Conveyor systems and methods of controlling moving stage

Patent metadata

Field	Value
Publication number	US-10364103-B2
Application number	US-201815974100-A
Country	US
Kind code	B2
Filing date	May 8, 2018
Priority date	Aug 28, 2017
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

A conveyor system includes a moving stage, a track, a control circuit and a driver. The moving stage has a plurality of magnets and an optical scale. The track carries the moving stage and includes a first work area provided with a plurality of Hall sensor modules and a second work area provided with the Hall sensor modules and a read head module. When the moving stage is in the first work area, the Hall sensor module generates a first sensing signal. When the moving stage is in the second work area, the Hall sensor module generates the first sensing signal and the read head module generates a second sensing signal. The control circuit determines the position of the moving stage based on the first sensing signal and the second sensing signal, and generates a driving signal. The driver drives the coil windings according to the driving signal.

First claim

What is claimed is:

1. A conveyor system, comprising:
a moving stage, provided with a plurality of magnets and an optical scale;
a track, having a plurality of coil windings, and carrying the moving stage, wherein the track further comprises:
a first work area, provided with a plurality of sets of Hall sensor modules; and
a second work area, provided with Hall sensor modules and a read head module;
wherein when the moving stage is in the first work area, the Hall sensor module generates a first sensing signal by sensing the magnets; and
wherein when the moving stage is in the second work area, the Hall sensor module generates the first sensing signal by sensing the magnets and the read head module generates a second sensing signal by sensing the optical scale;

a control circuit, determining a position of the moving stage according to the first sensing signal and the second sensing signal, controlling energization of the coil windings and generating a driving signal according to the position; and
a driver, driving the coil windings according to the driving signal.

2. The conveyor system as claimed in claim 1 , wherein the Hall sensor modules are arranged equidistantly along a moving direction of the moving stages, each of the Hall sensor modules consists of three Hall sensors, and there is a phase difference between two of the Hall sensors of 120 degrees.

3. The conveyor system as claimed in claim 1 , wherein the second work area has a length that is greater than a distance between two of the Hall sensor modules.

4. The conveyor system as claimed in claim 1 , wherein when the length of the second work area is less than a length of the moving stage, the read head module has only one read head, and the read head is arranged at a starting position of the second work area.

5. The conveyor system as claimed in claim 1 , wherein when the length of the second work area is greater than or equal to a length of the moving stage, the read head module has at least two read heads, and the read heads are arranged equidistantly along the moving direction of the moving stages from a starting position of the second work area.

6. The conveyor system as claimed in claim 1 , wherein the optical scale has a first track and a second track, the first track consists of a sensing element pitch, and the second track is a coding pattern corresponding to the optical scale.

7. The conveyor system as claimed in claim 1 , wherein the sensing accuracy of the first work area is 10 to 100 μm, and the sensing accuracy of the second work area is 0.1 to 9 μm.

8. A method of controlling a moving stage, adapted to a conveyor system having at least one moving stage, a track, a control circuit and a driver, wherein the moving stage is provided with a plurality of magnets and an optical scale, comprising:
generating, using one of the Hall sensor modules, a first sensing signal by sensing the magnets when the moving stage is in a first work area of the track;
generating, using the Hall sensor modules, the first sensing signal by sensing the magnets, and generating, with a read head module, a second sensing signal by sensing the optical scale when the moving stage is in a second work area of the track;
determining, by using a control circuit, the position of the moving stage according to the first sensing signal and the second sensing signal;
generating, with the control circuit, a driving signal according to the position; and
driving, via a driver, the coil windings provided on the track according to the driving signal for carrying the moving stage.

9. The method as claimed in claim 8 , wherein the Hall sensor modules are arranged equidistantly along the moving direction of the moving stages, each of the Hall sensor modules consists of three Hall sensors, and the phase difference between two of the Hall sensors is 120 degrees.

10. The method as claimed in claim 8 , wherein the length of the second work area is greater than the distance between two of the Hall sensor modules.

11. The method as claimed in claim 8 , wherein when the length of the second work area is less than the length of the moving stage, the read head module has only one read head, and the read head is arranged at the starting position of the second work area.

12. The method as claimed in claim 8 , wherein when the length of the second work area is greater than or equal to the length of the moving stage, the read head module has at least two read heads, and the read heads are arranged equidistantly along the moving direction of the moving stages from the starting position of the second work area.

13. The method as claimed in claim 8 , wherein the optical scale has a first track and a second track, the first track consists of a sensing element pitch, and the second track is a coding pattern corresponding to the optical scale.

14. The method as claimed in claim 8 , wherein the sensing accuracy of the first work area is 10 to 100 μm, and the sensing accuracy of the second work area is 0.1 to 9 μm.

Assignees

• Delta Electronics Inc

Inventors

• Tsai Ching-Hsiung
• Lu Chieh-Huang
• Chung Chi-Wen

Classifications

• B65G2203/044

  Optical · CPC title

• B65G2203/043

  Magnetic · CPC title

• B65G54/02 Primary

  electrostatic, electric, or magnetic · CPC title

• B65G35/00

  Mechanical conveyors not otherwise provided for · CPC title

• B65G2203/0266

  relating to the load carrier(s) · CPC title