Patent Grant
11549236
The present subject matter relates generally to work vehicles and, more particularly, to systems and methods for automatically adjusting the orientation or angular position of an implement of a work vehicle using closed-loop control so as to provide bi-directional self-leveling functionality as the vehicle's boom or loader arms are being moved.
Work vehicles having lift assemblies, such as skid steer loaders, telescopic handlers, wheel loaders, backhoe loaders, forklifts, compact track loaders and the like, are a mainstay of construction work and industry. For example, skid steer loaders typically include a lift assembly having a pair of loader arms pivotally coupled to the vehicle's chassis that can be raised and lowered at the operator's command. In addition, the lift assembly includes an implement attached to the ends of the loader arms, thereby allowing the implement to be moved relative to the ground as the loader arms are raised and lowered. For example, a bucket is often coupled to the loader arms, which allows the skid steer loader to be used to carry supplies or particulate matter, such as gravel, sand, or dirt, around a worksite.
When using a work vehicle to perform a material moving operation or any other suitable operation, it is often desirable to maintain the vehicle's bucket or other implement at a constant angular position relative to the vehicle's driving surface (or relative to any other suitable reference point or location) as the loader arms are being raised and/or lowered. To achieve such control, conventional work vehicles typically rely on the operator manually adjusting the position of the implement as the loader arms are being moved. Unfortunately, this task is often quite challenging for the operator and can lead to materials being inadvertently dumped from the implement. To solve this problem, control systems have been disclosed that attempt to provide a control algorithm for automatically maintaining a constant angular implement position as the vehicle's loader arms are being moved. However, such previously disclosed automatic control systems still suffer from many drawbacks, including poor system responsiveness and imprecise implement position control. In particular, previously disclosed control systems have been unable to properly accommodate the non-linearity of the operational dynamics of the lift assembly as the loader arms are being moved, thereby providing less than desirable results. This particularly true for work vehicles that include a Z-bar linkage between the tilt cylinder and the implement for adjusting the position of the implement.
Accordingly, an improved system and method for automatically adjusting the position of an implement of a work vehicle so as to maintain the implement at a desired angular orientation relative to a given reference point would be welcomed in the technology.
Aspects and advantages of the technology will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the technology.
In one aspect, the present subject matter is directed to a method for automatically adjusting the position of an implement of a lift assembly of a work vehicle, the lift assembly comprising a boom coupled to the implement. The method includes determining, with the computing system, a tilt transition boom angle for the lift assembly that corresponds to a position within a boom travel range of the boom at which a direction of movement of the implement must be reversed to maintain the implement at a target implement angle as the boom is being moved across such position. The method also includes determining, with the computing system, a closed-loop control signal associated with controlling movement of the implement based at least in part on the tilt transition boom angle, generating, with the computing system, a valve command signal based at least in part on the closed-loop control signal, and controlling, with computing system, an operation of at least one valve associated with the implement based at least in part on the valve command signal to maintain the implement at the target implement angle as the boom is being moved across the boom travel range.
In another aspect, the present subject matter is directed to a system for controlling the operation of a work vehicle. The system includes a lift assembly including a boom and an implement coupled to the boom. The system also includes at least one tilt valve in fluid communication with a corresponding tilt cylinder, with the tilt valve(s) being configured to control a supply of hydraulic fluid to the tilt cylinder to adjust a position of the implement relative to the boom. Additionally, the system includes a computing system communicatively coupled to the tilt valve(s). The computing system is configured to receive an input indicative of a target implement angle at which the implement is to be maintained as the boom is being moved across a boom travel range of the boom and determine a tilt transition boom angle for the lift assembly based at least in part on the target implement angle. The tilt transition boom angle corresponds to a position within the boom travel range at which the tilt cylinder must transition between being stroked and de-stroked in order to maintain the implement at the target implement angle as the boom is being moved across such position. The computing system is also configured to determine a closed-loop control signal associated with controlling movement of the implement based at least in part on the tilt transition boom angle, generate a valve command signal based at least in part on the closed-loop control signal, and control an operation of the tilt valve(s) based at least in part on the valve command signal to maintain the implement at the target implement angle as the boom is being moved across the boom travel range.
These and other features, aspects and advantages of the present technology will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the technology and, together with the description, serve to explain the principles of the technology.
