Abstract: A system and method of facilitating excavating a below grade opening at a construction site in a parcel of land includes a first vehicle having a motor operably connected to at least a pair of traction members and a second excavating vehicle. The motor is operably connected to a first receiver for receiving a signal from a remotely controlled transmitter to actuate the motor. Upon actuation of the motor, the motor rotates the traction members for maneuvering the first vehicle within the opening. The first vehicle has a graduated measurement device mounted generally vertically thereon for remotely controlled vertical telescopic movement. A second beam receiver is mounted to the graduated measurement device for receiving a laser beam from a laser transmitter to facilitate precise determination of the depth of the floor of the opening.

Abstract: An implement has a tongue used to tow the implement that can be raised or lowered with respect to the rest of the implement. The tongue is raised or lowered by a hydraulic cylinder. The raising and lowering ports of the cylinder are connected to two hydraulic accumulators to permit the tongue to flex up or down while the implement is towed through the field. These accumulators are disconnected from the cylinder when the wings of the implement are lifted and the implement is towed over the road to prevent the implement from oscillating backwards and forward about an axis defined by its wheels.

Abstract: An apparatus and method using GPS for dynamically adjusting side-to-side positioning of a farm implement along a geographical path. The apparatus includes a global positioning system (GPS) antenna disposed on the farm implement, a GPS receiver coupled to the GPS antenna for determining a location of the GPS antenna, and a dual guidance computer for comparing the location to stored geographical coordinates of a desired path or providing a guide signal for offsetting the lateral position of an adjustable hitch or angling a wheel or ground rudder in a steerable implement for guiding the implement along the path; and a range extent signal for maintaining the offset of the hitch or steering angle of the implement within its dynamic range.

Abstract: A system and method for controlling a mechanical arm comprises planning a desired path of a mechanical arm. An actual path segment of the mechanical arm is measured. An error is determined between the measured actual path segment and the planned desired path. A corrective force is applied to the mechanical arm based on the determined error to conform to the desired path.

Abstract: A universal optical adapter assembly for use with a planar automatic grading system for an earth-moving vehicle having a grading implement that defines a graded surface. The automatic grading system includes an energy beam receiver mounted on the earth-moving vehicle and operable for detecting the height at which a datum energy beam strikes the receiver along a detection portion thereof. A control device is operably coupled to the energy beam receiver and the grading implement to control the elevation of the grading implement in response to the position at which the datum energy beam strikes the detection portion of energy beam receiver. The optical interface adapter assembly includes an optical interface apparatus having an energy source emitting one or more implement controlling energy beams strategically onto selected positions of the detection portion the energy beam receiver to control the elevation of the grading implement.

Abstract: An ice resurfacing machine laser control is used to optimize the ice layer on an artificial ice track, such as an ice hockey rink and is adapted for use in ice resurfacing machines. The thickness of an ice layer is optimized with a beam for a laser transmitter. The ice resurfacing machine comprises a laser receiver and mechanisms to regulate the elevation of the scraper blade.

Abstract: The present invention provides a solution that enables a single rotary laser apparatus to control more than one construction machines so that the construction machines can simultaneously level the terrain up or down to different elevations, respectively.

Abstract: A land-leveling system that uses the Global Positioning System is provided. The system provides for an earth-moving machine mounted with an antenna that receives GPS signals from the satellites of the Global Positioning System. The earth-moving machine comprises a vehicle attached to a work implement, which is also connected to an actuator. A decision unit mounted on the vehicle sends control signals to the actuator, which controls the elevation of the work implement. These control signals are generated using the signals received from the antenna and the desired grade map. This system has an increased coverage area, more accuracy and round-the-clock operability. The system could be used to carry out all the land-leveling operations viz. surveying, leveling and verifying.

Abstract: A soil cultivating apparatus including a tractor (2) towing a row cultivator (4) by means of a three-point linkage (6). The row cultivator (4) includes a fixed portion (8) and a moveable portion (10) having soil scarifying tools (18a-18n). The movable portion (10) is laterally moveable relative to the fixed portion (8) by means of linkages (12a-12d) and is effected by a hydraulic actuator (22) under control of tool-bar control system (20) which is able to determine the position of the moveable portion (10) relative to the fixed portion (8) by means of a sensor (24). Mounted upon the moveable portion (10) is a DGPS antenna (26) GPS receiver that forms part of the control system (20). The control system (20) has a microprocessor which operatively executes a stored program. The microprocessor receives data from an intra-rig sensor and from the GPS receiver specifying the absolute coordinate of the movable portion (10) relative to the earth.

