Abstract:
Tip-off is a process of bringing a transport vehicle to a target weight by using only part of a bucket of a loader. By observing sensor data, tip-off may be automatically determined. Once determined, a visual indication may be made to an operator, allowing the operator to both confirm that tip-off mode is active and to show what tip-off mode is selected, truck tip-off or pile tip-off. Among other benefits, automatic tip-off allows an operator to maintain contact with the loader controls when entering tip-off mode of operation.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates generally to loaders and more particularly to loading a container with a desired payload weight of loose material, and automatically detecting and displaying a tip-off mode of operation. 
       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. Payload information, including the desired type and amount of payload material for each truck needs to be communicated to the quarry personnel who operate the loaders. For instance, this information might be transmitted from a quarry office based computer to a mobile computer on the loader via wireless communication as described in co-owned U.S. Pat. No. 5,848,368. This information enables the loader operator to proceed to the correct pile corresponding to the requested material. 
         [0003]    A typical work cycle can begin with the operator first positioning the bucket of the loader at a pile of the requested material. The bucket is then lowered so that the work implement is near the ground surface. The operator then advances into the pile and controls the bucket to raise the work implement through the pile to fill the bucket and lift the material. The operator then tilts or pitches the bucket back to capture the material. The operator then moves the loader to a desired target location, such as an over the road truck, and dumps the captured material from the bucket. The operator then moves the loader back to the pile to start this work cycle over again. In the case of typical over the road trucks, depending upon their size, a full load will typically require between three and six bucket loads to fill the truck with the desired material up to a target load weight. 
         [0004]    Many of today&#39;s loaders have payload control systems that allow for accurate measurements of the bucket payload. Thus, with each successive bucket, the loader can sum the load weight of the bucket loads to determine an estimated amount of payload already in the truck. Typically, on a final pass of the truck loading cycle, the loader adds less than a full bucket payload to the truck in a process known as tip-off. 
         [0005]    There are two approaches to tip-off. One approach is to load the bucket at the pile and use in-vehicle sensors to determine the load in the bucket and tip-off the excess amount at the pile, leaving in the bucket the amount needed at the road truck. This is known as pile tip-off. Another approach is to rack the bucket and partially empty the bucket into the road truck to reach the target road truck capacity, known as truck tip-off. 
         [0006]    Because the loader can keep track of how much material, by weight, has been added to the road truck it is important that the loader know what type of tip-off was used. In pile tip-off, the amount remaining in the bucket will be added to the truck load. In truck tip-off, the amount off-loaded will be added to the truck load. In many cases, the final truck payload determines both the sale price of the payload, but may also be used to calculate incentives for the loader operator. 
         [0007]    Co-owned U.S. Pat. No. 6,211,471 describes a process that reweighs material in the bucket after the operator performs a partial dump. However, in practice, operators must first pre-set what type of tip-off is being used (pile vs. truck) and then explicitly indicate that they are about to perform a tip-off. This raises several potential issues. If the type of tip-off is incorrect, the load delivered to the truck will be incorrectly calculated, with a potential financial impact. If the operator forgets to indicate a tip-off, the load also may be incorrectly calculated and may require re-weighing or even reloading. In addition, there is a safety concern because the operator must remove his or her hand from the controls to push the tip-off button each time a tip-off is performed. This continuous attention to tip-off setting and the physical motions associated with may, over a period of time, increase operator fatigue. 
       SUMMARY 
       [0008]    In one aspect, a method of enhancing tip-off operation in a loader, the method includes receiving at least one input from one or more sensors in the loader, using the at least one input, automatically detecting a tip-off and setting a tip-off mode to active. The method may also include setting an operator display to indicate that the tip-off mode is active, and setting an operator display to indicate a tip-off location. After determining that the tip-off is complete the method may continue by setting the tip-off mode to inactive and setting the operator display to indicate that the tip-off mode is inactive. 