A full and enabling disclosure of the present technology, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present technology.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
In general, the present subject matter is directed to systems and methods for automatically adjusting the position of an implement of a lift assembly of a work vehicle in order to maintain the implement at a fixed or constant angular orientation relative to a given reference point as the boom of the lift assembly is being raised or lowered. In several embodiments, such control of the position of the implement may be achieved using a closed-loop control algorithm employing feed-forward control. In accordance with aspects of the present subject matter, the feed-forward control of the closed-loop control algorithm may be configured to generate an output signal for adjusting the position of the implement based at least in part on an input signal associated with a tilt transition boom an of the lift assembly. As will be described below, the tilt transition boom angle may correspond to a position within the boom's travel range at which a direction of movement of the implement must be reversed in order to maintain the implement at a target implement angle as the boom is being moved across such position. For instance, when the movement of the implement is being adjusted via one or more tilt cylinders, the tilt transition boom angle may correspond to the position within the boom travel range at which the tilt cylinder(s) must transition between being stroked and de-stroked in order to maintain the implement at the target implement angle. Such tilt-transition-based input signal(s) may allow for the feed-forward control to reduce system delays, thereby increasing the system's overall responsiveness.
Additionally, in several embodiments, the disclosed systems and methods may also be configured to apply one or more additional control functions to further improve overall responsiveness and/or performance when automatically controlling the operation of the vehicle's lift assembly. For instance, in one embodiment, a valve standby control mode may be executed to reduce the amount of jerky motion or vibrations as the associated hydraulic valves are being transitioned between their opened and closed states, as well as to increase the system responsiveness when transitioning the valves from the closed state to the opened state. Additionally, in one embodiment, one or more valve lock-up control functions may be applied to minimize the frequency at which the valves are switched back and forth between the opened and closed states in certain instances. Moreover, as will be described below, a boom cushion control mode may be executed to allow lift valve control commands to be ramped down according to a variable rate in a manner that minimizes the likelihood that the boom experiences a hard impact against its upper limit stop as the boom is being moved towards the top end of its travel range.
Referring now to the drawings,
As shown in
As shown in
Furthermore, in several embodiments, the work vehicle 10 may include a boom position sensor 40. In general, the boom position sensor 40 may be configured to capture data indicative of the angle or orientation of the boom 24 relative to the chassis 16. For example, the boom position sensor 40 may correspond to a potentiometer positioned between the boom 24 and the chassis 16, such as within one of the pivot joints 30. In this respect, as the boom 24 and the implement 32 are raised and lowered relative to the ground, the voltage output by the lift position sensor 40 may vary, with such voltage being indicative of the angle of the boom 24 relative to the chassis 16. However, in other embodiments, the boom position sensor 40 may correspond to any other suitable sensor(s) and/or sensing device(s) configured to capture data associated with the angle or orientation of the boom 24 relative to the chassis 16 and/or relative to the ground.
Moreover, in some embodiments, the work vehicle 10 may include an implement position sensor 42. In general, the implement position sensor 42 may be configured to capture data indicative of the angle or orientation of the implement 32 relative to the boom 24. For example, in such an embodiment, the implement position sensor 42 may correspond to a potentiometer positioned between the implement 32 and the second ends 28 of the boom 24 and the chassis 16, such as within one of the pivot joints 34. In this respect, as the implement 32 is pivoted relative to the boom 24, the voltage output by the implement position sensor 42 may vary, with such voltage being indicative of the angle orientation of the implement 32 relative to the boom 24. However, in other embodiments, the implement position sensor 42 may correspond to any other suitable sensor(s) and/or sensing device(s) configured to capture data associated with the angle or orientation of the implement 32 relative to the boom 24, the chassis 16, and/or the ground. For example, in some embodiments, the implement position sensor 42 may be positioned at or within a pivot joint 44 about which portions of a bell crank assembly 46 of the work vehicle 10 rotates.
