[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-85374-en":3,"doc-seo-85374-105":29,"detail-sidebar-cat-0-en-105":90},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":13,"seo_description":14,"update_tm":27,"read_time":28},85374,7971461741311,"Ophelia","https://ap-avatar.wpscdn.com/avatar/74000253aff267980c6?x-image-process=image/resize,m_fixed,w_180,h_180&k=1779345379180704826",8,"Research & Report","Robust Bipedal Locomotion on Flowable Slopes via Foot-driven Terrain Manipulation","Bipedal robots face rapid instability when foot–terrain contact variations amplify underactuated dynamics, especially on flowable granular slopes where contact induces large deformations and solid–fluid-like transitions. The work studies terradynamics of cleated feet and shows that sparse and dense cleat spacing respectively cause excessive yielding/resistance and locomotion failure, while intermediate spacing keeps substrate stresses near or below the yield threshold, enabling climbs up to 30°. It then proposes an actively adjustable foot and validates the limb-centric principles on a larger 15 kg autonomous biped.","arXiv :2607 . 11855v1 [ cs .RO] 13 Jul 2026  \nRobust bipedal locomotion on flowable slopes via foot-driven terrain manipulation  \nDeniz Kerimoglu 1∗ , Junnosuke Kamohara 1 , Jiyeon Maeng2 , Ziwon Yoon 1 , Seth Hutchinson3 , Ye Zhao 1 , and Daniel I. Goldman2  \n1Department of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA  \n2 School of Physics, Georgia Institute of Technology, Atlanta, GA 30332, USA  \n3Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA  \n∗ Corresponding author; E-mail: [dkerimoglu6@gatech.edu](dkerimoglu6@gatech.edu)  \nBipedal robots are challenging to control because they operate close to instability, where small variations in foot-terrain contact can rapidly destabilize locomotion. On rigid terrain, bipedal robots mitigate this fragility by using well-established contact mechanics and control strategies. On flowable surfaces such as granular slopes, foot contact can induce large surface deformations and solid–fluid–like transitions, coupling terrain effects with robot dynamics, leading to underperformance or failure. This is partly due to the lack of reliable methods to represent the dynamics of flowable terrain, making it difficult to account for terrain effects in locomotion design. Here, we investigate how controlling terrain response can improve bipedal locomotion on granular slopes by studying the terradynamics of “cleated” feet, thin plates emanating from the foot soles. Systematic studies of a small-scale (1.4 kg) robophysical biped reveal that cleats with sparse and dense spacing lead to  \nexcessive terrain yielding and resistance, respectively, degrading performance and leading to failure. An intermediate cleat spacing distributes interaction forces to maintain substrate stresses near (or below) the yield threshold, enabling walking on granular slopes up to 30°. Guided by these principles, we design a foot that actively adjusts cleat depth and accommodates both rigid and granular terrain. We also demonstrate that the principles of effective foot-terrain interaction translate to a larger (15 kg) autonomous biped.  \nOur study presents an alternative to conventional “body-centric” robot control approaches, which regulate terrain-induced effects through body motion, by instead regulating terrain interactions through “limb-centric” approach.  \n[https://anonymous.4open.science/w/flowable-slope-locomotion-biped/](https://anonymous.4open.science/w/flowable-slope-locomotion-biped/)  \n1 INTRODUCTION  \nRobotic locomotion in natural environments is essential in performing operations such as exploration, deployment, and most importantly, collaboration with humans. Bipedal robots emerge as a suitable platform for these tasks, yet robust locomotion remains a central challenge due to their fragile stability: small perturbations in ground reaction forces can rapidly destabilize body dynamics (1–3) . To mitigate this fragility, most bipedal robots rely on well-established rigid contact models and control strategies that regulate center-of-mass dynamics and ground reaction forces, assuming that terrain response is predictable and largely decoupled from body dynamics (4) . However, many natural terrains, such as deserts, drylands, and soil, comprise yielding substrates that deform and flow once contact forces exceed their yield stress. Granular slopes are particularly challenging for bipedal systems as foot interactions on such substrates induce excessive deformations, downward flow, and solid– and fluid–like transitions. These terrain dynamics create a strong coupling between the robot and the substrate: the robot disturbs  \nthe terrain, while the evolving terrain perturbs robot motion. In bipeds, this coupling is particularly important because their tall, upright morphology and limited foot contact area increase susceptibility to locomotor instabilities (Fig. 1 A) . As a consequence, locomotor performance remains limited, and/or frequent f","cbCaiurPKbSJG3kd","https://ap.wps.com/l/cbCaiurPKbSJG3kd","pdf",11944362,1,38,"English","en",105,"# Introduction\n## Motivation and challenges on flowable terrain\n## Limitations of existing terrain models\n## Body-centric vs limb-centric control perspective","[{\"question\":\"Why is bipedal locomotion difficult on flowable granular slopes?