This paper presents an optimized control for independent metering hydraulic systems that integrates machine diagnostic features. The machine under study is a hydraulic crane for truck applications equipped with a post compensated Load Sensing Pressure Compensated (LSPC) independent metering valve. Control challenges of such hydraulic system pertain to the determination of the opening of the meter-out section under overrunning load conditions. In this work, the inlet actuator pressure was used as feedback for a PI control architecture. The gains of the PI regulator were defined through an Extremum Seeking (ES) optimization algorithm, which minimizes cost functions representative of energy consumption and occurrence of cavitation, to achieve optimal performance in different operating conditions. The control was tested on a simulation model of the reference machine developed in AMESim and validated against experimental results.
The paper shows that the same cost functions used to define the controller parameters can be used as additional inputs, along with conventional sensors, to monitor the health status of the machine.