On the Determination of the Worst Allowable Persistent Bounded Disturbance for a System With Constraints

1995 ◽  
Vol 117 (2) ◽  
pp. 126-133 ◽  
Author(s):  
Suhada Jayasuriya

The problem of explicitly determining the worst persistent input disturbance that a closed-loop system can tolerate under prespecified state and control constraints is studied. Verification of designs specifically aimed at maximizing the size of persistent bounded disturbances while satisfying system constraints, typically requires extensive simulations because the exact nature of the worst input is not known. In this paper the exact nature of the worst input is completely characterized for both SISO and MIMO cases. A finite number of specific impulse responses of the closed-loop system determines the worst persistent input disturbance. In the case of a SISO with n state constraints (|xi| ≤ βi), a control constraint (|u| ≤ βu) and an output constraint (|y| ≤ βo), n + 2 impulse responses are generally needed. With this new result the large number of simulations that is typically needed for design verification can be significantly reduced. Two examples illustrate how the new characterization can be utilized.

1967 ◽  
Vol 89 (2) ◽  
pp. 379-383 ◽  
Author(s):  
Donald M. Wiberg

The optimum feedback control of controllable linear distributed stationary systems is discussed. A linear closed-loop system is assured by restricting the criterion to be the integral of quadratics in the state and control. Feedback is obtained by expansion of the linear closed-loop equation in terms of uncoupled modes. By incorporating symbolic functions into the formulation, one can treat boundary condition control and point observable systems that are null-delta controllable.


Author(s):  
Shiming Duan ◽  
Jun Ni ◽  
A. Galip Ulsoy

Piecewise affine (PWA) systems belong to a subclass of switched systems and provide good flexibility and traceability for modeling a variety of nonlinear systems. In this paper, application of the PWA system framework to the modeling and control of an automotive all-wheel drive (AWD) clutch system is presented. The open-loop system is first modeled as a PWA system, followed by the design of a piecewise linear (i.e., switched) feedback controller. The stability of the closed-loop system, including model uncertainty and time delays, is examined using linear matrix inequalities based on Lyapunov theory. Finally, the responses of the closed-loop system under step and sine reference signals and temperature disturbance signals are simulated to illustrate the effectiveness of the design.


Author(s):  
С.Л. Подвальный ◽  
Д.В. Логунов ◽  
Е.М. Васильев

Рассматривается задача воспроизведения в искусственных объектах способности естественных систем к самовосстановлению вследствие существования в них замкнутого круговорота вещества и энергии. Показано, что создание замкнутого жизненного цикла в системе предполагает реализацию в ней процессов восстановления ресурсов и их накопления в виде внутренних резервов, расходуемых системой в неблагоприятных условиях существования. Получена функциональная схема системы с замкнутым циклом и предложена математическая модель её функционирования в виде дискретного однородного марковского процесса без последействия. Обнаружено, что введение в систему внутреннего резервирования требует рассмотрения двух альтернативных вариантов модели системы: варианта для случая, в котором объём резервов ограничен возможностями каналов восстановления в системе, и варианта, в котором указанное ограничение отсутствует. Составлены графы состояний системы для указанных режимов функционирования и получены выражения для финальных вероятностей этих состояний. На основе полученных финальных вероятностей составлены аналитические расчётные соотношения для характеристик эффективности системы с замкнутым циклом. В качестве основной характеристики эффективности такого рода систем предлагается использовать вероятность полного функционирования системы, т.е. вероятность её работы с использованием всего объёма активных ресурсов. Представлен числовой пример, подтверждающий работоспособность предложенной модели, и проведён сопоставительный анализ вариантов управления эффективностью замкнутой системы путём изменения объёма резервов, количества процессов восстановления и интенсивности этих процессов. Выявлено доминирующее значение внутренних резервов при обеспечении заданных показателей эффективности системы с замкнутым циклом Here we consider the problem of reproduction of the ability of natural systems to self-repair in artificial objects due to the existence of a closed loop of matter and energy in them. We show that the creation of a closed life cycle in the system presupposes the implementation of the process of restoring resources and their accumulation in the form of internal reserves consumed by the system in unfavorable conditions of existence. We obtained a functional diagram of a closed-loop system and proposed a mathematical model of its functioning in the form of a discrete homogeneous Markov process without aftereffect. We found that the introduction of internal redundancy into the system requires consideration of two alternative options for the system model: the option for the case in which the volume of reserves is limited by the capabilities of the recovery channels in the system, and the option in which the specified limitation is absent. We compiled the graphs of the states of the system for the specified modes of operation and obtained expressions for the final probabilities of these states. On the basis of the obtained final probabilities, we got analytical design ratios for the characteristics of the efficiency of a system with a closed loop. As the main characteristic of the efficiency of such systems, we propose to use the probability of the complete functioning of the system, i.e. the probability of its work using the entire volume of active resources. We present a numerical example that confirms the performance of the proposed model, and carried out a comparative analysis of options for managing the efficiency of a closed-loop system by changing the volume of reserves, the number of recovery processes and the intensity of these processes. We revealed the dominant value of internal reserves while ensuring the specified performance indicators of a closed-loop system


2007 ◽  
Vol 53 (5) ◽  
pp. 1405-1410 ◽  
Author(s):  
Takehiro Okabayashi ◽  
Kazuhiro Hnazaki ◽  
Isao Nishimori ◽  
Takeki Sugimoto ◽  
Hiromichi Maeda ◽  
...  

Robotica ◽  
2020 ◽  
Vol 39 (1) ◽  
pp. 23-41
Author(s):  
Yiqun Zhou ◽  
Jianjun Luo ◽  
Mingming Wang

SUMMARYThe dynamic manipulability of a manipulator refers to the capacity to generate accelerations given the joint torques, which is an important indicator for motion planning and control. In this paper, the dynamic manipulability analysis is extended to the multi-arm space robot, and further to the closed-loop system composed of the space robot and the captured target. According to the dynamic equations, the relation between the joint torques and the end-effector accelerations in the open-loop space robot and that between the joint torques and the target accelerations in the closed-loop system are derived. On this basis, the dynamic manipulability factor and dynamic manipulability ellipsoid are proposed as two tools for the dynamic manipulability measure, where the effects of the bias acceleration are considered. The influences of dynamic parameters, link lengths, joint variables, and velocities on the dynamic manipulability measure are mainly studied.


Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 1376-P
Author(s):  
GREGORY P. FORLENZA ◽  
BRUCE BUCKINGHAM ◽  
JENNIFER SHERR ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1066-P
Author(s):  
HALIS K. AKTURK ◽  
DOMINIQUE A. GIORDANO ◽  
HAL JOSEPH ◽  
SATISH K. GARG ◽  
JANET K. SNELL-BERGEON

Diabetes ◽  
2018 ◽  
Vol 67 (Supplement 1) ◽  
pp. 207-OR
Author(s):  
BRUCE A. BUCKINGHAM ◽  
JENNIFER SHERR ◽  
GREGORY P. FORLENZA ◽  
THOMAS A. PEYSER ◽  
JOON BOK LEE ◽  
...  

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