A Robot Submersible Gold Dredge

A robot submersible gold dredge designed to process five tons of sand per hour for a thirty-day period is described. The principal design approach is to use the river current to supply the primary mechanical power, as battery or other storage means are infeasible. A microcomputer system maintained two servo loops for system operation, as well as conducted communications with an on-shore computer via a low-frequency radio link. The first servo loop maintained the heading of the vehicle by sensing the river current direction and slope of the river bottom. The second servo loop maintained a variable-drag "anchor" in a configuration which permitted the rotary scoops to dig into the sand without stalling or rolling over the surface. Fabrication of the vehicle and a test sequence on the Feather River, north of Sacramento, CA are described. Conclusions and remarks are reported.