Patent Description:
Construction vehicles, such as loaders, diggers, graders, and the like, typically utilize hydraulically controlled implements, such as blades or buckets, to move or pick up dirt and other materials. Sometimes these vehicles include various types of sensors to track a position of a working edge of the implement. As an example, an excavator may include multiple global navigation satellite system (GNSS) units on a cab to determine location and heading of the excavator, as well as angle sensors on the boom, stick, and bucket to track a position of a cutting edge of the bucket. The sensors enable machine control of the construction vehicle to improve quality and efficiency. Despite the benefits of these systems, improvements are constantly sought to simplify hardware, improve accuracy, and reduce costs. A construction vehicle comprising a system for tracking a position of a working edge on an implement of the construction vehicle is known from <CIT>.

Embodiments of the present disclosure include improved construction vehicles comprising systems for tracking a working edge on an implement of the construction vehicle. Some embodiments use a survey pole with a GNSS receiver that is configured to provide tilt compensation. The survey pole is coupled to a rigid member of the construction vehicle, where the rigid member is coupled to the implement at a pivot point. Other embodiments include a mount on the rigid member, and the GNSS receiver is coupled to the mount. The GNSS receiver can be used to track a position of the pivot point and a heading of the rigid member. An angle sensor coupled to the implement can provide rotation information that allows coordinates of a working edge of the implement to be determined.

In accordance with a specific embodiment, an excavator comprising a system for tracking a position of a cutting edge on a bucket of the excavator, the bucket coupled to the excavator at a pivot point between a stick of the excavator and the bucket, a hydraulic mechanism coupled to the stick and configured to provide rotational movement of the bucket, an inertial measurement unit (IMU) coupled to the bucket and configured to determine rotation of the bucket, the system includes a survey pole coupled to the stick; a GNSS unit coupled to the survey pole, the survey pole arranged relative to the stick so that the GNSS unit remains free from contact with any part of the excavator, the bucket, or the stick during a full range of motion of the stick, the GNSS unit including an antenna arranged in a known spatial relationship with the pivot point between the stick of the excavator and the bucket, the GNSS unit configured to determine a position of the antenna and a tilt and a heading of the GNSS unit; and a mobile controller configured for wireless communications with the GNSS unit and the IMU, the mobile controller configured to receive the position of the antenna, the tilt, and the heading from the GNSS unit, and to receive the rotation of the bucket from the IMU, the mobile controller configured to determine coordinates of the cutting edge of the bucket in a real world coordinate frame.

In an embodiment, the survey pole includes an upper portion of a grade rod that has been removably detached from a lower portion of the grade rod and the survey pole does not include a tip.

In another embodiment, the GNSS unit includes a GNSS receiver.

In yet another embodiment, the mobile controller is a cell phone.

In accordance with another embodiment, a skidsteer comprising a system for tracking a position of a cutting edge on a bucket of the skidsteer, the bucket coupled to the skidsteer at a pivot point between arms of the skidsteer and the bucket, a hydraulic mechanism coupled to the arms and configured to provide rotational movement of the bucket, an IMU coupled to the bucket and configured to determine rotation of the bucket, the system includes a survey pole coupled to one of the arms of the skidsteer; a GNSS unit coupled to the survey pole, the survey pole arranged relative to the arms of the skidsteer so that the GNSS unit remains free from contact with any part of the skidsteer, the bucket, or the arms during a full range of motion of the arms, the GNSS unit including an antenna arranged in a known spatial relationship with the pivot point between the arms of the skidsteer and the bucket, the GNSS unit configured to determine a position of the antenna and a tilt and a heading of the GNSS unit; and a mobile controller configured for wireless communications with the GNSS unit and the IMU, the mobile controller configured to receive the position of the antenna, the tilt, and the heading from the GNSS unit, and to receive the rotation of the bucket from the IMU, the mobile controller configured to determine coordinates of the cutting edge of the bucket in a real world coordinate frame.

In accordance with another embodiment, a construction vehicle comprising a system for tracking a position of a working edge on an implement of a construction vehicle, the implement coupled to the construction vehicle at a pivot point between a rigid member of the construction vehicle and the implement, a hydraulic mechanism coupled to the rigid member and configured to provide rotational movement of the implement, an angle sensor coupled to the implement and configured to determine rotation of the implement, the system includes a GNSS unit coupled to a mount on the rigid member, the mount arranged relative to the rigid member so that the GNSS unit remains free from contact with any part of the construction vehicle, the implement, or the rigid member during a full range of motion of the rigid member, the GNSS unit arranged in a known spatial relationship with the pivot point between the rigid member of the construction vehicle and the implement, the GNSS unit configured to determine a position, a tilt, and a heading of the GNSS unit; and a mobile controller configured for wireless communications with the GNSS unit and the angle sensor, the mobile controller configured to receive the position, the tilt, and the heading from the GNSS unit, and to receive the rotation of the implement from the angle sensor, the mobile controller configured to determine coordinates of the working edge of the implement in a real world coordinate frame.

