Abstract: The present invention provides an attachment for use with a power machine. An attachment control device includes a controller, such as a microprocessor, a microcontroller or other digital computer which senses the type of attachment and controls power to the attachment accordingly. In one embodiment, the attachment control device can be used for remotely controlling the attachment and includes an ignition switch and a stop switch and allows a user to operate the attachment from outside the operator compartment of the power machine, when the power machine is started from the attachment control device.

Abstract: Railroad beds require regrading in order to permit for an increased axial load. There are often cables or tubes embedded in the roadbed at the roadbed sides, making regrading difficult. In accordance with the present invention, material is moved by suction to form pits at each side of the track at intervals along the railroad bed, and a laser camera is used to obtain information relating to the profile adjacent to the pits and the positions of the embedded cables or tubes. This information is saved, and used to control a device for mechanically excavating material from the railroad bed sides without damaging the embedded cables or tubes and grading the railroad bed. A laser measuring device is provided for reading the railroad bed profile.

Abstract: In a lifting vehicle having a holding and lifting device(5, 6) for holding and raising or lowering goods (9) and having a central operating device for controlling the travelling and handling of the goods (9) held by the holding device (6), the handling of sensitive goods by the person operating the lifting vehicle can be made easier or monitored by the holding device (6) being equipped with a sensor device (8) for the instantaneous inclination and/or the instantaneous accelerations of the holding device (6).

Abstract: A system and method for estimating the position of a mechanical linkage is disclosed. An estimated position of a mechanical linkage is set to an initial position. The movement of the mechanical linkage is controlled based on a signal from an input device. The estimated position of the mechanical linkage is updated based upon the movement of the mechanical linkage. A determination is made when the estimated position of the mechanical linkage substantially corresponds to an actual position of the mechanical linkage.

Abstract: A method for controlling the raise/extend function of a work machine is provided. The method comprises sensing the lateral orientation of the work machine, comparing the sensed orientation to a desired orientation and controlling the raise/extend operation in response to the actual verses the desired position.

Abstract: A hydraulic function can be extended and retracted under the control of an electrohydraulic valve unit. An operator movable command lever is movable into extend, center and retract region. A sensor generates a lever position signal. An electronic lever command unit receives the lever position signal and generates a valve command signal. An electronic valve control unit is remote from and communicated with the lever command unit. The electronic valve control unit controls communication of hydraulic fluid to the hydraulic function in response to the valve command signal. A method of generating the valve command signal includes generating a command signal which is proportional to the lever position signal when the lever is moved relatively slowly, and generating a command signal which is based on a maximum excursion of the lever into the extend and retract regions when the lever is moved relatively rapidly.

Abstract: The present invention is directed to a material handler that includes a frame, a telescoping boom, a boom extension sensor, a boom angle sensor, and a control system. The telescoping boom is coupled to the frame, pivotable between a lowered and a raised position, and movable between a retracted and an extended position. The boom extension sensor generates a first signal that corresponds to the distance which the boom is extended. The boom angle sensor generates a second signal that corresponds to the angle which the boom is pivoted. The control system receives the signals and displays a cursor located at a position that is based on the first signal and the second signal.

Abstract: A method of handling a load at a high desired load handling position using a mobile loading machine of the kind having a loading arm connected at one end to a body of the machine for movement at least about a generally horizontal axis between a lower travelling position, and a higher load handling position, and the arm having at its outermost end a loading implement for carrying the load, the method including the steps of manoeuvring the machine with the arm in the lower travelling position generally below the load handling position, and then one of:

Abstract: The invention comprises a work vehicle, a boom attached to the vehicle, a tool pivotally attached to the boom, an actuator for controllably moving the tool about its pivot, and an angular velocity sensor for sensing the angular velocity of the tool. A controller is adapted to perform a tool auto-hold function, automatically maintaining an initial tool orientation by processing the angular velocity data and commanding movement of the tool actuator to hold the angular velocity at zero. The controller is adapted to discontinue the tool auto-hold function when the operator manipulates a tool command input device affecting tool actuator movement, and resume the tool auto-hold function at the new orientation affected by the operator. Manipulation of an auto-hold command input device allows the operator to selectively enable and disable the tool auto-hold function.

