Rotation control device of working machine

• US 9,103,093 B2
• Filed: 01/19/2012
• Issued: 08/11/2015
• Est. Priority Date: 01/21/2011
• Status: Active Grant

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Sonoda, Mitsuo, Hiroki, Takenori, Sugiura, Manabu, Satake, Hidetoshi, Udagawa, Tsutomu, Edamura, Manabu
• Primary Examiner(s): MUSTAFA, IMRAN K
• Application Number:
  US13/980,607
• Publication Number:
  US 20140032059A1
• Time in Patent Office: 1,300 Days
• Field of Search: 701/50
• US Class Current: 1/1
• CPC Class Codes: E02F 9/123 Drives or control devices specially adapted therefor E02F9/125 and E02F9/128 take precedence
• CPC Class Codes: E02F 9/2095 Control of electric, electro-mechanical or mechanical equipment not otherwise provided for, e.g. ventilators, electro-driven fans control of hydraulic driven equipment E02F9/22

Abstract

To automatically prevent a reverse movement by inhibiting an excessive increase in an output torque of an electric motor.

A means (31) calculates a target value for a rotation speed based on a command from a system (20), a means (32) calculates a deviation between a detection value from a rotation speed sensor (81) and the target value, a means (33) calculates a first target torque in a direction that the deviation will be eliminated, and a means (34) calculates, based on a command from the system (20), a second target torque in the same direction as the target value. A means (50) calculates a variation in a rotation angle of an electric motor (12) in a first range, and a means (60) calculates the same variation in a second range. A means (40) calculates, based on the variations from the means (50, 60), a third target torque in a direction that the rotation angle will return to a rotation angle before a predetermined time (t), and a means (73) limits the first target torque to one of the second and third target torques, said one target torque being in the same direction as the first target torque and being greater in absolute value. Substantially an entirety of the first range specifies a range for the variation in one direction, a remaining small range specifies a range for the variation in the other direction, substantially an entirety of the second range specifies a range for the variation in the other direction, and a remaining small range specifies a range for the variation in the one direction.

Claims

1. A swing control system for a working machine, said swing control system being provided with a swing mechanism for driving an upperstructure by an output torque of an electric motor rotatable in opposite two directions, a swing operating device selectively operable in opposite two directions from a neutral position and capable of converting a operation direction and operation stroke to a swing command signal, and a control means for calculating, based on the swing command signal from the swing operating device, a target torque for the electric motor and controlling, based on the target torque, the output torque of the electric motor, wherein:

the control means is provided with;

a rotation speed detection means for detecting a rotation speed of the electric motor,

a target rotation speed calculation means for calculating, based on the swing command signal from the swing operating device, a target rotation speed for the electric motor,

a speed deviation calculation means for calculating a speed deviation of an actual rotation speed, which has been detected by the rotation speed detection means, relative to the target rotation speed,

a first target torque calculation means for calculating a first target torque in a direction that the speed deviation will be eliminated,

a second target torque calculation means for calculating, based on the swing command signal from the swing operating device, a second target torque in the same direction as the target rotation speed,

a first variation calculation means for calculating, based on a detection value of rotation speed by the rotation speed detection means, a variation in a rotation angle of the electric motor in a preset first calculation range,

a second variation calculation means for calculating, based on the detection value of rotation speed by the rotation speed detection means, a variation in a rotation angle of the electric motor in a preset second calculation range,

a third target torque calculation means for calculating, based on the variations calculated by the first and second variation calculation means, respectively, a third target torque in a direction that the rotation angle of the electric motor will return to a rotation angle before a predetermined time, and

a target torque limitation means for limiting the first target torque to one of the second and third target torques, said one target torque being in the same direction as the first target torque and being greater in absolute value than the other target torque;

substantially an entirety of the first calculation range specifies a calculation range for the variation in one of the two opposite directions of rotation of the electric motor, and a remaining calculation range other than the substantially the entirety of the first calculation range specifies a calculation range for the variation in the other direction; and

substantially an entirety of the second calculation range specifies a calculation range for the variation in the other direction, and a remaining calculation range other than the substantially the entirety of the second calculation range specifies a calculation range for the variation in the one direction.