The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 11, 2017
Filed:
Oct. 09, 2015
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
A construction machine includes: a swing structure; an electric motor that drives the swing structure; an operating device that outputs an operating signal according to an operating amount and an operating direction; an inverter device that controls the electric motor based on a control signal generated based on the operating signal; a position sensor that detects an actual speed of the electric motor; and a second controller that determines whether at least one of a first condition and a second condition is satisfied. The first condition is satisfied when a sign of a value computed by subtracting the actual speed from a target speed of the electric motor that defined by the control signal; and the second condition is satisfied when a difference between the target speed and the actual speed is greater than a first reference value, and when the acceleration is greater than a second reference value.