Abstract: An electronic control system for a machine having a boom assembly and an implement assembly. A microprocessor is provided having an input and generating first and second output signals. A first electrohydraulic valve is connected to receive the first output signal from the microprocessor, and connected to position the boom assembly in response to the first output signal. A second electrohydraulic valve is connected to receive the second output signal from the microprocessor, and connected to position the implement assembly in response to the second output signal. A boom position sensor is disposed on the boom assembly or the implement assembly and connected to send a boom position input signal to the microprocessor, the microprocessor being connected to receive the boom position input signal and generate at least one of the first output signal and the second output signal, thereby controlling a position of the implement assembly relative to the boom assembly.

Abstract: The invention comprises a backhoe with a tool pivotally attached to an extendable dipperstick, an actuator for controllably moving the tool about its pivot, and an angular velocity sensor for sensing the angular velocity of the tool about its pivot. A controller is adapted to perform a tool auto-hold function, automatically maintaining an initial tool orientation by processing the angular velocity data and commanding movement of the tool actuator to hold the angular velocity at zero. The controller is adapted to discontinue the tool auto-hold function when the operator manipulates a tool command input device affecting tool actuator movement, and resume the tool auto-hold function at the new orientation affected by the operator. Manipulation of an auto-hold command input device allows the operator to selectively enable and disable the tool auto-hold function.

Abstract: A method for controlling the raise/extend function of a work machine is provided. The method comprises sensing the position of a frame and the position of a telescopic boom of the work machine, comparing the sensed positions to a desired position and controlling the raise/extend operation in response to the actual verses the desired positions.

Abstract: A method for controlling an automatic bucket control system during loading of a work implement of a work machine is disclosed. The method includes the steps of determining when the work implement engages a pile of material, initiating the automatic bucket control system in response to the work implement engaging the pile of material, determining a ground speed of the work machine, and generating a lift command based upon the ground speed. After fully engaging the material, the system may further adjust tilt commands and/or lift commands based upon a monitored crowd factor to control operation of the work implement.

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: The present invention relates to a large-size manipulator, and also to truck-mounted concrete pumps with such a large-size manipulator, that comprises a boom (1) made up of several (2 to 5) and especially 3 to 5 segments and arranged on a frame, especially a vehicle frame, said boom being especially designed as a foldable distribution boom that preferably comprises a slewing track ring (6), so that by means of a driving unit it can be rotated about a substantially vertical axis of rotation, where the boom segments, by means of further driving units, can be swivelled with respect to each other and with respect to the slewing track ring about substantially horizontal and mutually parallel axes, where a distant steering system comprising a steering organ is provided to operate the driving units and to set a desired position of the driving units and/or the boom segments and the slewing track ring, where there is also provided a control system that comprises at least one monitoring unit (15) to ascertain a paramet

Abstract: The invention relates to a device for monitoring the safety of a bending pole (22) in a large manipulator, whereby the arms (23-27) of the mast can be pivoted in relation to each other by means of a drive unit (34-38). The relative position of the arms of the mast in relation to the respective adjacent arm of the mast or frame of the mast (21) is measured for adjusting the position thereof. According to the invention, the positing measuring values (&egr;I) of the arms of the mast are used in order to control the safety of the drive units (34-38) or the actuators thereof (80-84) in relation to a variation of predefined safety values.

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 method is provided for determining the location of a work machine at a work site, where the work machine includes a house, a boom connected to the house, a stick connected to the boom, and a work implement connected to the house. Reference signals are received from an external reference source. The position of a point on the house is determined in response to the received signals. Information about the work machine is determined based on the position of the point on the house. The status of center-of-rotation (COR) information is updated. The system determines if an event has occurred. If an event is determined to have occurred, event reactions occur.

