Method for indexing a gyroless inertial platform system

Abstract

This invention proposes a method for inertial platform system rotation without activating gyroscopes. Based on the target frame position information and the acquired real-time frame position information, the inertial platform system rotates the four frames sequentially using a frame rotation trajectory method and a PID control algorithm designed for each frame, without activating the gyroscopes. The rotation is complete when the real-time positions of all four frames deviate from their corresponding target positions within (-3.5°, 3.5°). This invention solves the problem of relying solely on manual rotation for frame rotation in scenarios where gyroscopes cannot be activated. By using frame angle data instead of gyroscope data as the input for inertial platform system rotation, and through a well-designed frame rotation trajectory method and PID control algorithm, precise frame angle rotation can be achieved quickly and with high control accuracy.

Description

Technical Field

[0001] This invention relates to a method for transposition of an inertial platform system without activating a gyroscope, belonging to the field of transposition methods for inertial platform systems. Background Technology

[0002] During long-term storage of weapons and equipment, due to the inherent characteristics of the mechanical gyroscope, it is necessary to rotate each frame of the inertial platform system to a designated position to ensure that the mechanical gyroscope is placed in the optimal storage location. This work is carried out after the mechanical gyroscope is turned off after each weapon and equipment test.

[0003] Existing inertial platform systems can only calculate the rotation rate based on the difference between the target position and the real-time position when the gyroscope is activated. This rotation rate is then tracked using a stabilizing loop based on the gyroscope output to achieve arbitrary rotation of the frame. However, this rotation function cannot be achieved if the gyroscope is not activated. Therefore, it is necessary to study an inertial platform system rotation method that does not require gyroscope activation to meet the rotation requirements in situations where gyroscope activation is not possible.

[0004] Since the existing inertial platform system rotation method is to perform rotation control with gyroscope data as input when the gyroscope is activated, a completely new rotation control method with frame angle data as input needs to be designed. The following difficulties exist: (1) Since the difference between the target position information of each frame and the real-time position information collected may be large, if this difference is directly used as the input of the controller, the frame rotation may run away from control; (2) The inertial platform system has four frames, and a reasonable rotation strategy needs to be designed to ensure that the four frames rotate in an orderly manner in the shortest possible time; (3) A reasonable control algorithm needs to be designed according to the rotation characteristics of each frame to ensure that the final control accuracy is within the specified range. Summary of the Invention

[0005] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for transposition of an inertial platform system without starting the gyroscope, thereby solving the problem that the frame cannot be arbitrarily transposed without starting the gyroscope.

[0006] The technical solution of this invention is:

[0007] A method for transposition of an inertial platform system without activating a gyroscope includes the following steps:

[0008] Step 1: The inertial platform system receives the rotation command through the communication interface. The rotation command includes the target position information of the four frames: the platform body, the inner loop, the outer loop, and the servo.

[0009] Step 2: After receiving the transposition command, the inertial platform system parses and verifies it. After the verification is successful, the four frame target positions to be achieved by the transposition are obtained.

[0010] Step 3: Based on the target positions of the four frames and the real-time position information of the four frames collected, the inertial platform system rotates the four frames sequentially under the control of the PID controller, without activating the gyroscopes, according to the frame rotation trajectory method. The PID controller uses proportional control and derivative control methods. During the rotation process, the proportional coefficient and derivative are adjusted to make the frames smoothly approach the target position and reduce the frame angular fluctuation amplitude.

[0011] Step four: When the real-time position of each of the four frames deviates from the corresponding target position by more than -3.5° but less than 3.5°, the inertial platform system completes the rotation; otherwise, repeat step three. Before the inertial platform system completes the rotation, the frames that have already rotated within the range are still under the control of the PID control algorithm.

[0012] Furthermore, the format of the transposition instruction is as follows:

[0013]

[0014] The instruction frame header and the transposition instruction identifier are both fixed values; the frame target position is a real number within the range of 0° to 360°; and the instruction frame tail is a check value.

[0015] Furthermore, during verification, the instruction is checked at the beginning and end of the frame. The frame header check directly determines whether the fixed value is correctly implemented, while the frame tail check is a checksum or CRC check. If both the frame header and frame tail checks are correct, the transposition instruction data frame is considered correct.

[0016] Furthermore, the rotation sequence of the four frames is platform, inner ring, outer ring, follower. When the difference between the previous frame and the target position is within the range of -3.5° to 3.5°, the rotation operation of the next frame is started until all four frames are in the rotation control state.

