Useful applications of closed-loop signal shaping controllers

A method to suppress the residual vibration of relative displacement is proposed. In factory automation, the positioning machines are precisely controlled by servo motors; however, their reaction force will unavoidably vibrate the machine stand on which the motors are mounted. A common problem is that the resulting residual vibrations cause disturbances that prevent high speed and accurate positioning, due to the inherent flexible structures in the machine stand, thereby unexpectedly extending the settling time in some industrial applications. This paper presents machine stand acceleration feedback (MSAFB) control, which detects the acceleration signal of the machine stand using an accelerometer to improve the robustness against disturbances from the environment and uncertainty in the system. This feedback strategy is superior to input shaping strategy, which is based on feedforward control. Simulations and experiments show the effectiveness of the proposed MSAFB controller, which was designed specifically for mechanical plants with rocking mode vibration.

show abstract

“…3, the mechanical plant encircled by the dashed line is modeled with reference to Eqs. (1) to (5). The rest of the area of Fig.…”

Section: Control Systemmentioning

confidence: 99%

Relative Vibration Suppression in a Positioning Machine Using Acceleration Feedback Control

2018

View full text Add to dashboard Cite

show abstract

“…Other works were interested in the machining process itself, like in (Pan et al 2006) where the authors show the effect of the conditions of the machining process on its stability. Regarding the control field, a large number of works have been done on trajectory planning, feedback control, system compensation and feedforward control (Lambrecht et al 2005) (Hakvoort et al 2008) (Goto et al 2007) (Huey et al 2008). Trajectory planning is one of the important control aspects.…”

Section: Introductionmentioning

confidence: 99%

Feedrate planning for machining with industrial six-axis robots

Olabi

Béarée

Gibaru

et al. 2010

Control Engineering Practice

View full text Add to dashboard Cite

Nowadays, the adaptation of industrial robots to carry out high-speed machining operations is strongly required by the manufacturing industry. This new technology machining process demands the improvement of the overall performances of robots to achieve an accuracy level close to that realized by machine-tools. This paper presents a method of trajectory planning adapted for continuous machining by robot. The methodology used is based on a parametric interpolation of the geometry in the operational space. FIR filters properties are exploited to generate the tool feedrate with limited jerk. This planning method is validated experimentally on an industrial robot.

show abstract

“…It can be concluded however that the signal shaper being placed in the loop between the controller and the system is rather ineffective in the given objective of suppressing the vibrations caused by disturbance variables. For example, in Huey, et al (2008), it is shown that the architecture is effective in suppressing the sensor disturbances, but completely ineffective in suppressing the oscillations themselves as they are excited by the disturbance, see also Vyhlidal et al (2015b). Let us remark that the ability of this scheme to reject sensor errors effectively has also been experimentally demonstrated in the study by Zuo et al (1995).…”

mentioning

confidence: 85%

Spectral design of output feedback controllers for systems pre-compensated by input shapers∗∗The presented research has been supported by the Czech Science Foundation under the project No. 13–06962S, by the Programme of Interuniversity Attraction Poles of the Belgian Federal Science Policy Office(IAP P6–DYSCO), by OPTEC, the Optimization in Engineering Center of the KU Leuven, and the project G.0712.11N and G.0717.11N of the Research Foundation –Flanders (FWO).

2015

View full text Add to dashboard Cite

The primary objective is to investigate the applicability of spectral methods for designing feedback controllers for a closed loop system with an input shaper with time delays. The shaper is included in the feedback loop in order to pre-compensate low-damped oscillatory modes of a flexible subsystem. However, after inserting a shaper into the feedback loop, the closed loop dynamics becomes infinite dimensional. A robust controller design then requires guaranteeing that all the infinitely many poles of the closed loop system will safely be located in the left half of the complex plane. Besides, the closed loop dynamics need to be sufficiently fast in order to take over and keep filtering properties of the input shaper. For the spectral design of the controller, the recently developed spectral abscissa minimization approach for interconnected time delay systems is applied. The presented methods are tested on a case study simulation example, which is a multi-degree of freedom mechanical system.

show abstract

Useful applications of closed-loop signal shaping controllers

Cited by 71 publications

References 22 publications

Relative Vibration Suppression in a Positioning Machine Using Acceleration Feedback Control

Relative Vibration Suppression in a Positioning Machine Using Acceleration Feedback Control

Feedrate planning for machining with industrial six-axis robots

Contact Info

Product

Resources

About