WO1999014559A1 - An apparatus for determining the position of a work implement - Google Patents

An apparatus for determining the position of a work implement Download PDF

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Publication number
WO1999014559A1
WO1999014559A1 PCT/US1998/019423 US9819423W WO9914559A1 WO 1999014559 A1 WO1999014559 A1 WO 1999014559A1 US 9819423 W US9819423 W US 9819423W WO 9914559 A1 WO9914559 A1 WO 9914559A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
signal
oscillator
implement
machine
Prior art date
Application number
PCT/US1998/019423
Other languages
French (fr)
Inventor
George Codina
Thomas W. Herrick
David J. Urbanc
Original Assignee
Caterpillar Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Caterpillar Inc. filed Critical Caterpillar Inc.
Priority to DE69816777T priority Critical patent/DE69816777D1/en
Priority to EP98947090A priority patent/EP0938647B1/en
Priority to AU93952/98A priority patent/AU9395298A/en
Priority to JP51816799A priority patent/JP2001507804A/en
Publication of WO1999014559A1 publication Critical patent/WO1999014559A1/en

Links

Classifications

    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02F—DREDGING; SOIL-SHIFTING
    • E02F3/00—Dredgers; Soil-shifting machines
    • E02F3/04—Dredgers; Soil-shifting machines mechanically-driven
    • E02F3/76—Graders, bulldozers, or the like with scraper plates or ploughshare-like elements; Levelling scarifying devices
    • E02F3/80—Component parts
    • E02F3/84—Drives or control devices therefor, e.g. hydraulic drive systems
    • E02F3/844—Drives or control devices therefor, e.g. hydraulic drive systems for positioning the blade, e.g. hydraulically
    • E02F3/847—Drives or control devices therefor, e.g. hydraulic drive systems for positioning the blade, e.g. hydraulically using electromagnetic, optical or acoustic beams to determine the blade position, e.g. laser beams
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
    • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
    • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
    • G01D5/2006—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils
    • G01D5/202—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the self-induction of one or more coils by movable a non-ferromagnetic conductive element

