Active force-torque robot control without using wrist force-torque sensors

Abstract

A method of active force torque control of manipulator robots is considered; in this method it is proposed to use signals proportional to elastic deformations of flexible elements of the manipulators as feedback signals, rather than conventional forces and moments of reactions arising under the contact of the gripper and the moved object. It is proposed to construct control laws which are the functions of these feedback constraints in such a way that they generate artificial potential con trol forces. Due to it, unlike conventional approaches, simple and natural stability conditions are pro vided, as well as the weak dependence of dynamic properties of the control system on the variation of its parameters, i.e., the parametric robustness of the system. KULAKOV sors for measurement of link deformations. The method described here was first proposed in [8] and devel oped in [9][10][11][12][13][14][15]. This study presents the new results obtained in this direction.

Robot master slave and supervisory control with large time delays of control signals and feedback

“…The researches in this field and close to it directions are hold by the German Space Agency (DARA) [1,2], the National Aeronautics and Space Administration (NASA), as well as in Canada and Japan. This article presents the results of searches in St.-Petersburg National Research University (ITMO) [3][4][5], St.-Petersburg Institute of Informatics and Automation of RAS (SPIIRAS) [6][7][8][9][10] and in St. Petersburg State University (SPSU) [12][13][14][15][16][17][18][19]. The main crucial obstacle while constructing efficient systems of remote control over space robots is a significant delay of control signals transferring to the space robots from the ground control center, as well as delay of feedback signals receiving mainly in case of control over robot manipulators moving objects with constraints, in particular, holonomic [9,10].…”

Modeling and control of robot manipulators with the constraints at the moving objects

“…These methods are generally focused on solving the problems of using robots to automate the assembly and other operations which require interaction between robot and mechanically constrained objects [1]. Nevertheless, application of these methods in practice has not given the desired results.…”

“…It should be also noted that there is poor effectiveness in use of the pointed control laws in case of robot manipulators with flexible elements, in particular with flexible segments mostly used in space robotics [2]- [5]. The proposed approach to construction of an active force-torque control system is based on the use of the elastic deformations of the flexible manipulator's elements as feedback signals, rather than the traditional forces and reaction moments that occur while contacting of gripper with being moved objects [1]. Control laws as the functions of the feedback data are proposed to be built so that they could generate potential and quasi-potential control forces for the joints of the robot manipulator.…”