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This paper proposes a virtual sensor scheme designed to compensate for sensor fault effects in marine fuel engines. The proposed scheme design follows a distributed approach, where the marine fuel engine is decomposed in several subsystems. Then, for each subsystem we design a monitoring agent that can actively compensate for the effects of sensor faults occurring in the specific subsystem. This is realized using virtual sensors that can estimate the sensor fault in order to reconstruct the faulty measurements. Due to the Differential-Algebraic mathematical description of marine fuel engine dynamics, we design three types of virtual sensors; using adaptive observers, Set Inversion via Interval Analysis (SIVIA) and static models. Simulation results are used to illustrate the efficiency of the method.

peer-reviewed Fault-tolerant control system for marine robots, developed by researchers at Centre for Robotics & Intelligent Systems (CRIS), University of Limerick, utilises the hybrid method for control allocation, based on the integration of the pseudoinverse and the fixed-point iteration method. The algorithm is implemented as a two-step process. In the first step, the pseudoinverse solution is found, and the feasibility of the solution is examined analysing its components. If violation of actuator constraint(s) is detected, the fixed-point iteration method is activated in the second step. In this way, the hybrid method for control allocation can allocate the exact solution, optimal in the l2 sense, inside the entire attainable command set. This solution minimises a control energy cost function, the most suitable criteria for underwater applications. The performance of the thruster fault-tolerant control system has been validated during the research cruise CE19001, where the work-class ROV Étaín, deployed from support vessel Celtic Explorer via Tether Management System (TMS), successfully performed several complex subsea tasks with a faulty horizontal thruster. This paper describes the algorithm, provides geometric interpretation and presents the results from field trials.

International audience; Tilt rotor unmanned aerial vehicle (TRUAV) is a transformable aircraft with abilities of hovering and high-speed cruise. Its transition control is still a difficult point due to varying structure and dynamic behaviour. The main contribution of this paper is to put forward a transition control method based on backstepping for a quad-TRUAV, and fault tolerant control is researched to keep its cruise ability under rotor-tilt axle stuck fault. Explicit mode transition would be avoided by regarding rotor-tilt angle as a control input generated from decoupling with virtual control variables. Numerical results in transition procedure and facing rotor-tilt axle faults are provided to illustrate control effectiveness.