Non-singularity path continuous variable structure control method for servo loop of inertial stabilized platform

Abstract

This invention discloses a singularity-free path continuous variable structure control method for an inertial stabilization platform servo loop, comprising: obtaining the position of the platform in the X-axis... p Axis, Y p Axis and Z p The angular velocity component on the shaft and the measured rotation angle β of the outer frame are obtained. xk , rotation angle β of the middle frame yk Inner frame rotation angle β zk Given the values ​​of the parameters of the compliant continuous variable structure and the active region corresponding to the path without singularities, the angular velocity correction value Δω of the compliant continuous variable structure is calculated; based on β xk β yk β zk And Δω, calculate ω z ω y ω x and ω yk′ ; will ω z ω y ω x and ω yk′ The output, after being fed to the linear controller, acts on the torque motors at each axis end of the inertial stabilization platform, thereby stabilizing the platform body relative to inertial space. This invention overcomes the platform swaying caused by switching between different control signals when using partitioned variable structure control, thus enhancing the stability of the platform body relative to inertial space and improving the accuracy of navigation calculations.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of inertial measurement, and particularly relates to a singular point-free path continuous variable structure control method for a servo loop of an inertial stabilized platform. BACKGROUND

[0002] Since a three-axis inertial platform system has a "frame locking" phenomenon, it is difficult to meet the requirements of large maneuvering motion of a carrier, and therefore, a four-axis inertial platform system is generated. The four-axis inertial platform system increases an outer frame on the basis of a platform body, an inner frame and a middle frame relative to the three-axis inertial platform system, and the outer frame is between the middle frame and a base.

[0003] In engineering applications, in order to stabilize the platform body relative to an inertial space, limit stop pins are installed on the inner frame shafts to limit the range of the inner frame angle (generally not more than ±45°). When β xk = ±90°, the inner frame angle will change with the motion of the carrier and cannot be kept at zero. A solution is as follows: "a method of rotating the outer frame by 90° to make the inner frame angle return to the vicinity of zero, and at the same time, the middle frame is away from the ±90° position, so that the three-frame four-axis platform meets the working conditions of the traditional servo loop again", see the document "Research on Control Strategy of Four-axis Inertial Platform Servo Frame, Navigation and Control, 2017, No. 4".

[0004] When the method is adopted, the inner frame angle and the middle frame angle are in different intervals, and there is switching between different control signals when the partition control is adopted, but the switching time will also cause instantaneous jitter of the platform body, resulting in shaking of the platform body relative to the space.

[0005] Then, can the inner frame angle be free to move without being limited? The inner frame angle can be free to move by limiting the middle frame angle β xk Working at ±90° can also avoid that the four rotating shafts are in the same plane. Therefore, there is an urgent need in the field to research a new decoupling method to meet the requirements of full attitude motion. SUMMARY

[0006] The technical problem of the application is to overcome the shortcomings of the prior art, provide a singular point-free path continuous variable structure control method for a servo loop of an inertial stabilized platform, overcome the shaking of the platform body caused by switching between different control signals when the partition variable structure control is adopted, and enhance the stability of the platform body relative to the inertial space, which is beneficial to improve the accuracy of navigation solution.

[0007] In order to solve the above technical problems, the application discloses a singular point-free path continuous variable structure control method for a servo loop of an inertial stabilized platform, which comprises the following steps:

[0008] According to the angular velocity output by the gyroscope installed on the platform body, the angular velocity of the platform body in the X paxis, Y p axis and Z p angular velocity component on the axis and

[0009] measured outer frame rotates around the middle frame body coordinate system X p2 angle β of the axis rotation xk , middle frame rotates around the inner frame body coordinate system Y p1 angle β of the axis rotation yk , inner frame rotates around the table body coordinate system Z p angle β of the axis rotation zk ;

[0010] Given the value of the compliant continuously variable structure parameter, and the active region corresponding to the non-singularity path, the angular velocity correction value Δω of the compliant continuously variable structure is calculated;

[0011] According to β xk , β yk , β zk and Δω, the combined rotation angular velocity ω p of the table Z z axis, the combined rotation angular velocity ω p1 of the inner frame Y y axis, the combined rotation angular velocity ω p2 of the middle frame X x axis, and the combined rotation angular velocity ω p3 of the outer frame Y yk′ axis are calculated.

