Actuator Drive Control System in Construction Machine

Abstract

Drive control of an actuator is performed by using an operation amount versus control value map so that the actuator can be driven at a speed corresponding to an operation amount of an operation member, even if there is difference in load conditions or the like or deterioration over time. An operation amount control unit that determines an operation amount to be input into the operation amount versus control value map is provided. Said operation amount control unit is provided with a speed requirement computing unit that determines a speed requirement from an operation detected value of the operation member, a main map for determining an operation amount from a speed requirement, a sub-map for correcting an operation amount based on influencing factors that have an influence on drive speed of the actuator, and main map updating means for updating main maps, and sub-map updating means for updating sub-maps so as to decrease the speed difference between actual speed and speed requirement of the actuator, and is configured to determine an operation amount by using updated main map and sub-map.

1 . An actuator drive control system in a construction machine wherein, in a construction, machine provided with an actuator, an operation member configured to be operated so as to drive said actuator, and an operation amount versus control value map for outputting a control value for controlling a drive speed of the actuator based on an input of an operation amount, and configured to perform drive control of the actuator based on said control value output from said operation amount versus control value map, a control system configured to determine an operation amount input into the operation amount versus control value map is provided, and said control system is provided with an operation detecting means for detecting an operation of an operation member, a speed requirement computing unit for computing a speed requirement of the actuator based on a detected value from said operation detecting means, a main map for representing correlations between speed requirement and operation amount in order to determine an operation amount from the speed requirement of the actuator, an actual speed computing unit for computing a current drive speed of the actuator, a main map updating means for updating, at any time, a main map based on a speed difference between the speed requirement of the actuator and the current drive speed of the actuator, a sub-map for correcting an operation amount based on influencing factors that have an influence on the drive speed of the actuator, and a sub-map updating means for updating, at any time, the sub-map based on the speed difference between the speed requirement of the actuator and the current drive speed of the actuator, and is configured to determine an operation amount by using the main map and the sub-map updated by the main map updating means, and the sub-map updating means. 
     
     
         2 . The actuator drive control system in a construction machine according to claim L wherein the main map updating means, in updating the main map based on the speed difference between the speed requirement of the actuator and the current drive speed of the actuator, makes the weighting of the speed difference to the speed requirement to be small, and updates the main map so as to decrease said small-weighted speed difference. 
     
     
         3 . The actuator drive control system in a construction machine according to  claim 1 , wherein the sub-map updating means, in updating the sub-map based on the speed difference between the speed requirement of the actuator and the current drive speed of the actuator, makes the weighting of the speed difference to the speed requirement to be small, and updates the sub-map so as to decrease said small-weighted speed difference. 
     
     
         4 . The actuator drive control system in a construction machine according to  claim 3 , wherein the weighting of the speed difference in updating of the sub-map is set greater than the weighting of the speed difference in updating of the main map. 
     
     
         5 . The actuator drive control system in a construction machine according to  claim 1 , wherein an influencing factor for use in correction of an operation amount in the sub-map is at least either one out of a load acting on the actuator, individual operation/combined operation in case a plurality of actuators is provided, and an engine revolution speed. 
     
     
         6 . The actuator drive control system in a construction machine according to  claim 1 , wherein a construction machine is provided with a bendable articulated working arm composed of a plurality of arms, a work attachment attached to the distal end portion of said working arm, as well as provided with a plurality of hydraulic cylinders for arms for driving the plurality of arms respectively, and a hydraulic actuator for the work attachment serving as actuators. 
     
     
         7 . The actuator drive control system in a construction machine according to  claim 6 , wherein a construction machine is provided with right and left operation members operable in front-back, and right-left directions serving as operation members for a working arm, and an operation mode selecting means selectable by an operator, wherein in case an attachment position control mode for controlling a work attachment position by operations of the right and left operation members by said operation mode selecting means is selected, the control system computes a desired work attachment position based on detected values from an operation detecting means for detecting operations of the right and left operation members, and computes speed requirements of a plurality of hydraulic cylinders for arms respectively in order to control the work attachment position based on said computation result, wherein a main map and a sub-map are provided in correspondence to each hydraulic cylinder for arm respectively. 
     
     
         8 . The actuator drive control system in a construction machine according to  claim 6 , wherein a construction machines is provided with one operation member operable in front-back, and up-down directions serving as an operation member for a working arm, wherein the control system computes a desired work attachment position based on detected values from the operation detecting means for detecting an operation of the operation member, and computes speed requirements of a plurality of hydraulic cylinders for arms respectively in order to control the work attachment position based on said computation result, and wherein the main map and the sub-map are provided in correspondence to each hydraulic cylinder for arm respectively.