Research On Force/Position Hybrid Control For Robonaut During Coordinate Operation

Along with the development of space exploration, space operation tasks become more and more complex. At present, our country is carrying out the construction work of space station, and will face even more complicated tasks in the near future. However, huge amounts of material and financial resources will be consumed if astronauts are sent to the space station to execute routine maintenance of the space station. Moreover, astronauts are faced with danger in the harsh space environment at any time. Therefore, a new generation of space robot (Robonaut) is necessary to be studied for the further development of space research.The research derives from the National973Project "the basic theory of control system and operational reliability of space agencies". This paper regards Robonaut as the research object and focuses on the study of kinematic and dynamic modeling, motion planning and hybrid control to improve Robonaut’s performance during space mission. The main contents of this paper include the following aspects:Firstly, the kinematic model is studied for Robonaut with the characteristics of complicated structure and high DOFs. Aiming at teleoperation and autonomous control of Robonaut during space mission, kinematic models in position level and velocity level are built accordingly. On this basis, motion planning methods in teleoperation control and autonomous control mode are designed respectively. The study of kinematic modeling and motion planning are the kinematic basis of coordinate operation and hybrid control for Robonaut.Secondly, the dynamic model of Robonaut is built and its dynamic characteristics are analyzed during coordinate operation. As the basis, dynamic recursion equations of single-link manipulator are built. Thereafter, considering the coupling branches, the dynamic model of Robonaut is achieved. For improving Robonaut’s dynamic performance during space mission, smooth operations and joint torque minimization are set as the optimization goals respectively. The study of dynamic modeling is the dynamic basis of hybrid control for Robonaut.Thirdly, the force/position hybrid control problem is studied for Robonaut during space mission. Contact between Robonaut and the environment is unavoidable when executing operation tasks. In order to extend the application and improve its safety and reliability, force/position hybrid control of Robonaut is studied. For different space operation tasks, the hybrid control methods of single arm and double arm are studied separately. The hybrid control technology is of great significance for improving Robonaut’s safety and operational ability when executing space operation tasks.Finally, the’3D simulation experiment platform and the physical verification platform are built separately to verify the validity and feasibility of the proposed algorithms.