A decoupling method for stabilizing a platform table body relative to inertial space

Abstract

The application discloses a decoupling method for stabilizing a platform body relative to inertial space, which comprises the following steps: obtaining angular velocity components of the platform body on X p axis, Y p axis and Z p axis according to angular velocity output by a gyroscope installed on the platform body, and obtaining an angle and angular velocity of internal relative rotation of a four-axis inertial stabilization platform system; calculating a resultant rotation angular velocity ω p of the platform body on Z z axis, a resultant rotation angular velocity ω p1 of an inner frame on Y y axis, a resultant rotation angular velocity ω p2 of a middle frame on X x axis and a resultant rotation angular velocity ω p3 of an outer frame on Y yk′ axis according to the angular velocity components and the angle of the internal relative rotation, respectively. The application has the characteristics of minimum output energy under the condition that the platform body is stabilized relative to inertial space.

Description

Technical Field

[0001] This invention relates to a decoupling method for stabilizing a platform relative to inertial space, belonging to the field of inertial measurement technology. Background Technology

[0002] Because three-axis inertial platform systems suffer from "frame locking," making it difficult to meet the requirements of large-scale maneuvering of the platform, four-axis inertial platform systems were developed. Compared to three-axis inertial platform systems, four-axis inertial platform systems add an outer frame to the platform body, inner frame, and middle frame. The outer frame is located between the middle frame and the base of the platform.

[0003] To stabilize the platform relative to inertial space, the traditional solution is as follows: the servo loop is based on the inner frame angle β. yk and the angle β of the middle frame xk Different decouplers are used in different regions, see the reference "Variable Structure Partition Control of Four-Axis Gyroscope Stabilized Platform, Tsinghua University Journal Vol.50, No.7, 2010". The reason for using partition control is that when controlling the four axis motors in conjunction with the outputs of the three gyroscopes and any frame angle, there is a region where the motor driving torque is infinite, which may cause control failure. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and solve the decoupling problem of the servo loop without the need to divide the interval.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] A decoupling method for stabilizing a platform relative to inertial space, wherein the platform is a four-axis inertial stabilized platform, the decoupling method includes:

[0007] Based on the angular velocity output by the gyroscope mounted on the platform, the position of the platform in the X direction is obtained. p Axis, Y p Axis and Z p angular velocity components on the axis

[0008] Measuring the X-axis of the outer frame around the coordinate system of the middle frame p2 The angle β of the shaft rotation xk The Y-axis of the middle frame around the inner frame's body coordinate system p1 The angle β of the shaft rotation yk Z-axis of the inner frame around the body coordinate system p The angle β of the shaft rotation zk ;

[0009] The combined rotational angular velocity of the platform, inner frame, middle frame, and outer frame is determined using the following formula:

[0010]

[0011]

[0012]

[0013]

[0014] Where, ω z For Taiwan Z p The resultant rotational angular velocity of the shaft; ω y For the inner frame Y p1 The resultant rotational angular velocity of the shaft; ω x For the medium frame X p2 The resultant rotational angular velocity of the shaft; ω yk′ For the outer frame Y p3 The resultant rotational angular velocity of the shaft;

[0015] The output energy of the servo loop of the four-axis inertial stabilization platform is expressed as the sum of the squares of all the combined rotational angular velocities.

[0016] In one embodiment of the present invention, the decoupling method outputs the minimum energy.

[0017] In one embodiment of the present invention, the middle frame X p2 The combined rotational angular velocity of the shaft and the Y-axis of the outer frame p3 The combined rotational angular velocity of the shaft has a singular value.

[0018] In one embodiment of the present invention, the condition for singular values ​​is cos 2 β xk sin 2 β yk =1.

[0019] In one embodiment of the present invention, the singular value points include the following four points (β). yk ,β xk ) = (90°, 0°), (90°, 180°), (270°, 0°), (270°, 180°).

[0020] A four-axis inertial stabilization platform system employing the aforementioned decoupling method includes a base, an outer frame, a middle frame, an inner frame, and a platform. The platform is mounted on the inner frame, the inner frame is mounted on the middle frame, the middle frame is mounted on the outer frame, and the outer frame is mounted on the base.

