Communication and Control Method via Pressure Supply Tube for Teleoperation Hydraulic Robot

A self-propelled hydraulic robot is currently being developed for use in teleoperation within nuclear power plants. In this paper, we proposed a new communication and control method that uses a water pressure supply tube instead of signal lines for signal transmission to improve the robot mobility by eliminating some of the numerous electrical signal lines in the robot cable. We evaluated the method using a hydraulic drive circuit simulating an actual robot and reached the following conclusions. 1) Adding pulse signals to the drive pressure caused delays due to tube expansion. 2) Setting the regulator set pressure higher than the target pulse height and controlling the pressurization time with a solenoid valve reduced expansion effects. The transmission time was 190 ms and the number of possible transmission signal patterns was 18; these results confirmed applicability of the method to controlling an 8-degrees of freedom arm of a teleoperated hydraulic robot.