A Convex Approach Solving Simultaneous Mechanical Structure and Control System Design Problems With Multiple Closed-loop Performance Specifications

2004 ◽  
Vol 127 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Ke Fu ◽  
James K. Mills
Keyword(s):  
System Design ◽  
Transfer Matrix ◽  
Closed Loop ◽  
Mechanical Design ◽  
Design Method ◽  
Convex Combination ◽  
Integrated Design ◽  
Design Parameters ◽  
Performance Specifications ◽  
And Control

In this paper, a new integrated design method, referred to as the extended multiple simultaneous specification (EMSS) method, is proposed to solve simultaneous mechanical structure and control system design problems in which a set of n multiple closed-loop performance specifications must be simultaneously satisfied. To utilize this approach, all closed-loop performance specifications considered must have the property that they are convex with respect to the closed-loop system transfer matrix. With the proposed approach, a simply implemented two-stage design approach is used to determine a set of open-loop mechanical system design parameters and a closed-loop controller which simultaneously satisfies a set of n closed-loop performance specifications. In the first stage, for each closed-loop performance specification, one “sample system,” i.e., the closed-loop system with one set of mechanical design parameters with a closed-loop controller chosen from the set of all linear controllers, is determined by trial and error, such that the specification is satisfied. In the second stage, the transfer matrix of the final system, which satisfies all n performance specifications, is determined through the convex combination of the transfer matrices of n sample systems. A linear programming problem is solved to give the combination vector for this convex combination. With the closed-loop transfer matrix given, the mechanical design parameters, the closed-loop controller structure and its gains, are solved algebraically. In this paper, we establish conditions for the existence of a solution to this integrated design problem as well as prove that the EMSS approach retains the stability properties of the sample systems. Experimental results of the EMSS method, carried out on a linear positioning system are given, verifying the effectiveness of the proposed method. We note that the proposed EMSS method works well when the number of design parameters to be determined is small. Further, the proposed EMSS method also has some utility as a controller design method, to determine a closed-loop controller that satisfies a set of n multiple closed-loop performance specifications, given a fixed mechanical system structure.

A New Iterative Identification and Control Method of Closed-Loop Power System Based on Ambient Signals

2015 ◽  
Vol 798 ◽  
pp. 261-265
Author(s):  
Miao Yu ◽  
Chao Lu
Keyword(s):  
Power System ◽  
Closed Loop ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Stability Margin ◽  
System Stability ◽  
Iterative Identification ◽  
Effective Performance ◽  
And Control

Identification and control are important problems of power system based on ambient signals. In order to avoid the model error influence of the controller design, a new iterative identification and control method is proposed in this paper. This method can solve model set and controller design of closed-loop power system. First, an uncertain model of power system is established. Then, according to the stability margin of power system, stability theorem is put forward. And then controller design method and the whole algorithm procedure are given. Simulation results show the effective performance of the proposed method based on the four-machine-two-region system.

Enabling Variation of Manufacturing Process Parameters in Early Stages of Product Development

2006 ◽  
Author(s):  
Patrik Boart ◽  
Ola Isaksson
Keyword(s):  
Product Development ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Mechanical Design ◽  
Design Method ◽  
Local Level ◽  
Simulation Models ◽  
Design Parameters ◽  
Functional Requirements ◽  
Early Stages

Currently, mechanical design of aero engine structural components is defined by dimensioning of Design Parameters (DP's) to meet Functional Requirements (FR's). FR's are typically loads, geometrical interfaces and other boundary conditions. Parameters from downstream processes are seldom actually seen as DP's. This paper proposes that downstream process parameters are treated as DP's which calls for engineering methods that can define and evaluate these extended set of DP's. Using the proposed approach manufacturing process alternatives can be used as DP's in early stages of product development. Both the capability to quantitatively assess impact of varying manufacturing DP's, and the availability of these design methods are needed to succeed as an early phase design method. One bottleneck is the preparation time to define and generate these advanced simulation models. This paper presents how these manufacturing process simulations can be made available by automating the weld simulation preparation stages of the engineering work. The approach is based on a modular approach where the methods are defined with knowledge based engineering techniques-operating close to the CAD system. Each method can be reused and used independently of each other and adopted to new geometries. A key advantage is the extended applicability to new products, which comes with a new set of DP's. On a local level the lead time to generate such manufacturing simulation models is reduced with more than 99% allowing manufacturing process alternatives to be used as DP's in early stages of product development.

