Trajectory

The Trajectory class is used to create a trajectory for a differential drive robot that can be used by a path/trajectory following algorithm.

Creating a Trajectory

The constructor for Trajectory will automatically compute the trajectory. The constructor takes the following arguments:

• std::vector<LouLib::Math::Pose2D> waypoints

  List of poses that the robot should drive through.

• LouLib::Units::Velocity maxVel

  Maximum velocity the robot should reach while driving on the path.

• LouLib::Units::Acceleration maxAccel

  Maximum acceleration the robot should reach while driving on the path.

• LouLib::Units::Length maxFullSpeedTurnRadius

  Smallest radius circle that the robot can travel around while driving at maxVel. A smaller value will result in the robot slowing down more while turning.

• LouLib::Units::Velocity finalVel (optional)

  The velocity the robot should be traveling at the end of the path. If this value of not provided, it will default to zero (the robot will stop at the end of the path)

Using the Trajectory

The final computed trajectory will contain a set of x-positions, y-positions, headings, velocities, and angular velocities, with 10 milliseconds between each.

The following methods can be used to access the calculated trajectory:

• int size()

  Returns the number of samples in the calculated trajectory

• LouLib::Units::Length getX(int i)

  Returns the i-th x-position

• LouLib::Units::Length getY(int i)

  Returns the i-th y-position

• LouLib::Units::Angle getTheta(int i)

  Returns the i-th heading

• LouLib::Units::Velocity getVelocity(int i)

  Returns the i-th velocity

• LouLib::Units::AngularVelocity getAngularVelocity(int i)

  Returns the i-th angular velocity

• LouLib::Units::Length getDistFromStart(int i)

  Returns the distance from the start of the trajectory to the i-th sample. This returns the arc length of the trajectory, and not the point-to-point distance.