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ASIMO (Advanced Step in Innovative Mobility) was a humanoid robot developed by Honda Motor Co., Ltd. Unveiled on October 31, 2000, ASIMO became one of the most recognized robots in the world and served as a symbol of Japan's leadership in robotics for over two decades. Standing 130 cm tall and weighing 48 kg in its final iteration, ASIMO could walk, run, climb stairs, recognize faces and voices, carry objects, pour drinks, and even conduct a symphony orchestra.
ASIMO represented the culmination of Honda's humanoid robotics research program that began in 1986. Over its lifetime, the robot went through multiple generations of upgrades, appeared before world leaders, performed on television, and entertained millions of visitors at museums and technology exhibitions around the globe. Honda retired ASIMO from public performances on March 31, 2022, shifting its focus to avatar robot technology and other practical robotics applications.
The name ASIMO is an acronym for "Advanced Step in Innovative Mobility." The acronym also draws from the Japanese word "asi" (meaning "foot" or "leg"), reflecting the project's original focus on bipedal locomotion. While some have noted the phonetic resemblance to science fiction author Isaac Asimov, Honda has stated that the name derives solely from the acronym. Honda also declared that ASIMO would never be employed for any military purpose.
ASIMO did not emerge overnight. Its development traces back to 1986, when Honda's fundamental research division began studying the principles of bipedal walking. This research progressed through two distinct prototype series before ASIMO was ready for public introduction.
The E series (short for "Experimental") was Honda's first collection of walking robot prototypes. These machines were legs-only platforms, meaning they had no torso or arms, and were built purely to solve the problem of stable two-legged locomotion.
E0 (1986): The first prototype, E0 was created to study the basic principle of bipedal walking. It could walk in a straight line on two feet, taking approximately 5 seconds to complete a single step using static walking. It had 6 degrees of freedom: one in each hip, one in each knee, and one in each ankle.
E1 (1987): A larger successor, E1 achieved dynamic walking at a speed of 0.25 km/h. It increased the degrees of freedom to 12 (3 in each hip, 1 in each knee, and 2 in each ankle), which became the standard for the remaining E-series prototypes.
E2 (1989): E2 incorporated lightweight alloys and composites, resulting in a frame weighing 67.7 kg and standing 132 cm tall. Through the development of dynamic walking techniques, it achieved a walking speed of 1.2 km/h.
E3 (1991): E3 reached a walking speed of 3 km/h, roughly the average speed of a human walking at a normal pace.
E4 (1991): E4 featured a lengthened knee mechanism that pushed walking speeds up to 4.7 km/h.
E5 (1992): E5 achieved autonomous walking, though it required a disproportionately large head to house its computing and sensor hardware. Despite its heavy body, it maintained a walking speed of 4.7 km/h.
E6 (1993): The final E-series prototype, E6 integrated full autonomous balancing with the capability to walk over obstacles up to 30 cm high and climb stairs. It stood 174.3 cm tall, weighed 150 kg, and retained 12 degrees of freedom.
From E0 to E6, Honda engineers progressed from a robot that needed 5 seconds per step to one that could autonomously navigate stairs and uneven terrain.
With bipedal walking largely solved, Honda shifted to building full humanoid robots by attaching torsos and arms to walking platforms. The P series (short for "Prototype") represented this transition.
P1 (1993): Honda's first full humanoid robot, P1 stood 1,915 mm tall, weighed 175 kg, and had 30 degrees of freedom. It required an external power source and computer but could perform coordinated arm and leg movements, including turning switches on and off, grabbing doorknobs, and carrying objects.
P2 (December 1996): P2 was described as the world's first self-regulating bipedal humanoid walking robot. Standing 1,820 mm tall and weighing 210 kg, it had 30 degrees of freedom and a walking speed of 2 km/h. P2 was a breakthrough because all essential components, including a computer, motor drivers, a 138V nickel-zinc battery, and wireless communication equipment, were built into the robot's body. P2 could walk on flat surfaces, climb stairs, and push carts autonomously, with a continuous operating time of 15 minutes.
P3 (September 1997): P3 achieved significant miniaturization. Standing 1,600 mm (about 5 feet 4 inches) tall and weighing 130 kg, it was substantially smaller and lighter than P2. Honda accomplished this reduction by revising component materials and adopting a distributed control system. P3 was the first completely independent bipedal humanoid walking robot that could operate in human environments without being tethered to external equipment.
Building on all the knowledge gained from the E and P series, Honda unveiled ASIMO in 2000. Over the next 11 years, the robot went through several major upgrades.
