System and method for calculation of capacity charts at intermediate counterweight positions

Patent metadata

Field	Value
Publication number	US-10173868-B2
Application number	US-201615579367-A
Country	US
Kind code	B2
Filing date	Jun 10, 2016
Priority date	Jun 12, 2015
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

A system and method for calculating a crane capacity for a crane having a variable position counterweight at an intermediate position is disclosed. In the method a boom combination is determined and a maximum capacity at a hook position is determined for the boom combination. A target value for an operating condition is established dependent on a balance of the crane between the variable position counterweight and a load on the hook. An indication is received of an intermediate counterweight position, and a load is calculated for the hook at the hook position for the boom combination and the intermediate counterweight position that results in the operating condition having the target value to determine an intermediate capacity. The intermediate capacity is compared with the maximum capacity and the lower of the maximum capacity and the intermediate capacity is output.

First claim

The invention claimed is:

1. A method for determining a capacity of a boom combination for a crane having a variable position counterweight in an intermediate position, the method comprising:
using a processor configured to implement computer executable instructions to perform the steps of:
determining a boom combination of a crane having a variable position counterweight;
determining a maximum capacity at a hook position for the boom combination;
establishing a target value for an operating condition dependent on a balance of the crane between the variable position counterweight and a load on the hook;
receiving an indication of an intermediate counterweight position;
calculating a load on the hook at the hook position for the boom combination and the intermediate counterweight position that results in the operating condition having the target value to determine an intermediate capacity;
comparing the intermediate capacity with the maximum capacity; and
outputting a lower of the maximum capacity and the intermediate capacity.

2. The method of claim 1 , wherein outputting the lower of the maximum capacity and the intermediate capacity comprises displaying a higher of the maximum capacity and the intermediate capacity on a visual display.

3. The method of claim 1 , wherein determining a boom combination comprises receiving a user input identifying a boom combination.

4. The method of claim 1 , wherein determining a boom combination comprises detecting, by a sensor, at least one component making up the combination.

5. The method of claim 1 , wherein determining the maximum capacity comprises looking up a load chart for the boom configuration.

6. The method of claim 1 , wherein the operating condition comprises a backhitch tension.

7. The method of claim 1 , wherein calculating a load comprises summing a load moment of a beam supporting the variable position counterweight, a load moment of a mast hinge supporting a mast, and load moment of a boom hinge supporting a boom.

8. A crane control system comprising:
a processor configured to implement computer executable instructions;
a first input interface in communication with the processor and configured to receive an indication of an intermediate counterweight position;
a second input interface in communication with the processor and configured to receive a sensor input corresponding to an operating condition indicative of a balance between a load on a crane boom and a variable position counterweight;
a first output interface in communication with the processor and configured to output a control signal for controlling the position of a variable position counterweight;
a second output interface in communication with the processor and configured to output an indication of an intermediate crane capacity; and
a computer memory in communication with the processor and storing data representing a load chart and computer executable instructions, that when implemented by the processor cause the processor to perform functions comprising:
calculate the control signal for controlling the position of the variable position counterweight based on keeping a sensor input received at the second input interface at a predetermined value;
calculate an intermediate crane capacity based on an indication of the intermediate counterweight position received over the first input interface and a known value of the operating condition indicative of a balance between the crane boom and the variable position counterweight;
compare the intermediate crane capacity to a capacity indicated by the load chart for a boom combination; and
output an indication of the lower of the intermediate crane capacity and the capacity indicated by the load chart over the second output interface.

9. The crane control system of claim 8 , wherein the sensor input is configured to receive the output of a strain gauge in a back hitch.

10. The crane control system of claim 8 , wherein the function of calculate an intermediate crane capacity comprises summing a load moment of a beam supporting the variable position counterweight, a load moment of a mast hinge supporting a mast, and load moment of a boom hinge supporting a boom.

11. The crane control system of claim 8 , further comprising a third input configured to receive an indication of the boom combination.

12. A crane comprising:
an upper works;
a boom mounted to the upper works at a first end and having a hook at a second end;
a variable position counterweight horizontally extendable from the upper works;
a counterweight movement device configured to move the variable position counterweight relative to the upper works;
a sensor configured to measure an operating condition indicative of a balance between a load on the hook and the variable position counterweight; and
a crane control system in communication with an actuator and the sensor, comprising:
a processor configured to implement computer executable instructions;
an input in communication with the processor and configured to receive an indication of an intermediate counterweight position;
an output in communication with the processor and configured to output an indication of an intermediate crane capacity; and
a computer memory in communication with the processor and storing data representing a load chart and computer executable instructions, that when implemented by the processor cause the processor to perform functions comprising:
calculate a control signal for the actuator, the control signal causing the actuator to adjust a position of the variable position counterweight to maintain the operating condition measured by the sensor at a predetermined value;
calculate an intermediate crane capacity based on an indication of the intermediate counterweight position received over the input and the predetermined value of the operating condition indicative of a balance between the load on the hook and the variable position counterweight;
compare a capacity indicated by the load chart for a boom combination to the intermediate crane capacity;
output an indication of the lower of the capacity indicated by the load chart and the intermediate crane capacity over the output.

13. The crane of claim 12 , further comprising a fixed mast coupled to the upper works and a back hitch between the fixed mast and the variable position counterweight, wherein the sensor comprises a strain gauge configured to measure a tension in the back hitch.

14. The crane of claim 12 , wherein the function of calculate an intermediate crane capacity comprises summing a load moment of a beam supporting the variable position counterweight, a load moment of a mast hinge supporting a mast, and a load moment of a boom hinge supporting a boom.

15. The crane of claim 12 , further comprising a third input configured to receive an indication of the boom combination.

Assignees

• Manitowoc Crane Companies Llc

Inventors

• Nysse Brian Nicholas
• Albinger Timothy James

Classifications

• B66C23/76

  and movable to take account of variations of load or of variations of length of jib · CPC title

• B66C23/42

  with jibs of adjustable configuration, e.g. foldable · CPC title

• B66C23/905 Primary

  electrical · CPC title

• B66C13/18

  Control systems or devices (exclusively for rope, cable, or chain winding mechanisms B66D1/40) · CPC title

• B66C13/16

  Applications of indicating, registering, or weighing devices (in crane hooks B66C1/40; in safety gear B66C15/00; weighing-apparatus G01G; remote indicating in general G08) · CPC title