[0012] After ω z , ω y , ω x and ω yk′ are output to the linear controller, they act on the torque motors at the ends of the axes of the inertially stabilized platform to realize the stability of the table of the inertially stabilized platform relative to the inertial space.

[0013] In the above inertially stabilized platform servo loop non-singularity path continuously variable structure control method, the inertially stabilized platform is a four-axis inertially stabilized platform, which comprises a base, an outer frame, a middle frame, an inner frame and a table;

[0014] The body coordinate systems corresponding to the base, the outer frame, the middle frame, the inner frame and the table respectively are: the base body coordinate system X1Y1Z1, the outer frame body coordinate system X p3 Y p3 Z p3 , the middle frame body coordinate system X p2 Y p2 Z p2 , the inner frame body coordinate system X p1 Yp1 Z p1 and the X coordinate system of the platform body p Y p Z p ;

[0015] Base body coordinate system X1Y1Z1, outer frame body 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 The origins coincide, and: the Z-axis of the platform's body coordinate system coincides with the origin of the platform. p Z-axis and the coordinate system of the inner frame p1 The axes coincide, and the Y-axis of the middle frame body coordinate system 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 axes coincide, the X1 axis of the base body coordinate system and the Y axis of the outer frame body coordinate system. p3 Axis coincidence;

[0016] The base is fixed to the carrier. When the four-axis inertial stabilized platform undergoes internal relative rotation under the drive of the carrier, the base rotates around the Y-axis of the outer frame's body coordinate system. p3 The axis rotates, and the outer frame revolves around the X coordinate system of the middle frame. p2 The axis rotates, and the middle frame rotates around the Y-axis of the inner frame's body coordinate system. p1 The axis rotates, and the inner frame rotates around the Z-axis of the platform's coordinate system. p The shaft rotates.

[0017] In the above-mentioned continuous variable structure control method for the servo loop of the inertial stabilization platform without singularity path, the active region corresponding to the non-singularity path includes: a "+" shaped active region and a "#" shaped active region.

[0018] In the above-mentioned servo loop control method for continuous variable structure without singularity paths in the inertial stabilization platform, when the active region corresponding to the path without singularity is a "+" shaped active region, the angular velocity correction value Δω of the compliant continuous variable structure is calculated as follows:

[0019] Given the value of the compliant continuous variable structure parameter k, and the "+" shaped active region β nx ≤β xk ≤β mxor β ny ≤β yk ≤β my ; where β nx Indicates β xk Minimum value of the active region, β mx Indicates β xk The maximum value of the active region, β ny Indicates β yk Minimum value of the active region, β my Indicates β yk The maximum value of the active area;

[0020] The angular velocity correction value Δω of the compliant continuous variable structure can be calculated using the following formula:

[0021]

[0022] Among them, (β) ny +β my ) / 2=0° or (β) ny +β my ) / 2=180°, (β) nx +β mx ) / 2=90° or (β) nx +β mx ) / 2 = -90°.

[0023] In the above-mentioned servo loop continuous variable structure control method for inertial stabilization platforms without singularity paths, when the active region corresponding to the path without singularity is a "#" shaped active region, the angular velocity correction value Δω of the compliant continuous variable structure is calculated as follows:

[0024] Given the value of the compliant continuous variable structure parameter k, and the "#" shaped active region β n1x ≤β xk ≤β m1x or β n2x ≤β xk ≤β m2x or β n1y ≤β yk ≤β m1y or β n2y ≤β yk ≤β m2y ; where β n1x Indicates β xk At its minimum value in the activity region greater than 0°, β m1x Indicates β xk The maximum value of β in the activity region greater than 0° n2x Indicates β xk At its minimum value in the activity region less than 0°, β m2x Indicates β xk The maximum value of β in the activity region less than 0°n1y Indicates β xk At its minimum value in the activity region less than 90°, β m1y Indicates β xk β is the maximum value in the activity region less than 90°. n2y Indicates β xk The minimum value of β in the activity region greater than 90° m2y Indicates β xk Maximum value in the activity region greater than 90°;

[0025] The angular velocity correction value Δω of the compliant continuous variable structure can be calculated using the following formula:

[0026]

[0027] Where, β n2x <β m2x <β n1x <β m1x ,β n1y <β m1y <β n2y <β m2y , and (β) n1x +β m1x ) / 2=90°、(β n2x +β m2x ) / 2=-90°、(β n1y +β m1y ) / 2=0°、(β n2y +β m2y ) / 2 = 180°.