The original ASIMO was announced on November 20, 2000 (following an initial unveiling on October 31). It represented a dramatic reduction in size compared to its P-series predecessors, standing just 1,200 mm (120 cm) tall and weighing 43 kg.
| Specification | Value |
|---|---|
| Height | 120 cm |
| Weight | 43 kg |
| Degrees of freedom | 26 |
| Walking speed | 0 to 1.6 km/h |
| Battery | 38.4V Ni-MH (10 Ah) |
| Operating time | Approximately 30 minutes |
| Frame material | Magnesium alloy |
| Exterior | Plastic resin |
The first-generation ASIMO featured "predicted movement control" technology that allowed it to walk smoothly on flat surfaces, up and down stairs, and along slopes. Its 26 degrees of freedom were distributed as follows: 2 in the head, 5 per arm (10 total), 1 per hand (2 total), and 6 per leg (12 total). Sensors included 6-axis foot sensors, a torso-mounted gyroscope, and a deceleration sensor. Honda found through research that 120 cm was an ideal height for a robot intended to share living spaces with people, as it could operate light switches and door handles while remaining non-intimidating.
In 2002, Honda released an upgraded ASIMO with expanded physical dimensions and significantly improved capabilities.
| Specification | Value |
|---|---|
| Height | 130 cm |
| Weight | 54 kg |
| Degrees of freedom | 34 |
| Walking speed | 2.5 km/h |
| Operating time | 1 hour |
The 2002 version added gesture recognition, facial identification, and network integration, allowing ASIMO to answer simple questions about news and weather. Internet connectivity enabled the robot to function as a receptionist or information guide. The jump from 26 to 34 degrees of freedom gave ASIMO more expressive body movements, while the doubling of battery life from 30 minutes to 1 hour made practical demonstrations far more feasible.
In December 2004, Honda announced technologies that gave ASIMO the ability to run, a first for any humanoid robot of its kind at the time.
| Specification | Value |
|---|---|
| Height | 130 cm |
| Weight | 54 kg |
| Degrees of freedom | 34 |
| Walking speed | 2.5 km/h |
| Running speed | 3 km/h |
| Running airborne time | 0.05 seconds per step |
| Operating time | 1 hour |
Running required ASIMO to briefly leave the ground with both feet during each stride cycle (0.36-second step cycle with a 0.05-second airborne phase). Honda achieved this through "Posture Control" technology that allowed the robot to proactively bend and twist its torso to maintain balance during high-speed movement. The 2004 update also introduced "Autonomous Continuous Movement," which used floor and visual sensors for dynamic obstacle detection and path adjustment, as well as wrist force sensors for handshakes and synchronized movement with humans.
Also in 2004, ASIMO was inducted into the Carnegie Mellon Robot Hall of Fame as the first robot to demonstrate true human-like mobility.
On December 13, 2005, Honda debuted a further refined ASIMO designed to perform tasks in real-world environments such as offices.
| Specification | Value |
|---|---|
| Height | 130 cm |
| Weight | 54 kg |
| Degrees of freedom | 34 |
| Walking speed | 2.7 km/h |
| Running speed (straight) | 6 km/h |
| Running speed (circular) | 5 km/h (2.5 m radius) |
| Walking speed while carrying objects | 1.6 km/h (1 kg load) |
| Running airborne time | 0.08 seconds |
The 2005 model doubled the running speed from 3 km/h to 6 km/h and could run in circular patterns. New capabilities included walking hand-in-hand with a human at synchronized pace, pushing carts with adaptive force control, and transferring objects using force sensors in the hands. This version moved ASIMO closer to Honda's vision of a practical assistant robot.
In December 2007, Honda advanced ASIMO's intelligence technologies rather than its physical specifications.
Key additions included:
This upgrade focused on making ASIMO viable for real-world service environments where multiple robots might operate simultaneously.
On November 8, 2011, Honda unveiled what it called the "all-new" ASIMO, the most substantial redesign in the robot's history.
| Specification | Value |
|---|---|
| Height | 130 cm |
| Weight | 48 kg (down 6 kg) |
| Degrees of freedom | 57 (up from 34) |
| Walking speed | 2.7 km/h |
| Running speed | 9 km/h |
| Battery | 51.8V lithium-ion |
| Operating time | 1 hour (40 min while running) |
The 2011 ASIMO featured 57 degrees of freedom, a dramatic increase of 23 over the previous model. The breakdown was: 3 in the head, 7 per arm (14 total), 13 per hand (26 total), 2 in the hip, and 6 per leg (12 total). The massive increase in hand dexterity (from 1 degree of freedom per hand to 13) was the most notable change. Each finger could move independently, with tactile sensors in the palms and force sensors on each finger.
