How to change size of simscape multibody models
조회 수: 24 (최근 30일)
이전 댓글 표시
When I changed the size of the Stewart Platform model to 10 times the default size, the model fell apart and failed as the figure shows. What other model paprameters do I need to modify after changing the size?
The attachment is the original model.
Thank you for your help!
댓글 수: 3
Yifeng Tang
2024년 10월 4일
The model you uploaded seems to be the original one from Simscape Multibody documentation. Could you please let the community know what parameters you attempted to change and ran into error? Some screenshots and explanation will be helpful.
채택된 답변
Yifeng Tang
2024년 10월 4일
I just multiplied most of the dimensions in the subsystem mask by 10, and the model seems to assemble OK. See below. Are you able to reproduce this?
댓글 수: 5
Yifeng Tang
2024년 10월 8일 13:02
When the dimensions are now 1.5x of what it was, the control reference/target probably needs to be different as well. Did you scale that up? In this particular case, the dz reference needs to be scaled up. This seems to give me nearly identical looking results as before.
Then, you can start tuning the controller gain. When I tried to scale by 2.5, the original control gains are no longer sufficient. Using reasonably higher values will stablize the platform. Repeat the steps and I was able to bring it to 10x larger. I attached the model and the script with scale values and sample control gains. You can uncomment part of the param_scale.mlx script to see the progression towards 10x larger.
% scale = 1.0;
% Kp = 300;
% Ki = 20;
% Kd = 5;
% scale = 1.5;
% Kp = 300;
% Ki = 20;
% Kd = 5;
% scale = 2.5;
% Kp = 1000;
% Ki = 100;
% Kd = 20;
% scale = 5.0;
% Kp = 4000;
% Ki = 400;
% Kd = 100;
scale = 10;
Kp = 20000;
Ki = 2000;
Kd = 500;
BTW: crazily high control gains almost always lead to unstable system. Take small steps and happy modeling.
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Simscape Multibody에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!