glnc222 wrote:What if you ran each wheel separately over USB and compared stats for each to see if there is binding? The rpm cannot be set apparently, but a speed and acceleration, and there's a GetMotors with all sorts of detail on control.
The figure above shows the data from the experiments suggested by glnc222. It appears the new motors are functionally improved. A complete description is below.
The XV12 that suffered the "Right Wheel Stuck" was running software version 3.0 and the Remanufactured XV12 was running software version 2.6. Each XV12 was connected to a Lenovo windows XP laptop via USB and commands were issued using PuTTy. The command "SetMotor 3000 3000 100" was used to achieve a slow speed over 3 meters. The command "SetMotor 3000 3000 300" was used to achieve a fast speed over 3 meters. During each run, the GetMotor command was issued 3-times and the results were averaged. Tests were performed on a hardwood floor.
The GetMotor command returned slightly different perameters when issued to units running the 3.0 and 2.6 softwares. For example,
Software version 3.0 (defective unit) returned:
Software version 2.6 (remanufactured unit) returned:
The Wheel_Load% parameter was used directly from the XV12 running 3.0, but since the Wheel_Load% was not directly given in the 2.6 version, it was calculated using the equation:
Wheel_Load% = Wheel_PWM / Wheel_MaxPWM X 100.
The motors from the XV12 that failed from a "Wheel stuck" error had higher percent loads at both high and low speeds compared to the remanufactured unit. At the high speed, the remanufactured unit achieved an ~80% load compared to over 90-95% for the unit which failed. The right wheel of the failed unit, which was repaired as previously described ( viewtopic.php?f=20&t=16527&start=40#p111933
), achieved a slightly higher percent load than the wheel which did not fail ( 90 vs 95% at the high speed). At the low speed, the motors from the defective unit achieved a % load of 43-46% compared to only 26-27% generated by the remanufactured replacement unit.
It appears that the new motors used in this particular replacement unit generate a lower % load than the motors in the unit that ultimately failed from a " wheel stuck" error. The data might indicate that the motors in the replacement unit are functionally distinct and improved compared to the motor that failed. However, it is not clear whether the way the Wheel_Load% parameter is reported by the 3.0 software is the same as the Wheel_PWM / Wheel_MaxPWM X 100 used to analyse the 2.6 software. Time will tell.