Method for detecting state of elastic transmission gear of diesel engine online

The invention discloses a method for detecting the state of an elastic transmission gear of a diesel engine online. The method comprises the following steps: firstly, monitoring instantaneous rotatingspeed, gear shaft vibration and power load of the diesel engine through a data acquisition card; secondly, converting signals acquired in the first step into standard electric signals; thirdly, carrying out acquisition and digital-to-analog conversion on the standard electric signals by the data acquisition card; fourthly, by coupling the instantaneous speed of the diesel engine and the vibrationof a cylinder, converting the vibration in a time domain into an angle domain corresponding to a crank angle for order analysis; fifthly, measuring an order ratio data matrix shown in the specification of the diesel engine under normal conditions; sixthly, introducing the order ratio data matrix in a formula to change the power P kW and the rotating speed n RMP of the diesel engine into margin coefficients; and seventhly,