Patent Publication Number: US-11035095-B2

Title: Electrically powered mining vehicle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of prior application Ser. No. 29/578,769, filed Sep. 23, 2016, the entirety of which is herein incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to mining vehicles. 
     Various types of mining vehicles may be used to remove and transport material in a mining operation. One type of vehicle, a load-haul-dump machine (LHD) may be used. LHDs may be similar to front-end loaders but with features that facilitate better operation in hard-rock mining applications. Typically, LHDs are rugged and highly maneuverable. 
     Traditionally, LHDs have been designed to have relatively longer lengths to improve axial weight and bucket capacity. However, the longer length, as well as overall frame geometry of conventional vehicles may limit visibility. Traditional LHDs may also operate with diesel-powered engines that may provide indirect constraints on power and capacity for a machine of a given size and weight. 
     SUMMARY OF THE INVENTION 
     Various embodiments of a mining vehicle are disclosed. The embodiments provide mining vehicles that are battery powered rather than diesel powered. The embodiments also provide vehicles that have relatively high hauling capacity relative to their length and footprint (area). The embodiments also provide vehicles with improved forward and rearward ground visibility. 
     In one aspect, a mining vehicle includes a frame, a set of wheels and a scoop. The mining vehicle also includes a first end and a second end, where the first end is associated with the scoop. The mining vehicle has a first end ground visibility distance associated with the first end of the mining vehicle. The mining vehicle has a hauling capacity, the hauling capacity being a weight of material that can be loaded into the scoop and transported by the mining vehicle, where the hauling capacity is at least 1 metric ton. The first end ground visibility distance is substantially less than 15 meters. 
     In another aspect, a mining vehicle includes a frame, a set of wheels and a scoop. The mining vehicle includes a first end and a second end, where the first end is associated with the scoop. The mining vehicle has a second end ground visibility distance associated with the second end. The mining vehicle has a hauling capacity, the hauling capacity being a weight of material that can be loaded into the scoop and transported by the mining vehicle, where the hauling capacity is at least 1 metric ton. The second end ground visibility distance is less than 30 meters. 
     In another aspect, a mining vehicle includes a frame, a set of wheels and a scoop. The mining vehicle further includes a power system including an electric motor, the electric motor having a peak power value. The mining vehicle has an overall length, an overall width and an overall height. The mining vehicle has an envelope volume equal to a product of the overall length, the overall width and the overall height. The mining vehicle has a power density equal to a ratio of the peak power value to the envelope volume and the power density is approximately 6 kilowatts per cubic-meter or greater. 
     Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description and this summary, be within the scope of the invention, and be protected by the following claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like reference numerals designate corresponding parts throughout the different views. 
         FIG. 1  shows an embodiment of a mining vehicle; 
         FIG. 2  shows another view of the mining vehicle of  FIG. 1 ; 
         FIG. 3  shows an embodiment of a mining vehicle with some components removed for clarity; 
         FIG. 4  shows an embodiment of a mining vehicle with some components removed for clarity; 
         FIG. 5  shows an embodiment of a mining vehicle with some portions of a chassis highlighted; 
         FIG. 6  shows a schematic view of two alternative constructions for a mining vehicle chassis; 
         FIG. 7  shows a side schematic view of an embodiment of a mining vehicle in which a variety of dimensions are indicated; 
         FIG. 8  shows a rear view of the mining vehicle of  FIG. 1 ; 
         FIG. 9  shows an embodiment of a mining vehicle turning, according to an embodiment; 
         FIG. 10  shows a schematic view of a footprint for a mining vehicle, according to an embodiment; 
         FIG. 11  shows a schematic view of a three-dimensional envelope for a mining vehicle, according to an embodiment; 
         FIG. 12  shows a comparison of the sizes of two different mining vehicles, according to an embodiment; 
         FIG. 13  shows a comparison of the degree of visibility available in two different mining vehicles according to an embodiment; 
         FIGS. 14-17  show charts of the ratio of the hauling capacity to another characteristic parameter for two different mining vehicles having a hauling capacity in a range between 2.7-3 metric tons, according to an embodiment; 
         FIG. 18  shows a chart of the ratio of power to vehicle weight for two different mining vehicles, according to an embodiment; 
         FIG. 19  shows a chart of the ratio of power to vehicle volume for two different mining vehicles, according to an embodiment; and 
         FIGS. 20-23  show charts of the ratio of the hauling capacity to another characteristic parameter for two different mining vehicles having a 4 metric ton capacity, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The embodiments are directed to a working vehicle with a scoop. The vehicle is electric and uses only a battery to power the vehicle in place of a conventional diesel engine. The vehicle may be used in mining operations. The vehicle is designed with a substantially smaller form factor compared to conventional vehicles. Because the vehicle is all electric, there is a lot of space saved compared to diesel machines that require an engine, transmission, torque converter, etc. The vehicle has been designed with a small footprint—including a reduction in length as well as a reduction in vertical height, compared to similar diesel vehicles. 
