Control of robot manipulator for storing cord blood in cryogenic environments

This paper studies a control method for the manipulator of an automatic cryogenic storing vessel which can improve a ratio of survival of a cord blood. The cord blood keeps in liquid nitrogen in the cryogenic vessel. The integrated robot control system for storing a cord blood based on mechanism of SCARA robot is developed. The system consists of a cryogenic vessel, a robot arm controller using a multimotion controller (MMC) board, and control program. The robot manipulator consists of four axes. Each axis consists of a rotation of a major lid, a rotation of a minor lid, a rotation of periscope and a linear motion of periscope. The main software has functions of operating task, dynamic simulator, three dimensional animation, and trajectory planning. To overcome a difficulty to detect collision between canister and the pin of a slot in a rack of the vessel, a collision detection algorithm for the robot is proposed. The trajectory tracking performance of these algorithms are evaluated by implementing to design SCARA type robot using MMC board which has conventional PID control algorithm. To improve performance of the integrated system, the proposed algorithm for the collision avoidance is applied to the end-effector of the robot manipulator.