Caterpillar Inc.

David J Rocke

Lonnie J Devier

Andrew Gordon Shull

Marvin K Palmer

Dale B Herget

A method and system for automatically controlling a work implement of an earthmoving machine, the work implement including a bucket, to capture, lift and dump material, the bucket being controllably actuated by a hydraulic tilt cylinder and at least one hydraulic lift cylinder, based on discrete values of torque is disclosed. The control system includes a torque indicating mechanism that provides a representative value for an amount of torque applied to the wheels of the earthmoving machine, an electronic controller for receiving the representative torque value from the torque indicating mechanism and determining if the representative value of torque received from the torque indicating mechanism exceeds a first predetermined value and then responsively generating a first command signal, and a hydraulic implement controller for controlling hydraulic fluid flow to the hydraulic tilt cylinder in a predetermined sequence activated in response to the first command signal with the hydraulic tilt cylinder controllably actuating the bucket of the earthmoving machine in order to remove material from a pile.

System and method for automatically controlling a work implement of an earthmoving machine based on discrete values of torque

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.

Method for adjusting a process for automated bucket loading based on engine speed

A control system including a weight sensing mechanism for sensing weight of the material in a bucket of an earth moving machine and a logic mechanism for receiving the weight signals for the material in the bucket from the weight sensing mechanism and then determining a total summed weight of the material for a total number of capture, lift, and dump cycles needed to capture, lift and dump a predetermined weight of the material with the bucket and then generating various command signals based on the weight signal from each capture, lift and dump cycle and the total summed weight for the total number of capture, lift and dump cycles. In addition, there is a hydraulic implement controller for controlling hydraulic fluid flow to the hydraulic tilt cylinder and the hydraulic lift cylinder in response to the command signals thereby controllably actuating the bucket of the earthmoving machine in order to capture, lift and dump material.

Control system for automatically controlling a work implement of an earthmoving machine to capture, lift and dump material

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.

Method and apparatus for determining a material condition

An electrohydraulic control system for loading a bucket of an earthmoving machine includes sensors for sensing when the machine is crowding a pile of material to be loaded. A command signal generator monitors the sensed 'crowd' parameters to trigger one of a learning or playback mode for hydraulic cylinder command signals when the parameter indicates pile contact.

Automatic bucket loading using teaching and playback modes triggered by

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.

System and method for automatic bucket loading using crowd factors

A control system for automatically controlling a work implement of an excavating machine through a machine work cycle in disclosed. The work implement including a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder. A plurality of command signal magnitudes associated with at least one hydraulic cylinder are stored. The command signal magnitudes are represented by a plurality of control curves, where each control curve is responsive to a material condition setting that is representative of a predetermined condition of the excavating material. A microprocessor selects one of the plurality of control curves and responsively produces a command signal having a magnitude dictated by the selected control curve. A electrohydraulic system receives the command signal and controllably actuates predetermined ones of the hydraulic cylinders to perform the work cycle.

Self-adapting excavation control system and method

In one aspect of the present invention, an automatic control system for loading a bucket of a wheel loader is disclosed. The system includes a pressure sensor that produces pressure signals in response to the hydraulic pressures associated with one of the lift and tilt cylinders. A microprocessor receives the pressure signals, compares at least one of the pressure signals to a predetermined one of a plurality of pressure setpoints, and produces lift and tilt command signals in response to the pressure comparisons. Finally, an electrohydraulic system receives the lift command signals and controllably extends the lift cylinder to raise the bucket through the material, and receives the tilt command signals and controllably extends the tilt cylinder to tilt the bucket to capture the material.

Control system for automatically controlling a work implement of an

According to one aspect of the present invention, a control system for automatically controlling a work implement of an excavating machine through an excavation work cycle is provided. The work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder, the hydraulic cylinders containing pressurized hydraulic fluid. The control system includes an operator control element adapted to produce an operator control signal indicative of a desired velocity of one of the hydraulic cylinders. An electrohydraulic valve actuates predetermined ones of the hydraulic cylinders to perform an excavation work cycle in response to the control signal. A sensor produces signals indicative of the forces associated with at least one of the hydraulic cylinders. A logic device receives the operator control signals, compares the control signal magnitudes to predetermined control signal magnitudes, and determines operating parameters associated with predetermined portions of the work cycle. Finally, the logic device receives the operator control signals and force signals, and responsively produces command signals to the electrohydraulic valve to automatically perform subsequent work cycles in accordance with the determined operating parameters.

Teaching automatic excavation control system and method

A control system for automatically controlling a work implement of an excavating machine through a machine work cycle is disclosed. The work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder. A position sensor produces respective position signals in response to the respective position of the boom, stick and bucket. A pressure sensor produces respective pressure signals in response to the associated hydraulic pressures associated with the boom, stick, and bucket hydraulic cylinders. A microprocessor receives the position and pressure signals, and produces a command signal. An electrohydraulic system receives the command signal and controllably actuates predetermined ones of the hydraulic cylinders to perform the work cycle. The microprocessor determines the external force applied to the bucket and the angle of the bucket force, compares the angle of the bucket force to a predetermined value, and responsively determines when a digging portion of the work cycle is complete.

System and method for determining the completion of a digging portion of

A control system automatically controls a work implement of an excavating machine through a machine work cycle. The work implement includes a boom, stick and bucket, each being controllably actuated by at least one respective hydraulic cylinder. A position sensor produces respective position signals in response to the respective position of the boom, stick and bucket. A microprocessor receives the position signals, compares at least one of the boom, stick and bucket position signals to a predetermined one of a plurality of position setpoints. A pressure sensor produces respective pressure signals in response to the associated hydraulic pressures associated with the boom, stick, and bucket hydraulic cylinders. The microprocessor receives the pressure signals, and compares at least one of the boom, stick and bucket pressures to a predetermined one of a plurality of pressure setpoints. An operator interface produces a material condition setting, the material condition setting being representative of a predetermined condition of the excavating soil. The logic device produces a command signal in response to the pressure and position comparisons, the command signal having a magnitude responsive to the material condition setting. An electrohydraulic system receives the command signal and controllably actuates predetermined ones of the hydraulic cylinders to perform the work cycle.

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Eureka, IL, United States of America

David J Rocke