Patent Application
20220186469
The present disclosure generally relates to work vehicles and, more particularly, to systems and methods for controlling implement operation of a work vehicle using a speed-based parameter associated with the implement.
Work vehicles having loader arms, such as wheel loaders, skid steer loaders, backhoe loaders, compact track loaders, and the like, are a mainstay of construction work and industry. For example, wheel loaders typically include a pair of loader arms pivotably coupled to the vehicle's chassis that can be raised and lowered at the operator's command. As such, wheel loaders may include one or more hydraulic cylinders to raise and lower the loader arms. Moreover, the loader arms typically have an implement attached to their end, 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 wheel loader to be used to carry supplies or particulate matter, such as gravel, sand, or dirt, around a worksite.
Many wheel loaders include systems that are capable of automatically moving the implement to one or more preset or target positions. For example, in some configurations, wheel loaders include a return-to-dig function. In such configurations, upon receipt a return-to-dig command from the operator, the system moves the bucket to a position at which the height and orientation of the bucket are suitable for obtaining a quantity of particulate matter from a pile.
These systems typically monitor the position of the implement and control the movement of the implement solely based on this monitored position. However, due to the cracking pressure tolerance associated with the valve(s) controlling the hydraulic cylinder(s) that move the implement, position-based control may result in the implement stopping short of the target position. In this respect, some systems move the implement at a greater speed to overcome this issue. However, such systems generally require an abrupt deceleration of the implement upon reaching the target position, which is uncomfortable to the operator.
Accordingly, an improved system and method for controlling implement operation of a work vehicle 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 system for controlling implement operation of a work vehicle. The system includes a vehicle chassis, a loader arm pivotably coupled to the vehicle chassis, and an implement pivotably coupled to the loader arm. Furthermore, the system includes a fluid-driven actuator configured to adjust a position of the implement relative to the vehicle chassis. Additionally, the system includes a sensor configured to capture data indicative of the position of the implement relative to the vehicle chassis and a computing system communicatively coupled to the sensor. In this respect, the computing system configured to receive an input associated with a target position of the implement. Moreover, the computing system is configured to monitor a current position of the implement based on the data captured by the sensor. In addition, the computing system is configured to control an operation of the actuator such that the implement is moved toward the target position based on the monitored current position. Furthermore, the computing system is configured to determine a speed-based parameter associated with a speed at which the implement is being moved across a time period. Additionally, after the time period has elapsed, the computing system is configured to control the operation of the actuator such that the implement is moved to the target position based on the monitored current position and the determined speed-based parameter.
In another aspect, the present subject matter is directed to a method for controlling implement operation of a work vehicle. The work vehicle, in turn, includes an implement and a fluid-driven actuator configured to adjust a position of the implement relative to a chassis of the vehicle. The method includes receiving, with a computing system, an input associated with a target position of the implement. Moreover, the method includes monitoring, with the computing system, a current position of the implement based on received sensor data. In addition, the method includes controlling, with the computing system, an operation of the actuator such that the implement is moved toward the target position based on the monitored current position. Furthermore, the method includes determining, with the computing system, a speed-based parameter associated with a speed at which the implement is being moved across a time period. Additionally, after the time period has elapsed, the method includes controlling, with the computing system, the operation of the actuator such that the implement is moved to the target position based on the monitored current position and the determined speed-based parameter.
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 a system for controlling implement operation of a work vehicle. As will be described below, the work vehicle may include a chassis, one or more loader arms pivotably coupled to the vehicle chassis, and an implement (e.g., a bucket) pivotably coupled to the loader arm(s). Moreover, the work vehicle may include one or more fluid-driven actuators (e.g., a hydraulic cylinder(s)) configured to adjust a position of the implement relative to the vehicle chassis.
