Robust mixed-norm position and vibration control of flexible link mechanisms

Mechatronics ◽  
2005 ◽  
Vol 15 (7) ◽  
pp. 767-791 ◽  
Author(s):  
R. Caracciolo ◽  
D. Richiedei ◽  
A. Trevisani ◽  
V. Zanotto
2018 ◽  
Vol 148 ◽  
pp. 11005 ◽  
Author(s):  
Darren Williams ◽  
Hamed Haddad Khodoparast ◽  
Chenyuang Yang

Within robot systems the use of flexible links could solve many issues raised by their rigid counterparts. However, when these flexible links are integrated within systems which include moving parts their main issue lies in the vibrations experienced along their length due to disturbances. Much research effort has been made to solve this issue, with particular attention being paid to the application of piezoelectric patches as actuators within active vibration control (AVC). The study will consist of accurate models of a flexible link and two surface bonded piezoelectric patches, where the link and the piezoelectric patches will be modelled through the use of Euler-Bernoulli beam theory (EBT). The link will be subject to an initial displacement at its free end, and the resulting displacement of this end of the beam is to be controlled using a classic proportional-differential (PD) controller. The voltages to be applied across each of the actuators is to be controlled in accordance with the displacement of the free end of the beam, the actuators will then induce a strain upon the link opposing the movement of the tip. This research outlines this general method, obtains the best location of the piezoelectric patches and the control gains to be used, and proves that the method can be used to attenuate the vibrations experienced by a flexible link.


Author(s):  
Giovanni Boschetti ◽  
Dario Richiedei ◽  
Alberto Trevisani

This paper extends the use of delayed reference controllers to the simultaneous motion and vibration control of flexible link mechanisms. Vibration damping is achieved by introducing an “equivalent damping force” into the system through the computation of a suitable delayed time. The delayed time, which is based on the measured vibrations, is then employed in the trajectory planner to set the reference input. The stability of the controller is discussed and its effectiveness is proved by applying it to a four-bar planar linkage with flexible links.


2014 ◽  
Vol 2014.52 (0) ◽  
pp. _617-1_-_617-3_
Author(s):  
Barlas Raheel Khan ◽  
Shingo Okamoto ◽  
Jae Hoon Lee

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Qinghua Zhang ◽  
Xianmin Zhang ◽  
Junyang Wei

An active vibration control experiment of planar 3-RRR flexible parallel robots is implemented in this paper. Considering the direct and inverse piezoelectric effect of PZT material, a general motion equation is established. A strain rate feedback controller is designed based on the established general motion equation. Four control schemes are designed in this experiment: three passive flexible links are controlled at the same time, only passive flexible link 1 is controlled, only passive flexible link 2 is controlled, and only passive flexible link 3 is controlled. The experimental results show that only one flexible link controlled scheme  suppresses elastic vibration and cannot suppress the elastic vibration of the other flexible links, whereas when three passive flexible links are controlled at the same time, they are able to effectively suppress the elastic vibration of all of the flexible links. In general, the experiment verifies that a strain rate feedback controller is able to effectively suppress the elastic vibration of the flexible links of plane 3-RRR flexible parallel robots.


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