Thanks Radu, that makes sense. I appreciate the code updates and the explanation.
Dan On Wednesday, November 26, 2025 at 8:10:09 AM UTC-6 Radu Serban wrote: > Hi Dan, > > > > This is because we do not have an efficient, robust, and general method > for extracting terrain height and normal from CRM simulations. > ChTire::CalculateKinematics relies on that information in order to > calculate a tire frame and then the various quantities (such longitudinal > slip and slip angle). By the way, the same is true for DEM terrains. > > > > These tire kinematic values must be obtained outside of the tire code, > using additional information about the concrete terrain type and geometry. > Having said that, this type of additional information is actually available > in the setup of a ChTireTestRig (where we know the terrain is always flat > and horizontal, regardless of its type). I pushed changes to ChTireTestRig > to calculate the longitudinal slip, slip angle, and camber angle. Look at > how I modified the two demos (including the one for CRM terrain) to extract > and plot these values: use the functions on the rig object and not those on > the tire. > > > > --Radu > > > > *From:* [email protected] <[email protected]> *On > Behalf Of *Dan Fenn > *Sent:* Wednesday, November 26, 2025 1:51 AM > *To:* ProjectChrono <[email protected]> > *Subject:* [chrono] Longitudinal slip not being updated in > demo_VEH_TireTestRig_CRM > > > > I'm putting together a simulation based on the demo_VEH_TireTestRig_CRM > demo, and I'm trying to log the slip. I've noticed that even when I run the > unmodified demo that ships with Chrono, the longitudinal slip isn't being > calculated. The plots are all 0s. It seems that `CalculateKinematics()` is > potentially not being called, but I'm not certain of that. > > > > Any thoughts/help? > > > > Dan > > -- > You received this message because you are subscribed to the Google Groups > "ProjectChrono" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/projectchrono/4bab36cb-174f-48d3-89d7-1b25150c02c4n%40googlegroups.com > > <https://urldefense.com/v3/__https:/groups.google.com/d/msgid/projectchrono/4bab36cb-174f-48d3-89d7-1b25150c02c4n*40googlegroups.com?utm_medium=email&utm_source=footer__;JQ!!Mak6IKo!Lpj0cxMPjm7AI3OHAHREUmH2UlrHbNl3FvNz_6xQ_-QRqYK2oyK-qTtgJuX3pX9NdA41lxz0P3xPRTg7V0wxMGE$> > . > -- You received this message because you are subscribed to the Google Groups "ProjectChrono" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/projectchrono/8c2ba505-0df7-4a0e-9426-25ea24ed3350n%40googlegroups.com.