[0021] In one embodiment of the present invention, the base, outer frame, middle frame, inner frame, and platform are respectively defined by the base body coordinate system X1Y1Z1 and the outer frame coordinate system X... p3 Yp3 Z p3 , Medium frame body coordinate system X p2 Y p2 Z p2 The inner frame body coordinate system X p1 Y p1 Z p1 and the X coordinate system of the platform body p Y p Z p ;

[0022] Z of the platform body coordinate system p Z-axis and the coordinate system of the inner frame p1 The axes coincide, and the Y-axis of the body coordinate system of the middle frame is... p2 Y-axis and the coordinate system of the inner frame p1 The axes coincide, and the X coordinate of the outer frame body coordinate system is... p3 The X-axis of the axis and the body coordinate system of the middle frame p2 The X1 axis of the base body coordinate system coincides with the Y-axis of the follower frame body coordinate system. The base is fixed to the carrier. When the stable platform system undergoes internal relative rotation under the drive of the carrier: the base rotates around the Y-axis of the outer frame body coordinate system... p3 The axis rotates by an angle β. yk′ The X coordinate system of the outer frame around the middle frame body. p2 The axis rotates by an angle β. xk ; Y-axis of the middle frame around the inner frame body coordinate system p1 The axis rotates by an angle β. yk The Z-axis of the inner frame around the body coordinate system of the platform p The axis rotates by an angle β. zk .

[0023] In one embodiment of the present invention, the relative rotation angle inside the four-axis inertial stabilized platform system is measured by the following method:

[0024] X in the outer frame p2 An angle sensor is mounted on the axis to measure the X-axis of the outer frame around the coordinate system of the middle frame. p2 The angle β of the shaft rotation xk ; in the inner frame Y p1 An angle sensor is installed on the axis to measure the Y-axis of the middle frame around the inner frame's coordinate system. p1 The angle β of the shaft rotation yk ; in Taiwan Z p A sensor mounted on the axis measures the Z-axis coordinate of the inner frame around the body coordinate system of the stage. p The angle β of the shaft rotation zk .

[0025] In one embodiment of the present invention, β zk βyk′ The value range of β is -180 to 180°; yk The value range of β is -90 to 270°; xk The value range is -180 to 180°, and cos is excluded. 2 β xk sin 2 β yk Angle = 1.

[0026] A computer-readable storage medium having stored thereon computer program instructions, which, when loaded and run by a processor, cause the processor to perform the above-described decoupling method.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) The servo loop output energy minimum decoupling method given by the present invention has only one expression form. Compared with the variable structure partition control which has different expressions in different intervals, the decoupling method of the present invention has the characteristics of simple structure and strong adaptability, which is conducive to physical implementation or mathematical programming.

[0029] (2) The method of the present invention has the characteristic of minimizing the output energy under the premise of stabilizing the platform, which is beneficial to saving control energy.

[0030] (3) The method described in this invention has the advantage of not requiring interval control signal switching compared to variable structure partition control, avoiding the platform jitter problem caused by switching during variable structure partition control, which is conducive to achieving stability of the platform relative to the inertial space and has the characteristics of high precision. Attached Figure Description

[0031] Figure 1 This is a schematic diagram illustrating the relationship between five body coordinate systems in a four-axis inertial stabilization platform system according to an embodiment of the present invention.

[0032] Figure 2 This is a flowchart of the steps of a servo loop decoupling method for a four-axis inertial stabilization platform system proposed in this invention;

[0033] Figure 3 This is the singularity point with the minimum output energy of the present invention;

[0034] Figure 4 It is a region divided according to the angles of the inner frame and the middle frame in the variable structure zoning control;

[0035] Figure 5 It is the process of the frame angle changing over time during variable structure zoning control;

[0036] Figure 6It refers to the area where the inner frame and middle frame angles are located during variable structure zoning control;

[0037] Figure 7 This describes the change of the platform's angular velocity over time during variable structure zone control.

