Delta's Stacker Crane Motion Control Solution Optimizes Warehousing for an Italian Client

The advent of Industry 4.0 and Smart Manufacturing evokes upgrades of manufacturing industries and factories. Logistics and warehousing feature the management of raw materials and finished products. Stocking, manufacturing, packaging, storage and delivery processes require becoming more automated and smarter. Automatic warehousing thus is becoming a trend. Automated equipment including stacker cranes and palletizers provides the optimal solutions for businesses and plants equipped with automatic warehouses. This can achieve quick product stacking, efficient control of warehouse in-and-out, commissioning increases, labor and cost savings, greater safety for staff, and much more.

Delta recently provided a stacker crane motion control solution for an Italian automatic warehousing system/equipment provider that helps with more precise sorting of packed products. The processes of this solution are as follows:

1.Cartons are placed on sorting conveyors.
2.The system detects the dimensions and measures the weights of the cartons with sensors, and transfers them to correspondent conveyors for stacking.
3.The stacker cranes move forward placing and retrieving packed cartons with the help of built-in sensors and 16 forks.
4.The retrieved products are then left on transmission conveyors to stake on skids until a certain amount is loaded.
5.Automatic guided vehicles (AGVs) pick up skids toward the trucks when the products are ready to deliver.

In general, induction motors (IM) are mostly applied to stacker cranes. However, the IMs fail to satisfy customers with larger sizes and operation with limit switches. The complex programming also makes the cranes less functional and lacks precise placing and retrieving. Therefore, the system is unable to control its working efficiency and more defects and worn cases are reported.

To solve the issue, Delta's solution adopts the AH series PLC-based modular motion control. It features a hot swappable function and compact size, and the system programming is simple with reduced impact from the limit switch. The basic working principle is as below: The AH series connects to 16 ASDA-A2-E Series AC servo drives with ECMA motors through EtherCAT, controlling 16 axes together and driving the 16 forks to move forward or backward. Depending on the weights and dimensions of the packed items it senses, the system supports the crane using only 2 to 4 forks for smaller packages or more forks with larger ones. The AH series is also highly efficient when it comes to real-time monitoring. It links to a client's existing visualization system via PROFIBUS communication, updating data and reporting errors in time. In other words, the upgraded system is time-efficient, cost-effective, secure and reliable.

The stacker crane solution Delta offers brought the following advantages to the Italian customer:
• Efficient automatic warehousing to save labor: The system supports the use of forks depending on the weights and dimensions of cartons. The precise and steady placing and retrieving of products improves the management of warehousing, ensuring a smooth working process, enhancing productivity & delivery and saving on labor.
• Secured system: To detect discrepancies between the command position and the real position for any axes, movement can be stopped at any time to reduce incidents.
• Reliability improvement: The smooth acceleration curve reduces the wear and tear on gear and mechanical parts, saving on equipment life and energy.
• Simple programming: Less complex programming with the AH series PLC.
• Highly integrated and cost-effective: The solution links to a customer's existing SCADA system via PROFIBUS communication, upgrading without too much extra investment.
• Compact size & easy maintenance: The servo drive is smaller than a regular induction motor and is easier to maintain.

Delta's stacker crane motion control solution has helped to upgrade the automatic warehouse system for the client, improving their market competitiveness and productivity.