US20200299930A1

US20200299930A1 - Selectable velocity-based or position-based work vehicle operator control system

Info

Publication number: US20200299930A1
Application number: US16/358,481
Authority: US
Inventors: Giovanni A. Wuisan; Scott J. Breiner; Ronald J. Huber
Original assignee: Deere and Co
Current assignee: Deere and Co
Priority date: 2019-03-19
Filing date: 2019-03-19
Publication date: 2020-09-24
Also published as: DE102020203545A1

Abstract

A control system is provided for a work vehicle having one or more actuation devices. The control system includes an operator input device configured to receive operator input from an operator of the work vehicle and a controller operatively connected to the operator input device and to the one or more actuation devices. The controller is configured to: receive a control mode selection input including a position control mode selection input or a velocity control mode selection input; receive an actuation request input from the operator input device; determine an operating command corresponding to the actuation request input from the operator input device according to the control mode selection input; and issue the operating command to the one or more actuation devices based on the position or velocity control mode.

Description

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE DISCLOSURE

This disclosure generally relates to work vehicles, and more specifically to operator control systems of work vehicles.

BACKGROUND OF THE DISCLOSURE

Heavy equipment operators often operate large work vehicles using an operator control system with a variety of operator control devices. Such devices may include joysticks, dials, buttons, switches, wheels, pedals, and the like. In complex vehicles, such as motor graders or wheel loaders, the operator may be required to manipulate a large number of operator control devices in succession or simultaneously to operate numerous independent or interdependent sub-systems of the vehicle, including a steering system for directing the heading rate and direction of the vehicle, as well as systems that operate the tools or implements carried by the vehicle.
Effective and efficient operation of the vehicle and its implements may require the operator to perform intricate hand and arm gestures in order to manipulate the control devices required to actuate these systems timely and accurately. Such effective and efficient operation may be complicated by operator control strategies that differ from vehicle to vehicle and/or from manufacturer to manufacturer.

SUMMARY OF THE DISCLOSURE

The disclosure provides a control system for a work vehicle that enables the operator to selectively operate under a position-based control strategy or velocity-based control strategy for operating an actuation device on the work vehicle.
The disclosure provides a control system for a work vehicle that includes one or more actuation devices. The control system includes an operator input device configured to receive operator input from an operator of the work vehicle and a controller operatively connected to the operator input device and to the one or more actuation devices. The controller is configured to: receive a control mode selection input including a position control mode selection input or a velocity control mode selection input; receive an actuation request input from the operator input device; determine an operating command corresponding to the actuation request input from the operator input device according to the control mode selection input; and issue the operating command to the one or more actuation devices.
In one aspect, the disclosure provides a control system for a work vehicle having one or more actuation devices. The control system includes an operator input device configured to receive operator input from an operator of the work vehicle and a controller operatively connected to the operator input device and to the one or more actuation devices. The controller is configured to: receive a control mode selection input including a mode selection input as a position control mode or a velocity control mode; receive an actuation request input from the operator input device; determine an operating command corresponding to the actuation request input from the operator input device according to the control mode selection input; and issue the operating command to the one or more actuation devices. In the position control mode, the operating command includes an instruction to move the one or more actuation devices to a position corresponding to a position corresponding to the actuation request input from the operator input device. In the velocity control mode, the operating command includes an instruction to move the one or more actuation devices at a rate of change corresponding to a rate of change of the actuation request input from the operator input device.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a work vehicle in the form of a motor grader in which the operator control system of this disclosure may be incorporated;

FIG. 1B is a perspective view of a work vehicle in the form of a wheel loader in which the operator control system of this disclosure may be incorporated;

FIG. 2 is simplified view inside an operator cabin of the motor grader of FIG. 1A or the wheel loader of FIG. 1B showing example operator input devices;

FIG. 3 is a functional block diagram depicting dataflows of an operator control system on an example embodiment;

FIG. 4 is a perspective view of an active feedback force joystick device that may be implemented in the operator control system of FIG. 3 according to an embodiment;

FIGS. 5A and 5B are schematic views of a passive feedback force joystick device that may be implemented in the operator control system of FIG. 3 according to an embodiment;

FIGS. 6A-6C are cross-sectional views of a portion of the joystick device of FIG. 5A through line 6-6; and

