Patent Publication Number: US-2022227283-A1

Title: Load stabilizer for stabilizing loads transported by a ground vehicle

Description:
BACKGROUND 
     In industry, ground vehicles are generally used to move heavy or large loads within facilities. One traditional example is a forklift, which includes multiple “forks” that can be inserted into a pallet to raise and lower loads resting on the pallet. By raising the load off the floor, the forklift can then move the load from one location to the next. Most ground vehicles, like the forklift, include a cab or other control area that supports a human driver or human operator who controls the ground vehicle and movement of the load. 
     Some ground vehicles include a counterweight. The counterweight&#39;s role is to lower the center of mass of the vehicle and counteract the change in weight distribution as the ground vehicle raises or lowers the load. For example, in a forklift, the counterweight is located opposite the forks that raise and lower the load, and generally located low to the ground to lower the ground vehicle&#39;s center of mass. 
     Recently, industries have started using autonomous ground vehicles that do not have a human driver or operator. Many of these autonomous systems use traditional designs, such as a fork lifting system or scissor lifting system, for lifting and moving loads. 
     Both manned and autonomous ground systems are not only concerned with the systems&#39; center of mass, but they are also concerned about load stability when the system is in motion. Many traditional designs do not include additional measures to enhance load stability, as their main use is to move symmetrical, heavy loads that have less risk of becoming unstable and tipping to the side. Other lift systems are restricted to lifting loads with a maximum height. Further, other systems are designed to have a wide turn radius to lower the horizontal forces applied on the load when engaged in a turning motion. 
     SUMMARY 
     At a high level, aspects described herein include a load stabilizer and a ground vehicle using the load stabilizer. The load stabilizer provides additional stability to a load being transported by the ground vehicle, while at the same time, being lightweight so that it minimally affects the center of mass of the ground vehicle. 
     One example includes a load stabilizer having a securing arm that is configured at one end to movably mate with the ground vehicle. At the other end, the securing arm is coupled to a support frame that supports a pad coupled to the support frame. The securing arm is formed of a strong material that resists bending or becoming damage from the force applied by the mass of the support frame and pad. The support frame is a lightweight material that can support releasable coupling of the pad, making it removable. The pad includes a foam that is equal to or less than about two inches thick. 
     The ground vehicle includes a motor, such as a stepper motor, servomotor, or the like with a motor control brake. The motor and break may provide servo functionality for the load stabilizer. The motor is configured to move the load stabilizer. The motor can move the load stabilizer by actuating a shuttle, such as a lift mechanism, where the load stabilizer is secured to the shuttle at the securing arm. Some motors include a brake, such as a controller for a stepper motor or a solenoid switch for a servomotor, and the brake includes an associated torque threshold. The brake stops the motor when it experiences a torque equal to or greater than the torque threshold. One specific example type of stepper motor suitable for use is an integrated closed-loop stepper motor that is a single unit comprising motor, drive electronics and position sensor. The electronic control board is attached to the motor, and it includes control electronics, power stage, and magnetic encoder. Other types of stepper motors may be suitable for use in addition to or in lieu of this example. 
     In operation, the ground vehicle receives a load for transport. The ground vehicle actuates the motor to move the load stabilizer toward the load. As the pad of the load stabilizer contacts the load and exerts a force on the load, the motor experiences a torque force. When the torque force experienced by the motor meets or exceeds the torque threshold, the brake stops the motor. This provides a consistent way to determine a stopping position of the load stabilizer in a manner where the load stabilizer does not damage the load. Further, the motor provides the force applied by the pad to the load, as opposed to the weight of the load stabilizer, thus allowing a lightweight load stabilizer, which reduces the effect on the center of mass of the ground vehicle. 
     This summary is intended to introduce a selection of concepts in a simplified form that is further described in the Detailed Description section of this disclosure. The Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Additional objects, advantages, and novel features of the technology will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the disclosure or learned through practice of the technology. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present technology is described in detail below with reference to the attached figures, wherein: 
         FIG. 1  illustrates a side perspective view of an example ground vehicle having a load stabilizer, in accordance with an aspect described herein; 
         FIG. 2  illustrates an exploded view of an example load stabilizer that can be employed by the ground vehicle of  FIG. 1 , in accordance with an aspect described herein; 
         FIG. 3  illustrates an upward view of an example pad and load, in accordance with an aspect described herein; 
         FIG. 4  illustrates a side view of an example ground vehicle employing a motor for positioning a support arm of a load stabilizer, in accordance with an aspect described herein; 
         FIG. 5  illustrates an example method of operating a ground vehicle having a load stabilizer, in accordance with an aspect described herein; 
         FIG. 6  illustrates an example method of assembling a load stabilizer, in accordance with an aspect described herein; and 
         FIG. 7  illustrates an example method of manufacturing a load stabilizer, in accordance with an aspect described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Aspects of the disclosure relate to a load stabilizer that is configured for use with a ground vehicle to assist in stabilizing loads transported by the ground vehicle. Such ground vehicles can be manned or unmanned systems, and they are generally used in industry to transport heavy or large objects. 
     One example aspect generally provides for a lightweight load stabilizer that is positioned above a load-receiving area of the ground vehicle where a load is placed during transit. The load stabilizer is lightweight relative to the ground vehicle system as a whole. 
     The load stabilizer can be raised and lowered relative to the load-receiving area of the ground vehicle. When a load is placed on the load-receiving area for transport, the load stabilizer is lowered, contacts the load, and applies a force to the load. Thus, when the ground vehicle is in motion, the load is less likely to tip. This allows the ground vehicle to move at higher speeds and allows for a sharper turn radius, since tipping of the load is less likely. 
