A human and computer co-operative control based telerobotic system: Control concept and implementation.

In this research work, a study has been carried out on the current development of teleoperation and the control strategies adopted to co-ordinate human operator input and computer autonomous control. Based on the findings, a human and computer cooperative control concept has been developed to overcome the shortcomings of the existing control strategies. It utilises the human and computer characteristic advantages to complement each other to improve task performance and increase task success rate. Some aspects of the tasks are shared between humans and computers while computer assistance is introduced into the human supervisory functions in this co-operative control. Traditional problems of teleoperation such as time delay and task dependence of high-level control have been addressed and overcome by utilising the distributed and parallel processing system architecture and an expandable knowledge base incorporated with generic and task specific modules. Guidelines and an ideal system model have been proposed to provide system developers with future design guidance. A telerobotic system has been built based on the developed human and computer cooperative control concept. It uses the client/server model to achieve distributed and parallel processing. Operators can perform tasks through direct manual control and computer assisted task-level control provided in the system. Multiple manual inputs have been introduced to suit different control conditions. They provide the operator with intuitive and hardware independent input methods to manipulate the remote robot. A computer vision system has been developed to provide not only the visual feedback of the remote environment but also assistance in object location and robot navigation. Task modules containing generic and specific task handling functions are used for achieving human and computer co-operation at both task planning and execution levels. The experiment results obtained from the system evaluation have shown that the task completion time in co-operative control mode is half the time required in human direct manual control. Task performance achieved in co-operative control mode is less sensitive to the difference between the operators' capability. In conclusion, the usability and effectiveness of the co-operative control, and the validity of the techniques of camera calibration and image processing has been proven through the demonstration task