A real-time trajectory optimization approach is developed for an underactuated rigid spacecraft using differential flatness property. By employing a fictitious input variable along the uncontrolled axis, a general und...
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Use of the augmented Lagrangians to solve the constrained structural control problems is explained. The basic idea of this approach is to transform the constrained optimization problem into a sequence of unconstrained...
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Self-optimizing control is a promising method for finding appropriate controlled variables. Recently, locally optimal methods were introduced for finding controlled variables by minimizing the worst-case loss. In this...
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This paper present a new effective algorithm for the optimal realization of state estimate feedback controller structures for discrete time systems subject to finite-word-length constraints. The problem is formulated ...
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作者：
Lewis, Robert MichaelICASE
NASA Langley Research Center Mail Stop 132C HamptonVA23681-0001 United States
We describe an approach to managing the use of approximate models in optimization. This approach combines the idea of approximation models from engineering design optimization with the model trust region approach from...
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A modern space mission is usually composed of several events such as impulsive maneuvers, thrust arcs, and flybys. Traditionally, a mission planner would develop a structure for the mission using categorical variables...
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ISBN:
(纸本)9780877035411
A modern space mission is usually composed of several events such as impulsive maneuvers, thrust arcs, and flybys. Traditionally, a mission planner would develop a structure for the mission using categorical variables, and then find the best spacecraft trajectory solving a continuous optimal control problem. A problem of this type involving categorical and continuous variables in the formulation is known as a hybrid optimal control (HOC) problem. A recent approach to solving HOC problems has the potential to automate the mission planning process by minimizing human intervention in the loop. The method uses two nested loops: an outer-loop which handles the finite dynamics and finds a solution sequence in terms of the categorical variables, and an inner-loop which performs the optimization of the continuous-time dynamical system and obtains the required control law. In this work, we introduce genetic algorithms and Runge-Kutta parallel-shooting with nonlinear programming as methods of solution for the outer-loop and inner-loop problems respectively.
The problem of monitoring and regulating the freeway traffic flow to increase safety and efficiency is commonly considered to be a difficult task. In this paper, a variable speed signal-based control strategy is prese...
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ISBN:
(纸本)9783952426906
The problem of monitoring and regulating the freeway traffic flow to increase safety and efficiency is commonly considered to be a difficult task. In this paper, a variable speed signal-based control strategy is presented to solve an optimal control problem. The freeway traffic behaviour is described by means of a macroscopic model and the effects of the variable speed signalling are modelled with the introduction of suitable parameters. An optimal control problem over a finite-time horizon is stated with the aim of reducing the probability of freeway congestion. A suboptimal solution is found based on an on-off control logic, which depends on some switching parameters to be chosen.
Commingling is employed in the petroleum industry to enhance oil recovery and reduce costs. It is of great importance to monitor the production of each oil well oilfields. Nowadays, more and more oilfields use chromat...
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This paper presents an approach to determine the load demand response that aims at maximizing the benefits for distribution utilities and consumers through the optimization of unit costs within a practical tariff syst...
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As part of the EU-research project CityHush a microphone array system including a camera module is being developed allowing for the detection, separation and quantification of the various noise sources contributing to...
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As part of the EU-research project CityHush a microphone array system including a camera module is being developed allowing for the detection, separation and quantification of the various noise sources contributing to the overall noise of road traffic, which consists of many individual vehicles. Each vehicle contains a number of noise sources (e.g. tire-road interaction, engine etc.). The combination of optical and acoustical information will be used for identifying the noise sources of each passing vehicle. The spatial resolution of a microphone array depends strongly on the array size. To resolve the complex traffic noise, a modular system consisting of square grids (1.5m × 1.5m) has been developed. The grids can be combined arbitrarily to build e.g. an array of 6m × 3m with up to 192 microphones and 3 video cameras to cover an entire street. This paper describes the physical setup of the measurement system and a non-linear optimization technique to identify the positions of all microphones needed for source localization. Further work within the project is related to developing and implementing algorithms for vehicle detection, classification (e.g. passenger car, motorcycles, trucks) and tracking. Finally, the system will be tested and validated with measurements of real vehicles passing-by and complex traffic scenarios.
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