#include <cost_interpreter.h>

Public Types
typedef std::shared_ptr< CostInterpreter >	Ptr

Public Member Functions
float	getCost (const unsigned int x, const unsigned int y) const

unsigned char	getNeutralCost () const

void	initialize (ros::NodeHandle &nh, nav_core2::Costmap::Ptr costmap)

float	interpretCost (const unsigned char cost) const

bool	isLethal (const float cost) const

void	setConfiguration (const unsigned char neutral_cost, const float scale, const UnknownInterpretation mode)

Protected Attributes
std::array< float, 256 >	cached_costs_

nav_core2::Costmap::Ptr	costmap_

unsigned char	neutral_cost_

Detailed Description

There is a fundamental tradeoff in planning between the length of the path and the costs contained in the costmap. The neutral cost is a penalty for moving from one cell to an adjacent cell. The raw values in the costmap can be weighted as well. See the README for more conceptual explanations.

Practically speaking, we take the cost for each cell (c) and generally interpret it as a float: c' = neutral_cost + scale * c

The caveat is that c' should not be greater than the the lethal cost, so non-lethal costs c with c' >= lethal_cost will be interpreted as c' = lethal_cost -1

A plot of this can be seen here: https://www.desmos.com/calculator/2haig4ki8h

The special case is when c==255, i.e. NO_INFORMATION. There are three intepretations possible here.

LETHAL - Unknown cells are treated as lethal obstacles and cannot be passed through.
EXPENSIVE - Unknown cells are valid, but assigned a high cost. (lethal_cost - 1)
FREE - Unknown cells are valid and given the same weight as free cells. (neutral_cost)

Definition at line 66 of file cost_interpreter.h.

Member Typedef Documentation

typedef std::shared_ptr<CostInterpreter> dlux_global_planner::CostInterpreter::Ptr

Definition at line 89 of file cost_interpreter.h.

Member Function Documentation

float dlux_global_planner::CostInterpreter::getCost	(	const unsigned int	x,
		const unsigned int	y
	)		const

inline

Definition at line 79 of file cost_interpreter.h.

unsigned char dlux_global_planner::CostInterpreter::getNeutralCost ( ) const

inline

Definition at line 72 of file cost_interpreter.h.

void dlux_global_planner::CostInterpreter::initialize	(	ros::NodeHandle &	nh,
		nav_core2::Costmap::Ptr	costmap
	)

Definition at line 43 of file cost_interpreter.cpp.

float dlux_global_planner::CostInterpreter::interpretCost ( const unsigned char cost ) const

inline

Definition at line 74 of file cost_interpreter.h.

bool dlux_global_planner::CostInterpreter::isLethal ( const float cost ) const

inline

Definition at line 84 of file cost_interpreter.h.

void dlux_global_planner::CostInterpreter::setConfiguration	(	const unsigned char	neutral_cost,
		const float	scale,
		const UnknownInterpretation	mode
	)

Definition at line 90 of file cost_interpreter.cpp.

Member Data Documentation

std::array<float, 256> dlux_global_planner::CostInterpreter::cached_costs_

protected

Definition at line 92 of file cost_interpreter.h.

nav_core2::Costmap::Ptr dlux_global_planner::CostInterpreter::costmap_

protected

Definition at line 95 of file cost_interpreter.h.

unsigned char dlux_global_planner::CostInterpreter::neutral_cost_

protected

Definition at line 93 of file cost_interpreter.h.

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

Public Types

Public Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

Member Function Documentation

Member Data Documentation