Abstract: A method and apparatus for determining a location of an underground object during a digging operation. The method and apparatus includes delivering a signal toward the underground object, receiving a reflected signal from the underground object, determining an initial location of the underground object, creating a region of uncertainty around the underground object as a function of a level of confidence of the determined initial location, performing at least one process to improve the level of confidence, and adjusting the region of uncertainty as a function of the improved level of confidence.

Abstract: A backhoe loader is provided with a reversible operator's seat having a first working position facing the loader and a second working position facing the backhoe. A first hydraulic pump directs pressurized hydraulic fluid through a first supply line to loader control valves, stabilizer control valves and backhoe control valves that are mounted in series. A second hydraulic pumps directs pressurized hydraulic fluid through a second supply line to the first supply line upstream from the loader control valves. The second supply line is provided with a two-position solenoid valve. In its first position, the valve directs pressurized hydraulic fluid from the second hydraulic pump to sump. In its second position, the valve directs pressurized hydraulic fluid from the second hydraulic pump to the first supply line. The solenoid of the two-position solenoid valve is in electrical communication with a seat switch signaling the working position of the operator's seat.

Abstract: A hybrid construction equipment capable of sufficiently exhibiting performance of a battery with strategic arrangement of the apparatuses being carried out is provided. For this purpose, the hybrid construction equipment includes, on an upper revolving superstructure (10) rotatably placed on a lower traveling unit, an engine (1), a generator (3) driven by the engine (1), a battery (5) charged with electric power generated by the generator (3), an electric motor (7) driven by electric power of the battery (5), an inverter (6) for controlling drive of the electric motor (7) and a driver's cab (12), and the battery (5) is placed to be isolated from the engine (1) and the generator (3).

Abstract: A method for determining a position and a heading of a work machine having a work implement controllably attached. The method includes the steps of positioning the work machine at a desired work location, determining an initial position and heading of the work machine in site coordinates, determining a position of the work implement relative to the work machine, positioning the work implement at a desired reference point, determining the position of the work implement at the reference point in site coordinates, periodically positioning the work implement at the reference point during work operations, and determining a new position and heading of the work machine as a function of the position of the work implement relative to the work machine.

Abstract: A drive for a hydraulic excavator having an electric motor as a main drive. In order to provide a compact, low-maintenance and reliable drive system, at least one diesel engine is arranged on the excavator vehicle itself and can be switched on as required and supplies the chassis with power independently of the main drive.

Abstract: An excavating device configured to form a channel of predetermined cross section in the ground in an excavation direction. The excavating device includes an assembly of jet excavating units which together define the cross section of the channel and are each provided with at least one jet device. The excavating device also includes at least one sensor which is connected to at least one of the jet excavating units for measuring a force which is exerted on the jet excavating units by the ground substantially parallel to the excavation direction. A controller is provided for controlling the excavation by the excavating device on the basis of the force measured by the at least one sensor. The controller is adapted to set a flow rate of jet liquid which is used in at least one jet device.

Abstract: In a construction machine provided with a control unit for outputting actuating commands to actuators based on operating signals from operating levers, interlocking relationships between the operating levers and the actuators can be set as desired respectively, while avoiding enlargement of the memory. Interlocking relationships desired by an operator are adapted to be input into a control unit from a service tool, and the control unit is provided with a memory for rewritably storing the interlocking relationships thus input.

Abstract: In accordance with the present invention, a system to organize and coordinate components associated with earthmoving machinery capable of performing excavating and loading tasks autonomously is disclosed. The system comprises an earthmoving machine equipped with a scanning sensor system operable to provide data regarding regions within an earthmoving environment including an excavation region and a loading region and a planning and control module operable to receive data from the scanning sensor system to plan a task associated with the control of the earthmoving machine while concurrently performing another task associated with control of the earthmoving machine. Any number and type of sensor systems, such as a laser rangefinder or a radar rangefinder, may be incorporated in the system depending on requirements and the capabilities of the system.

Abstract: An autonomous dispatch system links positioning-system units mounted on mining and haulage equipment to a computerized mine development plan for ascertaining the origin of mined material and directing its disposition according to a predetermined downstream-processing plan. A destination signal is automatically communicated to the haulage vehicle, which is then autonomously guided to the correct destination and tracked until the load is released after arrival. If the haulage vehicle is manually operated, the destination signal and the vehicle's progress toward it are preferably also displayed on a monitor for the operator's information and use. The system may further include hardware for blocking the release of a load from the haulage vehicle until and unless the vehicle has reached the prescribed destination.

