Work machine and method for controlling work machine
A hydraulic excavator has a boom, an arm, a bucket, and a boom cylinder which drives the boom. A load value within the bucket is computed based on a load of the boom cylinder, and the load value obtained by computing is corrected based on an acceleration of extension/retraction of the boom cylinder.
1. A work machine, comprising:
a boom;
an arm attached to a leading end of the boom;
a bucket attached to a leading end of the arm;
a boom cylinder which drives the boom and has a cylinder rod;
a stroke sensor which detects a displacement amount of the cylinder rod in the boom cylinder;
a pressure sensor which senses at least one pressure, the at least one pressure being at least one of a head pressure of the boom cylinder and a bottom pressure of the boom cylinder; and
a controller configured to:
calculate an acceleration of extension/retraction of the boom cylinder based on the detected displacement amount of the cylinder rod in the boom cylinder,
compute a load value within the bucket based on a load of the boom cylinder as determined by the at least one pressure, and
correct the computed load value based on the calculated acceleration of extension/retraction of the boom cylinder.
2. The work machine according to claim 1 , wherein, in addition to correcting the computed load value based on the calculated acceleration of extension/retraction of the boom cylinder, the controller corrects the computed load value based on relational data indicative of a magnitude of an error of a load value in the bucket with respect to a load value in the bucket.
3. The work machine according to claim 2 , wherein the relational data has a relation that the error of the load value in the bucket is decreased with an increase in the load value in the bucket.
4. The work machine according to claim 3 , wherein the error of the load value in the bucket is decreased quadratically.
5. A method for controlling a work machine including a boom, an arm, a bucket, and a boom cylinder which has a cylinder rod and drives the boom, comprising:
detecting a displacement amount of the cylinder rod in the boom cylinder with a stroke sensor;
sensing at least one pressure with a pressure sensor, the at least one pressure being at least one of a head pressure of the boom cylinder and a bottom pressure of the boom cylinder;
calculating an acceleration of extension/retraction of the boom cylinder based on the detected displacement amount of the cylinder rod in the boom cylinder;
computing a load value within the bucket based on a load of the boom cylinder as determined by the at least one pressure; and
correcting the computed load value based on the calculated acceleration of extension/retraction of the boom cylinder.
6. The method for controlling the work machine according to claim 5 , further comprising, in addition to correcting the computed load value based on the calculated acceleration of extension/retraction of the boom cylinder, correcting the computed load value based on relational data indicative of a magnitude of an error of a load value in the bucket with respect to a load value in the bucket.