Résumé
This paper describes a new parallel kinematics mechanism for Schonflies motion: the Lambda-Quadriglide. The structure of Lambda-Quadriglide provides four degrees of freedom (DOF) with three translations and one rotation around a horizontal axis. Four linear actuators with the same direction are used, which allows the workspace to be particularly long in this direction. The special feature of this mechanism is the lambda-configuration, based on two kinematic chains acting directly on the traveling plate, and two other kinematic chains acting on the first ones. This configuration allows a large rotational angular range for the mobile platform. The design concept of Lambda-Quadriglide is introduced and kinematics models are derived. Optimization of the mechanism parameters and the workspace of the optimized mechanism are also presented. This architecture allows a physical implementation with no collision problems between the arms. Finally, the Lambda-Quadriglide prototype is presented, together with experimentation results.