FIGS. 7A-7C are cross-sectional views of a portion of the joystick device of FIG. 5A through line 7-7.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The following describes one or more example embodiments of the disclosed operator control system, as shown in the accompanying figures of the drawings described briefly above. Various modifications to the example embodiments may be contemplated by one of skill in the art.
Generally, the disclosed operator control systems and methods (and work vehicles in which they are implemented) provide for improved operator experience to perform steering tasks as compared to conventional systems by enabling the operator to select between a velocity-based control strategy and a position-based control strategy for steering or other actuation devices, thereby simplifying steering and/or improving operation of the work vehicle for each operator.
Work vehicles used in various industries, such as the agriculture, construction and forestry industries, may include systems, tools, or implements used to maneuver and carry out various functions for which the work vehicle was designed. Typically, this requires the vehicle operator to be familiar with the vehicle devices for controlling the vehicle heading and speed and operating the implement. Certain work vehicles, such as those with a number of implements having multiple degrees of freedom in movement, may be rather complex to operate and require the operator to have considerable related skill and experience. Suboptimal operation of the vehicle or the implements may result in inefficient or imprecise performance at the work site or generally discourage potential operators from attempting to operate unfamiliar or different vehicles.
One particularly complex work vehicle is the motor grader, which is generally used in the construction industry to set grade. Modern motor graders are typically large machines with a lengthy articulated chassis formed by a front frame with steered wheels pivotally connected to a rear frame with drive wheels. Motor graders may also have the capability to tilt the steered wheels. These features thus provide for an improved (i.e., shorter) turning radius, thereby making the large machine nimbler than otherwise possible. Beyond the heading and speed control, motor graders may have rather complex implements. The primary tool on motor graders is the moldboard or blade, which is mounted to a turntable known in the industry as a circle. The circle is adjustably mounted to the vehicle frame, and the blade in turn is adjustably mounted to the circle, thus giving the blade a wide-range of possible movements. Other types of vehicles, such as wheel loaders, may present similar operational complexities.
To perform the aforementioned functions and operations, the motor graders and other types of vehicles may be outfitted with a relatively large number of joysticks, control levers, buttons, switches, knobs, and other devices that may each control operation of a single, discrete operation or motion. As examples, one arrangement includes a dual joystick control system with left and right multi-axis joystick devices that, in addition to multiple inputs by manipulation of the joystick grip interfaces, each carry a large number of other input devices. In one example, manipulation of one of the joystick devices along one axis may control the steering system (e.g., pivoting the steered wheels to the right and left). Such steering must be performed along with numerous other possible control functions. Even though the steering control is already challenging while undertaking the numerous other tasks, steering control issues may be compounded by the multiple control strategies that may vary from vehicle to vehicle. Certain operators may have a control strategy preference and/or unfamiliar operation may result in inefficiencies. Potential steering control strategies may include a velocity-based steering control strategy and a position-based steering control strategy. Additionally, although the steering system is discussed below, the control strategies may also be applicable to other actuation devices on the work vehicle, including implement actuation devices, such as booms, buckets, blades, and the like.
In a velocity-based steering (or other actuation) control strategy, an operator control system generates velocity-based commands in response to velocity-based operator inputs to control the associated actuation devices of the work vehicle. Generally, in the velocity-based steering control strategy, the position (e.g., the absolute position or angle relative to neutral) of the actuation request input at the operator input device is interpreted to request a command to move an actuation device at a corresponding rate of change. As such, a relatively small amount of movement by the operator input device to a particular position may thus correspond to a relatively slower movement of the associated actuation device as long as the position of the operator input device is maintained, as compared to a larger movement by the operator input device, which results in a relatively faster movement of the associated actuation device. As such, the controller may thus receive velocity-based input commands corresponding to a desired movement of the machine or implement, and the controller may resolve the velocity-based inputs, possibly in conjunction with inputs from sensors or other position-indicating devices, and command one or more target actuation device velocities (e.g., depending on the number of actuation devices required to effectuate the desired end movement). The joystick device additionally provides a feedback force in accordance with the velocity-based steering control strategy. In particular, in the velocity-based steering control strategy, the operator makes the intended control input (e.g., joystick device movement) and then lets the control input return to a neutral position without continuing to hold the joystick grip interface until the actuation device movement cycle time is completed, as may be required in a position-based steering control strategy. Typically, the velocity-based steering control strategy implements a feedback force opposing the direction of input that increases as the joystick grip interface moves away from the neutral position and decreases as the joystick grip interface moves towards the neutral position. As an example, a curve the depicts feedback force in view of joystick grip interface angle according to the velocity-based steering control strategy may have a V-shaped appearance that is centered about the neutral position.
