Communication Architecture Design for Real-Time Networked Control Systems

Networked control over data networks has received increasing attention in recent years. Among many problems in networked control systems (NCSs) is the need to reduce control latency and jitter and to deal with packet dropouts. This paper introduces our recent progress on a queuing communication architecture for real-time NCS applications, and simple strategies for dealing with packet dropouts. Case studies for a middle-scale process or multiple small-scale processes are presented for TCP/IP based real-time NCSs. Variations of network architecture design are modelled, simulated, and analysed for evaluation of control latency and jitter performance. It is shown that a simple bandwidth upgrade or adding hierarchy does not necessarily bring benefits for performance improvement of control latency and jitter. A co-design of network and control is necessary to maximise the real-time control performance of NCSs

Person tracking using motion detection and optical flow

Person tracking systems to date have either relied on motion detection or optical flow as a basis for person detection and tracking. As yet, systems have not been developed that utilise both these techniques. We propose a person tracking system that uses both, made possible by a novel hybrid optical flow-motion detection technique that we have developed. This provides the system with two methods of person detection, helping to avoid missed detections and the need to predict position, which can lead to errors in tracking and mistakes when handling occlusion situations. Our results show that our system is able to track people accurately, with an average error less than four pixels, and that our system outperforms the current CAVIAR benchmark system.

From emotional suppression to regulated empathy : the changing face of control in the CES

Between the 1970s and the 1990s the level and type of emotionality in the Commonwealth Employment Service (the Australian national employment service) altered. Within a context of changing economic conditions and concomitant work intensification, it is argued that untenable working conditions resulted in new recruits adopting a coping strategy that led to the use rather than the suppression of emotions. The use of emotions provided workers with job satisfaction and greater control over service interactions. Management subsequently commandeered the use of emotions to complement the introduction of private sector management techniques and service delivery reforms, regaining control over worker-client interactions.