Definitions

  • This invention relates generally to an apparatus for determining the position of a work implement using radar technology.
  • Transducers used in the heavy equipment industry are particularly subject to damage from the severe work environment.
  • Such heavy equipment work implements are typically located in relatively unprotected areas and are subject to; for example, high g-forces, wide temperature variations, dust, water, debris, etc., which can result in both electrical and mechanical failure .
  • the present invention is directed toward overcoming one or more of the problems as set forth above .
  • an apparatus for determining the position of a work implement relative to an earthworking machine is disclosed.
  • An antenna is mounted to the machine and is oriented to transmit a high frequency signal toward the implement and receive a reflected signal back from the implement.
  • An oscillator is electrically coupled to the antenna and energizes the antenna with electrical energy to generate the high frequency signal .
  • the oscillator produces an output signal having a frequency responsive to the inductance of the antenna.
  • a microprocessor based circuit receives the output signal of the oscillator and responsively determines the position of the work implement relative to the machine.
  • the position of the work implement is a function of the frequency of the output signal.
  • Fig. 1 illustrates a planar view of a bulldozer
  • Fig. 2 illustrates an antenna array in relation to the blade of the bulldozer
  • Fig. 3 illustrates an oscillator circuit used in conjunction with each antenna of the antenna array
  • Fig. 4 illustrates a circuit used to measure the frequency of the oscillator circuit shown in Fig. 3.
  • Fig. 1 shows a planar view of an earthmoving machine 10 having a work implement 12.
  • the work implement 12 is utilized to move earth or soil.
  • the earthmoving machine 10 shown in Fig. 1 is a track-type bulldozer 14 and the earthmoving implement 12 is a bulldozer blade 16. While the invention is described using the bulldozer 14 and the bulldozer blade 16, it is intended that the invention also be used on other types of earthmoving machines 10 and earthmoving implements 12 such as loaders, excavators, front shovels, and the like.
  • the bulldozer 14 includes hydraulic lift actuators 18 for raising and lowering the blade 16 and hydraulic tilt actuators 20 for tilting and tipping the blade.
  • the bulldozer 14 also includes a set of tracks 22 and a draft arm 24 to push the blade 16. The present invention is directed toward determining the position of the blade 16.
  • the present invention employs an antenna array 25 that directs high frequency signals to a metal target plate 27 located on the back portion of the blade 16.
  • an antenna array 25 including four antennas 200A-D are mounted in the front portion of the machine 10.
  • the antennas 200 are equally spaced apart and axially aligned with a vertical and horizontal axis 215,210.
  • the antennas 200 are affixed on a plate 26 in a position to transmit high frequency signals to the target 27.
  • the target 27 Upon receiving the high frequency signals, the target 27 reflects the signals back to the antenna array 25.
  • the wavelengths of the transmitted signals are less than half the distance between the antenna array 25 and target 27.
  • each energized antenna 200 induces a current mirror on the target 27 that electrically couples the respective portions of the target 27 to a respective antenna 200 of the antenna array 25.
  • each antenna 200 and the target portions form an inductor whose inductance is responsive to the distance between the respective antenna 200 and the target portions.
  • the transmitted signals may be pulsed at a frequency ranging from 100 to 200 MHz.
  • each antenna 200 is used as an inductor in an oscillator circuit .
  • Antennas 200A,B form an antenna pair that corresponds to the top and bottom portions of the blade 16 and are used to detect distance changes in response to the blade 16 tilting about the horizontal axis 210.
  • Antennas 200C,D form an antenna pair that correspond to the right and left portions of the blade 16 and are used to detect distance changes in response to the blade 16 tilting about a vertical axis 215. Note, it may be preferable for the left and right antenna pair 200C,D to be of a smaller size than the top and bottom antenna pair 200A,B so as to operate in a higher frequency range .
  • the effective inductance of the effected antenna 200 decreases.
  • the distance changes in the horizontal and vertical axis are used to determine the position of the blade 16, e.g., the elevation, pitch, roll and yaw of the blade 16.
  • a smaller axially located circular antenna may also be used as a reference antenna 205.
  • the oscillator circuit 300 is constructed in a similar manner to that of a Colpitt ' s oscillator.
  • the oscillator circuit 300 produces an output signal having a frequency that is a function of the inductance of the antenna 200. More particularly, the operating frequency of the output signal is described by the following equation:
  • L eq represents the inductance of the antenna 200.
  • the electronic circuitry 400 that is used to measure the frequency of the oscillator circuits 300 is shown in Fig. 4.
  • a heterodyne mixer 410 receives an output signal from a respective oscillator circuit 300, as well as, a reference signal from a reference oscillator 405.
  • the reference oscillator 405 is formed with the reference antenna 205 and produces a reference signal having a frequency responsive to the inductance of the reference antenna 205.
  • Each heterodyne mixer 410 produces a mixing signal having a frequency equal to the difference between the output signal of the respective oscillator 300 and the reference signal.
  • a digital comparator 415 is provided for each antenna pair 200A,B and 200C,D and receives the mixing signals from the respective heterodyne mixers 410 and produces a position signal having a magnitude equal to the difference in frequency between the mixing signals.
  • Each position signal represents the change in blade position about the vertical and horizontal axis 210,215.
  • the position signals are delivered to a microprocessor 420 which determines the position of the blade 16 relative to the bulldozer frame. For example, the microprocessor 420 inputs the magnitude of each position signal into a mathematical equation or a look-up table, and determines the blade position.
  • the circuits shown in Fig. 3 and 4 are exemplary, and the manner of design and construction of the circuit described, or similar circuits, would be commonly known to a person skilled in the art.
  • the present invention is directed toward determining the position of a work implement relative to an earthworking machine.
  • the present invention employs an antenna array 25 that transmits high frequency signals to the back portion 27 of the work implement.
  • the work implement reflects the high frequency signals back to the respective antennas 200 of the antenna array 25.
  • the inductance of the antennas 200A-D are monitored by electronic circuitry 400 that produce position signals that represent positional changes of the work implement.
  • a microprocessor 420 receives the position signals and determines the position of the work implement relative of the machine.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mining & Mineral Resources (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Mechanical Engineering (AREA)
  • Acoustics & Sound (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)
  • Position Fixing By Use Of Radio Waves (AREA)

