整车状态下发动机瞬态动力输出的测试研究

Reaserch On Transient Power Output Test Of Engine Under Vehicle Condition

车辆行驶条件下,发动机运行参数复杂多变,以瞬态工况为主,其瞬态动力输出一般通过CAN线读取,无法精确测量。文章通过对发动机燃烧原理和摩擦理论的研究,提出了通过缸压传感器检测瞬时缸压及建立发动机摩擦扭矩模型来计算发动机瞬态输出扭矩的方法,并使用发动机台架稳态和瞬态两种试验对本计算模型进行验证。试验结果表明:该方法操作简单,精度高,最高相对误差仅为1.65%,具有很高的可行性,为实现整车路试工况瞬态动力性能测试、校正CAN读取的瞬态动力输出值、竞品车整车状态下瞬态动力性能测试提供了理论指导和技术支撑。

The engine operating parameters are complex and changeable under vehicle driving conditions, and the engine in mainly in transient condition, its power output is usually read from the CAN line and connot be accurately measured. In this paper, a method of calculating transient torque of engine by detecting instantaneous cylinder pressure with cylinder pressure sensor and establishing the friction torque model of engine is presented based on studies of combustion principle and friction theory of the engine, and the steady state and transient tests of the engine bench test are used to verify the calculation model. Results of the trial indicated that this method is simple to operate, has high precision, and the maximum relative error is only 1.65%, so it is highly feasible. It provides theoretical guidance and technical support for realizing transient power performance test under road test conditions, calibration of the transient power output read from the CAN line, transient power performance test of complete vehicle of competing products.