[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-84223-en":3,"doc-seo-84223-105":29,"detail-sidebar-cat-0-en-105":91},{"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":20,"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},84223,962075114101,"Seraphina","https://ap-avatar.wpscdn.com/avatar/e000253a75eb197efd?x-image-process=image/resize,m_fixed,w_180,h_180&k=1780044092746381165",8,"Research & Report","Communicative Efficiency of Single vs. Multi-Axis Robot Neck Motion","Communicative head motion in human–robot interaction is shown to carry social meaning, yet the communicative role of neck movement as an independent expressive channel and its link to energy expenditure remain insufficiently studied. The work frames robot neck motion as a communication channel and introduces an information-theoretic characterisation using Shannon entropy over motion stimuli. It provides a motor-analysis and entropy-based design framework for humanoid necks, then validates perceptual meaning via participant ratings of movement type and intensity.","confirming that even task-directed head motion carries social meaning for human observers. At the control level, Haefflinger et al. [9] proposed a data-driven controller for coordinated eye and head movements in triadic human-robot interactions, highlighting the complexity of generating contextually appropriate gaze behavior in multi-person settings. The technical landscape for enabling such behaviors has been systematically reviewed by Neuber and Culemann [10], who catalogued approaches for humanoid gazefollowing, and by Fischer-Janzen et al. [11], who surveyed eye tracking-based control methods for assistive robotic systems. Complementary active perception strategies have been developed by Luzio et al. [12] for foveal visual search, and improved eye-gaze tracking hardware has been proposed by Bandi and Thomas [13] for real-time robotic applications. Field evidence for the significance of gaze in naturalistic encounters is provided by Zeng et al. [14], whose real-world eye-tracking study demonstrated structured attention patterns during human-robot encounters.  \nDespite this body of work, the communicative properties of neck movement as an independent expressive modality and its relationship to energy expenditure remain underexplored. Studies on human preferences for robot design suggest that perceptual cues including eyes and head orientation are prioritised by users even when other aspects of appearance are considered less important [15, 16], underscoring the communicative significance of head and neck motion in shaping social perception during HRI. This gap is particularly consequential for humanoid design, where the neck can be readily actuated and the decisions affect mechanical properties and social legibility of head-based nonverbal communication. The present work addresses this gap by providing the first information-theoretic characterisation of robot neck movements as a communication channel, offering quantitative design guidelines directly applicable to next-generation humanoid platforms. Here we consider single axis motions (humanlike) such as roll, pitch yaw and multi-axis motions (beyond human) by combining these three basic movements. The proposed approach can be naturally extended to the kinematic design of robotic necks, building on prior work in this area [17–19] . Furthermore, recent studies on human–robot synchrony [20] and medical facialexpression simulation [21] underscore the increasing interest in the physicality of robotic faces, particularly their embodied expressive and interactive capabilities. Shannon entropy has been used to quantify the complexity of facial expression signals generated by human avatars at different stages of transmission [22], and this concept can be extended to analyse other signals transmitted by robotic systems such as necks.  \nThe concept presented in this work is illustrated in Figure 1 . Robot neck movement is framed as a communication channel, characterised along two complementary axes. The first is a motor analysis examining the mechanical properties of communicative neck movements; roll, pitch, and yaw (motion categories) across varying motion parameters including speed, acceleration, and frequency (Figure 1A) . The second is an information-theoretic analysis quantifying the communicative content of each movement using Shannon entropy computed from the resulting motion stimuli (Figure 1B) . Together these two analyses form a design framework for robot necks that balances mechanical efficiency with maximum information transmission. To validate the perceptual validity of the generated motion features, the movements were presented to human participants in a structured survey, where participants rated their ability to perceive the intended communicative meaning and the intensity of each neck movement (Figure 1C) . This work seeks to advance understanding of two fundamental challenges: bridging the gap between physical efficiency and socially expressive behavior, and identify","cbCaiocgh9U7Prvm","https://ap.wps.com/l/cbCaiocgh9U7Prvm","pdf",3447133,1,26,"English","en",105,"# 2 Methods\n## 2.1 Robot Neck Mechanism\n## Neck Communication Framework and Information-Theoretic Quantification","[{\"question\":\"Why is robot neck movement treated as a communication channel in this work?