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AIAA Aviation Forum and Exposition

作者： Ghaemi, Reza Westervelt, Eric R. Visser, Nicholas Darnell, Mark Lax, David Gen Elect Res Ctr Controls & Optimizat Grp Niskayuna NY 12309 USA Gen Elect Aviat Aviat Av & Digital Syst Grand Rapids MI 49512 USA Gen Elect Aviat Customer Applicat Engn Grand Rapids MI 49512 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

In this paper, climb performance optimization is studied to determine control trajectories that minimize the Direct Operating Cost of an air transport. First a model of the vehicle motion is developed. A reduced-order model is then derived, and the calculus of variations is applied to formulate the optimization problem using the reduced-order model. An algorithm is designed to solve the problem, and the efficacy of the solver is validated using the high-order model. Two optimization methods are developed. In the first method, nonlinear programming (NLP) is used to determine the optimal open-loop control. In the second method, the reduced-order model is further simplified-relative to the equations used in the first method-and termed the energy state approximation (ESA) method. The second method is more robust and faster in terms of computing a solution, but the resulting control is marginally sub-optimal relative to the control determined by the first method. Accordingly, the relative benefits of each approach are studied to determine the best design for a real-time embedded application. It is shown that the optimal path determined by a simplified model (i.e., a point mass model and energy state approximation) is indeed a singular arc. It is further shown that if the optimal arrival to the singular arch and the optimal departure from the singular arc are added to the control trajectory, the resulting flight path is a close approximation of the optimal control determined by the NLP method. The optimal controls generated by the first method are tested using the higher-order-model and compared to the performance of a typical Flight Management System for a mid-range narrow-body transport. Minimum fuel burn is studied first. The time-related cost to operate the airplane is then included in the cost function to minimize the total Direct Operating Cost. A generic narrow-body transport with modern turbofan engines is the subject of the analyses, but the developed methods are

关键词： Fixed Wing Aircraft nonlinear programming Transversality Condition Flight Management System Supersonic Aircraft Direct Operating Cost Open Loop Turbofan Engines Computing Calibrated Airspeed

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Optimization of Thermal Protection Panels Subjected to Intense Heating and Mechanical Loading

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LOBACHEVSKII JOURNAL OF MATHEMATICS 2019年第7期40卷 887-895页

作者： Babaytsev, A. Dobryanskiy, V. Solyaev, Yu. Moscow Inst Aviat Technol Moscow 125993 Russia Russian Acad Sci Inst Appl Mech Moscow 125040 Russia

In this work we solve a higly-nonlinear structural optimization problem for the sandwich panel with external thermal protection layer that can be used in the spacecraft systems. Objective function of the problem is the mass per unit area of the panel. Constraints are formulated based on the simplified analytical solutions of structural mechanics and heat transfer problems, which are suitable for the preliminary design considerations. The set of design variables includes the geometric parameters of the panel and additional microstructural parameter-porosity of the heat protection material. Direct random search and simulated annealing method are applied to solve considered problem. Change of limit states and optimal configurations of the panel are studied for different levels of the mechanical loading.

关键词： structural optimization nonlinear programming sandwich panel minimum mass thermomechanical loading

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Energy Consumption Optimization in Two-Machine Bernoulli Serial Lines with Limits on Machine Efficiency 15

Energy Consumption Optimization in Two-Machine Bernoulli Ser...

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15th IEEE International Conference on Automation Science and Engineering (IEEE CASE)

作者： Yan, Chao-Bo Xi An Jiao Tong Univ State Key Lab Mfg Syst Engn Xian 710049 Shaanxi Peoples R China Xi An Jiao Tong Univ Fac Elect & Informat Engn Xian 710049 Shaanxi Peoples R China

ISBN: (纸本)9781728103563

Since the high energy consumption is prominent in production systems, reducing the energy consumption is of great significance. In this paper, the energy consumption optimization problem in a two-machine Bernoulli line with general lower- and upper-bounds of machine efficiencies is investigated. Specifically, the problem is formulated as a constrained nonlinear programming;taking advantage of existing results of the optimization model without additional limits on machine efficiencies, the structure of the feasible region and properties of the objective function on the feasible region are analyzed;based on the structure of the feasible region and properties of the objective function obtained, a method is developed to solve the energy consumption optimization problem in the two-machine Bernoulli line with general limits on machine efficiencies.

关键词： Production rate nonlinear programming feasible region monotonicity

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The Modeling for Train Optimal Driving Problem with Resistance Constrains and Solving with the Separation of Iteration Strategy

The Modeling for Train Optimal Driving Problem with Resistan...

