{"action":"created","issue":{"url":"https://api.github.com/repos/diydrones/ardupilot/issues/2360","labels_url":"https://api.github.com/repos/diydrones/ardupilot/issues/2360/labels{/name}","comments_url":"https://api.github.com/repos/diydrones/ardupilot/issues/2360/comments","events_url":"https://api.github.com/repos/diydrones/ardupilot/issues/2360/events","html_url":"https://github.com/diydrones/ardupilot/pull/2360","id":84301647,"number":2360,"title":"AP_NavEKF: Improve gyro bias learning rate for plane and rover","user":{"login":"priseborough","id":3596952,"avatar_url":"https://avatars.githubusercontent.com/u/3596952?v=3","gravatar_id":"","url":"https://api.github.com/users/priseborough","html_url":"https://github.com/priseborough","followers_url":"https://api.github.com/users/priseborough/followers","following_url":"https://api.github.com/users/priseborough/following{/other_user}","gists_url":"https://api.github.com/users/priseborough/gists{/gist_id}","starred_url":"https://api.github.com/users/priseborough/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/priseborough/subscriptions","organizations_url":"https://api.github.com/users/priseborough/orgs","repos_url":"https://api.github.com/users/priseborough/repos","events_url":"https://api.github.com/users/priseborough/events{/privacy}","received_events_url":"https://api.github.com/users/priseborough/received_events","type":"User","site_admin":false},"labels":[],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2015-06-03T01:40:13Z","updated_at":"2015-06-03T02:37:06Z","closed_at":"2015-06-03T02:37:06Z","pull_request":{"url":"https://api.github.com/repos/diydrones/ardupilot/pulls/2360","html_url":"https://github.com/diydrones/ardupilot/pull/2360","diff_url":"https://github.com/diydrones/ardupilot/pull/2360.diff","patch_url":"https://github.com/diydrones/ardupilot/pull/2360.patch"},"body":"This patch increases initial gyro bias uncertainty and plane and rover specific process noise to improve the rate of gyro bias learning.\r\nThis reduces the likelihood of a navigation failure due to rapid temperature changes in the inertial sensors causing rapid changes in zero rate offset.\r\n\r\nSee attached plot showing EKF yaw angle and gyro bias estimate following a 0.05 rad/sec step change in bias applied to IMU1. The EKF_GBIAS_PNOISE parameter has been tuned to provide the fastest response to bias changes without excessive overshoot.\r\n\r\n![yaw_gyro_bias_step_response](https://cloud.githubusercontent.com/assets/3596952/7951034/b760e590-09e5-11e5-8c48-657499edabea.png)\r\n\r\nThe increase in process noise cannot be applied to Copter due to different numerical stability limits arising from the faster update rate which means it already has a faster response to gyro bias changes."},"comment":{"url":"https://api.github.com/repos/diydrones/ardupilot/issues/comments/108166247","html_url":"https://github.com/diydrones/ardupilot/pull/2360#issuecomment-108166247","issue_url":"https://api.github.com/repos/diydrones/ardupilot/issues/2360","id":108166247,"user":{"login":"tridge","id":831867,"avatar_url":"https://avatars.githubusercontent.com/u/831867?v=3","gravatar_id":"","url":"https://api.github.com/users/tridge","html_url":"https://github.com/tridge","followers_url":"https://api.github.com/users/tridge/followers","following_url":"https://api.github.com/users/tridge/following{/other_user}","gists_url":"https://api.github.com/users/tridge/gists{/gist_id}","starred_url":"https://api.github.com/users/tridge/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tridge/subscriptions","organizations_url":"https://api.github.com/users/tridge/orgs","repos_url":"https://api.github.com/users/tridge/repos","events_url":"https://api.github.com/users/tridge/events{/privacy}","received_events_url":"https://api.github.com/users/tridge/received_events","type":"User","site_admin":false},"created_at":"2015-06-03T02:37:06Z","updated_at":"2015-06-03T02:37:06Z","body":"applied, thanks!"}}