Last updated: 12-19-01
Project: DEIMOS
Stage: Grating Slide
ID #: KDGS-001A
Engineer: J. Osborne
Mechanical Description of Stage:
Delivers one of four items: 3 gratings and one mirror. Has a 200
pound counterweight moving on it's own linear stage.
Electronic Description of Stage:
Two fiducial schemes: Main (Bit 4) and Primary
Reference Mark (PRM) (Bit 38).
Find the main fiducial edge, set position = 0. Drive to slider,
find PRM and back off (X distance) to clamp position.
Required setting accuracy:
TBD but we assume about 0.006"
Performance requirements and design goals
| Component |
Requirements 1 |
| Motors: Galil #50-1000 |
|
| Gearbox: Two stages of chain/sprockets plus spur gear set then ball
screw. Counter weight slide: Main stage has 1 stage of timing
belt/sprocket then ball screw. |
|
| Limits 2: Microswitch BZ-2RW822-A2 "primary" and DT-2RV22-A2
"secondary" |
|
| Fiducials: TRW #OPB-970-T55 (Optical) |
|
| Encoders: BEI #MX213-25-1000 (4000 quadrature counts/rev) |
|
| Air Cylinders:- |
|
| Air Solenoids:- |
|
| Lock/Clamp/Brake:- Yes |
See KDGS-002A
|
| Interlocks: See interlock
schedule |
|
-
Speed, temperature, accuracies, electrical power, pressurized air,
lubricant, coolant, N2 purge, ...
-
Primary (inner) and secondary (outer) limits. These can be magnetic,
optical, or physical contact
Manufacturer's specifications and limitations
| Component |
Maximum Operating Condition |
Safe Ops Condition |
Requirements |
| Motors: Galil 50-1000 |
3750 RPM, 205 oz-in peak torque |
|
|
| Gearbox: |
|
|
|
| Limits: |
|
|
|
| Fiducials: |
|
|
|
| Encoders: |
|
|
|
| Air Cylinders: |
|
|
|
| Air Solenoids: |
|
|
|
| Lock/Clamp/Brake: |
|
|
|
Final Mechanical Assembly and Testing Results
Tests performed by:
Motor tuning parameters under different spacial
orientations and environment
| Parameter |
|
Set |
| PID Filter: |
KD: |
154 (old) 200 (new)
|
| KP: |
29 (old) 20 (new)
|
| KI: |
27 (old) 2 (new)
|
| Acceleration (pulses/sec^2): |
|
256,000
|
| Deceleration (pulses/sec^2): |
|
256,000
|
| Speed (pulses/sec): |
|
75000 cps Maximum
|
Other: CN 1,1
CB 4 (home) or CB 38 (PRM) fiducials |
|
|
Motion Parameters
Linear Stage (constrained)
| Distance from "home" 1 |
Position |
Motor Counts |
Physical Units |
Time to Reach |
| Software Limits: |
Forward |
+300,000
|
|
|
| Reverse |
-13,000,00
|
|
|
| Primary (inner) Limits: |
Forward |
+306,700
|
|
|
| Reverse |
-13,006,000
|
|
|
| Secondary (outer) Limits: |
Forward |
+343,400
|
|
|
| Reverse |
Unknown
|
|
|
| Position # (@ 270 Degree Position Angle) |
2 (Mirror) |
-9,323,055 (Go To)
+28,652 (Offset)
|
|
|
| 3 |
-4,218,400 (Go To)
+57,586 (Offset)
|
|
|
| 4 |
+126,012 (Go To)
+51000 (Offset)
|
|
|
| 5 |
N.A.
|
|
|
-
"Coarse" if from optical interupter, "Fine" if from an encoder index
pulse. Home is defined as zero counts.
-
Primary limits signal the controller to stop motion. Secondary limits
cut motor power and require intervention to move out of them.
Resolution of Stage
| Encoder |
Counts/Inch |
Counts/Millimeter |
Counts/Degree |
| On Motor |
|
|
11.11
|
| On Stage |
388,125
|
|
|
-
Gear reduction function: Motor and belt/sprocket reduction: 72
teeth/16 teeth plus
-
spur gear set reduction of 69 teeth/16 teeth plus ballscrew at
5 threads per inch (5TPI).
-
72/16 X 69/16 = R = 19.40625
-
1 rev of ballscrew = 0.20 inches
-
1 rev of motor = 0.0103 inches
-
4000 counts/rev = 0.0000025 inches/count
-
Repeatability:
-
Fiducial:
-
Encoder:
-
Air Cylinders:
-
Air Solenoids:
NOTES:
Mechanical Drawing(s) # D0920, D4100 and D4189
Electronic Drawing(s) #EL-3066
Sign conventions are such that a positive motion of the motor turns
the motor in a CW direction as viewed from the drive shaft looking back
into the motor, and will drive the stage towards the forward limit.
The Grating Slider stage uses Controller # 2, amplifier 2A and is connected
to the D axis.