CN-121540089-B - Suspension type low-gravity simulation space swing angle measurement system, method and device

CN121540089BCN 121540089 BCN121540089 BCN 121540089BCN-121540089-B

Abstract

The invention relates to a suspension type low-gravity simulation space swing angle measuring system, method and device, and belongs to the technical field of space swing angle measurement. The system comprises a suspension cable connected with a tested object, a central measuring head used for clamping the suspension cable, a sliding assembly comprising a sliding block connecting plate and two groups of sliding blocks which are orthogonally arranged, wherein the central measuring head is arranged on the two groups of sliding blocks through the sliding block connecting plate, so that the central measuring head can freely slide in an X-Y plane, a measuring module connected with the sliding blocks and used for measuring linear displacement of the central measuring head in the X direction and the Y direction in real time, and a control module connected with the measuring module and used for calculating the inclination angles of the suspension cable in the X direction and the Y direction according to the linear displacement and real-time geometric structure parameters. The invention improves the gesture measurement precision in the suspended low gravity simulation, improves the real-time response performance, realizes the cost control optimization and enhances the environmental adaptability.

Inventors

SHEN YULING
WANG WENLIANG
CHEN TAO
FAN CHENG
LI XUAN
ZHU MINGLU

Assignees

苏州大学

Dates

Publication Date: 20260508
Application Date: 20260119

Claims (7)

1. A suspended low gravity simulated spatial pivot angle measurement system, comprising: A suspension cable (6) connected with the object (9) to be tested; the center measuring head is used for clamping the suspension cable (6), and comprises an upper pulley rope fixing mechanism (16), a self-aligning bearing universal joint (20) and a lower pulley rope fixing mechanism (23), wherein the upper pulley rope fixing mechanism (16) and the lower pulley rope fixing mechanism (23) comprise pre-tightening guide wheels which are orthogonally arranged and are used for realizing rigid constraint and vibration suppression on the suspension cable (6); the sliding assembly comprises a sliding block connecting plate (21) and two groups of sliding blocks (22) which are orthogonally arranged, wherein the aligning bearing universal joint (20) is arranged on the two groups of sliding blocks (22) through the sliding block connecting plate (21) to enable the center measuring head to freely slide in an X-Y plane, the sliding block connecting plate (21) is provided with a through hole, the aligning bearing universal joint (20) penetrates through the through hole and is respectively connected with the upper pulley rope fixing mechanism (16) and the lower pulley rope fixing mechanism (23) which are positioned at two sides of the sliding block connecting plate (21), and when the tested object (9) moves, the aligning bearing universal joint (20) pushes the sliding blocks (22) to move to decompose the space rotation movement of the suspension cable rope (6) and convert the space rotation movement into linear displacement of the sliding blocks (22) on the X-Y plane; the measuring module comprises an X-axis grating ruler (18) and a Y-axis grating ruler (19), wherein the X-axis grating ruler (18) and the Y-axis grating ruler (19) are respectively arranged on two groups of sliding blocks (22) which are orthogonally arranged and used for measuring the linear displacement in real time to obtain the linear displacement of the central measuring head in the X direction and the Y direction; The gesture sensing and force feedback module comprises a rope tension sensor (7) and a universal joint (8), wherein one end of the rope tension sensor (7) is connected with the suspension cable (6), the other end of the rope tension sensor is connected with the universal joint (8), and the universal joint (8) is connected with the tested object (9), wherein the structure of the universal joint (8) is of a laminated cross structure, and an axial rotary joint is arranged at the connecting end of the universal joint (8) and the tested object (9) so as to eliminate torsion and motion interference of the suspension cable (6); The Z-axis constant force unloading mechanism (3) comprises a displacement sensor, wherein the displacement sensor is used for monitoring the telescopic length of the suspension cable (6) in the vertical direction and the lifting displacement of the tested object (9) in real time; The control module is connected with the measurement module and the Z-axis constant force unloading mechanism (3) and is used for acquiring the displacement compensation quantity of the tested object (9) in the Z-axis direction in real time, and obtaining real-time geometric parameters according to the displacement compensation quantity; When the tested object (9) is subjected to pose transformation in the vertical direction, the control module receives the real-time displacement compensation quantity of the Z-axis constant force unloading mechanism (3) in real time And updating the calculation expression of the space swing angle as follows: ; ; Wherein, the Represents the real-time tilt angle of the X-axis direction, Represents the real-time tilt angle of the Y-axis direction, The displacement of the X-axis is represented, The displacement of the Y-axis is represented, Representing the initial vertical distance.
2. The suspended low gravity simulated space pivot angle measurement system of claim 1, further comprising a multi-axis motion control module and a drive module, wherein the multi-axis motion control module comprises an X-axis ball screw drive (10), the drive module comprises a Y-axis servo motor (11), and the X-axis ball screw drive (10) is connected with the Y-axis servo motor (11).
3. The suspended type low-gravity simulated space swing angle measurement system according to claim 1, further comprising a steel cable buckle (14) and a Z-axis connecting plate (15), wherein the steel cable buckle (14) is arranged on the surface of the Z-axis connecting plate (15), a coaxial through hole is formed in the steel cable buckle (14) corresponding to the Z-axis connecting plate (15), and the suspension cable (6) penetrates through the coaxial through hole and then enters the central measuring head.
4. A method for measuring a suspended low gravity simulated space pivot angle, implemented by a suspended low gravity simulated space pivot angle measuring system according to any one of claims 1 to 3, comprising: S1, a tested object (9) moves in a horizontal plane to pull a suspension cable rope (6) to incline, and the suspension cable rope (6) drives a central measuring head to move; S2, the central measuring head slides on two groups of sliding blocks (22) which are orthogonally arranged through a sliding block connecting plate (21), and the inclined movement of the suspension cable (6) is decoupled into linear movement in an X-Y plane; s3, measuring linear displacement amounts in the X direction and the Y direction when the central measuring head performs linear motion in real time; S4, acquiring displacement compensation quantity of the tested object (9) in the Z-axis direction in real time, obtaining real-time geometric structure parameters according to the displacement compensation quantity, and calculating the space swing angle of the suspension cable (6) according to the linear displacement quantity and the real-time geometric structure parameters.
5. The method for measuring the space pivot angle of the suspension type low gravity simulation according to claim 4, wherein the method for calculating the space pivot angle of the suspension cable (6) according to the linear displacement and the real-time geometrical parameters is as follows: the linear displacement comprises an X-axis displacement and a Y-axis displacement, a space swing angle of the suspension cable rope (6) is reversely calculated according to the X-axis displacement, the Y-axis displacement and the real-time geometric structure parameter, wherein the space swing angle comprises an inclination angle in the X-axis direction and an inclination angle in the Y-axis direction, and the calculation expression of the inclination angle in the X-axis direction is as follows: ; the calculation expression of the Y-axis direction inclination angle is as follows: ; Wherein, the The displacement of the X-axis is represented, The displacement of the Y-axis is represented, Representing real-time geometry parameters.
6. The method for measuring the space pivot angle of a suspended low gravity simulation according to claim 4, wherein the expression of the real-time geometrical parameters is: ; Wherein, the Representing the parameters of the geometry in real time, Representing the initial vertical distance of the device, Representing the real-time displacement compensation amount of the Z axis.
7. A suspended low gravity simulator comprising a suspended low gravity simulated space-swing angle measurement system according to any one of claims 1 to 3.

