Railroad car location, speed, and heading detection system and methods with self-powered wireless sensor nodes
A railroad car location, speed and heading sensor system including at least one self-powered, tie-mounted sensor node that is applicable universally to different railroad settings without using track circuits, inductive loops, radar systems, and wheel counters and associated disadvantages. Reliable and relatively low cost deterministic and redundant car presence detection is realized when multiple sensor nodes are arranged in a network, which may be a wireless mesh network, that is not affected by environmental conditions.
1. A system for detecting location, speed and heading information of a moving railroad car or string of railroad cars in a railroad switchyard, the system comprising:
a first plurality of processor-based sensor node devices arranged in spaced relation to one another to establish a first predefined protected area corresponding to an intersection of a connector track and a first classification track in a railroad switchyard;
a second plurality of processor-based sensor node devices arranged in spaced relation to one another to establish a second predefined protected area corresponding to an intersection of the connector track and a second classification track in the railroad switchyard;
each of the plurality of processor-based sensor node devices including at least one detection element configured to sense at least one of the location, speed and heading of the railroad car or string of railroad cars moving within the first or second predefined protected areas;
at least one concentrator node device in communication with each of the plurality of processor-based sensor node devices when the moving object is within the predefined protected area; and
a master processor device in communication with the at least one concentrator node device and a railroad yard control system.
2. The system of claim 1 , wherein each of the plurality of processor-based sensor node devices includes a radio transmitter establishing wireless communication with the at least one concentrator node device.
3. The system of claim 1 , wherein each of the plurality of processor-based sensor node devices includes a plurality of different detection elements configured to sense an aspect of the location, speed and heading of the moving object.
4. The system of claim 3 , wherein the plurality of different detection elements are selected from the group of: an inductor element, a magnetometer, a vibration sensor, an acoustic sensor, a pressure sensor, a wireless power element, a micro power impulse radar element, and ultrasonic detection element, and an ambient light sensor element.
5. The system of claim 1 , wherein each of the plurality of processor-based sensor node devices includes an onboard power supply, the onboard power supply including a plurality of independently operable power supplies of different types.
6. The system of claim 5 , wherein the plurality of independently operable power supplies of different types are selected from the group of: a battery power supply, a vibration energy harvesting element, a stress energy harvesting element, a pressure harvesting element, a wireless power harvesting element, and a solar assisted power element.
7. The system of claim 5 , wherein each of the plurality of processor-based sensor node devices is configured to enter a lower power sleep mode when a moving object is not present in the predefined protected area.
8. The system of claim 1 , wherein the plurality of processor-based sensor node devices are mountable to railroad ties of the connector track, the first classification track, or the second classification track.
9. The system of claim 1 , wherein the detected object is a railroad car or a string of railroad cars decoupled from a locomotive engine.
10. The system of claim 1 , wherein the plurality of processor-based sensor node devices are each configured to communicate with one another using near-field mesh network wireless communication with synchronized time division multiplexing.
11. The system of claim 1 , wherein the plurality of processor-based sensor node devices are configured to broadcast health information.
12. The system of claim 1 , wherein the at least one concentrator node device is configured to provide wireless power transfer to the plurality of processor-based sensor node devices.
13. The system of claim 1 , wherein the plurality of processor-based sensor node devices are configured to detect at least one of a size and weight of the moving object.
14. The system of claim 1 , wherein each of the plurality of processor-based sensor node devices includes redundant power supply elements including at least one battery, and power management circuitry prioritizing power management of the redundant power supply elements to limit the use of battery power and conserve battery power as long as possible.
15. The system of claim 14 , wherein each of the plurality of processor-based sensor node devices are configured to periodically communicate a quantitative measure of remaining battery energy.