 2 sensing component. A camera is installed on the derotation platform, which rotates with the rotation of the derotation platform. The derotation platform has an initial derotation zero point, so that the image collected by the camera at this position is horizontally positive, and the initial position is recorded as C_encoder; the derotation motor stator is provided with a limit switch motion guide path, and the two ends of the limit switch motion guide path are respectively the positive and negative limit points of the rotation of the derotation system, the limit switch 1 and the limit switch 2 sensing components are located at the reverse limit point of the limit switch motion guide path, the limit switch 2 and the limit switch 1 sensing component are located at the positive limit point of the limit switch motion guide path, the limit connection block is connected to the derotation motor rotor and is located at the derotation initial zero point, when the derotation platform moves forward, the limit connection block rotates with the derotation motor rotor, and the derotation motor rotor drives the limit When the position connecting block moves to the position of limit switch 1, this position is recorded as Limit1_encoder, and when it continues to move in the positive direction, it drives limit switch 1 to move in the positive direction along the limit switch motion guide path until it touches the limit switch 1 sensing component to trigger the reverse limit, and this position is recorded as Limit1_encoder1. Similarly, when the rotor of the de-rotation motor moves in the reverse direction, it drives the limit connecting block to toggle limit switch 2 to slide on the limit switch motion guide path, and the initial position of limit switch 2 is recorded as Limit2_encoder. It slides to the position of the limit switch 2 sensing component to trigger the reverse limit, and this position is recorded as Limit2_encoder2. The limit switch motion guide path is the limit overlap area; the de-rotation encoder reading head is used to read the value of the de-rotation encoder as the angular position of the de-rotation platform; the de-rotation motor stator is used to generate a magnetic field when the coil is energized to drive the de-rotation motor rotor to rotate; the de-rotation encoder is used to measure the rotational position of the de-rotation platform.

[0009] Furthermore, the position calculation module is specifically used to: calculate the derotation angle θ and derotation speed ω required to move at the derotation initial zero point through the derotation position and speed solver c The camera zero point encoder position offset processing calculator calculates the angle θ that the derotation encoder needs to run by using the derotation angle θ dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation.

[0010] Furthermore, the motion control module is specifically used to: receive the limit signal value of the forward limit and the reverse limit through the de-rotation system and the feedback value of the de-rotation platform as θ df The limit judgment controller is based on the limit signals of the forward limit and reverse limit and the feedback value of the de-rotation platform as θ df In order to calculate the position and speed that the de-rotation platform needs to move in various situations, and control the movement of the de-rotation platform through the position controller, speed controller and current controller, the de-rotation encoder measures the rotational position value of the de-rotation system, and the camera zero point encoder position offset processing calculator is used to offset the camera installation position to the zero point of de-rotation, so that the camera installation zero point position coincides with the absolute position measured by the encoder, and then the calculated de-rotation rotation position value is used for closed-loop control to the de-rotation position required in any area, so as to achieve the purpose of real-time de-rotation of position and speed.

[0011] Furthermore, the closed-loop control to the deracination position required in any area is specifically:

[0012] When the camera is installed horizontally, the encoder reading is exactly 0°, then C_encoder=0°, and the range of rotation of the derotation platform relative to the zero point of the camera installation horizontally is recorded as -A°~A°, where A>180°. At this time, the reading of the limit switch 1 sensing component on the encoder is Limit1_encoder1=A°, and the reading of the limit switch 2 sensing component on the encoder is Limit1_encoder2=(360-A)°, that is, the reading on the encoder when the limit switch 1 is triggered is A°, and the reading on the encoder when the limit switch 2 is triggered is (3 60-A)°, at this time, the position on the de-rotation encoder is divided into three areas, area one is Limit1_encoder1~360°, area two is Limit2_encoder2~Limit1_encoder1, and area three is 0°~Limit2_encoder2. The movement of the de-rotation platform is determined by determining in which area the position calculated by the de-rotation solution is located, and in which area the current position of the de-rotation platform is located, thereby realizing the motion control of the de-rotation platform. Specifically, the rotation angle and speed of the de-rotation platform are calculated according to the following formula;

[0013]

[0014]

[0015] Where Z is the calculated zenith distance angle in the horizon coordinate system, A is the azimuth angle in the horizon coordinate system, φ is the latitude of the telescope installation site, δ is the declination of the star in the celestial sphere coordinate system, t is the hour angle of the star, θ is the angle by which the de-rotation platform deviates from the de-rotation zero point, and ω is the image rotation speed. At this time, θ can be solved within the range of -180° to 180°;

[0016] If the zero position of the horizontally installed camera is within the encoder position value range of (360° - A°) to A°, then the 360° of the encoder, that is, the encoder zero position, coincides with the limit. At this time, the encoder value cannot be divided into three segments for processing. Let the de-rotation command value be θ dp , and the feedback value of the de-rotation platform is θ df , then when Limit1_encoder1 < θ dp < 360°, and 0 < θ df < Limit2_encoder2, that is, when the de-rotation platform needs to run from area three to area one, the speed of the de-rotation platform is:

[0017] ω c = -const;

[0018] When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < 360°, that is, when the de-rotation platform moves inside area one, a closed loop can be performed within area one;

[0019] ω c = PI{p_err};

[0020] Where p_err is the positioning error of the de-rotation platform;

[0021] When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < Limit2_encoder2, move the position of the de-rotation platform from the limit coincidence area two to area one,

[0022] Then there is ω c = const;

