Gravity gradient measurement satellite is a kind of drag-free satellite and suffers from multiple disturbances in the low earth orbit. So the disturbances estimation and compensation for the drag-free satellite is ver...
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ISBN:
(纸本)9784907764487
Gravity gradient measurement satellite is a kind of drag-free satellite and suffers from multiple disturbances in the low earth orbit. So the disturbances estimation and compensation for the drag-free satellite is very important to improve measurement precision. In this paper, the characteristics of multiple disturbances are analyzed. Then, the frequency domain disturbance observer is designed for disturbance estimation and compensation. Next, a composite controller combining the frequency domain disturbance observer with PID controller is presented to reject and attenuate the multiple disturbances. At last, the simulation verification is carried out to verify the effectiveness of the proposed method.
This paper develops a new adaptive multiple-model control scheme for a class of nonlinear multiple-input multiple-output (MIMO) dynamic systems to compensate uncertain actuator failures using an error transformation. ...
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This paper addresses the problem of multiple odor sources localization(MOSL) using a mobile robot in a time-varying airflow environment, and provides a localization method which applies the Dempster-Shafer(D-S) theory...
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ISBN:
(纸本)9781467374439
This paper addresses the problem of multiple odor sources localization(MOSL) using a mobile robot in a time-varying airflow environment, and provides a localization method which applies the Dempster-Shafer(D-S) theory to map the possible locations of several odor sources and then uses the map to plan a searching route online for the robot. In the proposed method, the robot carries out the D-S inference and iteratively updates a grid map in which each cell has two states(i.e., occupied by an odor source, and not occupied by odor source), using the successive measurements from a gas sensor and an anemometer when the robot follows the dynamic-planned searching route in the given work area. The searching route is planned online to maximize the decline of the uncertainties of the grid cells around the robot. The mapping of the odor sources and the planning of the searching route work side-by-side. Simulations are carried out and the results in a time-varying airflow environment show that the locations of the two odor sources can be estimated online with the D-S inference, and the time cost can be greatly reduced by following the dynamic-planned searching route compared with by following a predefined path shaped like rectangular wave to cover the given searching area.
Many networks can be modeled as collections of subsystems with complex internal dynamics, which are dynamically coupled according to a weighted digraph. This article characterizes the input-output behavior of a networ...
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Gravity gradient measurement satellite is a kind of drag-free satellite and suffers from multiple disturbances in the low earth orbit. So the disturbances estimation and compensation for the drag-free satellite is ver...
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The landing accuracy of a Mars lander is severely affected by a wide range of disturbances at the powered descent stage. To address this problem, a composite guidance law is proposed in this paper. The composite guida...
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ISBN:
(纸本)9781467374439
The landing accuracy of a Mars lander is severely affected by a wide range of disturbances at the powered descent stage. To address this problem, a composite guidance law is proposed in this paper. The composite guidance law is developed by the combination of disturbance observer-based control(DOBC) technique and multiple sliding surfaces guidance(MSSG)theory. Compared with other guidance laws, the proposed method achieves promising disturbance rejection performance and high landing accuracy in both position and velocity, reducing the conservatism to a certain extent. The proposed guidance law does not require any off-line trajectory generation and its global stability is verified by using Lyapunov direct method. Simulation results show that the proposed guidance law is superior to the conventional guidance laws in terms of both disturbance rejection and landing accuracy.
The calibration of a PointQ arterial microsimulation model is formulated as a quadratic programming problem (QP) whose decision variables are link flows, demands at entry links and turn movements at intersections, sub...
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ISBN:
(纸本)9789881581440
The calibration of a PointQ arterial microsimulation model is formulated as a quadratic programming problem (QP) whose decision variables are link flows, demands at entry links and turn movements at intersections, subject to linear constraints imposed by flow conservation identities and field measurements of a subset of link flows, demands and turn ratios. The quadratic objective function is the deviation of the decision variables from their measured values. The solution to the QP gives estimates of all unmeasured variables and thereby yields a fully specified simulation model. Runs of this specified model can then be compared with other field measurements, such as travel times along routes, to judge the reliability of the calibrated model. A section of the Huntington-Colorado arterial near I-210 in Los Angeles comprising 73 links and 16 intersections is used to illustrate the procedure. Several planning and signal control experiments are carried out with the calibrated model.
Iterative learning control technique is applied to a class of distributed parameters switched systems,using P-type learning control law to investigate the problem of target tracking *** condition of the P type iterati...
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ISBN:
(纸本)9781479970186
Iterative learning control technique is applied to a class of distributed parameters switched systems,using P-type learning control law to investigate the problem of target tracking *** condition of the P type iterative learning control law have been proposed in this paper,and the convergence analysis has been *** is assumed that the subsystem is operated during a finite time interval *** simulation results illustrate that the P-type iterative learning control algorithm for a class of distributed parameter switched system is effective.
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