Improving Teleoperator Efficiency Using Position–Rate Hybrid Controllers and Task Decomposition

In hazardous environments where direct human operation of machinery is not possible, such as in a nuclear power plant (NPP), teleoperation may be utilized to complete tasks safely. However, because teleoperation tasks are time consuming, complex, highly difficult, and need to be performed with incomplete information, they may increase the human operator’s cognitive load, which can affect the efficiency of the human operator as well as the completeness of the task. In this study, we propose a teleoperation system using a hybrid teleoperation controller that can increase operator efficiency for specific teleoperation tasks in complex sequences. First, we decomposed the task into a sequence of unit subtasks. For each subtask, the input space was allocated, and either position control or rate control by the hybrid controller was determined. Teleoperation experiments were conducted to verify the controller. To evaluate the efficiency improvement of the teleoperators, the completion time and NASA task-load index (NASA-TLX) were measured. Using the hybrid controller reduced the completion time and the NASA-TLX score by 17.23% and 34.02%, respectively, compared to the conventional position controller.