Collaborative sensing via local negotiations in ad hoc networks of smart cameras

Abstract

The paper develops an ad hoc network of active pan/tilt/zoom (PTZ) and passive wide field-of-view (FOV) cameras capable of carrying out observation tasks autonomously. The network is assumed to be uncalibrated, lacks a central controller, and relies upon local decision making at each node and inter-node negotiations for its overall behavior. To this end, we develop intelligent camera nodes (both active and passive) that can perform multiple observation tasks simultaneously. We also present a negotiation protocol that allows cameras nodes to setup collaborative tasks in a purely distributed manner. Camera assignments conflicts that invariably arise in such networks are naturally and gracefully handled through at-node processing and inter-node negotiations. We expect the proposed camera network to be highly scalable due to the lack of any centralized control.

A Negotiation Protocol with Conditional Offers for Camera Handoffs

“…The camera network can also be tasked to record higher-resolution imagery of a selected target. Qureshi presents a negotiation protocol that allows camera nodes to setup collaborative tasks in a purely distributed manner in [2]. The camera nodes, which are modelled as behaviour based autonomous agents, are able to ask other cameras to take over a task when they are no longer able to meet task requirements.…”

“…A camera might be tracking multiple individuals, it might be evaluating its suitability for tracking a new target, or in case of PTZ cameras, a camera might be performing a visual search in the pan/tilt/zoom space to fixate and zoom in on a pedestrian. Ignoring the innards of a camera node, it is possible to keep track of these activities using a finite state machine proposed in [2] (see Fig. 2).…”

“…Figure 3 illustrates the basic mechanics of negotiations for camera handoff [3,2]. Here, camera 1 is viewing a pedestrian that looks like a blue circle as it walks across a room.…”

“…In response camera 2 computes its suitability for taking on this task and returns this information to camera 1. 2 The negotiations are successful and camera 2 starts observing the pedestrian represented by a blue circle. Often camera 1 will initiate negotiations with more than one neighbouring cameras.…”

“…Ideally the control and coordination strategy should be distributed, as centralized schemes do not scale and defeat the raison d'êter of smart camera networks. Game-theory [1] based and contract-net [2,3] inspired auction based schemes have been proposed to address the issue of camera grouping and handoff in smart camera networks. This paper develops a new negotiation protocol for camera handoffs.…”