Description

Suspension type low-gravity simulation space swing angle measurement system, method and device Technical Field The invention relates to the technical field of space swing angle measurement, in particular to a suspension type low-gravity simulation space swing angle measurement system, method and device. Background In the aerospace field, complex systems such as spacecraft, space robots, moon or Mars detectors, and extravehicular mobile units of the aerospace industry all need to operate in a low gravity or microgravity environment of space. The reliability of these systems is directly related to the success or failure of the task, so high precision functional and performance testing must be performed on the ground before transmission. Among the numerous testing means, the suspended low gravity simulation system has become a core technical means for ground testing because of its large working space, controllable cost and capability of flexibly simulating various gravity levels. However, with the complexity of the aerospace task, the requirements on simulation fidelity and dynamic performance are improved, and the conventional suspension technology exposes a key bottleneck, and particularly the problems of insufficient attitude measurement precision and coupling interference under the motion of multiple degrees of freedom are most prominent. Specifically, most spacecrafts move in six degrees of freedom (three-dimensional translation and three-dimensional rotation), and the traditional system can only realize single-dimensional or double-dimensional force compensation, and is difficult to accurately capture the posture change of a test object. When an object (such as a space mechanical arm and a detector) is subjected to pitching, yawing and rolling, the relative position and angle of the suspension rope and the mass center are changed suddenly, unexpected parasitic moment is introduced, and the test data is distorted due to the interference of natural motion. The traditional scheme of installing the encoder through the far suspension point joint cannot accurately catch the rope swing angle in real time due to transmission errors, mechanical gaps and insufficient resolution, and parasitic moment is difficult to effectively compensate. In order to solve the problems of attitude measurement, parasitic moment compensation and dynamic response in suspension type low-gravity simulation, three main technical directions are formed at present. The first is a scheme based on a rotary encoder or potentiometer, and the principle is that the encoder or potentiometer is arranged on a universal joint of a suspension point or a rotating shaft similar to a cradle head structure, and the attitude of the suspension rope is calculated indirectly by reading an angle value. However, this solution has the obvious disadvantages that, firstly, the accuracy and resolution of the existing measuring device are limited and the error is large in the case of small angle changes. Second, mechanical physical limitations. Errors are inevitably introduced in the machining and assembly processes, and backlash exists in the transmission, resulting in nonlinear hysteresis between the measured and actual values. In particular, when the cable is slightly swayed, the sensor may not be able to read the data because the gear play has not been eliminated, thereby creating dead zones, which is particularly a problem in dynamic processes. In addition, in order to realize multi-degree-of-freedom measurement, a complex multi-axis nested cradle head needs to be matched, so that the system is large in size and weight. The second type is a scheme based on an external vision measurement system, which is characterized in that a plurality of high-speed infrared cameras (such as Vicon, optiTrack) are deployed in a laboratory, reflective mark points are pasted at key positions of a measured object and a hanging rope, three-dimensional coordinates of the mark points are calculated by means of original triangulation, and then the six-degree-of-freedom pose of the object is reconstructed. In suspended low gravity simulation, if the sensor reacts slowly, motor compensation will be delayed, resulting in system oscillations or simulation distortions. The third category is a scheme based on an Inertial Measurement Unit (IMU), which is based on the principle that an IMU module comprising an accelerometer and a gyroscope is arranged on a measured object, and an object attitude angle is obtained through integrating angular velocity, but has two major defects that firstly, the gyroscope has an integral drift problem, errors can be accumulated continuously along with time, so that long-term measurement accuracy is unreliable, and secondly, the IMU measures the object attitude rather than the included angle between a suspension rope and a plumb line, so that parasitic moment caused by rope inclination cannot be accurately calculated. In summary, the existing schemes have the b