Milestone-Proposal:Honda's P2, First Bipedal Robot, 1996
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Docket #:2025-14
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To the proposer’s knowledge, is this achievement subject to litigation? No
Is the achievement you are proposing more than 25 years old? Yes
Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes
Did the achievement provide a meaningful benefit for humanity? Yes
Was it of at least regional importance? Yes
Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes
Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes
Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes
Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes
Year or range of years in which the achievement occurred:
1996
Title of the proposed milestone:
Honda's P2, first autonomous bipedal walking humanoid Robot, 1996
Plaque citation summarizing the achievement and its significance; if personal name(s) are included, such name(s) must follow the achievement itself in the citation wording: Text absolutely limited by plaque dimensions to 70 words; 60 is preferable for aesthetic reasons.
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.
200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.
Honda’s P2 humanoid robot, introduced in 1996, represents a historic milestone in robotics history. As the first self-contained, autonomous humanoid robot capable of stable, dynamic bipedal walking, P2 demonstrated real-world feasibility of human-like locomotion, overcoming challenges such as dynamic balance and real-time feedback control. It introduced advanced dynamic balance control, real-time feedback systems, and highly articulated motion planning—setting a technical benchmark that would serve as the foundation for future generations of humanoid robots.
At a time when most global robotics research was focused on quadrupeds or wheeled robots with limited autonomy, P2 stood out for its fully integrated architecture and human-scale physicality, surpassing contemporaneous quadruped and wheeled robots in versatility and adaptability. Its development marked a major shift in robotics—from machines optimized for industrial tasks to intelligent, mobile agents designed for social and assistive roles.
Scientifically, P2 contributed to robotics, biomechanics, and AI by addressing the complex problem of dynamically stable bipedal locomotion. Socially, it reshaped public perception of robots and accelerated the development of applications in healthcare, rehabilitation, education, and personal assistance. Its technological and conceptual breakthroughs paved the way for the ASIMO series and inspired international research in humanoid robotics, setting a trajectory that continues to shape the industry today.
IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides. IEEE Robotics & Automation Society In what IEEE section(s) does it reside? IEEE Tokyo Section
IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:
IEEE Organizational Unit(s) paying for milestone plaque(s):
Unit: IEEE Tokyo Section
Senior Officer Name: Toshiro Hiramoto
IEEE Organizational Unit(s) arranging the dedication ceremony:
Unit: IEEE Tokyo Section
Senior Officer Name: Toshiro Hiramoto
IEEE section(s) monitoring the plaque(s):
IEEE Section: IEEE Tokyo Section
IEEE Section Chair name: Toshiro Hiramoto
Milestone proposer(s):
Proposer name: Chiaki Ishikawa
Proposer email: Proposer's email masked to public
Proposer name: Tadaaki Hasegawa
Proposer email: Proposer's email masked to public
Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.
Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):
Honda Collection Hall, Mobility Resort Motegi, 120-1, Hiyama, Motegi-cho, Haga-gun, Tochigi, 320-3533, Japan.
GPS Coordinate: 36.5268157,140.2266043,17
Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.
Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. The plaque will be desplayed on Honda Collection Hall.
Are the original buildings extant?
No.
Details of the plaque mounting:
It is placed on Honda Collection Hall where many displays related to Honda products are placed.
How is the site protected/secured, and in what ways is it accessible to the public?
Visitors can come to the Honda Collection Hall without security check.
Who is the present owner of the site(s)?
Mitsuomi Inaba, Director, General Manager, Mobility Resort Motegi, Honda Mobilityland Corporation.
What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include detailed support at the end of this section preceded by "Justification for Inclusion of Name(s)". (see section 6 of Milestone Guidelines)
Historical Significance
Overview of Honda P2
A demonstration video of the Honda Humanoid Robot P2, developed by Honda in 1996, is available following "P2model.flv" file. It showcases P2's advanced bipedal locomotion and human-like movements.
[Remarks] To play the file named 'P2model.flv' as follows, you will need software such as VLC Media Player.
The Honda P2 (Prototype 2), unveiled in December 1996, was the world's first self-regulating, two-legged humanoid robot capable of autonomous walking. As a groundbreaking development in the field of robotics, it embodied years of research into dynamic walking and human-robot interaction. The P2 represented a significant evolution from earlier prototypes, featuring a more compact and human-like design as well as an onboard power source and computing system (see Photo 1).
