Adaptive Control of Space Flying Robot Model in Virtual Environment Systems

The adaptive control task of an onboard space flying robot model with grasped payload in virtual environment systems is considered. The proposed solution to this problem is based on the manipulator links small masses assumption, which allows us to consider the robot as a system with his base link and payload. As part of this task, using the Newton-Euler method, a mathematical model of the robot’s motion was obtained, which linearly depends on the payload’s unknown mass estimation. This model is used to adaptive control synthesis to ensure the robot motion along a given trajectory with a given speed, as well as its rotations and stabilization. The robot control law is formed using the sliding mode theory and feedback by a continuous hyperbolic tangent function with respect to residuals. In addition, to implement of flying robot’s adaptive control synthesis, a differential equation was obtained in terms of the payload’s unknown mass. The methods and approaches proposed in the paper were implemented in the VirSim virtual environment system, developed at the NRC «Kurchatov Institute» — SRISA. Their approbation in this software package was carried out using the example of training person task to interact with onboard flying robots using voice interface. For these purposes, the Oculus Rift CV1 virtual reality headset was used for human immersion in a virtual environment and head tracking, Oculus Touch controllers and Manus Prime II VR gloves for tracking human hands and fingers. As part of this task, a training situation was simulated in which operator hands over the virtual payload with unknown mass to virtual flying robot, which then grasps it and moves with it to another part of the space station. Simulation results in VirSim showed the adequacy of the methods and approaches proposed in the paper for adaptive control of an onboard space flying robot with payload.