Abstract: The invention describes a device and a method for finding an actual or a virtual reference point on mobile equipment or implement. In agricultural technology the control and mapping of working processes as a function of the instantaneous position of the equipment on the field is gaining more and more importance. With increasing precision of the navigation systems, further possible applications are opening up. As a result of the higher precision of satellite navigation systems, the changes in inclination and direction of the equipment also have an effect on the measured position of the equipment. This effect is of the order of magnitude of the precision of modern-day navigation equipment and is therefore also taken into consideration in position finding according to the invention. For this the inclinations and direction of the machine referred to a predefined neutral position are determined and also calculated when finding any reference position.

Abstract: An automatic monitoring and display system for use with a digging machine in order to excavate holes having a predetermined depth and an excavation slope pitch from ground level to hole depth. The machine has a boom, a dipper stick connected to the boom and a bucket at the end of the dipper stick, all interconnected by three pivots. Only two sensors are used to detect the position of the bucket relative to a zero reference signal which is stored in a processor. The operator of the machine has a console whereby to select an excavation depth as well as a slope pitch angle and the console will display to him the hole depth and the percentage pitch on the slope as the excavation proceeds. The operator can reset his zero reference signal at any time from anywhere.

Abstract: An apparatus and method for a pitch state estimator is provided. The pitch state estimator generates a pitch state signal for establishing the orientation used in the control of a ground-traversing vehicle. The vehicle has a support for supporting a load which is preferably a human passenger. In one embodiment, the pitch state estimator includes a pitch sensor connected to the vehicle producing a pitch signal representing an estimate of a pitch angle of the vehicle. The pitch angle is associated with a coordinate system referenced to gravity. The pitch state estimator also includes at least one inertial reference sensor connected to the vehicle producing an inertial orientation signal with respect to the vehicle. Further included is a state estimator module for receiving the pitch signal and the inertial orientation signal and calculating a pitch state signal from the inertial orientation signal and the pitch signal sensor.

Abstract: A downhole buried utility sensing and data transmission system for connection at the lower end of a drill string has sensors capable of detecting the existence of various different types of buried utilities and objects and making calculations as to the radial separation distance between the detected utilities and the drill head and transmitting data between the down hole drill head to the surface. The sensors respond to material properties used to construct the utility lines or the energy fields created by the operation of these lines (pipes and cables) or from the energy associated with transmission of the particular utility service, including sound energy resulting from fluid flow and electromagnetic energy from electric currents.

Abstract: In a construction machine including a control unit for receiving operating signals from operating members and outputting operation commands to actuators, by using a monitor and control levers, correlations between the control levers or switches and the actuators, i.e., an input/output relationship between any of the control levers and corresponding one of electro-hydraulic conversion valves, can be freely set. The set input/output relationships are registered in a memory in a rewritable manner.

Abstract: A method and apparatus for displaying a location of an object at an earthworking site. The method and apparatus includes determining a location in geographical coordinates of an earthworking implement at the earthworking site, determining a location in geographical coordinates of the object, displaying the earthworking implement and the object on a display having a top view and a side profile view of the earthworking site, selecting a perimeter of interest in the top view with respect to the earthworking implement, determining the coordinates of a portion of the object bounded by the perimeter of interest, and displaying a three-dimensional image of the portion of the object in the side profile view as a function of the perimeter of interest.

Abstract: An improved level indicating system is provided for use with excavating equipment based upon a family of laser light receivers. In a first embodiment, a laser receiver with a single “long” photocell is mounted directly on the dipperstick of an excavator in a position that is designed to intercept pulses of laser light being emitted by a rotating laser light transmitter, and an angle-sensing sensor is also mounted to the dipperstick. In a second embodiment, a laser receiver with two parallel “long” photocells is mounted directly on the dipperstick, in which the pair of photocells are of sufficient precision to determine the angle of the dipperstick. In a third embodiment, a laser receiver with two parallel photocells is mounted directly on the dipperstick on a “servo mast” that can be re-positioned along the length of the dipperstick. The movable photocells thus can be shorter in length than the “long” photocells used in the second embodiment.

Abstract: The modulation characteristic (static characteristic or dynamic characteristic) of a clutch and a brake are changed according to various operating conditions of a vehicle such as a high load driving state, slope traveling state, low engine speed state, and high speed driving state, to enable optimum steering performance that matches each operating condition of the tracklaying vehicle.

