The Design Of ECU Interface Circuit And Research Of Signal Processing

Electronic control technology is the most effective means to ensure the efficient operation of the engine, also is the fundamental guarantee of the engine of various energy conservation and emissions reduction measures and reliable application. Electronic control unit (ECU) is the core component of engine management system (EMS), the input/output (I/O) interface circuit is directly related to the engine control of each control loop performance. Sensor input interface circuit’s function is to transmit signals without distortion or correctly signal transformation, output interface circuit is used to drive actuator control work and avoid failure, therefore, ECU I/O interface circuit design is the basis of the ECU hardware development, sensors, actuators, and matching the important work of ECU.In this paper, based on the engine ECU hardware circuit structure and the analysis of the components parameters, according to some typical input/output signals, the use of electronic circuit CAD software for circuit simulation and analysis of the I/O interface circuit design principles and standards, sensors, actuators and ECU hardware key elements and parameters matching, and the optimal design of the I/O interface circuit. The main contents are as follows:(1) Design of typical analog input interface circuit. According to the characteristics of different sensors and signal input anti-aliasing filtering and sampling requirements, by means of circuit simulation and calculation parameters, design parameters of the circuit structure and components, and sensor and interface circuit matching analysis.(2) Design of typical frequency signal conditioning circuit. Designed hysteresis comparator circuits, the zero crossing comparator circuits and differential comparison circuits, and simulation in the Pspice software, indicated the problems of three general circuit when handling magnetic crankshaft position sensor output signal. Design a new signal conditioning circuits, and conducted a simulation in Pspice software.(3) Design of optimizing a typical output interface circuit. According to the characteristics of different actuators and drives requirements, by means of circuit simulation and parameter calculation, parameter design circuit structure and components. Design of the ECP valve and the lower edge of OCV valve drive circuit, the selection principle of MOS tube is analyzed in detail; GDI engine fuel injector drive circuit are analyzed in detail in the Boost circuit steady-state process, and the selection principle of each component in the booster circuit, conducted a simulation in Pspice software; Detailed analysis of the characteristics of the ignition switch needs, analyzes the characteristics of IGBT, designed driving circuit, and carried out a simulation.