Personnel safety sensing system
A location system for locating workers including a plurality of light detectors mounted at known locations and configured to detect light from one or more workers, and a processing system configured to determine locations of the workers using the light detected by the light detectors. There is also disclosed a wearable device for locating a worker including a wireless transceiver, and a wearable device light source and/or one or more reflective elements. There is also disclosed a method for locating workers including detecting light from one or more workers using a plurality of light detectors mounted at known locations, and determining locations of the workers using the light detected by the light detectors.
1. A location system for locating workers comprising:
a plurality of light detectors mounted at known locations and configured to detect light from one or more workers;
wearable devices to be worn by one or more of the workers who are authorized workers, the wearable device including a wireless transceiver;
a plurality of wireless receivers mounted at known locations and configured to detect wireless signal transmissions from the wearable devices; and
a processing system configured to:
determine locations of the workers by measuring the time of flight of the light detected by the light detectors;
determine locations of the authorized workers using the wireless signal transmissions from the wearable devices detected by the wireless receivers;
compare the workers whose locations are determined by measuring the time of flight of the light detected by the light detectors with the authorized workers whose locations are determined using the wireless signal transmissions from the wearable devices detected by the wireless receivers; and
based on the comparison, identify as unauthorized workers any workers whose location is determined using the light detected by the light detectors who are not authorized workers whose location is determined using the wireless signal transmissions from the wearable devices.
2. The location system according to claim 1 , wherein the processing system is further configured to determine if the location of one or more of the workers is within a defined area and output a warning signal in response thereto.
3. The location according to claim 1 , wherein the light from the workers is light reflected from the workers.
4. The location system according to claim 3 , wherein the system further comprises illuminating light sources adjacent to respective light detectors, the light reflected from the workers being light from the illuminating light sources.
5. The location system according to claim 3 , wherein the system further comprises at least one reflective element to be mounted on respective workers, the light reflected from the workers being light reflected from the reflective element.
6. The location system according to claim 5 , wherein the light reflected from the reflective element is modulated light.
7. The location system according to claim 6 , wherein the modulated light is spatially modulated in intensity, and/or modulated in wavelength, and/or modulated in intensity over time.
8. The location system according to claim 6 , wherein the modulated light encodes a unique identifier.
9. The location system according to claim 5 , wherein the reflective element is a retroreflector.
10. The location system according to claim 1 , wherein the processing system is configured to determine locations of the authorized workers by combining the locations of the authorized workers determined using the light detected by the light detectors and the locations of the authorized workers determined using the wireless signal transmissions from the wearable device.
11. The location system according to claim 1 , wherein the processing system is configured to output a warning signal if the location of one or more of the workers identified as unauthorized workers is within a defined area.
12. The location system according to claim 1 , wherein the processing system is configured to control the activity of machinery based on the location of the workers identified as unauthorized workers.
13. The location system according to claim 1 , wherein the processing system is further configured to determine locations of machinery using light from the machinery detected by the light detectors.
14. The location system according to claim 1 , further comprising:
mountable devices to be mounted on machinery which is authorized, the mountable device including a wireless transceiver; and
a plurality of wireless receivers mounted at known locations and configured to detect wireless signal transmissions from the mountable device, the processing system being configured to determine locations of the authorized machinery using the wireless signal transmissions from the mountable device detected by the wireless receivers.
15. The location system according to claim 13 , wherein the processing system is further configured to:
compare the determined locations of workers to the determined locations of machinery; and
output a warning signal and/or control the activity of machinery based on the comparison of the locations of workers and the locations of machinery.