A METHOD OF AUTOMATIC DETERMINATION OF ROTATIONAL SPEED OF A SHAFT IN A SYSTEM POWERED BY A RECIPROCATING ENGINE

• Main Authors: Rzeszucinski, Pawel, Nowak, Jaroslaw, Ottewill, James
• Format: Patent
• Language: English; French; German
• Published: 23.05.2018
• Subjects: INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT; MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC ORINFRASONIC WAVES; MEASURING; MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION,OR SHOCK; PHYSICS; TESTING

A method of automatic determination of a rotational speed of a shaft in a system powered by a reciprocating engine, comprises a data acquisition and measurement processes, performed in a computer device for acquiring and processing the data, wherein the step of measuring data comprises the measurement of a vibration signal x[n], where n is the length of the acquired signal, of the rotational shaft, further comprises the steps of: obtaining an instantaneous angle signal x iA [n] of the measured vibration signals x[n] given to a standard preprocessing actions for receiving a filtered vibration signal samples x F [n] and receiving an analytic signal x A [n]; calculating an instantaneous frequency signal x iF [n] as the sample derivative of the instantaneous angle signal x iA [n] of the analytic signal x A [n]; creating an impulses samples vector M[m] from the time domain plot of the instantaneous frequency signal x iF [n], which vector represents the torsional oscillations of the shaft caused by abrupt combustion process of the reciprocating engine and determination of the shaft speed vector S[m].