CN-121978982-A - Six-degree-of-freedom electric platform electric cylinder passive derivative linear motion error compensation method

CN121978982ACN 121978982 ACN121978982 ACN 121978982ACN-121978982-A

Abstract

The invention relates to a method for compensating the passive derivative linear motion error of an electric cylinder of a six-degree-of-freedom electric platform, which comprises the steps of establishing a kinematic inverse solution equation of six-degree-of-freedom mechanical environment simulation equipment to obtain motion expansion quantity of the six-degree-of-freedom electric cylinder, establishing a motion equation of a branched chain of the six-degree-of-freedom mechanical environment simulation equipment, and calculating the rotation angle of a cylinder rod of the electric cylinder relative to a cylinder barrel through the variable quantity of a vector included angle between a cylinder rod fixed end of an upper Hooke assembly and a cylinder barrel fixed end of a lower Hooke assembly According to Calculating the error caused by the passive derivative linear motion of the electric cylinder by combining the motion equation of the six-degree-of-freedom mechanical environment simulation equipment branched chain ; Will The electric cylinder expansion amount obtained by the inverse kinematics solution is corrected as an error amount, and the corrected controlled expansion amount of the electric cylinder is obtained. The six-degree-of-freedom mechanical environment simulation equipment for the performance test and the semi-physical simulation test of the aerospace inertial navigation product can meet the requirements of technical indexes.

Inventors

MA JIANMING
DENG WEIJING
CHEN JIAWEI
ZHU RISHENG
XU ZEMIN
ZHAO QING
JING XUEWU

Assignees

北京航天控制仪器研究所
北京航天万鸿高科技有限公司

Dates

Publication Date: 20260505
Application Date: 20251212

Claims (10)

