This paper is concerned with the practical application control of a pneumatically actuated Stewart-Gough platform with 6-degrees of freedom （6-DOF）. The control approach for motion control of the platform is present...
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This paper is concerned with the practical application control of a pneumatically actuated Stewart-Gough platform with 6-degrees of freedom （6-DOF）. The control approach for motion control of the platform is presented using a modern control technique, namely, linear quadratic Gaussinn （LQG） with reference tracking. The LQG controller is the combination of a Kalman filter, i.e., a linear-quadratic estimator （LQE） with a linear-quadratic regulator （LQR）. The robustness of the control scheme is accessed under various load conditions, and the experimental results are shown.
This paper describes a method of measuring the variance of a noisy process on-line, enabling the application of adaptive Statistical Process control (SPC) to supervise a continuous process loop. A fundamental requirem...
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This paper describes a method of measuring the variance of a noisy process on-line, enabling the application of adaptive Statistical Process control (SPC) to supervise a continuous process loop. A fundamental requirement of SPC techniques is that the data are independent. Process control loops typically generate autocorrelated data, and this tends to create an increase in the false alarm rate when attempting to apply SPC techniques. The method presented here produces an uncorrelated sequence fr om potentially correlated data, overcoming this problem. The SPC supervisory unit acts externally to the control loop preventing any lags in feedback. When these SPC charts are used in a supervisory role with a conventional PID controller, application of individual PID terms achieves a much quieter control with little reduction in performance and without the need for prior off-line noise tests. The results of tests in simulation and on a steam-water heat exchanger are presented.
Locomotion and manipulation optimization is essential for the performance of tetrahedron-based mobile mechanism. Most of current optimization methods are constrained to the continuous actuated system with limited degr...
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Locomotion and manipulation optimization is essential for the performance of tetrahedron-based mobile mechanism. Most of current optimization methods are constrained to the continuous actuated system with limited degree of freedom(DOF), which is infeasible to the optimization of binary control multi-DOF system. A novel optimization method using for the locomotion and manipulation of an 18 DOFs tetrahedron-based mechanism called 5-TET is proposed. The optimization objective is to realize the required locomotion by executing the least number of *** control strategy is adopted, and forward kinematic and tipping dynamic analyses are performed, *** on a developed genetic algorithm(GA), the optimal number of alternative struts between two adjacent steps is obtained as 5. Finally, a potential manipulation function is proposed, and the energy consumption comparison between optimal 5-TET and the traditional wheeled robot is carried out. The presented locomotion optimization and manipulation planning enrich the research of tetrahedron-based mechanisms and provide the instruction to the successive locomotion and operation planning of multi-DOF mechanisms.
A structured genetic algorithm (SGA) approach is developed for robust controller design based on the concept of an H-infinity loop-shaping technique and the method of inequalities, Such an SGA is capable of simultaneo...
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A structured genetic algorithm (SGA) approach is developed for robust controller design based on the concept of an H-infinity loop-shaping technique and the method of inequalities, Such an SGA is capable of simultaneously searching the orders and coefficients of the precompensator and postcompensator for the weighted plant, It is, therefore, not necessary to predefine the order of compensators as in usual practice, A multiple objective ranking approach is also incorporated so that the design criteria of extreme plants can be easily achieved. The effectiveness of such a technique is illustrated by a high-purity distillation column design example.
Vertex cover of complex networks is essentially a major combinatorial optimization problem in network science, which has wide application potentials in engineering. To optimally cover the vertices of complex networks,...
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Vertex cover of complex networks is essentially a major combinatorial optimization problem in network science, which has wide application potentials in engineering. To optimally cover the vertices of complex networks, this paper employs a potential game for the vertex cover problem, designs a novel cost function for network vertices, and proves that the solutions to the minimum value of the potential function are the minimum vertex covering(MVC) states of a general complex network. To achieve the optimal(minimum) covering states, we propose a novel distributed time-variant binary log-linear learning algorithm,and prove that the MVC state of a general complex network is attained under the proposed optimization algorithm. Furthermore, we estimate the upper bound of the convergence rate of the proposed algorithm,and show its effectiveness and superiority using numerical examples with representative complex networks and optimization algorithms.