[0017] Furthermore, the frame rotation trajectory method is as follows: for each frame, the rated rotation speed of the frame is set to w, in ° / s; the execution cycle of the PID control algorithm is T, in ms; and the target frame angle is set at w × T × 10° per cycle when the frame starts. -3 The change gradually increases to the rated rotational speed w, and when approaching the target, the target frame angle increases by w×T×10 per cycle. -3 The change gradually decreases until the transposition requirement is met;

[0018] The specific calculation method is as follows:

[0019] Calculate the target frame angle track_att(k) for the kth execution cycle of the PID control algorithm:

[0020]

[0021] Where step(k) is the target frame angle change in the kth execution cycle, sign is the sign function, real_att(0) is the real-time position of the frame when it starts, and real_att(k) is the real-time position of the frame angle in the kth execution cycle.

[0022] The method for calculating sign is as follows:

[0023]

[0024] Where, goal_att is the target position of the frame to which the transposition instruction is sent;

[0025] The calculation method for step(k) is as follows:

[0026] when Or {step(k-1)<w×T×10} -3 When |goal_att-track_att(k-1)|>1.5}, the frame starts and gradually increases to the rated rotation speed, i.e.

[0027]

[0028] when When goal_att-track_att(k-1)≤1.5, the frame angular rotation speed is gradually reduced as the frame approaches the target until the rotation requirement is met.

[0029]

[0030] In other cases, step(k) = w × T × 10 -3 ;

[0031] When the difference between the calculated target position track_att(k) and the frame target position goal_att sent by the transposition instruction is within the range of (-step(k), step(k)), the value of track_att(k) is goal_att.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] (1) Using the frame angle input when the gyroscope is not started as the input variable, a reasonable frame motion trajectory is designed, which solves the problem that the frame rotation can only be manually rotated in the scenario where the gyroscope cannot be started. Small step size is used as input to make the frame continuously approach the target position and solve the problem of frame rotation out of control.

[0034] (2) A targeted PID control algorithm is adopted for the four frames, which can quickly achieve precise rotation of the frame angles and achieve high control accuracy. This avoids the risks associated with existing methods that require a lot of time to adjust the control accuracy and introduce unwanted objects when the gyroscope cannot be started.

[0035] (3) The method is also applicable to other frame rotation requirements of inertial platform systems that cannot use gyroscope data as input. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the process of a rotation method for an inertial system that does not require starting the gyroscope. Detailed Implementation

[0037] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0038] Figure 1 The flowchart shows a method for transposition of an inertial system without activating the gyroscope. The method includes the following steps:

[0039] Step 1: The inertial platform system receives the rotation command through the communication interface. The rotation command includes the target position information of the four frames: the platform body, the inner loop, the outer loop, and the servo.

[0040] The format of the transpose instruction is as follows:

[0041]

[0042] The instruction frame header and the transposition instruction identifier are fixed values; the frame target position is a real number within the range of 0° to 360°; and the instruction frame header and the instruction frame tail are check values.

[0043] Step 2: After receiving the transposition command, the inertial platform system parses and verifies it. During the verification, the command is checked at the frame header and frame tail. The frame header is directly checked to see if the fixed value is correct. The frame tail is checked by checksum or CRC check. If both the frame header and frame tail are correct, the transposition command data frame is considered to be correct. After the verification is passed, the four frame target positions to be achieved by the transposition are obtained.

[0044] Step 3: Based on the target positions of the four frames and the real-time position information of the four frames collected, the inertial platform system rotates the four frames sequentially under the control of the PID controller, without activating the gyroscopes, according to the frame rotation trajectory method. The rotation sequence of the four frames is: platform, inner ring, outer ring, follower. When the difference between the previous frame and the target position is within the range of -3.5° to 3.5°, the rotation operation of the next frame is started, until all four frames are in the rotation control state.

[0045] Step four: When the real-time position of each of the four frames deviates from the corresponding target position by more than -3.5° but less than 3.5°, the inertial platform system completes the rotation; otherwise, repeat step three.

