The present invention relates to work machines, and, more particularly, to work machines equipped with buckets.
In the heavy equipment industry, many types of work machines are known which include buckets used to move volumes of material from one location to another. One such type of work machine is known as a tractor/loader/backhoe, often referred to simply as a “TLB,” which—as its name suggests—includes a tractor carrying a loader at a front of the tractor and a backhoe at a rear of the tractor. TLBs are popular material movers in various industries due to the versatility that is offered by having both a loader and a backhoe.
Typically, the backhoe of the TLB has a boom at one end which is pivotably attached to the tractor, a bucket at the other end of the backhoe which is pivotably independently of the boom, and a stick connected to the boom at one end and the bucket at the other end. Such an arrangement allows for many possible positions and orientations of the bucket at the end of the backhoe in order to move material. Optionally, the stick may be pivotably and/or extendably connected to the boom to allow the bucket to extend further away from tractor.
One particular problem with backhoes of TLBs occurs when the bucket is positioned within a hole formed in a surface. Due to the tractor resting on the surface into which the hole is formed, the operator may lose a line of sight of the bucket when the bucket is sufficiently deep in the hole. Further, even assuming the operator has an unobstructed view of the bucket, it is difficult for an operator, inexperienced or not, to gauge the depth of the bucket's position within the hole. When digging holes which are adjacent to underground utility pipes, lines and conduits, for example, digging the hole incorrectly not only poses a significant safety risk to the operator and work machine, but could also result in a significant utility service disruption if the bucket damages a utility pipe, line, and/or conduit while digging the hole.
To address this problem, at least one system has been developed to visualize the location of the bucket during operation. The system, known as the EZDig Pro commercially produced and sold by AGL Lasers, has multiple sensors mounted to the backhoe of a TLB wirelessly connected to a display unit which can be placed in the operator cab of the TLB. Following a calibration which tracks movement of the sensors relative to a laser level and the display unit, the EZDig Pro purports to visualize the location and orientation of the bucket based on approximations of the bucket movement characteristics as the sensors move relative to each other. While the EZDig Pro claims to be effective, the extensive calibration process is inconvenient for an operator and, if performed incorrectly, will produce inaccurate approximations of the bucket location and orientations. Further, the EZDig Pro does not integrate with the other components of the work machine, which limits the functional possibilities of the EZDig Pro.
What is needed in the art is a way to consistently and accurately monitor the location and orientation of a work machine bucket.
In accordance with an aspect of the present invention, there is provided a work machine with a controller which outputs a bucket location signal corresponding to a current bucket position and a current bucket orientation based on a determined boom angle, stick extension, and bucket angle.
In accordance with another aspect of the present invention, there is provided a work machine including: a chassis; a backhoe assembly carried by the chassis, the backhoe assembly including: a boom pivotably linked to the chassis at a boom pivot point; a boom angle sensor associated with the boom pivot point; a stick extendably linked to the boom; a stick extension sensor associated with the stick; a bucket pivotably linked to the stick at a bucket pivot point; and a bucket angle sensor associated with the bucket pivot point; and a controller coupled to the boom angle sensor, the stick extension sensor, and the bucket angle sensor. The controller is configured to: determine a boom angle of the boom; determine a stick extension of the stick; determine a bucket angle of the bucket; and output a bucket location signal corresponding to a current bucket position and a current bucket orientation, relative to the chassis, based on the determined boom angle, stick extension, and bucket angle.
In accordance with yet another aspect of the present invention, there is provided a method of locating a bucket of a work machine including a chassis, including: determining a boom angle of a boom pivotably linked to the chassis at a boom pivot point based on at least one signal from a boom angle sensor associated with the boom pivot point; determining a stick extension of a stick extendably linked to the boom based on at least one signal from a stick extension sensor associated with the stick; determining a bucket angle of the bucket pivotably linked to the stick at a bucket pivot point based on at least one signal from a bucket angle sensor associated with the bucket pivot point; and outputting a bucket location signal corresponding to a current bucket position and a current bucket orientation, relative to the chassis, based on the determined boom angle, stick extension, and bucket angle.
An advantage of the work machine described herein is that the controller can output the bucket location signal based on actual mechanical readings of the various components of the work machine rather than approximations.
Another advantage of the work machine described herein is that the controller can control other work machine functions based on the current or future bucket position.
