Innovation in Motion: How TDK's 6-Axis IMU Enables Precise Movement in Humanoid Robots

This is Part 3 of a four-part series. See Part 1: Mastering Multitasking: Exploring the Distributed Processing Capabilities of TDKs Advanced Robotics and Part 2: Sensing the World: How TDK’s Multi-Sensor Fusion Improves Perception in Industrial and Service Robots.

Introduction

Humanoid robotics have seen remarkable growth in recent years, with applications expanding across healthcare, home assistance, and industrial sectors. The global market for humanoid robots is expected to grow from USD $2.03 billion in 2024 to USD 13.25 billion by 2030.^[1] However, this growth has been accompanied by significant challenges, notably in motion control and stability. 

The key to addressing these issues is the Inertial Measurement Unit (IMU), an important component for replicating human-like movements in humanoid robots. IMUs track orientation, acceleration, and movement, so that humanoid robots can replicate human-like movements effectively.  

TDK Corporation, a leader in electronic components and systems, has developed a unique MEMS-based 6-axis IMU technology that is transforming motion control in humanoid robotics. This advanced IMU integrates accelerometer and gyroscope data to provide real-time motion tracking, which enables precise limb control, dynamic stability, and fall detection in humanoid robots.^[2]

By combining high-precision sensors with sophisticated algorithms, TDK’s 6-axis IMU sets a new standard for motion control in the field of service robotics.

The Need for Precision in Humanoid Robots

Humanoid robots face unique motion challenges that require exacting solutions:

• Balance and Stability — Robots working in unpredictable environments near humans must stay upright on uneven terrain.

• Real-Time Motion Tracking — Robots need instant data processing and coordination to move naturally and respond to external stimuli.

• Fall Detection and Recovery — Preventing and recovering from falls is critical for safe operation, especially in spaces designed for humans.

Traditional motion sensors often struggle to keep up, and basic IMUs often fail to compensate for sudden disturbances. This leads to small errors that add up over time. Additionally, although optical and LiDAR-based systems are extremely accurate, they are computationally demanding and can introduce delays, which makes them less ideal for fast, responsive movement.^[3]

The limitations of conventional sensors show that there is a need for more advanced solutions in humanoid robotics. TDK’s 6-axis IMU addresses these shortcomings by providing high-precision, low-latency motion data. This responsive IMU helps humanoid robots move with greater agility and stability, bringing them a step closer to human-like motion. 

How TDK’s 6-Axis IMU Solves These Challenges

Advanced Motion Tracking Through Sensor Fusion

TDK’s 6-axis IMU combines accelerometers and gyroscopes to gather precise motion data. The working mechanism involves these components:

• Accelerometers measure linear acceleration in three axes.

• Gyroscopes detect angular velocity around three axes.

• Sensor fusion algorithms integrate both of these data streams to predict movement with accuracy.

Quantified performance indicators for TDK’s ICM-42688-P IMU:

• TDK’s ICM-42688-P IMU achieves a 40% lower noise figure compared to traditional consumer-grade IMUs.

• Temperature stability is improved by 2x, keeping data accurate across environmental conditions.

• The device features a high-resolution analog-to-digital converter that provides an 8x increase in gyroscope resolution and a 4x increase in accelerometer resolution.

• Rapid data processing and a 100% accurate clock eliminate timing errors for near-instantaneous motion tracking.^[4]

This fusion technology has several benefits:

• Drift Compensation — Advanced algorithms correct sensor drift, which keeps data accurate long term.

• Kalman Filtering — This technique refines and enhances motion estimates by combining sensor data with predictive models.

• Ultra-Low Latency — The rapid data processing results in near-instantaneous motion tracking.^[5]

• AI-Powered Motion Predictions — IMU data can be used for AI/ML predictive models for more human-like movement.  

Enhancing Dynamic Stability in Humanoid Robots

Dynamic stability is critical for humanoid robots, and TDK’s ICM-42688-P IMU helps maintain this with:

• Real-Time Posture Correction — The IMU detects imbalances and triggers adjustments to the robot’s stance. It reaches a heading accuracy of ≤10° per hour and operates at a data rate of up to 1000 Hz, enabling fast detection and correction of imbalances. 

• Adaptive Gait Optimization — The IMU’s high-frequency (up to 1000 Hz) keeps the robot walking smoothly on uneven terrain by continuous adjustment of leg movements.

• Multi-Sensor Integration — IMU data is fused with force sensor feedback and geometric models using Extended Kalman Filters (EKF). This fusion reduces contact force estimation errors to within 5 N·m and maintains balance stability above 95% in dynamic environments. When IMU and force sensor data are combined, interference errors are reduced by about 20%, and overall pose estimation accuracy improves by up to 30%

Fall Detection and Recovery

Safety is a priority in robotics, especially in assistive applications. The 6-axis IMU helps prevent falls by:

• Detecting sudden acceleration changes that might signal a potential fall.

• Analyzing body tilt and weight shifts to predict instability.

• Triggering corrective actions before impact, reducing the risk of falls.

