Patent Description:
A wide variety of businesses rely on utility carts to move items around inside their buildings. The carts hold and transport tools, equipment, component parts and completed products, many of which are heavy, bulky or awkward to carry, and often include associated paperwork that needs to be kept with an item as it moves from station to station or room to room. The carts come in a wide variety of shapes, sizes and styles. The corners of the carts typically include vertical risers and multiple horizontal trays. The carts are typically made of plastic or metal, and their front and rear corners are typically supported by caster wheels. Plastic carts often have trays and risers made of molded foam plastic. Metal carts frequently have metal tubes for risers and meshed wire baskets for trays. Some carts have metal tube risers and reinforced plastic trays. The utility carts are often rated for <NUM> to <NUM> lbs (<NUM> to <NUM>) load capacities. Examples of these utility carts are made by Rubbermaid Commercial Products, LLC of Winchester, VA and sold as Uline Model Nos. H-<NUM>, H-<NUM>, H-<NUM>, H-<NUM> and H-<NUM>, AMSA, Inc. of Boulder, CO and sold as Uline Model Nos. H2505 and H7435, and Suncast Technologies, LLC of Palm Beach Gardens, FL and sold as Model No. PUCPN1937. These and other utility carts are shown and described in <CIT> and <CIT>, <CIT> and <CIT>and <CIT>.

Autonomous mobile robots for manufacturing, warehouse and distribution applications are well known. Examples include <NUM> River Systems' CHUCK robot and <CIT> and <CIT>, Amazon Robotics' MARTI robot and <CIT>,<CIT>,<CIT>and<CIT>, Aethon's TUG robot and <CIT>, <CIT>,<CIT>, <CIT>, <CIT>and<CIT>, GreyOrange's BUTLER robot and <CIT> and <CIT>, Clearpath Robotic's manipulatable mobile robot and <CIT>, Fetch Robotic's mobile warehouse robot and <CIT>, In Via Robotics' autonomous warehouse robots and <CIT>, Locus Robotics' warehouse robot and <CIT>, Canvas Technology's robots, and MiR's mobile industrial robots.

<CIT> (<NUM>-<NUM>-<NUM>); <CIT> (<NUM>-<NUM>-<NUM>); <CIT> (<NUM>-<NUM>-<NUM>); <CIT>] disclose vehicles comprising weight measuring assemblies.

One problem with conventional autonomous mobile robots is their integral design. Many components form the autonomous navigation structures, such as environmental mapping and proximity sensors, a power supply, control and drive systems, warning systems and a wireless system. These components and their associated wiring are built into the overall robot design. Even when the robot takes the form of a cart, the components that form the autonomous navigation structures are built into the overall cart design. Determining the locations of the various sensors and their wiring so they can perform their intended function while keeping them safe from inadvertent damage and out of the way from interfering with the normal operation of the cart can be particularly challenging. Businesses must either buy manual carts or dramatically more expensive autonomous robotic carts. Due to their complexity, there is no presently known way to convert a manual cart into an autonomous cart. Existing navigation structures are not intended to convert an off-the-shelf, manually pushed cart into an autonomous mobile robotic cart.

Another problem with conventional autonomous vehicles is their dependency on wireless communication with an independent operating system. The robots do not operate independently. They require wireless communication with an off-board database or control system. The operator must interact with the operating system and database via a wireless communication system such as WiFi to control the movements of the robotic vehicle. The cost of installing a wireless communication system such as WiFi can be prohibitively expensive for many organizations. Moreover, even when a wireless communication system is installed, the system may include dead zones that can sever communication with an autonomous vehicle, or cause the vehicle to receive redundant signals when multiple communication cells or transceivers are transmitting a given signal. When the autonomous vehicle stops in a dead zone, the robot must be manual pushed out of the dead zone and reset to advise it of its current location.

A further problem with conventional robotic carts is they are not compatible with manual operation. First, many conventional robotic carts do not allow for manual movement. If a user attempts to push a robotic cart, the wheels drag or turn with a high amount of resistance. Second, robotic carts become disoriented when they are manually pushed to a different location than the location to which the cart last autonomously moved. They cannot determine their location when the robotic cart is turned off and manually moved. When power to the robot microprocessor and drive motor are turned off, the robot loses its ability to track its movements and determine its location. When the robotic vehicle is turned off, its motor encoder does not monitor drive shaft and wheel rotation. As a result, the robotic vehicle loses track of its location when it is turned off and manually pushed. When the robotic vehicle is turned back on, the new location coordinates for the robot must be entered or other means must be used to allow the robot to determine its current location.

A still further problem with conventional robotic vehicles is that unsafe loading conditions go undetected. There is no mechanism to determine the weight of the vehicle or the items placed on it. Similarly, there is no mechanism to determine if the load is unbalanced, which could cause the vehicle to tip over when making a turn. There is also no mechanism to determine if an object is extending outwardly from the vehicle to a point where that item could hit other objects when the vehicle is moving.

The present invention is intended to solve these and other problems.

<CIT> discloses a propulsion drive system operated by a controller to propel an industrial vehicle along a path in an unmanned mode. An autonomous processor module sends commands to the vehicle controller in response to messages received via a communication network from a guidance and navigation system. <CIT> describes a movement teaching device which teaches an appropriate movement route to an autonomous vehicle. <CIT> describes a laser automatically guided vehicle. <CIT> describes a self-propelled cleaning robot.

The invention provides a utility cart according to the claims.

In some embodiments, this invention pertains to a robotic cart platform with a navigation and movement system that integrates into a conventional utility cart to provide both manual and autonomous modes of operation. The platform includes a drive unit with drive wheels replacing the front wheels of the cart. The drive unit has motors, encoders, a processor and a microcontroller.

In some embodiments, the system has a work environment mapping sensor and a cabled array of proximity and weight sensors, lights, control panel, battery and on/off,"GO" and emergency stop buttons secured throughout the cart. The encoders obtain drive shaft rotation data that the microcontroller periodically sends to the processor. When in autonomous mode, the system provides navigation, movement and location tracking with or without wireless connection to a server. Stored destinations are set using its location tracking to autonomously navigate the cart. When in manual mode, battery power is off, and back-up power is supplied to the encoders and microcontroller, which continue to obtain shaft rotation data. When in autonomous mode, the shaft rotation data obtained during manual mode is used to determine the present cart location. An advantage of the present robotic cart platform of some embodiments is its ability to integrate into conventional, manually moved, utility cart designs. The components forming the robotic cart platform (RCP) include a drive unit, an autonomous mapping and navigation system, environmental mapping and obstacle avoidance sensor, input components and structures that are readily installed on a conventional cart. The drive unit is designed to fit under the cart, which is an area not utilized for payload transport. This area also offers a substantially unobstructed <NUM> degree view of the surrounding environment, which makes it desirable for mounting the LIDAR sensor. Proximity sensors are positioned near the comers of the cart to give them an optimal view of where the cart is moving. The front caster wheels are removed and replaced by the base unit and its drive wheels. A pre-fabricated array of electric cables that are harnessed together at one end near their terminal ports is plugged into the drive unit. The individual cables for the proximity sensors and input devices are routed through existing channels and openings in the conventional cart. Existing openings in the risers and trays are also used to mount proximity sensors and lights to convert the conventional utility cart into an autonomous robotic cart. Minimal modifications to the cart are required. Businesses that use conventional, off-the-shelf, manually pushed utility carts can inexpensively convert them into autonomous mobile robotic carts.

Another advantage of the present robotic cart platform of some embodiments is its independent operating system. The present cart platform design has an on-board operating system and database capable of operating independently, and does not require support from an off-board operating system or server. Workers interact directly with the robotic cart to control the movements of the cart. The cost of installing an off-board server and wireless support system is avoided, allowing the benefits of robotic carts to many companies that cannot practically install a WiFi system or otherwise cannot afford a more expensive robotic cart system. In addition, the independent operation of the autonomous cart avoids the problems associated with dead zones that occur in many robotic cart systems.

A further advantage of the present robotic cart platform of some embodiments is its compatibility with both autonomous and manual movement of the cart. First, a cart installed with the robotic platform can be manually pushed or pulled. When the drive motors are not powered, the motors allow substantially free rotation of their drive shafts, so the wheels do not drag or turn with a high amount of resistance. Workers can finely move the cart to a precise position, or move the cart when it does not have power. Second, carts installed with the robotic cart platform keep track of their location when manually pushed to a new location. Both the manual mode and the autonomous mode allow the robotic cart to independently determine its location. When power to the robot drive motors and main processor are turned off, a separate power source is activated to run its motor encoder and microcontroller, which continue to track wheel rotations to determine the location of the robotic cart. When the robotic vehicle is turned back on, the microcontroller transmits wheel and shaft rotation data to the main onboard processor to determine the current location of the robotic cart. The robotic vehicle does not lose track of its location when it is manually moved. A worker does not need to enter the new location of the cart, or otherwise require the cart to determine its new location, such as through the use of RFID tags or an off-board WiFi type operating system.

