Hybrid Position/Force Control of Robot Manipulators Based on Second Derivatives of Position and Force

1996 ◽  
Vol 8 (3) ◽  
pp. 243-251
Author(s):  
Satoshi Komada ◽  
◽  
Muneaki Ishida ◽  
Kouhei Ohnishi ◽  
Takamasa Hori ◽  
...  
Keyword(s):  
Coordinate System ◽  
Force Control ◽  
Disturbance Observer ◽  
Position Control ◽  
Robot Manipulators ◽  
Computational Effort ◽  
Direct Drive ◽  
Second Derivatives ◽  
Parameter Variations ◽  
Derivatives Of

This paper proposes a new robust hybrid position/force control of robot manipulators. The proposed method controls the second derivatives of control variables, such as position and force in a task coordinate system, in order to realize robust and high response control. To this end, the disturbances are estimated by a position-based disturbance observer and a force-based distrubance observer in the task coordinate system, and are compensated by feeding back the estimated distrubances. The proposed method requires less computational effort and is robust against the disturbance and parameter variations. The position-based distrubance observer has been proposed to linearize robot manipulators and has realized robust position control. However, when force control is performed, the force response is influenced by not only the nonlinearity of robot manipulators but also the charactersitics of the environment on which the force is imposed. Therefore, the force-based disturbance observer is developed to realize robust force control. A controller robust against the disturbance and parameter variations is realized by using the position-based disturbance observer and the force-based disturbance observer on performing the position control and the force control respectively. The effectiveness of the proposed method is shown by experiments by using a direct drive robot.

Earth's gravity field parameters determination by the space geodesy dynamical approach

2017 ◽  
Vol 919 (1) ◽  
pp. 7-12
Author(s):  
N.A Sorokin
Keyword(s):  
Coordinate System ◽  
Gravitational Potential ◽  
Coefficient Matrix ◽  
Measured Quantity ◽  
Second Derivative ◽  
Measured Variable ◽  
Second Derivatives ◽  
Rectangular Coordinates ◽  
Cartesian Coordinate ◽  
Derivatives Of

The method of the geopotential parameters determination with the use of the gradiometry data is considered. The second derivative of the gravitational potential in the correction equation on the rectangular coordinates x, y, z is used as a measured variable. For the calculated value of the measured quantity required for the formation of a free member of the correction equation, the the Cunningham polynomials were used. We give algorithms for computing the second derivatives of the Cunningham polynomials on rectangular coordinates x, y, z, which allow to calculate the second derivatives of the geopotential at the rectangular coordinates x, y, z.Then we convert derivatives obtained from the Cartesian coordinate system in the coordinate system of the gradiometer, which allow to calculate the free term of the correction equation. Afterwards the correction equation coefficients are calculated by differentiating the formula for calculating the second derivative of the gravitational potential on the rectangular coordinates x, y, z. The result is a coefficient matrix of the correction equations and corrections vector of the free members of equations for each component of the tensor of the geopotential. As the number of conditional equations is much more than the number of the specified parameters, we go to the drawing up of the system of normal equations, from which solutions we determine the required corrections to the harmonic coefficients.

Position Control of Direct-Drive Robot Manipulators with PMAC Motors Using Enhanced Fuzzy PD Control

2004 ◽  
Vol 8 (3) ◽  
pp. 324-331
Author(s):  
Dong Sun ◽  
◽  
Y. X. Su ◽  
James K. Mills ◽  
Keyword(s):  
Position Control ◽  
Robot Manipulators ◽  
Pd Controller ◽  
Control Performance ◽  
Direct Drive ◽  
Control Approach ◽  
Single Link ◽  
Nonlinear Tracking ◽  
Control Methodology ◽  
Fuzzy Pd

A position control approach for direct-drive robot manipulators with permanent magnet AC (PMAC) motors is proposed. The conventional vector control architecture has been simplified by specifying the motor stator phase so that the rotating d-axis current is zero. The position control is designed to be an enhanced fuzzy PD controller, by incorporating two nonlinear tracking differentiators into a conventional fuzzy PD controller. The proposed control methodology is easy to implement, and exhibits better control performance than conventional control methods. Experiments conducted on a single-link manipulator directly driven by a PMAC motor demonstrate the validity of the proposed approach.

scholarly journals A Stability Analysis for the Acceleration-Based Robust Position Control of Robot Manipulators via Disturbance Observer

