Networked Assembly of Mechatronic Linear Physical System Models

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Clark J. Radcliffe ◽  
Eliot Motato ◽  
Drew Reichenbach
Keyword(s):  
Physical System ◽  
Dynamic Models ◽  
External Input ◽  
Global Network ◽  
Analytical Models ◽  
Thermal Dynamics ◽  
Efficient System ◽  
Standard Format ◽  
System Models ◽  
Assembly Method

Engineering design is evolving into a global activity. Globally distributed design requires efficient global distribution of models of dynamic physical systems through computer networks. These models must describe the external input-output behavior of the electrical, mechanical, fluid, and thermal dynamics of engineering systems. An efficient system model assembly method is then required to assemble these component system models into a model of a yet higher-level dynamic system. Done recursively, these higher-level system models become possible components for yet higher-level analytical models composed of external model equations in the same standardized format as that of the lowest level components. Real-time, automated exchange, and assembly of engineering dynamic models over a global network requires four characteristics. The models exchanged must have a unique standard format so that they can be exchanged and assembled by an automated process. The exchange of model information must be executed in a single-query transmission to minimize network load. The models must describe only external behavior to protect internal model details. Finally, the assembly process must be recursive so that the transfer and assembly processes do not change with the level of the model exchanged or assembled. This paper will introduce the modular modeling method (MMM), a modeling strategy that satisfies these requirements. The MMM distributes and assembles linear dynamic physical system models with a dynamic matrix representation. Using the MMM method, dynamic models of complex assemblies can be built and distributed while hiding the topology and characteristics of their dynamic subassemblies.

Networked Assembly of Affine Physical System Models

2006 ◽  
Author(s):  
E. Motato ◽  
C. Radcliffe
Keyword(s):  
Physical System ◽  
Dynamic Models ◽  
Dynamic Stiffness ◽  
Global Strategy ◽  
Standard Format ◽  
Modular Modeling ◽  
Assembly Algorithm ◽  
System Models ◽  
Stiffness Matrices ◽  
External Behavior

Engineering design is evolving into a global strategy that distributes model information through computer networks. This strategy requires companies to provide dynamic models of supplied components. Component models must be assembled to obtain the product dynamic model. Four characteristics are needed. Specifically, models require a unique standard format, the exchange of model information must be executed in a single-query transmission, the models must describe only external behavior, and the assembly process must be recursive. The Modular Modeling Method (MMM) [1], is a model assembly algorithm that satisfies these requirements. The MMM algorithm assembles linear physical systems models with dynamic stiffness matrices. This paper will extend MMM to nonlinear affine behavior. In an affine system, deviations in the inputs and outputs exhibit a proportional relationship, but the outputs of the system are not zero at zero input [2]. The main reason for developing a process to assemble affine systems is the possibility of using this method to assemble general differentiable nonlinear physical system models performing around a constant operating point.

Networked Assembly of Affine Physical System Models

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
E. Motato ◽  
C. Radcliffe
Keyword(s):  
Engineering Design ◽  
Physical System ◽  
Standard Form ◽  
Operating Point ◽  
Assembly Process ◽  
System Models ◽  
Assembly Method ◽  
Affine System ◽  
Component Models ◽  
Assembly Constraints

Engineering design is evolving into a global strategy that distributes engineering effort to team members around the world. Because modern engineering design uses analytical models, model information must be distributed globally through computer networks. This strategy would be improved if component suppliers were able to efficiently provide dynamic models of supplied components. Furthermore, to use these component models, they must be efficiently assembled to obtain a dynamic model of a product using them. Four characteristics are needed to enable this distribution and assembly process. These characteristics are a unique standard model format, an exchange of model information through a single-query network transmission, external component models protecting proprietary internal design details, and, finally, a recursive assembly process. The modular model assembly method (MMAM) (Radcliffe et al., 2009, “Networked Assembly of Mechatronic Linear Physical System Models,” ASME J. Dyn. Syst., Meas., Control, 131, p. 021003) is a model assembly algorithm that satisfies these requirements. The MMAM algorithm assembles linear physical system models with dynamic stiffness matrices. In an affine system, deviations in the inputs and outputs exhibit a proportional relationship, but the outputs of the system are nonzero at zero input (Buck and Willcox, 1971, Calculus of Several Variables, Houghton Mifflin, Boston). One motivation for developing a process to assemble affine systems is the wide use of such models resulting from local linearization of general differentiable nonlinear physical system models about a nonzero, but constant, operating point. This paper provides the first general approach to the “operating point problem,” where the operating points of each individual component are solved as a function of the desired operating point of the model of an assembly of those components. The solution of this problem allows the assembly of linearized system models at any requested system operating point. This paper extends the MMAM to nonlinear affine system models. The MMAM uses internet agents to provide external models of components when requested by either users or other model agents. Assembly agents use the models provided by component agents to build an analytical model using models provided by component agents and assembly constraints within the assembly model agent. MMAM models are supplied in a standard form that allows an assembly agent to put together efficiently a model of the assembly that is also in the standard form. The process is recursive and facilitates hierarchical use of agents to efficiently build assemblies of assemblies to any level of complexity.

