Simulate Your Way out of a Difficult Real Time Control Problem:

To resolve the operational issues, such as process instability and excessive gate movements seen at the City of Edmonton real time control site RTC#4, an external MATLAB® simulator was developed to allow for off-site testing and development of a stable control solution that would account for all of the equipment specifications and on-site configurations. The simulator was built and configured using on-site data from previous rainfalls, and validated by being able to accurately reproduce the recorded on-site data for a chosen rainfall. Afterward, the simulator was used to create an optimum control strategy by testing various strategies and control parameters. Once the optimum control strategy was found, it was implemented on-site for evaluationThe new controller built from the simulation not only respected the equipment's constraints but also helped stabilize the control process and did not require any site modifications. The setpoint overshoot was eliminated, the upstream level oscillation was reduced by 80% from ±50 cm (1.0 m span) to only ±10 cm, and the downstream level oscillations were reduced by 80% from ±25 cm (0.5 m span) to only ±5 cm. The obtained results proved that a well-built simulator can be reliable and that simulation can be considered as a new and safe tool to resolve difficult real time control issues.