Conference Paper

Analysis and design of networked control loops with synchronization at the actuation instants

Autom. Control Dept., Tech. Univ. of Catalonia, Barcelona
DOI: 10.1109/IECON.2008.4758420 Conference: Industrial Electronics, 2008. IECON 2008. 34th Annual Conference of IEEE
Source: IEEE Xplore

ABSTRACT

Varying time delays prevent successful operation of control loops closed over communication networks, i.e. networked control system (NCS). To mitigate the negative effects of delays, existing research mainly focuses on deriving control approaches/solutions built upon the assumption that the operation of control loops is synchronized at the sampling instants. In this paper we propose an approach to design networked control systems with synchronization at the actuation instants. The immediate benefit is that the harmful effects that delays within control loops have in stability/performance are removed. However, the application of the proposed solution requires accurate clock synchronization among the network nodes. This requirement is discussed and analyzed for the specific case of NCS based on the controller area network (CAN).

Download full-text

Full-text

Available from: Josep M. Fuertes
  • Source
    • "[1], or implementation-based approaches, e.g. [20]. One or more of them can be simulated and implemented. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a hands-on course in net-worked control systems (NCS) to be integrated in the education of embedded control systems engineers. The course activities have a strong practical component and most of them are applied exercises to be implemented in a NCS setup. The paper describes the experimental setup and then proposes several activities that can be shaped into a course program according to the needs and diverse background of the targeted audience.
    Full-text · Conference Paper · Jul 2012
  • Source
    • "7) NCS advanced controller design (NCS): In order to design a controller capable of dealing with varying time delays, several strategies are available, including controlcentered approaches, see e.g. [1], or implementationbased approaches, such as [20]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a hands-on course in networked control systems (NCS) to be integrated in the education of embedded control systems engineers. The course activities have a strong practical component and most of them are applied exercises to be implemented in a NCS setup. The paper describes the experimental setup and then proposes several activities that can be shaped into a course program according to the needs and diverse background of the targeted audience.
    Full-text · Conference Paper · Jan 2012
  • Source
    • "There it is suggested that the controller should predict the state of the system at the control instant and then apply a control law based in the predicted state. A similar approach was studied in [10], but with the prediction of a future (network delayed) state and the application of the control law. Less sophisticated approaches include the use of basic interpolators to achieve the same goal. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Nowadays the use of so-called Network Control Systems is a common practice. Although convenient, networks introduce several perturbations to the control system, due to the additional latency, jitter and even errors that arise when messages fail to be delivered. This paper presents a control architecture that attenuates the impact of the network on the controller performance. The proposed architecture is based on a series of data buffering and estimation, decoupling the controller execution from the instants in which messages are transmitted. In the sequel, important bandwidth are also attained, due to the batch transmission of sensor and control data.
    Full-text · Article · Jul 2011
Show more