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

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.

I claim:  
     
         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 event 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 or occurrence of the transmission events;  
   a receiver for sensing said signal and for implementing locally an action in dependence upon a contents 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 signal to a remote receiver by creating 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, said method comprising the steps of: 
 generating a signal to be transmitted,    transmitting said signal successively to create the succession of signal transmission events at a rate that varies over time.    
     
     
         19 ) A method, as defined in  claim 18 , comprising the step of altering the duration the time intervals to alter the rate of occurrence of the signal transmission events.