A still further advantage of the robotic cart platform of some embodiments is its harnessed array of cabled sensors, safety/status lights and input devices, such as the control panel, battery and on/off, "GO," and emergency stop buttons. While the drive unit is located under the cart, these components are not. Cabled sensors and lights that need to be substantially unobstructed or highly visible are located in optimal locations on the cart. Input devices that would be awkward to reach and use if placed under the cart, are located at appropriate and easily accessed locations on the cart. Components such as the battery that might need to be periodically recharged or replaced are located at more easily accessible locations. The RCP drive unit circuitry has multiple power supply input terminals, so battery packs can be hot swapped while the RCP processor continues to run. There is no need to power off the RCP processor to charge the batteries. Once the particular off-the-shelf cart is selected, the appropriate harnessed array of cabled sensors is selected so that the necessary number of individual cables and cable lengths is available to hook up the appropriate components for that make and model of utility cart. The cabled sensors and input devices conform to the unique configuration of a particular cart, instead of the cart conforming to the sensors and input devices. Cable lengths are easily changed for varying carts without changing the size, configuration, mounting structures and internal components of the RCP drive unit.

A still further advantage of the robotic cart platform of some embodiments is serviceability. The cables and each of these components are replaced or upgraded without needing to replace or modify the main robotic cart platform. Each cable has ports at both its ends. To remove and replace an external component, such as a sensor, light, control panel, battery, etc., the appropriate cable simply has to be disconnected from the port of that particular external component. To replace the harnessed cable array, the ports at both ends of the cables are disconnected.

As still further advantage of the robotic cart platform is its ease of integration into a conventional cart. The cables are routed through existing channels and openings in conventional carts. The sensors and safety lights are mounted in or via existing openings in the carts. Speakers and WiFi unit are mounted inside compartments in the trays.

A still further advantage of the robotic cart platform of some embodiments is the scanning area of its proximity sensors. Each corner riser of the autonomous cart has four proximity sensors. Two sensors point sideward, and two sensors point forward or rearward. Two sensors are located higher up on the cart frame, and two sensors are located lower on the frame. The higher sensors are angled downwardly and the lower sensors are angled upwardly, so that the scanning cones of paired sensors intersect at about half of the cart height. Should one of the paired sensor fail, the other paired sensor will still cover the area where their scanning cones intersect. The upward angling sensors detect instances where an item placed on a cart extends out from the edge of the cart a significant distance, and a worker is alerted as this can lead to a collision of that overhanging item or an unbalanced payload. The downward angled proximity sensors more reliably detect lower height obstacles and drop offs such as stairwells, which help prevent the cart from falling into a stairwell or out of a shipping dock.

A still further advantage of the robotic cart platform of some embodiments is the location and scanning area of its LIDAR sensor. The sensor is located at a protected location between the drive unit and the lower tray. The LIDAR sensor peers out from between the drive unit and lower tray to scan in almost a full <NUM> degrees. Only the tops of the drive wheels, drive unit mounting posts and the front caster wheel assemblies obstruct the full <NUM> degree of view.

A still further advantage of the RCP of some embodiments is its weight sensors. Two weight sensors are located just above the rear caster wheel assemblies, and two sensors are located just above the RCP mounting assembly. These sensors measure the weight of the cart (not including the caster wheels or RCP). The weight measurements are used multiple ways. The cart uses the measurements to determine if an object has been placed onto or taken off of the cart. The cart also uses the weight measurements when the cart is planning its movements (e.g. will need more power for heavier payloads). The cart can also determine if the payload is exceeding a threshold and causing a safety issue, or if the payload is balanced or unbalanced. The cart will then warn a worker and use the weight information to take appropriate action, such as turn at a slow rate or stop altogether. Weight measurements and safety determinations can be performed when the cart is stationary or when it is moving. If there is a change from balanced to unbalanced while moving, the cart can act upon that to prevent the loss of the payload or to inform the user of the imbalance. Lastly, the cart detects when a person presses on the cart (like pressing a button), which is recognized as user input, such as an indication that the cart is empty.

Other aspects and advantages of the invention will become apparent upon making reference to the specification, claims and drawings.

While this invention is susceptible of embodiments in many different forms, the drawings show and the specification describes in detail preferred embodiments of the invention. It should be understood that the drawings and specification are to be considered an exemplification of the principles of the invention. They are not intended to limit the broad aspects of the invention to the embodiments illustrated.

Conventional manually pushed utility carts are widely used to move tools, equipment, component parts, partially or fully assembled products and associated paperwork from one room or work station to another throughout a building. An example of a conventional utility cart <NUM> is shown in <FIG> and <FIG>. The conventional plastic cart <NUM> has a front end 2a, rear end 2b and sides 2c. The cart or vehicle <NUM> has a structure or frame <NUM> that includes a number of stacked trays <NUM> and vertical risers <NUM>. Each tray <NUM> has a generally flat and horizontal surface <NUM> upon which items are placed and an upwardly extending lip <NUM> around its perimeter to keep items from sliding or rolling off the tray. Each riser <NUM> has a generally linear shape with top 11a and bottom 11b ends. Two risers <NUM> are located at the front 2a of the cart <NUM>, and two risers <NUM> are located at the rear 2b. The vertical risers <NUM> join and space apart the horizontal trays <NUM>. The trays <NUM> are secured proximal the upper 11a and lower 11b ends of the risers <NUM>. A handle <NUM> is secured proximal the upper ends 11a of the rear risers <NUM>, and extends rearwardly from the rear risers to provide walking space behind the cart <NUM>. Workers grip and hold the handle <NUM> to push or pull the cart. The underside or bottom of the cart structure <NUM> or lower tray <NUM> includes caster wheel mounting structures <NUM> to firmly and securely mount a number of caster wheel assemblies <NUM>. One caster wheel mounting structure <NUM> is typically located proximal each lower corner of the cart structure <NUM> or lower tray <NUM>. The mounting structure <NUM> includes a number of vertical fastener openings 8a, which are relatively deep to ensure the caster wheels are securely attached to the cart frame or structure <NUM>.

Conventional utility carts <NUM> typically have four caster wheel assemblies <NUM>. Each caster wheel assembly <NUM> has a wheel <NUM> and a swiveling hub <NUM>. Each hub <NUM> supports an axel 15a that rotatably holds its wheel <NUM> to allow the wheel to rotate and roll along the floor of the building. Each hub <NUM> also has a caster mounting structure <NUM> that swivelingly secures the wheel <NUM> and hub <NUM> to the cart mounting structure <NUM>. The upper surface of the caster mounting structure <NUM> frequently has a central area 17c having a rounded crown <NUM> with a curved surface 18a as in <FIG> and <FIG>. The caster mounting structure <NUM> has fastener openings 17a formed around its perimeter portion 17b, and is secured to the cart mounting structure <NUM> by fasteners <NUM> so that each hub <NUM> is free to rotate or swivel about a hub mounting axis which allows the wheel to turn to the right or left through <NUM> degrees (<NUM>°) and allows the cart <NUM> to move in any direction. Each hub <NUM> is free to directionally swivel or rotate independently of the other caster wheel hubs to allow the cart <NUM> to be pushed or pulled in any direction through <NUM> degrees, so the cart can turn, move sideways or back up. Two caster wheel assemblies <NUM> are located proximal the corners of the front end 2a of the cart <NUM>, and two caster wheel assemblies <NUM> are located proximal the corners of the rear end 2b of the cart. While the cart <NUM> is shown to have a certain shape and height, with two trays <NUM>, four risers <NUM> and four caster wheel assemblies <NUM>, it should be readily understood that the cart can have a variety of shapes and heights, one or more trays, and three or more caster wheel assemblies.

A plastic embodiment <NUM> of the conventional utility cart <NUM> is shown in <FIG>, <FIG> and <FIG>-<NUM>. Although the size and shape of the plastic utility cart <NUM> can vary, the cart <NUM> shown has a length of about <NUM> inches (<NUM> meter), width of about <NUM> inches (<NUM>), height of about <NUM> inches (<NUM>) and weight of about <NUM> pounds (<NUM>) , and four caster wheel assemblies <NUM> with five inch (<NUM>) diameter wheels. The cart <NUM> has two robustly designed plastic trays <NUM> and <NUM>. The stacked trays <NUM> and <NUM> have a rectangular shape and a depth of about <NUM>-<NUM>/<NUM> inches (<NUM>). Each tray <NUM> and <NUM> has structural webbing <NUM> supporting its upper surface <NUM>. The webbing <NUM> forms compartments or openings <NUM> under the surface <NUM> of the tray. The solid upper wall or surface <NUM> of each tray uniformly spans the length and width of the rectangular tray <NUM> and <NUM>. The cart <NUM> has four robustly designed plastic risers <NUM>. Each riser <NUM> has an L-shaped cross-sectional shape with perpendicular sides 25a and 25b that form an inner channel <NUM> along its vertical length. Each riser <NUM> has a forwardly or rearwardly facing side 25a and a sidewardly facing side 25b. Openings <NUM> are formed at spaced locations along the vertical height of both sides 25a and 25b of each riser <NUM>. Each riser <NUM> has three forwardly or rearwardly facing openings <NUM>, and three sidewardly facing openings <NUM>. The upper tray <NUM> includes an integrally formed rearwardly cantilevered tray <NUM>. The handle <NUM> extends upwardly from the rear end 2b of the cantilevered tray <NUM>. Each of the caster wheel mounting structure takes the form of a plate or bracket <NUM> that is secured by four fasteners <NUM>, such as screw-type fasteners. The fasteners <NUM> extend through bracket holes 17a and into the four aligned holes 8a of the mounting structure <NUM> to firmly secure a caster wheel assembly <NUM> to the cart structure <NUM> or lower tray <NUM>.

