| 摘要 |
In a transporting system, four magnetic units (31) are mounted on corners of carrier (15) and the carrier is suspended under rails (12a, 12b) by electromagnetic attractive forces acting between the magnetic units (31) and the bottom section of the rails (12a, 12b). Each of the magnetic unit (31) has a permanent magnet (53) and electromagnets (51, 52) and gap sensors (34) are provided on the carrier (15) to sense a gap between each magnetic unit (31) and the rail (12a, 12b). A battery (42, 43) for supplying a current to the magnetic unit (31) is mounted on the carrier 15. The carrier (15) is floated in a zero power control mode, even when an external force is applied to the carrier (15) by a zero power control circuit (63, 68, 79, 81) which maintain the current supplied to the magnetic unit (31) to be substantially zero. The carrier (15) is softly landed on the rail (12a, 12a) or started to flow from the rail (12a, 12a) in response to an external command in a soft landing or a soft start mode by an actuating unit 67. In the soft landing and the soft start mode, the zero power control circuit (63, 68, 79, 81) is opened and the current supplied to the magnetic unit (31) is controlled in accordance with a target value by an actuating unit. |
