Active fault tolerant control of an electro-hydraulic servo axis with a duplex-valve-system

In this paper fault detection, fault diagnosis and active fault tolerant control of an electro-hydraulic servo-axis with a duplex-valve-system are described. The fault detection is based on parity equations. The semi-physical models allow the detection of even small faults in the hydraulic system. The fault diagnosis used on the testbed is based on fuzzy-logic. In order to tolerate a failed hydraulic proportional valve, a duplex-valve-system built up with standard direct-driven proportional valves is applied. The fault management module allows the supervision of the hydraulic servo axis and decides on reconfiguration and fault accomodation of the control-loop. The Internal Model Control (IMC)-tracking control structure used for reconfiguration allows bumpless transfer between controllers. Experimental results show the industrial applicability of the approach

Fault-tolerant control of an electro-hydraulic servo axes with a duplex-valve-system

This paper presents fault detection, fault diagnosis, the fault-tolerant control of an electro-hydraulic servo axes with a duplex-valve-system. The fault detection is based on parity equations and is load independent. The semi-physical models allow the detection of even small faults in the hydraulic system. The fault diagnosis used at the testbed is based on fuzzy-logic. In order to tolerate a faulty hydraulic proportional valve, a duplex-valve-system built up with standard proportional valves is applied. The fault management module allows the supervision of the hydraulic servo axes and decides on the reconfiguration of the control-loop. An Internal Model Control (IMC)-tracking control structure for bumpless transfer between controllers is presented. Experimental results show the industrial applicability of the approach