System dynamics _ Final term project Report

소개

성균관대학교 대학원 과정중
구자춘 교수님이 강의하시는 시스템 동역학 (system dynamics) 과목의
Final term project 의 Report 입니다.

내용은 긴 파이프로 연결되어 있는 드릴 비트를 회전시킬 때,
파이프와 벽면의 마찰과 파이프의 inertia, 파이프의 twist등을 고려했을때
시스템을 모델링하고 응답을 확인하는데 있습니다.

목차

SYSTEM DYNAMICS
1. Develop a complete bond graph model.
2. List the constitutive relations for all elements in your model.
3. Develop a set of state equations.
4. Identify the matrices A, B, C, D
5. Get a time domain simulation
6. Get a frequency response.

본문내용

SYSTEM DYNAMICS
Final Term Project Spring 2012

Refer to the Figure 1 showing a schematics of a simplified oil drilling system. The top of the drill stem is turned with a diesel engine which can be assumed a ow source (t). The drill stem is an annular steel shaft 1Km long with an inner diameter 10cm and outer diameter 12cm. In order to obtain the required weight on drill bit, a drill collar is placed on top of the bit. The collar is an annular steel pipe 25m in length with a 5cm inner diameter and a 15cm outer diameter. The drill has an effective diameter of 25cm.

(Note: Normally models presented by each student could rarely be identical due to the nature of modeling. especially in DOF, in friction model, and shape of model matrices. A simple copy of others` work may result in fail for this course. No tolerance on this!!! )

<중 략>

clc,clear;

N=3; % number of discretization
W1=20; % input velocity
T=0.8*0.06*500*2*pi*0.06*1000/N; % long shaft friction
Tr=353.429+11632.3; % collar friction + bit friction
J=82.74/N; % long shaft`s mass momentum of inertia
Jr=9.6334; % collar`s mass momentum of inertia
K=1686.41*N/2; % long shaft`s stiffness as torsion spring

A=zeros(2*N); % define A mat

A(1,N+1)=-1;
A(2*N,N)=K/Jr;

% insert repeated value to A matrix.
for indx=1:N-1
A(indx+1,N+indx)=1;
A(indx+1,N+indx+1)=-1;
A(N+indx,indx)=K/J;
A(N+indx,indx+1)=-K/J;
end

참고자료

· System Dynamics(Modeling And Simulation of Mechatronic Systems)
· Donald L. Margolis, Dean Karnopp, Ronald C. Rosenberg 저 |John Wiley & Sons Inc|2005.12.14