In this paper a generalized hp method is combined with pseudospectral methods and convex optimization to provide a high-accuracy, real-time capable method able to compute optimal trajectories for planetary powered des...
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We study the local behavior of a primal-dual inexact interior point methods for solving nonlinear systems arising from the solution of nonlinear optimization problems or more generally from nonlinear complementarity p...
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We study the local behavior of a primal-dual inexact interior point methods for solving nonlinear systems arising from the solution of nonlinear optimization problems or more generally from nonlinear complementarity problems. The algorithm is based on the Newton method applied to a sequence of perturbed systems that follows by perturbation of the complementarity equations of the original system. In case of an exact solution of the Newton system, it has been shown that the sequence of iterates is asymptotically tangent to the central path (Armand and Benoist in Math. Program. 115:199-222, 2008). The purpose of the present paper is to extend this result to an inexact solution of the Newton system. We give quite general conditions on the different parameters of the algorithm, so that this asymptotic property is satisfied. Some numerical tests are reported to illustrate our theoretical results.
Motion planning trajectories for a multi-limbed robot to climb up walls requires a unique combination of constraints on torque, contact force, and posture. This paper focuses on motion planning for one particular setu...
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ISBN:
(纸本)9781728140049
Motion planning trajectories for a multi-limbed robot to climb up walls requires a unique combination of constraints on torque, contact force, and posture. This paper focuses on motion planning for one particular setup wherein a six-legged robot braces itself between two vertical walls and climbs vertically with end effectors that only use friction. Instead of motion planning with a single nonlinear programming (NLP) solver, we decoupled the problem into two parts with distinct physical meaning: torso postures and contact forces. The first part can be formulated as either a mixed-integer convex programming (MICP) or NLP problem, while the second part is formulated as a series of standard convex optimization problems. Variants of the two wall climbing problem e.g., obstacle avoidance, uneven surfaces, and angled walls, help verify the proposed method in simulation and experimentation.
In this paper the limiting performance analysis of a head protection helmet is performed. A discrete model of the human head is used. A multicriteria optimum control problem is formulated in order to minimize the risk...
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ISBN:
(纸本)9781538685075;9781538685068
In this paper the limiting performance analysis of a head protection helmet is performed. A discrete model of the human head is used. A multicriteria optimum control problem is formulated in order to minimize the risk of injuries in case of impact. Several injury criteria are minimized and are required to remain below a safety threshold value. The optimal control force acting on the head is found. The optimal control force is determined by nonlinear programming. The equations of motion are integrated at-once, as it is typical for static response, instead of the traditional step-by-step integration.
Virtually coupled train set (VCTS) provides new prospects for dynamic train formation and dispatching method for rail transit. A new method that considers the distribution of passenger flow is put forward to improve t...
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ISBN:
(纸本)9781538670248
Virtually coupled train set (VCTS) provides new prospects for dynamic train formation and dispatching method for rail transit. A new method that considers the distribution of passenger flow is put forward to improve transportation efficiency and achieve transportation capacity configurable. The dynamic train formation technology is presented to coordinate and dispatch all running trains in virtually coupled train set. After dispatching methods based on the form of train formation are discussed in details, the dynamic train formation technology connotations are then expatiated. The adaptability of the technology to the unbalanced spatial and temporal distribution of passenger flow is analyzed. According to dynamic train formation technology, an integer nonlinear programming model which is suitable for real-time passenger flow is proposed to make spatial-temporal dispatching. Finally, actual data of the Beijing-Shanghai high-speed railway is used to verify the proposed model. The optimal solution can be found using Lingo11.0 in 6 seconds. Compared with the existing methods, the vacant seat mileage is reduced by 20%-40% and the passenger load factor is increased by 5%-10% by applying the proposed method. We show that the model is adaptable to the unevenly spatial-temporal distributed passenger flow. The proposed model effectively enhances the configurability of transportation capacity that fits the characteristics of passenger flow.
Solvers of nonlinear systems of equations are important in software engineering. There are various methods which use gradient approach to find the solution in accordance to gradient descent. This paper presents softwa...
