A palletizing robot is a machine device used to automate tasks. It can be commanded by a human and correctly execute pre-programmed procedures. Acting according to principles established using artificial intelligence technology, it automatically stacks objects already packed in containers onto pallets or stacks (wooden or plastic) in a specific arrangement, up to multiple layers, and then pushes them out for easy transport by forklift to warehouse storage. Its purpose is to assist or replace repetitive human tasks, and it can be applied in industries such as manufacturing and construction.
Palletizing robots can be integrated into any production line, providing intelligent, robotic, and networked services to the production site. They can handle a variety of palletizing and logistics operations in the beer, beverage, and food industries, and are widely used for cartons, plastic boxes, bottles, bags, drums, film-wrapped products, and filled products. They are also integrated with three-in-one filling lines to palletize various bottles, cans, boxes, and bags. The automatic operation of the palletizing machine includes steps such as automatic box feeding, box transfer, sorting, stacking, stack moving, stack lifting, pallet feeding, stack unloading, and stack unloading.
Palletizing robot gripper principle
Palletizing robots primarily perform grasping and placing operations, meaning the robot picks up materials from the conveyor belt and places them at designated positions on a pallet along a movement path in a cyclical motion. Therefore, based on the robot's positional relationship with the conveyor belt and pallet during palletizing operations, and considering obstacles during the movement process, a "gate"-shaped motion trajectory is selected. It is noted that the robot's end effector follows a "gate"-shaped trajectory when placing cartons at different positions on the pallet, with the endpoint coordinates differing only due to the varying positions of the cartons on the pallet.
Palletizing, in essence, is the process of stacking materials into pallets according to a specific pattern, based on the concept of integrated unitization. This allows for the storage, handling, loading, unloading, and transportation of these unitized pallets. Compared to traditional manual palletizing and gantry palletizing machines, palletizing robots are increasingly being applied across various fields due to their high production efficiency, small footprint, high maneuverability, and low labor intensity.
Commonly used palletizing robot grippers
• Gripper-type robotic gripper: Primarily used for high-speed bag stacking;
• Clamping-type robotic gripper: Primarily suitable for palletizing boxes and cartons;
• Vacuum suction robotic gripper: Primarily suitable for stacking items that can be sucked up;
• Hybrid gripping robotic gripper: Primarily suitable for stackable items that can be picked up;
• Hybrid gripping robotic arm: suitable for collaborative gripping and releasing at several workstations.
When using palletizing robots, an important consideration is how the robot grips a product. Vacuum grippers are the most common end-of-arm tools (EOAT) for robotic arms. They are relatively inexpensive, easy to operate, and can effectively load most items. However, vacuum grippers can encounter problems in certain applications, such as porous substrates, flexible packaging containing liquids, or packaging with uneven surfaces.
Palletizing robot classification
1. Classification based on structure
Depending on their mechanical structure, palletizing robots can be categorized into three types: Cartesian type, rotary joint type, and gantry crane type.
① Cartesian palletizing robot: It mainly consists of four parts: column, X-arm, Y-arm, and gripper. It completes the palletizing of materials with four degrees of freedom (including three translation joints and one rotation joint). This type of palletizing mechanism has a simple structure, strong body rigidity, and can handle a large weight, making it suitable for palletizing heavier materials.
② Rotary Joint Robot: This type of palletizer rotates around its body and includes four rotational joints: waist, shoulder, elbow, and wrist. This type of palletizer is programmed via a teach pendant system. The operator holds a teach pendant and controls the robot to move according to prescribed actions. The movement process is then stored in memory and can be reproduced during subsequent automatic runs. This robot has a small body but a large range of motion, allowing it to palletize one or more pallets simultaneously and flexibly adapt to various product production lines.
③ Gantry crane type: The robot arm is mounted on a gantry crane and is called a gantry crane palletizing robot. This type of palletizing robot has a large working range and can grab heavier materials.
2. Divide according to stacking requirements
① Single-layer palletizing robot
A single-layer palletizing robot is relatively basic. It mainly relies on a conveyor belt to transport materials. When the materials reach the turning mechanism, they can be adjusted to the prescribed direction. After preparation, they can enter the layer conveying mechanism. Here, the products are simply arranged closely according to the set order. Then, the arranged products are moved to the next workstation by the conveyor rollers. This completes the palletizing robot's stacking operation.
② Multi-layer palletizing robot
There are certainly multi-layer palletizing robots, which are more complex than single-layer ones. We can see that the pallet of a multi-layer palletizing robot is located below the conveyor belt and can move left and right. During stacking, the materials are neatly arranged on the pallet, which is then set to its left limit position. When the material conveyed by the conveyor belt is blocked by the baffle, it forms a straight line. Then the pallet moves to the right, and the materials are arranged in a line again, just like before. This process continues, with the height of the palletizing robot's lifting platform decreasing by one layer for each additional layer, until the material is stacked to a certain height and then stops.
③ Stacking and palletizing robots
This type of palletizing robot arranges materials in rows before conveying them. A pusher plate places the conveyed materials onto a collection platform. Then, it moves to the left and pushes the materials from bottom to top, stacking three layers of materials together. A ramp device ensures smooth completion of the process, and the unique design of the collection platform also helps the palletizing robot to complete the stacking. These are just some of the more common types of palletizing robots.
Main advantages of palletizing robots
• Palletizing robots have a much higher palletizing capacity than traditional palletizing machines or manual palletizing;
• The structure is very simple, with a low failure rate, and it is easy to maintain and repair;
• Few main components and low maintenance costs;
• Low power consumption, approximately one-fifth that of mechanical palletizers.
• Palletizing robotic arms can be installed in narrow spaces, making high use of space and offering flexible applications;
All operations can be completed via touch on the control cabinet screen, making it very easy to use.
• Palletizing robotic arms are highly flexible in their applications; a single robotic arm can handle different products from up to six production lines simultaneously. When products are updated, simply input the new data, recalculate, and the system can resume operation without any modifications to the hardware or equipment.
• The stack type and number of stacking layers can be set arbitrarily, resulting in neat stacks that are convenient for storage and transportation.