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16th IEEE Vehicle Power and Propulsion Conference (VPPC)

作者： Feng, JiangHua Wang, Bin Hu, YunQing Li, XiangYu CRRC Zhuzhou Inst Co Ltd CRRC ZIC Res Inst Elect Technol & Mat Engn Zhuzhou Peoples R China

ISBN: (纸本)9781728112497

A model of train optimal operation problem is established in according to the process dynamics equations, the fraction and brake capability, the railway resistance, and the speed limits. As the ramp resistance and the running resistance are introduced, the process described by Ordinary Differential Equations (ODEs) in the constrains are then transformed into Differential Algebraic Equations (DAEs), which makes the problem more difficult. In order to solve this problem, the state and control variables are parameterized in the time domain, converting the original control problem into a constrained nonlinear programming problem, which is finally solved by primal-dual predictor-corrector interior-point algorithm.

关键词： train optimal driving nonlinear programming convex quadratic programming separation of iteration strategy primal-dual predictor-corrector interior-point algorithm

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A Comparative Study on the Performance of Metaheuristics Applied to the Preventive Maintenance Planning Definition Problem

A Comparative Study on the Performance of Metaheuristics App...

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AIAA Science and Technology (SciTech) Forum and Exposition

作者： Moura, Fernando Lucas Rodrigues, Leonardo Ramos Yoneyama, Takashi Aeronaut Inst Technol ITA BR-12228900 Sao Jose Dos Campos SP Brazil Inst Aeronaut & Space IAE Elect Div BR-12228904 Sao Jose Dos Campos SP Brazil Inst Aeronaut Elect Engn Dept Sao Jose Dos Campos SP Brazil

ISBN: (数字)9781624105784

ISBN: (纸本)9781624105784

Metaheuristic algorithms are useful techniques to cope with complex real-life optimization problems due to their efficiency, flexibility and adaptability to different classes of problems and restrictions. A wide variety of metaheuristic algorithms can be found in the literature. In this paper, we compare the performance of three different metaheuristics, namely Teaching-Learning Based Optimization (TLBO), Genetic Algorithm (GA) and Simulated Annealing (SA), in the solution of the system-level preventive maintenance planning problem. The problem consists in defining a maintenance interval for each component within the system to minimize the Estimated Cost of Repair (ECR), subjected to a reliability constraint. Numerical experiments were performed using systems with different complexity levels. The algorithms were compared in terms of relative speed of convergence, implementation complexity, accuracy, precision and execution time.

关键词： Preventive Maintenance Annealing Process Genetic Algorithm Electric Power Generation Particle Swarm Optimization Design of Experiments nonlinear programming Integrated Circuits Fault Tree Analysis Aeroplane

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Simulation Study of HIV Temporal Patterns Using Bayesian Methodology 4th

Simulation Study of HIV Temporal Patterns Using Bayesian Met...

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4th Bayesian Young Statisticians Meeting (BAYSM)

作者： Rocha, Diana Scotto, Manuel Pinto, Carla Tavares, Joao Gouveia, Sonia Univ Aveiro UA Ctr R&D Math & Applicat CIDMA Aveiro Portugal Univ Lisbon CEMAT IST Lisbon Portugal Univ Lisbon Dept Math IST Lisbon Portugal Polytech Porto Sch Engn Porto Portugal Univ Porto CMUP Ctr Math Porto Portugal UA Inst Elect & Informat Engn Aveiro IEETA Aveiro Portugal

ISBN: (纸本)9783030306113;9783030306106

Viral load values and CD4(+)T cells count are markers currently evaluated in the clinical follow-up of HIV/AIDS patients. In this context, it is relevant to develop methods that provide a more complete temporal description of these markers, e.g. in between clinical appointments. To this end, we combine a mathematical model and a Bayesian methodology to estimate trajectories from a set of observed values. Also, we construct a variation band containing the most central trajectories for one patient, by exploring the range of values in the a posteriori distributions. The methods are illustrated with simulated data.

关键词： Bayesian statistics Human immunodeficiency virus (HIV) Mathematical models nonlinear programming Parameter estimation

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Caching on Vehicles: A Lyapunov Based Online Algorithm 10th

Caching on Vehicles: A Lyapunov Based Online Algorithm

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10th EAI Annual International Conference on Ad Hoc Networks (AdHocNets)

作者： Zhang, Yao Li, Changle Luan, Tom H. Fu, Yuchuan Zhu, Lina Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China

ISBN: (纸本)9783030058883;9783030058876

With the explosive increase of mobile data and users, data tsunami seriously challenges the mobile operators worldwide. The vehicular caching, which caches mobile data on widely distributed vehicles, is an efficient method to solve this problem. In this paper, we explore the impact of vehicular caching on cellular networks. Specifically, targeting on network performance in energy efficiency, we first formulate a fractional optimization model by considering the network throughput and energy consumption. We then apply nonlinear programming and Lyapunov technology to relax the nonlinear and nonconvex model. Based on analysis, we propose a novel online task decision algorithm. Based on this algorithm, vehicles determine to act either as servers or task schedulers for the requests of users. The burden of cellular MBS (Macro Base Station) then can be alleviated. Extensive simulations are finally conducted and results verify the effectiveness of our proposal.

关键词： Caching nonlinear programming Lyapunov optimization

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Optimal Rendezvous of Unmanned Aerial and Ground Vehicles via Sequential Convex programming

Optimal Rendezvous of Unmanned Aerial and Ground Vehicles vi...