\",\"answer\":\"Small variations in foot-terrain contact can destabilize locomotion, and on flowable granular slopes foot forces trigger large deformations and solid–fluid-like transitions that strongly couple terrain dynamics with robot motion.\"},{\"question\":\"How does cleat spacing affect locomotion performance on granular slopes?\",\"answer\":\"Sparse cleats lead to excessive terrain yielding and dense cleats create excessive resistance, both degrading performance and causing failure. Intermediate spacing distributes interaction forces to maintain substrate stresses near or below the yield threshold, enabling walking on slopes up to 30°.\"},{\"question\":\"What is the document’s key control idea compared with conventional approaches?\",\"answer\":\"Instead of regulating terrain effects through body-centric motion, it proposes a limb-centric approach that regulates foot–terrain interactions by actively shaping terrain response through a cleated, depth-adjusting foot.\"}]",1784202950,96,{"code":4,"msg":30,"data":31},"ok",{"site_id":24,"language":23,"slug":32,"title":13,"keywords":33,"description":14,"schema_data":34,"social_meta":85,"head_meta":87,"extra_data":89,"updated_unix":27},"robust-bipedal-locomotion-on-flowable-slopes-via-foot-driven-terrain-manipulation","",{"@graph":35,"@context":84},[36,53,67],{"@type":37,"itemListElement":38},"BreadcrumbList",[39,43,47,50],{"item":40,"name":41,"@type":42,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":44,"name":45,"@type":42,"position":46},"https://docshare.wps.com/document/","Document",2,{"item":48,"name":12,"@type":42,"position":49},"https://docshare.wps.com/document/research-report/",3,{"item":51,"name":13,"@type":42,"position":52},"https://docshare.wps.com/document/robust-bipedal-locomotion-on-flowable-slopes-via-foot-driven-terrain-manipulation/85374/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":23,"description":14,"dateModified":61,"datePublished":61,"encodingFormat":60,"isAccessibleForFree":62,"interactionStatistic":63},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":40,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-16",true,{"@type":64,"interactionType":65,"userInteractionCount":4},"InteractionCounter",{"@type":66},"ViewAction",{"@type":68,"mainEntity":69},"FAQPage",[70,76,80],{"name":71,"@type":72,"acceptedAnswer":73},"Why is bipedal locomotion difficult on flowable granular slopes?","Question",{"text":74,"@type":75},"Small variations in foot-terrain contact can destabilize locomotion, and on flowable granular slopes foot forces trigger large deformations and solid–fluid-like transitions that strongly couple terrain dynamics with robot motion.","Answer",{"name":77,"@type":72,"acceptedAnswer":78},"How does cleat spacing affect locomotion performance on granular slopes?",{"text":79,"@type":75},"Sparse cleats lead to excessive terrain yielding and dense cleats create excessive resistance, both degrading performance and causing failure. Intermediate spacing distributes interaction forces to maintain substrate stresses near or below the yield threshold, enabling walking on slopes up to 30°.",{"name":81,"@type":72,"acceptedAnswer":82},"What is the document’s key control idea compared with conventional approaches?",{"text":83,"@type":75},"Instead of regulating terrain effects through body-centric motion, it proposes a limb-centric approach that regulates foot–terrain interactions by actively shaping terrain response through a cleated, depth-adjusting foot.","https://schema.org",{"og:url":51,"og:type":86,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":88,"canonical":51},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":91},[92,96,100,104,109,114,119,122,127,130,134],{"id":20,"doc_module":4,"doc_module_name":45,"category_name":93,"show_sort_weight":94,"slug":95},"Story & Novel",90,"story-novel",{"id":46,"doc_module":4,"doc_module_name":45,"category_name":97,"show_sort_weight":98,"slug":99},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":45,"category_name":101,"show_sort_weight":102,"slug":103},"Exam",70,"exam",{"id":105,"doc_module":4,"doc_module_name":45,"category_name":106,"show_sort_weight":107,"slug":108},5,"Comic",60,"comic",{"id":110,"doc_module":4,"doc_module_name":45,"category_name":111,"show_sort_weight":112,"slug":113},6,"Technology",50,"technology",{"id":115,"doc_module":4,"doc_module_name":45,"category_name":116,"show_sort_weight":117,"slug":118},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":45,"category_name":12,"show_sort_weight":120,"slug":121},30,"research-report",{"id":123,"doc_module":4,"doc_module_name":45,"category_name":124,"show_sort_weight":125,"slug":126},9,"Religion & Spirituality",20,"religion-spirituality",{"id":125,"doc_module":4,"doc_module_name":45,"category_name":128,"show_sort_weight":125,"slug":129},"World Cup","world-cup",{"id":131,"doc_module":4,"doc_module_name":45,"category_name":132,"show_sort_weight":131,"slug":133},10,"Lifestyle","lifestyle",{"id":135,"doc_module":4,"doc_module_name":45,"category_name":136,"show_sort_weight":105,"slug":137},19,"General","general"]