Abstract

An apparatus for determining the position of a work implement (12) relative to an earthworking machine (10). An antenna (200) is mounted to the machine (10) and is oriented to transmit a high frequency signal toward the implement (12) and receive a reflected signal back from the implement (12). An oscillator (300) is electrically coupled to the antenna (200) and energizes the antenna (200) with electrical energy to generate the high frequency signal. The oscillator (300) produces an output signal having a frequency responsive to the inductance of the antenna (200). A microprocessor based circuit (400) receives the output signal of the oscillator (300) and responsively determines the position of the work implement (12) relative to the machine (10). The position of the work implement (12) is a function of the frequency of the output signal.

Description

Description
An Apparatus For Determining The Position Of A Work Implement
Technical Field
This invention relates generally to an apparatus for determining the position of a work implement using radar technology.
Background Art
In the field of implement position sensing, a variety of systems have been proposed in which the movement of the implement is electrically sensed and displayed or used to perform control functions.
Conventional transducers have serious deficiencies in detecting the movement of implements, owing in part to difficulties in mounting the transducers and the harsh environmental conditions to which they are exposed. Transducers used in the heavy equipment industry are particularly subject to damage from the severe work environment. Such heavy equipment work implements are typically located in relatively unprotected areas and are subject to; for example, high g-forces, wide temperature variations, dust, water, debris, etc., which can result in both electrical and mechanical failure .
One attempt to provide a sensor which is particularly suitable for the heavy equipment industry uses radio frequency (RF) signals. One such system is disclosed in U.S. Patent No. 4,737,705 issued 12 April 1988 to Bitar, et al . Bitar transmits a ramping RF signal into a coaxial resonant cavity formed by the hydraulic cylinder. When the cylinder's resonant frequency is transmitted, the signal detected by a receiving antenna reaches a peak. The resonant frequency has a one to one relationship with the cylinder's extension. Thus, by determining the cylinder's resonant frequency, the cylinder's linear extension can be determined. However, such a system is quite expensive and may not be considered to be cost effective for certain work sites.
The present invention is directed toward overcoming one or more of the problems as set forth above .
Disclosure of the Invention
In one aspect of the present invention, an apparatus for determining the position of a work implement relative to an earthworking machine is disclosed. An antenna is mounted to the machine and is oriented to transmit a high frequency signal toward the implement and receive a reflected signal back from the implement. An oscillator is electrically coupled to the antenna and energizes the antenna with electrical energy to generate the high frequency signal . The oscillator produces an output signal having a frequency responsive to the inductance of the antenna. A microprocessor based circuit receives the output signal of the oscillator and responsively determines the position of the work implement relative to the machine. The position of the work implement is a function of the frequency of the output signal.
Brief Description of the Drawings
For a better understanding of the present invention, reference may be made to the accompanying drawings in which: Fig. 1 illustrates a planar view of a bulldozer;
Fig. 2 illustrates an antenna array in relation to the blade of the bulldozer;
Fig. 3 illustrates an oscillator circuit used in conjunction with each antenna of the antenna array; and
Fig. 4 illustrates a circuit used to measure the frequency of the oscillator circuit shown in Fig. 3.
Best Mode for Carrying Out the Invention
With reference to the drawings, Fig. 1 shows a planar view of an earthmoving machine 10 having a work implement 12. The work implement 12 is utilized to move earth or soil.
For illustrative purposes, the earthmoving machine 10 shown in Fig. 1 is a track-type bulldozer 14 and the earthmoving implement 12 is a bulldozer blade 16. While the invention is described using the bulldozer 14 and the bulldozer blade 16, it is intended that the invention also be used on other types of earthmoving machines 10 and earthmoving implements 12 such as loaders, excavators, front shovels, and the like. The bulldozer 14 includes hydraulic lift actuators 18 for raising and lowering the blade 16 and hydraulic tilt actuators 20 for tilting and tipping the blade. The bulldozer 14 also includes a set of tracks 22 and a draft arm 24 to push the blade 16. The present invention is directed toward determining the position of the blade 16. To accomplish this, the present invention employs an antenna array 25 that directs high frequency signals to a metal target plate 27 located on the back portion of the blade 16. The present invention is more fully illustrated with reference to Fig. 2. In the preferred embodiment, an antenna array 25 including four antennas 200A-D are mounted in the front portion of the machine 10. Preferably, the antennas 200 are equally spaced apart and axially aligned with a vertical and horizontal axis 215,210. The antennas 200 are affixed on a plate 26 in a position to transmit high frequency signals to the target 27. Upon receiving the high frequency signals, the target 27 reflects the signals back to the antenna array 25. Preferably, the wavelengths of the transmitted signals are less than half the distance between the antenna array 25 and target 27. This provides for the target 27 to be electrically coupled to antenna array 25. For example, as shown by the dashed lines on the target 27, each energized antenna 200 induces a current mirror on the target 27 that electrically couples the respective portions of the target 27 to a respective antenna 200 of the antenna array 25.
