GitHub PullRequestEvent at 2014-03-19 15:27:15
Repository: drake
Actor: jacob-izr
Payload: {"action":"opened","number":65,"pull_request":{"url":"https://api.github.com/repos/RobotLocomotion/drake/pulls/65","id":13741573,"html_url":"https://github.com/RobotLocomotion/drake/pull/65","diff_url":"https://github.com/RobotLocomotion/drake/pull/65.diff","patch_url":"https://github.com/RobotLocomotion/drake/pull/65.patch","issue_url":"https://api.github.com/repos/RobotLocomotion/drake/issues/65","number":65,"state":"open","title":"Added mass and buoyancy forces, with example code","user":{"login":"jacob-izr","id":6045751,"avatar_url":"https://avatars.githubusercontent.com/u/6045751?","gravatar_id":"254889f9bc2eaf34f700ed55bbfd332f","url":"https://api.github.com/users/jacob-izr","html_url":"https://github.com/jacob-izr","followers_url":"https://api.github.com/users/jacob-izr/followers","following_url":"https://api.github.com/users/jacob-izr/following{/other_user}","gists_url":"https://api.github.com/users/jacob-izr/gists{/gist_id}","starred_url":"https://api.github.com/users/jacob-izr/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jacob-izr/subscriptions","organizations_url":"https://api.github.com/users/jacob-izr/orgs","repos_url":"https://api.github.com/users/jacob-izr/repos","events_url":"https://api.github.com/users/jacob-izr/events{/privacy}","received_events_url":"https://api.github.com/users/jacob-izr/received_events","type":"User","site_admin":false},"body":"Hi Russ,\r\n\r\nI've been working on setting up Drake to model flapping flight dynamics. So far I've implemented the added-mass forces, and I'll be working on some low-order wake models next. The added-mass forces are implemented as an additional force element definition called RigidBodyAddedMass, which integrates in with RigidBodyManipulator by reading data from the URDF file and appropriately augmenting the inertia of the parent body. I have also written a similar force element RigidBodyBuoyancy, which allows for placing a center of buoyancy on a body for performing underwater simulations.\r\n\r\nFor validation, I've included a simple underwater robot arm plant UnderwaterAcrobot with both added-mass and buoyancy. UnderwaterAcrobot runs equations of motion derived by hand from Lagrange.  The test urdfDynamicsTest() compares the UnderwaterAcrobot and RigidBodyManipulator solutions, and you can see both solutions with runURDFandAnalyticSoln(). I think I got everything to integrate with the unit tests. \r\n\r\nIf you're curious, the added-mass formulation is similar to http://www.itk.ntnu.no/ansatte/Fossen_Thor/papers/jmms95.pdf. Please let me know if you have any questions.\r\n\r\nThanks,\r\nJacob","created_at":"2014-03-19T15:27:13Z","updated_at":"2014-03-19T15:27:13Z","closed_at":null,"merged_at":null,"merge_commit_sha":null,"assignee":null,"milestone":null,"commits_url":"https://api.github.com/repos/RobotLocomotion/drake/pulls/65/commits","review_comments_url":"https://api.github.com/repos/RobotLocomotion/drake/pulls/65/comments","review_comment_url":"https://api.github.com/repos/RobotLocomotion/drake/pulls/comments/{number}","comments_url":"https://api.github.com/repos/RobotLocomotion/drake/issues/65/comments","statuses_url":"https://api.github.com/repos/RobotLocomotion/drake/statuses/8372abe6d796ff495dc1355ed51296a94d2d48a1","head":{"label":"jacob-izr:master","ref":"master","sha":"8372abe6d796ff495dc1355ed51296a94d2d48a1","user":{"login":"jacob-izr","id":6045751,"avatar_url":"https://avatars.githubusercontent.com/u/6045751?","gravatar_id":"254889f9bc2eaf34f700ed55bbfd332f","url":"https://api.github.com/users/jacob-izr","html_url":"https://github.com/jacob-izr","followers_url":"https://api.github.com/users/jacob-izr/followers","following_url":"https://api.github.com/users/jacob-izr/following{/other_user}","gists_url":"https://api.github.com/users/jacob-izr/gists{/gist_id}","starred_url":"https://api.github.com/users/jacob-izr/