Hydraulic shovel work amount detection apparatus, work amount detection method, work amount detection result display apparatus

• US 20050000703A1
• Filed: 10/16/2002
• Published: 01/06/2005
• Est. Priority Date: 10/18/2001
• Status: Active Grant

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Furuno, Yoshinori, Kurosawa, Takao
• Granted Patent: US 6,931,772 B2
• Time in Patent Office: Days
• US Class Current: 172/2
• CPC Class Codes: E02F 9/264 Sensors and their calibration for indicating the position of the work tool
• CPC Class Codes: G01G 19/08 for incorporation in vehicles
• CPC Class Codes: G01G 19/10 having fluid weight-sensitive devices

Abstract

During transfer of a material by a hydraulic excavator, load computing means periodically computes the weight of the material in a bucket of the excavator. Average value computing means computes an average value of weights of the material including a currently computed weight and a predetermined number of weights computed prior to the currently computed weight (M6), and standard deviation computing means computes, based on the average value, a standard deviation of the weights of the material (M7). True load value determining means selects a minimum standard deviation from among the standard deviations computed by the standard deviation computing means from the start of the transfer of the material to a different location until the end of the transfer of same, and judges the average value based on which the minimum standard deviation was computed, to be a true value of the weight of the material (M10, M11).

Claims

1. A work amount detection device for a hydraulic excavator which scoops a material with a bucket thereof and transfers the material to a different location, said work amount detection device comprising:

transfer start detecting means for detecting start of the transfer of the material to the different location;

transfer end detecting means for detecting end of the transfer of the material to the different location;

load computing means for periodically computing weight of the material in the bucket during the transfer;

average value computing means for computing an average value of weights of the material periodically computed by said load computing means, the weights of the material including a currently computed weight and a predetermined number of weights computed prior to the currently computed weight;

standard deviation computing means for computing, based on the average value computed by said average value computing means, a standard deviation of the weights of the material including the currently computed weight and the predetermined number of weights computed prior to the currently computed weight; and

true load value determining means for selecting a minimum standard deviation from among the standard deviations computed by said standard deviation computing means from the start of the transfer of the material to the different location until the end of the transfer of same, and judging the average value based on which the minimum standard deviation was computed, to be a true value of the weight of the material.

3. The work amount detection device according to claim 1, wherein said transfer start detecting means detects, as the start of the transfer, completion of scooping of the material with the bucket, and said transfer end detecting means detects, as the end of the transfer, bucket dump operation.

2. A work amount detection device for a hydraulic excavator which scoops a material with a bucket thereof and transfers the material to a transportation vehicle, said work amount detection device comprising:

teaching means for teaching a position for the transportation vehicle;

transportation vehicle detecting means for detecting the transportation vehicle when the transportation vehicle is located at the position taught by said teaching means;

transfer start detecting means for detecting start of the transfer of the material to the transportation vehicle;

transfer end detecting means for detecting end of the transfer of the material to the transportation vehicle;

load computing means for periodically computing weight of the material in the bucket during the transfer;

average value computing means for computing an average value of weights of the material periodically computed by said load computing means, the weights of the material including a currently computed weight and a predetermined number of weights computed prior to the currently computed weight;

standard deviation computing means for computing, based on the average value computed by said average value computing means, a standard deviation of the weights of the material including the currently computed weight and the predetermined number of weights computed prior to the currently computed weight; and

true load value determining means for selecting a minimum standard deviation from among the standard deviations computed by said standard deviation computing means from the start of the transfer of the material to the transportation vehicle until the end of the transfer of same, and judging the average value based on which the minimum standard deviation was computed, to be a true value of the weight of the material.