[0028] In the above-mentioned singularity-free path continuous variable structure control method for the servo loop of the inertial stabilization platform, ω is calculated using the following formula. z ω y ω x and ω yk′ :

[0029]

[0030] In the above-mentioned singularity-free path continuous variable structure control method for the servo loop of the inertial stabilization platform, the X-axis of the outer frame around the body coordinate system of the middle frame is measured. 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 The Z-axis of the inner frame around the body coordinate system of the platform p The angle β of the shaft rotation zk ,include:

[0031] X in the outer frame p2An angle sensor is installed on the shaft to measure β. xk ;

[0032] Y in the inner frame p1 An angle sensor is installed on the shaft to measure β. yk ;

[0033] In the Z of the platform p An angle sensor is installed on the shaft to measure β. zk .

[0034] In the above-mentioned singularity-free path continuous variable structure control method for the servo loop of the inertial stabilized platform, β yk The value range of β is -90 to 270°; zk and β xk The value range is -180 to 180°.

[0035] The present invention has the following advantages:

[0036] (1) This invention discloses a continuous variable structure control method for the servo loop of an inertial stabilization platform without singularity points. It overcomes the influence of the transition process on the stability of the platform during the interval switching process of the partitioned discrete variable structure control, eliminates the dynamic error caused by the frequent shaking caused by the interval switching, and thus improves the accuracy of inertial navigation.

[0037] (2) This invention discloses a continuous variable structure control method for the servo loop of an inertial stabilization platform without singularity points. Compared with the partitioned variable structure control method when the inner frame is limited, it has the characteristic of smaller output energy, which is beneficial to saving control energy.

[0038] (3) This invention discloses a continuous variable structure control method for the servo loop of an inertial stabilization platform without singularity. Compared with the partitioned variable structure control method when the inner frame is limited, it has the characteristics of small overshoot, no partitioning is required, the control algorithm is simple, and it is easy to implement in engineering. Attached Figure Description

[0039] Figure 1 This is a schematic diagram showing the relationship between the five body coordinate systems in a four-axis inertial stabilization platform according to an embodiment of the present invention;

[0040] Figure 2 This is a flowchart illustrating the steps of a continuous variable structure control method for a servo loop without singularities in an inertial stabilization platform according to an embodiment of the present invention.

[0041] Figure 3 This is a schematic diagram of the area divided according to the inner frame angle and the middle frame angle in a variable structure zoning control according to an embodiment of the present invention;

[0042] Figure 4This is a schematic diagram illustrating the change of frame angle over time during variable structure partitioning control in an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the area where the angles of the inner frame and the middle frame are located during a variable structure partitioning control in an embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram illustrating the change of the platform's angular velocity over time during a variable structure partition control scenario according to an embodiment of the present invention.

[0045] Figure 7 This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time during a variable structure partition control method according to an embodiment of the present invention.

[0046] Figure 8 This is a schematic diagram illustrating the change of frame angle over time during continuous variable structure control based on a "+" shaped active area, according to an embodiment of the present invention.

[0047] Figure 9 This is a schematic diagram of the angle regions of the inner frame and the middle frame when performing continuous variable structure control based on a "+" shaped active area in an embodiment of the present invention.

[0048] Figure 10 This is a schematic diagram illustrating the change of the platform's angular velocity over time during continuous variable structure control based on a "+" shaped active area, according to an embodiment of the present invention.

[0049] Figure 11 This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time during continuous variable structure control based on a "+" shaped active area, according to an embodiment of the present invention.

[0050] Figure 12 This is a schematic diagram illustrating the change of the frame angle over time during continuous variable structure control based on a "+" shaped active area, as described in another embodiment of the present invention.

[0051] Figure 13 This is a schematic diagram of the area where the angles of the inner frame and the middle frame are located when performing continuous variable structure control based on the "+" shaped active area in another embodiment of the present invention;

[0052] Figure 14 This is a schematic diagram illustrating the change of the platform's angular velocity over time during continuous variable structure control based on a "+" shaped active area, as described in another embodiment of the present invention.

[0053] Figure 15 This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time when performing continuous variable structure control based on a "+" shaped active area in another embodiment of the present invention.