Consequently, each antenna 200 and the target portions (represented by the dashed lines) form an inductor whose inductance is responsive to the distance between the respective antenna 200 and the target portions. For example, the transmitted signals may be pulsed at a frequency ranging from 100 to 200 MHz. As will be explained below, each antenna 200 is used as an inductor in an oscillator circuit .
Antennas 200A,B form an antenna pair that corresponds to the top and bottom portions of the blade 16 and are used to detect distance changes in response to the blade 16 tilting about the horizontal axis 210. Antennas 200C,D form an antenna pair that correspond to the right and left portions of the blade 16 and are used to detect distance changes in response to the blade 16 tilting about a vertical axis 215. Note, it may be preferable for the left and right antenna pair 200C,D to be of a smaller size than the top and bottom antenna pair 200A,B so as to operate in a higher frequency range . As the distance from each antenna 200 to the target 27 increases, the effective inductance of the effected antenna 200 decreases. The distance changes in the horizontal and vertical axis are used to determine the position of the blade 16, e.g., the elevation, pitch, roll and yaw of the blade 16. A smaller axially located circular antenna may also be used as a reference antenna 205.
The oscillator circuit will now be described in detail with reference to Fig. 3. As shown, the oscillator circuit 300 is constructed in a similar manner to that of a Colpitt ' s oscillator. The oscillator circuit 300 produces an output signal having a frequency that is a function of the inductance of the antenna 200. More particularly, the operating frequency of the output signal is described by the following equation:
ffb=2Juo= h* °. where ;
C Cl1 **CC22 ceq / <and ~ C1 + C2
Leq represents the inductance of the antenna 200.
The electronic circuitry 400 that is used to measure the frequency of the oscillator circuits 300 is shown in Fig. 4. A heterodyne mixer 410 receives an output signal from a respective oscillator circuit 300, as well as, a reference signal from a reference oscillator 405. The reference oscillator 405 is formed with the reference antenna 205 and produces a reference signal having a frequency responsive to the inductance of the reference antenna 205. Each heterodyne mixer 410 produces a mixing signal having a frequency equal to the difference between the output signal of the respective oscillator 300 and the reference signal. A digital comparator 415 is provided for each antenna pair 200A,B and 200C,D and receives the mixing signals from the respective heterodyne mixers 410 and produces a position signal having a magnitude equal to the difference in frequency between the mixing signals. Each position signal represents the change in blade position about the vertical and horizontal axis 210,215. The position signals are delivered to a microprocessor 420 which determines the position of the blade 16 relative to the bulldozer frame. For example, the microprocessor 420 inputs the magnitude of each position signal into a mathematical equation or a look-up table, and determines the blade position. The circuits shown in Fig. 3 and 4 are exemplary, and the manner of design and construction of the circuit described, or similar circuits, would be commonly known to a person skilled in the art.
Thus, while the present invention has been particularly shown and described with reference to the preferred embodiment above, it will be understood by those skilled in the art that various additional embodiments may be contemplated without departing from the spirit and scope of the present invention. Industrial Applicability
The present invention is directed toward determining the position of a work implement relative to an earthworking machine. Advantageously, the present invention employs an antenna array 25 that transmits high frequency signals to the back portion 27 of the work implement. The work implement reflects the high frequency signals back to the respective antennas 200 of the antenna array 25. As the position of the work implement changes, the distance between the back portion 27 of the work implement and the antenna array 25 changes, which causes the effective inductance of the antennas 200 to change. The inductance of the antennas 200A-D are monitored by electronic circuitry 400 that produce position signals that represent positional changes of the work implement. A microprocessor 420 receives the position signals and determines the position of the work implement relative of the machine. Other aspects, objects and advantages of the present invention can be obtained from a study of the drawings, the disclosure and the appended claims.

