Editing Resolution of motors
Your changes will be displayed to readers once an authorized user accepts them. (help) |
Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.
The edit can be undone.
Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 2: | Line 2: | ||
==Servo motor== | ==Servo motor== | ||
===Resolution=== | ===Resolution=== | ||
− | Servo motor resolution is determined by [[Feedback devices|feedback device]] of motor. I.e. 1000 PPR (pulses per revolution) [[quadrature]] encoder yields 1/4000 | + | Servo motor resolution is determined by [[Feedback devices|feedback device]] of motor. I.e. 1000 PPR (pulses per revolution) [[quadrature]] encoder yields 1/4000 revolutions because 1000 PPR equals 4000 counts per revolution after standard 4X decoding. |
− | + | ||
===Accuracy=== | ===Accuracy=== | ||
In most cases accuracy is more important value than resolution. Accuracy is more difficult to measure because it largely depends on mechanical load characteristics and dynamics. In ideal conditions the accuracy is very close to resolution but in most of practical cases the accuracy is 5 to 10 times less than resolution. I.e. 1000 PPR encoder can be expected to provide 1/400 to 1/800 revolutions accuracy. | In most cases accuracy is more important value than resolution. Accuracy is more difficult to measure because it largely depends on mechanical load characteristics and dynamics. In ideal conditions the accuracy is very close to resolution but in most of practical cases the accuracy is 5 to 10 times less than resolution. I.e. 1000 PPR encoder can be expected to provide 1/400 to 1/800 revolutions accuracy. | ||
− | If feedback device has very high resolution, such as 1/1000000, then limiting factor of accuracy will be other error sources than feedback device alone. | + | If feedback device has very high resolution, such as 1/1000000, then limiting factor of accuracy will be other error sources than feedback device alone. |
− | + | ||
==Stepping motor== | ==Stepping motor== | ||
===Resolution=== | ===Resolution=== | ||
− | + | Stepper resolution depends on number of magnetic steps per revolution and drive's electrical step angle size. Most modern drives implement microstepping to increase resolution and motion smoothness. Most common stepper resolution is 200 full steps per revolution but when driven for example with 16-microstep drive, the resulting resolution is 1600 steps per revolution (1/1600 revolutions). | |
− | + | ||
===Accuracy=== | ===Accuracy=== | ||
Because steppers don't usually have [[Feedback devices|feedback devices]], the accuracy depends on motor load torque and motor linearity. Most stepping motor manufacturers quote angular accuracy of ±0.9° or 1/400 revolutions. Stepper accuracy can't be increased by increasing microstepping resolution. | Because steppers don't usually have [[Feedback devices|feedback devices]], the accuracy depends on motor load torque and motor linearity. Most stepping motor manufacturers quote angular accuracy of ±0.9° or 1/400 revolutions. Stepper accuracy can't be increased by increasing microstepping resolution. | ||
==See also== | ==See also== | ||
*[[Wikipedia:Accuracy and precision]] | *[[Wikipedia:Accuracy and precision]] | ||
− |