Systems, methods, and apparatus for a tank inspection robot and tether management system

A system for inspecting a tank containing a flammable fluid, the system comprising:

• a power source disposed outside the tank;
• a float configured coupled to a tether management system such that a first portion of the tether management system is configured to remain above a surface of the flammable fluid and a second portion of the tether management system is configured to remain below the surface of the flammable fluid when deployed inside the flammable fluid of the tank;
• a cover coupled to the tank and having an adjustable cable passageway extending therethrough;
• a cable coupled to the power source, extending through the adjustable cable passageway, and coupled to a switch of a tether management system, the cable secured in the adjustable cable passageway such that the tether management system remains positioned substantially beneath a roof manway of the tank at a first position;
• a tether coupled to the switch of the tether management system and to a tank inspection vehicle, the tether configured to provide power to the tank inspection vehicle when the tether is fully submerged in the flammable fluid;
• and
• a control unit configured to operate a reel to control a target length of the tether extending between the tether management system and the tank inspection vehicle, the target length configured to increase or decrease corresponding to a change in a distance between the tank inspection vehicle and the first position of the tether management system.

A method for managing a tether of a tank inspection vehicle, the method comprising:

• submerging the tank inspection vehicle in a flammable fluid of a tank;
• at least partially submerging a tether management system in the flammable fluid of the tank, the tether management system comprising:
• a cable configured to provide power across a vapor layer of the flammable fluid in the tank;
• the tether coupling the tank inspection vehicle to a reel of the tether management system, the tether configured to provide power and communications signals to the tank inspection vehicle;
• a switch configured to electrically couple the tether to the cable;
• a control unit configured to operate the reel to control a target length of the tether extending between the tether management system and the tank inspection vehicle;
• after an entirety of the tether is submerged beneath the flammable fluid, actuating the switch to provide power and communications signals to the tank inspection vehicle via the tether;
• during an operation of the tank inspection vehicle, determining, by the control unit, the target length based on a position of the tether management system within the tank and a position of the vehicle such that the target length does not exceed a maximum length based on a size of the tank;
• and
• operating the reel by the control unit such that the target length extends between the tether management system and the tank inspection vehicle.