Patent ID: 6496766
Filing Date: 2002-12-17
Classification: B66C,G05B,G07C

Abstract:
A method for monitoring critical operations of a crane, and for safely and automatically storing records of alarm events arising from such operations, comprising the steps of:(a) providing a plurality of input channels over which crane condition signals can be transferred from a plurality of sensors mounted to a crane, each crane condition signal generated by one of the sensors and including a value representative of a specific measurement or condition of the crane during operation thereof; (b) continuously sampling a data set at a predetermined sampling rate during operation of the crane by communicating with the input channels, each sampled data set including the value detected for each crane condition signal at the time of sampling and also including time and date information corresponding to the respective time and date of sampling, wherein the time of sampling substantially corresponds to the time at which the crane condition occurred; (c) storing each data set sampled into a non-volatile memory device; (d) for each data set sampled, comparing the values of the crane condition signals to a set of predetermined safe operating parameters to determine whether an alarm event has occurred, the alarm event defined when one or more of the values of the sampled crane condition signals falls outside a corresponding one or more of the safe operating parameters; (e) if an alarm event has occurred, comparing the values of the crane condition signals to the safe operating parameters to determine whether the alarm event has ceased, the cessation of the alarm event defined when one or more of the values of the sampled crane condition signals falls back inside a corresponding one or more of the safe operating parameters; and (f) if an alarm event has occurred, generating an event log for the alarm event by storing, into a separately addressed location of the non-volatile memory device, all data sets sampled over a period of event history, the period of event history defined as starting at a predetermined number of seconds prior to the occurrence of the alarm event and ending at a predetermined number of seconds after the cessation of the alarm event.