In some embodiments, the construction vehicle may be an excavator, while in other embodiments, the construction vehicle may be a skidsteer. The implement may be a bucket, and the rigid member may include a stick of an excavator or arms of a skidsteer. The angle sensor may include an IMU.

The system also includes a survey pole coupled to the mount, wherein the GNSS unit is coupled to the survey pole.

In accordance with yet another embodiment, a construction vehicle comprising a system for tracking a position of a working edge on an implement of a construction vehicle includes a GNSS unit including an antenna, the GNSS unit configured to determine a position of the antenna and a tilt and a heading of the GNSS unit; a mount configured to couple the GNSS unit to a rigid member of the construction vehicle, the rigid member coupling the implement to the construction vehicle and the rigid member coupled to the implement at a pivot point between the rigid member and the implement, the mount configured to couple the GNSS unit to the rigid member so that the antenna is arranged in a known spatial relationship with the pivot point between the rigid member and the implement; and a mobile controller configured for wireless communications with the GNSS unit and an angle sensor, the angle sensor configured to determine rotation of the implement, the mobile controller configured to receive the position of the antenna, the tilt, and the heading from the GNSS unit, and to receive the rotation of the implement from the angle sensor, the mobile controller configured to determine coordinates of the working edge of the implement in a real world coordinate frame.

In an embodiment, the system also includes a survey pole, wherein the mount is a mounting mechanism configured so that the survey pole can be rigidly attached to the mounting mechanism and so that the survey pole can be detached from the mounting mechanism, and wherein the mounting mechanism is configured so that when the survey pole is attached to the mounting mechanism, the antenna of the GNSS unit is arranged in approximately the known spatial relationship with the pivot point between the rigid member and the implement.

Numerous benefits are achieved using embodiments described herein over conventional systems. Some embodiments, for example, simplify hardware requirements for tracking a position of a working edge on an implement of a construction vehicle. Conventional systems require multiple GNSS units and multiple angle sensors, whereas some embodiments need only a single GNSS unit and a single angle sensor. This reduces the components that are subject to damage and wear. The GNSS unit is used to measure position and heading of the construction vehicle, and the GNSS unit can be used with a survey pole for other purposes such as standard stake-out operations. This reduces duplication of equipment and also reduces costs. Depending on the embodiment, one or more of these features and/or benefits may exist.

The accompanying drawings, which are included to provide a further understanding of the embodiments described herein, are incorporated in and constitute a part of this specification, illustrate various embodiments, and together with the detailed description, serve to explain some principles of operation. No attempt is made to show structural features in more detail than may be necessary for a fundamental understanding of the various embodiments and ways in which they may be practiced.

In the appended figures, similar components and/or features may have the same numerical reference label. Further, various components of the same type may be distinguished by following the reference label with a letter or by following the reference label with a dash followed by a second numerical reference label that distinguishes among the similar components and/or features. If only the first numerical reference label is used in the specification, the description is applicable to any one of the similar components and/or features having the same first numerical reference label irrespective of the suffix.

Embodiments of the present disclosure include systems for tracking a working edge on an implement of a construction vehicle. As an example, some embodiments track a cutting edge on a bucket of an excavator. A survey pole with a GNSS receiver is configured to provide positioning and tilt compensation. The survey pole is coupled to a stick of the excavator in some embodiments, while in other embodiments the GNSS receiver is coupled directly to a mount on the stick. The GNSS receiver can be used to track a position of a pivot point between the stick and the bucket and a heading of the stick. An angle sensor coupled to the bucket can provide rotation information that allows coordinates of the cutting edge to be determined.

An excavator and skidsteer are used herein as exemplary construction vehicles. Embodiments of the present disclosure can also be used with other types of construction vehicles. For example, the systems described herein can be implemented with other diggers that include sticks, other loaders that include arms, as well as dozers, graders, and similar construction vehicles that include frames (e.g., C-Frames). One of ordinary skill in the art would understand how to implement the features on other construction vehicles based on the examples provided herein.

Also, a bucket and blade are used herein as exemplary implements that may be coupled to construction vehicles. Embodiments of the present disclosure can also be used with other types of implements that are permanently or removably coupled to construction vehicles. For example, the systems described herein can be implemented with any of the numerous types of implements that can be coupled to construction vehicles. Additionally, the systems described herein can be used to track the position of any particular part of the implement. The working edge is used herein to refer specifically, for example, to a cutting edge of a bucket or blade, or generally to a particular part or point on the implement. In some embodiments, the working edge refers to a particular part of the implement whose position is tracked and used for machine control.

