AP_NavEKF: Cleaned up on-ground state and covariance update logic

This commit is contained in:
Paul Riseborough 2013-12-31 10:21:04 +11:00 committed by Andrew Tridgell
parent 9c5647eef3
commit 9515f6c745
1 changed files with 30 additions and 19 deletions

View File

@ -1359,8 +1359,15 @@ void NavEKF::FuseMagnetometer()
// associated with sequential fusion
if (fuseMagData || obsIndex == 1 || obsIndex == 2)
{
// Sequential fusion of XYZ components to spread processing load across
// three prediction time steps.
// Prevent access last 11 states when on ground.
if (!onGround)
{
indexLimit = 23;
}
else
{
indexLimit = 12;
}
// Calculate observation jacobians and Kalman gains
if (fuseMagData)
{
@ -1561,15 +1568,6 @@ void NavEKF::FuseMagnetometer()
// Check the innovation for consistency and don't fuse if > 5Sigma
if ((innovMag[obsIndex]*innovMag[obsIndex]/varInnovMag[obsIndex]) < 25.0f)
{
// Limit access to first 13 states when on ground.
if (!onGround)
{
indexLimit = 23;
}
else
{
indexLimit = 12;
}
// correct the state vector
for (uint8_t j= 0; j<=indexLimit; j++)
{
@ -1588,33 +1586,46 @@ void NavEKF::FuseMagnetometer()
// correct the covariance P = (I - K*H)*P
// take advantage of the empty columns in KH to reduce the
// number of operations
for (uint8_t i = 0; i<=23; i++)
for (uint8_t i = 0; i<=indexLimit; i++)
{
for (uint8_t j = 0; j<=3; j++)
{
KH[i][j] = Kfusion[i] * H_MAG[j];
}
for (uint8_t j = 4; j<=17; j++) KH[i][j] = 0.0;
for (uint8_t j = 4; j<=17; j++) KH[i][j] = 0.0f;
if (!onGround)
{
for (uint8_t j = 18; j<=23; j++)
{
KH[i][j] = Kfusion[i] * H_MAG[j];
}
}
for (uint8_t i = 0; i<=23; i++)
else
{
for (uint8_t j = 0; j<=23; j++)
for (uint8_t j = 18; j<=23; j++)
{
KH[i][j] = 0.0f;
}
}
}
for (uint8_t i = 0; i<=indexLimit; i++)
{
for (uint8_t j = 0; j<=indexLimit; j++)
{
KHP[i][j] = 0;
for (uint8_t k = 0; k<=3; k++)
{
KHP[i][j] = KHP[i][j] + KH[i][k] * P[k][j];
}
if (!onGround)
{
for (uint8_t k = 18; k<=23; k++)
{
KHP[i][j] = KHP[i][j] + KH[i][k] * P[k][j];
}
}
}
}
for (uint8_t i = 0; i<=indexLimit; i++)
{
for (uint8_t j = 0; j<=indexLimit; j++)