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2.
2. COORDINATED MOTION (CONTROLLING TIP)

CHOICE OF COORDINATE FRAMES

• TIED TO ORBITER 
THC - in, TIP of arm →
RHC - pitch, TIP PITCH (in orbiter frame)
THC/RHC COMMAND RATES (max 2 ft/sec): CMD → GPC → (algorithm to resolve) into CMDs for each joint
→ CMDS TO JOINT
(6 DEG of FREEDOM)

• TIED TO END OF ARM (SITTING ON CAMERA)
USED DURING REL/CAPTURE: EYES GLUED TO TV MON (EE CAMERA)
→ FLYING THE CAMERA

→ (PROBLEMS INVOLVED IN DESIGNING SOMETHING MECHANICAL ON SHUTTLE) (WILL SEE IN VIDEO)
[WEIGHTLESS] (THINGS ARE WEIGHTLESS: GOOD NEWS + BAD NEWS)

GOOD: CAN LIFT ANYTHING (ELECTRIC MOTORS, HOLLOW BOOMS → 950lbs)

[[left margin]]
(10)
[[/left margin]]

BAD: CAN'T TEST IT THOROUGHLY ON GROUND
-CAN'T SUPPORT WT
-CAN'T TEST WTLESSNESS → DON'T KNOW (MEASURE)

SYSTEM FLEXIBILITY
MODES ([[x y?]])
COUPLING BETWEEN MODES

→ UNCERTAINTY ABOUT PERF. IN ORBIT
(DYNAMICS) + HOW ASTRONAUT WILL EXCITE DYNAMICS

(1) PROBLEM FOR SYSTEM VERIFICATION (COMPUTER SIM)
(2) CREW TRAINING [NO REAL ARM
SEVERAL SIMULATORS + TRAINERS TO GET PIECES]
---------
[SES]
3 SIMULATORS
• SMS (COMPUTER GEN. VISUALS
LOOKS LIKE SHUTTLE COCKPIT) (BAD DYNAMICS)
• SIMFAL (GOOD DYNAMICS, LINE DRAWINGS [[)]]
• MDF (PRACTICE CONTROLLING SOMETHING 50' long
THAT CAN BREAK THINGS)