Height and Weight
The P2 stood approximately 182 centimeters (6 feet) tall, giving it a human-like stature that enabled research into more natural interactions with people and environments.
The robot weighed about 210 kilograms (463 pounds), with the bulk of the weight consisting of actuators, control systems, and the onboard power supply.
Figure 1 P2 Height and Weight (Sourece: Reference 2)
P2 was the direct predecessor to the later and more famous ASIMO robot [7]. As the first prototype to achieve autonomous, dynamic walking with a human-scale body, it laid the technological foundation for modern humanoid robotics.
Photo 1: Honda's P2 humanoid robot walking autonomously.
This image demonstrates the robot in motion, supported by its self-contained power and control systems. The dynamic walking posture reflects the real-time balance and coordination achieved by P2 in 1996.
Technological Breakthroughs in Bipedal Locomotion
Details of the history of each generation of Honda’s robots, as shown in Figure 1, can be found on Honda’s website. An excerpt of this information is provided in Appendix 1.
Honda’s P2 robot, demonstrated in 1996, marked a historic breakthrough in the field of humanoid robotics. As one of the world’s first practical bipedal robots, P2 demonstrated stable and autonomous walking—something that had long eluded researchers due to the complexity of dynamic balance control.
Compared to its predecessor P1, P2 featured significant advancements in motion control, sensor integration, and real-time responsiveness, enabling more human-like gait and posture. These innovations laid the technical foundation for future humanoid robots, including Honda’s ASIMO [7].
The history of Honda's robot development is shown in Figure 1 and its specibication is shwn in Table 1.
Figure 2 Honda_Robot_history (Source: Honda website, https://global.honda/jp/ASIMO/history/)
Table 1 Developement and specification of HONDA's biped robots (Sourece: Reference 2)
Scientific Contributions to Human-Machine Understanding
Beyond engineering, P2 also contributed significantly to scientific fields such as biomechanics, human-robot interaction, and computational control. The robot’s design necessitated interdisciplinary insights—combining mechanical engineering, control theory, sensor fusion, and biological inspiration. As researchers worked to approximate human-like movement, they deepened their understanding of human balance, locomotion dynamics, and adaptive control systems. These contributions had downstream effects on fields such as prosthetics, rehabilitation engineering, and assistive technologies.
Societal Impact and Public Engagement
P2’s public demonstrations were pivotal in changing perceptions of robotics. By showing that humanoid robots could perform lifelike movements and function in familiar environments, P2 sparked global interest and inspired a new generation of roboticists. It was not merely a research project—it was a statement that robots could one day serve practical and social roles beyond factory automation. Through media coverage and public exhibitions, Honda successfully positioned P2 as a symbol of technological progress and social benefit.
Technical Achievements of P2
Real-Time Dynamic Balance Control
One of P2’s most remarkable technical achievements was its ability to perform dynamically stable walking in real time. Unlike static robots that relied on fixed postures or support mechanisms, P2 utilized feedback loops from onboard sensors to adjust its joint movements instantaneously. This allowed it to shift its center of gravity and adapt to varying surfaces—enabling human-like walking over flat, inclined, and uneven terrain.
This accomplishment represented a major leap forward from earlier robotics, which often depended on external computation or guide rails. P2’s onboard processing enabled it to operate untethered, autonomously assessing and responding to its environment.
Sensor Integration and Control Algorithms
P2 employed an advanced array of sensors—including gyroscopes, accelerometers, and joint encoders—that worked in concert to determine posture, velocity, and impact forces. These sensors fed into a custom control system that calculated optimal joint torques and trajectories in real time. The robot’s motion was smooth, responsive, and stable—far beyond what had been seen in any humanoid system before.
The algorithms developed for P2 served as the basis for future humanoid control architectures, and their principles continue to influence robotics education and design standards today.
Power Autonomy and Full-Body Integration
P2 was one of the first full-sized bipedal robots to operate without a tethered power supply or external processor. It carried its own batteries and computing hardware, representing a significant achievement in energy management, component miniaturization, and thermal regulation [10].
Moreover, P2’s physical structure—joint placements, limb lengths, and mass distribution—was engineered to resemble human biomechanics, further supporting balance and coordination [1]. This physical realism allowed P2 to serve as a testbed for biomechanical modeling and future assistive robotics.
