For manipulators, such as those on the RUWS (figure 12) and work systems 

 package (WSP), it is anticipated that tasks requiring force feedback will occur. Examples 

 are drilling and tapping operations where too much force or misdirected force might result 

 in a broken tool. Of course, wherever possible, tool drive, feed, and alignment should be 

 automatic functions of the tool itself and not of the manipulator. Unfortunately, this is 

 not always possible. Another situation in which force-sensing could be important occurs 

 when the manipulator unexpectedly comes in contact with the work task or the vehicle. 

 Another difficulty that the operator encounters is in maintaining a sense of orientation. 

 Orientation and station-point feedback are provided by two methods: fixed camera and 

 monitor or head-coupled television (the latter method should incorporate head- following 

 translation, if possible). Head-coupled television also alleviates the problem of limited field 

 of view, since a sweep of the head allows the operator to encompass visually as much of 

 the remote environment as desired and the spatial relationship of objects not simultaneous- 

 ly visible in the camera's field of view is instinctively retained. 



Figure 12. RUWS manipulator. 



It must be cautioned that the best general-purpose manipulator for underwater 

 work is not necessarily the most sophisticated or complex. Cost, reliability, maintainability, 

 and the ability of the trained operator to work within limitations must also be weighed in 

 deciding whether to incorporate seemingly desirable features. 



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