Many industrial and commercial plants, government and private research facilities, and industrial facilities perform potentially dangerous processes. Automated warning and alarm systems alert personnel to dangerous or abnormal conditions inside or near a plant so the personnel may take prompt protective action such as evacuation, co-location, or shelter in place. Such automated systems include simple fire and smoke detectors that detect the presence of fire or smoke and immediately activate a connected, audible alarm confined to a specific area of a plant. Many systems include a central hub for receiving detection signals from detectors located throughout a plant. In some systems, the central hub also is connected to a network of alarms including audible alarms — both siren-like and information-based — and visual alarms, including flashing emergency lights and textual-based information screens.
Unfortunately, in some environments, currently available automated warning and alert systems are not entirely effective. They may not provide complete notification coverage over a wide area, or they may not provide for personal accountability during an emergency alert. Improved systems are needed for alerting persons of impending or actual hazardous conditions that could endanger their safety.
The Personal Annunciation Device (PAD) is a wireless emergency alert technology that can be easily adapted for multiple-hazard or high-consequence events where traditional notification means are not adequate, and rapid alert and accountability are required. It not only provides the user an emergency alert and an approximate location of the hazard, but also notifies command-and-control personnel of the user's location.
This technology integrates radio frequency identification (RFID), wireless communication, and sensors with alarm states into an integrated recognize-send-receive account system. The RFID feature uses a “bread-crumb approach,” acting as a tracker as the individual moves from area to area. The device can receive either an automatic signal from a network of detectors, or a coded message from a sender. The PAD prototype of the non-nuclear-based, radio frequency receiver is about the size of a car key fob, making it easy to wear over an extended time (Figure 1).
A sensor or other detector indicates an abnormal condition, and a wireless transmission system transmits to the PAD. The PAD has a housing enclosing the components, including a communication module for receiving the wireless transmission, a power supply, processor, memory, annunciation system, and RFID module. The RFID module has an RFID receiver that listens for a transmission from an RFID reader in an area of interest. The PAD identifies the transmission and changes its operating state based on the transmission. The RFID readers recognize, record, and transmit the state of the PAD to a base station, providing accountability of the wearer.
The PAD has concurrent alarms for vibration, light, and sound, and contains embedded self-checking “intelligence” for enhanced reliability (Figure 2), providing information on battery life. It uses commercially available parts, and requires minimal human interface. Applications include coal mines and high-hazard industrial facilities, chemical companies, convention and sport venues, hospitals, and schools.