The Role of Hybrid Time-of-Flight (ToF) Technology in Advancing Robotics and Beyond

Introduction

The accurate real-time perception and mapping of environments pose substantial challenges to several industries, such as robotics, automotive, and augmented reality platforms. Even minor detection errors trigger safety concerns, operational flaws, and poor user experience standards. Dynamic real-world applications require sensing methods that reach high precision and operate at rapid speeds, but most traditional sensing systems fail to meet these requirements. Time-of-flight (ToF) technology serves as the solution for this purpose. It measures the time light travels to an object and reflects, leading to accurate depth sensing and real-time environment mapping. This capability makes ToF a vital tool for autonomous systems, industrial automation applications, and additional domains.

Infineon Technologies has been at the forefront of advancing ToF technology, particularly with its REAL3TM family of ToF sensors. These sensors are transforming several industries, such as robotics, automotive, consumer electronics, and industrial automation.   This article explores the principles of ToF technology, Infineon’s contributions through its Hybrid ToF (hToF) Camera systems, utilizing its iToF sensors and optimized illumination techniques, and their potential in technologies such as robotics, automotive systems, consumer electronics, and industrial automation.

Figure 1: REAL3™ 3D Image Sensor. Image credit: Infineon.

Infineon's Hybrid ToF (hToF) Technology

Building on the industry standard, Infineon has advanced ToF technology by introducing Hybrid Time-of-Flight (hToF). The hToF camera system, integrating Infineon’s iToF sensors, optimizes camera performance by delivering high resolution and highly accurate long-range depth data within a single system. Additionally, pmd technologies contribute advanced software and algorithms, enhancing depth processing and real-time environmental perception for improved performance in robotics and automation.  

Hybrid Time-of-Flight (hToF) technology is based on iToF technology and utilizes flood and spot illumination to enhance performance. Spot illumination mimics a direct ToF-like system in terms of long-range accuracy, while flood illumination ensures the high-resolution characteristics of iToF systems. This combination enables hToF to deliver precise long-range depth data and high-resolution imaging within a single system.

Roborock, a global leader in intelligent home robotics, uses Infineon's hToF sensors for Robotic Vacuum Cleaners (RVCs). The results demonstrate significant advantages over the traditional LDS (Laser Distance Sensor) and structured light systems while maintaining a slim design, obstacle avoidance of small objects, and rich real-time data for navigation. Though hToF is currently mainly used in RVCs, it has potential applications in other industries, such as automation, consumer electronics, and healthcare.

Applications of Time of Flight (ToF) Sensors and Potential of Hybrid ToF (hToF) Systems Across Industries:

Robotics

ToF sensors have the potential to significantly improve robotics by enabling accurate real-time obstacle detection and navigation, which are critical for autonomous mobile robots operating in dynamic environments. Additionally, they enhance Simultaneous Localization and Mapping (SLAM) algorithms by providing high-resolution depth data, allowing robots to create more precise and reliable 3D maps of their surroundings. Furthermore, ToF sensors can improve human-robot interaction by enabling robots to better perceive and respond to human presence and gestures, facilitating safer and more intuitive collaboration in shared workspaces.

The hToF camera system combines flood and spot illumination techniques, enabling the generation of high-resolution 3D depth maps with improved accuracy, even at long ranges. This dual-illumination approach enhances SLAM performance by providing more detailed environmental data, critical for navigation and high resolution for advanced obstacle avoidance. A key application of this technology is today in Robotic Vacuum Cleaners (RVCs), where hToF cameras enable high-resolution obstacle avoidance, efficient room mapping and precise navigation, even in complex or cluttered environments.

Automotive

TOF sensors find extensive applications in the automotive industry to support Occupant Monitoring Systems (OMS). The sensors adjust airbags and seat belts according to passenger positioning so that safety deployments reach their optimal configuration. The automotive industry relies on ToF sensors to establish a Driver Monitoring System (DMS), which monitors driver attention and fatigue patterns and enables face recognition authentication during contactless vehicle entry.

