Systems and methods for sway control

• US 7,648,036 B2
• Filed: 09/26/2007
• Issued: 01/19/2010
• Est. Priority Date: 11/14/2003
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Recktenwald, Alois, Wichner, Wolfgang, Arman, Farshid
• Primary Examiner(s): Brahan; Thomas J.
• Application Number:
  US11/904,456
• Publication Number:
  US 20080021592A1
• Time in Patent Office: 846 Days
• Field of Search: 212/273
• US Class Current: 212/273
• CPC Class Codes: B25J 9/1638 compensation for arm bending/inertia, pay load weight/inertia
• CPC Class Codes: B66C 13/063 electrical
• CPC Class Codes: G05B 19/416 characterised by control of velocity, acceleration or deceleration G05B19/19 takes precedence
• CPC Class Codes: G05B 2219/40043 Move object without swinging, no pendulum or swing motion at stop point
• CPC Class Codes: G05B 2219/45046 Crane

Abstract

Systems, methods and computer program code for the measurement and control of sway in load transportation systems are provided which include using Micro-Electro-Mechanical Systems (MEMS) devices to measure and control the sway of suspended loads such as loads suspended from cranes.

Claims

1. A system, comprising:

a first object suspended from a second object via one or more trolley ropes, wherein each of the one or more trolley ropes is moveably coupled to one or more pulleys;

a power cable connecting a first point on the first object and a second point on the second object, wherein the power cable is electrically coupled to the first object and the second object;

a gyroscope fixed to the power cable and disposed between the first point and the second point to measure an angle of displacement of the power cable, the gyroscope generating a signal representing the angle of displacement of the power cable; and

a processor in communication with the gyroscope, the processor determines a sway of the first object with respect to the second object based at least in part on the signal, the sway representing a relative displacement of the first object with respect to the second object.

2. The system of claim 1, wherein the angle of displacement is the angle formed between the power cable and a vertical line extending downward from the second point.

3. The system of claim 1, wherein the processor generates a sway signal representing the sway of the first object with respect to the second object.

4. The system of claim 3, further comprising:

a control system receiving the sway signal and causing the second object to move along an axis, the control system responsive to the sway signal.

5. The system of claim 4, wherein the control system comprises:

a motor operable to move the second object along the axis; and

a control processor to receive the sway signal and to generate a control signal to compensate for the sway.

6. The system of claim 5, wherein the motor receives the control signal and moves the second object along the axis to compensate for the sway.

7. The system of claim 5, wherein a new sway signal is received by the control system and a new control signal is generated by the control processor to compensate for the sway.

8. The system of claim 1, wherein the first object includes a load spreader and a load carried by the load spreader, and the second object is a trolley.

9. The system of claim 8, wherein the power cable provides power to the load spreader.

10. The system of claim 1, wherein the gyroscope is a micro-electro-mechanical system gyroscope.

11. The system of claim 1, wherein the gyroscope comprises:

a micro-electro-mechanical system gyroscope to generate an analog signal;

a power source to supply power to the micro-electro-mechanical system gyroscope;

a memory device to store the analog signal; and

an analog-to-digital convener to receive the analog signal and convert the analog signal to produce the signal representing the angle of displacement of the cable.

12. The system of claim 11, wherein the gyroscope further includes the processor.

13. A computer-readable medium having instructions thereon, wherein said instructions, when executed by a processor, cause the processor to:

receive, from a gyroscope fixed to a power cable extending between a first point of a first object and a second point of a second object suspended from the first object, a signal representing an angle of displacement of the cable, wherein the gyroscope is disposed between the first point and the second point, wherein the power cable is electrically coupled to the first object and the second object, wherein the second object is suspend from the first object via one or more trolley ropes, and wherein each of the one or more trolley ropes is moveably coupled to one or more pulleys; and

determine a sway of the second object with respect to the first object based at least in part on the signal, the sway representing a relative displacement of the second object with respect to the first object.

14. The computer-readable medium of claim 13, further comprising instructions causing the processor to:

generate a sway signal representing the sway of the second object with respect to the first object; and

transmit the sway signal to a control system that is operable to control the motion of the first object along an axis.

15. The computer-readable medium of claim 14, wherein the control system is responsive to the sway signal to adjust the movement of the first object.

16. The computer-readable medium of claim 13, wherein the second object is a load spreader and the power cable provides power to the load spreader.