Since SAE International defined the levels of automation for assessing autonomous driving technology, it has become a global industry benchmark for defining automated/autonomous vehicles. This has also given the global automotive industry an exciting prospect: achieving the highest level, Level 5, of autonomous driving technology. While this path may be long, the evolution from ADAS to autonomous driving, like vehicle electrification, is an irreversible technological evolution for all automakers.
In the advancement of autonomous driving, safety remains the most crucial and unavoidable consideration. To achieve accurate perception, analysis, and judgment of the external environment, an increasing number of sensors are being installed in automobiles, from the earliest image sensors to today's millimeter-wave radar, lidar, and inertial navigation systems. Recently, at the Munich Electronics Show, Chris Jacobs, Vice President of Automotive Mobility and Safety at Analog Devices (ADI), showed a picture to a reporter from EEWorld, vividly illustrating the development trends of automotive sensors.
◆Sensors used in modern cars
◆Sensors used in future cars
According to Chris, to ensure the safety of autonomous vehicles, we need various data to help the system analyze and make judgments, including weather robustness, light intensity, object classification, lateral resolution, direct speed measurement, and distance measurement. Meeting these requirements cannot be achieved by a single sensor or even just one type of sensor. Therefore, future automotive sensors will be a diverse mix of products, complementing each other. Image sensors, millimeter-wave radar, LiDAR, and inertial navigation systems will all have their place. As a veteran player in the automotive electronics market, especially in automotive safety, for over 25 years, ADI possesses deep technological expertise in these sensor products and will play a significant role in the current and future fields of autonomous vehicles.
Chris Jacobs, Vice President of Automotive Mobility and Safety at Analog Devices, Inc.
In the field of image radar, autonomous driving requires high resolution of 1° or higher for azimuth and elevation angles, faster warning times/low latency, accurate velocity measurement at 400kph+, and scalable solutions operating from USRR to LRR. ADI can provide solutions with azimuth and elevation angular resolutions below 1°, using scalable 28nm CMOS process technology. This supports next-generation 7*GHz ADAS and autonomous driving image radar applications, enabling 360° surround view and high-fidelity image radar that can detect smaller objects at greater distances while maintaining high reliability.
◆ADI booth at Electronica Munich
◆ BMW electric vehicles built using ADI technology
◆ADI In-Car Intelligent SensorFusion Solution
In the field of LiDAR, ADI offers a 1500nmλ LiDAR, which achieves a four-fold increase in scanning range, is less affected by sunlight, and has better environmental robustness. Its short-wave infrared capability is better suited to certain environments (including fog, smoke, and dust). In addition, ADI provides complete product solutions for automotive LiDAR, including high-performance linearization, data conversion, and power management solutions, supporting systems at 900nm and 1500nm. It also offers long-range and short-to-medium-range scanning solutions. For long-range scanning, it provides solid-state scanning solutions with non-mechanical beam steering, excellent robustness to shock and vibration, and intelligent adaptive scanning. For short-to-medium-range scanning, it provides medium-resolution flash memory solutions with special ambient light and interference suppression capabilities.
Inertial MEMS units (IMUs) are crucial for autonomous driving navigation and guidance systems, ensuring the reliability of precise maps, GPS, and SLAM sensors. They are also unaffected by environmental conditions, as gravity is a constant force on Earth. Therefore, the relative and absolute position calculations of IMUs do not rely on any external devices or signals. They can be installed in concealed locations such as the vehicle chassis, thus avoiding electronic or mechanical attacks. Furthermore, because IMUs inherently possess redundancy between their angular velocity and acceleration measurements, coupled with redundant information from wheel speedometers and steering wheel angle measurements, the confidence level of their output results is far higher than that of absolute or relative positioning results provided by other sensors.
Chris proudly stated that the widespread adoption of ADI's IMU products stems from two main reasons. Firstly, ADI has a wealth of technological expertise. They began developing MEMS accelerometers in 1987 and MEMS gyroscopes in 2002. By 2007, both MEMS accelerometer and gyroscope technologies had matured, and recognizing significant market demand for integrating these two sensors, ADI released its industrial-grade IMU product that year. ADI possesses a complete signal chain processing product suite, including ADCs and processors, all industry-leading products that can integrate all these components, including sensors, into a single module to achieve high-performance IMUs. Secondly, stability is crucial. Imagine a car traveling on uneven roads, encountering speed bumps and vibrations. In such conditions, stable sensor output is paramount. ADI's sensors, whether gyroscopes or accelerometers, maintain stable output even under strong vibrations, a key competitive advantage. This core competitiveness relies on sensor design and subsequent calibration, making ADI's IMU products extremely reliable. ADI also has many patented technologies here.
In the field of autonomous driving, ADI offers the Drive360 autonomous driving sensor solution, focusing on radar, lidar, and IMU inertial navigation. As a sensor and system-level solution provider, ADI is collaborating with ecosystem players such as suppliers and OEMs to research and discuss autonomous driving solutions. "Because the addition of more and more sensing systems constitutes new electronic device systems and is becoming increasingly complex, exceeding the experience of traditional Tier 1 suppliers and OEMs, chip manufacturers often need to provide system-level technical guidance and advice. Therefore, ADI works closely with OEMs and Tier 1 suppliers, leveraging our system design experience to provide services for the industry and the realization of autonomous driving systems," said Chris.