Abstract: The invention concerns a kinematic device for supporting and programmably moving a terminal element. The platform (11) bearing the terminal element (12) is linked by four swivel joints (9) and (10) with two legs each consisting of two support rods (7) or (8) forming deformable parallelograms mounted each on slides (3) or (4) mobile in the x direction. The pivot plate (29) articulated on the platform (11) about the hinge pin (30) is controlled by the control rods (27), controlling pivoting (14) and lateral displacement (18) connected respectively by the swivel joints (26, 13 and 17) to the slides (3, 12 and 26). It consists in a parallel kinematics with four degrees of freedom, namely three translational and one rotational whereof the angle can be greater than 120°.

Abstract: A device for operating an articulated arm of a large manipulator connected to a boom base. The large manipulator comprises an articulated boom (22), composed of three boom arms (23 to 27), the boom arms of which may each be pivoted around mutually parallel horizontal articulation axis (28 to 32), in a limited manner. Furthermore, a control device (74), for the boom displacement is provided, which may be controlled from a remote controller (50) over a data transmission path (68).

Abstract: A level sensing system for use with an excavating machine includes a light receiving sensor, mounted on the dipper stick of the machine, and an inclinometer, also mounted on the dipper stick of the machine. The sensor and inclinometer provide indications of the relative location of a beam of light and the inclination of the dipper stick. The inclinometer includes a gyroscopic inclination sensor and an accelerometer arrangement for sensing acceleration due to gravity and providing a static vertical reference. A position determining circuit is responsive to the sensor and the inclinometer and calculates the position of a pivot joint on the dipper stick to which a digging bucket is attached. The beam of light is a beam of laser light which is projected by a laser transmitter. An angle-measuring sensor may be provided for measuring the angular orientation between the dipper stick and a cutting edge of the bucket.

Abstract: A set amount of fluid can be constantly supplied to an actuator and a flow-back of fluid from the actuator can be prevented, even in case of developing variations of a load pressure of the actuator and a pressure of a hydraulic pump, and provided is a control valve for controlling the driving of the actuator connected to the hydraulic pump, a logic check valve mounted in a path between the hydraulic pump and the control valve to be opened and shut, and a logic control valve mounted between the hydraulic pump and the pressure chamber of the logic check valve and for controlling an amount of fluid passing through the upper side of the logic check valve from the hydraulic pump upon switching.

Abstract: A hoisting hook is arranged on a stick boom top pin for attaching a bucket to a distal end of a stick boom and hung at a bucket scooping face side. A bucket fall prevention valve is provided at least on a head side of a bucket cylinder for maintaining the cylinder inner pressure in order to prevent the bucket from free fall. A crane work by the hoisting hook is performed with the bucket dumped to the stick boom back side to the maximum extent. During the crane work, even if the hydraulic oil hose connected to the bottom side of the oil chamber of the hold pressure generation side of the bucket cylinder is broken by an external force, the bucket fall prevention valve acts instantaneously, cuts off the head side oil chamber from the exterior oil passage completely, and maintains the hold pressure of the head side oil chamber, so that the bucket is prevented from rotating suddenly downward.

Abstract: In a working apparatus, a recessed portion is formed at an end surface of a pin provided at a boom to house a case of an angle sensor in the recessed portion. A flange is projected from the case along the direction of the axis of an input shaft so as to enclose the input shaft outside the movement range of a lever. By projecting the flange further out than the distance over which the input axis projects out, the protection provided by the flange for the input shaft is enhanced.

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: An apparatus and method for providing coordinated control of a work implement of a work machine. The implement includes a boom having a first end portion and a second end portion, with the first end portion pivotally connected to the frame and the second end portion pivotally connected to a load-engaging member. The apparatus includes a boom position sensor adapted for providing a boom position signal, and an input device adapted for delivering a desired boom velocity signal indicative of the desired velocity of the boom. The desired velocity of the boom includes a desired angular velocity and a desired linear velocity. The apparatus receives the boom position signal and the desired boom velocity signal, and determines an actual velocity of the boom as a function of the boom position signal.

