减速制动时机械式自动变速器车辆换档控制策略

Shifting Control Strategy of Deceleration Braking for Automated Mechanical Transmission Vehicle

将制动工况分为普通制动、紧急制动和惯性制动三种,研究不同制动工况下手动变速器(Manual transmission,MT)车辆优秀驾驶员的操控特点。将普通制动工况和紧急制动工况归为减速制动这一类情况对机械式自动变速器(Automated mechanical transmission,AMT)车辆进行研究。结合某重型越野车辆的车辆参数和试验数据,分析位置式电控柴油机的特性,提出油门关闭时其发动机转速存在一个固有转速下降率的概念,指出由于外界的原因来延缓或加快这一变化率时,发动机都将产生阻碍这一运动趋势的转矩。在对制动过程中传动系统动力学模型进行详细分析的基础上,讨论不同制动工况下发动机的作用。根据发动机转速及其下降率、变速器输出轴转速及其下降率,结合当前档位、离合器状态以及制动信号来识别普通制动和紧急制动,制定减速制动时AMT车辆换档控制策略,通过实车道路试验进行验证。

Braking conditions are divided into three categories： ordinary braking, emergency braking and inertia braking, then a research about the characteristics of manual transmission（MT） vehicle excellent drivers’ manipulation in different braking conditions is made. The conditions of ordinary braking and emergency braking are classified as deceleration braking, and then begin the study of the automated mechanical transmission（AMT） vehicle. Combined with a heavy off-road vehicle’s parameters and test data, a detailed analysis of the characteristics of Position-type electronically controlled diesel engine is carried out. Then the concept of the natural descending rate of engine speed when throttle is closed is put forward, to slow down or speed up the rate due to external reasons, the engine will produce torque to hinder this movement trends. On the basis of a detailed analysis of the drive system dynamics model of the braking process, the role of engine in different braking conditions is discussed. According to the engine speed and the rate of its decline, the transmission output shaft speed and the rate of its decline, the current gear, clutch state and brake signal, ordinary braking and emergency braking is distinguished, and a shifting control strategy for AMT vehicle in deceleration braking conditions is established. It’s verified by road test in finally.