US3674094A - Automatic slope controller - Google Patents

Automatic slope controller Download PDF

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Publication number
US3674094A
US3674094A US68290A US3674094DA US3674094A US 3674094 A US3674094 A US 3674094A US 68290 A US68290 A US 68290A US 3674094D A US3674094D A US 3674094DA US 3674094 A US3674094 A US 3674094A
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United States
Prior art keywords
sensing means
slope
set forth
machine
pendulum
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Legal status (The legal status 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 status listed.)
Expired - Lifetime
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US68290A
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English (en)
Inventor
Leland E Kuntz
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Danfoss Power Solutions US Co
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Honeywell Inc
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Assigned to SUNDSTRAND CORPORATION, A CORP. OF DE reassignment SUNDSTRAND CORPORATION, A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HONEYWELL INC., A CORP. OF DE
Anticipated expiration legal-status Critical
Assigned to SUNDSTRAND-SAUER COMPANY, A GENERAL PARTNERSHIP OF DE reassignment SUNDSTRAND-SAUER COMPANY, A GENERAL PARTNERSHIP OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SUNDSTRAND CORPORATION, A DE CORP.
Expired - Lifetime legal-status Critical Current

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    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
    • E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
    • E01C19/004—Devices for guiding or controlling the machines along a predetermined path

