Comparison of two feedforward design methods aiming at accurate trajectory tracking of the end point of a flexible robot arm

1998 ◽  
Vol 6 (1) ◽  
pp. 2-14 ◽  
Author(s):  
D.E. Torfs ◽  
R. Vuerinckx ◽  
J. Swevers ◽  
J. Schoukens
1994 ◽  
Vol 27 (14) ◽  
pp. 687-692
Author(s):  
L. Benvenuti ◽  
M.D. Di Benedetto

Author(s):  
Kiyoharu NAKAGAWA ◽  
Ryouta AIKAWA ◽  
Toru WATANABE ◽  
Kazuto SETO

2020 ◽  
Vol 26 (13-14) ◽  
pp. 1145-1156 ◽  
Author(s):  
Karel Kraus ◽  
Zbyněk Šika ◽  
Petr Beneš ◽  
Jan Krivošej ◽  
Tomáš Vyhlídal

Serial robots are typically able to cover large workspace, but their mass/stiffness ratio does not allow combining high accuracy and high dynamic of the end effector operations. Widely spread usage of serial robots, even for tasks such as drilling, leads to high accuracy demands through its workspace. Absolute measurement of the end point for position feedback can be challenging due to objects or even a workpiece in the workspace. Moreover, inbuilt motors of the serial robot cannot response in the frequency range high enough as vibration of the end point. Instead, an additional spring–mass system is attached to the robot to suppress vibrations. The narrow frequency range of a passive dynamic absorber can be extended with active elements between the robot and absorber. An active approach is also necessary because of robots eigenfrequencies and eigenmodes variability. The study deals with a planar flexible robot equipped with a three-degree-of-freedom planar active absorber. The absorber is tuned passively to one value of multiple eigenfrequency. The linear-quadratic regulator control with a state observer has been designed as an active absorber control algorithm. Feedback inputs are absorber body acceleration, end effector acceleration, and relative motions in three absorber actuators realized by voice coils. The end effector vibration suppression along the robot trajectory is achieved using gain scheduling of local controller’s outputs.


1993 ◽  
Vol 115 (2) ◽  
pp. 289-293 ◽  
Author(s):  
T. Kokkinis ◽  
M. Sahraian

The problem of end-point positioning of flexible arms is discussed. Because of the nonminimum phase nature of the problem, inversion fails to produce bounded joint torques. Bounded noncausal joint torques for achieving the task of end-point tracking for a multilink arm are found using optimal control theory. The torques obtained have no high-frequency content, and are suitable for practical applications. The method is illustrated by simulation of a single-link arm, for which stability and robustness considerations for design are given.


1996 ◽  
Vol 118 (1) ◽  
pp. 167-172 ◽  
Author(s):  
P. Lucibello ◽  
F. Bellezza

A self-tuned version of a controller for asymptotic trajectory tracking of the end point of a two-link flexible robot arm is presented. The bounded solution to the inverse system, which is used in the control law, is tuned by the estimates of the unknown robot parameters, generated by a least square identification scheme. Soundness of the state of the adaptive controller is achieved by a stabilizing linear feedback from the output error, with fixed gains and robust with respect to variations of the parameters. This guarantees the total stability of the system, which is the main ingredient used in the proof of the controller properties, through a Lyapunov-like approach. The controller performance is finally illustrated by numerically simulating the tracking of an end point ramp under payload mass variations.


2000 ◽  
Vol 33 (27) ◽  
pp. 321-326 ◽  
Author(s):  
M. Benosman ◽  
G. Le Vey

Sign in / Sign up

Export Citation Format

Share Document