In recent years, more and more devices have adopted light detection and ranging (LiDAR) that accurately measures distance and identifies space in automation applications such as sweep robots, automated guided vehicles (AGVs), and autonomous vehicles. In addition, power conversion devices play an important role in the stable operation of automation devices. This paper will show you the development of LiDAR and power conversion devices, as well as the functionality and characteristics of laser diodes and power conversion device solutions introduced by ROHM.
AI technology improves LiDAR's ability to identify objects
In recent years, cutting edge AI technologies based on deep learning (convolutional networks) using point cloud data from LiDAR measurements and object detection algorithms (YOLO/Faster-RCNN/SSD, etc) have been developing rapidly year by year. Innovation combining 3D imaging technology with depth learning has also become the core technology of AI robots. With the growing maturity and decreasing cost of LiDAR technology, LiDAR has been widely used in many robotics and automotive applications to accurately measure distance and identify objects in space.
Cameras and LiDARs supported by AI and machine learning technology are significantly superior to traditional camera computer visual technology. Algorithms can be adapted to various lighting and weather conditions automatically to detect, track, and classify road conditions more correctly, flexibly, and stably, in order to distinguish drivers and pedestrians on and around roads. Therefore, in order to detect information further, more accurately, and with lower power consumption, there is also a higher requirement for laser diodes to be used as light sources.
Provide higher-quality high-output power laser diodes
In LiDAR and object detection techniques, the output of high-definition beam light sources is essential for accurate object location, classification, and segmentation. ROHM laser diodes can contribute to the development of AI and robotics that will require increasingly complex operations in the future by achieving high-quality beam shapes through optical waveguide design and process technologies cultivated over the years.
ROHM has patented technology to achieve a narrower emission width, which helps LiDAR support longer range and ensure higher accuracy. Since 2019, RLD90QZW5, a 25W high-output laser diode from ROHM, has been mass produced. It has been highly acclaimed in applications mainly in the consumer electronics sector, with remarkable import results. In order to extend the application to the market's growing industrial control equipment, ROHM developed RLD90QZW3, a 75W laser diode with high output power.
RLD90QZW3 uses 905nm, 75W, 225μm invisible pulse laser diodes to achieve narrow emission width, help extend detection distance, and improve induction accuracy. With the advanced structure of ROHM, RLD90QZW3 has high energy conversion efficiency and reduces wavelength temperature fluctuations, contributing to low power consumption and long life. RLD90QZW3 is packaged with Φ5.6 CAN in accordance with industry standards and is suitable for laser rangefinders, AGVs, and security applications.
RLD90QZW3 is an infrared 75W high-output laser diode developed for LiDAR using a 3D ToF system for ranging and spatial recognition. With ROHM proprietary component R&D technology, the ultra-narrow emission width of 225 µm was achieved in the industry, which is equivalent to the output power of a laser diode. Compared with other market competitors at 290 µm, the emission width was reduced by 22%. Therefore, it features high beam performance, narrow emission area, and high optical density, allowing higher resolution and wider range.
In addition to successfully making the luminous intensity more uniform in the overall emission width range, the temperature dependence of the laser wavelength is as low as 0.15 nm/℃ and is not susceptible to temperature changes. Therefore, its performance can be stabilized. The temperature dependence of the laser wavelength can be 40% lower than that of market competitors with the same output power, an emission width of 290 µm, and a temperature dependence of 0.25 nm/℃. The use of smaller wavelength bandpass filters can provide a narrower wavelength range, thus improving signal-to-noise ratio, and thus supporting LiDAR long-distance applications. On the other hand, RLD90QZW3 has uniform optical intensity and uniform optical intensity throughout the emission width, which can improve the resolution of the image edge.
In addition, RLD90QZW3 uses patented technology. Among products with the same output power, it not only has the industry's narrowest emission width, but also a power-optical conversion efficiency (PCE) that is difficult to match with an emission width. It has also reached 21% of the market competition (at 24A and 75W positive current output). Therefore, there is no need to worry about increased power consumption when used.
