Patent ID: 9621097
Date: 2017-04-11
CPC Classifications: H02K,H02P

Claim:
1. A linear conveyor, comprising: a linear motor stator which includes a plurality of electromagnets arranged along a predetermined conveyance path, and in which each section of said predetermined conveyance path is individually controlled for conduction; a first conveyance carriage and a second conveyance carriage each including a linear motor mover which is a permanent magnet and constitutes a linear motor in tandem with a linear motor stator, the conveyance carriages being movably disposed along the conveyance path; a linear scale which includes scale members secured to each of the conveyance carriages, and detectors disposed along the conveyance path so that the scale members are detected; a plurality of motor controllers which are disposed in correspondence with the sections of the linear motor stator respectively, and individually control conduction of the electromagnets for each section based on the results of detecting the scale member by the detector; a first data storage unit which stores position correction data determined based on a movement error unique to the first conveyance carriage that occurs due to an assembly error of the first conveyance carriage including an installation position error of the scale member, the movement error of the first conveyance carriage being obtained by means of a measurement jig which includes a data acquisition stator having a configuration identical to the section of the linear motor stator, a data acquisition detector having a configuration identical to the detector, and which is used to control conduction of electromagnets of the data acquisition stator based on a detection result of the scale member obtained by the data acquisition detector to thereby move the first conveyance carriage along a conveyance path for the data acquisition stator and measure a position of the first conveyance carriage to obtain, based on a measurement result, the unique movement error of the first conveyance carriage, and a second data storage unit which stores position correction data determined based on a movement error unique to the second conveyance carriage that occurs due to an assembly error of the second conveyance carriage including an installation position error of the scale member, the movement error of the second conveyance carriage being obtained by using the measurement jig to control the conduction of the electromagnets of the data acquisition stator based on a detection result of the scale member obtained by the data acquisition detector to thereby move the second conveyance carriage along the conveyance path for the data acquisition stator and measure a position of the second conveyance carriage to obtain, based on a measurement result, the unique movement error of the second conveyance carriage, wherein each of the plurality of motor controllers determines, as control data, either the position correction data stored in the first data storage unit or processed data obtained through processing using the position correction data, and controls the conduction of the electromagnets using the control data, so as to stop the first conveyance carriage at a target stopping point, and determines, as control data, either the position correction data stored in the second data storage unit or processed data obtained through processing using the position correction data, and controls the conduction of the electromagnets using the control data, so as to stop the second conveyance carriage at a target stopping point.