Control and method for positioning a tool of a construction apparatus

• US 6,364,028 B1
• Filed: 11/22/2000
• Issued: 04/02/2002
• Est. Priority Date: 09/23/1998
• Status: Expired due to Term

• Current Assignee: Hexagon Holdings Incorporated
• Original Assignee: Laser Alignment, Inc. (Hexagon AB)
• Inventors: Steenwyk, Timothy E., Ferrell, Dirrick J., Stoepker, Ross C., Walstra, Eric Jon
• Primary Examiner(s): Novosad, Christopher J.
• Application Number:
  US09/718,762
• Time in Patent Office: 496 Days
• Field of Search: 172/2, 172/4, 172/4.5, 172/781, 172/811, 172/1, 701/50
• US Class Current: 172/1
• CPC Class Codes: E02F 3/847 using electromagnetic, optical or acoustic beams to determine the blade position, e.g. laser beams
• CPC Class Codes: G01S 2007/52014 involving a reference reflector integrated in the sensor or transducer configuration

Abstract

A control system for establishing grade and elevation control for a tool of a construction apparatus for maintaining the vertical position of the tool relative to a reference includes a first ultrasonic transducer configured to be carried by the construction apparatus, with the first transducer transmitting and receiving acoustic waves, at least one reflector, a second ultrasonic transducer configured to be carried by the construction apparatus, with the second transducer receiving acoustic waves, and a controller coupled to the first and second ultrasonic transducers which drive the transducers to produce an acoustic wave and monitors the time reflections of the acoustic wave are respectively received by the first and second transducers. The controller determines the local speed of sound based on a first in time reflection received by the second ultrasonic transducer and determines the distance from the construction tool to a reference based on the local speed of sound and a second in time reflection received by both the first and second ultrasonic transducers. The controller produces at least one electrical signal as a function of the distance of the ultrasonic transducers from the reference. In preferred form, the controller communicates the signal to a positioning device, which signal actuates the positioning device to adjust the position of the construction tool with respect to the reference.

Claims

1. A control system for establishing grade and elevation control for a tool of a construction apparatus and for maintaining the vertical position of the tool relative to a reference, the tool being carried by the construction apparatus, and the construction apparatus including at least one positioning device that responds to signals from said control system to adjust the position of the tool, said control system comprising:

a first ultrasonic transducer configured to be carried by the construction apparatus, said first transducer transmitting and receiving acoustic waves;

at least one reflector;

a second ultrasonic transducer configured to be carried by said construction apparatus and spaced a distance from said first ultrasonic transducer, said second transducer receiving acoustic waves, and said reflector spaced from said second transducer a distance less than said distance between said transducers whereby said reflector is at least in close proximity to said second transducer;

a controller coupled to said first and second ultrasonic transducers, said controller driving said first and second transducers to produce an acoustic wave and monitoring the time reflections of the acoustic wave are respectively received by said first and second transducers; and

said controller determining the local speed of sound based on a first in time reflection received by said second ultrasonic transducer from said reflector and determining the distance from the construction tool to a reference based on the local speed of sound and a second in time reflection received by both of said first and second ultrasonic transducers, said controller producing at least one electrical signal as a function of the distance of said ultrasonic transducers from the reference.

2. The control system according to claim 1, wherein said controller communicates said signal to the positioning device, and said signal actuating the positioning device to adjust the position of the construction tool with respect to the reference.

3. The control system according to claim 1, wherein said controller determines distance to at least one of a string, a ground surface, and a curb.

4. The control system according to claim 1, wherein said at least one reflector comprises a first reflector, further comprising a second reflector, said second reflector reflecting said first acoustic wave from said first reflector to said second transducer.

5. The control system according to claim 4, wherein at least one of said first and second reflectors comprises a cylindrical member.

6. The control system according to claim 5, wherein said cylindrical member comprises an aluminum rod.

7. The control system according to claim 4, wherein said second reflector is positioned in close proximity to said first transducer.

8. The control system according to claim 7, wherein said first and second ultrasonic transducers each have a piezoelectric element and a screen over the piezoelectric element, said first reflector being mounted at said screen of said second ultrasonic transducer.

9. The control system according to claim 8, wherein said at least one reflector is mounted to said screen of said one ultrasonic transducer.

10. The control system according to claim 9, wherein said first and second reflectors are mounted to respective surfaces of said first and second transducers.

11. The control system according to claim 4, wherein each of said first and second reflectors are positioned in close proximity to a respective transducer of said first and second ultrasonic transducers.

