Resolution of motors - Revision history

WikiAdmin: /* Resolution */

2012-05-02T10:30:14Z

‎Resolution

WikiAdmin: /* Accuracy */

2012-05-02T09:57:13Z

‎Accuracy

WikiAdmin: /* Resolution */

2012-05-02T09:54:42Z

‎Resolution

WikiAdmin at 22:56, 1 May 2012

2012-05-01T22:56:20Z

77.86.192.128 at 22:51, 1 May 2012

2012-05-01T22:51:31Z

77.86.192.128: Created page with "Resolution and accuracy of position control motors depend on several factors. ==Servo motor== ===Resolution=== Servo motor resolution is determined by [[Feedback devices|feed..."

2012-05-01T22:48:00Z

Created page with "Resolution and accuracy of position control motors depend on several factors. ==Servo motor== ===Resolution=== Servo motor resolution is determined by [[Feedback devices|feed..."

New page

Resolution and accuracy of position control motors depend on several factors.
==Servo motor==
===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 revolutions because 1000 PPR equals 4000 counts per revolution after standard 4X decoding.
===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.
==Stepping motor==
===Resolution===
Stepper resolution depends on number of magnetic steps per revolution and drive's electrical step size. Most modern drives do microstepping to increase resolution. Most common stepper resolution is 200 steps per revolution but when driven with 16-microstep drive, the resulting resolution is 1/1600 revolutions.
===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.
==See also==
*[[Wikipedia:Accuracy and precision]]

@@ Line 11: / Line 11: @@
 ==Stepping motor==
 ===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).
+[[Stepping motor]] 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===
 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.

@@ Line 7: / Line 7: @@
 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. High resolution feedback are some times used to maximize motion smoothness at low speeds.
 ==Stepping motor==
 ===Resolution===

@@ Line 2: / Line 2: @@
 ==Servo motor==
 ===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 revolutions because 1000 PPR equals 4000 counts per revolution after standard 4X decoding.
+Servo motor resolution is determined by [[Feedback devices|feedback device]] of motor. I.e. 1000 PPR (pulses per revolution) [[quadrature]] encoder yields 1/4000 revolution resolution because 1000 PPR equals 4000 counts per revolution after standard 4X decoding.
 ===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.