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EP-4367043-B1 - STORAGE SYSTEM WITH A MULTI-LEVEL STORAGE RACK, A VERTICAL LIFT CONNECTING THE LEVELS OF THE MULTI-LEVEL STORAGE RACK AND METHOD OF OPERATION

EP4367043B1EP 4367043 B1EP4367043 B1EP 4367043B1EP-4367043-B1

Inventors

  • YAMASHITA, SHIN

Dates

Publication Date
20260506
Application Date
20220630

Claims (10)

  1. Storage system (100) with a multi-level storage rack (2), a vertical lift (6, 7) connecting the levels of the multi-level storage rack (2), the vertical lift (2) having a conveyor platform (P), at least one rack level having a driven rack conveyor (B) adjacent to the vertical lift (6, 7), and a controller (1000) configured for controlling the lift, the conveyor platform (P) having a driven conveying means (P1) controlled by the controller (1000) to transfer loads (T) to and from the conveyor platform (P) and the rack conveyor (B) such that the lift conveyor platform (P) and rack conveyor (B) are controlled to transfer a load (T) between the lift conveyor platform (P) and the rack conveyor (B) or vice versa, characterized by the lift (6, 7) having a sensor (11) arranged to determine a height positioning of the lift platform (P) verses the rack level and coupled with the controller (1000), wherein the transfer is controlled by the controller (1000) to be performed as soon as the lift conveyor platform (P) and the rack conveyor (B) are at same height based on height positioning from the sensor (11) and the controller (1000) controlling the lifting platform (P) to travel vertically beyond the rack level for transition thus allowing the transfer to be initiated by the controller (1000) earlier by transferring the load from the higher lift conveyor platform (P) to the lower rack conveyor (B) or vice versa by the controller (1000) controlling the driven conveying means (P1, B1) of the conveyor platform (P) and the conveyor (B) adjacent to the vertical lift (6, 7).
  2. Storage system according to claim 1, characterized in that each storage level has a rack conveyor (B) adjacent to the vertical lift (6, 7) controlled by the controller (1000) to function as a buffer decoupling the lift (6, 7) or to function as a supply and discharge conveyor for the storage rack (2).
  3. Storage system according to claim 1 or 2, characterized in that the at least one rack level storage has a rack conveyor (B) adjacent the vertical lift (6, 7) on each side functioning as buffer.
  4. Storage system according to claim 3, characterized in that each storage level has a rack conveyor (B) adjacent to the vertical lift (6, 7) on each side.
  5. Storage system according to claim 3 or 4, characterized in that the controller (1000) is configured for controlling the lift (6, 7), the driven conveying means (P1) of the conveyor platform (P) and the drive of the driven rack conveyor (B) such that the lift conveyor platform (P) and conveyor (B) are controlled to transfer a load (T) between the lift conveyor platform (P) and the rack conveyor (B) or vice versa simultaneously.
  6. Storage system according to claim 5, characterized in that the vertical lift conveyor platform (P) which is either statically tilted or dynamically tilted by a tilting mechanism (P2) from a horizontal plane, such that that one side can be over travelled whilst opposite side is aligned with the opposing conveyor (B) of the rack level for transition.
  7. Storage system according to any preceding claims 1 - 5, characterized in that vertical lift conveyor platform (P) is horizontally oriented and the opposing rack conveyors (B) are on different heights.
  8. Storage system according to any preceding claim, characterized in that the system comprises at least two parallel racks (2) with an aisle (3) in between and a single level rack servicing vehicle (5) running the length of the aisle (3) between storage positions and the conveyor (B) adjacent to the vertical lift (6, 7).
  9. Storage system according to any preceding claim, characterized in that the lift conveyor platform (P) is controlled to slowly move opposite direction to the initial vertical direction of movement to the rack level of transition after the over travel beyond the transition rack level.
  10. Method for operation of a storage system according to claims 1 - 9 wherein the lift conveyor platform (P) and rack conveyor (B) are controlled to transfer a load (T) between the lift conveyor platform (P) and the rack conveyor (B) or vice versa, wherein the transfer is controlled to be performed as soon as the lift conveyor platform (P) and the rack conveyor (B) are at same height and lifting platform (P) over travels beyond transition level allowing the transfer to be initiated earlier by transferring the load (T) from the higher lift conveyor platform (P) to the lower rack conveyor (B) or vice versa.