     As noted, some conventional ground vehicle systems have encountered problems when the center of mass of the vehicle changes. For instance, as part of a ground vehicle having mass is moved upward, the overall center of mass of the ground vehicle raises. 
     To overcome this conventional problem, the disclosed load stabilizer is lightweight relative to the ground vehicle as a whole. By making the load stabilizer relatively lightweight, the raising and lowering of the load stabilizer has little effect on the ground vehicle&#39;s center of mass. In turn, this makes for a safer ground vehicle. 
     Other conventional problems with ground vehicles when transporting loads occur when the center of mass moves horizontally based on whether the ground vehicle is carrying a load. For example, this occurs with a conventional forklift. As the forklift picks up a load on the front end, the center of mass moves toward the load, making the forklift more likely to tip toward the load. As a result, forklifts, and other similar ground vehicle systems apply counterweights on the opposite end. This, however, makes such systems extremely heavy, thus limiting where the system can be employed and how the system is transported and maintained. 
     One design of the load stabilizer that will be further described provides for a load stabilizer that is directly positioned above the load-receiving area of the ground vehicle. This design allows for little to no horizontal deviation in the center of mass of the ground vehicle when the load stabilizer is raised and lowered, helping to prevent tipping, and reducing or eliminating the need for counterweights. 
     Accordingly, one example includes a load stabilizer comprising a securing arm, a support frame, and a pad. The securing arm is configured to secure to a ground vehicle that employs the load stabilizer. The securing arm includes a securing arm shaft that has a first securing arm shaft end extending to a second securing arm shaft end. The securing arm is coupled to the support frame at the first securing arm shaft end, and the second securing arm shaft end is configured to engage a shuttle, such as a lift mechanism shuttle, of the ground vehicle that is movable by the motor. 
     The securing arm is coupled to the support frame at a first support frame side using, for example, a securing arm bracket that is transversely coupled to the securing arm at the first securing arm shaft end. The pad is then coupled to the support frame at a second support frame side that is opposite the first support frame side. The ground vehicle utilizes the load stabilizer by moving the load stabilizer to a position where the pad is in contact with the load and applying force to the load. 
     For added strength, the securing arm can comprise a relatively strong material. For instance, the securing arm can comprise metals such as iron, tungsten, titanium, nickel, and chromium. 
     The support frame to which the securing arm is coupled generally provides support for the pad. The support frame can comprise lightweight materials, such as metals of aluminum, magnesium, titanium, or beryllium. 
     The support frame includes an outer edge, and the securing arm is coupled to the support frame at a location within the outer edge. The securing arm can be coupled to the support frame so that a portion of the securing arm extends beyond the outer edge to easily engage the shuttle of the ground vehicle. To further reduce weight, the support frame can have an opening enclosed by the outer edge of the support frame. 
     The pad is coupled to the support frame on the second support frame side. When coupled, the pad can extend to or beyond the outer edge of the support frame. In some cases, the pad is removably coupled to the support frame so that the pad can be easily and quickly changed if there is any damage or wear. Hook-and-loop fasteners can be applied to the support frame and the pad as one example to removably secure the pad. 
     Generally, the pad can be made of any material having some flexibility. Foam padding is one example suitable for use. One specific example of foam that has beneficial durability includes a closed-cell foam material, such as a closed-cell polyurethane or polyethylene. In one example, the pad has a thickness equal to or less than two inches. 
     The load stabilizer can be used with the ground vehicle by mating the securing arm with the shuttle of the ground vehicle. In one configuration, when the securing arm is mated to the shuttle, the load stabilizer is positioned so that the pad is directly above the load-receiving area of the ground vehicle. 
     To utilize the load stabilizer, the ground vehicle actuates a motor that is configured to move the shuttle from a first position to a second position. In doing so, the lift mechanism shuttle moves the securing arm of the load stabilizer from a first securing arm position toward a second securing arm position. The second securing arm position places the pad in contact with the top of the load at the load-receiving area on the ground vehicle. The second position of the shuttle is determined, and may also be maintained, by the torque limit associated with the brake of the motor. An upper or lower limit for the shuttle can be determined by a limit switch, which may fix these limits at particular positions such that the shuttle is not moved by the motor beyond the upper or lower limit. 
     In operation, the ground vehicle receives a load onto the load-receiving area. On the load-receiving area, the load is disposed between the load-receiving area and the load stabilizer. The ground vehicle actuates the motor to begin moving the load stabilizer closer to the load. As the pad contacts the load and force is applied, the motor experiences an increasing torque. When the torque reaches the torque threshold value of the brake, the brake stops the motor. In this way, the load stabilizer is configured to apply a consistent pressure to the load. 
     This method of utilizing the load stabilizer to apply pressure to the load is beneficial because it provides consistent pressure across loads of different sizes. Further, different loads have different crush values, the point at which the load is damaged by the force. The accuracy and precision of this method helps to ensure that loads having different crush values are not damaged by the load stabilizer. 
     Further, although the load stabilizer can be used with manned or unmanned ground vehicle systems, the use of the motor with the brake activated based on torque is particularly beneficial for autonomous ground vehicles. This is because it provides a method for stopping the load stabilizer at the correct position without the use of a human input, thus ensuring that a consistent and correct pressure is applied to the load without damaging it. 
     The preceding example is just one example that can be practiced using the technology that is described with reference to the figures. 
