Physics

rc.physics

Copyright MIT MIT License

BWSI Autonomous RACECAR Course Racecar Neo LTS

File Name: physics.py File Description: Defines the interface of the Physics module of the racecar_core library

class physics.Physics

Returns the linear acceleration and angular velocity measured by the IMU.

abstractmethod get_angular_velocity() → NDArray[3, Float]

Returns a 3D vector containing the car’s angular velocity.

Returns:

The average angular velocity of the car along the (x, y, z) axes during the last frame in rad/s.

Note

— In the Simulator — The x-axis (pitch) points out of the right of the car. The y-axis (yaw) points directly up (perpendicular to the ground). The z-axis (roll) points out of the front of the car. Rotation sign uses the right hand rule. For example, when the car turns to the left, it has a positive angular velocity along the y axis.

— In the Physical RACECAR — The x-axis (roll) points out of the front of the car. The y-axis (pitch) points out of the right of the car. The z-axis (yaw) points directly up (perpendicular to the ground).

Example:

# ang_vel stores the average angular velocity over the previous frame
ang_vel = rc.physics.get_angular_velocity()

# yaw stores the yaw of the car, which is positive when it turns to the left
# and negative when it turns to the right.
yaw = ang_vel[1]

abstractmethod get_linear_acceleration() → NDArray[3, Float]

Returns a 3D vector containing the car’s linear acceleration.

Returns:

The average linear acceleration of the car along the (x, y, z) axes during the last frame in m/s^2.

Note

— In the Simulator — The x-axis points out of the right of the car. The y-axis points directly up (perpendicular to the ground). The z-axis points out of the front of the car.

— In the Physical RACECAR — The x-axis points out of the front of the car. The y-axis points out of the right of the car. The z-axis points directly up (perpendicular to the ground).

Example:

# accel stores the average acceleration over the previous frame
accel = rc.physics.get_linear_acceleration()

# forward accel stores acceleration in the forward direction.  This will be
# positive when the car accelerates, and negative when it decelerates.
forward_accel = accel[2]

abstractmethod get_magnetic_field() → NDArray[3, Float]

Returns a 3D vector containing the car’s magnetic field measurements.

Returns:

The average magnetic field measurements from the magnetometer along the (x, y, z) axis during the last frame in Teslas.

Note

— In the Simulator — This function does not exist.

— In the Physcial RACECAR — The x-axis points towards the back of the car. The y-axis points towards the right of the car. The z-axis points directly up (perpendicular to the ground).