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Ray Ground Filter#

Purpose#

The purpose of this node is that remove the ground points from the input pointcloud.

Inner-workings / Algorithms#

The points is separated radially (Ray), and the ground is classified for each Ray sequentially from the point close to ego-vehicle based on the geometric information such as the distance and angle between the points.

ray-xy

Inputs / Outputs#

This implementation inherits pointcloud_preprocessor::Filter class, please refer README.

Parameters#

Node Parameters#

This implementation inherits pointcloud_preprocessor::Filter class, please refer README.

Core Parameters#

ray-xz

Name Type Description
input_frame string frame id of input pointcloud
output_frame string frame id of output pointcloud
general_max_slope double The triangle created by general_max_slope is called the global cone. If the point is outside the global cone, it is judged to be a point that is no on the ground
initial_max_slope double Generally, the point where the object first hits is far from ego-vehicle because of sensor blind spot, so resolution is different from that point and thereafter, so this parameter exists to set a separate local_max_slope
local_max_slope double The triangle created by local_max_slope is called the local cone. This parameter for classification based on the continuity of points
min_height_threshold double This parameter is used instead of height_threshold because it's difficult to determine continuity in the local cone when the points are too close to each other.
radial_divider_angle double The angle of ray
concentric_divider_distance double Only check points which radius is larger than concentric_divider_distance
reclass_distance_threshold double To check if point is to far from previous one, if so classify again
min_x double The parameter to set vehicle footprint manually
max_x double The parameter to set vehicle footprint manually
min_y double The parameter to set vehicle footprint manually
max_y double The parameter to set vehicle footprint manually

Assumptions / Known limits#

The input_frame is set as parameter but it must be fixed as base_link for the current algorithm.

(Optional) Error detection and handling#

(Optional) Performance characterization#

(Optional) Future extensions / Unimplemented parts#