[0038] Figure 8 The process of the angle of the platform relative to the inertial space changing over time when the variable structure zoning control is implemented;

[0039] Figure 9 This describes the change of the frame angle over time when the minimum output energy is controlled using the present invention.

[0040] Figure 10 This refers to the region where the inner and middle frames are located when the output energy is minimized using the present invention.

[0041] Figure 11 This describes the change in the platform's angular velocity over time when the output energy is minimized using the present invention.

[0042] Figure 12 This describes the change in the angle of the platform relative to the inertial space over time when the output energy is minimized using the present invention. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0044] The present invention provides a method for minimizing the output energy of the servo loop of a four-axis inertial stabilization platform, which is implemented based on a four-axis inertial stabilization platform system. This four-axis stabilization platform system includes a base, an outer frame, a middle frame, an inner frame, and a platform body, with corresponding body coordinate systems of X1Y1Z1 for the base and X2Y1Z1 for the outer frame. p3 Y p3 Z p3 , Medium frame body coordinate system X p2 Y p2 Z p2 The inner frame body coordinate system X p1 Y p1 Z p1 and the X coordinate system of the platform body p Y p Z p .

[0045] like Figure 1 The diagram shows the relationship between the five coordinate systems. The origins of these five coordinate systems coincide, and they have the following relative constraints: the Z-axis of the platform body coordinate system... p Z-axis and the coordinate system of the inner frame p1 The axes coincide, and the Y-axis of the body coordinate system of the middle frame is...p2 Y-axis and the coordinate system of the inner frame p1 The axes coincide, and the X coordinate of the outer frame body coordinate system is... p3 The X-axis of the axis and the body coordinate system of the middle frame p2 The X1 axis of the base body coordinate system coincides with the Y-axis of the follower frame body coordinate system. The base is fixed to the carrier. When the stable platform system undergoes internal relative rotation under the drive of the carrier: the base rotates around the Y-axis of the outer frame body coordinate system... p3 The axis rotates by an angle β. yk′ The X coordinate system of the outer frame around the middle frame body. p2 The axis rotates by an angle β. xk ; Y-axis of the middle frame around the inner frame body coordinate system p1 The axis rotates by an angle β. yk The Z-axis of the inner frame around the body coordinate system of the platform p The axis rotates by an angle β. zk .

[0046] like Figure 2 The processing flowchart shown illustrates the following steps for implementing the minimum output energy decoupling method for the servo loop of the four-axis inertial platform system of this invention:

[0047] (1) Based on the angular velocity output by the gyroscope mounted on the platform, the position of the platform in the X direction is obtained. p Axis, Y p Axis and Z p angular velocity components on the axis

[0048] (2) The relative rotation angles inside the four-axis inertial stabilized platform system were measured, including: the X-axis of the outer frame around the coordinate system of the middle frame. p2 The angle β of the shaft rotation xk ; Y-axis of the middle frame around the inner frame body coordinate system p1 The angle β of the shaft rotation yk ; Z-axis of the inner frame around the body coordinate system of the platform p The angle β of the shaft rotation zk ;

[0049] (3) Calculate the rotational angular velocities of the platform, inner frame, middle frame, and outer frame. The specific calculation formulas are as follows:

[0050]

[0051]

[0052]

[0053]

[0054] Where, ω z For Taiwan Z p The resultant rotational angular velocity of the shaft; ω y For the inner frame Y p1 The resultant rotational angular velocity of the shaft; ω x For the medium frame X p2 The resultant rotational angular velocity of the shaft; ω yk′ For the outer frame Y p3 The resultant rotational angular velocity of the shaft.

[0055] When cos 2 β xk sin 2 β yk When ω = 1, the resultant rotational angular velocity ω x and ω yk′ There are singular values. The condition cos... 2 β xk sin 2 β yk The angle = 1 includes the following four points (β) yk ,β xk ) = (90°, 0°), (90°, 180°), (270°, 0°), (270°, 180°). Singularities are as follows: Figure 3 As shown by the dots in the diagram, (90°, 180°) and (90°, -180°) are one point, and (270°, 180°) and (270°, -180°), (-90°, 180°), and (-90°, -180°) are another point.