     In contrast to conventional designs, this vehicle is designed to optimize the ratio of power to size (e.g., maximize the power-to-size ratio given some other constraints). Here the size could refer to either total volume or a combination of one or more linear measurements. 
     For purposes of clarity the following terms may be used in the detailed description and the specification. The term “hauling capacity,” or simply capacity, is used to characterize the amount of material that can be held in the scoop of a vehicle, and that can also be lifted by the scoop and transported. The hauling capacity may also be referred to as the “tramming capacity.” As discussed in further detail below, a vehicle may also be characterized by the ratio of its hauling capacity with some other characteristic such as its length, footprint, volume, density, or other characteristic. As an example, some of the following embodiments are characterized by a hauling capacity per unit overall length, which is simply a ratio of the hauling capacity and the overall length of the vehicle. Such a ratio may be understood to provide a constraint on the length of a vehicle for a given hauling capacity (or vice versa). In another case, a ratio of the hauling capacity to a ground visibility distance is given. Such a ratio provides a constraint on the degree of visibility of a driver sitting in the cab of the vehicle. 
       FIGS. 1 and 2  illustrate schematic isometric views of vehicle  100 . Vehicle  100  may include standard provisions for a mining vehicle, such as wheels  110  and scoop  112 . Vehicle  100  may also include provisions for powering wheels  110  and scoop  112 . Vehicle  100  may include an electric motor (not shown), which is powered by onboard battery  104 . In some embodiments, vehicle  100  has an electric motor that operates with a continuous torque of approximately 695 Newton-meters and a peak torque of approximately 400 Newton-meters. 
     In different embodiments, the hauling capacity of vehicle  100  could vary. In some embodiments, vehicle  100  could have a hauling capacity approximately in the range between 1 and 2 metric tons. In other embodiments, vehicle  100  could have a hauling capacity approximately in the range between 2 and 3 metric tons. In still other embodiments, vehicle  100  could have a hauling capacity approximately in the range between 3 and 4 metric tons. In still other embodiments, vehicle  100  could have a hauling capacity substantially greater than 4 metric tons. 
     Battery  104  may be removably attached to vehicle  100 . Onboard battery  104  may be any type of rechargeable battery suitable for use in a mine vehicle. In some embodiments, battery  104  may be a lithium iron phosphate battery. In some cases, batter  104  may be a 600 Volt DC battery with an energy of 88 kilowatt-hours. 
     Vehicle  100  is also provided with various standard vehicular mechanisms and capacities, such as passenger cab  116  for receiving one or more operators. 
     Vehicle  100  includes vehicle body  120 , which is best shown in  FIGS. 3 and 4 . Vehicle body  120  includes body structural supports (e.g., chassis components) as well as panels and other elements that protect or otherwise cover other elements of vehicle  100 . In the embodiment of  FIGS. 3 and 4 , vehicle body  120  may be separated into first body portion  122  and a second body portion  124 . First body portion  122  includes portions of vehicle body  120  that surround and support two of wheels  110  as well as scoop  112 . Second body portion  124  includes portions of vehicle body  120  that surround and support onboard battery  104  (not shown in  FIGS. 3-4 ), two of wheels  110 , and passenger cab  116 . 
     Second body portion  124  further includes rear chassis assembly  130 . Rear chassis assembly  130  includes various chassis members that surround and support a battery. Specifically, rear chassis assembly  130  includes first side chassis member  132 , second side chassis member  134 , and rear chassis member  136 . Together these chassis members form the side and rear walls of battery compartment  139 . 
     As best seen in  FIG. 5 , first side chassis member  132  and second side chassis member  134  are positioned along the outer sides of vehicle  100 . Likewise, rear chassis member  136  is positioned along the outer rear side of vehicle  100 . 
