B&R automation has developed a virtual sensor for its ACOPOS P3 servo drive, the Safe Speed Observer. It determines speed in accordance with SIL 2 / PL d / CAT 3 requirements, reducing the cost of implementing the safely limited speed safety function by eliminating the need for a safe encoder.

The Safe Speed Observer calculates two redundant models of the motor – achieving a high safety level for the calculated speed from the electrical variables of a permanent magnet synchronous motor,. The virtual sensor can be used for both linear and rotary synchronous motors.

The Safe Speed Observer is easy to configure in the automation studio engineering environment via the respective encoder interface. The user can implement the safety functions available for the safe axis from the safety library. This new solution is made possible by the drive-integrated safety technology of SafeMOTION.