Weight calculation compensation

• US 8,126,619 B2
• Filed: 10/23/2008
• Issued: 02/28/2012
• Est. Priority Date: 10/23/2007
• Status: Active Grant

• Current Assignee: Trimble Inc.
• Original Assignee: Actronic Limited
• Inventors: Corder, Paul John, Lee, David Warren
• Primary Examiner(s): Hayes, Bret
• Application Number:
  US12/256,787
• Publication Number:
  US 20090127031A1
• Time in Patent Office: 1,223 Days
• Field of Search: 187/393, 187/394, 372/34, 372/35, 372/36, 374/44, 700/89, 701/50, 177/131, 177/148, 177/149, 177/245, 177/264, 212/283
• US Class Current: 701/50
• CPC Class Codes: E02F 9/26 Indicating devices E02F5/145 takes precedence
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: G01G 19/10 having fluid weight-sensitive devices
• CPC Class Codes: G01G 23/01 Testing or calibrating of weighing apparatus

Abstract

A method and apparatus for determining weight of a payload lifted by a rig of a load lifting machine. The weight is determined from at least one parameter being or indicative of the force or pressure existing in or applied by the rig while the payload is lifted and a compensation for friction and/or other losses in the rig 14.

Claims

1. A method for determining weight of a payload lifted by a rig of a load lifting machine comprising:

receiving a raise parameter that is or is indicative of force or pressure required to raise the rig during a compensation lift,

receiving a lower parameter that is or is indicative of force or pressure required to lower the rig during a compensation lift,

receiving a lift parameter that is or is indicative of force or pressure required to lift the payload using the rig,

calculating a compensation coefficient based on the difference between the raise parameter and the lower parameter, wherein said compensation coefficient compensates for intrinsic losses in the rig; and

then

calculating the weight of the payload using the lift parameters and the compensation coefficient.

2. A method according to claim 1 wherein the rig comprises one or more actuators to raise and lower the rig, wherein:

the raise parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators while raising the rig during a compensation lift,

the lower parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators while lowering the rig during a compensation lift, and

the lift parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators to lift the payload using the rig.

3. A method according to claim 1 further comprising:

receiving a first speed parameter that is or is indicative of the speed of the rig while the rig is raised during a compensation lift, and

receiving a second speed parameter that is or is indicative of the speed of the rig while the rig is being lowered during a compensation lift, and

wherein the compensation coefficient calculation is also based on the difference between the first and second speed parameters.

4. A method according to claim 3 wherein the load lifting machine comprises a hydraulic cylinder coupled to the rig and the weight of the payload is calculated using:

Weight=((Lift*(1−

C))−

(k*Return)−

Zero−

C*n*|V|)*Span

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span,

|V| is a speed of the rig, and

C and/or n form the compensation coefficient for friction and/or other losses.

5. A method according to claim 4 wherein the rig comprises arms and:

6. A method according to claim 1 wherein the load lifting machine comprises a hydraulic cylinder coupled to the rig and the weight of the payload is calculated using:

Weight=((Lift*(1−

C))−

(k*Return)−

Zero)*Span,

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span, and

C forms the compensation coefficient for friction and/or other losses.

7. A method according to claim 6 wherein the rig comprises arms and

8. A load lifting machine comprising:

a rig for lifting a payload,

at least one sensor attached to the rig to measure a parameter that is or is indicative of a force or pressure required to raise or lower the rig, and

a processor operatively connected to the sensor for receiving one or more of the following;

a raise parameter that is or is indicative of a force or pressure required to raise the rig during a compensation lift,

a lower parameter that is or is indicative of a force or pressure required to lower the rig during a compensation lift, and

a lift parameter that is or is indicative of a force or pressure required to lift the payload using the rig,

said processor being programmed for

calculating a compensation coefficient that compensates for intrinsic losses in the rig, wherein the compensation coefficient is determined based on the difference between the raise parameter and lower parameter; and

then

calculating the weight of the payload using the lift parameter and the compensation coefficient.

9. A load lifting machine according to claim 8 wherein the rig comprises one or more actuators to raise and lower the rig, wherein:

the raise parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators while raising the rig during a compensation lift,

the lower parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators while lowering the rig during a compensation lift, and

the lift parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators to lift the payload using the rig.

