Division Ratio For Parameters - Panasonic minas a4 series Instruction Manual

Division Ratio for Parameters

Relation between Electronic Gear and Position Resolution or Traveling Speed
Pulse train position
command
[
Travel distance : P1 [P]
Traveling speed : F [PPS]
Here we take a ball screw drive as an example of machine.
A travel distance of a ball screw M [mm] corresponding to travel command P1 [P], can be described by the
following formula (1) by making the lead of ball screw as L [mm]
M = P1 x (D/E) x (1/R) x L .................. (1)
therefore, position resolution (travel distance ∆M per one command pulse) will be described by the formula (2)
∆M = (D/E) x (1/R) x L ........................ (2)
modifying the above formula (2), electronic gear ratio can be found in the formula (3).
D = (∆M x E x R) x L ...........................(3)
Actual traveling velocity of ball screw, V[mm/s] can be described by the formula (4) and the motor rotational
speed, N at that time can be described by the formula (5).
V = F x (D/E) x (1/R) x L ..................... (4)
N = F x (D/E) x 60 ...............................(5)
modifying the above formula (5), electronic gear ratio can be found in the formula (6).
D = (N x E)/ (F x 60) ........................... (6)
<Notes>
1) Make a position resolution, ∆M as approx. 1/5 to 1/10 of the machine positioning accuracy, ∆ , consider-
ing a mechanical error.
2) Set up Pr48 and Pr4B to any values between 1 to 10000.
3) You can set up any values to a numerator and denominator, however, action by an extreme division ratio
or multiplication ratio cannot be guaranteed. Recommended range is 1/50 to 20 times.
4)
2 n Decimal
0
2 1
1
2 2
2 2 4
3
2 8
2 4 16
5
2 32
2 6 64
7
2 128
2 8 256
9
2 512
10
2 1024
2 11 2048
12
2 4096
2 13 8192
14
2 16384
2 15 32768
16
2 65536
17
2 131072
306
Driver
Electronic gear ratio
Pr4A
Pr48 x 2
D=
Pr4B
]
Example of ball screw drive
by servo motor
Rotational speed : N[r/min]
+
Motor
–
Encoder
Encoder pulse counts : E [P/r]
* 10000 (=A/B-phase 2500 [P/r] x 4)
* 131072 (=17-bit)
Gear
Machine
Reduction ratio : R