12. The control system according to claim 4, wherein said first and second transducers are mounted in a housing, said first and second reflectors being positioned in said housing whereby said first and second reflectors do not protrude from said housing.

13. The control system according to claim 1, wherein said first and second transducers and said controller are supported in a common housing.

14. The control system according to claim 1, further comprising a remote sensor, said controller driving said first and second ultrasonic transducers to produce an acoustic wave and monitoring time reflections of the acoustic wave are respectively received by said first and second ultrasonic transducers from said remote reflector, said controller determining the local speed of sound based on the first in time reflection received by said second ultrasonic transducer from one of said at least one reflector and said remote reflector and determining the distance from the tool to a reference based on the local speed of sound and a second in time reflection received by both of said first and second ultrasonic transducers, and said controller producing at least one electrical signal as a function of the distance of said ultrasonic transducers from the reference.

15. The control system according to claim 14, wherein said remote reflector is spaced from said first and second ultrasonic transducers in a range of about 8 to 13 inches.

16. A control system for establishing at least one of grade and elevation control for a tool on a construction apparatus, said control system for maintaining a vertical lateral position of the tool relative to a reference, the tool being movably mounted on a construction apparatus, and the construction apparatus including at least one positioning device that responds to signals from said control system to adjust the position of the tool, control system comprising:

a first sensor configured to be carried by construction tool, said first sensor measuring distance to a reference and generating sensor signals, said sensor signals being a function of the distance to the reference;

a sensor control coupled to said first sensor and adapted to define a target position, said sensor control comparing said sensor signals with said target position of the construction tool, said sensor control selectively producing a drive signal in response to the relationship of said sensor signals to said target position and transmitting the drive signal to the tool positioning device to maintain a desired position of said construction tool with respect to said reference;

a reflector; and

a second sensor coupled to said sensor control and spaced from said first sensor the distance, said reflector being spaced from said second sensor less than said distance whereby said reflector is at least in close proximity to said second sensor, said first sensor generating at least a first sensor signal, said second sensor detecting a first reflection of said first sensor signal from said reflector, and said sensor control determining the local speed of sound based on said first reflection.

17. The control system according to claim 16, wherein said reflector comprises a pair of cylindrical reflector members, each of said cylindrical reflector members being associated with a respective sensor of said first and second sensors and being mounted in close proximity to said respective sensor.

18. The control system according to claim 17, wherein said first and second sensors each include an emitting surface, and each of said cylindrical reflector members being mounted adjacent said emitting surfaces of said respective sensor.

19. The control system according to claim 16, wherein said sensor control is further adapted to detect on which side of the construction apparatus said sensor is mounted.

20. The control system according to claim 19, wherein said sensor control includes a diode bridge for detecting which side of the construction apparatus said sensor is mounted.

21. The control system according to claim 16, wherein said sensor control includes at least one microprocessor.

22. The control system according to claim 21, wherein said at least one microprocessor comprises a first microprocessor, said sensor control further including a second microprocessor, and said first microprocessor driving said sensor, and said second microprocessor being adapted to drive the positioning device of the construction apparatus.

23. The control system according to claim 16, wherein said sensors comprise ultrasonic transducers.

24. The control system according to claim 16, wherein said reflector comprises an ultrasonic reflector, said first sensor comprising a first ultrasonic transducer, said second sensor comprising a second ultrasonic transducer, said first ultrasonic transducer generating an ultrasonic wave, and said second ultrasonic transducer detecting a first reflection of said ultrasonic wave from said ultrasonic reflector, and said sensor control determining the local speed of sound based on said first reflection.

25. A method of controlling the grade and elevation of a tool on a construction apparatus relative to a reference, the construction tool being movably mounted on a construction apparatus, and the construction apparatus including at least one positioning device for adjusting the position of the construction tool, the method comprising the steps of:

providing a controller and first and second ultrasonic transducers on the construction apparatus in a spaced relationship having a distance therebetween;

mounting a reflector at a distance to said second transducer that is less than the distance between the transducers to provide a close reflector;

driving said first transducer to produce an acoustic wave;

monitoring the time reflections of the acoustic wave are respectively received by said first and second transducers;

determining the local speed of sound based on a first in time reflection received by the second ultrasonic transducer;

determining the distance from the construction tool to a reference based on the local speed of sound and a second in time reflection received by said first and second ultrasonic transducers; and

producing at least one electrical signal with said controller as a function of the distance.

26. A method according to claim 25, further comprising:

communicating said electrical signal to the positioning device; and

actuating the positioning device with said electrical signal to adjust the position of the construction tool with respect to the reference.