         [0009]    In another aspect, a system for enabling hands-free tip-off operation in a loader with a bucket can include a display configured to display icons related to truck payload, bucket payload, tip-off location, and tip-off mode, an input that receives operating instructions, a plurality of sensors that report a position of the bucket and a mass of material in the bucket and an electronics control module (ECM). The ECM can include a processor, a memory, and computer-executable modules stored in the memory that are executed on the processor. The modules can include a first module that receives the operating instructions and sets a tip-off location, a second module that receives information from the plurality of sensors and determines a tip-off operation and sets a tip-off mode to active, a third module that causes the display to show that a tip-off mode is active and a current tip-off location, and a fourth module that stores tip-off payload information until an indication that the tip-off mode has ended. This may cause the third module to store the tip-off payload in the current tip-off location and further cause the second module to a change the display to show that tip-mode is inactive. 
         [0010]    In yet another aspect, a method of reducing human-computer interaction in a loader during tip-off operation may include without human input, automatically detecting a tip-off operation, displaying an indication of operation in a tip-off mode, displaying an indication of a tip-off location, and storing payload data according to the tip-off mode and tip-off location. The method may also include detecting completion of the tip-off operation and clearing the display of the indication of operation in the tip-off mode. 
         [0011]    These and other benefits will become apparent from the specification, the drawings and the claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a view of a loader; 
           [0013]      FIG. 2  is a block diagram of an electronics system of the loader; 
           [0014]      FIG. 3  is a screen shot of a display of the electronics system showing payload operation; 
           [0015]      FIG. 4A  is a screen shot of the display of the electronics system showing tip-off operation; 
           [0016]      FIG. 4B  is a screen shot of a portion of the display of the electronics system in one state; 
           [0017]      FIG. 4C  is a screen shot of a portion of the display of the electronics system in another state; 
           [0018]      FIG. 5  is a flowchart of a method of dynamic tip-off detection, display, and location selection; 
           [0019]      FIG. 6  is a flowchart illustrating tip-off mode detection; and 
           [0020]      FIG. 7  is a flowchart of a method of determining tip-off mode completion. 
       
    
    
     DESCRIPTION 
       [0021]      FIG. 1  illustrates a loader  10  having a bucket  12 , a payload controller  14 , a communication line  16 , a displacement sensor  17  that communicates a position of a bucket tilt cylinder  18 , a lift cylinder  19 , and a lift cylinder position sensor  20 . The bucket  12  is shown in a number of positions. Position  12   a  illustrates the bucket  12  in position for a dig. Position  12   b  illustrates the bucket  12  fully racked, or tipped up. Position  12   c  illustrates the bucket  12  fully dumped. 
         [0022]      FIG. 2  is a block diagram of the payload controller  14 . The payload controller  14  may be part of or adjunct to another electronics computing module (not depicted) that may include an engine controller, chassis controller, etc. The payload controller  14  may include a processor  102  and a memory  104  that communicate via an internal communication bus  106 . The payload controller  14  may include or may provide data to a display  108 , discussed in more detail below. 
         [0023]    The payload controller  14  may also include a cab control input block  110  that receives input from the cab, such as, but not limited to load information and switch position data, such as a store switch or a clear switch related to bucket payloads. A communication port  112  may send and receive data via the communication line  16 . Sensor input block  114  may receive information from a variety of sensors, including displacement sensor  17  and lift cylinder position sensor  20 . The cab control input block  110  and the sensor input block  114  may receive information via direct connections with, for example, a sensor or may receive information via the communication line  16  and communication port  112 . 
         [0024]    The sensor input block  114  may be configured to receive and process information about bucket tilt, lift arm position, various hydraulic pressures such as pressure at the lift cylinder  19  or bucket tilt cylinder  18 . 
         [0025]    The memory  104  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  104  may include an operating system  116  and utilities  118 , such as diagnostic routines, etc. The memory  104  may also include a number of modules  120 ,  121 ,  122 ,  123 ,  124  having executable code that may be executed by the processor to cause specific effects and actions to be taken in the payload controller  14  or at the display  108 . These exemplary modules  120 - 124  will be discussed in more detail below. 
         [0026]      FIG. 3  illustrates a screen shot of the display  108  showing an exemplary payload display screen  130 . The payload display screen  130  may include information both about the loader  10  itself and the truck (not depicted) that is being loaded. The embodiment of the payload display screen  130  illustrated has current condition information that may include a current truck payload weight  132  and a number of buckets used  134  to reach the designated weight. The payload display screen  130  may include a remaining weight  136  to be added to the current truck to reach its target weight, the amount of material currently in the bucket  138  and the units of measure  140  (in this case tons). 
