This paper presents an efficient application of a model based predictive control in parallel mechanisms. A predictive functional control control strategy based on a simplified dynamic model is implemented. Experimental results are shown for the H4 robot, a fully parallel structure providing 3 degrees of freedom (dof) in translation and 1 dof in rotation. Predictive functional control, computed ...

We are developing a visually-guided autonomous underwater vehicle. We have implemented a computed torque controller, using Euler parameters, for position and velocity control. This formulation eliminates singularity in the model and controller and offers some degrees of coupling between vehicle degrees of freedom. A calibrated thruster model which computes thrust output from measured voltage an...

In this paper, progress efforts towards an open control architecture for a PUMA 560 manipulator are described. The original UNIMATE architecture was modified to allow direct control, trajectory planning, task planning and external sensors handling by a network of dedicated personal computers. Meanwhile the new platform was tested by the implementation of one-PD-per-joint and computed torque con...

This paper deals with the dynamic control of a parallel robot with C5 joints. Computed torque control and robust control have been studied and implemented. For this purpose, we have used the inverse dynamic model whose parameters have been experimentally identified. The closed loop stability has been studied using the Lyapunov principle. The addition of a robustness term based on sliding mode t...

This paper presents a hybrid dynamic control approach to the realisation of humanoid biped robotic walk, focusing on the policy gradient episodic reinforcement learning with fuzzy evaluative feedback. The proposed structure of controller involves two feedback loops: a conventional computed torque controller and an episodic reinforcement learning controller. The reinforcement learning part inclu...

This work presents the development of mathematical model of a mobile manipulator and its use to develop a controller based on backstepping nonlinear control and the computed torque control law. This MIMO nonlinear controller was implemented on the Robot Operating System (ROS) environment. The mobile robot is based on the Barrett WAM (Whole Arm Manipulator) and a custom build mobile platform. Th...

The tracking problem for a class of dynamic nonholonomic systems with uncertainties is considered. First, under the assumption that the dynamics of the nonholonomic systems are exactly known without uncertainties, a simpler model-based controller is proposed by means of cascade design approach, in which the virtual velocity controller is linear, and the actual torque controller is derived by co...

It is well known that computed torque robot control is subjected to performance degradation due to uncertainties in robot model, and application of neural network(NN) compensation techniques are promising. In this paper we examine the eeectiveness of neural network(NN) as a compensator for the complex problem of Cartesian space control. In particular we examine the diierences in system performa...

In this paper, a new neural network technique for robot manipulator control is proposed. This technique called reference compensation technique(RCT), is to compensate for uncertainties in robot dynamics at input trajectory level rather than at the joint torque level. The ultimate goal of the proposed technique is to achieve an ideal computed-torque controlled system. Compensating at trajectory ...

A novel method of Zero-Moment-Point (ZMP) compensation is proposed to improve the stability of locomotion of a biped, which is subjected to disturbances. A compensating torque is injected into the ankle-joint of the foot of the robot to improve stability. The value of the compensating torque is computed from the reading of the force sensors located at the four corners of each foot. The effectiv...