[0054] Figure 16 This is a schematic diagram illustrating the change of the frame angle over time during continuous variable structure control based on a "+" shaped active area in another embodiment of the present invention.

[0055] Figure 17 This is a schematic diagram of the angle regions of the inner frame and the middle frame when performing continuous variable structure control based on the "+" shaped active area in another embodiment of the present invention;

[0056] Figure 18 This is a schematic diagram illustrating the change of the platform's angular velocity over time during continuous variable structure control based on a "+" shaped active area, as described in another embodiment of the present invention.

[0057] Figure 19 This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time when performing continuous variable structure control based on a "+" shaped active area in another embodiment of the present invention.

[0058] Figure 20 This is a schematic diagram illustrating the change of frame angle over time during continuous variable structure control based on a "#" shaped active area, according to an embodiment of the present invention.

[0059] Figure 21 This is a schematic diagram of the angle regions of the inner frame and the middle frame when performing continuous variable structure control based on the "#" shaped active area in an embodiment of the present invention;

[0060] Figure 22 This is a schematic diagram illustrating the change of the platform's angular velocity over time during continuous variable structure control based on a "#" shaped active area, according to an embodiment of the present invention.

[0061] Figure 23 This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time during continuous variable structure control based on a "#" shaped active area, according to an embodiment of the present invention.

[0062] Figure 24 This is a schematic diagram illustrating the change of the frame angle over time during continuous variable structure control based on a "#" shaped active area, as described in another embodiment of the present invention.

[0063] Figure 25 This is a schematic diagram of the angle regions of the inner frame and the middle frame when performing continuous variable structure control based on the "#" shaped active area in another embodiment of the present invention;

[0064] Figure 26 This is a schematic diagram illustrating the change of the platform's angular velocity over time during continuous variable structure control based on a "#" shaped active area, as described in another embodiment of the present invention.

[0065] Figure 27This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time when performing continuous variable structure control based on the "#" shaped active area in another embodiment of the present invention.

[0066] Figure 28 This is a schematic diagram illustrating the change of the frame angle over time during continuous variable structure control based on a "#" shaped active area in another embodiment of the present invention.

[0067] Figure 29 This is a schematic diagram of the area where the angles of the inner frame and the middle frame are located when performing continuous variable structure control based on the "#" shaped active area in another embodiment of the present invention;

[0068] Figure 30 This is a schematic diagram illustrating the change of the platform's angular velocity over time during continuous variable structure control based on a "#" shaped active area, as described in another embodiment of the present invention.

[0069] Figure 31 This is a schematic diagram illustrating the change of the angle of the platform relative to the inertial space over time when performing continuous variable structure control based on the "#" shaped active area in another embodiment of the present invention. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0071] This invention discloses a singularity-free path continuous variable structure control method for an inertial stabilization platform servo loop. This method is implemented based on a four-axis inertial stabilization platform, which includes a base, an outer frame, a middle frame, an inner frame, and a platform. The body coordinate systems corresponding to the base, outer frame, middle frame, inner frame, and platform are respectively: base body coordinate system X1Y1Z1, outer frame body 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 .like Figure 1 As shown, the base body coordinate system is X1Y1Z1, and the outer frame body coordinate system is X... p3 Y p3 Z p3 , Medium frame body coordinate system X p2 Y p2 Z p2The 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 The origins coincide, and: the Z-axis of the platform's body coordinate system coincides with the origin of the platform. p Z-axis and the coordinate system of the inner frame p1 The axes coincide, and the Y-axis of the middle frame body coordinate system 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 axes coincide, the X1 axis of the base body coordinate system and the Y axis of the outer frame body coordinate system. p3 The axes coincide. The base is fixed to the carrier. When the four-axis inertial stabilized platform undergoes internal relative rotation under the drive of the carrier, the base rotates around the Y-axis of the outer frame's body coordinate system. p3 The axis rotates, and the outer frame revolves around the X coordinate system of the middle frame. p2 The axis rotates, and the middle frame rotates around the Y-axis of the inner frame's body coordinate system. p1 The axis rotates, and the inner frame rotates around the Z-axis of the platform's coordinate system. p The shaft rotates.

