How to set initial position of prismatic joint

"I'm currently controlling a linear actuator model in Simulink, and I want to set an initial position offset of 0.5 meters in the base coordinate system for the prismatic joint using the 'specify position target' option, so that it starts 0.5 meters higher. Is this the correct way to set it? Or is there another way to set the initial position? If so, could you please let me know?"

Answer 1

[Shivam Gothi]

Hi,

In Simulink, the joints can start simulation from different states. For example, the prismatic joint of your model can start at any value from its lower limit to the upper limit. As a result, during model assembly, you can set the initial state of the actuator by specifying “state targets” in the “prismatic joint block” dialog boxes.

Follow the below given steps :

• Open “Block parameters” for prismatic joint.
• Then look for “Z Prismatic Primitive (Pz)” property. Expand the corresponding drop down menu.
• Then find the property “State Targets” and again expand the corresponding drop down menu.
• Select the check box “Specify Position target”
• Two fields will appear:

1. Priority: a ranking that determines which of two state targets to satisfy if they prove to be mutually incompatible. You can set the priority level to Low or High.
2. Value: Initial state from which simulation starts.

• Enter value of 0.5 and set the units to meter “m”.

This will set the initial actuator position at 0.5m.

Please Refer to the following documents for more information:

https://in.mathworks.com/help/releases/R2023b/sm/ug/assembling-multibody-systems.html#busaiy6-1

https://www.mathworks.com/help/releases/R2023b/sm/ref/prismaticjoint.html

You could also refer to this post on MATLAB answer community for more information:

https://www.mathworks.com/matlabcentral/answers/2123116-limiting-slider-part-motion-distance-of-the-prismatic-joint-in-simulink

I hope this helps !