Telemetry channels broken?

Discussion in 'Bug Reports' started by BT7 Driver, Dec 23, 2020.

  1. BT7 Driver

    BT7 Driver Registered

    Joined:
    Oct 22, 2020
    Messages:
    14
    Likes Received:
    6
    When driving a Skip Barber at Lime Rock Park, I'm seeing a number of problems in the telemetry data. I'm using the standard headers from the Example Plugin v7.

    TelemWheelV01 channels mLateralGroundVel and mLongitudinalGroundVel appear to be reporting velocities in local vehicle coordinates rather than world coordinates. It's unclear what vehicle channels mLateralPatchVel and mLongitudinalPatchVel are actually reporting, but the longitudinal channels are approximately two orders of magnitude smaller than the vehicle speed.

    TelemWheelV01 channels mLateralForce, mLongitudinalForce, mTireLoad and mGripFract are always reporting zero.

    TelemInfoV01 channels mDrag, mFrontDownforce and mRearDownforce are always reporting zero.
     
  2. Lazza

    Lazza Registered

    Joined:
    Oct 5, 2010
    Messages:
    12,346
    Likes Received:
    6,572
    The skip disables aero and 'tireforce' telemetry which is why you're not seeing those. (defined in HDV, you can see it in the ModDev folder as it's an example car).

    I can't remember how the ground and patch vel values work, if I saw someone work it out at all. Safe to say if the values are orders of magnitude away from what you're expecting then they aren't showing what you're expecting :)
     
    BT7 Driver and Kahel like this.
  3. BT7 Driver

    BT7 Driver Registered

    Joined:
    Oct 22, 2020
    Messages:
    14
    Likes Received:
    6
    Thank you, that is very helpful. I will run some tests in Dev Mode with the sensors re-enabled.

    I think you are right about the channels :)

    I was assuming the ground channels were expressed in world coordinates and the patch channels in vehicle coordinates. However, staring at the telemetry, it seems to me that both channel sets use axes derived from the vehicle coordinate system, but the ground channels express velocities relative to the ground (as the naming implies), but the patch channels express relative to a fixed point on the vehicle, which is why the velocities are small.
     
  4. BT7 Driver

    BT7 Driver Registered

    Joined:
    Oct 22, 2020
    Messages:
    14
    Likes Received:
    6
    With the Skippy's Aero and Tyre Force sensors enabled and running in Dev Mode, I am now seeing data in all channels. Thanks again for the tips @Lazza
     

Share This Page