factorPoseSE3Prior

Full-state prior factor for SE(3) pose

Since R2022a

Description

The factorPoseSE3Prior object is a full-state prior factor for an SE(3) state space pose for a factorGraph object.

Creation

Syntax

F = factorPoseSE3Prior(nodeID)

F = factorPoseSE3Prior(nodeID,Name=Value)

Description

F = factorPoseSE3Prior(nodeID) creates a factorPoseSE3Prior object, F, with the node identification numbers property NodeID set to nodeID.

F = factorPoseSE3Prior(nodeID,Name=Value) specifies properties using one or more name-value arguments. For example, factorPoseSE3Prior(1,Measurement=[1 2 3 4 5 6 7]) sets the Measurement property of the factorPoseSE3Prior object to [1 2 3 4 5 6 7].

Properties

NodeID — Node ID numbers

N-element column vector of nonnegative integers

This property is read-only.

Node ID numbers, specified as an N-element vector of nonnegative integers, where N is the total number of desired factors. Each element represents a factor that connects to a node of type POSE_SE3 in the factor graph using the specified node ID.

If a factor in the factorPoseSE3Prior object specifies ID that does not correspond to a node in the factor graph, the factor graph automatically creates an POSE_SE3 type node with that ID and adds it to the factor graph when adding the factor to the factor graph.

You must specify this property at object creation.

For more information about the expected node types of all supported factors, see Expected Node Types of Factor Objects.

Measurement — Measured absolute SE(3) prior pose in local coordinates

[zeros(N,3) ones(N,1) zeros(N,3)] (default) | N-by-7 matrix

Measured absolute SE(3) prior pose in local coordinates, specified as an N-by-7 matrix, where each row is of the form [x y z qw qx qy qz]. N is the total number of factors. x, y, and z are the position measurements. qw, qx, qy, and qz are the quaternion rotation measurements.

This measurement provides an initial node state for the specified nodes during optimization.

The specified quaternion is expected to be normalized.

Information — Information matrices associated with measurements

eye(6) (default) | 6-by-6 matrix | 6-by-6-by-N array

Information matrices associated with the measurements, specified as a 6-by-6 matrix or a 6-by-6-by-N array. N is the total number of factors specified by the factorPoseSE3Prior object. Each information matrix corresponds to the measurements of the corresponding node in NodeID.

If you specify this property as a 6-by-6 matrix when NodeID contains more than one element, the information matrix corresponds to all measurements in Measurement.

Object Functions

nodeType

Get node type of node in factor graph

Examples

Add factorPoseSE3Prior Object to Factor Graph

Create a prior SE(3) pose factor with a node ID of 1.

f = factorPoseSE3Prior(1);

Create a default factor graph and add the factor to the graph using the addFactor function.

g = factorGraph;
addFactor(g,f);

More About

Expected Node Types of Factor Objects

These are the node types that the NodeID property of each factor object specifies and connects to:

Factor Object	Expected Node Types of Specified Node IDs
factorGPS	["POSE_SE3"]
factorIMU	["POSE_SE3","VEL3","IMU_BIAS","POSE_SE3","VEL3","IMU_BIAS"]
factorCameraSE3AndPointXYZ	["POSE_SE3","POINT_XYZ"]
factorPoseSE2AndPointXY	["POSE_SE2","POINT_XY"]
factorPoseSE3AndPointXYZ	["POSE_SE3","POINT_XYZ"]
factorTwoPoseSE2	["POSE_SE2","POSE_SE2"]
factorTwoPoseSE3	["POSE_SE3","POSE_SE3"]
factorIMUBiasPrior	["IMU_BIAS"]
factorPoseSE3Prior	["POSE_SE3"]
factorVelocity3Prior	["VEL_3"]

For example, factorPoseSE2AndPointXY([1 2]) creates a 2-D landmark factor connecting to node IDs 1 and 2. If you try to add that factor to a factor graph that already contains nodes 1 and 2, the factor expects nodes 1 and 2 to be of types "POSE_SE2" and "POINT_XY", respectively.

Extended Capabilities

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

Version History

Introduced in R2022a

R2023a: Specify multiple factors

The NodeID, Measurement, and Information properties now accept additional rows to specify multiple factors.