Abstract: A construction apparatus (12) and method of controlling a construction apparatus from a laser source (38) made up of a substantially non-rotating beam (56). The construction apparatus includes a body (14), a construction tool (16) adapted to move material, a support moveably supporting the construction tool from the body and a control for guiding movement of the construction tool. A control is provided including a camera (28) that is adapted to capture an illuminated image that is derived from the laser source. The control determines direction information of the illuminated image with respect to the apparatus at least in part from an output of the camera. The control is further adapted to determine separation information of the spot with respect to the body and a physical relationship between the construction tool and the illuminated image.

Abstract: A course-grooming vehicle with a rear tool carrier, to which a course-grooming device can be detachably connected, where the height and/or the angle of the rear tool carrier and/or of the course-grooming device can be varied by means of at least one adjusting element, and with an electronic control unit, which actuates the minimum of one adjusting element, is known. At least one sensor for the direct or indirect detection of an actual state of the surface of the course to be groomed by the course-grooming device is provided, which sensor is connected to the control unit, the control unit comprising a memory for storing at least one characteristic diagram and an evaluation unit, which compares the actual values detected by the sensor with corresponding nominal values of the characteristic diagram and which, as a function of the result of the evaluation, actuates the minimum of one adjusting element accordingly.

Abstract: A system and method for updating parameter data available to a machine control system. A work machine having an implement attached thereto includes a machine control system for controlling the machine and the implement and for providing additional functionality, such as mapping and payload systems, to the machine. The machine control system is configurable for operation of a variety of work implements. Data associated with the attached work implement is retrieved from a remote system and utilized to adjust the machine control system to accommodate the attached implement.

Abstract: A control system for orienting a swing axis of a work machine is disclosed. The work machine includes a swing frame and a frame structure, and the control system includes an operator interface configured to receive operator inputs, wherein the operator inputs represent a desired orientation of the swing axis of the swing frame. The control system also includes a sensor assembly configured to determine an actual orientation of the swing axis of the swing frame and a controller configured to compare the desired orientation to the actual orientation of the swing axis to determine a swing angle. The controller is adapted to output the swing angle. The swing axis may be adjusted by adjusting the work machine frame or by adjusting a frame assembly independent of the work machine frame.

Abstract: A towable scraper system for contour surface grading. The system includes a rigid chassis member that has a coupler configured for attachment to a conventional three-point tractor hitch. A scraper blade is pivotally suspended from the rigid chassis member and is equipped with a blade motivator for causing an angular rotation of the blade around an axis aligned with a towing direction. A lift assembly raises and lowers the rigid chassis member to control a height of the scraper blade relative to a work surface to be graded. The towable scraper system is provided with a carriage assembly that offers rolling support for the rigid chassis as it moves over the work surface. The carriage assembly is pivotally coupled to the rigid chassis at a location opposed to the coupler and is configured for angular rotation around a second axis aligned with the towing direction.

Abstract: An agricultural combine includes a rotor drive system to which sensors are coupled to signal the rotational speed of a hydraulic motor and an engine. An electronic controller that contains a mathematical model of the system reads the sensors and using the model estimates additional parameters of the system. The estimated parameters include a gearbox's gear ratio and a planetary ring gear's speed. These estimated parameters and the sensor readings are used in a PID feedback control loop to control the speed of a planetary ring gear by controlling the speed of a hydraulic motor driving the sun gear. In this manner, the controller can drive the ring gear to a predetermined speed that reduces the difference in the input and output speeds of a hydraulic clutch and thereby engage that clutch while reducing shock to the clutch and other mechanical components of the combine.

Abstract: A method and apparatus for providing for real time automated control of the position of a blade on a earth-moving machine. The method includes providing a geography altering machine, including a blade and a computer, the computer having stored therein a reference line and a three dimensional computer model of a desired topography, providing a user defined offset relative to the reference line, determining a blade position in local coordinates, converting the local coordinates to reference line coordinates, utilizing the reference line coordinates and the user defined offset to calculate blade movement commands, and moving the blade in a direction required by the blade movement commands.