Although not yet widely adopted, TOF technology holds significant potential for enhancing in-cabin monitoring systems. Compared to other technologies like stereo vision, the distance data from a ToF sensor is directly measured and not only calculated. The operational capacity of ToF sensors produces complete 3D maps of the vehicle interior, providing more accurate data on occupant positions and movements. Higher accurate inputs from this technology generate better outcomes for airbag and seat belt safety systems. The robust depth-sensing capabilities of ToF sensors across different lighting conditions make them appropriate for exterior sensing systems, including blind spot detection and autonomous parking. Infineon is advancing ASIL B-compliant ToF cameras, which hold significant potential for automotive safety applications such as in-cabin monitoring, driver assistance, and autonomous parking. 

Consumer Electronics

Consumer Electronics, such as smartphones and Extended Reality (XR) headsets, use iToF sensors. They enable augmented reality (AR), portrait photography, and features like cinematic mode. They also provide solutions for smart home devices, such as smart lighting and security systems, as they can sense and detect motion.

hToF camera systems provide high-resolution depth maps and precise long-range depth points. This could enhance AR experiences by improving accuracy and realism. Furthermore, it will also improve smart home devices due to its responsiveness and accurate motion-sensing ability.

Industrial Automation

In industrial automation, the TOF sensors enhance the precision of robotic arms for several tasks such as sorting, assembly, etc. The sensors also provide real-time perception for monitoring the systems and ensuring safety in smart factories. 

The hToF camera system offers the potential for further improvement in automated processes' accuracy and efficiency, as they provide high-resolution 3D mapping and precise depth measurements. Enabling the robotic arms and other automated systems for better obstacle detection, positioning and navigation.

Advantages of Infineon's Sensors

Infineon's ToF sensors provide distinct advantages in depth sensing and 3D imaging applications due to their ability to deliver high-resolution depth data and operate effectively in various lighting conditions, particularly under strong sunlight. The advantages are evident in their ability to perform better while maintaining the design compactness and lower power consumption.

Higher Depth Accuracy and Resolution

Infineon Sensors provides exceptional depth, accuracy, and resolution for autonomous vehicles and smart camera applications that require precise mapping and real-time environmental awareness. These high-level details enhance the performance and reliability of these systems.

Robust Performance in Challenging Lighting

The ToF sensor's primary feature is its robustness in various lighting conditions. They are designed to perform in outdoor environments, including direct sunlight, and due to their illumination, they are also used in night-time operations. These sensors result in consistent and reliable depth sensing regardless of the ambient lighting conditions.

Compact Design and Low Power Consumption

The sensors of Infineon are engineered to be compact and energy-efficient, which allows for integration into smaller platforms such as consumer robots, electronics, drones, etc. The lower power consumption ability enables the devices to operate for an extended period without compromising battery life, making them ideal for portable and mobile applications. 

Scalability across Applications

The versatility of the Infineon sensors allows them to be used in various industries and applications. Different use cases benefit from these sensors because they operate across multiple applications, from RVCs to automotive safety systems. These sensors achieve high performance across different environments, making them suitable as essential components for future smart devices.

Advantages Over Other Depth-Sensing Technologies

Infineon's ToF sensors, particularly in Hybrid ToF (hToF) camera systems, surpass conventional depth sensors in LDS, stereo vision, and structured light through better performance in multiple aspects. The hToF technology enables robotic vacuum cleaner manufacturers to reduce mechanical space requirements by 100x while maintaining performance standards because it replaces LDS and line laser structured light systems. The Roborock Saros Z70 implements hToF camera, giving space to a robotic arm integration keeps slim profile and high cleaning performance.

The Future of ToF and Hybrid ToF (hToF) Technology

Time-of-flight (ToF) technology is rapidly evolving and will fundamentally boost the development of robots, autonomous systems, and smart devices. Infineon's Hybrid ToF (hToF) camera system, with its compact design, high accuracy, and robust performance, is expected to drive innovation in next-generation technologies. hToF cameras provide robots with improved systems that become better at acquiring perceptions and making navigational decisions. 

