Milestone-Proposal talk:Honda's P2, First Bipedal Robot, 1996

Advocates’ Checklist (Read Only; Do Not Edit)

1. Is the proposal for an achievement rather than for a person? If the citation includes a person's name, have the proposers provided the required justification for inclusion of the person's name?
2. Was the proposed achievement a significant advance rather than an incremental improvement to an existing technology?
3. Were there prior or contemporary achievements of a similar nature? If so, have they been properly considered in the background information and in the citation?
4. Has the achievement truly led to a functioning, useful, or marketable technology?
5. Is the proposal adequately supported by significant references (minimum of five) such as patents, contemporary newspaper articles, journal articles, or citations to pages in scholarly books? At least one of the references should be from a peer-reviewed scholarly book or journal article. The full text of the material, not just the references, shall be present. If the supporting texts are copyright-encumbered and cannot be posted on the ETHW for intellectual property reasons, the proposers shall email a copy to the History Center so that it can be forwarded to the Advocate. If the Advocate does not consider the supporting references sufficient, the Advocate may ask the proposer(s) for additional ones.
6. Are the scholarly references sufficiently recent?
7. Does the proposed citation explain why the achievement was successful and impactful?
8. Does the proposed citation include important technical aspects of the achievement?
9. Is the proposed citation readable and understandable by the general public?
10. Will the citation be read correctly in the future by only using past tense? Does the citation wording avoid statements that read accurately only at the time that the proposal is written?
11. Does the proposed plaque site fulfill the requirements?
12. Is the proposal quality comparable to that of IEEE publications?
13. Are any scientific and technical units correct (e.g., km, mm, hertz, etc.)? Are acronyms correct and properly upper-cased or lower-cased? Are the letters in any acronym explained in the title or the citation?
14. Are date formats correct as specified in Section 6 of Milestones Program Guidelines? Helpful Hints on Citations, plaque locations
15. Do the year(s) appearing in the citation fall within the range of the year(s) included at the end of the title?
16. Note that it is the Advocate's responsibility to confirm that the independent reviewers have no conflict of interest (e.g., that they do not work for a company or a team involved in the achievement being proposed, that they have not published with the proposer(s), and have not worked on a project related to the funding of the achievement). An example of a way to check for this would be to search reviewers' publications on IEEE Xplore.
17. Are the GPS coordinates correct and in decimal format?
18. Is the proposed achievement controversial because of various reasons including but not limited to: ecological, environmental, social impact, political scandal, etc.? (A relatively simple Google search on the achievement by the advocate, combined with words such as "protest", "scandal", "environmental impact" should be sufficient to alert the advocate.)

Independent Expert Reviewers’ Checklist

1. Is suggested wording of the Plaque Citation accurate?
2. Is evidence presented in the proposal of sufficient substance and accuracy to support the Plaque Citation?
3. Does proposed milestone represent a significant technical achievement?
4. Were there similar or competing achievements? If so, have the proposers adequately described these and their relationship to the achievement being proposed?
5. Have proposers shown a clear benefit to humanity?

Submission and Approval Log (For staff use only)

Submitted date: 26 June 2025
Advocate approval date:
History Committee approval date:
Board of Directors approval date:

Citation as originally submitted -- Administrator4 (talk) 12:54, 26 June 2025 (UTC)

Honda's P2, first autonomous bipedal walking humanoid Robot, 1996

In 1996, Honda’s P2 became the first autonomous bipedal humanoid robot capable of stable walking and stair climbing, marking a significant advancement in humanoid robotics. Incorporating real-time posture-control, dynamic-balance, gait-generation, and multi-joint coordination, P2 marked a breakthrough in legged robotics. Its innovative integration of mechatronics and control algorithms had a profound impact on subsequent humanoid robot development, shaping research directions and setting benchmarks in mobility, autonomy, and human-robot interaction.

Suggested Revised Title and Citation -- Bberg (talk) 18:46, 30 June 2025 (UTC)

Thank you for this interesting Milestone proposal!

I suggest this revised title since I feel that these critical words effectively describe this important work:

"The Honda P2 Walking Humanoid Robot, 1996"

I also suggest this revised citation:

In 1996, Honda’s Prototype 2 (P2) incorporated significant advancements in humanoid robotics as the first autonomous bipedal humanoid robot capable of stable walking and stair climbing. Its legged robotics incorporated real-time posture control, dynamic balance, gait generation, and multi-joint coordination, and its mechatronics and control algorithms set technical benchmarks in mobility, autonomy, and human-robot interaction. P2 had a profound impact on subsequent humanoid robot development.

