Target

#include "navground/core/target.h"

struct Path

A generic, twice differentiable, curve (to follow), parametrized by length.

Public Types

using Point = std::tuple<Vector2, float, float>

using Projection = std::function<ng_float_t(const Vector2&, ng_float_t, ng_float_t)>

The projection of a curve parametrized by length.

The function finds the coordinate in [begin, end] where curve(coordinate) is nearest to the given point point:

(point, begin, end) -> coordinate

using Curve = std::function<Point(ng_float_t)>

The parametrization of a (G2) curve by length.

The function returns position, tangential orientation and curvature at a coordinate:

(coordinate) -> (point, orientation, curvature)

Public Functions

inline Path(const Projection &projection, const Curve &curve_fn, ng_float_t length, bool loop = false)

Constructs a new instance.

Parameters:

• projection – [in] The projection

• curve_fn – [in] The parametrized curve

• length – [in] The curve length

• loop – [in] Whether the path is an infinite loop

inline ng_float_t track(const Vector2 &position, ng_float_t look_ahead = 0)

Returns the coordinate ahead of a position.

It projects the point to the curve using project, updates coordinate with this value. It returns the value advanced by the look-ahead distance.

Parameters:

• position – [in] The position

• look_ahead – [in] The look ahead distance

Returns:

The coordinate.

inline Point get_point(const Vector2 &position, ng_float_t look_ahead = 0)

Returns the point the point corresponding the track coordinate.

Parameters:

• position – [in] The position

• look_ahead – [in] The look ahead distance

Returns:

The point.

Public Members

Projection project

The projection

Curve curve

The parametrized curve

ng_float_t coordinate

The current coordinate during tracking. A negative value means undefined.

ng_float_t length

The curve length

bool loop

Whether the path is an infinite loop

struct Target

Represents the union of all targets supported by a generic Behavior.

• poses

• positions

• orientations

• directions

• velocities

• twists

• paths to be followed to reach a position

Public Functions

inline explicit Target(const std::optional<Vector2> &position = std::nullopt, const std::optional<Radians> &orientation = std::nullopt, const std::optional<ng_float_t> &speed = std::nullopt, const std::optional<Vector2> &direction = std::nullopt, const std::optional<Radians> &angular_speed = std::nullopt, const std::optional<int> &angular_direction = std::nullopt, const std::optional<Path> &path = std::nullopt, ng_float_t position_tolerance = 0, Radians orientation_tolerance = 0)

Constructs a new instance.

Parameters:

• position – [in] The position

• orientation – [in] The orientation

• speed – [in] The speed

• direction – [in] The direction

• angular_speed – [in] The angular speed

• angular_direction – [in] The angular direction

• path – [in] The path

• position_tolerance – [in] The position tolerance

• orientation_tolerance – [in] The orientation tolerance

inline bool valid() const

Verify that a target is set.

Returns:

True if the target is not empty.

inline bool satisfied(Radians angle) const

Returns whether a given orientation satisfies the target.

The target is satisfied if it does not have an angular speed and if the given value is near to the target’s orientation.

Parameters:

angle – [in] The orientation

Returns:

True if the target is satisfied.

inline bool satisfied(const Vector2 &point) const

Returns whether a given position satisfies the target.

The target is satisfied if it does not have an linear speed and if the given value is near to the target’s position.

Parameters:

point – [in] The position

Returns:

True if the target is satisfied.

inline bool satisfied(const Pose2 &pose) const

Returns whether a given pose satisfies the target.

The target is satisfied if the position and orientation are both satisfied.

Parameters:

pose – [in] The pose

Returns:

True if the target is satisfied.

Public Members

std::optional<Vector2> position = std::nullopt

The position

std::optional<Radians> orientation = std::nullopt

The orientation

std::optional<ng_float_t> speed = std::nullopt

The speed

std::optional<Vector2> direction = std::nullopt

The direction

std::optional<Radians> angular_speed = std::nullopt

The angular speed

std::optional<int> angular_direction = std::nullopt

The angular direction

std::optional<Path> path = std::nullopt

The path to follow.

ng_float_t position_tolerance = 0

The position tolerance

Radians orientation_tolerance = 0

The orientation tolerance

Public Static Functions

static inline Target Point(const Vector2 &position, ng_float_t tolerance = 0, std::optional<Path> along_path = std::nullopt)

Constructs a target to reach a point.

Parameters:

• position – [in] The target position

• tolerance – [in] The tolerance

• along_path – [in] The path to follow

Returns:

The target

static inline Target Pose(const Pose2 &pose, ng_float_t position_tolerance = 0, Radians orientation_tolerance = 0, std::optional<Path> along_path = std::nullopt)

Constructs a target to reach a pose.

Parameters:

• pose – [in] The pose

• position_tolerance – [in] The position tolerance

• orientation_tolerance – [in] The orientation tolerance

• along_path – [in] The path to follow

Returns:

The target

static inline Target Orientation(Radians orientation, Radians tolerance = 0)

Constructs a target to reach an orietation.

Parameters:

• orientation – [in] The orientation

• tolerance – [in] The tolerance

Returns:

The target

static inline Target Velocity(const Vector2 &velocity)

Constructs a target to follow a velocity.

Parameters:

velocity – [in] The velocity

Returns:

The target

static inline Target Direction(const Vector2 &direction)

Constructs a target to follow a direction.

Parameters:

direction – [in] The direction

Returns:

The target

static inline Target Twist(const Twist2 &twist)

Constructs a target to follow a twist.

Parameters:

twist – [in] The twist

Returns:

The target

static inline Target Stop()

Constructs a target to stop.

Returns:

The target