Definitions

  • a controller for a road finishing machine which is adapted to match the slope of the surface presently being prepared to the ⁇ 5 References Cited slope of an adjacent surface previously prepared embodying a first means for sensing the slope of the previously prepared UNITED STATES PATENTS surface, a second means for sensing the slope of the surface currently being prepared and control means for comparing the outputs of the two sensors and for providing an error signal indicative of the difference of the two slopes.
  • This invention is designed to eliminate that error by providing for the automatic control of the slope of the surface prepared by the machine.
  • This automatic control is accomplished by providing a traveling ski dragged behind or along the side of the road finishing machine. Mounted on the ski .is a gravity sensing device which gives an output indicative of the slope angle of the previously prepared surface. A second gravity sensing device is mounted on the road finishing machine to indicate the slope angle of the machine as it makes its current pass. The outputs of these two sensors are then compared to indicate the difierence between the actual slope angle of the machine and the desired slope angle. This difference in slope angles of the two adjacent passes results in an error signal which is used to adjust the machine in a manner tending to eliminate the error signal.
  • FIG. 1 is a diagrammatic representation of a machine as it makes its current pass.
  • FIG. 2 is a simplified circuit diagram of the automatic control.
  • FIG. 3 is a detailed schematic drawing of the automatic controller for the road finishing machine.
  • FIG. I a machine M is shown performing its road finishing operations.
  • the machine traveling into the drawing for example, either drags behind or alongside a traveling ski upon which the reference pendulum is mounted.
  • the traveling ski rides over the surface previously prepared and the reference pendulum is used to measure the slope angle of that surface.
  • Mounted upon the machine is a second pendulum utilized to indicate the slope angle of the machine as it makes its current pass. Because pendulums are used, they have for their reference the gravity of the earth. The outputs of these two pendulums will then be compared and the error signal that results will indicate the difference by which the slope angle of the surface prepared by the machine in making its current pass has deviated from the slope angle of the surface prepared in the previous pass.
  • This error signal is then used to adjust the slope of the machine in its current pass.
  • the slope angle of all of the passes of the machine had to 'be non-automatically, continuously varied.
  • Such nonautomatic control made it extremely difficult, if not impossible, to adequately match the slope angle of the current pass to the slope angle of the previous pass.
  • the slope angle of the first pass is manually controlled; thereafter, the slope angles of succeeding passes may be completely, automatically controlled.
  • FIG. 2 is a brief schematic diagram of the automatic controller.
  • the automatic controller comprises essentially three elements: a machine mounted pendulum to indicate the current slope angle of the machine; a reference pendulum to indicate the desired slope angle of the machine; and, a comparator to produce an error signal representative of the deviation of the slope angles of the machine between the actual and desired values.
  • the machine mounted pendulum comprises a structure D upon which a weight W1 is mounted. The weight causes the structureD to seek a gravity reference.
  • the structure D is mounted on one end of the shaft at the other end of which is mounted a core C which will rotate in accordance with the rotation of structure D.
  • the core cooperates with a transformer having a primary P and two secondaries, S1 and S2, which are connected to a comparator.
  • the reference pendulum comprises an arm which is weighted by W2 causing the arm to seek a gravity reference and, in so doing, sweeps across the potentiometer P2.
  • a potentiometer P1 is provided for controlling the machine whenever manual operation is desired.
  • the ends of the potentiometer of the reference pendulum and the setpoint potentiometer are connected together and to a comparator, and the arms of the two potentiometers are connected to a switch S.
  • the switch S has a movable contact, a manual contact M connected to the arm of P1, and an automatic contact A connected to the arm of P2. The movable contact of the switch S will thus connect either P1 or P2 to the comparator to provide either manual or automatic control.
  • Offset potentiometers P3 and P4 are included to facilitate an initial adjustment of the reference potentiometer to insure that the traveling ski will have a predetermined angle with respect to the machine.
  • potentiometers P3 and P4 ganged together, an increase in resistance of one will result in a decrease in resistance of the other.
  • the resistances on either side of the arm of P2 will change. The machine will see this change as though there had been a change in slope angle of the travelling ski. The machine, therefore, will adjust its slope angle.
  • a crown in the road can be prograrned into the automatic controller or an initial alignment of the machine and traveling ski can be made.
  • the comparator compares the outputs of the two secondaries with either the reference pendulum or the set point potentiometer, depending upon the state of switch S, and produces an error signal representative of the deviation of the machine pendulum from the reference pendulum or the set point potentiometer, whichever is used. This error signal is then amplified by the amplifier used to control the machine.
  • FIG. 3 is a more detailed description of the circuit controller and shows, by way of example only, the contents of the comparator.
  • Secondary S1 is connected across the input of a full wave bridge rectifier comprising diodes D1, D2, D3, and D4, and secondary S2 is connected across the inputs of a full wave bridge rectifier comprising diodes D5, D6, D7, and D8.
  • These two full wave bridge rectifiers are connected in series additive fashion. The output of these two rectifiers is taken across three terminals, 14, 15 and 16. Terminal 14 is connected to the movable contact of switch SW1 and terminal 16 is connected to the movable contact of switch SW2.
  • switch SW1 is connected to one side of the reference pendulum potentiometer P2 while contact A2 of switch SW2 is connected to the other side of potentiometer P2.
