This method of diesel engine fault diagnosis is feasible theoretically . while the fault diagnosis system using this method is rare , just because the crankshaft instantaneous angular acceleration measurement is demanding , such as , good frequency response , high precision 这种柴油机故障诊断的方法在理论上是可行的,但目前这种成型的系统不多,究其原因是测量曲轴的瞬时角加速度需要系统具有良好的频率响应特性与高精度。
Then the modal parameter of test of studying the cracked smoothshaft and cracked crankshaft discerns the principle , analysed and tests the modal analytical method to describe about the theory mode , is it build cracked smoothshaft and cracked crankshaft principle equation that parameter indentify to derive 然后研究了裂纹光轴和裂纹曲轴的试验模态参数识别原理，对理论模态分析和试验模态分析方法进行了论述，并建立裂纹光轴和裂纹曲轴参数识别的原理方程。
It is applied to sorts of locomotive engine , in course of revolving of crank and connecting rod mechanism , there are revolving of the crankshaft , swinging of the connecting rod and reciprocating motion , so its motion state is complex , and periodic unbalanced force , by a few components , is great 曲柄连杆机构在高速运转过程中，有曲轴的转动、连杆的摆动及活塞的往复运动，其运动状态复杂，各个部件所产生的周期性不平衡惯性力大，是引起发动机振动的主要原因。
