Abstract: A control system is adapted to provide substantially linear movement of a work implement. The control system receives signals from at least one control lever and coordinates the movements of the work implement's appendages through coordination of hydraulic cylinders.
Type:
Grant
Filed:
September 6, 1990
Date of Patent:
November 3, 1992
Assignee:
Caterpillar Inc.
Inventors:
William E. Allen, Paul D. Anderson, Walter J. Bradbury, John M. Hadank, Richard B. League
Abstract: An apparatus is adapted to detect the linear extensions of a plurality of hydraulic cylinders. Each hydraulic cylinder defines a variable length coaxial resonant cavity. Under the control of a controller, a transmitting section, a receiving section and multiplexers are used to multiplex RF signals to and from the cavity of each cylinder and to determine the resonant frequency of the cavity. The controller determines the linear extension of each cylinder as a function of its resonant frequency.
Abstract: Full diagnostic capability is provided in a serial datalink network having a plurality of control modules. Each control module includes a differential receiver for providing noise immunity and a transmitter having a positive line driver and a negative line driver. Positive and negative transmission wires connect differential receivers to the positive and negative line drivers. Circuits sense the occurrence of a short circuit condition between the positive transmission wires and ground and between the negative transmission wires and supply voltage. Overcurrents in the positive and negative transmission wires are also detected.
Abstract: An apparatus is adapted to assess the performance of a vehicle's powertrain. A microcomputer collects sensor data indicative of the rotational velocity of an output shaft and a transmission input shaft and of the pressure of a directional clutch and a speed clutch. The microcomputer calculates a set of powertrain parameters based on the collected sensor data and produces an error signal in response to predetermined conditions of the powertrain parameters.
Type:
Grant
Filed:
September 6, 1990
Date of Patent:
May 5, 1992
Assignee:
Caterpillar Inc.
Inventors:
Irving Bright, Ronald C. Erickson, Dennis K. Greene, Gerald D. Hardy, Robert E. Hefner, Lowell E. Johnson, Donald J. Schwingel, Richard E. Spring
Abstract: A dynamic payload monitor measures and displays payload weight for a loader vehicle by sensing the hydraulic pressure of a lift arm cylinder. The payload weight is computed by curve fitting the second cylinder pressure to a second order polynomial, calculating a pressure differential, and then performing interpolation or extrapolation with a pair of pressure versus position or time reference parabolas obtained during calibration. The weight computation algorithms used in the dynamic payload monitor are applicable to a number of work vehicles having at least one work implement linkage and at least one hydraulic cylinder for modifying the linkage geometry.
Abstract: A dynamic payload monitor measures and displays payload weight for a loader vehicle during tip loading by sensing the hydraulic pressure of the lift and tilt cylinders and the geometry of an implement linkage. The payload weight is computed by curve fitting the sensed lift cylinder pressure and geometry data to a second order polynomial, and then performing interpolation or extrapolation with a pair of pressure versus position reference parabolas obtained during calibration. Tilt cylinder curves are derived by curve fitting tilt cylinder pressure and lift cylinder geometry data to a third order polynomial. The tilt cylinder curves are then compared to a plurality of tabulated tilt cylinder curves. Tip loading conditions are detected and the computed payload weight is modified in response to the magnitude of the tilt cylinder pressure.
Abstract: A control system and method automatically controls a work implement of an excavating machine to perform a complete excavation work cycle. In performing the work cycle, the control system automatically extends the work implement down into the trench, completes a dig stroke, captures the excavated material, swings the work implement to dump, dumps the load, returns the work implement to the trench, and repeats the work cycle until a trench is excavated according to operator programmed specifications. The control system monitors the position of the work implement and the forces exerted on the work implement and controllably actuates the work implement according to predetermined position and force setpoints.
Abstract: An apparatus is adapted to detect an end-of-fill condition of an actuator having a varying control volume, C. The apparatus includes a solenoid having a coil and an armature. The armature is movable relative to the coil in response to energization of the coil. A control valve delivers a flow of fluid to the actuator. The rate of the fluid flow is responsive to the movement of the armature. An electrical circuit detects a voltage spike across the coil and responsively produces an end-of-fill signal. The voltage spike is generated by an electromotive force produced by the armature in response to the control volume achieving a predetermined end-of-fill pressure.
Abstract: An apparatus controllably moves the forks of a material handling vehicle in traverse directions relative to a carriage assembly. The carriage assembly includes fork position sensors which detect the transverse location of each fork. A controller receives signals from the position sensors and moves the forks to locations a preselected or calculated distance apart. Forktip sensors detect the opening in a load during movement of the forks. The controller receives signals from the forktip sensors and positions the forks such that they are disposable within the load opening. The apparatus is especially suitable for use on an Automatic Guided Vehicle (AGV).
Type:
Grant
Filed:
October 24, 1990
Date of Patent:
October 1, 1991
Assignee:
Caterpillar Industrial Inc.
Inventors:
Andrew P. Blau, Paul D. Grohsmeyer, Joseph J. Harding, Darren L. Krahn
Abstract: A work vehicle (2) having an implement position controller (50). Set elevations and orientations of the work implement (5) can be preselected and changed. The controller (50) automatically positions the implement (5) in the desired elevation and orientation. Means (51) for preventing the work implement (5) from falling into the ground are also provided.
Abstract: The work implements on earthmoving and material handling vehicles are generally controlled with two or more operator control handles or pedals that do not intuitively correspond to the movement of the implement. Generally, the assignment of the implement linkages to the controls is entirely arbitrary, and there exists little correlation between the direction of movement of the implement linkages and those of the control levers and pedals. Inconsistencies also abound between manufacturers and even among different type vehicles within a single manufacturer. These problems compromise the ability and productivity of even the most skilled operator. The invention comprises of two multi-axis joysticks that provide the operator an intuitive control interface to the vehicle. The control system of the invention also provides a coordinated control for spatial placement of the end effector of the work implement.
Type:
Grant
Filed:
March 19, 1990
Date of Patent:
March 26, 1991
Assignee:
Caterpillar Inc.
Inventors:
John M. Hadank, William E. Allen, Walter J. Bradbury, Paul D. Anderson
Abstract: An apparatus is provided for use with non-contacting torque sensors. Many non-contacting torque sensors use bulky inductive coil structures to induce magnetic flux into the shaft whose torque is to be measured, and to sense a change in magnetic permeability of the shaft in response to torque applied thereto. These large, cumbersome structures are quite expensive to fabricate, and difficult to manufacture and install. As a solution, a flexible, ribbonlike inductive coil structure is provided. The dual layer construction of this coil structure enables it to provide adequate magnetic flux distribution, similar to that of much larger coil structures. Furthermore, the unique layout of the coils results in an efficient, accurate structure for inducing and sensing magnetic flux.