In a position-based steering (or other actuation) control strategy, an operator control system generates position-based commands in response to position-based operator inputs to control the associated actuation devices of the work vehicle. Generally, in the example of a joystick, the position of an actuation request at the operator input device relative to a neutral position is interpreted by the controller to represent the desired corresponding position (e.g., angle) of the steering system in the designated direction. Moreover, rate at which the joystick grip interface is moved may be considered by the controller to represent the desired speed at which to implement the command. As such, the controller may thus receive position-based input commands corresponding to a desired movement of the machine or implement, and the controller may resolve the position-based inputs, possibly in conjunction with inputs from sensors or other position-indicating devices, and command one or more target actuation device positions (e.g., depending on the number of actuation devices required to effectuate the desired end movement). The operator input device additionally provides a feedback force in accordance with the position-based steering control strategy. In particular, in the position-based scheme, the operator makes the intended control input (e.g., joystick movement) and then the joystick grip interface generally stays in that position until adjusted by the operator, thereby providing a stabilizing feedback force. In addition to this aspect of the feedback force, the position-based steering control strategy typically implements a further feedback force opposing the direction of input that increases as the joystick moves away from an initial position, which may or may not be the neutral position. In this instance, the feedback force represents an overspeed response corresponding to the reaction of the steering system. In other words, as the joystick grip interface is moved quickly from a neutral position, the feedback force will be relatively high to, in effect, enable implementation of the corresponding command, while if the joystick is moved slowly from a neutral position, the feedback force will be relatively low since the steering system has time to react appropriately. In position-based steering control strategies, this feedback force function is also applicable to initial positions other than the neutral position. As an example, the feedback force-angle curve of a position-based steering control strategy may have a V-shaped appearance that is centered about the current position that is lagged based on steering system articulation.
Now with reference to the drawings, one or more example implementations of the operator control system for use on a work vehicle will now be described. While a motor grader is illustrated and described herein as an example work vehicle, one skilled in the art will recognize that principles of the operator control system disclosed herein may be readily adapted for use in other types of work vehicles, including, for example, various crawler dozer, loader, backhoe and skid steer machines used in the construction industry, as well as various other machines used in the agriculture and forestry industries. As such, the present disclosure should not be limited to applications associated with motor graders or the particular example motor grader shown and described. Similarly, the operator control systems are discussed below with respect to the steering system. However, other systems may implement corresponding operator control systems in which velocity-based and position-based control strategies may be applicable.
As shown in FIG. 1, a motor grader 100 includes an operator control system 110 that controls various functions associated with the motor grader 100, including a steering function based on manual inputs from an operator and other inputs, as discussed in greater detail below. The operator control system 110 is implemented with a controller 120 and may further be considered to include one or more operator input devices 130 and/or a steering system 140. Generally, as described in greater detail below, the operator input devices 130 may include one or more operator control apparatuses 132, 134 (e.g., as joystick-type or other types of controls) to receive operator inputs that control various aspects of the motor grader 100 and a steering mode selection switch 136 to receive operator inputs that select a mode associated with a control strategy. Additional details about the operator control system 110 will be provided below after a more general description of the motor grader 100.
In the depicted example, the motor grader 100 is formed by a front frame 150 and a rear frame 152 that are pivotably connected to each other via an articulation joint 154. The front frame 150 and the rear frame 152 are respectively supported by front wheels 156 and rear wheels 158. In other embodiments, the motor grader 100 may include other ground-engaging devices for propelling the machine, such as track assemblies, for example, as known in the art.
