Jet fans are installed on the ceiling or side walls of the tunnel to create the air stream. The jet fans take in tunnel air and blow it out at higher speed along the axis of the tunnel. In the tunnel is mounted severa...
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Jet fans are installed on the ceiling or side walls of the tunnel to create the air stream. The jet fans take in tunnel air and blow it out at higher speed along the axis of the tunnel. In the tunnel is mounted several fans with about hundred kW each. The design and industrial implementation of automaticcontrolsystems requires powerful and economic techniques together with efficient tools. In order to solve a control problem it is necessary to describe somehow the dynamic behaviors of the system to be controlled. Predictive control seems to be a promising approach that can help to improve properties of existing ventilation systems applied in road tunnels. Advantages of predictive control result mainly from its ability to solve both SISO and MIMO tasks, to have regard for dynamics of process changes in a broad extent, to compensate effect of measurable and non-measurable failures and to formulate the task as an “optimization control task” considering limiting conditions of control actions, changes of control actions and output variables. Data characterizing the existing ventilation system can be used to analyze and identify the system and create its models. In this paper, we discuss the feedback linearization theory and particular relevance to process control in applications. The nonlinear controller design techniques can be used; input-output linearization and state-space linearization. Advanced topics such as dynamic feedback linearization, time delay compensation, constraint handling, and sampled-data systems are also discussed.
In this paper, it is considered a wave equation with a one-dimensional space variable, which describes the dynamics of string deflection. The slope has a finite length and is attached at both boundaries. It is equippe...
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Lifting as geometric operation can be defined as a pseudo-inverse of orthogonal projection. It has received attention in different fields and applications (mechanics, geometry, control, etc). Numerous studies have bee...
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ISBN:
(纸本)9781479947287
Lifting as geometric operation can be defined as a pseudo-inverse of orthogonal projection. It has received attention in different fields and applications (mechanics, geometry, control, etc). Numerous studies have been dedicated to the existence conditions of a convex lifting in a higher dimension for a given cell complex. It is worth noting that this notion can be extended for a polyhedral partition for applications in control theory, and it is recently shown to be the key step in solving the inverse parametric linear/quadratic programming problems. The present paper presents in a succinct manner the main elements of this topological problem with specific attention to the case of polyhedral partitions and their liftings. Furthermore, we are interested from the practical point of view, in the use of these concepts in control system design. Practically, a construction for the Voronoi diagram class is presented. Secondly, a methodological result is presented which leads to the modification of partitions guaranteeing a theoretically liftable result. In addition, a generic constructive procedure for the partitions based on convexity, continuity and linear (or quadratic) programming is proposed. In order to bring the discussion closer to the control related formulations, the correspondence between convex liftings of a given partition in ℝ d onto (d+1)-space and n-space with n > d+1 is provided. Finally an analysis with respect to predictive control related problems will conclude our contribution.
Photoelectric autocollimator is a kind of small angle measuring instrument of high accuracy. For the increasing demand of the measurement accuracy, each link to affect the precision of photoelectric autocollimator nee...
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ISBN:
(纸本)9781479965762
Photoelectric autocollimator is a kind of small angle measuring instrument of high accuracy. For the increasing demand of the measurement accuracy, each link to affect the precision of photoelectric autocollimator needs to be analyzed and derived. In view of the analysis of the lack for the right angle prism pien errors which effect on the measurement precision, this paper adopts the method of vector analysis and coordinate transformation, to solve the relationship between the image type photoelectric autocollimator reticules imaging and prism space angle. On this basis, analyze the influence of the right angle prism error on the measurement. To verify the correctness of test derivation, using a type of photoelectric autocollimator and right angle prisms for experiments, the test results coincide with the conclusion of theoretical derivation.
This paper proposes a new actuator-fault detection and isolation (FDI) strategy for closed-loop discrete time-invariant systems by using invariant sets and tubes. In this approach, invariant sets are used for fault de...
This paper proposes a new actuator-fault detection and isolation (FDI) strategy for closed-loop discrete time-invariant systems by using invariant sets and tubes. In this approach, invariant sets are used for fault detection (FD) and the establishment of FDI conditions, while the tubes are generated for fault isolation (FI) at transient state. Comparing with the existing set-theoretic FDI techniques, the advantage of this approach consists in that it exhibits a balance between the conservativeness of FDI conditions, the fast FI response and the computational complexity. The effectiveness of the proposed technique is illustrated by a numerical example.
