Development of the Nist Robot Crane Teleoperation Controller

An inexpensive and easy to operate controller has been developed for the teleoperation control of the NIST Robot Crane. This robot crane has the Stewart platform parallel link manipulator design, with cables as parallel links and winches as actuators. The controller is currently capable of rate-position control and force control of the crane platform. The control action can take place with respect to the base-frame coordinate axes, the moving platform coordinate axes, or the tool-tip coordinate axes. The front panel display of the controller is designed to interact with the operator in simple, easy to understand, menu selection type icons. Critical parameters are displayed in real time plots and digital displays. A 3-D animation window of the workspace and the moving crane platform can help the operator with command planning and premotion detecting of collisions. The operator can interact with the controller without the need for any computer programming knowledge and without having to type any commands. The rate-position movement commands are input from a spaceball or a Stewart mechanism joy-stick. Critical control mode selection choices can be made from a set of nine buttons attached to the spaceball joystick support.