The rapid development of sophisticated sensor technology in the automotive industry is to improve road safety and help reduce accidents. Today, advanced driver assistance systems (ADAS) are driving the development of such solutions. Although optical sensing technologies such as LiDAR and cameras have been put into use, bad weather conditions will affect its performance, so other technologies are needed to ensure the robustness of the system. The progress of automotive radar (using wireless microwave signals) is seen as a key element of future autonomous driving (AD).
As usual in the automotive industry, radar-based functions were initially used in high-end models to test the applicability and reliability of the technology. These systems use 24 GHz radar technology based on a silicon germanium (SiGe) manufacturing process, incorporating all-weather ADAS functions such as parking assist, blind spot detection (BSD) and lane change assist (LCA).
Nowadays, radar is a core automotive technology, and Semiconductor suppliers are now offering highly optimized chipsets to solve the problem of the industry’s shift to the 77GHz frequency band, which can provide 4GHz scanning bandwidth.
Blind spot detection
As a company that provides a wide range of 77GHz radar based on RFCMOS technology, NXP has always been at the forefront of this technology, focusing on comprehensive system capabilities. CMOS-based radar transceivers, dedicated high-performance radar processors and our system knowledge are delivered to OEMs around the world in batches to serve every customer. The development team can quickly move from the smallest viable product to the application adjusted to its specific needs, either independently or in collaboration with partners.
Our fifth-generation automotive radar solution was conceived with both scalability and good angular resolution. The radio frequency transceiver TEF82x integrates three transmitters and four receivers, covering 76 to 81 GHz. It is integrated with four 40 MS/s analog-to-digital converters (ADC), the device includes a phase rotator and a low phase noise voltage controlled oscillator (VCO). In order to be used in critical safety applications, the transceiver has a built-in safety monitoring module and complies with the ISO 26262 ASIL Class B standard.
Lane change assistance
Matching with TEF82xx is S32R294 radar microcontroller, using 16nm FinFET technology. It receives radar data through MIPI-CSI2 and provides multi-core processing and signal processing toolkit (SPT) hardware accelerators to support the need for higher angular resolution. It is an automotive AEC-Q100 level 1 certified product and meets the requirements of ISO 26262 ASIL B (D). The microcontroller can use a large number of general-purpose automotive-grade compilers and debuggers, including AUTOSAR Safety MCAL, and radar accelerator simulation models (for MATLAB®).
Mastering radar technology requires many years of experience, and professional knowledge is difficult to obtain. It is relatively simple to build proprietary functions on functional solutions. The radar technology of NXP’s gold partner smartmicro provides such an entry point for OEMs and Tier 1 suppliers. With decades of experience in the field of automotive radar, they provide a series of ready-made solutions for short-range and long-range applications, and also provide advanced driver assistance system design services that meet customer needs.
smartmicro worked closely with NXP to develop two new multi-mode products based on TEF82x and S32R294. Their new 4D short-range radar targets corner applications such as BSD, LCA, and front intersection traffic warning/rear intersection traffic warning (FCTA/RCTA). It can provide four different waveform modes, with a resolution of 10 cm at ultra-short distances, and a resolution of 1.3 meters at a long distance of 130 meters. Its antenna array uses a single TEF8232 radar transceiver, which supports up to 12 channels (3 transmitters, 4 receivers).
For medium and long-range multi-mode applications, a new 4D forward/backward radar came into being. The 48-channel array (6 transmitters, 8 receivers) uses two cascaded TEF8232 and one S32R294. The device provides medium-range (66 meters) and long-range (240 meters) modes. The sensor has an angular distance of 2°, which is ideal for automatic emergency braking (AEB) and adaptive cruise control (ACC).
Both new products use sensor fusion technology to achieve 360° omnidirectional sensing. Both sensors are independent, providing point cloud output and various synchronization options for integration into automotive systems. The new product also provides application-level software, including target tracking and occupancy grids. Data is shared via CAN-FD or automotive Ethernet interface.
Automatic emergency braking system
In order to meet the 360-degree sensing requirements of advanced driver assistance systems and autonomous driving, more and more 77GHz radar sensors are needed. Such scalable chip solutions ensure that software and hardware can be easily reused. At the same time, the bill of materials (BOM) has been significantly reduced. In addition, to ensure the rapid launch of products and services, NXP design partner smartmicro provides ready-made sensor solutions and engineering design services for the development of custom radars.