Design and Implementation of Supervisory Wireless Control: Aircraft Braking System Case Study

There is a strong trend towards wireless networked Real-Time Control Systems. However, a variety of factors such as the variability of wireless channel capacities, multi-path fading, and ambient interference make it extraordinarily difficult to design and implement Wireless Control Systems (WCSs). To attack the uncertainty in available communication resource in WCSs, this chapter presents an Adaptive Feedback Scheduling scheme that takes advantage of the methodology of cross-layer design. The proposed approach exchanges information across the physical layer and the application layer in the presence of noise interference and link transmission rate variations. The overall QoC is guaranteed through controlling the deadline miss ratio of control loops. Design parameters of the feedback scheduler are adapted to dynamic changes in wireless channel capacity. To further improve the feedback scheduling performance, an event-driven invocation mechanism for feedback schedulers is suggested. Simulation results demonstrate that this approach is efficient to deal with channel capacity variations and noise interference, thus providing an enabling technology for wireless control in dynamic environments. It is also argued that in this context event-driven invocation mechanism improves the performance of the feedback scheduling system.KeywordsSampling PeriodTransmission RateMedium Access ControlControl PerformanceMedium Access Control ProtocolThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

In order to overcome the power frequency electromagnetic interference existing in the wireless liquid level control system and realize the accurate control to the liquid level, a compound digital filter algorithm is proposed and implemented. This article discusses the topology of the wireless liquid level control system, the form and characteristics of the electromagnetic interference signal, the architecture of the digital filter and the algorithm flow chart, finally compares and analyzes actual operation results. The digital filtering algorithm runs effectively and can achieve the purpose of filtering the electromagnetic interference.

The design of a wireless water level control system is introduced and discussed in detail. In this system, the wireless Proportional Integral (PI) controller is developed using the LabVIEW graphical user programming language. Zigbee wireless technology is chosen for the wireless data transfer system. The experimental testbed was built and the system software and hardware were implemented. In order to compare the performance of the wired and wireless system, a corresponding wired water level control system was built. Experimental results show that under the same PI parameters, the settling time of the wired system is 3.3 times faster than the wireless system. However, the percent overshoot using the wireless controller is 4% smaller.

Wireless sensor-actuator networks (WSANs) are being adopted in process industries because of their advantages in lowering deployment and maintenance costs. While there has been significant theoretical advancement in networked control design, only limited empirical results that combine control design with realistic WSAN standards exist. This paper presents a cyber-physical case study on a wireless process control system that integrates state-of-the-art network control design and a WSAN based on the WirelessHART standard. The case study systematically explores the interactions between wireless routing and control design in the process control plant. The network supports alternative routing strategies, including single-path source routing and multi-path graph routing. To mitigate the effect of data loss in the WSAN, the control design integrates an observer based on an Extended Kalman Filter with a model predictive controller and an actuator buffer of recent control inputs. We observe that sensing and actuation can have different levels of resilience to packet loss under this network control design. We then propose a flexible routing approach where the routing strategy for sensing and actuation can be configured separately. Finally, we show that an asymmetric routing configuration with different routing strategies for sensing and actuation can effectively improve control performance under significant packet loss. Our results highlight the importance of co- joining the design of wireless network protocols and control in wireless control systems.

Introduction. In order to ensure the sustainable functioning of critical infrastructures (CI), in conditions of the growth of various types of threats, security systems (SB) for various purposes, for example, technical SB, should be created on them. As such systems, first of all, there are security alarm systems, access control and some others. These systems are usually integral parts of the overall physical protection of CI, so they play an important role in ensuring the security of CI. One of the most important SB on the CI is the identification and access control system. In recent years, specialists in these systems have paid closer attention to the issues of ensuring the security of checkpoints for vehicles. It is known that they can be one of the most vulnerable places in the system of physical protection of the CI. Based on this, the task of improving identification and access control systems, including the vehicle, is currently an urgent scientific and practical task, and therefore require further study. Aims and Purposes. The purpose of this study is to develop a simplified conceptual design of the wireless identification and access control system of the vehicle on the CI. Methods. To achieve this goal, the methods of system analysis, elements of the theory of radio engineering, as well as methods of analysis, description, generalization, results of research works on the subject of research were used. Results and discussion. The existing systems of wireless identification and access control on CI are considered on the example of wireless identification and access control systems of the vehicle. Some ways of improving the safety and reliability of the operation of these systems are outlined. The analysis of ways to improve the systems of wireless identification and access control on CI is carried out on the example of wireless identification and access control systems of the vehicle. A simplified conceptual design of the wireless identification and access control system of the vehicle on CI has been developed. The main primary provisions of the system under development related to the circuit engineering stage of conceptual design are formulated. Conclusions. As a result of the conducted research, a simplified conceptual design of the wireless identification and access control system of the vehicle on CI has been developed. According to the authors, the developed simplified conceptual project, with appropriate adaptation, can be applied in practice for the purposes of ensuring the physical protection of CI. Keywords: critical infrastructure; identification systems; access control; wireless data transmission systems; conceptual project.