A metal embodiment <NUM> of the conventional cart <NUM> with its two front caster wheel assemblies <NUM> removed is shown in <FIG>. This cart <NUM> has three robustly designed lower <NUM>, upper <NUM> and middle <NUM> wire mesh trays or baskets. The stacked trays <NUM>-<NUM> have a rectangular shape. The corners of the trays <NUM>-<NUM> are joined together by four metal, vertical, tubular risers <NUM>. Each tubular riser <NUM> has an open interior <NUM> and an open bottom end <NUM>. The mounting structure of each caster wheel assembly <NUM> takes the form of a mounting bracket or plate <NUM> with an upwardly extending mounting post <NUM>. Each mounting post <NUM> is secured to the cart mounting structure <NUM>, which takes the form of the open bottom end <NUM> of the tubular risers <NUM> that receives the post <NUM> in an in-line manner.

The present invention pertains to a robotic cart platform system integrated into a conventional cart <NUM>, <NUM>, <NUM> to form an autonomous robotic cart or vehicle generally indicated by reference numbers <NUM> and <NUM> as shown in <FIG>. The components forming the robotic cart platform <NUM> and its navigation and movement system <NUM> are shown in <FIG>5B. The integration of these components into a conventional plastic <NUM> or metal <NUM> cart to form an autonomous cart <NUM> with the navigation and movement system <NUM> is shown in <FIG>. The robotic cart platform <NUM> has a drive unit <NUM> that propels itself and the autonomous cart <NUM> in a forward <NUM> or rearward <NUM> direction of travel, and can readily turn by moving in arcuate directions <NUM> of travel as shown in <FIG>, <FIG> and <FIG>.

The robotic cart platform or RCP <NUM> has a motor driven autonomous drive unit <NUM> shown in <FIG>. The RCP <NUM> and its navigation and movement system <NUM> use the wheeled drive unit <NUM> to autonomously propel the cart <NUM>, <NUM>. The drive or base unit <NUM> is compact and has a low profile to fit under the cart structure <NUM> or lower tray <NUM>, <NUM>. The drive unit <NUM> has a weight of about <NUM> kilograms, width of about <NUM> centimeters, height of about <NUM> centimeters, length of about <NUM> centimeters and a top speed of about <NUM> meters per second. The drive unit <NUM> has a generally rectangular block shaped housing <NUM> with a front, rear, top, bottom and right and left sides <NUM>-<NUM>. The front <NUM> of the drive unit is located even with or proximal the front 2a of the cart structure <NUM> or lower tray <NUM>, <NUM>. The front <NUM> and rear <NUM> sides are generally parallel, as are the top <NUM> and bottom <NUM> sides, and the right <NUM> and left <NUM> sides, respectively.

The housing <NUM> is robustly designed to maintain its shape during use, and is formed by upper <NUM> and lower <NUM> metal portions best shown in <FIG>. The load-bearing upper portion <NUM> is made of <NUM>/<NUM> inch (<NUM>) plate steel, and has side flaps 58a that form the right and left housing side surfaces <NUM> and <NUM>. The lower portion <NUM> is made of <NUM> gauge sheet metal, and has flaps 59a that form the front and rear housing surfaces <NUM> and <NUM>. The thick metal construction of the housing <NUM> acts as a heat sink to dissipated heat from internal electrical components. The top surface <NUM> of the upper portion <NUM> has a central LIDAR scanner opening. The side flaps 58a have wheel holes 58b aligned to form a linear wheel axis parallel to the front and rear housing surfaces <NUM> and <NUM>. The rear flap 59a includes a series of punch-outs or openings 59b for the input/output terminals or connections of various external input and communication devices, such as sensors, lights, power supply, control panel and optional WiFi unit.

An adjustable mounting assembly <NUM> secures the autonomous drive unit <NUM> to the conventional utility cart <NUM>, <NUM> as shown in <FIG>. To adjust for the height of the RCP <NUM> and its mounting assembly <NUM>, spacers <NUM> are inserted above each of the rear caster wheel assemblies <NUM>. The adjustable mounting assembly <NUM> includes a mounting bracket or bar <NUM> rigidly secured to the top <NUM> of the housing <NUM> along the front end <NUM> or edge of the housing <NUM>. The bracket <NUM> has a cross-sectional shape forming a generally upside-down T-shaped opening along its length. The bracket <NUM> and T-shaped opening form an adjustable mounting track <NUM> along the length of the bracket. The adjustable assembly <NUM> and bracket <NUM> accommodate both a cart <NUM> with a caster wheel mounting structure <NUM> formed with fasteners holes 8a, and a cart <NUM> with a caster wheel mounting structure formed by a mounting bracket <NUM> with a mounting post <NUM> that is received by the open bottom ends <NUM> of the tubular cart risers <NUM>. For a cart <NUM> with a caster wheel mounting structure that takes the form of mounting brackets <NUM> and fasteners <NUM> (<FIG> , <FIG> and <FIG>), headed fasteners <NUM> are slidingly received by the track <NUM> and matingly held by the bracket <NUM>. The wider head of each headed fastener <NUM> is received inside the broader portion of the T-shaped track opening with the narrower elongated shaft of the fastener <NUM> extending upwardly through and out of the narrower portion of the T-shaped track <NUM>. A spacer <NUM> is placed over each of the two fasteners <NUM> to adjust the height of the drive unit <NUM> and mounting assembly <NUM>. A mounting plate <NUM> with fastener openings 66a formed around its perimeter portion 66b is secured to the upper protruding end of the fastener <NUM>. The mounting plate <NUM> has a threaded hole <NUM> for receiving the threaded shaft of the fastener <NUM> to securely fix and set the height of the mounting plate <NUM>. When assembled, the top or tip 64a of the threaded fastener <NUM> protrudes through hole <NUM> a predetermined amount to form a raised abutment above the upper surface of the mounting plate <NUM>. As discussed below, the focusing area <NUM> of the sensor plate <NUM> rests on the tip 64a of the fastener <NUM> as shown in <FIG> and <FIG>, which forms a gap <NUM> as in <FIG> between the mounting and sensor plates <NUM> and <NUM>. For a cart <NUM>, <NUM> with a caster wheel mounting structure that takes the form of a mounting bracket <NUM> with mounting post <NUM>, headed mounting posts <NUM> are used as shown in <FIG>. The height of the drive unit <NUM> and mounting assembly <NUM> generally equals the height of the rear caster wheel assemblies <NUM> and spacers <NUM> so that the cart <NUM>, <NUM>, <NUM> and their trays <NUM>, <NUM>- <NUM>, <NUM>-<NUM> are level.

The cart has four weight sensor assemblies <NUM>. Two weight sensor assemblies <NUM> are located directly above the mounting plates <NUM> of the mounting assembly <NUM> as shown in <FIG>, and two weight sensor assemblies are located directly above the mounting structure or bracket <NUM> of the rear caster wheel assemblies <NUM> as shown in <FIG>, <FIG>. Each sensor assembly <NUM> includes a sensing plate <NUM> and a spacer plate <NUM>. The sensor plate <NUM> has a perimeter portion <NUM> with fastener openings 72a. The plate <NUM> has a generally U-shaped slot or opening <NUM> is cut out of the plate around and proximal its center to form an inwardly extending weight supporting tab <NUM>. The support tab <NUM> extends from one side of the perimeter portion <NUM> toward and into the center of the plate <NUM>. The support tab <NUM> has an upper surface <NUM>, a semi-flexible neck <NUM> and a weight supporting central area <NUM>. When needed, the central area <NUM> has a downwardly facing crown, dimple or depression <NUM> with a curved surface 79a as in <FIG>. The neck <NUM> is semi-flexible in that it elastically bends a slight amount (less than about an eighth of an inch (<NUM>) depending on the weight or force applied, but continues to support the weight of the cart <NUM> and items or payload placed on the cart. A weight sensor <NUM> such as a piezoelectric sensor is secured to the upper surface <NUM> of the semi-flexible neck <NUM>. The threaded fasteners <NUM> are non weight-bearing and move down to form a gap between the fastener heads 19b and the mounting plates <NUM> when an item is placed on the cart. When the weight sensor assemblies <NUM> are used without the RCP <NUM>, a visual display <NUM> (<FIG>) having a programmed processor 90a and memory 90b is secured to the cart <NUM>. The processor 90a is in electrical communication with the visual display <NUM>, and each sensor <NUM> sends weight data to the processor via wires 90c. When used with the RCP <NUM>, each sensor <NUM> is in electrical communication with the RCP circuitry via wires <NUM>.

