Abstract:
Real time monitoring and comparison of bucket payload and truck payload during a loading process allows calculation of material lost in transfer between the loader and the truck. The lost or spilled material represents increased costs due to additional trips of the loader to fully load trucks and also in non-value added worksite cleanup time. The payload monitoring system can not only evaluate the mass of material lost over a period of time but can also calculate the value of that lost material using real time commodity pricing. The period of time can range from a single bucket dump to a workshift or longer. Payload masses and/or calculated values may be communicated directly between vehicles or may be communicated in conjunction with a central station.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to loaders and more particularly to a process for determining losses to due undesired events during the process of loading a truck using a loader. 
       BACKGROUND 
       [0002]    In quarries and other types of payload material collection sites, mobile loaders, such as wheel loaders, backhoe loaders, and track type loaders are used to load loose payload material into haul vehicles, such as over the road trucks. In the course of loading the truck some material may not successfully transfer from the loader to the truck and drop to the ground. The material that misses the truck requires, over a day, more trips of the loader to fill the trucks as well as periodic cleanup work to clear the spilled material, both of which require non-productive work time. 
         [0003]    European patent EP2144191 discloses a system that weights material when it is stored in a warehouse and weights it again when it is removed from storage and loaded on a truck for use in inventory tracking and in order to determine if a theft has occurred while the material was in the warehouse. The &#39;191 patent fails to disclose lost material mass that occurs while loading a truck. 
         [0004]    Co-owned U.S. Pat. No. 7,864,066 describes a system that monitors for material falling off a truck while traveling to its destination but fails to quantify the loss or discuss material that is lost during the loading process. 
       SUMMARY 
       [0005]    In one aspect, a method of measuring material lost during vehicle loading includes receiving, at a controller, a bucket payload mass of a material delivered via the bucket of a loader to a truck and a truck payload mass of the material received via the bucket of the loader at the truck. The controller or a related computing device may calculate a lost material mass of the material as a difference between the bucket payload mass and the truck payload mass. 
         [0006]    In another aspect, A system for use in measuring material lost during vehicle loading at a worksite may include a loader having a bucket and a bucket payload monitor that reports a first payload mass of a material delivered via the bucket of the loader. The system may also include a truck configured to carry the material and a truck payload monitor that reports a second payload mass of the material loaded onto the truck via the bucket of the loader. The system may further include a controller that subtracts the second payload mass from the first payload mass to generate a lost payload mass. 
         [0007]    In yet another aspect, a controller for use in measuring a lost mass of a material developed during vehicle loading at a worksite may include a memory that stores program modules and data, a processor coupled to the memory that executes the program modules, an input that receives a bucket payload mass from a loader and a truck payload mass of the material delivered from the bucket to a truck, and a program module stored in the memory that, when executed by the processor, subtracts the truck payload mass from the bucket payload mass to produce the lost material mass. 
         [0008]    These and other benefits will become apparent from the specification, the drawings and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a view of a worksite with a loader and truck; 
           [0010]      FIG. 2  is a block diagram of a system for payload monitoring comparison; 
           [0011]      FIG. 3  is a block diagram of an alternate embodiment of a system for payload monitoring comparison; 
           [0012]      FIG. 4  is a block diagram of a controller for use in payload monitoring comparisons, and 
           [0013]      FIG. 5  is a flowchart of a method of performing payload monitoring comparisons. 
       
    
    
     DESCRIPTION 
       [0014]      FIG. 1  illustrates worksite  100  illustrating a loader  102  having a bucket  104 , and a controller  106  that presents information via an operator display  108 . The controller  106  may use sensors (not depicted) to calculate a bucket payload of material  114  prior to the bucket  104  being emptied. The worksite  100  also illustrates a truck  110  loaded with a payload  112  of material  114 . Also illustrated is a quantity of lost material  116  spilled during the process of emptying the bucket  104  into the truck  110 . A controller  118  (hidden) may use sensors to calculate a mass of the payload  112  of material  114 , which may be displayed via display  120 . Both the operator display  108  and the truck display  120  may be parts of user interfaces supported by the respective controllers  106  and  118 . These user interfaces may also present selections for what metric to display and, in the case of the loader  102 , whether or not this is a calibration sample. The controllers  106  and  118  may be part of a respective payload control system, engine or body control system, or may be separate standalone units. 
         [0015]      FIG. 2  is a block diagram of a system configuration  130  for implementing a payload monitoring comparison. In this embodiment, the loader  102  may report the bucket payload mass of material  114  delivered after a dump operation to a central station  132  over a network link  134 . The network link  134  may be a real time wireless link but in other embodiments bucket payload amounts may be reported via a wired network or flash drive once the loader  102  has returned to a work center, for example, at the end of a shift. 
         [0016]    Similarly, the truck  110  may report truck payload amounts corresponding to a particular delivery of material  114  via the bucket  104  using a wireless link  136  to the central station  132 . 
         [0017]    The central station  132  may use the bucket payload mass and the truck payload  112  mass to arithmetically arrive at a mass of the lost material, such as lost material  116  (e.g., spillage) of  FIG. 1 . The lost material may occur if the truck  110  is overfilled either in one area or entirely, so that excess material spills out of one or both sides of the truck  110 . In other cases, the bucket  104  may be incorrectly positioned when emptying so that some of the material misses the truck  110  entirely and is dumped directly on the ground. 
         [0018]    In an embodiment, the central station  132  may have a commodity price of the material, for example, that may be received via a satellite  138  or other network service. The commodity price may be used to calculate a value of the lost material. Additionally, the mass or even the volume of the lost material may be used to calculate an approximate cleanup time, using for example, a number of minutes per cubic yard for cleanup multiplied by the cost per minute to operate the loader  102  and/or other vehicles used in the cleanup. 
