[{"@context":"https:\/\/schema.org\/","@type":"BlogPosting","@id":"https:\/\/blog.terabox.com\/insights\/pi-0-5-physical-intelligence-vla-deep-dive#BlogPosting","mainEntityOfPage":"https:\/\/blog.terabox.com\/insights\/pi-0-5-physical-intelligence-vla-deep-dive","headline":"Pi 0.5 Deep Dive: Physical Intelligence Open-Source VLA","name":"Pi 0.5 Deep Dive: Physical Intelligence Open-Source VLA","description":"\ud83d\udcfa Today’s recommended deep-dive video: https:\/\/www.youtube.com\/watch?v=QgGhK1LaUe8 Pi 0.5 Deep Dive: The State of Open-Source VLA PoliciesThe Evolution from Pi 0 to Pi 0.5The Magic of FAST TokenizationKnowledge Insulation and Dual-System ReasoningSmoothing Action with Real-Time ChunkingKey TakeawaysQ&A Pi 0.5 Deep Dive:... ","datePublished":"2026-08-21","dateModified":"2026-08-21","author":{"@type":"Person","@id":"https:\/\/blog.terabox.com\/author\/flextech-admin\/#Person","name":"flextech-admin","url":"https:\/\/blog.terabox.com\/author\/flextech-admin\/","image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/ad516503a11cd5ca435acc9bb6523536?s=150&d=mm&r=gforcedefault=1","url":"https:\/\/secure.gravatar.com\/avatar\/ad516503a11cd5ca435acc9bb6523536?s=150&d=mm&r=gforcedefault=1","height":96,"width":96}},"publisher":{"@type":"Organization","name":"terabox","logo":{"@type":"ImageObject","@id":"http:\/\/blog.terabox.com\/wp-content\/uploads\/2021\/11\/logo\u4ea7\u54c1\u540d-\u7ad6\u7248.png","url":"http:\/\/blog.terabox.com\/wp-content\/uploads\/2021\/11\/logo\u4ea7\u54c1\u540d-\u7ad6\u7248.png","width":900,"height":900}},"image":{"@type":"ImageObject","@id":"https:\/\/img.youtube.com\/vi\/QgGhK1LaUe8\/maxresdefault.jpg","url":"https:\/\/img.youtube.com\/vi\/QgGhK1LaUe8\/maxresdefault.jpg","height":"","width":""},"url":"https:\/\/blog.terabox.com\/insights\/pi-0-5-physical-intelligence-vla-deep-dive","video":{"@context":"http:\/\/schema.org\/","@type":"VideoObject","@id":"https:\/\/www.youtube.com\/watch?v=QgGhK1LaUe8#VideoObject","contentUrl":"https:\/\/www.youtube.com\/watch?v=QgGhK1LaUe8","name":"Controlling the robot with VLA policy: Pi0.5 explained (FAST, System 1\/2, KI, RTC) (VLA Series Ep.3)","description":"\ud83e\udd16 VLA Series Ep.3: Pi0.5 (Physical Intelligence)\n\nIn the previous episode, we covered Pi0. Today we go one step further: Pi0.5, one of the strongest open-source VLA policies right now.\n\n\ud83c\udfaf What you\u2019ll learn in this video:\n\u2705 Pi0 vs Pi0.5 (what actually changed)\n\u2705 FAST tokenization deep dive (DCT + BPE, with intuitive examples)\n\u2705 Knowledge Insulation (why they stop gradients from the action expert)\n\u2705 System 1 vs System 2 (Hi Robot style planning + execution)\n\u2705 Real-Time Chunking (RTC) and why it fixes \u201cshaky\u201d motion\n\u2705 Practical fine-tuning demo on my robot + what to realistically expect from small datasets\n\n\ud83c\udfaf Chapters:\n\n00:00 Intro \n02:17 Pi0.5 overview\n03:52 FAST tokenizer explained\n20:45 