[0072] like Figure 2 As shown, the singularity-free path continuous variable structure control method for the servo loop of the inertial stabilization platform includes:

[0073] Step 1: Based on the angular velocity output by the gyroscope mounted on the platform, obtain the angular velocity of the platform in the X direction. p Axis, Y p Axis and Z p angular velocity components on the axis and

[0074] Step 2: Measure the X coordinate 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 The Z-axis of the inner frame around the body coordinate system of the platform p The angle β of the shaft rotation zk .

[0075] In this embodiment, the X-axis of the outer frame can be... p2 An angle sensor is installed on the shaft to measure β. xk ; in the inner frame Y p1 An angle sensor is installed on the shaft to measure β. yk ; in the Z of the platform pAn angle sensor is installed on the shaft to measure β. zk Among them, β yk The value range of β is -90 to 270°; zk and β xk The value range is -180 to 180°.

[0076] Step 3: Given the values ​​of the parameters of the compliant continuous variable structure and the active region corresponding to the path without singularities, calculate the angular velocity correction value Δω of the compliant continuous variable structure.

[0077] In this embodiment, the active regions corresponding to singularity-free paths include, but are not limited to, "+" shaped active regions and "#" shaped active regions.

[0078] Preferably, when the active region corresponding to the path without singularities is a "+" shaped active region, the angular velocity correction value Δω of the compliant continuous variable structure is calculated as follows:

[0079] Given the value of the compliant continuous variable structure parameter k, and the "+" shaped active region β nx ≤β xk ≤β mx or β ny ≤β yk ≤β my Among them, β nx Indicates β xk Minimum value of the active region, β mx Indicates β xk The maximum value of the active region, β ny Indicates β yk Minimum value of the active region, β my Indicates β yk The maximum value of the active area.

[0080] The angular velocity correction value Δω of the compliant continuous variable structure can be calculated using the following formula:

[0081]

[0082] Among them, (β) ny +β my ) / 2=0° or (β) ny +β my ) / 2=180°, (β) nx +β mx ) / 2=90° or (β) nx +β mx ) / 2 = -90°.

[0083] Preferably, when the active region corresponding to the singularity-free path is a "#" shaped active region, the angular velocity correction value Δω of the compliant continuous variable structure is calculated as follows:

[0084] Given the value of the compliant continuous variable structure parameter k, and the "#" shaped active region β n1x ≤β xk ≤β m1x or β n2x ≤β xk ≤β m2x or β n1y ≤β yk ≤β m1y or β n2y ≤β yk ≤β m2y Among them, β n1x Indicates β xk At its minimum value in the activity region greater than 0°, β m1x Indicates β xk The maximum value of β in the activity region greater than 0° n2x Indicates β xk At its minimum value in the activity region less than 0°, β m2x Indicates β xk The maximum value of β in the activity region less than 0° n1y Indicates β xk At its minimum value in the activity region less than 90°, β m1y Indicates β xk β is the maximum value in the activity region less than 90°. n2y Indicates β xk The minimum value of β in the activity region greater than 90° m2y Indicates β xk The maximum value in the activity area greater than 90°.

[0085] The angular velocity correction value Δω of the compliant continuous variable structure can be calculated using the following formula:

[0086]

[0087] Where, β n2x <β m2x <β n1x <β m1x ,β n1y <β m1y <β n2y <β m2y , and (β) n1x +β m1x ) / 2=90°、(β n2x +β m2x ) / 2=-90°、(β n1y +β m1y) / 2=0°、(β n2y +β m2y ) / 2 = 180°.

[0088] Step 4, according to β xk β yk β zk And Δω, the Z of the frustum is calculated. p The resultant rotational angular velocity ω of the shaft z Inner frame Y p1 The resultant rotational angular velocity ω of the shaft y , medium framework X p2 The resultant rotational angular velocity ω of the shaft x and outer frame Y p3 The resultant rotational angular velocity ω of the shaft yk′ .

[0089] In this embodiment, ω can be calculated using the following formula. z ω y ω x and ω yk′ :

[0090]

[0091] Step 5, ω z ω y ω x and ω yk′ The output is sent to the linear controller and then acts on the torque motors at each axis of the inertial stabilization platform to achieve the stabilization of the platform body relative to the inertial space.

[0092] To further illustrate the high precision of the decoupler of the present invention, several examples are provided below.

