A new robust position control algorithm for a linear belt-drive

The paper deals with a linear belt-driven servomechanism. It proposes new position tracking control algorithm that has been designed by sliding mode control theory. The selected sliding manifold was extended by non-rigid modes of the elastic servodrive. However, the proposed control scheme retains simple and practical for implementation. The experiments presented in the paper show that it effectively suppresses vibrations and furthermore extend the closed-loop bandwidth

Bilateral Teleoperation by Sliding Mode Control Design Approach

Sliding mode control has been used extensively in robotics to cope with parameters uncertainty, model perturbations and system disturbance. Bilateral robotic teleoperators are often required to provide a haptic interaction in telerobotic applications in which human kinesthetic sense is stimulated locally by remote environment. The paper deals with bilateral control for a force-reflection master-slave telerobotic architecture. It involves a short overview of basic bilateral modes. Chattering-free SMC design procedure for force-reflecting master-slave teleoperator is presented. The proposed bilateral control scheme was experimentally validated for a 1DOF master-slave teleoperator

Artificial Neural Network Control For Manipulators And Lyapunov Theory

: The paper presents a neural network controller design for trajectory tracking for manipulators. Lyapunov's stability theory was used to design the adaptive law for a computed torque method based artificial neural network controller. A joint space control scheme was used to test this type of controller. The controller was tested through simulation experiments and on the laboratory two D.O.F. SCARA mechanism. Keywords: manipulator, tracking control, artificial neural networks, Lyapunov function 1. INTRODUCTION Advanced manufacturing processes require ever greater accuracy and speed of performed smooth movements. Positioning tasks of robot mechanisms represent quite a difficult problem, which is due to great nonlinearities and influences of coupling in robot joints. Control tasks can be efficiently performed if advanced control schemes are used because manipulators are subjected to structured and unstructured uncertainties in all industrial applications. Structured uncertainty is defin..

Robust Impedance Control

Industrial robots are confronted with performing tasks where a contact with their environment occurs. Therefore, a need for control algorithms with position tracking performance and the force control ability appears. Up to date a lot of algorithms were proposed which deal with robot motion and force control. In this paper a robust impedance control law based on an attractive theory of sliding mode is proposed. The control law guarantees a robot predefined impedance and therefore a force regulation based on the possessed impedance properties is feasible. The proposed impedance controller is used in a force-tracking task. Experimental results on a simple 1DOF mechanism and 3DOF direct drive robot mechanism are reported. 1. Introduction During many robot tasks a relatively permanent contact of the robot with the environment is needed. Such tasks are for example: drawing, cleaning, deburring, cutting, drilling, assembling etc. A robot is able to cope with such tasks if it is equipped wit..

Robust Biaxial Motion Control for Laser Cutting Machine

¾ A position control algorithm for a beltdriven servomechanism of a laser-cutting machine is described. High-accuracy position tracking control procedure for the system with inherent elasticity due to the low-cost belt-driven servomechanism is derived using sliding mode motion control strategy and Lyapunov design. The control design results in continuos sliding mode control law. It possesses all the good properties of the robust sliding mode and avoids the unnecessary discontinuity of the control input, thus eliminating chattering. The proposed robust position tracking control algorithm is used in an industrial application of a biaxial motion controller for the CNC laser-cutting machine. Experimental results are reported. I. INTRODUCTION Performances of movement transformation elements from motors to a machine tool play important role in a design of a motion controller. A mechanical construction of the machine and built-in drives define drive's performances. There are two major sourc..

SMC with disturbance observer for a linear belt-drive

Accurate position tracking control in a belt-driven servomechanism can experience vibrations and large tracking errors due to compliance and elasticity introduced by force transmission through the belt and nonlinear friction phenomenon. In this paper, a new control algorithm based on sliding mode control that is able to deal with these problems is proposed. In order to further optimize position tracking performance the control scheme has been extended by an asymptotic disturbance observer. It has been proven that robust and vibration-free operation of a linear belt-driven system can be achieved. The experiments presented in the paper show improved position tracking error response while maintaining vibration suppression

SMC with disturbance observer for a linear belt-drive

Accurate position tracking control of a linear belt-driven servomechanism can cause vibrations in the drive response due to compliance and elasticity introduced by force transmission through the belt. This paper proposes a new control algorithm that has been designed by Sliding Mode Control theory. Though it has been proved to assure robust and vibration-free operation, position error peaks still appear at velocity reversals due to nonlinear friction phenomenon. Thus, the control scheme has been extended by asymptotic disturbance observer. The experiments presented in the paper show improved position tracking error response while maintaining vibration suppression

Improved design of VSS controller for a linear belt-driven servomechanism

This paper proposes a new control algorithm for a linear belt-driven servomechanism. The elasticity of the belt and large nonlinear friction along with large variation of parameters limit the applicability of the belt driven servosystems. Design of simple control that can guarantee stable, vibration-free operation for large variation of load is needed to extend application of such a linear stage. The proposed control is based on the application of sliding mode methods combined with Lyapunov design so it guarantees the stability of the system. Due to the restriction of the system motion to specially selected sliding mode manifold the vibration free position tracking is achieved with very good disturbance rejection. Proposed algorithm is simple and practical for an implementation and the tuning procedure of the control parameters is simple. The experiments have shown that the proposed control scheme effectively suppresses vibrations and assures wide closed-loop bandwidth for position tracking control

Robust Motion Control of XYTable for Laser Cutting Machine

The position control algorithm for a beltdriven servomechanism of the laser cutting machine is described. High-accuracy position tracking control procedure for system with inherent elasticity due to the low-cost belt-driven servomechanism is derived based on continuos sliding mode technique. The proposed robust position tracking control algorithm was tested by simulations and used in the industrial application of a motion controller for the CNC machine. Simulation and experimental results are reported. I. INTRODUCTION Tool machines have several motion axes. In order to control all motion axes servo controls with motion controllers are indispensable in CNC controllers for machining centers. Motion controllers must be able to guarantee execution of demanded motion, which satisfies the desired tolerance of the finished workpiece. There are two fundamental motion tasks, which are used in modern mechanical systems: PTP (Point-To-Point) movement for moving from one position point to another ..

Robust Sliding Mode Based Impedance Control

The industrial robots are confronted with performing tasks where a contact with their environment occurs. Therefore, a need for control algorithms with position tracking performance and the force control ability appears. Up to date a lot of algorithms were proposed which deal with robot motion and force control. They could be mainly separated into two great classes, namely Hybrid control, where constrained and unconstrained DOFs of the robot are observed separately based on the principe of the ortoghonality, and Impedance control where the robot should adopt some physical properties such as mass, damping and stiffness in order to assure stable dynamic interaction with the environment. In this paper the robust impedance control law based on the attractive theory of sliding mode is proposed. The control law guarantees a robot predefined impedance and therefore force regulation based on possessed impedance properties is discussed. Experimental result on a simple 1 DOF mechanism is shown t..