Design and Stability Analysis of an Integral Time-Delay Feedback Control Combined With an Open-Loop Control for an Infinitely Variable Transmission System

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
X. F. Wang ◽  
W. D. Zhu
Keyword(s):  
Differential Equation ◽  
Time Delay ◽  
Feedback Control ◽  
Control Variable ◽  
Open Loop ◽  
Speed Ratio ◽  
Open Loop Control ◽  
Loop Control ◽  
Variable Transmission ◽  
Delay Feedback Control

The kinematic model of an infinitely variable transmission (IVT) is introduced, and the nonlinear differential equation for the dynamic model of the IVT system with a permanent magnetic direct current (DC) motor and a magnetic brake is derived. To make the average of the input speed converge to a desired constant for any input power and output load, an integral time-delay feedback control combined with an open-loop control is used to adjust the speed ratio of the IVT. The speed ratio for the open-loop control is obtained by a modified incremental harmonic balance (IHB) method. Existence and convergence of a periodic solution are proved under a condition for parameters of the IVT system, and uniqueness of the periodic solution is proved by converting the nonlinear differential equation to a new differential equation that is Lipchitz in the dependent variable and piecewise continuous in the independent variable. A time-delay variable that is an approximation of the average of the input speed is used as the feedback to control the changing rate of the speed ratio. The IVT system with the time-delay control variable can be converted to a distributed-parameter system. Thus, the spectral Tau method is used to design the time-delay feedback control so that the IVT system is locally exponentially stable. The static error from the open-loop control is eliminated; the feedback control variable with time-delay is smoother than that without time-delay, which yields a lower control effort and more robust control design, since the time-delay variable that acts as a low-pass filter reduces the effect of the instantaneous change of the IVT system.

Error field feedback control system in the Keda Torus eXperiment and open loop control experiment

2020 ◽  
Vol 27 (5) ◽  
pp. 052502
Author(s):  
Yanqi Wu ◽  
Hong Li ◽  
Yolbarsop Adil ◽  
Yuan Zhang ◽  
Wentan Yan ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Control Experiment ◽  
Open Loop ◽  
Feedback Control System ◽  
Open Loop Control ◽  
Loop Control ◽  
Error Field

SYNCHRONIZATION ANALYSIS FOR MULTIVALUED LOGICAL NETWORKS

2013 ◽  
Vol 23 (04) ◽  
pp. 1350059 ◽  
Author(s):  
FANGFEI LI ◽  
JITAO SUN
Keyword(s):  
Feedback Control ◽  
Tensor Product ◽  
Discrete Time ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Logical Network ◽  
Discrete Time Systems ◽  
Time Systems ◽  
Product Of Matrices

The synchronization for two k-valued logical networks of the same dimensions is studied in this paper. First, based on the theory of semi-tensor product of matrices, the master-slave systems (two k-valued logical networks) are converted into discrete-time systems. Second, both open-loop control and feedback control are provided to make the slave network synchronize with the master k-valued logical network. Finally, examples are provided to illustrate the efficiency of the obtained results.

A Method for Teaching Feedback Control Using the Enhanced Mass-Spring-Damper System

2011 ◽  
Author(s):  
Dean H. Kim
Keyword(s):  
Feedback Control ◽  
Control Strategies ◽  
Open Loop ◽  
Open Loop Control ◽  
Improve Performance ◽  
Loop Control ◽  
System Input ◽  
Advanced Controls ◽  
Mass Spring ◽  
Force Generator

This paper presents a method that the author has developed to teach students about the need for feedback control and to facilitate the understanding of controller implementation. The initial discussion focuses on the limitations of open-loop control to improve performance of the traditional mass-spring-damper system. The key contribution is the introduction of an enhanced mass-spring-damper system with a position sensor and force generator, resulting in voltages as system input and output. This enhanced system provides a foundation for discussion of basic feedback control strategies such as PID-Control in addition to advanced controls concepts. The analysis is provided in time-domain to facilitate the understanding of these important controls concepts.

scholarly journals Sliding Mode Control with Dynamical Correction for Time-Delay Piezoelectric Actuator Systems

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 132 ◽  
Author(s):  
Javier Velasco ◽  
Oscar Barambones ◽  
Isidro Calvo ◽  
Joseba Zubia ◽  
Idurre Saez de Ocariz ◽  
...  
Keyword(s):  
Time Delay ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Sliding Mode ◽  
Open Loop ◽  
Open Loop Control ◽  
Loop Control ◽  
Mode Control ◽  
Control Response ◽  
Dynamical Correction

In piezoelectric actuators (PEAs), which suffer from inherent nonlinearities, sliding mode control (SMC) has proven to be a successful control strategy. Nonetheless, in micropositioning systems with time delay, integral proportional control (PI), and SMC, feedback control schemes have a tendency to overcompensate and, consequently, high controller gains must be rejected. This may produce a slow and inaccurate response. This paper presents a novel control strategy that deals with time-delay micropositioning systems aimed at achieving precise positioning by combining an open-loop control with a modified SMC scheme. The proposed SMC with dynamical correction (SMC-WDC) uses the dynamical system model to adapt the SMC inputs and avoid undesirable control response caused by delays. In order to develop the SMC-WDC scheme, an exhaustive analysis on the micropositioning system was first performed. Then, a mixed control strategy, combining inverse open-loop control and SMC-WDC, was developed. The performance of the presented control scheme was analyzed and compared experimentally with other control strategies (i.e., PI and SMC with saturation and hyperbolic functions) using different reference signals. It was found that the SMC-WDC strategy presents the best performance, that is, the fastest response and highest accuracy, especially against sudden changes of reference setpoints (frequencies >10 Hz). Additionally, if the setpoint reference frequencies are higher than 10 Hz, high integral gains are counterproductive (since the control response increases the delay), although if frequencies are below 1 Hz the integral control delay does not affect the system’s accuracy. The SMC-WDC proved to be an effective strategy for micropositioning systems, dealing with time delay and other uncertainties to achieve the setpoint command fast and precisely without chattering.

Open-loop control of compensation for optical propagation through a turbulent shear flow

1998 ◽  
Author(s):  
C. Truman ◽  
Lenore McMackin ◽  
Robert Pierson ◽  
Kenneth Bishop ◽  
Ellen Chen
Keyword(s):  
Shear Flow ◽  
Open Loop ◽  
Turbulent Shear ◽  
Turbulent Shear Flow ◽  
Open Loop Control ◽  
Loop Control ◽  
Optical Propagation
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