{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T16:39:28Z","timestamp":1775666368110,"version":"3.50.1"},"reference-count":49,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,9,21]],"date-time":"2022-09-21T00:00:00Z","timestamp":1663718400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Robotics"],"abstract":"<jats:p>Geriatric disorders, strokes, spinal cord injuries, trauma, and workplace injuries are all prominent causes of upper limb disability. A two-degrees-of-freedom (DoFs) end-effector type robot, iTbot (intelligent therapeutic robot) was designed to provide upper limb rehabilitation therapy. The non-linear control of iTbot utilizing modified sliding mode control (SMC) is presented in this paper. The chattering produced by a conventional SMC is undesirable for this type of robotic application because it damages the mechanical structure and causes discomfort to the robot user. In contrast to conventional SMC, our proposed method reduces chattering and provides excellent dynamic tracking performance, allowing rapid convergence of the system trajectory to its equilibrium point. The performance of the developed robot and controller was evaluated by tracking trajectories corresponding to conventional passive arm movement exercises, including several joints. According to the results of experiment, the iTbot demonstrated the ability to follow the desired trajectories effectively.<\/jats:p>","DOI":"10.3390\/robotics11050098","type":"journal-article","created":{"date-parts":[[2022,9,22]],"date-time":"2022-09-22T23:07:55Z","timestamp":1663888075000},"page":"98","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Development of an End-Effector Type Therapeutic Robot with Sliding Mode Control for Upper-Limb Rehabilitation"],"prefix":"10.3390","volume":"11","author":[{"given":"Md Mahafuzur Rahaman","family":"Khan","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA"}]},{"given":"Asif Al Zubayer","family":"Swapnil","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9277-0322","authenticated-orcid":false,"given":"Tanvir","family":"Ahmed","sequence":"additional","affiliation":[{"name":"Biomedical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4627-0009","authenticated-orcid":false,"given":"Md Mahbubur","family":"Rahman","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2677-930X","authenticated-orcid":false,"given":"Md Rasedul","family":"Islam","sequence":"additional","affiliation":[{"name":"Richard J. Resch School of Engineering, University of Wisconsin\u2014Green Bay (UWGB), Green Bay, WI 54311, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4486-0710","authenticated-orcid":false,"given":"Brahim","family":"Brahmi","sequence":"additional","affiliation":[{"name":"Electrical Engineering Department, College Ahuntsic, Montreal, QC H2M 1Y8, Canada"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6289-3049","authenticated-orcid":false,"given":"Raouf","family":"Fareh","sequence":"additional","affiliation":[{"name":"Electrical Engineering Department, University of Sharjah, Sharjah P.O. Box 27272, United Arab Emirates"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6370-8757","authenticated-orcid":false,"given":"Mohammad Habibur","family":"Rahman","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,21]]},"reference":[{"key":"ref_1","unstructured":"National Spinal Cord Injury Statistical Center (2016). Facts and Figures at a Glance, University of Alabama at Birmingham."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Burns, M., Zavoda, Z., Nataraj, R., Pochiraju, K., and Vinjamuri, R. (2020, January 20\u201324). HERCULES: A Three Degree-of-Freedom Pneumatic Upper Limb Exoskeleton for Stroke Rehabilitation. Proceedings of the 2020 42nd Annual International Conference of the IEEE Engineering in Medicine & Biology Society (EMBC), Montreal, QC, Canada.","DOI":"10.1109\/EMBC44109.2020.9176549"},{"key":"ref_3","unstructured":"Mackay, J., Mensah, G.A., and Greenlund, K. (2004). The Atlas of Heart Disease and Stroke, World Health Organization."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"634","DOI":"10.2471\/BLT.16.181636","article-title":"Stroke: A global response is needed","volume":"94","author":"Johnson","year":"2016","journal-title":"Bull. World Health Organ."