  • the movable arm of P2 is connected to the automatic contact, A3, of switch SW3.
  • the manual contact, M1, of switch SW1 is connected to one side of the set point potentiometer P1 whereas the contact M2 of switch SW2 is connected to the other side of this potentiometer.
  • the movable arm of potentiometer P1 is connected to the manual contact M3 of switch SW3.
  • the movable contact of switches SW1, SW2 and SW3 are ganged together for simultaneous operation, and operate to connect either P1 or P2 to the comparator to provide either manual or automatic control of the machine.
  • the machine pendulum is designed such that when the core is in a neutral position with respect to both of the secondaries,
  • the outputs across the two bridge rectifier circuits will be equal and if the reference pendulum, used when automatic operation is desired, senses a level slope of the previous pass, the movable arm of potentiometer P2 will be at its mid point position such that the voltage impressed on either side of the arm will be equal. Thus, the voltages on the arm of the reference pendulum potentiometer will equal the voltage at terminal 15, and the output taken across 12 and 13 will be zero indicating that no correction is needed.
  • the reference potentiometer arm is moved due to a change in the slope angle in the previous pass, such movement of the potentiometer arm will cause an unbalance of the voltage across that potentiometer and, therefore, an output will result across terminals 12 and 13. This output is used to adjust the slope angle of the machine such that core C will be moved in a manner to alter the voltages across the two rectifier bridges to equal their respective voltages across potentiometer P2 thus reducing the voltage across terminals 12 and 13 to zero.
  • Output terminals 12 and 13 are connected across a differential amplifier consisting of transistors Q1, Q2, Q3 and Q4 and biasing resistors R2, R3, R4 and R5. Resistor R1, diodes D9, D and D11 and transistor OS are included to provide a temperature-compensated bias for the differential amplifier transistors.
  • Output terminal 12 is connected to the base of transistor Q4, and transistor O3 is connected to transistor Q4 in emitter follower fashion.
  • Output terminal 13 is connected to transistor Q1, and transistor Q2 is connected to transistor 01 in emitter follower fashion.
  • the output of the differential amplifier is taken across the collectors of transistors Q2 and Q3, and these outputs are amplified by suitable transistor power amplifiers to provide outputs at terminals 10 and l 1.
  • a triangular wave form generator is connected to the junction of terminal 13 and the base of O1 to provide time base proportioning operation of the differential amplifier and the transistors of the power amplifier stages.
  • the reason for using such time base proportioning is to operate the transistors in a fully on or fully off condition.
  • a DC proportioning system i.e., where no additional voltage is added to the base of Q1
  • the transistors are operated in a partly on state thus increasing the wattage on the transistors which raises their temperature.
  • the wattage is decreased and, therefore, the temperature is decreased.
  • smaller and less expensive transistors may be used.
  • the transistors of the differential amplifier are biased such that they fully saturate just after an input is received from the triangular wave form generator; thus, although the input is a triangular wave form, the output of the differential amplifier is a square wave.
  • the outputs of the terminals 10 and 11 are equal but 180 out of phase such that the total effect on the output as seen by terminals 10 and 11 is essentially zero.
  • this output in the form of a DC voltage, offsets the biasing of the differential amplifier causing the square wave output to shift.
  • This shifiing of the output will result in an average output across terminals 10 and 1 1 indicating the necessity of adjusting the slope angle of the machine.
  • An example of a device which can be used to adjust this slope angle is a servo valve.
  • a device for automatically controlling a road finishing machine wherein the machine makes several consecutive parallel passes in its road finishing operations and wherein it is desired to match the slope of the current pass of the machine to the slope of the surface prepared by the previous pass, comprising:
  • first sensing means for producing an output indicative of the slope angle of the surface prepared by the road finishing machine in making its previous pass
  • second sensing means for producing an output indicative of the slope angle of the current pass of the road finishing machine
  • comparison means connected to said first and second sensing means for comparing the outputs of the first and second sensing means and producing an error signal, said error signal representing the difference in the slope angles of the current pass and of the surface prepared by the previous pass.
  • said first sensing means comprises a pendulum gravity sensor.
  • a device as set forth in claim 1 wherein said second sensing means comprises a pendulum gravity sensor.
  • said pendulum 3 gravity sensor comprises:
  • a primary coil adapted to receive an alternating current signal
  • a core connected to and movable by said weighted structure whereby movement of said core produces a change in the output signals across said secondary coils.
  • said comparison means comprises:
  • each secondary coil being connected across its respective bridge, said bridges being interconnected so as to be series additive so that the bridge has two end junctions and a midpoint, and means connecting said first sensing means across the two end points of the bridge.
  • a device as set forth in claim 5 further comprising, a manually adjustable reference means, and switching means for selectively connecting either the first sensing means or the manually adjustable reference means across the end junctions of the bridges.
  • each of said first and second sensing means comprises a pendulum gravity sensor.
  • offset means are connected to the first sensing means for adjusting the output of said first sensing means.
  • said first sensing means comprises a traveling ski adapted to be mechanically connected to said machine, said ski extending over a substantial transverse portion of said previously prepared surface, and a pendulum gravity sensor mounted upon said ski to sense the means.

