174 research outputs found

    A digital computer program for control system analysis

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    Lovell digital computer program written in Fortran for calculation of control system

    Radiation exposure to the orbiting lunar station and lunar surface related to reusable nuclear shuttle operations

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    The radiation environment created by the Reusable Nuclear Vehicle (RNS) in performing its normal mission functions while in the lunar vicinity and the impact of that environment on the Orbiting Lunar Station (OLS) and/or the lunar surface are examined. Lunar surface exposures from the operating reactor were evaluated for both the arrival and departure burns and while there is little probability that manned bases would lie along the paths in which measurable exposures would be recorded, the analyses do indicate the need to consider this possibility in planning such operations. Conclusions supported by the analyses and recommended operational constraints for the RNS are presented

    Integral Input-to-State Stability of Nonlinear Time-Delay Systems with Delay-Dependent Impulse Effects

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    This paper studies integral input-to-state stability (iISS) of nonlinear impulsive systems with time-delay in both the continuous dynamics and the impulses. Several iISS results are established by using the method of Lyapunov-Krasovskii functionals. For impulsive systems with iISS continuous dynamics and destabilizing impulses, we derive two iISS criteria that guarantee the uniform iISS of the whole system provided that the time period between two successive impulse moments is appropriately bounded from below. Then we provide an iISS result for systems with unstable continuous dynamics and stabilizing impulses. For this scenario, it is shown that the iISS properties are guaranteed if the impulses occur frequently enough. For impulsive systems with stabilizing impulses and stable continuous dynamics for zero input, we obtain an iISS result which shows that the entire system is uniformly iISS over arbitrary impulse time sequences. As applications, iISS properties of a class of bilinear systems are studied in details with simulations to demonstrate the presented results

    Extended Kalman filtering with stochastic nonlinearities and multiple missing measurements

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    Copyright @ 2012 ElsevierIn this paper, the extended Kalman filtering problem is investigated for a class of nonlinear systems with multiple missing measurements over a finite horizon. Both deterministic and stochastic nonlinearities are included in the system model, where the stochastic nonlinearities are described by statistical means that could reflect the multiplicative stochastic disturbances. The phenomenon of measurement missing occurs in a random way and the missing probability for each sensor is governed by an individual random variable satisfying a certain probability distribution over the interval [0,1]. Such a probability distribution is allowed to be any commonly used distribution over the interval [0,1] with known conditional probability. The aim of the addressed filtering problem is to design a filter such that, in the presence of both the stochastic nonlinearities and multiple missing measurements, there exists an upper bound for the filtering error covariance. Subsequently, such an upper bound is minimized by properly designing the filter gain at each sampling instant. It is shown that the desired filter can be obtained in terms of the solutions to two Riccati-like difference equations that are of a form suitable for recursive computation in online applications. An illustrative example is given to demonstrate the effectiveness of the proposed filter design scheme.This work was supported in part by the National 973 Project under Grant 2009CB320600, National Natural Science Foundation of China under Grants 61028008, 61134009 and 60825303, the State Key Laboratory of Integrated Automation for the Process Industry (Northeastern University) of China, the Engineering and Physical Sciences Research Council (EPSRC) of the U.K. under Grant GR/S27658/01, the Royal Society of the U.K., and the Alexander von Humboldt Foundation of Germany

    Delay

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    This is a functioning delay which allows you to dial in your delay times and and gain with included impulse response wave file with graphical representation. Accompanying this is a report and matlab .m file.Architecture & Allied Art

    Input-to-state stability of stochastic nonlinear system with delayed impulses

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    Stochastic input-to-state stability (SISS) of the stochastic nonlinear system has received extensive research. This paper aimed to investigate SISS of the stochastic nonlinear system with delayed impulses. First, when all subsystems were stable, using the average impulsive interval method and Lyapunov approach, some theoretical conditions ensuring SISS of the considered system were established. The SISS characteristic of the argumented system with both stable and unstable subsystems was also discussed, then the stochastic nonlinear system with multiple delayed impulse jumps was considered and SISS property was explored. Additionally, it should be noted that the Lyapunov rate coefficient considered in this paper is positively time-varying. Finally, several numerical examples confirmed validity of theoretical results

    The Design and Realization for a Multiplex Time Sequence Controller

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    AbstractIn order to meet the demand of activating several devices at different moments, a multiplex time sequence controller is developed in this paper. When the controller receives the trigger signal for starting, the time sequential control circuit module, consisting of the microcontroller and the FPGA, it can generate a delay trigging signal according to the preset delay value, which will activate the testing device after being driven. The delay value is import by the computer or the dial on the panel. The real firing results show that the time sequence controller can realize the delay of 20-channel independently, one of which is able to be adjustable within 0∼10s, the maximum amplitude of output delay trigging signal is 12V, the width of the signal is 5ms and the error of the delay time is less than 2colons. The multiplex time sequence controller can satisfy the requirements of technical specifications of testing system in conventional shooting range, and it can meet the demand of activating several testing devices operating at different moments
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