Data processing: structural design – modeling – simulation – and em – Simulating nonelectrical device or system – Mechanical
Reexamination Certificate
1999-09-07
2001-10-16
Teska, Kevin J. (Department: 2123)
Data processing: structural design, modeling, simulation, and em
Simulating nonelectrical device or system
Mechanical
C703S008000, C703S009000
Reexamination Certificate
active
06304835
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a simulation apparatus and the like and, more particularly, to a simulation apparatus which can efficiently model and simulate a system including complicated combinations of a plurality of elements or components like a power train of a vehicle, and the like.
2. Description of the Related Art
For the purpose of shortening the time required for product development, it is becoming increasingly important to perform estimation and confirmation of performance and functions, which are conventionally done by tests using samples, during the initial period of development.
Various kinds of performance of a vehicle appear as integrated characteristics of individual units such as an engine, gear box, and the like. Since these characteristics stretch across a plurality of different fields, different theoretical systems are combined and modeled by a unique method that meets the purpose of simulation. However, it is not efficient to fulfill simulations against many problems and to maintain and manage them.
To solve this problem, a modeling technique which is common to different fields and can easily integrate them is required.
The present inventors have proposed a technique for expressing each component by concepts called potential and flow variables using a system equation in Japanese Patent Application No. 7-250974 and the like, thereby expressing a unit built by a plurality of components as a matrix.
SUMMARY OF THE INVENTION
The present invention has been made as an extension of and based on the above proposal, and has as its object to provide a simulation apparatus which can simulate while easily coping with changes in component and model.
In order to achieve the above object, as proposed in claim
1
, a simulation apparatus for simulating, using a system model, dynamic performance of a target apparatus to be simulated including a driving source and a plurality of units for transmitting a driving force output from the driving source, said simulation apparatus comprising:
functional modeling means for representing each of the units included in the target apparatus by exchange of energy by dynamic performance of an individual unit and a parameter that determines the dynamic performance of the unit;
data storage means for storing static characteristic data of each unit; and
data modeling means for computing a parameter of each unit on the basis of static characteristic data for the unit read out from said data storage means.
According to claim
2
as a preferred aspect of the present invention, the parameter of each unit represents at least one of a mass, spring, and damper. In an embodiment to be described later, the mass is an inertial mass, the spring is rigidity, and the damper is a viscous coefficient.
According to claim
3
as a preferred aspect of the present invention, the functional modeling means represents the dynamic performance of each unit by a matrix.
According to claim
4
as a preferred aspect of the present invention, the apparatus further comprises further comprising means for integrating matrices representing dynamic performances of the individual units generated by said functional modeling means into a matrix representing the entire target apparatus.
According to claim
5
as a preferred aspect of the present invention, the dynamic performance of each unit is expressed by a state equation.
According to claim
6
as a preferred aspect of the present invention, the data modeling means converts static characteristic data read out from the data storage means into a parameter in accordance with a progressive state of a simulation of the unit.
According to claim
7
as a preferred aspect of the present invention, the individual units are represented as being coupled to each other via a potential variable that expresses a potential, and a flow variable that expresses a flow.
According to claim
8
as a preferred aspect of the present invention, the parameter includes a state variable of each unit, and a state change variable upon infinitesimal state transition. Since the state change is that in the infinitesimal state, even when each unit is nonlinear, accurate simulation can be done while assuring linearity.
According to claim
9
as a preferred aspect of the present invention, each unit performs a nonlinear operation.
According to claim
10
as a preferred aspect of the present invention, the apparatus further comprises a number of data modeling means equivalent to said data modeling means, said number being set in correspondence with types of units.
According to claim
11
as a preferred aspect of the present invention, the dynamic performance is expressed by a time in a discrete system, and the parameter of each unit is approximated to a zero-th order (constant) per unit time.
The object of the present invention is also achieved by a simulation apparatus of claim
12
.
Especially, according to the simulation apparatus of claim
13
, since data modeling is done for each unit, simulation precision and the degree of freedom in a control system can be improved.
The object of the present invention is also achieved by a simulation method of claim
14
.
REFERENCES:
patent: 5249151 (1993-09-01), Chang et al.
patent: 5431261 (1995-07-01), Olgac
patent: 5651341 (1997-07-01), Harada et al.
patent: 9-91334 (1997-04-01), None
IEEE, Crossley, P. R. et al. “A nonlinear engine model for drivetrain system development,” Control 1991, Control 1991, International Conference, pp. 921-925, vol. 2.
IEEE, Jung-ho Kim, et al. “Autotool, a PC-based object-oriented automotive powertrain simulation tool,” Intelligent Transportation System, Nov. 9-12, 1997, pp. 753-758.
Barsoum et al.; “Observation and simulation of a large signal mechanical vibrating system”; Comp. Methods in Appl. Mech. and Engineering; vol. 135; pp. 1-13, Aug. 1986.*
Lee: “Flexural vibration of an orthotropic rotating shaft moving over supports”; J. Sound and Vibration; vol. 179; pp. 347-357, Jan. 1995.*
Ellis et al.: “Two numerical issues in simulating constrained dynamics”; IEEE 1992 Int. Conf. Proc. Robotics and Automation; pp. 312-318, May 1992.*
Shigeki Hiramatsu, et al. Modeling of Power Train by Applying the Virtual Prototype Concept, 974, (Oct. 1997), cover pg., pp. 177-180, and end page (brief English Abstract on p. 177).
Arakawa Hiroyuki
Harada Yasuhiro
Hiramatsu Shigeki
Komori Satoshi
Sumida Shizuo
Jones Hugh
Mazda Motor Corporation
Teska Kevin J.
LandOfFree
Simulation system using model does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Simulation system using model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Simulation system using model will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608497