In the process of exploration of space in various countries,on-orbit assembly technology has gradually become the focus of research and is one of the important technologies for aerospace power.The establishment of large-scale space structures in space takes a lot of time and costs,and the environment is harsh in space and the operations are complicated.In order to solve the in-orbit assembly problem of large-scale space structures in space and complete intelligent assembly of large-scale institutions under long-distance and large-scale complex operating environments,this paper developed a R+2SPS/RRPRR+R seven degree of freedom hybrid assembly robot.It is mainly divided into a few-branch parallel mechanism and a terminal smart series mechanism.It combines the advantages of a series mechanism and a parallel mechanism.It has the functions of mobile dynamic and static conversion,high precision,high rigidity,high efficiency,and real-time monitoring and adjustment of attitude.Achieve the combination and control of robots on large institutions.In this paper,the above-mentioned seven degree of freedom hybrid assembly robot is deeply studied.The main research contents include:Firstly,the research background and domestic and foreign research status of mobile assembly robot technology are introduced.The research background and significance of the research are elaborated,and the research direction and content of this topic are clarified.Secondly,according to the requirements of the assembly robot,the configuration design of the seven degree of freedom hybrid robot is analyzed.Based on the configuration design,a kinematic model was established for the robot and an inverse kinematics analysis was performed.By writing a kinematic inverse solution program before and after the dynamic and static conversion,the dynamic and static conversion function of this mechanism is realized,and a theoretical basis is established for robot motion control.Workspace analysis was performed based on structural constraints.Further,the robot control system was designed and the control system architecture and control strategy were analyzed.Again,according to the work requirements of the ground test,collision detection and robot trajectory planning design are performed between the assemblies.A bilateral docking method was proposed for the interference of the module docking process.By constructing the bilateral docking mathematical model and establishing the constraint conditions,a set of docking collision algorithms between the assemblies was developed and verified by simulation.Based on the simulation results,the path design rules for the task are established,and the initial pose of each module to be assembled and the key interpolation points on the path of each assembled module are designed.By planning the joint space and the Cartesian space separately,the trajectory planning in the ground test of the end tool of the assembled robot is realized.Then,based on the ADAMS software,a ground test system and a robot parameterized model were built for the assembly robot ground test task.By programming motion scripts and drivers,motion planning simulations for ground tests were implemented.Finally,the joint simulation of MATLAB and ADAMS for the ground test system is implemented.A joint simulation block diagram was built in SIMULINK.By defining the input and output and parameter configuration,the trajectory planning for the first six degrees of freedom and the seventh degree of freedom was verified respectively,and the joint control of the robot in ADAMS was realized by MATLAB.In this paper,two different simulation experiments are carried out to verify the feasibility of various functional indexes of the R+2SPS/RRPRR+R seven-degree-of-freedom mixed configuration,which lays the foundation for similar configurations.On this basis,this project has developed a set of R + 2SPS/RRPRR + R seven-degree-of-freedom hybrid assembly robot with the ability to perform mobile assembly on a large space structure to meet the requirements and design goals. |