Why robots using stepping motors
Usually, unique technology of Robot using micro-stepper motors, encoders, DSP control and polyurethane drives is how can make very low cost robots with real industrial performance and durability.
1. For equivalent performance stepping motors are cheape.
2. Stepping motors are brushless motors so have longer lifetimes.
3. Being digital motors they can be positioned accurately without hunting or overshoot.
4. Drive modules are not linear amplifiers which means less heat sinks, higher efficiency, greater reliability.
5. Drive modules are less expensive than linear amplifiers.
6. No expensive servo control electronics are required since signals originate directly from the MPU.
7. Software is fail-safe. The MPU issues stepping pulses. If the software fails to work or crashes the motors stop.
8. Electronic drives are fail-safe. In case of drive amplifier failure the motors lock solid and will not run. When a servo drive fails the motor can still run, possibly at full speed.
9. Speed control is accurate and repeatable (crystal controlled).
10. Stepping motors will run extremely slowly if required.
11. All robots have encoder feedback which is compared to software motor counts. In the event of any error which cannot be corrected the system will halt. Thus the integrity of the system is much higher.
12. Stepping motors are low speed high torque devices so transmissions are shorter which means higher reliability, greater efficiency, less backlash and lower cost. It is precisely this characteristic that makes steppers ideal for robotics since most robot motions are short distance requiring high accelerations to achieve low cycle times.