Reference Input Generation for High Speed Coordinated Motion of a Two Axis System

1991 ◽  
Vol 113 (1) ◽  
pp. 67-74 ◽  
Author(s):  
J. Butler ◽  
B. Haack ◽  
M. Tomizuka
Keyword(s):  
Tracking Control ◽  
High Speed ◽  
Actuator Saturation ◽  
Phase Error ◽  
Smooth Curve ◽  
Order System ◽  
Positioning System ◽  
Reference Trajectories ◽  
Reference Input ◽  
Zero Phase

A method for generating two-dimensional reference trajectories to be followed by a linear second-order system under feedforward/feedback control is proposed. A differential equation is derived which assigns tracking velocity and tangential tracking acceleration as functions of time in such a way to allow high speed motion through an arbitrary smooth curve while guaranteeing the absence of actuator saturation. A method for using preview information for motion along curves with corners is also presented. The results are verified by simulation of a two axis cartesian positioning system under discrete time zero phase error tracking control.

A zero phase error tracking based path precompensation method for high-speed machining

2015 ◽  
Vol 230 (2) ◽  
pp. 230-239 ◽  
Author(s):  
Xuewei Li ◽  
Jun Zhang ◽  
Wanhua Zhao ◽  
Bingheng Lu
Keyword(s):  
Tracking Control ◽  
High Speed ◽  
Control Algorithm ◽  
Phase Error ◽  
Great Influence ◽  
Contour Error ◽  
Machining Accuracy ◽  
High Speed Machining ◽  
Feed System ◽  
Zero Phase

Contour error due to the dynamic characteristics of feed system has a great influence on machining accuracy, in high-speed machining. In this paper, a new path precompensation method is proposed using zero phase error tracking control algorithm to improve the contouring accuracy for multiaxis machining with large feed rates. In this method, the outputs are predicted with the identified position-loop models of feed systems, and a contour error calculator is designed to calculate contour error in each sample instance using the predicted output and reference input. In order to compensate the contour error resulting from the dynamic tracking error of feed systems, the contour error vector is decomposed orthogonally and the compensation components for individual axis are calculated using zero phase error tracking control algorithm. Simulations showed that contour errors can be significantly improved with small compensation using the new path precompensation method for linear, circular, and parabola contours. Experimental results showed that the new method can reduce contour error significantly and achieve a better compensation compared with zero phase error tracking control and cross-coupled path pre-compensation.

Tracking Control of Non-Minimum Phase Systems Using Filtered Basis Functions: A NURBS-Based Approach

2015 ◽  
Author(s):  
Molong Duan ◽  
Keval S. Ramani ◽  
Chinedum E. Okwudire
Keyword(s):  
Tracking Control ◽  
Phase Error ◽  
Approximate Model ◽  
Basis Functions ◽  
Minimum Phase ◽  
Tracking Errors ◽  
Model Inversion ◽  
B Spline ◽  
Phase Systems ◽  
Zero Phase

This paper proposes an approach for minimizing tracking errors in systems with non-minimum phase (NMP) zeros by using filtered basis functions. The output of the tracking controller is represented as a linear combination of basis functions having unknown coefficients. The basis functions are forward filtered using the dynamics of the NMP system and their coefficients selected to minimize the errors in tracking a given trajectory. The control designer is free to choose any suitable set of basis functions but, in this paper, a set of basis functions derived from the widely-used non uniform rational B-spline (NURBS) curve is employed. Analyses and illustrative examples are presented to demonstrate the effectiveness of the proposed approach in comparison to popular approximate model inversion methods like zero phase error tracking control.

