Monitoring control performance via structured closed-loop response subject to output variance/covariance upper bound

2006 ◽  
Vol 16 (9) ◽  
pp. 971-984 ◽  
Author(s):  
Fangwei Xu ◽  
Kwan Ho Lee ◽  
Biao Huang
2019 ◽  
Vol 12 (2) ◽  
Author(s):  
Nicolò Cavina ◽  
Nahuel Rojo ◽  
Andrea Businaro ◽  
Ruggero Cevolani

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 657 ◽  
Author(s):  
Uyen Tu Thi Hoang ◽  
Hai Xuan Le ◽  
Nguyen Huu Thai ◽  
Hung Van Pham ◽  
Linh Nguyen

The paper addresses the problem of effectively and robustly controlling a 3D overhead crane under the payload mass uncertainty, where the control performance is shown to be consistent. It is proposed to employ the sliding mode control technique to design the closed-loop controller due to its robustness, regardless of the uncertainties and nonlinearities of the under-actuated crane system. The radial basis function neural network has been exploited to construct an adaptive mechanism for estimating the unknown dynamics. More importantly, the adaptation methods have been derived from the Lyapunov theory to not only guarantee stability of the closed-loop control system, but also approximate the unknown and uncertain payload mass and weight matrix, which maintains the consistency of the control performance, although the cargo mass can be varied. Furthermore, the results obtained by implementing the proposed algorithm in the simulations show the effectiveness of the proposed approach and the consistency of the control performance, although the payload mass is uncertain.


2014 ◽  
Vol 525 ◽  
pp. 583-587
Author(s):  
Bing Tu ◽  
Wei Zhang ◽  
Teng Xi Zhan

This paper presented a excitation liquid-cooled retarder control system based on a microprocessor MC9SXS128. In order to achieve the constant speed, It used PWM to adjust the output current of excitation liquid-cooled retarder. It analyzed and calculated the inductance value in PWM output circuit and also analyzed the excitation liquid-cooled retarder control systematical mathematical model . It divided the brake stalls based on the current flowing through the field coil. by adding the PID closed-loop control system, the retarder could quickly reach the set speed. It tested the PID control algorithm at the experiments in retarder drum test rig and the results show that the control algorithm has good control performance to meet the application requirements.


2007 ◽  
Vol 2 (1) ◽  
Author(s):  
Ming T. Tham ◽  
Richard W. Jones ◽  
Ibrahim Al-Hinai

This paper attempts to address a common difficulty encountered when trying to justify a process control revamp or upgrading project — the ability to quantify potential savings/profits. A relatively simple procedure that is applicable to both continuous and digital controllers is described. Given models of the process and the controller, knowledge of the disturbance frequencies and their variances, the method is able to predict accurately the variance of the controlled output of linear control systems.


2002 ◽  
Vol 12 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Kenji Kurosawa ◽  
Takashi Watanabe ◽  
Ryoko Futami ◽  
Nozomu Hoshimiya ◽  
Yasunobu Handa

We have developed a closed-loop FES system using a magnetic 3-D position and orientation measurement system (FASTRAK, Polhemus Inc). The purpose of this development was to resolve some experimental difficulties involved in our previous goniometer-based experimental system. The new system enabled us to perform FES control experiments on the multi-joint musculoskeletal system of the upper limbs including forearm pronation/supination. In this paper, we evaluated the system by some single-joint tracking tasks in order to compare its control performance with that of the previous system. Four muscles (ECRL(B), ECU, FCR, and FCU) of neurologically intact subjects were stimulated to control the wrist joint's two degrees of freedom movement. Stimulation currents were determined by a multi-channel PID controller that was designed for a musculoskeletal system with redundancy (i.e. the number of muscles stimulated is more than that of the degree-of-freedom of the movement). The results showed that the system had sufficient control performance on tracking desired trajectories. Moreover, the system could compensate for unwanted external disturbances.


Author(s):  
Dingding Cheng ◽  
Lijun Liu ◽  
Zhen Yu

Traditional steady-state control methods are applied to turbofan engines operating in the small region near certain operating conditions, which need to switch controllers for operating in the large region and then may lead to instability and performance degradation of the closed-loop system. In this paper, a novel multivariable nonlinear robust control method for turbofan engines is proposed to improve the control performance within the large region. To enlarge the controllable region, a polynomial state-space model describes the nonlinear characteristics of turbofan engines. Based on the analysis of the closed-loop control system, by using the Lyapunov function theorems, a polynomial robust controller is designed to ensure the stability and desired nonlinear control performance of turbofan engines. Compared with the classical PI, mixed sensitivity, and H∞ control, simulation results show that the proposed method has better transient responses, disturbance rejection, and other control performance for the turbofan engine within the large region.


2016 ◽  
Vol 28 (3) ◽  
pp. 304-313 ◽  
Author(s):  
Reesa Akbar ◽  
◽  
Bambang Sumantri ◽  
Hitoshi Katayama ◽  
Shigenori Sano ◽  
...  

[abstFig src='/00280003/05.jpg' width=""230"" text='Quadcopter for repeated control verification' ] The reduced-order observer design we present estimates the velocity states of a quadrotor helicopter, or quadcopter, based on sampled measurements of position and attitude states. This observer is based on the forward-differentiation Euler model. The observer is robust enough against observation noise that the gain of a closed-loop controller is high enough to improve control performance. A sliding-mode controller stabilizes and implements quadcopter tracking control effectively, as is verified experimentally when compared to a conventional backward-difference method.


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