High Energy Laser Testbed for Accurate Beam Pointing Control

capability to monitor analog input signals. In addition, eight 16-bit analog voltage output channels and 16 digital
input/output channels are provided and are connected to motor control command, FSM control command, and various
discrete signals. Lastly, rotary encoders providing relative positions are connected to the Counter Timer board. The
External Interface Diagram of the target computer is presented in Figure 3.
BW Camera (IPX-VGA210)
NFOV
CCD
WFOV
CCD
C
C
Terminal Board
Gimbal Limit SW
Hall Sensor
Camera
Link
Camera
Link
Fiber Optic Gyro (DSP3000)
AZ Gyro
EL Gyro
AZ+ AZ-
EL+ EL-
AZ
EL
AZ
Encoder
EL
Encoder
Rotary Encoder
Synchronous IF
CLK/Data/Sync
12 Ch
Analog Input
Limit SW 1
Limit SW 2
Limit SW 3
Limit SW 4
Phase A/B/C
Phase A/B/C
Target Computer
PMC
(Frame
Grabber)
PMC
IP1K110
IO Board
Ch 0-11 16 Bit
ADC
Ch 1
Ch 2
Ch 3
Ch 4
Ch 5-7
Ch 9-11
IMP2A
( PowerPC
CompactPCI
Processor
Board )
ACPC8630
( IO Pack
Carrier
Board )
16 Bit
DAC
ACPC730
( Multifunction
CompactPCI
Board )
Digital
Input
(12Ch)
Digital
Output
(24Ch)
ACPC484
(Counter Timer
Board)
Figure 3. External Interface Diagram of the Target Computer
PCI I/F
PCI I/F
PCI I/F
D/O
Ch 0-1
Ch 2-3
Ch 4
Ch 5
Ch 6-7
Ch 0
Ch 1-23
Ch 0
Ch 1
Ch 2
Ethernet
Host Computer
AZ Motor Phase A/B
EL Motor Phase A/B
AZ FSM Command
EL FSM Command
Spare CH’s (set 0's)
Track Mode cmd (set 0)
Spare DOs (set 0's)
Laser On/Off (set 1)
Disable AZ Amp (set 0)
Disable EL Amp (set 0)
EL Motor AZ Motor
A
Position x
Position y
SW 1
SW 2
B
C
BL 10-80-A
Linear Power AMP
FSM Controller
A
Joystick
Brushless DC Motor
Video
Trackers
B
Terminal Board
C
FSM
LASER
BL 10-80-A
Power AMP
The major components of the beam control system consists of Wide Field-of-View (WFOV) video tracking system,
Narrow Field-of-View (NFOV) video tracking system, alignment and beam jitter control system, supporting optics, and
laser sources. The schematic of the beam control system is shown in Figure 4. The WFOV video tracking system
consists of a WFOV camera, two rate gyros, two rotational stages, and supporting hardware. The WFOV control system
is designed to stabilize the azimuth and elevation of the telescope gimbals and maintain the line of sight (LOS) to the
target in the inertial space with respect to external disturbances.
The NFOV video tracking system consists of a NFOV camera and a Fast Steering Mirror (FSM). The NFOV control
system maintains fine tracking and pointing of a laser beam on a target.
The alignment and beam jitter control system consists of a reference laser, a beam Position Sensing Device (PSD), and a
FSM. The reference laser at the end of the telescope travels through the telescope and the optical path to reach PSD. The
FSM is used to correct any misalignment and relative jitter.
Proc. of SPIE Vol. 7587 75870G-3
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