[0023] Let the limit signal Clockwise_Limit1 = 1 indicate reaching the positive limit. When Clockwise_Limit1 = 1, then record Clockwise_Flag = 1, indicating that the platform has reached the limit signal while moving in the positive direction. At this time, it is necessary to move in the reverse direction, that is, let

[0024] ω c = -const;

[0025] First, let the raceway platform start moving in the forward direction. When it touches the first limit switch, it means that the raceway platform has reached the positive limit. Then it moves in the reverse direction until it runs out of Area 2. After reaching Area 3, it can move according to the operation control instruction from Area 3 to Area 1, and keep the raceway platform running into Area 1. Then perform closed-loop control within Area 1. When reaching the corresponding position, set the limit Clockwise_Flag = 0;

[0026] Similarly, when 0 < θ dp <Limit2_encoder2, Limit1_encoder1 < θ df <360°, and when this is the case, that is, when the raceway platform needs to move from Area 1 to Area 3, the speed of the raceway platform is:

[0027] ω c = const;

[0028] Then there is 0° < θ dp <Limit2_encoder2, and 0° < θ df <Limit2_encoder2, that is, when the raceway platform is moving inside Area 3, then perform closed-loop control within Area 3;

[0029] ω c = PI{p_err};

[0030] When 0° < θ dp <Limit2_encoder2 and Limit1_encoder1 < θ df <Limit2_encoder2, move the position of the raceway platform from the limit coincidence area to Area 3. Record that when the limit signal AntiClockwise_Limit2 = 1, it reaches the negative limit. When AntiClockwise_Limit2 = 1, then record AntiClockwise_Flag = 1, indicating that the platform has moved in the negative direction and reached the negative limit signal. At this time, it needs to move in the reverse direction, that is, let;

[0031] ω c = const;

[0032] First, let the raceway platform start moving in the reverse direction. When it touches the second limit switch, it means that the raceway platform has reached the negative limit. Then it moves in the reverse direction until it runs out of Area 2. After reaching Area 3, it can move according to the operation control instruction from Area 1 to Area 3, and keep the raceway platform running into Area 3. Then perform closed-loop control within Area 3. When reaching the corresponding position, set the limit AntiClockwise_Flag = 0;

[0033] When the zero point encoder value is not zero when the camera is installed horizontally, that is, the de-rotation zero point and the encoder zero point cannot coincide with each other, which is not the case in most cases, and the de-rotation zero point and the encoder zero point of the de-rotation encoder in different telescopes are inconsistent, then record C_encoder = θ df0 =Δ, in order to ensure that the position of the camera is 0° when it is installed horizontally, the feedback of the encoder reading data needs to be offset by a Δ, then:

[0034]

[0035] In order to match the derotation instruction with the derotation encoder to achieve position fixed-point closed-loop and derotation motion control, the following processing is required:

[0036] θ dp =θ-Δ;

[0037] if

[0038] As a second aspect of the present invention, a deracination system control method is provided, the method comprising:

[0039] Step 1: Calculate the angle θ that the derotation encoder needs to run dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation;

[0040] Step 2: The de-rotation system receives the limit signals of the forward limit and reverse limit and the feedback value of the de-rotation platform is θ df , in order to calculate the position and speed at which the de-racing platform needs to move in various situations, and control the de-racing platform to move accordingly.

[0041] Further, step 1 is specifically as follows: the derotation angle θ and the derotation speed ω required to move at the derotation initial zero point are calculated by the derotation position and speed solver. c The camera zero point encoder position offset processing calculator calculates the angle θ that the derotation encoder needs to run by using the derotation angle θ dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation.

[0042] Furthermore, step 2 is specifically as follows:

[0043] The de-rotation system receives the limit signal value of the forward limit and reverse limit and the feedback value of the de-rotation platform as θ df The limit judgment controller is based on the limit signals of the forward limit and reverse limit and the feedback value of the de-rotation platform as θ dfIn order to calculate the position and speed that the de-rotation platform needs to move in various situations, and control the movement of the de-rotation platform through the position controller, speed controller and current controller, the de-rotation encoder measures the rotational position value of the de-rotation system, and the camera zero point encoder position offset processing calculator is used to offset the camera installation position to the zero point of de-rotation, so that the camera installation zero point position coincides with the absolute position measured by the encoder, and then the calculated de-rotation rotation position value, that is, the de-rotation angle θ, is closed-loop controlled to the de-rotation position required in any area, so as to achieve the purpose of real-time de-rotation of position and speed.

[0044] Furthermore, the closed-loop control to the deracination position required in any area is specifically:

[0045] When the camera is installed horizontally, the encoder reading is exactly 0°, then C_encoder=0°, and the range of rotation of the derotation platform relative to the zero point of the camera installation horizontally is recorded as -A°~A°, where A>180°. At this time, the reading of the limit switch 1 sensing component on the encoder is Limit1_encoder1=A°, and the reading of the limit switch 2 sensing component on the encoder is Limit1_encoder2=(360-A)°, that is, the reading on the encoder when the limit switch 1 is triggered is A°, and the reading on the encoder when the limit switch 2 is triggered is (3 60-A)°, at this time, the position on the de-rotation encoder is divided into three areas, area one is Limit1_encoder1~360°, area two is Limit2_encoder2~Limit1_encoder1, and area three is 0°~Limit2_encoder2. The movement of the de-rotation platform is determined by determining in which area the position calculated by the de-rotation solution is located, and in which area the current position of the de-rotation platform is located, thereby realizing the motion control of the de-rotation platform. Specifically, the rotation angle and speed of the de-rotation platform are calculated according to the following formula;