<FIG> are simplified drawings of a GNSS unit <NUM> and conventional survey poles or grade rods <NUM>. The GNSS unit <NUM> and survey pole <NUM> may be a conventional GNSS rover. In <FIG>, the survey pole <NUM> is a single piece that extends between the GNSS unit <NUM> and a tip <NUM>.

In <FIG>, the survey pole <NUM> includes a top portion 102a that is detached from a bottom portion 102b. The top and bottom portions 102a, 102b may include threads or other conventional attachment means that allow the top portion 102a to be attached to the bottom portion 102b. The GNSS unit <NUM> and tip <NUM> may also be removably attached to the survey pole <NUM>.

In <FIG>, the GNSS unit <NUM> is detached from the survey pole <NUM>. The GNSS unit <NUM> and/or the survey pole <NUM> may include threads or other conventional attachment means that allow the GNSS unit <NUM> to be attached to and removed from the survey pole <NUM>.

<FIG> provide examples of single piece and multi-piece survey poles. Other survey pole configurations exist including telescoping poles and multi-leg poles such as tripods. The embodiments described herein are not limited to a particular type of survey pole and may be implemented with any survey pole including the single piece survey pole shown in <FIG>, as well as the multi-piece survey pole shown in <FIG>.

The GNSS unit <NUM> includes an antenna for receiving GNSS signals and a receiver for processing the signals and determining position information. In some embodiments, a remote computing device (e.g., a cell phone or mobile controller) may perform part of the processing. Thus, when the GNSS unit is described herein as determining a position or position information, it should be appreciated that the GNSS signals are received by the antenna and at least some of the processing is performed by the receiver. A part of the processing may be performed by another computing device.

The GNSS unit <NUM> may include a radio, modem, or other means for wireless communications. As examples, the GNSS unit <NUM> may be configured to receive GNSS corrections using satellite, radio, WiFi, or other wireless communications. The GNSS unit <NUM> may also be configured to send partially processed GNSS signals or position information to a computing device such as a mobile controller.

The GNSS unit <NUM> also includes other sensors to determine tilt and heading information. The position, tilt, and heading information can be determined in accordance with any technique and typically requires an initialization process that may be dependent on the particular device. An example of a GNSS unit <NUM> that can determine position, tilt, and heading information is the Trimble SPS986 GNSS Smart Antenna. Other GNSS units exist that can also provide this information. The embodiments described herein are not limited to a particular configuration and can be used with any GNSS unit that provides these features.

<FIG> is a simplified perspective view of an excavator <NUM> with a GNSS unit <NUM> in accordance with an embodiment. The excavator <NUM> includes a cab <NUM> for an operator to control the various functions of the excavator <NUM> and tracks <NUM> for tramming the excavator <NUM> from one location to another. In other embodiments, the excavator may include wheels or other means for providing translational movement rather than the tracks <NUM>. The excavator <NUM> in this example also includes a blade <NUM> for moving dirt or debris and for providing stabilization during digging operations.

A boom <NUM>, stick <NUM>, and bucket <NUM> enable the digging operations. The boom <NUM> and stick <NUM> are rigid members that link the bucket <NUM> to a body of the excavator <NUM>. The boom <NUM> is coupled to the body at a pivot point <NUM> and is moved up and down by a hydraulic mechanism <NUM>. The stick <NUM> is coupled to the boom <NUM> at a pivot point <NUM> and is moved in and out by a hydraulic mechanism <NUM>. The bucket <NUM> is coupled to the stick <NUM> at a pivot point <NUM> and is moved (or curled) by a hydraulic mechanism <NUM>. It should be appreciated that each of the parts of the excavator may be coupled directly to each other or may be coupled indirectly by other intermediate linkages.

A survey pole <NUM> is coupled to the stick <NUM>, and the GNSS unit <NUM> is coupled to the survey pole <NUM>. The survey pole <NUM> may be arranged relative to the stick <NUM> so that the GNSS unit <NUM> remains free from contact with any part of the excavator <NUM>, including the boom <NUM> and the stick <NUM>, during a full range of motion of the boom <NUM>, the stick <NUM>, and/or the bucket <NUM>. The GNSS unit <NUM> includes an antenna for receiving GNSS signals and is configured to determine a three-dimensional position (or coordinates) of the antenna in a real world coordinate frame. The GNSS unit <NUM> also includes other sensors for determining a tilt and heading of the survey pole <NUM> in the real world coordinate frame.