[0093] Reference: "Research on Control Strategy of Four-Axis Inertial Platform Follower Frame, Navigation and Control, 2017, No. 4", assuming the inner frame limit value β. n =45°, β m =135°, the area controlled by the locking partition discrete variable structure when the inner frame angle is limited is as follows: Figure 3 As shown. The main problem with this method is that the motion trajectory cannot cross from region 32 to region 31; it can only move forward by constantly switching along the boundary, causing the platform to shake.

[0094] Let β yk′ β xk β yk β zk The initial values ​​are 0°, 90°, 0°, and 0° respectively. When using variable structure zoning control, the initial position is in region 32. Let the platform base angular velocity...

[0095] The time-varying process of the frame angle in the locking-type discrete variable structure partition control when using inner frame angle limiting is as follows: Figure 4 As shown, the areas where the inner and outer frames are located are as follows: Figure 5 As shown, the change of the angular velocity of the platform with time is as follows: Figure 6 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 7 As shown. Throughout the entire operation, the inner frame angle never exceeded the limit of 45°, but during the switching process, both the platform's angular velocity and angle exhibited high-frequency vibrations. Specifically, the platform's angular velocity ω... xp The maximum value is approximately -291° / s, ω yp At the switching moment, the maximum value is approximately -167° / s, and the angle θ of the platform relative to the inertial space is... x At instantaneous closure at time zero, the maximum value can reach 1.983°, θ y The maximum value at the switching moment is approximately 0.96°.

[0096] Example 1

[0097] To overcome the swaying problem, a "+" shaped path continuous variable structure control method is adopted. Let β... nx =45°, β mx =135°, β ny =-45°, β my = -45°, β yk′ β xk β yk β zk The initial values ​​are 0°, 90°, 0°, and 0°, respectively. The change of the frame angle over time is as follows: Figure 8 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 9 As shown, the change of the angular velocity of the platform with time is as follows: Figure 10 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 11 As shown. During operation, the angular velocity ω of the platform... xp ω yp The angle θ between the platform and the inertial space x θ y It is close to zero.

[0098] By comparing the partitioned discrete variable structure control with the "+" shaped path continuous variable structure control method of the present invention, it can be seen that the overshoot of the angle and angular velocity of the platform relative to the inertial space is significantly reduced, and there is no continuous swaying process. The "+" shaped path continuous variable structure control method of the present invention has higher accuracy.

[0099] Example 2

[0100] To overcome the swaying problem, a "+" shaped path continuous variable structure control method is adopted. Let β... nx =45°, β mx =135°, β ny =-45°, β my = -45°, β yk′ β xk β yk β zk The initial values ​​are 0°, 10°, 30°, and 0°, respectively, and the base angular velocity is... The change of frame angle over time is as follows Figure 12 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 13 As shown, the change of the angular velocity of the platform with time is as follows: Figure 14 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 15 As shown. During operation, the angular velocity ω of the platform... xp The maximum is -3.44 × 10 -3 ° / s、ω yp The maximum is 5.89 × 10 -3 ° / s, the angle θ of the platform relative to inertial space. x The maximum is -6.356×10 -4 °、θ y The maximum is -5.794×10 -4 °.

[0101] By comparing the partitioned discrete variable structure control with the "+" shaped path continuous variable structure control method of this invention, it can be seen that the angular motion of the platform relative to the inertial space is on the order of arcseconds throughout the entire operation.

[0102] Example 3

[0103] To overcome the swaying problem, a "+" shaped path continuous variable structure control method is adopted. Let β... nx =-135°, β mx =-45°, β ny =135°, β my =225°, β yk′ βxk β yk β zk The initial values ​​are 0°, -80°, -20°, and 0°, respectively, and the base angular velocity is... The change of frame angle over time is as follows Figure 16 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 17 As shown, the change of the angular velocity of the platform with time is as follows: Figure 18 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 19 As shown. During operation, the angular velocity of the platform... The maximum is -0.334° / s. The maximum value is 0.377° / s, and the angle θ of the platform relative to inertial space is... x The maximum is -0.0368°, θ y The maximum value is -0.0368°.

[0104] By comparing the partitioned discrete variable structure control with the "+" shaped path continuous variable structure control method of this invention, it can be seen that the angular motion of the platform relative to the inertial space is relatively stable throughout the entire operation.

