Background:  Extra Sets of Eyes

Approach

The objective of this project is to develop a set of portable (the size of a baseball), inexpensive (less than $500 in production), self-contained (sensors, processing, radio, and battery) Small Sentry Modules (SSMs) that can autonomously detect, characterize, classify, and report moving objects, such as people, animals, and vehicles. These sensors will be small enough so that a warfighter could carry several of them and deploy them as extra sets of eyes, instead of using people, to monitor key areas for possible approaching threats. When a module detects a significant event, such as a person running along a path, it radios a description of the event to the warfighter and/or combat unit, providing them with advanced warning of possible danger.

Numerous modules could be used to establish a sentry network in which the sensors cooperate to verify detections and estimate the 3D locations and velocities of moving objects. SRI has already developed the critical stereo sensor that makes this project feasible -- the parts cost is approximately $200, in large quantities, and this price can be reduced significantly if special chips are fabricated. Within the first six months of the project, we plan to construct 20 copies of an initial stereo-based SSM, implement a development environment for it, and then distribute sets of the SSMs and the environment to the Integrated Feasibility Demonstration (IFD) contractor and the other FREs as a common experimental device. Throughout the project we will explore ways to integrate additional sensor modalities (including acoustic and radar), enhance our moving object detection and tracking techniques, and explore strategies for forming networks of these modules to perform the tasks more reliably and robustly. In summary, we believe that technology is available today to build SSMs that can save lives and provide substantial force multiplication.
 

Military/Battlefield Relevance

The nature of war has changed in several ways. First, many of the `conflicts' are ``missions other than war'' or Military Operations in Urban Terrain (MOUT), as opposed to conventional warfare. Second, the number of warfighters in the U.S. armed forces has been reduced significantly, increasing the tactical importance of each one. And third, the death of a warfighter, although never `acceptable,' is less tolerable today than in the past. Two consequences of these changes are an increased need to protect each warfighter and a renewed interest in force multiplication. In this project, we propose to develop a sequence of increasingly competent SSMs that can help fulfill both needs -- protect the warfighter and enhance his effectiveness.

Our vision is to develop SSMs that are sufficiently competent to be used by a warfigther as an extra pair of eyes to watch his backside, while he continues with his primary mission. If a warfighter is clearing a building in a MOUT scenario, she can leave one device at the entrance to warn her if someone enters the building. If she's on a trail, she set up one on a tree to warn her of someone approaching from the rear. In addition, a warfighter can use one of the modules as a periscope to look around a corner and into a tunnel without exposing herself to enemy fire. For this application, the warfighter attaches her head-mounted display to the module's high-definition video output and visually explores the hidden area by physically moving the module to scan it. The ultimate modules will have sensors that combine infrared (IR) and image-intensified data to provide an excellent night-vision capability.

We expect the deployed modules to incorporate multiple sensor modalities, such as stereo, motion, radar, and acoustic, in order to maximize their applicability and minimize their errors. For example, a combination of a radar sensor to detect movement and a stereo sensor to construct 3D descriptions of the moving object will be one of the first devices to be considered. For some applications, a combination of acoustic and visual sensors is appropriate. For other applications, inclusion of chemical and biological sensors would add a critical new dimension.

An enhanced version of the SSM will include techniques for multiple modules to cooperate, setting up communication channels, a common coordinate system, and a procedure for operating together to verify detections nd estimate their 3D locations. And our vision of the ultimate SSM is a mobile sensor package that can be used either to explore ahead of a warfighter or to trail behind, checking for potential danger signals.