residual

Residuals and residual covariances from direct state measurements for insfilterErrorState

Syntax

[res, resCov]= residual(FUSE,idx,measurement,measurementCovariance)

Description

[res, resCov]= residual(FUSE,idx,measurement,measurementCovariance) computes the residual, res, and the residual covariance, resCov, based on the direct state measurement and measurement covariance. The measurement maps directly to the states specified by indices, idx.

Examples

Obtain Measurement Residual from insfilterErrorState

Create an insfilterErrorState object and display its state.

filter = insfilterErrorState;
disp(filter.State')

     1     0     0     0     0     0     0     0     0     0     0     0     0     0     0     0     1

Specify a measurement of altitude and vertical velocity.

idx = [5 6 7];
measure = [10 20 30];
measureCov = 1e-2*diag([5 5 5]);

Obtain the residual for the measurement.

[res,rescov] = residual(filter,idx,measure,measureCov)

res = 1×3

    10    20    30

rescov = 3×3

    1.0500    1.0000    1.0000
    1.0000    1.0500    1.0000
    1.0000    1.0000    1.0500

Input Arguments

FUSE — INS filter object

insfilterErrorState

insfilterErrorState, specified as an object.

idx — State vector index of measurements to correct

N-element vector of increasing integers in the range [1, 17]

State vector index of measurements to correct, specified as an N-element vector of increasing integers in the range [1, 17].

The state values represent:

State	Units	Index
Orientation (quaternion parts)	N/A	1:4
Position (NED)	m	5:7
Velocity (NED)	m/s	8:10
Gyroscope Bias (XYZ)	rad/s	11:13
Accelerometer Bias (XYZ)	m/s2	14:16
Visual Odometry Scale (XYZ)	N/A	17

Data Types: single | double

measurement — Direct measurement of state

N-element vector

Direct measurement of state, specified as a N-element vector. N is the number of elements of the index argument, idx.

measurementCovariance — Covariance of measurement

N-by-N matrix

Covariance of measurement, specified as an N-by-N matrix. N is the number of elements of the index argument, idx.

Output Arguments

res — Measurement residual

1-by-N vector of real values

Measurement residual, returned as a 1-by-N vector of real values.

resCov — Residual covariance

N-by-N matrix of real values

Residual covariance, returned as a N-by-N matrix of real values.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2020a