This hand dexterity allowed the 2011 ASIMO to perform Japanese Sign Language, open bottle caps, pour liquids into cups without crushing them, and handle a wide variety of objects with appropriate grip force. The robot could also run backward, jump continuously, and hop on one foot.
The sensor suite included cameras and microphones in the head, a gyroscope and accelerometer in the torso, six-axis force sensors in the feet, and tactile sensors throughout the hands. The robot ran on the VxWorks real-time operating system with custom control software, and its locomotion was based on ZMP (Zero Moment Point) control.
The following table summarizes the key specifications across all ASIMO generations.
| Generation | Year | Height | Weight | DoF | Max Speed | Battery | Operating Time |
|---|---|---|---|---|---|---|---|
| ASIMO (1st gen) | 2000 | 120 cm | 43 kg | 26 | 1.6 km/h (walk) | 38.4V Ni-MH | ~30 min |
| ASIMO (2nd gen) | 2002 | 130 cm | 54 kg | 34 | 2.5 km/h (walk) | N/A | 1 hour |
| ASIMO (running) | 2004 | 130 cm | 54 kg | 34 | 3 km/h (run) | N/A | 1 hour |
| ASIMO (new) | 2005 | 130 cm | 54 kg | 34 | 6 km/h (run) | N/A | N/A |
| ASIMO (intelligent) | 2007 | 130 cm | 54 kg | 34 | 6 km/h (run) | N/A | N/A |
| ASIMO (all-new) | 2011 | 130 cm | 48 kg | 57 | 9 km/h (run) | 51.8V Li-ion | 1 hour |
ASIMO's mobility was its defining feature. By its final iteration, the robot could walk forward, backward, and sideways at up to 2.7 km/h, run at 9 km/h, climb and descend stairs, walk on sloped surfaces, and navigate through crowds of people. It could also run in circular patterns, jump continuously with both feet, and hop on a single foot. The robot used a combination of floor sensors (laser and infrared), visual cameras, gyroscopes, and accelerometers to maintain balance and navigate its environment.
The 2011 ASIMO's 13-degree-of-freedom hands enabled fine manipulation tasks. The robot could open twist-off bottle caps, pour beverages into paper cups without crushing them, pick up and carry trays, push carts with adaptive force control, grasp and transfer objects, and perform sign language gestures. Tactile sensors in the palms and force sensors on individual fingers allowed the robot to adjust grip strength based on the object it was handling.
ASIMO could recognize faces and voices, identify the direction a person's voice was coming from (even when multiple people spoke simultaneously), understand pre-programmed spoken commands, respond to gestures, and adjust its behavior based on predicted human intentions. With Internet connectivity (introduced in 2002), the robot could answer questions about news and weather, serving as an information kiosk or receptionist.
With the 2007 and 2011 upgrades, ASIMO gained progressively greater autonomy. It could navigate complex environments, avoid obstacles in real time, coordinate tasks with other ASIMO units over a network, manage its own battery by returning to a charging station when power ran low, and make decisions about yielding right-of-way to approaching humans.
ASIMO became one of the most publicly visible robots in history, making appearances that ranged from science museums to world stages.
On February 14, 2002, ASIMO rang the opening bell at the New York Stock Exchange (NYSE), becoming the first non-human to do so. The event celebrated the 25th anniversary of Honda's listing on the NYSE.
ASIMO met numerous heads of state and dignitaries throughout its career:
On May 13, 2008, ASIMO conducted the Detroit Symphony Orchestra in a performance of "The Impossible Dream." Honda's engineers had programmed the robot to replicate the conducting movements of Charles Burke, the orchestra's education director, who had been recorded conducting the same piece approximately six months earlier. It was the first time any robot had conducted a live orchestral performance. The event was tied to Honda's $1 million gift to the orchestra for a music education fund. Famed cellist Yo-Yo Ma also performed later that evening.
ASIMO appeared on The Ellen DeGeneres Show in 2006, where it danced for the studio audience. The robot was a regular fixture at technology trade shows, including the Consumer Electronics Show (CES), and appeared at science museums and exhibitions worldwide.
In June 2005, ASIMO became a featured attraction at Disneyland's Innoventions exhibit in Tomorrowland, coinciding with the theme park's 50th anniversary celebration. The show, titled "Say 'Hello' to Honda's ASIMO," ran for a decade until Innoventions closed in April 2015. This was the only permanent ASIMO installation in North America.
