Accurate feedback on the angular position, direction, and speed of the rotor shaft is essential to optimize control of the motor inverter and drive electric motors with the best possible efficiency. With lower weight, smaller dimensions, immunity to stray fields and comparably lower cost, Piher Sensing System’s eMotor Rotor Position Sensors offer a true alternative to conventional resolvers. Furthermore, inductive eMotor rotary position sensors can be designed to be ASIL-D compliant on sensor level.
Inductive sensors use the physical principle of induction in a wire loop and eddy currents to detect the position of a solid metallic target rotating above a set of coils. This allows a reduction in parts and higher design flexibility (e.g. through-shaft, end-of-shaft and arc configurations).
Development according to functional safety ASIL-D on sensor level possible.
No shielding required as inductive technology is not affected by electromagnetic stray fields.
A direct, demodulated analog output means no additional electronics are needed to calculate rotor position.
Reduced size and weight compared to resolvers.
Integration options
Inductive position sensors use the physical principles of induction in a wire loop and eddy currents to detect the position of a conductive metallic target that is rotating above a set of printed copper coils consisting of one transmitter coil and two receiver coils. The possibility to perfectly customize the sensor to the motor dimensions enables more flexibility in the development of the electric / hybrid powertrain of the future.
Compared to conventional resolvers material costs can be significantly reduced as neither magnets, nor extensive copper windings or external components are needed and the overall number of parts is lower. Furthermore, the high robustness to misalignments and tilt enable further cost savings at the assembly line.
Completely adapted designs in through-shaft, on-shaft or arc configuration can be provided by Piher Sensing Systems and are together with low weight and compact dimensions a further argument that speaks in favor of inductive technology. Support for safety-critical applications up to ASIL-D on sensor level can be reached through integration of an additional chip.