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: An automatic excavator for automatically excavating an excavation object and loading a loading object with the result excavation by utilizing a measuring instrument for determining the distance between the excavator and the excavation object and the loading object, an excavation object recognition system for recognizing a three-dimensional shape of the excavation object on the basis of an output from the measuring instrument, a target excavation position computing system for computing the target excavation position on the basis of the three-dimensional shape of the recognized excavation object, a target loading position computing system for computing a relative position of the loading object with respect to the excavator and a relative attitude of the excavator with respect to the loading object on the basis of an output from the measuring instrument, and computing a target loading position on the basis of the computed relative position, an automatic positioning system for automatically positioning the excava

Abstract: A work vehicle includes a frame, an excavating apparatus movably secured to the frame, an operator's station, and a control system. The excavating apparatus includes a material engaging member and a plurality of actuators having positions for positioning the material engaging member with respect to the frame. The control system controls the positions of the plurality of actuators and thereby the position of the material engaging member. The controls system includes a plurality of manual operator input devices, an operator presence sensor, a control circuit, and an override device. The plurality of manual operator input devices are located at the operator station for providing material engaging member position commands. The operator presence sensor is configured to generate an operator presence signal.

Abstract: When an arm end exceeds a boundary line K2 and enters a slowdown area R1, a proportional solenoid pressure reducing valve 13 is operated to reduce a pilot pressure for slowing down a first boom cylinder 1A, thereby slowing down an arm end speed. When the arm end exceeds a boundary line K1 and enters a restoration area R2, a restoration gain is calculated in control gain block 200 depending on an intrusion amount by which the arm end enters the restoration area, while a feedback gain is calculated depending on an arm end speed at that time on the basis of functions 204, 205, 206, 207, 208 and 209. In accordance with these gains, a second boom 2 is automatically dumped depending on the intrusion amount of the arm end into the restoration area and the arm end speed at that time so that the arm end is moved for return to the slowdown area. As a result, such work as requiring a work front to be moved toward the operator is continuously smoothly performed and working efficiency is improved.

Abstract: A construction machine (10) with a laser measuring instrument which includes a construction machine body, a working apparatus, and a manually operable member for driving a cylinder apparatus of the working apparatus to operate a plurality of arm members and an end working member is constructed such that it comprises an array type laser receiver (114) mounted on the arm member positioned on the free end side for receiving a laser beam parallel to an aimed floor face irradiated from a laser apparatus (120) disposed at a position spaced away from the construction machine (10): posture detection structure (3-1 to 3-3, 4) for detecting a posture of the construction machine, and control structure (2) for controlling the working apparatus based on a result of detection by the posture detection structure (3-1 to 3-3, 4) so that the array type laser receiver (114) may receive the laser beam from the laser apparatus (120) at a predetermined angle.

Abstract: An apparatus for determining a condition indicative of a level of difficulty of excavation of a material engaged by a work machine having a work implement. A controller receives a first signal during a dig pass of the work machine, and determines a material condition indicative of a level of difficulty of excavation during the dig pass as a function of the first signal, and transmits an output signal during the dig pass as a function of the material condition.

Abstract: An excavator data acquisition and control system and process for characterizing the subsurface geology of an excavation site, and for utilizing the acquired data to optimize the production performance of an excavator. A geologic imaging system and a geographic positioning system are employed to initially survey a predetermined excavation site or route. A geologic characterization unit may also be employed to enhance the geologic imaging data. The acquired data are processed to provide detailed geologic and position data for the excavation site and utilized by a main control unit to optimize excavator production performance. In one embodiment, the main control unit accesses a geologic filter database, which includes geologic profile data for numerous types of geology, when analyzing unknown subsurface geology. Removing geological filter data content corresponding to known geology from the acquired geologic imaging data provides for immediate recognition of unknown and suspect subsurface objects.

Abstract: Two GPS units are mounted at two separate points on the body of a work machine to periodically measure their three-dimensional coordinates with respect to a chosen reference system. As soon as two sets of measurements are recorded, a plane is fitted through the four points so collected and it is used to determined the current orientation of the machine. As each additional set of position data is collected at predetermined intervals for the two points on the machine, a new plane equation is calculated to update the orientation of the machine based on a predetermined number of prior measurements. Standard-deviation analysis is used to check the validity of each plane calculation and the process is restarted when the deviation is found to be greater than an acceptable parameter.