Thank you. Brian Berg, 2024 Milestones Subcommittee Chair

Re: Suggested Revised Title and Citation -- Tadaaki Hasegawa (talk) 23:58, 30 June 2025 (UTC)

Thank you for your comment.
I completely agree with your comment. I will change title and citation.

Tadaaki Hasegawa, Proposer

Expert Reviewer's Report_1_Caldwell uploaded by Advocate -- Tomohiro Hase (talk) 11:44, 1 July 2025 (UTC)

Dear Prof. Hase,

Writing the comments below I feel privileged to have been asked to comment on such an important technological step for robotics and humanity. The first time I saw the Honda P2 on TV as a young researcher I was astonished. It inspired me and I am sure many of my peers were equally motivated.

In your review, the IEEE History Committee would like you to assess five particular aspects of the proposal:

(1) Is suggested wording of the Plaque Citation accurate?

Yes – The achievements in the development of the Honda P2 were truly groundbreaking. The combination of hardware and software produced a step change in our understanding of, and expectations for humanoid robots. The wording is a reflection of the many technical achievements that contributed to the demonstration and deployment of P2.

(2) Is evidence presented in the proposal of sufficient substance and accuracy to support the Plaque Citation?

Yes- The information provided is extremely detailed and accurate. It is a comprehensive collection of the range of knowledge of the Honda P2. It is the most comprehensive I have ever read. The impact across all areas of robotics and the potential benefit to society is clearly outlined. The Honda P2 is the precursor of the current wave of intense developments in humanoids. It certainly formed the vital first step in humanoid technology. Although humanoids and bipeds had existed before P2 the demonstration of this technology in 1996 was truly remarkable. I well remember my first time seeing this on TV and being astounded. The Honda P2 set a very, very high bar for future humanoid researchers to aim for.

(3) Does proposed milestone represent a significant technical achievement?

Yes - This milestone represents not just one, but a series of technical achievements encompassed and package within one system. It transformed the area of legged robotics and humanoids and open up this technology to the achievements that we see almost 30 years later.

(4) Were there similar or competing achievements?

If so, have the proposers adequately described these and their relationship to the achievement being proposed? Prior to the P2 there had been research in humanoid and biped robots. The quality of this research and it position with respect to P2 is well presented in the submission. Certainly the prior work was of a high quality but there is no doubt that the Honda P2 was a step change in humanoid technology and it left all other humanoid robotics in its wake. The P2 was truly awe inspiring when I first saw it!

(5) Have proposers shown a clear benefit to humanity?

Yes- The benefits have been clearly outlined. The potential rewards arising from this development are truly immense, however, as with all developments there is a risk of malevolent use. It is the responsibility of mankind (and especially roboticists) to ensure the vast potential that is clearly shown is used for the benefit of all!

I am completely convinced that the Honda P2 is a highly valued technological and historical asset. I recommend it in the strongest possible terms as being worthy of the IEEE Milestone.

Best Regards

Darwin

Prof Darwin G Caldwell FREng FIEEE MAE
Founding Director, Istituto Italiano di Tecnolgia
Vice President, IEEE RAS (Robotics and Automation Society)
Director, Dept. of Advanced Robotics
Italian Institute of Technology

Re: Expert Reviewer's Report_1_Caldwell uploaded by Advocate -- Tadaaki Hasegawa (talk) 00:42, 3 July 2025 (UTC)

Thank you very much for your comment. It was an honor for me, as a member of the development team, to hear that you were surprised when you first saw it. As you mentioned, the Honda P2 is the result of complex technology and engineering, and I believe it was a moment that demonstrated the possibility of what seemed impossible.

Tadaaki Hasegawa, Proposer

Expert Reviewer's Report_2_Uemura uploaded by Advocate -- Tomohiro Hase (talk) 19:39, 2 July 2025 (UTC)

IEEE Milestone Proposal Review Report: Honda’s P2, First Bipedal Robot, 1996

(1) Is suggested wording of the Plaque Citation accurate?

Yes. The proposed citation, “Honda’s P2: First Bipedal Robot, 1996,” is concise, technically accurate, and appropriately reflects the achievement documented in the proposal. It clearly identifies P2 as the first autonomous humanoid robot capable of sustained bipedal walking, a claim supported throughout the proposal with compelling technical details. The date (1996) corresponds correctly to P2’s public debut and first operational demonstration, as stated in the “Historical Significance” section. Although the term “first” can invite scrutiny, it is justified here by the uniqueness and completeness of P2’s capabilities compared to preceding efforts, which lacked real-time balance, autonomous locomotion, or full-body integration. Therefore, the citation is appropriate and requires no modification.