     This configuration for the chassis of vehicle  100  may be seen to contrast with conventional chassis designs in diesel vehicles. This contrast is best seen in  FIG. 6 , which shows schematic views of a portion of vehicle  100  and a corresponding portion of alternative diesel vehicle  200 . In the conventional design, diesel engine  204  may be supported by inner chassis elements  202  that are positioned inwardly from the sides of alternative diesel vehicle  200  to support the engine. Additional components, such as exhaust system  206  (shown schematically) may be positioned outside of the narrowly arranged inner chassis elements  202 . These components may be held in place or covered by other framing elements  208  that extend on the exterior of alternative diesel vehicle  200 . Framing elements  208  generally do not provide as much support and strength as inner chassis elements  202 . 
     In contrast, the strongest portions of the frame or chassis of vehicle  100  are arranged on the outer sides of vehicle  100 . In some cases, first side chassis member  132  and second side chassis member  134  may serve as both structural elements and the outermost parts of the frame of vehicle  100  along the sides. In other cases, first side chassis member  132  and second side chassis member  134  could be disposed adjacent to, and at least partially covered by, outer frame elements (e.g., sheets, bars, etc.). 
     Not only the position, but also the size, shape, and density of chassis elements of vehicle  100  may differ from those of alternative diesel vehicle  200 . In some cases, first side chassis member  132  and second side chassis member  134  may be designed to increase the total weight of vehicle  100 . That is, it may be desirable to use larger and/or heavier chassis elements for first side chassis member  132  and second side chassis member  134 , as compared to the size and/or weight of inner chassis elements  202 . In some embodiments, the chassis of vehicle  100  may be more comparable to a unibody chassis, while the chassis of alternative diesel vehicle  200  has more of a ladder frame type of chassis. 
     By using a heavier chassis, vehicle  100  is designed to incorporate a greater amount of mass than a conventional chassis used in diesel vehicles. This creates a higher density vehicle (more weight for the volume), which helps improve traction and overall stability of the machine. By contrast, it is generally desirable for the chassis in diesel vehicles to be as light as possible since diesel mining vehicles are often constrained to run at or below a predetermined horsepower to minimize exhaust emissions in the mine. 
     Some embodiments of a mining vehicle may include provisions for reducing the form factor of the vehicle compared with conventional diesel vehicles. In discussing the form factor, the description discusses the overall length, overall width, and overall height of a vehicle, as well as various other dimensions. As used herein, the term overall length refers to the distance between the forward-most location on a vehicle and the rearward-most location on the vehicle. In some cases, the forward-most location may be a location on the scoop. The term overall width refers to the distance between opposing sides of the vehicle, and is measured at the “outermost” locations along the opposing sides. The term overall height refers to the distance between the lowest point of a vehicle (usually the bottom of the wheels) and the highest point of a vehicle. When a canopy is present, the highest point of a vehicle is usually located on the canopy. 
       FIG. 7  illustrates a side schematic view of vehicle  100  for purposes of illustrating a variety of dimensions. Vehicle  100  has overall height  300 , measured from the ground vertically up to the highest point of vehicle  100 . In one embodiment, overall height  300  has a value of approximately 1,651 millimeters (65 inches). In other embodiments, overall height  300  could have any value approximately in the range of 1,500 to 2,000 mm. In some other embodiments; vehicle  100  may be provided with a canopy. In such embodiments, the overall height of vehicle  100  may extend higher than the location where overall height  300  is measured in the example shown in  FIG. 7 . 
     Vehicle  100  has overall length  302 , measured from the rearward-most location on second body portion  124  to the forward-most location on first body portion  122 . In one embodiment, overall length  302  has a value of approximately 5,706 mm (224.6 in). In other embodiments, overall length  302  could have any value approximately in the range between 5,500 to 6,500 mm. 