Abstract: A setting device for a front control system for a construction machine includes a direct setting switch for instructing a direct teaching setting, a numeral input key consisting of up- and down-keys for instructing a numeral input setting, a setting changeover switch for changing over a setting mode from the direct teaching setting to the numeral input setting, an LED lighting up when the setting changeover switch is pushed, an area limiting switch for starting an area limiting excavation control, an LED lighting up when the area limiting switch is pushed, and a display screen for indicating the position of a bucket end of a front device in terms of a numeral value when the setting changeover switch is not pushed, and indicating the numeral value input with the numeral input with the numeral input setting when the setting changeover switch is pushed.

Abstract: In one embodiment of the present invention, a planning apparatus and method for earthmoving operations with a front-end loader, such as loading a bucket with material and unloading the material in a receptacle, is disclosed including multi-level processing for planning the operation. One of the processing levels is a coarse-level planner that uses geometry of the site and heuristics specified by expert operators to find an optimal area from which to remove material. The next level involves searching the area for an exact starting location. This is accomplished by choosing among candidate excavations for the site with the optimum performance criteria including maximum amount of material protruding from the pile, minimum side loading of the bucket, and minimum distance from the loading receptacle.

Abstract: Weight sensors coupled to the bed of a conventional haulage truck measure the weight applied to each tire strut as the truck is being loaded. Based on the weight applied to each strut, the exact position of the center of gravity of the load in the truck's bed is calculated and displayed on a monitor relative to a target position deemed optimal for uniform weight distribution. Based on this information, the operator of the loading machine can complete the loading operation in such a way as to shift the center of gravity toward the chosen target position. In another embodiment of the invention, an automated algorithm calculates and displays where the next bucket load should be dropped, based on its approximate weight, in order to shift the center of gravity toward the target location.

Abstract: A construction machine comprising two hydraulic pumps; right and left traveling motors for causing the construction machine to travel; work machine actuators for actuating a work machine of the construction machine; a control valve which makes control so that a hydraulic oil discharged from the two hydraulic pumps is fed to at least either the right and left traveling motors or the work machine actuators and so that when both traveling operation and work machine operation are performed simultaneously, the hydraulic oil discharged from one of the two hydraulic pumps is fed to the traveling motors and the hydraulic oil from the other hydraulic pump is fed to the work machine actuators, the control valve providing communication between the two hydraulic pumps through a pump communication path; a drive signal detecting device which detects drive signals with respect to the two hydraulic pumps when the traveling operation and the work machine operation are performed simultaneously; and a controller which controls

Abstract: An apparatus and method for controlling the clamping forces on an object being held between a bucket and a thumb of a work machine is disclosed. The apparatus and method controls the head and rod end pressures of the bucket and thumb hydraulic cylinders to substantially maintain a desired clamping pressure on the gripped object, thereby providing at a touch of a switch, a work machine that can be controlled as the thumb and forefinger combination of the human hand which gives a "wristlike" action to the bucket thumb combination.

Abstract: A method and apparatus for preventing underdigging of a work machine, which may occur if the implement digs under or too close to the work machine, is disclosed. An underdigging boundary or a space of allowable implement movement is established relative to the work machine. The position of the implement is sensed, and the movement of the implement is controllably prevented from underdigging the work machine.

Abstract: An apparatus and method is disclosed for preventing the performance of an automatic sequence of operations of a work vehicle. The apparatus is a system that includes a databus, a plurality of input devices, a primary control unit coupled to the plurality of input devices and to the databus, a plurality of output devices and a plurality of secondary control units coupled to the databus, each of the secondary control units also being coupled to at least one of the output devices. The primary control unit directs the performance of the automatic sequence of operations by generating commands to be provided onto the databus. Each of the secondary control units directs an output function by the at least one output device coupled thereto in response to the commands on the databus.

Abstract: A control system controls the actuation of a plurality of control devices of a utility vehicle, including a PTO shaft control device. The control system includes a control unit which is electrically connected to the control devices and to switches for the manual actuation of the control devices. One of the switches is an automatic mode switch which controls activation of an automatic mode wherein the control unit automatically controls the control devices. In response to signals from a hitch switch, the control system transmits control signals to a hitch control which controls raising and lowering of an implement hitch. When the automatic mode is activated the control unit automatically disengages the PTO shaft if the hitch is raised above a pre-set hitch position.

