Autonomous Utility Cart and Robotic Cart Platform

An autonomous utility cart for use by a worker to carry an item through a working environment with open areas and fixed structures, said autonomous utility cart comprising:

• a cart structure adapted to carry the item, said cart structure having at least one rotatable and turnable wheel;
• a drive unit with first and second drive wheels, said drive unit being spaced from said turnable wheel, said drive unit having a navigation and movement system including a first drive motor with a first drive shaft to selectively rotate said first drive wheel and a second drive motor with a second drive shaft to selectively rotate said second drive wheel, a programmed processor with a processor memory, first and second motor encoders to obtain rotational movement data for each of said drive shafts, drive unit circuitry electrically and communicatingly connecting said processor, memory, motors and encoders, said processor sending movement instructions to said drive motors sufficient to independently rotate said first and second drive shafts to propel said drive unit and cart structure along straight and curved paths of travel, and said processor using said rotational movement data to determine current location data when said drive unit is at a current location;
• a communication device with at least one key to obtain selected destination data when said current location of said drive unit is at a selected destination, said communication device being in electrical communication with said navigation and movement system and mounted to one of either said cart structure and said drive unit, and the worker touching said at least one key to store said selected destination data in said processor memory;
• a scanning device with a circumferential sensing range to obtain working environment data sufficient to locate the open areas and fixed structures, said scanning device being mounted on one of either said drive unit and said cart structure and being in electrical communication with said drive unit circuitry;
• a power source in electric power supplying communication with said drive unit circuitry, said communication device and said scanning device, said power source being mounted to one of either said drive unit and said cart structure;
• and,
• wherein said navigation and movement system uses said working environment data, said selected destination data and said current location data to plan a route and movement instructions for said drive unit and cart structure to travel through the working environment to said selected destination.

A robotic cart platform for integrating into an existing manually operated utility cart to convert the cart into an autonomous utility cart, the cart having a cart structure with a front, rear, first side and second side, lower and upper trays, front and rear risers and front and rear caster wheels, each riser having angled exterior riser walls forming an interior riser channel and having multiple spaced openings extending through the exterior riser walls, the front and rear risers having forward facing openings, rearward facing openings, first side facing openings and second side facing openings, the trays having a top surface supported by structural webbing forming a matrix of tray compartments under the top surface, the cart being used in a working environment including open areas, fixed structures, temporary obstacles and multiple destinations, said robotic cart platform comprising:

• a drive unit located below the lower tray and replacing the front caster wheels of the manually operated utility cart, said drive unit having first and second drive wheels, said drive unit having a navigation and movement system including a first drive motor with a first drive shaft to selectively rotate said first drive wheel and a second drive motor with a second drive shaft to selectively rotate said second drive wheel, a programmed processor with a first memory to plan a route and movement instructions for said drive unit to travel through the working environment to a selected destination, a microcontroller with a second memory to execute said movement instructions via a motor controller, said motor controller being electrically connected to said drive motors to control rotational movement of said drive shafts and drive wheels, said motor controller rotating said first drive shaft and first drive wheel independently of said second drive shaft and second drive wheel to propel said drive unit and cart structure along straight and curved paths of travel, first and second motor encoders obtaining rotational movement data for each of said drive shafts, and drive unit circuitry electrically and communicatingly connecting said processor, first memory, microcontroller, second memory, motor controller and encoders;
• a main power source in electric power supplying communication with said drive unit circuitry, said power source being secured to said cart;
• a time-of-flight laser scanner with a rotating sensor and a circumferential sensing range to obtain working environment data sufficient to locate the open areas and fixed structures, said laser scanner being secured to one of either said drive unit and said cart and being in electrical communication with said drive unit circuitry;
• a plurality of proximity sensors, each said proximity sensor having a sensing direction and being in electrical communication with said drive unit circuitry, said proximity sensors being secured in the interior riser channels proximal the riser openings, at least one of said proximity sensors being aimed from at least one of said forward facing openings, at least one of said proximity sensors being aimed from at least one of said rearward facing openings, at least one of said proximity sensors being aimed from at least one of said first side openings, and at least one of said proximity sensors being aimed from at least one of said second side openings;
• a cable array including first and second cable lines, said first cable line including a power source cable and first and second proximity sensor cables, said power source cable having opposed terminal connections for electrically connecting to said power source port to said power source, said first proximity sensor cable having opposed terminal connections for electrically connecting said first proximity sensor port to said proximity sensors located on the first side of the cart, said second proximity sensor cable having opposed terminal connections for electrically connecting said second proximity sensor port to said proximity sensors located on the second side of the cart;
• and, said cable array being routed through the interior riser channels and the matrix of tray compartments.

A utility cart to carry at least one item having an item weight, said utility cart comprising:

• a cart structure adapted to carry the item, said cart structure having a cart structure weight and a cart mounting structure, said cart mounting structure having a plurality of spaced apart cart fastener openings extending into said cart mounting structure;
• a caster wheel assembly having a wheel mounting bracket with a bracket perimeter portion and an integrally formed bracket central area, said bracket perimeter portion having a plurality of bracket fastener openings in mated alignment with said cart fastener openings;
• a weight sensor assembly located between said wheel mounting bracket and said cart mounting structure, said weight sensor assembly including a sensor plate with a sensor plate perimeter portion and an integral inwardly extending semi-flexible cantilevered support tab, said support tab having a tab neck, central focal area, tab surface and a strain gauge sensor, said strain gauge sensor being secured to said tab surface, said tab neck and focal area being surrounded by a flex accommodating opening, and said focal area being aligned directly over and in load supporting engagement with said central area of said wheel mounting bracket;
• a weight bearing crown formed on one of either said central area of said wheel mounting bracket and said central focal area of said support tab;
• a plurality of fasteners passing through said bracket fastener openings and into said cart fastener openings to firmly secure said caster wheel mounting bracket to said cart mounting structure;
• said fasteners leaving a non-load bearing gap between said bracket perimeter portion and said sensor plate perimeter portion;
• and,
• wherein said semi-flexible support tab flexes responsive to said cart weight and the item weight, and said strain gauge sensor produces strain gauge weight data sufficient to indicate one of either the item weight and said cart weight and the item weight.