The spacer plate <NUM> is located above the weight sensing plate <NUM>. The spacer plate <NUM> has a perimeter portion <NUM> with fastener openings 86a, and a hollowed out center opening <NUM>. The central opening <NUM> accommodates the upward flexing of the support tab <NUM>, and provides a pathway for routing the sensor wires <NUM>. The central weight focusing area <NUM> of the sensing plate <NUM> rides on top of and is in weight supporting engagement with mounting plate <NUM> (<FIG>) or fastener tip 64a of mounting plate <NUM>. In some situations, such as for the two rear weight sensor assemblies <NUM>, the upwardly extending central crown <NUM> of the caster wheel mounting plate <NUM> supportingly engages the bottom surface of the central focusing area <NUM> as shown in <FIG>. In other situations, such as for the drive unit mounting assembly <NUM>, the downwardly facing crown, dimple or depression <NUM> (<FIG>) of the focusing area <NUM> rides on and engages the upper surface of the mounting bracket <NUM> or <NUM>. (<FIG> and <FIG>). The sensing and spacer plates <NUM> and <NUM> above the rear caster wheel assemblies <NUM> are located between the caster mounting bracket <NUM> and lower surface of the cart mounting structure <NUM>. The sensing and spacer plates <NUM> and <NUM> above the drive unit mounting assembly <NUM> are located between the upper surface of each mounting plate <NUM> or <NUM> and the lower surface of the cart mounting structure <NUM>.

The weight of the cart <NUM>, <NUM> is supported by the central focusing areas <NUM> of the support tabs <NUM> of the four sensor plates <NUM>. The sensor <NUM> is firmly secured to the semi-flexible portion or neck <NUM> of the sensor plate <NUM>. The deformation of the support tab <NUM> by the weight of the cart <NUM>, <NUM>, <NUM> and its load causes a change in resistance in the sensors <NUM>. The sensor <NUM> changes resistance when force is applied to the focal area <NUM> or dimple point <NUM> of plate <NUM>. This change in resistance data or weight level data is sent to the visual display processor 90a or RCP processor <NUM> and automatically used by the processor to determine a digital weight measurement of the amount of weight carried by each sensing plate <NUM>. The weight measurement data is then used by the higher-level functions of the visual display or RCP processor. For example, to compare the weight measurement data with a weight threshold value stored in the memory 90b, <NUM> to determine if the payload is beyond a threshold or maximum supportable weight, or to determine if the load is balanced or unbalanced. For a balanced load, each sensor plate <NUM> carries a quarter of the load weight. For unbalanced loads, one or two sensors carry significantly more of the load weight than the other sensor plates. The processor then sends a digital warning message to the visual display <NUM> or control panel <NUM> (discussed below) to display a warning message via an icon on a key (such as "load capacity exceeded," "unbalanced load" and lighting the key "red"). Although the weight sensor <NUM> is shown and described as being a strain gauge sensor, such as a piezoelectric sensor, it should be understood that other embodiments such as a force resistor may also be used.

The drive unit <NUM> has two drive motors <NUM> and <NUM> and two drive wheels <NUM> and <NUM> as shown in <FIG>, <FIG> and <FIG>. Each wheel <NUM>, <NUM> has a hub <NUM> that securely receives the drive shaft or wheel axel <NUM> of its associated motor <NUM> or <NUM>. The motor <NUM> on the right side <NUM> of the base unit <NUM> drives the right wheel <NUM>, and the motor <NUM> of the left side <NUM> of the base unit drives the left wheel <NUM>. Each motor <NUM> and <NUM> independently drives or turns its associate drive shaft <NUM> and wheel <NUM> or <NUM>. Each motor <NUM> and <NUM> can turn its drive shaft <NUM> and wheel <NUM> or <NUM> either in a clockwise direction or a counterclockwise direction. The independent operation of the drive motors <NUM> and <NUM> allows the RCP drive unit <NUM> to rotate in place, and allows the autonomous cart <NUM>, <NUM> to make turns with a minimal distance of travel.

The right and left motors <NUM> and <NUM> are mounted to the inside surface of the right and left sides <NUM> and <NUM> of the housing <NUM>, respectively. The motors <NUM> and <NUM> are securely mounted by screw fasteners, so that their drive shaft or wheel axel <NUM> extends through the housing wheel openings 58b in side flaps 58a. The wheel axels <NUM> are colinear, and the drive wheels <NUM> and <NUM> are parallel to the sides 2c of the cart <NUM>. The wheels <NUM> and <NUM> do not swivel to the right or left as do the rear caster wheels <NUM>. Turns are taken by differing the rate of rotation or direction of rotation of the right and left drive wheels <NUM> and <NUM>. The wheels <NUM> and <NUM> have a diameter of about six inches (<NUM>) and are sized and positioned outside of housing <NUM> with their outer perimeters riding along the ground. There is preferably about <NUM> inch (<NUM>) of clearance between the bottom <NUM> of the housing <NUM> and level ground so that the RCP <NUM> can traverse deviation in the ground surface. The drive wheels <NUM> and <NUM> are also sized in combination with the height of the base unit <NUM> and its mounting assembly <NUM> to ensure the cart <NUM>, <NUM> is level.

When the RCP <NUM> is turned on or activated, the cart <NUM>, <NUM> is in its autonomous mode. Electric power is supplied to the motors <NUM> and <NUM>, which turn their respective wheels <NUM> and <NUM> to propel the cart from one location to another along straight <NUM>, <NUM> or curved <NUM> paths of travel. When the RCP <NUM> is turned off or deactivated, the cart <NUM>, <NUM> is in a manual mode, and power to the motors <NUM> and <NUM> is cut off. The deactivated motors <NUM> and <NUM> do not inhibit the free rotation of the drive wheels <NUM> and <NUM> so that workers can readily push or pull the cart <NUM>, <NUM> from one location to another. The drive motors <NUM> and <NUM> are preferably brushless direct current (BLDC) motors with both clockwise and counterclockwise rotation connected to a planetary reduction gearbox. Each high torque electric motor <NUM>, <NUM> has a length of about <NUM> inches (<NUM>), diameter of about <NUM> inches(<NUM>), rated voltage of about <NUM> volts, no-load speed of about <NUM> rotations per minute, rated torque of about <NUM> kilograms-centimeters, a reduction ratio of about <NUM>/<NUM> and output shaft diameter of about <NUM>/<NUM> inch (<NUM>). The output shaft <NUM> extends from the motor housing about <NUM> inch (<NUM>), and the end of the shaft is notched to facilitate the rotationally locked securement of its associated wheel <NUM> or <NUM>.

The motors <NUM> and <NUM> are interfaced to an associated dual motor controller <NUM>. The rotational speed and direction (clockwise or counterclockwise) of each output shaft <NUM> is controlled by the controller <NUM>, which is in electrical communication with motor <NUM> or <NUM> and controls the electric power supplied to each motor. The controlled power supply to each motor <NUM> or <NUM> via the motor controller <NUM> controls the speed of drive shaft <NUM> of each motor, and thus the rotational speed of the drive wheels <NUM> and <NUM>. The controller <NUM> is preferably a brushless direct current (BLDC) motor controller with a <NUM> to <NUM> volt input, <NUM> watt brushless DC motor speed regulator control module, a <NUM> volt, <NUM> volt, <NUM> volt and <NUM> volt high power BLDC speed motor controller driver board with heat sinks and <NUM> to <NUM> volt PWM duty ratio control with an FG pulse signal and <NUM> pulse/round.

Each motor <NUM> and <NUM> is interfaced to an associated "always-on" encoder <NUM> and <NUM>. Each encoder <NUM> and <NUM> has a rotary disk and output cable. Each rotary disk is mounted to its respective motor <NUM> or <NUM> to optically view the rotational movements of its associated motor drive shaft <NUM>, and thus the rotational movements of its associated wheel <NUM> or <NUM>. The rotary disk transmits this shaft rotational movement data or information via its output cable to the microcontroller <NUM> and its memory <NUM>, which is then periodically transmitted to the RCP processer <NUM> and its memory <NUM>. This shaft rotation or wheel movement data is used by the RCP processor <NUM> to determine the distance of travel and path of travel taken by the RCP <NUM> and autonomous cart <NUM> from its start location or start location coordinates, and to determine the coordinates or coordinated data associated with the current physical location <NUM> of the RCP <NUM> and cart <NUM>. The high impact resistance encoders <NUM> and <NUM> preferably have a power supply of about <NUM> volts DC, resolution of about <NUM> pulses per rotation, speed of about <NUM> rotations per minute, optical disk with a thickness of about <NUM> inches (<NUM>), diameter of about one inch (<NUM>) and hole diameter of about <NUM> inches (<NUM>), AB <NUM> phase output, and line driver with ABZA-B-Z channels.

The RCP navigation and movement system <NUM> and drive unit <NUM> have circuit boards including a single board computer <NUM>, power board <NUM> and digital board <NUM> as shown in <FIG> and <FIG>. The single board computer <NUM> includes the main processor or CPU <NUM> with associated long-term hard drive memory <NUM>. The digital board <NUM> includes a microcontroller <NUM> with associated short-term dynamic rapid access memory or (DRAM) <NUM>. Circuitry <NUM> interconnects the boards <NUM>-<NUM>, processor <NUM>, microcontroller <NUM> and their associated memories <NUM> and <NUM>, motor controller <NUM>, drive units <NUM>, <NUM> and encoders <NUM>, <NUM>, as well as components external to the housing <NUM>, such as weight sensors <NUM>, power supply, LIDAR scanner <NUM>, proximity sensors <NUM>, safety lights <NUM>, control panel <NUM>, etc., as discussed below. Components mounted inside the drive unit housing <NUM>, such as motors <NUM> and <NUM>, motor controller <NUM> and encoders <NUM> and <NUM>, are wired for power and communication with the processor <NUM> and microcontroller <NUM> directly to connections in the drive unit circuitry <NUM>. Devices mounted on the cart structure <NUM> external to the drive unit <NUM> are electrically connected for power and communication to the drive unit circuitry <NUM> and circuit boards <NUM>, <NUM> and <NUM> via a number of input/output terminals or ports <NUM>, including two battery ports <NUM> and <NUM>, LED lights port <NUM>, control panel port <NUM>, two proximity sensor line ports <NUM> and <NUM>, weight sensor port <NUM>, WiFi port <NUM> and an audio port. The LIDAR scanner mounted atop the drive unit <NUM> is wired directly to LIDAR connections in the circuitry <NUM> or to a LIDAR port <NUM>. The control panel port <NUM> is equipped to power and communicate with switches, such as an On/Off switch, and "GO" and emergency stop buttons, discussed below.

