1. Overview of Automotive Electronics Development Automotive electronics is built upon the foundation of advancements in electronics. From vacuum tubes, transistors, integrated circuits, large-scale integrated circuits to very large-scale integrated circuits, technological progress has led to the emergence of various electronic devices such as computers. Automotive electronics have also deepened and developed year by year, with some electronic devices accounting for one-third of the total vehicle cost. High-end cars may even have dozens of microcontrollers and hundreds of sensors. The degree of electronics integration can be considered a major indicator of a car's luxury. In the 1950s, people began installing vacuum tube radios in cars, marking the rudimentary application of electronic technology in automobiles. After the invention of transistor radios in 1959, they were quickly adopted in cars. In the 1960s, silicon rectifier alternators and transistor regulators were used in cars. By the mid-1960s, transistor voltage regulators and transistor ignition systems began to be used. However, the widespread application of electronic technology began after the 1970s, primarily to address three major issues: automotive safety, pollution, and fuel efficiency. In the late 1970s, the electronics industry made significant progress, particularly in integrated circuits, large-scale integrated circuits, and very large-scale integrated circuits. The application of microcomputers in automobiles brought about a revolutionary change. In the 1990s, automotive electronics technology entered its third stage of development, the most valuable and contributing stage to the automotive industry. The miniaturization of ultra-miniature magnets, ultra-high-efficiency motors, and integrated circuits provided the foundation for centralized control in automobiles. Currently, automotive electronics technology has evolved to its fourth generation, encompassing small systems integrating electronic technology (including microcomputer technology), optimized control technology, sensor technology, network technology, and mechatronics coupling technologies. It has long since moved from the research stage to the mature stage of commercial production. Automotive electronics technology mainly includes hardware and software aspects: hardware includes microcomputers and their interfaces, actuators, sensors, etc.; software mainly consists of programs written in assembly language and other high-level languages ​​for data acquisition, calculation and judgment, alarm, program control, optimized control, monitoring, and self-diagnostic systems. The microcomputer is the core of the entire system, responsible for directing the operation of other equipment. Currently, the microcomputers used in automobiles are mainly general-purpose single-chip microcomputers and automotive-specific microcomputers with high anti-interference and vibration resistance. Their speed and accuracy requirements are not as high as those of computer microcomputers, but they have stronger anti-interference performance and can adapt to harsh working environments such as those with high vibration levels. Some systems are evolving from single-computer control (i.e., one microcomputer controlling one item, such as ignition control) to centralized control, while automotive centralized control is transitioning from multiple computer communications to networked management. 2. Overview of the Development of Automotive Electronic Control Theory The theoretical foundation of automotive electronic control is both a difficult and a key point in "automotive electronics technology." Open-loop, closed-loop, optimal, and adaptive control systems established using automatic control theory are all used in automotive optimization control. When establishing these control systems, the first step is to identify a specific automotive system, such as the ignition advance angle optimization control system, establish a mathematical model, and then use corresponding control methods for optimization control. However, the engine itself has a complex structure, and many factors affect ignition, making it difficult to theoretically derive the mathematical model for optimizing ignition conditions. Therefore, experimental methods are generally used to find the optimal ignition advance angle under various operating conditions, and then store it in the microcomputer's memory. During the control process, the microcomputer continuously monitors the engine's operating condition, uses a lookup table to find the optimal ignition advance angle under that condition, makes corrections, and then controls ignition through the microcomputer interface and amplifier circuit. This is a widely used optimization control method abroad. Another mature method currently used is the adaptive online search method, which includes two types: vertex holding and mountain climbing. This method does not require knowledge of the prototype model; instead, the microcomputer searches for the optimal operating condition during vehicle operation, bringing the control close to or reaching optimization. Fuzzy control is a new control theory that has emerged in recent years and has also been applied in automobiles. A fuzzy control system is also a type of automatic control system. It is a digital control system with a closed-loop structure, based on fuzzy numbers, fuzzy language knowledge representation, and fuzzy logic reasoning, and constructed using computer control technology. Fuzzy logic is closer to human thought and natural language in meaning than other traditional logics. 3. Application of Network Technology in Automobiles 3.1 Application of Network Technology Inside Automobiles More advanced automobiles are equipped with dozens of microcomputer controllers and hundreds of sensors. This provides conditions for network applications in automobiles and resolves the long-standing contradiction between centralized and decentralized control in automobiles. Distributed control refers to a system where a single component in a car, such as ignition or fuel injection, is controlled by a microcontroller. This marks the beginning of microcomputer applications in automobiles. Later, this evolved into centralized control systems, including fully centralized systems (e.g., General Motors' microcomputer system controls anti-skid braking, traction control, optimized ignition, overspeed warning, automatic door locking, and anti-theft); hierarchical control systems (e.g., Nissan's hierarchical control system uses a central control computer to direct four microcomputers, each controlling anti-skid braking, optimized ignition, fuel injection, and data transmission); and distributed centralized control systems, which are based on different parts of the car and centrally controlled in sections, such as the engine, chassis, information, display, and alarm systems. For example, Isuzu's I-TEC system centrally controls engine ignition, fuel injection, idling, and exhaust gas recirculation. Each of these types of control has its advantages and disadvantages, but the application of networks in automobiles allows each type to leverage its advantages and overcome its disadvantages. For instance, the biggest problem with both centralized and distributed control is reliability; in fully centralized control, a microcomputer failure would paralyze the entire vehicle. With the adoption of network technology, not only can all sensors be shared, but other devices can also be shared. For example, with ring network control, even if a few microcomputers malfunction, the entire vehicle can still operate normally. Therefore, networks in automotive applications not only add many functions but also greatly increase reliability. To meet the needs of automotive network control and better facilitate information exchange, coordinated control, resource sharing, and standardization and generalization among various control systems, countries around the world are actively cooperating in the research and development of automotive local area networks (LANs). Foreign countries have already made progress in the formulation of network standards and in the development of microprocessors and communication protocols that conform to network communication standards. In terms of network standards, there are the Controller Area Network (CAN) protocol developed by Bosch and the SAE J18065 network standard launched by Intel. Furthermore, companies such as Philips, Intel, and Motorola have launched microprocessor products that conform to relevant network protocols. Meanwhile, to integrate various standards, an international standard for automotive networks is being drafted by the International Organization for Standardization. 