Renesas develops highly accurate induction motor position sensing technology

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Renesas Electronics has developed an inductive position sensor (IPS) technology for highly accurate motor position sensor ICs for robotics, industrial and medical applications.

Utilising non-contact coil sensors, the technology can be used to replace expensive magnetic and optical encoders now commonly used in motor control systems that require absolute position sensing, high speed, accuracy and reliability.

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, however, the IPS products can operate at 600 Krpm (electrical) and detect the position right at startup, while the propagation delay is less than 2μs, making them suitable for motors with high rotational speeds.

In addition, the sensor technology can support auto-calibration and linearization features, ensuring consistent performance throughout a motor’s operational life.  

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, which makes them superior to most comparable products on the market. The robust sensor technology is able to operate reliably in harsh environments, where they can be exposed to high temperatures, dust, moisture, vibration and electromagnetic interference (EMI).

The sensors are immune to stray fields, require no maintenance, and are less susceptible to error than magnetic sensors all of which makes them, according to Renesas, a more attractive option than conventional optical encoders or magnetic-based encoders, which tend to be heavier and expensive.

“Our induction position sensor technology represents a significant leap forward in motor position sensors,” said Jan Leuckfeld, Senior Director, HPC Analog (Sensor) 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.”

“Position sensors for factory floors must endure extreme conditions such as humidity, high temperatures and vibration,” said Ulrich Marl, Key Account Manager at Lenord+Bauer, a Renesas customer and a manufacturer of encoders for industrial systems. “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, ensuring integration into industrial networks and facilitating real-time monitoring and data analysis.

Additionally, the new senor technology will be backed by a complete toolchain that includes dedicated software for user customisation and precision optimization.

According to Renesas, it plans to combine the new sensor with numerous compatible devices from its portfolio to offer a wide array of Winning Combinations.