You don’t say anything about the tire model and terrain model you use. You cannot leave that out when doing such a back of the envelope calculation. You are assuming rolling without slip. First thing I would do is monitor the longitudinal slip at each wheel.
--Radu From: 'Meninstick' via ProjectChrono <[email protected]> Sent: Thursday, October 12, 2023 12:29 PM To: ProjectChrono <[email protected]> Subject: [chrono] Low acceleration Hello, I am currently modelling a simple vehicle, using the simpleEngine, AutomaticTransmissionSimpleMap and SimpleDriveline templates. Using 40Nm tourque on the engine and a 1:1 gear ratio, 0.5 Front [cid:[email protected]] Torque Fraction I get only about half the excpected acceleration. Are there any losses I havn't acounted for? For the acceleration test the throttle is set to 1, resulting in instant maximum tourque. The graph shows an acceleration from 0 to 1.03 m/s in 0.57s. Resulting in a = 1.807 m/s^2. Using the effective mass (taking wheel inertia into account), F = m*a results in F = 125N, 31.5N per wheel. With a tire radius of 0.165m I get 5.2N/wheel. Not the 10N/ wheel expected. Total mass: 66.3kg Tire radius: 0.165m Tire inertia: [0.015, 0.019, 0.015], Wheel inertia: [0.002, 0.004, 0.002] Effective mass: 69.8kg Any answers are appreciated :) tldr: Are there any losses between SimpleEngine, AutomaticTransmissionSimpleMap, SimpleDriveline and the ground? -- 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 on the web visit https://groups.google.com/d/msgid/projectchrono/1dc252e8-ef9e-4f00-bd5a-12c793c22de9n%40googlegroups.com<https://groups.google.com/d/msgid/projectchrono/1dc252e8-ef9e-4f00-bd5a-12c793c22de9n%40googlegroups.com?utm_medium=email&utm_source=footer>. -- 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 on the web visit https://groups.google.com/d/msgid/projectchrono/PH0PR06MB8237BEC922F1EE0861221872A7D0A%40PH0PR06MB8237.namprd06.prod.outlook.com.