Abstract: A skid steer vehicle has sprung suspensions, variable displacement pumps and motors connected to those pumps that drive the wheels on the vehicle as well as an electronic controller that receives signals that indicate lateral acceleration of the skid steer vehicle during turns. The controller determines whether the lateral acceleration exceeds a predetermined value, and locks up the outboard suspensions if that value is exceeded. The signals can be provided by an accelerometer, a satellite receiver, wheel/motor speed sensors, sensors in the pumps that signal the specific displacement of the pumps (such as their swash plate position, or memory locations that contain previously calculated specific displacement commands that are used to drive the pumps to a particular displacement.

Abstract: A work machine is often used to spread material from an initial location across a wider area. It is desirable to raise and lower a work implement of the work machine such that the material can be quickly and easily spread to a uniform or otherwise desirable thickness. The present invention provides a method and apparatus of automatically controlling the position of the work implement. The automatic implement control system of the present invention lowers and raises the work implement based on at least one of a directional characteristic of the work machine and a position of an operator input device. The work implement is then automatically lowered or raised to the desired position to facilitate an efficient work cycle for spreading material.

Abstract: A method and apparatus for updating a machine database. The database includes data representing the desired and actual terrain of a work site. Additional data represents portions of the work site which have been further worked. An indicator detects the machine's current work function and updates the data in the database based on the current work function.

Abstract: Methods for operating a laser scanning system. The laser scanning system can be used in construction projects to generate a field survey. An architect or engineer can use the field survey to create construction drawings. In addition, relevant points from the construction drawings can be identified at the construction site with the scanning system. Further, earth moving equipment can be controlled using the same information. The laser scanning system can also be used to determine if two parts can be mated together by scanning and comparing the parts that are to be mated. The laser scanning system can further be used to determine if an object can be moved through an opening in a structure by comparing scan points of the structure with scan points from the object. The laser scanning system can additionally be used to identifying objects within the site, to build databases that have relevant information about the objects, and to guide reproducing machines.

Abstract: The invention relates to a three-dimensional measuring device, comprising a rotating 360 degree sensor head, a laser scanner and an extendable mast system. The sensor head contains a 360 degree rotating multi-faceted mirror, which determines total path distance from the laser scanner to a particular target. Angular orientations on both the scanner and the faceted mirrors are calculated by a precision encoding system. The measured total path distance, mast system extension, scanner head rotation, mirror rotation angles, and mast deflection are all used to calculate the location of a target point in 3-D space relative to the scanner. The sensing device can be utilized in the construction and nuclear power areas. In the nuclear power area, the mast system can be extended into a contaminated area which the sensor remains outside the contaminated area, thereby avoiding contamination problems.

Abstract: A system for measuring the amount of crop material located on a field to be harvested uses a scanning laser device. The scanning laser device has a transmitter for emitting electromagnetic radiation, a receiver for receiving reflected radiation from the crop material and providing resolution in terms of location and/or angle from which the reflected radiation was received. The receiver also generates an intensity signal indicating the intensity of the reflected electromagnetic radiation. A controller is in communication with the scanning laser device and determines the amount of the crop material located on the field on the basis of the crop material location signals and the intensity signals received from the receiver.

Abstract: A system and method for monitoring moving equipment operations for determining operator efficiencies for moving operations. The system and method for monitoring moving equipment operations includes a position locating assembly coupled to an moving equipment for determining a current position of the moving equipment on an interval basis, a data storage means operationally coupled to the position locating assembly for recording the current position for each interval, and a data processing means for processing and presenting the position information for a user.

Abstract: An intuitive control for a motor grader controls the blade high lift assembly by adjustment of a miniature representation available at the operator's station. This miniature representation allows the direction of adjustment of various hydraulic components to be made by moving the representation in the desired directions. The control is intuitive in that it corresponds to the actual high lift assembly. A similar miniature representation can be used for controlling the steering of the motor grader.

Abstract: A universal optical adapter assembly for use with a planar automatic grading system for an earth-moving vehicle having a grading implement that defines a graded surface. The automatic grading system includes an energy beam receiver mounted on the earth-moving vehicle and operable for detecting the height at which a datum energy beam strikes the receiver along a detection portion thereof. A control device is operably coupled to the energy beam receiver and the grading implement to control the elevation of the grading implement in response to the position at which the datum energy beam strikes the detection portion of energy beam receiver. The optical interface adapter assembly includes an optical interface apparatus having an energy source emitting one or more implement controlling energy beams strategically onto selected positions of the detection portion the energy beam receiver to control the elevation of the grading implement.