3.2 Applications of Network Technology Outside the Vehicle An automotive internet system is a wireless network structure. Through it, people can perform all online operations such as browsing the internet and sending emails while driving, just like at home. Many companies are currently working on this area. For example, IBM and Motorola have collaborated to develop in-vehicle wireless Internet technology. This technology will allow drivers and passengers to send emails and engage in various online activities while in the car, such as e-commerce and online shopping, checking stock market information and weather forecasts. Microsoft has also launched AutoPC software specifically designed for "in-vehicle internet," using the Windows CE operating system. It features interactive speech recognition and various multimedia functions. This functionality effectively ensures driving safety because it allows drivers to exchange information with a PC system without taking their hands off the steering wheel or their eyes off the road. This includes information such as traffic conditions ahead, navigation speed, and sending and receiving emails, making VoIP calls, and engaging in other internet activities. General Motors has not only developed an "in-vehicle internet" system but also installed an in-vehicle automated office system. Because this system uses a high-speed fiber optic serial data channel (MML), it has multi-channel digital audio and video capabilities and can effectively control high-capacity input and output signals across multiple channels. For example, CD players, DVD players, monitors, television receiving antennas, audio systems, and GPS systems can all exchange information with this system. 4 Development Trends of Automotive Sensors Automotive sensors are one of the key technologies for promoting the high-end, electronic, and automated development of automobiles. Countries around the world attach great importance to the research and development of automotive sensors and improving their cost-effectiveness. The view that "there is no modern automobile without sensor technology" is now recognized worldwide. The more developed the automotive electronics and the higher the degree of automation, the greater the dependence on sensors. Therefore, both domestic and foreign countries have listed automotive sensor technology as a key high technology for development. The general development trend of modern automotive sensors is: multi-functionality, integration, intelligence, and miniaturization. The development direction of their technology is: (1) to carry out basic research, discover new phenomena, adopt new principles, develop new materials, and adopt new processes; (2) to expand the functions and application scope of sensors. 4.1 Discovering New Phenomena The basic principles of various sensors are physical phenomena, chemical reactions, and biological effects. Therefore, discovering new phenomena and effects is an important foundation for the development of modern sensors. 4.2 Developing New Materials Functional materials are another important foundation for the development of sensor technology. Due to the progress of materials science, people can control the composition of various materials at will when manufacturing them, so as to design and manufacture various functional materials for sensors. For example, controlling the composition of semiconductor oxides can create various gas sensors; the use of optical fibers in sensors is a major discovery in sensor functional materials; organic materials, as functional materials, are attracting great attention from automotive electronics experts both domestically and internationally. 4.3 The performance of sensor sensing elements using new processes is determined not only by their functional materials but also by their processing technology. With the application of new materials such as semiconductors and ceramics in sensor sensing elements, many modern advanced manufacturing technologies have been introduced into automotive sensor manufacturing technology, such as integration technology, microfabrication technology, ion implantation technology, and thin-film technology, enabling the production of miniaturized sensing elements with stable performance, high reliability, small size, and light weight. In recent years, microelectromechanical systems (MEMS) technology, developed from semiconductor integrated circuit technology, has matured significantly. This technology can be used to fabricate various miniature sensors capable of sensing and detecting mechanical, magnetic, thermal, chemical, and biological quantities. These sensors are small in size and consume little energy, can achieve many new functions, are easy to mass-produce and produce with high precision, have low unit costs, and are easily configured into large-scale and multifunctional arrays. These characteristics make them very suitable for automotive applications. In the early 1980s, miniature piezoresistive multichannel absolute pressure sensors began mass production, replacing earlier pressure sensors using LVDT technology. In the mid-1980s, miniature accelerometers began to be used in automotive airbags; these are the miniature sensors that are currently mass-produced and widely used in automobiles. However, the large-scale application of miniature sensors will inevitably extend beyond engine combustion control and airbags. In the next 5-7 years, applications including engine operation management, exhaust gas and air quality control, ABS, vehicle power control, adaptive navigation, and vehicle driving safety systems will provide a broad market for MEMS technology. 4.4 Research on Multifunctional Integrated Sensors Research on multifunctional integrated sensors is an important direction in sensor development, integrating multiple functional sensitive components and multiple sensitive components with the same function onto a single chip. For example, Japan has developed a composite piezoresistive sensor, where a single chip can simultaneously detect automotive pressure and temperature. 4.5 Research on Intelligent Sensors Intelligent sensors are sensors with a microcomputer that combines detection, judgment, and information processing functions. Compared with traditional sensors, they have many unique characteristics. For example, it can determine the sensor's operating status, correct measurement data to reduce errors caused by environmental factors such as temperature, solve problems that are difficult to address with hardware using software, and perform data calculations and processing. Countries worldwide are striving to use software to address the impact of factors such as high electrical interference and harsh environments (high temperature, large temperature gradients, severe pollution, etc.) on automotive parameter measurements, building upon existing automotive sensor hardware. Furthermore, intelligent sensors offer high accuracy, wide measurement range, large output signal, high signal-to-noise ratio, and good anti-interference performance; some even have self-testing functions. Many large automotive companies have conducted research and development in this area and achieved success and application.