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"442","DOI":"10.3389\/fnhum.2016.00442","article-title":"Rehabilitation of motor function after stroke: A multiple systematic review focused on techniques to stimulate upper extremity recovery","volume":"10","author":"Hatem","year":"2016","journal-title":"Front. Hum. Neurosci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1279","DOI":"10.1161\/01.STR.32.6.1279","article-title":"Estimates of the prevalence of acute stroke impairments and disability in a multiethnic population","volume":"32","author":"Lawrence","year":"2001","journal-title":"Stroke"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1480","DOI":"10.1161\/01.STR.0000170706.13595.4f","article-title":"Factors influencing stroke survivors\u2019 quality of life during subacute recovery","volume":"36","author":"Clark","year":"2005","journal-title":"Stroke"},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Liu, F., Han, X., Lin, M., Wu, X., Sun, Q., and Song, A. (2019, January 24\u201327). Remote Upper Limb Exoskeleton Rehabilitation Training System Based on Virtual Reality. Proceedings of the 2019 16th International Conference on Ubiquitous Robots (UR), Jeju, Korea.","DOI":"10.1109\/URAI.2019.8768618"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1007\/s12369-016-0393-4","article-title":"A novel human-robot cooperative method for upper extremity rehabilitation","volume":"9","author":"Bai","year":"2017","journal-title":"Int. J. Soc. Robot."},{"key":"ref_10","unstructured":"Khan, M.M.R., Ahmed, T., Pallares, J.R.H., Islam, M.R., Brahmi, B., and Rahman, M.H. (2021, January 26\u201327). Development of A Desktop-mounted Rehabilitation Robot For Upper Extremities. Proceedings of the International Conference on Industrial & Mechanical Engineering and Operations Management, Dhaka, Bangladesh."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1682\/JRRD.2010.04.0063","article-title":"Upper-limb robot-assisted therapy in rehabilitation of acute stroke patients: Focused review and results of new randomized controlled trial","volume":"48","author":"Masiero","year":"2011","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"482389","DOI":"10.1155\/2015\/482389","article-title":"Use of a robotic device for the rehabilitation of severe upper limb paresis in subacute stroke: Exploration of patient\/robot interactions and the motor recovery process","volume":"2015","author":"Duret","year":"2015","journal-title":"BioMed Res. Int."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1109\/TASE.2020.3027748","article-title":"Effect of hip assistance modes on metabolic cost of walking with a soft exoskeleton","volume":"18","author":"Cao","year":"2020","journal-title":"IEEE Trans. Autom. Sci. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"492","DOI":"10.1109\/TSMCA.2010.2076404","article-title":"Ontology-based unified robot knowledge for service robots in indoor environments","volume":"41","author":"Lim","year":"2010","journal-title":"IEEE Trans. Syst. Man Cybern.-Part A Syst. Humans"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1109\/RBME.2016.2552201","article-title":"Upper-limb robotic exoskeletons for neurorehabilitation: A review on control strategies","volume":"9","author":"Proietti","year":"2016","journal-title":"IEEE Rev. Biomed. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1186\/s12984-018-0383-x","article-title":"Rehabilitation robots for the treatment of sensorimotor deficits: A neurophysiological perspective","volume":"15","author":"Gassert","year":"2018","journal-title":"J. Neuroeng. Rehabil."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1103","DOI":"10.1007\/s11517-011-0797-0","article-title":"Advances in upper limb stroke rehabilitation: A technology push","volume":"49","author":"Loureiro","year":"2011","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"127","DOI":"10.1080\/11762320902840179","article-title":"ARMin III\u2013arm therapy exoskeleton with an ergonomic shoulder actuation","volume":"6","author":"Nef","year":"2009","journal-title":"Appl. Bionics Biomech."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1017\/S0263574714000034","article-title":"Development of a whole arm wearable robotic exoskeleton for rehabilitation and to assist upper limb movements","volume":"33","author":"Rahman","year":"2015","journal-title":"Robotica"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1177\/0278364917706743","article-title":"An upper-body rehabilitation exoskeleton Harmony with an anatomical shoulder mechanism: Design, modeling, control, and performance evaluation","volume":"36","author":"Kim","year":"2017","journal-title":"Int. J. Robot. Res."