Robust Hierarchical Sensor Optimization Placement Method for Leak Detection in Water Distribution System

The quality of sensor placement in water distribution systems (WDSs) has considerable impact on leak detection accuracy and identification efficiency. Sensor-placement optimization has long been a major issue in the research of WDS. Conventional hierarchical algorithms based on joint entropy have been widely applied to sensor-placement optimization in the engineering-safety monitoring field. Although such algorithms can effectively reduce information redundancy and are computationally very efficient, they fail to fully account for various practical failure scenarios. Sensor failures introduce bias into monitored data and disrupt the monitoring process, thereby compromising the monitoring performance of a given sensor network. To overcome this drawback, this study proposes a new optimal sensor-placement scheme for WDSs based on an improved hierarchical algorithm. The new optimization scheme works by sequentially selecting sensors using joint entropy as a sensor-placement objective function and fully considers various scenarios of a single-sensor failure to ensure minimal information entropy loss during sensor failure. Simulation is performed on an example network (i.e., Net 3 from EPANET), revealing that when a sensor fails, information entropy loss is 0.011 for conventional sensor-placement schemes, but it is only 0.007 for the improved scheme. Statistical analysis shows that the improved scheme has a higher robustness and adaptability for leak detection and identification, owing to the full consideration of various scenarios of a single-sensor failure.