Local GridMap

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Local GridMap#

A state estimation that integrates lidar scans and optional odometry readings in an local occupancy map. Uses one of the simplest mapping algorithms, following the implementation of the obstacle layer in nav2 local costmap.

Updates fields “local_gridmap” with a local 8-bit gridmap (0 = obstacle, 128 = unknown, 255 = free). Optionally also update the transformation between map frame and world (which is different than identity when using an odometry source).

Example#

The video has been recorded in the Sensors notebook with the following configuration

steps: 600
time_step: 0.033
record_pose: true
record_sensing:
  - agent_indices: [0]
scenario:
  walls:
    - line: [[-10, -6], [10, -6]]
    - line: [[-10, -6], [-10, 6]]
    - line: [[10, -6], [10, 6]]
    - line: [[-10, 6], [10, 6]]
    - line: [[-8, -4], [8, -4]]
    - line: [[-8, -4], [-8, 4]]
    - line: [[8, -4], [8, 4]]
    - line: [[-8, 4], [8, 4]]
    - line: [[-5, 6], [-6, 5.5]]
    - line: [[-6, 5.5], [-7, 6]]
  groups:
    - type: wheelchair
      color: darkorange
      number: 1
      radius: 0.25
      orientation: 3.14
      position: [0, 5]
      kinematics:
        type: 2WDiff
        max_speed: 1
        wheel_axis: 0.5
      behavior:
        type: Dummy
        environment: Sensing
      task:
        type: Path
        points: [[-9, -5], [9, -5], [9, 5], [-9, 5], [-9, -5]]
        tolerance: -1
      state_estimations:
        - type: Lidar
          name: lidar
          resolution: 1001
          range: 10
          start_angle: {-np.pi}
          field_of_view: {2 * np.pi}
          error_std_dev: 0.02
        - type: Odometry
          name: odom
        - type: LocalGridMap
          height: 300
          width: 300
          resolution: 0.02
          name: gridmap
          external_lidars: [lidar]
          external_odometry: odom
    - type: human
      color: red
      number: 5
      radius: 0.2
      orientation: 3.14
      position: [[8, -5], [5, -5], [2, -5], [-1, -5], [-4, -5]]
      kinematics:
        type: Ahead
        max_speed: 1
        max_angular_speed: 10.0
      behavior:
        type: HL
        horizon: 10
      task:
        type: Path
        points: [[-9, 5], [9, 5], [9, -5], [-9, -5], [-9, 5]]
        tolerance: -1
      state_estimation:
        type: Bounded
        range: 10
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