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Zhang, L., Guo, S., and Sun, Q. (2020). Development and assist-as-needed control of an end-effector upper limb rehabilitation robot. Appl. Sci., 10.","DOI":"10.3390\/app10196684"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Nef, T., Mihelj, M., Kiefer, G., Perndl, C., Muller, R., and Riener, R. (2007, January 13\u201315). ARMin-Exoskeleton for arm therapy in stroke patients. Proceedings of the 2007 IEEE 10th International Conference on Rehabilitation Robotics, Noordwijk, The Netherlands.","DOI":"10.1109\/ICORR.2007.4428408"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1332","DOI":"10.1016\/j.apmr.2007.07.016","article-title":"Effects of robot-aided bilateral force-induced isokinetic arm training combined with conventional rehabilitation on arm motor function in patients with chronic stroke","volume":"88","author":"Chang","year":"2007","journal-title":"Arch. Phys. Med. Rehabil."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1640023","DOI":"10.1142\/S0219519416400236","article-title":"A novel multi-dof exoskeleton robot for upper limb rehabilitation","volume":"16","author":"Liu","year":"2016","journal-title":"J. Mech. Med. Biol."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Pignolo, L., Dolce, G., Basta, G., Lucca, L., Serra, S., and Sannita, W. (2012, January 24\u201327). Upper limb rehabilitation after stroke: ARAMIS a \u201crobo-mechatronic\u201d innovative approach and prototype. Proceedings of the 2012 4th IEEE RAS & EMBS International Conference on Biomedical Robotics and Biomechatronics (BioRob), Rome, Italy.","DOI":"10.1109\/BioRob.2012.6290868"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"011022","DOI":"10.1115\/1.4048754","article-title":"Design and Kinematic Analysis of a Flexible-Link Parallel Mechanism With a Spatially Quasi-Translational End Effector","volume":"13","author":"Pan","year":"2021","journal-title":"J. Mech. Robot."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"031006","DOI":"10.1115\/1.4050150","article-title":"Design of a Single-Degree-of-Freedom Immersive Rehabilitation Device for Clustered Upper-Limb Motion","volume":"13","author":"Zhao","year":"2021","journal-title":"J. Mech. Robot."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1682\/JRRD.2010.04.0062","article-title":"Robot-assisted upper-limb therapy in acute rehabilitation setting following stroke: Department of Veterans Affairs multisite clinical trial","volume":"48","author":"Burgar","year":"2011","journal-title":"J. Rehabil. Res. Dev."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Rahman, M.H., Saad, M., Kenn\u00e9, J.P., and Archambault, P.S. (2012, January 3\u20135). Nonlinear sliding mode control implementation of an upper limb exoskeleton robot to provide passive rehabilitation therapy. Proceedings of the International Conference on Intelligent Robotics and Applications, Montreal, QC, Canada.","DOI":"10.1007\/978-3-642-33515-0_6"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"134635","DOI":"10.1109\/ACCESS.2019.2941973","article-title":"Rbfn-based adaptive backstepping sliding mode control of an upper-limb exoskeleton with dynamic uncertainties","volume":"7","author":"Wu","year":"2019","journal-title":"IEEE Access"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Feng, Y., Zhou, M., Zheng, X., and Han, F. (2016, January 5\u20137). Continuous adaptive terminal sliding-mode control. Proceedings of the 2016 IEEE 11th Conference on Industrial Electronics and Applications (ICIEA), Hefei, China.","DOI":"10.1109\/ICIEA.2016.7603574"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"974","DOI":"10.1109\/TMECH.2021.3076956","article-title":"Flatness Based Control of a Novel Smart Exoskeleton Robot","volume":"27","author":"Brahmi","year":"2021","journal-title":"IEEE\/ASME Trans. Mechatron."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"270","DOI":"10.12720\/joace.3.4.270-276","article-title":"EMG based control of a robotic exoskeleton for shoulder and elbow motion assist","volume":"3","author":"Rahman","year":"2015","journal-title":"J. Autom. Control Eng."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"44","DOI":"10.1016\/j.conengprac.2016.11.015","article-title":"Fuzzy logic based adaptive admittance control of a redundantly actuated ankle rehabilitation robot","volume":"59","author":"Ayas","year":"2017","journal-title":"Control Eng. Pract."