[0046]

[0047]

[0048] Where Z is the calculated zenith distance angle of the horizontal coordinate system, A is the azimuth of the horizontal coordinate system, φ is the latitude of the telescope installation site, δ is the declination of the star in the celestial coordinate system, t is the hour angle of the star, θ is the angle of the derotation platform offset from the derotation zero point, ω is the image rotation speed, and θ can be solved to be between -180° and 180°;

[0049] If the zero point of the horizontally installed camera is between the encoder position value range (360°-A°) and A°, the zero point of the encoder falls in the middle of the range. At this time, the encoder value cannot be divided into three segments for processing. Let the derotation command value be θ dp , the feedback value of the racemic platform is θdf , then when Limit1_encoder1 < θ dp < 360°, and 0 < θ df < Limit2_encoder2, that is, when the racemization platform needs to run from area three to area one, the speed of the racemization platform is:

[0050] ω c = -const;

[0051] When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < 360°, that is, when the racemization platform moves inside area one, a closed loop can be carried out within area one;

[0052] ω c = PI{p_err};

[0053] where p_err is the positioning error of the racemization platform;

[0054] When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < Limit2_encoder2, move the position of the racemization platform from the limit coincidence area two to area one,

[0055] then there is ω c = const;

[0056] Let the forward limit value Clockwise_Limit1 = 1 when reaching the positive limit. When Clockwise_Limit1 = 1, then record Clockwise_Flag = 1, indicating that the platform has reached the limit signal when moving in the positive direction. At this time, it needs to move in the reverse direction, that is, let

[0057] ω c = -const;

[0058] First, let the racemization platform start moving in the positive direction. After touching the limit switch one, it means that the racemization platform has reached the positive limit. Then, it moves in the reverse direction until it runs out of area two. After reaching area three, it moves according to the operation control instruction from area three to area one until the racemization platform runs into area one, and then a closed-loop control is carried out within area one. At this time, after reaching the corresponding position, set the limit Clockwise_Flag = 0;

[0059] Similarly, when 0 < θ dp < Limit2_encoder2, Limit1_encoder1 < θdf <360°, and when, that is, when the racemic platform has to move from Region 1 to Region 3, the speed of the racemic platform is:

[0060] ω c = const;

[0061] Then 0° < θ dp <Limit2_encoder2, and 0° < θ df <Limit2_encoder2, that is, when the racemic platform is moving inside Region 3, then a closed loop can be carried out within Region 3;

[0062] ω c = PI{p_err};

[0063] When 0° < θ dp <Limit2_encoder2 and Limit1_encoder1 < θ df <Limit2_encoder2, move the position of the racemic platform from the limit coincidence area to Region 3. Denote that when the limit signal AntiClockwise_Limit2 = 1, it reaches the negative limit. When AntiClockwise_Limit2 = 1, then denote AntiClockwise_Flag = 1, record that the platform has moved in the negative direction to reach the negative limit signal. At this time, it is necessary to move in the reverse direction, that is, let;

[0064] ω c = const;

[0065] First, let the racemic platform start to move in the reverse direction. After touching the limit switch 2, it means that the racemic platform has reached the negative limit. Then move in the reverse direction until it runs out of Region 2. After reaching Region 3, it can move according to the operation control instructions from Region 1 to Region 3. Keep the racemic platform running into Region 3, and then carry out closed-loop control within Region 3. At this time, after reaching the corresponding position, set the limit AntiClockwise_Flag = 0;

[0066] When the value of the zero encoder when the camera is horizontally installed is not zero, that is, when the racemic zero point and the encoder zero point cannot coincide. In most cases, they cannot coincide, and the racemic zero point and the encoder zero point are inconsistent in different telescopes. At this time, record C_encoder = θ df0 = Δ. In order to ensure that the position when the camera is horizontally installed is 0°, it is necessary to offset the feedback of the encoder reading data by a Δ. At this time, there is:

[0067]

[0068] In order to match the derotation instruction with the derotation encoder to achieve position fixed-point closed-loop and derotation motion control, the following processing is required:

[0069] θ dp =θ-Δ;

[0070] if

[0071] The present invention has the following beneficial effects:

[0072] The scheme of the present invention adopts the method of installing Hall limit switches at both ends, and comprehensively judges the limit logic of the de-rotation system according to the de-rotation angle value measured by the high-precision encoder feedback original on the de-rotation platform. The measurement value of the de-rotation position encoder of the de-rotation platform is 0~360°, which is equivalent to -180°~180°. Therefore, when the de-rotation platform rotates, there is a section of 180°~A° (overlapping area one) and -180°~-A° (overlapping area two) overlapping areas. When moving from overlapping area one to overlapping area two, it is bound to cross the limit. After reaching the limit, since the telescope continues to track, the de-rotation system needs to continue to move in one direction at the original absolute position, but at this time it needs to switch through the limit. Therefore, the present invention adopts a segmented fast switching area control method to achieve fast position switching and continuous tracking of the de-rotation system. Considering that in multiple different derotation mechanisms of multiple different telescopes, the installation angles of the high-precision derotation encoders are inconsistent, so the absolute position values ​​of the encoders at the Hall logic switches in each derotation mechanism are inconsistent, and the horizontal initial position of the camera installation is not necessarily the 0-point position read by the encoder. Therefore, the absolute position values ​​of the encoders of the initial values ​​of the cameras on the derotation platform are inconsistent, and the absolute values ​​of the encoders at the overlapped areas are also inconsistent. The overlapped areas may pass through the encoder zero point or not pass through the encoder absolute zero point. If each derotation system performs limit logic judgment and camera initial position calibration according to the absolute position value of the absolute value of the encoder, it is bound to be inconsistent, resulting in diverse limit logics, cumbersome and complicated limit processing, and inconsistent procedures, which causes many changes in the maintenance and processing of multiple derotation systems of multiple telescopes. In order to ensure that the limit logics of multiple derotation systems are consistent and the installation angle of the encoder does not need to be considered, the present invention adopts a method combining segmented limit offset processing with segmented fast switching area control, which can unify the initial positions, limit positions and limit processing methods of multiple derotation system cameras, and can achieve program unification, and at the same time, can achieve fast area switching of derotation systems with limits. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 A schematic diagram of the telescope position where the de-racing platform provided in an embodiment of the present invention is located.