Data processing by the navigation and movement system <NUM> is handled by the programmed RCP processor <NUM> and microcontroller <NUM>. The microcontroller <NUM> runs low level firmware that provides very fast, real time processing. The RCP processor <NUM> provides higher level functionality such as planning a route <NUM> and motor movement instructions for the RCP <NUM> and communicating with workers via the safety lights, control panel, audio speakers and WiFi unit, as discussed below. RCP mapping data obtained by the LIDAR sensor <NUM> flows from the microcontroller <NUM> to the main RCP processor <NUM>. The microcontroller <NUM> saves mapping data in its short-term memory or DRAM <NUM>, and then periodically conveys that data to the RCP processor <NUM> for storage in its long-term hard drive memory <NUM>. Both the processor <NUM> and microcontroller <NUM> do some processing of data. For example, the microcontroller <NUM> use the proximity sensors <NUM> to scan or detect an obstacle that is present for several seconds then goes away (someone walking by). As the microcontroller <NUM> passes this data to the RCP processor <NUM>, the RCP processor filters out the temporary or passing obstacle data from long term storage <NUM> since the obstacle was more momentary and not long term like a wall, pillar or the edge of a loading dock. The RCP processor <NUM> has both associated dynamic memory, such as DRAM that is deleted from storage when power is removed, and long term hard drive memory <NUM> that remains stored even when power is removed.

The RCP <NUM> includes a portable power supply or battery pack <NUM> mounted to the autonomous cart <NUM>. The battery <NUM> has power and communication ports <NUM> and <NUM>, and supplies electric power to all the internal and external components and devices of the RCP <NUM> via its drive unit circuitry <NUM> and terminals <NUM>. The battery pack <NUM> is secured to the cart <NUM> at a location that avoids interfering with loading and unloading the cart or impairs other activities of the workers using the cart, and allows easy access for swapping out a first battery pack with a second replacement battery pack when the first battery pack needs recharging. The power source <NUM> is designed to provide sufficient power to the RCP <NUM> for a four hour work shift and propel the cart for <NUM> to <NUM>,<NUM> meters carrying a <NUM> to <NUM> kilogram payload at a walking speed of about one meter per second. The main power source <NUM> is preferably a multi-cell battery pack with multiple lithium ion batteries (about <NUM> cells) to produce about <NUM> Wh, with each cell having a rechargeable capacity of about <NUM> volt/ <NUM> mAh, a <NUM> volt output port and an RS-<NUM> (two wire) communication port. The battery pack <NUM> is secured to the cart <NUM>, <NUM> via a mounting bracket assembly <NUM> that includes a support bracket <NUM> with a slide bar <NUM>. The slide bar <NUM> allows the battery pack <NUM> to be quickly removed for recharging and allows a fully charged battery pack to be quickly secured.

The RCP circuitry <NUM> includes a backup power circuit <NUM> on the digital board <NUM> as shown in <FIG>. When the RCP <NUM> is turned on, power from the battery <NUM> is supplied to the encoders <NUM> and <NUM> via a normal encoder power line <NUM>, and is supplied to the microcontroller or MCU <NUM> and its memory or DRAM <NUM> via a normal microcontroller power line <NUM>. When battery <NUM> power is turned off or otherwise disrupted, the backup circuit <NUM> supplies electric backup power to the encoders <NUM> and <NUM>, MCU <NUM> and DRAM <NUM>. The backup power circuit <NUM> has a backup power source <NUM>, such as a super capacitor. Electric power from the super capacitor <NUM> is supplied to the encoders <NUM> and <NUM> via an encoder backup line <NUM>, and is supplied to the microcontroller <NUM> via an microcontroller backup line <NUM>. The backup power lines <NUM> and <NUM> are electrically connected to the super capacitor and the normal power lines <NUM> and <NUM>, respectively. Diodes <NUM> and <NUM> in the normal power lines <NUM> and <NUM> prevent power from the super capacitor <NUM> from flowing to the battery <NUM>. Then, when the battery <NUM> power to the RCP <NUM> is turned back on, power from the battery <NUM> flows through the diodes <NUM> and <NUM> and backup lines <NUM> and <NUM> to recharge the super capacitor <NUM>. The super capacitor <NUM> holds sufficient power to operate the encoders <NUM> and <NUM>, MCU <NUM> and DRAM <NUM> for about one week. The super capacitor <NUM> is preferably an SCCY83B507SLBLE by AVX corporation.

The autonomous cart <NUM> includes a time-of-flight laser scanner <NUM> as shown in <FIG>, <FIG>and <FIG>As discussed below, the laser scanner <NUM> creates constantly updated mapping data or a high-resolution image map <NUM>' (<FIG>) of the surrounding work environment <NUM> (<FIG>) for navigation and avoidance of fixed structures (such as walls, posts, support columns and staircases) and more permanent obstacles (such as furniture, workbenches and shelving units). Although the scanner <NUM> also detects temporary obstacles (such as workers walking by or packages temporarily placed on the floor), the processor <NUM> deletes these temporary obstacles from its environmental mapping data stored in its long-term memory <NUM>.

The laser scanner <NUM> is preferably a triangulation type laser scanner such as a LIDAR (light detection and ranging) sensor with 2D imaging, three hundred and sixty degree (<NUM>°) omnidirectional laser range, scanning range of about <NUM> meters, power input of about <NUM> volts, sample rate of about <NUM>,<NUM>, configurable scan rate from about <NUM> to <NUM> hertz, breakout of about <NUM> and is plug-and-play, such as an RPLIDAR A2 by Slamtec. The RCP <NUM> uses the LIDAR scanner <NUM> to obtain environmental mapping data that is stored in its memory <NUM>. The RCP <NUM> uses this mapping data to identify open areas <NUM> in the building through which the RCP <NUM> and cart <NUM> can travel, and to identify fixed structures <NUM> in the building through which it cannot travel. The RCP <NUM> uses the mapping data and current location <NUM> data to determine a route <NUM> along which the cart <NUM> can travel to a selected destination <NUM> as discussed below. (<FIG> and <FIG>). The RCP <NUM> also uses the LIDAR scanner <NUM> to detect obstacles as it is en route to a destination.

The LIDAR scanner <NUM> is preferably mounted on the RCP drive unit <NUM> below the cart structure <NUM> and lower tray <NUM>, <NUM>. The scanner <NUM> is secured to the autonomous cart <NUM> at a location providing a substantially unobstructed <NUM>° view of the environment <NUM> around the cart, is protected from inadvertent contact by workers and objects, and does not interfere with the operation of the cart or workers. A particularly good location for the <NUM>° scanner <NUM> is in the middle of the top surface <NUM> of the drive unit housing <NUM>, although other locations on the RCP drive unit <NUM> or cart <NUM> are possible. The rotating scanner (not shown) of the LIDAR scanner <NUM> is located above the drive unit mounting bracket <NUM>, so the bracket does not obstruct the view of the scanner. Only the drive unit mounts <NUM> and a small portion of the rear caster wheel assemblies <NUM> obstruct the <NUM>° scanning area or plane <NUM> of the LIDAR scanner <NUM> as shown in <FIG>. In this mounting location, the LIDAR scanner <NUM> views a working range of greater than about <NUM>° of the surrounding environment. The forward viewing area <NUM> in front of the cart <NUM> is virtually unobstructed through about <NUM>° and is completely open and unobstructed through about <NUM>°. The rearward viewing area <NUM> to the rear of the cart <NUM> is virtually unobstructed through about <NUM>° and is completely open and unobstructed through about <NUM>°. As the LIDAR scanner <NUM> is mounted directly to the drive unit housing <NUM> via a mounting bracket <NUM>, its electrical power and communication wires <NUM> pass through an opening in the top <NUM> of the housing <NUM> (<FIG>), and are directly connected to designated LIDAR connections in drive unit circuitry <NUM> as discussed above.

