Self-repairing Control System Research Articles

Self-repairing Control against Actuator Failures Using a Spiking Neuron Model

This paper presents a new Self-repairing Control System (SRCS) for plants with actuator failures. The proposed SRCS uses the well-known Izhikevich spiking neuron model as a fault detector. When the actuator fails, the neuron model is excited and then spikes occur. Thus, counting up spikes makes it possible to find failures. Compared with the existing active fault-tolerant control systems, the SRCS has the following advantages: one can not only set a maximum detection time in advance, but also construct a simple control system whose structure is independent of the mathematical model of the plant. To confirm the effectiveness of the SRCS, this paper shows theoretical performance analysis and numerical simulation.

FitzHugh-Nagumoモデルを用いる自己修復制御

For plants with sensor failures, this paper presents a new design method for a self-repairing control system (SRCS) with the FitzHugh-Nagumo (FHN) model. The FHN equation is well-known as the mathematical model which represents various electrical behaviors in membrane excitation. The proposed SRCS exploits this model as a fault detection filter. By monitoring a spike caused by an abnormal signal from the sensor, the faulty sensor can be detected and replaced with the healthy backup so as to maintain the stability of the control system. Furthermore, to confirm the effectiveness of the proposed SRCS, several numerical simulations are explored.

Self-Repairing Control System for a Hybrid Underwater Vehicle

A novel remotely operated underwater vehicle-a hybrid remotely operated underwater vehicle (HROV) capable of working to the full ocean depth has been developed. The battery powered vehicle operates in two modes. For broad-area survey, the vehicle can operate as an autonomous underwater vehicle (AUV) capable of mapping the sea floor with sonars and cameras. For close up imaging and sampling, the vehicle can operate as a remotely operated underwater vehicle (ROV) employing a optic fiber tether for real-time telemetry of data and video to its operators on a surface ship. In order for the vehicle to achieve a certain survivability and reliability level, a self-repairing control system (SRCS) has been designed. This paper presents the two basic technologies in SRCS: fault diagnosis and isolation (FDI) and reconfigurable control. For FDI, a model-based hierarchical fault diagnosis system is designed for the HROV. Then, control strategies which reconfigure the control system at intervals according to information from the FDI system are presented. Combining the two technologies, we obtained the fundamental frame of SRCS for the HROV.

Self‐Repairing Control Against Unknown Sensor Failures and Biases

AbstractIn this paper, a self‐repairing control system (SRCS) is presented for a plant with unknown sensor failure and bias. The simultaneous use of an unstable filter and a differential filter makes a monitored signal hit the prescribed threshold whenever the failure of a stuck‐type occurs. Then, the failed sensor can be found exactly, and be switched to the healthy backup. The advantage of the method is that any information about the plants for fault detection is not necessary. Also, the introduction of the differential filter can eliminate the effect of the sensor bias. Thus, the SRCS copes with the problems on both sensor failures and biases. Through several numerical simulations, the effectiveness of the proposed SRCS is confirmed.

Self-repairing control via an unstable filter

This paper presents a new self-repairing control system (SRCS) for nonlinear plants with unknown sensor failures of a stuck-type. The SRCS can detect the failure and replace the faulty sensor with the healthy one. The advantage of the SRCS is that no plant model is required to detect the failure. Hence, one can construct the SRCS of an extremely simple structure. To achieve exact and early fault detection, an unstable filter and an auxiliary switching signal are introduced. The detection period can be shortened arbitrarily by choosing a large pole of the filter. Also, this paper shows an application to a nonlinear continuous stirred tank reactor. To confirm the effectiveness, several numerical experiments are explored.

Self-Repairing and Adaptive Tracking for MIMO Systems with Sensor Failures

This paper presents a new self-repairing control system (SRCS) for unknown stable multiple-input-multiple-output (MIMO) plants with sensor failures. The proposed method can automatically switch from the faulty sensors to the healthy ones if the sensor failures occur. Only the artificial test signals and the integrators are utilized to detect the sensor failures. Hence, the SRCS requires no mathematical model of the plant. Furthermore, the adaptive λ-tracker is introduced not only to cope with uncertainties in parameters but also to eliminate the bias effects of the injected test signals.

アクチュエータの切り替えによる自己修復制御

This paper develops a new self-repairing control system (SRCS) based on switching actuators. The method can automatically detect the actuator failure and switch from the faulty actuator to the healthy one. The switching logic (repairing policy) needs no a priori information about the plants. The advantage of the proposed design method is that one can construct the simple SRCS whose structure does not depend on the order of the plant. In this paper, it is also shown that the proposed method can be applied to stable plants with sensor failures.

Real-time implementation of an algorithm for self-repairing control systems based on LQG optimization

In this paper a self-repairing real-time control (SRC) system based on LQG (Linear Quadratic Gaussian) optimization is proposed. Its transputer implementation and a real-time aircraft application are presented. The SRC system is composed of the monitoring of the control system, the detection and diagnosis of the failure and the reconfiguration of the control laws. The proposed SRC system is suitable for real-time operation because of the parallel nature of its architecture. The INMOS multitransputer implementation of the SRC applied to an aircraft model provides 56 per cent efficiency compared to a single-transputer implementation.