As particularly shown in
It should also be appreciated that the configuration of the work vehicle 10 described above and shown in
Referring now to
As shown, the control system 100 may generally include a computing system 102 configured to electronically control the operation of one or more components of the work vehicle 10, such as the various hydraulic components of the work vehicle 10 (e.g., the lift cylinders 36, the tilt cylinders 38 and/or the associated valve(s)). In general, the computing system 102 may comprise any suitable processor-based device known in the art, such as a computing device or any suitable combination of computing devices. Thus, in several embodiments, the computing system 102 may include one or more processor(s) 104 and associated memory device(s) 106 configured to perform a variety of computer-implemented functions. As used herein, the term “processor” refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s) 106 of the computing system 102 may generally comprise memory element(s) including, but are not limited to, computer readable medium (e.g., random access memory (RAM)), computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disc (DVD) and/or other suitable memory elements. Such memory device(s) 106 may generally be configured to store suitable computer-readable instructions that, when implemented by the processor(s) 104, configure the computing system 102 to perform various computer-implemented functions, such as the closed-loop control algorithm 200 described below with reference to
It should be appreciated that the computing system 102 may correspond to an existing controller of the work vehicle 10 or the computing system 102 may correspond to a separate processing device. For instance, in one embodiment, the computing system 102 may form all or part of a separate plug-in module that may be installed within the work vehicle 10 to allow for the disclosed system and method to be implemented without requiring additional software to be uploaded onto existing control devices of the vehicle 10.
In several embodiments, the computing system 102 may be configured to be coupled to suitable components for controlling the operation of the various cylinders 36, 38 of the work vehicle 10. For example, the computing system 102 may be communicatively coupled to a suitable lift valve assembly 107 including valves 108, 110 (e.g., solenoid-activated valves) configured to control the supply of hydraulic fluid to each lift cylinder 36 (only one of which is shown in
During operation, the computing system 102 may be configured to control the operation of each valve 108, 110, 116, 118 in order to control the flow of hydraulic fluid supplied to each of the cylinders 36, 38 from a suitable hydraulic tank 124 of the work vehicle 10 via an associated pump 125. For instance, the computing system 102 may be configured to transmit suitable control commands to the lift valves 108, 110 in order to regulate the flow of hydraulic fluid supplied to the cap and rod ends 112, 114 of each lift cylinder 36, thereby allowing for control of a stroke length 126 of the piston rod associated with each cylinder 36. Similarly, the computing system 102 may be configured to transmit suitable control commands to the tilt valves 116, 118 in order to regulate the flow of hydraulic fluid supplied to the cap and rod ends 120, 122 of each tilt cylinder 38, thereby allowing for control of a stroke length 128 of the piston rod associated with each cylinder 38. Thus, by carefully controlling the actuation or stroke length 126, 128 of the lift and tilt cylinders 36, 38, the computing system 102 may, in turn, be configured to automatically control the manner in which the boom 24 and the implement 32 are positioned or oriented relative to the vehicle's driving surface and/or relative to any other suitable reference point. For instance, the computing system 102 may be configured to cause the implement 32 to be tilted in the rollback direction 52 (
It should be appreciated that the current commands provided by the computing system 102 to the various valves 108, 110, 116, 118 may be in response to inputs provided by the operator via one or more input devices 130. For example, one or more input devices 130 (e.g., the control lever(s) 20 shown in
Additionally, it should be appreciated that the work vehicle 10 may also include any other suitable input devices 130 for providing operator inputs to the computing system 102. For instance, in accordance with aspects of the present subject matter, the operator may be allowed to select/input an angular orientation for the implement 32 (e.g., a target implement angle) that is to be maintained as the boom 24 is being moved. In such instance, the desired orientation may be selected or input by the operator using any suitable means that allows for the communication of such orientation to the computing system 102. For example, the operator may be provided with a suitable input device(s) 130 (e.g., a button(s), touch screen, lever(s), etc.) that allows the operator to select/input a particular angle at which the implement 32 is to be maintained during movement of the boom 24, such as a specified target implement angle defined relative to the vehicle's driving surface. In addition, or as an alternative thereto, the operator may be provided with a suitable input device(s) 130 (e.g., a button(s), touch screen, lever(s), etc.) that allows the operator to record or select the current angular orientation of the implement 32 as the desired or target implement agnel, which may then be stored within the memory 106 of the computing system 102. Moreover, in one embodiment, one or more pre-defined implement orientation/position/angle settings may be stored within the memory 106 of the computing system 102. In such an embodiment, the operator may simply select one of the pre-defined orientation/position/angle settings in order to instruct the computing system 102 as to the target angle for the implement 32.
