{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,18]],"date-time":"2026-01-18T02:47:22Z","timestamp":1768704442553,"version":"3.49.0"},"reference-count":57,"publisher":"Association for Computing Machinery (ACM)","issue":"4","license":[{"start":{"date-parts":[[2022,9,8]],"date-time":"2022-09-08T00:00:00Z","timestamp":1662595200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/www.acm.org\/publications\/policies\/copyright_policy#Background"}],"funder":[{"name":"National Science Foundation","award":["1329891, and 1637764"],"award-info":[{"award-number":["1329891, and 1637764"]}]},{"DOI":"10.13039\/100014037","name":"National Defense Science and Engineering Graduate","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100014037","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["dl.acm.org"],"crossmark-restriction":true},"short-container-title":["J. Hum.-Robot Interact."],"published-print":{"date-parts":[[2022,12,31]]},"abstract":"<jats:p>Advances in exoskeletons and robot arms have given us increasing opportunities for providing physical support and meaningful feedback in training and rehabilitation settings. However, the chosen control strategies must support motor learning and provide mathematical task definitions that are actionable for the actuation. Typical robot control architectures rely on measuring error from a reference trajectory. In physical human-robot interaction, this leads to low engagement, invariant practice, and few errors, which are not conducive to motor learning. A reliance on reference trajectories means that the task definition is both over-specified\u2014requiring specific timings not critical to task success\u2014and lacking information about normal variability. In this article, we examine a way to define tasks and close the loop using an ergodic measure that quantifies how much information about a task is encoded in the human-robot motion. This measure can capture the natural variability that exists in typical human motion, enabling therapy based on scientific principles of motor learning. We implement an ergodic hybrid shared controller (HSC) on a robotic arm as well as an error-based controller\u2014virtual fixtures\u2014in a timed drawing task. In a study of 24 participants, we compare ergodic HSC with virtual fixtures and find that ergodic HSC leads to improved training outcomes.<\/jats:p>","DOI":"10.1145\/3526106","type":"journal-article","created":{"date-parts":[[2022,3,26]],"date-time":"2022-03-26T11:19:37Z","timestamp":1648293577000},"page":"1-20","update-policy":"https:\/\/doi.org\/10.1145\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Ergodic Shared Control: Closing the Loop on pHRI Based on Information Encoded in Motion"],"prefix":"10.1145","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9752-9925","authenticated-orcid":false,"given":"Kathleen","family":"Fitzsimons","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Pennsylvania State University, University Park, PA, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2262-8176","authenticated-orcid":false,"given":"Todd D.","family":"Murphey","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Northwestern University, Evanston, IL, USA"}]}],"member":"320","published-online":{"date-parts":[[2022,9,8]]},"reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1109\/TASE.2020.3043636"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1109\/TRO.2016.2596768"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.robot.2008.10.024"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1109\/ICVR.2008.4625154"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1109\/TRO.2013.2283410"},{"issue":"6","key":"e_1_3_3_7_2","first-page":"663","article-title":"Development of robots for rehabilitation therapy: The Palo Alto VA\/Stanford experience","volume":"37","author":"Burgar Charles G.","year":"2000","unstructured":"Charles G. Burgar, Peter S. Lum, Peggy C. Shor, and H. F. Machiel Van der Loos. 2000. Development of robots for rehabilitation therapy: The Palo Alto VA\/Stanford experience. Journal of Rehabilitation Research and Development 37, 6 (2000), 663\u2013674.","journal-title":"Journal of Rehabilitation Research and Development"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.nahs.2015.11.002"},{"issue":"6","key":"e_1_3_3_9_2","first-page":"693","article-title":"Treadmill training of paraplegic patients using a robotic orthosis","volume":"37","author":"Colombo Gery","year":"2000","unstructured":"Gery Colombo, Matthias Joerg, Reinhard Schreier, and Volker Dietz. 2000. Treadmill training of paraplegic patients using a robotic orthosis. Journal of Rehabilitation Research and Development 37, 6 (2000), 693\u2013700.","journal-title":"Journal of Rehabilitation Research and Development"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(08)70223-0"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1109\/TNSRE.2009.2033061"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1109\/TAC.2005.861711"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1177\/1545968309332927"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1109\/TRO.2009.2017111"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1126\/scirobotics.aav6079"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1177\/0278364920933654"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1109\/ACC.2016.7525614"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1109\/TSMCC.2012.2226444"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1109\/CDC.2010.5717469"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1007\/s11517-011-0809-0"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1682\/JRRD.2005.06.0103"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1145\/3359614"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1186\/1743-0003-3-12"},{"key":"e_1_3_3_24_2","volume-title":"Robotics: Science and Systems","author":"Kalinowska Aleksandra","year":"2018","unstructured":"Aleksandra Kalinowska, Kathleen Fitzsimons, Julius P. Dewald, and Todd D. Murphey. 