Abstract: A method and apparatus for providing for real time automated control of the position of a blade on a earth-moving machine. The method includes providing a geography altering machine, including a blade and a computer, the computer having stored therein a reference line and a three dimensional computer model of a desired topography, providing a user defined offset relative to the reference line, determining a blade position in local coordinates, converting the local coordinates to reference line coordinates, utilizing the reference line coordinates and the user defined offset to calculate blade movement commands, and moving the blade in a direction required by the blade movement commands.

Abstract: An apparatus and method for controlling a hydraulically movable tool carried by a machine in order to maintain a selected horizontal orientation and a selected elevation relative to an external light reference. The apparatus is a control device, having a light detector, placed at a known location along a longitudinal axis of the tool and a single-axis gravity-based sensor. The gravity-based sensor is also provided within the housing of the control device to measure the horizontal orientation (side-to-side slope or pitch) of the longitudinal axis of the tool relative to true horizontal at the known location. Finally, with internal valve drivers, the control device individually controls the lift mechanism(s) of the hydraulically movable tool to maintain both a selected elevation and a selected horizontal orientation with only the signals provided by the light detector and the gravity-based sensor.

Abstract: The present invention relates to a construction equipment control system, which comprises a plurality of rotary laser irradiating systems for forming laser reference planes by irradiating laser beams by rotary irradiation, a surveying system for measuring positions of the rotary laser irradiating systems, and a construction operation system for controlling and operating construction work of a construction equipment based on the laser reference planes, wherein the construction operation system comprises a photodetection sensor for receiving light beams from the rotary laser irradiating systems as reference positions for the construction operation, a global positioning system (GPS) for detecting a position of the construction equipment, and transmitting structure for transmitting detection results of said GPS to the surveying system, the surveying system comprises transmitting structure for transmitting data relating to the reference planes to be formed based on the results of measurement and results of detecti

Abstract: The present invention provides a rotary laser irradiating apparatus, which comprises a laser source, a rotator for forming a laser reference plane by rotary irradiation of laser beam from said laser source, scanning gear for deflecting the laser beam from said laser source, and a controller for controlling said scanning gear, whereby a plurality of laser reference planes are formed within a predetermined range as desired during one turn of rotary irradiation of the laser beam, and different levels can be set at a plurality of points.

Abstract: The present invention provides a rotary laser irradiating apparatus, which comprises a laser source, a rotator for forming a laser reference plane by rotary irradiation of a laser beam from the laser source, scanning gear for deflecting the laser beam from the laser source, and a controller for controlling the scanning gear, whereby a plurality of laser reference planes are formed within a predetermined range as desired during one turn of rotary irradiation of the laser beam, and different levels can be set at a plurality of points.

Abstract: The present invention provides a rotary laser irradiating apparatus, which comprises a laser source, a rotator for forming a laser reference plane by rotary irradiation of laser beam from said laser source, scanning means for deflecting the laser beam from said laser source, and control means for controlling said scanning means, whereby a plurality of laser reference planes are formed within a predetermined range as desired during one turn of rotary irradiation of the laser beam, and different levels can be set at a plurality of points.

Abstract: A method of synchronized survey with computer aid with which a working drawing of engineering is transformed into a drawing file in the computer. The drawing file on the screen accompanying with the window page can appear locations and coordinates of a reference point, a rear view point or all control points specifically. The computer and the theodolite connect with a modem respectively to transmit data related to survey to each other by way of communication network. Place the theodolite at the reference point in the job site and the locating prism at the rear view point or each control point. The screen of display in the computer may appear the location of locating prism in the working drawing on the instant such that the operator of locating prism may be informed to move toward a correct operating point.

Abstract: A control system controls a work vehicle towing a towed implement. The control system includes a steering angle sensor, an implement position generating unit generating an actual implement position signal, a desired implement position generating unit generating a desired implement position signal, a vehicle position generating unit generating an actual vehicle position signal, a processor unit generating an implement angle signal as a function of the actual implement position signal and the actual vehicle position signal, and a control processor generating the steering control signal as a function of the actual implement position signal, the actual vehicle position signal, the implement angle signal, the steering angle signal and the desired implement position signal. A vehicle steering actuator steering vehicle steerable wheels in response to the control signal.