[0056] According to the decoupler of the present invention, its output energy is expressed as the sum of squares of angular velocities.

[0057]

[0058] To further illustrate that the decoupler of the present invention has the characteristic of minimum energy consumption, three embodiments are given below.

[0059] Example 1:

[0060] For the variable structure partitioning control method Figure 4 Regions 1, 2, and 3 in the diagram, when cosβ yk When ≠0, a decoupling method to stabilize the platform relative to inertial space is as follows:

[0061]

[0062]

[0063]

[0064] Where, ωz1 For Taiwan Z p The resultant rotational angular velocity of the shaft; ω y1 For the inner frame Y p1 The resultant rotational angular velocity of the shaft; ω x1 For the medium frame X p2 The resultant rotational angular velocity of the shaft.

[0065] Its output energy is expressed as the sum of squares of angular velocities.

[0066]

[0067] Example 2:

[0068] For the variable structure partitioning control method Figure 4 Region 4 in the middle, when sinβ xk sinβ yk When ≠0, a decoupling method to stabilize the platform relative to inertial space is as follows:

[0069]

[0070]

[0071]

[0072] Where, ω z2 For Taiwan Z p The resultant rotational angular velocity of the shaft; ω y2 For the inner frame Y p1 The resultant rotational angular velocity of the shaft; ω yk′2 For the outer frame Y p3 The resultant rotational angular velocity of the shaft.

[0073] Its output energy is expressed as the sum of squares of angular velocities.

[0074]

[0075] As can be seen from the two examples above, the decoupler of the present invention outputs the least amount of energy.

[0076] Compare Figure 3 The output energy minimum decoupling method of the present invention is shown below. Figure 4 The variable structure partitioning control method shown in the figure can be seen to be applicable to all regions except singularities, while variable structure partitioning control requires consideration of switching control between different regions. Simulation results of the two methods are given below for performance comparison.

[0077] Example 3:

[0078] Let β yk′ β xk βyk β zk The initial values ​​are 0°, 60°, 40°, and 0° respectively. When using variable structure zoning control, the initial position is in region 3. Let the platform base angular velocity be...

[0079] The time-varying process of the frame angle controlled by variable structure zoning is as follows: Figure 5 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 6 As shown, the change of the angular velocity of the platform with time is as follows: Figure 7 As shown, the angle θ between the platform and the inertial space x θ y θ z The process of change over time is as follows Figure 8 As shown. At 0.5s, the platform enters region 1 from region 3, and the angular velocity of the platform is... Up to -80° / s The angle θ of the platform relative to inertial space can reach over -300° / s. x At the switching moment, it can reach -2.5°, θ y The temperature can reach -0.7° at the switching moment.

[0080] When using the minimum output energy decoupling method of this invention for control, the change process of the frame angle over time is as follows: Figure 9 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 10 As shown, the change of the angular velocity of the platform with time is as follows: Figure 11 As shown, the angle θ between the platform and the inertial space x θ y θ z The process of change over time is as follows Figure 12 As shown. During the control process, the angular velocity of the platform... Reachable to -2.3×10 -8 ° / s、 Up to 4.5×10 -5 ° / s, the angle θ of the platform relative to inertial space. x and θ y Not exceeding 2.8 × 10 -5 °, less than 1″.

[0081] By comparing the variable structure partition control with the minimum output energy decoupling method of the present invention, it can be seen that the method of the present invention has higher accuracy due to the absence of region switching.

