Research On The Key Technologies Of On-orbit Teleoperation For Mobile Manipulators On Planetary Surface

On-orbit teleoperation for robots on planetary surface is referred to the operation process in which the astronauts in planet-orbited manned space station control robots to perform tasks according to the environment of planetary surface and the operating state of robots.On-orbit teleoperation can be classified to action level and mission level according to the autonomy degree of robots in the operation process.It is advantageous in terms of high reliability,high controllability and low operational risk compared with other operation modes,such as fully autonomous operation.In this paper,for the need of system construction and simulation experiment for on-orbit teleoperation,an on-orbit teleoperation system for a mobile manipulator on planetary surface is established,and algorithm design and experiments are carried out for two types of on-orbit teleoperation tasks: action level and mission level.First,for the modeling requirement of the communication delay in on-orbit teleoperation,two communication modes of space-station-to-ground teleoperation are analyzed.After that an on-orbit teleoperation delay modeling method based on SGP4 orbit preditive model is proposed,which overcomes the defect that the time delay in operation process is assumed to be constant in the traditional teleoperation systems.Second,the integrated model of mobile manipulator is established,including the3 D model of the mobile manipulator,the kinematics of the mobile platform,the forward and inverse kinematics of the manipulator and the target approaching model of the manipulator,which is the basis of mobile manipulator control.In addition,for the static target tracking problem in mission-level teleoperations,the path planning from the start point to the target point is realized based on A* and the improved artificial potential field algorithms,and the tracking of the planned path is achieved by the model predictive control theory.For the dynamic target tracking problem,consider the time delay in measurement data uploading and control signal returning,the Kalman filter algorithm is adopted to obtain the estimation of target location,according to which a dynamic path planning and tracking scheme is designed to achieve the effective target tracking of the mobile platform.Finally,a visual simulation system for the concerned on-orbit teleoperated mobile manipulator is established,by which the teleoperation experiments for both action level and mission level are carried out to verify the integrality of the constructed teleoperation system and the effectiveness of the designed algorithm.