Transport device
A stacker crane includes a transporter, a slide fork, first to third sensors, a counter, and a main controller. The transporter moves from a shelf on which an article is supported to an empty shelf. The slide fork is mounted on the lift stage and transfers the article to and from the shelf. The first, second and third sensors recognize an abnormality of the article moved by the movement of the transporter. The counter counts the number of event occurrences. When an abnormality is recognized by the sensor, the main controller reduces a moving speed of the transporter, and when no abnormality is recognized by the sensor upon reduction in the moving speed, the movement of the transporter is continued. When the number of event occurrences reaches a first threshold, the stacker crane is brought into an abnormal-stop state.
1. A transport device that transports an article, the transport device comprising:
a transporter that moves from a support on which the article is supported to an empty support;
a transfer device that is mounted on the transporter and transfers the article to and from the support;
an abnormality detector that recognizes an abnormality of the article moved by the transporter;
a counter that counts a number of occurrences of an event related to a problem in transport during execution of one transport command; and
a movement controller configured or programmed to:
reduce a moving speed of the transporter when an abnormality is recognized by the abnormality detector;
continue the movement of the transporter when the abnormality is no longer recognized by the abnormality detector when the moving speed has been reduced; and
bring the transport device into an abnormal-stop state when the number of occurrences of the event counted by the counter reaches a first threshold.
2. The transport device according to claim 1 , wherein the movement controller is configured or programmed to change a movement condition of the transporter when the number of occurrences counted by the counter exceeds a second threshold smaller than the first threshold.
3. The transport device according to claim 1 , wherein the movement controller changes a movement condition of the transporter each time the event related to the problem in transport occurs.
4. The transport device according to claim 1 , wherein the movement controller brings the transporter into the abnormal-stop state when the abnormality detector recognizes the abnormality while the movement of the transporter is stopped.
5. The transport device according to claim 1 , further comprising:
a detector that recognizes the support located in a vicinity of the transfer device when the number of occurrences is counted by the counter during the movement of the transporter; and
a notifier that notifies there is an abnormality in an article supported on the support when the number of times the support on which the article is supported is recognized by the detector exceeds a third threshold while the article is supported on the support.