Vector field path-following control for a small unmanned ground vehicle with Kalman filter estimation

2020 ◽  
pp. 095440542097734
Author(s):  
Yun-Ping Sun ◽  
Yen-Chu Liang
Keyword(s):  
Kalman Filter ◽  
Vector Field ◽  
Design Method ◽  
Path Following ◽  
Labor Cost ◽  
Design Parameters ◽  
Ground Vehicles ◽  
Level Control ◽  
Path Following Control ◽  
And Control

Industry 4.0 accelerates the growth of unmanned technology that reduces the labor cost and creates high automation in manufacturing system. The automated guided vehicle which is capable of transferring materials or executing tasks without human intervention becomes a necessary system for modern unmanned factories. The study explores the guidance and control design to accomplish the common task of path-following control for unmanned ground vehicles (UGV). A complete design method is presented that includes the lateral-directional autopilot, the vector field guidance for path-following, and multi-sensor fusion. The lateral-directional autopilot produces the low-level control action, the higher level guidance indicates the course direction of UGV at every spatial point based on the lateral path error, and the accurate UGV position relies on the estimate obtained by dynamically fusing sensors with extended Kalman filter. The design parameters in every stage are analyzed theoretically first and then fine-tuned in practice. The process is clearly described in this study, and the field test results are discussed in details to verify the performance of the proposed method and demonstrate the superiority over others.

Wheel-Based Stair Climbing Robot with Hopping Mechanism – Demonstration of Continuous Stair Climbing Using Vibration –

2008 ◽  
Vol 20 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Yuji Asai ◽  
◽  
Yasuhiro Chiba ◽  
Keisuke Sakaguchi ◽  
Naoki Bushida ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Mechanical Design ◽  
Stair Climbing ◽  
Design Parameters ◽  
Mass Ratio ◽  
Climbing Robot ◽  
Soft Landing ◽  
Hopping Mechanism ◽  
And Control ◽  
Two Bodies

We propose a simple hopping mechanism using vibration of a two-degrees-of-freedom (2-DOF) system for a fast stair-climbing robot. The robot, consisting of two bodies connected by springs and a wire, hops by releasing energy stored in springs and travels quickly using wheels mounted on its lower body. The trajectories of bodies during hopping change based on mechanical design parameters such as reduced mass of the two bodies, the mass ratio between the upper and lower bodies, and spring constant, and control parameters such as initial contraction of the spring and wire tension. This property allows the robot to quickly and economically climb stairs and land softly without complex control. In this paper, we propose a mathematical model of the robot and investigate required tread length for continuous hopping to climb a flight of stairs. Furthermore, we demonstrate fast stair-climbing and soft landing for a flight of stairs in experiments.

On the Coupling of Inverse Design and Optimization Techniques for Turbomachinery Blade Design

2006 ◽  
Author(s):  
Duccio Bonaiuti ◽  
Mehrdad Zangeneh
Keyword(s):  
Mechanical Design ◽  
Design Method ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Optimization Techniques ◽  
Operating Conditions ◽  
Inverse Design ◽  
Design Parameters ◽  
Optimization Strategy ◽  
Design And Optimization

Optimization strategies have been used in recent years for the aerodynamic and mechanical design of turbomachine components. One crucial aspect in the use of such methodologies is the choice of the geometrical parameterization, which determines the complexity of the objective function to be optimized. In the present paper, an optimization strategy for the aerodynamic design of turbomachines is presented, where the blade parameterization is based on the use of a three-dimensional inverse design method. The blade geometry is described by means of aerodynamic parameters, like the blade loading, which are closely related to the aerodynamic performance to be optimized, thus leading to a simple shape of the optimization function. On the basis of this consideration, it is possible to use simple approximation functions for describing the correlations between the input design parameters and the performance ones. The Response Surface Methodology coupled with the Design of Experiments (DOE) technique was used for this purpose. CFD analyses were run to evaluate the configurations required by the DOE to generate the database. Optimization algorithms were then applied to the approximated functions in order to determine the optimal configuration or the set of optimal ones (Pareto front). The method was applied for the aerodynamic redesign of two different turbomachine components: a centrifugal compressor stage and a single-stage axial compressor. In both cases, both design and off-design operating conditions were analyzed and optimized.

scholarly journals Dynamic analysis of two-link flexible manipulator considering the link length ratio and the payload

2017 ◽  
Vol 39 (4) ◽  
pp. 303-313
Author(s):  
Duong Xuan Bien ◽  
Chu Anh My ◽  
Phan Bui Khoi
Keyword(s):  
Mechanical Design ◽  
Flexible Manipulator ◽  
Length Ratio ◽  
Elastic Displacement ◽  
Design Parameters ◽  
Nonlinear Dynamic Model ◽  
Link Length ◽  
Modeling And Analysis ◽  
Robot Systems ◽  
And Control

Dynamic modeling and analysis of flexible manipulators play an essential role in optimizing mechanical design parameters and control law of real robot systems. In this paper, a nonlinear dynamic model of a manipulator is formulated based on the Finite Element Method. To analyze the dynamic behavior effectively, a numerical simulation scheme is proposed by taking full advantages of MATLAB and SIMULINK toolboxes. In this manner, the effect of varying payload and link length ratio of the manipulator to its elastic displacement is dynamically taken into account. The simulation results show that the payload and length link ratio have significant influences on the elastic displacements of the system. In particular, a proper spectrum of the link length ratio, in which the flexural displacement of the end point of the manipulator is smallest, is demonstrated. To this end, the proposed methodology could be used further to select optimal geometric parameters for the links of new robot designs.

