A robotic carton unloader for unloading a carton pile resting on a floor, comprising: a mobile body movable across the floor; a conveyor system mounted on the mobile body to convey unloaded cartons thereon; and a robotic arm assembly comprising: right and left lower arms pivotally attached at a lower end respectively to the mobile body on opposing lateral sides of the conveyor system passing there between to rotate about a lower arm axis that is perpendicular to a longitudinal axis of the conveyor system; an upper arm assembly having a rear end pivotally attached at an upper end respectively of the right and left lower arms to pivotally rotate about an upper arm axis that is perpendicular to the longitudinal axis of the conveyor system and parallel to the lower arm axis; and a manipulator head attached to a front end of the upper arm assembly, the manipulator head engages at least one carton at a time from a carton pile resting on a floor for movement to the conveyor system, wherein a pivotal movement of the right and left lower arms maintains the upper arm axis at a height that enables the at least one carton to be conveyed by the conveyor system without being impeded by the robotic arm assembly; and the manipulator head comprises at least one vacuum manipulator, characterised in that the robotic carton unloader further comprises a pneumatic system to selectively perform a sequence of operations of (i) engaging the at least one carton with suction; (ii) disengaging the at least one carton by removing the suction; and (iii) clearing debris from the at least one vacuum manipulator by directing compressed air through the at least one vacuum manipulator. a mobile body movable across the floor; a conveyor system mounted on the mobile body to convey unloaded cartons thereon; and a robotic arm assembly comprising: right and left lower arms pivotally attached at a lower end respectively to the mobile body on opposing lateral sides of the conveyor system passing there between to rotate about a lower arm axis that is perpendicular to a longitudinal axis of the conveyor system; an upper arm assembly having a rear end pivotally attached at an upper end respectively of the right and left lower arms to pivotally rotate about an upper arm axis that is perpendicular to the longitudinal axis of the conveyor system and parallel to the lower arm axis; and a manipulator head attached to a front end of the upper arm assembly, the manipulator head engages at least one carton at a time from a carton pile resting on a floor for movement to the conveyor system, wherein a pivotal movement of the right and left lower arms maintains the upper arm axis at a height that enables the at least one carton to be conveyed by the conveyor system without being impeded by the robotic arm assembly; and the manipulator head comprises at least one vacuum manipulator, characterised in that the robotic carton unloader further comprises a pneumatic system to selectively perform a sequence of operations of (i) engaging the at least one carton with suction; (ii) disengaging the at least one carton by removing the suction; and (iii) clearing debris from the at least one vacuum manipulator by directing compressed air through the at least one vacuum manipulator. right and left lower arms pivotally attached at a lower end respectively to the mobile body on opposing lateral sides of the conveyor system passing there between to rotate about a lower arm axis that is perpendicular to a longitudinal axis of the conveyor system; an upper arm assembly having a rear end pivotally attached at an upper end respectively of the right and left lower arms to pivotally rotate about an upper arm axis that is perpendicular to the longitudinal axis of the conveyor system and parallel to the lower arm axis; and a manipulator head attached to a front end of the upper arm assembly, the manipulator head engages at least one carton at a time from a carton pile resting on a floor for movement to the conveyor system, wherein a pivotal movement of the right and left lower arms maintains the upper arm axis at a height that enables the at least one carton to be conveyed by the conveyor system without being impeded by the robotic arm assembly; and the manipulator head comprises at least one vacuum manipulator, characterised in that the robotic carton unloader further comprises a pneumatic system to selectively perform a sequence of operations of (i) engaging the at least one carton with suction; (ii) disengaging the at least one carton by removing the suction; and (iii) clearing debris from the at least one vacuum manipulator by directing compressed air through the at least one vacuum manipulator.