Long-Term Influence and Legacy
Foundation for ASIMO and Successor Systems
P2 served as the direct forerunner of ASIMO [7], one of the world’s most recognized humanoid robots. Many of ASIMO’s capabilities—such as smoother walking, running, and stair climbing—were made possible through the foundational work conducted on P2. The knowledge gained from P2's design, testing, and public demonstration cycles translated directly into more sophisticated iterations of Honda’s humanoid robot line.
Catalyzing Global Research and Development
P2’s unveiling was a wake-up call for the global robotics community. It showed that humanoid robotics was no longer theoretical—it was possible, and happening. This motivated universities, private companies, and government institutions around the world to accelerate their humanoid research programs.
Additionally, P2’s success helped validate humanoid robotics as a viable field of study and industry investment. Numerous robotics curricula began incorporating dynamic balance control, human-inspired locomotion, and sensor-driven adaptability—areas where P2 had already demonstrated real-world success.
Influence on Non-Industrial Robotics Applications
Honda's P2, introduced in 1996, marked a significant advancement in humanoid robotics by achieving stable bipedal locomotion. This milestone laid the groundwork for subsequent developments in assistive technologies aimed at enhancing human mobility.
(a) Advancement of Humanoid Robotics:
The P2's innovative design and control systems demonstrated the feasibility of human-like walking in robots. This achievement directly influenced the development of Honda's ASIMO, which further refined these capabilities and showcased the potential for robots to interact with and assist humans in various environments.
(b) Inspiration for Assistive Technologies:
Building upon the insights gained from P2 and ASIMO, Honda developed walking assist devices designed to support individuals with mobility challenges. These devices, such as the Bodyweight Support Assist, reduce the load on leg muscles and joints, facilitating easier movement for users with weakened leg muscles or those engaged in physically demanding activities. The development of these assistive devices was informed by the cooperative control technologies and human gait analysis techniques honed during the P2 and ASIMO projects.
(c) Impact on Rehabilitation and Elderly Care The principles established by P2 and ASIMO have been instrumental in the design of rehabilitation technologies and mobility aids for the elderly. By understanding human biomechanics and applying this knowledge to robotic systems, Honda has contributed to the creation of devices that assist with walking, standing, and performing daily activities, thereby improving the quality of life for individuals with mobility impairments.
(d) Academic and Industry Recognition
The influence of P2 and its successors extends beyond Honda's internal developments. Academic research and industry applications have drawn upon the technologies pioneered by P2, leading to advancements in fields such as prosthetics, exoskeletons, and assistive robotics. These innovations have been recognized in various scholarly articles and industry reports, underscoring the broader impact of Honda's work on non-industrial robotics applications.
What obstacles (technical, political, geographic) needed to be overcome?
Development Challenges and Solutions
Religious Concerns and Solutions
Concerns:
In the field of robot development, Asimov's Three Laws of Robotics have long been well known. However, beyond these, there have been religious concerns—especially in Western countries—regarding bipedal robots due to their human-like appearance and behavior [N4], [N5].
Solutions:
To address this, Honda engineers visited the Vatican and consulted with Christian priests about these concerns. Through this dialogue, they learned that there was no need for worry [N4], [N6].
Overcoming Technological Limitations of the Late 20th Century
Issue:
When Honda began its humanoid robot project in the late 1980s, the technological landscape was vastly different from today. Computational power, sensor precision, and actuator performance were all limited. One of the greatest challenges in bipedal locomotion was ensuring real-time balance and motion control with the hardware available at the time. Falling or instability during walking was a common issue.
Solution:
To solve these challenges, Honda developed a proprietary dynamic balance control system using gyroscopes, accelerometers, and force sensors to monitor the robot’s posture. With sophisticated software and custom-built actuators, P2 was able to adjust its movements in real time to maintain stability—even on uneven terrain. These technologies greatly exceeded the state-of-the-art capabilities of the era.
Development Challenges and Solutions in the Creation of Humanoid Robot P2
Challenge: Achieving High-Quality Bipedal Walking
Background:
Bipedal robots had been researched for decades, including dynamic walking models. However, their walking remained unstable and experimental.
Issue:
Existing robots lacked the walking quality necessary for practical applications.
Solution:
Honda achieved robust, stable, and lifelike bipedal walking that surpassed previous efforts.
P2 could walk smoothly, stop precisely, and maintain balance without appearing unstable—leading many to describe it as “a person might be inside”.
Challenge: Improving Performance Without Revolutionary Hardware
Background:
P2 used standard components—DC servo motors, harmonic drives, aluminum alloy structures, and common sensors.