1. The method for compensating the passive derivative linear motion error of the electric cylinder of the six-degree-of-freedom electric platform is characterized by comprising the following steps of: Establishing a coordinate system of the six-degree-of-freedom mechanical environment simulation equipment, wherein the coordinate system comprises an inertial coordinate system and a body coordinate system, and further establishing a kinematic inverse solution equation of the six-degree-of-freedom mechanical environment simulation equipment to obtain the motion expansion and contraction quantity of the six electric cylinders; Establishing a single branched chain closed loop driving system of an electric cylinder, a servo motor, an encoder and a driver, and establishing a motion equation between linear displacement output of a cylinder rod of the electric cylinder and rotation angle input of the servo motor on the basis; constructing a corner change equation between the cylinder rod and the cylinder barrel of the electric cylinder under an inertial coordinate system, namely calculating the rotation angle of the cylinder rod of the electric cylinder relative to the cylinder barrel through the change quantity of a vector included angle between the fixed end of the cylinder rod of the upper hook assembly and the fixed end of the cylinder barrel of the lower hook assembly ,i=1~6; According to the relative rotation angle I=1-6, and calculating an error caused by passive derivative linear motion of the electric cylinder by combining a motion equation of a six-degree-of-freedom mechanical environment simulation device branched chain ; Will be The electric cylinder expansion amount obtained by the inverse kinematics solution is corrected as an error amount, and the corrected controlled expansion amount of the electric cylinder is obtained.
2. The method for compensating the passive derivative linear motion error of the electric cylinder of the six-degree-of-freedom electric platform according to claim 1, wherein the establishing a coordinate system of the six-degree-of-freedom mechanical environment simulation device is specifically as follows: An inertial coordinate system { g } is established at the plane center of the lower hook component, O g -X g Y g Z g , a body coordinate system { p } is established at the plane center of the upper hook component, O p -X p Y p Z p is established, the coordinates of the rotation centers of the upper hook component and the lower hook component are respectively A i 、B i , i=1-6, the coordinate of the rotation center of the upper hook component under the body coordinate system { p } is represented as ：a i p =[a ix p , a iy p , a iz p ] T ,i=1,…,6,, the coordinate of the rotation center of the lower hook component under the inertial coordinate system { g } is represented as b i =[b ix , b iy , b iz ] T , i=1, the angle of 6, t= [ x, y, z ] T is represented as a coordinate vector of the origin of the body coordinate system under the inertial coordinate system, and ω is represented as an angular velocity vector of the upper platform.
3. The method for compensating the passive derivative linear motion error of the electric cylinder of the six-degree-of-freedom electric platform according to claim 2, wherein the method for establishing the inverse solution equation of the kinematics of the six-degree-of-freedom mechanical environment simulation device is specifically as follows: length vector of 6 electric cylinders I=1 to 6 is expressed as Wherein R is a rotation transformation matrix which represents coordinate transformation from an inertial coordinate system to a body coordinate system, and the expression of R is as follows by adopting a transformation sequence of Z ψ -Y θ -X φ : wherein phi, theta, phi are three Euler angles representing the upper platform attitude q t , respectively referred to as yaw, pitch and roll; c represents cos and s represents sin, and assuming that the length of the electric cylinder is L i , i=1, 2,..6 The extension and contraction amount of the electric cylinder is then Wherein The initial length of the electric cylinder when the six-degree-of-freedom mechanical environment simulation equipment is in a working zero position; assuming that the generalized coordinates q of the platform on the six-degree-of-freedom mechanical environment simulation device are known, the motion expansion and contraction amounts of the six electric cylinders are obtained through calculation according to the above formula.
4. The method for compensating the passive derivative linear motion error of the electric cylinder of the six-degree-of-freedom electric platform according to claim 3, wherein the establishing a motion equation of a branched chain of the six-degree-of-freedom mechanical environment simulation device is specifically as follows: assuming that the rotation angle of the servo motor is beta, the linear motion of the electric cylinder is expressed as follows by utilizing the principle of a lead screw nut Wherein P is the lead of the screw rod of the electric cylinder, n is 2 when the screw rod is screwed right, and n is 1 when the screw rod is screwed left.
5. The method for compensating for the error in the passive derivative linear motion of an electric cylinder of a six-degree-of-freedom electric platform according to claim 4, wherein the calculated rotation angle of the cylinder rod of the electric cylinder relative to the cylinder barrel The method specifically comprises the following steps: In the inertial coordinate system { g }, the unit direction vector of the two axes of the upper Hooke's joint assembly is represented by a vector k i 、j i , the unit direction vector of the two axes of the lower Hooke's joint assembly is represented by a vector m i 、n i , the change of the rotation angle between the cylinder rod and the cylinder barrel is represented by the change of the included angle between the vector k i and the vector m i , and the vector j i is represented as follows Wherein Is a unit vector of the connecting axis of the upper hook component and the upper platform in a body coordinate system, and comprises the following components according to the structural form of the two-degree-of-freedom hook , , , Vector k i , i=1, 2,..6 and m i , i=1, 2,..6 is expressed as: 、 ,i=1,2,...,6; Thus, the spatial angle between k i and m i is expressed as: ,i=1,2,...,6; Obtained by the above method Modifying the initial vector between 0 DEG and 180 DEG Is set to be in the default positive direction of (1), the calculated included angle of the upper platform at the working zero position Normalizing to 0-90 degrees, wherein the method comprises the following steps: definition that the electric cylinder rod rotates anticlockwise relative to the cylinder barrel to be positive, the relative rotation angle is expressed as I=1, 2, &..6 wherein When the upper platform of the six-degree-of-freedom mechanical environment simulation device is located at a working zero position, an initial included angle between a vector k i and m i is formed, and l z is a unit vector, namely l z = (0, 0, 1).
6. The method for compensating for error in passive linear motion of an electric cylinder of a six-degree-of-freedom electric platform according to claim 5, wherein the error caused by the passive linear motion of the electric cylinder is calculated The following is shown: ,i=1~6。
7. The method for compensating for the error in the passive derivative linear motion of an electric cylinder of a six-degree-of-freedom electric platform according to claim 6, wherein the method is characterized by comprising the following steps of The position and posture errors of the platform on the six-degree-of-freedom mechanical environment simulation equipment caused by the passive derivative motion of the electric cylinder can be obtained: wherein Is a jacobian matrix of the change from the length of the electric cylinder to the position and the posture of the upper platform.
8. A computer readable storage medium storing a computer program, wherein the computer program when executed by a processor performs the steps of the method according to any one of claims 1 to 7.
9. An electronic device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any one of claims 1-7 when executing the computer program.
10. A computer program product comprising a computer program which, when executed by a processor, implements the steps of the method according to any one of claims 1 to 7.

