Last updated: 6-28-00
Project:DEIMOS
Stage:Guider TV Focus
ID #: KDTV-001A
Engineer: D. Cowley (T. Freeman)
Mechanical Description of Stage:
Electronic Description of Stage: Standard
constrained rotary stage. Movement is constrained to the motion of the
focus mechanism. The stage uses an EL-1236 Stage Interconnect Box, SPDTprimary
limits, DPDT secondary limits, and an optical fiducial. The first limit
the stage encounters is the software limit. Just beyond the software limit
is the primary hardware limit. If the stage makes it past these limits,
the secondary limit will break the connection to the motor itself. The
software will inform the user that the secondary limit has been encountered.
If this happens, the only way to back out of these limits is to manually
move the motor shaft. The optical fiducial is used to define the home
point. Note that the optical interrupter is only enabled when the stage
is moving. This means that the IR emmitter is turned offwhen the focus
stage is not moving, e.g., during exposures.
Required setting accuracy :
Performance requirements and design goals
Component |
Requirements 1 |
Motors: Galil #50-1000 |
- |
Gearbox:- |
- |
Limits 2: Microswitch BZ-2RW822-A2 "primary limit" and DT-2RV22-A7"secondary
limit" |
- |
Fiducials: TRW #OPB-970-T55 (Optical) |
- |
Encoders: BEI #MX213-25-1000 (4000 quadrature counts/rev) |
- |
Air Cylinders:- |
- |
Air Solenoids:- |
- |
Lock/Clamp/Brake:- |
- |
Interlocks:- |
- |
-
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: K. Dietsch 6-28-00
Motor tuning parameters under different spacialorientations
and environment
Parameter |
|
Neutral Gravity |
Uphill 1 |
Downhill |
Cold |
Cold Uphill |
PID Filter: |
KD: |
200 |
- |
- |
- |
- |
KP: |
92 |
- |
- |
- |
- |
KI: |
33 |
- |
- |
- |
- |
Acceleration (pulses/sec^2): |
- |
256,000 |
- |
- |
- |
- |
Deceleration (pulses/sec^2): |
- |
256,000 |
- |
- |
- |
- |
Speed (pulses/sec): |
- |
500 |
- |
- |
- |
- |
Other:
Configure: |
- |
CN 1,-1 |
- |
- |
- |
- |
-
Uphill defined as motor (or driven end of shaft) in lowest position
Rotary Stage (constrained)
Distance from "home" |
Position |
Motor Counts |
Physical Units |
Time to Reach |
Software Limits: |
Forward |
2200 |
- |
4.5 Seconds |
Reverse |
-2000 |
- |
4.5 Seconds |
Primary (inner) Limits: |
Forward |
2230 |
- |
4.5 Seconds |
Reverse |
-2090 |
- |
4.5 Seconds |
Secondary (outer) Limits: |
Forward |
2367 |
- |
4.5 Seconds |
Reverse |
-2174 |
- |
4.5 Seconds |
Resolution of Stage
Encoder |
Counts/Inch |
Counts/Millimeter |
Counts/Degree |
On Motor |
- |
- |
11.1 |
On Stage |
- |
- |
11.1 |
-
Repeatability:
-
Forward: Primary Limit - 9 counts
-
Reverse: Primary Limit - 39 counts
-
Fiducial:
-
Encoder:
-
Air Cylinders:
-
Air Solenoids:
NOTES:
*Linear motion "stage" is actually internal to Cannon lens. But itappears
to be a rotory stage.
Mechanical Drawing(s) # D8140, #D0920
Electronic Drawing(s) # EL-3051
Sign conventions are such that a positive motion of the motor turnsthe
motor in a CW direction as viewed from the drive shaft looking backinto
the motor, and will drive the stage towards the forward limit.