2018 ◽  
Vol 23 (5) ◽  
pp. 2369-2378 ◽  
Author(s):  
Emre Sariyildiz ◽  
Hiromu Sekiguchi ◽  
Takahiro Nozaki ◽  
Barkan Ugurlu ◽  
Kouhei Ohnishi
Keyword(s):  
Stability Analysis ◽  
Disturbance Observer ◽  
Position Control ◽  
Robot Manipulators

Zero Phase Robust Control of XY Table Linear Servo System

2013 ◽  
Vol 419 ◽  
pp. 713-717
Author(s):  
Xi Mei Zhao ◽  
Ming Ming Jiang ◽  
Hong Yi Li ◽  
Hao Liu
Keyword(s):  
Disturbance Observer ◽  
Position Control ◽  
Control Method ◽  
Phase Error ◽  
Tracking Error ◽  
Servo System ◽  
Direct Drive ◽  
Tracking Accuracy ◽  
Control Scheme ◽  
Zero Phase

For direct drive XY table servo system, position control is designed. Considering the error which is caused by the disturbance of the system, friction factor and so on. The control method combing the zero phase error tracking controller (ZPETC) with the disturbance observer (DOB) is adopted. The system tracking error is reduced by adopting ZPETC, and through influences of disturbance to the system is diminished by the disturbance observer. Thus the tracking accuracy and robustness of the system are improved. Simulation results show that this control scheme is effective. It can obviously improve the accuracy of the system.

scholarly journals Hybrid Position/Force Control of Direct Drive Robots by Disturbance Observer in Task Coordinate Space.

1992 ◽  
Vol 112 (12) ◽  
pp. 1235-1242 ◽  
Author(s):  
Jeong-Ho Shin ◽  
Satoshi Komada ◽  
Muneaki Ishida ◽  
Takamasa Hori
Keyword(s):  
Force Control ◽  
Disturbance Observer ◽  
Coordinate Space ◽  
Direct Drive

scholarly journals A Family of Hyperbolic-Type Explicit Force Regulators with Active Velocity Damping for Robot Manipulators

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Fernando Reyes-Cortés ◽  
César Chávez-Olivares ◽  
Emilio J. González-Galván
Keyword(s):  
Force Control ◽  
Closed Loop ◽  
Robot Manipulator ◽  
Robot Manipulators ◽  
Force Sensor ◽  
Experimental Comparison ◽  
Direct Drive ◽  
New Family ◽  
System Equilibrium ◽  
Control Schemes

This paper addresses the explicit force regulation problem for robot manipulators in interaction tasks. A new family of explicit force-control schemes is presented, which includes a term driven by a large class of saturated-type hyperbolic functions to handle the force error. Also, an active velocity damping term with the purpose of obtaining energy dissipation on the contact surface is incorporated plus compensation for gravity. In order to ensure asymptotic stability of the closed-loop system equilibrium point in Cartesian space, we propose a strict Lyapunov function. A force sensor placed at the end-effector of the robot manipulator is used in order to feed back the measure of the force error in the closed-loop, and an experimental comparison of the performanceL2-norm between 5 explicit force control schemes, which are the classical proportional-derivative (PD), arctangent, and square-root controls and two members of the proposed control family, on a two-degree-of-freedom, direct-drive robot manipulator, is presented.

Sensorless Force Control for High-speed Pressurization

2001 ◽  
Vol 13 (3) ◽  
pp. 222-229
Author(s):  
Shigeyasu Kawaji ◽  
◽  
Fuminori Ozaki ◽  
Ryutaro Higashi ◽  
Keyword(s):  
Force Control ◽  
Semiconductor Manufacturing ◽  
Disturbance Observer ◽  
High Speed ◽  
Position Control ◽  
Piecewise Polynomial ◽  
Speed Sensorless ◽  
Model Following ◽  
Ic Testing ◽  
Key Techniques

Force control technology needs a breakthrough to be used for practical purposes because it is rarely used in the industry although it is being improved in academic circles. We propose solving problems of conventional position control in pressurization using high-speed sensorless force control for the IC testing handler used in semiconductor manufacturing. The key techniques to solve the problem are piecewise polynomial trajectory generation to meet needs for high-speed operation, a model-following force servo to achieve pressurizing conditions, and a disturbance observer to estimate pressurization. The effectiveness of the proposed method is confirmed in experiments.

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