Description

Storage systems with a vertical lift connecting levels of a multi-level storage rack, wherein the vertical lift has a conveyor platform and each rack level has a buffer conveyor adjacent to the vertical lift and a controller configured for controlling the lift, a conveyor platform and rack conveyor such that the lift conveyor platform or rack conveyor are controlled to transfer a load between the lift conveyor platform and the rack conveyor or vice versa, are known. Loads are transferred between storage spaces in the racks and the buffer conveyors by storage and retrieval vehicles. Such systems are usually referred to as shuttle storage systems and for example known from the applicant: https://www.dematic.com/de-de/produkte/produktueberblick/lagertechnik/multishuttle/. In such shuttle systems the vertical lift throughput performance has been one of the most critical parts of the system design and is often seen as a bottle neck, as there are many shuttles serving a lift. Increasing speed and acceleration and/or deceleration of vertical lift and transfer operation is the easiest way to realize an increase in throughput. However, this also tends to compromise hardware cost, the system reliability and stability and increase energy consumption. Additionally, the vertical lift speed is limited, especially on the downward movement by the items losing contact to the lift, if the acceleration is too high. US 2016/264356 A1 discloses that in a lift carrier device, a controller causes a first longitudinal drive device and a second longitudinal drive device respectively to be lifted or lowered by a first lift drive device and a second lift drive device, to cause a first article stage and a second article stage to pass by each other in a state where the first article stage and the second article stage have been moved by the first longitudinal drive device and the second longitudinal drive device to positions where the first article stage and the second article stage do not longitudinally overlap each other in plan view. Therefore, the object of the present invention is to provide a way to increase vertical lift performance without increase in lift dynamics and compromising the system reliability or stability. This object is solved by claim 1 detailing a storage system with a multi-level storage rack, a vertical lift connecting the levels of the multi-level storage rack, the vertical lift having a conveyor platform, at least one rack level having a driven rack conveyor adjacent to the vertical lift, and a controller configured for controlling the lift, the conveyor platform having a driven conveying means controlled by the controller to transfer loads to and from the conveyor platform and the rack conveyor such that the lift conveyor platform and rack conveyor are controlled to transfer a load between the lift conveyor platform and the rack conveyor or vice versa, the lift having a sensor arranged to determine a height positioning of the lift platform verses the rack level and coupled with the controller, wherein the transfer is controlled by the controller to be performed as soon as the lift conveyor platform and the rack conveyor are at same height based on height positioning from the sensor and the controller controlling the lifting platform to travel vertically beyond the rack level for transition, thus allowing the transfer to be initiated by the controller earlier by transferring the load from the higher lift conveyor platform to the lower rack conveyor or vice versa by the controller controlling the driven conveying means of the conveyor platform and the conveyor adjacent to the vertical lift. The principle of this invention is to make the vertical lift ready for transferring a load as early as possible. A load transfer can only be initiated after the lift conveyor platform has arrived on a specific level and has settled at the transfer level, i. e. leveling with the adjacent conveyer, so as to prevent a load from collision with either the lift conveyor platform or the buffer conveyor. Normally leveling is performed with a tolerance of no more than 3 mm to prevent collision. However, in order to accomplish this, the vertical lift needs to go through a positioning process consisting of certain slow creeping movement towards the transfer level and settling time for lifting carriage bouncing, swinging or vibration, both of which take time. Moreover, settling time is increased if the vertical lift has a long vertical length (height) as frequency of bouncing, swinging gets lower with increasing height. The inventor has realized that it is possible to minimize or omit the slow and time consuming creeping and settling process by means of over traveling of the lifting carriage beyond the transfer level. In other words, and according to the invention, the transfer is controlled to be performed before the lift conveyor platform and the rack conveyor are at same height by transferring the load from the higher lift conveyor p