     With reference now to  FIG. 1 ,  FIG. 1  illustrates an example ground vehicle  100  in which the disclosed technology may be employed. Ground vehicle  100  is illustrated as an autonomous ground vehicle. However, as noted, any of the aspects described herein may also be employed in a manned ground vehicle unless explicitly recited otherwise. 
     Ground vehicle  100  is illustrated as having vehicle base  102 , load-receiving area  104 , track  106 , lift mechanism shuttle  108 , and load stabilizer  110 . It will be recognized that this illustration is a simple example provided to assist in describing the technology. Additional components, fewer components, and different arrangements, including any of those that will be discussed, may be alternatively employed. Since various ground vehicles for transporting loads are known in the art, only a few specific arrangements are illustrated and described in this disclosure; however, it is intended and will be understood that the load stabilizer can be employed on any number of ground vehicle systems, both manned and autonomous. 
     As for the illustrated example in  FIG. 1 , ground vehicle  100  includes vehicle base  102 . Vehicle base  102  generally moves ground vehicle  100  from one location to another and positions ground vehicle for receiving and off-loading loads. 
     In an aspect, vehicle base  102  includes an autonomous guidance system that determines and controls the position of ground vehicle  100 . Autonomous navigation systems are known in the art. Such systems may employ any number of sensors hosted by ground vehicle  100 , including lasers, optical visions sensors, sonar, and so forth, to move and position ground vehicle  100  into a particular location or orientation, and to perform obstacle avoidance maneuvers. It will be appreciated that the autonomous navigation system and sensors are not restricted to vehicle base  102 , and they may be located on other areas of ground vehicle  100  or remote from ground vehicle  100 , communicating with ground vehicle  100  through wireless or direct communication channels. 
     Vehicle base  102  is illustrated as including wheels  103 A and  103 B that position and move ground vehicle  100 . While illustrated as having wheels  103 A and  103 B, vehicle base  102  can have any motion system, including a track system, an air system, rollers, and the like. In this example, the wheels of the motion system for vehicle base  102  are vertically aligned with center of mass  112  for ground vehicle  100 , as illustrated via theoretical vertical line  114  extending through vehicle base  102  and center of mass  112 . 
     Ground vehicle  100  is further illustrated as having load-receiving area  104 . Generally, load-receiving area  104  is a location where a load can be placed for transport by ground vehicle  100 . 
     As shown, load-receiving area  104  includes rollers to aid in receiving and off-loading loads. Other positioning systems can be employed in addition to or in lieu of the rollers, including conveyors, air systems, mechanical pushers, and the like. The positioning system can also assist in positioning the load onto load-receiving area  104 , such that the load is positioned in vertical alignment with center of mass  112 . In another aspect, load-receiving area  104  does not include a positioning system, and instead, includes a flat area where the load is placed. 
     Load-receiving area  104  can be vertically aligned with center of mass  112 , as illustrated using theoretical vertical line  114  in  FIG. 1 . Here, load-receiving area  104  is positioned directly above vehicle base  102 . 
     Ground vehicle  100  further includes track  106  and shuttle  108 . Ground vehicle  100  utilizes track  106  and shuttle  108  to position load stabilizer  110 . In the illustrated aspect, track  106  and shuttle  108  are used to vertically position load stabilizer  110 . In one case, shuttle  108  may be included as part of a lift mechanism system, and be referred to as a lift mechanism shuttle. The lift mechanism shuttle moves load stabilizer  110  along a vertical axis. In one instance, track  106  and shuttle  108  are used to transition load stabilizer  110  vertically relative to vehicle base  102  from a first position having a first distance from load stabilizer  110  to load-receiving area  104  that is greater than a second distance of a second position from load stabilizer  110  to load-receiving area  104 . The vertical direction of movement is illustrated using arrow  116 . Shuttle  108  may be part of an overall system and may include one or more shuttle components. While illustrated as a part of ground vehicle  100  or a part separate from ground vehicle  100 , other aspects include shuttle  108  as part of load stabilizer  110 , which may be a separate component or integrally formed as part of other components of load stabilizer  110 . In an aspect, shuttle  108  is part of another movement mechanism for moving load stabilizer  110  and is used with other movement mechanism components that do not include track  106 . 
     In general, load stabilizer  110  is operated by ground vehicle  100  to apply pressure to a load placed on load-receiving area  104  in order to provide additional stability to the load during transport. 
     As illustrated, load stabilizer  110  mates with shuttle  108  of ground vehicle  100 . Load stabilizer  110  is vertically raised and lowered along track  106  by shuttle  108  in order to engage a load positioned on load-receiving area  104 . 
     In this example, load stabilizer  110  is positioned generally parallel to load-receiving area  104 . That is, load stabilizer  110  extends along a theoretical top plane  118 , while load-receiving area  104  extends along a theoretical bottom plane  120 . Top plane  118  and bottom plane  120  are parallel and offset from each other. 
     In  FIG. 1 , load stabilizer  110  is positioned perpendicular to track  106  for raising and lowering load stabilizer  110 . More specifically, top plane  118  along which load stabilizer  110  extends, is perpendicular to theoretical vertical line  114 . Similarly, load-receiving area  104  is perpendicular to track  106 , in that bottom plane  120 , along which load-receiving area  104  extends, is perpendicular to theoretical vertical line  114 . 
     With reference now to  FIG. 2 , an exploded view of load stabilizer  200  is provided. Load stabilizer  200  is one type of load stabilizer suitable for use as load stabilizer  110  described with reference to  FIG. 1 . Load stabilizer  200  is an example of a type of load stabilizer that can be practiced from the disclosed technology. Each component of load stabilizer  200  is also provided as an illustrative example with the understanding that other designs and arrangements can be derived and practiced from this disclosure. 