Abstract: A control system for a backhoe apparatus is disclosed. Backhoe apparatus control system includes a kinematic optimal control including the augmentation of additional tasks that can be formulated into the optimal control problem. Further, the control system may include a dynamic adaptive control that accounts for the backhoe linkage dynamics. Still further, the control system is configured to control the flow of hydraulic fluid into and out of the hydraulic actuators.

Abstract: An arrangement is provided for determining the relative angular orientation between an excavator bucket and the dipper stick of an excavator. The excavator bucket is mounted on a bucket linkage that is pivotally secured to the end of the dipper stick. A hydraulic actuator has a hydraulic cylinder pivotally connected to the dipper stick, and a piston rod pivotally connected to the bucket linkage. Extension or contraction of the hydraulic actuator causes the excavator bucket to be pivoted by the bucket linkage with respect to the dipper stick. A cable extension linear position transducer having a transducer casing, a sheath extending from the casing to a pulley system, and an extensible belt cable extending from the sheath through the pulley system to an end of the piston rod, provides an electrical output related to the extension of the belt cable from the sheath. A transducer mounting secures the casing of the cable extension linear position transducer in fixed relationship to the hydraulic cylinder.

Abstract: The present invention is directed to a control circuit for automatically bringing a hydraulically operated work arm into a particular position without having to manually reverse the direction of the hydraulic operating system.

Abstract: A loader of the type controlled with an electronic digital controller is disclosed herein. The loader may include conventional mechanical components. However, the hydraulic valve is electronically controlled to provide improved motion control. In particular, the operator controls the loader with a two-axis joystick. When the joystick is moved left or right, the bucket is rolled at a speed proportional to the rate of change of the joystick position and independent of the loader arms. When the joystick is moved forward or backwards, the loader arms of the bucket are raised or lowered. When the joystick is only moved forward or backward with substantially no component of motion left or right, the controller rolls the bucket to maintain a substantially constant angle between the bucket and the loader's frame. This constant attitude control decreases the operator workload and increases control accuracy.

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: 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.

Abstract: A refuse collection vehicle (10) has a body (14) into which refuse may be loaded having an exit passage (34) from which loaded refuse may be emptied. The vehicle also has arms (56) and a fork (58) for lifting a container into a dumping position over the body. A control circuit coordinates simultaneous operation of the arms and forks by monitoring the position of the arms and forks through rotary potentiometers (200, 201).

Abstract: A controller for a work implement, such as the arm of a backhoe, a feller buncher, an excavator or the like provides a number of advantages over previous controllers and control methods. The controller responds to an operator's inputs to a joystick control such that the work implement moves parallel to the direction in which the joystick is deflected at a speed which is proportional to the amount of deflection of the joystick. The controller used the joystick position to generate a path and attempts to cause the work implement to move along the path. The controller computes a maximum available speed in the direction of motion specified by the joystick and is self calibrated so that full deflection of the joystick selects the maximum available speed. The controller has a self calibration mode which compensates for variability in the motion produced by the various actuators in response to given control signals.

Abstract: An apparatus and method for automatically reducing engine exhaust noise from a dump truck including a heated bed without the additional requirement of diverting the flow of exhaust through a separate muffler apparatus. An engine noise reduction system associated with the truck includes an engine control unit for controlling high idle engine speed parameters of the truck engine. When the truck bed is raised upwardly from an initial lowered position to release a material load from the bed, or hydraulics associated with the truck bed are actuated to raise the bed, the engine control unit automatically lowers the high idle engine speed of the truck engine to reduce engine noise from the truck engine. The high idle engine speed of the truck engine is automatically reset to the standard setting when the truck bed returns to the initial lowered position.