Issue:
How to achieve exceptional performance using ordinary hardware.
Solution:
Honda engaged in extensive trial-and-error prototyping (E0 to E6 models), maintaining consistent leg structures across models.
Through repeated fine-tuning, they optimized motor outputs, gear ratios, material thickness, and mechanical arrangements.
This incremental refinement led to a highly reliable and high-precision leg mechanism.
Challenge: Limitations of Control Theory Alone
Background:
Robotics research often emphasized advanced control algorithms to compensate for mechanical shortcomings.
Issue:
Relying solely on control logic cannot overcome poor mechanical design.
Solution:
Demonstrated that mechanical excellence enables simpler control.
On flat surfaces, P2 achieved dynamic walking with trajectory control alone, without sensor-based feedback.
This proved the mechanical system's accuracy, rigidity, and responsiveness, essential for natural motion.
Challenge: Structural Constraints of Academic Research
Background:
University research focuses on novelty and publishes results from small numbers of prototypes, often with drastic design changes.
Issue:
This approach hinders the refinement necessary for high-quality performance.
Solution:
As an automobile manufacturer, Honda had the infrastructure and mindset for long-term, incremental development.
They leveraged a strong prototyping division to support iterative design, fabrication, and testing, accumulating know-how across years.
This process emphasized engineering discipline over research novelty.
Conclusion: The Key to P2’s Success
Honda’s breakthrough was not in new technologies, but in refining existing ones through persistence and precision.
The success of P2 teaches that advanced control requires a solid mechanical foundation.
Like climbing a mountain: no matter how skilled the climber (control), the peak you reach is determined by the height of the mountain (mechanism).
What features set this work apart from similar achievements?
Comparison with Contemporary Robotic Approaches
At the time of its unveiling in 1996, Honda’s P2 stood apart from other robotic systems being developed worldwide. A number of approaches existed—most notably quadruped robots, wheeled robots, and other bipedal platforms—but P2 offered a combination of human-like form, autonomous control, and practical mobility that was unprecedented. The following comparisons illustrate how P2 surpassed its contemporaries:
Comparison with Quadruped Robots
Quadruped robots, such as early prototypes developed by Boston Dynamics [10], were primarily engineered for stability and mobility on rugged terrain. Their four-legged structure gave them superior balance and load distribution, making them well-suited for traversing uneven ground or climbing over obstacles. However, these robots typically required external control systems and were often tethered to off-board power supplies. Their mechanical design, while robust, lacked the compact integration necessary for real-world deployment in human environments.
In contrast, Honda’s P2 was a fully autonomous, self-contained humanoid robot that operated untethered. Its bipedal form was not only a technical challenge but a strategic decision aimed at integrating robots into daily human life. By mimicking human gait and posture, P2 could navigate stairs, doorways, and other architectural features common in homes, offices, and public infrastructure—tasks that quadrupeds of the time could not perform effectively. While quadruped robots had advantages in outdoor scenarios, P2’s anthropomorphic design made it better suited for collaborative and assistive roles in human-centric environments.
Comparison with Other Bipedal Robots
During the late 1990s and early 2000s, several other bipedal humanoid robots emerged, including Honda's ASIMO [7] and Sony’s QRIO [8]. These robots often prioritized user interaction, compact design, and entertainment value. QRIO, for example, focused on expressive motion, communication, and personality-driven behavior. However, these designs typically sacrificed physical mobility and robustness for size and accessibility, limiting their effectiveness in tasks requiring substantial locomotion or load-bearing capability.
In contrast, Honda’s P2 was conceived as a full-sized humanoid robot with an emphasis on real-world utility. Its large frame, sophisticated control systems, and powerful actuators enabled it to perform stable, dynamic walking across a variety of surfaces. Unlike smaller bipedal robots, P2 demonstrated not just anthropomorphism but functional parity with human movement. This made it a foundational model for future service robots, as it bridged the gap between robotic novelty and practical application. Its emphasis on stability, autonomy, and scalability made it far more advanced than its peers at the time.
Conclusion
Honda’s P2 surpassed other robotic approaches of its time by delivering a holistic integration of human-like motion, autonomous control, and real-world applicability. Unlike quadruped, wheeled, or entertainment-focused robots, P2 demonstrated the potential for humanoid robots to operate independently in environments designed for people. Its success laid the groundwork for future humanoid systems and shifted global expectations of what robotics could achieve in society.
