This paper studies the coordinated motion control of robotic manipulators driven by single-rod hydraulic actuators. Compared to conventional robot manipulators driven by electrical motors, hydraulic robot arms have a richer nonlinear dynamics and stronger couplings among various joints (or hydraulic cylinders). This paper presents a physical model based adaptive robust control (ARC) strategy to...

This paper studies the coordinated motion control of robotic manipulators driven by single-rod hydraulic actuators. Compared to conventional robot manipulators driven by electrical motors, hydraulic robot arms have a richer nonlinear dynamics and stronger couplings among various joints (or hydraulic cylinders). This paper presents a physical model based adaptive robust control (ARC) strategy to...

To help people with impairment of lower extremity movement regain the ability to stand and walk, enhance limb function, this study proposes an anthropomorphic design electrically driven, lower-limb exoskeleton rehabilitation robot. The angular range robot’s motion was determined according characteristics targeted joints; robot given active–passive 12 degrees freedom. multi-degree-of-freedom hip...

In this paper, a novel adaptive sliding mode control for rigid robot manipulators is proposed. In the proposed system, since there may exist explicit unknown parameters and perturbations, a Lyapunov based approach is presented to increase system robustness, even in presence of arbitrarily large (but not infinite) discontinuous perturbations. To control and track the robot, a continuous controll...

In this paper a flexible software framework is presented, that allows for the easy configuration, modeling, simulation, and collision avoidance for the manipulators of a service robot. The configuration of the robot including the number of manipulators, their degrees of freedom, the corresponding Denavit-Hartenberg parameters, geometry, fieldbus parameters etc. can be specified easily in xml co...

In this paper, the inverse kinematics solutions for 16 industrial 6-Degrees-of-Freedom (DOF) robot manipulators with offset wrists are solved analytically and numerically based on the existence of the closed form equations. A new numerical algorithm is proposed for the inverse kinematics of the robot manipulators that cannot be solved in closed form. In order to illustrate the performance of th...

The DELTA robot and the manipulators derived from the DELTA robot are a relevant class of translational manipulators. In this paper, the mobility analysis of these parallel translational manipulators is developed in full. The manufacturing and mounting conditions that guarantee the pure translation of the platform are analytically derived. Moreover, it is demonstrated that these manipulators ca...

Continuum robotic manipulators are increasingly adopted in minimal invasive surgery. However, their nonlinear behavior is challenging to model accurately, especially when subject external interaction, potentially leading poor control performance. In this letter, we investigate the feasibility of adopting a model-free multiagent reinforcement learning (RL), namely deep Q network (MADQN), 2-degre...

A model-free robust control (MFRC) approach is proposed for position control of robot manipulators in the state space. The control approach is verified analytically to be robust subject to uncertainties including external disturbances, unmodeled dynamics, and parametric uncertainties. There is a high flexibility to work on different systems including actuators by the use of the proposed control...

1.1 Robot manipulators Robot manipulators are well-known as nonlinear systems including strong coupling between their dynamics (Craig, 1996). These characteristics, in company with: 1) structured uncertainties caused by model imprecision of link parameters, payload variation, etc., and 2) unstructured uncertainties produced by un-modeled dynamics –such as nonlinear friction and external disturb...