In this example, the survey pole <NUM> is coupled to the stick <NUM> using a mounting mechanism <NUM>. The GNSS unit <NUM> is arranged in a known spatial relationship with the pivot point <NUM> between the stick <NUM> and the bucket <NUM>. Because the GNSS unit <NUM> is arranged in a known spatial relationship with the pivot point <NUM>, coordinates of the pivot point <NUM> can be determined in the real world coordinate frame in a manner similar to how a conventional GNSS rover with tilt compensation determines coordinates at a tip of the survey pole. In some embodiments, the survey pole <NUM> is aligned with the pivot point <NUM> and the known spatial relationship is a distance between the GNSS unit <NUM> (or the antenna) and the pivot point <NUM>. In other embodiments, the known spatial relationship may include horizontal and vertical offsets between the GNSS unit <NUM> (or the antenna) and the pivot point <NUM>.

The survey pole <NUM> in <FIG> does not include a tip like that used for conventional rover measurements. In this example, the survey pole <NUM> only includes an upper portion similar to the top portion 102a shown in <FIG>. This is simply to reduce an overall length so that the survey pole <NUM> is less likely to be damaged or bumped. A full length survey pole having a tip, including a multi-leg survey pole, may be used with any of the embodiments described herein and an appropriate mounting mechanism.

The mounting mechanism <NUM> rigidly couples the survey pole <NUM> to the stick <NUM>. Using the mounting mechanism <NUM>, the survey pole <NUM> may be removably attached to the stick <NUM>. For example, the survey pole <NUM> may be attached to the stick <NUM> for use in tracking a cutting edge <NUM> of the bucket <NUM>, and the survey pole <NUM> may be detached from the stick <NUM> and used to perform conventional GNSS survey measurements.

The mounting mechanism <NUM> and/or the survey pole <NUM> may be configured so that the survey pole <NUM> can be rigidly attached to the mounting mechanism <NUM>, and also so that the survey pole <NUM> can be detached from the mounting mechanism <NUM>. The mounting mechanism <NUM> and/or the survey pole <NUM> may also be configured so that when the survey pole <NUM> is attached to the mounting mechanism <NUM>, the antenna of the GNSS unit <NUM> is arranged in approximately the known spatial relationship with the pivot point <NUM>. This allows the survey pole <NUM> to be detached and re-attached without changing the known spatial relationship between the antenna of the GNSS unit <NUM> and the pivot point <NUM>. The survey pole <NUM> may have a notch, mark, mounting receiver, or the like to ensure the survey pole <NUM> is attached at a same point each time. Alternatively or additionally, the mounting mechanism <NUM> may be arranged to receive the survey pole <NUM> at a same point each time. The mounting mechanism <NUM> and/or the survey pole <NUM> may also be configured so that when the survey pole <NUM> is attached to the mounting mechanism <NUM>, an orientation of the GNSS unit <NUM> relative to the mounting mechanism <NUM> is approximately the same each time.

An angle sensor <NUM> is coupled either directly or indirectly to the bucket <NUM>. In this example, the angle sensor <NUM> is coupled indirectly to the bucket <NUM> and directly to a part of the linkage <NUM> that connects the stick <NUM> to the bucket <NUM>. The angle sensor <NUM> determines rotation of the bucket <NUM>. Because the bucket <NUM> is used for digging and other functions, the angle sensor <NUM> may be mounted on the part of the linkage <NUM> (e.g., the dog bone) where rotation of the bucket <NUM> can be determined while protecting the angle sensor <NUM> from contact with dirt or other materials that may damage the angle sensor <NUM> and/or impact sensor measurements. The angle sensor <NUM> may be an inertial measurement unit (IMU) or other sensor configured to determine or track rotation of the bucket <NUM>.

As the bucket <NUM> rotates (or curls), a distance between the pivot point <NUM> and the cutting edge <NUM> of the bucket <NUM> remains constant so that a spatial relationship between the pivot point <NUM> and the cutting edge <NUM> is fixed. Thus, coordinates of the cutting edge <NUM> can be determined in the real world coordinate frame using the position of the antenna, the tilt and heading of the survey pole <NUM>, the known spatial relationship between the GNSS unit <NUM> (or antenna) and the pivot point <NUM>, the rotation of the bucket <NUM>, and the spatial relationship between the pivot point <NUM> and the cutting edge <NUM>.

