A parallel three degrees of freedom (3-DOF) manipulator known as Maryland manipulator is considered in this paper. The manipulator model considered in this paper is more practical because the offset lengths are not taken zero. The trajectory tracking control of the Maryland manipulator is done using linear–quadratic regulator (LQR) based proportional–integral–derivative (PID) controller. Three ...

This paper shows how to generate underactuated manipulators by substituting nonholonomic spherical pairs for (holonomic) spherical pairs in ordinary (i.e. not underactuated) manipulators. As a case study, an underactuated manipulator, previously proposed by one of the authors, is demonstrated to be generated, through this pair substitution from an inversion of the 6-3 fully parallel manipulator...

This paper proposes a novel application of the Stewart–Gough parallel platform as a climbing robot and its kinematics control to climb through long structures describing unknown spatial trajectories, such as palm trunks, tubes, etc. First, the description and design of the climbing parallel robot is presented. Second, the inverse and forward kinematics analysis of a mobile six-degrees-of-freedo...

The nonlinearity of the position equations of most parallel manipulators burdens the control and is a serious drawback for industrial applications. In this paper the authors have developed a 5 degrees of freedom parallel manipulator 3T2R whose position equations are explicit and partially decoupled. In order to get that, several platforms, partially actuated by limbs joined to the base, have be...

For parallel manipulator systems a fundamental distinction is drawn between displacement and motion. The former is a spatial relation adequately modelled by standard vector and matrix algebra. The latter is a spatial trajectory whose ‘history’ also requires modelling. Quaternion, spinor and Clifford algebra representations are utilised for this purpose specifically for rigid body finite rotatio...

In this paper the kinematics, (position, velocities and accelerations) and the dynamics of a 6-RUS parallel manipulator by using the natural coordinates are analysed. One numerical example of kinematics and inverse dynamics is presented.

Absfracf-The goal of this study is to develop a mechanical system which display elastic characteristic like stiffness on the surface of human body aiming at applying to palpation simulator. Pneumatic parallel manipulator is employed as a driving mechanism, consequently, it brings capability of minute force displaying property owing to the air compressibility. Compliance control system without u...

In the most general case the measurement of the links lengths of a 6 d.o.f parallel manipulator is not sufficient to determine the actual unique posture of its platform. We investigate how this posture can be determined by adding sensors to the manipulator. We show that by adding four sensors on the passive joints a unique closed-form solution of the posture of the endeffector can be obtained f...

A novel n(4-SPS+SP) serial-parallel manipulator (S-PM) formed by n 4-SPS+SP PMs with four degrees of freedom (DOF) connected in series is proposed in this paper. The kinematics , statics and stiffness modeJ of this seriaJ-PM is established. First , the forward kinematics of 4-SPS十SP (spherical jo口比-prismatic joint-revoJute十spherical joint-prismatic joint) PM is d 由er引l口附飞 SPS+SP) S-PM i 比s s 民t...

In this study, a new terminal converging adaptive control approach with bounded control inputs is developed for the 6 degree of freedom (DOF) parallel robot manipulator. The non-smooth feedback control principle is combined with particular bounded functions to define both the control input and associated adaptive law. The Lyapunov method is used to present a stability analysis in order to prove...