Abstract: A method of retrieving a mobile platform from a tank at least partially filled with a non-conductive, energetic substance includes configuring the mobile platform to include at least a retrieval system including a buoyant body, an electrically conductive member, and a tether. The tether electrically isolates the buoyant body from the enclosure.

Abstract: A method for controlling charge accumulation on a mobile platform in a tank containing a non-conductive, energetic substance includes configuring the mobile platform to include at least an electrical power supply and a charge accumulation control system. The power supplied from the electrical power supply to one or more electrical power consumers associated with the mobile platform adds an electrical charge to the mobile platform. The charge accumulation control system controls an accumulation of the electrical charge on the mobile platform by one of: (i) reducing the supplied power and preventing an increase in the supplied power later while the mobile platform is inside the tank, and (ii) disengaging the electrical power consumer(s) from the supplied power and preventing a reengagement of the supplied power with the electrical power consumer(s) later while the mobile platform is inside the tank.

Abstract: A method of retrieving a mobile platform from a tank having a hatch and at least partially filled with a non-conductive, energetic substance includes configuring the mobile platform to include at least a retrieval system disposed at least partially on an enclosure. The retrieval system includes at least: a primary tether connected to a buoyant body and to the enclosure, and a secondary tether connected to the buoyant body and to the enclosure. The method further includes: predetermining a buoyant body retrieval zone within the tank, and positioning a released buoyant body within the buoyant body retrieval zone by using the primary tether. The method also includes retrieving the primary tether by using the buoyant body; using the primary tether to release the secondary tether; and inserting a retrieval member through the hatch to retrieve the buoyant body, the primary tether, and/or the secondary tether.

Abstract: A method of performing a selected task in a tank containing an energetic substance uses an inherently safe mobile platform that includes a marker detector, a control unit, a power supply, a propulsion system, and an inherently safe enclosure. The inherently safe enclosure prevents a spark occurring inside the inherently safe enclosure from passing to an exterior of the inherently safe enclosure. All spark-generating components of the mobile platform are positioned inside the inherently safe enclosure. The method includes lowering the mobile platform into the tank, at least partially submerging the mobile platform in the energetic substance, and detecting a marker using the marker detector. No active physical carrier connects the mobile platform to an object exterior of the tank while the mobile platform is in the tank.

Abstract: A mobile platform uses a charge accumulation control system to control a charge accumulation while the mobile platform is in the tank. Alternatively or additionally, the mobile platform includes a retrieval system having a buoyant body, a primary tether, and a secondary tether. Alternatively or additionally, an electrical cable is used to reduce a voltage difference between the mobile platform and the tank or other structure by electrically connecting to an electrically conductive member on the mobile platform.

Abstract: A mobile platform uses a charge accumulation control system to control a charge accumulation while the mobile platform is in the tank. Alternatively or additionally, the mobile platform includes a retrieval system having a buoyant body, a primary tether, and a secondary tether. Alternatively or additionally, an electrical cable is used to reduce a voltage difference between the mobile platform and the tank or other structure by electrically connecting to an electrically conductive member on the mobile platform.

Abstract: A method of performing a selected task in a tank containing an energetic substance uses an inherently safe mobile platform that includes a marker detector, a control unit, a power supply, a propulsion system, and an inherently safe enclosure. The inherently safe enclosure prevents a spark occurring inside the inherently safe enclosure from passing to an exterior of the inherently safe enclosure. All spark-generating components of the mobile platform are positioned inside the inherently safe enclosure. The method includes lowering the mobile platform into the tank, at least partially submerging the mobile platform in the energetic substance, and detecting a marker using the marker detector. No active physical carrier connects the mobile platform to an object exterior of the tank while the mobile platform is in the tank.

Abstract: A mobile platform uses a charge accumulation control system to control a charge accumulation while the mobile platform is in the tank. Alternatively or additionally, the mobile platform includes a retrieval system having a buoyant body, a primary tether, and a secondary tether. Alternatively or additionally, an electrical cable is used to reduce a voltage difference between the mobile platform and the tank or other structure by electrically connecting to an electrically conductive member on the mobile platform.