     The example load stabilizer  200  of  FIG. 2  is illustrated having securing arm  202 , support frame  204 , and pad  206 . In general, securing arm  202  is configured to mate with a ground vehicle (e.g., ground vehicle  100 ), such that the ground vehicle positions load stabilizer  200  by moving securing arm  202  from a first securing arm position to a second securing arm position. Support frame  204  generally supports pad  206  and provides a mechanism by which pad  206  can be retained within load stabilizer  200 . Generally, pad  206  provides a point of contact for the load. 
     Securing arm  202  is shown having securing arm shaft  208  that extends from first securing arm shaft end  210  to second securing arm shaft end  212 , illustrated in  FIG. 2  as separated by theoretical shaft line  214 . First securing arm shaft end  210  is opposite second securing arm shaft end  212 . The word “shaft” is not meant to imply any particular shape or design, only that the material extends from a first end to a second end. 
     First securing arm shaft end  210  is configured to couple to support frame  204 . Second securing arm shaft end  212  is configured to mate with a shuttle or similar mechanism of a ground vehicle for positioning load stabilizer  200 . 
     One method of coupling securing arm  202  to support frame  204  at first securing arm shaft end  210  is by way of securing arm bracket  216 . In the aspect shown, securing arm bracket  216  is transversely coupled to securing arm shaft  208  at first securing arm shaft end  210 . Securing arm bracket  216  comprises first securing arm bracket end  218  and second securing arm bracket end  220  illustrated as separated by theoretical bracket line  222 . Securing arm bracket  216  can be fastened to support frame  204  at both first securing arm bracket end  218  and second securing arm bracket end  220 . By coupling securing arm  202  using securing arm shaft  208  transversely coupled to securing arm bracket  216 , the overall weight of securing arm  202  can be reduced. This T-shaped design both reduces the overall weight and provides a mechanism for coupling securing arm  202  to support frame  204  in a manner that reduces the forces applied to the junction where the components are coupled, as this design reduces rotational force applied to the point at which the components are coupled. As illustrated in  FIG. 2 , securing arm bracket  216  includes holes  224 A and  224 B that correspond to holes  226 A and  226 B on support frame  204 . These can be used to fasten the components using pins, bolts, and the like. It will be understood that this is just an example method suitable for practicing the technology and that other methods of coupling the components are also possible. 
     Securing arm  202  can be configured to mate with the ground vehicle using securing arm mating bracket  228 . Here, securing arm mating bracket  228  is coupled to securing arm shaft  208  at second securing arm shaft end  212 . 
     In  FIG. 2 , securing arm shaft  208  extends from first securing arm shaft end  210  configured to couple to support frame  204  at a location within support frame outer edge  230 . Securing arm shaft  208  extends beyond support frame outer edge  230  to second securing arm shaft end  212 . This configuration assists the ground vehicle in positioning load stabilizer  200  because extending securing arm  202  beyond support frame outer edge  230  allows easy movement of load stabilizer  200  when moving securing arm  202 , as support frame  204  is out of the way of the ground vehicle and the motion device used by the ground vehicle to position load stabilizer  200 . 
     Securing arm  202  includes first securing arm brace  232  and second securing arm brace  234 . First securing arm brace  232  couples to securing arm bracket  216  at first securing arm bracket end  218 . First securing arm brace  232  extends from securing arm bracket  216  toward second securing arm shaft end  212 . Illustrated here, first securing arm brace  232  couples to securing arm mating bracket  228 . Second securing arm brace  234  couples to securing arm bracket  216  at second securing arm bracket end  220 . Second securing arm brace  234  extends from securing arm bracket  216  toward second securing arm shaft end  212 . Second securing arm brace  234  is also illustrated as coupled to securing arm mating bracket  228 . In this example, first securing arm brace  232  and second securing arm brace  234  extend outward and away from securing arm mating bracket  228  in opposite directions, such that first securing arm brace  232  and second securing arm brace  234  extend in a non-parallel relationship to one another. Using securing arm braces such as these helps to increase the stability of securing arm  202 . In particular, it reduces or eliminates the rotational forces applied to securing arm shaft  208 . At the same time, the use of securing arm braces, including those illustrated, helps to reduce overall weight of securing arm  202  by reducing the amount of material, yet still providing strong structural support. 
     In some designs, such as that shown in  FIG. 2 , securing arm  202  experiences a rotational or torque force by virtue of the mass of support frame  204  and pad  206  that exerts a downward force at first securing arm shaft end  210  when securing arm  202  is mated to the ground vehicle at second securing arm shaft end  212 . Because of this, it is beneficial to use a strong material that reduces deflection and has a bending force or fail point greater than the rotational or torque force experienced by securing arm  202 . For example, securing arm  202  can be formed of a metal comprising iron, tungsten, titanium, nickel, or chromium. This includes alloys thereof, such as forms of steel, which have been found suitable for use. 
     Support frame  204  comprises first support frame side  236  that is opposite second support frame side  238 . As noted previously, support frame  204  includes support frame outer edge  230 . Support frame  204  is one example of a type of support frame that can be practiced from the described technology. It will be understood that other configurations and arrangements are possible and may be used. Thus, support frame outer edge  230  is not intended to imply that support frame  204  is entirely enclosed by support frame outer edge  230 , such as the example illustrated in  FIG. 2 . Instead, support frame outer edge  230  is intended to more broadly encompass the outermost locations to which a support frame may extend. For instance, another example support frame is H-shaped, then the outer edge could include the two parallel portions. 
