Patent ID: 7698418
Filing Date: 2010-04-13
Classification: G05B

Abstract:
1. A monitoring system including a controlling device for monitoring a response time between sending information and receiving a response to the information, the controlling device comprising: a memory storing executable instructions; a processor executing the executable instructions causing the processor to operate as: a previous value holding unit to hold a response time value T(t−1) measured in last monitoring and a response time value T(t−2) measured in last but one monitoring; a calculating unit to calculate a maximum value of an normal range to be applied to a response time value T(t) measured in this monitoring by calculation of an expression 1 employing the response time value T(t−1), the response time value T(t−2), a weight value a (0<a<1) and an offset value dt, and to calculate a minimum value of the normal range to be applied to the response time value T(t) measured in this monitoring by calculation of an expression 2 employing the response time value T(t−1), the response time value T(t−2), the weight value a and the offset value dt, wherein the expressions 1 and 2 are as follows, a measuring unit to measure the response time value T(t) in this monitoring; and a judgment unit to judge whether or not the response time value T(t) is in the normal range between the calculated maximum value and the calculated minimum value, wherein the calculating unit, in case where the response time value T(t) is in the normal range, updates the response time value T(t−2) held in the previous value holding unit with the response time value T(t−1) and updates the response time value T(t−1) held in the previous value holding unit with the response time value T(t) to calculate a maximum value and a minimum value of a new normal range to be applied to a next response time value T(t+1) in a next monitoring by calculation of the expressions 1 and 2 employing the updated response time values T(t−2) and T(t−1) held in the previous value holding unit, the weight value a, and the offset value dt, and wherein the judging unit, in case where the response time value T(t) is out of the normal range, performs judging whether or not the response time value T(t+1) in the next monitoring is in the normal range of the response time value T(t) without update of the response values T(t−2) and T(t−1) held in the previous value holding unit.