Using a width of the bucket <NUM> and a spatial relationship between the cutting edge <NUM> and the pivot point <NUM>, coordinates of any point along the cutting edge <NUM> of the bucket <NUM> can be determined (assuming the bucket <NUM> does not tilt). If the bucket <NUM> tilts in addition to curling, a second angle sensor can be used to determine the tilt of the bucket <NUM> (or the same angle sensor may be used to determine curl and tilt). Using the tilt of the bucket <NUM> and the spatial relationship between the pivot point <NUM> and the cutting edge <NUM>, in addition to the position of the antenna, the tilt and heading of the survey pole <NUM>, the known spatial relationship between the GNSS unit <NUM> (or antenna) and the pivot point <NUM>, and the rotation of the bucket <NUM>, the coordinates of the cutting edge <NUM> can be determined in the real world coordinate frame.

The coordinates of the cutting edge <NUM> may be determined using a mobile controller. The mobile controller may be a controller that is normally used in conjunction with the survey pole <NUM> and GNSS unit <NUM> or it may be a separate device such as a cell phone. The mobile controller may be configured for wireless communications with the GNSS unit <NUM> and the angle sensor <NUM>. The mobile controller receives the position of the antenna, the tilt, and the heading from the GNSS unit <NUM>, and the mobile controller receives the rotation of the bucket <NUM> from the angle sensor <NUM>. The mobile controller may also receive or have in memory the known spatial relationship between the GNSS unit <NUM> (or antenna) and the pivot point <NUM>, the distance between the pivot point <NUM> and the cutting edge <NUM> of the bucket <NUM>, the width of the cutting edge <NUM> of the bucket <NUM>; and or a spatial relationship between the cutting edge <NUM> and the pivot point <NUM>.

The excavator <NUM> shown in <FIG> is used merely as an example of a construction vehicle that includes a rigid member (e.g., the stick <NUM>) coupled to an implement (e.g., the bucket <NUM>) at a pivot point. Other excavators having different configurations may be used with the embodiments described herein. For example, the embodiment described with regard to <FIG> may be used with backhoes or more complex construction vehicles such as multi-piece boom excavators, offset boom excavators, swing boom excavators, and the like. The embodiments described herein can simplify tracking of a working edge of an implement on complex construction vehicles by reducing a number of sensors and eliminating the need to track a position or orientation of the boom. With more complex construction vehicles, the survey pole may be coupled to the last rigid member that is coupled either directly or indirectly to the implement.

<FIG> is a simplified side view of a skidsteer <NUM> with a GNSS unit <NUM> in accordance with an embodiment. The skidsteer <NUM> includes a cab <NUM> for an operator to control the various functions of the skidsteer <NUM> and wheels <NUM> for providing translational movement of the skidsteer <NUM>. In other embodiments, the skidsteer may include tracks or other means for providing translational movement.

Arms <NUM> (only one is shown in the side view) enable movement of bucket <NUM>. The arms <NUM> are rigid members that link the bucket <NUM> to a body of the skidsteer <NUM>. The arms <NUM> are coupled to the body of the skidsteer <NUM> at a pivot point (not shown) and are moved up and down by a hydraulic mechanism (not shown). The bucket <NUM> is coupled to the arms <NUM> at a pivot point <NUM> and is moved (or curled) by a hydraulic mechanism <NUM>.

A survey pole <NUM> is coupled to one of the arms <NUM>, and the GNSS unit <NUM> is coupled to the survey pole <NUM>. The survey pole <NUM> may be arranged relative to the arms <NUM> so that the GNSS unit <NUM> remains free from contact with any part of the skidsteer <NUM>, including the arms <NUM> and the bucket <NUM>, during a full range of motion of the arms <NUM> and/or the bucket <NUM>. The GNSS unit <NUM> includes an antenna for receiving GNSS signals and is configured to determine a three-dimensional position (or coordinates) of the antenna in a real world coordinate frame. The GNSS unit <NUM> also includes other sensors for determining a tilt and heading of the survey pole <NUM> in the real world coordinate frame.

In this example, the survey pole <NUM> is coupled to one of the arms <NUM> using a mounting mechanism <NUM>. The GNSS unit <NUM> is arranged in a known spatial relationship with the pivot point <NUM> between the arms <NUM> and the bucket <NUM>. Because the GNSS unit <NUM> is arranged in a known spatial relationship with the pivot point <NUM>, coordinates of the pivot point <NUM> can be determined in the real world coordinate frame in a manner similar to how a conventional GNSS rover with tilt compensation determines coordinates at a tip of the survey pole. In some embodiments, the survey pole <NUM> is aligned with the pivot point <NUM> and the known spatial relationship is a distance between the GNSS unit <NUM> (or the antenna) and the pivot point <NUM>. In other embodiments, like the example shown in <FIG>, the known spatial relationship may include horizontal and vertical offsets between the GNSS unit <NUM> (or the antenna) and the pivot point <NUM>.