Abstract: An excavator data acquisition and control system and process for characterizing the subsurface geology of an excavation site, and for utilizing the acquired data to optimize the production performance of an excavator is disclosed. A geologic imaging system and a geographic positioning system are employed to initially survey a predetermined excavation site or route. A geologic characterization unit may also be employed to enhance the geologic imaging data. The acquired data are processed to provide detailed geologic and position data for the excavation site and utilized by a main control unit to optimize excavator production performance. In one embodiment, the main control unit accesses a geologic filter database, which includes geologic profile data for numerous types of geology, when analyzing unknown subsurface geology. Removing geological filter data content corresponding to known geology from the acquired geologic imaging data provides for immediate recognition of unknown and suspect subsurface objects.

Abstract: In one aspect of the present invention, a method for determining and displaying a correlated position of a truck as it is being loaded by an earth moving machine is provided. The method includes the steps of receiving a loading event signal and then determining the correlated position of the truck in response to the loading event signal. The correlated position of the truck is then displayed relative to the land size.In an alternative embodiment, a method for determining and displaying productivity information regarding material excavated by an earth moving machine and loaded into a truck is provided. The method includes the steps of determining the bucket load material type of the material loaded in the bucket. Productivity information is then displayed at a remote location in response to the bucket load material type.

Abstract: A blade control system is configured to control the spatial orientation of an earthmoving blade mounted on a frame of an earthmoving machine for working a surface of earth to a desired shape. The blade slope angle required to maintain a selected cross-slope angle is calculated and the blade slope is then controlled so that the sensed blade slope angle is substantially equal to the calculated blade slope angle. The method and apparatus of the present invention is capable of maintaining the desired cross-slope even when the motorgrader is steered through a turn. The control system includes an input circuit, a sensor system and a processor. The input circuit is arranged to generate an output signal representative of the desired shape of the surface of earth to be worked. The sensor system includes a first sensor coupled to the frame of the earthmoving machine to generate a first signal indicative of a longitudinal slope angle of the frame with respect to horizontal.

Abstract: A control method and apparatus for construction machine. A joint type arm mechanism is provided on a construction machine which is driven by a cylinder type actuator, which is itself connected to a fluid pressure circuit having a pump. The cylinder type actuator's delivery pressure is variable in response to the movement of an operation member and is operated by the delivery pressure from the pump. The delivery pressure of the pump is maintained greater than or equal to a predetermined value even when the operation member is in a neutral position for the cylinder type actuator, so that, even immediately after the movement of the arm mechanism is initiated, a response delay of the pump or an increase of the dead zone can be suppressed and the accuracy of the completed movement of a working member can be enhanced.

Abstract: A speed command value X1 for a first arm 3 is decided depending on a lever input amount in the direction c, d. Assuming that the side d corresponding to move-up of the first arm is positive, the side c corresponding to move-down thereof is negative, and a speed command value resulted upon full lever operation and corresponding to a rated speed of the first arm is 1, X1 is given by -1<X1<1. A speed command value X3 for a third arm 5 is decided depending on a lever input amount in the direction e, f. Assuming that the side f corresponding to dumping of the third arm is positive, the side e corresponding to crowding thereof is negative, and a speed command value resulted upon full lever operation and corresponding to a rated speed of the third arm is 1, X3 is given by -1<X3<1. A speed command value X2 for a second arm 4 is here given by X2=K1.times.X1+K3.times.X3 on condition that the side corresponding to move-up of the second arm is positive.

Abstract: A pump failure alarm system which is provided in a hydraulic working machine comprising hydraulic pumps driven by a prime mover, delivery lines joining with one another into one common delivery line on the downstream side, check valves provided in the delivery lines upstream of a point where the delivery lines join with one another, a hydraulic cylinder driven by a hydraulic fluid introduced through the common delivery line, and a hydraulic reservoir. The pump failure alarm system comprises pressure sensors for detecting respective delivery pressures of the hydraulic pumps, bypass lines having one ends connected to the delivery lines at points upstream of the check valves and the other ends connected to the hydraulic reservoir, solenoid switching valves for opening and closing the associated bypass lines, an alarm display unit for giving an alarm in correspondence to each of the hydraulic pumps, and a controller.

Abstract: Two control lever units 11, 12 for operating a first arm 3, a second arm 4 and a third arm 5 of a 3-articulation work front 2 are provided, and signals 132, 133 from the two control lever units are sent to a controller 131. On condition that a virtual 2-articulation type work front comprising a virtual first arm 13 and a virtual second arm 14 is imaginarily provided and the relationship in movement between the virtual second arm and the actual third arm is set in advance as if both the arms constitute a rigid body together, the controller 131 determines respective command values .omega..sub.1, .omega..sub.2 and .omega..sub.