Still another advantage of the work machine described herein is that the controller can predict a future bucket location and prevent work machine functions which may cause the bucket to be placed in a location that may cause user damage, machine damage or other types of damage.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of (an) exemplary embodiment(s) of the invention taken in conjunction with the accompanying drawing(s), wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
As shown, the loader 110 is connected to a front end 108A of the chassis 101 and includes a shovel 111 connected to the chassis 101 by a pair of adjustable shovel arms 112. The shovel 111 can be pivotably connected to the shovel arms 112 to adjust the orientation of the shovel 111 during use by activating one or more shovel actuators 113 connected to the shovel 111 via controls 105. The shovel arms 112 may also be pivotably mounted to the chassis 101, if desired. It should be appreciated that the loader 110 shown in
The backhoe assembly 120, as shown, is connected to a rear end 108B of the chassis 101 and is controlled by the controls 106 in the cabin 104. The backhoe assembly 120 includes a boom 121 pivotably linked to the chassis 101 at a boom pivot point 122, a stick 123 extendably linked to the boom 121 at one end 124A of the stick 123, and a bucket 125 pivotably linked to the stick 123 at a bucket pivot point 126 at an opposite end 124B of the stick 123. In addition to being pivotable about the boom pivot point 122, the boom 121 may also be adjustable laterally, relative to a travel direction T of the work machine 100, which is sometimes referred to as “sideshift.” Pivoting of the boom 121 relative to the chassis 101 may be controlled by a boom actuator 127 connected to the chassis 111 and the boom 121, and which may also be electrically coupled to the controller 140 as will be described further herein. Extension of the stick 123 relative to the boom 121 can be controlled by a stick actuator 128 connected to the end 124A of the stick 123 and the boom 121 and also electrically coupled to the controller 140 as will be described further herein. Pivoting of the bucket 125 relative to the stick 123 can be controlled by a bucket actuator 129 connected to the stick 123 and a corresponding linkage 130 of the bucket 125.
As is known, the boom 121 forms a boom angle αBO relative to the chassis 101 at the boom pivot point 122 and is adjustable to not only change the orientation of the boom 121, but the stick 123 and bucket 125 carried by the boom 121 as well. As described herein, the boom angle αBO is defined between a boom longitudinal axis BOA extending through the boom 121 and a longitudinal axis LA of the chassis 101, which can extend parallel to the travel direction T. Similarly, the stick 123 can define a stick axis SA extending through the stick 123 and forming a stick angle αS relative to the boom 121. The stick 123 can be angularly fixed to the boom 121, so the stick angle αS does not change, or pivotably linked to the boom 121 at a stick pivot point 131 so that the stick angle αS can be adjusted by, for example, activation of a stick angle actuator 132. Finally, the bucket 125 can define a bucket axis BUA extending through the bucket 125 and forming a bucket angle αBU relative to the stick 123. It should thus be appreciated that the boom angle αBO, stick angle αS, and bucket angle αBU are inter-related in the sense that pivoting of the boom 121 relative to the chassis 111, for example, will alter the boom angle αBO but may not necessarily alter the stick angle αS relative to the boom 121 or the bucket angle αBU relative to the stick 123. However, because the boom 121 connects the rest of the backhoe assembly 120 to the chassis 101, pivoting of the boom 121 will always necessarily affect the position and/or orientation of the stick 123 and bucket 125 relative to the chassis 101.
In order to track the location of the bucket 125 relative to the chassis 101, the backhoe assembly 120 includes a boom angle sensor 133 associated with the boom pivot point 122 and coupled to the controller 140, a stick extension sensor 134 associated with the stick 123 and coupled to the controller 140, and a bucket angle sensor 135 associated with the bucket pivot point 126 and coupled to the controller 140. If the stick 123 is pivotably connected to the boom 121, a stick angle sensor 136 may also be associated with the stick pivot point 131 and coupled to the controller 140. As used herein, the sensors 133, 134, 135, 136 are “coupled” to the controller 140 in the sense that respective data signals output by the sensors 133, 134, 135, 136 can be received by the controller 140, via a wired and/or wireless connection, and used to control various functions of the work machine 100, which will be described further herein. The boom angle sensor 133, bucket angle sensor 135, and (optional) stick angle sensor 136 can be any type of rotational angle sensors which are suitable for determining the boom angle αBO, bucket angle αBU, and stick angle αS, respectively, as well as changes in the respective angles αBO, αBU, αS. Many suitable angle sensors are known which may be suitably used for the angle sensors 133, 135, and 136, so the details of their construction are omitted for brevity. The stick extension sensor 134, on the other hand, can be any type of linear sensor which is suitable for determining a current stick length SL of the stick 123, which corresponds to a stick extension relative to the chassis 101. Many suitable linear sensors are known which may be suitably used for the stick extension sensor 134, so the details of their construction are omitted for brevity.
