Tip Position Control of a Flexible Robot Arm Considering the Reduction Gear's Friction

1990 ◽  
Vol 2 (2) ◽  
pp. 91-96
Author(s):  
Yasuo Yoshida ◽  
◽  
Masato Tanaka
Keyword(s):  
Feedback Control ◽  
Dynamic Characteristics ◽  
Position Control ◽  
Viscous Friction ◽  
Open Loop ◽  
Robot Arm ◽  
Flexible Robot ◽  
Position Feedback ◽  
Linear Friction ◽  
Tip Position

The reduction gear's friction strongly affects the dynamic characteristics of a one-link flexible robot arm. Experiments of open loop response by motor torque were performed in two cases of large and small values of the reduction gear's friction, and compared with simulation. The reduction gear's friction has both viscous and Coulomb aspects and can be approximately treated as an equivalent viscous friction. However, tip position control was very difficult in the case of large friction with an equivalent viscous friction. Experiments indicated that tip position feedback control was possible by using a dither signal and linearizing the non-linear friction.

Tip Position Control of Single Flexible Links via Parallel Feedforward Compensation

2019 ◽  
Author(s):  
Keyvan Noury ◽  
Bingen Yang
Keyword(s):  
Closed Loop ◽  
Position Control ◽  
Control Method ◽  
Robot Arm ◽  
Flexible Robot ◽  
Order Process ◽  
Nonminimum Phase ◽  
Model Mismatch ◽  
Tip Position ◽  
And Performance

Abstract Developed in this work, is a simple and innovative control method, by which a nonminimum-phase (NMP) process can be easily stabilized in a closed-loop setting. The method is named as the parallel feed-forward compensation with derivative effort (PFCD). Through use of a high order process, the control system designed by the PFCD method is shown to be less influenced by noise, disturbance, and model mismatch, compared to other methods. Moreover, the necessary data required for implementing the PFCD method are discussed. The proposed control method is illustrated on tip position control in a slewing beam as a flexible robot arm, in which the effectiveness of the PFCD method is demonstrated. In addition, the proposed control method is compared with the existing methods in terms of stability and performance. The paper is concluded with notes about the advantages.

Discrete-Time Tip Position Control of a Flexible One Arm Robot

1992 ◽  
Vol 114 (3) ◽  
pp. 428-435 ◽  
Author(s):  
Sabri Cetinkunt ◽  
Sijun Wu
Keyword(s):  
Control Algorithm ◽  
Position Control ◽  
System Response ◽  
Model Parameters ◽  
Robot Arm ◽  
Flexible Robot ◽  
Filter Parameter ◽  
Actuator Dynamics ◽  
Lattice Filter ◽  
Tip Position

A predictive adaptive control algorithm is developed for tip position control based on the zero-order-hold equivalence of the nondimensionalized dynamic model of a flexible robot arm. A lattice filter is utilized for the purpose of parameter identification. The proposed control scheme provides an optimal output feedback control and, together with the lattice filter parameter identifier, it forms a special self-tuning regulator. It is then compared with other methods, such as linear quadratic Gaussian and stable factorization. A stability criterion for this control algorithm is also presented. The effects of the actuator dynamics on the overall system response and stability are investigated. Actuator dynamics model parameters are chosen from the actual specifications provided by manufacturers.

scholarly journals Evolutionary computing approaches to optimum design of fuzzy logic controller for a flexible robot system

2013 ◽  
Vol 23 (4) ◽  
pp. 395-412 ◽  
Author(s):  
Bidyadhar Subudhi ◽  
Subhakanta Ranasingh
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Position Control ◽  
Fitness Function ◽  
Flexible Manipulator ◽  
Position Tracking ◽  
Flexible Robot ◽  
Robot System ◽  
Single Link ◽  
Tip Position

Abstract This paper presents the design of a Fuzzy Logic Controller (FLC) whose parameters are optimized by using Genetic Algorithm (GA) and Bacteria Foraging Optimization (BFO) for tip position control of a single link flexible manipulator. The proposed FLC is designed by minimizing the fitness function, which is defined as a function of tip position error, through GA and BFO optimization algorithms achieving perfect tip position tracking of the single link flexible manipulator. Then the tip position responses obtained by using both the above controllers are compared to suggest the best controller for the tip position tracking.

Dynamic Finite Element Analysis of the Position Control System of a Two-Link Horizontal Flexible Robot

1990 ◽  
Vol 2 (2) ◽  
pp. 83-90
Author(s):  
Hiroyuki Kojima ◽  
Keyword(s):  
Finite Element ◽  
Control System ◽  
Position Control ◽  
Velocity Curve ◽  
Element Formulation ◽  
Robot Arm ◽  
Flexible Robot ◽  
Element Analysis ◽  
Flexible Arm ◽  
Position Control System

In this paper, a finite element formulation method for a horizontal flexible robot arm with two links is first presented. In the analysis, the kinetic energy of the flexible arm is represented in brief compared with previous methods, and the matrix equation of motion in consideration of the nonlinear forces, such as the Coriolis force, is derived by the finite element method and the variational theorem. Then, the state equation of the mechatronics system consisting of the flexible arm and the position control system is obtained. Secondly, numerical simulations in the case of applying path control based on the trapezoidal velocity curve are carried out by use of the Wilson-<I>θ</I> method, and the effects of the bending rigidity and the shape of the trapezoidal velocity curve on the dynamic characteristics of the mechatronics system are demonstrated.

About the Use of the Floating Frame in the Optimal Control of the Flexible Robot Arm

1992 ◽  
Vol 4 (4) ◽  
pp. 330-338 ◽  
Author(s):  
M. Bisiacco ◽  
◽  
R. Caracciolo ◽  
M. Giovagnoni ◽  
◽  
...  
Keyword(s):  
Optimal Control ◽  
Linear Model ◽  
Equations Of Motion ◽  
Flexible Manipulator ◽  
Robot Arm ◽  
Flexible Robot ◽  
Coupled Equations ◽  
Weakly Coupled ◽  
Tip Position ◽  
The Mathematical Model

The mathematical model of a single-link flexible manipulator is obtained by measuring transverse deflections in a rotating reference frame which is floating with respect to the link. The use of this particular frame, the rigidbody mode frame, enables one to obtain weakly coupled equations of motion. The size of the inertia coupling terms can be easily evaluated: these terms can be shown to be negligible thus leading to an essentially linear model. An example of optimal control of manipulator's tip position is numerically reproduced. The same controller is first applied to the mechanical model of the arm accounting for non-linear coupling and then to the linear model: the two responses are found to be very close to each other.

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