[0046] Furthermore, the frame rotation trajectory method is as follows: for each frame, the rated rotation speed of the frame is set to w, in ° / s; the execution cycle of the PID control algorithm is T, in ms; and the target frame angle is set at w × T × 10° per cycle when the frame starts. -3 The change gradually increases to the rated rotational speed w, and when approaching the target, the target frame angle increases by w×T×10 per cycle. -3 The change gradually decreases until the transposition requirement is met;

[0047] The specific calculation method is as follows:

[0048] Calculate the target frame angle track_att(k) for the kth execution cycle of the PID control algorithm:

[0049]

[0050] Where step(k) is the target frame angle change in the kth execution cycle, sign is the sign function, and real_att(0) is the real-time position of the frame at startup.

[0051] The method for calculating sign is as follows:

[0052]

[0053] Where, goal_att is the target position of the frame to which the transposition instruction is sent;

[0054] Furthermore, step(k) is calculated as follows:

[0055] when Or {step(k-1)<w×T×10} -3 And when |goal_att-track_att(k-1)|>1.5}, that is, the frame starts to gradually increase to the rated rotation speed;

[0056]

[0057] when When goal_att-track_att(k-1)≤1.5, that is, when the frame is close to the target, the angular rotation speed of the frame is gradually reduced until the rotation requirement is met;

[0058]

[0059] In other cases, step(k) = w × T × 10-3 .

[0060] Furthermore, when the difference between the calculated target position track_att(k) and the frame target position goal_at sent by the transposition instruction is within the range of (-step(k), step(k)), the value of track_att(k) is goal_att.

[0061] Furthermore, the PID control employs proportional and derivative control methods. During the rotation process, the proportional and derivative coefficients are adjusted to ensure the frame smoothly approaches the target position, reducing the frame angle fluctuation amplitude. The PID controller controlling the frame rotation is implemented digitally. The designed PID model is discretized, and the formula for calculating the frame angle output y(k) in the kth execution cycle of the PID controller is as follows:

[0062] y(k)=k×(a0×x(k)+a1×x(k-1)+b0×y(k-1))

[0063] Where x(k) is the input quantity of the controller in the current execution cycle, x(k) = track_att(k) - real_att(k); k, a0, a1, b0 are coefficients, which are discretized by MATLAB software in specific implementation.

[0064] Example:

[0065] (1) Connect the 1553B communication interface between the test equipment and the inertial platform system;

[0066] (2) When the inertial platform system is powered on, the test equipment sends the rotation command to the inertial platform system through the communication interface. An example of the command content is as follows:

[0067]

[0068] (3) The inertial platform system acquires the transposition command and parses the information it contains to obtain the target position information to be achieved by the transposition: 0°, 0°, 0°, 0°;

[0069] (4) Set the rated rotation speed of the frame to 3° / s, the execution cycle of the control algorithm to 1ms, calculate the target change step(k) for each execution cycle, and obtain the target position track_att(k) for each execution cycle.

[0070] (5) Design PID control algorithms suitable for each frame respectively. The specific implementation is as follows: In each execution cycle, the controller is used to control the rotation of each frame so that it follows the target position of each frame in that execution cycle.

[0071] Platform frame control algorithm:

[0072] y(k)=2730.32×(3.792647·x(k)-3.661765·x(k-1)+0.6744·y(k-1))

[0073] Inner ring frame control algorithm:

[0074] y(k)=6049.365×(3.196·x(k)-3.129·x(k-1)+0.7744·y(k-1)

[0075] Outer ring frame control algorithm:

[0076] y(k)=1160.386×(2.665773·x(k)-2.64925·x(k-1)+0.9744·y(k-1))

[0077] Follow-up frame control algorithm:

[0078] y(k)=14689.1216×(2.232·x(k)-2.213·x(k-1)+0.6744·y(k-1))

[0079] Where y(k) is the output of the PID controller in the kth execution cycle, x(k) is the frame angle input of the PID controller in the kth execution cycle, x(k) = track_att(k) - real_att(k), real_att(k) is the real-time position information of the frame angle collected in the kth execution cycle, and track_att(k) is the target position of the frame angle in the kth execution cycle;

[0080] (6) Based on the designed rotation trajectory and control algorithm, rotate each frame sequentially in the order of first the platform body, then the inner ring, then the outer ring, and finally the follower. When the difference between the previous frame and the target position is within the range of (-3.5°, 3.5°), start the rotation operation of the next frame until all four frames are in the rotation control state. The specific implementation flowchart is as follows: Figure 1 As shown;

[0081] (7) When the real-time position of the four frames deviates from the target position transmitted by the transposition command within (-3.5°, 3.5°), the inertial platform system uploads the "transposition complete" status.

