Automated Flattening of Absorbent Pads

Students: Joël Bruinvels, Dimitar PrisadnikovMaurice TacxJort Leroij


An automated robotics solution bridges the gap between washing and folding processes for industrial laundry equipment by allowing flattening of absorbent pads

Vlaardingen, Netherlands – 19 June 2024
Landuwasco provides robotics and mechanical solutions for industrial washing. Among the multiple products their machines handle are absorbent pads. The automated solution for flattening absorbent pads allows the company to manage the entire process – from washing to folding them. Machine learning and computer vision are utilised at various stages to ensure consistency and reliability. Additionally, the system is designed to accommodate the unpredictable properties of the textiles, enabling it to recover from unexpected scenarios.

The company has existing solutions for the industrial washing and folding of absorbent pads. However, the folding process requires the pads to be fed into the machine flat, which their current system does not achieve. They aim to bridge the washing and folding processes, but an additional solution is needed to flatten the pads. Handling textiles can be challenging and unpredictable, so the system connecting the washing and folding processes must handle a wide variety of scenarios. Furthermore, since the company serves diverse customers and products (pads in different shapes, sizes, and colours), the solution must be easily scalable to work with different products. Lastly, the folding process requires the pads to be fed into the machine flat with a specific side facing up.

To address the challenge of flattening absorbent pads before folding, a sophisticated system featuring a Doosan collaborative robot (cobot), a camera with YOLO machine learning capabilities, and a custom-made air-powered flattening tube have been implemented.

The process begins with the Doosan cobot picking up pads from a container. Utilizing Doosan’s Force Control technology, the cobot navigates inside the container until it detects a specific level of force, ensuring precise handling. The robot then drags the pad across a table to reveal a corner. If a corner is not detected, the vision provides a new pick-up point which the robot uses to re-grab and re-drag the pad. Once a corner is identified, the vision keeps track of which side of the pad was picked up and sends the coordinates to the robot. The detected corner is first flattened and then picked up by the robot arm. If the detected side is incorrect, the cobot performs a 180-degree rotation while moving to the flattening stage. Afterwards, the absorbent pad is dragged across a custom flattening tube equipped with an air-pressure system designed to blow out any folds around the pick-up point. Finally,  the vision system checks if the pad is lying flat and free of creases. If the pad is not perfectly flat, the robot repeats the flattening process but with a different corner. Once the pad being flat is confirmed, it is released by the gripper.

There are 2 processes necessary to run the process. The first is on the robot itself, which is uploaded to the robot using the Homberger hub. Simply download the DRL studio software, create a connection and run the file for the robot. The code on the laptop has some dependencies which need to be installed first, such as some Python libraries and the camera software. Once this is done, the script can be run and the robot will flatten the pad.

“It is better than expected”
– Alex van Nieuwenhuijsen, CEO of Landuwasco B.V.