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ISBN:
(纸本)9783030209124;9783030209117
Solvers of nonlinear systems of equations are important in software engineering. There are various methods which use gradient approach to find the solution in accordance to gradient descent. This paper presents software testing for proposed implementation of rapid gradient descent method. Results show that implementation is able to solve problems better than classic approach. The gradient path is smooth and faster converge to the final location.
Situational awareness in wireless networks refers to the availability of information on node locations and their environments. Fifth generation millimeter wave multiple-input multiple-output communication systems have...
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ISBN:
(纸本)9781538665282
Situational awareness in wireless networks refers to the availability of information on node locations and their environments. Fifth generation millimeter wave multiple-input multiple-output communication systems have the potential to jointly estimate the position, orientation, and clock offset of user equipments together with the positions of reflecting or scattering objects in their propagation environments. However, even in a static setting, the corresponding maximum a posteriori estimation problem is nonlinear and non-convex, and thus very difficult to solve in moderate computation time. We present an augmented version of the optimization problem underlying maximum a posteriori estimation, where geometric constraints are introduced to limit the size of the search space considerably. The constrained problem is then solved using a conventional interior point optimization method. Numerical results show that our approach has a very low computational complexity and that it can typically reach the Cramer-Rao lower bound.
Optimization models are proposed for selecting the required number of universal prefabricated devices and non-separable special devices. As a modeling apparatus, nonlinear programming problems and discrete dynamic pro...
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Optimization models are proposed for selecting the required number of universal prefabricated devices and non-separable special devices. As a modeling apparatus, nonlinear programming problems and discrete dynamic problems are used. The work formulates mathematical models that allow implementing a management technique based on the principles: Just in Time, Design to Cost, Risks Management.
This paper presents a novel approach to the solution of multi-phase multi-objective hybrid optimal control problems. The proposed solution strategy extends previous work which integrated the Direct Finite Elements Tra...
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ISBN:
(纸本)9780877036593
This paper presents a novel approach to the solution of multi-phase multi-objective hybrid optimal control problems. The proposed solution strategy extends previous work which integrated the Direct Finite Elements Transcription (DFET) method to transcribe dynamics and objectives, with a memetic strategy called Multi Agent Collaborative Search (MACS). The problem is reformulated as two non-linear programming problems: a bi-level and a single level one. In the bi-level formulation the outer level, handled by MACS, generates trial control vectors that are then passed to the inner level, which enforces the feasibility of the solution. Feasible control vectors are then returned to the outer level to evaluate the corresponding objective functions. The single level formulation is also run periodically to ensure local convergence to the Pareto front. In order to treat mixed integer problems, the heuristics of MACS have been modified in order to preserve the discrete nature of integer variables. For the single level refinement and the inner level of the bi-level approach, discrete variables are relaxed and treated as continuous. Once a solution to the relaxed problem has been found, a smooth constraint is added to systematically force the relaxed variables to assume integer values. The approach is first tested on a simple motorised travelling salesmen problem and then applied to the mission design of a multiple debris removal mission.
As an emerging manufacture technology, block copolymer directed self-assembly (DSA) is promising for via layer fabrication. Meanwhile, redundant via insertion is considered as an essential step for yield improvement. ...
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ISBN:
(纸本)9781450360074
As an emerging manufacture technology, block copolymer directed self-assembly (DSA) is promising for via layer fabrication. Meanwhile, redundant via insertion is considered as an essential step for yield improvement. For better reliability and manufacturability, in this paper, we concurrently consider DSA guiding template assignment with redundant via and dummy via insertion at post-routing stage. Firstly, by analyzing the structure property of guiding templates, we propose a building-block based solution expression to discard redundant solutions. Then, honoring the compact solution expression, we construct a conflict graph with dummy via insertion, and then formulate the problem to an integer linear programming (ILP). To make a good trade-off between solution quality and run-time, we relax the ILP to an unconstrained nonlinear programming (UNP). Finally, a line search optimization algorithm is proposed to solve the UNP. Experimental results verify the effectiveness of our new solution expression and the efficiency of our proposed algorithm.
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