The motor grader 100 further includes a drive system 160 adapted to drive or power the motor grader 100 and collectively formed by an engine or other type of power source 162, and a transmission 164 supported, in this example, by the rear frame 152. The engine 162 may be any suitable type of engine, including a diesel engine, a gasoline engine, a gaseous fuel powered engine such as a natural gas engine, or any other type of engine apparent to one skilled in the art. Other power sources may alternatively embody a non-combustion source of power such as a fuel cell, a power storage device, an electric motor, or other similar mechanism. Although not shown in detail, the transmission 164 includes a plurality of forward and reverse gears and a neutral gear and is connected to a differential axle for driving one or more of the rear wheels 158 based on torque from the engine 162. In some embodiments, the motor grader 100 may include an all-wheel drive system in which one or more of the front wheels 156 are also driven.
An operator cab 170 is mounted to the front frame 150. The operator cab 170 may contain many controls of the motor grader 100, including operator input devices 130 described in greater detail below, used to steer and otherwise operate the motor grader 100. The operator cab 170 may also include a display device 172 adapted to convey information to the operator concerning the operation of the motor grader 100. In some examples, the display device 172 may accept operator inputs (e.g., as a touchscreen display) such that the display device 172 may also be considered to be one of the operator input devices 130.
As introduced above, the motor grader 100 includes the steering system 140 to maneuver the motor grader 100 during operation based on signals from the controller 120 and/or operator input devices 130 according to a selected steering control strategy, described in greater detail below. As is generally known, the steering system 140 includes various linkages, levers, joins, gears, pins, rods, and the like to position one or more driven wheels 156, 158 to orient the motor grader 100 in the desired direction. In one example and as schematically shown in FIG. 1, the steering system 140 includes one or more steering actuation devices, such as one or more steering cylinders 142 (schematically shown) coupled to the front or rear wheels 156, 158 configured to be hydraulically operated to articulate or reposition of the wheels 156, 158 (e.g., pivoting about a vertical axis) to steer the motor grader 100. Additional steering mechanisms may be provided, including one or more lean cylinders 144 (schematically shown) coupled to the front or rear wheels 156, 158 configured to be hydraulically operated to control the position of the wheels 156, 158 (e.g., pivoting about a horizontal axis). Further, the steering system 140 may include one or more articulation cylinders 146 (schematically shown) mounted to one or both of the frames 150, 152 to rotate the front frame 150 relative to the rear frame 152 about the articulation joint 154. The components of the steering system 140 introduced above are merely examples, and any number of additional components or systems may be provided. For example, the steering system 140 may further incorporate various types of circuits, including a hydraulic circuit and/or an electrical circuit for facilitating and controlling operation of the cylinders 142, 144, 146 and other actuation devices of the steering system 140. Although not shown, such a hydraulic circuit may include hoses, pumps, tanks, valves, and the like.
The motor grader 100 includes one or more implements 180, 182 for performing work functions. As examples, the motor grader 100 includes a circle 180 and blade assembly 182 are mounted to the front frame 150 in front of the operator cab 170. Various types of actuators (as well as brackets, couplings, motors, hydraulic and electric components, etc.) are provided to manipulate the circle 180 and/or blade assembly 182, including lifting, tilting, rotating, shifting, repositioning, and the like to advantageously perform the functions of the motor grader 100. Other implements may be provided.
As noted above, the controller 120 is provided to control various operational aspects of the motor grader 100. Generally, the controller 120 may receive inputs from a number of sources, including the operator via the operator input devices 130 and from various sensors, units, and systems onboard or remote from the motor grader; and in response, the controller 120 generates one or more types of commands for implementation by the various systems of motor grader 100. As one example discussed in greater detail below, the controller 120 may facilitate operation of the operator control system 110, particularly with respect to receiving steering or other actuation request inputs from the operator via the operator input devices 130 and generating associated steering or other actuation device commands for the steering system 140 based on a selected mode associated with a respective control strategy.
Broadly, the controller 120 may be configured as a computing device with associated processor devices and memory architectures, as a hard-wired computing circuit (or circuits), as a programmable circuit, as a hydraulic, electrical or electro-hydraulic controller, or otherwise. As such, the controller 120 may be configured to execute various computational and control functionality with respect to the motor grader 100 (or other machinery). In some embodiments, the controller 120 may be configured to receive input signals in various formats (e.g., as hydraulic signals, voltage signals, current signals, and so on), and to output command signals in various formats (e.g., as hydraulic signals, voltage signals, current signals, mechanical movements, and so on). In some embodiments, the controller 120 (or a portion thereof) may be configured as an assembly of hydraulic components (e.g., valves, flow lines, pistons and cylinders, and so on), such that control of various devices (e.g., pumps or motors) may be implemented with, and based upon, hydraulic, mechanical, or other signals and movements.
