BallFilter Class Reference

#include <ball_filter.h>

Public Member Functions
	BallFilter ()
std::optional< Ball >	estimateBallState (const std::vector< BallDetection > &new_ball_detections, const Rectangle &filter_area)

Static Public Attributes
static constexpr unsigned int	MIN_BUFFER_SIZE = 4
static constexpr unsigned int	MAX_BUFFER_SIZE = 10
static constexpr double	MIN_BUFFER_SIZE_VELOCITY_MAGNITUDE = 0.5
static constexpr double	MAX_BUFFER_SIZE_VELOCITY_MAGNITUDE = 4.0
static constexpr double	MAX_ACCEPTABLE_BALL_SPEED_BUFFER = 2.0
static constexpr double	LINEAR_REGRESSION_ERROR_THRESHOLD = 1000.0

Detailed Description

Given ball data from SSL Vision, filters and returns the position/velocity of the "real" ball.

This ball filter stores a buffer of previous SSL Vision detections, and uses linear regression to find the path the ball is travelling on and estimate its position and velocity. This buffer/regression system was chosen because it results in a very stable output, particularly for the ball velocity. The data we receive isn't perfect (which is why we have a filter). If we receive a noisy position that is off the ball's current trajectory, it will have minimal impact. This means that as the ball is travelling, this filter will return a very steady velocity vector. This is important because small deviations in velocity orientation can have large effects when the AI tries to predict the future position of the ball. For example, consistently receiving a pass relies on the ball's velocity being very stable, otherwise the robot would "jiggle" back and forth as the estimated receiver position would keep changing.

Constructor & Destructor Documentation

BallFilter()

BallFilter ( )

explicit

Creates a new Ball Filter

Member Function Documentation

estimateBallState()

std::optional< Ball > estimateBallState	(	const std::vector< BallDetection > &	new_ball_detections,
		const Rectangle &	filter_area
	)

Update the filter with the new ball detection data, and returns the new estimated state of the ball given the new data

Parameters

new_ball_detections	A list of new Ball detections
filter_area	The area within which the ball filter will work. Any detections outside of this area will be ignored.

Returns

The new ball based on the estimated state of the ball given the new data. If a filtered result cannot be calculated, returns std::nullopt

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The documentation for this class was generated from the following files:

• src/software/sensor_fusion/filter/ball_filter.h
• src/software/sensor_fusion/filter/ball_filter.cpp