The safety of people interacting with robots is a top priority, especially when humans and robots work side by side instead of being separated from each other by security fences. The Fraunhofer Institute for Factory Operation and Automation IFF web design tool helps companies design their cobots. The Cobot Designer helps minimize the risk of accidents and increases employee safety. The tool is available as a free web application.
Humans and robots share the workspace in more and more sectors, be they manufacturing, logistics or medical. Safety plays a major role here. Until now, rangefinders on robots have prevented strong impact or crushing in collisions, but these sensors do not work when humans and machines have to stand close to each other, for example in subassemblies. . This requires other solutions. Teams of researchers from Fraunhofer IFF have developed a web application, the Cobot Designer, which determines the speeds of the robots that guarantee safe collaboration. The design tool helps programmers to safely design cobots. The project was contracted by the German Social Accident Insurance Institution for the Wood and Metal Industries (BGHM).
Digital risk prevention for cobotic workstations
Anyone acquiring cobots for their business must complete a legally required risk assessment. Companies should first identify specific potential dangers and foreseeable abuse by employees. The maximum speed that a robot is allowed to achieve is measured when it is certified for safety. A special device measures the impact forces and pressures acting on anyone who comes in contact with the robot. The limits of ISO / TS 15066 must not be exceeded. Otherwise, the speed of the robot should be reduced to avoid injury to employees caused by clamping or impact. Such a measure is expensive and requires expertise. The robot must be programmed and built.
“Small businesses in particular can’t afford it. In addition, the measurements are taken too late since the robot has already been purchased. Our Cobot Designer for digital risk prevention comes into play here, ”explains Dr. Roland Behrens, Fraunhofer IFF researcher. Businesses can use the interactive tool before making a purchase to assess whether the robot’s speed is sufficient to perform a particular job productively and, most importantly, safely. “The amount of force depends on the speed of the robot,” explains Behrens. If the limits are exceeded, productivity subsequently suffers. “Suppose the robot has to sort a pallet in a minute. If the speed has to be reduced by fifty percent for safety reasons, the cycle time drops to two minutes, which reduces the economic efficiency of the robot by fifty percent, ”explains the researcher. , adding: “That is why it would be desirable to be able to perform an economic feasibility analysis before purchasing a robot. “
Cobot designer is intended to replace the measurement by a tester
The Cobot Designer avoids bad purchases and more potentially necessary measurements. Using the design tool will allow companies to significantly reduce their engineering work when implementing future HRC applications. “The goal is to use computer simulation, like the Cobot Designer does, to do away with measurements entirely in the future. The tool is available free of charge at www.cobotplaner.de for anyone designing an HRC workstation. The digital design tool works on all browsers.
Its use is simple: the user only has to enter the robot parameters, the danger and the tool used, for example a clamp. Then, the Cobot Designer automatically calculates the effect of the contact between a human and the robot as well as the maximum authorized speed of the robot. The tool also offers the ability to load proprietary and custom robot models. It is then no longer necessary to enter parameters.
Various biomechanical robots and hazard models form the technological basis. The user can combine different robots, dangerous situations and tools, thus constantly constituting and expanding a catalog. All entered data can be downloaded and reused later. Entries are not stored on the Cobot Designer server to protect data.
Stress tests with subjects provide data for the biomechanical model
The biomechanical model accurately simulates the extent to which the clamping and impact strain a person. It includes the twenty-nine relevant body parts where a person may experience pain, including the head, for example. This model is based on the results of the world’s one and only study on human subjects to determine biomechanical limits, which was conducted by the Fraunhofer IFF and contracted by the German social accident insurance DGUV and the BGHM. The Fraunhofer IFF has experimentally validated the results of the Cobot Designer simulation in stress tests on human subjects with doctors from the trauma clinic of the Otto von Guericke University Hospital and with the participation of the Ethics Commission appropriate. The tests took place from 2015 to 2019.
A contact of a robot in conversation is linked to a positive emotional state
Web design tool for better safety at work: www.fraunhofer.de/content/dam/… etter-job-safety.pdf
Provided by Fraunhofer-Gesellschaft
Quote: Web Design Tool for Better Safety at Work (2021, July 1) retrieved July 1, 2021 from https://techxplore.com/news/2021-07-web-based-tool-job-safety.html
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