Trajectory Tracking Control Algorithm Research Articles

Trajectory Tracking Control and Impedance Control of Mine Detection Robot.

Two topics about mine detection robot are described in this paper. First, we propose a trajectory tracking control algorithm based on RTK-GPS for hexapod robot. ln extreme environment, for example a mine field, it is necessary for robot to observe the position and follow the reference trajectory. So we constructed a hierarchical control system including the high and low authority controllers. The low authority controller is sliding mode controller that is useful for robot system which contains the nonlinear characteristics at the drive system. And the high authority controller changes the gait by using GPS data. Next, we propose a foot control by using non-contact impedance control (NCIC) when hexapod robot acts on mine avoidance. NCIC can regulate virtual impedance between the end-effector and external objects using position information. First, a controller put a virtual column on a mine position by using GPS data and potentiometer. The virtual force is calculated from the non-contact impedance and the foot can avoid the mine position owing to revise base reference. We have already verified the usefulness of these schemes by simulation and experiments.

Second Order Sliding Modes Control of Underwater Vehicles Tracking the Gradient of Artificial Potential Fields

In this paper a multiinput second order sliding rnode control algorithm for underwater vehicles trajectory tracking will be introduced. The proposed approach guarantees perfect tracking and stabilization even in presence of disturbances and uncertainties typical of this kind of systerns. The trajectories to be tracked are designed basing on an artificial potential field technique. The control objectives are achieved by acting on the voltage of the motors driving the thrusters and the resulting forces and torques are continuous.

Velocity-Based Control of Manipulator/Vehicle System Floating on Water

A manipulator/vehicle system floating on water consists of a vehicle with a manipulator attached to it. Similar to the space manipulator system, the system on water is not fixed to an inertial coordinate system. So, external forces affect the motion of the system. In this paper, we propose an algorithm for controlling the position and orientation of the end-effector of the manipulator/vehicle system in an inertial coordinate system under the assumption that the stability of the vehicle is maintained. We derive the kinematics of the system and propose a trajectory tracking control algorithm based on the resolved motion rate control, then prove convergence of the control algorithm using the Lyapunov's method. Experimental results illustrate the validity of the proposed control algorithm.

Comparative Study of D.D. Robot Control Algorithms for Trajectory Tracking

This paper is a comparative study of D.D. robot control algorithms for the purpose of trajectory tracking. In order to achieve real time control, we propose a Transputer- based robot controller with parallel processing to meet the massive computational requirements of advanced robot control algorithms. They are feedforward control, computed torque control, sliding mode control and adaptive control. Based on detailed theoretical analysis and experimental research, some important conclusions are reached.

Robust adaptive decentralized control of robot manipulators

The authors proposes a robust adaptive decentralized control algorithm for trajectory tracking of robot manipulators. The controller is designed based on a Lyapunov method, which consists of a PD (proportional plus derivative) feedback part and a dynamic compensation part. It is shown that, without any prior knowledge of manipulator or payload parameters and possibly under deterioration of parameter variation with time or state-independent input disturbances, the tracking error is bound to converge to zero asymptotically. In particular, the algorithm does not require explicit system parameter estimation and therefore makes the controller structurally simple and computationally easy. Moreover, the controller is implemented in a decentralized manner, i.e. a subcontroller is independently and locally equipped at each joint servoloop. To illustrate the performance of the controller, a numerical simulation example is provided.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Computer Aided Determination of Robot Arm Dynamics and Adaptive Control Algorithms

A computer program package is developed to analyse the dynamic behaviour of an n degree of freedom manipulator with rotational and/or translational joints. Computer oriented algorithms for robot arm dynamics are implemented together with suboptimal control algorithms for trajectory tracking. The program package allows in an interactive way the synthesis of the manipulator structure as well as its control system, and the simulation of the dynamic behaviour of the whole system under different scenarios. Two adaptive control schemes based on minimum energy terminal control are proposed. Performances of the proposed algorithms are tested with a simulation study carried on for a typical manipulator and a specific scenario.