[0074] Figure 2 A composition diagram of a racemization control system provided by an embodiment of the present invention;

[0075] Figure 3 The limit position under ideal conditions provided by the embodiment of the present invention;

[0076] Figure 4 The zero point of the encoder provided by the embodiment of the present invention is within the overlap region;

[0077] Figure 5 A schematic diagram of a de-rotation platform camera zero point and an encoder zero point having a deviation provided by an embodiment of the present invention;

[0078] Figure 6 A flow chart of a control method for a racemization system provided by an embodiment of the present invention;

[0079] Figure 7 A schematic diagram of the overall flow of the racemization system control method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0080] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0081] like Figure 1 As shown, the position of the de-rotation platform 1 provided by an embodiment of the present invention on the telescope, the de-rotation platform 1 is installed on the main mirror 3 of the telescope, and the main mirror 3 is installed on the telescope frame 4, wherein the camera 2 rotates with the rotation of the de-rotation platform 1, and there is an initial position on the de-rotation platform 1, so that the image collected by the camera 2 at this position is horizontal and positive, and the initial position is recorded as C_encoder.

[0082] like Figure 2As shown, it is a composition diagram of the de-rotation control system provided by an embodiment of the present invention, wherein the de-rotation platform 1 includes a de-rotation motor rotor 11, a de-rotation motor stator 12, a de-rotation encoder 13, a de-rotation encoder reading head 14, a limit switch 15, a limit switch 2 16, a limit connection block 17, a limit switch 1 induction switch 18 and a limit switch 2 induction switch 19. A camera 2 is installed on the de-rotation platform 1, and the camera 2 is driven to rotate as the de-rotation platform 1 moves. The de-rotation encoder reading head 14 reads the value of the encoder as the angular position of the de-rotation platform 1. The coil of the de-rotation motor stator 12 is energized to generate a magnetic field, which drives the de-rotation motor rotor 11 to rotate, and the de-rotation encoder 13 accurately measures the rotation position of the de-rotation platform 1 to perform a position closed loop. The limit switch 15 and the limit switch 2 16 use Hall switches of switching quantity. The limit connection block 17 is connected to the de-rotation motor rotor 11 for movement, and the limit switch 1 15 and the limit switch 2 16 are connected to the stator of the de-rotation motor. The limit switch 15 and the limit switch 2 16 can move along the limit switch movement guide path 110. The limit connection block 17 is connected to the de-rotation motor rotor 11 and rotates with the de-rotation motor. When the de-rotation platform 1 drives the limit connection block 17 to move to the position of the limit switch 15, the position is recorded as Limit1_encoder, and continues to move in the positive direction, it drives the limit switch 15 to move in the positive direction along the limit switch movement track until it touches the limit switch 1 induction switch 18 to trigger the limit, and this position is recorded as Limit1_encoder1. Similarly, when the turntable moves in the reverse direction, the limit connection block 17 drives the limit switch 2 16 to slide on the limit switch movement guide path 110, and the initial position of the limit switch 2 16 is recorded as Limit2_encoder. It slides to the position where the limit switch 2 sensing switch 19 is located, triggering the reverse limit, and this position is recorded as Limit2_encoder2. The limit switch movement guide path 110 is the limit overlap area.

[0083] The principle of the specific segmented offset limit processor is as follows. Ideally, assuming that the reading value of the encoder when the camera 2 is installed horizontally and correctly is exactly 0°, then at this time C_encoder = 0°. Let the rotation range of the de-rotation platform 1 relative to the horizontal installation zero point of the camera 2 be denoted as -A° to A°, where A > 180°. Then at this time, the reading of the limit switch one sensing switch 18 on the encoder Limit1_encoder1 = (A)°, that is, the reading on the encoder when limit 1 is triggered is (A)°, and the reading on the encoder when limit 2 is triggered is (360 - A)°. At this time, the position on the de-rotation encoder 13 can be divided into three parts for processing. One part is Limit1_encoder1 to 360°, one part is 0° to Limit2_encoder2, and one part is Limit2_encoder2 to Limit1_encoder1. To determine how the de-rotation platform 1 moves, it can be judged by determining which area the position calculated by the de-rotation is in and which area the current position of the de-rotation platform 1 is in, and then the motion control of the de-rotation platform 1 is realized. Specifically, the rotation angle and speed of the de-rotation platform 1 are calculated according to the following formula.

[0084]

[0085]

[0086] Where Z: is the calculated zenith distance angle in the horizontal coordinate system, A: is the azimuth angle in the horizontal coordinate system, φ: is the latitude of the telescope installation site, δ is the declination of the star in the celestial coordinate system, t is the hour angle of the star, and θ is the angle by which the de-rotation platform 1 deviates from the de-rotation zero point. ω is the image rotation speed. At this time, θ can be solved to be between -180° and 180°.

