CONTROL SYSTEM FOR A PALLET LOAD TRANSPORT SYSTEM

Abstract

A pallet load transport system includes a shuttle car that is supported by and moves along a track between a pick-up location to a deposit location. A control system monitors and controls all operation of the shuttle car, ensuring proper and safe transfer of pallet loads from the pick-up location to the deposit location. Signal from various measuring devices and/or sensors are input into a programmable logic controller. Based on the application of a control logic to the received signals, output signals are generated and sent to a variable frequency drive, which controls the linear movement of the shuttle car along the track through operation of a motor mounted on the shuttle car.

Description

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a pallet load transport system incorporating a control system in accordance with the present invention;

FIG. 2 is a side view of the pallet load transport system of FIG. 1, illustrating the shuttle car in a home or queue position;

FIG. 3 is a side view of the pallet load transport system of FIG. 1, illustrating the shuttle car at the mainline conveyor for pickup (or deposit) of a pallet load;

FIG. 4 is a side view of the pallet load transport system of FIG. 1, illustrating the shuttle car at the crane interface station for deposit (or pickup) of a pallet load; and

FIG. 5 is a schematic illustration of the control system of the pallet load transport system of FIGS. 1-4.

Claims

1. A pallet load transport system for moving pallet loads from a pick-up location to a deposit location, comprising: a track extending between said pick-up location and said deposit location;a shuttle car adapted for movement along said track, including a lower carriage and an upper carriage, the upper carriage being adapted for movement between a raised position and a lowered position relative to the lower carriage;a drive, which controls movement of the shuttle car along said track; anda control system, including at least one measuring device for determining a linear position of the shuttle car along the track, anda programmable logic controller receiving a signal from said measuring device and sending signals to said drive to control movement of the shuttle car along said track based on the received signal.

2. The pallet load transport system as recited in claim 1, wherein the at least one measuring device for determining the linear position of the shuttle car along the track is installed on the shuttle car.

3. The pallet load transport system as recited in claim 1, wherein the at least one measuring device for determining the linear position of the shuttle car along the track is an encoder.

4. The pallet load transport system as recited in claim 1, wherein said control system further includes at least one sensor for determining if a pallet load is present on the shuttle car, said programmable logic controller also receiving a signal from this sensor, and then sending signals to said drive to control movement of the shuttle car along said track based on the received signals.

5. The pallet load transport system as recited in claim 4, wherein the at least one sensor for determining if the pallet load is present on the shuttle car is a photoelectric eye installed on the shuttle car.

6. The pallet load transport system as recited in claim 1, wherein said control system further includes at least one sensor for determining whether said upper carriage is in the raised or the lowered position, said programmable logic controller also receiving a signal from this sensor, and then sending signals to said drive to control movement of the shuttle car along said track based on the received signals.

7. The pallet load transport system as recited in claim 4, wherein said control system further includes at least one sensor for determining whether said upper carriage is in the raised or the lowered position, said programmable logic controller also receiving a signal from this sensor, and then sending signals to said drive to control movement of the shuttle car along said track based on the received signals.

8. The pallet load transport system as recited in claim 1, wherein said control system further includes at least one sensor installed on the shuttle car for detecting any over travel of the shuttle car at the pick-up location and/or deposit location, said programmable logic controller also receiving a signal from this sensor.

9. The pallet load transport system as recited in claim 1, wherein said control system further includes at least two proximity switches installed on the shuttle car with corresponding targets installed at either end of the track near the pick-up location and the deposit location for detecting any over travel of the shuttle car, said programmable logic controller also receiving a signal from each of these proximity switches.

10. The pallet load transport system as recited in claim 1, wherein said control system further includes a sensor installed near the pick-up location to indicate that a pallet load is present, said programmable logic controller also receiving a signal from this sensor.

11. The pallet load transport system as recited in claim 1, wherein said control system further includes a sensor installed near the deposit location to indicate that a pallet load is present, said programmable logic controller also receiving a signal from this sensor.

12. The pallet load transport system as recited in claim 1, wherein said control system further receives input signals from an existing automatic storage and retrieval system (ASRS) control system to verify safe conditions at the pick-up location and/or deposit location.

13. The pallet load transport system as recited in claim 1, wherein said drive includes a variable frequency drive and a motor.

14. The pallet load transport system as recited in claim 13, wherein said motor is mounted on the shuttle car.

15. The pallet load transport system as recited in claim 1, wherein said control system includes a control panel with one or more input devices that allow for manual operation of the shuttle car by a user.

16. The pallet load transport system as recited in claim 1, wherein said control system includes a control panel with one or more input devices for initiating a repositioning sequence to establish a zero reference identifying the linear position of the shuttle car along the track.

17. The pallet load transport system as recited in claim 1, wherein said control system includes a control panel with one or more visual indicators that provides notification of a status of the pallet load transport system and/or warnings as to fault conditions.

18. The pallet load transport system as recited in claim 1, wherein said control system includes a display screen that provides various information about a status of the pallet load transport system and/or fault conditions.

19. A control system for a pallet load transport system for moving pallet loads from a pick-up location to a deposit location through movement of a shuttle car along a track extending between said pick-up location and said deposit location, comprising: at least one measuring device for determining a linear position of the shuttle car along the track;at least one sensor for determining if a pallet load is present on the shuttle car;at least one sensor for determining whether an upper carriage of the shuttle car is in a raised position or a lowered position relative to a lower carriage of the shuttle car; anda programmable logic controller receiving signals from said measuring device and said sensors, and then sending signals to a drive to control linear movement of the shuttle car along said track based on the received signals.

20. The control system for a pallet load transport system as recited in claim 19, wherein said drive includes a variable frequency drive and a motor.

21. The control system for a pallet load transport system as recited in claim 20, wherein said motor is mounted on the shuttle car.

22. The control system for a pallet load transport system as recited in claim 19, and further comprising at least one sensor installed on the shuttle car for detecting any over travel of the shuttle car at the pick-up location and/or deposit location, said programmable logic controller also receiving a signal from this sensor.

23. The control system for a pallet load transport system as recited in claim 19, and further comprising at least two proximity switches installed on the shuttle car with corresponding targets installed at either end of the track near the pick-up location and the deposit location for detecting any over travel of the shuttle car, said programmable logic controller also receiving a signal from each of these proximity switches.

24. The control system for a pallet load transport system as recited in claim 19, and further comprising a sensor installed near the pick-up location to indicate that a pallet load is present, said programmable logic controller also receiving a signal from this sensor.

25. The control system for a pallet load transport system as recited in claim 19, and further comprising a sensor installed near the deposit location to indicate that a pallet load is present, said programmable logic controller also receiving a signal from this sensor.

26. The control system for a pallet load transport system as recited in claim 19, wherein said control system further receives input signals from an existing automatic storage and retrieval system (ASRS) control system to verify safe conditions at the pick-up location and/or deposit location.

27. The control system for a pallet load transport system as recited in claim 19, and further comprising a control panel with one or more input devices that allow for manual operation of the shuttle car by a user.

28. The control system for a pallet load transport system as recited in claim 19, and further comprising a control panel with one or more input devices for initiating a repositioning sequence to establish a zero reference identifying the linear position of the shuttle car along the track.

29. The control system for a pallet load transport system as recited in claim 19, and further comprising a control panel with one or more visual indicators that provides notification of a status of the pallet load transport system and/or warnings as to fault conditions.

30. The control system for a pallet load transport system as recited in claim 19, and further comprising a display screen that provides various information about a status of the pallet load transport system and/or fault conditions.