[0105] Example 4

[0106] To overcome the swaying problem, the inner frame is designed to be unrestricted, and a continuous variable structure control method using a "#" shaped path is employed. Let β... n1x =45°, β m1x =135°, β n2x =-135°, β m2x =-45°, β n1y =-45°, β m1y =45°, β n2y =135°, β m2y =225°, β yk′ β xk β yk β zk The initial values ​​are 0°, 90°, 0°, and 0°, respectively. The change of the frame angle over time is as follows: Figure 20 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 21 As shown, the change of the angular velocity of the platform with time is as follows: Figure 22 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 23 As shown. During operation, the angular velocity of the platform... The angle θ between the platform and the inertial space x θ y It is close to zero.

[0107] By comparing the partitioned discrete variable structure control with the "#" shaped path continuous variable structure control method of the present invention, it can be seen that the overshoot of the angle and angular velocity of the platform relative to the inertial space is significantly reduced, and there is no continuous swaying process. The method of the present invention has higher accuracy.

[0108] Example 5

[0109] To overcome the swaying problem, the inner frame is designed to be unrestricted, and a continuous variable structure control method using a "#" shaped path is employed. Let β... n1x =45°, β m1x =135°, β n2x =-135°, β m2x =-45°, β n1y =-45°, β m1y =45°, β n2y =135°, β m2y =225°, β yk′ β xk β yk β zk The initial values ​​are 0°, 10°, 30°, and 0°, respectively, and the base angular velocity is... The change of frame angle over time is as follows Figure 24 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 25 As shown, the change of the angular velocity of the platform with time is as follows: Figure 26 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 27 As shown. During operation, the angular velocity of the platform... The maximum is -2.32 × 10 -4 ° / s、 The maximum is 4.45 × 10 -6 ° / s, the angle θ of the platform relative to inertial space. x The maximum is -1.2 × 10 -4 °、θ y The maximum is -1.43 × 10 -6 °.

[0110] By comparing the partitioned discrete variable structure control with the "#" shaped path continuous variable structure control method of this invention, it can be seen that the angular motion of the platform relative to the inertial space is better than 1 arcsecond during the entire operation.

[0111] Example 6

[0112] To overcome the swaying problem, the inner frame is designed to be unrestricted, and a continuous variable structure control method using a "#" shaped path is employed. Let β... nx =-135°, β mx =-45°, β ny =135°, β my =225°, β yk′ β xk β yk β zk The initial values ​​are 0°, -80°, -20°, and 0°, respectively, and the base angular velocity is... The change of frame angle over time is as follows Figure 28 As shown, the areas where the inner frame and middle frame angles are located are as follows: Figure 29 As shown, the change of the angular velocity of the platform with time is as follows: Figure 30 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 31 As shown. During operation, the angular velocity of the platform... The maximum is -0.0426° / s. The maximum value is -0.044° / s, and the angle θ of the platform relative to inertial space is... x The maximum is -6.95×10 -3 °、θ y The maximum is -0.113°.

[0113] By comparing the partitioned discrete variable structure control with the "#" shaped path continuous variable structure control method of this invention, it can be seen that the angular motion of the platform relative to the inertial space is relatively stable throughout the entire operation.

[0114] 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.

[0115] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A method for continuous variable structure control of a servo loop without singularities in an inertial stabilization platform, characterized in that, include: 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 and The X coordinates of the outer frame around the body coordinate system of the middle frame were measured. 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 The Z-axis of the inner frame around the body coordinate system of the platform p The angle β of the shaft rotation zk ; Given the values ​​of the parameters of the compliant continuous variable structure and the active region corresponding to the path without singularities, the angular velocity correction value Δω of the compliant continuous variable structure is calculated. according to β xk β yk β zk And Δω, the Z of the frustum is calculated. p The resultant rotational angular velocity ω of the shaft z Inner frame Y p1 The resultant rotational angular velocity ω of the shaft y , medium framework X p2 The resultant rotational angular velocity ω of the shaft x and outer frame Y p3 The resultant rotational angular velocity ω of the shaft yk′ ; ω z ω y ω x and ω yk′ The output is sent to the linear controller and then acts on the torque motors at each axis of the inertial stabilization platform to achieve the stabilization of the platform body relative to the inertial space. When the active region corresponding to the path without singularities is a "+" shaped active region, the angular velocity correction value Δω of the compliant continuous variable structure is calculated as follows: Given the value of the compliant continuous variable structure parameter k, and the "+" shaped active region β nx ≤β xk ≤β mx or β ny ≤β yk ≤β my ; where β nx Indicates β xk Minimum value of the active region, β mx Indicates β xk The maximum value of the active region, β ny Indicates β yk Minimum value of the active region, β my Indicates β yk The maximum value of the active area; The angular velocity correction value Δω of the compliant continuous variable structure can be calculated using the following formula: where, (β ny + β my ) / 2 = 0° or (β ny + β my ) / 2 = 180°, (β nx + β mx ) / 2 = 90° or (β nx + β mx ) / 2 = -90°.

