Patent ID: 7577517

Claim:
A guided vehicle system, comprising: a master guided vehicle which obtains transfer data for transferring an article at a master transfer position and one or more non-master transfer positions, one or more non-master guided vehicles, each of which obtain transfer data for transferring said article at said master transfer position, each of said non-master guided vehicles determining a difference between said transfer data for transferring said article at said master transfer position obtained by said master guided vehicle and said transfer data for transferring said article at said master transfer position obtained by each said non-master guided vehicle as machine difference data, and a determination means for determining whether said machine difference data needs to be measured again based on conditions of each of said master guided vehicle and said non-master guided vehicles, wherein data obtained by adding said machine difference data to said transfer data obtained by said master guided vehicle is stored as transfer data at each of said plurality of transfer positions, wherein said determination means is provided in each of said non-master guided vehicles for storing the vehicle's operating condition and determining whether said machine difference data needs to be measured again, wherein if said determination means determines that said machine difference data needs to be measured again, said non-master guided vehicle travels to said master transfer position to obtain the machine difference data again, wherein each of said master guided vehicle and non-master guided vehicles has a travel unit supported by a travel rail in an overhead space for traveling along the travel rail, and an elevation unit supported by said travel unit for elevating/lowering said article; wherein a mark indicating a stop position for stopping each of said master guided vehicle and non-master guided vehicles at said transfer position is provided along said travel rail, and said travel unit has a sensor for detecting said mark to determine an error at said stop position; wherein said elevation unit has means for detecting a failure in transferring said article at said transfer position; and wherein said determination means determines a value indicating the degree of the error at said stop position, and a value indicating the degree of the transfer failure.