scholarly journals Refinement of Timing Constraints for Concurrent Tasks with Scheduling

2018 ◽  
pp. 219-233 ◽  
Author(s):  
Chenyang Zhu ◽  
Michael Butler ◽  
Corina Cirstea
Keyword(s):  
Timing Constraints ◽  
Concurrent Tasks

Effects of Dynamic Model Errors in Task-Priority Operational Space Control

Robotica ◽  
2021 ◽  
pp. 1-12
Author(s):  
Paolo Di Lillo ◽  
Gianluca Antonelli ◽  
Ciro Natale
Keyword(s):  
Inverse Kinematics ◽  
Degrees Of Freedom ◽  
Inverse Dynamics ◽  
Null Space ◽  
Control Algorithms ◽  
Model Errors ◽  
Operational Space ◽  
Dynamic Level ◽  
Concurrent Tasks ◽  
Modeling Errors

SUMMARY Control algorithms of many Degrees-of-Freedom (DOFs) systems based on Inverse Kinematics (IK) or Inverse Dynamics (ID) approaches are two well-known topics of research in robotics. The large number of DOFs allows the design of many concurrent tasks arranged in priorities, that can be solved either at kinematic or dynamic level. This paper investigates the effects of modeling errors in operational space control algorithms with respect to uncertainties affecting knowledge of the dynamic parameters. The effects on the null-space projections and the sources of steady-state errors are investigated. Numerical simulations with on-purpose injected errors are used to validate the thoughts.

Microcode compaction with timing constraints

1988 ◽  
Vol 19 (1-2) ◽  
pp. 34-39
Author(s):  
B. Su ◽  
S. Ding ◽  
J. Wang ◽  
J. Xia
Keyword(s):  
Timing Constraints

scholarly journals Network Calculus-Based Latency for Time-Triggered Traffic under Flexible Window-Overlapping Scheduling (FWOS) in a Time-Sensitive Network (TSN)

2021 ◽  
Vol 11 (9) ◽  
pp. 3896
Author(s):  
Khaled M. Shalghum ◽  
Nor Kamariah Noordin ◽  
Aduwati Sali ◽  
Fazirulhisyam Hashim
Keyword(s):  
Real Time ◽  
Connected Vehicles ◽  
Network Calculus ◽  
Timing Constraints ◽  
Traffic Scheduling ◽  
Worst Case ◽  
Continuous Increase ◽  
Scheduled Traffic ◽  
Support Time ◽  
New Framework

Deterministic latency is an urgent demand to pursue the continuous increase in intelligence in several real-time applications, such as connected vehicles and automation industries. A time-sensitive network (TSN) is a new framework introduced to serve these applications. Several functions are defined in the TSN standard to support time-triggered (TT) requirements, such as IEEE 802.1Qbv and IEEE 802.1Qbu for traffic scheduling and preemption mechanisms, respectively. However, implementing strict timing constraints to support scheduled traffic can miss the needs of unscheduled real-time flows. Accordingly, more relaxed scheduling algorithms are required. In this paper, we introduce the flexible window-overlapping scheduling (FWOS) algorithm that optimizes the overlapping among TT windows by three different metrics: the priority of overlapping, the position of overlapping, and the overlapping ratio (OR). An analytical model for the worst-case end-to-end delay (WCD) is derived using the network calculus (NC) approach considering the relative relationships between window offsets for consecutive nodes and evaluated under a realistic vehicle use case. While guaranteeing latency deadline for TT traffic, the FWOS algorithm defines the maximum allowable OR that maximizes the bandwidth available for unscheduled transmission. Even under a non-overlapping scenario, less pessimistic latency bounds have been obtained using FWOS than the latest related works.

scholarly journals Constructing Test Suites for Real-Time Embedded Systems Under Input Timing Constraints

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 20920-20937
Author(s):  
Yunlong Sheng ◽  
Shouda Jiang ◽  
Changan Wei
Keyword(s):  
Embedded Systems ◽  
Real Time ◽  
Timing Constraints ◽  
Test Suites

Working memory and executive control

1996 ◽  
Vol 351 (1346) ◽  
pp. 1397-1404 ◽  
Keyword(s):  
Working Memory ◽  
Prefrontal Cortex ◽  
Executive Control ◽  
Cognitive Model ◽  
Central Executive ◽  
Executive Processes ◽  
Concurrent Tasks ◽  
Dual Task Performance ◽  
Suitable Framework ◽  
Frontal Lesions

A major problem in analysing the executive processes that seem to depend upon the prefrontal cortex stems from the absence of a well developed cognitive model of such processes. It is suggested that the central executive component of an earlier model of working memory might provide a suitable framework for such an analysis. The approach is illustrated using one proposed component of executive control, namely the capacity to combine two concurrent tasks. The application of the approach to patients suffering from Alzheimer’s disease, and patients with acquired brain damage is discussed. Finally, a study is described in which the dual task performance of patients with known frontal lesions is shown to be associated with observed behavioural problems. The paper concludes with the discussion of the prospects for extending the approach to include a range of other executive processes, and to the way in which such an analysis may subsequently lead to a more integrated model of the central executive, and a better understanding of its relationship to the prefrontal cortex.

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