The controller 120 may be in electronic, hydraulic, mechanical, or other communication with various other systems or devices of the motor grader 100 (or other machinery). For example, the controller 120 may be in electronic or hydraulic communication with various actuators, sensors, and other devices within (or outside of) the motor grader 100, including various devices associated with pumps, control valves, and so on. The controller 120 may communicate with other systems or devices (including other controllers) in various known ways, including via a CAN bus (not shown) of the motor grader 100, via wireless or hydraulic communication means, or otherwise. An example location for the controller 120 is depicted in FIG. 1. It will be understood, however, that other locations are possible including other locations on the controller 120, or various remote locations.
In some embodiments, the controller 120 may be configured to receive input commands and to interact with an operator via the operator input devices 130, which may be disposed inside an operator cab 170 of the motor grader 100 for easy access by the operator. The operator input devices 130 may be configured in a variety of ways. In some embodiments, the operator input devices 130 may include one or more joystick devices, various switches or levers, one or more buttons, a touchscreen interface that may be overlaid on a display, a keyboard, an audible device, a microphone associated with a speech recognition system, or various other human-machine interface devices. In one example, the one or more switches (e.g., switch 136) may receive an input associated with a steering mode selection and a joystick (or other) device (e.g., apparatuses 132, 136) may receive steering requests associated with the steering system 140 according to a selected steering mode to implement an associated steering control strategy. More specific examples of operator input devices 130 are provided below with reference to FIG. 2.
Various sensors (not shown) may also be provided to observe various conditions and other parameters associated with the motor grader 100. For example, various sensors may be associated with the steering system 140, drive system 160, and/or the implements 180, 182. Example sensors include sensors for measuring the articulation angle at the articulation joint 154; pressure and/or position sensors to evaluate the positions of the various cylinders, pumps, and valves; travel speed sensors; steering feedback angle sensors; and steering velocity sensors. One or more sensors may also be incorporated into the operator input devices 130, discussed below.
As shown in FIG. 1B, a wheel loader 100′ includes an operator control system 110′ that controls various functions associated with the wheel loader 100′ in a similar manner to the motor grader 100 discussed in reference to FIG. 1A, including steering or other actuation functions based on manual inputs from an operator and other inputs, as discussed in greater detail below. As above, the operator control system 110′ is implemented with a controller 120′ and may further be considered to include one or more operator input devices 130′ and/or a steering system 140′. Generally, the operator input devices 130′ may include one or more operator control apparatuses 132′, 134′ (e.g., as joystick-type or other types of controls) to receive operator inputs that control various aspects of the wheel loader 100′ and a mode selection switch 136′ to receive operator ii inputs that select a mode associated with a control strategy (e.g., a steering or other actuation control mode). Additional details about the operator control system 110′ will be provided below after a more general description of the loader 100′.
In the depicted example, the wheel loader 100′is formed by a chassis or frame 150′ supported by front wheels 156′ and rear wheels 158′. In other embodiments, the wheel loader 100′ may include other ground-engaging devices for propelling the machine, such as track assemblies, for example, as known in the art. The wheel loader 100′ further includes a drive system 160′ adapted to drive or power the wheel loader 100′ and collectively formed by an engine or other type of power source 162′ and a transmission 164′, as generally described above.
An operator cab 170′ is mounted to the frame 150′. The operator cab 170′ may contain many controls of the wheel loader 100′, including operator input devices 130′ described in greater detail below, used to steer and otherwise operate the wheel loader 100′. The operator cab 170′ may also include a display device 172′ adapted to convey information to the operator concerning the operation of the wheel loader 100′. In some examples, the display device 172′ may accept operator inputs (e.g., as a touchscreen display) such that the display device 172′ may also be considered to be one of the operator input devices 130′.
