Travel system and control method of travel system

A travel system, comprising:

• a travelling carriage to travel on a predetermined track;
• a plurality of access points including a plurality of first access points to wirelessly communicate with the travelling carriage and a plurality of second access points to wirelessly communicate with the travelling carriage in a communication slot different from a communication slot of the plurality of first access points;
• and
• a controller to receive position information from the travelling carriage and transmit a travel instruction to the travelling carriage, via any one of the plurality of access points, the position information indicating a current position of the travelling carriage, and the travel instruction being an instruction to control travel of the travelling carriage;
• wherein
• each of the plurality of first access points is disposed so that a portion of a communication area of the first access point overlaps a communication area of an adjacent first access point;
• each of the plurality of second access points is disposed so that a portion of a communication area of the second access point overlaps a communication area of an adjacent second access point;
• each of the plurality of first access points is disposed so that at least a portion of the communication area of the first access point overlaps a communication area of any one of the plurality of second access points;
• and
• the travelling carriage includes a wireless interface to wirelessly communicate with a first access point among the plurality of first access points, and wirelessly communicate with a second access point among the plurality of second access points when wireless communication with the first access point is not possible.

A control method of a travel system in which each of a plurality of first access points is disposed so that a portion of a communication area of the first access point overlaps a communication area of an adjacent first access point, each of a plurality of second access points is disposed so that a portion of a communication area of the second access point overlaps a communication area of an adjacent second access point, each of the plurality of first access points is disposed so that at least a portion of the communication area of the first access point overlaps a communication area of any one of the plurality of second access points, the travel system including a travelling carriage including a wireless interface to wirelessly communicate with at least one of a first access point or a second access point, the control method of a travel system comprising:

• (a) causing a plurality of access points to wirelessly communicate with the travelling carriage, the plurality of access points including the plurality of first access points to wirelessly communicate with the travelling carriage and a plurality of second access points to wirelessly communicate with the travelling carriage in a communication slot different from a communication slot of the plurality of first access points;
• (b) receiving position information from the travelling carriage and transmitting a travel instruction to the travelling carriage, via any one of the plurality of access points, by a controller, the position information indicating a current position of the travelling carriage, and the travel instruction being an instruction to control travel of the travelling carriage;
• and
• (c) causing the travelling carriage to travel on a predetermined track;
• wherein
• the step (c) includes, by the travelling carriage, wirelessly communicating with the first access point via the wireless interface, and wirelessly communicating with the second access point via the wireless interface when wireless communication with the first access point is not possible.