“In the past few years, the four letters “CASE” have represented the future development direction of automobiles. It refers to “networking”, “autonomous driving, “sharing” and “electricity.” Of these four development directions, two seem to be Gathered more research and development (R&D).
In the past few years, the four letters “CASE” have represented the future development direction of automobiles. It refers to “networking”, “autonomous driving, “sharing” and “electricity.” Of these four development directions, two seem to be Gathered more research and development (R&D).
The first problem is related to the electrification of OEMs. In fact, the European Union has set a carbon dioxide emission reduction target: 95 g/km by 2021 and 81 g/km by 2025. With these goals, OEMs have almost no other choice besides choosing electric vehicles.
The second question is about autonomous driving and how automakers can integrate more and more autonomous driving functions to achieve the long-term goal of fully autonomous driving. OEM manufacturers are expected to achieve this goal because they will add many sensors and increase the computational performance required to process all the data generated by the sensors.
Sustainable development policy promotes the popularization of electric vehicles
According to estimates by Yole Development, the market for electric vehicles and hybrid electric vehicles (EV/HEV) is growing rapidly and will reach more than 30 million vehicles by 2025. There is no doubt that the development of electrification is the most powerful response to social and environmental challenges.
One of the most important benefits is to reduce carbon dioxide emissions from passenger cars and reduce air pollution in densely populated areas. Electrification may also be pragmatic, because the government has set strict CO2 emission reduction targets, forcing automakers to drastically reduce the average CO2 emission level of cars. The electrification of automobile power systems can significantly reduce carbon dioxide emissions, and therefore becomes a mandatory part of the strategy of automobile manufacturers.
For more than 20 years, under the leadership of a few electric vehicle/hybrid vehicle manufacturers, we have entered the stage of large-scale deployment of electric vehicles/hybrid vehicles by traditional mainstream automakers and emerging OEMs.
For a market with historically high barriers to entry, electrification is providing opportunities for a large number of newly established companies, although many of them are unlikely to be accepted by the mainstream. Automobile manufacturers around the world are releasing a large number of electric vehicle product portfolios, allowing customers to freely choose among different electric vehicle types and vehicle designs. The range of electric vehicles is increasing, pricing is becoming more affordable, and most importantly, electric vehicle charging infrastructure is being widely deployed. All these factors increase the motivation of customers or reduce the previous reluctance to purchase electric vehicles/hybrid vehicles.
Different types of electric vehicles emerge in endlessly
Among different types of electric vehicles, we distinguish between hybrid vehicles (including electric and internal combustion engines) and pure electric vehicles. All-electric vehicles with zero CO2 emissions are considered the ultimate goal of passenger car electrification.
However, due to technology, cost, raw material, and manufacturing constraints, the transition from internal combustion engine vehicles to all-electric vehicles cannot be accomplished overnight. The lack of charging infrastructure is also a key obstacle.
Traditional car OEMs are gradually adopting electric vehicles, which may affect the sales of their ICE cars. They must bear the burden of existing ice-related production facilities, employees, distribution and sales networks. It also requires the development of new intellectual property rights, engineering technology, and the ability to manufacture electric vehicles, which are often isolated from traditional internal combustion engine manufacturing.
The entire automotive supply chain needs to be rebuilt, which will take some time. Therefore, there is a transitional period when providing customers with cars with different electrification levels (Figure 2). Compared with ICE cars, hybrid electric vehicles can provide different levels of carbon dioxide emission reduction, from a small proportion of mild hybrid electric vehicles (MHEV) to about 50% of plug-in hybrid electric vehicles (PHEV).
The transition from hybrid vehicles to all-electric vehicles
In the past 20 years, pure electric vehicles/hybrid vehicles have dominated the electric vehicle industry, mainly due to the commercial success of the Toyota Prius launched in 1997. As the government has set a strong carbon dioxide emission reduction target, which will inevitably promote the improvement of lithium-ion batteries and the reduction of their costs, the automotive industry is following the “accelerated electrification trend”-the transition to a longer electric mode driving range, such as plug-in Hybrid vehicles and pure electric vehicles.
In fact, plug-in hybrid vehicles and all-electric vehicles have significantly reduced the carbon dioxide emissions required by automakers to meet government standards and avoid heavy penalties.
Some special factors have also accelerated the initial strategic path of vehicle electrification, including incentive mechanisms and penalties.
Both plug-in hybrid vehicles and pure electric vehicles are rechargeable vehicles; they can be charged from the grid, preferably using electricity generated by clean energy sources such as photovoltaics, wind energy, and hydroelectric power. The electric driving range of a plug-in hybrid vehicle is about 50 to 80 kilometers. Because plug-in hybrids can be used in full electric mode, they can also reduce urban air pollution emissions, but since the full electric mode is only suitable for short-distance urban commuters, this contribution is limited.
In order to achieve a longer driving range in electric mode, reduce carbon dioxide emissions, and improve the impact of electric vehicles on the environment, it is necessary to innovate in batteries, power Electronic equipment and systems, and vehicle design.
The main trends in power electronics technology include the use of SiC and GaN semiconductor technologies in traction inverters, on-board chargers and DC-DC converters, and device packaging technologies (silver sintered mold connection, copper wire bonding, solderless connection, Si3N4 AMB (Active metal brazing) ceramic substrates, high temperature epoxy packaging), and the mechatronics of different systems.