2. The method for continuous variable structure control of the servo loop of an inertial stabilization platform without singularities according to claim 1, characterized in that, The inertial stabilization platform is a four-axis inertial stabilization platform, comprising: a base, an outer frame, a middle frame, an inner frame, and a platform body; The body coordinate systems corresponding to the base, outer frame, middle frame, inner frame, and platform are respectively: base body coordinate system X1Y1Z1, outer frame body 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 ; Base body coordinate system X1Y1Z1, outer frame body 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 The origins coincide, and: the Z-axis of the platform's body coordinate system coincides with the origin of the platform. p Z-axis and the coordinate system of the inner frame p1 The axes coincide, and the Y-axis of the middle frame body coordinate system 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 axes coincide, the X1 axis of the base body coordinate system and the Y axis of the outer frame body coordinate system. p3 Axis coincidence; The base is fixed to the carrier. When the four-axis inertial stabilized platform undergoes internal relative rotation under the drive of the carrier, the base rotates around the Y-axis of the outer frame's body coordinate system. p3 The axis rotates, and the outer frame revolves around the X coordinate system of the middle frame. p2 The axis rotates, and the middle frame rotates around the Y-axis of the inner frame's body coordinate system. p1 The axis rotates, and the inner frame rotates around the Z-axis of the platform's coordinate system. p The shaft rotates.

3. The method for continuous variable structure control of the servo loop of an inertial stabilization platform without singularities according to claim 1, characterized in that, When the active region corresponding to the singularity-free path is a "#" shaped active region, the angular velocity correction value Δω of the compliant continuous variable structure is calculated as follows: Given the value of the compliant continuous variable structure parameter k, and the "#" shaped active region β n1x ≤β xk ≤β m1x or β n2x ≤β xk ≤β m2x or β n1y ≤β yk ≤β m1y or β n2y ≤β yk ≤β m2y ; Where, β n1x Indicates β xk At its minimum value in the activity region greater than 0°, β m1x Indicates β xk The maximum value of β in the activity region greater than 0° n2x Indicates β xk At its minimum value in the activity region less than 0°, β m2x Indicates β xk The maximum value of β in the activity region less than 0° n1y Indicates β xk At its minimum value in the activity region less than 90°, β m1y Indicates β xk β is the maximum value in the activity region less than 90°. n2y Indicates β xk The minimum value of β in the activity region greater than 90° m2y Indicates β xk Maximum value in the activity region greater than 90°; The angular velocity correction value Δω of the compliant continuous variable structure can be calculated using the following formula: among them,b n2x <b m2x <b n1x <b m1x ,b n1y <b m1y <b n2y <b m2y ,and(b n1x +b m1x ) / 2=90°、(β n2x +b m2x ) / 2=-90°、(β n1y +b m1y ) / 2=0°、(β n2y +b m2y ) / 2 = 180°.

4. The method for continuous variable structure control of the servo loop of an inertial stabilization platform without singularities according to claim 1, characterized in that, ω is calculated using the following formula. z ω y ω x and ω yk′ :

5. The method for continuous variable structure control of the servo loop of an inertial stabilization platform without singularities according to claim 1, characterized in that, The X coordinates of the outer frame around the body coordinate system of the middle frame were measured. 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 The Z-axis of the inner frame around the body coordinate system of the platform p The angle β of the shaft rotation zk ,include: X in the outer frame p2 An angle sensor is installed on the shaft to measure β. xk ; Y in the inner frame p1 An angle sensor is installed on the shaft to measure β. yk ; In the Z of the platform p An angle sensor is installed on the shaft to measure β. zk .

6. The method for continuous variable structure control of the servo loop of an inertial stabilization platform without singularities according to claim 1, characterized in that, β yk The value range of β is -90 to 270°; zk and β xk The value range is -180 to 180°.

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