Robust MDSDO for Co-Design of Stochastic Dynamic Systems

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Saeed Azad ◽  
Michael J. Alexander-Ramos
Keyword(s):  
Dynamic System ◽  
Design Optimization ◽  
System Design ◽  
Design Problem ◽  
Integrated Design ◽  
Problem Formulation ◽  
Robust Design Optimization ◽  
Design Problems ◽  
Embodiment Design ◽  
And Control

Abstract Optimization of dynamic engineering systems generally requires problem formulations that account for the coupling between embodiment design and control system design simultaneously. Such formulations are commonly known as combined optimal design and control (co-design) problems, and their application to deterministic systems is well established in the literature through a variety of methods. However, an issue that has not been addressed in the co-design literature is the impact of the inherent uncertainties within a dynamic system on its integrated design solution. Accounting for these uncertainties transforms the standard, deterministic co-design problem into a stochastic one, thus requiring appropriate stochastic optimization approaches for its solution. This paper serves as the starting point for research on stochastic co-design problems by proposing and solving a novel problem formulation based on robust design optimization (RDO) principles. Specifically, a co-design method known as multidisciplinary dynamic system design optimization (MDSDO) is used as the basis for an RDO problem formulation and implementation. The robust objective and inequality constraints are computed per usual as functions of their first-order-approximated means and variances, whereas analysis-based equality constraints are evaluated deterministically at the means of the random decision variables. The proposed stochastic co-design problem formulation is then implemented for two case studies, with the results indicating the importance of the robust approach on the integrated design solutions and performance measures.

Integrated Design and Control of a Biped Robot

2005 ◽  
Author(s):  
James P. Schmiedeler ◽  
Eric R. Westervelt ◽  
Adam R. Dunki-Jacobs
Keyword(s):  
Performance Enhancement ◽  
Mechanical Design ◽  
Integrated Design ◽  
Biped Robot ◽  
Systematic Design ◽  
Biped Robots ◽  
Control Approach ◽  
Design Changes ◽  
And Performance ◽  
And Control

This paper introduces a methodology for the integration of mechanical and control system design of planar biped robots. The control approach is a procedure for the systematic design, analysis, and performance enhancement of controllers that induce provably stable dynamic walking in planar bipeds. Iterative application of this procedure with variations in the mechanical parameters of the biped model enables a designer to drive design changes based upon analytical metrics of stability and efficiency. The outcomes are a dynamically-informed mechanical design and controllers that maximally exploit the unforced dynamics of that design. This methodology has been applied to the design and construction of the prototype biped BIRT (BIped Robot with Three legs). BIRT is a planar biped whose two outside legs are slaved by means of control to act together. The paper provides a detailed description of BIRT’s mechanical system.

Simultaneous Structural and Control Design Using Constraint Functions

1988 ◽  
Vol 110 (1) ◽  
pp. 65-72 ◽  
Author(s):  
J. M. Starkey ◽  
P. M. Kelecy
Keyword(s):  
Control System ◽  
System Dynamics ◽  
Structural Design ◽  
Closed Loop ◽  
Control Design ◽  
Pole Placement ◽  
Design Parameters ◽  
Weighted Sum ◽  
Design Technique ◽  
And Control

A design technique is presented which modifies system dynamics by simultaneously considering control system gains and structural design parameters. Constraint functions are devised that become smaller as (1) structural design parameters and feedback gains become smaller, and (2) closed-loop eigenvalues migrate toward more desirable regions. By minimizing a weighted sum of these functions, the interaction between design performance and design parameters can be explored. Examples are given that show the effects of the weighting parameters, and the potential advantages of this technique over traditional pole placement techniques.

Optimal Design and Fabrication of “CEDRA” Rescue Robot Using Genetic Algorithm

2004 ◽  
Author(s):  
A. Meghdari ◽  
H. N. Pishkenari ◽  
A. L. Gaskarimahalle ◽  
S. H. Mahboobi ◽  
R. Karimi
Keyword(s):  
Genetic Algorithm ◽  
Mechanical Design ◽  
Design Parameters ◽  
Robot Design ◽  
Preliminary Step ◽  
Laboratory Environment ◽  
Rescue Robot ◽  
Optimum Parameters ◽  
And Control ◽  
Clean Laboratory

This article presents an overview of the mechanical design features, fabrication and control of a Rescue Robot (CEDRA) for operation in unstructured environments. As a preliminary step, the essential characteristics of a robot in damaged and unstable situations have been established. According to these features and kinematical equations of the robot, design parameters are optimized by means of Genetic Algorithm. Optimum parameters are then utilized in construction. Upon fabrication, this unit has been tested in clean laboratory environment, as well as, ill-conditioned arenas similar to earthquake zones. The obtained results have been satisfactory in all aspects, and improvements are currently underway to enhance capabilities of the rescue robot unit for various applications.

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