Wheel diameter and wheel track
Somehow it is so obvious how to measure wheel diameter and wheel track that I could not find any information regarding it. Could somebody please provide a link or a sketch on how to precisely measure the distance between the left and right wheel on a 2wd and the distance between the front and rear wheels on a 4wd base as well as wheel diameter?
Thank you
Asked by arminf82 on 2019-09-11 05:39:50 UTC
Answers
The right answer I was looking for was provided by @Choco93:
Distance between left and right wheel also called wheel separation distance is taken from centre of one wheel to the centre of other wheel. Same goes for rear and front wheel, distance between points of both wheels that touch the ground.
Thank you.
Asked by arminf82 on 2019-09-17 09:37:35 UTC
Comments
Can you describe the problem you're having? Are you measuring a CAD model or an actual robot? Most commercial hardware will have this information published in its specification. If it's an actual rover you should be able to get fairly accurate measurements using a tape measure.
Asked by PeteBlackerThe3rd on 2019-09-11 06:22:37 UTC
Perhaps the question of the OP is more: how are those distances and diameters defined exactly? As in: between which and which points should they be measured or determined?
Asked by gvdhoorn on 2019-09-11 07:16:01 UTC
Distance between left and right wheel also called wheel separation distance is taken from centre of one wheel to the centre of other wheel. Same goes for rear and front wheel, distance between points of both wheels that touch the ground (I don't think I have seen this one being used anywhere).
If you maybe tell us what you are trying to do we can help better.
Asked by Choco93 on 2019-09-11 08:53:46 UTC
Yes, @gvdhoom was right. I simply wanted to know the exact points between I have to take the measurement on my real robot. I build a custom robot with random spare parts lying around using linorobot software and simply wanted to make sure that I measure the right values. @Choco93: What do you mean by "I don't think I have seen this one being used anywhere"? At the moment I use 2 wheels and one caster wheel but wanted to switch to 4wd (no steering) for more outdoorability.
Asked by arminf82 on 2019-09-11 12:06:42 UTC
Please note that you can not measure the wheelbase with a rule for use with odometry for a 4wd. I tried to explain that here (but not sure how good/bad to understand that is). The usual approach is to rotate the robot 360° and to calculate the wheelbase from the odometry values. Problem is that it varies from surface to surface, you better get an IMU.
Asked by Humpelstilzchen on 2019-09-11 13:22:23 UTC
Thanks, at the moment I have an MPU6050. I'll give it a try with two more wheels.
Asked by arminf82 on 2019-09-11 14:04:35 UTC
I meant I haven't seen it being used in formulas, but the distances will be as I mentioned.
Asked by Choco93 on 2019-09-11 14:05:42 UTC