In order to speed up the market import process for this series of products, a wealth of design data, including application guides for driving circuit design methods, data for circuit board R&D and simulation models (SPICE models, Ray data), etc, are also available free of charge on the ROHM official website for the evaluable import of this series of new products.
To provide solutions in the future, ROHM is prototyping a reference design for LiDAR sensors and also starting commercialization of its next-generation device GaN HEMT and higher output power 120W Laser Diode RLD90QZW8, which will help reduce design-hours for customers and support rapid launching.
ROHM’s Reference Design for LiDAR sensors
Power conversion efficiency improves robot performance
China, with its "world factory", already has a fairly high level of industrial manufacturing technology and a high level of machine tools/robots in various industrial fields. It is also one of the 10 areas designated by the Chinese government for the "Made in China 2025" project. China aims to improve its manufacturing process and parts used in China by 2025, making China a world leader in robotics. As a result, many robotic companies have been born in China.
Robotic applications require more power due to higher functionality and enhanced drive capabilities such as artificial intelligence, sensing (image recognition), etc. As a result, the power conversion technology problems to be solved are increasing. In addition, power conversion efficiency is a very important factor for mobile robots.
Innovations in power conversion technologies are driving changes in robotic design, and new power devices are now meeting the needs of robotic applications in terms of size, weight, power budget, and cost efficiency, thus bringing robots from factories to home and commercial applications and further expanding the market space.
Advanced power converters for industrial equipment applications
In order to solve power problems for industrial equipment, ROHM launched the DC/DC converter BD9G500EFJ-LA for industrial equipment, which supports 48V power supplies for industrial robots. Currently, 24-72V power supply is mainstreamed in battery-powered mobile robots. BD9G500EFJ-LA provides industry-leading 80V high withstand voltage 5A high current, helps improve the functionality and size of advanced industrial equipment, miniaturizes devices integrating multiple functions, and pursues more functional industrial applications by combining AI and/or IoT.
BD9G500EFJ-LA can be widely used in electric bicycles, industrial robots, power tools, and other applications requiring 48V/60V power input, as well as servers, charging stations, and power amplifiers for 5G base stations requiring 48V power input. In addition, applications such as vacuum cleaners, washing machines, and other motors exposed to surge voltage will also be important applications for BD9G500EFJ-LA.
BD9G500EFJ-LA increases output current, expands operating temperature range, and improves output voltage accuracy. ROHM also provides 10-year supply guaranteed that it meets ROHM's high-quality design standards and LA rank products.
BD9G500EFJ-LA adopts the high-voltage Bi-CDMOS process, and achieves the best-in-class 80V voltage rating and wide safe operating range in non-isolated DC/DC converter chips with a high-side MOSFET (asynchronous rectification type). Compared with standard products with the same output current, the chip has successfully increased withstand voltage by about 20%, providing a sufficient surge voltage margin for 48V main power supply for 5G base stations and servers, and enough margin for commonly used 60V systems. Therefore, larger battery sizes can be used in electric bicycles and power tools, thus improving application reliability.
At the same time, BD9G500EFJ-LA has built-in low on-resistance, high-speed transient response, easy-to-set phase compensation and adjustable frequency between 100kHz and 650kHz. Built-in low-loss MOSFET is within the wide output current range of 2A to 5A (despite asynchronous rectification), achieving a high power conversion efficiency of 85%, which translates into greater power saving performance. ROHM also provides BD9G500EFJ-EVK-001 evaluation boards for BD9G500EFJ-LA devices.
Conclusion
The new LiDAR and power conversion chip, with high quality and efficiency, will help improve the performance of industrial equipment such as robots and extend robotics applications to the home and business sectors. High-quality laser diodes introduced by ROHM have higher accuracy and detection ranges, and new power conversion chips can also provide higher power conversion efficiency and will be the best partner for robots and automation equipment.