Mechanisms that consist of many elements and are potentially small sized, benefit from kinematic elementary units like revolute joints compliant monolithic, therefore could be produced without need for assembly. We present a novel concept joint features low axis drift, high support stiffness large range motion. The is based on helicoidal shell which portion reverses its twist direction upon app...

This paper presents a novel 1-DOF (degree-of-freedom) single-loop reconfigurable 7R mechanism with multiple operation modes (SLR7RMMOM), composed of seven revolute (R) joints, via adding a revolute joint to the overconstrained Sarrus linkage. The SLR7RMMOM can switch from one operation mode to another without disconnection and reassembly, and is a non-overconstrained mechanism. The algorithm fo...

We use the recently introduced factorization of motion polynomials for constructing overconstrained spatial linkages with a straight line trajectory. Unlike previous examples, the end-effector motion is not translational and the link graph is a cycle. In particular, we obtain a number of linkages with four revolute and two prismatic joints and a remarkable linkage with seven revolute joints one...

In order to improve the control precision and robustness of the existing proportion integration differentiation (PID) controller of a 3-Revolute–Revolute–Revolute (3-RRR) parallel robot, a variable PID parameter controller optimized by a genetic algorithm controller is proposed in this paper. Firstly, the inverse kinematics model of the 3-RRR parallel robot was established according to the vect...

This paper explores the applicability of a Linear Quadratic Regulator (LQR) controller design to the problem of bipedal stance on the Minitaur [1] quadrupedal robot. Balancing the body on only the rear legs affords the possibility of using the front legs for other tasks such as manipulation or bracing. Restricted to the sagittal plane, this behavior exposes a 3DOF (degree of freedom) double inv...

In human body movement simulation such as vertical jump by a forward dynamic model, optimal control theories must be used. In the recent years, new methods were created for solving optimization problems which they were adopted from animal behaviors and environment events such as Genetic algorithm, Particle swarm and Imperialism competitive. In this work, the skeletal model was constructed by Ne...

In this research, as the main contribution, a comprehensive study is carried out on the mathematical modeling and analysis of the inverse kinematics and dynamics of an over-constraint three translational degree-of-freedom parallel manipulator. Due to the inconsistency between the number of equations and unknowns, the problem of obtaining the constraint forces and torques of an over-constraint m...

In this paper, an inverse dynamics approach by means of adaptive coupled oscillators is used in the modelling and control of a lower limb orthosis applied at the knee and ankle joint level. This design is aimed at providing assistance and rehabilitative measures to humans with lower limb disorders and as such presents a platform for which their mobility performance can be improved. Adaptive osc...

The Inverse Kinematics (IK) problem is concerned with finding robot control parameters to bring the into a desired position under kinematics and joint limit constraints. We present globally optimal solution IK for general serial 7DOF manipulator revolute joints polynomial objective function. show that kinematic constraints due rotations can be all generated by second-degree polynomials. This an...

The rst part of this thesis includes a brief comparison between electricmotors and hydraulic actuators for high performance robotics applications. Hydraulic actuators with fast valves are shown to be superior because of their large torque to mass ratios and their extended bandwidth. One such hydraulic actuator is characterized and its highly nonlinear dynamics are modeled and identi ed. A simul...