Why was the achievement successful and impactful?
Why the achievement was successful and impactful?
Honda’s P2, unveiled in 1996, was a groundbreaking achievement in robotics, marking the first autonomous, full-scale bipedal humanoid robot capable of dynamic walking. This milestone demonstrated the feasibility of human-like locomotion in machines, setting a new standard in robotics.
The success of P2 can be attributed to several key factors:
(a) Innovative Engineering:
P2 was equipped with advanced technologies, including a 138V 6Ah Nickel-Zinc battery, four Micro SPARC II microprocessors, and a wireless Ethernet modem. These components enabled real-time control of its movements and interactions with the environment [10].
(b) Human-Like Mobility:
Unlike previous robots that used springs or wheels, P2 achieved stable walking by analyzing human biomechanics. It could navigate uneven surfaces and stairs, maintaining balance even when subjected to external forces .
(c) Advanced Control Systems:
P2 utilized a sophisticated control system, including a six-axis force sensor on each ankle and wrist, and two cameras for vision processing. This system allowed for precise movement and adaptability in various environments [10].
(d) Impact on Robotics and Society:
P2's development shifted the focus of robotics from industrial applications to human-centric designs. It inspired subsequent advancements in humanoid robots, including Honda's ASIMO [7], and influenced research in fields like biomechanics and artificial intelligence .
In summary, Honda's P2 was not just a technical achievement; it was a catalyst that propelled the field of humanoid robotics forward, demonstrating the potential for robots to interact with and assist humans in meaningful ways.
Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.
Bibliography
Reference
[1] Kazuo Hirai, Masato Hirose, Yuji Haikawa, Toru Takenaka: “The Development of Honda Humanoid Robot”, Proceedings of 1998 IEEE International Conference on Robotics & Automation, Leuven Belgium, May 1998.
[2] JRM staff writer: JRM’s 25 Years Anniversary of Publication Reviews “Autonomous Walking Humanoid that Astonished the World – Honda’s ASIMO”, JOURNAL OPEN ACCESS, 2014 Volume 26 Issue 1 Pages 15-17, DOI https://doi.org/10.20965/jrm.2014.p0015
Media:Fujipress_JRM-26-1-3.pdf
[3] Masato Hirose and Kenichi Ogawa: “Honda humanoid robots development”, Philosophical Transactions of The Royal Society, A 2007, 365, 11-19, doi:10,1098/rsta.2006.1917
[4] S. V. Viraktamath, Rashmi N Raikat: "Humanoid Robot: A Review", Irnternational Journal for Research in Applied Science & Engineering Technology (IJRASET), Vol. 9, Issue: VIII, August 2021
ISSN: 2321-9653;
Media:Humanoid_Robot_A_Review.pdf
[Remarks] There is a description of Honda's P2 on 2885 page.
[5] Sangbae Kim, Patrick M. Wensing: “Design of Dynamic Legged Robots”, Foundations and Trends in Robotics, Vol. 5, No. 2, pp. 117–190, (2014)
DOI: 10.1561/2300000044
[Remarks] There is a description of Honda's P2 on pages 18 to 19.
[6] A demonstration of the Honda Humanoid Robot P2 can be viewed on [YouTube - Honda P2 by H-Tune]
https://www.youtube.com/watch?v=d2BUO4HEhvM
[Remarks] If you are unable to play this YouTube video, please try searching for "Honda Human Robot P2" by "H-Tune".
[7] Y. Sakagami, R. Watanabe, C. Aoyama, S. Matsunaga. N. Higaki, K. Fujimura; “Intelligent ASIMO: System Overview and Integration”
IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2002)
DOI: 10.1109/IRDS.2002.1041641, ISBN:0-7803-7398-7
[Abstract]
We present the system overview and integration of the ASIMO autonomous robot that can function successfully in indoor environments. The first model of ASIMO is already being leased to companies for receptionist work. In this paper, we describe the new capabilities that we have added to ASIMO. We explain the structure of the robot system for intelligence, integrated subsystems on its body, and their new functions. We describe the behavior-based planning architecture on ASIMO and its vision and auditory system. We describe its gesture recognition system, human interaction and task performance. We also discuss the external online database system that can be accessed using internet to retrieve desired information, the management system for receptionist work, and various function demonstrations.