\",\"answer\":\"Neck motion is analyzed as an additional nonverbal channel that encodes message type and intensity. The study requires decoding both movement category and strength for correct interpretation by human observers.\"},{\"question\":\"How does the study quantify information conveyed by neck motions?\",\"answer\":\"It computes Shannon entropy from the motion stimuli, using the distribution of mean absolute pixel differences between consecutive video frames. This provides an information-theoretic measure of the communicative content of each movement.\"},{\"question\":\"What mechanism is used to generate the robot neck motion signals?\",\"answer\":\"Instead of building a dedicated multi-motor neck, the study exploits the UR3 robotic arm’s existing six-DoF architecture. A compliant lattice neck with coloured silicone skin is mounted as an end-effector to realize the required roll, pitch, and yaw motions.\"}]",1784194134,66,{"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":86,"head_meta":88,"extra_data":90,"updated_unix":27},"communicative-efficiency-of-single-vs-multi-axis-robot-neck-motion","",{"@graph":35,"@context":85},[36,53,68],{"@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/communicative-efficiency-of-single-vs-multi-axis-robot-neck-motion/84223/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":23,"description":14,"dateModified":61,"datePublished":62,"encodingFormat":60,"isAccessibleForFree":63,"interactionStatistic":64},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":40,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-17","2026-07-16",true,{"@type":65,"interactionType":66,"userInteractionCount":20},"InteractionCounter",{"@type":67},"ViewAction",{"@type":69,"mainEntity":70},"FAQPage",[71,77,81],{"name":72,"@type":73,"acceptedAnswer":74},"Why is robot neck movement treated as a communication channel in this work?","Question",{"text":75,"@type":76},"Neck motion is analyzed as an additional nonverbal channel that encodes message type and intensity. The study requires decoding both movement category and strength for correct interpretation by human observers.","Answer",{"name":78,"@type":73,"acceptedAnswer":79},"How does the study quantify information conveyed by neck motions?",{"text":80,"@type":76},"It computes Shannon entropy from the motion stimuli, using the distribution of mean absolute pixel differences between consecutive video frames. This provides an information-theoretic measure of the communicative content of each movement.",{"name":82,"@type":73,"acceptedAnswer":83},"What mechanism is used to generate the robot neck motion signals?",{"text":84,"@type":76},"Instead of building a dedicated multi-motor neck, the study exploits the UR3 robotic arm’s existing six-DoF architecture. A compliant lattice neck with coloured silicone skin is mounted as an end-effector to realize the required roll, pitch, and yaw motions.","https://schema.org",{"og:url":51,"og:type":87,"og:title":13,"og:site_name":58,"og:description":14},"article",{"robots":89,"canonical":51},"index,follow",{"doc_id":7,"site_id":24},{"code":4,"msg":5,"data":92},[93,97,101,105,110,115,120,123,128,131,135],{"id":20,"doc_module":4,"doc_module_name":45,"category_name":94,"show_sort_weight":95,"slug":96},"Story & Novel",90,"story-novel",{"id":46,"doc_module":4,"doc_module_name":45,"category_name":98,"show_sort_weight":99,"slug":100},"Literature",80,"literature",{"id":52,"doc_module":4,"doc_module_name":45,"category_name":102,"show_sort_weight":103,"slug":104},"Exam",70,"exam",{"id":106,"doc_module":4,"doc_module_name":45,"category_name":107,"show_sort_weight":108,"slug":109},5,"Comic",60,"comic",{"id":111,"doc_module":4,"doc_module_name":45,"category_name":112,"show_sort_weight":113,"slug":114},6,"Technology",50,"technology",{"id":116,"doc_module":4,"doc_module_name":45,"category_name":117,"show_sort_weight":118,"slug":119},7,"Healthcare",40,"healthcare",{"id":11,"doc_module":4,"doc_module_name":45,"category_name":12,"show_sort_weight":121,"slug":122},30,"research-report",{"id":124,"doc_module":4,"doc_module_name":45,"category_name":125,"show_sort_weight":126,"slug":127},9,"Religion & Spirituality",20,"religion-spirituality",{"id":126,"doc_module":4,"doc_module_name":45,"category_name":129,"show_sort_weight":126,"slug":130},"World Cup","world-cup",{"id":132,"doc_module":4,"doc_module_name":45,"category_name":133,"show_sort_weight":132,"slug":134},10,"Lifestyle","lifestyle",{"id":136,"doc_module":4,"doc_module_name":45,"category_name":137,"show_sort_weight":106,"slug":138},19,"General","general"]