Similar to the example shown in <FIG>, the survey pole <NUM> in <FIG> does not include a tip like that used for conventional rover measurements. Instead, the survey pole <NUM> only includes an upper portion similar to the top portion 102a shown in <FIG>. A full length survey pole having a tip, including a multi-leg survey pole, may be used with any of the embodiments described herein.

The mounting mechanism <NUM> rigidly couples the survey pole <NUM> to one of the arms <NUM>. Using the mounting mechanism <NUM>, the survey pole <NUM> may be removably attached to the arm. For example, the survey pole <NUM> may be attached to one of the arms <NUM> for use in tracking a cutting edge <NUM> of the bucket <NUM>, and the survey pole <NUM> may be detached from the skidsteer <NUM> and used to perform conventional GNSS survey measurements. The mounting mechanism <NUM> and/or the survey pole <NUM> may be configured as described above with regard to <FIG> so that the known spatial relationship between the GNSS unit <NUM> and the pivot point <NUM> is substantially the same each time the survey pole <NUM> is coupled to the skidsteer <NUM>.

An angle sensor <NUM> is coupled either directly or indirectly to the bucket <NUM>. In this example, the angle sensor <NUM> is coupled to a backside of the bucket <NUM> where it is protected from contact with dirt or other materials that may damage the angle sensor <NUM> and/or impact sensor measurements. The angle sensor <NUM> determines rotation of the bucket <NUM>. The angle sensor <NUM> may be an IMU or other sensor configured to determine rotation of the bucket <NUM>.

Using a width of the bucket <NUM> and a spatial relationship between the cutting edge <NUM> and the pivot point <NUM>, coordinates of any point along the cutting edge <NUM> of the bucket <NUM> can be determined (assuming the bucket <NUM> does not tilt). If the bucket <NUM> tilts in addition to curling, a second angle sensor can be used to determine the tilt of the bucket <NUM> (or the same angle sensor may be used to determine curl and tilt). Using the tilt of the bucket <NUM> and the spatial relationship between the pivot point <NUM> and the cutting edge <NUM>, in addition to the position of the antenna, the tilt and heading of the survey pole <NUM>, the known spatial relationship between the GNSS unit <NUM> (or antenna) and the pivot point <NUM>, and the rotation of the bucket <NUM>, the coordinates of the cutting edge <NUM> can be determined in the real world coordinate frame. The coordinates may be determined using a mobile controller as described previously with regard to the example of <FIG>.

The skidsteer <NUM> shown in <FIG> is used merely as an example of a construction vehicle that includes rigid members (e.g., the arms <NUM>) coupled to an implement (e.g., the bucket <NUM>) at a pivot point. Other loaders having arms, or dozers or graders having frames, may be used in a similar manner with the embodiments described herein.

<FIG> is a simplified perspective view of an excavator <NUM> with a GNSS unit <NUM> in accordance with another embodiment. The excavator <NUM> is similar to the excavator <NUM> shown in <FIG>, and a description of the various features can be found in the description of <FIG>. In this example, the GNSS unit <NUM> is coupled to a mount <NUM> on a stick <NUM> of the excavator <NUM>. The mount <NUM> may be permanently or removably attached to the stick <NUM>. The GNSS unit <NUM> and the mount <NUM> may include threads or other attachment means for coupling the GNSS unit <NUM> to the mount <NUM>.

The mount <NUM> may be arranged relative to the stick <NUM> so that the GNSS unit <NUM> remains free from contact with any part of the excavator <NUM>, including a boom <NUM> and the stick <NUM>, during a full range of motion of the boom <NUM>, the stick <NUM>, and/or a bucket <NUM>. The GNSS unit <NUM> includes an antenna for receiving GNSS signals and is configured to determine a three-dimensional position (or coordinates) of the antenna in a real world coordinate frame. The GNSS unit <NUM> also includes other sensors for determining a tilt and heading of the GNSS unit <NUM> in the real world coordinate frame.

The GNSS unit <NUM> is arranged in a known spatial relationship with the pivot point <NUM> between the stick <NUM> and the bucket <NUM>. Because the GNSS unit <NUM> is arranged in a known spatial relationship with the pivot point <NUM>, coordinates of the pivot point <NUM> can be determined in the real world coordinate frame in a manner similar to how a conventional GNSS rover with tilt compensation determines coordinates at a tip of the survey pole. The known spatial relationship may include horizontal and/or vertical offsets between the GNSS unit <NUM> (or the antenna) and the pivot point <NUM>.

The mount <NUM> rigidly couples the GNSS unit <NUM> to the stick <NUM>. Using the mount <NUM>, the GNSS unit <NUM> may be removably attached to the stick <NUM>. For example, the GNSS unit <NUM> may be attached to the stick <NUM> for use in tracking a cutting edge <NUM> of the bucket <NUM>, and the GNSS unit <NUM> may be detached from the stick <NUM> and used with a survey pole to perform conventional GNSS survey measurements.