Wireless sensor networks have rapidly matured in recent years to offer data acquisition capabilities on par with those of traditional tethered data acquisition systems. Entire structural monitoring systems assembled from wireless sensors have proven to be low cost, easy to install, and accurate. However, the functionality of wireless sensors can be further extended to include actuation capabilities. Wireless sensors capable of actuating a structure could serve as building blocks of future generations of structural control systems. In this study, a wireless sensor prototype capable of data acquisition, computational analysis and actuation is proposed for use in a real-time structural control system. The performance of a wireless control system is illustrated using a full-scale structure controlled by a semi-active magnetorheological (MR) damper and a network of wireless sensors. One wireless sensor designated as a controller automates the task of collecting state data, calculating control forces, and issuing commands to the MR damper, all in real time. Additional wireless sensors are installed to measure the acceleration and velocity response of each system degree of freedom. Base motion is applied to the structure to simulate seismic excitations while the wireless control system mitigates inter-storey drift response of the structure. An optimal linear quadratic regulation solution is formulated for embedment within the computational cores of the wireless sensors. Copyright © 2007 John Wiley & Sons, Ltd.

The PIDPLUS algorithm is one of the candidates to be used in wireless automation systems. The control performance of this algorithm under packet losses is investigated in the paper. First, the performance of PIDPLUS is evaluated with respect to packet loss rates for a general first-order plus time-delay process, a model widely used for controller tuning. This simulation study reveals how the performance is affected by packet losses in a wireless control system. Secondly, we will elaborate on the implementation of PIDPLUS and discuss its design, tuning and performance in wireless control systems in light of an unstable case process. The results suggest that PIDPLUS can well be used for wireless control, but better performance could be attained by further development of the controller tuning methodology.

The aircraft braking system is an essential subsystem of the aircraft, with high safety requirements. The conventional aircraft braking system has complex and long pipelines that are prone to leakage and vibration. To improve the reliability and safety of the aircraft, a dual-redundancy more-electric braking system (DMEBS) based on <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> / <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> valves was proposed. The DMEBS has dual-redundant nonsimilar hydraulic power sources to improve the reliability of the system. The <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> / <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> valves were utilized as brake control valves to improve the robustness of the system. In addition, an energy management strategy and a high-precision brake pressure regulation algorithm were designed for the DMEBS. The rule-based logical threshold energy management strategy relies on real-time velocity and multiple thresholds for allocating hydraulic power sources, aiming to reduce the electrical power of the DMEBS. The nonlinear flow rate control method (NFRCM) can realize high-precision brake pressure and low power. A prototype was developed, and then, it was tested on an experimental bench and a ground inertial test bench to verify the performance of the DMEBS and regulation strategy. The experimental results show that the pressure error of the NFRCM is within 0.2 MPa, while the standard deviation and other indicators show superior performance compared to conventional controllers.

A safe and high-efficiency braking process is the primary consideration for the aircraft braking system. The traditional servo valve is prone to blockage, which can cause serious safety accidents. Based on the analysis of the operation principle of the braking system, a safer aircraft braking system based on an on/off valve is proposed, which uses a normally open valve as the downstream valve. The braking system based on on/off valves has problems such as fluctuating pressure, harsh working conditions, and strong nonlinearity of the system. An algorithm with a strong antidisturbance ability and high braking efficiency is proposed to solve the above three problems. The algorithm typically consists of two main components: outer and inner loops. The outer loop uses the active disturbance rejection control, and the inner loop adopts the segmented nonlinear predictive pressure regulation algorithm with compensation. The outer loop can compensate for the internal uncertainty and external disturbance of the system. The inner loop can compensate for the flow rate during the closing process of the on/off valve to ensure the pressure regulation effect and the life of the on/off valve. The experimental results show that the proposed algorithm has a strong antidisturbance ability and high regulation precision. The braking distance of the algorithm can be reduced by 5.48–15.15% under three different working conditions, which significantly improves the braking efficiency of the aircraft.