4. A work amount detection method for a hydraulic excavator which scoops a material with a bucket thereof and transfers the material to a different location, said work amount detection method comprising:

a transfer start detecting step of detecting start of the transfer of the material to the different location;

a transfer end detecting step of detecting end of the transfer of the material to the different location;

a load computing step of periodically computing weight of the material in the bucket during the transfer;

an average value computing step of computing an average value of weights of the material periodically computed in said load computing step, the weights of the material including a currently computed weight and a predetermined number of weights computed prior to the currently computed weight;

a standard deviation computing step of computing, based on the average value computed in said average value computing step, a standard deviation of the weights of the material including the currently computed weight and the predetermined number of weights computed prior to the currently computed weight; and

a true load value determining step of selecting a minimum standard deviation from among the standard deviations computed in said standard deviation computing step from the start of the transfer of the material to the different location until the end of the transfer of same, and judging the average value based on which the minimum standard deviation was computed, to be a true value of the weight of the material.

5. The work amount detection method according to claim 4, wherein in said transfer start detecting step, completion of scooping of the material with the bucket is detected as the start of the transfer, and in said transfer end detecting step, bucket dump operation is detected as the end of the transfer.

6. A work amount detection result display device for a hydraulic excavator which scoops a material with a bucket thereof and transfers the material to a different location, said work amount detection result display device comprising:

transfer start detecting means for detecting start of the transfer of the material to the different location;

transfer end detecting means for detecting end of the transfer of the material to the different location;

load computing means for periodically computing weight of the material in the bucket during the transfer;

average value computing means for computing an average value of weights of the material periodically computed by said load computing means, the weights of the material including a currently computed weight and a predetermined number of weights computed prior to the currently computed weight;

standard deviation computing means for computing, based on the average value computed by said average value computing means, a standard deviation of the weights of the material including the currently computed weight and the predetermined number of weights computed prior to the currently computed weight;

true load value determining means for selecting a minimum standard deviation from among the standard deviations computed by said standard deviation computing means from the start of the transfer of the material to the different location until the end of the transfer of same, and judging the average value based on which the minimum standard deviation was computed, to be a true value of the weight of the material; and

weight display means for displaying at least an integrated value of the true values determined by said true load value determining means over a predetermined period.

7. The work amount detection result display device according to claim 6, wherein said weight display means displays an integrated value of the true values determined by said true load value determining means over a period from the time an engine ignition key of the hydraulic excavator is turned ON until the engine ignition key is turned OFF.

9. The work amount detection result display device according to claim 6, wherein said transfer start detecting means detects, as the start of the transfer, completion of scooping of the material with the bucket, and said transfer end detecting means detects, as the end of the transfer, bucket dump operation.

10. The work amount detection result display device according to claim 6, wherein said weight display means additionally displays the average value of the weights of the material computed by said average value computing means.

8. A work amount detection result display device for a hydraulic excavator which scoops a material with a bucket thereof and transfers the material to a transportation vehicle, said work amount detection result display device comprising:

teaching means for teaching a position for the transportation vehicle;

transportation vehicle detecting means for detecting the transportation vehicle when the transportation vehicle is located at the position taught by said teaching means;

transfer start detecting means for detecting start of the transfer of the material to the transportation vehicle;

transfer end detecting means for detecting end of the transfer of the material to the transportation vehicle;

load computing means for periodically computing weight of the material in the bucket during the transfer;

average value computing means for computing an average value of weights of the material periodically computed by said load computing means, the weights of the material including a currently computed weight and a predetermined number of weights computed prior to the currently computed weight;

standard deviation computing means for computing, based on the average value computed by said average value computing means, a standard deviation of the weights of the material including the currently computed weight and the predetermined number of weights computed prior to the currently computed weight;

true load value determining means for selecting a minimum standard deviation from among the standard deviations computed by said standard deviation computing means from the start of the transfer of the material to the transportation vehicle until the end of the transfer of same, and judging the average value based on which the minimum standard deviation was computed, to be a true value of the weight of the material; and

weight display means for displaying at least an integrated value of the true values determined by said true load value determining means over a period for which the transportation vehicle located at the taught position is continuously detected by said transportation vehicle detecting means.