[0087] If the zero position of the horizontal installation of the camera 2 is between (360° - A°) and A° in the encoder position value, then the zero position of the encoder falls in the middle of this area. At this time, the encoder value cannot be divided into three segments by three areas. If the de-rotation command value is denoted as θ dp , and the feedback value of the de-rotation platform 1 is θ df ;

[0088] Then when Limit1_encoder1 < θ dp < 360°, and 0 < θ df < Limit2_encoder2, that is, when the de-rotation platform 1 needs to run from area three to area one, the speed of the de-rotation platform 1 is:

[0089] ω c =-const;

[0090] When Limit1_encoder1 < θ dp< 360°, and Limit1_encoder1 < θ df < When < 360°, that is, when the racemization platform 1 moves inside area one, closed-loop control can be carried out within area one;

[0091] ω c = PI{p_err};

[0092] Where p_err is the positioning error of the racemization platform 1.

[0093] When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < When < Limit2_encoder2, it is necessary to move the position of the racemization platform 1 from the limit coincidence area two to area one.

[0094] Then there is ω c = const;

[0095] It is recorded that when the limit signal Clockwise_Limit1 = 1, it reaches the positive limit. When Clockwise_Limit1 = 1, then it is recorded that Clockwise_Flag = 1, recording that the platform has reached the limit signal when moving in the positive direction. At this time, it is necessary to move in the reverse direction, that is, let;

[0096] ω c = -const;

[0097] First, let the racemization platform 1 start to move along the positive direction. After touching the limit switch one 15, it means that the racemization platform 1 has reached the positive limit. Then it moves in the reverse direction until it runs out of area two. After reaching area three, it can move according to the operation control instruction from area three to area one, and keep the racemization platform 1 running into area one. Then, closed-loop control is carried out within area one. At this time, after reaching the position, set the limit Clockwise_Flag = 0;

[0098] Similarly, when 0 < θ dp < Limit2_encoder2, Limit1_encoder1 < θ df < 360°, and at this time, that is, when the racemization platform 1 needs to move from area one to area three, the speed of the racemization platform 1 is: ω c = const;

[0099] Then there is 0° < θ dp < Limit2_encoder2, and 0° < θ df < Limit2_encoder2, that is, when the racemization platform 1 moves inside area three, closed-loop control can be carried out within area three;

[0100] ω c = PI{p_err};

[0101] When 0° < θ dp <Limit2_encoder2 and Limit1_encoder1 < θ df <Limit2_encoder2, it is necessary to move the position of the racemization platform 1 from the limit coincidence area two to area three.

[0102] Record that when the limit signal AntiClockwise_Limit2 = 1, it reaches the negative limit. When AntiClockwise_Limit2 = 1, then record AntiClockwise_Flag = 1, indicating that the platform has moved to the negative limit in the negative direction. At this time, it is necessary to move in the reverse direction, that is, let

[0103] ω c = const;

[0104] First, let the racemization platform 1 start to move along the negative direction. After touching the limit switch two 16, it means that the racemization platform 1 has reached the negative limit, and then move in the reverse direction until it runs out of area two. When it reaches area one, it can move according to the operation control instructions from area one to area three, and keep the racemization platform 1 running into area three, and then perform closed-loop control within area three. After reaching the position at this time, set the limit AntiClockwise_Flag = 0.

[0105] When the value of the zero encoder when the camera 2 is horizontally installed is not zero, that is, when the racemization zero point and the encoder zero point cannot coincide. In most cases, they cannot coincide, and the racemization zero point of the racemization encoder 13 in different telescopes is inconsistent with the encoder zero point. At this time, record C_encoder = θ df0 = Δ. In order to ensure that the position of the camera 2 when it is horizontally installed is 0°, it is necessary to offset the feedback of the encoder reading data by a Δ. At this time, there is:

[0106]

[0107] Then, in order to correspond the racemization instruction with the racemization encoder 13 to achieve position fixed-point closed-loop and racemization motion control. The following processing is required:

[0108] θ dp = θ - Δ

[0109] If

[0110] Finally, the control block diagram of the racemization control method with limit in the present invention is as follows Figure 5-6As shown, the derotation position and speed calculation controller calculates the derotation angle θ and derotation speed ω required to move at the initial zero point of the derotation. c , where the derotation angle θ is used together with the camera 2 zero point encoder position offset processing calculator to calculate the angle θ at which the derotation encoder 13 should operate dp , this angle is the position to which the derotation encoder 13 needs to move during derotation. At the same time, the system receives the limit signal values ​​of the positive limit and the negative limit, and uses the limit judgment controller to calculate the position and speed that the derotation platform 1 needs to move in various situations. Then the derotation system controls the movement of the derotation platform 1 through the position controller, the speed controller and the current controller. The derotation encoder 13 accurately measures the rotation position of the derotation system, and then the camera 2 zero point encoder position offset processing calculator can be used to offset the installation position of the camera 2 to the zero point of derotation, so that the zero point position of the camera 2 installation coincides with the absolute position measured by the encoder. At this time, the derotation rotation position value calculated, that is, the derotation angle θ, can be closed-loop controlled to the derotation position required by any sky area, so as to achieve the purpose of real-time derotation of position and speed. At the same time, when the derotation is in progress, if the derotation platform 1 encounters a limit, it will immediately move in the opposite direction to the other side and continue to move in the direction required for derotation, so as to ensure normal derotation during telescope tracking. For example, when the installation encoder position of camera 2 is 20°, the original encoder position of the installation position of touch limit 1 is 220°, and the installation position of the encoder triggered by touch limit 2 is 180°, the limit is Δ=20°. At this time, -20° is directly subtracted from the directly read encoder feedback, and then the encoder position of camera 2 installed horizontally in the positive direction is 0. The touch limit 1 is 200°, and the touch limit 2 is 160°, that is, -200°. Therefore, the range of motion at this time is -200°~200°. At the same time, it is assumed that when the telescope is tracking, the de-rotation platform 1 is moving in the positive direction and touches the positive limit 1. At this time, the encoder position is 200°. According to the limit judgment controller, the de-rotation platform 1 will move in the reverse direction to 201°, and continue to move in the positive direction to ensure the normal de-rotation. On the contrary, if the de-rotation platform 1 touches the limit switch 2 16 when moving in the reverse direction, the encoder position is 160°, that is, -200°, and the de-rotation platform 1 will move forward until it reaches the overlap area -59°, and then continue the reverse de-rotation movement to complete the continuous de-rotation tracking of the telescope.

