New motor position sensing tech

Magnetic-free dual-coil technology can provide high-resolution, precision and reliability for motor position sensing used in robotics, industrial and medical devices. Taking this technology to new heights, Renesas Electronics Corporation has introduced an inductive position sensor (IP) technology for highly accurate motor position sensor ICs for such applications. Leveraging non-contact coil sensors, the position sensing technology can replace expensive magnetic and optical encoders often used in motor control systems that require absolute position sensing, high speed, accuracy and reliability.

“Our induction position sensor technology represents a significant leap forward in motor position sensors,” says Jan Leuckfeld, Senior Director of the HPC Analog Division at Renesas. “They will enable us to provide differentiated motor position sensor ICs for industrial applications that are robust, highly accurate and cost-effective.”

PROPRIETARY TECHNOLOGY

The proprietary IPS technology from Renesas uses sensing elements consisting of copper coils etched on a printed circuit board (PCB) to detect the position of a metallic target. Unlike heavy magnet-based sensors, the IPS products can operate at 600Krpm and detect the position right at startup, while the propagation delay is less than 2μs, making them ideal for motors with high rotational speeds. The sensing technology also supports auto-calibration and linearisation features to ensure consistent performance throughout a motor’s operational life.

RELIABILITY IN HARSH ENVIRONMENTS

Based on the vernier principle, the dual-coil sensor technology supports a resolution of up to 19 bits and an accuracy of up to 14 bits. The robust sensor technology is capable of operating reliably in harsh environments where exposure to high temperatures, dust, moisture, vibration and electromagnetic interference (EMI) is common. Additionally, the induction sensors are immune to stray fields, require no maintenance, and are less susceptible to error than magnetic sensors. These advantages make induction position sensors a more attractive option than conventional optical encoders or magnetic-based encoders, which tend to be heavier and costly.

“Position sensors for factory floors must endure extreme conditions such as humidity, high temperatures and vibration,” adds Ulrich Marl, Key Account Manager at Renesas customer, Lenord+Bauer. “Through our collaboration with Renesas, we’ve integrated IPS-based technology into our encoder portfolio to ensure reliability and safety, while reducing downtime in critical applications.”

The induction position sensor technology will support commonly-used UART, ABI and I2C communications interfaces to ensure a seamless integration into industrial networks while facilitating real-time monitoring and data analysis. The technology will also be backed by a complete toolchain comprising dedicated software for user customisation and precision optimisation.