Computed velocity and real velocity not matching in velocity continuous mode

[David9696]

Hi,

I have tested the latest velocity_control_sample.launch file. However, I realized that the computed velocity and real velocity do not matching.

Previously. I was using the vesc package version of [f0d983c].

(https://github.com/sbgisen/vesc/commit/f0d983c0ef787e3cb42fa917bcbfd7a7651f62a0) on Dec 14, 2022]

In this version, the computed velocity and real velocity are matching.

The following parameters are the same for both cases.

  num_rotor_poles_pairs (half for the latest version)
  gear_ratio
  torque_const

May I know what is the problem?

Thanks.

[Tacha-S]

Please show me the result of rosparam get /vesc_hw_interface_node in both versions. Also do you know what the measured and actual speed values are? I would appreciate any relationship such as the measured value is greater than the actual speed.

[David9696]

I would update the rosparam once I have the access to my setup.

As a quick reply, this is what I have found:

1. The odometry/position estimation is correct.
2. The actual speed is about 2X lesser than the command speed.

Thanks.

[jsupratman13]

Sorry, forgot to fix the conversion bug on vesc_hw_interface.cpp https://github.com/sbgisen/vesc/blob/fb520b663c0c5df1a03cc46ccebb9d08fce110c7/vesc_hw_interface/src/vesc_hw_interface.cpp#L307

should be

const double velocity_rpm = values->getVelocityERPM() / static_cast<double>(num_rotor_poles_ / 2);

[jsupratman13]

@David9696

I opened PR #78 which should fix the velocity conversion bug. Let us know if this fixes your environment.

[David9696]

Hi @jsupratman13 ,

Yes, is working correctly now. Thanks for your great help.