Method and system for non-contact sensing of motion of a roller drum

• US 6,750,621 B2
• Filed: 09/10/2001
• Issued: 06/15/2004
• Est. Priority Date: 09/10/2001
• Status: Expired due to Fees

• Current Assignee: Sauer-Danfoss Incorporated (Danfoss A/S)
• Original Assignee: Sauer-Danfoss Incorporated (Danfoss A/S)
• Inventors: Gandrud, Michael D.
• Primary Examiner(s): Mullins, Burton S.
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US09/950,894
• Publication Number:
  US 20030048082A1
• Time in Patent Office: 1,009 Days
• Field of Search: 735/79, 735/83, 735/84, 735/87, 735/93, 404/113, 404/117, 404/122, 404/128, 318/114, 310/20, 310/51, 310/80, 310/81, 310/82
• US Class Current: 318/114
• CPC Class Codes: E01C 19/288 adapted for monitoring characteristics of the material being compacted, e.g. indicating resonant frequency, measuring degree of compaction, by measuring values, detectable on the roller; using detected values to control operation of the roller, e.g. automatic adjustment of vibration responsive to such measurements
• CPC Class Codes: G01H 3/00 Measuring characteristics of vibrations by using a detector in a fluid G01H7/00, G01H9/00, G01H11/00 take precedence
• CPC Class Codes: G01H 9/00 Measuring mechanical vibrations or ultrasonic, sonic or infrasonic waves by using radiation-sensitive means, e.g. optical means

Abstract

The present invention discloses a system for non-contact measurement of vibrational motion in a vibratory compacting machine. The system includes a vibrating element such as a roller drum adapted for vibrational motion and a non-contact sensor positioned a distance from the vibrating element and adapted for sensing the vibrational motion of the vibrating element. The present invention also discloses a method for non-contact measurement of vibrational motion of a vibrating element in a vibrating element that includes sensing position information of the roller drum with a non-contact sensor positioned a distance from the vibrating element and determining at least one vibration characteristic based on the position information sensed with the non-contact sensor.

Claims

1. A method for non-contact measurement of vibrational motion of a vibrating element in a drum roller comprising:

sensing a vibration waveform of the roller drum with an active non-contact sensor positioned a distance from the roller drum;

sensing a change in position of the non-contact sensor with a position sensor; and

combining the vibration waveform and the change in position to provide a corrected vibration waveform.

2. A system for non-contact measurement of vibrational motion in a vibrating element of a vibratory compaction machine comprising:

a machine frame;

a vibrating element coupled to the machine frame adapted for imparting vibrational motion to a surface to be compacted;

an active non-contact sensor positioned a distance from the vibrating element and adapted for sensing a vibrational motion characteristic of the vibrating element;

a vibration damping structure coupled between the machine frame and the active non-contact sensor for isolating the sensor from the frame;

a control unit operatively connected to the active non-contact sensor for receiving the vibrational motion characteristic of the vibrating element; and

a movement sensor operatively connected to the control unit for determining a movement of the active non-contact sensor, the control unit adapted to correct for error created by the movement of the non-contact sensor.

3. The system of claim 2 wherein the non-contact sensor is selected from the set comprising a microwave sensor, a light interferometer, and inductive sensor, and a capacitive sensor.

4. The system of claim 2 wherein the active non-contact sensor is a Doppler shift sensor.

5. The system of claim 4 wherein the Doppler shift sensor is a microwave sensor.

6. The system of claim 5 further comprising a control unit electrically connected to the microwave sensor.

7. The system of claim 2 wherein the vibrating element includes an eccentric mass.

8. The system of claim 2 wherein the vibrating element is a roller drum.

9. The system of claim 2 wherein the vibrating element is a plate.

10. The system of claim 2 wherein the vibrating element includes and eccentric mass and the control unit is adapted to determine an eccentric mass setting.

11. The system of claim 2 wherein the movement sensor is an accelerometer.

12. A method of operating a vibratory compacting machine comprising the steps of:

providing a vehicle frame;

providing a roller drum movably coupled to the vehicle frame, wherein the roller drum has a frequency range over which it vibrates;

mounting a sensor using a vibration isolator that is designed such that the frequency at which the vibration isolator vibrates is not within the same frequency range as the drum vibration;

inducing vibrations on the vibratory drum to cause the vibratory drum to compact a material;

measuring vibrations using the sensor;

generating a waveform representing the measured vibrations; and

filtering out frequency components at the frequency at which the vibration isolator vibrates to generate a second waveform representing the vibration of the roller drum.

13. The method of claim 12 wherein the step of measuring vibrations includes the steps of sending a signal towards the rolling drum and receiving a reflected signal from the roller drum.

14. The method of claim 12, further comprising the step of determining a plurality of vibrational characteristics of the roller drum.

15. The method of claim 14, wherein at least one of the vibrational characteristics is selected from the set comprising:

an amplitude of vibration, a frequency of vibration, a phase of vibration, a vibrational velocity, and a vibrational acceleration.

16. The method of claim 12, wherein the roller drum vibrates at a frequency of approximately 60 Hz.

17. The method of claim 16, wherein the vibration isolator vibrates at approximately 8 Hz.

18. The method of claim 12, wherein the frequency range of the roller drum is greater than the frequency of the vibration isolator.

19. The method of claim 12, wherein the sensor is a non-contact sensor.

20. The method of claim 19, wherein the non-contact sensor is a Doppler shift sensor.

21. The method of claim 19, wherein the non-contact sensor is a microwave sensor.

22. A vibratory compacting machine comprising:

a frame;

a vibrating element coupled to the frame, wherein the vibrating element has a frequency range over which it vibrates;

a sensor coupled to the frame with a vibration isolator that is designed such that the frequency at which the vibration isolator vibrates is not within the frequency range of the vibrating element;

a control unit electrically connected to the sensor for receiving signals relating to measured vibrations; and

a filter for filtering out frequency components at the frequency at which the vibration isolator vibrates.

23. The vibratory compacting machine of claim 22, wherein the sensor is a non-contact sensor.

24. The vibratory compacting machine of claim 23, wherein the non-contact sensor is a Doppler shift sensor.

25. The vibratory compacting machine of claim 23, wherein the non-contact sensor is a microwave sensor.

26. The vibratory compacting machine of claim 22, wherein the vibrating element is a roller drum.

27. The vibratory compacting machine of claim 22, wherein the vibrating element is a plate.

28. A method of operating a vibratory compacting machine comprising the steps of:

providing a vehicle frame;

providing a vibratory drum movably coupled to the vehicle frame;

inducing vibrations on the vibratory drum to cause the vibratory drum to compact a material;

providing a first sensor coupled to the vehicle frame;

using the first sensor to sense the vibrations induced on the vibratory drum;

providing a second sensor;

using the second sensor to sense vibrations in the first sensor caused by vibrations in the vehicle frame which are due to the induced vibrations; and

adjusting the speed and/or amplitude of the induced vibrations based on information from the first and second sensors.

29. The method of claim 28, wherein the step of using the first sensor to sense the vibrations includes sending a signal towards the vibratory drum and receiving a reflected signal from the vibratory drum.

30. The method of claim 28, wherein the first sensor is a non-contact sensor.

31. The method of claim 30, wherein the first sensor is passive.

32. The method of claim 30, wherein the first sensor is a Doppler shift sensor.

33. The method of claim 30, wherein the first sensor is a microwave sensor.