Release
Jan 1, 2009
Price
Price TBA
Connectivity
2
Status
Discontinued
Height
158cm
Weight
43kg (including battery)
Battery
~20 minutes
HRP-4C
HRP-4C, nicknamed Miim, is a feminine-looking humanoid robot created by Japan's National Institute of Advanced Industrial Science and Technology (AIST). Standing 158cm tall and weighing 43kg (including battery), she was designed with the proportions of an average young Japanese female based on national body dimension data. HRP-4C uses 30 body motors, 8 facial expression motors, and 4 eye motors for a total of 42 degrees of freedom. She can walk bipedally, recognize speech and ambient sounds, and even sing using Yamaha's Vocaloid vocal synthesizer. First demonstrated publicly on March 16, 2009, she was later upgraded with more realistic walking and dancing abilities. Part of Japan's long-running Humanoid Robotics Project (HRP) series, she represented a leap toward human-like appearance and motion in research robotics.
Listed price
Price TBA
Research platform (not commercially sold)
Release window
Jan 1, 2009
Current status
Discontinued
AIST
Last verified
Feb 27, 2026
Technical overview
Core specifications and system stack
A fast read on the mechanical profile, sensing package, and platform integrations behind HRP-4C.
Technical Specifications
Height
158cm
Weight
43kg (including battery)
Battery Life
~20 minutes
Charging Time
Not disclosed
Max Speed
Not disclosed
Tech Components
Sensors (4)
Voice Assistants
Operational profile
How this robot is configured
Capabilities
8
Connectivity
2
Key capabilities
Ecosystem fit
Explore further
Benchmark set
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About the HRP-4C
The HRP-4C is a Research robot built by AIST. HRP-4C, nicknamed Miim, is a feminine-looking humanoid robot created by Japan's National Institute of Advanced Industrial Science and Technology (AIST). Standing 158cm tall and weighing 43kg (including battery), she was designed with the proportions of an average young Japanese female based on national body dimension data. HRP-4C uses 30 body motors, 8 facial expression motors, and 4 eye motors for a total of 42 degrees of freedom. She can walk bipedally, recognize speech and ambient sounds, and even sing using Yamaha's Vocaloid vocal synthesizer. First demonstrated publicly on March 16, 2009, she was later upgraded with more realistic walking and dancing abilities. Part of Japan's long-running Humanoid Robotics Project (HRP) series, she represented a leap toward human-like appearance and motion in research robotics.
Pricing has not been publicly disclosed. See all AIST robots on the AIST page.
Spec Breakdown
Detailed specifications for the HRP-4C
Height
158cmAt 158cm, the HRP-4C is sized for its intended operating environment and use cases.
Weight
43kg (including battery)Weighing 43kg (including battery), the HRP-4C balances structural integrity with portability and maneuverability.
Battery Life
~20 minutesWith a battery life of ~20 minutes, the HRP-4C can operate for sustained periods before requiring a recharge. Battery life is measured under typical operating conditions and may vary based on workload intensity and environmental factors.
The HRP-4C uses OpenRTP platform (OpenRTM-aist, OpenHRP3), Linux-based control system as its intelligence backbone. This AI platform powers the robot's decision-making, perception processing, and autonomous behavior. The sophistication of the AI stack directly impacts how well the robot handles unexpected situations and adapts to new environments.
HRP-4C Sensor Suite
The HRP-4C integrates 4 sensor types, forming the perceptual foundation that enables autonomous operation.
This sensor configuration enables the HRP-4C to perceive its environment and operate autonomously in its intended use cases. Multiple sensor modalities provide redundancy and more robust perception than any single sensor type alone.
Explore sensor technologies: components glossary · full components directory
HRP-4C Use Cases & Applications
Research robots serve as platforms for advancing robotics science and engineering. They enable researchers to test theories about locomotion, manipulation, perception, and human-robot interaction in controlled and real-world environments.
Capabilities That Enable Real-World Use
The HRP-4C offers 8 distinct capabilities, each contributing to the robot's practical utility.
These capabilities work together with the robot's 4 onboard sensor types and OpenRTP platform (OpenRTM-aist, OpenHRP3), Linux-based control system AI platform to deliver practical, real-world performance.
Ecosystem Integration
The HRP-4C integrates with the following platforms and ecosystems, extending its utility beyond standalone operation.
This ecosystem compatibility enables the HRP-4C to work as part of a broader automation setup rather than operating in isolation.
HRP-4C Capabilities
8
Capabilities
4
Sensor Types
AI
OpenRTP platform (OpenRTM-ai…
Connectivity & Integration
How the HRP-4C communicates with your network, smart home devices, cloud services, and companion apps.
Network & Communication Protocols
Voice Assistant Integration
HRP-4C Technology Stack Overview
The HRP-4C by AIST integrates 9 distinct technology components across sensing, connectivity, intelligence, and interaction layers. The physical platform features a height of 158cm, a weight of 43kg (including battery), providing the foundation on which this technology stack operates.
