Productive and safe interaction between humans and KUKA robots

GO BEYOND. Discovery #5

Collaboration between humans and robots in shared work areas is more in demand than ever. The trend towards robot cells without protective fences and the smallest possible size continues in industry. At the same time, the robot should be integrated into manual work steps as simply as possible and without compromise. KUKA, together with SICK and Blue Danube Robotics, is now offering a complete solution that combines both maximum productivity and the latest safety standards for collaborative applications.

Creative ideas and practicable solutions are necessary to meet this increasing demand for human-robot collaboration. The advantages of a classic industrial robot cell, such as speed, accuracy, high productivity and durability, should by no means be neglected. The robot’s payload also plays an important part, but is very limited in existing human-robot collaborations.

Collaborative robots cannot serve these high demands of industry, as they work at significantly lower speeds and with lower payloads than industrial robots. The limits also quickly become apparent in the area of connectivity and integration options in existing systems. For this reason, KUKA, together with SICK and Blue Danube Robotics, is now offering a complete solution that combines both maximum productivity and the latest safety standards for collaborative applications. First and foremost, safe collaboration between robots and humans is guaranteed, even with payloads of several 100 kg. Smooth interaction between all components is made possible by the robot controller and the KUKA.SafeOperation technology package.

An application in which components are assembled manually and then a visual inspection is carried out by the robot serves as an example application. The robot cell can be designed without a safety fence and it is possible to approach the robot or work directly with it at any time. The dangers of this close teamwork are reliably safeguarded by the microScan3 safety laser scanner from SICK – and therefore enable both safe and efficient collaboration between humans and robots.

sBot Speed CIP safety system

The sBot Speed CIP system variant for KUKA from SICK combines a microScan3 with the Flexi Soft safety controller and the EFI-pro gateway. The robot-specific settings and communication parameters are already pre-configured and can be integrated quickly and safely into the KUKA KR C4 robot controller thanks to EtherNet/IP™ CIP Safety™. This saves valuable time in project planning and evaluating the safety concept.

3-zone safety concept

The microScan3 permanently monitors the robot cell and divides the working area into three zones. If there is no person in the danger zone (green zone), the robot can reach linear speeds of up to 2 m/s. A comparable collaborative robot operates at a maximum speed of 1 m/s. If a person approaches the robot and is therefore in the orange area, the speed of the robot is reduced so that it meets the requirements of the risk assessment according to ISO TS15066. The orange area serves as a detection area and is used as a buffer zone so that the robot can reduce to the required speed. Entering the yellow area now activates the safe monitoring of this reduced speed. If this speed is exceeded, the robot stops with a safety stop 1 (near-track EMERGENCY STOP) according to EN 60204. Once the orange and yellow areas of the laser scanner are vacated again and there is no person in the hazardous area, the robot accelerates to the programmed speed independently.

Intelligent skin protects against injury

If an employee is now in the immediate vicinity of the robot, it moves at a reduced monitored speed. If there is contact between a person and the robot, the AIRSKIN's sensor system also triggers a safety stop 1. The AIRSKIN consists of air cushions specially adapted to the robot, in which the pressure is permanently monitored. If contact occurs, the internal pressure changes by pressing in the air cushion and the AIRSKIN is actuated. Once triggered, an employee has to make sure that the robot can continue working. Once confirmed, the robot resumes work at the point in the program where it was interrupted. Integrated LEDs also show the operator the AIRSKIN’s status.

The microScan3 permanently monitors the robot cell and divides the working area into three zones.

KUKA.SafeOperation

The SafeOperation technology package is the interface between the safety components. It processes the signals from the safety interface, monitors the robot movement and offers other safety features. These include defining safe monitoring areas, the safe monitoring of speeds and regular adjustment referencing. With these additional features, the position of the tool can be monitored during the entire operation and the robot can be stopped safely in case of malfunction. In order to be able to stop the robot movements quickly enough in the event of malfunctions or violations of spatial limits, the brakes must be guaranteed to be in perfect condition. This is checked using an automated brake test. This involves cyclically checking whether the motors’ braking torques are high enough and ensure the safe stopping of the robot if necessary.

KUKA.Handguiding with ready2_pilot

The KUKA.Handguiding optional package is used to ensure that the operation between the industrial robot and human is also as practical and efficient as possible. The control package enables wireless hand-guiding of industrial robots in an extremely user-friendly way. The robot is controlled by a 6D mouse mounted on the robot, which makes it possible to program movement points and record movement sequences. This allows the KUKA industrial robot to be moved in a simple and intuitive manner. The use of this package does not require any training or time-consuming employee induction.

System setup

The communication between the components must also be in synch to ensure smooth operation. The SICK safety system (microScan3 safety laser scanner + Flexi Soft safety controller) is connected to the robot controller by a safe fieldbus such as EtherCat/FSoE, EtherNet/IP/CIP Safety or PROFINET/PROFIsafe. The AIRSKIN is connected to the safety controller’s safety inputs by 2 channels.

Conclusion: Achievement of maximum productivity for collaborative robots

With this complete package of industrial robot, AIRSKIN and SICK safety system, the demands of collaborative robotics can be realised with maximum productivity. The advantages are clear:

Less space required due to omission of protective fences
Safe collaboration between humans and robots in every situation
High productivity & quality through the use of industrial robots and components
Scalable concept or the entire load range from 3 to 250 kg

KUKA's many years of experience in the industry guarantee reliability in production. The cooperation between KUKA and Blue Danube Robotics also covers a broad product portfolio of various industrial robots including AIRSKIN. The range extends from very small robots with payloads of 3 kg to robots with payloads of 250 kg. The most diverse applications in the field of robot-based automation can be realised with this selection.

*Copyright Images: KUKA CEE GmbH