     As seen in  FIG. 7 , the overall length of vehicle  100  can be separated into front overhang length  310 , wheelbase length  312  and rear overhang length  314 . Specifically, wheelbase length  312  is measured between the center of front wheels  320  and the center of rear wheels  322 . Front overhang length  310  is measured from the center of front wheels  320  to the forward-most location on scoop  112 . Rear overhang length  314  is measured from the center of rear wheels  322  to the rearward-most location on second body portion  124 . In one embodiment, front overhang length  310  has a value of approximately 1,805 mm (71 in); wheelbase length  312  has a value of approximately 1; 880 mm (74 in); and rear overhang length  314  has a value of approximately 2,020 mm (79.5 in). Of course, in other embodiments, these values can be varied to accommodate desirable modifications to the wheelbase length, the length of the forward and/or rearward part of the body or to the size and/or extension of the scoop. Moreover; it may be understood that as the overall length is adjusted in different embodiments, the values of front overhang length  310 , wheelbase length  312 , and rear overhang length  314  may be varied accordingly. 
     The height of scoop  112  may vary according to its operating position. For example, in a fully lowered state, an upward-most location of scoop  112  has lowered scoop height  330  as measured from the ground. In one embodiment, lowered scoop height  330  has a value of approximately 1,220 mm (48 in). In a fully raised state, an upward-most location of scoop  112  has raised scoop height  332  as measured from the ground. In one embodiment, raised scoop height  332  has a value of approximately 3,408 mm (134.2 in). 
       FIG. 8  shows a rearward view of vehicle  100 . Vehicle  100  has overall width  340 . In one embodiment, overall width  340  has a value of approximately 1,524 mm (60 in). In other embodiments, overall width  340  could have any value approximately in the range of 1; 400 to 1,600 mm. 
       FIG. 9  is a schematic view of vehicle  100  in a turning position. In particular, first body portion  122  is angled with respect to second body portion  124  at angle  370 . In one embodiment, angle  370  has a value of approximately 40 degrees. In other embodiments, angle  370  could have any value approximately in the range between 30 and 50 degrees. In addition; the inner turning path has radius  372 . The outer turning path has radius  374 . In one embodiment, radius  372  has a value of approximately 1,803 mm (or 81 in). Also, in one embodiment, radius  374  has a value of approximately 3,785 mm (or 149 in). Of course, any of angle  370 ; radius  372 , and/or radius  374  could be varied in other embodiments as the length and/or width of the vehicle are varied, and/or as other features are modified (such as the mechanical linkage between first body portion  122  and second body portion  124 ). 
     Vehicle  100  may be characterized by a footprint as well as an envelope; which are two-dimensional and three-dimensional representations of the vehicle&#39;s form factor. As used herein, the term “vehicle footprint area” is equal to the product of the overall length and the overall width of a vehicle. In addition, the term “vehicle envelope volume” is equal to the product of the vehicle footprint area and the overall height of the vehicle. 
     As seen in  FIGS. 10-11 , vehicle  100  has vehicle footprint area  500 . Vehicle  100  also has vehicle envelope volume  502 . In one embodiment, vehicle footprint area  500  has a value of approximately 8.7 m 2 . Similarly, vehicle envelope volume  502  has a value of approximately 14.4 m 3 . Of course, in other embodiments, both the footprint area and the envelope volume may be varied by changing one or more of the overall length, overall width, or overall height of vehicle  100 . In some other embodiments, the vehicle footprint area may have any value approximately in the range of 8 to 10 m 2 . Also, the vehicle envelope volume may have any value approximately in the range of 14 to 20 m 3 . 
       FIG. 12  depicts a schematic view of vehicle  100  and benchmark vehicle  400 . Here, benchmark vehicle  400  is intended to represent a conventional mining vehicle that may have similar hauling capacity (for example, around 3 metric ton hauling capacity). For example, benchmark vehicle  400  could be a diesel-powered mining vehicle with a hauling capacity of 3 metric tons. 
     For purposes of comparison, benchmark vehicle  400  is shown to have the following specifications that may be representative of conventional mining vehicles with a hauling capacity close to 3 metric tons. In particular, benchmark vehicle  400  has length  410  with a value of approximately 6,365 mm. 
     As clearly seen in  FIG. 12 , vehicle  100  has a substantially shorter length than benchmark vehicle  400 . In an embodiment where vehicle  100  has overall length  302  of approximately 5,706 mm, this results in vehicle  100  being shorter than benchmark vehicle  400  by approximately 660 mm. In other words, vehicle  100  provides more than a 10 percent reduction in length compared to benchmark vehicle  400 . 