     Support frame  204  may include one or more open areas, such as open area  240 , that are defined by arrangement of the material within support frame  204 . In the example aspect of  FIG. 2 , support frame outer edge  230  entirely encloses the frame. In this case, open area  240  is enclosed by support frame outer edge  230 . In the H-shaped example, open areas comprise the locations between the two parallel portions. In this case, the open areas are not entirely enclosed by the outer edge. Open areas within support frame  204  reduce the overall weight of support frame  204  by using less material and providing a more skeleton-like frame. However, in yet another example, a support frame could have no open areas and provide only a flat surface. 
     As shown in  FIG. 2 , support frame outer edge  230  fully encloses support frame  204 . One or more open areas, such as open area  240 , are fully enclosed within support frame outer edge  230 . Here, support frame  204  comprises first support frame portion  242  that is perpendicular to second support frame portion  244 . This forms a t-shaped structure that extends over the area occupied by support frame  204  and reduces weight by not having material completely covering the entire area. The t-shaped design formed from first support frame portion  242  and second support frame portion  244  is entirely enclosed by support frame outer edge  230  to provide additional strength and form to support frame  204 . 
     Support frame  204  can be coupled to securing arm  202  at first support frame side  236 . As illustrated, securing arm  202  can be coupled to support frame  204  at one or more locations. Securing arm  202  can be coupled to support frame  204  at one or more locations along second support frame portion  244  that extends parallel with securing arm bracket  216  and perpendicular to securing arm shaft  208 . In another aspect, securing arm  202  is coupled to one or more locations on first support frame portion  242  (not illustrated), which extends perpendicular to securing arm bracket  216  and parallel with securing arm shaft  208 . An aspect couples securing arm  202  to one or more locations on both first support frame portion  242  and second support frame portion  244 . 
     Reducing weight of support frame  204  is beneficial because it reduces the overall weight of load stabilizer  200  and reduces the rotational or torque force experienced by securing arm  202 . However, since support frame  204  does not experience the type of forces that are experienced by securing arm  202 , lighter materials can be used to construct support frame  204 , such as any material having a density less than or equal to about 0.300 lbs/in 3 . In other aspects, materials having a density less than or equal to about 0.200 lbs/in 3  and materials having a density of less than or equal to about 0.100 lbs/in 3  are suitable for use. For instance, support frame  204  can be formed of a metal comprising aluminum, magnesium, titanium, or beryllium. Similarly, this is intended to include alloys of these metals. Aluminum having a density of less than 0.100 lbs/in 3  has been found to provide good structural stability for coupling to pad  206  and to securing arm  202 , while also providing a lightweight material that helps reduce the overall weight of load stabilizer  200 . 
     Pad  206  is coupled to support frame  204  at second support frame side  238 . In the example provided by  FIG. 2 , pad  206  is sized congruent to support frame  204 . That is, pad  206  is sized to extend over an area about equal to an area of support frame  204 . Pad  206  may comprise a single pad piece or may comprise more than one pad pieces. 
     Pad  206  is releasably coupled to support frame  204 . By releasably coupling pad  206 , pad  206  can easily be removed and replaced. There are various methods for releasably securing pad  206  to support frame  204 . One suitable method is to use hook-and-loop fasteners, such as hook-and-loop fastener  246  illustrated in  FIG. 2 . Other methods can include using pins, bolts, double-sided tape, glue, clamps, and the like. 
     In general, pad  206  can be made of any material. Flexible materials are beneficial in that they cushion or conform to a load when force is applied by load stabilizer  200 . Some loads may not be perfectly flat or parallel with the pad, and as such, some areas could experience more force. Flexible materials help to disperse this force across the entire load, rather than have some areas of the load experience significantly greater amounts of force. Flexible materials also help to contour the material to the load, thus providing even more stability of the load during transport, as the contouring helps grip the load and prevent side-to-side motion. 
     One flexible material that has been found to provide such benefits is a foam material. One type of foam that has been found to be durable and suitable for use is a closed-cell foam material. These resist wear from repeated forces encountered when in use with load stabilizer  200 . One example is a closed-cell polyurethane foam, while another is a closed-cell polyethylene foam. 
     While many different variations of foam can be used, foams having a thickness of less than or equal to about 5 inches are suitable. Foams having a thickness of less than or equal to about 4 inches, less than or equal to about 3 inches, less than or equal to about 2 inches, and less than or equal to about 1 inch can each be used in aspects of the technology. Lower thicknesses of foam used in pad  206  are beneficial in that there is less weight. 
     Further, foams having densities of less than or equal to about 5 lbs/ft 3  may be used. Other aspects of the technology can employ foams having densities of less than or equal to about 4 lbs/ft 3 , less than or equal to about 3 lbs/ft 3 , less than or equal to about 2 lbs/ft 3 , and less than or equal to about 1 lb/ft 3 . The lower the density, the less weight and increased flexibility. 
     Any combination of these foams can be used in aspects of the technology. Other similar foams and flexible materials, such as rubber, can be used and are intended to be within the scope of “flexible material.” In some case, the flexible material is a flexible, non-metallic, synthetic material. 
     In general, pad  206  can include a flat surface opposite the portion of pad  206  secured to support frame  204 . However, other alternative pad designs are contemplated.  FIG. 3  provides an example pad design that may be used. 
     With reference briefly to  FIG. 3 , generally a pad can be formed to have a pad surface that corresponds to a surface of a particular load type. This is beneficial because it provides additional support against side-to-side movement of loads that do not have a regular top surface, such as those not having a flat, square top surface.  FIG. 3  provides an example; although, it will be understood that there are other pad designs that are intended to be within the scope of this disclosure. 