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jacob-izr/subscriptions","organizations_url":"https://api.github.com/users/jacob-izr/orgs","repos_url":"https://api.github.com/users/jacob-izr/repos","events_url":"https://api.github.com/users/jacob-izr/events{/privacy}","received_events_url":"https://api.github.com/users/jacob-izr/received_events","type":"User","site_admin":false},"repo":{"id":16960673,"name":"drake","full_name":"jacob-izr/drake","owner":{"login":"jacob-izr","id":6045751,"avatar_url":"https://avatars.githubusercontent.com/u/6045751?","gravatar_id":"254889f9bc2eaf34f700ed55bbfd332f","url":"https://api.github.com/users/jacob-izr","html_url":"https://github.com/jacob-izr","followers_url":"https://api.github.com/users/jacob-izr/followers","following_url":"https://api.github.com/users/jacob-izr/following{/other_user}","gists_url":"https://api.github.com/users/jacob-izr/gists{/gist_id}","starred_url":"https://api.github.com/users/jacob-izr/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jacob-izr/subscriptions","organizations_url":"https://api.github.com/users/jacob-izr/orgs","repos_url":"https://api.github.com/users/jacob-izr/repos","events_url":"https://api.github.com/users/jacob-izr/events{/privacy}","received_events_url":"https://api.github.com/users/jacob-izr/received_events","type":"User","site_admin":false},"private":false,"html_url":"https://github.com/jacob-izr/drake","description":"A planning, control, and analysis toolbox for nonlinear dynamical systems.  Please see the WIKI for documentation.","fork":true,"url":"https://api.github.com/repos/jacob-izr/drake","forks_url":"https://api.github.com/repos/jacob-izr/drake/forks","keys_url":"https://api.github.com/repos/jacob-izr/drake/keys{/key_id}","collaborators_url":"https://api.github.com/repos/jacob-izr/drake/collaborators{/collaborator}","teams_url":"https://api.github.com/repos/jacob-izr/drake/teams","hooks_url":"https://api.github.com/repos/jacob-izr/drake/hooks","issue_events_url":"https://api.github.com/repos/jacob-izr/drake/issues/events{/number}","events_url":"https://api.github.com/repos/jacob-izr/drake/events","assignees_url":"https://api.github.com/repos/jacob-izr/drake/assignees{/user}","branches_url":"https://api.github.com/repos/jacob-izr/drake/branches{/branch}","tags_url":"https://api.github.com/repos/jacob-izr/drake/tags","blobs_url":"https://api.github.com/repos/jacob-izr/drake/git/blobs{/sha}","git_tags_url":"https://api.github.com/repos/jacob-izr/drake/git/tags{/sha}","git_refs_url":"https://api.github.com/repos/jacob-izr/drake/git/refs{/sha}","trees_url":"https://api.github.com/repos/jacob-izr/drake/git/trees{/sha}","statuses_url":"https://api.github.com/repos/jacob-izr/drake/statuses/{sha}","languages_url":"https://api.github.com/repos/jacob-izr/drake/languages","stargazers_url":"https://api.github.com/repos/jacob-izr/drake/stargazers","contributors_url":"https://api.github.com/repos/jacob-izr/drake/contributors","subscribers_url":"https://api.github.com/repos/jacob-izr/drake/subscribers","subscription_url":"https://api.github.com/repos/jacob-izr/drake/subscription","commits_url":"https://api.github.com/repos/jacob-izr/drake/commits{/sha}","git_commits_url":"https://api.github.com/repos/jacob-izr/drake/git/commits{/sha}","comments_url":"https://api.github.com/repos/jacob-izr/drake/comments{/number}","issue_comment_url":"https://api.github.com/repos/jacob-izr/drake/issues/comments/{number}","contents_url":"https://api.github.com/repos/jacob-izr/drake/contents/{+path}","compare_url":"https://api.github.com/repos/jacob-izr/drake/compare/{base}...