In accordance with aspects of the present subject matter, a computing system may be configured to control the operation of the fluid-driven actuator(s) to move the implement from its current position to a target position. Specifically, in several embodiments, the computing system may receive an input associated with a target position of the implement (e.g., from the operator via a suitable user interface of the vehicle). Furthermore, the computing system may monitor the current position of the implement based received sensor data. Additionally, the computing system may control the operation of the actuator(s) such that the implement is moved toward the target position based on the monitored current position. Moreover, during a time period across which the implement is being moved toward the target position, the computing system may determine a speed-based parameter associated with a speed at which the implement is being moved. For example, in some embodiments, the speed-based parameter may be an acceleration associated with the implement, such as the angular acceleration of the loader arm(s) relative to the vehicle chassis. After the time period has elapsed, the computing system may control the operation of the actuator(s) such that the implement is moved to the target position based on the monitored current position and the determined speed-based parameter.
Controlling the operation of the actuator(s) based on the monitored current position and the determined speed-based parameter may provide one or more technical advantages. As mentioned above, moving an implement to a target position based on monitored position alone may result in the implement stopping short of the target position or the need for a large and uncomfortable deceleration of the implement to not overshoot the target position. However, determining the speed-based parameter during a time period across which the implement is being moved toward the target position and then subsequently using this parameter in addition to the monitored position to control the remaining movement of the implement to target position allows for adjustment of the speed at which the implement is being moved. Such speed adjustments allow the implement to reach the target position (i.e., the implement does not stop short) without a large and uncomfortable deceleration of the implement.
Referring now to the drawings,
As shown in
As shown in
Furthermore, in several embodiments, the work vehicle 10 may include a lift position sensor 40. In general, the lift position sensor 40 may be configured to capture data indicative of the angle or orientation of the loader arms 24 relative to the chassis 16. For example, in such an embodiment, the lift position sensor 40 may correspond to a potentiometer positioned between the loader arms 24 and the chassis 16, such as within one of the pivot joints 30. In this respect, as the loader arms 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 loader arms 24 relative to the chassis 16. However, in other embodiments, the lift 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 loader arms 24 relative to the chassis 16.
Moreover, in some embodiments, the work vehicle 10 may include a tilt position sensor 42. In general, the tilt position sensor 42 may be configured to capture data indicative of the angle or orientation of the implement 32 relative to the loader arms 24. For example, in such an embodiment, the tilt position sensor 42 may correspond to a potentiometer positioned between the implement 32 and the second ends 28 of the loader arms 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 loader arms 24, the voltage output by the tilt position sensor 42 may vary, with such voltage being indicative of the angle orientation of the implement 32 relative to the loader arms 24. However, in other embodiments, the tilt 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 loader arms 24. For example, in some embodiments, the tilt position sensor 42 may be positioned at or within a pivot joint 44 about which a bell crank 46 coupled to the implement 32 rotates.
It should be appreciated that the configuration of the work vehicle 10 described above and shown in
Referring now to
In several embodiments, as shown in
As shown in
In several embodiments, the pump 102 may be a variable displacement pump configured to discharge hydraulic fluid across a given pressure range. Specifically, the pump 102 may supply pressurized hydraulic fluid within a range bounded by a minimum pressure and a maximum pressure capability of the variable displacement pump. In this respect, a swash plash plate 112 may be configured to be controlled mechanically via a load sense conduit 114 to adjust the position of the swash plate 112 of the pump 102, as necessary, based on the load applied to the hydraulic system of the vehicle 10. However, in other embodiments, the pump 102 may correspond to any other suitable pressurized fluid source. Moreover, the operation of the pump 102 may be controlled in any other suitable manner, such as by an electronically controlled actuator (e.g., a solenoid).