The automotive sector will gain better autonomous vehicle perception from ToF sensors combined with hToF technology, bringing robustness to outdoor applications. The smart city infrastructure, emerging industries, consumer electronics, drones, and smart homes will also be supported by ToF sensors. The combination of increased real-time 3D mapping and depth sensing needs, financial efficiency, Internet of Things (IoT) and Artificial Intelligence (AI) integration, and standardization protocols will speed up market-wide acceptance. 

The hToF technology developed by Infineon Technologies and partners and by camera module makers provides superior opportunities for robotic vacuum cleaners. It shows promise for robotic applications, industrial automation, and consumer electronics applications. Additionally, future advancements could see the adoption of RGB-D cameras, which combine a 2D sensor with a ToF sensor, for enhanced depth perception using AI. However, this technology is still in the early stages of many applications.

Conclusion

Time-of-flight (ToF) technology is fundamental for depth sensing and real-time 3D mapping to address challenges in robotics, automotive systems, consumer electronics, and industrial automation applications. They measure the time it takes for light to travel to an object and reflect for precise depth information, applications such as obstacle detection, SLAM, and enhanced human-machine interaction.

Infineon Technologies and partners have transformed depth sensing technology through ToF sensors and camera system development, like hToF. These technologies provide precise depth information and real-time 3D mapping to revamp several sectors, ranging from robotics to automotive manufacturing, consumer electronics, and industrial automation. The REAL3™ ToF sensors from Infineon generate systems with precise depth-sensing capabilities, leading to smarter, safer, and more efficient operations.

Hybrid ToF camera systems represent an essential breakthrough that unites high-resolution and accurate long-range indirect ToF techniques for unmatched performance levels. The current robotic vacuum cleaner optimization of hToF cameras opens new possibilities for industrial automation, automotive, and consumer electronics applications.

Infineon's depth sensing and 3D imaging sensors demonstrate superiority because they feature advanced depth accuracy, lighting robustness, compact size, and power-efficient operation. The continuous advancement of ToF technology has made it essential to develop future smart technologies that will lead to more autonomous systems.

Infineon leads the depth sensing market by focusing on innovation and superior depth sensing expertise for ToF applications, enabling advanced robotics capabilities, smart autonomous car systems, and beyond.

References

1. Brzozowski, E., & Vogel, S. (2020). State-of-the-Art Photography and Immersive AR/MR Experiences: REAL3 TM 3D ToF Imager with Longest Range in the Market. www.eetimes.eu.

2. Infineon. (n.d.). ToF 3D image sensors. Retrieved February 1, 2025, from https://www.infineon.com/cms/en/product/sensor/tof-3d-image-sensors/.

3. Market News. (2023, February 24). New i-ToF imager enables smallest 3D camera systems with improved quantum efficiency at optimized cost. https://www.infineon.com/cms/en/about-infineon/press/market-news/2023/INFPSS202302-067.html.

4. Lee, Y. (2024). Hybrid hToF 3D-sensing DYSON TECHDAY.

5. Leitner, R., Steurer, E., Berger, A., & Bell, W. (2024). Enabling the next generation of smarter self-navigating robots using Hybrid ToF.

6. pmd. (2024). Roborock uses hybrid Time-of-Flight technology by Infineon and pmd For advanced sweeping and mopping robots.

7. Market News. (2024, September 5). Roborock uses hybrid Time-of-Flight system by Infineon and pmdtechnologies for sweeping and mopping robots. https://www.infineon.com/cms/en/about-infineon/press/market-news/2024/INFPSS202409-137.html.

8. Roborock. (n.d.). Saros Z70 Grasp the future with Intelligence. Retrieved February 1, 2025, from https://us.roborock.com/pages/roborock-saros-z70