Controller and method for transporting devices

Patent metadata

Field	Value
Publication number	US-12595126-B2
Application number	US-202118005471-A
Country	US
Kind code	B2
Filing date	Jul 15, 2021
Priority date	Jul 16, 2020
Publication date	Apr 7, 2026
Grant date	Apr 7, 2026

Abstract

A controller is provided to control movement of a plurality of transporting devices. In particular, the controller provides improved robot shunting. More specifically, the controller delays the planning of a shunt path for an idle robot until closer to the time the idle robot needs to move out of the way. Advantageously this avoids the computing burden of planning shunts in advance that are never performed because the idle robot is subsequently tasked before the shunt were due to start. In particular, shunt paths can be planned very close to the time at which they need to be executed thereby providing a more efficient solution to robot shunting because very close to the execution time there is a very small probability that the plan will change in a way that the shunt needs to be recalculated.

First claim

The invention claimed is:

1 . A controller configured to control movement of a plurality of transporting devices, the controller comprising:
a route determination unit configured to determine a plurality of routes from one location on a grid-like structure to another location on the grid-like structure for a first transporting device; a waypoint generation unit configured to generate at least one leg for each of the plurality of routes determined by the route determination unit; a shunt calculation unit configured to calculate a shunt path for a second transporting device so as to shunt the second transporting device, wherein the shunt path is calculated at a predetermined time before which the second transporting device must commence movement to permit an uninterrupted passage of the first transporting device; and a clearance unit configured to provide clearance for the first transporting device to traverse a leg of a determined route, wherein the controller is configured to control the first transporting device to traverse the at least one leg of the determined route, wherein a portion of the at least one leg includes the uninterrupted passage.

2 . The controller according to claim 1 , wherein the shunt calculation unit is configured to calculate the shunt path for the second transporting device at a predetermined time before the first transporting device reaches a current position of the second transporting device.

3 . The controller according to claim 1 , wherein the shunt calculation unit configured to calculate the shunt path for the second transporting device whilst the first transporting device is moving in a leg immediately before a leg in which the second transporting device is located.

4 . The controller according to claim 1 , wherein the shunt calculation unit is configured to calculate the predetermined time before which the shunt path is calculated for the second transporting device; and
wherein the predetermined time is calculated by considering a probability that a shunt solution is pre-calculated and is evaluated by relative costs of a value of delaying a decision to make a shunt move compared with costs of having to re-plan a larger number of transporting device routes over a representative period of work.

5 . The controller according to claim 4 , wherein costs considered comprise at least one or more of:
grid throughput in terms of orders per hour, operator productivity in terms of items picked per hour, and/or transporting device productivity in terms of orders per transporting device per hour.

6 . The controller according to claim 4 , wherein costs considered comprise at least one or more of:
minimising a number of transporting devices for a required throughput, and/or minimising a number of operators for a required throughput.

7 . The controller according to claim 4 , wherein costs are determined using a Monte Carlo simulation over a predetermined time period.

8 . The controller according to claim 7 , wherein the Monte Carlo simulation is based on at least digital twin simulations including statistically sampled system factors including: more than one possible stock-holding scenarios including positioning of containers, quantities of stock keeping units, quantities of items of each stock keeping unit; and at least one of: possible ranges in variations in orders being picked including items and quantities, possible ranges in variations in orders being decanted, possible ranges in variations in pick-times and possible ranges in variations in decant-times; where the digital twin simulations are repeated many times with randomly selected values from the statistically varying parameters and the parameter value is determined to maximise one of: grid throughput in terms of orders per hour, operator productivity in terms of items picked per hour, or transporting device productivity in terms of orders per transporting device per hour; or minimise one of the number of transporting devices for a required throughput or the number of operators for a required throughput.

9 . The controller according to claim 1 , wherein each of the plurality of routes determined by the route determination unit includes a start time for each route.

10 . The controller according to claim 9 , wherein the start time for each route is less than a predetermined future maximum time.

11 . A storage system in combination with a controller according to claim 1 , the storage comprising:
a first set of parallel rails or tracks extending in an X-direction, and a second set of parallel rails or tracks extending in a Y-direction transverse to the first set in a substantially horizontal plane to form a grid pattern including a plurality of grid spaces; a plurality of stacks of containers located beneath the rails, and arranged such that each stack is located within a footprint of a single grid space; and a plurality of transporting devices each arranged to selectively move in the X and/or Y directions, above the stacks on the rails and arranged to transport a container.

12 . The storage system according to claim 11 , wherein the at least one transporting device has a footprint that occupies only a single grid space in the storage system, such that a transporting device occupying one grid space does not obstruct a transporting device occupying or traversing adjacent grid spaces in the X and/or Y directions.

13 . The storage system according to claim 11 , comprising:
a picking station arranged to receive a container transported by the at least one transporting device; and wherein the picking station is arranged for operation by an operator to pick items from one container to another container so as to form orders.

14 . A method for controlling movement of a plurality of transporting devices, the method comprising:
(1) determining a plurality of routes from one location on a grid-like structure to another location on the grid-like structure for a first transporting device; (2) generating at least one leg for each of the plurality of routes determined by the determining step; (3) calculating a shunt path for a second transporting device so as to shunt the second transporting device, wherein the shunt path is calculated at a predetermined time before which the second transporting device must commence movement to permit uninterrupted passage of the first transporting device; (4) providing clearance for the first transporting device to traverse a leg of a determined route; and (5) controlling the first transporting device to traverse the at least one leg of the determined route, wherein a portion of the at least one leg includes the uninterrupted passage.

15 . The method according to claim 14 , wherein the calculating step calculates the shunt path for the second transporting device at a predetermined time before the first transporting device reaches a current position of the second transporting device.

16 . The method according to claim 14 , wherein the calculating step calculates the shunt path for the second transporting device whilst the first transporting device is moving in a leg immediately before a leg in which the second transporting device is located.

17 . The method according to claim 14 , wherein the calculating step calculates the predetermined time before which the shunt path is calculated for the second transporting device; and
wherein the predetermined time is calculated by considering a probability that a shunt solution is pre-calculated and is evaluated by relative costs of a value of delaying a decision to make a shunt move compared wit

Assignees

• Ocado Innovation Ltd

Inventors

• Stadie Robert
• Czarny Andrzej
• Oliver Thomas
• Siret Gareth
• Brett Christopher Richard James

Classifications

• G06Q10/087

  Inventory or stock management, e.g. order filling, procurement or balancing against orders · CPC title

• G06Q10/047

  Optimisation of routes or paths, e.g. travelling salesman problem · CPC title

• B65G1/0464

  with access from above · CPC title

• G05D1/0289

  with means for avoiding collisions between vehicles (vehicle fittings for automatically controlling speed including means for detecting potential obstacles B60K31/0008; avoiding obstacles by action on the steering system B62D; radar, sonar, lidar systems designed for anti-collision purposes G01S13/93, G01S15/93, G01S17/93) · CPC title

• G05B17/02

  electric · CPC title