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GPS drift using r_l while stationary?

Hi,

My GPS drifts laterally (y direction) when sitting stationary. I would have thought that my odometry and IMU would have bound this error? Is there a way to fix this?

r_l params

ekf_se_odom:
  frequency: 20
  sensor_timeout: 0.1
  two_d_mode: true
  transform_time_offset: 0.0
  transform_timeout: 0.0
  print_diagnostics: true
  debug: false

  map_frame: map
  odom_frame: odom
  base_link_frame: base_link
  world_frame: odom

  odom0: /wheel_odom/odom
  odom0_config: [false, false, false,
                 false, false, false,
                 true,  true,  true,
                 false, false, true,
                 false, false, false]
  odom0_queue_size: 10
  odom0_nodelay: true
  odom0_differential: false
  odom0_relative: false

  imu0: /imu/data
  imu0_config: [false, false, false,
                true,  true,  true,
                false, false, false,
                true,  true,  true,
                true,  false,  false]
  imu0_nodelay: false
  imu0_differential: false
  imu0_relative: false
  imu0_queue_size: 10
  imu0_remove_gravitational_acceleration: false #Already removed in IMU

  use_control: false

  process_noise_covariance: [1e-3, 0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    1e-3, 0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    1e-3, 0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0.01,  0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0.01,  0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0.01, 0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0.1,   0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0.5,   0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0.1,  0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0.5,  0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0.5,  0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0.3,  0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0.3,  0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0.3,  0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0.01 ]

  initial_estimate_covariance: [1e-9, 0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    1e-9, 0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    1e-9, 0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    1.0,  0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    1.0,  0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    1e-9, 0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    1.0,  0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    1.0,  0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    1.0,  0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    1.0,   0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     1.0,   0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     1.0,   0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     1.0,  0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    1.0,  0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    1.0]

ekf_se_map:
  frequency: 20
  sensor_timeout: 0.1
  two_d_mode: true
  transform_time_offset: 0.0
  transform_timeout: 0.0
  print_diagnostics: true
  debug: false

  map_frame: map
  odom_frame: odom
  base_link_frame: base_link
  world_frame: map

  odom0: /wheel_odom/odom
  odom0_config: [false, false, false,
                 false, false, false,
                 true,  true,  false,
                 false, false, true,
                 false, false, false]
  odom0_queue_size: 10
  odom0_nodelay: true
  odom0_differential: false
  odom0_relative: false

  odom1: odometry/gps
  odom1_config: [true,  true,  false,
                 false, false, false,
                 false, false, false,
                 false, false, false,
                 false, false, false]
  odom1_queue_size: 10
  odom1_nodelay: true
  odom1_differential: false
  odom1_relative: false

  imu0: /imu/data
  imu0_config: [false, false, false,
                false,  false,  true,
                false, false, false,
                false,  false,  true,
                true,  false,  true]
  imu0_nodelay: false
  imu0_differential: false
  imu0_relative: false
  imu0_queue_size: 10
  imu0_remove_gravitational_acceleration: false #Already removed in IMU

  use_control: false

  process_noise_covariance: [1.0,  0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    1.0,  0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    1e-3, 0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0.5,  0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0.5,  0,    0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0.01, 0,     0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0.5,   0,     0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0.5,   0,    0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0.1,  0,    0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0.3,  0,    0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0.3,  0,    0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0.3,  0,    0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0.3,  0,    0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0.3,  0,
                             0,    0,    0,    0,    0,    0,    0,     0,     0,    0,    0,    0,    0,    0,    0.3]

  initial_estimate_covariance: [1.0,  0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    1.0,  0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    1e-9, 0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    1.0,  0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    1.0,  0,    0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    1e-9, 0,    0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    1.0,  0,    0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    1.0,  0,    0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    1.0,  0,     0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    1.0,   0,     0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     1.0,   0,     0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     1.0,   0,    0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     1.0,  0,    0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    1.0,  0,
                                0,    0,    0,    0,    0,    0,    0,    0,    0,    0,     0,     0,     0,    0,    1.0]

navsat_transform:
  frequency: 30
  delay: 3.0
  magnetic_declination_radians: 0 #IMU accounts for this based on GPS location
  yaw_offset: 0 #assume, correct
  zero_altitude: true
  broadcast_utm_transform: true
  publish_filtered_gps: true
  use_odometry_yaw: true
  wait_for_datum: false

Asked by PapaG on 2019-11-05 17:51:24 UTC

Comments

Is your GPS drifting or your odom? How did you find your GPS drift?

Asked by Choco93 on 2019-11-06 03:30:43 UTC

@Choco93, my odom frame is fine, sits stationary when stationary. The map frame, however, drifts off.

Asked by PapaG on 2019-11-07 18:37:46 UTC

can you try with setting imu rotational (yaw) components to false for map

Asked by Choco93 on 2019-11-08 06:54:49 UTC

it's position, not heading, that drifts

Asked by PapaG on 2019-11-14 20:37:54 UTC

then try turning false imu acceleration components

Asked by Choco93 on 2019-11-18 02:59:04 UTC

Answers