Two wheels differential drive

module:

navground.core.kinematics

class TwoWheelsDifferentialDriveKinematics

Bases: WheeledKinematics

Two differential drive wheels (left, right) (e.g., a wheelchair) with a physical maximal wheel speed, and software-limited forward/backwards speeds.

It implements two types of kinematics constrains:

• a maximal wheel speed that adds a linear coupling between linear and angular speed (e.g., the robot can move at maximal linear speed only straights) (same as TwoWheelsDifferentialDriveKinematics) - a controller that clamps linear and angular speed inside a box: these constrains when the related bounds are set to negative values.

Registered properties:

• max_forward_speed (float, max_forward_speed)

• max_backward_speed (float, max_backward_speed)

• wheel_axis (float, wheel_axis)

__init__(max_speed: float = float('inf'), wheel_axis: float = 1, max_angular_speed: float = float('inf'), max_forward_speed: float = float('inf'), max_backward_speed: float = 0) → None

Constructs a new instance.

Parameters:

• max_speed – The maximal wheel speed

• wheel_axis – The wheel axis (i.e., the distance between the wheels)

• max_angular_speed – The maximal angular speed, that is also limited by the 2 * max_speed / axis, if the axis is positive.

• max_forward_speed – The maximal linear speed when moving forwards (set to negative or infinite to leave unconstrained)

• max_backward_speed – The maximal linear speed when moving backwards (set to negative or infinite to leave unconstrained)

property can_move_backwards

Type:

bool

Whether the agent can move backwards.

property can_move_forwards

Type:

bool

Whether the agent can move forwards.

property max_backward_speed

Type:

float

The maximal linear speed when moving backwards.

property max_forward_speed

Type:

float

The maximal linear speed when moving forwards.

property wheel_axis

Type:

float

The wheel axis.