Abstract: A front loading refuse collection vehicle is provided, comprising (a) a mobile vehicle including a vehicle cab and a vehicle chassis; (b) a body forming a container into which refuse may be loaded, the body mounted to the vehicle chassis and having an exit passage from which loaded refuse may be emptied; and (c) a loader device for loading refuse into the body. The loader device comprises (i) an arm which pivots about a first pivot axis located on the chassis from a loading position to an unloading position, the arm including a lifting mechanism for lifting the arm, (ii) a fork which extends from the arm and which pivots about a second pivot axis located on the arm from a loading position to an unloading position, the fork including a rotating mechanism for rotating the fork about the second pivot axis, (iii) a container mounted upon the fork, and (iv) a control circuit for coordinating simultaneous operation of the lifting mechanism and the rotating mechanism.

Abstract: An industrial vehicle including a frame, an axle pivotally mounted on the frame, a restriction mechanism for restricting the pivotal movement of the axle, a pair of vehicle wheels rotatably supported on the axle, and a steering mechanism having a steering wheel for steering the vehicle wheels in accordance with rotation of the steering wheel. A first detecting device detects an angular position of the steering wheel. The angular position represents a steering amount of the steering wheel. A second detecting device detects a wheel angle. The wheel angle is the angle between a plane perpendicular to a rotation axis of the vehicle wheel and a line representing straight running of the vehicle. A third detecting device detects a yaw rate of the vehicle. A fourth detecting device detects a vehicle speed. A calculating mechanism calculates a plurality of variables based on the detected angular position of the steering wheel, wheel angle, yaw rate and vehicle speed.

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: 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 area where a front device (1A) is allowed to move is set beforehand and the operation of the front device is controlled so that the front device will not go out of the set area. For this control process, an arm cylinder speed calculating portion (9d) of a control unit (9) estimates an arm cylinder speed for use in control by taking the sum of a low-frequency component of an arm cylinder speed which is derived through coordinate transformation and differentiation of an arm rotational angle detected by an angle sensor (8b), and a high-frequency component of an arm cylinder speed which is derived from a command value applied from a control lever unit (14b) to a flow control valve (15b) for an arm and a flow rate characteristic of the flow control valve (15b). The control unit controls the operation of the front device with the estimated operating speed.

Abstract: An apparatus and method for controlling a hydraulically operated construction machine having a plurality of tandem articulated members which move in a particular pattern, wherein movement of one of the articulated members is controlled in response to movement of a second one of the articulated members. Anticipated future movement of the second articulated member is determined and the first articulated member is controlled as a function at least of the anticipated future movement of the second articulated member. Anticipated future movement is determined by measuring actual delay between movement of the first and second articulated members. Operation of the articulated members is a function of operation of an actuator and a selectable command level.

Abstract: Automated bucking loading is achieved through the use of sensor feedback provided by pressure and extension sensors on hydraulic cylinder(s) to control the trajectory of the bucket to be loaded by a computer algorithm. Additional sensors may be used to provide further control of the loading cycle and of the vehicle operation. The structure and steps can be integrated with existing machinery or used on new loaders equipped with suitable control interfaces capable of taking computerized control of the vehicle's actions.

Abstract: A method is disclosed for controlling the cutting depth and angle of an excavator bucket to excavate a surface to a desired contour. The method includes the steps of: (1) inputting data to a machine control system to define a desired contour of the excavated surface; (2) positioning the excavator bucket close to the desired contour; (3) enabling automatic control; and (4) automatically controlling movement of the excavator bucket only when the position of the excavator bucket is within a predetermined distance or angle of the desired contour. The method is used to automatically control the excavation to a desired depth if the bucket is within a predetermined distance of a desired depth. The method is also used to automatically control the angular orientation of bucket if the slope of the bucket is within a predetermined angle of a desired slope.