Proximity sensors <NUM> are mounted on the autonomous cart <NUM> shown in <FIG>, <FIG>and <FIG>. These sensors <NUM> allow the autonomous cart <NUM> to detect, and when necessary navigate around, fixed and temporary obstacles. The proximity sensors <NUM> are a type of time-of-flight distance sensor or ranging system integrated into a compact module. The sensors <NUM> are preferably a laser ranging system with a maximum sensing range of about four meters, working voltage of about <NUM> volts to <NUM> volts, supply current of about <NUM> milliamps, eye-safe <NUM> invisible emitter, programmable region of interest (ROI), field or view (FoV) or scanning cone of <NUM> degrees, configurable detection interrupts and dimensions of about <NUM> x <NUM> x <NUM> inches (<NUM>). As shown in <FIG>, each sensor <NUM> is pointed in a particular aimed direction <NUM> and has a <NUM>° sensing cone <NUM> extending from the sensor for a range of about four meters. Each sensor <NUM> independently detects the presence of objects within its range and scanning cone <NUM>. Each sensor <NUM> has a terminal for receiving electric power and sending or receiving communication signals from the microprocessor <NUM> or drive unit circuitry <NUM>, and is secured inside the riser opening <NUM> by a mounting clip.

Multiple proximity sensors <NUM> are mounted to the autonomous cart <NUM> as shown in <FIG>. Together these sensors <NUM> provide a substantially unobstructed view of the environment around the cart, particularly in the forward <NUM> and rearward <NUM> directions of travel, as well as outward from the sides 2c of the cart <NUM>. The RCP <NUM> uses the proximity sensors <NUM> to detect obstacles when it is en route to a destination, and the microcontroller <NUM> can determine which of the sensors <NUM> was triggered by an obstacle. The sensors <NUM> are placed at locations that protect them from inadvertent contact by workers and objects and do not interfere with the operation of the cart or workers. For the plastic autonomous cart <NUM>, <NUM> the proximity sensors <NUM> are mounted inside the riser channel <NUM>, with each sensor peering from or out of riser openings <NUM>. Four proximity sensors <NUM> are mounted in each L-shaped riser <NUM>. One sensor <NUM> is mounted to peer from the top opening on each side 25a and 25b of each of the four risers <NUM>, and one sensor <NUM> is mounted to peer from the bottom opening on each side of the risers, as best shown in <FIG>. Each riser <NUM> has two proximity sensors <NUM> pointing sideward 2c, and two proximity sensors pointing forward 2a or rearward 2b. The top sensors <NUM> are aimed <NUM> downward at an angle of about thirty degrees (<NUM>°), and the bottom sensors are aimed upward at an angle of about thirty degrees (<NUM>°), so that their scanning cones <NUM> start to overlap <NUM> about half way up the height of the cart <NUM>.

For the metal autonomous cart <NUM>, <NUM> (<FIG>), the proximity sensors <NUM> are mounted to the outside of the lip <NUM> of the upper tray <NUM>. Two proximity sensors <NUM> are mounted along each side of the tray <NUM>. Two sensors are directed outwardly or forwardly from the front side 2a of the cart <NUM>. Two sensors are directed rearwardly from the rear side 2b of the cart <NUM>, and two sensor are directed sidewardly from each side 2c of the cart. No matter which direction the autonomous cart <NUM>, <NUM>, <NUM> is traveling, forward <NUM>, rearward <NUM> or turning to the right or left <NUM>, the cart has two proximity sensor <NUM> facing in that general direction.

Warning or safety lights <NUM> are mounted to and around the autonomous cart <NUM>. For the plastic autonomous cart <NUM>, <NUM> the lights <NUM> are mounted inside the riser channel <NUM>, with each light peering from or out of a riser opening <NUM>. Two safety lights <NUM> are mounted in each L-shaped riser <NUM>. One light <NUM> is mounted to peer from the middle opening <NUM> on each side 25a and 25b of each of the four risers <NUM>. Each riser <NUM> has one light <NUM> facing sideward 2c, and one light facing forward 2a or rearward 2b. The lights <NUM> are preferably LED lights that consume a minimal amount of electric power. The LED lights <NUM> slowly blink on and off when the cart is moving, and change color (orange) and do not blink when and obstruction is detected. Diferent colors can flag different situations such as purple - proximity sensor not working, white - cart is moving in that direction (headlights), red - cart is moving away (taillights) and green - all actions completed and cart is ready for another command. Each light <NUM> has a connection terminal for receiving electric power, and is secured inside the riser openings <NUM> by a mounting clip <NUM>.

A control panel <NUM> or suitable device to allow a worker to communicate with the navigation and movement system <NUM> is mounted on the autonomous cart <NUM> as shown in <FIG>, <FIG>, <FIG>. The panel <NUM> is mounted at a location that provides easy access by a worker, such as on or near the cart handle <NUM>. The communication device <NUM> is preferably a <NUM>-key input device with customizable LCD keys <NUM> and a microprocessor with nonpermanent rapid access memory, and is capable of displaying custom icons and animated gifs, such as the Eltato Stream Deck Mini pad by Corsair. Each key <NUM> has a surface that is touched or pressed to operate the key, although other activation mechanisms to physically operate the key are possible. Each key also has a tap-to-switch scene to launch various custom programmed capabilities.

The communication device or control panel <NUM> is preferably secured to the to the rear side 2b of the utility tray <NUM> by a mounting bracket and fasteners. The panel <NUM> has a connection that receives a USB cable to provide electric power from the battery as well as send and receive signals, or otherwise communicate with the navigation and movement systems <NUM>, processor <NUM> and memory <NUM>. The RCP memory <NUM> is loaded with sets of icons <NUM> and <NUM> to selectively display on the six control keys <NUM>. One set of icons <NUM> or <NUM> is displayed at a time on the keys. By pressing, touching or otherwise physically engaging or activating a designated key, such as the bottom right key displaying battery charge level information and a "battery charge level" icon), the control pad <NUM> switches between displaying the first <NUM> and second <NUM> set of icon images. One set of icon images <NUM> or <NUM> is displayed at a time. When a key <NUM> is pressed displaying a particular icon image, the control panel <NUM> sends a recognized instruction signal or command associated with that icon image to the RCP processor <NUM>, which then uses the navigation and control system <NUM> to perform the particular navigation and movement operations necessary to complete that command.

The <NUM>-key control panel <NUM> allows the navigation and movement system <NUM> to perform a wide range of functions. When the RCP <NUM> is turned on, the RCP processor <NUM> displays the set of destination icons <NUM> on the keys <NUM> as shown in <FIG>. The workers use this set of destination icons <NUM> (e.g. icon "<NUM>," "<NUM>," "<NUM>," etc.) to enter multiple distinct desired destination locations <NUM> into the RCP memory <NUM>. Once the cart <NUM> is positioned at a desired destination <NUM> as in <FIG>, the worker presses and holds one of the keys <NUM> displaying a destination icon <NUM> (e.g., icon "<NUM>") for more than a predetermined threshold period of time, such as more than three seconds. The RCP processor <NUM> then uses RCP movement data such as drive shaft rotation data obtained from encoders <NUM> and <NUM> to determine the current physical location <NUM> and associated coordinates or coordinate data of the cart <NUM>, and saves the coordinate data for this location in the RCP memory <NUM> as the desired or selected destination <NUM> associated with that particular key <NUM> and its associated icon image <NUM> ("<NUM>" icon). The background color of the destination key <NUM> will change from an unset color (gray) to a set color (green). This provides a visual indication to the workers that the desired destination <NUM> has been successfully set and stored in the RCP memory <NUM>. Now, when the key <NUM> with this destination icon ("<NUM>" icon) is subsequently pressed for less the threshold period of time (less than three seconds), the cart <NUM> will go to that previously set and stored destination location <NUM>. Each key <NUM> with a particular destination icon ("<NUM>-<NUM>") is used to set and then later select a particular desired destination <NUM> associated with that icon.

The autonomous cart or vehicle <NUM> is programmable to stop when it gets to a desired destination <NUM> and wait for a worker to enter further control panel instructions, or move in a looped manner from one predetermined destination location <NUM> to another. For the later, once the cart <NUM> reaches a first desired destination <NUM> ("<NUM>" icon) and waits a predetermined period of time, the cart <NUM> goes to the next numerical predetermined destination <NUM> ("<NUM>" icon). Workers can change the order of the loop by resetting the particular destination <NUM> associated with each destination icon. Workers can delete a predetermined destination <NUM>, and if desired replace it with another destination location <NUM> as noted above.

The set of arrow or movement icons <NUM> (<FIG>) allows workers to use the RCP drive motors <NUM> and <NUM> to move the cart or vehicle <NUM> in a self propelled manner as they walk behind the cart. When a key <NUM> with an arrow icon <NUM> (e.g., "↑" icon) is pressed, the cart <NUM> moves under its own power in the direction of the arrow until the worker stops pressing the key with that arrow icon. Destinations can be set by manually pushing the cart <NUM> or by using the keys <NUM> with the arrow icons to move the cart to a desired destination. Given backup circuit <NUM> and "always on encoders" <NUM> and <NUM>, the cart <NUM> can be turned off and manually pushed to a location to be set as a destination. The RCP <NUM> uses its encoders <NUM> and <NUM> and drive shaft rotation data to determine the current, real-time location <NUM> of the cart <NUM> when a key <NUM> displaying a destination icon <NUM> (e.g., "<NUM>" icon) is pressed. To set a desired destination <NUM>, the autonomous cart <NUM> and communication device <NUM> needs to be powered on. The <NUM>-key control pad <NUM> does not function when the cart <NUM> is not powered on.

