Control of heterogeneous systems over communications networks
Control of heterogeneous systems over communications networks
The scenario
This work concerns the teleoperation of a satellite’s attitude for earth observation. A human operator steers the satellite via a joystick. The human operator receives video stream from the satellite and uses this information to find or locate point of interest. Due to communication delay and packet drop, this interactive teleoperation is accompanied with overshooting and laggard responses. In this work, we consider to develop a teleoperation scheme that incorporates the time delays and packet drop in the communication, while enabling a transparent steering for the human operator. In other words, he shall feel as if he steers the satellite without any communication constraints.
a. Switching operation between manual and autonomous mode Once the human operator locates a certain point of interest on the video, he should click the joystick to give a signal of “freeze”. Due to communication delay, the satellite still keeps changing its attitude according to the commands transferred earlier, and the video feedback will keep displaying delayed areas. This implies that an initial overshoot is not avoidable. However, the closed-loop system should be able to give both the human operator and the satellite appropriate information, such that the satellite attitude returns fast to the proper angle of view, while further overshoots are minimized.
b. Image Predictor based Teleoperation It is possible to build up a satellite pose predictor, which uses the real-time command input of the human operator and the delayed status of the satellite. And with the help of current earth image database (e.g. Google Map), the predictor can map the predicted pose of the satellite to the database, so that it is possible to display the non-delayed satellite FOV (Field of View) to the user.