[0111] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A control device for a racemization system, characterized in that: The device comprises: a de-rotation platform, a position calculation module and a motion control module; The position calculation module is used to calculate the angle θ that the derotation encoder needs to run dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation; The motion control module is used to receive the limit signals of the forward limit and the reverse limit and the feedback value of the de-rotation platform through the de-rotation system, so as to calculate the position and speed at which the de-rotation platform needs to move in various situations, and control the de-rotation platform to perform corresponding movements; The derotation platform includes a derotation motor rotor, a derotation motor stator, a derotation encoder, a derotation encoder reading head, a limit switch 1, a limit switch 2, a limit connection block, a limit switch 1 sensing component and a limit switch 2 sensing component. A camera is installed on the derotation platform, and the camera rotates with the rotation of the derotation platform. The derotation platform has an initial derotation zero point, so that the image collected by the camera at this position is horizontally positive, and the initial position is recorded as C_encoder; the derotation motor stator is provided with a limit switch motion guide path, and the two ends of the limit switch motion guide path are respectively the positive and negative limit points of the rotation of the derotation system, the limit switch 1 and the limit switch 2 sensing components are located at the reverse limit point of the limit switch motion guide path, the limit switch 2 and the limit switch 1 sensing component are located at the positive limit point of the limit switch motion guide path, the limit connection block is connected to the derotation motor rotor and is located at the derotation initial zero point, when the derotation platform moves forward, the limit connection block rotates with the derotation motor rotor, and the derotation motor rotor drives the limit connection block to rotate. The connecting block moves to the position of limit switch 1, which is recorded as Limit1_encoder. When it continues to move in the positive direction, it drives limit switch 1 to move in the positive direction along the limit switch motion guide path until it touches the limit switch 1 sensing component to trigger the reverse limit. This position is recorded as Limit1_encoder1. Similarly, when the de-rotation motor rotor moves in the reverse direction, it drives the limit connecting block to toggle limit switch 2 to slide on the limit switch motion guide path. The initial position of limit switch 2 is recorded as Limit2_encoder, and it slides to the position of the limit switch 2 sensing component to trigger the reverse limit. This position is recorded as Limit2_encoder2. The limit switch motion guide path is the limit overlap area. The de-rotation encoder reading head is used to read the value of the de-rotation encoder as the angular position of the de-rotation platform. The de-rotation motor stator is used to generate a magnetic field when the coil is energized to drive the de-rotation motor rotor to rotate. The de-rotation encoder is used to measure the rotation position of the de-rotation platform.

2. The control device for the deracination system according to claim 1, characterized in that: The position calculation module is specifically used to calculate the derotation angle θ and derotation speed ω required to move at the derotation initial zero point through the derotation position and speed solver. c The camera zero point encoder position offset processing calculator calculates the angle θ that the derotation encoder needs to run by using the derotation angle θ dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation.

3. The control device for the deracination system according to claim 1, characterized in that: The motion control module is specifically used to: receive the limit signal value of the forward limit and the reverse limit through the de-rotation system and the feedback value of the de-rotation platform is θ df The limit judgment controller is based on the limit signals of the forward limit and reverse limit and the feedback value θ of the de-rotation platform. df , calculate the position and speed that the de-rotation platform needs to move in various situations, and control the movement of the de-rotation platform through the position controller, speed controller and current controller. The de-rotation encoder measures the rotational position value of the de-rotation system, and the camera zero point encoder position offset processing calculator is used to offset the camera installation position to the zero point of de-rotation, so that the camera installation zero point position coincides with the absolute position measured by the encoder, and then the calculated de-rotation rotation position value is used for closed-loop control to the de-rotation position required in any area, so as to achieve the purpose of real-time de-rotation of position and speed.

