0478921 20240111140946.720171005235959.9 85039736370 10 s. E cav_un_epca*03734582223-703862 (2017)47-56Rossiiskaya Akademiya Nauk Underactuated walking Virtual holonomic constraints Poincaré section method collocated constraints cav_un_auth*0252057 Anderle Milan Teorie řízení Department of Control Theory TŘ TR UTIA-B Department of Control Theory CZ Ústav teorie informace a automatizace AV ČR, v. v. i. cav_un_auth*0101074 Čelikovský Sergej Teorie řízení Department of Control Theory TŘ TR UTIA-B Department of Control Theory Ústav teorie informace a automatizace AV ČR, v. v. i. http://lib.physcon.ru/doc?id=60655c1961ed 503 KB cav_un_auth*0347203 GA17-04682S GA ČR CZ This paper presents proof of the hybrid stability of the pre-designed walking like trajectory and its feedback tracking controller for the so-called four-link. The four-link is a planar mechanical chain having four degrees of freedom and three actuators placed between its links. In such a way it resembles a pair of legs with knees. The proof of hybrid stability is based on computing the appropriate Poincar´emap linear approximation and showing numerically that its eigenvalues are inside the unit disk in the complex plane. Unlike the frequent approach in robotic walking showing the stable path following, nature of our designed trajectory enables to prove its tracking including the time dependence. The tested trajectory and the feedback controller were obtained via combination of the design for the so-called Acrobot and suitable selected collocated holonomic constraints enforced by feedback imposed in knees actuators. This approach was published before but it will be briefly repeated here for the sake of completeness. BC 20000 20200 20205 2018 2 RVO:67985556 http://hdl.handle.net/11104/0274968 S 2017 85039736370 SCOPUS PUBMED WOS 503 KB cav_un_epca*0373458 Cybernetics and Physics 2223-7038 Roč. 6 č. 2 2017 47 56 Rossiiskaya Akademiya Nauk