Furthermore, the system 100 may include one or more flow control valves. In general, the flow control valve(s) may be fluidly coupled to a fluid supply conduit(s) upstream of the corresponding hydraulic actuator such that the flow control valve(s) is configured to control the flow rate of the hydraulic fluid to the actuator(s). Specifically, in several embodiments, the system 100 may include a first flow control valve 116 fluidly coupled to the first fluid supply conduit 104 upstream of the lift cylinders 36. The first flow control valve 116 may, in turn, define an adjustable orifice (not shown). In this respect, by adjusting the cross-sectional area of the orifice, the first flow control valve 116 is able to control the flow rate of the hydraulic fluid to the lift cylinders 36 and, thus, the movement of the loader arms 24 relative to the vehicle frame 16. Moreover, in such embodiments, the system 100 may include a second flow control valve 118 fluidly coupled to the second fluid supply conduit 106 upstream of the tilt cylinders 38. The second flow control valve 118 may, in turn, define an adjustable orifice. As such, by adjusting the cross-sectional area of the orifice, the second flow control valve 118 is able to control the flow rate of the hydraulic fluid to the tilt cylinders 38 and, thus, the movement of the implement 32 relative to the loader arms 24.
The first and second flow control valves 116, 118 may be configured as any suitable valves defining adjustable orifices. For example, in one embodiment, first and second flow control valves 116, 118 may be proportional directional valves. Such valves 116, 118 may include actuators (e.g., solenoid actuators) configured to adjust the cross-sectional areas of the orifices in response to receiving control signals, such as from a computing system 120.
Additionally, as indicated above, the system 100 may include a load sense conduit 114. In general, the load sense conduit 114 may receive hydraulic fluid bled from the first or second fluid supply conduit 104, 106 having the greater pressure therein. More specifically, the system 100 may include a first bleed conduit 122 fluidly coupled to the first fluid supply conduit 104 downstream of the first flow control valve 116. Furthermore, the system 100 may include a second bleed conduit 124 fluidly coupled to the second fluid supply conduit 106 downstream of the second flow control valve 118. Thus, the first bleed conduit 122 may receive hydraulic fluid bled from the first fluid supply conduit 104 and the second bleed conduit 124 may receive hydraulic fluid bled from the second fluid supply conduit 106. Furthermore, the system 100 may include a shuttle valve 126 fluidly coupled to the first and second bleed conduits 122, 124 and the load sense conduit 114. The shuttle valve 126 may, in turn, be configured to supply hydraulic fluid from the first or second bleed conduit 122, 124 having the greater pressure therein to the load sense conduit 114. In this respect, the hydraulic fluid supplied to the load sense conduit 114 may have the same pressure as the fluid supply conduit 104, 106 having the greater pressures therein.
The hydraulic fluid within the load sense conduit 114 may be indicative of the load on the hydraulic system of the vehicle 10 and, thus, may be used to control the operation of the pump 102. More specifically, the load sense conduit 114 may supply the hydraulic fluid therein to a pump compensator 128. The pump compensator 128 may also receive hydraulic fluid bled from the first and/or second fluid supply conduits 104, 106 upstream of the flow control valves 116, 118 via a bleed conduit 130. Additionally, the pump compensator 128 may have an associated a pump margin. In this respect, the pump compensator 128 may control the operation of the pump 102 such that the pump 102 discharges hydraulic fluid at a pressure that is equal to the sum of the pump margin and the pressure of the hydraulic fluid received from the load sense conduit 114.
In this illustrated embodiment, the pump compensator 128 corresponds to a mechanical device. For instance, the pump compensator 128 may correspond to a passive hydraulic cylinder coupled to the swash plate 112 of the pump 102. In such an embodiment, hydraulic fluid from the load sense conduit 114 is supplied to one chamber of the cylinder and hydraulic fluid from a bleed conduit 130 is supplied to the other chamber of the cylinder. Moreover, the pump compensator 128 may include a biasing element, such as a spring, in association within the cylinder to set the pump margin. In this respect, when the sum of the pressure received from the load sense conduit 114 and the pump margin exceeds the pressure within the bleed conduit 130, the pump compensator 128 may move the swash plate 112 to increase the pressure of the hydraulic fluid discharged by the pump 102. Conversely, when the sum of the pressure received from the load sense conduit 114 and the pump margin falls below the pressure within the bleed conduit 130, the pump compensator 128 may move the swashplate 112 to decrease the pressure of the hydraulic fluid discharged by the pump 102. However, as will be described below, in other embodiments, the pump compensator 128 may be configured as any other suitable device for controlling the operation of the pump 102.
