- Lift capability in claw center with fully extended arm: 9 pounds 

 in air, 14 pounds in salt water. 



- Manipulator weight: 35 pounds in air, 20.2 pounds in salt water. 



Each motor unit is driven by a low-speed dc torque motor with a one-step 

 gear reduction (see assembly drawings: foldout assembly of motor units I and 

 II). Position feedback is provided by one installed potentiometer per motor 

 unit. The system operates on 24-V electrical power (dc). 



3.3 SYSTEM INTEGRATION 



Plans are to incorporate the manipulator into a total supervisory-control- 

 led configuration during FY 1981. This final hardware configuration (fig 9) 

 will consist of a topside LSI/11-23 computer interfacing with a very simple 

 lightweight master arm and operator feedback CRT display located in a topside 

 console. A similar LSI/11-23 computer will be located in the left forward 

 housing on the free swimmer. This computer will then provide resolved posi- 

 tion control of the manipulator and interface with the topside computer 

 through a fiber-optic link (ref 7). The fiber-optic link can then later be 

 replaced with an acoustic link that takes advantage of the relatively low 

 bandwidth required to operate the manipulator in a supervisory-controlled 

 configuration. A vehicle-mounted underwater television camera and light will 

 provide the operator with sensor feedback from the manipulator and task envi- 

 ronment during operation. This sensor data will also be transmitted through 

 the fiber-optic link by using pulse frequency modulation (PFM) techniques (ref 

 8) and a multiplexing technique to place digital-control sensor information on 

 the video retrace (ref 7). When the fiber-optic link is replaced with an 

 acoustic communication command and control link, the television data will also 

 be transmitted acoustically via slow-scan techniques developed fairly recently 

 at NOSC (ref 9, 10, 11). A picture resolution of 256 by 256 elements has been 

 achieved at depths to 3720 feet with an update rate of 32 seconds. An 8- 

 second update rate was achieved from 128-by-128-element resolution displays. 

 It is hoped that this information, plus an updated transmission of key points 

 located on the manipulator, will be sufficient for the control of a supervi- 

 sory control configuration. Concepts involved in working out such problems of 

 man/machine interface are the subject of continuing research and development 

 on a program being conducted jointly by MIT and NOSC. Technological problems 

 to be attacked under this follow-on program are as follows: 



1. The validation of operator performance models with supervisory- 

 controlled teleoperator systems. 



2. The investigation of control/display factors that most significantly 

 mediate operator control performance (eg, the allocation of control 

 functions between the operator and computer components, the dynamics 

 of operator-computer interaction, and the effects of limited bandwidth 

 and degraded visual feedback). 



3. The use of a measurement arm to facilitate operation when relative 

 motion is present between the vehicle and the work site. 



4. The use of electrically induced compliance to facilitate final 

 approach and grasp operations. 



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