Wireless sensors replace vulnerable robot wiring

ABB has turned to wireless communications to tackle an Achilles heel in robotic systems - the failure of sensor cables resulting from the robot arm`s continuous turning and twisting. Cable failure is the most common cause of downtime in industrial robots.

The new system (above) - which has been installed at an ABB plant in Germany where robots assemble motor starters - uses radio waves to gather data from proximity sensors on the robot arm. As well as eliminating cable failures, this approach made it easier to install the robots and saved time and money.

One problem that ABB had to overcome when designing the wireless sensing system was finding a way of powering the sensor transmitters. After rejecting batteries, solar cells and fuel cells as being impractical, the researchers developed an inductive power technology. Energy is picked up by tiny coils in the sensors from a field generated by power cables looped around the perimeter of the manufacturing site. One advantage of this approach is that, because the field covers the whole site, the sensors can be placed anywhere in the plant.