Sensing at the edge is not new in concept or practice. Today it is commonplace for sensors to detect presence and take actions such as automatically opening doors, alerting drivers to obstacles behind them, or turning lights on or off.
Traditionally, though, there have been limits to the effectiveness of these sensing applications. Think about how often an automatic door opens when somebody moves nearby but is not approaching to pass through, or even stays stuck open when a shopping cart is sitting just within range of the sensor. The sensor detects something bulky within a few feet of the door, then wastes power opening the door and letting conditioned air from inside escape — with no useful result.
Suppose the door would open not only because it senses proximity, but also because someone approaching has changed speed, indicating an intention to enter. An extreme instance would be when an excited child runs directly at the door. Proximity sensing alone cannot react quickly enough, but a sensor that also detects the speed and angle of movement can trigger the door to open just in time, promoting safety and letting only the minimum air escape. The sensor is also clever enough to spot individual people and common objects, so that it can provide useful information to the building network, such as giving a store a count of customers or notifying managers when shopping carts need to be brought in from the parking lot. Considering the vast number of automatic doors in use, widespread installation of such sensors could bring considerable energy savings, as well as contributing to security, safety and convenience as a part of building automation.