10. A load lifting machine according to claim 8 comprising:

at least one sensor attached to the rig to measure a parameter that is or is indicative of the speed of the rig while the rig is raised or lowered during a lift,

wherein the processor is further configured to;

receive a first speed parameter that is or is indicative of the speed of the rig while the rig is raised during a compensation lift,

receive a second speed parameter that is or is indicative of the speed of the rig while the rig is being lowered during a compensation lift,

wherein the calculation of the compensation coefficient is also based on the difference between the first and second speed parameters.

11. A load lifting machine according to claim 10 which comprises a hydraulic cylinder coupled to said rig and wherein the weight of the payload is calculated using:

Weight=((Lift*(1−

C))−

(k*Return)−

Zero−

C*n*|V|)*Span

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span,

|V| is a speed of the rig, and

C and/or n form the compensation coefficient for friction and/or other losses.

12. A load lifting machine according to claim 11 wherein the rig comprises arms and:

13. A load lifting machine according to claim 8 which comprises a hydraulic cylinder coupled to said rig and wherein the weight of the payload is calculated using:

Weight=((Lift*(1−

C))−

(k*Return)−

Zero)*Span,

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span, and

C forms the compensation coefficient for friction and/or other losses.

14. A load lifting machine according to claim 13 wherein the rig comprises arms and

15. An apparatus for use with a load lifting machine that has a rig for lifting a payload, said apparatus comprising:

a sensor or an input for coupling to a sensor that receives;

a raise parameter that is or is indicative of force or pressure required to raise the rig during a compensation lift,

a lower parameter that is or is indicative of force or pressure required to lower the rig during a compensation lift, and

a lift parameter that is or is indicative of force or pressure required to lift the payload using the rig; and

a processor coupled to the sensor or input, the processor being programmed to;

calculate a compensation coefficient that compensates for intrinsic losses in the rig, wherein the compensation coefficient is determined based on the difference between the raise parameter and lower parameter; and

then

calculate the weight of the payload using the lift parameter and the compensation coefficient.

16. An apparatus according to claim 15 wherein the rig comprises one or more actuators to raise and lower the rig, wherein

the raise parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators while raising the rig during a compensation lift,

the lower parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators while lowering the rig during a compensation lift, and

the lift parameter is or is indicative of force or pressure existing in or applied by one or more of the actuators to lift the payload using the rig.

17. An apparatus according to claim 15 wherein

the sensor or the input for coupling to a sensor also receives:

a parameter that is or is indicative of the speed of the rig while the rig is raised or lowered during a lift, and

the processor is further configured to;

receive a first speed parameter that is or is indicative of the speed of the rig while the rig is raised during a compensation lift,

receive a second speed parameter that is or is indicative of the speed of the rig while the rig is being lowered during a compensation lift, and

wherein the calculation of the compensation coefficient is also based on the difference between the first and second speed parameters.

18. A apparatus according to claim 17 wherein the load lifting machine comprises a hydraulic cylinder coupled to the rig and the weight of the payload is calculated using:

Weight=((Lift*(1−

C))−

(k*Return)−

Zero−

C*n*|V|)*Span

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span,

|V| is a speed of the rig, and

C and/or n form the compensation coefficient for friction and/or other losses.

19. An apparatus according to claim 18 wherein the rig comprises arms and:

20. An apparatus according to claim 15 wherein the load lifting machine comprises a hydraulic cylinder coupled to the rig and the weight of the payload is calculated using:

Weight=((Lift*(1−

C))−

(k*Return)−

Zero)*Span,

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span, and

C forms the compensation coefficient for friction and/or other losses.

