How to build a custom expression in the Expression Builder

draucis

Hello,

I am using a two-wheeler model in motion view to conducting a stability analysis and in the event editor I have chosen a straight line as the path, the analysis mode is set to general force, under this I want to apply a torque-acting on the steering axis and I want to see the effect on the z-axis of the frame. The torque being applied is sinusoidal with the equation y(t)= A sin(2Pi*f*t). Now I want to give this expression as a value to Rot properties in the Ty tab. But it says error evaluation, where am I going wrong? Do I have to define a custom function and if yes how.  I have attached the expected graph which can give you an idea of what I want.  

Regards 

Draucis

AnanthK

Hey there Draucis - you can't specify steering torque and combine that with choosing straight line as the path, because the latter constrains the steering head to have a fixed angle. I would suggest using sinusoidal steer event instead, from looking at your expected graph. All our 2-wheeler vehicle dynamic events currently only support specifying lean angle as an input, from which a steering torque results. 

 

AnanthK

Hey there Draucis - you can't specify steering torque and combine that with choosing straight line as the path, because the latter constrains the steering head to have a fixed angle. I would suggest using sinusoidal steer event instead, from looking at your expected graph. All our 2-wheeler vehicle dynamic events currently only support specifying lean angle as an input, from which a steering torque results. 

 

draucis

Ananth Kamath Kota_20697 said:

Hey there Draucis - you can't specify steering torque and combine that with choosing straight line as the path, because the latter constrains the steering head to have a fixed angle. I would suggest using sinusoidal steer event instead, from looking at your expected graph. All our 2-wheeler vehicle dynamic events currently only support specifying lean angle as an input, from which a steering torque results. 

 

Hi Ananth,

thanks for your reply I am getting the graph result to some extent. But I still have a doubt about the stability analysis, can I not choose a different path profile, and then in the analysis mode can I not edit the torque equation in the Rot. properties? because I would want to be able to measure the torque frequency as well as the output yaw rate frequency. and the research paper I am referring to says that the analysis data was processed in motion view. I have attached a snippet for reference.

1.jpg is for the motionview stability analysis reference

2.png is for the research paper reference 

Thanks Again for your help