快速诊断内燃机各缸均匀性有利于为缸内燃烧过程控制提供信息，进而改善内燃机工作性能。以三缸机为例，对利用飞轮瞬时转速信号评价内燃机缸内做功能力的方法进行了研究。分析了瞬时转速信号的获取及滤波方法，研究了影响缸内做功能力评价的各种因素。通过对实测数据的分析得出：利用飞轮瞬时转速推求的是内燃机输出的有效扭矩，其与缸内产生的指示扭矩有一定的偏差，这个偏差随内燃机工况的不同而不同；在计算中，往复运动部件产生的惯性力及对当量转动惯量的影响可以忽略；由瞬时转速推求的扭矩离散度较大，平均处理后可用于评价内燃机各缸做功能力。

Rapid diagnosis of the homogeneity of each cylinder in an internal combustion engine is beneficial to provide the control information of in-cylinder combustion process in order to improve the working performance of internal combustion engine. For a three-cylinder diesel engine, the method was studied that used the instantaneous speed signal of flywheel to evaluate the in-cylinder work capacity of the internal combustion engine. The acquisition and filtering methods of instantaneous speed signal were analyzed, and various factors that affected the in-cylinder work capacity evaluation were studied. According to the analysis of the measured data, the instantaneous speed of flywheel was used to estimate the effective torque output of internal combustion engine, which had a certain deviation from the indicated torque generated in the cylinder. This deviation varied with the operating conditions of internal combustion engine. In the calculation, the inertial force generated by the reciprocating motion components and the effect on the equivalent rotational inertia could be ignored. The torque dispersion derived from the instantaneous speed was large, which could be used for evaluating the in-cylinder work capacity of each cylinder after average processing.