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RobustFieldAutonomyLab / LeGO-LOAM

LeGO-LOAM: Lightweight and Ground-Optimized Lidar Odometry and Mapping on Variable Terrain
BSD 3-Clause "New" or "Revised" License
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question about "void ShiftToStartIMU(float pointTime)" #157

Closed SakuraMemoryKnight closed 4 years ago

SakuraMemoryKnight commented 4 years ago

This function is only defined, and I don't find it used anywhere else,Is this an obsolete function?

void ShiftToStartIMU(float pointTime) { imuShiftFromStartXCur = imuShiftXCur - imuShiftXStart - imuVeloXStart pointTime; imuShiftFromStartYCur = imuShiftYCur - imuShiftYStart - imuVeloYStart pointTime; imuShiftFromStartZCur = imuShiftZCur - imuShiftZStart - imuVeloZStart * pointTime;

    float x1 = cosImuYawStart * imuShiftFromStartXCur - sinImuYawStart * imuShiftFromStartZCur;
    float y1 = imuShiftFromStartYCur;
    float z1 = sinImuYawStart * imuShiftFromStartXCur + cosImuYawStart * imuShiftFromStartZCur;

    float x2 = x1;
    float y2 = cosImuPitchStart * y1 + sinImuPitchStart * z1;
    float z2 = -sinImuPitchStart * y1 + cosImuPitchStart * z1;

    imuShiftFromStartXCur = cosImuRollStart * x2 + sinImuRollStart * y2;
    imuShiftFromStartYCur = -sinImuRollStart * x2 + cosImuRollStart * y2;
    imuShiftFromStartZCur = z2;
}
TixiaoShan commented 4 years ago

It is used to deskew the point cloud. However, the translation estimation of IMU drifts super fast. So I observed bad performance when using this for deskewing.

You can certainly try it. See its place in the code.

SakuraMemoryKnight commented 4 years ago

Thanks for your @TixiaoShan reply! I got it.