factorVelocity3Prior

Prior factor for 3-D velocity

Since R2022a

Description

The factorVelocity3Prior object is a factor that has information for a prior velocity in 3-D for a factorGraph object.

Creation

Syntax

F = factorVelocity3Prior(nodeID)

F = factorVelocity3Prior(nodeID,Name=Value)

Description

F = factorVelocity3Prior(nodeID) creates a factorVelocity3Prior object, F, with the node identification numbers property NodeID set to nodeID.

F = factorVelocity3Prior(nodeID,Name=Value) specifies properties using one or more name-value arguments. For example, factorVelocity3Prior(1,Measurement=[1 5 7]) sets the Measurement property of the factorVelocity3Prior object to [1 5 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 VEL3 in the factor graph using the specified node ID.

If a factor in the factorVelocity3Prior object specifies ID that does not correspond to a node in the factor graph, the factor graph automatically creates an VEL3 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 prior velocity

zeros(N,3) (default) | N-by-3 matrix

Measured prior velocity, specified as an N-by-3 matrix, where each row is of the form [xz yz vz]. N is the total number of factors. xz, yz, and vz are the velocity of the x, y, and z positions, respectively.

Information — Information matrix associated with measurements

eye(3) (default) | 3-by-3 matrix | 3-by-3-N array

Information matrix associated with the measurement, specified as a 3-by-3 matrix or a 3-by-3-N matrix. N is the total number of factors specified by this factorVelocity3Prior object. Each information matrix corresponds to the measurements of the specified nodes in NodeIDs.

If you specify this property as a 3-by-3 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 factorVelocity3Prior Object to Factor Graph

Create a velocity prior factor with a node ID of 1.

f = factorVelocity3Prior(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.