Claims

Claims
1. An apparatus for determining the position of a work implement (12) relative to an earthworking machine (10), the implement (12) being controllably mounted to the machine (10), comprising: an antenna (200) mounted to the machine (10) and oriented to transmit a high frequency signal toward the implement (12) and receive a reflected signal back from the implement (12) ; an oscillator (300) electrically coupled to the antenna and adapted to energize the antenna (200) with electrical energy to generate the high frequency signal, the oscillator (300) producing an output signal having a frequency responsive to the inductance of the antenna (200) ; and a circuit (400) adapted to receive the output signal of the oscillator (300) and responsively determine the position of the work implement (12) relative to the machine (10) , the position being a function of the frequency of the output signal.
2. An apparatus, as set forth in claim 1, including an antenna array (25) comprising four antennas (200) being mounted on a plate located on a front portion of the machine (10) and directed to transmit high frequency signals to a target plate (26) located on a back portion of the implement (12) , the antenna array (25) being electrically coupled to the target plate (25) , wherein the inductance of each antenna (200) is responsive to the distance between a respective antenna (200) and the target plate (26) .
3. An apparatus, as set forth in claim 2, wherein the four antennas (200A-D) include a pair of antennas (200A,B) being equally spaced apart and axially aligned with a vertical axis (215) , and another pair of antennas (200C,D) being equally spaced apart and axially aligned with a horizontal axis (210) that is perpendicular to the vertical axis (215) .
4. An apparatus, as set forth in claim 3, including four oscillators (300A-D) , each oscillator (300A-D) being electrically coupled to a respective antenna (200A-D) .
5. An apparatus, as set forth in claim 4, including a circular antenna (205) axially aligned with the junction formed by the horizontal and vertical axis (210,215), the circular antenna (205) including a reference oscillator (405) that produces a reference signal having a frequency responsive to the inductance of the circular antenna (205) .
6. An apparatus, as set forth in claim 5, including four heterodyne mixers (410) , each mixer being adapted to receive an output signal from a respective oscillator (300A-D) and a reference signal from the reference oscillator (405) , and produce a mixing signal having a frequency equal to the difference between the output signal and the reference signal .
7. An apparatus, as set forth in claim 6, including a digital comparator (415) provided for each antenna pair (200A-B, 200C-D) , each comparator (415) receiving the respective mixing signals and producing a position signal having a magnitude equal to the difference in frequency between the respective mixing signals .
8. An apparatus, as set forth in claim 7, including a microprocessor (420) being adapted to receive the position signals and determine the position of the work implement (12) relative to the machine (10) based on the position signal magnitude.
PCT/US1998/019423 1997-09-16 1998-09-14 An apparatus for determining the position of a work implement WO1999014559A1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
DE69816777T DE69816777D1 (en) 1997-09-16 1998-09-14 EARTH CONSTRUCTION MACHINE WITH A DEVICE FOR LOCATING A TOOL
EP98947090A EP0938647B1 (en) 1997-09-16 1998-09-14 Earthworking machine including an apparatus for determining the position of a work implement
AU93952/98A AU9395298A (en) 1997-09-16 1998-09-14 An apparatus for determining the position of a work implement
JP51816799A JP2001507804A (en) 1997-09-16 1998-09-14 A device that determines the position of the work implement

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US08/931,335 US5880681A (en) 1997-09-16 1997-09-16 Apparatus for determining the position of a work implement
US08/931,335 1997-09-16

Publications (1)

Publication Number Publication Date
WO1999014559A1 true WO1999014559A1 (en) 1999-03-25

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Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1998/019423 WO1999014559A1 (en) 1997-09-16 1998-09-14 An apparatus for determining the position of a work implement

Country Status (6)