These capabilities make TDK’s IMU valuable in applications like assistive robotics, where fall prevention is required for user safety.^[6]

Real-World Applications of TDK’s 6-Axis IMU

Assistive Robotics in Healthcare

TDK’s IMU technology finds significant applications in healthcare robotics:

• Exoskeletons for Rehabilitation — Helps impaired patients regain movement with precise motion control and balance support.

• Elderly Support Robots — Improves stability for home care robotic assistants by providing safe navigation and facilitating interaction in domestic environments. ^[7]

Home Service Robots

The 6-axis IMU also has applications in domestic settings, where there are opportunities to improve robotic efficiency:

• Autonomous Navigation — Enables smooth movement for cleaning, delivery, and household assistance.

• Precision in Object Handling — Provides stability and control for AI-powered robotic arms, which allows for safe handling of household items.

Industrial and Inspection Robotics: ANYbotics Case Study

TDK Ventures has partnered with ANYbotics, a leader in autonomous industrial inspection robots. Their ANYmal robot integrates TDK’s IMU technology to enhance performance in:

• Harsh Environments — Enables stable movement on uneven surfaces and improves obstacle avoidance in industrial settings. The IMU ensures that the robot maintains balance even in hazardous areas such as offshore platforms, underground tunnels, and power plants.

• Factory Automation — Supports self-balancing robotic arms for precise manufacturing tasks, increasing efficiency in automated production lines. The IMU's real-time motion tracking allows robots to detect micro-vibrations and adjust accordingly, reducing errors in delicate assembly processes.^[8]

ANYmal’s ability to navigate complex environments with high stability demonstrates how TDK’s IMU complements robotic autonomy. By improving movement precision and safety, this technology provides industries with a way to reduce human risk exposure while maintaining high operational efficiency.

TDK’s Competitive Edge in IMU Technology

TDK's 6-axis IMU has several advantages that make it stand out from conventional IMUs:

• High Precision — Delivers more accurate motion data with minimal drift.

• Robust Noise Filtering — Maintains clean data even in noisy environments.

• Compact Design — MEMS-based miniaturization helps keep robot designs lightweight and power-efficient.^[9]

TDK’s MEMS-based IMU is unique because it can provide micro-scale motion tracking with high precision, which is key to replicating human-like movements in robots. The compact size of the technology also makes way for the development of more agile and energy-efficient robotic systems.

Looking ahead, TDK is exploring AI and machine learning integration:

• AI-powered motion predictions can refine IMU tracking for even greater accuracy.

• Adaptive learning algorithms could enable humanoid robots to improve movement by learning about the environment over time.

Conclusion

TDK’s 6-axis IMU is positioned to shape the future of humanoid robotics with industry-leading precision, robust noise filtering, and ultra-compact MEMS design. Devices like the ICM-42688-P offer precise, real-time motion data and unparalleled performance metrics that enable more stable, agile, and safe robotic systems. These advancements position TDK at the forefront of robotic motion tracking for replicating human-like movement.

As TDK continues to innovate in MEMS-based IMU technology, we can anticipate even more advanced and capable robotic systems in years to come. Learn more about TDK’s innovative advancements at https://www.tdk.com/en/index.html.

Reference

[1] Markets and Markets. “Humanoid Robot Market Size, Share & Growth”. Accessed from https://www.marketsandmarkets.com/Market-Reports/humanoid-robot-market-99567653.html

[2] TDK IMU Product Page. Accessed from https://product.tdk.com/en/products/sensor/mortion-inertial/imu/index.html 

[3] Ohidul Islam. “Challenges in Humanoid Robotics and How to Overcome Them”. Accessed from https://robozaps.com/challenges-in-humanoid-robotics/ 

[4] Shannon Davis. “TDK Launches High-Performance 6-axis IMU with Industry-Leading Motion Sensor Performance”. Semiconductor Digest. Accessed from https://www.semiconductor-digest.com/tdk-launches-high-performance-6-axis-imu-with-industry-leading-motion-sensor-performance/ 

[5] TDK IMU Product Page.

[6] “TDK launches high-performance 6-axis IMU with industry-leading motion sensor performance for IoT, robotics, AR/VR and wearable applications”. Industry EMA. Accessed from https://www.industryemea.com/news/27191-tdk-launches-high-performance-6-axis-imu-with-industry-leading-motion-sensor-performance-for-iot,-robotics,-ar-vr-and-wearable-applications 

[7] Rika Melissa. “Service Robot Market: Trends, Growth, and Future Outlook” (22 May 2024). Sateton. Accessd from https://statzon.com/insights/humanoid-helpers-and-beyond-service-robot-market-expansion

[8] “TDK Ventures Invests in ANYbotics, a World Leader in Industrial Inspection Autonomous Robots” (11 Dec. 2024). Accessed from https://tdk-ventures.com/news/announcements/tdk-ventures-invests-in-anybotics-a-world-leader-in-industrial-inspection-autonomous-robots/

[9] TDK IMU Product Page.