Abstract: A method and apparatus for calibrating sensors of a tool positioning mechanism on a mobile machine are provided. The mobile machine includes a tool, a tool positioning mechanism having a plurality of sensors for providing signals indicative of the physical configuration of the mechanism, a satellite positioning system, and a plurality of positioning system antennas. One of the antennas is detachably mounted on the tool while an other antenna is mounted to a location on the machine other than on the tool. With the positioning mechanism configured so that the tool is at its maximum height, the satellite positioning system is operated to acquire real-time kinematic (RTK) data from the antennas and to process the RTK data to precisely determine the position of the tool. The sensors are then calibrated based on the precisely determined position of the tool.

Abstract: A method and apparatus for accurately positioning a tool on a mobile machine are provided. The machine operates within a work area about which one or more stationary laser-based subsystems are positioned. The machine includes an on-board subsystem, which comprises a processor, a satellite positioning system (SPS) receiver, a stored digital terrain model (DTM), and a photosensor for detecting a laser beam. The laser beam provides a reference level that is used to adjust the position of the tool. The on-board subsystem determines the current position of the machine using the SPS receiver and accesses the DTM to determine a design elevation corresponding to the current location of the machine. Based on the design elevation, the on-board subsystem computes a height command and transmits the height command to at least one of the laser-based subsystems.

Abstract: A method and apparatus for accurately positioning a tool on a mobile machine are provided. The machine is equipped with a satellite positioning system (SPS) receiver, a robotic total station with an integrated scanning laser and a storage facility storing a digital terrain model (DTM) of a work area. The machine operates within the work area and a number of stationary reflectors are positioned at various locations about the work area. The SPS receiver determines the current location of the machine. A system controller then references the DTM to determine the closest stationary reflector to the current location of the machine. Location data of the closest reflector is then provided to the robotic total station, which locates the closest reflector. The scanning laser then locks on to the reflector and the system controller determines the angle between the laser and the reflector.