4. The control device for the deracination system according to claim 3, characterized in that: The closed-loop control to any area requires the following deracination positions: When the camera is installed horizontally, the encoder reading is exactly 0°, then C_encoder=0°, and the range of rotation of the derotation platform relative to the zero point of the camera installation horizontally is recorded as -A°~A°, where A>180°. At this time, the reading of the limit switch 1 sensing component on the encoder is Limit1_encoder1=A°, and the reading of the limit switch 2 sensing component on the encoder is Limit1_encoder2=(360-A)°, that is, the reading on the encoder when the limit switch 1 is triggered is A°, and the reading on the encoder when the limit switch 2 is triggered is (3 60-A)°, at this time, the position on the de-rotation encoder is divided into three areas, area one is Limit1_encoder1~360°, area two is Limit2_encoder2~Limit1_encoder1, and area three is 0°~Limit2_encoder2. The movement of the de-rotation platform is determined by determining in which area the position calculated by the de-rotation solution is located, and in which area the current position of the de-rotation platform is located, thereby realizing the motion control of the de-rotation platform. Specifically, the rotation angle and speed of the de-rotation platform are calculated according to the following formula; Where Z is the calculated zenith distance angle of the horizontal coordinate system, A is the azimuth of the horizontal coordinate system, φ is the latitude of the telescope installation site, δ is the declination of the star in the celestial coordinate system, t is the hour angle of the star, θ is the angle of the derotation platform offset from the derotation zero point, ω is the image rotation speed, and θ can be solved to be between -180° and 180°; If the zero point position of the horizontally installed camera is between the encoder position value area (360°-A°) and A°, the 360° of the encoder, that is, the zero point position of the encoder, falls on the overlap of the limit. At this time, the encoder value cannot be divided into three sections for processing. Let the derotation command value be θ dp , the feedback value of the racemization platform is θ df , then: When Limit1_encoder1 < θ dp < 360°, and 0 < θ df < Limit2_encoder2, that is, when the racemization platform needs to run from area three to area one, the speed of the racemization platform is: ω c =-const; When Limit1_encoder1<θ dp <360°, and Limit1_encoder1<θ df When it is <360°, that is, the racemization platform moves within area 1, then a closed loop can be performed within area 1; ω c =PI{p_err}; Where p_err is the positioning error of the de-racing platform; When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < Limit2_encoder2, move the racemization platform position from the second limit coincidence area to the first area Then there is ω c =const; When the positive limit signal Clockwise_Limit1=1, it means that the positive limit has been reached. When Clockwise_Limit1=1, Clockwise_Flag=1 is recorded, and the platform moves in the positive direction and reaches the limit signal. At this time, it needs to move in the reverse direction, that is, ω c =-const; First, let the de-rotation platform start to move in the positive direction. When it touches limit switch 1, it means that the de-rotation platform has reached the positive limit. Then it moves in the reverse direction until it runs out of area 2. After reaching area 3, it can move according to the operation control instructions from area 3 to area 1. Let the de-rotation platform run into area 1, and then perform closed-loop control in area 1. At this time, when it reaches the corresponding position, set the limit Clockwise_Flag = 0; Similarly, when 0<θ dp <Limit2_encoder2,Limit1_encoder1<θ df <360°, and when the de-racing platform moves from area 1 to area 3, the speed of the de-racing platform is: ω c =const; Then 0° < θ dp <Limit2_encoder2, and 0° < θ df <When Limit2_encoder2, that is, when the racemization platform moves inside Region III, a closed loop can be performed within Region III; ω c =PI{p_err}; When 0° < θ dp <Limit2_encoder2 and Limit1_encoder1 < θ df <Limit2_encoder2, move the racemization platform position from the limit coincidence area to area three. Denote that when the limit signal AntiClockwise_Limit2 of the reverse limit is 1, it reaches the negative limit. When AntiClockwise_Limit2 = 1, then record AntiClockwise_Flag = 1, indicating that the platform has moved to the negative limit in the negative direction. At this time, reverse movement is required, that is, let; ω c =const; First, let the anti-rotation platform start to move in the reverse direction. When it touches limit switch 2, it means that the anti-rotation platform has reached the negative limit. Then it moves in the reverse direction until it runs out of area 2. After reaching area 3, it can move according to the operation control instructions from area 1 to area 3. Let the anti-rotation platform run into area 3, and then perform closed-loop control in area 3. At this time, when it reaches the corresponding position, set the limit AntiClockwise_Flag = 0; When the zero point encoder value is not zero when the camera is installed horizontally, that is, the de-rotation zero point and the encoder zero point cannot coincide with each other, which is not the case in most cases, and the de-rotation zero point and the encoder zero point of the de-rotation encoder in different telescopes are inconsistent, then record C_encoder = θ df0 =Δ, in order to ensure that the position of the camera is 0° when it is installed horizontally, the feedback of the encoder reading data needs to be offset by a Δ, then: In order to match the derotation instruction with the derotation encoder to achieve position fixed-point closed-loop and derotation motion control, the following processing is required: i dp =θ-Δ; if 5. A racemization system control method, characterized in that: The method comprises: Step 1: Calculate the angle θ that the derotation encoder needs to run dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation; Step 2: The de-rotation system receives the limit signals of the forward limit and reverse limit and the feedback value θ of the de-rotation platform. df , calculate the position and speed that the de-racing platform needs to move in various situations, and control the de-racing platform to move accordingly.

6. The control method of the racemization system according to claim 5, characterized in that: Step 1 is as follows: the de-rotation angle θ and the de-rotation speed ω required to move from the initial zero point of the de-rotation are calculated by the de-rotation position and speed solver. c The camera zero point encoder position offset processing calculator calculates the angle θ that the derotation encoder needs to run through the derotation angle θ dp , the angle θ dp This is the position to which the derotation encoder needs to move during derotation.

