Alibaba Tech

Mar 15, 2018

6 min read

Delivering the Future

What’s behind Cainiao’s Automated UCS for Warehousing and Distribution?

Facing explosive cost growth due to a thinning labor force, many logistics companies begin to utilize new technologies to offset this issue.

Cainiao, Alibaba’s logistics partner, was founded with the aim of building the most efficient logistics networks not only in China, but across the world. However, instead of using a Warehouse Control System (WCS), as is common among most logistics companies, Cainiao opted to use a Unified Control System (UCS), to provide real-time access to buyers and sellers and helping to successfully deliver more than 57 million deliveries a day. During the 2017 Double 11 shopping festival, Cainiao delivered 812 million parcels, and is expected to cross the one billion mark for the 2018 Double 11 sales event this coming November.

What is UCS?

Cainiao helped develop a Unified Control System (UCS) to schedule and control all automated equipment in warehouses and distribution centers. This allows upstream business systems to thoroughly cover gaps in the operation of bottom layer equipment.

As a unified production line control system, UCS is the medium between business systems and automated production lines, and helps manage Cainiao’s Intelligent Warehouse system, organize production lines, and pull data from the production lines.

UCS versus WCS

A Warehouse Control System (WCS) is a pure control system overseeing warehousing equipment. Usually, one WCS controls one automated production line. Warehouse Control Systems are usually delivered with automated equipment, and Warehouse Management Systems (WMS) directly connect to Warehouse Control Systems.

A UCS, on the other hand, controls all automated equipment production lines. In this way, a UCS is a unified version of WCS — not designed for a specific production line, but to control all downstream automated equipment and provide a set of unified APIs to upstream businesses. These upstream businesses then assign tasks to the automated production lines, again using the UCS. This enables them to shift focus from specific lines and switch-in to fully-automated processes.

Standard UCS tasks

Unified Control Systems can be configured to provide a wide variety of services, including:

1. Integrated switch-in of various automated production lines such as goods-to-human AGV, sorters, automated storage and retrieval systems (AS/RS), and robotic arms.

2. Shielding various downstream production lines and unifying interfaces for the benefit of upstream businesses. Siasun, KSEC, Zhongding, Daifuku are prominent examples of AS/RS solution providers. Sorter brands include Dematic, Vanderlande, Damon, Swisslog, and Li Sheng, all of whom use different communication protocols unnecessary for upstream businesses to learn.

3. Quick replication of automated production lines; for example, by using a standardized switch-in system to conduct switch-ins for multiple warehouses.

4. Ensuring highly available channels for quickly sending route control commands to guarantee orderly production, even in weak network conditions.

5. Scheduling and coordinating hardware equipment for complicated production lines; for example, delivering a pallet into/out of an AS/RS through the coordination of conveyor lines, stackers, and RGVs.

6. Realizing quick, orderly, and safe production regardless of volume size.

7. Properly monitoring automated business processes, quickly identifying and locating problems, and providing stable support for safe production.

UCS architecture

The entire UCS architecture comprises five parts:

· Task & Data Center (TDC)

The TDC is the core data center of an automated UCS, and is used for storing task-related data and results. It receives automation tasks and task-related business data (sorter parcel data, waybill information, etc.) from upstream business systems. The TDC also stores intermediate context data when executing automation tasks, and result data after completion. It provides APIs for querying task result data to upstream businesses as business compensation logic for instances when businesses fail in getting results. It also provides data support to the UCS and UCS console.

· Central Control System (CCS)

The core responsibility of the CCS is to process automation tasks. The CCS plans routes for scheduling tasks, and executes them according to the set sequence. Every section of a scheduling route can be mapped into an ISA command distributed to local control systems through the UCS warehouse cloud channel. The CCS can also distribute non-scheduling automation tasks into the warehouse through the warehouse cloud channel, where a local control system then executes the task.

Standard events control alerts going to the CCS, with each event triggering certain behaviors. For example, the Cainiao CCS deems AS/RS pallet code scanning an attempt to execute a warehousing logic.

The CCS uses the automation scheduling module to schedule automated tasks and coordinate the working sequence of different equipment. For example, when a pallet of products is put on the shelf in an AS/RS, it first enters through the shelf inlet and is then shifted to the stacker dock by the conveyor line, where products are carried away by stackers that execute the delivery command to complete the entire process. This is a typical scheduling process, involving questions like when to notify the conveyor line to move, when to instruct the stackers to carry away products, and when to instruct the stackers to deliver products. Such a close-knit process requires a scheduling system to decide when each step is completed.

The CCS can be likened to a command center that controls and distributes the ISA for all production lines. The UCS’s standard control command tells the CCS which event from the LCS triggers what ISA interaction. This aids the CCS in sending the correct ISA down to the LCS of a specific production line. Using expansion points of production lines helps expand processing logic according to their standard events, thus enabling particular production lines to use expansive business logic.

Equipment status functions can record real-time status data during production, which can be used for scheduling business algorithms. Production data notices inform upstream business systems of events occurring during warehouse production processes.

· Local Control System (LCS)

The core responsibility of the LCS is to establish communications with automated equipment to send task execution commands. By driving and adapting different vendor protocols, the LCS inputs ISA into the drive, where the ISA is then parsed into vendor commands sent to the vendor’s PLC or WCS for the automated production lines to execute. After this, the drive converts events reported by the equipment to standard events for the LCS to process. When an ISA is executed, the LCS must report the execution result to upstream businesses through the UCS warehouse cloud channel. The LCS also provides interfaces to query in-warehouse execution logs and communication logs. These interfaces support direct access to in-warehouse logs from the cloud for analyzing problems.

· UCS console

The UCS console is a production line configuration center that can be used to start, configure, and initialize a production line. It is a task automation console that can be used for tracking the status of automated tasks. It can also be used for processing production exceptions, rendering forced success or failure of tasks, or repeating task steps. The UCS console can also effectively monitor automated tasks, promptly identify problems, and quickly notify on-site staff and instruct them on how to solve the problems to prevent or mitigate production line interruptions. The UCS console enables users to control on-site activities without being personally present, making it easier to operate and maintain automated production lines.

What next?

The UCS is the foundation of Cainiao’s entire automated control link. In the past year, this architecture has supported several Cainiao automation projects, and will play an important role in the launch of the Cainiao Intelligent Warehouse project. 2017 marked the first year of Cainiao’s automated operations, where several automation scenarios were established from scratch. Alibaba has already earmarked RMB 100 billion (approximately USD$15 billion) for Cainiao, and industry watchers can expect its automation to grow in leaps and bounds during 2018.

(Original article by Wen Song温松)

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