An explicit expression for the minimum-variance steady-state fixed-point smoothing estimate of the output of linear, discrete-time invariant system is obtained in terms of the measurement spectral factor. The filtered...
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An explicit expression for the minimum-variance steady-state fixed-point smoothing estimate of the output of linear, discrete-time invariant system is obtained in terms of the measurement spectral factor. The filtered estimate of the states of the system is first derived by finding the spectral factor for the power density matrix of the measurement signal. The z-transform of the time-varying gain matrix, which produces the optimal smoothing estimate by multiplying the innovations process of the Kalman filter, is also obtained in terms of this factor. The results are easily extended to cases with colored measurement and driving noise signals; they are particularly simple to apply in the single-input-single-output case.< >
Advances in recent years in the manufacture of metal oxide Field Effect Transistors (Mosfets) have paved the way for new design criteria in solid-state switching power circuits. This paper gives an insight into the kn...
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Advances in recent years in the manufacture of metal oxide Field Effect Transistors (Mosfets) have paved the way for new design criteria in solid-state switching power circuits. This paper gives an insight into the knowledge gained in the design of gate drive circuits for power mosfet switching devices.
The ultrasonic motor (USM) possesses heavy nonlinearities which vary with driving conditions and load-dependent characteristics such as the dead-zone. In this paper, an identification method for the rotary travelling-...
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The ultrasonic motor (USM) possesses heavy nonlinearities which vary with driving conditions and load-dependent characteristics such as the dead-zone. In this paper, an identification method for the rotary travelling-wave type ultrasonic motor (RTWUSM) with dead-zone is proposed based on a modified Hammerstein model structure. The driving voltage contributing effect on the nonlinearities of the RTWUSM was transformed to the change of dynamic parameters against the driving voltage. The dead-zone of the RTWUSM is identified based upon the above transformation. Experiment results showed good agreement be- tween the output of the proposed model and actual measured output.
This paper presents the theory of dissipative systems in the context of finite dimensional stationary linear systems with quadratic supply rates. A necessary and sufficient frequency domain condition for dissipativene...
This paper presents the theory of dissipative systems in the context of finite dimensional stationary linear systems with quadratic supply rates. A necessary and sufficient frequency domain condition for dissipativeness is derived. This is followed by the evaluation of the available storage and the required supply and of a time-domain criterion for dissipativeness involving certain matrix inequalities. The quadratic storage functions and the dissipation functions are then examined. The discussion then turns to reciprocal systems and it is shown that external reciprocity and dissipativeness imply the existence of a state space realization which is also internally reciprocal and dissipative. The paper proceeds with an examination of reversible systems and of relaxation systems. In particular, it is shown how a unique internal storage function may be defined for relaxation systems. These results are applied to the synthesis of electrical networks and the theory of linear viscoelastic materials.
The first part of this two-part paper presents a general theory of dissipative dynamical systems. The mathematical model used is a state space model and dissipativeness is defined in terms of an inequality involving t...
The first part of this two-part paper presents a general theory of dissipative dynamical systems. The mathematical model used is a state space model and dissipativeness is defined in terms of an inequality involving the storage function and the supply function. It is shown that the storage function satisfies an a priori inequality: it is bounded from below by the available storage and from above by the required supply. The available storage is the amount of internal storage which may be recovered from the system and the required supply is the amount of supply which has to be delivered to the system in order to transfer it from the state of minimum storage to a given state. These functions are themselves possible storage functions, i.e., they satisfy the dissipation inequality. Moreover, since the class of possible storage functions forms a convex set, there is thus a continuum of possible storage functions ranging from its lower bound, the available storage, to its upper bound, the required supply. The paper then considers interconnected systems. It is shown that dissipative systems which are interconnected via a neutral interconnection constraint define a new dissipative dynamical system and that the sum of the storage functions of the individual subsystems is a storage function for the interconnected system. The stability of dissipative systems is then investigated and it is shown that a point in the state space where the storage function attains a local minimum defines a stable equilibrium and that the storage function is a Lyapunov function for this equilibrium. These results are then applied to several examples. These concepts and results will be applied to linear dynamical systems with quadratic supply rates in the second part of this paper.
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