Method and apparatus for automatic repetition rate assignment in a remote control system

• US 6,456,674 B1
• Filed: 09/28/1998
• Issued: 09/24/2002
• Est. Priority Date: 09/25/1998
• Status: Expired due to Fees

• Current Assignee: Cattron Intellectual Property Corporation
• Original Assignee: CANAC Incorporated
• Inventors: Brousseau, Andre, Horst, Folkert, Szklar, Oleh, Ethier, Luc
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): Liu, Shuwang
• Application Number:
  US09/162,170
• Time in Patent Office: 1,457 Days
• Field of Search: 375/347, 375/259, 375/295, 375/316, 370/60, 340/825.64, 340/825.62, 340/825.58, 455/70, 246/187, 246/187.B, 246/187.A
• US Class Current: 375/347
• CPC Class Codes: H04L 1/02 by diversity reception

Abstract

The invention relates to a method and an apparatus for remotely controlling devices, more particularly to a system and method for controlling locomotives in a railway environment using radio frequency signals. This invention makes use of equalized pseudo-random transmission intervals obtained using a random number generator to regulate the times at which the signals are sent from a transmitter to a receiver. The use of these randomly generated transmission intervals allows eliminating the requirement of having an operator manage these intervals for transmitters in simultaneous operation. The invention also provides communication systems operating concurrently with substantially uniform response times by constraining the values of the transmission intervals to lie within a given range.

Claims

1. An apparatus for transmitting a signal to a remote receiver, said apparatus comprising:

a signal transmitting unit including;

a) a first input for receiving a signal to be transmitted, said signal transmitting unit being operative to transmit said signal repetitively to create a succession of signal transmission events, each signal transmission event being spaced in time from a previous signal transmission event by a certain time interval characterized by a duration;

b) a second input for receiving a data element to control a duration of the time interval, said signal transmitting unit being responsive to the data element to set the time interval between two successive signal transmission events at a duration conveyed by the data element;

a time interval duration control module for successively generating different data elements and supplying the different data elements to said second input for varying said time interval to alter over time a rate or occurrence of the transmission events.

2. An apparatus as defined in claim 1, wherein the data elements generated by said time interval duration control module are selected to alter in a pseudo-random manner the rate of occurrence of the transmission events.

3. An apparatus as defined in claim 2, wherein the signal to be transmitted received at said first input is indicative of a command to be implemented at said remote receiver.

4. An apparatus as defined in claim 3, wherein the remote receiver is mounted in a locomotive and the signal to be transmitted received at said first input is indicative of an action to be effected by the locomotive.

5. An apparatus as defined in claim 2, wherein said time interval duration control module includes a data structure containing a plurality of data elements that can individually control the duration of a time interval between two successive transmission events.

6. An apparatus as defined in claim 5, wherein said time interval duration control module includes means for successively outputting from said data structure one data element that is supplied to said second input.

7. An apparatus as defined in claim 6, wherein said time interval duration control module includes a pointer indicating a data element in said data structure to output for application to said second input, and means to alter said pointer once the data element has been output, toward a new data element in said data structure to be output next.

8. An apparatus as defined in claim 7, wherein said data structure is a circular buffer.

9. An apparatus as defined in claim 5, wherein said time interval duration control module includes a pseudo-random number generator operative in generating a plurality of data elements for populating said data structure.

10. A remote control system comprising:

a transmitter for transmitting a signal indicative of an action to be performed remotely, said transmitter including

a) a signal transmitting unit having

i) a first input for receiving a signal to be transmitted, said signal transmitting unit being operative to transmit said signal repetitively to create a succession of signal transmission events, each signal transmission being spaced in time from a previous signal transmission event by a certain time interval;

ii) a second input for receiving a data element to control a duration of the time interval, said signal transmitting unit being responsive to the data element to set the time interval between two successive signal transmission events at a duration conveyed by the data element;

b) a time interval duration control module for successively generating different data elements and supplying the different data elements to said second input for varying said time interval to alter over time a rate of occurrence of the transmission events;

receiver for sensing said signal and for implementing locally an action in dependence upon a content of the signal.

11. A remote control system as defined in claim 10, wherein the data elements generated by said time interval duration control module are selected to alter in a pseudo-random manner the rate of occurrence of the transmission events.

12. A remote control system as defined in claim 11, wherein the remote receiver is mounted in a locomotive and the signal to be transmitted received at said first input is indicative of an action to be effected by the locomotive.

