Searcharxiv⌕ Search

arXiv subjects

Maiying Zhong

Publications and source records attributed to Maiying Zhong.

3 recordsLinked to original sources

System representations in subspaces of finite-sample signals and their application to data-driven fault detection

This paper deals with system representations in finite-sample signal subspaces and their application to data-driven fault detection. The first part addresses concepts of finite-sample image and kernel system representations and, associated with them, image and residual subspaces of finite-sample signals. On this basis, the equivalence between the fundamental lemma and finite-sample image subspace is demonstrated. While the image representation models the nominal system dynamics, the residual representation describes uncertainties in the input-output data and is essential for fault detection. This result extends the fundamental lemma and builds the basis for exploring data-driven fault detection. In the second part, a data-driven projection-based fault detection approach is developed. By means of a singular value decomposition, orthogonal projections onto the image and residual subspaces are realized in the context of a low-rank matrix approximation, leading to projection-based residual generation and evaluation. Finally, analysis of detection performance in the framework of matrix perturbation theory and comparison with existing data-driven fault detection methods are explored.

eess.SY↗

Analysis, detection and control of secure and safe cyber-physical control systems in a unified framework

This paper deals with analysis, simultaneous detection of faults and attacks, fault-tolerant control and attack-resilient of cyber-physical control systems. In our recent work, it has been observed that an attack detector driven by an input residual signal is capable of reliably detecting attacks. In particular, observing system dynamics from the perspective of the system input-output signal space reveals that attacks and system uncertainties act on different system subspaces. These results motivate our exploration of secure and safe cyber-physical control systems in the unified framework of control and detection. The unified framework is proposed to handle control and detection issues uniformly and in subspaces of system input-output data. Its mathematical and control-theoretic basis is system coprime factorizations with Bezout identity at its core. We firstly explore those methods and schemes of the unified framework, which serve as the major control-theoretic tool in our work. It is followed by re-visiting and examining established attack detection and resilient control schemes. The major part of our work is the endeavours to develop a control-theoretic paradigm, in which analysis, simultaneous detection of faults and attacks, fault-tolerant and attack-resilient control of cyber-physical control systems are addressed in a unified manner.

eess.SY↗

The system dynamics analysis, resilient and fault-tolerant control for cyber-physical systems

This paper is concerned with the detection, resilient and fault-tolerant control issues for cyber-physical systems. To this end, the impairment of system dynamics caused by the defined types of cyber-attacks and process faults is analyzed. Then, the relation of the system input and output signals with the residual subspaces spanned by both the process and the controller is studied. Considering the limit capacity of standard observer-based detection and feedback control schemes in detecting and handling the cyber-attacks, a modified configuration for cyber-physical systems is developed by transmitting the combinations of the input and output residuals instead of the input and output signals, which is facile for dealing with both the process faults and cyber-attacks. It is followed by the integrated design of fault and attack detection, resilient and fault-tolerant control schemes. To enhance the detectability of cyber-attacks, the potential stealthy attack mechanisms on deteriorating the tracking behavior and feedback control performance are developed from the attackers' point of view, and the associated detection schemes for such stealthy attacks are proposed from the defenders' point of view. A case study on the robotino system is utilized to demonstrate the proposed resilient cyber-physical configuration.

eess.SY↗