tap::algorithms::ballistics Namespace Reference

Classes
struct	AbstractKinematicState
struct	SecondOrderKinematicState

Functions
bool	computeTravelTime (const modm::Vector3f &targetPosition, float bulletVelocity, float *travelTime, float *turretPitch, const float pitchAxisOffset)
bool	findTargetProjectileIntersection (const AbstractKinematicState &targetInitialState, float bulletVelocity, uint8_t numIterations, float *turretPitch, float *turretYaw, float *projectedTravelTime, const float pitchAxisOffset)

Function Documentation

computeTravelTime()

bool tap::algorithms::ballistics::computeTravelTime	(	const modm::Vector3f &	targetPosition,
		float	bulletVelocity,
		float *	travelTime,
		float *	turretPitch,
		const float	pitchAxisOffset = 0
	)

Computes an iterative numerical approximation of the pitch angle to aim the turret in order to hit a given target and the time it will take for that target to be hit, given the velocity of a bullet out of the turret and the position of the target relative to the turret.

Parameters

[in]	targetPosition	The 3D position of a target in m. Frame requirements: RELATIVE TO PROJECTILE RELEASE POSITION, Z IS OPPOSITE TO GRAVITY.
[in]	bulletVelocity	The velocity of the projectile to be fired in m/s.
[out]	travelTime	The expected travel time of a turret shot to hit a target from this object's position.
[out]	turretPitch	The pitch angle of the turret to hit the target at the given travel time.
[in]	pitchAxisOffset	The distance between the pitch and yaw axes (in meters) as seen from a plane parallel to the ground. A positive offset indicates that the pitch axis is located behind the yaw axis.

Returns

Whether or not a valid travel time was found.

findTargetProjectileIntersection()

bool tap::algorithms::ballistics::findTargetProjectileIntersection	(	const AbstractKinematicState &	targetInitialState,
		float	bulletVelocity,
		uint8_t	numIterations,
		float *	turretPitch,
		float *	turretYaw,
		float *	projectedTravelTime,
		const float	pitchAxisOffset = 0
	)

Parameters

[in]	targetInitialState	The initial 3D kinematic state of a target. Frame requirements: RELATIVE TO PROJECTILE RELEASE POSITION, Z IS OPPOSITE TO GRAVITY.
[in]	bulletVelocity	The velocity of the projectile to be fired in m/s.
[in]	numIterations	The number of times to project the kinematics forward. Guidelines on choosing this parameter: If the target is moving very slow relative to bulletVelocity, 1 is probably enough. For higher target speeds, 2-3 is probably a good estimate. If the target is approaching the projectile speed, this algorithm may have a difficult time converging (but it may be possible with enough iterations). If the target is moving faster than the projectile, this algorithm will diverge.
[out]	turretPitch	The world-relative turret pitch (in radians above level) at which our robot should aim to hit the given target, taking into account the path a projectile takes to hit the target.
[out]	turretYaw	Analogue of turret pitch
[out]	projectedTravelTime	The expected time between projectile launch and impact with the target, in seconds.
[in]	pitchAxisOffset	The distance between the pitch and yaw axes (in meters) as seen from a plane parallel to the ground. A positive offset indicates that the pitch axis is located behind the yaw axis.

Returns

Whether or not a valid aiming solution was found. Out parameters only valid if true.