Perception — 4 Sensor Types
The perception layer is built on Stereo Cameras (eyes), Speech Recognition Microphones, Ambient Sound Recognition, Gyroscope / IMU. These work in concert to give the robot a detailed understanding of its operating environment. This multi-sensor approach provides redundancy and enables the robot to function reliably even when individual sensors encounter challenging conditions such as low light, reflective surfaces, or cluttered spaces.
Connectivity — 2 Protocols
Intelligence — OpenRTP platform (OpenRTM-aist, OpenHRP3), Linux-based control system
OpenRTP platform (OpenRTM-aist, OpenHRP3), Linux-based control system serves as the computational brain, processing sensor data, making navigation decisions, and orchestrating the robot's autonomous behaviors. The quality of this AI platform directly influences how well the robot handles novel situations, adapts to changes in its environment, and improves its performance over time through learning.
Voice — Vocaloid Vocal Synthesizer (CV-4Cβ voicebank), Speech Recognition
Voice interaction is handled through Vocaloid Vocal Synthesizer (CV-4Cβ voicebank) and Speech Recognition, providing natural language understanding and speech synthesis that enable conversational control and integration with broader smart home ecosystems.
Who Should Consider the HRP-4C?
Target Audience
Research robots are acquired by universities, government labs, and corporate R&D departments. They serve as experimental platforms for developing new algorithms, testing locomotion strategies, and advancing the field of robotics. Some are also used for educational purposes.
Key Considerations
Open-source software compatibility (ROS/ROS 2), sensor modularity, programmability, available SDK/API quality, community support, and published research papers using the platform are key factors. Documentation quality and the ability to modify both hardware and software are essential for research use.
Pricing
Availability
DiscontinuedThe HRP-4C has been discontinued by AIST. It may still be available through secondary markets or refurbished channels.
HRP-4C: Strengths & Trade-offs
Engineering compromises and where this research robot excels
What the HRP-4C does well
Solid sensor coverage
The HRP-4C integrates 4 sensor types, providing good perceptual coverage for its intended applications. This sensor complement covers the essential modalities needed for effective research operation while keeping complexity manageable.
Broad capability set
With 8 distinct capabilities, the HRP-4C is designed as a versatile platform rather than a single-task device. This breadth means the robot can handle varied scenarios and workflows, reducing the need for multiple specialized robots and increasing its utility across different situations.
Multi-platform voice support
Supporting 2 voice assistant platforms (Vocaloid Vocal Synthesizer (CV-4Cβ voicebank), Speech Recognition) means the HRP-4C integrates with whichever voice ecosystem you already use. This flexibility avoids platform lock-in and enables broader smart home interoperability.
What to consider carefully
Limited battery runtime
A battery life of ~20 minutes means shorter operational windows between charges. For applications requiring continuous or extended operation, this may necessitate scheduling around charge cycles or deploying multiple units in rotation. Evaluate whether the runtime meets your minimum session requirements before committing.
Undisclosed pricing
AIST has not published a public price for the HRP-4C. While common for enterprise-class robotics, the absence of transparent pricing can complicate budgeting and comparison shopping. Prospective buyers will need to engage directly with the manufacturer for quotes, which may vary by configuration and volume.
Discontinued product
The HRP-4C has been discontinued by AIST. This means no new units are being manufactured, software updates may become infrequent or stop entirely, and replacement parts availability will eventually decline. Consider long-term support viability carefully if evaluating this robot through secondary markets.
Note: This strengths and trade-offs assessment is based on the HRP-4C's documented specifications as tracked in the ui44 database. Real-world performance depends on deployment conditions, firmware maturity, and environmental factors. For the most current information, check the AIST manufacturer page or visit the official product page. Use the comparison tool to evaluate these trade-offs against competing robots in the same category.
How Research Robot Technology Works
Understanding the engineering behind this category
Research robots serve a fundamentally different purpose than commercial or consumer models. They are platforms for discovery — enabling scientists and engineers to test theories, develop algorithms, and push the boundaries of what robots can do. The technology in research robots prioritizes openness, flexibility, and access to raw data over consumer-friendly packaging or commercial reliability. Understanding this distinction is important for anyone considering a research robot platform.
Navigation & Mobility
Research robots typically expose their navigation systems at a much lower level than commercial products. Researchers can access raw sensor data, modify SLAM algorithms, implement custom path planners, and test novel navigation approaches. ROS (Robot Operating System) and ROS 2 compatibility is standard, providing a common framework for sharing navigation modules across the research community. This openness enables rapid iteration — a researcher can swap between different SLAM implementations, test new obstacle avoidance strategies, or develop entirely novel navigation paradigms without being locked into a vendor's proprietary stack.
The Role of AI
Research robots serve as physical testbeds for AI algorithms that may eventually appear in commercial products years later. Reinforcement learning, imitation learning, few-shot task learning, and human-robot interaction studies all require robot platforms that can execute AI-generated commands in the physical world. The gap between simulation (where training is cheap and fast) and reality (where physics is unforgiving) makes physical robot platforms essential for validating AI approaches. Research robots must support rapid deployment of new AI models without extensive integration work.
