Optimizing container delivery vehicle task scheduling

A control system for utilizing operational capacity of container handling vehicles when assigned tasks of delivering or retrieving identified storage containers at a same port of an automatic storage and retrieval system comprising a framework structure defining a storage grid for storing storage containers in storage columns, and wherein the storage containers are handled by the container handling vehicles running on top of the storage grid, and wherein the port is used for transferring storage containers to and from the storage and retrieval system, wherein the control system comprises a master controller, a database keeping track of the storage containers, a routing planner for finding optimal routes for the container handling vehicles and a transmitter/receiver for communicating instructions to each container handling vehicle, wherein the control system further comprises a processor arranged for running a computer program that when executed performs a method comprising:

• assigning tasks without deadlines and with deadlines for the container handling vehicles to arrive at the port;
• calculating end times and end positions of the container handling vehicles when the assigned tasks without a deadline complete;
• checking if container handling vehicles can meet a deadline after first completing a task without a deadline;
• ranking the tasks assigned to the container handling vehicles, where tasks for which the deadline can be met after first finishing a task without a deadline are ranked first, and further according to arrival times of the container handling vehicles at the port;
• and
• executing tasks by communicating instructions to the container handling vehicles according to the ranking of tasks.

A computer program that when executed by a processor in a control system of an automated storage and retrieval system performs a method for utilizing operational capacity of container handling vehicles when assigned tasks of delivering or retrieving identified storage containers at a same port of an automatic storage and retrieval system, wherein the automatic storage and retrieval system comprises a framework structure defining a storage grid for storing storage containers in storage columns, and wherein the storage containers are handled by the container handling vehicles running on top of the storage grid, and wherein the port is used for transferring storage containers to and from the storage and retrieval system, the method comprising:

• assigning tasks without deadlines and with deadlines for the container handling vehicles to arrive at the port;
• calculating end times and end positions of the container handling vehicles when the assigned tasks without a deadline complete;
• checking if container handling vehicles can meet a deadline after first completing a task without a deadline;
• ranking the tasks assigned to the container handling vehicles, where tasks for which the deadline can be met after first finishing a task without a deadline are ranked first, and further according to arrival times of the container handling vehicles at the port;
• and
• executing tasks by communicating instructions to the container handling vehicles according to the ranking of tasks.