System and method for determining a material entity to be removed from a pile and a control unit for a working machine comprising such a system

Abstract

A system for determining a material entity to be removed from a pile by an implement of a material moving machine is provided. The system includes an arrangement for generating a current pile shape of the actual surface shape of the pile. Moreover, the system is adapted to determine a nominal pile shape of at least a portion of the pile. The nominal pile shape is determined on the basis of at least the current pile shape and information regarding the material type of the pile. Further the system is adapted to determine a surplus volume between the nominal pile shape and the current pile shape and the system is adapted to determine the material entity to be removed from the pile on the basis of the surplus volume.

1 . A system for determining a material entity to be removed from a pile by means of an implement of a material moving machine, the system comprising means for generating a pile shape model representing the actual shape of the pile, moreover, the system being adapted to determine a nominal pile shape of at least a portion of the pile, the nominal pile shape being determined on the basis of at least the pile shape model and information regarding the material type of the pile, the system being adapted to determine a surplus volume between the nominal pile shape and the pile shape model, the system being adapted to determine the material entity to be removed from the pile on the basis of the surplus volume. 
     
     
         2 . The system according to  claim 1 , wherein the information regarding the material type of the pile comprises a nominal angle of repose for the material type. 
     
     
         3 . The system according to  claim 1 , wherein the system is adapted to determine an excluding portion of the pile which should be excluded from a portion of the nominal pile shape which portion is determined by the information regarding the material type of the pile. 
     
     
         4 . The system according to  claim 3 , wherein the system is adapted to determine a horizontal main extension direction of the excluding portion, the system being adapted to determine the material entity to be removed from the pile on the basis also of the horizontal main extension direction. 
     
     
         5 . The system according to  claim 4 , wherein the system is adapted to determine a main material removal direction that is substantially parallel to the horizontal main extension direction. 
     
     
         6 . The system according to  claim 3 , wherein the excluding portion comprises a portion approximated by a line or a polygon, preferably a rectangle. 
     
     
         7 . The system according to  claim 3 , wherein the pile has an extension in a vertical direction and the excluding portion of the pile is determined to be located above the nominal pile shape in the vertical extension. 
     
     
         8 . The system according to  claim 3 , wherein the pile has a bottom portion, the system being adapted to determine if the excluding portion extends to the bottom portion. 
     
     
         9 . The system according to  claim 8 , wherein, when the system determines that the excluding portion extends to the bottom portion, the system determines that the material entity to be removed from the pile comprises the excluding portion. 
     
     
         10 . The system according to  claim 1 , wherein the system comprises a perception assembly for generating the pile shape model, the perception assembly preferably comprising at least one of a camera and a laser sensor. 
     
     
         11 . The system according to  claim 10 , wherein the perception assembly is adapted to generate a three-dimensional pile shape model representing the actual shape of the pile, the perception assembly preferably comprising at least one of a time-of-flight camera, a stereo camera, a structured light camera or an actuated laser range finder. 
     
     
         12 . The system according to  claim 1 , wherein the system is adapted to determine the pile shape model and/or the nominal pile shape when material has been removed from the pile. 
     
     
         13 . The system according to  claim 1 , wherein the material entity is a material volume. 
     
     
         14 . The system according to  claim 1 , wherein the implement has a maximum material loading capacity and the system is adapted to determine the material entity to be removed from the pile on the basis also of the maximum material loading capacity. 
     
     
         15 . A material moving machine, comprising an implement, the material moving machine further comprising a system according to  claim 1 . 
     
     
         16 . A method for determining a material entity to be removed from a pile by means of an implement of a material moving machine, the method comprising:
 generating a pile shape model representing the actual shape of the pile,   determining a nominal pile shape of at least a portion of the pile, the nominal pile shape being determined on the basis of at least the pile shape model and information regarding the material type of the pile,   determining a surplus volume between the nominal pile shape and the pile shape model, and   determining the material entity to be removed from the pile on the basis of the surplus volume.   
     
     
         17 . The method according to  claim 16 , wherein the information regarding the material type of the pile comprises a nominal angle of repose for the material type. 
     
     
         18 . The method according to  claim 16 , wherein the method further comprises determining an excluding portion of the pile which should be excluded from a portion of the nominal pile shape which portion is determined by the information regarding the material type of the pile. 
     
     
         19 . The method according to  claim 18 , further comprising determining a horizontal main extension direction of the excluding portion, the method further comprises determining the material entity to be removed from the pile on the basis also of the horizontal main extension direction. 
     
     
         20 . The method according to  claim 19 , further comprising determining a main material removal direction that is substantially parallel to the horizontal main extension direction. 
     
     
         21 . The method according to  claim 18 , wherein the excluding portion is defined by a portion approximated by a line or a polygon. 
     
     
         22 . The method according to  claim 18 , wherein the pile has an extension in a vertical direction and the excluding portion of the pile is located above the nominal pile shape in the vertical extension. 
     
     
         23 . The method according to  claim 18 , wherein the pile has a bottom portion, the method comprises determining if the excluding portion extends to the bottom portion. 
     
     
         24 . The method according to  claim 23 , wherein, upon determination that the excluding portion extends to the bottom portion, the method determines that the material entity to be removed from the pile comprises the excluding portion. 
     
     
         25 . The method according to  claim 18 , wherein the pile has an extension in a vertical direction and the excluding portion of the pile is located above the nominal pile shape. 
     
     
         26 . The method according to  claim 18 , wherein the material entity is a material volume. 
     
     
         27 . The method according to  claim 18 , wherein the implement has a maximum material loading capacity, the method comprises determining the material entity to be removed from the pile on the basis also of the maximum material loading capacity. 
     
     
         28 . A method for removing material from a pile by means of an implement of a material moving machine, the method comprising:
 determining a material entity to be removed from the pile using a method according to  claim 16  and   operating the implement so as to remove the thus determined material entity from the pile.   
     
     
         29 . The method according to  claim 28 , wherein the method further comprises:
 determining the pile shape model and/or the nominal pile shape when material has been removed from the pile.