The mount <NUM> may be configured so that when the GNSS unit <NUM> is attached to the mount <NUM>, the antenna of the GNSS unit <NUM> is arranged in approximately the known spatial relationship with the pivot point <NUM>. This allows the GNSS unit <NUM> to be detached and re-attached without changing the known spatial relationship between the antenna of the GNSS unit <NUM> and the pivot point <NUM>. The mount <NUM> and/or the GNSS unit <NUM> may also be configured so that when the GNSS unit <NUM> is attached to the mount <NUM>, an orientation of the GNSS unit <NUM> relative to the mount <NUM> is approximately the same each time.

An angle sensor <NUM> is coupled either directly or indirectly to the bucket <NUM> similar to the arrangement described with regard to <FIG>. The angle sensor <NUM> may be an IMU or other sensor configured to determine or track rotation of the bucket <NUM>.

As described above with regard to <FIG>, coordinates of the cutting edge <NUM> of the bucket <NUM> can be determined in the real world coordinate frame. In some embodiments, the coordinates of the cutting edge <NUM> are determined using the position of the antenna, the tilt and heading of the GNSS unit <NUM>, the known spatial relationship between the GNSS unit <NUM> (or antenna) and the pivot point <NUM>, the rotation of the bucket <NUM>, and a spatial relationship between the pivot point <NUM> and the cutting edge <NUM>. Using a width of the bucket <NUM> and the spatial relationship between the cutting edge <NUM> and the pivot point <NUM>, coordinates of any point along the cutting edge <NUM> of the bucket <NUM> can be determined. Additional angle sensors can be used to account for tilt of the bucket <NUM> if necessary based on the configuration of the excavator <NUM>. The coordinates of the cutting edge <NUM> may be determined using a mobile controller as described previously.

The excavator <NUM> shown in <FIG> is used merely as an example of a construction vehicle that includes a rigid member (e.g., the stick <NUM>) coupled to an implement (e.g., the bucket <NUM>) at a pivot point. This example includes a mount <NUM> for the GNSS unit <NUM>. Other excavators having different configurations may be used with the embodiments described herein. For example, the embodiment described with regard to <FIG> may be used with skidsteers, backhoes, or with more complex construction vehicles such as multi-piece boom excavators, offset boom excavators, swing boom excavators, and the like. The embodiments described herein can simplify tracking of a working edge of an implement on complex construction vehicles by reducing a number of sensors and eliminating the need to track position or orientation of the boom. With more complex construction vehicles, the GNSS unit may be coupled to a mount on the last rigid member that is coupled either directly or indirectly to the implement.

<FIG> is a simplified block diagram of a mobile controller <NUM> in accordance with an embodiment. The mobile controller <NUM> in this example includes a communications subsystem <NUM> that allows communications with a GNSS unit and one or more angle sensors. The mobile controller <NUM> also includes one or more processors <NUM> for determining a position of a working edge of an implement. The mobile controller <NUM> may also include working memory <NUM> with instructions that when executed by the one or more processors <NUM> provide an operating system <NUM> and applications <NUM> that facilitate determining the position of the working edge.

The mobile controller <NUM> in <FIG> is provided merely as an example. Other mobile controllers having different configurations may be used with the embodiments described herein. The mobile controller <NUM> illustrated in <FIG> may be incorporated into devices such as a portable electronic device, cell phone, or other computing devices. <FIG> provides a schematic illustration of one embodiment of a mobile controller <NUM> that can perform some or all of the steps of the methods provided by various embodiments. It should be noted that <FIG> is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate.

The mobile controller <NUM> is shown comprising physical or functional elements that can be electrically coupled via a bus <NUM>, or may otherwise be in communication, as appropriate. The hardware elements may include one or more processors <NUM>, including without limitation one or more general-purpose processors and/or one or more special-purpose processors such as digital signal processing chips, graphics acceleration processors, and/or the like; one or more input devices <NUM>, which can include, without limitation a mouse, a keyboard, a camera, and/or the like; and one or more output devices <NUM>, which can include, without limitation a display device, a printer, and/or the like.

The mobile controller <NUM> may further include and/or be in communication with one or more non-transitory storage devices <NUM>, which may comprise, without limitation, local and/or network accessible storage. Such storage devices may be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and/or the like.

