Closed loop control system for pavement surfacing machine

Abstract

Apparatus and methods for controlling the operation of a pavement surfacing machine are described. One embodiment that controls a pavement surfacing machine having a vehicle moveable in a preselected direction of travel along a pavement surface under the influence of a prime mover and configured to urge a rotatable grinding head against the pavement surface includes at least one sensor configured to measure a preselected operational parameter of the pavement surfacing machine and provide an output representative of the parameter and a controller that is configured to control the rate at which the vehicle moves in response to the sensor output.

1 . A system for controlling a pavement surfacing machine having a vehicle moveable in a preselected direction of travel along a pavement surface under the influence of a prime mover and configured to urge a rotatable grinding head against the pavement surface, comprising: a controller; at least one sensor configured to measure a preselected operational parameter of the pavement surfacing machine and provide an output representative of the parameter; and wherein the controller is configured to control the rate at which the vehicle moves in response to the sensor output.  
   
   
       2 . The control system of  claim 1 , wherein the preselected operational parameter is indicative of the weight on a depth control assembly.  
   
   
       3 . The control system of  claim 2 , wherein the controller is configured to decrease the speed of the vehicle when the weight on the depth control assembly falls below a predetermined threshold.  
   
   
       4 . The control system of  claim 2 , wherein the controller is configured to increase the speed of the vehicle when the weight on a depth control assembly exceeds a predetermined threshold.  
   
   
       5 . The control system of  claim 2 , wherein the sensor is a load cell connected to the controller and located within a depth control assembly for measuring the weight on the depth control assembly.  
   
   
       6 . The control system of  claim 1 , wherein the preselected operational parameter is indicative of the rotational speed of the grinding head.  
   
   
       7 . The control system of  claim 6 , wherein the controller is configured to increase the speed of the vehicle when the rotational speed of the grinding head is greater than a predetermined threshold.  
   
   
       8 . The control system of  claim 6 , wherein the controller is configured to decrease the speed of the vehicle when the rotational speed of the grinding head is less than a predetermined threshold.  
   
   
       9 . The control system of  claim 6 , wherein the sensor is an electronic control module connected to the controller and located within a grinding engine to measure the power output of the grinding engine.  
   
   
       10 . The control system of  claim 1 , further comprising: an engine connected to a hydraulic system for moving the vehicle; and wherein the sensor comprises a rotary transducer connected to a front wheel of the vehicle.  
   
   
       11 . A method of controlling the rate at which a rotatable grinding head mounted on a pavement surfacing machine wears comprising: measuring a preselected operational parameter of the pavement surfacing machine; and moving the pavement surfacing machine at a rate dependent upon the operational parameter.  
   
   
       12 . The method of  claim 11 , wherein the operational parameter is indicative of the weight on a depth control assembly.  
   
   
       13 . The method of  claim 12 , wherein the speed of the pavement surfacing machine is decreased when the weight on the depth control assembly falls below a predetermined threshold.  
   
   
       14 . The method of  claim 12 , wherein the speed of the pavement surfacing machine is increased when the weight on the depth control assembly exceeds a predetermined threshold.  
   
   
       15 . The method of  claim 11 , wherein the operational parameter is indicative of the rotational speed of the grinding head.  
   
   
       16 . The method of  claim 15 , wherein the speed of the pavement surfacing machine is increased when the rotational speed of the grinding head is greater than a predetermined threshold.  
   
   
       17 . The method of  claim 15 , wherein the speed of the pavement surfacing machine is decreased when the rotational speed of the grinding head is less than a predetermined threshold.  
   
   
       18 . The method of  claim 11 , wherein the operational parameter is the speed of the pavement surfacing machine.  
   
   
       19 . The method of  claim 11 , wherein: the operational parameter is the output power of the grinding engine; and the speed of the pavement surfacing machine is decreased when the output power of the grinding engine exceeds a predetermined threshold.  
   
   
       20 . A pavement surfacing machine, comprising: a vehicle movable in a preselected direction of travel along a pavement surface; a prime mover for propelling the vehicle; a grinding head mounted for rotation on the vehicle and driven at a controlled rate of rotation; a mechanism for urging the grinding head against the pavement surface; at least one sensor configured to measure a preselected operational parameter of the pavement surfacing machine and provide an output representative of the parameter; and a controller configured to control the rate of travel of the vehicle in response to the sensor output.