System Engineering and Automation Deparment, Faculty of Engineering of Vitoria-Gasteiz, Basque Country University (UPV/EHU), 01006 Vitoria-Gasteiz, Spain.
Department of Electronic Technology, Faculty of Engineering of Vitoria-Gasteiz, Basque Country University (UPV/EHU), 01006 Vitoria-Gasteiz, Spain.
Sensors (Basel). 2021 Oct 26;21(21):7107. doi: 10.3390/s21217107.
The nature of wireless propagation may reduce the QoS of the applications, such that some packages can be delayed or lost. For this reason, the design of wireless control applications must be faced in a holistic way to avoid degrading the performance of the control algorithms. This paper is aimed at improving the reliability of wireless control applications in the event of communication degradation or temporary loss at the wireless links. Two controller levels are used: sophisticated algorithms providing better performance are executed in a central node, whereas local independent controllers, implemented as back-up controllers, are executed next to the process in case of QoS degradation. This work presents a reliable strategy for switching between central and local controllers avoiding that plants may become uncontrolled. For validation purposes, the presented approach was used to control a planar robot. A Fuzzy Logic control algorithm was implemented as a main controller at a high performance computing platform. A back-up controller was implemented on an edge device. This approach avoids the robot becoming uncontrolled in case of communication failure. Although a planar robot was chosen in this work, the presented approach may be extended to other processes. XBee 900 MHz communication technology was selected for control tasks, leaving the 2.4 GHz band for integration with cloud services. Several experiments are presented to analyze the behavior of the control application under different circumstances. The results proved that our approach allows the use of wireless communications, even in critical control applications.
无线传播的性质可能会降低应用程序的服务质量，导致某些数据包延迟或丢失。出于这个原因，无线控制应用程序的设计必须以整体的方式进行，以避免降低控制算法的性能。本文旨在提高无线控制应用程序在无线链路通信降级或暂时丢失时的可靠性。使用了两个控制器级别：在中央节点上执行提供更好性能的复杂算法，而在靠近过程的地方执行作为备用控制器的本地独立控制器，以防 QoS 降级。这项工作提出了一种在中央和本地控制器之间切换的可靠策略，以避免设备失去控制。为了验证目的，本文提出的方法用于控制平面机器人。在高性能计算平台上实现了模糊逻辑控制算法作为主控制器。在边缘设备上实现了备份控制器。这种方法避免了机器人在通信失败时失去控制。虽然在这项工作中选择了平面机器人，但所提出的方法可以扩展到其他过程。选择了 XBee 900MHz 通信技术来执行控制任务，将 2.4GHz 频段留作与云服务集成。进行了多项实验来分析在不同情况下控制应用程序的行为。结果证明，我们的方法允许使用无线通信，即使在关键的控制应用中也是如此。
