This paper presents a novel miniaturized and modular dual-axis Electromagnetic Actuator (EMA). It mainly consists of two electromagnetic coils in an orthogonal orientation with a permanent magnet fixed on a free moving frame that rotates around two axes/joints. By actuating either of the coils, the free moving frame rotates around the corresponding axis. Simulations and experimental analyses are conducted in order to characterize the performance of our EMA. Thus, our actuator achieves a torque of 100 mNm at simulation and 80 mNm through experimentation for the same applied current. Additionally, it can achieve a rotation of 10o (≈0.2 rad), according to simulations and experimental work. Because of modularity, multiple units of our EMA can be connected together in different configuration to serve in several applications. As an example application, we used a pair of our EMA in order to generate a miniaturized 4-DOF robotic manipulator. This manipulator demonstrates the advantages of light weight, small size, and a high level of manipulability. Kinematic analyses and experimental work are performed in order to validate our manipulator and to prove the concept of our proposed EMA. Through this experiment, we applied an open-loop controller on our EMAs, so that the end-effector of our manipulator can track a predefined circular trajectory. The movement of the end-effector is detected while using image processing techniques. Although we used an open-loop controller, our manipulator is still able to track the trajectory with moderate errors. |
