SYSTEM AND METHOD OF CALCULATING A PAYLOAD WEIGHT

• US 20170370075A1
• Filed: 12/24/2014
• Published: 12/28/2017
• Est. Priority Date: 12/24/2014
• Status: Active Grant

• Current Assignee: CQMS Razer PTY Ltd
• Original Assignee: CQMS Razer PTY Ltd
• Inventors: LESLIE, Bruce Alexander, ANDREWS, David Clinton, HILLIER, Nicholas Simon
• Granted Patent: US 10,982,415 B2
• Time in Patent Office: Days
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: G01G 19/083 lift truck scale
• CPC Class Codes: G01G 19/12 having electrical weight-sensitive devices
• CPC Class Codes: G01G 23/01 Testing or calibrating of weighing apparatus
• CPC Class Codes: G01G 23/48 Temperature-compensating arrangements G01G1/14, G01G1/42, G01G3/18 take precedence
• CPC Class Codes: G01G 5/06 with electrical indicating means

Abstract

A system of calculating a payload weight, the system including: a first sensor configured to assist in determining an actuator load associated with a ram, the ram being connected to a lifting member; and a calibration module configured to retrieve a calibration factor based on movement of the ram, the calibration factor being applied to the actuator load to thereby provide an adjusted actuator load; wherein the payload weight is calculated based on the adjusted actuator load.

Claims

1. A system of calculating a payload weight, the system including:

a first sensor configured to assist in determining an actuator load associated with a ram, the ram being connected to a lifting member; and

a calibration module configured to retrieve a calibration factor based on movement of the ram, the calibration factor being applied to the actuator load to thereby provide an adjusted actuator load;

wherein the payload weight is calculated based on the adjusted actuator load.

2. The system of claim 1, wherein retrieving the calibration factor based on movement of the ram includes retrieving a comparison error value.

3. The system of claim 2, wherein the comparison error value adjusts the actuator load such that the payload weight, when based on the actuator load taken with a known payload weight, substantially matches the known payload weight.

4. The system of claim 3, wherein the known payload weight is zero.

5. The system of claim 2, wherein retrieving the comparison error value is based on an associated system state.

6. The system of claim 5, wherein the associated system state includes a flow rate of fluid being supplied to the ram.

7. The system of claim 2, wherein in retrieving the comparison error value, the calibration module is configured to first calculate the comparison error value.

8. The system of claim 7, wherein the calibration module calculates the comparison error value by:

calculating the payload weight based on the actuator load taken with a known payload weight;

comparing the payload weight to the known payload weight; and

determining an error value to adjust the actuator load such that the payload weight substantially matches the known payload weight.

9. The system of claim 7, wherein the calibration module is configured to calculate a range of comparison error values by moving the ram through a range of actuation positions.

10. The system of claim 1, wherein retrieving the calibration factor based on movement of the ram includes retrieving a temperature error value that is associated with a measured fluid temperature related to the ram.

11. The system of claim 1, wherein the system includes a first related sensor configured to measure a first related load associated with the ram.

12. The system of claim 11, wherein the actuator load is in the form of a pressure difference between the first load measured by the first sensor and a first related load measured by the first related sensor.

13. The system of claim 12, wherein the first sensor is located in a first inlet/outlet hose connected to the ram and the first related sensor is located in a first related inlet/outlet hose connected to the ram.

14. The system of claim 1, wherein the ram is a hydraulic ram.

15. The system of claim 1, wherein the lifting member includes an excavator arm and a bucket.

16. A method of calculating a payload weight, the method including the steps of:

determining an actuator load associated with a ram connected to a lifting member;

retrieving a calibration factor based on movement of the ram;

applying the calibration factor to the actuator load to form an adjusted actuator load; and

calculating the payload weight based on the adjusted actuator load.

17. The method of claim 16, wherein the step of retrieving the calibration factor based on movement of the ram includes determining a movement differential of the ram in the form of a flow rate of fluid being supplied to the ram.

18. The method of claim 16, wherein the step of retrieving the calibration factor based on movement of the ram includes retrieving a comparison error value that adjusts the actuator load such that the payload weight, when based on the actuator load taken with a known payload weight, substantially matches the known payload weight.

19. The method of claim 18, the step of calculating the calibration factor includes combining the comparison error value and a temperature error value.

20. The method of claim 16, wherein the lifting member is in the form an excavator arm and bucket.