Optimizing Learning Convergence Speed and Converged Error for Precision Motion Control

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
Douglas A. Bristow ◽  
Andrew G. Alleyne ◽  
Marina Tharayil
Keyword(s):  
Motion Control ◽  
Convergence Speed ◽  
Optimal Time ◽  
Time Varying ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Bandwidth ◽  
Precision Motion Control ◽  
Time Frequency ◽  
Precision Motion

This brief paper considers iterative learning control (ILC) for precision motion control (PMC) applications. This work develops a methodology to design a low pass filter, called the Q-filter, that is used to limit the bandwidth of the ILC to prevent the propagation of high frequencies in the learning. A time-varying bandwidth Q-filter is considered because PMC reference trajectories can exhibit rapid changes in acceleration that may require high bandwidth for short periods of time. Time-frequency analysis of the initial error signal is used to generate a shape function for the bandwidth profile. Key parameters of the bandwidth profile are numerically optimized to obtain the best tradeoff in converged error and convergence speed. Simulation and experimental results for a permanent-magnet linear motor are included. Results show that the optimal time-varying Q-filter bandwidth provides faster convergence to lower error than the optimal time-invariant bandwidth.

Optimal Time-Varying ILC Design to Monotonically Minimize Converged Error

2005 ◽  
Author(s):  
Marina Tharayil ◽  
Andrew Alleyne
Keyword(s):  
Design Method ◽  
Optimal Time ◽  
Time Varying ◽  
Error Norm ◽  
Filter Bandwidth ◽  
Precision Motion Control ◽  
Monotonic Convergence ◽  
Potential Benefits ◽  
Constrained Minimization Problem ◽  
Precision Motion

This paper presents a design method for Iterative Learning Control (ILC) algorithms using time-varying Q-filters. The design of an optimal bandwidth profile for a given plant model is formulated as a constrained minimization problem. The resultant time-varying ILC algorithm generates the lowest converged error norm possible while guaranteeing monotonic convergence. The time-varying ILC background, problem setup to optimize the time-varying Q-filter bandwidth, as well as results obtained using computational methods are presented. A simulation example is used to demonstrate the potential benefits of the algorithm in comparison with LTI ILC. Lastly, experimental validation is provided by application of the ILC algorithm developed here on a Microscale Robotic Deposition system for precision motion control.

Adaptive Robust Precision Motion Control of Single-Rod Hydraulic Actuators With Time-Varying Unknown Inertia: A Case Study

1999 ◽  
Author(s):  
Fanping Bu ◽  
Bin Yao
Keyword(s):  
Effective Mass ◽  
Motion Control ◽  
Time Varying ◽  
Robot Arm ◽  
Hydraulic Actuator ◽  
Precision Motion Control ◽  
Output Tracking ◽  
Swing Angle ◽  
Precision Motion

Abstract This paper studies the precision motion control of single-rod hydraulic actuators with time-varying unknown inertia loads. The swing motion control of a robot arm driven by a single-rod hydraulic actuator (a scaled down version of industrial backhoe loader arm) is used as a case study. During the swing motion, the effective mass acting on the hydraulic actuator varies greatly with the swing angle and thus time-varying. Furthermore, due to the change of the load of the robot arm in operations, the effective mass is also unknown. A discontinuous projection based adaptive robust controller is constructed to take into account this strong dependence of the effective mass on the fast changing swing angle and the unknown payload of the arm. The resulting ARC controller is able to take into account not only the effect of parametric uncertainties coming from the payload and various hydraulic parameters but also the effect of uncertain nonlinearities such as uncompensated friction forces and external disturbances. The ARC controller guarantees a prescribed output tracking transient performance and final tracking accuracy while achieving asymptotic output tracking in the presence of parametric uncertainties. In addition, the zero output tracking error dynamics for tracking a large class of time-varying trajectories is shown to be globally uniformly asymptotically stable. Comparative experimental results are presented to show the effectiveness and the high performance nature of the proposed control algorithm.

The Study of Control System for Reconfigurable Machine Tool Model

2011 ◽  
Vol 188 ◽  
pp. 499-502
Author(s):  
L. Zhou ◽  
Wen Jie Nie ◽  
Z.R. Liao ◽  
X.R. Liang ◽  
G.Q. Pan
Keyword(s):  
Control System ◽  
Machine Tool ◽  
Motion Control ◽  
Machine Tools ◽  
Single Chip ◽  
Single Chip Microcomputer ◽  
Precision Motion Control ◽  
Single Function ◽  
Precision Motion ◽  
Reconfigurable Machine Tool

With the higher requirements of product processing, single-function machine can not meet the production needs. By analyzing the principles of reconfigurable machine tools, based on 51 single-chip microcomputer, this article researches the control system of reconfigurable machine tool, implements precision motion control for motors. The research can also reduce costs, so the practicality and economy all have a certain advantage, which will help promote the use in practice.

scholarly journals Compact D-CRLH resonator for low-pass filter with wide rejection band, high roll-off, and transmission zeros

2018 ◽  
Vol 11 (5-6) ◽  
pp. 509-516 ◽  
Author(s):  
Dilip Kumar Choudhary ◽  
Mahmoud A. Abdalla ◽  
Raghvendra Kumar Chaudhary
Keyword(s):  
Filter Design ◽  
Short Circuit ◽  
Tank Circuit ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Bandwidth ◽  
Transmission Zeros ◽  
Low Pass ◽  
Lc Tank ◽  
Rejection Band

AbstractA compact low-pass filter (LPF) with wide rejection band based on T-type circuit of an enhanced dual composite right-/left-handed (D-CRLH) resonator is presented in this paper. The resonator has only one cell with series and parallel tank circuit. The parallel LC tank circuit has been realized by an interdigital capacitor and one shorted finger, whereas its series LC tank circuit is realized by an air gap capacitance and a short circuit stub. The filter has wide rejection band bandwidth with three transmission zeros (TZs). The filter bandwidth and TZs frequencies are controlled by the D-CRLH element values. The results of the proposed filter demonstrate minimum insertion loss in passband, high roll-off rate, and good figure of merit. The measured results are in good agreement with the simulated results. The detailed filter design is discussed in terms of circuit modeling, dispersion analysis, and full-wave simulation. Finally, the filter size is compact (0.10 λg × 0.15 λg) at cut-off frequency.

scholarly journals Improved accuracy of biomechanical motion data obtained during impacts using a time-frequency low-pass filter

2020 ◽  
Vol 101 ◽  
pp. 109639 ◽  
Author(s):  
Simon Augustus ◽  
Arif Mithat Amca ◽  
Penny E. Hudson ◽  
Neal Smith
Keyword(s):  
Pass Filter ◽  
Low Pass Filter ◽  
Time Frequency ◽  
Motion Data ◽  
Low Pass ◽  
Improved Accuracy
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