Networked Control Systems with Intermittent Acknowledgement

具有间歇确认功能的网络控制系统

• 批准号: RGPIN-2021-02537
• 负责人: Shu, Zhan
• 金额: $ 2.4万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=752272
• 关键词: Networked; Control; Systems; Intermittent; Acknowledgement

Networked control systems (NCSs) utilize communication channels or networks to transmit signals among different components. A crucial issue in NCSs is that data transmission is no longer lossless, and data packets may be dropped due to various reasons. Two well-known transport protocols, Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), are usually used to treat this issue. NCSs with TCP and UDP deployed are called TCP-like and UDP-like NCSs, respectively. TCP-like NCSs feature the reliable data transmission by sending an acknowledgement (ACK) of receipt from destination to source but require extra resources to establish and maintain a connection between source and destination. Also, handshake, retransmission, and other mechanisms may cause a significant delay in the feedback loop. By contrast, UDP-like NCSs, at the cost of lower data delivery reliability, reduce resource consumption and cause lower latency. However, the performance deterioration resulting from data loss may be unacceptable for some control tasks. Despite the remarkable progress in TCP-like and UDP-like NCSs, emerging control-related applications such as wireless process automation, autonomous driving, and networked factory have posed new challenges. On the one hand, high data reliability and control performance are desired as many packets are related to the safety-critical message, whose loss and resulting performance deterioration can be harmful to people or equipment. On the other hand, low latency is essential to fulfiling stringent timeliness and agility requirements of control tasks. Besides, reduced resource consumption is desired as many devices are powered by batteries and have limited resources for computation, control, and communication. Neither TCP-like NCSs nor UDP-like NCSs is able to address all these issues, and this calls for new approaches and tools. To this end, a new type of NCSs with intermittent ACK (iACK-NCSs), and related control analysis and design framework covering modelling, estimation, control, and distributed deployment are to be developed in this research program. The novelty of iACK-NCSs is that a pair of source and destination generates ACK signals adaptively according to control targets, plant dynamics, and network conditions. Through deliberate integration of active and adaptive ACK, it has the potential to achieve fast responses, low latency, and high-performance estimation/control with minimum use of resources. The successful completion of the research program will not only deepen understanding of theory on control and communication in the context of networked and distributed systems but also provide novel algorithms and protocols which can be applied to practical networked control problems. Also, it will lead to the training of research students in a significant and rapidly growing area, enabling them to develop new approaches and skills which are very likely to impact both academic and industrial sectors.

网络控制系统（NCS）利用通信通道或网络在不同组件之间传输信号，NCS 中的一个关键问题是数据传输不再是无损的，并且数据包可能由于各种原因而丢失。传输控制协议（TCP）和用户数据报协议（UDP）通常用于解决这个问题，部署了 TCP 和 UDP 的 NCS 分别称为类 TCP 和类 UDP NCS。 NCS 通过从目的地向源发送接收确认 (ACK) 来实现可靠的数据传输，但需要额外的资源来建立和维护源与目的地之间的连接。此外，握手、重传和其他机制可能会导致显着的延迟。相比之下，类似 UDP 的 NCS 以较低的数据传输可靠性为代价，减少了资源消耗并降低了延迟。然而，尽管在某些控制任务中取得了显着的进步，但由于数据丢失而导致的性能下降可能是不可接受的。类似 TCP 和类似 UDP 的 NCS、无线过程自动化、自动驾驶和联网工厂等新兴控制相关应用提出了新的挑战。一方面，由于许多数据包与安全关键相关，因此需要高数据可靠性和控制性能。另一方面，低延迟对于满足控制任务严格的及时性和敏捷性要求至关重要，因为许多设备都是由电池供电的。并且资源有限类似 TCP 的 NCS 和类似 UDP 的 NCS 都无法解决所有这些问题，为此需要一种具有间歇性 ACK（iACK-）的新型 NCS。本研究计划将开发涵盖建模、估计、控制和分布式部署的相关控制分析和设计框架。 iACK-NCS 的新颖之处在于一对源和目标生成 ACK 信号。根据控制目标、工厂动态和网络条件进行自适应调整，通过主动和自适应 ACK 的仔细集成，有可能以最少的资源使用来实现快速响应、低延迟和高性能估计/控制。该研究计划不仅将加深对网络和分布式系统背景下的控制和通信理论的理解，而且还将提供可应用于实际网络控制问题的新颖算法和协议，并且还将带来研究培训。学生在一个重要且快速发展的领域，使他们能够开发新的很可能影响学术和工业部门的方法和技能。