PurposeFiber-reinforced polymers (FRP) contain critical electrical conductivity for high-intensity radiated fields such as lightning strike susceptibility, electromagnetic energy from radar, airborne radio frequency transmitter. To provide high-intensity radiated field protection (HIRFP) for the electric and electronic aircraft system and defied the EMI effect on it, metal matrix composite was conquered. To provide the dynamic ever-increasing requirement of industries, it is necessary that Al6061 metal matrix composite assisted with AL2O3 and fly ash is used to construct the aircraft to provide HIRFP. The thickness of the material can be maintained as low as possible to use it as a coating material for the aircraft surface. X-band for oblique incidence is used to measure electromagnetic and mechanical safeguarding properties of composites.Design/methodology/approachDay by day, the applications of aerospace are becoming digital and automated. Proper shielding techniques are required to operate digital electronic devices without electromagnetic interference. It leads to a rapid rise in temperature, thermal ablation, delamination, and adverse effects on the electric and electronic aircraft system. Fly ash, a metal matrix material composite AL6061 with different percentages of reinforcement of Al2O3, was contemplated and experimented with for mechanical properties like tensile strength, density and hardness.FindingsThe obtained results compared with adjusted values and an improvement of 0.19, 0.18, 0.14 g/cm3 for density of MMC-1, MMC-2, MMC-3.31, 11 MPa for tensile strength of MMC-1, MMC-2. 24, 27, 23 BHN for hardness of MMC-1, MMC-2, MMC-3. With regard to the shielding effectiveness the results compared with adjusted values and obtained 11.36, 14.56, 19.47 dB better value than it. According to the above results, fabricated MMC’s provide superior results for a defined application like HIRFP(Surface material of aircraft).Practical implicationsIt can be used to protect electronic devices under a high-intensity radiated field, mainly in aircraft design to protect from lightning effect.Originality/valueFor a better approximation of the signal toward the practical case, the oblique incidence was considered with a different combination of Al2O3 and fly ash, reinforced to pure AL6061 to get better shielding and mechanical properties.

Wireless is now a pervasive aspect of everyday life; from the Bluetooth module in a mobile handset to broadband wireless networks covering scores of square kilometres. No longer is wireless networking an experimental technology, it has become ubiquitous, and wireless closed-loop control is now being seriously considered for industrial applications. Wireless networking enables the vision of a security enterprise - ease of expansion with minimal implementation and maintenance costs. The bottom line is that wireless networking is cheaper. Computer-based simulation can help develop a thorough understanding of wireless control systems; the network and control system can be configured quickly and the results from modifications to either the protocol or the control strategy can be implemented and tested scientifically, without time-consuming and difficult hardware implementation.

Wireless control has advantages in the case of synchronous cooperative motion control. We consider a wireless feedback control system with multiple plants. In such situation, not only the control performance of individual plants but also the synchronization among the plants is important. However, synchronization errors occur because of packet losses in the wireless channel. In this paper, we propose a relay transmission scheme with predictive control information to reduce the influence of packet losses in the synchronization performance. Numerical examples clarify the reduction of synchronization errors by the proposed scheme.

The wireless channel can influence the design of industrial applications. A majority of existing scheduling models of industry control network are designed without considering the characteristic of wireless technology. They face serious degradations in wireless industrial applications. This paper uses a secondary architecture of dual-band and presents a scheduling mechanism based on communication task deadline for wireless industrial control system. Thus the adverse effect on real-time and reliability, caused by transmission errors and other problems of the wireless channel, can be (partially) compensated.

Monitoring and control of critical parameters is of paramount importance for most of the industrial processes. But laying cables from various sensors and actuators to monitoring stations increases cost and complexity. This problem calls for wireless implementations for monitoring and control applications. This paper presents a low cost wireless temperature monitoring and control system based on ZigBee wireless communication protocol. The system uses Microchip's PIC18F458 microcontroller as the field unit and NI LabVIEW interface as the monitoring unit. It utilizes a precision temperature sensor IC, which being a low cost sensor provides a reliable output within its operating range. The system follows a request-response methodology, where the field unit responds to the requests made by the monitoring unit.

The integration of wireless communication and control systems revealed wireless networked control systems (WNCSs). One fundamental problem in WNCSs is to have a wide coverage area. For the first time in the literature, we address this problem and we obtain the maximum coverage area by solving an optimization problem. In this technical note, we consider a WNCS where the output sensor measurements are transmitted over separate heterogeneous multi-hop wireless ad-hoc subnetworks. The observation process is divided into N parts and the system state is estimated using the Kalman filter. We present the critical arrival probability for a sensor measurement packet such that if the packet arrival probability is larger than the critical value, it is guaranteed that the estimator of the WNCS converges. We derive the maximum total coverage area of the heterogeneous wireless subnetworks having maximum cost-efficiency under the constraint of the convergence of the WNCS estimator.