http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Simon X. Yang (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
-
Active control of a flexible structure with time delay
Cai, Guo-Ping,Yang, Simon X. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.20 No.2
Time delay exists inevitably in active control, which may not only degrade the system performance but also render instability to the dynamic system. In this paper, a novel active controller is developed to solve the time delay problem in flexible structures. By using the independent modal space control method, the differential equation of the controlled mode with time delay is obtained from the time-delay system dynamics. Then it is discretized and changed into a first-order difference equation without any explicit time delay by augmenting the state variables. The modal controller is derived based on the augmented system using the discrete variable structure control method. The switching surface is determined by minimizing a discrete quadratic performance index. The modal coordinate is extracted from sensor measurements and the actuator control force is converted from the modal one. Since the time delay is explicitly included throughout the entire controller design without any approximation, the system performance and stability are guaranteed. Numerical simulations show that the proposed controller is feasible and effective in active vibration control of dynamic systems with time delay. If the time delay is not explicitly included in the controller design, instability may occur.
-
Yulong Tuo,Yuanhui Wang,Simon X. Yang,Mohammad Biglarbegian,Mingyu Fu 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4
For floating production storage and offloading (FPSO) vessels, a dynamic positioning controller is necessary because using only a mooring system is not possible to keep the ship within a predefined region. Position control of the FPSO vessel is extremely challenging due to model uncertainties and unknown control coefficients. This paper develops a new robust adaptive positioning controller consisting of several components: adaptive law, dynamic surface control (DSC) technology, sigmoid tracking differentiator (STD), Nussbaum gain function, and structural reliability index. Model uncertainties can be estimated by the adaptive law derived from the Lyapunov theory. The DSC technology is used to eliminate repeated differentiation by introducing first-order filtering of the virtual control. The chattering-free STD with the characteristics of global fast convergence can estimate the derivatives of model uncertainties that are difficult to calculate directly. Therefore, the DSC and STD techniques make the proposed controller simpler to compute and easier to implement in engineering practice. Most of the traditional controllers require the information about the control coefficients to guarantee the stability of the closed-loop system while the Nussbaum gain function can remove the requirement for a priori knowledge of the sign of control coefficients. The capacity of the mooring system can be fully utilized to position the FPSO vessel by adjusting the structural reliability index on the premise of ensuring the safety of mooring lines, and hence less control effort is needed for the positioning controller. Simulations using two sets of system parameters demonstrate the proposed controller’s effectiveness. In addition, a qualitative comparison with the adaptive backstepping controller shows that our proposed controller is computationally more efficient and does not require a priori knowledge of the sign of control coefficients. A quantitative comparison with robust adaptive controller without the structural reliability shows that less control effort is needed using our proposed controller.
-
Yi Xin,Zhu Anmin,Li Chaofan,Yang Simon X 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.6
For multi-robot systems (MRSs), conventional path planning with single resolution mapping is challenging to balance information and computation. Regarding path planning of MRS, the previous research lacked systematic definition, quantitative evaluation, and the consideration of complex environmental factors. In this paper, a new systematic formulation is proposed to redefine the multi-robot path planning problem in complex environments, and evaluate the related solutions of this problem. To solve this problem, a novel bio-inspired approach based on reaction-diffusion system is given to deal with the path planning of MRS in complex environments, such as electromagnetic interference, ocean currents, and so on. Furthermore, a multi-layer neural dynamic network is proposed to describe environments with multiple resolutions, which can improve time performance while ensuring the integrity of environmental information. Comparative experimental results indicate that the proposed approach shows the excellent path planning performance of MRS in complex environments. The stability of the proposed method is determined by the mathematical basis.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
