Distance measurement for wireless building automation devices
View Patent ↗In a building environment, a distance associated with a building automation device is determined as a function of an inserted time delay between a wireless transmission of a signal and wireless reception of another signal. For example, a two-way communication is provided with a time delay inserted before responding to a received transmission. By using two-way transmissions, the building automation devices may be free of clock synchronization. Acoustic signals may be used in a building environment to determine a distance. The building automation device may also use radio frequency information for communicating with other devices. Communication between devices allows a controller to coordinate the determination of distances associated with different devices within a network, such as through transmission of a test signal and assigning distance measurement operations to devices that receive the test signal with sufficient strength or other characteristics.
1. A building automation device for determining distance after placement within a building, the building automation device comprising:
a sensor or an actuator operable for control of an environment of the building;
an acoustic transceiver; and
a radio frequency transceiver; and
a processor operable to control the acoustic transceiver for distance determination operation in response to control signals from the radio frequency transceiver, the processor operable to process data of the sensor or actuator.
2. The building automation device of claim 1 wherein the processor is operable to cause the acoustic transceiver to transmit a first ultrasound signal and is operable to determine a distance from the building automation device to another device as a function of a received second ultrasound signal.
3. The building automation device of claim 2 wherein the processor is operable to cause the radio frequency transceiver to transmit the distance and the data of the sensor or actuator.