Moreover, as shown in
In other embodiments, the position sensor(s) 132 may correspond to any other suitable sensor(s) that is configured to provide a measurement signal associated with the position and/or orientation of the boom 24 and/or the implement 32. For instance, the position sensor(s) 132 may correspond to one or more linear position sensors and/or encoders associated with and/or coupled to the piston rod(s) or other movable components of the cylinders 36, 38 in order to monitor the travel distance of such components, thereby allowing for the position of the boom 24 and/or the implement 32 to be calculated. Alternatively, the position sensor(s) 132 may correspond to one or more non-contact sensors, such as one or more proximity sensors, configured to monitor the change in position of such movable components of the cylinders 36, 38. In another embodiment, the position sensor(s) 132 may correspond to one or more flow sensors configured to monitor the fluid into and/or out of each cylinder 36, 38, thereby providing an indication of the degree of actuation of such cylinders 36, 38 and, thus, the location of the corresponding boom 24 and/or implement 32. In a further embodiment, the position sensor(s) 132 may correspond to a transmitter(s) configured to be coupled to a portion of one or both of the boom 24 and/or the implement 32 that transmits a signal indicative of the height/position and/or orientation of the boom/implement 24, 32 to a receiver disposed at another location on the vehicle 10.
It should be appreciated that, although the various sensor types were described above individually, the work vehicle 10 may be equipped with any combination of position sensors 132 and/or any associated sensors that allow for the position and/or orientation of the boom 24 and/or the implement 32 to be monitored. For instance, in one embodiment, the work vehicle 10 may include both a first set of position sensors 132 (e.g., angle sensors) associated with the pins located at the pivot joints defined at the pivot points 30, 34 for monitoring the relative angular positions of the boom 24 and the implement 32 and a second set of position sensors 132 (e.g., a linear position sensor(s), flow sensor(s), etc.) associated with the lift and tilt cylinders 36, 38 for monitoring the actuation of such cylinders 36, 38.
Additionally, it should be appreciated that the computing system 102 may also be coupled to various other sensors for monitoring one or more other operating parameters of the work vehicle 10. For instance, the computing system 102 may also be coupled to one or more pressure sensors configured to monitor the fluid pressure of the hydraulic fluid at one or more locations within the system 100 and/or one or more temperature sensors configured to monitor the temperature of the hydraulic fluid supplied between the tank 124 and the various cylinders 36, 38. In addition, the computing system 102 may be coupled to one or more velocity sensors and/or accelerometers (not shown) for monitoring the velocity and/or acceleration of the boom 24 and/or the implement 32.
It should also be appreciated that, as used herein, the term “monitor” and variations thereof indicates that the various sensors of the system 100 may be configured to provide a direct or indirect measurement of the operating parameters being monitored. Thus, the sensors may, for example, be used to generate signals relating to the operating parameter being monitored, which can then be utilized by the computing system 102 to determine or predict the actual operating parameter.
In addition, it should be appreciated that, as described herein, the computing system 102 may be configured to receive a signal indicative of a given operating parameter or state of the work vehicle 10 from an external source (e.g., from a sensor coupled to the computing system 102) or from an internal source. For example, signals transmitted to, within and/or from the processor(s) 104 and/or memory 106 of the computing system 102 may be considered to have been “received” by the computing system 102. Thus, in embodiments in which the computing system 102 is utilizing a constant value for a given operating parameter of the work vehicle (e.g., the hydraulic pressure and/or the fluid temperature), a signal indicative of such operating parameter may be received by the computing system 102 when the constant value is, for example, retrieved from memory by the processor(s) 104 and/or utilized by the processor(s) 104 as an input within a given processing step (e.g., when implementing the closed-loop control algorithm described below).