[8] J.R. Movellan, F. Tanaka, B. Fortenberry, K. Aisaka; “The RUBI/QRIO Project: Origins, Principles, and First Steps”
IEEE Proceedings. The 4th International Conference on Development and Learning, 2005
ISBN:0-7803-9226-4 / ISSN: 2161-9476, DOI: 10.1109/DEVLRN.2005.1490948
[Abstract]
Computers are already powerful enough to sustain useful robots that interact and assist humans in every-day life. However, progress requires a scientific shakedown in goals and methods not unlike the cognitive revolution that occurred 40 years ago. The document presents the origin and early steps of the RUBI/QRIO project, in which two humanoid robots, RUBI and QRIO, are being brought to an early childhood education center on a daily bases for a period of time of at least one year. The goal of the RUBI/QRIO project is to accelerate progress on everyday life interactive robots by addressing the problem at multiple levels, including the development of new scientific methods, formal approaches, and scientific agenda. The current focus of the project is on educational environments, exploring the ways in which this technology could be used to assist teachers and enrich the educational experiences of children. We describe the origins, philosophy and first steps of the project, which included immersion of the researchers in the Early Childhood Education Center at UCSD, development of a social robot prototype named RUBI, and daily field studies with RUBI and QRIO, a prototype humanoid developed by Sony.
[9] Kazuo Hirai; “The Honda humanoid robot: development and future perspective”, Industrial Robot: An International Journal, Volume 26 . Number 4 . 1999 . pp. 260±266 # MCB University Press . ISSN 0143-991X
[10] David Wooden, Matthew Malchano, Kevin Blankespoor, Andrew Howardy, Alfred A. Rizzi, and Marc Raibert; "Autonomous Navigation for BigDog", Proc. of 2010 IEEE International Conference on Robotics and Automation, pp. 4736-4741, May 3-8, 2010. ISBN: 978-1-4244-5040-4
[11] Masato Hirose and Kenichi Ogawa; “Honda humanoid robots development”, Phycological Transactions of the Royal society A, mathematical, Physical and Engineering Science, 17 November 2006, https://doi.org/10.1098/rsta.2006.1917
[Abstract]
Honda has been doing research on robotics since 1986 with a focus upon bipedal walking technology. The research started with straight and static walking of the first prototype two-legged robot. Now, the continuous transition from walking in a straight line to making a turn has been achieved with the latest humanoid robot ASIMO. ASIMO is the most advanced robot of Honda so far in the mechanism and the control system. ASIMO's configuration allows it to operate freely in the human living space. It could be of practical help to humans with its ability of five-finger arms as well as its walking function. The target of further development of ASIMO is to develop a robot to improve life in human society. Much development work will be continued both mechanically and electronically, staying true to Honda's ‘challenging spirit’.
[12] Hirai, K., Hirose, M., Haikawa, Y., & Takenaka, T. (2007). The development of Honda humanoid robots. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 365(1850), 11–19. https://doi.org/10.1098/rsta.2006.1917.
[Abstract]
Honda has been doing research on robotics since 1986 with a focus upon bipedal walking technology. The research started with straight and static walking of the first prototype two-legged robot. Now, the continuous transition from walking in a straight line to making a turn has been achieved with the latest humanoid robot ASIMO. ASIMO is the most advanced robot of Honda so far in the mechanism and the control system. ASIMO's configuration allows it to operate freely in the human living space. It could be of practical help to humans with its ability of five-finger arms as well as its walking function. The target of further development of ASIMO is to develop a robot to improve life in human society. Much development work will be continued both mechanically and electronically, staying true to Honda's ‘challenging spirit’.
News paper
[N1] Asahi newspaper, Dec. 21, 1996
[Remarks: Title and Lead Paragraph Translation]
Evolving Humanoid Robots:
On the Dec. 20th, Honda Motor Co., Ltd. unveiled the research results of its humanoid robot (pictured) through a video presentation.
Resembling a human with two arms and two legs, the robot is capable of going up and down stairs and slopes.
It can also walk sideways and backwards.
[N2] Mainich news paper, dec. 21, 1996
[Remarks: Translation of the Title and Lead Paragraph]
Walking Robot:
On the Dec. 20th, Honda Motor Co., Ltd. announced that it has completed a prototype (photo) of a "self-standing humanoid walking robot" with two legs and two arms. The robot walks while assessing road conditions using a camera, and it can perform tasks similar to those of a human using its two hands.
[N3] “Honda introduces Walking Robot”, The Spokesman Review, Aug. 2, 1997.