(2) Is evidence presented in the proposal of sufficient substance and accuracy to support the Plaque Citation?

Yes. The proposal provides substantial and credible technical evidence supporting the milestone’s claim. The “Historical Significance” and “Supporting Materials” sections offer thorough documentation, including descriptions of key technologies developed by Honda engineers to achieve stable, autonomous bipedal locomotion. Specific innovations cited include real-time ZMP (Zero Moment Point) control algorithms, distributed motor control architectures, and a six-degree-of-freedom leg structure mimicking human lower-body kinematics.

Patent references (e.g., Japanese Patent P3132156) and early technical demonstrations further substantiate the claim. The inclusion of official Honda technical papers and images depicting P2’s real-world operation enhances the credibility of the evidence. Moreover, the proposal highlights P2’s ability to walk on uneven surfaces, ascend stairs, and maintain balance—capabilities unprecedented in robotic systems at that time. This establishes that P2 was not merely an experimental device but a functional prototype embodying a major engineering breakthrough.

(3) Does proposed milestone represent a significant technical achievement?

Yes. The development of Honda’s P2 robot represents a landmark achievement in robotics and control systems history. Bipedal locomotion has long been a formidable research challenge due to the complexities of balance, dynamic motion control, and real-time feedback needed to replicate human walking. P2 was the first robot to achieve these capabilities autonomously on a self-contained platform, as well documented in the proposal.

This achievement required solving numerous multidisciplinary problems spanning mechanical engineering, control theory, artificial intelligence, and sensor fusion. The control system, based on ZMP trajectory planning and real-time compensation for ground reaction forces, was pioneering. Unlike earlier efforts, P2 integrated these systems into a mobile, humanoid form without relying on tethers or external control units. The proposal further demonstrates that P2 laid the technological foundation for subsequent Honda robots, notably the ASIMO series, which became internationally recognized symbols of advanced robotics. Thus, P2 is rightfully acknowledged as a significant technical and historical milestone.

(4) Were there similar or competing achievements? If so, have the proposers adequately described these and their relationship to the achievement being proposed?

Yes. The proposal includes a well-reasoned comparison to other robotic systems developed prior to and contemporaneous with P2, notably the WL (Walking Leg) series developed internally at Honda, as well as research at institutions such as MIT Leg Lab and Waseda University. While some of these efforts succeeded in developing rudimentary bipedal walking mechanisms, they lacked the autonomous balance and full-scale locomotion that characterized P2.

The section titled “Features Setting This Work Apart from Similar Achievements” clearly explains how P2 differed: it was the first bipedal robot to incorporate a full-body structure with integrated sensors and actuators, capable of three-dimensional motion in real-world environments without external support. Importantly, P2 was mobile, untethered, and operated in real-time using embedded processing. Earlier robots were typically static, relied on external control systems, or required suspension rigs to avoid falling. The proposal respectfully acknowledges these prior efforts, situating P2 not as an isolated leap but as the culmination of evolutionary advances, while clearly articulating why it stands apart.

(5) Have proposers shown a clear benefit to humanity?

Yes. The proposal convincingly argues that Honda’s P2 contributed significant long-term benefits to both technology and society. Although P2 itself was not a commercial product, it served as a critical testbed for technologies later applied in fields including personal assistance robotics, elder care, rehabilitation, and disaster recovery. As noted in the “Benefit to Humanity” section, the control algorithms, actuation mechanisms, and balance systems developed for P2 became foundational elements for future robotic platforms.

Moreover, P2’s influence extended beyond Honda, inspiring academic and industrial research worldwide in humanoid robotics and dynamic mobility. Its public demonstrations garnered global attention and helped reshape public perceptions of robotics’ potential. In this sense, P2 played an important role not only in engineering advancement but also in fostering public interest and investment in the future of robotics. Thus, the milestone embodies both historical significance and human-centered innovation.

Conclusion
In conclusion, the development and demonstration of Honda’s P2 in 1996 marked a transformational moment in robotics history. As the first autonomous, full-body bipedal robot capable of stable, real-time walking and navigation, it represented a leap in both theoretical understanding and practical engineering. The IEEE Milestone proposal provides clear, well-documented evidence of P2’s technical breakthroughs, contextualizes its uniqueness among global efforts, and presents a compelling argument for its long-lasting impact on technology and society.

I believe this achievement is not only technically meritorious but also of significant cultural and historical value. I strongly recommend the approval of this proposal as an IEEE Milestone.