Abstract: An intuitive control for a motor grader controls the blade high lift assembly by adjustment of a miniature representation available at the operator's station. This miniature representation allows the direction of adjustment of various hydraulic components to be made by moving the representation in the desired directions. The control is intuitive in that it corresponds to the actual high lift assembly. A similar miniature representation can be used for controlling the steering of the motor grader.

Abstract: A device on a mobile agricultural machine for contactless scanning of contours extending over the ground, such as the contour of a swath of crop material. In this case there is used a laser distance measuring device consisting of a laser beam transmitting and receiving device which determines the distance from a contour point by measuring the running time of a laser scanning beam emitted and reflected at the contour point. The laser scanning beams are pivoted within a certain angular range stepwise or continuously in a scanning beam plane. In this case the laser distance measuring device is mounted with an orientation on the agricultural machinery such that the scanning beam plane is inclined to the ground at an acute angle forwards in the direction of travel. With the aid of an analyzer, the position of the contour point corresponding to each pivot angle, based upon the measured distance and the arrangement and orientation of the laser distance measuring device on the agricultural machine, can be determined.

Abstract: The present invention provides a method and apparatus for determining the cross slope created by a work implement on a work machine operating in an articulated or non-articulated manner. The method includes the steps of determining a position of the work implement, determining a direction of travel of the machine, and responsively determining the cross slope.

Abstract: A control system for establishing grade and elevation control for a tool of a construction apparatus for maintaining the vertical position of the tool relative to a reference includes a first ultrasonic transducer configured to be carried by the construction apparatus, with the first transducer transmitting and receiving acoustic waves, at least one reflector, a second ultrasonic transducer configured to be carried by the construction apparatus, with the second transducer receiving acoustic waves, and a controller coupled to the first and second ultrasonic transducers which drive the transducers to produce an acoustic wave and monitors the time reflections of the acoustic wave are respectively received by the first and second transducers.

Abstract: A method for adjusting a process for automated bucket loading of a work machine having an engine and a work implement. The work implement includes a bucket. The method includes the steps of determining when the bucket engages a pile of material, initiating the automated bucket loading process in response to the bucket engaging the pile of material, determining an actual engine speed relative to a full engine speed, and adjusting a lift velocity command to the work implement, the lift velocity command adjustment being made as a function of a comparison of the actual engine speed to full engine speed.

Abstract: A method and a device are provided for detecting a tendency of a vehicle to tip about a vehicle axis oriented in the longitudinal direction of the vehicle. To this end, a variable is ascertained describing the dynamics of the vehicle linear motion. The detection strategy used for detecting the tendency of the vehicle to tip is selected from at least two detection strategies at least as a function of the variable describing the dynamics of the vehicle linear motion and/or the detection strategy used for detecting a tendency of the vehicle to tip is adapted, at least as a function of the variable describing the dynamics of the vehicle linear motion, to the dynamics of the vehicle linear motion existing at any one time.

Abstract: Apparatuses and methods for controlling the slip of a work machine having a ground-engaging traction device and a hitch operable to receive a ground-engaging implement. A control system receives an actual velocity signal indicative of an actual velocity of the work machine, an apparent velocity signal indicative of an apparent velocity of the work machine, and a desired slip signal indicative of a desired slip of the work machine. The control system determines an actual derivative of slip of the work machine as a function of the actual velocity signal and the apparent velocity signal, and transmits a control signal as a function of the desired slip signal, the actual velocity signal, the apparent velocity signal, and the actual derivative of the slip. The control signal controls the vertical position of one of the hitch and the ground-engaging implement.

Abstract: A method and apparatus for controlling movement of a work implement movably connected to a work machine. Movement of the work implement is controlled by manual and automatic control valves that are associated with “manual” and “automatic” modes of operation. The manual and automatic control valves are connected between hydraulic motors for controlling movement of the work implement and a hydraulic fluid supply. Each of the manual and automatic control valves governs hydraulic fluid flow to the hydraulic motors. A pressure sensing device is associated with the manual control valves to detect operator modulation of the manual control valves and thereby alter operation of the automatic control valves in the “automatic” mode on the same side of the implement.