Retrieved 15 May 2025: https://www.spokesman.com/stories/1997/aug/02/honda-introduces-walking-robot/?utm_source=chatgpt.com
[Reamrks]
Science fiction came that much closer to science fact Monday, when Honda Motor Co. introduced a two-legged robot that can walk, reconnoiter - even do simple fix-it jobs.
The 6-foot, 462-pound “P-2” has two arms, two legs, a squarish head, small platforms for feet, and resembles a man in a boxy space suit.
As in the U.S. Sojourner rover currently picking its way around rocks on Mars, the P-2’s circuitry is sophisticated enough to decide for itself when to try to step over an obstacle, and when to look for and try another route.
That allows it to do uncannily human-seeming things - such as finding a work site, pushing a cart to it, and tightening a loose bolt there - all without continuous radio control. It only needs a simple initial command.
P-2 can walk stairs, forward or backward, and keep its balance if given a shove, even on a slope it hasn’t been on before.
Susumu Tachi, a robotics professor at Tokyo University, likened it to the androids of science fiction.
“A truly humanoid robot was always considered to be just a dream or a product of fiction, but this proves that it is reality,” he said.
[N4] Todd Zaun; “Honda grapples with the morality of a 2-legged robot”. Deseret News, The Wall Street Journal, Sept 5, 2001.
Retrieved 15 May 2025: https://www.deseret.com/2001/9/5/19605020/honda-grapples-with-the-morality-of-a-2-legged-robot/
[Remarls: Front three paragraphs]:
TOKYO — Katsuyoshi Tagami, an engineer at Honda Motor Co., spent a decade building a secret product: a two-legged humanoid robot, one of the first of its kind. But as he was about to go public with his creation, he was seized with doubt: Might religious leaders object that Honda was playing God?
Tagami did some research and could find no other groups at the time working on a two-legged robot. "There were six-legged robots and four-legged ones, even a one-legged hopping robot. But no two-legged robots. That made us a little nervous".
Tagami ultimately went all the way to Rome to consult a Vatican theologian over his doubts and emerged with assurances that the Catholic Church wouldn't complain. The 4-foot-tall tubby-looking robots that resulted, named Asimo, can dance, shake hands and answer simple questions.
[N5] Azusa Maejima; "Modern Engineers Weaving the History of Astro Boy", Sunday History Exploration, ITMedia, May 31, 2009.
Retrieved 15 May 2025: https://www.itmedia.co.jp/enterprise/articles/0905/31/news002.html
[Remarks: Translation from Japanese to English of 3rd Paragraph]:
In the research and development of such robots, Japan has undergone a unique evolution. Generally speaking, in the West, robots are considered tools to be controlled by humans. This view is thought to be rooted in Christianity, where humans are believed to be created by God, and therefore, creating humanoid robots is seen as a form of blasphemy against God. Additionally, the influence of functionalism may also play a role. As a result, while industrial robots have seen remarkable development, they have primarily been of the remotely operated type or those not designed to interact with humans.
[N6] Azusa Maejima; "Honda's Robot Development That Raced Toward ASIMO", ITMedia, Sunday History Exploration, June 14, 2009.
Retrieved 15 May 2025: https://www.itmedia.co.jp/enterprise/articles/0906/14/news002.html
[Remarks: Translation from Japanese to English of 2nd and 3rd paragraphs]
On December 20, 1996—45 years after Osamu Tezuka began serializing Ambassador Atom, the precursor to Astro Boy—Honda broke its silence and unveiled the P2 robot to the world. The impact of this reveal was immense, especially among robot developers. To achieve dynamic walking through trajectory control alone, every joint from the supporting foot to the other foot must be precisely controlled, and the rotation of every motor must be accurately transmitted to the tips of the feet for the robot to land in the correct position. Precision must also be maintained to withstand the impact when the foot touches the ground. By overcoming challenges that had been considered insurmountable in the 20th century, Honda presented a humanoid robot that moved with remarkable smoothness, captivating the world.
What’s particularly noteworthy is the reaction from Western societies. As mentioned previously, in societies influenced by Christianity, developing robots that mimic humans tends to be viewed as taboo. The unveiling of P2 directly challenged this taboo. For this reason, it is said that before Honda introduced P2 to the world, the company visited the Vatican—an influential authority in Christian society—to seek guidance. Reportedly, a priest told them, "The creation of P2 was permitted by God—it, too, is one of God's acts." With this declaration, Honda was finally able to present P2 to the world.