         [0027]    The payload display screen  130  may also include other operational information or inputs including a zero button  142  that allows zeroing the weight of the bucket, for example, if material is stuck in the bucket, a reweight button  144  that enables a new bucket weight to be calculated, for example, by lowering and lifting the bucket  12 . A truck identifier  146  allows a truck being loaded to be identified and a material identifier  148  allows the type of material to be selected from, for example, a previously stored list. Other buttons may include a standby button  150 , a clear button  152  that excludes the current truck load from memory, and a print button  154 . 
         [0028]      FIGS. 4A ,  4 B and  4 C illustrate a dynamic tip-off display screen  160  that may include much of the data presented in the payload display screen  130  but that may also include modified or re-purposed icons. 
         [0029]    Turning to  FIG. 4A , the truck and material identifier buttons of  FIG. 3  may be re-purposed to illustrate tip-off mode. For example, the soft button  168  is illustrated as being redefined to allow the tip-off mode to be toggled between pile tip-off and truck tip-off. The soft button  170  may be re-purposed to allow splitting a bucket load across two trucks. 
         [0030]    Turning briefly to  FIGS. 4B and 4C , the icons  162  and  164  are shown separately for clarity. In  FIG. 4B , the highlight  172  illustrates both that the payload controller  14  is operating in tip-off mode and that the mode is set to pile tip-off.  FIG. 4C  illustrates via a highlight  172  both that the payload controller  14  is operating in tip-off mode and that the mode is set to truck tip-off. That is, the highlight in either position indicates tip-off mode is active and the location of the highlight indicates which tip-off mode is active. 
       INDUSTRIAL APPLICABILITY 
       [0031]    Accurate load weights are used both to maximize the efficiency of a loading operation and also to incentivize loader operators to accurately hit target weights in vehicles. At the same time, operator activity associated with tip-off mode operation can become a both a distraction to an operator and can cause fatigue that can be exhibited in a range of consequences from inaccurate weights being reported to injury and/or damage caused by an operator repeatedly removing his or her hands from the controls in order to manually enter tip-off mode. 
         [0032]    Automatically determining tip-off operation and setting the display to show a readily discernible indication of both tip-off operation and tip-off mode benefits both a loading operation and a loading operator. Further, the ability to change tip-off mode at any time during the tip-off means that fewer loads need to be emptied or re-weighed. In addition, work site safety may be improved because operators experience less distraction using automatic tip-off detection compared to manually entering tip-off mode each time it is required. 
         [0033]      FIG. 5  is a flow chart of a method  200  of dynamic tip-off detection, display, and location selection. At a block  202 , input from one or more sensors in the loader  10  may be received at a payload controller  14  or other electronic control module (ECM). 
         [0034]    At block  204 , using the at least one input, automatically detecting a tip-off. The process of automatically detecting a tip-off is discussed in more detail below with respect to  FIG. 6 . 
         [0035]    At block  206 , a tip-off mode may be set to active, for example, by setting a memory location in the payload controller  14  or other ECM. In an embodiment, setting the memory location causes certain modules stored in the payload controller  14  or other ECM to be used for determining tip-off mode or location, storing partial bucket weights, and monitoring sensors for indications that tip-off mode has ended. 
         [0036]    At block  208 , an operator display may be set to indicate that the tip-off mode is active. This may include, as shown in  FIG. 4B and 4C , highlighting an icon on a display in the loader that also indicates what tip-off mode is currently selected at block  210 . Other indications of tip-off location may be used, such as a text indicator (not depicted). 
         [0037]    At block  212 , an input to change the tip-off location may be received. Of course, if the current tip-off location is accurate, there would be no reason for an operator to change the selection of tip-off location. As discussed above, the selection of tip-off location affects the nature of the bucket payload data that is stored. At its simplest, a pile tip-off retains the weight of material stored after a partial dump and a truck tip-off retains the weight of material removed by a partial dump. 
         [0038]    At block  214 , determining that the tip-off is complete may be accomplished by any one of several mechanisms. See  FIG. 7  and the discussion below for more details. 
