Moving body system and method for controlling travel of moving body

• US 9,292,018 B2
• Filed: 05/08/2012
• Issued: 03/22/2016
• Est. Priority Date: 07/22/2011
• Status: Active Grant

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Hanaka, Satoshi, Shimizu, Tetsuya
• Primary Examiner(s): Olszewski, John R
• Assistant Examiner(s): Whittington, Jess
• Application Number:
  US14/131,995
• Publication Number:
  US 20140142792A1
• Time in Patent Office: 1,414 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B61L 25/026 Relative localisation, e.g. using odometer
• CPC Class Codes: B65G 54/02 electrostatic, electric, or magnetic
• CPC Class Codes: G05D 1/0259 using magnetic or electromagnetic means

Abstract

A detector detects positions of a moving body in a travel direction at a position shifted from a center of control of travel of the moving body in a direction different than the travel direction of the moving body. Positions of the center of control in the travel direction relative to the output of the detector is stored in a storage unit for at least a curved section of a travel route of the moving body, and the travel of the moving body is controlled by a controller, based on the positions of the center of control read out from the storage unit.

Claims

1. A moving body system comprising:

a travel route;

a moving body that travels along the travel route;

a detector including at least one linear sensor that detects and outputs positions of the moving body in a travel direction of the moving body, the at least one linear sensor of the detector being located at a position that is shifted from a center of control of travel of the moving body in a direction different than the travel direction;

a lookup table that stores positions of the center of control in the travel direction corresponding to the positions output by the at least one linear sensor of the detector, for at least a curved section of the travel route of the moving body;

a controller that controls the travel of the moving body, based on the positions of the center of control read out from the lookup table; and

a linear motor;

wherein

a first element of the linear motor is provided in the moving body and a second element of the linear motor is provided along the travel route; and

the center of control is a reference position in the travel direction that is referenced to control the travel of the moving body.

2. The moving body system according to claim 1, wherein:

the center of control is referenced when controlling the linear motor; and

the at least one linear sensor of the detector is a magnetic sensor provided laterally to the linear motor provided on the travel route or the moving body, and is disposed so as to detect magnets or magnetic materials provided laterally to the linear motor on the moving body or the travel route.

3. The moving body system according to claim 2, wherein

a plurality of the detectors are provided along the travel route, so as to detect magnets or magnetic materials provided on the moving body;

and

the controller is programmed to obtain the position of the center of control from the lookup table, according to an output of at least one detector of the plurality of the detectors.

4. The moving body system according to claim 1, wherein a radius of curvature of the curved section of the travel route is larger at an entrance and an exit of the curved section than at a middle portion of the curved section.

5. The moving body system according to claim 1, wherein, in the curved section of the travel route, the moving body is at least partially guided by guide rollers.

6. The moving body system according to claim 1, wherein:

the lookup table stores pre-calibrated positions of the center of control and corresponding outputs of the at least one linear sensor.

7. The moving body system according to claim 6, wherein the pre-calibrated positions of the center of control are measured with at least an encoder attached to an axis of a wheel of the moving body, in a travel state of the moving body system where slippage between the wheel of the moving body and the travel route is negligible.

8. A moving body travel control method for repeatedly executing the steps of:

causing a moving body to travel by a linear motor;

detecting and outputting positions of a moving body in a travel direction of the moving body with a detector that includes at least one linear sensor, at a position shifted from a center of control of travel of the moving body in a direction different than the travel direction;

reading out the positions of the center of control from a lookup table that stores positions of the center of control in the travel direction corresponding to the positions output by the at least one linear sensor of the detector for at least a curved section of a travel route of the moving body; and

controlling the travel of the moving body, based on the positions of the center of control read out from the lookup table;

wherein

a first element of the linear motor is provided in the moving body and a second element of the linear motor is provided along the travel route; and

the center of control is a reference position in the travel direction that is referenced to control the travel of the moving body.

9. The moving body travel control method according to claim 8, further comprising the steps of:

detecting, by a plurality of the detectors provided along the travel route, magnets or magnetic materials provided on the moving body;

extracting an output of at least one of the plurality of detectors that is detecting the magnets or magnetic materials; and

reading out, from the lookup table, the position of the center of control according to the extracted output of the at least one of the plurality of detectors.