Referring now to
As shown in
A similar pattern is followed when lowering the boom 24 towards the ground from the top end 154 of its travel range. For example, as shown in
It should be appreciated that the dataset illustrated in
Thus, in accordance with aspects of the present subject matter, the tilt transition boom angle associated with maintaining a constant angular orientation of the implement 32 may be determined for each of a plurality of potential target implement angles for a given lift assembly configuration (e.g., via experimentation and/or modeling). Each tilt transition boom angle may then be stored in association with or correlated to its associated target implement angle for subsequent use. For instance, in one embodiment, a look-up table may be developed that correlates each tilt transition boom angle to the associated target implement angle for a given machine. In such an embodiment, when the operator provides an input selecting a target implement angle at which the implement 32 is to be maintained, the look-up table may be accessed or referenced to determine the tilt transition boom angle associated with the operator-selected target implement angle. The look-up table may, for example, be stored within the memory 106 of the computing system 102 (
Referring now to
In several embodiments, the closed-loop control algorithm 200 may employ both a feed-forward control portion (indicated by dashed box 202 in
In several embodiments, the feed-forward control portion 202 of the disclosed algorithm 200 may be configured to receive one or more input signals associated with the position of the boom 24 relative to the specific tilt transition boom angle (see
In general, the feed-forward output signal 216 may correspond to a speed control signal that, based on the input signals, is associated with a calculated rate of change or speed at which the implement 32 needs to be moved in order to maintain the implement 32 at the target implement angle relative to the vehicle's driving surface (or other reference point) as the boom 24 is being moved. Specifically, in several embodiments, the feed-forward block 214 may be configured to calculate the feed-forward output signal 216 as a function of the boom position differential (i.e., the difference between the actual boom angle and the tilt transition boom angle) and an applicable feed-forward gain(s) applied within the feed-forward control portion 202, such as by multiplying the boom angle differential by the applicable gain(s).
It should be appreciated that the actual boom angle signal 206 may, in several embodiments, generally derive from any suitable sensor(s) configured to monitor the position of the boom 23 relative to a known reference point. For instance, as indicated above, the computing system 102 may be communicatively coupled to one or more position sensors 132 for monitoring the boom's position. In such an embodiment, the actual boom angle signal 206 may be based directly (or indirectly) on the measurement signals provided by the position sensor(s) 132.
Additionally, in one embodiment, the actual boom angle signal 206 may represent or correspond to the current boom angle of the boom 24. Alternatively, the actual boom angle signal 206 may represent or correspond to an expected or future boom angle of the boom 24. For instance, in one embodiment, the computing system 102 may be configured to calculate an estimated or predicted angle at which it is believed that the boom 24 will be moved at some point in the future (e.g., at time (Δt)) based on, for example, the current implement speed and/or the average speed of the implement 32 over a given time period (e.g., over the previous 100 to 300 milliseconds). Such predicted boom angle (e.g., as the actual boom angle signal 206) may then be utilized with the tilt transition boom angle signal 208 to calculate the boom position differential signal 210.
It should also be appreciated that the tilt transition boom angle signal 208 may, in several embodiments, generally be determined based on the operator-selected target implement angle (e.g., box 205). For example, as indicated above, a look-up table may be stored within the memory 106 of the computing system 102 that correlates each potential target implement angle to a corresponding tilt transition boom signal. In such an embodiment, upon the operator providing an input associated with the selected target implement angle, the look-up table may be referenced or accessed to determine the applicable tilt transition boom angle.
Referring still to
It should be appreciated that the desired implement position signal 220 may generally correspond to the specific position at which the implement 32 must be located based on the current position of the boom 24 in order to maintain the implement 32 at the target implement angle. As indicated above with reference to
It should also be appreciated that the actual implement position signal 222 may, in several embodiments, generally derive from any suitable sensor(s) configured to monitor the position of the implement 32 relative to a known reference point. For instance, as indicated above, the computing system 102 may be communicatively coupled to one or more position sensors 132 for monitoring the implement's position. In such an embodiment, the actual implement position signal 222 may be based directly (or indirectly) on the measurement signals provided by the position sensor(s) 132. Alternatively, the actual implement position signal 222 may be calculated based on one or more input signals. For instance, as shown in dashed lines in
Referring still to
It should be appreciated that the feed-forward and feedback output signals 216, 232 may be combined or otherwise processed in any suitable manner in order to generate the final valve control command(s) 242. For instance, in one embodiment, one of the signals may be used as a multiplier or modifier to adjust the other signal. In another embodiment, the feed-forward and feedback output signals 216, 232 may simply be summed to generate the final valve control command(s) 242.
