Method and device for monitoring the stability of a loading crane mounted on a vehicle

• US 8,874,329 B2
• Filed: 10/07/2013
• Issued: 10/28/2014
• Est. Priority Date: 04/08/2011
• Status: Active Grant

• Current Assignee: Palfinger AG
• Original Assignee: Palfinger AG
• Inventors: Zinke, Thomas
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): Foster, Gerrad A
• Application Number:
  US14/047,388
• Publication Number:
  US 20140032060A1
• Time in Patent Office: 386 Days
• Field of Search: None
• US Class Current: 701/50
• CPC Class Codes: B66C 23/78 Supports, e.g. outriggers, for mobile cranes
• CPC Class Codes: B66C 23/905 electrical

Abstract

A method for monitoring a stability parameter of a loading crane mounted on a vehicle supported on the ground by wheels and by support elements separate from the wheels includes calculating, using a processor, the stability parameter of the loading crane mounted on the vehicle supported on the ground by the wheels and the support elements, and comparing the magnitude of the stability parameter to at least one predetermined limit value. The calculating includes detecting contributions to a magnitude of the stability parameter of the wheels of the vehicle on which the loading crane is mounted and detecting contributions to the magnitude of the stability parameter of the support elements of the vehicle on which the loading crane is mounted.

Claims

1. A method for monitoring a stability parameter of a loading crane mounted on a vehicle supported on the ground by one or more wheels and by one or more support elements separate from the wheels, wherein there is a predetermined minimum number of wheels and support elements by which the vehicle must be supported, the method comprising:

calculating, using a processor, the stability parameter of the loading crane mounted on the vehicle supported on the ground by the wheels and the support elements, including detecting contributions to a magnitude of the stability parameter of the wheels of the vehicle on which the loading crane is mounted, and detecting contributions to the magnitude of the stability parameter of the support elements of the vehicle on which the loading crane is mounted; and

comparing the magnitude of the stability parameter to at least one predetermined limit value.

2. The method of claim 1, further comprising:

outputting a warning signal and/or implementing a measure for return to compliance with at the at least one predetermined limit value when the magnitude exceeds or falls below the at least one predetermined limit value.

3. The method of claim 1, further comprising:

detecting a rotational angle of the loading crane about a vertical axis and/or an extension condition of the support elements.

4. The method of claim 3, wherein the stability parameter is monitored in dependence on the rotational angle of the loading crane and/or the extension condition of the support elements.

5. The method of claim 1, wherein said determining includes monitoring a number of the wheels and the support elements.

6. The method of claim 1, wherein a force-stability coefficient (S_F) is monitored as the stability parameter, and

wherein the force-stability coefficient (S_F) is calculated from support forces (F_i) provided by the wheels and the support elements.

7. The method of claim 6, wherein the force stability coefficient (S_F) is calculated in accordance with the following formula:

8. The method of claim 7, wherein the vehicle is configured to be supported on the ground by two front wheels and two rear wheels which in particular are in the form of twin wheels, and two laterally extendable support extensions each having two support elements,

wherein the rotational angle of the loading crane about a vertical axis and the extension condition of the support elements is detected,

wherein with laterally fully extended support extensions a_min=6 or a_min=5, depending on the rotational angle of the loading crane, and

wherein with laterally not fully extended support extensions a_min=6.

9. The method of claim 8, wherein the vehicle is configured to be supported on the ground by two front wheels and two rear wheels which in particular are in the form of twin wheels, and a laterally extendable support extension having two support elements,

wherein the rotational angle of the loading crane about a vertical axis and the extension condition of the support elements is detected,

wherein with laterally fully extended support extensions a_min=6 or a_min=4, depending on the rotational angle of the loading crane, and

wherein with laterally not fully extended support extensions a_min=6.

10. The method of claim 1, wherein the wheels of the vehicle are arranged on axles, wherein the method further comprises:

calculating axle loads from the support forces (F_i) of the wheels; and

monitoring the axle loads.

11. The method of claim 6, further comprising:

detecting the support forces (F_i) provided by the wheels by measurement of spring relief travel.

12. The method of claim 1, wherein lengths (L_i) of vibration dampers of the wheels are detected and a length-stability coefficient (S_L) is monitored, the length-stability coefficient (S_L) being calculated from the detected lengths (L_i).

13. The method of claim 12, wherein the length-stability coefficient (S_L) is calculated in accordance with the following formula:

14. The method of claim 7, further comprising:

operating the loading crane; and

observing a condition S_F>

1 and/or a condition S_L>

1 during crane operation.

15. The method of claim 1, further comprising:

operating the loading crane; and

calculating tipping lines (K_j) of the vehicle during crane operation.

16. The method of claim 15, further comprising calculating distances (l_i,Kj) of the wheels and the support elements relative to the tipping lines (K_j).

17. The method of claim 16, wherein the rotational angle of the loading crane about a vertical axis is detected and the support forces (F_i) provided by the wheels and the support elements are detected,

wherein a remaining stability moment (M_rem,Kα

) is monitored in dependence on the rotational angle of the loading crane in relation to a current tipping line (K_α

) as the stability parameter, and

wherein the remaining stability moment (M_rem,Kα

) is calculated in accordance with the following formula;

18. A device for monitoring a stability parameter of a loading crane mounted on a vehicle, wherein during crane operation the vehicle is supported on the ground by one or more wheels and by one or more support elements separate from the wheels, and wherein there is a predetermined minimum number of wheels and support elements by which the vehicle must be supported, the device comprising:

wheel and support element measuring devices configured to detect contributions of the wheels and also contributions of the support elements to the magnitude of the stability parameter; and

a control and regulating unit, to which measured signals of the wheel and support element measuring devices are sent,

wherein the control and regulating unit calculates a magnitude of the stability parameter and compares the magnitude of the stability parameter to at least one predetermined limit value.

19. The device of claim 18, wherein the control and regulating unit is configured to generate a warning signal and/or control at least one measure for returning to compliance of the at least one predetermined limit value when the magnitude exceeds or falls below the at least one predetermined limit value.

20. The device of claim 18, wherein the device has a rotational angle measuring device for detecting a rotational angle of the loading crane about a vertical axis and/or an extension condition measuring device for detecting an extension condition of the support elements, and

wherein measured signals of the rotational angle and/or extension condition measuring device are sent to the control and regulating unit.

21. The device of claim 18, wherein the support elements are arranged on at least one laterally extendable support extension and the loading crane rests on a crane base connected to the at least one support extension, wherein the support element measuring devices are arranged in the support elements and/or at a connection of the support elements to the support extension and/or at a connection of the support extension to the crane base.

22. The device of claim 18, wherein the wheel and support element measuring devices detect the support forces (F_i) provided by the wheels and the support elements.

23. The device of claim 22, further comprising springs,

wherein the wheel and support element measuring devices detect the support forces (F_i) provided by the wheels by a measurement of spring relief travels.

24. The device of claim 18, wherein the wheels include vibration dampers, and

wherein the wheel measuring devices detect lengths (L_i) of vibration dampers of the wheels.

25. The device of claim 18, wherein the control and regulating unit calculates tipping lines (K_j) of the vehicle during the crane operation.

26. The device of claim 25, wherein the control and regulating unit calculates distances (l_i,Kj) of the wheels and support elements relative to the tipping lines (K_j).

27. A vehicle comprising:

a loading crane;

wheels;

extendable support elements; and

the device of claim 18.