{head}","merges_url":"https://api.github.com/repos/jacob-izr/drake/merges","archive_url":"https://api.github.com/repos/jacob-izr/drake/{archive_format}{/ref}","downloads_url":"https://api.github.com/repos/jacob-izr/drake/downloads","issues_url":"https://api.github.com/repos/jacob-izr/drake/issues{/number}","pulls_url":"https://api.github.com/repos/jacob-izr/drake/pulls{/number}","milestones_url":"https://api.github.com/repos/jacob-izr/drake/milestones{/number}","notifications_url":"https://api.github.com/repos/jacob-izr/drake/notifications{?since,all,participating}","labels_url":"https://api.github.com/repos/jacob-izr/drake/labels{/name}","releases_url":"https://api.github.com/repos/jacob-izr/drake/releases{/id}","created_at":"2014-02-18T19:23:02Z","updated_at":"2014-03-19T15:27:13Z","pushed_at":"2014-03-19T15:09:25Z","git_url":"git://github.com/jacob-izr/drake.git","ssh_url":"git@github.com:jacob-izr/drake.git","clone_url":"https://github.com/jacob-izr/drake.git","svn_url":"https://github.com/jacob-izr/drake","homepage":"https://github.com/RobotLocomotion/drake/wiki","size":49057,"stargazers_count":0,"watchers_count":0,"language":"Matlab","has_issues":false,"has_downloads":true,"has_wiki":true,"forks_count":0,"mirror_url":null,"open_issues_count":0,"forks":0,"open_issues":0,"watchers":0,"default_branch":"master","master_branch":"master"}},"base":{"label":"RobotLocomotion:master","ref":"master","sha":"0de4cf016b889b49e22a183c72cdafda74d16c72","user":{"login":"RobotLocomotion","id":6496345,"avatar_url":"https://avatars.githubusercontent.com/u/6496345?","gravatar_id":"7ced8e1c168977e98e880a286ab2d7e6","url":"https://api.github.com/users/RobotLocomotion","html_url":"https://github.com/RobotLocomotion","followers_url":"https://api.github.com/users/RobotLocomotion/followers","following_url":"https://api.github.com/users/RobotLocomotion/following{/other_user}","gists_url":"https://api.github.com/users/RobotLocomotion/gists{/gist_id}","starred_url":"https://api.github.com/users/RobotLocomotion/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/RobotLocomotion/subscriptions","organizations_url":"https://api.github.com/users/RobotLocomotion/orgs","repos_url":"https://api.github.com/users/RobotLocomotion/repos","events_url":"https://api.github.com/users/RobotLocomotion/events{/privacy}","received_events_url":"https://api.github.com/users/RobotLocomotion/received_events","type":"Organization","site_admin":false},"repo":{"id":16256144,"name":"drake","full_name":"RobotLocomotion/drake","owner":{"login":"RobotLocomotion","id":6496345,"avatar_url":"https://avatars.githubusercontent.com/u/6496345?","gravatar_id":"7ced8e1c168977e98e880a286ab2d7e6","url":"https://api.github.com/users/RobotLocomotion","html_url":"https://github.com/RobotLocomotion","followers_url":"https://api.github.com/users/RobotLocomotion/followers","following_url":"https://api.github.com/users/RobotLocomotion/following{/other_user}","gists_url":"https://api.github.com/users/RobotLocomotion/gists{/gist_id}","starred_url":"https://api.github.com/users/RobotLocomotion/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/RobotLocomotion/subscriptions","organizations_url":"https://api.github.com/users/RobotLocomotion/orgs","repos_url":"https://api.github.com/users/RobotLocomotion/repos","events_url":"https://api.github.com/users/RobotLocomotion/events{/privacy}","received_events_url":"https://api.github.com/users/RobotLocomotion/received_events","type":"Organization","site_admin":false},"private":false,"html_url":"https://github.com/RobotLocomotion/drake","description":"A planning, control, and analysis toolbox for nonlinear dynamical systems.  Please see the WIKI for documentation.","fork":false,"url":"https://api.github.com/repos/RobotLocomotion/drake","forks_url":"https://api.github.com/repos/RobotLocomotion/drake/forks","keys_url":"https://api.github.com/repos/RobotLocomotion/drake/keys{/key_id}","collaborators_url":"https://api.github.com/repos/RobotLocomotion/drake/collaborators{/collaborator}","teams_url":"https://api.github.com/repos/RobotLocomotion/drake/teams","hooks_url":"https://api.github.com/repos/RobotLocomotion/drake/hooks","issue_events_url":"https://api.github.com/repos/RobotLocomotion/drake/issues/events{/number}","events_url":"https://api.github.com/repos/RobotLocomotion/drake/events","assignees_url":"https://api.github.com/repos/RobotLocomotion/drake/assignees{/user}","branches_url":"https://api.github.com/repos/RobotLocomotion/drake/branches{/branch}","tags_url":"https://api.github.com/repos/RobotLocomotion/drake/tags","blobs_url":"https://api.github.com/repos/RobotLocomotion/drake/git/blobs{/sha}","git_tags_url":"https://api.github.com/repos/RobotLocomotion/drake/git/tags{/sha}","git_refs_url":"https://api.github.com/repos/RobotLocomotion/drake/git/refs{/sha}","trees_url":"https://api.github.com/repos/RobotLocomotion/drake/git/trees{/sha}","statuses_url":"https://api.github.com/repos/RobotLocomotion/drake/statuses/{sha}","languages_url":"https://api.github.com/repos/RobotLocomotion/drake/languages","stargazers_url":"https://api.github.com/repos/RobotLocomotion/drake/stargazers","contributors_url":"https://api.github.com/repos/RobotLocomotion/drake/contributors","subscribers_url":"https://api.github.com/repos/RobotLocomotion/drake/subscribers","subscription_url":"https://api.github.com/repos/RobotLocomotion/drake/subscription","commits_url":"https://api.github.com/repos/RobotLocomotion/drake/commits{/sha}","git_commits_url":"https://api.github.com/repos/RobotLocomotion/drake/git/commits{/sha}","comments_url":"https://api.github.com/repos/RobotLocomotion/drake/comments{/number}","issue_comment_url":"https://api.github.com/repos/RobotLocomotion/drake/issues/comments/{number}","contents_url":"https://api.github.com/repos/RobotLocomotion/drake/contents/{+path}","compare_url":"https://api.github.com/repos/RobotLocomotion/drake/compare/{base}...{head}","merges_url":"https://api.github.com/repos/RobotLocomotion/drake/merges","archive_url":"https://api.github.com/repos/RobotLocomotion/drake/{archive_format}{/ref}","downloads_url":"https://api.github.com/repos/RobotLocomotion/drake/downloads","issues_url":"https://api.github.com/repos/RobotLocomotion/drake/issues{/number}","pulls_url":"https://api.github.com/repos/RobotLocomotion/drake/pulls{/number}","milestones_url":"https://api.github.com/repos/RobotLocomotion/drake/milestones{/number}","notifications_url":"https://api.github.com/repos/RobotLocomotion/drake/notifications{?since,all,participating}","labels_url":"https://api.github.com/repos/RobotLocomotion/drake/labels{/name}","releases_url":"https://api.github.com/repos/RobotLocomotion/drake/releases{/id}","created_at":"2014-01-26T16:11:05Z","updated_at":"2014-03-15T11:06:28Z","pushed_at":"2014-03-15T11:06:28Z","git_url":"git://github.com/RobotLocomotion/drake.git","ssh_url":"git@github.com:RobotLocomotion/drake.git","clone_url":"https://github.com/RobotLocomotion/drake.git","svn_url":"https://github.com/RobotLocomotion/drake","homepage":"https://github.com/RobotLocomotion/drake/wiki","size":60722,"stargazers_count":6,"watchers_count":6,"language":"Matlab","has_issues":true,"has_downloads":true,"has_wiki":true,"forks_count":11,"mirror_url":null,"open_issues_count":23,"forks":11,"open_issues":23,"watchers":6,"default_branch":"master","master_branch":"master"}},"_links":{"self":{"href":"https://api.github.com/repos/RobotLocomotion/drake/pulls/65"},"html":{"href":"https://github.com/RobotLocomotion/drake/pull/65"},"issue":{"href":"https://api.github.com/repos/RobotLocomotion/drake/issues/65"},"comments":{"href":"https://api.github.com/repos/RobotLocomotion/drake/issues/65/comments"},"review_comments":{"href":"https://api.github.com/repos/RobotLocomotion/drake/pulls/65/comments"},"review_comment":{"href":"https://api.github.com/repos/RobotLocomotion/drake/pulls/comments/{number}"},"commits":{"href":"https://api.github.com/repos/RobotLocomotion/drake/pulls/65/commits"},"statuses":{"href":"https://api.github.com/repos/RobotLocomotion/drake/statuses/8372abe6d796ff495dc1355ed51296a94d2d48a1"}},"merged":false,"mergeable":null,"mergeable_state":"unknown","merged_by":null,"comments":0,"review_comments":0,"commits":5,"additions":877,"deletions":0,"changed_files":19}}