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  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Road Repair (AREA)
  • Control Of Position Or Direction (AREA)
  • Control Of Position, Course, Altitude, Or Attitude Of Moving Bodies (AREA)
US68290A 1970-08-31 1970-08-31 Automatic slope controller Expired - Lifetime US3674094A (en)

Applications Claiming Priority (1)

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US6829070A 1970-08-31 1970-08-31

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Application Number Title Priority Date Filing Date
US68290A Expired - Lifetime US3674094A (en) 1970-08-31 1970-08-31 Automatic slope controller

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US (1) US3674094A (de)
DE (1) DE2143231A1 (de)
FR (1) FR2103624B1 (de)
GB (1) GB1363728A (de)

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3791452A (en) * 1971-03-17 1974-02-12 Grad Line Control system for road grader
US3831683A (en) * 1971-09-06 1974-08-27 Hitachi Construction Machinery System for controlling the level of an earth-removing blade of a bulldozer
US3873226A (en) * 1973-07-11 1975-03-25 Laserplane Corp Laser beam control system for road paving machines
US3879149A (en) * 1972-09-18 1975-04-22 Barber Greene Co Method and apparatus for providing grade control for the screed of a paver or the like
US3908765A (en) * 1973-03-01 1975-09-30 Honeywell Inc Floating position proportional control system
US3946825A (en) * 1973-08-14 1976-03-30 Maschinenfabrik Fahr Ag Automatic steering system for standing-crop harvester
USRE28979E (en) * 1971-03-17 1976-09-28 Grad-Line, Inc. Control system for road grader
US4072349A (en) * 1973-12-07 1978-02-07 Coal Industry (Patents) Limited Steering of mining machines
US4363377A (en) * 1980-09-22 1982-12-14 Deere & Company Active seat suspension control system
US4545439A (en) * 1983-07-01 1985-10-08 Sellett Andrew J Apparatus for determining the true cross slope of a blade
US4925340A (en) * 1989-05-12 1990-05-15 Sundstrand-Sauer Screed slope controller for a paver
US5009546A (en) * 1987-04-10 1991-04-23 Domenico Domenighetti Road paver-finisher with a combination of axles with steering wheels and crawler units
US5944168A (en) * 1998-09-28 1999-08-31 Cambelt International Corporation Crescent shaped support cover
US6109825A (en) * 1999-05-26 2000-08-29 Power Curbers, Inc. Paving apparatus with automatic mold positioning control system
US6530721B2 (en) * 2001-01-19 2003-03-11 Trimble Navigation Limited Method for control system setup
US6672797B1 (en) * 1999-01-27 2004-01-06 Trimble Navigation Limited Linear transducer arrangement
US6692185B2 (en) 2001-10-17 2004-02-17 Power Curbers, Inc. Adjusting arrangement for steerable transport assembly for self-propelled construction vehicle
US6715957B2 (en) 2001-10-17 2004-04-06 Power Curbers, Inc. Paving apparatus with retractable pavement forming assembly
US20040086337A1 (en) * 1999-01-27 2004-05-06 Zachman Mark E. Transducer arrangement
US20140110990A1 (en) * 2012-10-19 2014-04-24 Wirtgen Gmbh Self-Propelled Building Machine
US8807867B2 (en) 2006-12-22 2014-08-19 Wirtgen Gmbh Road milling machine and method for measuring the milling depth
US8899689B2 (en) * 2011-12-21 2014-12-02 Caterpillar Paving Products Inc. Automatic cut-transition milling machine and method
US9010871B2 (en) 2005-09-12 2015-04-21 Wirtgen Gmbh Automotive construction machine, as well as lifting column for a construction machine

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2883594A (en) * 1956-04-12 1959-04-21 Honeywell Regulator Co Servomotor control system adapted for stabilizing
US2905878A (en) * 1957-03-20 1959-09-22 Preco Inc Servo control system
US3026638A (en) * 1960-01-28 1962-03-27 Sanders Associates Inc Automatic blade slope control system
US3029716A (en) * 1958-02-27 1962-04-17 Preco Inc Paving machine control system
US3111070A (en) * 1961-12-08 1963-11-19 Iowa Mfg Co Cedar Rapids Paving machine with automatically controlled screed
US3181441A (en) * 1961-10-12 1965-05-04 Honeywell Inc Control apparatus
US3229391A (en) * 1964-03-11 1966-01-18 Caterpillar Tractor Co Automatic blade control for a road grader with a blade simulator mounted in a ball and socket connection
US3264959A (en) * 1963-08-06 1966-08-09 Preco Inc Paving machine slope control system
US3264958A (en) * 1962-04-19 1966-08-09 Preco Inc Slope and grade control for paving machines
US3334560A (en) * 1964-05-25 1967-08-08 George E Long Control system for establishing predetermined surfaces
US3454101A (en) * 1967-06-12 1969-07-08 Caterpillar Tractor Co Electronic circuit for automatic blade control for motor graders

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2883594A (en) * 1956-04-12 1959-04-21 Honeywell Regulator Co Servomotor control system adapted for stabilizing
US2905878A (en) * 1957-03-20 1959-09-22 Preco Inc Servo control system
US3029716A (en) * 1958-02-27 1962-04-17 Preco Inc Paving machine control system
US3026638A (en) * 1960-01-28 1962-03-27 Sanders Associates Inc Automatic blade slope control system
US3181441A (en) * 1961-10-12 1965-05-04 Honeywell Inc Control apparatus
US3111070A (en) * 1961-12-08 1963-11-19 Iowa Mfg Co Cedar Rapids Paving machine with automatically controlled screed
US3264958A (en) * 1962-04-19 1966-08-09 Preco Inc Slope and grade control for paving machines
US3264959A (en) * 1963-08-06 1966-08-09 Preco Inc Paving machine slope control system
US3229391A (en) * 1964-03-11 1966-01-18 Caterpillar Tractor Co Automatic blade control for a road grader with a blade simulator mounted in a ball and socket connection
US3334560A (en) * 1964-05-25 1967-08-08 George E Long Control system for establishing predetermined surfaces
US3454101A (en) * 1967-06-12 1969-07-08 Caterpillar Tractor Co Electronic circuit for automatic blade control for motor graders

