Multi-rate feedforward tracking control for plants with nonminimum phase discrete time models

1999 ◽  
Keyword(s):  
Discrete Time ◽  
Tracking Control ◽  
Nonminimum Phase ◽  
Discrete Time Models

Precision Tracking Control of Discrete Time Nonminimum-Phase Systems

1993 ◽  
Vol 115 (2A) ◽  
pp. 238-245 ◽  
Author(s):  
Chia-Hsiang Menq ◽  
Jin-jae Chen
Keyword(s):  
Discrete Time ◽  
Tracking Control ◽  
Tracking Performance ◽  
Nonminimum Phase ◽  
Nonminimum Phase Systems ◽  
Control Scheme ◽  
Feedforward Controller ◽  
Precision Tracking ◽  
Phase Systems ◽  
Precision Tracking Control

In this paper, a precision tracking control scheme for linear discrete time nonminimum-phase systems is proposed. This control scheme consists of a preview filter, a tracking-performance filter, a command feedforward controller, and a feedback controller. A command feedforward controller, whose design is based on the minimal order inverse model of the plant being controlled, will result in a completely decoupled system. The preview filter is introduced to compensate the phase and gain errors induced by the nonminimum phase zeros or lightly damped zeros of the system. Using the command feedforward controller along with the proposed preview filter, the tracking performance of the proposed control scheme can be characterized by the frequency response of the tracking-performance filter. For the design of the preview filter, a generalized Nth order preview filter and its associated penalty function that quantifies the tracking error of a design are defined. It is shown that, given the desired bandwidth and the order of the preview filter, the optimal solution for the design of the preview filter can be obtained explicitly. The proposed control scheme together with the optimal preview filter is shown to be very effective in achieving precision tracking control of discrete time MIMO nonminimum phase systems. It is also shown that the tracking performance is improved as the order N of the preview filter is increased.

scholarly journals Simulation and Experimental Studies on Perfect Tracking Optimal Control of an Electrohydraulic Actuator System

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
R. Ghazali ◽  
Y. M. Sam ◽  
M. F. Rahmat ◽  
Zulfatman ◽  
A. W. I. M. Hashim
Keyword(s):  
Optimal Control ◽  
Discrete Time ◽  
Tracking Control ◽  
Phase Error ◽  
Experimental Studies ◽  
Phase System ◽  
Nonminimum Phase ◽  
Gain Error ◽  
Feedforward Controller ◽  
Electrohydraulic Actuator

This paper presents a perfect tracking optimal control for discrete-time nonminimum phase of electrohydraulic actuator (EHA) system by adopting a combination of feedback and feedforward controller. A linear-quadratic regulator (LQR) is firstly designed as a feedback controller, and a feedforward controller is then proposed to eliminate the phase error emerged by the LQR controller during the tracking control. The feedforward controller is developed by implementing the zero phase error tracking control (ZPETC) technique in which the main difficulty arises from the nonminimum phase system with no stable inverse. Subsequently, the proposed controller is performed in simulation and experimental studies where the EHA system is represented in discrete-time model that has been obtained using system identification technique. It also shows that the controller offers better performance as compared to conventional PID controller in reducing phase and gain error that typically occurred in positioning or tracking systems.

scholarly journals Tracking control of ship course system using new six-step zead (Zhang et al discretization) formula with high precision

Filomat ◽  
2020 ◽  
Vol 34 (15) ◽  
pp. 5059-5071
Author(s):  
Jinjin Guo ◽  
Yunong Zhang ◽  
Binbin Qiu
Keyword(s):  
High Precision ◽  
Discrete Time ◽  
Tracking Control ◽  
Truncation Error ◽  
Sampling Period ◽  
Fourth Power ◽  
Scs Model ◽  
The Stability ◽  
Theoretical Analyses ◽  
Discrete Time Models

In this paper, firstly, a new six-step Zhang et al discretization (SSZeaD) formula is proposed, which is with the truncation error proportional to the fourth power of sampling period. Then, the SSZeaD formula is used to discretize a ship course system (SCS) for tracking control, and thus the SSZeaD-type SCS model is developed. For comparison purposes, the classical Euler forward formula (EFF) with the truncation error proportional to the first power of sampling period is also used to discretize the SCS, and thus the EFF-type SCS model is obtained. Besides, there is an important parameter called stepsize, which is closely related to the stability and the precision of the above two discrete-time models. In view of the importance of the stepsize, the effective stepsize domains of these two discrete-time models are confirmed by theoretical analyses. Finally, numerical experimental results well verify the higher tracking precision of the SSZeaD-type SCS model as compared with the EFF-type SCS model.

scholarly journals Semiglobal exponential input-to-state stability of sampled-data systems based on approximate discrete-time models

Automatica ◽  
2021 ◽  
Vol 131 ◽  
pp. 109742
Author(s):  
Alexis J. Vallarella ◽  
Paula Cardone ◽  
Hernan Haimovich
Keyword(s):  
Discrete Time ◽  
Data Systems ◽  
Sampled Data ◽  
Discrete Time Models
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