Knowledge Insulation\n28:20 System 1 vs System 2 (Hi Robot)\n34:44 Pi0.5 summary\n37:04 Real-Time Action Chunking\n44:12 Fine-tuning Pi0.5 with demo\n53:03 Outro\n\n\ud83c\udfac Series playlist:\nhttps:\/\/www.youtube.com\/playlist?list=PLaqgu2SjelC6yZprhmbkLZUGXw3njRxME\n\n\ud83d\udd17 Physical Intelligence Resources:\nPi0.5 blog: https:\/\/www.physicalintelligence.company\/blog\/pi05\nPi0.5 paper: https:\/\/arxiv.org\/abs\/2504.16054\nOpenPI repo: https:\/\/github.com\/Physical-Intelligence\/openpi\nFAST: https:\/\/www.physicalintelligence.company\/research\/fast\nFAST tokenizer on HF: https:\/\/huggingface.co\/physical-intelligence\/fast\nKnowledge Insulation: https:\/\/www.physicalintelligence.company\/research\/knowledge_insulation\nHi Robot: https:\/\/www.physicalintelligence.company\/research\/hirobot\nReal-Time Action Chunking (RTC): https:\/\/www.physicalintelligence.company\/research\/real_time_chunking\n\nSome illustrations shown in the video are from the Physical Intelligence website (https:\/\/www.physicalintelligence.company). Used for educational commentary. All rights belong to the original authors.\n\n\ud83e\udd17  LeRobot Pi0.5 implementation: https:\/\/github.com\/huggingface\/lerobot\/tree\/main\/src\/lerobot\/policies\/pi05\n\n\ud83d\udce6 My demo dataset: https:\/\/huggingface.co\/datasets\/IliaLarchenko\/vla_demo\n\n\ud83d\udd17 My repo with configs and inference code: https:\/\/github.com\/IliaLarchenko\/lerobot_random\/tree\/main\/vla\n\n\ud83c\udfac Previous + related videos:\nEp.1 (Intro to VLAs): https:\/\/www.youtube.com\/watch?v=8dZUOo5xWFw\nEp.2 (Pi0): https:\/\/www.youtube.com\/watch?v=ejk6-ffDXFw\nMCP server (LLMs controlling robots): https:\/\/www.youtube.com\/watch?v=EmpQQd7jRqs\nLeRobot + SO-ARM100: https:\/\/www.youtube.com\/watch?v=DeBLc2D6bvg\nMultimodality in robotics: https:\/\/www.youtube.com\/watch?v=6oZe_tKE3YA\n\nOther:\nVideo from Andrej Karpathy about tokenization (I recommend it to learn about BPE): https:\/\/www.youtube.com\/watch?v=zduSFxRajkE\n\n\ud83d\udcac Questions or ideas for the next episodes? Drop a comment, I read them all \ud83d\ude42\n\u2b50 If this was useful, like + subscribe!","thumbnailUrl":["https:\/\/i.ytimg.com\/vi\/QgGhK1LaUe8\/default.jpg","https:\/\/i.ytimg.com\/vi\/QgGhK1LaUe8\/mqdefault.jpg","https:\/\/i.ytimg.com\/vi\/QgGhK1LaUe8\/hqdefault.jpg","https:\/\/i.ytimg.com\/vi\/QgGhK1LaUe8\/sddefault.jpg","https:\/\/i.ytimg.com\/vi\/QgGhK1LaUe8\/maxresdefault.jpg"],"uploadDate":"2025-12-23T11:27:16+00:00","duration":"PT53M52S","embedUrl":"https:\/\/www.youtube.com\/embed\/QgGhK1LaUe8","publisher":{"@type":"Organization","@id":"https:\/\/www.youtube.com\/channel\/UC7wfx5BG_Ad6pxD56b8IVIg#Organization","url":"https:\/\/www.youtube.com\/channel\/UC7wfx5BG_Ad6pxD56b8IVIg","name":"Ilia","description":"Welcome to my personal channel! I'm Ilia, an ML, DS, and AI expert and robotics enthusiast. 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