13. A remote control system as defined in claim 12, wherein said time interval duration control module includes a data structure containing a plurality of data elements that can individually control the duration of a time interval between two successive transmission events.

14. A remote control system as defined in claim 13, wherein said time interval duration control module includes means for outputting from said data structure data elements that are supplied successively to said second input.

15. A remote control system as defined in claim 14, wherein said time interval duration control module includes a pointer indicating a data element in said data structure to output for application to said second input, and means to alter said pointer once the data element has been output, toward a new data element in said data structure to be output next.

16. A remote control system as defined in claim 15, wherein said data structure is a circular buffer.

17. A remote control system as defined in claim 13, wherein said time interval duration control module includes a pseudo-random number generator operative in generating a plurality of data elements for populating said data structure.

18. A method for transmitting a plurality of signals to a remote receiver, said method comprising the steps of:

transmitting signals to the remote receiver as a succession of respective signal transmission events, each respective signal transmission event being spaced in time from a previous signal transmission event by a certain time interval, said certain time interval having duration;

supplying a given signal to a transmitter; and

transmitting said given signal repetitively within said succession of respective signal transmission events, so as to repeatedly transmit said given signal in a succession of repeated signal transmission events, said repeated signal transmission events being repeated at a rate that varies over time, each repeated signal transmission event being spaced in time from a previous repeated signal transmission event by a respective time interval, said respective time interval having a respective duration.

19. The method as defined in claim 18, comprising the step of altering the respective durations of the time intervals between respective successive repeated signal transmission events so as to alter the rate of occurrence of the repeated signal transmission events.

20. The method as defined in claim 19, wherein the durations of the time intervals are selected to alter in a pseudo-random manner the rate of occurrence of the transmission events.

21. The method as defined in claim 18, wherein the signal to be transmitted is indicative of a command to be implemented at the remote receiver.

22. The method as defined in claim 21, wherein the remote receiver is mounted in a locomotive and the signal to be transmitted is indicative of an action to be effected by the locomotive.

23. The method as defined in claim 19, wherein said method comprises selecting a data element from a plurality of data elements, each data element being indicative of a duration of a time interval between two successive transmission events.

24. The method as defined in claim 23, wherein said method comprises successively selecting data elements from the plurality of data elements.

25. Apparatus for transmitting a signal to a remote receiver, said apparatus comprising a signal transmitting unit including:

a) an input for receiving a signal to be transmitted;

b) a processing unit operative to transmit said signal repetitively to create a succession of signal transmission events, the signal transmission events in the succession of signal transmission events being spaced in time according to a certain pattern;

c) a second input for receiving data elements for controlling said certain pattern, said signal transmitting unit being responsive to the data elements to set the time interval between two successive signal transmission events at a duration conveyed by the data elements; and

d) a time interval duration control module for successively generating data elements and supplying the different data elements to said second input for controlling the certain pattern.

26. The apparatus as defined in claim 25, wherein the signal to be transmitted received at said first input is indicative of a command to be implemented at said remote receiver.

27. The apparatus as defined in claim 26, wherein the remote receiver is mounted in a locomotive and the signal to be transmitted received at said first input is indicative of an action to be effected by the locomotive.

28. The apparatus as defined in claim 25, wherein said time interval duration control module includes a data structure containing a plurality of data elements that can individually control the duration of a time interval between two successive transmission events.

29. The apparatus as defined in claim 28, wherein said time interval duration control module includes means for successively outputting from said data structure one data element.

30. The apparatus as defined in claim 29, wherein said time interval duration control module includes a pseudo-random number generator operative in generating a plurality of data elements for populating said data structure.

31. A remote control system comprising in combination:

a first transmitter for transmitting a signal indicative of an action to be performed remotely, said first transmitter being operative to transmit said signal repetitively to create a succession of signal transmission events, the signal transmission events in the succession of signal transmission events being spaced in time according to a first transmission pattern;

a second transmitter for transmitting a signal indicative of an action to be performed remotely, said second transmitter being operative to transmit said signal repetitively to create a succession of signal transmission events, the signal transmission events in the succession of signal transmission events being spaced in time according to a second transmission pattern distinct from the first transmission pattern; and

a receiver for sensing signals from either one of said first transmitter unit and said second transmitter unit and for implementing locally an action in dependence upon contents of the signals.