Hi Osman, Sorry for the very late reply.
My suspicion is that you have the wrong suspension/steering geometry. Note that, for an all-wheel steering vehicle, you can not simply copy the geometry of the front axle and steering mechanism from a traditional front steering vehicle and place it on the rear axle. You’ll need to get data from an actual all-wheel steering vehicle and model that. --Radu From: [email protected] <[email protected]> On Behalf Of osman cankurtaran Sent: Friday, July 4, 2025 2:02 PM To: ProjectChrono <[email protected]> Subject: [chrono] Re: Rear Wheel Rotation Error under Full-Steer in 8×8 Wheeled Vehicle Does anyone have any ideas? Even a small suggestion would be a great help to me. On Friday, June 27, 2025 at 8:28:42 AM UTC+3 osman cankurtaran wrote: I’m simulating an 8×8 vehicle with all-wheel steering in PyChrono. Everything behaves correctly when driving straight or at moderate steering angles (up to ~15°), but as soon as I apply full lock steering and drive forward, the very last (eighth) wheel exhibits a completely unrealistic rotation—as if its joint has “snapped.” Details: * Vehicle: 8×8, all-wheel steer enabled on every axle * Suspension: DoubleWishboneReplica on all four axles * Steering: Pitman-arm linkage on front axles, mirrored geometry on rear axles * Observed Behavior: * OK: Straight-line driving; steering up to ±15° * Fail: Full-lock steering (~±30°): rearmost wheel suddenly spins/tilts uncontrollably What I’ve Checked: 1. Attachment points and body names in the rear suspension JSON 2. Steering index and Pitman-arm link geometry for the rear axles 3. No error messages—simulation continues but the wheel motion is clearly wrong Questions: 1. What common mistakes cause a single wheel joint to behave “broken” only at extreme steering angles? 2. Are there known pitfalls when mirroring Pitman-arm steering linkages on rear axles? 3. Which debugging steps or visualization techniques work best for isolating axle-specific joint misconfigurations in PyChrono? Any advice or pointers would be greatly appreciated! -- 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]<mailto:[email protected]>. To view this discussion visit https://groups.google.com/d/msgid/projectchrono/48e7be1e-f589-48be-9987-b8c9e47d9e0fn%40googlegroups.com<https://urldefense.com/v3/__https:/groups.google.com/d/msgid/projectchrono/48e7be1e-f589-48be-9987-b8c9e47d9e0fn*40googlegroups.com?utm_medium=email&utm_source=footer__;JQ!!Mak6IKo!Nu13GP8arVNXE013-gcEbpnfP88gKwUm-TF71ePx93Z4rz-Xe2BkpndkRzIMDRiuyoJeBKKHrXfg6u1Q9GwfPlWsog$>. -- 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/CH3PPF46CDC21850A0A94A72A3F9CC1D03FA72DA%40CH3PPF46CDC2185.namprd06.prod.outlook.com.
