German engineers are developing a new type of intelligent motor capable of functioning as its own multifunctional sensor.
They are relying on measurements of the magnetic field generated in the motor to extract all crucial data about how it is running, as well as enabling it to communicate with other motors in related systems.
“We're developing an important new type of sensor: the motor itself,” said Professor Matthias Nienhaus, drive systems specialist at Saarland University in Germany, who is leading the work. “That makes our approach very cost-effective as there's no need to install any additional sensors. We're looking at elegant ways of extracting data from the motor and of using this data for motor control and for monitoring and managing processes.”
The incentive to look at alternative ways to extract information from various types of motors, the researcher said, was the fact that sensors are prone to failure. And in the ever more connected world, the failure of a simple sensor could make the whole system impossible to use.
The researchers found that variations in the magnetic field generated by electric current flowing through coils within the outer ring of rotating permanent magnets could provide a surprisingly deep insight into what's going on with the motor. By recording changes in the field, they were able to extract information about the position of the rotor and its status, as well as interferences and error states.
“We examine how our measured data correlates with specific motor states and how specific measured quantities change when the motor is not operating as it should,” Nienhaus explained.
At the first stage, the team focused on gathering data from a nominally running motor. By analysing a vast amount of data, they were able to find patterns that can be used to infer information about the current status or problems. Eventually, the researchers would like to teach the motor to diagnose and fix its own problems itself.
The motor's microcontroller - essentially a brain running a set of complex mathematical algorithms - would be able to detect changes, identify the underlying error and take a corrective action. Moreover, the motor would be able to exchange information with other motors connected to the same network. This, the researchers say, would make maintenance easier, enhance quality assurance and improve production.
The technology will be presented at this year’s Hannover Messe industrial fair in late April.