There are two methods to design software model, object-oriented and component-oriented. Embedded system has the characteristics of real-time, hierarchy and heterogeneousness. Disadvantage of object-oriented method is ...
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SERCOS-III is the international standard on the third generation serial communication protocol for real-time data communication among the controller and actuators with the advantage of openness, compatibility, high sp...
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SERCOS-III is the international standard on the third generation serial communication protocol for real-time data communication among the controller and actuators with the advantage of openness, compatibility, high speed, and reliability. Based on studying on the SERCOS-III protocol and ARM embedded control technology, presents one kind of SERCOS-III high speed communication system and discusses the technical implement details of hardware and software. Furthermore, a reduced TCP/IP protocol is supported in the IP channel so that the configuration parameters and the situation detections of the slaves can be operated through the internal IP channel. The simulation experiments of a network control system are presented to validate the proposed system.
One of the biggest problems in sensitive data wiping is to determine if a file is sensitive or not. Data wiping applications have improved a lot, but they cannot determine by themselves if a file is sensitive. The met...
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One of the biggest problems in sensitive data wiping is to determine if a file is sensitive or not. Data wiping applications have improved a lot, but they cannot determine by themselves if a file is sensitive. The method we propose tries to determine if a file is sensitive by using a pre-defined set of rules initially specified by the user. These rules can update themselves in time, by “learning” from data patterns in previous sensitive files. The hard drive is monitored continuously to detect new sensitive data. Also, our method replaces the standard delete function from Windows with a secure wiping algorithm (overwriting data several times with pre-defined passes), but only for files that are determined to be sensitive.
Abstract This paper concerns a trajectory tracking control problem for a pendulum with variable length, which is an underactuated mechanical system of two degrees-of-freedom with a single input of adjusting the length...
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Abstract This paper concerns a trajectory tracking control problem for a pendulum with variable length, which is an underactuated mechanical system of two degrees-of-freedom with a single input of adjusting the length of the pendulum. We aim to study whether it is possible to design a time-invariant control law to pump appropriate energy into the variable-length pendulum for achieving a desired swing motion (trajectory) with given desired energy and length of the pendulum. First, we show that it is difficult to avoid singular points in the controller designed by using the conventional energy-based control approach in which the total mechanical energy of the system is controlled. Second, we propose a tracking controller free of singular points by shaping only the kinetic energy of rotation and the potential energy of the pendulum and not utilizing the kinetic energy related to the motion along the rod. Third, we analyze globally the motion of the pendulum and clarify the stability issue of some closed-loop equilibrium points; and we also provide some conditions on control parameters for achieving the tracking objective. Finally, we present numerical simulation results to validate the presented theoretical results.
The robust H ∞ control problem for a class of uncertain switched linear systems by using the variable structure control is investigated. A robust H ∞ single sliding surface is shown to exist as long as a convex co...
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The robust H ∞ control problem for a class of uncertain switched linear systems by using the variable structure control is investigated. A robust H ∞ single sliding surface is shown to exist as long as a convex combination of the subsystems of the switched system is robustly stabilizable with disturbance attenuation level γ. A switching law is constructed via the single Lyapunov function technique. Variable structure controllers of subsystems are designed so as the resulting closed-loop system guarantees the robust H ∞ performance. An illustrative example and simulation results are given to demonstrate the effectiveness of the proposed design method.
Robust H ∞ output feedback control problem for a class of switched linear discrete-time systems possessing norm-bounded uncertainty and time-varying delay is investigated. A switched dynamic output feedback controll...
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Robust H ∞ output feedback control problem for a class of switched linear discrete-time systems possessing norm-bounded uncertainty and time-varying delay is investigated. A switched dynamic output feedback controller is sought that can robust exponentially stabilize and reduce to a prescribed level the effect of disturbance input on the controlled output in the closed loop. A delay-dependent linear matrix inequality based sufficient condition for the problem to be solvable is derived via the switched Lyapunov functions. Controller design is performed by solving a set of linear matrix inequalities. An illustrative example along with simulation results is given to demonstrate the validity of these novel derivations.
The most powerful methods of systems analysis have been developed for linear control systems. For a linear control system, all the relationships between the variables are linear differential equations, usually with co...
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The most powerful methods of systems analysis have been developed for linear control systems. For a linear control system, all the relationships between the variables are linear differential equations, usually with constant coefficients. Actual control systems usually contain some nonlinear elements. In the following we show how the equations for nonlinear systems may be linearized. But the result is only applicable in a sufficiently small region in the neighbourhood of equilibrium point. The table in this paper includes the nonlinear equations and their the linear approximation. Then it is easy to find out if the nonlinear system is or is not stable;the task that usually ranks among the difficult tasks in engineering practice.
Heuristic reduction algorithm has got an extensive application in decision table; based on rough sets theory and partition of set, the attribute reduction of information systems without decision attributes is discusse...
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ISBN:
(纸本)9781612844589
Heuristic reduction algorithm has got an extensive application in decision table; based on rough sets theory and partition of set, the attribute reduction of information systems without decision attributes is discussed. And a heuristic rule and an algorithm are given out. Some example shows the algorithm is effective and is an instructive attempt.
Distributed generation systems convert energy from solar panels, wind turbines, fuel cells etc. and supply DC/AC buses with energy of improved quality. The article describes the analysis and design of a mixed topology...
Distributed generation systems convert energy from solar panels, wind turbines, fuel cells etc. and supply DC/AC buses with energy of improved quality. The article describes the analysis and design of a mixed topology consisting of a phase shift converter responsible for transferring energy from the DC bus to the storage elements, and an interleaved boost converter responsible for transferring energy from the storage element to the DC bus. A new method for controlling the reverse transfer mode is developed. Also a new method for the determination of the transfer functions of the converter will be presented.
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