I worked on a much larger solar car motor (3 phase synchronous AC) and used the AS5048A for position sensing. It worked pretty well, although care must be taken to adequately shield the very high speed SPI lines from the sensor.
I think this type of sensor could work very well for closed loop control, and have been toying with the idea for a while. It could work both for a stepper motor, brushed DC motor, or 3 phase AC motor. In this context a stepper motor is basically a 2 phase AC motor.
You get a couple of advantages from position feedback. One is the obvious "no more missed steps". A more important advantage, in my opinion, is that you can do field oriented control. Maximum torque is always achieved by applying a flux 90 degrees out of phase from the rotor flux. Normal stepper drive does not do this, leading to very high vibration and wasted power / heat. The rotor flux corresponds to the position of the rotor (not exactly for hybrid steppers and IPM drives, but close), so a sensor makes it easy to do this properly.
I've been looking at a possible implementation of this consisting of a PCB containing the sensor, as well as the motor driver, mounted to the back of a stepper. The sensor magnet would be glued to the end of the shaft - a dual ended stepper would be preferred, but even single ended ones usually have the shaft exposed. I think using a traditional bipolar stepper would be a good place to start, because they are very common, rated for continuous stalling, and can easily fall back to open-loop drive.
I think this type of sensor could work very well for closed loop control, and have been toying with the idea for a while. It could work both for a stepper motor, brushed DC motor, or 3 phase AC motor. In this context a stepper motor is basically a 2 phase AC motor.
You get a couple of advantages from position feedback. One is the obvious "no more missed steps". A more important advantage, in my opinion, is that you can do field oriented control. Maximum torque is always achieved by applying a flux 90 degrees out of phase from the rotor flux. Normal stepper drive does not do this, leading to very high vibration and wasted power / heat. The rotor flux corresponds to the position of the rotor (not exactly for hybrid steppers and IPM drives, but close), so a sensor makes it easy to do this properly.
I've been looking at a possible implementation of this consisting of a PCB containing the sensor, as well as the motor driver, mounted to the back of a stepper. The sensor magnet would be glued to the end of the shaft - a dual ended stepper would be preferred, but even single ended ones usually have the shaft exposed. I think using a traditional bipolar stepper would be a good place to start, because they are very common, rated for continuous stalling, and can easily fall back to open-loop drive.