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"984","DOI":"10.1109\/TCYB.2016.2536149","article-title":"Disturbance observer-based fuzzy control of uncertain MIMO mechanical systems with input nonlinearities and its application to robotic exoskeleton","volume":"47","author":"Chen","year":"2016","journal-title":"IEEE Trans. Cybern."},{"key":"ref_36","first-page":"539","article-title":"Sliding mode control with model-based switching functions applied on a 7-dof exoskeleton arm","volume":"26","author":"Fallaha","year":"2020","journal-title":"IEEE\/ASME Trans. Mechatron."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"261","DOI":"10.1016\/j.isatra.2019.08.010","article-title":"Improvement of sliding mode controller by using a new adaptive reaching law: Theory and experiment","volume":"97","author":"Brahmi","year":"2020","journal-title":"ISA Trans."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"10244","DOI":"10.1016\/j.jfranklin.2020.06.018","article-title":"Conventional and high order sliding mode control","volume":"357","author":"Utkin","year":"2020","journal-title":"J. Frankl. Inst."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"2099","DOI":"10.1017\/S0263574719001851","article-title":"A novel exoskeleton with fractional sliding mode control for upper limb rehabilitation","volume":"38","author":"Islam","year":"2020","journal-title":"Robotica"},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Babaiasl, M., Goldar, S.N., Barhaghtalab, M.H., and Meigoli, V. (2015, January 7\u20139). Sliding mode control of an exoskeleton robot for use in upper-limb rehabilitation. Proceedings of the 2015 3rd RSI International Conference on Robotics and Mechatronics (ICROM), Tehran, Iran.","DOI":"10.1109\/ICRoM.2015.7367867"},{"key":"ref_41","unstructured":"Khalil, H. (2002). Chapter 13: State Feedback Stabilization. Nonlinear Systems, Prentice Hall. [3rd ed.]."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1109\/TIE.2010.2045995","article-title":"Sliding-mode robot control with exponential reaching law","volume":"58","author":"Fallaha","year":"2010","journal-title":"IEEE Trans. Ind. Electron."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"S197","DOI":"10.3233\/THC-150954","article-title":"A passively safe cable driven upper limb rehabilitation exoskeleton","volume":"23","author":"Chen","year":"2015","journal-title":"Technol. Health Care"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Ahmed, T., Islam, M.R., Brahmi, B., and Rahman, M.H. (2022). Robustness and Tracking Performance Evaluation of PID Motion Control of 7 DoF Anthropomorphic Exoskeleton Robot Assisted Upper Limb Rehabilitation. Sensors, 22.","DOI":"10.3390\/s22103747"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1375","DOI":"10.1109\/LRA.2017.2669369","article-title":"Learning by demonstration for planning activities of daily living in rehabilitation and assistive robotics","volume":"2","author":"Lauretti","year":"2017","journal-title":"IEEE Robot. Autom. Lett."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"3","DOI":"10.3233\/THC-171300","article-title":"Design of a wearable cable-driven upper limb exoskeleton based on epicyclic gear trains structure","volume":"25","author":"Xiao","year":"2017","journal-title":"Technol. Health Care"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1115\/1.3149599","article-title":"On-line computational scheme for mechanical manipulators","volume":"102","author":"Luh","year":"1980","journal-title":"J. Dyn. Syst. Meas. Control"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"92","DOI":"10.1007\/s12555-011-0135-1","article-title":"Control of an exoskeleton robot arm with sliding mode exponential reaching law","volume":"11","author":"Rahman","year":"2013","journal-title":"Int. J. Control Autom. Syst."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"408","DOI":"10.1109\/TMECH.2007.901934","article-title":"Upper-limb powered exoskeleton design","volume":"12","author":"Perry","year":"2007","journal-title":"IEEE\/ASME Trans. Mechatron."}],"container-title":["Robotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2218-6581\/11\/5\/98\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:36:37Z","timestamp":1760142997000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2218-6581\/11\/5\/98"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,9,21]]},"references-count":49,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2022,10]]}},"alternative-id":["robotics11050098"],"URL":"https:\/\/doi.org\/10.3390\/robotics11050098","relation":{},"ISSN":["2218-6581"],"issn-type":[{"value":"2218-6581","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,9,21]]}}}