Design strategy and issues of the Delthaptic, a new 6-DOF parallel haptic device

Abstract

The design of an optimal and versatile haptic device should enable human to achieve complex remote tasks in a safe and ergonomic environment. The paper presents a design strategy applied to the development of the Delthaptic, a new 6-DOF parallel haptic device. The Delthaptic is based on a coupled-parallel structure. It combines two Delta robots, linked to the two extremities of the customized ball-screw handle, to obtain its 6 degrees of freedom. The proposed haptic device provides a large and singularity-free workspace while keeping the benefits of parallel mechanisms.The design process first consists in a phase of structural design where the mechanical architecture is defined in order to meet requirements. During a second step, the parameters of this architecture are optimized by minimizing objective functions based on desired kinematic performances. Then, a generic procedure is proposed to select the actuation with respect to dynamic capability-based criteria as well as technological aspects. Actuators and transmission systems are chosen for the Delthaptic. A prototype of the haptic device is built to experimentally assess its mechanical functioning and check the design requirements.