Pressure problems when controlling a double acting actuator (IL) in Simscape

17 次查看（过去 30 天）
Sandro G
Sandro G 2024-2-1
评论： Flávio Luiz 2024-5-21
Hello, I am currently working on a simple hydraulic project using isothermal liquid components. What I`m essentially trying to do is to replicate a real hydraulic cylinder in Simscape and measure the maximum force it delivers. I put in the cylinder dimensions and tried to simulate. At a pressure of 210 bar a force of around 26kN are expected. My simulation shows however, that the force is only about 24kN. When looking at the pressure of the individual components I realised that the valve seems to be the troublemaker. The input pressure of 210bar drops to 202 bar at the connection P-A. Furthermore the pressure at B is not equal to the atmospheric pressure at T. When I looked at the valve characteristics plot I realised that at the valve position s=2 not only P-A and B-T are open, but also P-B to some extend. This would explain why the cylinder only delivers 24KN instead of 26KN.
To get the desired force I tried to change the parameters within the valve. For example I tried to change the spool travel distance so that P-A and P-B are not open at the same time. I also tried to change the discharge coefficient, to decrease the pressure drop between P-A. Doing so however, always resulted in the following error message:
An error occurred while running the simulation and the simulation was terminated
Caused by:
['Pruefmaschinenzylinder/Prüfmaschinenzylinder/Solver Configuration']: At time 0.118000, one or more assertions are triggered.
Pressure of liquid volume must be greater than or equal to Minimum valid pressure. The assertion comes from:
Block path: Pruefmaschinenzylinder/Prüfmaschinenzylinder/Double-Acting Actuator (IL)1
Apparently the pressure delivered by the pump is not big enough to move the cylinder properly.
My question now is: What makes this system so unstable? Why does changing the spool travel distance of the valve result in this error message? Is my system missing a component, or is there something else to it? I have attached the simscape file.
I would really appreciate any help.

请先登录，再回答此问题。

采纳的回答

Sandro G
Sandro G 2024-2-20
I solved this problem by replacing the ideal pressure source with a fixed displacement pump, that is able to provide the system with the needed pressure and volumetric flow rate.

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Upgrading Hydraulic Models to Use Isothermal Liquid Blocks 的更多信息

标签

产品


版本

R2023a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by