Hot people shown up to be counted

Tom Shelley reports on a novel thermal array suited for counting people to reduce queues

Tom Shelley reports on a novel thermal array suited for counting people to reduce queues Novel un-cooled infra red detection arrays can be connected together to count people, and ascertain what they are doing, whether they be trying to find a shorter checkout queue in a supermarket or in danger of suffering some catastrophe from too many people arriving in the same place. The key technology is a 16 x 16 element pyroelectric ceramic array on a silicon substrate behind a germanium lens. This forms the sensing element in what is designated the Irysis IRC1004 and 1014 Indoor People Counters. The devices observe pedestrians from above and have relays and CANbus interfaces, with a further IWC2020 module available to convert this to RS232. The 1014 has a 60 deg field of view and is designed to be mounted at heights of 2.5m to 4.5m, while the 1014 has a 40 deg field of view and is designed to be mounted at heights of 4m to 7m. At 3.5m height, the 1004 sees a 3.25m x 3.25m area of the floor. The devices may be used as single counters, or as networks of up to 30 counters, or 8 counters linked to span a wide opening. There are two count lines to allow counting in both directions, which may be user configured by drag and drop into different shapes and positions. The devices may either be used to count pedestrians moving across the lines, or the number of pedestrians within an area. Temperature sensitivity is less than 2 deg K, and detection speed range is 0.5 to 3 m/s. A popular application is detecting how many people are queuing at supermarket checkouts and whether they are showing signs of irritation, such as trying to move around to find shorter queues. Other applications include: market research, determining whether people are pausing in front of a particular display, access control, area denial, security and safety. As well as units designed for indoor applications in shops, malls, banks and building societies, supermarkets, leisure complexes, rail stations and other facilities, there is also an IRC 1003 version available for more severe environments. InfraRed Integrated Systems email InfraRed Integrated Systems