Development and study of a robot for transferring Mycobacterium tuberculosis samples

As an essential part of the Mycobacterium tuberculosis automatic testing system, a 3-DOF robot for transferring testing samples has been developed in this paper. Mechanical structure of the robot has been first presented. The control system of the robot is then studied. A closed loop control method of stepping motors, which are motion actuators of each joint, is developed with a Proportion Integration (PI) controller so that high precision and fast response can be obtained. In order to avoid sudden increase of motor speed when it starts, which may cause mechanical shock, a starting acceleration algorithm is applied. An upper computer interface is developed for operators to easily program the robot. Finally, experiments have been performed to verify the design performance.