Development trend of laser ranging sensors

With the development of electronic technology, the degree of automobile electronics is constantly improving. The usual mechanical system has been unable to solve some problems related to automobile functional requirements, and has been replaced by electronic control systems. The role of the sensor is to provide a useful electrical output signal according to the specified measured value, that is, the sensor converts the physical and chemical quantities of light, time, electricity, temperature, pressure and gas into signals. As a key component of the automobile electronic control system, the sensor directly affects the performance of the automobile's technical performance.

At present, an ordinary family car is equipped with about dozens to nearly a hundred sensors, while the number of sensors on luxury cars can be as many as more than 200. Automobile sensors are mainly used in engine control systems, chassis control systems, body control systems and navigation systems in automobiles.

1. Sensors for engine control systems are the core of the entire automobile sensor, and there are many types, including temperature sensors, pressure sensors, speed and angle sensors, flow sensors, position sensors, gas concentration sensors, knock sensors, etc. These sensors provide the engine's electronic control unit (ECU) with information about the engine's operating conditions, so that the ECU can accurately control the engine's operating conditions to improve the engine's power, reduce fuel consumption, reduce exhaust emissions, and perform fault detection. Since the engine operates in a harsh environment with high temperature (engine surface temperature can reach 150°C, exhaust manifold can reach 650°C), vibration (acceleration 30g), impact (acceleration 50g), humidity (100%RH, -40°C-120°C), steam, salt spray, corrosion, and sludge pollution, the technical indicators of the engine control system's sensors for resistant to harsh environments are 1-2 orders of magnitude higher than those of general industrial sensors, among which the most critical are measurement accuracy and reliability. Otherwise, the measurement error caused by the sensor will eventually make it difficult for the engine control system to work properly or cause failures.

2. Temperature sensors are mainly used to detect engine temperature, intake gas temperature, cooling water temperature, fuel temperature, and catalytic temperature. There are three main types of temperature sensors: wirewound resistor, thermistor, and thermocouple resistor. The three types of sensors have their own characteristics, and their application scenarios are also slightly different. Wirewound resistor temperature sensors have high accuracy but poor response characteristics; thermistor temperature sensors have high sensitivity and good response characteristics, but poor linearity and low adaptability to temperature; thermocouple resistor temperature sensors have high accuracy and a wide measurement temperature range, but need to be used with amplifiers and cold end processing.

3. Practical products include thermistor temperature sensors (general type -50℃～130℃, accuracy 1.5%, response time 10ms; high temperature type 600℃～1000℃, accuracy 5%, response time 10ms), ferrite temperature sensors (ON/OFF type, -40℃～120℃, accuracy 2.0%), metal or semiconductor film air temperature sensors (-40℃～150℃, accuracy 2.0%, 5%, response time 20ms), etc.