Abstract: On a slurry wall device having a cable mounting, on which is attached a supporting cable for guiding the slurry wall device, is provided an adjusting device, with which a supporting cable contact point can be laterally displaced, so that the slurry wall device can be controlled with respect to its deflection in the trench. This permits the orientation of the slurry wall device and consequently its contact angle ofthe bore hole bottom to be controlled by a particularly simple device. It is also easily possible to retrofit a slurry wall device with such an adjusting device.

Abstract: A site database structure for storing elevation data for access by an application program being executed on a control system on a work machine. The data is stored in a Triangular Irregular Network (TIN). The elevation of a point on the work site based on the three points forming the triangle containing the point.

Abstract: A method for determining the front and rear axle weights of an earth moving machine. The method includes determining the weight of a portion of the earth moving machine, and the forces acting on the lift cylinder pin, lift arm pin, and the tilt cylinder pin. The axle weights are determined in response to the above mentioned weights and forces.

Abstract: A method and apparatus for controllably preventing an implement from damaging a work machine or itself, which may occur if the implement strikes the work machine, by restricting the movement of the implement. A boundary is established a predetermined distance from the work machine. By controllably restricting the movement of the implement when it approaches the boundary, the implement is prevented from making contact with the work machine.

Abstract: A power machine includes a pair of traction motors to provide for travel of the machine. The power machine also includes a boom, an arm and a tool (such as a bucket). The power machine includes a hydraulic power circuit which has a valve stack that enables the boom and at least one of the arm and tool to be operated simultaneously.

Abstract: Excavating apparatus includes a vehicle having excavator in the form of a pivotal cutting boom pivotably mounted on the vehicle. The cutting boom has an endless cutting clain drivingly mounted thereon and the boom is pivoted relative to the vehicle so as to vary the depth to which a trench is current. In seeking to cut a trench having a level floor irrespective of any undulations in the surface upon which the vehicle travels, a sensor is associated with the apparatus and is arranged to receive a reference signal. Any variation in the location at which the reference signal impinges on the sensor, for instance due to the passage of the vehicle up an incline, serves to determine the angle at which the cutting boom extends from the vehicle and so varies the depth to which the trench is cut.

Abstract: There are provided with an electric motor driven by a battery, a hydraulic pump driven by the electric motor, a proximal actuator for actuating a working member by working oil from the hydraulic pump, a hydraulic motor for moving a working machine body, and an operating lever which can be operated between a neutral position and an operating position. There are provided with a control valve capable of cutting off a supply of working oil to the proximal actuator in a state where operating lever is positioned at an operating position, and a battery capacity sensor for detecting the capacity of the battery. There is provided a controller for outputting a control signal for cutting off a supply of working oil to the proximal actuator to the switching control valve in a state where the battery capacity value detected by the battery capacity sensor is at a level lower than a preset battery capacity reference value. It is possible to positively prevent the machine from being immoved at the working site.

Abstract: An electrohydraulic control system for loading a bucket of a work machine includes sensors for producing signals representative of bucket position and forces. A command signal generator receives the signals and calculates a target angle on the basis of accumulated energy, and a force vector angle representing actual forces produced at an reference point on the bucket. Lift and tilt command signals are modified in response to differences between the target and actual angles, and used to controllably extend the lift cylinder to raise the bucket through the material, while racking the bucket at rates calculated to efficiently capture the material.

Abstract: An electrohydraulic control system for loading a bucket of an earthmoving machine includes sensors for producing machine parameter signals representative of how strongly the machine is crowding the pile of material to be loaded. A command signal generator monitors crowd factors corresponding to the sensed parameters to determine when the bucket contacts the pile, then generates bucket lift hydraulic cylinder command signals to maintain a traction force. The command signal generator next determines from the crowd factors when the pile is engaged near the machine capacity, then generates bucket tilt hydraulic cylinder command signals in proportion to the monitored crowd factors to rack the bucket at rates calculated to efficiently capture the material.

Abstract: A farming system which identifies the boundaries of agricultural fields and performs functions based upon whether a vehicle is located within a particular field is disclosed. The system includes a location signal generation circuit which receives positioning signals and generates location signals representative of the location of the vehicle. The system further includes a memory circuit which stores geo-referenced digital maps of the fields and may include boundary data or application maps for each field. The system further includes a control circuit which compares the location signals to the data stored in the memory circuit to determine when the vehicle is located in a particular field. In one embodiment, the control circuit selects a variable-rate application map for the particular field and generates variable-rate control signals from the map data which are applied to a variable-rate applicator.