The main goal of improving mileage is to increase power density while reducing volume and weight. Other developments help improve overall reliability and reduce manufacturing costs. Although the increasing popularity of electrification is partly due to increased consumer awareness, an important reason should be the acceleration of the pace of engineering in the automotive industry.
Sensor trends for electrification and ADAS
The number of sensors on vehicles will gradually increase.
Under CASE, the sensor mainly includes two main lines: electrification and ADAS functions, including automatic driving and V2X connection. The addition of sensors is part of the development of new electrical/electronic architectures and ADAS systems. As with emission control, safety improvements are also driven by government regulation-such as the New Assessment Vehicle Program (NCAP) and the National Highway Traffic Safety Administration (NHTSA).
For the electrification of cars, more current sensors will be used in BMS. Traditional powertrain pressure sensors-MAP, BAP, transmission fluid, GPF, etc. pressure-may be affected by the decline in the dependence of electric vehicles on ICE, but this should be a long-term development process. At present, the development trend of hybrid vehicles and their hybrid power systems provides favorable conditions for the integration of new and traditional sensors. These sensors include optical sensors for head-up vision, magnetic sensors for wheel torque, and distance measurement and navigation sensors. Inertial sensors, pressure sensors for power system monitoring, current sensors for power systems, etc.
In addition to electrification, ADAS is also another driving factor for sensor density in all vehicle models. In order to give the car more autonomy, it should develop its own situational awareness. For this reason, suitable sensors are needed that can simulate the way humans perceive the environment.
However, the sensor kits used for ADAS in the consumer car market are quite different from the fully autonomous mobile-as-a-service (MaaS) business models such as Waymo and Cruise. The latter uses high-cost, high-performance industrial-grade sensors and advanced processing platforms, and its cost and energy consumption far exceed those of consumer cars. For ADAS, the key is to provide very good performance at low cost. Below we list some of the most important ADAS sensors:
• The image sensor is becoming the most important sensor in ADAS. These cameras are the eyes of the car. Car cameras use complementary metal oxide semiconductor (CMOS) image sensors almost everywhere. The dependency rate of car cameras is getting higher and higher, which can help realize various functions.
• Forward-looking perspective: The trend of extended range and ADAS range from a single camera to three cameras continues.
• Surround view: The rear camera only deals with reversing and parking assistance issues. The future trend is to provide more 360° viewing angles to better perceive the environment (reversing, parking in restricted spaces, turning and other maneuvers).
• Cabin driver monitoring: According to the Euro NCAP 2025 roadmap, it is recommended to implement driver monitoring to reduce driver distraction and injury caused by alcohol, fatigue or other hazards. It also monitors passengers and detects forgotten children or animals. Exist to avoid heat stroke or similar events. Once, other technologies were competing for the dominance of in-cabin surveillance, such as thermal sensors, time of flight (ToF) or radar.
•Ultrasonic sensors are mainly used for close detection of obstacles or pedestrians. Their main functions are parking assistance and collision avoidance.
• Radar is still the best sensing technology for measuring relative distance and speed, mainly driven by the automatic emergency braking (AEB) that has been enforced in the past few years. With the improvement of its angular resolution, major manufacturers are working on 3D radar or 4D imaging radar and monolithic microwave integrated circuit (MMIC) solutions.
•Lidar is the latest sensor to enter the automotive ecosystem. It can work in dark conditions and can accurately monitor the surrounding environment, which makes it a necessary sensor for the development of more advanced perception capabilities. The effective fusion of data from ADAS cameras and lidars is important for deep detection of objects as well as short-range and long-range object detection. However, compared with radar and camera, Lidar is still a very complex sensor for Tier 1 and OEM. In order to better integrate, process data or reduce costs, OEMs need to do more work.
•The thermal imaging sensor “looks” at the far infrared spectrum (8 – 14µm) is more proficient in low light conditions. Dusk is particularly difficult for drivers. ADAS cameras sometimes encounter difficulties when exposed to direct sunlight, deep shadows and low ambient light. The use of these sensors can be a good supplement to CMOS sensors to detect the heat emitted by living beings and other heat-generating objects, and improve the safety function of the car. FLIR is the largest manufacturer of thermal imaging cameras, and it advocates ADAS thermal imaging as a redundant sensor.
• Global Navigation Satellite System (GNSS) receivers use connectivity to enhance ADAS functions by locating vehicles on digital maps. This is essential for ADAS to have situational awareness. However, in some cases (urban canyons, tunnels, under trees, etc.), GNSS signals may be lost. Therefore, it is increasingly combined with other positioning systems.
• Odometer sensors located on the wheels record the distance from the last known position.
• Inertial measurement unit (IMU) detects inertial changes.
The last two sensors listed are short-range backups. When GNSS is unavailable, they can help estimate the location of the vehicle, thereby improving the accuracy of positioning at all times.
In addition to ADAS, automotive connectivity and E/E architecture are also changing. In terms of connectivity, regulations are pushing most countries to achieve basic V2I and V2V communications based on the 5.9 GHz frequency band by 2023. 5G connectivity is powering advanced V2X.