Sensor Fusion & Perception
Research platforms prioritize sensor modularity and data access. Standard mounting interfaces allow researchers to attach custom sensors alongside built-in ones. Raw sensor data streams (not just processed results) are accessible for developing novel perception algorithms. Precise time-stamping and synchronization across sensor streams enable accurate multi-modal fusion research. Many research robots include more sensors than strictly necessary for any single application, providing researchers with rich datasets for developing and testing new algorithms.
Power & Battery Management
Research robots balance operational runtime with practical lab use. Sessions of one to four hours are typical, with quick charging between experiments. Some research setups use tethered power for long-running experiments where battery limitations would interrupt data collection. Power monitoring and logging capabilities help researchers understand the energy costs of different behaviors and algorithms — important for developing efficient approaches that will eventually run on battery-constrained commercial systems.
Safety by Design
Research environments present unique safety challenges because robots are constantly being programmed with untested behaviors. Hardware safety limits (joint speed caps, force limits, emergency stops) must be robust regardless of software commands. Safety-rated monitored stop and speed monitoring ensure the robot cannot exceed safe operating parameters even when running experimental code. Collaborative operation standards apply when researchers work alongside the robot during experiments. Many labs implement layered safety with physical barriers for high-speed testing and open-area operation restricted to validated, lower-risk behaviors.
What's Next for Research Robots
Research robot platforms are becoming more accessible and capable. Cloud robotics enables remote experiment execution and shared datasets. Digital twins and high-fidelity simulators reduce the need for physical hardware time while improving sim-to-real transfer. Standardized benchmarks and open datasets enable fair comparison of results across labs. The democratization of robotics research — through lower-cost platforms, open-source software, and cloud infrastructure — is expanding who can contribute to advancing the field.
The HRP-4C by AIST incorporates many of these technology pillars. For a detailed look at the specific sensors and components used in the HRP-4C, see the sensor analysis and connectivity sections above, or browse the complete components glossary for explanations of every technology used across the robotics industry.
HRP-4C in the Research Market
How this robot compares in the research landscape
AIST has not publicly disclosed pricing for the HRP-4C, which is typical for enterprise-focused robotics platforms that offer customized solutions and direct-sales relationships.
The HRP-4C's 4 sensor types provide solid perceptual coverage for its intended use cases. This mid-range sensor suite balances cost with capability, covering the essential modalities needed for research applications.
Head-to-Head Comparisons
Side-by-side specs, capability overlap analysis, and key differentiators.
For the full picture of AIST's portfolio and market strategy, visit the AIST manufacturer page.
Owning the HRP-4C: Setup, Maintenance & Tips
Practical guide from day one through years of ownership
Initial Setup
Research robot setup combines hardware assembly with software environment configuration. Unpack and assemble the platform following the manufacturer's documentation. Install the development framework — typically ROS or ROS 2 — and verify sensor connectivity. Calibrate all sensors using the manufacturer's tools and procedures. Set up the simulation environment (Gazebo, Isaac Sim, or equivalent) alongside the physical platform for parallel development. Establish version control for your experiment code and configuration. Document the initial calibration values and system state as your baseline for future reference. Plan network and computing infrastructure to handle the data rates your sensors will generate.
Ongoing Maintenance
Research robots need maintenance that preserves the precision required for valid experimental results. Regularly verify sensor calibration — drift in camera intrinsics or IMU biases can invalidate experiment data. Maintain clean workspace conditions to protect optical sensors. Document any hardware modifications or maintenance performed, as these can affect experimental reproducibility. Update software dependencies carefully, documenting versions used for each experiment. Joint and actuator wear in research robots that perform repetitive tasks should be monitored and factored into experimental design.
Software Updates & Long-Term Support
Research robot software updates require careful management to maintain experiment reproducibility. Document the exact software versions used for each experiment. Test updates in a separate environment before applying to your experiment platform. Contribute bug fixes and improvements back to the community when using open-source frameworks. Be aware that ROS and other framework updates may require code changes in your custom packages — budget time for integration testing after major framework updates.
Maximizing Longevity
Research robots often have longer productive lives than commercial products because they can be upgraded and repurposed. Extend your investment by maintaining clean mechanical and electrical systems, documenting all modifications for future lab members, and keeping spare parts for common wear items. When specific components become obsolete, community forums and lab networks can be valuable sources for replacements. Consider the platform's modularity when planning future research directions — a platform that can accept new sensors and actuators adapts to evolving research questions.
For AIST-specific support resources and documentation, visit the AIST page on ui44 or check the manufacturer's official website at AIST's product page.
Frequently Asked Questions
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What AI does the HRP-4C use?
How does the HRP-4C compare to the HRP-5P?
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How current is the HRP-4C data on ui44?
Data Integrity
All HRP-4C data on ui44 is verified against official AIST sources, including spec sheets, product pages, and press releases. Last verified: 2026-02-27. Official source: AIST product page. If you find outdated or incorrect information, please let us know — accuracy is our top priority.
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