     In general,  FIG. 3  illustrates a bottom-up view of pad  300  and load  302 , which is resting atop pallet  304 . Pad  300  includes a pad design that conforms to a shape of load top surface  306 . That is, pad  300  includes raised pad areas  308  and recessed pad areas  310 . To correspond to load  302 , raised pad areas  308  have locations corresponding to locations of recessed load areas  312 . Similarly, recessed pad areas  310  have locations corresponding to locations of raised load areas  314 . To form raised pad areas  308  and recessed pad areas  310 , pad  300  can be milled out or initially formed around a blank having a structure similar to the structure of load top surface  306 . 
     Turning now to  FIG. 4 , an example ground vehicle  400  is provided. Ground vehicle  400  may be any type of ground vehicle configured to transport loads. The autonomous system of  FIG. 4  is one example, and other examples may include manned or remotely operated ground vehicles. 
     Ground vehicle  400  is shown in operation with securing arm  402 . Other components of the load stabilizer associated with securing arm  402  have been omitted for clarity. However, it will be appreciated that the securing arm  402  may be used with other components to provide a load stabilizer for ground vehicle  400 , and that any of the described load stabilizers are suitable for use. 
     Ground vehicle  400  positions securing arm  402 , and thus any load stabilizer associated with it, using track  404  and shuttle  406 . That is, securing arm  402  is configured to mate with shuttle  406  as illustrated. Shuttle  406  is vertically moved about track  404  to move securing arm  402  from a first securing arm position to a second securing arm position, where the second securing arm position is relatively closer to load-receiving area  408 . As noted, shuttle  406  may also be referred to or include a lift mechanism shuttle that assist in vertical movement about ground vehicle  400 . 
     The system comprising track  404  and shuttle  406  is illustrated as one example method that can be utilized. Other systems may employ hydraulics, chains, gears, mechanical lifts, and so forth. 
     Ground vehicle  400  can employ motor  410  for positioning securing arm  402  along track  404 . Thus, motor  410  is configured to move securing arm  402  from a first securing arm position to a second securing arm position. That is, ground vehicle  400  actuates motor  410  to move securing arm  402  along track  404 . Some aspects of the technology utilize motor  410  having a solenoid brake. The solenoid brake stops motor  410  when motor  410  experiences a specific torque. Some aspects use a stepper motor that is braked by a controller programed with a torque threshold value. It will be understood that, although motor  410  is illustrated as part of ground vehicle  400 , motor  410  could be positioned at any location of ground vehicle  400 , including positioned on any component of a load stabilizer of ground vehicle  400 . It will also be understood that some stepper motors include a brake and controller integrated into the same hardware or that are separate. 
     A brake integrated with or part of motor  410  can be used to stop securing arm  402  at a lower position when the torque experienced by motor  410  is equal to or greater than the torque threshold defined by the brake. Thus, the lower limit position is based on the size of the load being carried by ground vehicle  400 . A capacitive switch can be used to determine an upper limit position of securing arm  402  to stop motor  410 . As noted, several motors are suitable for use, including stepper motor, servomotors, and the like. These may work in conjunction with any type of brake, including a solenoid brake, potentiometer, controller, and the like, including digital or mechanical, or both. The brake may have a torque threshold value associated with it that stops the motor when the motor experience a torque equal to or greater than the torque threshold value. In an example, a stepper motor can be used where the controller controls the stepper motor position, and the stepper motor position is determined by the controller based on the stepper motor experiencing a torque equal to or greater than the torque threshold value. In this example, the brake is then applied to the stepper motor to maintain the stepper motor position, thus maintaining a position of a load stabilizer moved by the stepper motor. The brake and the controller of the stepper motor may be integrated into a single piece of hardware or may be separate components. 
     One benefit to reducing the weight of the overall load stabilizer, using methods previously described, is that the reduced weight allows smaller motors to be used. That is, the weight of the load stabilizer correlates to the size of the motor needed to move the load stabilizer. Higher weighted load stabilizers will generally use larger motors with higher torque thresholds and specifications. By reducing the weight of the load stabilizer, relatively smaller motors can be used, thus requiring less voltage to operate. This allows for smaller batteries and extends battery life for batteries associated with the ground vehicle that are used to power the motor. 
     While there are various methods to configure motor  410  to move securing arm  402 , one method uses a belt system. One example system is illustrated and comprises belt  412  that is moved using pulley  414  joined to motor  410 . Shuttle  406  is joined to belt  412  using belt clasp  416 . Shuttle  406  is joined to belt  412  such that, when belt  412  is rotated about pulley  414 , shuttle  406  moves in the direction of rotation. One specific system suitable for use employs a timing belt having grooves that is rotated around a pulley with teeth, where the teeth of the pulley are configured to rest within the grooves of the timing belt. 
     With reference now to  FIG. 5 , an example method  500  of operating a ground vehicle having a load stabilizer is provided. Any load stabilizer or variation of load stabilizer described may be employed. At block  502 , a load is received at a load-receiving area of the ground vehicle. The load can be positioned by the ground vehicle to rest in vertical alignment with the center of mass of the ground vehicle. The load can be positioned by a positioning system employed by the ground vehicle or may be placed onto a flat surface of the load-receiving area. In an aspect, the load is positioned so that it is disposed between the load-receiving area and the load stabilizer of the ground vehicle, where the load stabilizer is positioned parallel with the load-receiving area. 