7. The control method of the racemization system according to claim 5, characterized in that: Step 2 is as follows: The de-rotation system receives the limit signal value of the forward limit and reverse limit and the feedback value of the de-rotation platform as θ df The limit judgment controller is based on the limit signals of the forward limit and reverse limit and the feedback value θ of the de-rotation platform. df , calculate the position and speed that the de-rotation platform needs to move in various situations, and control the movement of the de-rotation platform through the position controller, speed controller and current controller. The de-rotation encoder measures the rotational position value of the de-rotation system, and the camera zero point encoder position offset processing calculator is used to offset the camera installation position to the zero point of de-rotation, so that the camera installation zero point position coincides with the absolute position measured by the encoder, and then the calculated de-rotation rotation position value is used for closed-loop control to the de-rotation position required in any area, so as to achieve the purpose of real-time de-rotation of position and speed.

8. The control method of the racemization system according to claim 7, characterized in that: The closed-loop control to any area requires the following deracination positions: When the camera is installed horizontally, the encoder reading is exactly 0°, then C_encoder=0°, and the range of rotation of the derotation platform relative to the zero point of the camera installation horizontally is recorded as -A°~A°, where A>180°. At this time, the reading of the limit switch 1 sensing component on the encoder is Limit1_encoder1=A°, and the reading of the limit switch 2 sensing component on the encoder is Limit1_encoder2=(360-A)°, that is, the reading on the encoder when the limit switch 1 is triggered is A°, and the reading on the encoder when the limit switch 2 is triggered is (3 60-A)°, at this time, the position on the de-rotation encoder is divided into three areas, area one is Limit1_encoder1~360°, area two is Limit2_encoder2~Limit1_encoder1, and area three is 0°~Limit2_encoder2. The movement of the de-rotation platform is determined by determining in which area the position calculated by the de-rotation solution is located, and in which area the current position of the de-rotation platform is located, thereby realizing the motion control of the de-rotation platform. Specifically, the rotation angle and speed of the de-rotation platform are calculated according to the following formula; Where Z is the calculated zenith distance angle of the horizontal coordinate system, A is the azimuth of the horizontal coordinate system, φ is the latitude of the telescope installation site, δ is the declination of the star in the celestial coordinate system, t is the hour angle of the star, θ is the angle of the derotation platform offset from the derotation zero point, ω is the image rotation speed, and θ can be solved to be between -180° and 180°; If the zero point of the horizontally installed camera is between the encoder position value range (360°-A°) and A°, the zero point of the encoder falls in the middle of the range. At this time, the encoder value cannot be divided into three segments for processing. Let the derotation command value be θ dp , the feedback value of the racemic platform is θ df , then: When Limit1_encoder1 < θ dp < 360°, and 0 < θ df < Limit2_encoder2, that is, when the racemization platform needs to run from area three to area one, the speed of the racemization platform is: ω c =-const; When Limit1_encoder1<θ dp <360°, and Limit1_encoder1<θ df When it is <360°, that is, the racemization platform moves within area 1, then a closed loop can be performed within area 1; ω c =PI{p_err}; Where p_err is the positioning error of the de-racing platform; When Limit1_encoder1 < θ dp < 360°, and Limit1_encoder1 < θ df < Limit2_encoder2, move the racemization platform position from the second limit coincidence area to the first area Then there is ω c =const; When the positive limit signal Clockwise_Limit1=1, it means that the positive limit has been reached. When Clockwise_Limit1=1, Clockwise_Flag=1 is recorded, and the platform moves in the positive direction and reaches the limit signal. At this time, it needs to move in the reverse direction, that is, ω c =-const; First, let the de-rotation platform start to move in the positive direction. When it touches limit switch 1, it means that the de-rotation platform has reached the positive limit. Then it moves in the reverse direction until it runs out of area 2. After reaching area 3, it can move according to the operation control instructions from area 3 to area 1. Let the de-rotation platform run into area 1, and then perform closed-loop control in area 1. At this time, when it reaches the corresponding position, set the limit Clockwise_Flag = 0; Similarly, when 0<θ dp <Limit2_encoder2,Limit1_encoder1<θ df <360°, and when the de-racing platform moves from area 1 to area 3, the speed of the de-racing platform is: ω c =const; Then 0° < θ dp <Limit2_encoder2, and 0° < θ df <When Limit2_encoder2, that is, when the racemization platform moves inside Region Three, then a closed loop can be carried out within Region Three; ω c =PI{p_err}; When 0° < θ dp <Limit2_encoder2 and Limit1_encoder1 < θ df <Limit2_encoder2, move the racemization platform position from the limit coincidence area to area three. Denote that when the limit signal AntiClockwise_Limit2 of the reverse limit is 1, it reaches the negative limit. When AntiClockwise_Limit2 = 1, then record AntiClockwise_Flag = 1, indicating that the platform has moved to the negative limit in the negative direction. At this time, reverse movement is required, that is, let; ω c =const; First, let the anti-rotation platform start to move in the reverse direction. When it touches limit switch 2, it means that the anti-rotation platform has reached the negative limit. Then it moves in the reverse direction until it runs out of area 2. After reaching area 3, it can move according to the operation control instructions from area 1 to area 3. Let the anti-rotation platform run into area 3, and then perform closed-loop control in area 3. At this time, when it reaches the corresponding position, set the limit AntiClockwise_Flag = 0; When the value of the zero encoder is not zero when the camera is installed horizontally, that is, the de-rotation zero point and the encoder zero point cannot coincide with each other, which is not the case in most cases, and the de-rotation zero point and the encoder zero point are inconsistent in different telescopes, then record C_encoder = θ df0 =Δ, in order to ensure that the position of the camera is 0° when it is installed horizontally, the feedback of the encoder reading data needs to be offset by a Δ, then: In order to match the derotation instruction with the derotation encoder to achieve position fixed-point closed-loop and derotation motion control, the following processing is required: i dp =θ-Δ; if

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