Claims
- 1. A unidirectional telemetry system comprising:a monitoring receiver operative to receive transmitted packets over successive frames, each frame being constituted by a plurality of equal length time slots, without acknowledging receipt of any of said transmitted packets; and a plurality of beacons, each beacon including a transmitter operative to transmit packets autonomously relative to any transmitter of any other beacon, and each transmitter being operative to transmit packets asynchronously relative to said monitoring receiver; wherein each said transmitter is operative to transmit a given packet a plurality of times within a corresponding frame, with each packet transmitted by a respective transmitter being transmitted within any one of said time slots and retransmitted at random times within said corresponding frame; wherein random collisions between packets transmitted and retransmitted by corresponding transmitters occur during a frame, a frequency of random packet retransmission being selected in accordance with packet length and total number of transmitters to obtain a sufficiently small probability of jamming as to ensure receipt by said monitoring receiver of information contained in each transmitted packet; and wherein no beacon receives an acknowledgement that any transmitted packet has been received by said monitoring receiver.
- 2. The telemetry system of claim 1, further including a plurality of sensors, each respective sensor being operative to periodically perform a predetermined measurement and each respective sensor being operative to supply a signal representative of performed measurement data to one of said plurality of transmitters whereby information relating to a performed measurement may be transmitted to said monitoring receiver.
- 3. The telemetry system of claim 1, wherein at least one transmitter receives measurement data from multiple sensors.
- 4. The telemetry system of claim 2, wherein at least one of said plurality of sensors has a tolerance range wherein a transmitter associated with said at least one sensor repeats a transmitted packet representative of data measured by said at least one sensor more frequently during a frame than if data measured is outside of said tolerance range.
- 5. The telemetry system of claim 2, wherein each sensor has a priority level assigned thereto which is known by an associated transmitter and wherein an associated transmitter adaptively repeats data from a sensor having a higher priority level more often over a frame than data from a sensor having a lower priority level.
- 6. The telemetry system of claim 1, wherein each transmitter is operative to transmit each packet within approximately one-half of a time slot.
- 7. A telemetry system for use in monitoring wear in moving parts of a locomotive, comprising:at least one car control unit including a monitoring receiver operative to receive transmitted packets communicating performed measurements over successive frames, each frame being constituted by a plurality of equal length time slots, without acknowledging receipt of any of said transmitted packets; a plurality of beacons associated with said at least one car control unit, each beacon including a transmitter operative to transmit packets autonomously relative to any transmitter of any other beacon, and each transmitter being operative to transmit packets asynchronously relative to said monitoring receiver; and a plurality of sensors associated with said at least one car control unit, each respective sensor being operative to periodically perform a predetermined measurement and each respective sensor being operative to supply a signal representative of a performed measurement to a corresponding one of said plurality of transmitters; wherein each said transmitter is operative to transmit a given packet a plurality of times within a corresponding frame, with each packet transmitted by a respective transmitter being transmitted within any one of said time slots and retransmitted at random times within said corresponding frame; wherein random collisions between packets transmitted and retransmitted by corresponding transmitters occur during a frame, a frequency of random packet retransmission being selected in accordance with packet length and total number of transmitters to obtain a sufficiently small probability of jamming as to ensure receipt by said monitoring receiver of information contained in each transmitted packet; and wherein no beacon receives an acknowledgement that any transmitted packet has been received by said monitoring receiver.
- 8. The telemetry system of claim 7, wherein at least one transmitter receives measurement data from multiple sensors.
- 9. The telemetry system of claim 7, wherein at least one of said plurality of sensors has a tolerance range wherein a transmitter associated with said at least one sensor repeats a transmitted packet representative of data measured by said at least one sensor more frequently during a frame than if data measured is outside of said tolerance range.
- 10. The telemetry system of claim 7, wherein each sensor has a priority level assigned thereto which is known by an associated transmitter and wherein an associated transmitter adaptively repeats data from a sensor having a higher priority level more often over a frame than data from a sensor having a lower priority level.
- 11. The telemetry system of claim 7, wherein each transmitter is operative to transmit each packet within approximately one-half of a time slot.
- 12. The telemetry system of claim 7, further including a locomotive control unit, said locomotive unit being operative to receive signals representative of said sensor measurements from each of a plurality of car control units, each respective car control unit being associated with a corresponding locomotive car and being operative to report sensor measurements associated with said corresponding locomotive car.
- 13. A method of monitoring wear in a locomotive, comprising the steps of:providing in at least one car, a monitoring receiver operative to receive transmitted packets communicating performed measurements associated with said at least one car over successive frames, each frame being constituted by a plurality of equal length time slots, without acknowledging receipt of any of said transmitted packets; providing a plurality of beacons associated with said at least one car, each beacon including a transmitter operative to transmit packets autonomously relative to any transmitter of any other beacon, and each transmitter being operative to transmit packets asynchronously relative to said monitoring receiver; providing a plurality of sensors associated with said at least one car, at least some of said sensors being operative to periodically perform a predetermined measurement of one of temperature, vibration, and wheel revolutions per unit of time; supplying signals representative of measurements performed by said plurality of sensors to said plurality of transmitters; and transmitting to the monitoring receiver, using the transmitters, packets containing measurement data collected by said plurality of sensors, each packet being transmitted a plurality of times within a corresponding frame, with each packet transmitted by a respective transmitter being transmitted within any one of said time slots and retransmitted at random times within said corresponding frame; wherein during said transmitting step, random collisions between packets transmitted and retransmitted by corresponding transmitters occur during a frame, a frequency of random packet retransmission being selected in accordance with packet length and total number of transmitters to obtain a sufficiently small probability of jamming as to ensure receipt by the monitoring receiver of information contained in each transmitted packet; and wherein no beacon receives an acknowledgement that any transmitted packet has been received by the monitoring receiver.
- 14. The method of claim 13, further including a step of receiving from the monitoring receiver, at a locomotive control unit, signals representative of measurements associated with the at least one car.
- 15. The method of claim 14, further including a step of generating an alarm to alert maintenance personnel to a need to service a component monitored by one of the sensors.
Parent Case Info
This application claims benefit to U.S. Provisional Application 60/042,216 filed Mar. 31, 1997.
US Referenced Citations (15)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0627841 A2 |
May 1994 |
EP |
2297663 |
Aug 1996 |
GB |
Non-Patent Literature Citations (2)
Entry |
PCT International Application No.: PCT/US95/03911, dated Oct. 12, 1995; International Publication No.: WO 95/27272. |
PCT International Search Report, International application No.: PCT/US98/06204, International filing dated Mar. 30, 1998. |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/042216 |
Mar 1997 |
US |