Just had a couple of ideas for new features for ODrive v4, and wanted to see what people think:
Batteryless Encoder Count Retention
This is fast becoming a standard feature in most commercial industrial servos. As I understand (though I may be wrong EDIT: the following is probably incorrect ), a supercapacitor is used to power the encoder and thereby maintain the encoder count during power down and drive reset conditions. This would mean we no longer have to worry about selecting an absolute encoder for applications where homing is not an easy process (e.g. robotic arms). This also addresses the multi-turn issue. I think this feature would improve the standing of ODrive significantly when compared to commercial hardware. I’m not sure exactly how this would be implemented, but I imagine the supercapacitor would power only the encoders and an auxiliary microcontroller that is used to keep the encoder counts (including as many turns as possible with the remaining bits).
All commercial servo systems include integrated safety features that comply with relevant industry standards. As ODrive gains popularity, and is used to drive higher power motors, the need for integrated safety becomes more and more important. This wouldn’t have to be anything complex… I think the standard is just two Safe Torque Off inputs for a servo drive.
Please let me know what you think of these ideas.