| 1. |
- Henriksson, Dan, et al.
(författare)
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Maximizing the Use of Computational Resources in Multi-Camera Feedback Control
- 2004
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Ingår i: Proceedings of the 10th IEEE Real-Time and Embedded Technology and Applications Symposium (RTAS04). - 1080-1812. - 0769521487 ; , s. 360-367
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Konferensbidrag (refereegranskat)abstract
- In vision-based feedback control systems, the time to obtain sensor information is usually non-negligible, and these systems thereby possess fundamentally different timing behavior compared to standard real-time control applications. For many image-based tracking algorithms, however, it is possible to trade-off the computational time versus the accuracy of the produced position/orientation estimates.This paper presents a method for optimizing the use of computational resources in a multi-camera based positioning system. A simplified equation for the covariance of the position estimation error is calculated, which depends on the set of cameras used and the number of edge detection points in each image. An efficient algorithm for selection of a suitable subset of the available cameras is presented, which attempts to minimize the estimation covariance given a desired, pre-specified maximum input-output latency of the feedback control loop.Simulations have been performed that capture the real-time properties of the vision-based tracking algorithm and the effects of the timing on the performance of the control system. The suggested strategy has been compared with heuristic algorithms, and it obtains large improvements in estimation accuracy and performance for objects both in free motion and under closed-loop position control.
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| 2. |
- Pathan, Risat, 1979, et al.
(författare)
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Overhead-Aware Temporal Partitioning on Multicore Processors
- 2014
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Ingår i: Real-Time Technology and Applications - Proceedings. - 1080-1812. ; 2014-October:October, s. 251-262
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Konferensbidrag (refereegranskat)abstract
- Many previously proposed interface models for composability analysis of hierarchical scheduling are overhead-unaware, which is unsafe for real systems. This paper proposes an overhead-aware schedulability analysis to guarantee temporal partitioning among real-time applications/components hosted on a multicore platform. First, a new interface model and the method to generate an interface for a given component is proposed. Each interface has a tunable parameter d (degree) that can balance between abstraction and accuracy in capturing each component's task-level timing constraints. Second, the problem of constructing an overhead-aware system-level schedule of all the components is addressed. The system designer has the flexibility to select parameters (e.g., allocated processor bandwidth) for each component such that overhead (e.g., preemptions across partitions) is minimized. Third, a slack distribution algorithm to reduce various overhead is proposed and its effectiveness is evaluated using randomly generated interface sets and also using workload of a real space-borne application provided by RUAG Space Sweden AB
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