Simplified Realization of Zero Phase Error Tracking

2020 ◽  
Author(s):  
Masayoshi Tomizuka ◽  
Liting Sun
Keyword(s):  
Transfer Function ◽  
Tracking Control ◽  
Control Method ◽  
Feedforward Control ◽  
Phase Error ◽  
Time Varying ◽  
Time Transfer ◽  
Simple Implementation ◽  
Tracking Time ◽  
Zero Phase

Abstract Zero phase error tracking (ZPET) control has gained popularity as a simple yet effective feedforward control method for tracking time varying desired trajectories by the plant output. In this paper, we will show that the zero-order hold equivalent of continuous time transfer function, i.e. pulse transfer function, naturally has a property to realize zero phase effort tracking. This property is exploited to realize a simple implementation of zero phase error tracking control. The effectiveness of the proposed approach is demonstrated by simulations.

Feedforward Tracking Controller Design Based on the Identification of Low Frequency Dynamics

1993 ◽  
Vol 115 (3) ◽  
pp. 348-356 ◽  
Author(s):  
E. D. Tung ◽  
M. Tomizuka
Keyword(s):  
High Speed ◽  
Linear Models ◽  
Controller Design ◽  
Phase Error ◽  
Low Frequency ◽  
Reference Trajectory ◽  
Accurate Identification ◽  
Tracking Controller ◽  
Feed Drive System ◽  
Zero Phase

Several methodologies are proposed for identifying the dynamics of a machine tool feed drive system in the low frequency region. An accurate identification is necessary for the design of a feedforward tracking controller, which achieves unity gain and zero phase shift for the overall system in the relevant frequency band. In machine tools and other mechanical systems, the spectrum of the reference trajectory is composed of low frequency signals. Standard least squares fits are shown to heavily penalize high frequency misfit. Linear models described by the output-error (OE) and Autoregressive Moving Average with eXogenous Input (ARMAX) models display better closeness-of-fit properties at low frequency. Based on the identification, a feedforward compensator is designed using the Zero Phase Error Tracking Controller (ZPETC). The feedforward compensator is experimentally shown to achieve near-perfect tracking and contouring of high-speed trajectories on a machining center X-Y bed.

Tracking of a Target Payload via a Combination of Input Shaping, Zero Phase Error Tracking Control, and Fuzzy Logic

2016 ◽  
Author(s):  
Robert Schmidt ◽  
Matthew Begneaud ◽  
Joshua Vaughan
Keyword(s):  
Fuzzy Logic ◽  
Tracking Control ◽  
Phase Error ◽  
Input Shaping ◽  
Membership Functions ◽  
Tracking Accuracy ◽  
Autonomous Surface Vehicle ◽  
Tracking Controller ◽  
Initial Move ◽  
Zero Phase

During crane operation, the task of retrieval and deployment of payloads can be partitioned into two components: the initial move towards the target or deployment location and the retrieval or deployment of the payload. If the payload is not stationary, as is the case in the retrieval of a sea-going vessel, a third component, tracking, must be included. The target payload in this research is an Autonomous Surface Vehicle (ASV) primarily used for surveying. This paper studies the transition between the initial move towards the payload and the initialization of tracking. Input Shaping is used to limit residual vibration caused by the initial move to the ASV. A set of Fuzzy Logic membership functions are then used to transition from the initial move to the tracking portion of the retrieval process. These membership functions map position and velocity error to a gain that is applied to the tracking controller. As the gain increases, the contribution of the tracking controller input is increased. Zero Phase Error Tracking Control is utilized for accurate tracking of the target payload. Through a combination of these control methods, the tracking accuracy is improved.

High-Speed Tracking Method Using Zero Phase Error Tracking-Feed-Forward (ZPET-FF) Control for High-Data-Transfer-Rate Optical Disk Drives

2004 ◽  
Vol 43 (7B) ◽  
pp. 4811-4815 ◽  
Author(s):  
Daiichi Koide ◽  
Hitoshi Yanagisawa ◽  
Haruki Tokumaru ◽  
Shoichi Nakamura ◽  
Kiyoshi Ohishi ◽  
...  
Keyword(s):  
Transfer Rate ◽  
High Speed ◽  
Data Transfer ◽  
Phase Error ◽  
Disk Drives ◽  
Data Transfer Rate ◽  
Tracking Method ◽  
High Data ◽  
Speed Tracking ◽  
Zero Phase
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