[0082] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0083] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A decoupling method for stabilizing a platform body relative to inertial space, characterized in that, The platform is a four-axis inertial stabilized platform, and the decoupling method includes: Based on the angular velocity output by the gyroscope mounted on the platform, the position of the platform in the X direction is obtained. p Axis, Y p Axis and Z p angular velocity components on the axis Measuring the X-axis of the outer frame around the coordinate system of the middle frame p2 The angle β of the shaft rotation xk The Y-axis of the middle frame around the inner frame's body coordinate system p1 The angle β of the shaft rotation yk Z-axis of the inner frame around the body coordinate system p The angle β of the shaft rotation zk ; The combined rotational angular velocity of the platform, inner frame, middle frame, and outer frame is determined using the following formula: Where, ω z For Taiwan Z p The resultant rotational angular velocity of the shaft; ω y For the inner frame Y p1 The resultant rotational angular velocity of the shaft; ω x For the medium frame X p2 The resultant rotational angular velocity of the shaft; ω yk′ For the outer frame Y p3 The resultant rotational angular velocity of the shaft; The output energy of the servo loop of the four-axis inertial stabilized platform is expressed as the sum of the squares of all the combined rotational angular velocities; This decoupling method outputs the least amount of energy; Medium Frame X p2 The combined rotational angular velocity of the shaft and the Y-axis of the outer frame p3 The combined rotational angular velocity of the shaft has a singular value.

2. The decoupling method according to claim 1, characterized in that, The condition for singular values ​​is cos 2 β xk sin 2 β yk =1.

3. The decoupling method according to claim 1, characterized in that, The singular values ​​include the following four points (β). yk ,β xk ) = (90°, 0°), (90°, 180°), (270°, 0°), (270°, 180°).

4. A four-axis inertial stabilization platform system employing the decoupling method described in any one of claims 1 to 3, characterized in that, The four-axis inertial stabilization platform system includes a base, an outer frame, a middle frame, an inner frame, and a platform. The platform is mounted on the inner frame, the inner frame is mounted on the middle frame, the middle frame is mounted on the outer frame, and the outer frame is mounted on the base.

5. The four-axis inertial stabilization platform system according to claim 4, characterized in that, The base, outer frame, middle frame, inner frame, and platform have corresponding body coordinate systems: base body coordinate system X1Y1Z1, outer frame coordinate system X... p3 Y p3 Z p3 , Medium frame body coordinate system X p2 Y p2 Z p2 The inner frame body coordinate system X p1 Y p1 Z p1 and the X coordinate system of the platform body p Y p Z p ; Z of the platform body coordinate system p Z-axis and the coordinate system of the inner frame p1 The axes coincide, and the Y-axis of the body coordinate system of the middle frame is... p2 Y-axis and the coordinate system of the inner frame p1 The axes coincide, and the X coordinate of the outer frame body coordinate system is... p3 The X-axis of the axis and the body coordinate system of the middle frame p2 The X1 axis of the base body coordinate system coincides with the Y axis of the follower frame body coordinate system. The base is fixed to the carrier. When the stable platform system undergoes internal relative rotation under the drive of the carrier: the base rotates around the Y axis of the outer frame body coordinate system... p3 The axis rotates by an angle β. yk ′; The outer frame around the middle frame's body coordinate system X p2 The axis rotates by an angle β. xk ; Y-axis of the middle frame around the inner frame body coordinate system p1 The axis rotates by an angle β. yk The Z-axis of the inner frame around the body coordinate system of the platform p The axis rotates by an angle β. zk .

6. The four-axis inertial stabilization platform system according to claim 4, characterized in that, The relative rotation angles inside the four-axis inertial stabilized platform system were measured using the following method: X in the outer frame p2 An angle sensor is installed on the axis to measure the X-axis of the outer frame around the coordinate system of the middle frame. p2 The angle β of the shaft rotation xk ; in the inner frame Y p1 An angle sensor is installed on the axis to measure the Y-axis of the middle frame around the inner frame's coordinate system. p1 The angle β of the shaft rotation yk ; in Taiwan Z p A sensor mounted on the axis measures the Z-axis coordinate of the inner frame around the body coordinate system of the stage. p The angle β of the shaft rotation zk .

7. The four-axis inertial stabilization platform system according to claim 4, characterized in that, β zk β yk′ The value range of β is -180 to 180°; yk The value range of β is -90 to 270°; xk The value range is -180 to 180°, and cos is excluded. 2 β xk sin 2 β yk Angle = 1.

8. A computer-readable storage medium having stored thereon computer program instructions, which, when loaded and executed by a processor, cause the processor to perform the method as described in any one of claims 1 to 3.

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