{"action":"created","issue":{"url":"https://api.github.com/repos/PX4/Firmware/issues/3683","repository_url":"https://api.github.com/repos/PX4/Firmware","labels_url":"https://api.github.com/repos/PX4/Firmware/issues/3683/labels{/name}","comments_url":"https://api.github.com/repos/PX4/Firmware/issues/3683/comments","events_url":"https://api.github.com/repos/PX4/Firmware/issues/3683/events","html_url":"https://github.com/PX4/Firmware/issues/3683","id":131854577,"number":3683,"title":"LPE X-Y Position estimation based on Flow not in correct units","user":{"login":"ecmnet","id":7580193,"avatar_url":"https://avatars.githubusercontent.com/u/7580193?v=3","gravatar_id":"","url":"https://api.github.com/users/ecmnet","html_url":"https://github.com/ecmnet","followers_url":"https://api.github.com/users/ecmnet/followers","following_url":"https://api.github.com/users/ecmnet/following{/other_user}","gists_url":"https://api.github.com/users/ecmnet/gists{/gist_id}","starred_url":"https://api.github.com/users/ecmnet/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ecmnet/subscriptions","organizations_url":"https://api.github.com/users/ecmnet/orgs","repos_url":"https://api.github.com/users/ecmnet/repos","events_url":"https://api.github.com/users/ecmnet/events{/privacy}","received_events_url":"https://api.github.com/users/ecmnet/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":10,"created_at":"2016-02-06T13:06:08Z","updated_at":"2016-02-07T15:03:44Z","closed_at":null,"body":"Although position hold is working basically, it seems as if the absolute units LPE estimates for local position in XY direction are not correct. Having moved the vehicle by about 1m, LPE shows a movement of about 0.2m. \r\n\r\nhttp://logs.uaventure.com/view/RBzbbkjLCfPtU69py7w5QQ#Local_X_PLOT\r\n\r\nTo achieve better position hold results, I need to tune PIDs, but I would like to do that based on correct estimations. "},"comment":{"url":"https://api.github.com/repos/PX4/Firmware/issues/comments/181027540","html_url":"https://github.com/PX4/Firmware/issues/3683#issuecomment-181027540","issue_url":"https://api.github.com/repos/PX4/Firmware/issues/3683","id":181027540,"user":{"login":"ecmnet","id":7580193,"avatar_url":"https://avatars.githubusercontent.com/u/7580193?v=3","gravatar_id":"","url":"https://api.github.com/users/ecmnet","html_url":"https://github.com/ecmnet","followers_url":"https://api.github.com/users/ecmnet/followers","following_url":"https://api.github.com/users/ecmnet/following{/other_user}","gists_url":"https://api.github.com/users/ecmnet/gists{/gist_id}","starred_url":"https://api.github.com/users/ecmnet/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ecmnet/subscriptions","organizations_url":"https://api.github.com/users/ecmnet/orgs","repos_url":"https://api.github.com/users/ecmnet/repos","events_url":"https://api.github.com/users/ecmnet/events{/privacy}","received_events_url":"https://api.github.com/users/ecmnet/received_events","type":"User","site_admin":false},"created_at":"2016-02-07T15:03:44Z","updated_at":"2016-02-07T15:03:44Z","body":"Just removed the sonar compensation in PX4Flow (=assume altitude 1m). Flying in that height approximately gives now correct LPE scales. So for users that don't want to rely on sonar (indoors you have e.g. carpets or reflexions) but on laser range finders, I would suggest\r\n\r\na) add a parameter to PX4Flow to disable sonar compensation (or sonar at all?)\r\nb) add a parameter to LPE to compensate flow by altitude within LPE\r\n\r\nWhat do you think?"}}