A Model Accuracy and Validation Algorithm

2002 ◽  
Author(s):  
Polat Sendur ◽  
Jeffrey L. Stein ◽  
Huei Peng ◽  
Loucas S. Louca
Keyword(s):  
Physical System ◽  
Dynamic Models ◽  
System Model ◽  
System Response ◽  
Model Accuracy ◽  
Physical Systems ◽  
System Models ◽  
Points Of Interest ◽  
Measured System

Dynamic models of physical systems with physically meaningful states and parameters have become increasingly important, for design, control and even procurement decisions. The successful use of models in these contexts requires that the models be of sufficient quality. However, while algorithms have been developed to help formulate and integrate physical system models, as well as to generate minimum complexity physical system models, algorithms to assess the “quality” of dynamic system models have not been produced. This is true even if the attributes of model are limited to accuracy and validity. The objective of this paper is to introduce a new methodology that systematically quantifies the accuracy of a predicted system response and determines the validity of the physical system model used to predict the system response. The accuracy and validity of the model are evaluated using statistical properties of measured system response. The new algorithm is called Accuracy & Validation Algorithm for Simulation (AVASIM), and is a time-domain perspective comparing the model’s time trajectories at user-defined points of interest as well as over the entire simulation horizon. To illustrate AVASIM, the quality of a handling model of a DaimlerChrysler Grand Cherokee is compared to the measurements obtained from that vehicle subjected to known steering inputs. Results demonstrate that the accuracy and validity of the Grand Cherokee model can be systematically assessed using the proposed methodology, and, thus, AVASIM appears to be a powerful tool for assessing the quality of system models.

Networked Assembly of Nonlinear Physical System Models

2007 ◽  
Author(s):  
Eliot Motato ◽  
Clark J. Radcliffe
Keyword(s):  
Dynamic Models ◽  
Transfer Functions ◽  
Nonlinear Behavior ◽  
Extensive Literature ◽  
Standard Format ◽  
Physical Systems ◽  
Volterra Models ◽  
Assembly Method ◽  
Common Location ◽  
Systems Models

Engineering design is evolving into a global strategy that distributes model information through computer networks. This strategy requires companies to provide dynamic models of supplied physical components. Component models are transmitted through the Internet to a common location and then assembled to obtain a product dynamic model. Internet connection permitting, real-time, automated assembly of models requires four characteristics. Specifically, physical models must have a unique standard format, the exchange of model information must be executed in a single-query transmission, the models must describe only external behavior, and the assembly process must be recursive. The Modular Modeling Method (MMM) is an energy based model distribution and assembly algorithm that satisfies these four requirements. The MMM distributes and assembles linear and affine physical systems models using dynamic matrices. Though the MMM procedure can be used for a large class of systems, the dynamic matrices cannot be used to represent nonlinear behavior. A more general nonlinear model representation is required. This work is an extension of the MMM algorithm to assemble physical systems models characterized by analytic nonlinearities. This is a more general procedure that uses Volterra transfer functions to represent nonlinear behavior. Any analytic nonlinear system can be represented through a Volterra model. The reason why we use Volterra models instead ODEs is because Volterra models are only in function of input and output variables. This characteristic facilitates their use in an energy based model assembly method such as the MMM procedure. A procedure to assemble standard Volterra models using conservation energy principle is described. Even though there are extensive literature about gluing models, these techniques do not have all the characteristics needed by the MMM procedure. Using the approach proposed here, complex model assemblies can be executed recursively while hiding the topology and characteristics of their structural model subassemblies.

scholarly journals VeriPhy: verified controller executables from verified cyber-physical system models

2018 ◽  
Vol 53 (4) ◽  
pp. 617-630 ◽  
Author(s):  
Brandon Bohrer ◽  
Yong Kiam Tan ◽  
Stefan Mitsch ◽  
Magnus O. Myreen ◽  
André Platzer
Keyword(s):  
Physical System ◽  
Cyber Physical System ◽  
System Models

New Higher-Order Models for Sandwich Plates with a Flexible Core and their Accuracy Assessment

2019 ◽  
Vol 19 (03) ◽  
pp. 1950024 ◽  
Author(s):  
Ali Tian ◽  
Renchuan Ye ◽  
Peng Ren ◽  
Pengming Jiang ◽  
Zengtao Chen ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Accuracy Assessment ◽  
Order Theory ◽  
Higher Order ◽  
Analytical Models ◽  
Core Material ◽  
Sandwich Plates ◽  
Higher Order Theory ◽  
Flexible Core

Two higher-order analytical models based on a new higher-order theory for sandwich plates with flexible cores are developed considering the effect of the core material density and skin-to-core-stiffness-ratio (SCSR). The main difference between the two models is the role of the flexible core in the dynamic response of sandwich plates with cores of different stiffnesses. Firstly, the governing equations of a simply supported sandwich plate with a flexible core are derived based on the two models, and the analytical solutions are determined by using Navier’s approach. Then, the free vibration, static, dynamic bending and stress field characteristics of the sandwich plates with different SCSRs are investigated. The results obtained by the proposed method are compared with other published results. In particular, an accuracy assessment of the present dynamic models is conducted for different SCSRs. Finally, conclusions on the applicability of the proposed method and other theories on sandwich plates with different SCSRs are drawn.

scholarly journals The Physical Basis of Analogies in Physical System Models

Mechatronics ◽  
2005 ◽  
pp. 8-1-8-10
Author(s):  
Neville Hogan ◽  
Peter Breedveld
Keyword(s):  
Physical System ◽  
Physical Basis ◽  
System Models
Sign in / Sign up

Export Citation Format

Share Document