This arm lends a strong hand
Hard and repetitive work weakens the body. The consequences are chronic back pain and other ailments that can keep workers off the job, resulting in high costs. The Cobot robotic arm is aimed at changing this. It holds the tool and the worker simply has to guide it – like a partner in a dance.
Every fourth employee in Europe suffers from severe back pain. Musculoskeletal disorders are among the most common work-related illnesses. The reasons are simple: high paced work, monotonous procedures and heavy loads. The consequences are severe. Not only does the health of the individual suffer, but the economic and social costs are immense.
To combat this societal problem, new solutions are needed. One of these is the Cobot 7A 15, created by French company RB3D. Cobot takes a load off the industrial worker's back – literally. The robot arm, which is mounted to a wall, is equipped with seven axes and has an action radius of more than two metres. A heavy tool such as a grinder can be attached to the lower end of the robot arm. This means that the workers no longer need to carry the weight of the device themselves, but instead only guide it. Cobot takes care of the heavy lifting.
Sensors transmit the desired movements
The robot assists the operators in executing the movements that they would like to perform, whether up, down, left or right. A sensor immediately recognises the operator's intent. The controller then ensures that the robot arm goes where it should, without exertion on the part of the worker. The quick, smooth movements of the arm are executed by maxon DC motors from the RE series. These are used on all of the Cobot's axes.The high-precision brushed DC motors, with 150 W and 250 W of power, amplify the force exerted by the worker many times over. The worker saves energy and can concentrate on the work itself. “If a certain task would usually require 20 kg of force, the Cobot reduces the force needed to 1 kg,” says Serge Grygorowicz, CEO and founder of RB3D. Together with his team, he has made it his goal to improve work conditions in the industrial sector and to thus reduce musculoskeletal disorders. maxon drives were his team's first choice. “They provide the best combination of weight, quality and power density.” The requirements that the motors have to meet are high. They have to provide both speed and torque and have to transmit large forces with high precision yet remain easy to control.
Important know-how from the nuclear industry
maxon motor supplied not only the motors, but also the entire drive system. The DC motors of the RE series are used in combination with the matching planetary gearheads, encoders and EPOS positioning motor controllers. There were several key factors that contributed to the French developer's decision to work with maxon: the compactness, torque and acceleration of the solution, as well as having all parts of the system come from a single source. In designing the solution, maxon worked closely with CEA LIST, a French research institute which played an important role in the development of the Cobot. Up till now, there were hardly any industrial robots that could be controlled and guided by means of a human's strength. Those that did exist were slow and did not significantly reduce the amount of effort required from the worker. This made the experience that CEA LIST has gained with force feedback controllers in the nuclear industry even more valuable. With this specialized knowledge, RB3D succeeded in developing a new generation of industrial robots that could permanently change the work conditions in workshops.
Oct 31, 2014 Author: Roschi Stefan 2014 © maxon motor ag