Additionally, it should be appreciated that the feed-forward and feedback output signals 216, 232 may also be utilized to generate the final valve control command(s) 242 by predicting a future position for the boom 24 based on such signal(s), which may then be used to calculate the final valve control command(s) 242. In such instance, the future position for the boom 24 may generally correspond to an estimated or predicted position to which it is believed that the boom 24 will be moved at some point in the future (e.g., at time (Δt)) based on the adjusted implemented speed calculated using the feed-forward and feedback output signals 216, 232. Such predicted loader position may then be utilized to generate the appropriate valve command signal(s) 242.
Moreover, it should be appreciated that, when executing closed-loop control, one or both of the tilt valves 116, 118 may need to be switched back-and-forth between opened and closed states to maintain the implement 32 at the target implement angle as the boom 24 is being lifted or lowered, particularly due to overshoot conditions and/or when the boom is approaching the tilt transition boom angle along the associated tilt cylinder control curve (e.g., curve 150 shown in
For example,
By identifying the valve cracking buffer region 262 relative to the expected valve cracking control command 260, the tilt valves 116, 118 can be controlled in a manner that both minimizes jerkiness and improves overall responsiveness. Specifically, as shown in
It should be appreciated that, in addition to the above-described standby control function (or as an alternative thereto), the computing system 102 may be configured to apply a valve lock-up control function that locks the operation of one or both tilt valves 116, 118 in certain instances, thereby reducing the frequent transitions between opened and closed states during dynamic control processing. For example, in one embodiment, the computing system 102 may be configured to lock-up the first tilt valve 116 (and, thus, prevent tilting of the implement 32 in the rollback direction) when the boom 24 is being lifted between the bottom end of its travel range and the tilt transition boom angle (e.g., lifting across the first range of boom angles 162 of
In addition, the computing system 102 may also be configured to apply a valve lock-up control methodology upon the occurrence of one or more other lock-up trigger events or conditions. For instance, in one embodiment, the computing system 102 may be configured to lock-up both tilt valves 116, 118 as the boom 24 is lifted or lowered across a small range of boom angles defined relative to the tilt transition boom angle (e.g., range 272 shown in
Referring now to
For example, in several embodiments, the input/output control mapping may be adjusted such that a variable ramp-down rate is applied as the boom 24 is raised towards the top end 282 of its travel range. Specifically, as shown in
It should be appreciated that, although the illustrated embodiment applies the same ramp-down rate across the first and third ramp-down zones, the ramp-down rate may, in other embodiments, differ between the first and third ramp-down zones. Additionally, although the illustrated embodiment ramps down the control command linearly, a non-linear relationship may be defined between the boom valve control command the boom angle as the boom 24 is raised between the top and bottom ends 282, 281 of its travel range.
As shown in
Referring now to
As shown in
Additionally, at (304), the method 300 incudes determining a closed-loop control signal associated with controlling movement of an implement of the lift assembly based at least in part on the tilt transition boom angle. Specifically, as indicated above, the computing system 102 may be configured to determine a feed-forward output control signal based at least in part on the tilt transition boom angle. For instance, in one embodiment, the computing system may be configured to determine a boom position differential between the tilt transition boom angle and an actual boom angle of the boom (e.g., a current boom angle or a predicted future boom angle of the boom), with the boom position differential being used to generate the feed-forward output control (e.g., by multiplying the boom position differential by an applicable control gain(s)).
Moreover, at (306), the method 300 includes generating a valve command signal based at least in part on the closed-loop control signal. For example, as indicated above, the computing system 102 may be configured to execute a closed-loop control algorithm 200 that utilizes a combination of feed-forward and feedback control to generate a tilt valve command for controlling the operation of the tilt valves 116, 118.
Referring still to
It is to be understood that the steps of the control algorithm 200 and/or method 300 are performed by the computing system 102 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 computing system 102 described herein, such as the control algorithm 200 and/or method 300, is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. The computing system 102 loads the software code or instructions via a direct interface with the computer readable medium or via a wired and/or wireless network. Upon loading and executing such software code or instructions by the computing system 102, the computing system 102 may perform any of the functionality of the computing system 102 described herein, including any steps of the control algorithm 200 and/or method 300 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 or by a controller.
This written description uses examples to disclose the technology, including the best mode, and also to enable any person skilled in the art to practice the technology, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the technology is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
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