Loop-shaping H∞ controller is designed for unstable process. It is observed that the H∞ controller for such process can be approximated with a PID controller. Moreover, we note that the `design indicator' is a f...
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Loop-shaping H∞ controller is designed for unstable process. It is observed that the H∞ controller for such process can be approximated with a PID controller. Moreover, we note that the `design indicator' is a function of the normalized delay. This fact leads us to derive the direct relation between the PID controller's parameters and the plant constants, and the results can be regarded as a PID tuning rule for unstable process. The tuning rule has only one parameter which reflects the trade-off between performance and robustness of the closed-loop system. Simulation results show that it works for first-order delayed unstable process with the normalized delay smaller than unity.
Future jet engines will be more complex with more variables to control to meet increasing demands or functionality. The interaction between the engine and aircraft systems will also increase, with mission-specific con...
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Future jet engines will be more complex with more variables to control to meet increasing demands or functionality. The interaction between the engine and aircraft systems will also increase, with mission-specific control and with control of thrust direction. To utilize the potential of these engines, it is also necessary to use more advanced control concepts than are conventionally used today. Multivariable controllers are most often at the core of these advanced control concepts. Important parts of multivariable controldesign are to select suitable inputs and outputs and how to configure the control laws. This is referred to as control Structure design (CSD). Some methods to accomplish this have been evaluated at Volvo Aero. A model of a typical jet engine has been used as application in this evaluation. The general impression from this work is that the tested methods are very usable to select between a large number of possible structures. However, it is essential to combine the use of the methods with application knowledge and understanding of the control objectives.
This paper presents experimental results of the first-stage implementation of a new generation of longitudinal controllers for commercial heavy vehicles. The experimental vehicle used is a Class-8 18-wheel tractor-tra...
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This paper presents experimental results of the first-stage implementation of a new generation of longitudinal controllers for commercial heavy vehicles. The experimental vehicle used is a Class-8 18-wheel tractor-trailer combination vehicle, equipped with electronic throttle, brake, and steering actuators, and the corresponding sensors for automated operation. In the first stage of the experiments we tested two of our speed control algorithms: fixed-gain PID and PIQ controllers. The verification of our theoretical predictions by the experimental results provides the basis for investigating further control performance improvement with more advanced controllers.
Temperature control in single-wafer semiconductor reactors has become a hot topic. The interest in the subject illustrates the fact that the temperature measurement and control issues are far from trivial. This is due...
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Temperature control in single-wafer semiconductor reactors has become a hot topic. The interest in the subject illustrates the fact that the temperature measurement and control issues are far from trivial. This is due to the reactor design which is inherently non-isothermal, to the principal difficulties in measuring wafer temperature (or film thickness) in real-time and to the typically large interaction present between zones in radiantly heated systems. CVD-RTP (Chemical Vapor Deposition - Rapid Thermal Processing) reactors offer a challenge to control engineers in that the control of temperature uniformity over the wafer surface is of utmost importance for the next generation of processing equipment. This paper presents a solution based on the methodology of MBPC (Model Based Predictive control).
We present an optimizing control method for electric district heating and cooling (DHC) plants. The purpose of the method is to minimize the operating cost of the plants. The optimization models are constructed by inp...
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We present an optimizing control method for electric district heating and cooling (DHC) plants. The purpose of the method is to minimize the operating cost of the plants. The optimization models are constructed by input-output properties of the components into mixed 0-1 linear programming problem. The advanced feature of the method is to be able to handle 1) double-bundle heat pumps, 2) thermal storage tanks, and 3) peak-cut strategy. The numerical example shows that the optimization result based on the method gives appropriate schedule for DHC plant operation.
The present paper proposes a new simple adaptive control scheme taking account of disturbances for a non-ASPR system and investigates the global stability of the obtained adaptive algorithm. Two schemes for rejecting ...
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The present paper proposes a new simple adaptive control scheme taking account of disturbances for a non-ASPR system and investigates the global stability of the obtained adaptive algorithm. Two schemes for rejecting disturbance effects are discussed from feedback and adaptive feedforward points of view. The validity of the proposed algorithm is examined in numerical simulation and experimental study in which the adaptive torsional vibration control of an induction motor connected with a load by a flexible shaft can be achieved in the presence of torque disturbance without using any sensor for the load.
This paper proposed a robust output feedback controller of an atomic force microscope (AFM) device for the purpose of high rate date sampling. The AFM device is modeled as a cantilever-sample system in which the inter...
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This paper proposed a robust output feedback controller of an atomic force microscope (AFM) device for the purpose of high rate date sampling. The AFM device is modeled as a cantilever-sample system in which the interactive forces between the cantilever and the sample consists of a long range attractive force and short range repulsive force. By using the feedback linearization and the singular perturbation technique, an output high-gain feedback controller is designed such that the cantilever tip can track the surface of the sample at a high rate of date sampling even though the topology of the surface is arbitrary and not given a priori. By adopting the controller developed here, the signals to be measured are the deflection of the cantilever. Finally a computer simulation is provided to demonstrate the effectiveness of the proposed controller.
Manipulating payloads with gantry cranes can be difficult given the inherent system flexibility. In fact, the payload cannot move until some deflection occurs in the support cable, thereby generating a horizontal forc...
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Manipulating payloads with gantry cranes can be difficult given the inherent system flexibility. In fact, the payload cannot move until some deflection occurs in the support cable, thereby generating a horizontal force. Gantry crane dynamics can often be effectively modeled as a single linear flexible mode. However, if the crane is equipped with a large-mass hook and the payload is sufficiently light, then the dynamics can become complicated by double-pendulum effects. This paper presents a method for determining the contribution of the second pendulum mode to the overall dynamic response. Furthermore, an input shaping scheme is developed to reduce residual oscillations. This control method utilizes the double-pendulum dynamics to determine the parameters of the input shaping algorithm.
In this study, a fuzzy gain scheduling controller is proposed to parallel park the car-like robot. At first, a fuzzy sliding mode controller (FSMC) embedded by driving experience is developed to locally track a most t...
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In this study, a fuzzy gain scheduling controller is proposed to parallel park the car-like robot. At first, a fuzzy sliding mode controller (FSMC) embedded by driving experience is developed to locally track a most typical path for the parallel parking. In order to extend the controlled region, several typical paths are formed and can be pieced together to constitute a complete parking path in a large region. Then, a fuzzy gain scheduler with knowledge-based structure is proposed to decide the best parking path and to generate the proper control gains.
So as to achieve high density and high speed access of magnetic disk drives, integrated optimization method is applied for designing the head-suspension assemblies. Approximation is used to the model of a head-suspens...
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So as to achieve high density and high speed access of magnetic disk drives, integrated optimization method is applied for designing the head-suspension assemblies. Approximation is used to the model of a head-suspension assembly, which makes it possible to enjoy a nice analytical result on Ricatti equations. Using this trick, we can obtain an explicit expression of the optimal controller in state space form. Based on this setup, the simultaneous optimization problem both on active and passive parameters is reduced to a simpler one. A numerical example is given to show that a better performance of a magnetic disk drive can be obtained by the simple design procedure.
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