Composable Platform-Aware Embedded Control Systems on a Multi-core Architecture

Abstract

Abstract-In this work, we propose a design flow for efficient implementation of embedded feedback control systems targeted for multi-core platforms. We consider a composable tile-based architecture as an implementation platform and realise the proposed design flow onto one instance of this architecture. The proposed design flow implements the feedback loops in a datadriven fashion leading to time-varying sampling periods with short average sampling period. Our design flow is composed of two phases: (i) representing the timing behaviour imposed by the platform by a finite and known set of sampling periods, which is achieved exploiting the composability of the platform, and (ii) a linear matrix inequality (LMI) based platform-aware control algorithm that explicitly takes the derived platform timing characteristics and the shorter average sampling period into account. Our results show that the platform-aware implementation outperforms traditional control design flows (i.e., almost 2 times) in terms of quality of control (QoC).

Optimising Quality-of-Control for Data-Intensive Multiprocessor Image-Based Control Systems Considering Workload Variations

“…Generally, the analysis of the image processing step is limited to a measurement or estimate of the computational delay and is assumed to be negligible compared to other delays in the control loop [2][3] [20]. Control engineers tackle a long sample period of IBC systems using state estimation [12], robust design [13], predictive control [14], observer-based [1], multi-rate sampling [26] and reconfigurable pipelining methods [15]. However, these approaches do not model and consider platform constraints like resource availability and mapping, and/or workload variations in image processing [1].…”

Comparing Platform-aware Control Design Flows for Composable and Predictable TDM-based Execution Platforms

“…• Single-Rate (SR) design flow: Platform configured with equidistant sampling. This controller design has been adapted from [Valencia et al 2015] by replacing the pole-placement design with an Linear Quadratic Regulator (LQR) controller [Åström and Murray 2008]. We use the settling time as the control performance metric.…”

“…We optimise the controller design for the nominal sampling interval. We adapted this design from [Valencia et al 2015] by replacing the pole-placement controller with an LQR controller accompanied with the PSO tuning technique. We ensure the overall switching stability between the non-equidistant sampling intervals by using a Lyapunov-based Linear Matrix Inequality (LMI) stability condition.…”

Delay-based Design of Feedforward Tracking Control for Predictable Embedded Platforms

“…In this paper, we propose 1 Mojtaba Haghi, Dip Goswami, Kees Goossens {s.m.haghi, d.goswami, k.g.w.goossens}@tue.nl, fwgsbc@live.com an alternative approach where we consider a predictable implementation platform with limited/no time-variation in execution time. Such platforms offer extensive timer mechanism to extract the precise knowledge of delay and sampling period at the design time which can be exploited in the controller design for an improved performance [13].…”