     At block  504 , the ground vehicle actuates a motor that is configured to move the load stabilizer via a securing arm. The load stabilizer is moved from a first securing arm position to a second securing arm position. The second securing arm position is relatively closer to the load and ground level. 
     As a pad of the load stabilizer begins to contact a surface of the load, the motor moving the load stabilizer begins to experience a torque force. The motor may be configured with a solenoid brake that stops the motor when the experienced torque is equal to or greater than a torque threshold associated with the solenoid brake. Thus, at block  506 , motor is stopped based on the torque threshold of the motor. The load stabilizer is stopped at the lower limit position. 
       FIG. 6  illustrates an example method  600  of assembling a load stabilizer configured for use with a ground vehicle. At block  602 , a securing arm is coupled to a support frame. The securing arm can be coupled to a first support frame side of the support frame that is opposite a second support frame side of the support frame. The securing arm may include a securing arm shaft having a first securing arm shaft end extending to a second securing arm shaft end. The securing arm can be coupled to the support frame at the first securing arm shaft end at a location within an outer edge of the support frame. The securing arm can be coupled such that the second securing arm shaft end extends beyond the outer edge of the support frame. The support frame can be configured to movably mate with the ground vehicle at a location corresponding to the second securing arm shaft end. 
     At block  604 , a pad is coupled to the support frame. The pad can be coupled to the support frame at the second support frame side. The pad may be removably coupled to the second support frame side. In an aspect, a first part of a hook-and-loop fastener is secured to the pad, while a second corresponding part is secured to the second support frame side of the support frame, and the first and second parts are placed in contact. 
       FIG. 7  provides an example method  700  of manufacturing a load stabilizer for use in stabilizing a load of a ground vehicle. At block  702 , a securing arm is formed. The securing arm can be formed of any bend-resistant material having sufficient strength to withstand forces created by a mass of a support frame and pad. Metals having a bend force greater than the force created by the mass of the support frame and pad when accelerated into motion are sufficient for use. In an aspect, the securing arm or components thereof are formed of a metal comprising iron, tungsten, titanium, nickel, or chromium. The securing arm metal can be shaped or cast into one or more components. Other non-metallic materials can be formed into shape, cut to shape, three-dimensionally printed, or the like. Example components include a securing arm shaft, a securing arm bracket, a securing arm brace, and a securing arm mating bracket. Any combination of these components can be separately formed or formed as a single integrated piece. The method may include assembling components of the securing arm or configuring components of the securing arm for assembly. 
     At block  704 , a support frame is formed. The support frame can be formed of any lightweight material, such as a material with a density equal to or less than about 0.300 lb/in 3 . In aspects, the support frame or components thereof can be formed of a metal comprising aluminum, magnesium, titanium, or beryllium. Similarly, such metals can be cast or cut into the support frame or individual components of the support frame. Other non-metallic materials can be formed into shape, cut to shape, three-dimensionally printed, or the like. The support frame can be formed as a single support frame piece, or it can be formed into more than one support frame piece configured to assemble into the support frame. The method may include assembling components of the support frame or configuring components of the support frame for assembly. 
     At block  706 , a pad is formed. The pad is formed such that it is configured to be coupled to the support frame. That is, the pad is formed congruent with the support frame. The pad can be formed from a natural or synthetic, flexible material. One example pad is formed using a closed-cell synthetic material. Polyethylene and polyurethane are two materials that can be used to form the pad. The pad can be formed from one or more pad pieces. Where a plurality of pad pieces is formed, the pad pieces can be configured to assemble into a pad congruent with the support frame. To size the pad congruent to the support frame or size the pad pieces, pieces of the pad material can be cut to shape. In another aspect, the pad material is formed into the shape. One method is to cut the pad to have recessed areas and raised areas corresponding to recessed areas and raised areas of a load surface for a specific load type. The pad can be formed using a blank of the load surface, a mold, a digital three-dimensional representation, or the like. The method can include coupling the pad to the support frame or configuring the pad to be coupled the support frame. 
     In general, method  700  can include forming the securing arm, the support frame, and the pad, or any combination of these components. For instance, method  700  may include forming only the securing arm, only the support frame, or only the pad. Method  700  may also include forming any combination of two of the securing arm, the support frame, or the pad. 
     Throughout this disclosure, the terms “step” or “block” are used to connote different elements of methods employed, the terms should not be interpreted as implying any particular order among or between various steps herein disclosed unless and except when the order of individual steps is explicitly stated. 
     The words “above” and “below,” and other positional words throughout this disclosure are intended to describe a position relative to ground level. For example, a component that is “above” another component is relatively further from ground level, while a component that is “below” another component is relatively closer to the ground level. Other positional actions, such as “raise” and “lower” are also used relative to the ground level. 
     The words “couple,” “mate,” “affix,” “fasten,” “secure,” “join,” and other similar words used in this disclosure are intended to broadly describe joining components at a junction. These words are not meant to imply a particular type of or method of joining, unless explicitly stated otherwise. For instance, components may be joined at a junction using permanent methods or reversible methods. That is, components may be joined at a junction so that they are permanently affixed at the location or they are releasable affixed at the location. Similarly, to aid in describing the technology, certain components have been shown as separate components joined together at a junction. However, in practice, various components may be integrally formed, meaning that there may be no physical distinction between individual components. Each of these words is also intended to capture such integrally formed constructions. For example, components may be “joined” at a junction even where there is no physical or easily discernable difference between the components. 
     The word “about” is intend to mean±10%. For example, about 2.0 means a range equal to or less than 2.2, and equal to or greater than 1.8. Using another example, “about perpendicular” means having a relative angle of 90°±10%. Unless otherwise stated to the contrary, “parallel” and “perpendicular” as used herein are intended to mean “about parallel” and “about perpendicular.” 