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AIAA Aviation Forum and Exposition

作者： Wang, Zhenbo McDonald, Spencer T. Univ Tennessee Dept Mech Aerosp & Biomed Engn Knoxville TN 37996 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

In this paper, we develop an efficient approach to better enable coordination control of unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs). Our particular interest is placed on the optimal UAV-UGV rendezvous problem for wide implementation for package delivery, aerial mapping, target tracking, etc. To this end, we formulate and solve the UAV-UGV rendezvous problem as a general optimal control problem subject to various state and control constraints as well as nonlinear dynamics. Through change of variables, the nonlinearity and the coupling of state and control variables in the dynamics are significantly reduced, which facilitates the design of a successive convex optimization method to find the solution. Specifically, we transform the original problem into a sequence of simpler, convex problems via convexification techniques. Preliminary results of a rendezvous scenario demonstrate that the developed methodology is able to generate precise, optimal, three-dimensional rendezvous trajectories within a second using state-of-the-art convex solvers.

关键词： Unmanned Aerial Vehicle Unmanned Ground Vehicle Trajectory Optimization nonlinear programming Three Degrees of Freedom Flight Path Angle Heading Angle Flight Control System Predictor Corrector Method Lift Coefficient

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Optimal control and design of an underactuated ball-pitching robotic arm using large-scale multidisciplinary optimization

Optimal control and design of an underactuated ball-pitching...

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AIAA Aviation Forum and Exposition

作者： Yan, Jiayao Li, Ning Lu, Tongji Tolley, Michael T. Hwang, John T. Univ Calif San Diego Dept Mech Engn La Jolla CA 92093 USA Univ Calif San Diego Dept Mech & Aerosp Engn La Jolla CA 92093 USA

ISBN: (数字)9781624105890

ISBN: (纸本)9781624105890

The ball-pitching problem with an underactuated two-link robotic arm is frequently studied in the field of mechanical engineering design because of the simplicity with which it captures the elements of mechanical systems control. Thus, it is a great testbed for testing new approaches to mechanical system design. Using this problem as an great example, we presented a new solution approach based on large-scale system design optimization using the OpenMDAO optimization framework. In this approach, we formulated a nonlinear programming problem solved using gradient-based algorithms that scale efficiently to large numbers of design variables. This scalable formulation provides two benefits: (1) it allows us to consider models of high complexity, enabling more accurate models of the system dynamics;and (2) we can simultaneously perform optimal design and optimal control. We discussed how to set up the model as a modular set of components in OpenMDAO that translated a finite-time optimal control problem into the numerical solution of a set of equations. The gradients required for optimization were computed semi-automatically by OpenMDAO. We first performed a control optimization and then went further to a optimization with control and design parameters as design variables. The optimization yielded a 0.7563m improvement in pitching distance compared to the baseline optimization. Experimental investigations were also conducted to verify the release angle of the model using a simplified model. In addition, a two-link arm was also fabricated according to the optimal design solution. We were able to get a 0.6291m increase in pitching distance compared to the largest pitching distance from the initial design. As we demonstrated with this robotic arm problem, large-scale system design optimization provides a platform for optimal design and control of mechanical systems with design variables from multiple disciplines with reduced effort from the engineers.

关键词： Time Optimal Control Control Optimization nonlinear programming Stepping Motors Robotics Humanoid Robot Computing Robot Arms Multidisciplinary Design Optimization Python

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First Steps Towards Full Model Based Motion Planning and Control of Quadrupeds: A Hybrid Zero Dynamics Approach

First Steps Towards Full Model Based Motion Planning and Con...

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IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Ma, Wen-Loong Hamed, Kaveh Akbari Ames, Aaron D. CALTECH Dept Mech Engn Pasadena CA 91125 USA Virginia Polytech Inst & State Univ Faulty Mech Engn Blacksburg VA 24061 USA CALTECH Dept Control Dynam Syst Pasadena CA 91125 USA

ISBN: (纸本)9781728140049

The hybrid zero dynamics (HZD) approach has become a powerful tool for the gait planning and control of bipedal robots. This paper aims to extend the HZD methods to address walking, ambling and trotting behaviors on a quadrupedal robot. We present a framework that systematically generates a wide range of optimal trajectories and then provably stabilizes them for the full-order, nonlinear and hybrid dynamical models of quadrupedal locomotion. The gait planning is addressed through a scalable nonlinear programming using direct collocation and HZD. The controller synthesis for the exponential stability is then achieved through the Poincare sections analysis. In particular, we employ an iterative optimization algorithm involving linear and bilinear matrix inequalities (LMIs and BMIs) to design HZD-based controllers that guarantee the exponential stability of the fixed points for the Poincare return map. The power of the framework is demonstrated through gait generation and HZD-based controller synthesis for an advanced quadruped robot, -Vision 60, with 36 state variables and 12 control inputs. The numerical simulations as well as real world experiments confirm the validity of the proposed framework.

关键词： nonlinear programming

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