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AP_NavEKF3: Fix bug preventing horizontal position reset if badIMUdata

This commit is contained in:
Paul Riseborough 2021-06-17 10:07:04 +10:00 committed by Randy Mackay
parent 5d00b7d042
commit 36160ba9ce
1 changed files with 29 additions and 16 deletions
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45
libraries/AP_NavEKF3/AP_NavEKF3_PosVelFusion.cpp
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@ -589,9 +589,8 @@ void NavEKF3_core::SelectVelPosFusion()
void NavEKF3_core::FuseVelPosNED()
{
// health is set bad until test passed
bool posHealth = false; // boolean true if position measurements have passed innovation consistency check
bool velCheckPassed = false; // boolean true if velocity measurements have passed innovation consistency checks
bool posCheckPassed = false; // boolean true if position measurements have passed innovation consistency check
bool hgtCheckPassed = false; // boolean true if height measurements have passed innovation consistency check
// declare variables used to control access to arrays
@ -689,46 +688,60 @@ void NavEKF3_core::FuseVelPosNED()
}
}
// calculate innovations and check GPS data validity using an innovation consistency check
// test position measurements
// Test horizontal position measurements
if (fusePosData) {
// test horizontal position measurements
innovVelPos[3] = stateStruct.position.x - velPosObs[3];
innovVelPos[4] = stateStruct.position.y - velPosObs[4];
varInnovVelPos[3] = P[7][7] + R_OBS_DATA_CHECKS[3];
varInnovVelPos[4] = P[8][8] + R_OBS_DATA_CHECKS[4];
// apply an innovation consistency threshold test, but don't fail if bad IMU data
// Apply an innovation consistency threshold test
// Don't allow test to fail if not navigating and using a constant position
// assumption to constrain tilt errors because innovations can become large
// due to vehicle motion.
float maxPosInnov2 = sq(MAX(0.01f * (float)frontend->_gpsPosInnovGate, 1.0f))*(varInnovVelPos[3] + varInnovVelPos[4]);
posTestRatio = (sq(innovVelPos[3]) + sq(innovVelPos[4])) / maxPosInnov2;
posHealth = ((posTestRatio < 1.0f) || badIMUdata);
// use position data if healthy or timed out
if (PV_AidingMode == AID_NONE) {
posHealth = true;
if (posTestRatio < 1.0f || (PV_AidingMode == AID_NONE)) {
posCheckPassed = true;
lastPosPassTime_ms = imuSampleTime_ms;
} else if (posHealth || posTimeout) {
posHealth = true;
}
// Use position data if healthy or timed out or bad IMU data
// Always fuse data if bad IMU to prevent aliasing and clipping pulling the state estimate away
// from the measurement un-opposed if test threshold is exceeded.
if (posCheckPassed || posTimeout || badIMUdata) {
posCheckPassed = true;
lastPosPassTime_ms = imuSampleTime_ms;
// if timed out or outside the specified uncertainty radius, reset to the external sensor
if (posTimeout || ((P[8][8] + P[7][7]) > sq(float(frontend->_gpsGlitchRadiusMax)))) {
// reset the position to the current external sensor position
ResetPosition(resetDataSource::DEFAULT);
// don't fuse external sensor data on this time step
// Don't fuse the same data we have used to reset states.
fusePosData = false;
// Reset the position variances and corresponding covariances to a value that will pass the checks
zeroRows(P,7,8);
zeroCols(P,7,8);
P[7][7] = sq(float(0.5f*frontend->_gpsGlitchRadiusMax));
P[8][8] = P[7][7];
// Reset the normalised innovation to avoid failing the bad fusion tests
posTestRatio = 0.0f;
// also reset velocity if it has timed out
// Reset velocity if it has timed out
if (velTimeout) {
// reset the velocity to the external sensor velocity
ResetVelocity(resetDataSource::DEFAULT);
// Don't fuse the same data we have used to reset states.
fuseVelData = false;
// Reset the normalised innovation to avoid failing the bad fusion tests
velTestRatio = 0.0f;
}
}
} else {
fusePosData = false;
}
}
@ -828,7 +841,7 @@ void NavEKF3_core::FuseVelPosNED()
fuseData[2] = true;
}
}
if (fusePosData && posHealth) {
if (fusePosData) {
fuseData[3] = true;
fuseData[4] = true;
}