System and method for dynamic adjustment of filtering in an alarm system

摘要

A system and a method for dynamically adjusting a level of filtering or smoothing applied to data received from fire detectors produces shortened response times for detection of a fire condition while at the same time minimizing the effects of uncorrelated noise in the absence of any fire condition. An increasing probability of a fire results in less filtering. Increasing values of the input signal from a respective detector, indicative of an increasing selected ambient condition such as combustion or temperature, provide a control input for reducing or bypassing the level of filtering of the respective input signal thereby reducing system response time. Where the unfiltered input data from a respective detector indicates a combustion or temperature profile moving toward clear air, the filtering or smoothing level can also be dynamically decreased thereby enabling the filtered signal values to return to their respective clear air values faster than would otherwise be the case. Detectors can be grouped and multiple unfiltered outputs can be assessed substantially simultaneously to determine whether or not levels of filtering or smoothing for the members of the group should be dynamically decreased.