Setting Example - Mitsubishi Electric MR-J5 Series User Manual

Setting example

The electronic gears on the position command side are illustrated in the function block diagrams. The position
feedback side is multiplied by the inverse number of the electronic gear ratio.
In the cyclic synchronous position mode
Adjust [Pr. PA06 Electronic gear - Numerator] and [Pr. PA07 Electronic gear - Denominator] so that the travel distance set in
the controller matches the travel distance on the machine. [Motor revolutions (Obj. 6091h: 01h)] and [Shaft revolutions (Obj.
6091h: 02h)] can also be used for the setting.
Electronic gear
([Pr. PA06]/[Pr. PA07])
([Obj. 6091h: 01h]/[Obj. 6091h: 02h])
Travel distance
[Command unit]
P : Servo motor encoder resolution [pulse/rev]
t
ΔS: Travel distance per servo motor revolution [command unit/rev]
CMX: Electronic gear - Numerator
CDV: Electronic gear - Denominator
CMX/CDV = P /ΔS
t
The following setting example shows how to calculate the electronic gear.
The following specification symbols are necessary for calculation of the electronic gear.
Pb: Ball screw lead [mm]
1/n: Reduction ratio
P : Servo motor encoder resolution [pulse/rev]
t
ΔL : Travel distance per command pulse [mm/pulse]
0
ΔS: Travel distance per servo motor revolution [mm/rev]
Δθ°: Angle per pulse [°/pulse]
Δθ: Angle per revolution [°/rev]
■Setting example of a ball screw
The following shows the example of when the ball screw is moved at 10 μm per pulse.
Machine specifications
1/n
1/n = Z /Z = 1/2
1 2
Z
2
Z
Servo motor encoder resolution
67108864 [pulse/rev]
Ball screw lead Pb = 10 [mm]
Reduction ratio: 1/n = Z
Z : Number of gear teeth on servo motor side
1
Z : Number of gear teeth on load gear
2
Servo motor encoder resolution: P
3 BASIC FUNCTION
82
3.7 Electronic gear function [G] [WG]
or
+
CMX
Deviation counter
CDV -
Pb = 10 [mm]
1
/Z = 1/2
1 2
= 67108864 [pulse/rev]
t
Servo motor
M
Encoder