In accordance with aspects of the present subject matter, the system 100 may include a computing system 120 communicatively coupled to one or more components of the work vehicle 10 and/or the system 100 to allow the operation of such components to be electronically or automatically controlled by the computing system 120. For instance, the computing system 120 may be communicatively coupled to the first flow control valve 116 via a communicative link 132. As such, the computing system 120 may be configured to control the operation of the valve 116 to regulate the flow of the hydraulic fluid to the lift cylinders 36 such that the lift cylinders 36 raise and lower the loader arms 24 relative to the field surface. Furthermore, the computing system 120 may be communicatively coupled to the second flow control valve 118 via the communicative link 132. In this respect, the computing system 120 may be configured to control the operation of the valve 118 to regulate the flow of the hydraulic fluid to the tilt cylinders 38 such that the tilt cylinders 38 adjust the tilt of the implement 32 relative to the loader arms 24. Moreover, the computing system 120 may be communicatively coupled to the lift and tilt position sensors 40, 42 via the communicative link 132. Thus, the computing system 120 may be configured to receive data from these sensors 40, 42 indicative of the position of the implement 32, namely the angular position of the loader arms 24 relative to the vehicle frame 16 and the angular position of the implement 32 relative to the loader arms 24.
In general, the computing system 120 may comprise one or more processor-based devices, such as a given controller or computing device or any suitable combination of controllers or computing devices. Thus, in several embodiments, the computing system 120 may include one or more processor(s) 134 and associated memory device(s) 136 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 circuit (PLC), an application specific integrated circuit, and other programmable circuits. Additionally, the memory device(s) 136 of the computing system 120 may generally comprise memory element(s) including, but not limited to, a computer readable medium (e.g., random access memory RAM)), a computer readable non-volatile medium (e.g., a flash memory), a floppy disk, a compact disk-read only memory (CD-ROM), a magneto-optical disk (MOD), a digital versatile disk (DVD) and/or other suitable memory elements. Such memory device(s) 136 may generally be configured to store suitable computer-readable instructions that, when implemented by the processor(s) 134, configure the computing system 120 to perform various computer-implemented functions, such as one or more aspects of the methods and algorithms that will be described herein. In addition, the computing system 120 may also include various other suitable components, such as a communications circuit or module, one or more input/output channels, a data/control bus and/or the like.
The various functions of the computing system 120 may be performed by a single processor-based device or may be distributed across any number of processor-based devices, in which instance such devices may be considered to form part of the computing system 120. For instance, the functions of the computing system 120 may be distributed across multiple application-specific controllers or computing devices, such as an implement controller, a navigation controller, an engine controller, and/or the like.
Furthermore, in some embodiment, the system 100 may also include a user interface 138. More specifically, the user interface 138 may be configured to receive inputs (e.g., inputs associated with a target position of the implement 32) from the operator. As such, the user interface 138 may include one or more input devices, such as touchscreens, keypads, touchpads, knobs, buttons, sliders, switches, mice, microphones, and/or the like, which are configured to receive user inputs from the operator. For example, in one embodiment, the user interface 138 may include the joystick(s) 20. The user interface 138 may, in turn, be communicatively coupled to the computing system 120 via the communicative link 132 to permit the received inputs to be transmitted from the user interface 138 to the computing system 120. In addition, some embodiments of the user interface 138 may include one or more feedback devices (not shown), such as display screens, speakers, warning lights, and/or the like, which are configured to provide feedback from the computing system 120 to the operator. In one embodiment, the user interface 138 may be mounted or otherwise positioned within the cab 18 of the vehicle 10. However, in alternative embodiments, the user interface 138 may mounted at any other suitable location.
