A motion base with 6-DOF by parallel cable drive architecture

This paper proposes a new type of motion base for virtual sensation of acceleration by applying a parallel cable drive architecture. It has outstanding advantages in comparison with conventional Stewart platforms. Especially, 1) rotational motion range is large; 2) the motion platform can be grounded on the floor; 3) scene projection to all the walls is possible; and 4) its redundancy of cables improves safety for cut of cables. Optimal fundamental mechanical design is performed from the viewpoint of kinematics. Simulation results show that a 3-3-2 cable configuration is one of the best designs as a motion base. The prototype developed has the maximum motion range of translation ±0.45 m × ±0.4 m × 1.1 m and that of rotation ±45° in roll angle, ±45° in pitch, and ±35° in yaw. It can produce acceleration 1 G for 0.8 s at its maximum, even if gravity is not used. A trajectory planning method for longer-term sensation utilizing gravity is proposed. Low-frequency component of acceleration is realized by rotational motion and high frequency is produced by translational motion. Experimental results to create virtual acceleration of a roller coaster demonstrated effectiveness of this new design