A large visible on/off switch <NUM> is provided on or near the control panel <NUM>. This switch or depressible button <NUM> is used to turn on or activate the RCP drive unit <NUM> by allowing electric power from the battery <NUM> to energize the internal and external RCP drive unit <NUM> components and devices that form the RCP <NUM>, and place the RCP <NUM>, navigation and movement system <NUM> and cart <NUM> in an autonomous mode of operation. The switch <NUM> is also used to turn off or deactivate the RCP <NUM> by disconnecting the flow of electric power from the battery <NUM> to the RCP, and place it and cart <NUM> in a manual mode of operation. The switch <NUM> is mounted through a hole drilled into the cart <NUM> and secured by a nut on the back side. Two wires <NUM> on the back of the button <NUM> provide its electrical connection with the system circuitry <NUM>. An emergency stop button <NUM> is located at the front 2a of the cart <NUM>. This button <NUM> can also be used by a worker to turn off or deactivate the RCP <NUM>, and place it and the cart <NUM> in a manual mode of operation. The button <NUM> has a rear connection <NUM> for receiving a USB cable to send and receive communication signals.

The control panel <NUM> has a "GO" button <NUM>. For the plastic cart <NUM>, <NUM> (<FIG>), the <NUM>-key control panel <NUM> is programmed to have one of its keys serve as the GO button. For the metal cart <NUM>, <NUM> (<FIG>), the GO button <NUM> is located on the control panel <NUM>. The "GO" button is a momentary switch that is pressed to signal to the RCP processor <NUM> that it should instruct the RCP drive unit <NUM> to move. When the "GO" button <NUM> is pressed, the cart <NUM> will autonomously move to the next predetermined destination <NUM> selected by the worker or on the organized list of destinations <NUM> stored in the RCP memory <NUM>, as discussed below. The cart <NUM> autonomously moves to the list of predetermined destinations in a loop, and then repeats that movement cycle. When the "GO" button <NUM> is pressed, the RCP <NUM> uses its navigation and movement system <NUM> to plan a route <NUM> to the selected destination or next destination on its list of destinations, and then moves along that route to the designation. When more than one destination is entered, set or otherwise downloaded into the RCP memory <NUM>, the RCP <NUM> will move from destination to destination in a round loop each time the "GO" button is pressed. The RCP drive unit <NUM> and cart <NUM> stop once the RCP drive unit reaches the next destination. The control panel <NUM>, switch <NUM>, and emergency stop and GO buttons <NUM> and <NUM> are used by workers standing next to the cart <NUM>, but can be remotely controlled by an optional server and wireless communication system as discussed below.

The RCP <NUM> is equipped with an audio speaker <NUM> for communicating with workers. For a plastic cart <NUM>, <NUM>, the speaker <NUM> is secured in a webbing compartment <NUM> on the underside of the upper tray <NUM> as shown in <FIG>. A speaker mount <NUM> is provided to secure the speaker in place. The speaker <NUM> is electrically connected by a USB cable for power and communication to the RCP <NUM> and its processor <NUM> via the circuitry <NUM> and an input/output terminal of the RCP drive unit <NUM>. The processor <NUM> is programmed to send one of several audio messages stored in its memory <NUM> to the speaker <NUM> for a variety of reasons. For example, these reasons include when the proximity sensors <NUM> detect a moving object (such as a person) in the vicinity, the weight sensors <NUM> detect a load in excess of the capacity of the cart <NUM>, the weight sensors <NUM> detect an unbalanced load, the battery pack <NUM> is running low or needs recharging or a worker enters invalid destination coordinates into the key pad <NUM>. The audible message can be a simple beeping, buzzing or siren sound, or a verbal message (such as "warning load capacity exceeded," "warning unbalanced load," "battery low," "recharge battery" or "invalid destination coordinates"). The message is repeated until a corrective action is detected by the processor <NUM>, the identified moving object (person) moves away or a worker acknowledges the receipt of the message via the key pad <NUM>. The audio speaker <NUM> has a rear connection terminal for receiving electric power and sending and receiving communication signals.

The RCP <NUM>, navigation and movement system <NUM> and autonomous cart <NUM> are optionally equipped with a WiFi unit <NUM>. The WiFi unit <NUM> is mounted inside a webbing compartment <NUM> on the upper tray <NUM> as shown in <FIG>, and is in electrically connected via a USB cable for power and communication to the RCP <NUM> and its processor <NUM> via the circuitry <NUM> and input/output terminal <NUM> of the RCP drive unit <NUM>. The WiFi unit <NUM> preferably has input power of <NUM> volts, an operating wavelength of about <NUM> to <NUM> gigahertz, and a transmission range of about <NUM> meters, such as an B07J65G9DD by Techkey.

A cable array <NUM> shown in <FIG> connects the exterior components of the RCP <NUM> and navigation and movement system <NUM> to the input/output terminals <NUM> of the RCP drive unit <NUM> circuitry <NUM>. The cabled components include the weight sensors <NUM>, battery <NUM>, proximity sensors <NUM>, safety lights <NUM>, control panel <NUM>, On/Off switch <NUM>, emergency stop <NUM> button, "GO" button <NUM>, audio speakers <NUM> and Wi Fi unit <NUM>. As noted above, the LIDAR sensor <NUM> mounted atop the drive unit <NUM> can be directly wired to the drive unit circuitry <NUM> as in <FIG> or cabled through an input terminal <NUM> as in <FIG>. The cabled array <NUM> includes two lines <NUM> and <NUM> routed through the cart <NUM> as shown in <FIG>, <FIG> and <FIG> to connect the external components with their associated input/output terminals <NUM>-<NUM>. One line <NUM> is routed along the rights side of the cart <NUM>, and one line <NUM> is routed along the left side of the cart.

The right <NUM> and left <NUM> lines each include multiple and separate wire lines <NUM> for powering and communicating with two weight sensors <NUM>, eight proximity sensors <NUM> and four safety lights <NUM>. The right line <NUM> also includes separate wiring lines <NUM> for powering and communicating with the control panel <NUM>, On/Off switch <NUM>, emergency stop <NUM> button, "GO" button <NUM>, audio speakers <NUM> and WiFi unit <NUM>. The individual wires <NUM> at one end of each power and communication wiring line <NUM> for a specific external component are connected to a component-specific connection <NUM> that electrically connect its wires <NUM> to the terminal for that external component. The individual wires <NUM> at the other end of each wiring line <NUM> are connected to an input/output connector <NUM> that plugs into and electrically connects the wiring line with its appropriate input/output port <NUM>-<NUM> of the drive unit <NUM>. The wiring lines <NUM> for the proximity sensors <NUM> in one line <NUM> or <NUM> share a common input/output connector <NUM>. The individual wires <NUM> in the two lines <NUM> and <NUM> of the cabled array <NUM> are harnessed <NUM> together near the input/output ports <NUM>-<NUM> and joined to their appropriate terminal <NUM>. The appropriate terminals <NUM> are then plugged into their appropriate input/output port <NUM>-<NUM>. It should be understood that the lines of the cabled array <NUM> can be divided into four line <NUM>-<NUM> as shown in <FIG>, with one line being routed through the internal channel <NUM> of each of the four risers <NUM>.

When the RCP <NUM> is turned on via switch <NUM>, electric power from the battery <NUM> is supplied to the RCP <NUM> and navigation and movement system <NUM>, which includes circuit boards and internal components <NUM>, <NUM>, <NUM>-<NUM>, <NUM>-<NUM> and <NUM> as well as external components <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> via cabled array <NUM>. When the RCP <NUM> is turned off, electric power from the battery <NUM> to the RCP <NUM> and its navigation and movement system <NUM> are turned off, except for the encoders <NUM> and <NUM>, MCU <NUM> and DRAM <NUM> which remain powered by the backup circuit <NUM> as discussed above. When the RCP processor <NUM> detects that the power or charge remaining in the battery <NUM> is running low or meets a predetermined charge threshold value, the processor plans a route to a recharging station <NUM> (<FIG>) and navigates the cart <NUM> to the recharging station. A worker then connects the battery <NUM> to a power outlet at recharging station <NUM> to recharge the battery, or swaps out the battery with an already charged battery at the work station.

Modifications are made to the conventional carts <NUM>, <NUM> to integrate the RCP <NUM> and form the autonomous cart <NUM>. The front caster wheel assemblies <NUM> are removed and replaced with the RCP drive unit <NUM>. For the conventional plastic cart <NUM>, four riser channel cover plates <NUM> are secured inside each riser <NUM> to enclose the inner channel <NUM> and house and protect the proximity sensors <NUM>, lights <NUM> and cable lines <NUM> and <NUM> inside these channels. A tray cover plate <NUM> is secured to the bottom of the upper tray <NUM> to house and protect the audio speaker <NUM>, WiFi device <NUM> inside the webbing chambers <NUM> of the upper tray, as well as the cable lines <NUM> and <NUM> extending through the walls forming it matrix of webbing chambers. Cabling holes <NUM> are formed in the corners of the flat tray surface <NUM> of the lower tray <NUM>. A first line of web holes <NUM> is formed in the structural webbing <NUM> of the lower tray <NUM> to route the cables <NUM> and <NUM> in a supported manner from the rear of the RCP drive unit <NUM> to the front of the lower tray, as best shown in <FIG> and <FIG>.