27. The method according to claim 25, wherein determining the distance includes determining the distance to at least one of a string, a ground surface, and a curb.

28. The method according to claim 25, wherein determining the local speed of sound includes:

receiving the first-in-time reflection of an acoustic wave from the reflector; and

measuring the time between generating an acoustic wave with one of the ultrasonic transducers and said receiving.

29. A method for controlling a tool on a construction apparatus relative to a reference, the construction tool being movably mounted on a construction apparatus, the construction apparatus including at least one positioning device having a solenoid operated hydraulic valve for adjusting the position of the construction tool, the method comprising the steps of:

providing at least one sensor on the construction apparatus;

providing a sensor control;

coupling said sensor control to the at least one sensor;

communicating and driving said sensor with said sensor control;

generating sensor signals as a function of the distance from the sensor to a reference with said sensor;

determining the position of the construction tool relative to the reference based on the sensor signals;

producing a drive signal in response to said sensor signals with said sensor control;

transmitting said drive signal to the tool position device to maintain a desired position of the construction tool with respect to the reference; and

detecting a particular configuration of the solenoid operated hydraulic valve and producing the drive signal based on the detected configuration of the at least one solenoid hydraulic valve.

30. The method according to claim 29, further comprising:

providing a second sensor and a reflector;

generating a first sensor signal with the at least one sensor;

detecting at least a first reflection of said first sensor signal with the second sensor from the reflector; and

measuring the time between generating the first sensor signal and detecting the first reflection in order to determine the local speed of sound.

31. The method according to claim 29, further comprising detecting the side of the construction apparatus to which the sensor is mounted with said sensor control.

32. A method of controlling the elevation of a tool of a construction apparatus and for maintaining the vertical position of the tool relative to a reference, the tool being carried by the construction apparatus, and the construction apparatus including at least one positioning device that responds to actuating signals to adjust the position of the tool, said method comprising:

providing a transducer assembly comprising at least one ultrasonic transducer being configured to be carried by the construction apparatus, the transducer having an emitting surface and a screen;

driving said transducer assembly to produce an acoustic wave;

providing a reflector at the screen of the transducer;

receiving at least one reference reflection of the acoustic wave from a reference and at least one reflector reflection is received from the reflector;

monitoring the time the reflection of the acoustic wave are received by the transducer assembly;

determining the local speed of sound based on a first in time reflector reflection is received by said transducer assembly from the reflector; and

determining the distance from the construction tool to the reference based on the received at least one reference reflection and the local speed of sound.

33. The method according to claim 32, further comprising:

detecting the configuration of the at least one positioning device; and

producing at least one electrical signal based on the configuration of the at least one positioning device.

34. The method according to claim 32, further comprising providing a movable target position within the sensing range of at least one of said first and second ultrasonic transducers.

35. A control system for establishing at least one of grade and elevation control of a tool of a construction apparatus and for maintaining at least a vertical position of the tool relative to a reference, the tool be carried by the construction apparatus, and the construction apparatus including at least one positioning device that responds to signals from said control system to adjust the position of the tool, said control system comprising:

a first transducer configured to be carried by the construction apparatus, said first transducer transmitting and receiving energy waves;

first and second reflectors, said first reflector comprising a close reflector and said second reflector comprising a remote reflector;

a second transducer configured to be carried by the construction apparatus, said second transducer being spaced a distance from said firsts transducer and receiving energy waves, and said close reflector being spaced from said second transducer less than the distance between said transducers;

a controller coupled to said first and second transducers, said controller driving said first transducer to produce an energy wave and monitoring a first in time reflection received by said second transducer from said close reflector; and

said controller determining the local speed of sound based on the first in time reflection received by said second transducer and determining the distance from the construction tool to a reference based on local speed of sound and a second in time reflection from the reference received by both of said first and second transducers.

36. The control system according to claim 35, wherein said controller determines distance to at least one of a string, a ground surface, and a curb.

37. The control system according to claim 35, further comprising a third reflector, said third reflector reflecting said first energy wave from said first reflector to said second transducer.

38. The control system according to claim 37, wherein at least one of said first and third reflectors comprise a cylindrical member.

39. The control system according to claim 37, wherein said first and third reflectors are mounted in close proximity to said first and second transducers, respectively.

40. The control system according to claim 39, wherein said first and second transducers each have an emitting surface and a screen over said emitting surface, said first and third reflectors being mounted to said screens of said first and second transducers.

41. The control system according to claim 39, wherein said first and second transducers and said controller are supported in a common housing, said first and third reflectors being supported in said housing whereby said first and third reflectors do not protrude from said housing.