This study presents a sliding mode-based active disturbance rejection control (SMADRC) scheme for a steer-by-wire (SbW) system in road vehicles. First, a plant model that describes the mechanical dynamics of the SbW system is elaborated, where the viscous friction and the self-aligning torque are regarded as external disturbances. Second, the design of SMADRC is exposited, in which a non-linear extended state observer is utilised to estimate the non-linearities existing in the plant model, and a sliding mode control component is used to cope with the effect of the non-linearities and guarantee the control robustness against system uncertainties and varying road conditions. Finally, experimental results are shown to demonstrate the superiority of the designed SMADRC in comparison with a conventional sliding mode controller and a PD-based active disturbance rejection controller (PDADRC).

Vehicle computers, Internet of Things and cyber-physical systems are all examples of electronic devices in which embedded systems require greater flexibility to process different types of applications and communication protocols. High flexibility requires the use of general purpose processors as a solution for configuring and controlling several peripherals. However, this also increases the need for hardware-dependent software. Since this is a highly critical and error-prone component due to the nature of its coding and the surrounding environment, it is essential to support the development and runtime phases through methodologies that can detect violations and errors when accessing devices by monitoring the communication protocol. This approach proposes a technique for monitoring temporal properties in high-level communication protocols between devices and drivers using a contract-based specification mechanism for describing the interface and protocol. From this specification, a monitoring module is synthesised, which can detect violation during the simulation of virtual platforms or execution of hardware platforms. The proposed specification language is a domain-specific language that supports platform-based design and enables the iteractive refinement of communication protocol and temporal property specifications along with platform stepwise implementation. Some experiments have demonstrated the effectiveness of the proposed approach for detecting errors in device drivers and device access violation.

Nowadays, renewable energy sources in a micro-grid (MG) system have increased challenges in terms of the irregularly and fluctuation of the photovoltaic and wind turbine units. It is necessary to develop battery energy storage. The MG central controller is helping to develop it in the MG system for improving the time of availability. Thus, reducing the total energy expenses of MG and improving the renewable energy sources (battery energy storage) are considered together with the operation management of the MG system. This study proposes fitness-based modified game particle swarm optimisation (FMGPSO) algorithm to optimise the total costs of operation and pollutant emissions in the MG and multi-MG system. The optimal size of battery energy storage is also considered. A non-dominated sorting genetic algorithm-III, a multi-objective covariance matrix adaptation evolution strategy, and a speed-constrained multi-objective particle swarm optimisation are compared with the proposed FMGPSO to show the performance. The results of the simulation show that the FMGPSO outperforms both the comparison algorithms for the minimisation operation management problem of the MG and the multi-MG system.

The authors propose a discrete-level memristive memory design for analogue data processing in hardware implementations of hierarchical temporal memory (HTM). In this study, memristors were set to ternary and quaternary states in a sub-cell by application of different write voltage levels through a resistive network configuration. Simulations of the proposed circuit show that the highest number of discrete output levels of the memory was achieved using quaternary logic. However overall, using the same number of sub-cells and ternary logic exhibits the lowest relative error rate. For data classification purposes, the proposed discrete-level memristive cells are incorporated into the TM of HTM architecture, and its hardware circuit is presented for pattern recognition. They report improved results of face recognition using AR, ORL and UFI databases, and TIMIT database for speech recognition. These results are compared with the earlier design of HTM having only the spatial pooler (SP). Accuracy of the HTM architecture incorporating both SP and TM with discrete-level memristive cells for face recognition increased from 76.5 to 83.5% for AR database and speech recognition accuracy is improved from 73.3 to 93.3%.

Energy management system (EMS) is one of the most essential categories of the advanced applications in current cyber-physical power systems. However, because of the tight coupling relationship between a power network and EMS's communication network, a physical break-line fault may be accompanied by a communication line outage, which may result in regional unobservability and uncontrollability. To maximally avoid and eliminate such operation risks, referring to current EMS's ‘active + standby’ communication configuration scheme in China, the authors propose a dynamic routing optimisation mechanism for its standby communication routings, assigning the most reliable communication lines to the most important information. Such optimisation considers two factors: information's significance and the reliability of communication lines. By introducing cyber-physical sensitivity index and path-branch incidence matrix, both factors can be expressed numerically. In the case study, the authors optimise the standby communication routings for a power flow corrective control application under different scenarios. The results verify the effectiveness and superiority of their approach.

With the development of information and communications technology (ICT) and inundation of sensing devices, the control of smart grid is undergoing a paradigm shift from centralised/decentralised to a more distributed nature allowing each distributed generator to receive information from sensors at distant buses. In such systems, there is much interdependency between various power, control and communication parameters due to which the control of parameters from one domain gets affected by other. The central idea of this study is to develop a generic, hybrid and customised framework to jointly model the multi-disciplinary variables and their interactions present in the smart grid and to develop controllers in an adaptive manner to ensure better control of physical variables such as voltage irrespective of the changes in operating point brought about by changes in physical/cyber parameters. Hence, the different operating conditions of the power system have been modelled as multiple subsystems of a hybrid switching system and controller design is carried out by solving the optimisation formulations developed for delay-free and delay-existent cases using the theory of common Lyapunov function. The optimisation is carried out using the block coordinate descent methodology by converting the non-convex formulation into a series of convex problems to obtain a solution.