Abstract: The present invention relates to a construction equipment control system, which comprises a plurality of rotary laser irradiating systems for forming laser reference planes by irradiating laser beams by rotary irradiation, a surveying system for measuring positions of the rotary laser irradiating systems, and a construction operation system for controlling and operating construction work of a construction equipment based on said laser reference planes, wherein said construction operation system comprises a photodetection sensor for receiving light beams from said rotary laser irradiating systems as reference positions for the construction operation, a global positioning system (GPS) for detecting a position of said construction equipment, and transmitting means for transmitting detection results of said GPS to the surveying system, said surveying system comprises transmitting means for transmitting data relating to the reference planes to be formed based on the results of measurement and results of detection

Abstract: A method and apparatus for controlling a work implement movably connected to a work machine. An implement controller automatically controls simultaneous first and second control modes of operation assigned to the work implement. A sensor applies a signal to the implement controller indicating position of the work implement. The implement controller reverses the simultaneous first and second control modes assigned to the work implement upon detecting a predetermined movement of the work movement. The simultaneous first and second control mode assignments may also be changed by actuation of a manually actuatable device.

Abstract: The present invention provides a construction machine control system, which comprises a rotary laser irradiating system for irradiating a plurality of laser beams by separating in a vertical direction and for forming a plurality of laser beam reference planes by the plurality of laser beams, a construction machine having a ground leveling tool, a level sensor arranged on the ground leveling tool and for receiving and detecting the laser beams, a driving unit for driving the ground leveling tool to adjust height thereof, a control device for controlling the driving unit, and a GPS receiving system for detecting a position of the construction machine, wherein the control device detects the position of the construction machine by the GPS receiving system, the level sensor selects at least one of the plurality of laser beams and controls the driving unit based on a laser beam photodetecting position of the level sensor.

Abstract: A lift vehicle and a method for initializing a controller for controlling a lifting mechanism of lift vehicle. The controller controls the maximum forward tilt angle of a mast by controlling a solenoid of a hydraulic circuit. The controller employs a stored map or equation that defines a relationship between the forward tilt limit and another parameter. When the mast is tilted at two degrees, a CPU reads the detection value of a tilt angle sensor and sets it as a reference value. The reference value is used to calibrate the controller. The same function information can be used for many types of lift vehicles by selecting the appropriate control ranges for each vehicle.

Abstract: A position-finding device for locating the position of a working edge, especially the edge of a crop, wherein the position-finding signal therefrom is supplied in the form of a steering adjustment value to an electrically controlled steering device in an agricultural machine, and wherein the device comprises a first sub position-finding device including a transmitter and a receiver whose zone of reflection extends mainly over the field that has not yet been worked, especially the not yet harvested field, and a second sub position-finding device including a further transmitter and a further receiver whose differing reflection zone is aligned such as to overlap both sides of the working edge, wherein the two reflection zones partially overlap and the two transmitters are simultaneously triggered by a pulse whereby the two receivers accordingly receive overlapping partial reception signals originating from the two transmitters and reflected by the unworked field.

Abstract: The system includes a path planning system adapted to store a site model of the field. The site model includes data defining a plurality of parameters associated with the field. The path planning system is further adapted to receive information indicative of a work implement connected to the agricultural machine, and a desired work operation of the agricultural machine. A plurality of desired paths for the agricultural machine to traverse are planned as a function of the plurality of field parameters, the work implement, and the desired work operation. An autoguidance control system is adapted to receive the plurality of desired paths, and responsively produce a control signal upon activation of the autoguidance control system. A machine control system receives the control signal, and responsively controls the operation of the agricultural machine with respect to the plurality of desired paths.

Abstract: A system is described for setting a self-propelled harvesting machine having several machine components with respectively adjustable parameters wherein setting of these parameters takes into account external harvesting conditions. Means are provided for manually inputting and/or automatically detecting the external harvesting conditions for the particular harvesting application. Furthermore at least one storage means is provided for storing the machine parameters for the respective harvesting application and for different external harvesting conditions. Also, if the occasion arises, the storage means may take into account at least one target standard. The stored machine parameters for setting the harvesting machine can be called up from the storage means after the system knows the respective external harvesting conditions and, if necessary, the respective target standard.

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 dozing system for a bulldozer capable of providing high operational efficiency in dozing operation and a smooth excavation face. If it is determined when operation is performed in an automatic digging mode that the load exerted on the blade is stable, a target position for the cutting edge relative to the ground is corrected to the actual position of the cutting edge at that time. According to the ratio of the amount of excavated soil loaded on the front surface of the blade to the loading capacity of the blade front surface and/or the stability of the load exerted on the blade, a switching is performed between a weight characteristic for the operation amount of the load control and a weight characteristic for the operation amount of the smoothing control.