The mobile controller <NUM> might also include a communications subsystem <NUM>, which can include, without limitation, a modem, a network card (wireless or wired), an infrared communication device, a wireless communication device, and/or a chipset such as a Bluetooth™ device, an <NUM> device, a WiFi device, a WiMax device, cellular communication facilities, etc., and/or the like. The communications subsystem <NUM> may include one or more input and/or output communication interfaces to permit data to be exchanged with other devices such as a GNSS unit and angle sensor. In some embodiments, the mobile controller <NUM> may further comprise a working memory <NUM>.

The mobile controller <NUM> can also include software elements, shown as being currently located within the working memory <NUM>, including an operating system <NUM>, device drivers, executable libraries, and/or other code, such as one or more application programs <NUM>, which may comprise computer programs provided by various embodiments, and/or may be designed to implement methods, and/or configure systems, provided by other embodiments, as described herein. Merely by way of example, one or more procedures described with respect to the methods discussed above can be implemented as code and/or instructions executable by a processor. In an aspect, then, such code and/or instructions can be used to configure and/or adapt a general purpose computer or other device to perform one or more operations in accordance with the described methods.

A set of these instructions and/or code may be stored on a non-transitory computer-readable storage medium, such as the storage device(s) <NUM>. In some cases, the storage medium might be incorporated within a computer system, such as the mobile controller <NUM>. In other embodiments, the storage medium might be separate, e.g., a removable medium. These instructions might take the form of executable code, which is executable by the mobile controller <NUM> and/or might take the form of source and/or installable code, which, upon compilation and/or installation on the mobile controller <NUM>, e.g., using any of a variety of generally available compilers, installation programs, compression/decompression utilities, etc., then takes the form of executable code.

For example, customized hardware might also be used, and/or particular elements might be implemented in hardware or software including portable software, such as applets, etc., or both.

As mentioned above, in one aspect, some embodiments may employ the mobile controller <NUM> to perform methods in accordance with various embodiments. According to a set of embodiments, some or all of the procedures of such methods are performed by the mobile controller <NUM> in response to processor <NUM> executing one or more sequences of one or more instructions, which might be incorporated into the operating system <NUM> and/or other code, such as an application program <NUM>, contained in the working memory <NUM>. Such instructions may be read into the working memory <NUM> from another computer-readable medium, such as one or more of the storage device(s) <NUM>. Merely by way of example, execution of the sequences of instructions contained in the working memory <NUM> might cause the processor(s) <NUM> to perform one or more procedures of the methods described herein. Additionally or alternatively, portions of the methods described herein may be executed through specialized hardware.

The terms "machine-readable medium" and "computer-readable medium," as used herein, refer to any medium that participates in providing data that causes a machine to operate in a specific fashion. In an embodiment implemented using the mobile controller <NUM>, various computer-readable media might be involved in providing instructions/code to processor(s) <NUM> for execution and/or might be used to store and/or carry such instructions/code. In many implementations, a computer-readable medium is a physical and/or tangible storage medium. Such a medium may take the form of a non-volatile media or volatile media.

Specific details are given in the description to provide a thorough understanding of exemplary configurations including implementations. However, configurations may be practiced without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques may have been shown without unnecessary detail in order to avoid obscuring the configurations. This description provides example configurations only, and does not limit the scope, applicability, or configurations of the claims. Rather, the preceding description of the configurations will provide those skilled in the art with an enabling description for implementing described techniques.

Claim 1:
A construction vehicle (<NUM>) comprising a system for tracking a position of a working edge (<NUM>) on an implement (<NUM>) of the construction vehicle, the construction vehicle comprising the implement coupled to the construction vehicle at a pivot poin (<NUM>) between a rigid member (<NUM>) of the construction vehicle and the implement, a hydraulic mechanism (<NUM>) coupled to the rigid member and configured to provide rotational movement of the implement, the system comprising:
an angle sensor (<NUM>) coupled to the implement and configured to determine rotation of the implement;
a mounting mechanism (<NUM>) on the rigid member, and a survey pole (<NUM>) coupled to the mounting mechanism, wherein the mounting mechanism is configured for attaching the survey pole to the rigid member;
a global navigation satellite system, GNSS, unit (<NUM>) coupled to the survey pole, the mounting mechanism arranged relative to the rigid member so that the GNSS unit remains free from contact with any part of the construction vehicle, the implement, or the rigid member during a full range of motion of the rigid member, the GNSS unit arranged in a known spatial relationship with the pivot point between the rigid member of the construction vehicle and the implement, the GNSS unit configured to determine a position, a tilt, and a heading of the GNSS unit; characterised by
a mobile controller (<NUM>) configured for wireless communications with the GNSS unit and the angle sensor, the mobile controller configured to receive the position, the tilt, and the heading from the GNSS unit, and to receive the rotation of the implement from the angle sensor, the mobile controller configured to determine coordinates of the working edge of the implement in a real world coordinate frame.