基于变化速率的单变量报警系统设计

报警系统是现代工业安全运行的重要组成部分,其作用是检测工业信号的异常状态,以便操作人员能及时处理系统的异常运行状况。传统的单变量报警系统大多通过监测模拟信号的幅值变化来判断系统是否发生异常,当信号幅值超出报警阈值则触发报警。目前工业中有部分信号,明显需要根据变化速率来判断系统发生异常,因此,设计了一种新的报警系统——速率报警器,通过判断分布稳定的历史变化速率样本集合来确定速率信号的报警阈值,利用基于时间序列的分段线性表示法计算过程信号的变化速率并判断系统是否发生异常,提高了报警系统的性能,使用数据仿真和工业案例验证该方法的有效性。

Design of a Slope-based Univariate Alarm System

Alarm systems are used to detect abnormal conditions of industrial signals, communicate abnormal conditions to operators, and remind operators to deal with abnormal conditions in time. It plays critically important roles for the safe and efficient operation of industrial plants. Traditional univariate alarm systems rise alarms by comparing the amplitude of a process variable with an alarm threshold. A new slope-based alarm system is proposed in this paper, the abnormal (normal) conditions are determined by some special process variables based on their slopes instead of amplitudes. The piece-wise linear representation is exploited to obtain slopes of process variables. The alarm threshold of the slope-based alarm system is designed according to the statistical distributions of historical slope values. Numerical and industrial examples are used to illustrate the effectiveness of the proposed method.