Invention Grant
- Patent Title: Method for controlling ultrasonic motor and surveying instrument for the same
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Application No.: US15463920Application Date: 2017-03-20
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Publication No.: US10211387B2Publication Date: 2019-02-19
- Inventor: Kaoru Kumagai , Satoshi Yanobe , Tetsutaro Kouji
- Applicant: TOPCON CORPORATION
- Applicant Address: JP Tokyo
- Assignee: TOPCON CORPORATION
- Current Assignee: TOPCON CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Roberts Mlotkowski Safran Cole & Calderon, P.C.
- Priority: JP2016-087805 20160426
- Main IPC: H02P23/20
- IPC: H02P23/20 ; H01L41/04 ; B06B1/06 ; G01C3/08 ; G01D5/347 ; G01S3/786 ; H01L41/09 ; G01C15/00 ; H02N2/14 ; H02N2/16

Abstract:
Provided is a method for controlling an ultrasonic motor to reduce noise sounding during low-speed rotation in a surveying instrument adopting the ultrasonic motor for a rotary shaft, and a surveying instrument for the same. In a method for controlling an ultrasonic motor according to an aspect of the present invention, in a low-speed rotation range of an ultrasonic motor, a ratio of an acceleration period as a time of application of the drive signal in a control cycle is controlled, and a time to start the acceleration period is randomly shifted for each control cycle. In a method for controlling an ultrasonic motor according to another aspect, a time to start the acceleration period is regularly shifted for each control cycle. In a method for controlling an ultrasonic motor according to still another aspect, second-half acceleration control and first-half acceleration control are alternately repeated.
Public/Granted literature
- US20170309806A1 METHOD FOR CONTROLLING ULTRASONIC MOTOR AND SURVEYING INSTRUMENT FOR THE SAME Public/Granted day:2017-10-26
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