Induction motor position sensing technology uses dual-coil technology
Claimed to be cost-effective, “highly accurate” and robust, Renesas Electronics’ induction motor position sensing technology can be used in robotics, industrial and medical devices.
Based on magnetic-free, dual-coil technology, the inductive position sensor (IPS) technology uses non-contact coil sensors and can replace expensive magnetic and optical encoders which are commonly used in motor control systems. As well as the cost, these encoders require absolute position sensing, high speed, accuracy and reliability, said Renesas.
Its proprietary IPS technology uses sensing elements consisting of copper coils etched on a PCB to detect the position of a metallic target. Unlike heavy magnet-based sensors, the IPS products can operate at 600krpm (electrical) and detect the position right at startup. Propagation delay is less than two microseconds, which is suitable for motors with high rotational speeds. The sensor technology also supports auto-calibration and linearisation features, ensuring consistent performance throughout a motor’s operational life.
The dual-coil sensor technology is based on the Vernier principle and supports a resolution of up to 19 bits and an accuracy of up to 14 bits. The sensor technology will operate reliably in harsh environments, said Renesas, able to operate when exposed to high temperatures, dust, moisture, vibration and electromagnetic interference (EMI). The induction sensors are immune to stray fields, require no maintenance, and are less susceptible to error than magnetic sensors, added Renesas. The company added that these advantages make induction position sensors a more attractive option than conventional optical encoders or magnetic-based encoders, which tend to be heavier and expensive.
Jan Leuckfeld, senior director, HPC Analoueg (Sensor) division at Renesas, commented that the induction position sensor technology will enable the company to provide differentiated motor position sensor ICs for industrial applications that are robust, highly accurate and cost-effective.
The induction position sensor technology will support commonly used UART, ABI and I²C communications interfaces, for integration into industrial networks and facilitating real time monitoring and data analysis. Additionally, the new sensor technology will be backed by a toolchain that includes dedicated software for user customisation and precision optimisation.
