US 8,548,693 B2Granted

Control device and control method for working mechanism of construction vehicle

AssigneeKomatsu Ltd.

InventorsMasatsugu Numazaki, Isamu Satoh, Satoshi Kohsuge, Kyouhei Sawada, Yoshiaki Saito, Jun Kawayanagi, Minoru Wada

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Abstract

A control device for a work machine on a construction vehicle is provided so that a bucket cylinder is stopped at a target position, with high accuracy achieved in a bucket cylinder length, and with chock held down to a low level. A bucket cylinder length detection section refereces a cylinder length detection table on the basis of a boom angle and a bell crank angle, thereby detecting a bucket cylinder length. A bucket attitude control section controls the bucket cylinder length so that a target position will be reached. Feedback control is performed until a set value which is set short of a target value is reached. After the bucket cylinder length reaches the set value, open loop control is performed until the target value is reached.

Claims10

Dependent claims

A control device for a working mechanism of a construction vehicle for controlling the cylinder length of a predetermined hydraulic cylinder that is used in the working mechanism of the construction vehicle, comprising:

a cylinder length detection unit configured to determine the cylinder length of said predetermined hydraulic cylinder;
and
a cylinder length control unit configured to control the cylinder length of said predetermined hydraulic cylinder;
wherein said cylinder length control unit is configured to:
(A) in a first region, perform feedback control of the cylinder length by supplying hydraulic fluid to said predetermined hydraulic cylinder on the basis of a control characteristic that is set in advance and the cylinder length determined by said cylinder length detection unit, said first region extending from input of a start command that initiates control of said cylinder length until said cylinder length arrives at a set value that is set before a target value,
wherein said control characteristic includes a first control characteristic that is used if the cylinder length at the start of control is less than or equal to a control threshold value and a second control characteristic that is used if the cylinder length at the start of control is greater than said control threshold value;
and
(B) in a second region, perform open loop control of the cylinder length by supplying hydraulic fluid to said predetermined hydraulic cylinder while decreasing the control signal at a predetermined rate, said second region ranging from said set value until said cylinder length arrives at said target value,
wherein said predetermined rate includes a first rate that corresponds to said first control characteristic and a second rate that corresponds to said second control characteristic;
and said first rate is used is used if said first control characteristic was used in said first region, and said second rate is used, if said second control characteristic was used in said first region.

7 more elements

a cylinder length detection unit configured to determine the cylinder length of said predetermined hydraulic cylinder;
and
a cylinder length control unit configured to control the cylinder length of said predetermined hydraulic cylinder;
wherein said cylinder length control unit is configured to:
(A) in a first region, perform feedback control of the cylinder length by supplying hydraulic fluid to said predetermined hydraulic cylinder on the basis of a control characteristic that is set in advance and the cylinder length determined by said cylinder length detection unit, said first region extending from input of a start command that initiates control of said cylinder length until said cylinder length arrives at a set value that is set before a target value,
wherein said control characteristic includes a first control characteristic that is used during feedback control, if the cylinder length at the start of control is less than or equal to a control threshold value;
and a second control characteristic that is used during feedback control, if the cylinder length at the start of control is greater than said control threshold value;
said first control characteristic is set so as to decrease continuously according to a predetermined first characteristic line from the maximum value of a control signal to a control valve for supplying hydraulic fluid to said predetermined hydraulic cylinder to a first predetermined value;
and said second control characteristic is set so that a control signal that is larger than said first characteristic line is obtained in an earlier almost half portion of said first region, and moreover so that a control signal that is smaller than said first characteristic line is obtained in the latter half portion of said first region;
(B) in a second region, perform open loop control of the cylinder length by supplying hydraulic fluid to said predetermined hydraulic cylinder while decreasing the control signal at a predetermined rate, said second region ranging from said set value until said cylinder length arrives at said target value.

7 more elements

A control method for controlling the cylinder length of a predetermined hydraulic cylinder that is used in the working mechanism of a construction vehicle, comprising:

detecting the cylinder length of said predetermined hydraulic cylinder;
and
controlling the cylinder length by:
feedback controlling the cylinder length in a first region by supplying hydraulic fluid to said predetermined hydraulic cylinder on the basis of a control characteristic that is set in advance and the detected cylinder length, said first region extending from input of a start command that initiates control of said cylinder length until said cylinder length arrives at a set value that is set before a target value,
wherein said control characteristics includes a first control characteristic that is used during said feedback controlling, if the cylinder length at the start of control is less than or equal to a control threshold value;
and a second control characteristic that is used during said feedback controlling, if the cylinder length at the start of control is greater than said control threshold value;
open loop controlling the cylinder length in a second region by supplying hydraulic fluid to said predetermined hydraulic cylinder while decreasing the control signal at a predetermined rate from said set value until said cylinder length arrives at said target value,
wherein said predetermined rate includes a first rate that corresponds to said first control characteristic and a second rate that corresponds to said second control characteristic;
and said first rate is used if said first control characteristic was used in said first region, and said second rate is used, if said second control characteristic was used in said first region.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/515,324Filed 10 Mar 2011
Priority: JP 2010-05790815 Mar 2010
Published: US 2012/0330515 A127 Dec 2012
Granted: 1 Oct 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

E02F 9/2207
Arrangements for controlling the attitude of actuators, e.g. speed, floating function: for reducing or compensating oscillations
E02F 3/431
Control of dipper or bucket position; Control of sequence of drive operations: for bucket-arms, front-end loaders, dumpers or the like
E02F 9/2012
Control mechanisms, e.g. control levers: setting the functions of the control levers, e.g. changing assigned functions among operations levers,…
F15B 11/048
Depending on the position of the working member: with deceleration control