Research On Spacecraft Manipulator Trajectory Optimization Method Based On Computer Vision

In recent years,the robotic industry has developed rapidly and it has been involved in various fields such as home,industry,military,and aerospace.The robotic arm is an integral part of the robot.It is the robot’s actuator and has a large scope of research.Different robot arms have different functions for different environments.Especially in the aerospace field,robotic arms have an irreplaceable role in planetary exploration,satellite orbital docking,and so on.With the development of computer vision nowadays,its application range is very wide,and the research of robot arms based on computer vision is becoming increasingly common.The main research object of this article is to add a robot arm with seven degrees of freedom on the spacecraft,locate the coordinate information of the target object through binocular vision,and calculate the movement of the base point of the robot arm through the method of visual odometry.The uncertainty caused by the relative movement of the base point of the manipulator or the inaccuracy of its own model during the high-altitude flight of the spacecraft needs relative positioning in absolute positioning to ensure the accurate position information of the target object.The main research content of this article is:1.Establish a seven-degree-of-freedom robotic arm’s Modify D-H dynamic model through the mechanical size and mechanical quality of the mechanical arm.And then establish a dynamic differential equation according to each joint’s moment of inertia,joint quality,motor rotor inertia,and motor rotor mass.2.Through the position difference between pixel information between binocular cameras for each frame of the picture,plus the camera’s own internal and external parameters,the depth information of the object is calculated.The three-dimensional information coordinates of the target object are obtained by using the opencv library.Then get the 3D location.3.Based on the dynamic model of manipulator arm,which is established previously,the initial value of the manipulator arm is optimized using the sequential quadratic programming algorithm.The initial value of the trajectory optimization is obtained by using the optimization function fmincon function in MATLAB.The manipulator dynamics model is brought into the Gaussian pseudo-puop algorithm.By limiting the joint angle,angular velocity,and angular acceleration of the manipulator and simultaneously limiting the attitude,position,and speed of the manipulator arm,the optimal trajectory is obtained and simulated by MATLAB.The angle of each joint of the robot arm at each moment will be calculated.The main purpose of this paper is to use a redundant robot with seven degrees of freedom to use computer vision information to capture unknown objects and obtain an optimal energy-based trajectory.The optimization algorithm used this time is the dual optimization of the sequence quadratic optimization and the Gaussian pseudo-pseudooptimization.Compared with other optimization algorithms,the energy consumption is reduced.At the same time,computer vision information is also added.In the case of unknown accurate position information of the target,the object coordinate information can be obtained by the difference information of the pixels between the cameras,and the position of the object can be monitored in real time.So that,we can grab the target on planned trajectory.