21. An apparatus according to claim 20 wherein the rig comprises arms and:

22. A load lifting machine comprising:

a rig for lifting a payload, the rig comprising an actuator adapted to move the rig to lift a payload, said rig also comprising arms,

a sensor attached to the actuator to measure a parameter that is or is indicative of a force or pressure applied by or existing in the actuator during a lift, and

a processor coupled to the sensor,

wherein the processor is adapted to;

receive a first parameter that is or is indicative of a force or pressure existing in or applied by the actuator during a compensation lift,

receive a second parameter that is or is indicative of a force or pressure existing in or applied by the actuator during a payload lift, and

determine a weight of the payload during or after a payload lift from the parameters,

wherein the compensation lift comprises lifting the rig up and down using at least one hydraulic cylinder, wherein the processor further receives the following parameters;

a Boom Speed as the arms are raised,

the Boom Speed as the arms are lowered,

a Lift Pressure as the arms are raised at idle,

a Return Pressure as the arms are raised at idle,

the Lift Pressure as the arms are raised at full throttle,

the Return Pressure as the arms are raised at full throttle,

the Boom Speed as the arms are raised at idle,

the Boom Speed as the arms are raised at full throttle.

23. A load lifting machine comprising:

a rig for lifting a payload, the rig comprising at least one actuator adapted to move the rig to lift a payload, said actuator comprising a hydraulic cylinder,

at least one sensor attached to the actuator to measure parameters being or indicative of a force or pressure applied by or existing in the actuator during a lift, and

a processor coupled to the sensor,

wherein the processor is adapted to;

receive one or more parameters being or indicative of a force or pressure existing in or applied by the actuator during a compensation lift,

receive one or more parameters being or indicative of a force or pressure existing in or applied by the actuator during a payload lift, and

determine a weight of the payload during or after a payload lift from the parameters,

wherein the processor determines the weight of the payload during or after the payload lift using either;

Weight=((Lift*(1−

C))−

(k*Return)−

Zero)*Span, or

Weight=((Lift*(1−

C))−

(k*Return)−

Zero−

C*n*|V|)*Span

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span,

|V| is a speed of the rig,

C and/or n form a compensation coefficient for friction and/or other losses.

24. A load lifting machine according to claim 23 wherein the rig comprises arms and

25. An apparatus for use with a load lifting machine comprising a rig for lifting a payload, the rig comprising at least one actuator adapted to move the rig to lift a payload and said rig also comprising arms, the apparatus comprising a processor adapted to:

couple to at least one sensor attached to or for attachment to the actuator to measure parameters being or indicative of a force or pressure applied by or existing in the actuator during a lift,

receive one or more parameters being or indicative of a force or pressure existing in or applied by the actuator during a compensation lift,

receive one or more parameters being or indicative of a force or pressure existing in or applied by the actuator during a payload lift, and

determine a weight of the payload during or after a payload lift from the parameters,

wherein the compensation lift comprises lifting the rig up and down using at least one hydraulic cylinder, wherein the processor further receives the following parameters;

a Boom Speed as the arms are raised,

the Boom Speed as the arms are lowered,

a Lift Pressure as the arms are raised at idle,

a Return Pressure as the arms are raised at idle,

the Lift Pressure as the arms are raised at full throttle,

the Return Pressure as the arms are raised at full throttle,

the Boom Speed as the arms are raised at idle,

the Boom Speed as the arms are raised at full throttle.

26. An apparatus for use with a load lifting machine comprising a rig for lifting a payload, the rig comprising at least one actuator to adapted to move the rig to lift a payload, said actuator comprising a hydraulic cylinder, the apparatus comprising a processor adapted to:

couple to at least one sensor attached to or for attachment to the actuator to measure parameters being or indicative of a force or pressure applied by or existing in the actuator during a lift,

receive one or more parameters being or indicative of a force or pressure existing in or applied by the actuator during a compensation lift,

receive one or more parameters being or indicative of a force or pressure existing in or applied by the actuator during a payload lift, and

determine a weight of the payload during or after a payload lift from the parameters,

wherein the processor determines the weight of the payload during or after the payload lift using;

Weight=((Lift*(1−

C))−

(k*Return)−

Zero)*Span, or

Weight=((Lift*(1−

C))−

(k*Return)−

Zero−

C*n*|V|)*Span

wherein;

Lift is a lift pressure in the hydraulic cylinder when a payload lift is performed,

Return is a return pressure in the hydraulic cylinder when a payload lift is performed,

k is a rod bore mixing ratio,

Zero is a normal calibration zero,

Span is a normal calibration span,

|V| is a speed of the rig, and

C and/or n form a compensation coefficient for friction and/or other losses.

27. An apparatus according to claim 26 wherein the rig comprises arms and