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3791452A (en) * 1971-03-17 1974-02-12 Grad Line Control system for road grader
USRE28979E (en) * 1971-03-17 1976-09-28 Grad-Line, Inc. Control system for road grader
US3831683A (en) * 1971-09-06 1974-08-27 Hitachi Construction Machinery System for controlling the level of an earth-removing blade of a bulldozer
US3879149A (en) * 1972-09-18 1975-04-22 Barber Greene Co Method and apparatus for providing grade control for the screed of a paver or the like
US3908765A (en) * 1973-03-01 1975-09-30 Honeywell Inc Floating position proportional control system
US3873226A (en) * 1973-07-11 1975-03-25 Laserplane Corp Laser beam control system for road paving machines
US3946825A (en) * 1973-08-14 1976-03-30 Maschinenfabrik Fahr Ag Automatic steering system for standing-crop harvester
US4072349A (en) * 1973-12-07 1978-02-07 Coal Industry (Patents) Limited Steering of mining machines
US4363377A (en) * 1980-09-22 1982-12-14 Deere & Company Active seat suspension control system
US4545439A (en) * 1983-07-01 1985-10-08 Sellett Andrew J Apparatus for determining the true cross slope of a blade
US5009546A (en) * 1987-04-10 1991-04-23 Domenico Domenighetti Road paver-finisher with a combination of axles with steering wheels and crawler units
US4925340A (en) * 1989-05-12 1990-05-15 Sundstrand-Sauer Screed slope controller for a paver
US5944168A (en) * 1998-09-28 1999-08-31 Cambelt International Corporation Crescent shaped support cover
WO2000018672A1 (en) * 1998-09-28 2000-04-06 Cambelt International Corporation Crescent shaped support cover
US6672797B1 (en) * 1999-01-27 2004-01-06 Trimble Navigation Limited Linear transducer arrangement
US20040086337A1 (en) * 1999-01-27 2004-05-06 Zachman Mark E. Transducer arrangement
US7559718B2 (en) 1999-01-27 2009-07-14 Trimble Navigation Limited Transducer arrangement
US6109825A (en) * 1999-05-26 2000-08-29 Power Curbers, Inc. Paving apparatus with automatic mold positioning control system
US6530721B2 (en) * 2001-01-19 2003-03-11 Trimble Navigation Limited Method for control system setup
US6692185B2 (en) 2001-10-17 2004-02-17 Power Curbers, Inc. Adjusting arrangement for steerable transport assembly for self-propelled construction vehicle
US6715957B2 (en) 2001-10-17 2004-04-06 Power Curbers, Inc. Paving apparatus with retractable pavement forming assembly
US9010871B2 (en) 2005-09-12 2015-04-21 Wirtgen Gmbh Automotive construction machine, as well as lifting column for a construction machine
US9656530B2 (en) 2005-09-12 2017-05-23 Wirtgen Gmbh Automotive construction machine, as well as lifting column for a construction machine
US9523176B2 (en) * 2006-12-22 2016-12-20 Wirtgen Gmbh Road milling machine and method for measuring the milling depth
US20150137577A1 (en) * 2006-12-22 2015-05-21 Wirtgen Gmbh Road Milling Machine And Method For Measuring The Milling Depth
US8807867B2 (en) 2006-12-22 2014-08-19 Wirtgen Gmbh Road milling machine and method for measuring the milling depth
US9879390B2 (en) 2006-12-22 2018-01-30 Wirtgen Gmbh Road milling machine and method for measuring the milling depth
US9879391B2 (en) 2006-12-22 2018-01-30 Wirtgen Gmbh Road milling machine and method for measuring the milling depth
US11655599B2 (en) 2006-12-22 2023-05-23 Wirtgen America, Inc. Road milling machine and method for measuring the milling depth
US8899689B2 (en) * 2011-12-21 2014-12-02 Caterpillar Paving Products Inc. Automatic cut-transition milling machine and method
US8998344B2 (en) * 2012-10-19 2015-04-07 Wirtgen Gmbh Self-propelled building machine
US20140110990A1 (en) * 2012-10-19 2014-04-24 Wirtgen Gmbh Self-Propelled Building Machine
US9670630B2 (en) 2012-10-19 2017-06-06 Wirtgen Gmbh Self-propelled building machine

Also Published As

Publication number Publication date
FR2103624B1 (de) 1975-02-07
DE2143231A1 (de) 1972-03-09
GB1363728A (en) 1974-08-14
FR2103624A1 (de) 1972-04-14

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Owner name: SUNDSTRAND CORPORATION, 4751 HARRISON AVE., ROCKFO

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Effective date: 19890807