测功机动态负载模拟算法

Dynamometer controller algorithm for road load emulations

为了实现汽车动力系统排放及燃油经济性台架试验,需要采用动态负载模拟算法,利用测功机对动力系统进行加载,以模拟整车在道路上的负载。该文分析并比较了分别采用逆向模型和前向模型实现动态负载模拟的2种方法,选择基于前向模型跟踪的方法设计了测功机动态负载模拟算法。通过模型预测车辆速度,并采用测功机闭环跟踪模型车速的方法实现了测功机动态负载模拟。该文开发了基于实时系统的交流测功机控制器,并通过实验验证了动态负载模拟控制算法的效果。实验结果表明:该方法具有模拟精度高、稳定性较好的特点,动态负载模拟算法的实测转矩、转速和理论计算值一致性好,能够满足车辆动力性、经济性能实验的要求。

A dynamic load emulation algorithm was developed for a dynamometer controller to emulate vehicle road loads for automotive fuel consumption and emission tests. Two load emulation algorithms were developed based on inverse mechanical dynamics （IMD） and forward mechanical dynamics （FMD）. The FMD algorithm was then chosen for the real time controller for its stability. The FMD algorithm calculated the vehicle road load dynamics by predicting the reference vehicle speed, with a speed controller tracking the reference speed. The load emulation algorithm was installed on a dynamometer controller with a real-time operating system. A powertrain dynamic test on the dynamometer to evaluate the load emulation algorithm shows good agreement with theoretical calculations, suggesting that the algorithm is capable of emulating the vehicle dynamic loads effectively.