Self-Propelled Civil Engineering Machine And Method Of Controlling A Civil Engineering Machine

Abstract

A civil engineering machine and a method of controlling the machine are based on the position of at least one reference point which is relevant to the control of the civil engineering machine being changed, as the civil engineering machine moves, as a function of a relative position of the at least one reference point relative to a desired path of travel.

1 - 19 . (canceled) 
     
     
         20 . A self-propelled civil engineering machine, comprising:
 a chassis;   a working unit arranged on the chassis and configured to produce structures on a piece of ground or to change the piece of ground;   a drive unit configured to move the chassis and working unit in translatory and/or rotational movements on the piece of ground;   at least one reference point defined on the civil engineering machine;   at least one sensor configured to detect a position of the at least one reference point relative to the piece of ground; and   a controller configured to receive input signals from the at least one sensor and to send control signals to the drive unit, the controller being configured to determine a deviation of the at least one reference point from a desired path of travel and to control the drive unit as a function of the deviation, so that the at least one reference point moves along the desired path of travel or at preset spacing from the desired path of travel, the controller being configured such that as the civil engineering machine moves, the position of the at least one reference point relative to the civil engineering machine can be changed as a function of the position of the at least one reference point relative to the desired path of travel.   
     
     
         21 . The civil engineering machine of  claim 20 , wherein:
 the controller is configured such that before a transition from a substantially straight section of the desired path of travel to a curved section of the desired path of travel, the position of the at least one reference point can be shifted relative to the civil engineering machine rearward opposite to a direction of travel of the civil engineering machine.   
     
     
         22 . The civil engineering machine of  claim 20 , wherein:
 the at least one reference point includes a front reference point and a rear reference point; and   the controller is configured such that before or when the front reference point reaches a transition from a substantially straight section of the desired path of travel to a curved section of the desired path of travel, the position of the front reference point is shifted rearward relative to the civil engineering machine toward the rear reference point.   
     
     
         23 . The civil engineering machine of  claim 22 , wherein:
 the controller is configured such that when the rear reference point reaches the transition, the front reference point is substantially coincident with the rear reference point, and the front reference point is inactivated while the rear reference point traverses the curved section of the desired path of travel.   
     
     
         24 . The civil engineering machine of  claim 23 , wherein:
 the controller is configured such that as the rear reference point traverses the curved section of the desired path of travel the position of the front reference point is shifted forward, relative to the civil engineering machine away from the rear reference point.   
     
     
         25 . The civil engineering machine of  claim 22 , wherein:
 the controller is configured such that when the rear reference point reaches the transition, the front reference point is at a preset spacing from the rear reference point.   
     
     
         26 . The civil engineering machine of  claim 25 , wherein:
 the controller is configured such that before or when the rear reference point reaches a second transition from the curved section to another substantially straight section of the desired path of travel, the position of the front reference point relative to the civil engineering machine is shifted forward relative to the civil engineering machine to an original spacing between the front and rear reference points.   
     
     
         27 . The civil engineering machine of  claim 20 , wherein:
 the drive unit includes one or more front wheels or running-gear units and one or more rear wheels or running-gear units;   the at least one reference point includes a front reference point and a rear reference point; and   the controller is configured such that:
 in a first mode of control a position of the front wheels or running-gear units and of the rear wheels or running-gear units is varied as a function of a deviation of the front reference point from the desired path of travel and of a deviation of the rear reference point from the desired path of travel; and 
 in a second mode of control the position of the front wheels or running gear units is varied as a function of the deviation of the rear reference point from the desired path of travel. 
   
     
     
         28 . A method of controlling a drive unit of a self-propelled civil engineering machine, the method comprising:
 (a) defining a defined position of at least one reference point on the civil engineering machine;   (b) defining a desired path of travel of the at least one reference point relative to a ground surface, the desired path of travel including at least one substantially straight portion and at least one curved portion;   (c) determining a deviation of the at least one reference point from the desired path of travel;   (d) controlling the drive unit as a function of the deviation such that the at least one reference point on the civil engineering machine moves along the desired path of travel; and   (e) changing the defined position of the at least one reference point on the civil engineering machine as a function of a relative position of that at least one reference point relative to the desired path of travel.   
     
     
         29 . The method of  claim 28 , wherein:
 step (e) further comprises, before the relative position of the at least one reference point relative to the desired path of travel reaches a transition from the substantially straight portion to the curved portion, shifting the defined position of the at least one reference point rearward relative to the civil engineering machine.   
     
     
         30 . The method of  claim 28 , wherein:
 in step (a), the at least one reference point includes a front reference point and a rear reference point; and   step (e) further comprises, before or when the front reference point reaches a transition from the substantially straight section of the desired path of travel to the curved section of the desired path of travel, shifting the defined position of the front reference point rearward toward the rear reference point.   
     
     
         31 . The method of  claim 30 , wherein:
 step (e) further comprises, continuing to shift the defined position of the front reference point rearward so that the front reference point is substantially coincident with the rear reference point by the time the rear reference point reaches the transition.   
     
     
         32 . The method of  claim 31 , wherein:
 step (e) further comprises, shifting the front reference point forward as the rear reference point traverses the curved section of the desired path of travel.   
     
     
         33 . The method of  claim 30 , wherein:
 step (e) further comprises, continuing to shift the defined position of the front reference point rearward so that the front reference point is at a preset spacing from the rear reference point by the time the rear reference point reaches the transition.   
     
     
         34 . The method of  claim 33 , wherein:
 step (e) further comprises, before or when the rear reference point reaches a second transition from the curved section to another substantially straight section of the desired path of travel, shifting the defined position of the front reference point forward relative to the civil engineering machine to an original spacing between the front and rear reference points.   
     
     
         35 . The method of  claim 28 , wherein:
 step (a) further comprises defining defined positions of a front reference point and a rear reference point;   step (d) further comprises controlling positions of front and rear wheels or running gear units of the drive unit; and   step (d) further comprises:
 (d)(1) in a first mode of control, varying position of the front and rear wheels or running-gear units as a function of a deviation of the front reference point from the desired path of travel and a deviation of the rear reference point from the desired path of travel; and 
 (d)(2) in a second mode of control, varying the position of the front wheels or running-gear units as a function of the deviation of the rear reference point from the desired path of travel.