     Words such as “a” and “an,” unless otherwise indicated to the contrary, include the plural as well as the singular. Thus, for example, the constraint of “a feature” is satisfied where one or more features are present. Also, the term “or” includes the conjunctive, the disjunctive, and both (a or b thus includes either a or b, as well as a and b). 
     The subject matter of the present technology is described with specificity herein to meet statutory requirements. However, the description itself is not intended to limit the scope of this disclosure. Rather, the inventors have contemplated that the claimed or disclosed subject matter might also be embodied in other ways, to include different steps or combinations of steps similar to the ones described in this document, in conjunction with other present or future technologies. 
     From the foregoing, it will be seen that this technology is one well adapted to attain all the ends and objects described above, including other advantages that are obvious or inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the described technology may be made without departing from the scope, it is to be understood that all matter described herein or illustrated the accompanying drawings is to be interpreted as illustrative and not in a limiting sense. 
     Example aspects of the technology that can be practiced from this disclosure include: 
     Aspect 1: A ground vehicle for transporting loads, the ground vehicle comprising: a motor having a brake; a securing arm coupled to the ground vehicle and movable between a first securing arm position and a second securing arm position, wherein the securing arm transitions between the first securing arm position and the second securing arm position by actuation of the motor, and wherein the securing arm is maintained at the second securing arm position by the brake; a support frame coupled to the securing arm at a first support frame side opposite a second support frame side; and a pad coupled to the support frame at the second support frame side. 
     Aspect 2: The ground vehicle of Aspect 1, further comprising a load-receiving area extending along a base plane, wherein the pad extends along a top plane that is parallel to and offset from the base plane. 
     Aspect 3: The ground vehicle of any of Aspects 1-2, further comprising a load-receiving area, wherein, when the securing arm is positioned at the first securing arm position, the pad is separated from the load-receiving area by a first distance and when the securing arm is positioned at the second securing arm position, the pad is separated from the load-receiving area by a second distance, the first distance being greater than the second distance. 
     Aspect 4: The ground vehicle of any of Aspects 1-3, wherein the pad is removably coupled to the support frame. 
     Aspect 5: The ground vehicle of any of Aspects 1-4, wherein the securing arm is formed of a metal comprising iron, tungsten, titanium, nickel, or chromium, and wherein the support frame is formed of a metal comprising aluminum, magnesium, titanium, or beryllium. 
     Aspect 6: The ground vehicle of any of Aspects 1-5, wherein the motor is a stepper motor and a controller of the stepper motor determines at least the second securing arm position based on a torque experienced by the stepper motor. 
     Aspect 7: The ground vehicle of any of Aspects 1-6, wherein the pad is formed of a closed-cell foam. 
     Aspect 8: A load stabilizer configured for stabilizing a load transported by a ground vehicle, the load stabilizer comprising: a securing arm; a support frame coupled to the securing arm at a first support frame side opposite a second support frame side; and a pad removably coupled to the support frame at the second support frame side. 
     Aspect 9: The load stabilizer of Aspect 8, wherein the securing arm comprises a securing arm shaft extending from a first securing arm shaft end to a second securing arm shaft end, the securing arm coupled to the support frame at the first securing arm shaft end, and the second securing arm shaft end extending beyond an outer edge of the support frame. 
     Aspect 10: The load stabilizer of Aspect 9, wherein the first securing arm shaft end is transversely coupled to a securing arm bracket, the securing arm bracket coupled to the support frame. 
     Aspect 11: The load stabilizer of any of Aspects 8-10, wherein the support frame comprises an open area enclosed by an outer edge of the support frame. 
     Aspect 12: The load stabilizer of any of Aspects 8-11, wherein the pad is removably coupled to the support frame using a hook-and-loop fastener. 
     Aspect 13: The load stabilizer of any of Aspects 8-12, wherein the securing arm is formed of a metal comprising iron, tungsten, titanium, nickel, or chromium. 
     Aspect 14: The load stabilizer of any of Aspects 8-13, wherein the support frame is formed of a metal comprising aluminum, magnesium, titanium, or beryllium. 
     Aspect 15: The load stabilizer of any of Aspects 8-14, wherein the pad is formed of a closed-cell foam. 
     Aspect 16: The load stabilizer of any of Aspects 8-15, wherein the pad is equal to or less than two inches. 
     Aspect 17: A method of assembling a load stabilizer for stabilizing a load transported by a ground vehicle, the method comprising: coupling a securing arm having a securing arm shaft to a first support frame side of a support frame by fastening the securing arm to the support frame at a first securing arm shaft end such that the securing arm shaft extends from the first securing arm shaft end to a second securing arm shaft end, the second securing arm shaft end extending beyond an outer edge of the support frame; and coupling a pad to a second support frame side of the support frame opposite the first support frame side. 
     Aspect 18: The method of Aspect 17, wherein coupling the securing arm to the support frame further comprises fastening a securing arm bracket to the first support frame side, the securing arm bracket transversely coupled to the securing arm shaft at the first securing arm shaft end. 
     Aspect 19: The method of any of Aspects 17-18, wherein coupling the pad to the second support frame side includes removably securing the pad to the second support frame side using a hook-and-loop fastener. 
     Aspect 20: The method of any of Aspects 17-19, wherein the securing arm is formed of a metal comprising iron, tungsten, titanium, nickel, or chromium, and the support frame is formed of a metal comprising aluminum, magnesium, titanium, or beryllium.