Odometry¶

General¶

void lemlib::update()¶: Update the pose of the robot.

void lemlib::init()¶: Initialize the odometry system.

Pose¶

class Pose¶

A pose in 2D space.

A pose is a position and heading in 2D space. Representing a pose as a single object makes it easier to work with, especially in motion algorithms and position tracking.

The Pose class overloads operators so you can easily add, subtract, multiply, etc.

Public Functions

Pose(float x, float y, float theta = 0)¶

Create a new pose.

Example

// create a pose
lemlib::Pose poseA(5, // x position
                   10, // y position
                   1.57); // heading
// create a pose
lemlib::Pose poseB(5.2, 22); // x and y position, heading defaults to 0

Note

Pose is unitless. It is up to the user to ensure that the units are consistent.

Parameters:

x – component
y – component
theta – heading. Defaults to 0

Pose operator+(const Pose &other) const¶

Add a pose to this pose.

Example

// create a pose
lemlib::Pose poseA(5, 10, 1.57);
// create a pose
lemlib::Pose poseB(5.2, 22, 2.22);
// add the two poses
lemlib::Pose poseC = poseA + poseB;
// poseC.x = 10.2, poseC.y = 32, poseC.theta = 1.57

Note

heading is not modified, and is taken from this pose

Parameters:: other – other pose
Returns:: Pose

Pose operator-(const Pose &other) const¶

Subtract a pose from this pose.

Example

// create a pose
lemlib::Pose poseA(5, 10, 1.57);
// create a pose
lemlib::Pose poseB(5.2, 22, 2.22);
// subtract the two poses
lemlib::Pose poseC = poseA - poseB;
// poseC.x = -0.2, poseC.y = -12, poseC.theta = 1.57

Note

heading is not modified, and is taken from this pose

Parameters:: other – other pose
Returns:: Pose

float operator*(const Pose &other) const¶

Multiply a pose by this pose (dot product)

Example

// create a pose
lemlib::Pose poseA(5, 10, 1.57);
// create a pose
lemlib::Pose poseB(5.2, 22, 2.22);
// multiply the two poses
float result = poseA * poseB; // 246

Note

heading is not considered in this operation

Parameters:: other – other pose
Returns:: Pose

Pose operator*(const float &other) const¶

Multiply a pose by a float.

Example

// create a pose
lemlib::Pose pose(1, 2);
// multiply the pose by 4.0
lemlib::Pose result = pose * 4.0;
// result.x = 4, result.y = 8

Note

heading is not considered in this operation

Parameters:: other – float
Returns:: Pose

Pose operator/(const float &other) const¶

Divide a pose by a float.

Example

// create a pose
lemlib::Pose pose(6, 8);
// divide the pose by 2
lemlib::Pose result = pose / 2;
// result.x = 3, result.y = 4

Note

heading is not considered in this operation

Parameters:: other – float
Returns:: Pose

Pose lerp(Pose other, float t) const¶

Linearly interpolate between two poses.

Example

// create poses
lemlib::Pose poseA(0, 0);
lemlib::Pose poseB(0, 2);
// find the pose in between the 2 poses
lemlib::Pose result = poseA.lerp(poseB, 0.5);
// result.x = 0, result.y = 1

Note

heading is not considered in this operation

Parameters:

other – the other pose
t – t value

Returns:

Pose

float distance(Pose other) const¶

Get the distance between two poses.

Example

// create poses
lemlib::Pose poseA(0, 0);
lemlib::Pose poseB(3, 4);
// find the distance between the poses
float result = poseA.distance(poseB); // result = 5

Note

heading is not considered in this operation

Parameters:: other – the other pose
Returns:: float

float angle(Pose other) const¶

Get the angle between two poses.

Example

// create poses
lemlib::Pose poseA(-1, -2);
lemlib::Pose poseB(2, 1);
// find angle between poses
float result = poseA.angle(poseB); // result = 0.785398

Note

heading is not considered in this operation

Parameters:: other – the other pose
Returns:: float in radians

Pose rotate(float angle) const¶

Rotate a pose by an angle.

Example

// create pose
lemlib::Pose pose(1, 0);
// rotate pose by pi/2
lemlib::Pose result = pose.rotate(M_PI_2);
// result.x = 0, result.y = 1

Note

heading is not considered in this operation

Parameters:: angle – angle in radians
Returns:: Pose

std::string lemlib::format_as(const Pose &pose)¶

Format a pose.

Parameters:: pose –
Returns:: std::string