These resolver-based motor control solutions are motor control systems for industrial and consumer applications realized by combining resolver-to-digital converter (RDC) ICs and RX Family microcontrollers (MCUs). It is possible to easily control a resolver-based stepping motor or brushless DC motor using the driver software of the microcontroller. Solution kits, sample code, development support tools, and application notes for motors with resolvers are available, and motor control using resolvers can be started immediately.
- High-precision motor control is possible even in harsh environments with heat, dust, or vibration.
- Realize high-precision control at low cost using a new type of resolver control with superlative cost performance.
- Resolver signal gain, phase, and angle error are automatically corrected through the driver API that can be used in combination with an RX MCU to achieve high precision.
In resolver-based motor control solutions, the RDC IC and RX MCU process signals from the resolver as angle information, and the RX MCU controls the motor. A dedicated driver for the RDC IC is provided on the RX MCU, and resolver processing can be easily performed using the API.
- Drivers for stepping motors and brushless DC motors are available. Normally, it is difficult to use a resolver sensor with a stepping motor due to the effect of electromagnetic noise, but these solutions address this with noise countermeasures.
- These solutions are compatible with voltage detection type resolvers and current detection type resolvers. The resolver needs to be a one-phase excitation two-phase output type resolver. Not only general voltage detection type resolvers, but also current detection type resolvers that can be manufactured at low cost can be used.
- Stepping motors with resolvers and resolver motor control solutions developed by collaboration between MinebeaMitsumi Inc. and Renesas make possible servo control for stepping motors that are normally controlled by open loop control.
- These solution realize many advantages such as low noise, low vibration, low power consumption and maximization of motor torque.
Challenges Faced by Conventional Motor Solutions
- Need to select a larger motor to ensure torque step-out margin
- Stepping motors that use open loop control consume large current and generate large amounts of heat
- Torque ripple causes vibration and noise
- : New motor manufactured by MinebeaMitsumi Inc.
- : MCU for motor control
- : IC that converts resolver output into digital signal
- : All items necessary for controlling a stepping motor with resolver are provided
- : Development support tool essential for motor control debugging
Data provided by MinebeaMitsumi Inc.
Maximization of Motor Torque
- • By performing servo control, a motor can be used up to maximum torque, and high-speed rotation can be supported. Since you can select a motor simply based on the required torque without considering the step-out margin, motor size can be reduced compared to open-loop control methods.
Low Power Consumption
- By performing servo control using a resolver, standby current can be reduced significantly, and only the current necessary for the load is consumed. In addition, the heat generation of the motor can be suppressed by reducing the current consumption.
Since motor loses steps with load torque of 500mNm or more during open-loop control, no data has been acquired.
Low Noise and Low Vibration
- Compared to open-loop control, noise and vibrations up to the medium speed range can be suppressed by performing servo control using a resolver.
- Using the Driver for Resolver Digital Converter Control (Under development)
- Using the RX24T for Vector Control of a Two-Phase Stepping Motor Incorporating a Resolver Sensor (Under development)
- Usage Notes on Correcting Errors in Angles Detected by the Resolver-to-Digital Converter
- Guide to Selecting Peripheral Components for Use with the Resolver-to-Digital Converters