The optimization of the pressure angle in a cam-follower transmission is reported in this paper. This transmission is based on Slide-o-Cam, a cam mechanism with multiple rollers mounted on a common translating follower. The design of Slide-o-Cam, a transmission intended to produce a sliding motion from a turning drive, or vice versa, was reported elsewhere. This transmission provides pure-rolli...

The orthoglide is a 3-DOF parallel mechanism designed at IRCCyN for machining applications. It features three fixed parallel linear joints which are mounted orthogonally and a mobile platform which moves in the Cartesian x-y-z space with fixed orientation. The orthoglide has been designed as function of a prescribed Cartesian workspace with prescribed kinetostatic performances. The interesting ...

In this paper, a systematic approach is developed for the structural synthesis of a class of four-degrees-of-freedom (4-DoF) and 5-DoF overconstrained parallel manipulators with identical serial limbs. The theory of screws and reciprocal screws is employed for the analysis of the geometric conditions that must be met by the limbs of such parallel manipulators. Limb structures that can be used f...

This paper concerns the forward kinematics and tension distribution of sinking winches mechanism, which is a type of four-cable-driven partly constrained parallel robot. Conventional studies on forward kinematics of cable-driven parallel robot assumed that all cables are taut. Actually, given the lengths of four cables, some cables may be slack when the platform is in static equilibrium. Theref...

This paper studied the stiffness model and characteristics of a planar 3-RPS PM with 3-DOF. The 6 × 6 form stiffness matrix of the planar 3-RPS PM is derived with both active and constrained wrenches considered. To characteristic the stiffness of the planer 3-RPS PM, two decomposition methods including the eigenscrew decomposition and the principle axes decomposition are applied to the stiffnes...

ABSTRACT Study of parallel manipulators highlights the importance of identifying singular configurations (singularities) during the design, and of avoiding them during the operation; because in these configurations the instantaneous kinematics of the manipulator becomes indeterminate. This paper focuses on the determination of singular configurations of a kinematically redundant 3-RRRR spherica...

This chapter is dedicated to the so-called cuspidal robots, i.e. those robots that can move from one inverse geometric solution to another without meeting a singular confuguration. This feature was discovered quite recently and has then been fascinating a lot of researchers. After a brief history of cuspidal robots, the chapter provides the main features of cuspidal robots: explanation of the n...

In the respective publication [1] architecturally singular designs (Ma and Angeles [10] 1 ) of pentapods (5-degree-of-freedom fully-parallel manipulator with an axial spindle as moving platform) with coplanar base attachments are investigated. The authors correctly identified (cf. Section 1 of [1]) pentapods, which are special 5-SPU platforms, as rigid subassemblies in Stewart Gough (SG) platfo...

The parallel mechanism has become an alternative solution when micro manipulators are demanded in the fields of micro manipulation and micro assembly. In this paper, a threeDegree-Of-Freedom (3-DOF) parallel micro manipulator is presented, which is directly driven by three micro gas bubbles. Since the micro gas bubbles are generated and maintained due to the surface tension between the gas and ...

This paper presents a planar parallel mechanism which can achieve very rapid motion due to the low inertia of its moving parts and the use of multiple simultaneous specification (MSS) control. The proposed parallel manipulator was designed based on a Prismatic-RevoluteRevolute kinematic structure. The proximal prismatic joints were realized using a linear slider with a ball screw mechanism. All...