         [0019]    Any or all of the values for lost material mass, lost material value, and cleanup costs may be sent from the central station  132  to the loader  102 . In some cases, such as where a truck driver may have a direct involvement in material spills, for example, moving before loading is complete, the truck  110  may also display one or more of these values. 
         [0020]      FIG. 3  illustrates another system configuration  140  for implementing a payload monitoring comparison. In this embodiment, the truck  110  may report the truck payload  112  to the loader  102 , where the comparison of bucket payload, measured locally at the loader  102 , and the truck payload is made. In this exemplary embodiment, the loader  102  may report the results of the comparison to the central station  132 . As illustrated, the loader  102  itself may store or receive the commodity pricing of the material. Other combinations are possible, including the loader  102  providing the lost material mass to the central station  132  and the central station  132  adding the value calculations as in the configuration of  FIG. 2 . 
         [0021]    To illustrate further using a specific embodiment, the loader  102  may have a bucket  104  that carries 10 cubic yards of material. For dry gravel, a mass of 10 cubic yards may weigh about 26,700 pounds. If 26,100 pounds of payload gravel are received at the truck  110 , simple subtraction says that 600 pounds of material was lost in the transfer, assuming good calibration between loader  102  and truck  110  and minimal errors measuring the respective masses. If gravel sells for $28 per ton, the value of 600 pounds is about $8.40. 
         [0022]      FIG. 4  is a block diagram of a representative controller  170 . The controller  170  may be the same as or similar to the controller  106  or  118  of  FIG. 1 , or may be incorporated in the central station  132 . The controller  170  may be part of or adjunct to another electronics computing module (not depicted) that may include an engine controller, chassis controller, etc. The controller  170  may include a processor  171  and a memory  172  that communicate via an internal communication bus  174 . The controller  170  may include or may provide data to a display  108  via display output  182 . 
         [0023]    The controller  170  may send and receive data via a communication port  178 . Sensor input block  180  may receive information from a variety of sensors, including one or more strain gauges, lift cylinder position sensors, and/or hydraulic pressure sensors (not depicted) for use in determining bucket payload mass or truck payload mass. 
         [0024]    The memory  172  may be any combination of volatile and non-volatile memory, including rotating media, flash memory, conventional RAM, ROM or other non-volatile programmable memory, but does not include carrier waves or other propagated media. The memory  172  may include an operating system  184  and utilities  186 , such as diagnostic routines, etc. The memory  172  may also include executable code and data, such as a lost load monitor module  188  and data storage for values, such as but not limited to, bucket payload mass  190 , truck payload mass  192 , lost mass  194 , cumulative values  196 , such as cumulative lost mass and cumulative value of lost mass, and commodity prices  198  used for calculating value. 
         [0025]    The controller  170  is an illustration of one embodiment for implementing the payload monitoring comparison. In other embodiments, the functions supported by the controller  170  may be arranged differently, spread between processing units in separate vehicles or controls stations, or maintained in a cloud service remote from the worksite  100 , to name a few variations. 
       INDUSTRIAL APPLICABILITY 
       [0026]    The ability to track lost material during loading provides a valuable tool for improving productivity and for operator training and real time feedback. A worksite manager gets valuable information in the form of business metrics about the operation and can use these business metrics to improve conditions that may lead to more accurate loading, such as more consistent location of trucks  110  or position guidance for loaders  102 . 
         [0027]    These business metrics may include lost material per shift, worksite cleanup time costs, additional loader work cycles (extra trips) due to lost material, the operating expense of both the cleanup operation and the additional loader work cycles, etc. 
         [0028]      FIG. 5  is a flow chart of a method  200  of payload monitoring comparison. At block  202 , a bucket payload mass may be received at a controller  170 . The bucket payload mass may be calculated in one of several known manners, such as the use of hydraulic pressure sensors and bucket position sensors. The controller  170  may be part of a loader  102  or located at a central station  132 . The bucket payload is subsequently delivered to the truck  110 . If an operator has designated this bucket payload as a calibration payload, an assumption is made that the operator will exert care to see that all the bucket payload material is delivered to the truck  110  so that an adjustment factor can be applied to account for any differences in the payload mass calculation systems of the loader  102  and the truck  110 . In an embodiment, each truck  110  in use may have to have a calibration load to create a correction factor for each loader  102  in use. 
         [0029]    At block  204 , the truck payload mass is then received at the controller  170 . The truck payload mass may be developed at the truck by any number of known mechanisms including strain gauges. Alternatively, the truck payload may be developed externally using a worksite scale and a standard “weight before loading” subtracted from “weight after loading.” 
         [0030]    At block  206 , the truck payload mass may be subtracted from the bucket payload mass to calculate a lost material mass. 
         [0031]    Optionally, at block  208 , a commodity value of the material may be received at the controller  170 . As discussed above, the commodity value may be stored in the controller  170  at the beginning of a shift or for highly volatile commodities, may be received on a regular basis via a network or broadcast feed. 
         [0032]    In conjunction with block  208 , optional block  210  may provide for calculation of a monetary value of the lost material mass by multiplying the lost material mass by the value of the material per unit. 
         [0033]    At block  212 , the cumulative lost material mass, lost material value, or both, may be recorded in a local memory, a remote memory, or via hardcopy. At block  214 , the lost material mass, its value, or both may be presented in real time at an operator station in the loader  102  or at a dispatch or other console at the central station  132 . As discussed above, the ability to present lost material information provides timely feedback for both loader operators and worksite managers to improve efficiency and lower costs. 
         [0034]    In accordance with the provisions of the patent statutes and jurisprudence, exemplary configurations described above are considered to represent a preferred embodiment of the invention. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.