US 12,362,214 B2
OHT vehicle and method of controlling operation of same
Sung Hyun Lee, Anyang-si (KR)
Assigned to SEMES CO., LTD., Cheonan-si (KR)
Filed by SEMES CO., LTD., Cheonan-si (KR)
Filed on May 22, 2022, as Appl. No. 17/750,364.
Claims priority of application No. 10-2021-0163665 (KR), filed on Nov. 24, 2021.
Prior Publication US 2023/0159306 A1, May 25, 2023
Int. Cl. H01L 21/677 (2006.01); B65G 1/04 (2006.01); B66C 17/04 (2006.01); H01L 21/67 (2006.01); H01L 21/68 (2006.01)
CPC H01L 21/67733 (2013.01) [B65G 1/0457 (2013.01); H01L 21/67288 (2013.01); H01L 21/6773 (2013.01); H01L 21/67736 (2013.01); H01L 21/67775 (2013.01); H01L 21/68 (2013.01); B66C 17/04 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of controlling operation of an overhead hoist transfer (OHT) vehicle, the method comprising:
a transferring step of loading a transfer container and moving the transfer container to a destination port;
an error determining step of measuring a distance value between a hand unit and the transfer container and determining a degree of tilt of the transfer container on the basis of the distance value;
a position correcting step of adjusting a position of the hand unit by moving the transfer container to a load port of the destination port where the transfer container is to be unloaded on the basis of the degree of tilt of the transfer container; and
an unloading step of unloading the transfer container to the load port of the destination port.
 
12. An OHT vehicle comprising:
a transfer module configured to be movable along a rail;
a hoist module comprising:
a hand unit configured to hold a transfer container,
a hoist unit configured to move the hand unit in a vertical direction, and
a slide unit configured to move the hand unit in a horizontal direction;
a displacement measuring means mounted on the hand unit and configured to measure a distance value between the hand unit and the transfer container held by the hand unit; and
a controller configured to adjust a position of the hand unit by determining a degree of tilt of the held transfer container on the basis of the distance value between the hand unit and the transfer container.
 
20. A method of controlling operation of an OHT vehicle, the method comprising:
a transferring step of loading a transfer container and moving the transfer container to a destination port;
a distance measuring step of measuring a distance value between at least one of a front end and a rear end of a hand unit and at least one of a front end and a rear end of the transfer container;
a tilt determining step of calculating a tilt angle according to a degree of tilt of the transfer container by comparing a front end distance value or a rear end distance value with a reference value or by comparing the front end distance value with the rear end distance value;
a recess position determining step of determining a position of a recess of the transfer container on the basis of the degree of tilt;
an error distance calculating step of calculating an error distance between a downward vertical extension line for the determined position of the recess and a positioning pin provided on a load port of the destination port as a correction distance;
a position correcting step of horizontally moving the hand unit by the correction distance through a slide unit; and
an unloading step of lowering the hand unit through a hoist unit and unloading the transfer container to the load port of the destination port.