To track the location of the bucket 125, the controller 140 receives signals from the boom angle sensor 133 to determine the boom angle αBO relative to the chassis 101, the stick extension sensor 134 to determine the stick extension relative to the chassis 101 from the current stick length SL, and the bucket angle sensor 135 to determine the bucket angle αBU relative to the stick 123. If the stick 123 is pivotable relative to the boom 121, the controller 140 can also receive signals from the stick angle sensor 136 to determine the stick angle αS relative to the boom 121. Once the controller 140 determines the boom angle αBO relative to the chassis 101, stick extension relative to the chassis 101, bucket angle αBU relative to the stick 123, and (optional) stick angle αS relative to the boom 121, the controller 140 can determine a current bucket position, indicated as reference number 150 in
Upon determining the current bucket position 150 and current bucket orientation αCB, relative to the chassis 101, and referring now to
During operation, the operator can manipulate the backhoe assembly 120 via the controls 106 in the cabin 104. The controls 106, shown as manual levers and switches, can output control signals to the controller 140 which can couple to and selectively activate the boom actuator 127, stick actuator 128, bucket actuator 129, and/or stick angle actuator 132 to pivot the boom 121, extend the stick 123, pivot the bucket 125, and/or pivot the stick 123, respectively, based on the received control signals from the controls 106. By coupling the controls 106 to the controller 140 and the controller to the actuators 127, 128, 129, 132, the operator is able to control respective movements of the boom 121, stick 123, and bucket 125 from within the cabin 104. When the controls 106 are manipulated, the controller 140 can detect control signals from the controls 106 and appropriately activate one or more of the actuators 127, 128, 129, 132, depending upon which of the controls 106 are manipulated and the magnitude of the manipulation. Upon activating one or more of the actuators 127, 128, 129, 132 to alter the location and/or orientation of the boom 121, stick 123, and bucket 125, the controller 140 can query the coupled sensors 133, 134, 135, and/or 136 to re-determine the boom angle αBO, stick extension SL, bucket angle αBU, and stick angle αS and re-determine the current bucket position and current bucket orientation, relative to the chassis 101, and output a visualization update signal to the display 200 so the display 200 produces an updated visualization 300 of the work machine 100, as shown in
In certain instances, an operator may wish to not only know the current bucket position 150 and current bucket orientation αCB relative to the chassis 101, but also to a ground plane GP on which the work machine 100 is residing. For example, the operator may drive the work machine 100 from a relatively flat area to a sloped area of a work site without adjusting the backhoe assembly 120, in which case the previous visualization 200 of the work machine 100 showing the work machine 100 on a flat ground plane GP is not particularly helpful. To assist in determining and visualizing the relationship between the work machine 100 and the ground plane GP, and referring now to
In another exemplary embodiment formed in accordance with the present invention, and referring now to
In another exemplary embodiment formed in accordance with the present invention, and referring now to
With further reference to
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It is to be understood that the steps of the methods 900, 1000, and 1100 are performed by a respective controller 140 upon loading and executing software code or instructions which are tangibly stored on a tangible computer readable medium, such as on a magnetic medium, e.g., a computer hard drive, an optical medium, e.g., an optical disc, solid-state memory, e.g., flash memory, or other storage media known in the art. Thus, any of the functionality performed by the controller 140 described herein, such as the methods 900, 1000, and 1100, is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. Upon loading and executing such software code or instructions by the controller 140, the controller 140 may perform any of the functionality of the controller 140 described herein, including any steps of the methods 900, 1000, and 1100 described herein.
The term “software code” or “code” used herein refers to any instructions or set of instructions that influence the operation of a computer or controller. They may exist in a computer-executable form, such as machine code, which is the set of instructions and data directly executed by a computer's central processing unit or by a controller, a human-understandable form, such as source code, which may be compiled in order to be executed by a computer's central processing unit or by a controller, or an intermediate form, such as object code, which is produced by a compiler. As used herein, the term “software code” or “code” also includes any human-understandable computer instructions or set of instructions, e.g., a script, that may be executed on the fly with the aid of an interpreter executed by a computer's central processing unit, by a controller, or by a controller system.
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.