基于自适应LS-SVM的柴油机废气再循环冷却控制系统设计

Design of Diesel Engine Exhaust Recycling Cooling Control System Based on Adaptive LS-SVM

摘要:

针对当前柴油机废气再循环冷却控制系统受到时滞问题影响，导致系统开度走势与设定走势不一致、废气再循环效果差的问题，提出基于自适应LS-SVM的柴油机废气再循环冷却控制系统。以AT89C51单片机40针作为电控单元核心部件，利用位置传感器向系统发送负载信号，利用温度传感器来传输信号并反馈至D/A转换器。在 D/A转换器中，反馈信号以串行或并行方式进入寄存器，并在转换后输出电流电压，控制系统阀门在排气再循环时的开启。伺服泵采用冷却系统，为系统提供液压动力源。在最小二乘支持向量机基础上，利用求解线性方程组进行优化，消除了控制误差。根据控制差的大小，调整系统的速度。由试验结果可知，该系统开度走势与设定开度走势一致，且与设定开度误差为1开度，说明使用该系统具有良好稳态特性，有效克服了系统中时滞问题，废气再循环效果较好。

Abstract:

Aiming at the current diesel engine exhaust gas recirculation cooling control system affected by time lag, which causes the system opening trend to be inconsistent with the set trend and the exhaust gas recirculation effect is poor, a diesel exhaust gas recirculation cooling control system based on adaptive LS-SVM is proposed. The 40-pin AT89C51 single-chip microcomputer is used as the core component of the electronic control unit, and the position sensor is used to send load signals to the system, and the temperature sensor is used to transmit the signals and feedback to the D/A converter. In the D/A converter, the feedback signal enters the register in a serial or parallel manner, and outputs the current and voltage after the conversion, and controls the opening of the system valve during exhaust gas recirculation. The servo pump adopts a cooling system to provide a hydraulic power source for the system. On the basis of the least square support vector machine, the linear equations are solved to solve the optimization problem, and the control error is eliminated. Adjust the speed of the system according to the size of the control difference. It can be seen from the test results that the opening trend of the system is consistent with the setting opening trend, and the error of the setting opening degree is 1 opening degree, indicating that the system has good steady-state characteristics and effectively overcomes the time lag problem in the system. The recycling effect is better.