In this paper we propose a robust self-triggered model predictive control algorithm for linear systems with additive bounded disturbances and hard constraints on the inputs and state. In self-triggered control, at eve...
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In this paper we propose a robust self-triggered model predictive control algorithm for linear systems with additive bounded disturbances and hard constraints on the inputs and state. In self-triggered control, at every sampling instant the time until the next sampling instant is computed online based on the current state of the system. The goal is to achieve a low average sampling rate, thereby minimizing communication in the control system and possibly reducing the number of control updates as is required in sparse control applications. Naturally, and intentionally, our approach leads to long spans of time in which the plant is controlled in an open-loop fashion. Especially for unstable plants or large disturbances this necessitates taking into account the disturbance characteristics in the design of the control law in order to prevent constraint violation in the closed-loop system. We use constraint tightening methods as proposed in Tube Model Predictive control to guarantee robust constraint satisfaction. The self-triggered controller is shown to stabilize a robust invariant set in the state space for the closed-loop system.
A novel protection scheme for two-phase faults in power distribution system with neutral ungrounded is presented. The feasibility of tripping single-phase circuit when a phase-tophase or two-phase-to-ground fault occu...
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ISBN:
(纸本)9781849198349
A novel protection scheme for two-phase faults in power distribution system with neutral ungrounded is presented. The feasibility of tripping single-phase circuit when a phase-tophase or two-phase-to-ground fault occurs is studied with induction motor loads as the focus. The paper at first analyses the effect of a induction motor runs with one phase cut off theoretically. And then a real power distribution system model with 110kV, 35kV and 6kV voltage levels is built in PSCAD/EMTDC. Three feasibility criteria are proposed for motors in continuous operation with single-phase opened. At last, the novel protection scheme is testified in simulation with protection time and reclosing time as variables respectively. The results verify that the scheme is feasible and power supply reliability is improved.
In this paper we consider the minimization of ℓ 0 -regularized nonlinear optimization problems, where the objective function is the sum of a smooth convex term and the ℓ 0 quasi-norm of the decision variable. We intr...
In this paper we consider the minimization of ℓ 0 -regularized nonlinear optimization problems, where the objective function is the sum of a smooth convex term and the ℓ 0 quasi-norm of the decision variable. We introduce the class of coordinatewise minimizers and prove that any point in this class is a local minimum for our ℓ 0 -regularized problem. Then, we devise a random proximal alternating minimization method, which has a simple iteration and is suitable for solving this class of optimization problems. Under convexity and coordinatewise Lipschitz gradient assumptions, we prove that any limit point of the sequence generated by our new algorithm belongs to the class of coordinatewise minimizers almost surely. We also show that the state estimation of dynamical systems with corrupted measurements can be modeled in our framework. Numerical experiments on state estimation of power systems, using IEEE bus test case, show that our algorithm performs favorably on solving such problems.
In this paper, an improved algorithm for actuator-fault detection and isolation (FDI) using a bank of interval observers is presented, where each interval observer matches one considered system mode. In this approach,...
In this paper, an improved algorithm for actuator-fault detection and isolation (FDI) using a bank of interval observers is presented, where each interval observer matches one considered system mode. In this approach, interval observers and invariant sets are simultaneously used for FDI. Under a collection of improved FDI conditions, this new algorithm can detect and isolate the considered actuator faults. At the end of this paper, a circuit example is used to illustrate the effectiveness of the proposed strategy.
The circuit principle of construction of the low-speed selective amplifiers (SA) of microwave range on the energy-efficient converters "voltage-current" is developed. The proposed solution provides the possi...
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The circuit principle of construction of the low-speed selective amplifiers (SA) of microwave range on the energy-efficient converters "voltage-current" is developed. The proposed solution provides the possibility of cascade connection of several SA without additional loops of matching of the static mode. The principle of symmetry of the frequency-dependent feedback loop underlies in the circuit construction. The reviewed architecture of SA in contrast with the well-known ones reduces the asymptotic attenuation not only in the traditional high-frequency range but also in low-frequency one without a separating capacitor. This effect is achieved by using CMOS transistors in the input differential stage. The results of the mathematical analysis and simulation of SA on 0.25 um SiGe process are given. Shown the possibility of parametric optimization the sensitivity functions of quasi-resonance frequency and Q-factor SA instability parameters of passive elements.
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