2018. Online user assessment for minimal intervention during task-based robotic assistance. In Robotics: Science and Systems."},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1109\/ICRA48506.2021.9561746"},{"key":"e_1_3_3_26_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(13)70305-3"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.1109\/ICORR.2007.4428453"},{"key":"e_1_3_3_28_2","doi-asserted-by":"publisher","DOI":"10.1214\/aoms\/1177729694"},{"key":"e_1_3_3_29_2","first-page":"125","volume-title":"Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems","author":"Li Ming","year":"2003","unstructured":"Ming Li and Allison M. Okamura. 2003. Recognition of operator motions for real-time assistance using virtual fixtures. In Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems. IEEE, 125\u2013131."},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","DOI":"10.1109\/HAPTICS.2014.6775452"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.1177\/2055668319866311"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.1093\/brain\/awg079"},{"key":"e_1_3_3_33_2","doi-asserted-by":"publisher","DOI":"10.1053\/apmr.2001.33101"},{"key":"e_1_3_3_34_2","doi-asserted-by":"publisher","DOI":"10.1109\/TNSRE.2014.2329018"},{"key":"e_1_3_3_35_2","doi-asserted-by":"publisher","DOI":"10.1186\/1743-0003-6-20"},{"key":"e_1_3_3_36_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.physd.2010.10.010"},{"key":"e_1_3_3_37_2","doi-asserted-by":"publisher","DOI":"10.1109\/TRO.2015.2500441"},{"key":"e_1_3_3_38_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00221-009-2014-z"},{"key":"e_1_3_3_39_2","doi-asserted-by":"publisher","DOI":"10.1109\/IEMBS.2010.5626036"},{"key":"e_1_3_3_40_2","doi-asserted-by":"publisher","DOI":"10.1682\/JRRD.2005.05.0088"},{"key":"e_1_3_3_41_2","doi-asserted-by":"publisher","DOI":"10.1109\/TBME.2003.821035"},{"key":"e_1_3_3_42_2","doi-asserted-by":"publisher","DOI":"10.1109\/ACC.2001.945693"},{"key":"e_1_3_3_43_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.eswa.2013.11.047"},{"key":"e_1_3_3_44_2","doi-asserted-by":"publisher","DOI":"10.1109\/BioRob.2012.6290868"},{"key":"e_1_3_3_45_2","doi-asserted-by":"publisher","DOI":"10.1109\/RBME.2016.2552201"},{"key":"e_1_3_3_46_2","doi-asserted-by":"publisher","DOI":"10.1097\/PHM.0b013e31826bce79"},{"key":"e_1_3_3_47_2","doi-asserted-by":"publisher","DOI":"10.1109\/TNSRE.2005.848628"},{"key":"e_1_3_3_48_2","doi-asserted-by":"publisher","DOI":"10.3389\/fnins.2013.00172"},{"key":"e_1_3_3_49_2","doi-asserted-by":"publisher","DOI":"10.1097\/PHM.0b013e31826bcd42"},{"key":"e_1_3_3_50_2","doi-asserted-by":"publisher","DOI":"10.1137\/12086916X"},{"key":"e_1_3_3_51_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.physd.2009.05.003"},{"key":"e_1_3_3_52_2","doi-asserted-by":"publisher","DOI":"10.1186\/1743-0003-6-46"},{"key":"e_1_3_3_53_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00221-007-1029-6"},{"key":"e_1_3_3_54_2","doi-asserted-by":"publisher","DOI":"10.1038\/35037588"},{"key":"e_1_3_3_55_2","doi-asserted-by":"publisher","DOI":"10.1109\/ACC.2012.6314919"},{"key":"e_1_3_3_56_2","first-page":"331","volume-title":"Progress in Brain Research","author":"Winstein Carolee J.","year":"2015","unstructured":"Carolee J. Winstein and Dorsa Beroukhim Kay. 2015. Translating the science into practice: Shaping rehabilitation practice to enhance recovery after brain damage. In Progress in Brain Research, Vol. 218. Elsevier, 331\u2013360."},{"key":"e_1_3_3_57_2","doi-asserted-by":"publisher","DOI":"10.1109\/TNSRE.2008.918389"},{"key":"e_1_3_3_58_2","first-page":"1121","volume-title":"IEEE International Conference on Robotics and Automation","author":"Yu Wentao","year":"2005","unstructured":"Wentao Yu, Redwan Alqasemi, Rajiv Dubey, and Norali Pernalete. 2005. Telemanipulation assistance based on motion intention recognition. In IEEE International Conference on Robotics and Automation. IEEE, 1121\u20131126."}],"container-title":["ACM Transactions on Human-Robot Interaction"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/3526106","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/3526106","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/dl.acm.org\/doi\/pdf\/10.1145\/3526106","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,18]],"date-time":"2025-06-18T18:43:46Z","timestamp":1750272226000},"score":1,"resource":{"primary":{"URL":"https:\/\/dl.acm.org\/doi\/10.1145\/3526106"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,9,8]]},"references-count":57,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2022,12,31]]}},"alternative-id":["10.1145\/3526106"],"URL":"https:\/\/doi.org\/10.1145\/3526106","relation":{},"ISSN":["2573-9522","2573-9522"],"issn-type":[{"value":"2573-9522","type":"print"},{"value":"2573-9522","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,9,8]]},"assertion":[{"value":"2020-11-01","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2022-01-01","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2022-09-08","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}