         [0039]    At block  216 , after determining that the tip-off is complete, the tip-off mode may be set to inactive and at block  218 , the display may be reverted to non-tip-off mode functionality (see, e.g.,  FIG. 3 ). 
         [0040]      FIG. 6  is a flowchart of a method  220  of automatically detecting a tip-off mode of operation in a loader  10  and may be used at block  204  of  FIG. 5 . 
         [0041]    At block  222 , a dig operation may be identified by observing a position of the bucket  12  and at least a lift arm position, using, for example, lift cylinder position sensor  20 . The dig operation may result in the bucket  12  taking on a load of material. 
         [0042]    At block  224 , sensors may be used to identify that the bucket  12  is fully racked, indicating that the dig operation is complete. Fully racking the bucket  12  may provide weight and balance information to the payload controller that may be used to either calculate or estimate the weight of the payload in the bucket  12 . 
         [0043]    At block  226 , a partial dump of the bucket  12  may be identified. Pressure sensors associated with the lift cylinder  19  and bucket tilt cylinder  18  may provide information used to determine that the bucket  12  was not fully dumped, both by position and by weight. At the completion of this cycle, at block  228 , tip-off mode may be determined and tip-off mode may be set to active. 
         [0044]      FIG. 7  is a method  240  of determining completion of a tip-off mode of operation in a loader and may be used at block  214  of  FIG. 5 . Beginning at block  242  with tip-off mode active, a series of conditions may be checked, any of which may indicate completion of the tip-off mode. 
         [0045]    At block  244 , the operator may manually cause tip-off data to be stored via a user interface, such as a touch screen input on the display  108 , signifying an end to tip-off mode and causing execution to follow the ‘yes’ branch to block  252  where the tip-off mode is set to inactive. 
         [0046]    If the operator has not manually stored tip-off data, execution may continue at block  246 . 
         [0047]    At block  246 , the operator may manually cancel the tip-off mode also causing execution to follow the ‘yes’ branch to block  252 . If the operator has not canceled the tip-off mode, execution may continue at block  248 . 
         [0048]    At block  248 , input from sensors may be used to determine if a complete dump has occurred. In one embodiment, the split mode may have been used to split a bucket payload across two trucks. In another embodiment, the bucket  12  may simply have been dumped. Following a complete dump, execution may follow the ‘yes’ branch and execution continued at block  252 . If a complete dump has not occurred, execution may continue at block  250 . 
         [0049]    At block  250 , a determination of a dig may made, as described above, using bucket position and cylinder pressure sensors. A dig will cause partial payload information to be lost, so that effectively cancels the tip-off information available and therefore puts an end to the current tip-off mode operation by following the ‘yes’ branch to block  252 . 
         [0050]    If a dig has not occurred, execution may follow the ‘no’ branch to block  242  and the loop may be traversed again to determine completion of the tip-off mode. Other specific methods may be used to determine the end of tip-off mode, such as using interrupts to signal active states rather than the loop described above or any number of other techniques for determining a condition, such as polling. 
         [0051]    In an embodiment, various code modules may be used to implement the dynamic tip-off functionality. Referring again to  FIG. 2 , a first code module  120  may receive input from an operator, such as operating instructions and, more particularly, to set a tip-off location. A second code module  121  may receive information from the plurality of sensors and determine a tip-off operation and sets a tip-off mode to active as discussed above with respect to  FIG. 6 . 
         [0052]    A third code module  122  may cause the display to show that a tip-off mode is active and a current tip-off location. For example, a screen icon may be highlighted as discussed above with respect to  FIG. 4B  and  FIG. 4C . A fourth code module  123  may store tip-off payload information until an indication that the tip-off mode has ended, causing the third code module  122  to store the tip-off payload weights in the current tip-off location. In this state, the fourth code module may also cause the second code module  121  to a change the display to show that tip-mode is inactive. A fifth code module  124  may receive an indication of a tip-off location change that causes the third code module to store the tip-off payload in a new tip-off location. The fifth code module  124  may be active even after the tip-off mode is inactive, for example, until a new dig is detected, allowing an operator to change the tip-off mode after the load dump and potentially avoid misrepresenting actual truck loading or causing a truck to dump its contents and start over. 
         [0053]    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.