4. Super 8-mm motion pictures were taken by the vehicle; they were acti- 

 vated remotely by the surface operator. 



Similar results were obtained in the bay tests, except that visibility was 

 poor and television and motion picture coverage of the ocean floor was limited 

 accordingly. The controllability of the vehicle is amazing in that the ve- 

 hicle is long and narrow and side drag prevents the use of differential thrust 

 (reversing one motor) during turns. However, even with this limitation, a 

 minimum turn radius of approximately 9 ft was observed. 



Problems Encountered 



Only minor problems were encountered, but they indicated the direction 

 for improving the vehicle design which ultimately dictated the vehicle con- 

 figuration described in the section on system description. 



VEHICLE TRIM. Although two new 3-in battery bottles spanning the length of 

 the vehicle had been designed, they were not yet fabricated and installed on 

 the submersible at the time of these tests. Thus, the batteries again caused 

 a bad list, to one side of the vehicle. This caused an undue amount of delay 

 in trimming the vehicle in the water. It took 16 lb attached to the forward 

 starboard bottle and an additional 7 lb in the midsection of the vehicle on 

 the starboard side to trim the vehicle. For the saltwater operation, the 

 vehicle required an additional 12 lb attached to the center runner at the 

 midsection of the vehicle. The vehicle trimmed out at about 1 lb positive 

 buoyancy. Now that the new 3-in battery bottles have been fabricated and 

 installed, the time required to trim the vehicle should be greatly reduced. 



JOYSTICK CONTROLS. Direct control of the vehicle during this series of tests 

 was achieved through operator interaction with the cursor controls and the "D" 

 and "U" keys on the console keyboard. The use of these controls was a "quick 

 and dirty" approach to operator interaction. A fair amount of concentration 

 was required to remember which keys performed which function. This approach, 

 therefore, has been replaced with two joystick controls mounted on each side 

 of the console keyboard. The right-hand joystick controls continuous forward/ 

 reverse and right/left movements of the vehicle. The left-hand side dimen- 

 sional stick provides proportional depth control to the vertical thruster. 

 This approach has proven much more satisfactory in the laboratory and is now 

 the new permanent means of analogic control of the vehicle when used in pro- 

 jection or real-time control modes. 



CHARGING TIME. Much operational time was lost during these tests because of 

 the time required to charge the batteries. A more modular approach has been 

 adopted because of this experience. A set of extra battery bottles has been 

 fabricated, allowing the operation to continue by changing the bottles in the 

 field and recharging the first set while using the second set. 



47 



