Automatic tamping mechanism control

Abstract

A control system for use with an asphalt paving machine receives inputs from an operator interface for inputting a desired tamping frequency or a desired tamping rate (tamps/ft) and a speed sensor that produces a signal indicative of the speed of the asphalt paver. The control system includes an automatic mode and when in automatic mode the system modifies the tamping frequency to better achieve a desired number of tamps per foot traveled irrespective of speed.

What is claimed is:  
     
         1 . A control for a tamping mechanism on an asphalt paver, including: 
 a speed sensor, said speed sensor sensing the speed of said asphalt paver;    a desired tamping speed input;    an electronic control module that controls the speed of said tamping mechanism as a function of said tamping speed input and said speed sensor.    
     
     
         2 . The control according to  claim 1 , including: 
 a mode selector having a manual mode selection and an automatic mode selection; and    wherein said electronic control module controls the speed of said tamping mechanism in response to said desired tamping speed input when said mode selector is in said manual mode.    
     
     
         3 . The control according to  claim 1 , wherein: 
 said electronic control module control increases the speed of said tamping mechanism in response to an increase in the speed of said asphalt paver.    
     
     
         4 . The control according to  claim 1 , wherein: 
 said electronic control module control decreases the speed of said tamping mechanism in response to a decrease in the speed of said asphalt paver.    
     
     
         5 . An electronic control for an asphalt paver, said paver having a screed with a tamping mechanism, said electronic control including: 
 an asphalt paver speed sensor, said sensor outputting a signal as a function of the speed of said asphalt paver;    a mode selector including a plurality of tamping mechanism mode selections, said mode selector outputting a signal as a function of the mode selection;    a desired tamping speed selector, wherein said speed selector outputs a signal indicative of a desired tamping speed selected by an operator of said asphalt paver;    an electronic controller receiving said speed sensor signal, said mode selector signal and said desired tamping speed signal and outputting a tamping mechanism control signal, wherein said tamping mechanism control signal is a function of said asphalt paver speed sensor signal, said mode selector signal and said desired tamping speed signal;    said tamping mechanism receiving said tamping mechanism control signal and controlling the speed of said tamping mechanism as a function of said tamping mechanism control signal.    
     
     
         6 . The electronic control according to  claim 5  wherein said mode selector includes an automatic mode selection, a manual mode selection and an off selection.  
     
     
         7 . The electronic control according to  claim 6 , wherein: said electronic control produces said tamping mechanism control signal as a function of said asphalt paver speed sensor signal and said desired tamping speed signal when said mode selector is in said automatic mode selection.  
     
     
         8 . The electronic control according to  claim 6 , wherein said electronic control produces said tamping mechanism control signal as a function of said desired tamping speed signal when said mode selector is in said manual mode selection.  
     
     
         9 . The electronic control according to  claim 6 , wherein said electronic control produces a tamping mechanism control signal indicative of no desired movement of the tamping mechanism when said mode selector is in said off mode selection.  
     
     
         10 . The electronic control according to  claim 6 , wherein: 
 said electronic control produces said tamping mechanism control signal as a function of said asphalt paver speed sensor signal and said desired tamping speed signal when said mode selector is in said automatic mode selection;    said electronic control produces said tamping mechanism control signal as a function of said desired tamping speed signal when said mode selector is in said manual mode selection; and    said electronic control produces a tamping mechanism control signal indicative of no desired movement of the tamping mechanism when said mode selector is in said off mode selection.    
     
     
         11 . A method of controlling a tamping mechanism on an asphalt paving machine, said method including the steps of: 
 determining a velocity of said asphalt paving machine;    determining a desired speed of said tamping mechanism;    controlling said tamping mechanism in response to said velocity of said asphalt paving machine and said desired speed of said tamping mechanism.    
     
     
         12 . The method according to  claim 11 , wherein said step of controlling includes: 
 controlling the speed of said tamping mechanism to be proportional to the speed of the asphalt paving machine.    
     
     
         13 . The method according to  claim 11  wherein said step of controlling includes: 
 controlling said tamping mechanism to provide a relatively constant number of tamping strokes per unit of distance traveled by said asphalt paver.  
 
     
     
         14 . The method according to  claim 11 , wherein said step of controlling includes: 
 controlling said tamping mechanism in response to said desired frequency when said asphalt paver is stationary and increasing the speed of said tamping mechanism in response to an increasing velocity of said asphalt paver.