Country Link
US (1) US5880681A (en)
EP (1) EP0938647B1 (en)
JP (1) JP2001507804A (en)
AU (1) AU9395298A (en)
DE (1) DE69816777D1 (en)
WO (1) WO1999014559A1 (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6377215B1 (en) * 1998-06-09 2002-04-23 Wabtec Railway Electronics Apparatus and method for detecting railroad locomotive turns by monitoring truck orientation
US8478492B2 (en) * 1998-11-27 2013-07-02 Caterpillar Trimble Control Technologies, Inc. Method and system for performing non-contact based determination of the position of an implement
US10458099B2 (en) 2004-08-26 2019-10-29 Caterpillar Trimble Control Technologies Llc Auto recognition of at least one standoff target to determine position information for a mobile machine
US7121355B2 (en) * 2004-09-21 2006-10-17 Cnh America Llc Bulldozer autograding system
US7293376B2 (en) * 2004-11-23 2007-11-13 Caterpillar Inc. Grading control system
US20060124323A1 (en) * 2004-11-30 2006-06-15 Caterpillar Inc. Work linkage position determining system
US10030358B2 (en) * 2014-02-13 2018-07-24 Trimble Inc. Non-contact location and orientation determination of an implement coupled with a mobile machine
US9322148B2 (en) 2014-06-16 2016-04-26 Caterpillar Inc. System and method for terrain mapping
US9567731B2 (en) * 2015-05-18 2017-02-14 Caterpillar Inc. Implement position calibration using compaction factor
US10815642B2 (en) 2016-03-24 2020-10-27 Volvo Construction Equipment Ab Wheel loader front unit and a wheel loader
US11714178B1 (en) 2022-07-22 2023-08-01 United Arab Emirates University Method of aligning a first alignable element with a second alignable element and a system implementing the same

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0537747A2 (en) * 1991-10-15 1993-04-21 Omron Corporation Oscillator circuit and proximity switch using it
EP0544043A1 (en) * 1991-11-25 1993-06-02 Neopost Industrie Positional encoder
US5560431A (en) * 1995-07-21 1996-10-01 Caterpillar Inc. Site profile based control system and method for an earthmoving implement

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4737705A (en) * 1986-11-05 1988-04-12 Caterpillar Inc. Linear position sensor using a coaxial resonant cavity
US4757745A (en) * 1987-02-26 1988-07-19 Vickers, Incorporated Microwave antenna and dielectric property change frequency compensation system in electrohydraulic servo with piston position control
IT1240133B (en) * 1990-03-16 1993-11-27 Prima Electronics S.P.A. POSITION TRANSDUCER DEVICE
FR2675609B1 (en) * 1991-04-16 1995-06-16 Alsthom Gec DEVICE FOR SIGNALING THE POSITION OF A MOBILE MEMBER.
US5241278A (en) * 1991-07-05 1993-08-31 Caterpillar Inc. Radio frequency linear position sensor using two subsequent harmonics
US5438274A (en) * 1991-12-23 1995-08-01 Caterpillar Linear position sensor using a coaxial resonant cavity
US5438261A (en) * 1994-02-16 1995-08-01 Caterpillar Inc. Inductive sensing apparatus for a hydraulic cylinder
US5647439A (en) * 1995-12-14 1997-07-15 Caterpillar Inc. Implement control system for locating a surface interface and removing a layer of material
US5701793A (en) * 1996-06-24 1997-12-30 Catepillar Inc. Method and apparatus for controlling an implement of a work machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0537747A2 (en) * 1991-10-15 1993-04-21 Omron Corporation Oscillator circuit and proximity switch using it
EP0544043A1 (en) * 1991-11-25 1993-06-02 Neopost Industrie Positional encoder
US5560431A (en) * 1995-07-21 1996-10-01 Caterpillar Inc. Site profile based control system and method for an earthmoving implement

Also Published As

Publication number Publication date
EP0938647B1 (en) 2003-07-30
AU9395298A (en) 1999-04-05
JP2001507804A (en) 2001-06-12
EP0938647A1 (en) 1999-09-01
DE69816777D1 (en) 2003-09-04
US5880681A (en) 1999-03-09

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