Floating Platform Simulation Test Bench Motion Control System

Offshore drilling platforms move irregularly during the operation due to thestrong wind, load and other factors, which can affect the normal operation seriouslyand thus setting obstacles to the exploit of the offshore resources. A control system isintroduced in this paper which is designed to simulate the translation, swing andheave movement of the drilling platform. The main work includes the inverse solutionof the movement, design and manufacture of the experimental device and the softwaredevelopment.The Stewart platform is selected to do the experiment, which is driven by sixstepper motors and screws. The move platform and the static one are connected by theends of the screws with Hooke joint. The control system is made up by a hostcomputer, a main control board, six sub control board, limit switches and rotaryencoders.The main control procedure is described as follows: First, movement parametersare got from the host computer and inverse solution of movement is done by the maincontrol board to get the function of the motion. Second, the speeds of the motors aresolved according to the lead of the screw and the drove ratio of the timing belt; Last,the motor control parameters are sent to each sub control board which can generatethe relevant signal to control the motion of the motors and the platform. Relevantrotary encoders are used to detect the speed of the motors to send it back to thecontrol system.Experiments of one motor control and the whole platform control are committed,in which the theoretical motion parameters suit the actual motion parameters well andthis also verify the function of the control system.