Description

Six-degree-of-freedom electric platform electric cylinder passive derivative linear motion error compensation method Technical Field The invention belongs to the technical field of six-degree-of-freedom mechanical environment simulation equipment, and relates to a passive derivative linear motion error compensation method for an electric cylinder of a six-degree-of-freedom electric platform. Background The six-degree-of-freedom mechanical environment simulation equipment for the performance test and the semi-physical simulation test of the aerospace inertial navigation product is realized by adopting a 6-UCU type high-precision six-degree-of-freedom parallel mechanism driven by electric cylinders, and the six-degree-of-freedom motion of the upper platform in three-dimensional space is realized by combining the two-degree-of-freedom follow-up rotation of the upper and lower hook hinge assemblies through the coordinated telescopic and rotary motions of the six electric cylinders, so that the six-degree-of-freedom motions of longitudinal movement, transverse movement, lifting, rolling, pitching and yawing of the upper platform are provided for the performance test and the semi-physical simulation of the inertial navigation product, and a near-real mechanical simulation environment is provided for the performance test and the semi-physical simulation of the aerospace inertial navigation product. Because the electric cylinder realizes the linear motion of the cylinder rod through the screw pair, a screw relationship exists between the linear motion and the rotary motion of the electric cylinder, the passive rotation of the electric cylinder rod relative to the cylinder barrel can lead to the generation of passive derivative linear motion of the cylinder rod, and further corresponding errors are caused, and the actual position and the gesture precision of the six-degree-of-freedom mechanical environment simulation equipment are influenced. The existing 6-UCU type six-degree-of-freedom mechanical environment simulation equipment for the performance test and the semi-physical simulation test of the middle-low precision aerospace inertial navigation product is usually defaulted to be a system error aiming at errors generated by passive derivative linear motion of an electric cylinder, and cannot be compensated on the premise that the precision meets the technical requirements. For six-degree-of-freedom mechanical environment simulation equipment for performance test and semi-physical simulation test of aerospace high-precision inertial navigation products, one of the existing methods is to add a rotation degree of freedom around the axis of an electric cylinder on the electric cylinder with an internal rotation prevention mechanism, so that the axial telescopic motion and the rotation motion of a lever of the electric cylinder are mutually independent, derivative linear motion is fundamentally eliminated, the method increases the cost of the electric cylinder and the complexity of a system, the other method is to add a high-precision linear displacement sensor outside the electric cylinder, the feedback signal of the displacement sensor is utilized to realize the position closed-loop control of the electric cylinder, the method needs to add an additional high-precision displacement sensor, and an additional acquisition channel is added in a motion control computer, so that the development cost and the complexity of the system are also increased. Disclosure of Invention The invention solves the technical problems of overcoming the defects of the prior art, and providing a six-degree-of-freedom electric platform electric cylinder passive derivative linear motion error compensation method which compensates errors caused by the passive derivative linear motion of the electric cylinder in the motion process of six-degree-of-freedom mechanical environment simulation equipment, so that the position and posture precision of the six-degree-of-freedom mechanical environment simulation equipment for the aerospace inertial navigation product performance test and the semi-physical simulation test meets the technical index requirements. The technical problem is solved by the method for compensating the passive derivative linear motion error of the electric cylinder of the six-degree-of-freedom electric platform, which comprises the following steps: Establishing a coordinate system of the six-degree-of-freedom mechanical environment simulation equipment, wherein the coordinate system comprises an inertial coordinate system and a body coordinate system, and further establishing a kinematic inverse solution equation of the six-degree-of-freedom mechanical environment simulation equipment to obtain the motion expansion and contraction quantity of the six electric cylinders; Establishing a single branched chain closed loop driving system of an electric cylinder, a servo motor, an encoder and a driver, and establishing a motion equatio