     In some embodiments, vehicle  100  may have a similar width to benchmark vehicle  400 . In one embodiment, benchmark vehicle  400  has an overall width of 1,514 mm compared to the overall width of vehicle  100  (shown in  FIG. 8 ) of 1,524 mm. In other embodiments, vehicle  100  may have a substantially reduced width compared to benchmark vehicles. In some embodiments, vehicle  100  may have a smaller height compared to conventional mining vehicles with a similar hauling capacity. For example, benchmark vehicle  400  has an overall height of 1,895 mm. In contrast, in one embodiment, vehicle  100  may have an overall height of 1,651 mm. Though, as seen in  FIG. 12 , some of this height difference may result from the lack of a canopy on vehicle  100 . With an optional canopy, the overall height of vehicle  100  may be increased. In such cases, the envelope volume may also be increased relative to a vehicle without a canopy. 
     It may be seen that vehicle  100  is provided with a substantial reduction in size of at least one of the overall length, overall width, and/or overall height compared to conventional mining vehicles of similar hauling capacity. This reduction may result in a smaller vehicle footprint area and/or a smaller vehicle envelope volume. 
     The smaller form factor creates a smaller heading for the mining vehicle. This results in significantly less rock displacement during the mining operation and thereby provides significant cost improvements over mining operations using vehicles with larger sizes/headings. Moreover, the smaller form factor may also contribute to increased visibility as discussed further below. 
     The invention is directed to an improved line of sight or visibility for the mining vehicle. This improved line of sight is achieved by way of the reduced lengthwise form factor and the chassis/frame shape at the battery (in red) end of the vehicle. The shortened length along with the sloped chassis/frame shape (vs. a horizontal shape for conventional designs) allows for an improved line of sight when compared to the line of sight achieved in conventional designs. 
     As used herein, a sightline is a line of visibility between a driver/operator of a vehicle and some location away from the vehicle. If a driver/operator has a clear sightline to a location, then the location is visible. The term “ground visibility distance” refers to the horizontal distance between the cab of a vehicle (i.e., where the operator sits) and the nearest location on the ground at which a driver has a sightline to the ground (i.e., the shortest possible horizontal distance for which the driver can see the ground). 
       FIG. 13  shows schematic views of vehicle  100  and benchmark vehicle  400 , for purposes of comparing the sightlines of the two designs. In  FIG. 13 , vehicle  100  and benchmark vehicle  400  are shown to differ substantially due to differences in the vehicles&#39; form factors. Referring to  FIG. 13 , the relatively short length of vehicle  100  along with the distinctive geometry of vehicle body  120  provides significantly improved sightlines for a driver. In particular, driver  602  positioned within passenger cab  116  has clear sightline  610  to first location  620  (when the scoop is lowered) and second clear sightline  612  to second location  622 . Here, first location  620  represents the closest part of the ground that is visible to driver  602  over first end portion  606  of vehicle  100 . The horizontal distance between driver  602  and first location  620  is first ground visibility distance  630 . Likewise, second location  622  represents the closest part of the ground that is visible to driver  602  over second end portion  608 . The horizontal distance between driver  602  and second location  622  is second ground visibility distance  632 . In one embodiment, the value of first ground visibility distance  630  could be approximately 9.4 meters (31 feet) and the value of second ground visibility distance  632  could be approximately 7.9 meters (26 feet). In other embodiments, first ground visibility distance  630  and second ground visibility distance  632  could have any values approximately in the range between 5 and 30 meters. 
     By contrast, the sightlines provided to a driver (not shown) in benchmark vehicle  400  are significantly worse. In the example shown in  FIG. 13 , benchmark vehicle  400  provides first ground visibility distance  650  (over the scoop) of around 15 meters (50 feet). Benchmark vehicle  400  also provides second ground visibility distance  652  over the rear of the vehicle of around 30 meters (100 feet). 
     Thus, the exemplary embodiment of vehicle  100  provides a ground visibility distance over the front of the vehicle (or the scoop end) that is approximately 38 percent shorter than the ground visibility distance of benchmark vehicle  400 . Likewise, vehicle  100  provides a ground visibility distance over the rear of the vehicle (opposite the scoop end) that is 75 percent shorter than the ground visibility distance of benchmark vehicle  400 . This significant improvement in visibility (i.e., reduced ground visibility distances) translates to better maneuverability for the driver of vehicle  100 . 
