electronic control unit is the abbreviation of electronic control unit (ECU). The function of the electronic control unit is to calculate, process and judge the information input by the air flow meter and various sensors according to the programs and data in its memory, and then output instructions to provide electric pulse signals with a certain width to the fuel injector to control the fuel injection quantity. The electronic control unit consists of microcomputer, input, output and control circuits.
interpretation
electronic control unit (ECU), also known as? Driving computer? 、? Car computer? Wait. In terms of use, it is a special microcomputer controller for automobiles, also called a special single chip microcomputer for automobiles. It is composed of microprocessor (CPU), memory (ROM, RAM), input/output interface (I/O), analog-to-digital converter (A/D) and large-scale integrated circuits such as shaping and driving, just like a common single chip microcomputer.
generally, the voltage working range of ECU is 6.5-16V (with voltage stabilizing devices at key points inside), the working current is .15-.1A, and the working temperature is 4-8 degrees below zero. It can bear the vibration below 1Hz, so the probability of ECU damage is very small. The CPU is the core part of ECU, and it has the function of calculation and control. When the engine is running, it collects the signals of various sensors, performs calculation, and converts the calculation results into control signals to control the work of the controlled object. It also controls the memory (ROM, RAM), input/output interface (I/O) and other external circuits. The program stored in ROM is based on accurate calculation and a large number of experimental data. This inherent program is constantly compared and calculated with the signals collected from various sensors when the engine is working. The results of comparison and calculation control the ignition, air-fuel ratio, idle speed, exhaust gas recirculation and other parameters of the engine. It also has the function of fault self-diagnosis and protection. When the system has a fault, it can automatically record the fault code in RAM and take protective measures to read the replacement program from the above-mentioned inherent program to maintain the operation of the engine, so that the car can drive to the repair shop.
working environment of ECU:
the environment in which ECU for vehicle is located is very harsh and complicated. Besides environmental factors such as humidity, temperature, vibration, impact, dust, mud, sand, water, oil pollution and fluctuating voltage, the electromagnetic environment is a problem that cannot be ignored. In order to make ECU adapt to the harsh electromagnetic environment in automobile, it is very important to consider the environment of ECU and to test and evaluate ECU when designing automobile electronic products.
Self-diagnosis function of ECU:
Generally, ECU has the function of fault self-diagnosis and protection. When the system fails, it can also automatically record the fault code in RAM and take protective measures to read the replacement program from the above-mentioned inherent program to maintain the engine running. At the same time, these fault information will be displayed on the dashboard and will remain immortal, which will enable the owner to find the problem in time and drive the car to the repair shop.
ECU's adaptive function
Under normal circumstances, RAM will constantly record your driving data and become a learning program of ECU to provide the best control state for adapting to your driving habits. This program is also called adaptive program. But because it is stored in RAM, just like an error code, once the battery is removed and power supply is lost, all data will be lost.
ECU network
At present, ECU is not only applied to engines in some middle and high-class cars, but also can be found in many other places. For example, anti-lock braking system, four-wheel drive system, electronically controlled automatic transmission, active suspension system, airbag system, multi-directional adjustable electronically controlled seat, etc. are all equipped with their own ECU. With the improvement of car electronic automation, ECU will increase day by day, and the circuit will become increasingly complex. In order to simplify the circuit and reduce the cost, a technology called multiplex communication network is adopted to transfer information between multiple ecus on the vehicle, and the ecus of the whole vehicle form a network system, that is, CAN data bus. Electronic control unit ECU @219