ASIMO first visited the United Kingdom in January 2003 for demonstrations at the Science Museum in London. It subsequently toured Spain, the United Arab Emirates, Russia, South Africa, Australia, and other countries. From January 2003 to March 2005, ASIMO toured the United States and Canada, demonstrating its abilities to more than 130,000 people. In May 2011, the robot visited the Ontario Science Centre in Toronto and the Canadian Museum of Civilization in Ottawa.
In December 2006, ASIMO fell while attempting to climb a staircase during a live demonstration in Japan. The incident, which was captured on video and widely shared online, became one of ASIMO's most memorable moments. Stagehands rushed to erect a screen around the fallen robot, apparently to protect its dignity, but the footage had already been recorded. Honda had long highlighted ASIMO's stair-climbing ability as a key achievement, making the fall especially notable.
Honda announced in July 2018 that it would cease all development and production of ASIMO robots, choosing instead to redirect the accumulated technology toward more practical applications. ASIMO continued to perform at the Honda headquarters and the Miraikan museum for several more years.
On March 31, 2022, ASIMO held its farewell performance, executing some of its signature routines, including running across the stage and dancing. The retirement ended over 20 years of daily demonstrations. Across all ASIMO units throughout the robot's operational history, the combined step count reached 33.26 million steps, covering a total walking distance of 7,907 km (4,913 miles).
ASIMO's influence extends well beyond its own operational lifespan.
ASIMO demonstrated that a humanoid robot could walk, run, and interact with humans in real-world settings. Its success inspired a generation of humanoid robot projects at companies and research institutions around the world, including Boston Dynamics, Toyota, and many university research labs. The Zero Moment Point (ZMP) control approach used for ASIMO's locomotion became a foundational technique in bipedal robotics research.
Rather than building a direct successor to ASIMO, Honda pivoted to developing avatar robots: remote-controlled humanoid systems that allow a human operator to act through the robot at a distant location. Honda unveiled its avatar robot research in September 2021, aiming to deploy practical avatar robots by the 2030s. These avatar robots inherit core ASIMO technologies, including multi-fingered hand dexterity, bipedal mobility systems, and human-robot interaction principles. Former ASIMO engineers lead the avatar robot program.
Planned applications for Honda's avatar robots include remote work for hands-on professionals, emergency medical response, lunar surface exploration (reducing astronaut risk), and remote tourism services. The robots can switch between full remote control and AI-supported autonomy.
At CES 2025, Honda announced ASIMO OS, a vehicle operating system for its upcoming Honda 0 Series electric vehicles. The operating system manages automated driving, advanced driver assistance, and infotainment systems, with over-the-air software updates. The use of the ASIMO name pays tribute to the robot and reflects the technological continuity between Honda's robotics heritage and its automotive future.
Honda's two-plus decades of ASIMO research revealed important insights about the challenges of deploying bipedal humanoid robots in real-world human environments. The company acknowledged that creating fully autonomous bipedal robots for everyday settings requires development timelines extending well beyond the 25 years already invested, comprehensive safety protocols to address collision impacts and fall scenarios, and societal consensus-building along with legal frameworks for robots operating among people.
| Category | Detail |
|---|---|
| Full name | Advanced Step in Innovative Mobility |
| Manufacturer | Honda Motor Co., Ltd. |
| Country of origin | Japan |
| Height | 130 cm (4 ft 3 in) |
| Width | 45 cm |
| Weight | 48 kg (106 lb) |
| Total degrees of freedom | 57 |
| Head DoF | 3 |
| Arm DoF | 7 per arm (14 total) |
| Hand DoF | 13 per hand (26 total) |
| Hip DoF | 2 |
| Leg DoF | 6 per leg (12 total) |
| Walking speed | 2.7 km/h |
| Running speed | 9 km/h (5.6 mph) |
| Battery | 51.8V lithium-ion (rechargeable) |
| Operating time | 1 hour (40 min while running) |
| Frame material | Magnesium alloy |
| Exterior shell | Plastic resin |
| Actuators | 26+ DC motors and brushless DC motors |
| Operating system | VxWorks (real-time) with custom control software |
| Locomotion method | ZMP (Zero Moment Point) bipedal control |
| Sensors (head) | Cameras, microphones |
| Sensors (torso) | Gyroscope, accelerometer |
| Sensors (feet) | Six-axis force sensors |
| Sensors (hands) | Tactile sensors (palms), force sensors (fingers) |