reaching the approximate depth. It would then be released, allowing the vert- 

 ical thruster to maintain depth until the end of the mission. The normal pos- 

 itive buoyancy of the vehicle, aided perhaps by dropping additional weights, 

 would then allow it to return to the surface. Such methods would prolong the 

 mission duration at depth by conserving battery power while descending and 

 ascending. 



Electrical Configuration 



An electronic block diagram showing the hardware implementation of the 

 supervisory-control concept is in figure 8. An attempt was made to use com- 

 mercially available computer electronics wherever possible to reduce manu- 

 facturing costs, increase reliability and maintainability, and allow for easy 

 adaptation of the design concepts and software. 



The basis of the topside electronics is an Intecolor 8051 color graphics 

 display terminal and its associated minifloppy disk drive and keyboard. This 

 terminal costs only $4995, yet it has a tremendous amount of available soft- 

 ware and input/output flexibility, plus 24k of random access memory for user 

 programs. It is essentially a very inexpensive microprocessor system with 

 keyboard and display that can even be used as a development system. The color 

 graphics capability is not necessary for the basic requirement for a topside 

 computer console that conserves program space in the vehicle and implements a 

 supervisory-controlled design. However, the graphics capability has provided 

 a better man/machine interface by making it possible for the operator to 

 visualize items such as the pattern programmed into the vehicle, the movement 

 of the vehicle with respect to the preprogrammed path, analogic displays, and 

 color accentuation of pertinent parameters. 



Four bottles mounted on the frame directly beneath the floatation mate- 

 rial contain the electronics which drive the various sensors and effectors. 

 The two shorter bottles (30 in long) at the stern house the basic electronics 

 required for all configurations of the vehicle. The rear starboard bottle 

 contains microprocessor control electronics, while the port bottle contains 

 the motor controller electronics and switching relays. The longer bottles (4? 

 in long) in the front of the vehicle house the sensor and communication system 

 electronics. The contents of these bottles change for the various vehicle 

 configurations shown in figure 3. 



The basis of the vehicle control electronics is the microprocessor elec- 

 tronics card rack shown in figure 9, which contains the commercially available 

 printed circuit cards plus one NOSC-designed interface card (table 3). 



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