Junction Manager Node

Maintained by Ayush Sharma

Overview

This node controls the behavior of the car in a junction (Intersection). Given a junction grid (where each cell is either within an intersection or not), plus the current ego speed and occupancy grid, this node publishes a map that either includes the junction cost or not. This basically switches a junction’s cost on or off, hence allowing or blocking entrance into junctions based on perception data.

In:

/grid/occupancy/current (OccupancyGrid): Shows the current grid that is being occupied by the car
/grid/junction (OccupancyGrid): Shows the grid of the junction
/carla/hero/speedometer CarlaSpeedometer: Keeps track of current speed of the car

Out:

/grid/stateful_junction (OccupancyGrid): Defines the current junction cost
/node_statuses (DiagnosticStatus): Sends out the diagnostic status of the car

resizeOccupancyGrid()

This method resizes the received occupancy grid to match the expected size and format. It downsamples and trims the grid to ensure it has the correct dimensions.

junctionIsOccupied()

This method checks if a junction is occupied based on the occupancy and junction grids. It erodes both grids to denoise them and then checks for overlap to determine if the junction is occupied.

egoCanEnter()

This method determines if the ego vehicle can enter a junction. It considers various conditions, including if the ego vehicle has recently stopped, if the junction is occupied, and if the joystick button is pressed.

getWeightedArray()

This method converts an OccupancyGrid message into a numpy array and scales it by a given factor, returning the resulting array.