Award by IEEE
[A1] IEEE Robotics and Automation Society;
“The development of Honda humanoid robot”, Most Influential paper Award from ICRA 1998.
Patents
[P1] "Gait Generation Device for Legged Mobile Robot", Japan Patent, P3132156, Nov. 24, 2000
[Remarks: Translatin of the claims] Media:Translation_Patent_1.pdf
[P2] "Walking Control Device for Legged Mobile Robot", Japan Patent, P3148827, Jan. 19, 2001.
[Remarks: Translatin of the claims] Media:Translation_Patent_2.pdf
[P3] "Walking Control Device for Legged Mobile Robot", Japan Patent, P3148828, Jan. 19, 2001.
[Remarks: Translatin of the claims] Media:Translation_Patent_3.pdf
[P4] J"Walking Control Device for Legged Mobile Robot", apan Patent, P3148829, Jan. 19, 2001.
[Remarks: Translatin of the claims] Media:Translation_Patent_4.pdf
[P5] "Walking Control Device for Legged Mobile Robot", Japan Patent, P3148830, Jan. 19, 2001.
[Remarks: Translatin of the claims] Media:Translation_Patent_5.pdf
[P6] "Posture Stabilization Control Device for Legged Mobile Robot", Japan Patent, P3269852, Jan. 18, 2002.
[Remarks: Translatin of the claims] Media:Translation_Patent_6.pdf
[P7] "Posture Control Device for Legged Mobile Robot", Japan Patent, P3672426, Apr. 28, 2005.
[Remarks: Translatin of the claims] Media:Translation_Patent_7.pdf
Appendix 1: The History of Honda’s Robots
Evolution Toward Humanoid Robots – Developing New Technologies for Practical Use
[remarks] Excerpts translated from the Japanese website (https://global.honda/jp/ASIMO/history/)
1987–1991: Realizing Bipedal Walking – Achieving “Dynamic Walking” to Study How Humans Walk
Models: E1–E2–E3
In order to realize dynamic walking, Honda conducted in-depth research and analysis of human locomotion. This included not only human gait but also the walking patterns of animals, observing and studying all types of movement. Based on this research, Honda identified the joint arrangements and motions required for bipedal walking. Using data from human walking, a dynamic walking program was developed and implemented in robots for experimental testing.
1991–1993: Completion of Basic Bipedal Walking Functions – Establishing “Walking Stabilization Technology”
Models: E4–E5–E6
Honda focused on the development of walking stabilization technology, resulting in the creation of three core control systems to enable stable bipedal walking.
1993–1997: Research into Fully Autonomous Humanoid Robots – Advancing Toward a Human-like Form
Model: P1
With the addition of arms and a torso, the robot evolved into a fully-fledged humanoid.
P1 was the first humanoid robot prototype, standing at 1.915 meters tall and weighing 175 kg. Its power supply and computer system were external. It could perform tasks such as turning switches on and off, grasping door handles, and carrying objects. Research was conducted into the coordinated movement of its arms and legs.
Model: P2
The first humanoid robot introduced to the public, gaining attention for its realistic movements.
Announced in December 1996, P2 was the world’s first autonomous, bipedal humanoid robot.
It stood 1.82 meters tall and weighed 210 kg. For the first time, it featured a wireless design, with all essential components—including a computer, motor drives, battery, and wireless equipment—built into the torso. This allowed the robot to walk freely, climb stairs, push carts, and perform various actions autonomously and wirelessly.
Model: P3
Evolved with a focus on smaller size and lighter weight—becoming a robot companion for humans.
Completed in September 1997, P3 was a fully autonomous, bipedal humanoid robot.
It stood 1.6 meters tall and weighed 130 kg. By revising the materials used for components and adopting a distributed control system, P3 achieved both miniaturization and weight reduction, approaching a size more suitable for integration into human living environments.
2000– : More Familiar, More Fluid : Becoming a Partner for Humans – ASIMO, Born from New Technologies Aimed at Practical Use
ASIMO
ASIMO was further miniaturized and lightened, and equipped with even more advanced walking technology called “i-WALK” (2000).
Designed for use in everyday environments, ASIMO offered improved walking flexibility and a simplified system. It could freely move through spaces with regular stairs and slopes. It also allowed for the addition of custom actions and informational content tailored to users’ needs.
Figure 3 Robot History (Sourece: Reference 2)
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