[0082] This invention proposes a method for inertial platform system rotation without activating gyroscopes. Based on the target frame position information and the acquired real-time frame position information, the inertial platform system rotates the four frames sequentially using a frame rotation trajectory method and a PID control algorithm designed for each frame, without activating the gyroscopes. The rotation is complete when the real-time positions of all four frames deviate from their corresponding target positions within (-3.5°, 3.5°). This invention solves the problem of relying solely on manual rotation for frame rotation in scenarios where gyroscopes cannot be activated. By using frame angle data instead of gyroscope data as the input for inertial platform system rotation, and through a well-designed frame rotation trajectory method and PID control algorithm, precise frame angle rotation can be achieved quickly and with high control accuracy.

[0083] The contents not described in detail in this invention are common knowledge to those skilled in the art.

Claims

1. A method for transposition of an inertial platform system without activating a gyroscope, characterized in that... The steps include the following: Step 1: The inertial platform system receives the rotation command through the communication interface. The rotation command includes the target position information of the four frames: the platform body, the inner loop, the outer loop, and the servo. Step 2: After receiving the transposition command, the inertial platform system parses and verifies it. After the verification is successful, the four frame target positions to be achieved by the transposition are obtained. Step 3: Based on the target positions of the four frames and the real-time position information of the four frames collected, the inertial platform system rotates the four frames in sequence according to the frame rotation trajectory method and under the control of the PID controller, without starting the gyroscope, in the order of rotation of the platform body, inner ring, outer ring, and follower. The frame rotation trajectory method in step three is as follows: for each frame, the rated rotation speed of the frame is set to... The unit is ° / s, the execution cycle of the PID control algorithm is T, the unit is ms, and the target frame angle at frame startup is calculated per cycle. The change gradually increases to the rated rotational speed When approaching the target, the target frame angle changes per cycle. The change gradually decreases until the transposition requirement is met; The specific calculation method is as follows: Calculate the first step of the PID control algorithm The target framework angle of each execution cycle : in, For the first Change in the target frame angle for each execution cycle For symbolic functions, This is the real-time location of the framework at startup, as captured. For the first time collected Real-time position of the frame corner in each execution cycle; Step four: When the real-time position of each of the four frames deviates from the corresponding target position by more than -3.5° but less than 3.5°, the inertial platform system completes the rotation; otherwise, repeat step three.

2. The method for transposition of an inertial platform system without activating a gyroscope according to claim 1, characterized in that: The format of the transpose instruction in step one is as follows: The instruction frame header and the transposition instruction identifier are both fixed values; the frame target position is a real number within the range of 0° to 360°; and the instruction frame tail is a check value.

3. The inertial platform system rotation method without activating the gyroscope according to claim 1, characterized in that: In step two, the instruction is checked during verification, including frame header and frame tail checks. The frame header check directly determines whether the fixed value is correctly implemented, while the frame tail check is a checksum or CRC check. If both the frame header and frame tail checks are correct, the transposition instruction data frame is considered correct.

4. The method for transposition of an inertial platform system without activating a gyroscope according to claim 1, characterized in that: In steps three and four, the rotation sequence of the four frames is platform, inner ring, outer ring, follower. When the difference between the previous frame and the target position is within the range of -3.5° to 3.5°, the rotation operation of the next frame is started until all four frames are in the rotation control state.

5. The inertial platform system rotation method without activating the gyroscope according to claim 1, characterized in that: The calculation method is as follows: in, The target position of the frame for sending the transpose instruction.

6. The inertial platform system rotation method without activating the gyroscope according to claim 1, characterized in that: The calculation method is as follows: when At that time, the frame starts and gradually increases to the rated rotation speed, that is... when As the frame approaches the target, the angular rotation speed of the frame is gradually reduced until the rotation requirement is met. In other cases .

7. The inertial platform system rotation method without activating the gyroscope according to claim 6, characterized in that: When the calculated target position The target position of the frame sent by the transposition instruction The difference between them is in (- , When within the range, The value takes .

8. The method for transposition of an inertial platform system without activating a gyroscope according to claim 1, characterized in that: In step three, the PID controller uses proportional control and derivative control methods. During the rotation process, the proportional coefficient and derivative are adjusted to make the frame smoothly approach the target position.

9. The method for transposition of an inertial platform system without activating a gyroscope according to claim 1, characterized in that: In step four, before the inertial platform system completes the rotation, the frame that has already rotated within the range is still under the control of the PID control algorithm.

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