Referring now to
As shown in
Additionally, at (204), the method 200 may include monitoring, with the computing system, a current position of the implement based on received sensor data. More specifically, during operation of the work vehicle 10, the computing system 120 may receive data associated with the current position of the implement 32. For example, in some embodiments, the computing system 120 may receive data associated with angular position of the loader arms 24 relative to the vehicle frame 16 from the lift position sensor 40 (e.g., via the communicative link 132). Such data may, in turn, be indicative of the height of the implement 32 relative to the ground. Furthermore, in some embodiments, the computing system 120 may receive data associated with angular position of the implement 32 relative to the loader arms 24 from the tilt position sensor 42 (e.g., via the communicative link 132). Such data may, in turn, be indicative of the orientation of the of the implement 32 relative to the loader arms 24 (and, indirectly, the ground). In this respect, the computing system 120 may be configured to process or analyze the data received from the sensors 40, 42 to determine or estimate the current position of the implement 32, namely the height and orientation of the implement 32 relative to the ground. For instance, the computing system 120 may include a look-up table(s), suitable mathematical formula, and/or an algorithm(s) stored within its memory device(s) 136 that correlates the received sensor data to the corresponding implement position parameter.
Moreover, as shown in
In some embodiments, at (206), the method 200 may include controlling the operation of the actuator such that the speed at which the implement is moved toward the target is initially increased and then subsequently decreased. For example, in some embodiments, the computing system 120 may be configured to initiate an increase in a speed at which the implement 32 is being moved (e.g., by controlling the operation of the valves 116 and/or 118) as the implement 32 is moved from an initial position (e.g., its current position upon receipt of the input at (202)) to an intermediate position. Thereafter, the computing system 120 may subsequently initiate a decrease in the speed at which the implement 32 is being moved (e.g., by controlling the operation of the valves 116 and/or 118) from the intermediate position to the target position.
Additionally, at (206), in one embodiment, the computing system 120 may be configured to control the operation of the valves 116 and/or 118 such that the implement 32 gradually accelerated from the initial position to the intermediate position. Specifically, in such an embodiment, the computing system 120 may control the valves 116 and/or 118 such that the implement 32 is accelerated at a first acceleration rate from the initial position to a position between the initial and intermediate positions and at a second acceleration rate from this position to the intermediate position, with the second acceleration rate being greater than the first acceleration rate. Such a gradual acceleration of the implement 32 from the initial position may reduce accelerations felt by the operator and make the operation of the work vehicle 10 more comfortable.
Referring again to
The speed-based parameter may be any suitable parameter associated with the speed at which the implement 32 is being moved. For example, in several embodiments, the speed-based parameter may be an acceleration associated with the implement 32. In one such embodiment, the speed-based parameter may be the angular acceleration at which the implement 32 relative to the vehicle frame 16. However, in alternative embodiments, the speed-based parameter may be any other suitable parameter associated with the speed at which the implement 32 is being moved, such as the angular speed of the implement 32.
In some embodiments, at (208), the computing system 120 may be configured to determine a correction factor based on the speed-based parameter. As will be described below, the correction factor may be used in addition to the monitored speed to control the movement of the implement 32 such that the movement of the implement 32 is halted when the implement 32 reaches the target position. More specifically, in one embodiment, the computing system 120 may determine a first position of the implement 32 at a first time corresponding to the start of the time period and a second position of the implement 32 at a second time corresponding to the end of the time period. Such position determinations may be made based on the data received from the lift and/or tilt position sensors 40, 42 as described above. Based on these position measurements and the relevant times at which the position measurements were captured, the computing system 120 may determine the average acceleration of the implement 32. In this respect, the computing system 120 may determine or estimate a projected speed of the implement 32 at the target position based the determined acceleration of the implement 32. Thereafter, the computing system 120 may determine the correction factor based on the projected speed of the implement 32. For instance, the computing system 120 may include a look-up table(s), suitable mathematical formula, and/or an algorithm(s) stored within its memory device(s) 136 that correlates the received sensor data to the correction factor.
Referring to
In addition, as shown in
Referring to
It is to be understood that the steps of the method 200 are performed by the computing system 120 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 120 described herein, such as the method 200, is implemented in software code or instructions which are tangibly stored on a tangible computer readable medium. The computing system 120 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 120, the computing system 120 may perform any of the functionality of the computing system 120 described herein, including any steps of the method 200 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.