     In some cases, the degree of visibility can be measured using an H-point machine and a laser that rotates about a location where a driver&#39;s head would be. Such a method, already known in the art for evaluating front and rear visibility in traditional cars, may be used to provide an accurate measurement of the location on the ground at which the driver&#39;s view first becomes obstructed. 
       FIGS. 14 through 19  are charts comparing various performance parameters for vehicle  100  and benchmark vehicle  700 . It may be appreciated that the values given in the charts may be understood as representative of values for a given embodiment, and in other embodiments these values could vary. The parameters discussed here are ratios of hauling capacity to other vehicle characteristics such as vehicle length, footprint area, envelope volume, and visibility distance. 
     For purposes of making these comparisons, the following specifications for benchmark vehicle  700  have been used: a hauling capacity of 2.7 metric tons; dimensions of 6.3×1.6×1.5 (L×W×H in meters); ground visibility distance of 15 meters (in a forward direction) and 30 meters (in a rearward direction); and weight of 9.6 metric tons. Moreover, the values indicated for vehicle  100  in  FIGS. 14-19  are determined using exemplary parameters discussed above. These include a hauling capacity of 3 metric tons; dimensions of 5.7×1.5×1 0.6 (L×W×H in meters); ground visibility distance of 9.5 meters (in the forward direction) and 8 meters (in the rearward direction); and weight of 9.5 metric tons. 
     As previously discussed, the smaller length for vehicle  100  as compared to benchmark vehicle  700  provides for a greater hauling capacity per unit length. This comes about since vehicle  100  achieves this reduced length without sacrificing hauling capacity compared to vehicles in a similar class. As seen in  FIG. 14 , this parameter has a value of 0.5 metric tons per meter for vehicle  100  and 0.4 metric tons per meter for benchmark vehicle  700 . In other embodiments, vehicle  100  could have a hauling capacity per unit length with any value approximately in the range of 0.45 to 0.6 metric tons per meter. 
     As seen in  FIG. 15 , vehicle  100  has a greater hauling capacity per unit area than benchmark vehicle  700  (0.32 metric tons per meters-squared vs. 0.28 tons per meters-squared). In other embodiments, the hauling capacity per unit area of vehicle  100  could have any value approximately in the range between 0.3 and 0.4 metric tons per meters-squared. 
     As seen in  FIG. 16 , vehicle  100  has a greater hauling capacity per unit of front ground visibility distance than benchmark vehicle  700  (0.32 metric tons per meter vs. 0.18 metric tons per meter). In other embodiments, vehicle  100  may have a hauling capacity per unit of ground visibility distance with any value approximately in the range between 0.2 and 0.4 metric tons per meter. 
     As seen in  FIG. 17 , vehicle  100  has a greater hauling capacity per unit of rear ground visibility distance than benchmark vehicle  700  (0.38 metric tons per meter vs. 0.1 metric tons per meter). In other embodiments, vehicle  100  may have a hauling capacity per unit of ground visibility distance with any value approximately in the range between 0.2 and 0.5 metric tons per meter. 
     Embodiments can include provisions to provide increased vehicle handling. Mining vehicles that utilize electric motors may provide increased power when compared to diesel vehicles with similar hauling capacities. For example, one embodiment of vehicle  100  includes an electric motor that operates at a continuous power approximately in the range of 80 to 90 kilowatts. In some cases, vehicle  100  may operate at a peak power approximately in the range of 120-130 kilowatts. In contrast, a benchmark vehicle  700  with a hauling capacity of 2.7 metric tons may only operate with a peak power of 74 kilowatts. For reference the ratio of power to weight may be referred to herein as a “vehicle handling parameter,” as it may be considered a measure of how well the vehicle responds to input from the driver (e.g., how a vehicle responds during cornering, acceleration and breaking). In one embodiment, vehicle  100  may have a weight in the range approximately of 9400 to 9600 kilograms while vehicle  700  has a weight of 9600 kilograms. As shown in  FIG. 18 , the vehicle handling parameter (power to weight) for vehicle  100  may have a value of approximately 0.013 kilowatts per kilogram. In contrast, benchmark vehicle  700  may have a vehicle handling parameter of 0.008 kilowatts per kilogram. In some embodiments, the vehicle handling parameter of vehicle  100  could have a value approximately in the range between 0.1 and 0.15 kilowatts per kilogram. 