Dr. Wataru Uemura
Associate Professor, Ryukoku University
Chairperson, RoboCup Japanese Regional Committee

July 2, 2025

Re: Expert Reviewer's Report_2_Uemura uploaded by Advocate -- Tadaaki Hasegawa (talk) 00:43, 3 July 2025 (UTC)

Thank you very much for your comment. Defining what constitutes "the first" can be challenging, but I believe it was the first to surpass a certain level in terms of being an independent machine that operates autonomously. It does not have supporting wires, control, or power cables attached, and it adapts its movements through sensors.

Tadaaki Hasegawa, Proposer

Expert Reviewer's Report_3_Kosuge uploaded by Advocate -- Tomohiro Hase (talk) 00:51, 9 July 2025 (UTC)

Dear Hase-sama,

Here is the answers to your questions:

(1) Is suggested wording of the Plaque Citation accurate?

No, it is not correct. "The Honda P2 Walking Humanoid Robot, 1996" was one of the walking humanoid robots at that time. The P2 is the world' first self-contained dynamically walking humanoid robot. Probably, more accurate expression could be as follows:
The Honda P2 (1996): The World's First Self-Contained, Dynamically Walking Humanoid Robot. or The Honda P2: The World's First Self-Contained, Dynamically Walking Humanoid Robot, 1996
or The World's First Self-Contained, Dynamically Walking Humanoid Robot, Honda P2, 1996.

If we are not allowed to use " The World's First," then, " The World's First" can be removed from the citation.

(2) Is evidence presented in the proposal of sufficient substance and accuracy to support the Plaque Citation?

Yes. As shown in the provided proposal, there are many references which support the Plaque Citation modified above.

(3) Does proposed milestone represent a significant technical achievement?

Yes. Many humanoid robots have followed P2. Today's humanoid robots have started from P2.

(4) Were there similar or competing achievements? If so, have the proposers adequately described these and their relationship to the achievement being proposed.

P2 was the first humanoid robot, which had all of its computers, batteries, motors, sensors, and control systems inside its body. It was a truly world-first self-contained, untethered humanoid robot. Before P2, many walking robots were tethered by thick cables to external power sources and massive computers.

(5) Have proposers shown a clear benefit to humanity?

There are many benefits which can be included in the proposal.
The proposers can include today's humanoid robots, such as the one from Tesla, and Atlas from Boston Dynamics, for their various applications including the use in industries.
P2 has inspired us many potential applications of the humanoid robots.

Conclusions:

Remarkably, Honda unveiled the world’s first humanoid robot, the P2, way back in 1996. I was fortunate enough to be in the conference hall when it was unveiled. I still remember how shocked we all were to see it. Today, many companies, universities and institutes are developing humanoid robots for real-world applications.
The P2 is worthy of the IEEE Milestone Award.

Best regards,

Kazuhiro Kosuge Director, JC STEM Lab of Robotics for Soft Materials
Chair Professor of Robotic Systems
Department of Electrical and Electronic Engineering
The University of Hong Kong

Re: Expert Reviewer's Report_3_Kosuge uploaded by Advocate -- Tadaaki Hasegawa (talk) 10:36, 9 July 2025 (UTC)

Thank you very much for your comment.
Your revision of the plaque citation highlights its distinctive features, and I have decided to adopt the second version. I believe that in an era without modern high-speed computing devices and high density electorical devices, the integration of an independent robot was truly a testament to the best aspects of mechanical and control technologies.

Tadaaki Hasegawa, Proposer

Expert Reviewer's Report_4_Harada uploaded by Advocate -- Tomohiro Hase (talk) 01:04, 9 July 2025 (UTC)

Here is an Expert Reviewer's Report from Prof. Harada.

Media:Review report_Harada.pdf

[Advocate's Remarks] Reviewer:
Kensuke Harada, Ph.D
Director, Robotic Manipulation Research Lab.
Professor, Graduate School of Engineering Science, The University of Osaka
Cross Appointment Fellow, The National Institute of Advanced Industrial Science and Technology (AIST)

Re: Expert Reviewer's Report_4_Harada uploaded by Advocate -- Tadaaki Hasegawa (talk) 13:19, 9 July 2025 (UTC)

Thank you very much for your comment.
Real-time ZMP control was designed not only to bring the actual ZMP closer to the designed ZMP using whole-body movements, but also to adjust the next landing position by utilizing excess movements. Through theoretical and engineering efforts, it became possible to perform model-based calculations in real time, enabling robust walking.

Tadaaki Hasegawa, Proposer