The right and left lines <NUM> and <NUM> diverge and passes through a second line of web holes <NUM> along the front 2a of the lower tray <NUM> to the front corners of the tray. The lines <NUM> and <NUM> pass through their respective holes <NUM> in the lower tray <NUM> and extend up their respective riser channel <NUM>. Third and fourth lines of web holes <NUM> are formed along the sides 2c of the in the upper tray <NUM> to allow the right and left lines <NUM> ands <NUM> to extend in a supported manner along the right and left tray sides to the rear 2b of the tray just above the rear riser channels <NUM>. The lines <NUM> and <NUM> extend downward through these channels and pass through the tray holes to reach the two weight sensors <NUM> at the rear of the cart. Web holes <NUM> are also formed along the front of the of the upper tray <NUM> to allow one cable <NUM> to reach the emergency stop button <NUM> mounted in an emergency stop button opening <NUM> formed in the center of the front of the upper tray. Web holes <NUM> are also formed along the rear of the upper tray <NUM> to allow a cable line <NUM> to reach the battery <NUM>, control panel <NUM>, On/Off switch <NUM> and "Go" button <NUM>, mounted in a GO button opening <NUM> formed in the center of the utility tray <NUM>. For the conventional metal cart <NUM> with wire baskets <NUM>-<NUM>, riser holes <NUM> are formed proximal the top and bottom ends of the tubular risers <NUM> to allow cable wiring to extend from the lower tray to the upper tray in a protected manner.

The RCP <NUM> uses its WiFi unit <NUM> to communicate with a separate work station <NUM> shown in <FIG>. The conventional work station <NUM> has a computer processor <NUM>, keyboard input device <NUM> and monitor <NUM>. The work station processor <NUM> acts as a server or SRCP for the cart <NUM>. The RCP <NUM> transmits a variety of data or information to the workstation SRCP <NUM>. For example, environment map data, current or real-time RCP/cart location data and selected desired destination data in the RCP memory <NUM> is transmitted via the WiFi device <NUM> to the SRCP <NUM>. The SRCP <NUM> processes this data for visual display on its monitor <NUM> as shown in <FIG>. The monitor <NUM> visually displays a screen showing an environment map <NUM>' derived from the environmental map data in the RCP <NUM>. The map <NUM>' shows open areas <NUM>' of the building through which the cart <NUM> can travel, fixed structures <NUM>' in the building, a real-time RCP location marker (triangle) <NUM> identifying the current physical location <NUM> of the RCP <NUM> and listed destination markers (arrows) <NUM> presently stored in the RCP memory <NUM>.

The computer screen of the monitor <NUM> also shows a list of the coordinates <NUM> for each listed destination. The screen provides touch screen buttons <NUM> and <NUM> to add destinations to or delete destinations from the RCP memory <NUM>. New destination coordinates are entered via the keyboard <NUM>. The SRCP <NUM> and its touch screen buttons are operable to remotely select a specific destination for the cart <NUM> to travel next. Then a visually displayed "GO" button <NUM> on the screen of the SRCP monitor <NUM> is pressed to remotely control the RCP <NUM> and send the cart <NUM> to that selected destination. The SRCP monitor <NUM> screen also visually displays a touchable joystick <NUM> to remotely control the operation of the RCP <NUM> and movement of the cart <NUM>.

When multiple autonomous carts <NUM> are used, the SRCP <NUM> communicates with each of them. Mapping data from various carts <NUM> is combined to form a global map <NUM>' of the working environment <NUM> in the SRCP memories <NUM>, which is displayed on the SRCP monitor <NUM> along with the current locations <NUM> of each cart. Data containing the master or global map of the SRCP <NUM> is transmitted to the memory <NUM> of each RCP cart <NUM>, so that each cart learns from the other carts.

An alternate embodiment of the mounting assembly <NUM> is shown in <FIG>. In this embodiment, the mounting assembly <NUM> takes the form of two mounting blocks <NUM> and <NUM> secured to the top <NUM> of the drive unit housing <NUM>. Each block <NUM> and <NUM> has a base portion <NUM> and two spaced columns <NUM>. The right block <NUM> is located near the front <NUM> right <NUM> corner of the drive unit <NUM>. The left block <NUM> is located near the front <NUM> left <NUM> corner of the drive unit <NUM>. The bottom surface of each block <NUM> and <NUM> is flush with the top <NUM> of the drive unit <NUM>. Each block <NUM> and <NUM> is secured to the drive unit <NUM> by two threaded forward fasteners 365a. These forward fasteners 365a pass through an opening in the top <NUM> of the housing <NUM> as well as holes in the base portions <NUM> and front columns <NUM> of the blocks <NUM> and <NUM>, and are received by and secured to threaded holes 367a in its mounting plate <NUM>. The columns <NUM> open up as much space as possible for the LIDAR scanner so as not to obstruct the LIDAR scanning plane. The rear spacers <NUM> can also take the form of blocks <NUM> and <NUM> with columns <NUM>. As the rear spacers are a further distance from the LIDAR scanner <NUM>, the effect on the scanning plane is less significant.

Each block <NUM> and <NUM> also has two rearward fasteners 365b to help secure the mounting plate <NUM> to its mounting block <NUM> or <NUM>. The heads of these rearward fasteners 365b are received in recesses <NUM> in the bottom surface of the blocks <NUM> and <NUM>. These rearward fasteners 365b also pass through holes in the base portions <NUM> and rear columns <NUM> of the blocks <NUM> and <NUM>, and are received by and secured to threaded holes 367b in its mounting plate <NUM> to help secure the mounting plates to the drive unit <NUM>. As with mounting assembly <NUM>, threaded fasteners <NUM> are used to secure the mounting plates <NUM> to the support structure <NUM>, 8a of the cart <NUM>. These fasteners <NUM> pass through holes or fastener openings 366a around the perimeter portion 366b of the mounting plates <NUM>, which are aligned with the fastener holes 8a of the cart mounting structure <NUM>. Again, as with mounting assembly <NUM> shown in <FIG>, weight sensor assemblies <NUM> are held between the mounting plates <NUM> and the cart mounting structure <NUM>. Each of the inverted crowns <NUM> of the four sensor plates <NUM> ride on the central area 366c of their associate mounting plate <NUM> with a gap <NUM> between the perimeter portions <NUM> and 366b of the plates <NUM> and <NUM>. The weight of the cart <NUM> above the mounting brackets <NUM> is supported by the four crowns <NUM> riding on the centers 366c of the mounting plates <NUM>. The threaded fasteners <NUM> are non weight load-bearing so that the necks <NUM> of the sensor plates <NUM> flex when an item or load is placed on the cart <NUM>, with the fasteners <NUM> moving down to form gaps between the fastener heads 19b and the mounting plates <NUM>. The base portions <NUM> have a V-shaped groove <NUM> to secure the right and left cable lines <NUM> and <NUM> and keep them from obstructing the view of the LIDAR scanner <NUM>.

Claim 1:
A utility cart (<NUM>) to carry at least one item having an item weight, said utility cart (<NUM>) comprising:
a cart structure (<NUM>) adapted to carry the item, said cart structure (<NUM>) having a cart structure weight and a cart mounting structure (<NUM>), and a weight sensor assembly (<NUM>), characterized in that said cart mounting structure (<NUM>) has a plurality of spaced apart cart fastener openings (8a) extending into said cart mounting structure; and in that the utility cart further comprises
a caster wheel assembly (<NUM>) having a wheel mounting bracket (<NUM>) with a bracket perimeter portion (17b) and an integrally formed bracket central area (17c), said bracket perimeter portion (17b) having a plurality of bracket fastener openings (17a) in mated alignment with said cart fastener openings (8a);
the weight sensor assembly (<NUM>) being located between said wheel mounting bracket (<NUM>) and said cart mounting structure (<NUM>), said weight sensor assembly (<NUM>) including a sensor plate (<NUM>) with a sensor plate perimeter portion (<NUM>) and an integral inwardly extending semi-flexible cantilevered support tab (<NUM>), said support tab (<NUM>) having a tab neck (<NUM>), central focal area (<NUM>), tab surface (<NUM>) and a strain gauge sensor (<NUM>), said strain gauge sensor (<NUM>) being secured to said tab surface (<NUM>), said tab neck (<NUM>) and focal area (<NUM>) being surrounded by a flex accommodating opening (<NUM>), and said focal area (<NUM>) being aligned directly over and in load supporting engagement with said central area (17c) of said wheel mounting bracket (<NUM>);
a weight bearing crown (<NUM>) formed on one of either said central area (17c) of said wheel mounting bracket (<NUM>) and said central focal area (<NUM>) of said support tab (<NUM>);
a plurality of fasteners (<NUM>) passing through said bracket fastener openings (17a) and into said cart fastener openings (8a) to firmly secure said caster wheel mounting bracket (<NUM>) to said cart mounting structure (<NUM>); said fasteners (<NUM>) leaving a non-load bearing gap (<NUM>) between said bracket perimeter portion (17b) and said sensor plate perimeter portion (<NUM>); and,
wherein said semi-flexible support tab (<NUM>) flexes responsive to said cart weight and the item weight, and said strain gauge sensor (<NUM>) produces strain gauge weight data sufficient to indicate one of either the item weight and said cart weight and the item weight.