     Embodiments can include provisions to improve the power to volume ratio (or power density) of a vehicle. In the exemplary embodiment, vehicle  100  may have an envelope volume approximately in a range between 15 and 16 cubic-meters. Vehicle  700  may have an envelope volume of 14.5 cubic-meters. Moreover, the power to volume ratio for vehicle  100  may be approximately in the range between 7 and 9 kilowatts per cubic-meter. In one embodiment, the power to volume ratio for vehicle  100  is approximately 8.5 kilowatts per cubic meter. In contrast, benchmark vehicle  700  may have a power to volume ratio of 5 kilowatts per cubic-meter. This increased power density compared to other mining vehicles helps with improved performance in a mining environment where space (and therefore vehicle volume) may be constrained. 
       FIGS. 20 through 23  are charts comparing various performance parameters for another embodiment of vehicle  800  and benchmark vehicle  900 . It may be appreciated that the values given in the charts may be understood as representative of values for a given embodiment, and in other embodiments these values could vary. The parameters discussed here are ratios of hauling capacity to other vehicle characteristics such as vehicle length, footprint area, envelope volume, and visibility distance, and vehicle density. 
     For purposes of making these comparisons, the following specifications for benchmark vehicle  900  have been used: a hauling capacity of 4 metric tons; dimensions of 7.6×1.7×1.5 (L×W×H in meters); ground visibility distance of 15 meters (in a forward direction) and 30 meters (in a rearward direction); and weight of 14.5 metric tons. Moreover, some of the values indicated for vehicle  800  in  FIGS. 20-23  are similar to those of vehicle  800 . These include dimensions of 5.7×1.5×1.6; ground visibility distance of 9.5 meters (in the forward direction) and 8 meters (in the rearward direction); and weight of 9.5 metric tons. Vehicle  800  may have a hauling capacity of approximately 4 metric tons. 
     As seen in  FIG. 20  vehicle  800  has a hauling capacity per unit length approximately in the range between 0.6 and 0.8 metric tons per meter. In one embodiment, vehicle  800  has a hauling capacity per unit length of approximately 0.7 metric tons per meter. By contrast, benchmark vehicle  900  has a hauling capacity per unit length of 0.5 metric tons per meter. 
     As seen in  FIG. 21 , vehicle  800  has a greater hauling capacity per unit area than benchmark vehicle  900  (0.4 metric tons per meters-squared vs. 0.3 tons per meters-squared). In other embodiments, the hauling capacity per unit area of vehicle  800  could have any value approximately in the range between 0.35 and 0.45 metric tons per meters-squared. Although not shown in the figures, in some embodiments, vehicle  800  may have a greater hauling capacity per volume than benchmark vehicle  900  (0.25 metric tons per cubic-meter vs. 0.19 metric tons per cubic-meter). 
     As seen in  FIG. 22 , vehicle  800  has a greater hauling capacity per unit of front ground visibility distance than benchmark vehicle  900  (0.42 metric tons per meter vs. 0.26 metric tons per meter). In other embodiments, vehicle  800  may have a hauling capacity per unit of ground visibility distance with any value approximately in the range between 0.3 and 0.5 metric tons per meter. 
     As seen in  FIG. 23 , vehicle  800  has a greater hauling capacity per unit of rear ground visibility distance than benchmark vehicle  900  (0.5 metric tons per meter vs. 0.1 metric tons per meter). In other embodiments, vehicle  800  may have a hauling capacity per unit of ground visibility distance with any value approximately in the range between 0.3 and 0.6 metric tons per meter. 
     Although not shown in the figures, vehicle  800  may also have improved power to weight and power to volume over benchmark vehicle  900 . In embodiments where vehicle  800  has a peak power of 127 kilowatts and vehicle  900  has a peak power of 97 kilowatts, vehicle  800  may have a power to weight ratio of approximately 0.013 kilowatts per kilogram compared to a power to weight ratio of only 0.006 kilowatts per kilogram for benchmark vehicle  900 . Similarly, vehicle  800  may have a power to volume ratio of approximately 8.5 kilowatts per cubic-meter compared to a power to volume ratio of 4.6 kilowatts per cubic-meter for benchmark vehicle  900 . 
     While various embodiments of the invention have been described, the description is intended to be exemplary, rather than limiting, and it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of the invention. Any element of any embodiment may be substituted for another element of any other embodiment or added to another embodiment except where specifically excluded. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents. Also, various modifications and changes may be made within the scope of the attached claims.