An improved formulation for optimizing rocker-bogie suspension rover for climbing steps

2019 ◽  
Vol 233 (18) ◽  
pp. 6538-6558 ◽  
Author(s):  
Sam Noble ◽  
K Kurien Issac
Keyword(s):  
Nonlinear Programming ◽  
Optimal Design ◽  
Local Minimum ◽  
Single Step ◽  
Optimal Solutions ◽  
Performance Parameters ◽  
Smooth Functions ◽  
Gradient Based ◽  
Wheel Radius ◽  
Better Than

We address the problem of improving mobility of rovers with rocker-bogie suspension. Friction and torque requirements for climbing a single step were considered as performance parameters. The main contribution of the paper is an improved formulation for rover optimization using smooth functions, which enables use of powerful gradient based nonlinear programming (NLP) solvers for finding solutions. Our formulation does not have certain shortcomings present in some earlier formulations. We first formulate the problem of determining optimal torques to be applied to the wheels to minimize (a) friction requirement, and (b) torque requirement, and obtain demonstrably optimal solutions. We then formulate the problem of optimal design of the rover itself. Our solution for climbing a step of height two times the wheel radius is 13% better than that of the nominal rover. This solution is verified to be a local minimum by checking Karush–Kuhn–Tucker conditions. Optimal solutions were obtained for both forward and backward climbing. We show that some earlier formulations cannot obtain optimal solutions in certain situations. We also obtained optimal design for climbing steps of three different heights, with a friction requirement which is 15% lower than that of the nominal rover.

scholarly journals Analyze the optimal solutions of optimization problems by means of fractional gradient based system using VIM

2016 ◽  
Vol 6 (2) ◽  
pp. 75-83 ◽  
Author(s):  
Firat Evirgen
Keyword(s):  
Nonlinear Programming ◽  
Fractional Order ◽  
Optimization Problems ◽  
Variational Iteration Method ◽  
Optimal Solutions ◽  
Order Model ◽  
Fractional Order Differential Equations ◽  
Runge Kutta Method ◽  
Fractional Order Model ◽  
Gradient Based

In this paper, a class of Nonlinear Programming problem is modeled with gradient based system of fractional order differential equations in Caputo's sense. To see the overlap between the equilibrium point of the fractional order dynamic system and theoptimal solution of the NLP problem in a longer timespan the Multistage Variational ?teration Method isapplied. The comparisons among the multistage variational iteration method, the variationaliteration method and the fourth order Runge-Kutta method in fractional and integer order showthat fractional order model and techniques can be seen as an effective and reliable tool for finding optimal solutions of Nonlinear Programming problems.

Optimal Design of Robot Gripper Mechanism Using Force and Displacement Transmission Ratio

2014 ◽  
Vol 613 ◽  
pp. 117-125 ◽  
Author(s):  
Stanisław Krenich
Keyword(s):  
Optimal Design ◽  
Random Search ◽  
Optimization Procedure ◽  
Search Method ◽  
Transmission Ratio ◽  
Optimal Solutions ◽  
Force Transmission ◽  
Optimization Criteria ◽  
Robot Gripper ◽  
Gradient Based

The paper presents an approach to design optimization of robot gripper mechanism. There are two different optimization criteria, a force transmission ratio and a displacement transmission ratio, considered. In order to generate the optimal solutions, three algorithms are applied. There are gradient based method, random search method and evolutionary algorithm used. The results and a comparison with the industrial gripper, show possibility to improve parameters of the gripper mechanism using optimization procedure. They show as well, that conventional algorithms often fail during optimization process and the most suitable methods in this case are evolutionary algorithms.

scholarly journals THE STATIC OPTIMIZATION TASK OF OPTIMAL DESIGN OF NONLINEAR ELECTRONIC SCHEME

2019 ◽  
pp. 109-115
Author(s):  
Didmanidze Ibraim ◽  
Donadze Mikheil
Keyword(s):  
Optimal Design ◽  
Optimality Criteria ◽  
Pareto Optimal Solutions ◽  
Optimal Solutions ◽  
Design Task ◽  
Optimization Task ◽  
Minimum Capacity ◽  
Optimal Values ◽  
The Given ◽  
Selection Of

The article deals with such an important selection of the elements of electronic scheme of the given configuration, when the certain requirements of technical task are satisfied and at the same time the selected optimality criteria reach the extreme value. The gives task has been solved by the method of one-criterion optimization, in particular, the method of center gravity. To formalize the given scheme we have compiled a mathematical model of optimization, which considers the requirements of technical task. The optimal design task of the presented electronic scheme was brought to the task of multi criteria optimization. The computational experiments have been resulted in the Pareto-optimal solutions, from which there was selected a compromise on that corresponds to the minimum capacity, required by the scheme. According to the optimal values of resistors, we have conducted a computerized analysis of the transient process of the given electronic scheme with the help of a computer program Electronics Workbench.

