汽车感知传感器揭秘它们的类型与应用场景
导语：汽车传感器可分为车辆感知和环境感知两大类。动力、底盘、车身及电子电气系统中的传感器属于车辆感知范畴，ADAS以及无人驾驶系统中引入的车载摄像头、毫米波雷达、激光雷达等属于环境感知范畴。
汽车电子控制系统普遍遵循感知→控制→执行的工作流程。传感器作为关键组件获取系统的工作状态，控制单元处理传感器信号并计算输出控制指令，由执行单元完成相应动作。
(举例说明)
以电动助力转向系统(EPS)为例，车辆运行过程中，方向盘扭矩转角传感器监测方向盘转角及扭矩信息，轮速传感器监测车轮转速。ECU通过CAN总线实时获取这些信号，并根据特定逻辑实时处理信号，计算得到一个理想的助力力矩，然后通过MOSFET控制电机实现助力的效果。
汽车动力、底盘、车身四大系统中绝大部分电子控制具备类似的工作原理，从而体现出半导体技术在现代汽车中的重要性，它们包括但不限于用于智能化功能如自动驾驶辅助（ADAS）和无人驾驶技术所需的大量数据采集设备，如摄像头、高分辨率图像探测仪（HDI）、激光雷达和超声波探伤仪等。
MEMS MEMS是微型机械结构与微型传统晶片结合的一种先进制造技术，在现代汽车上广泛应用于压力类以及运动类检测领域，如加速度计陀螺仪及磁力计等惯导系统内使用，其性能越来越受到重视。MEMS材料具有优异性能，比如耐高温、高频响应灵敏度，可以用在各个方面，比如油门踏板位移检测、二次空气滤清过滤网压差检测、三元催化排放测试室温度检测等多种不同的应用场合。在此基础上，一些特殊工艺可以进一步提升其性能，使之适用于更高要求或更复杂环境下的任务。
化学化学类型主要包括氧气(O2)、氮氧化物(NOx)以及二氧化硫(SO2)三种常见污染物，以及其他有害物质例如苯系醇(C6H5CH3)，这些建立在分析样本从燃烧前后的变化上，以便判断发动机是否有效地将废气经过催化剂进行净化。此外，还有一些专门设计来追踪燃油质量问题及其对尾气排放影响的化学分析装置，这对于保证发动机健康状况至关重要，因为它能帮助维护者了解何时需要替换或清洁某些部件以避免长期损害。
温度Temperature sensors measure the temperature of various components within the vehicle. NTC (Negative Temperature Coefficient) thermistors are widely used to monitor temperatures in air, water, and other fluids. PTC (Positive Temperature Coefficient) thermistors are used for overcurrent protection, temperature limiting, and heating applications.
The Bosch company estimates that there are more than 50 MEMS sensors in a traditional gasoline-powered car, with an estimated value of around 500-1000 yuan per vehicle. The most common types of MEMS sensors include pressure sensors, accelerometers, gyroscopes, and magnetic field sensors.
Pressure MEMS: These devices use silicon's piezoresistive effect to detect changes in pressure. By applying pressure to a silicon membrane with four resistive elements that change resistance when deformed by mechanical stress or strain), these devices output a voltage signal proportional to the applied pressure.
Accelerometer: Accelerometers use Newton's second law of motion to determine acceleration based on the measurement of mass times acceleration force.
Gyroscopes: Gyroscopes use Coriolis force principles: When an object moves linearly through space while its reference coordinate system rotates around it at a constant angular velocity greater than zero degrees per second relative to inertial space; then this moving object experiences an additional force perpendicular both to its direction-of-motion vector as well as any line connecting its center-of-mass position directly above ground level down below along bottom side surface thereof but not parallel nor orthogonal thereto neither; thus causing said particle(s)/mass(es) under test become displaced from their equilibrium state towards either leftward (+ve sign), rightward (-ve sign). This displacement can be detected using capacitive or resonant sensing techniques which convert into electric signals for further processing by electronic circuits inside computer systems controlling overall behavior & decision-making processes within vehicles such as steering control algorithms during turns where lateral forces act upon tires' surfaces against friction coefficient limits before losing traction leading potentially dangerous loss control situations requiring prompt intervention via corrective actions taken instantly like automatic braking assistance activated by built-in safety features integrated within modern cars equipped advanced driver-assistance technologies designed improve road safety standards worldwide.
