When robot control gets difficult

Robot fails

Although the situations in the video above are a bit extreme and exaggerated, they illustrate that robot control is a crucial element in guaranteeing its correct functioning, accuracy and precision.

The same goes for robots used in manufacturing. Think about pick-and-place, welding, assembly, and packaging —they are often done by robots! And robots in manufacturing need to perform those tasks at higher and higher speeds of operation, but also need to keep the same level of accuracy and precision… and that is exactly where robot control might get difficult.

Vibration vs. accuracy: 1 – 0

With the trends of higher speeds and lighter robots, more flexibility is introduced in the arms and joints of modern robots. This increased flexibility causes higher (uncontrolled) vibrations that directly affect the accuracy and correct execution of the robot task at hand.

Knowing the forces and accelerations acting during operation, understanding the flexibility and dynamic behavior of robot arms, joints, motors and gearboxes is crucial to bring things back under control.

Testing can help in getting realistic real-life data, by:

  • characterizing unwanted resonances in robot arms using modal analysis
  • using strain gauges to measure forces and moments
  • studying the dynamic interaction with the robot’s foundations

Engineers can use this insight to feed and improve their simulation models and controls. Or it can directly hint manufacturers for the most effective design modification.

Quick acoustic troubleshooting

Next to vibrations, Simcenter testing solutions can also tackle acoustic problems when robots are used outside the noisy production environment. Think about medical robot arms, where unwanted noises might distract doctors, medical personnel or annoy patients.

The motor or the gearbox can generate high-frequency and tonal noises. Those can be amplified by resonances in the robot arms or foundation, making it difficult to know which of those components should be modified (as illustrated by this story on Spinea). A quick acoustic troubleshooting using the Simcenter Sound camera visualizes in real-time the location and frequency of the main sound sources. Looking at the live acoustic map, clearly and undoubtedly reveals the guilty component.

Sound source localization on a robot

Of course, there is a lot more to tell about noise and vibration testing on robots.

Join us in this free webinar and learn how the combined Simcenter Testing and Simulation solutions help designing better, faster, more accurate robots of the future – today.

You can also check out related blogposts from Simcenter for robotics here and here.

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This article first appeared on the Siemens Digital Industries Software blog at https://blogs.sw.siemens.com/simcenter/when-robot-control-gets-difficult/