Optimal Design of a Six-Bar Linkage for an Anthropomorphic Three-Jointed Finger Mechanism

1992 ◽  
Author(s):  
Jichuan Zhang ◽  
Gongliang Guo ◽  
William A. Gruver
Keyword(s):  
Mathematical Model ◽  
Nonlinear Programming ◽  
Optimal Design ◽  
Transmission Efficiency ◽  
Degree Of Freedom ◽  
Optimal Parameters ◽  
Joint Friction ◽  
Robotic Devices ◽  
End Effectors ◽  
Human Finger

Abstract We treat the design of a three-jointed, anthropomorphic, finger mechanism for prostheses and robotic end-effectors. Based on the study of configurations for the human finger, we propose a six-bar linkage with one degree of freedom for the finger mechanism. A model of the fingertip displacement of the mechanism is derived by a vector analysis approach. We study the effects of joint friction on the transmission efficiency. By measuring the joint positions of a human finger, we develop a mathematical model of the pinching and holding configurations for the human finger. Optimal parameters for the finger mechanism are obtained by nonlinear programming based on motion posture, locus, transmission efficiency, and weight subject to geometric and bionic constraints. Simulations indicate that the mechanism is useful in a variety of prosthetic and robotic devices.

scholarly journals Resilient optimal design of multi-family buildings in future climate scenarios

2019 ◽  
Vol 111 ◽  
pp. 06006 ◽  
Author(s):  
Matteo Bilardo ◽  
Maria Ferrara ◽  
Enrico Fabrizio
Keyword(s):  
Climate Change ◽  
Optimal Design ◽  
Building Design ◽  
Building Envelope ◽  
Future Climate ◽  
Future Scenarios ◽  
Optimal Solutions ◽  
Climate Scenarios ◽  
Global Cost ◽  
The Cost

In Europe, the second recast of EPBD promotes long-term strategies to accelerate the path to nZEBs, fostering the cost-optimized building design already suggested in the EPBD first recast. Since the nZEB design is a complex optimization problem that is subjected to uncertainty in its boundary conditions (climate, technologies, market, ...), it is necessary to guarantee the resilience of the NZEB optimal design to possible variations of future scenarios, especially as regards the climate change. This work applies the new EdeSSOpt methodology (Energy Demand and Supply Simultaneous Optimization) developed by the Authors aiming at investigating the variation of the cost-optimized multi-family building design in different Italian future climate scenarios, therefore considering parameters related to the building envelope, energy systems and renewable energy sources. The method is implemented into the TRNSYS® (energy model), GenOpt (optimizer) and WeatherShift® (future climate scenario generator) tools. The resulting cost-optimal solutions in future scenarios are related to a lower global cost and a decreased total primary energy consumption. Beyond the future trends of such performance indexes, the fact that most of technical solutions associated with the optimal solutions have not changed with the studied climate scenarios, indicates a certain resilience of the optimal design variables facing climate change.

Iterative Fixture Layout and Clamping Force Optimization Using the Genetic Algorithm

2001 ◽  
Vol 124 (1) ◽  
pp. 119-125 ◽  
Author(s):  
Krishnakumar Kulankara ◽  
Srinath Satyanarayana ◽  
Shreyes N. Melkote
Keyword(s):  
Genetic Algorithm ◽  
Nonlinear Programming ◽  
Primary Objective ◽  
Fixture Design ◽  
Clamping Force ◽  
Optimal Solutions ◽  
Fixture Layout ◽  
Force Optimization ◽  
Nonlinear Programming Methods ◽  
Objective Being

Fixture design is a critical step in machining. An important aspect of fixture design is the optimization of the fixture, the primary objective being the minimization of workpiece deflection by suitably varying the layout of fixture elements and the clamping forces. Previous methods for fixture design optimization have treated fixture layout and clamping force optimization independently and/or used nonlinear programming methods that yield sub-optimal solutions. This paper deals with application of the genetic algorithm (GA) for fixture layout and clamping force optimization for a compliant workpiece. An iterative algorithm that minimizes the workpiece elastic deformation for the entire cutting process by alternatively varying the fixture layout and clamping force is proposed. It is shown via an example of milling fixture design that this algorithm yields a design that is superior to the result obtained from either fixture layout or clamping force optimization alone.

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