3D printed “skin” helps robots work together safely and efficiently

In modern factories, collaboration between humans and collaborative robots has become an indispensable reality. Successful human-machine interaction is the key to future-oriented manufacturing. However, how to protect the safety of operators in such manufacturing scenarios and enable collaborative robots to operate efficiently is one of the challenges that factories need to face. OECHSLER, an additive manufacturing lean production service provider, and BASF's 3D printing solution Fward AM have developed a 3D printed "skin" for the Kuka iiwa collaborative robot using 3D printing technology. This new solution enables humans and collaborative robots to safely share the workspace and further optimizes the factory's human-machine collaborative production efficiency.

Balancing safety and efficiency
/Challenges

Collaborative robots (cobots for short) are increasingly appearing in the manufacturing industry, working alongside humans in shared areas. In factories where humans and machines work together, it is crucial to avoid collisions between cobots and their human colleagues and ensure production safety.

Typically, safety guards in human-robot collaborative factories are implemented by built-in. These stop the collaborative robot immediately in the event of accidental contact, and whenever a worker enters the warning zone, the system reduces its speed to a minimum. If the person continues to approach, the system stops until the person leaves, at which point the system accelerates back to full speed. However, this results in highly limited processing speeds for collaborative robots, which leads to increased costs and reduced production efficiency in manufacturing plants.
In order to achieve the robot's response to approaching workers, it needs to be based on the robot's task, the specific way they work with workers, and their actual location in the factory. This means that when the collaborative robot needs to be deployed at a different workstation or needs to perform a different task, the programming must be adjusted. This approach limits the flexibility and convenience of collaborative robots.
So, what are some ways to enable workers and collaborative robots to collaborate safely and keep the robots running efficiently at all times?
/ 3D printed "skin" RoboSkin

BASF Forward AM and OECHSLER have developed a thin and highly shock-absorbing second layer of "skin" RoboSkin for collaborative robots through additive manufacturing - 3D printing technology, which is used to wrap around the joints of the collaborative robot.

When OECHSLER made the second layer of "skin", the material used was Ultrasint TPU01 thermoplastic polyurethane powder developed by Forward AM, and the 3D printing technology was HP HP 5200 series Multi Jet Fusion equipment.

▲ The 3D printed "skin" for the Kuka iiwa robot axis 2 and axis 3. The lattice structure can be clearly seen in the picture. The material is Ultrasint TPU01. The 3D printed "skin" has a flexible and personalized lattice structure. Ultrasint TPU01 thermoplastic polyurethane powder is an elastic material suitable for the production of parts that require high shock absorption and excellent flexibility. The unique lattice structure of the collaborative robot's 3D printed "skin" brings unique added value to the collaborative robot: First of all, the buffer protection function of the 3D printed "skin" provides protection for workers who collaborate with the robot and reduces their risk of injury.

This layer of 3D printed lattice "skin" acts like a damper, absorbing the collision force and pressure of the collaborative robot, which can increase the speed of the collaborative robot by 150%, which improves the productivity of the manufacturer. In addition, the 3D printed lattice "skin" has good air permeability and can prevent heat accumulation in the collaborative robot. As an isolation layer, it can cover the robot's pipes and wires without restricting the robot's movement when working. The core technology behind such a "skin" that can bring added value to collaborative robot users lies in the lattice structure of additive manufacturing.

▲3D printed lattice lattice "skin" developed for robot axis 4 The lattice structure of the 3D printed "skin" can be designed according to the functional requirements of the robot. Thanks to the advantages of 3D printing in complex, customized flexible manufacturing, it can be quickly and cost-effectively adapted to various types of collaborative robots. As mentioned in the challenge, in the production workshop, collaborative robots are usually deployed at different workstations. The 3D printed "skin" RoboSkin can work without disassembling, reassembling and recalibrating the robot, which will save time and cost for the factory. The 3D printed "skin" RoboSkin solves a complex problem in the collaborative robot factory with a seemingly very simple solution, enabling end users to optimize the production efficiency of human-machine collaboration.

/ Increase value from the source of additive manufacturing lean production

The lattice structure design used in the 3D printed "skin" design is a typical design for additive manufacturing. Lattice design often has complex geometric structures, and manufacturing complex structures happens to be one of the competitive advantages of additive manufacturing technology in manufacturing. It can be said that the perfect combination of lattice design and additive manufacturing will bring unique innovation to the product.

Reviewing Editor: Huang Fei