Abstract: A control system controls actuation of a hydraulic cylinder on a skid steer loader. The control system includes a movable element, movable by an operator. A position sensor is coupled to the movable element and provides a position signal indicative of a position of the movable element. A controller is coupled to the position sensor to receive the position signal and provide a control signal based on the position signal. A valve spool controls flow of hydraulic fluid to the hydraulic cylinder. An actuator is coupled to the controller and the valve spool and moves the valve spool in response to the control signal from the controller.

Abstract: A locus control system of hydraulic excavators whereby a target locus for a front device is set beforehand. A control unit calculates a position and posture of the front device based on signals from angle sensors, and calculates a target speed vector of the front device based on signals from control lever devices. Through this calculation process, the control unit maintains the target speed vector as it is when the front device is not near the target locus, and modifies the target speed vector to a vector pointing to a second point on the target locus advanced in the excavating direction by a second distance from a first point located on the target locus at a minimum distance from a tip of the front device, when the front device is near the target locus.

Abstract: A control device for working machines capable of controlling the moving of a tool continuously over a wide range, and capable of moving it accurately along a desired path. Out of not less than three control shafts (3a, 4a, 5a), a first combination of two control shafts (3a, 5a) is selected, and a bucket (6) is moved in a first section (A-B) out of travelling path thereof with the driving of the two selected shafts (3a, 5a) controlled. A second combination of two control shafts (3a, 4a) which is different from the selected first combination of two control shafts (3a, 5a) is then selected, and the bucket (6) is moved in a second section (B-C), which is continuous from the first section (A-B), with the driving of the two selected shafts (3a, 4a) controlled.

Abstract: A control system for improving the roadability of a wheeled excavator is disclosed herein. The excavator is the type including an implement such as a bucket or backhoe which is moved relative to the excavator by hydraulic actuators. Hydraulic fluid is applied to the actuators via electronic valves which are controlled by an electronic controller. Based upon acceleration of the vehicle, the electronic controller controls the electronic valve to maintain fluid pressure in the actuator or the acceleration substantially constant. Additionally the controller can be configured to maintain the average position of the implement generally constant. By controlling the pressure in the hydraulic actuator, the undesirable bouncing or pitching of the excavator can be reduced when the vehicle is traveling at road or loading speeds.

Abstract: A control system for improving the roadability of a wheeled excavator is disclosed herein. The excavator is the type including an implement such as a bucket or backhoe which is moved relative to the excavator by hydraulic actuators. Hydraulic fluid is applied to the actuators via electronic valves which are controlled by an electronic controller. Based upon acceleration of the vehicle, the electronic controller controls the electronic valve to maintain fluid pressure in the actuator or the acceleration substantially constant. Additionally, the controller can be configured to maintain the average position of the implement generally constant. By controlling the pressure in the hydraulic actuator, the undesirable bouncing or pitching of the excavator can be reduced when the vehicle is traveling at road or loading speeds.

Abstract: A process for automatically controlling power excavators is disclosed. In the process, the motions of the working members in accordance with lever handling motions of an operator are stored in a controller and reproduced to approximately conduct the operation. The operational errors of the reproduced motions of the working members are corrected and compensated in accordance with newly inputted lever handling motions of the operator while approximately conducting the operation, thereby accomplishing the desired operation. The process optimally controls the excavators regardless of working conditions, thereby improving the operational precision of the excavators. The above process does not need to use any sensors.

Abstract: A method of using a touch screen control panel to input and display data to control excavation by an excavator includes the steps of: (1) providing a display panel with a touch-sensitive screen at a position accessible to an operator; (2) inputting data by touching the display panel to define a desired contour of the excavated surface; (3) displaying on the display panel information representing the desired contour of the excavated surface; and (4) controlling movement of the excavator bucket to excavate the desired contour of the excavated surface. The display panel displays a sequence of screens that convey information to the operator and permit the operator to select operational modes and to input data to define the control parameters for the various operational modes.