As introduced above, the wheel loader 100′ includes the steering system 140′ to maneuver the wheel loader 100′ during operation based on signals from the controller 120′ and/or operator input devices 130′ according to a selected steering control strategy, described in greater detail below as one example. As is generally known, the steering system 140′ includes various linkages, levers, joins, gears, pins, rods, and the like to position one or more driven wheels 156′, 158′ to orient the wheel loader 100′ in the desired direction. In one example and as schematically shown in FIG. 1B, the steering system 140′ includes one or more steering actuation devices, such as one or more steering cylinders 142′ (schematically shown) coupled to the front or rear wheels 156′, 158′ configured to be hydraulically operated to articulate or reposition of the wheels 156′, 158′ (e.g., pivoting about a vertical axis) to steer the wheel loader 100′. Additional steering mechanisms may be provided. The components of the steering system 140′ introduced above are merely examples, and any number of additional components or systems may be provided. For example, the steering system 140′ may further incorporate various types of circuits, including a hydraulic circuit and/or an electrical circuit for facilitating and controlling operation of the cylinders 142′ and other actuation devices of the steering system 140′. Although not shown, such a hydraulic circuit may include hoses, pumps, tanks, valves, and the like.
The wheel loader 100′ further includes a work implement, such as a bucket 180′, positioned at a front of the wheel loader 100′ and attached to the wheel loader 100′ through one or more linkage arms 182′ that include a series of pinned joints, structural members, and at least one hydraulic actuator 184′. This configuration allows the bucket 180′ to be moved up and down relative to the ground, and rotate around a lateral axis of the work vehicle 100′. Other implements may be provided.
Generally, the controller 120′ of the wheel loader 100′ operates in a manner similar to that described above with respect to the controller 120 of the motor grader 100 to control various operational aspects of the motor grader 100. In particular, the controller 120′ may receive inputs from a number of sources, including the operator via the operator input devices 130′ and from various sensors, units, and systems onboard or remote from the wheel loader 100′; and in response, the controller 120′ generates one or more types of commands for implementation by the various systems of wheel loader 100′. As one example discussed in greater detail below, the controller 120′ may facilitate operation of the operator control system 110′, particularly with respect to receiving steering request inputs from the operator via the operator input devices 130′ and generating associated steering actuation device commands for the steering system 140′ based on a selected mode associated with a respective control strategy.
Reference is briefly made to FIG. 2, which depicts the interior cabin of the operator cab 170 of the motor grader 100, although the cab 170 and description below may also refer to the wheel loader 100′. As shown, the operator cab 170 provides an enclosure for the operator to access a number of different operator input devices 130, including a steering wheel, accelerator, and brake pedals. The operator cab 170 may further house the display device 172. In this example, the operator input devices 130 include operator control apparatuses 132, 134 as a left operator control apparatus 132 and a right operator control apparatus 134 mounted to each side of the operator seat.
The operator control apparatuses 132, 134 are joystick-type controls with a grip interface and various types of inputs, such as buttons, switches, and dials, mounted on the grip interface. In one example, the left operator control apparatus 132 may include input mechanisms for lifting, lowering, and adjusting the pitch of the blade assembly 182; rotating the circle 180; shifting the transmission 164; and certain auxiliary functions. As a further example, the right operator control apparatus 134 may include input mechanisms for shifting the circle 180 and the blade assembly 182; adjusting the lean of the wheels 156, 158; adjusting the articulation of the frames 150, 152; and locking the differential axle.
According to one embodiment of the operator control system 110 with respect to the steering system 140, the left operator control apparatus 132 includes a joystick grip interface that may be pivoted to the left and right as a steering request to steer the front wheels 156 via the steering system 140. In particular, the operator provides manual operator steering inputs by pivoting the joystick grip interface, and the controller 120, upon receiving the steering inputs, generates appropriate steering actuation device commands to the steering system 140. Although the steering function is discussed below with respect to the joystick device, the steering function may be implemented into other operator input devices 130, such as the right operator control apparatus 134, steering wheel, and/or the other buttons, dials, and the like. Additional details about example implementations of a joystick device will be provided below.
As also depicted in FIG. 2, the operator input devices 130 further include the steering mode selection switch 136 that may form part of the operator control system 110. The steering mode selection switch 136 may take any form. In one example, the steering mode selection switch 136 is a mechanical, physical, and/or virtual switch that enables an operator to select between a velocity-based steering control strategy (e.g., as a velocity control mode) and a position-based steering control strategy (e.g., as steering control mode), as will be discussed in greater detail below. In one example, the steering mode selection switch 136 may have visual indicia reflecting the potential strategies of the system 110 such that the operator may position the switch 136 according to the desired strategy. As introduced above, switch 136 of the motor grader 100 may be analogous to the switch 136′ of the wheel loader 100′.
Reference is now made to FIG. 3, which is a functional block dataflow diagram of portions of the operator control system 110 (and operator control system 110′) according to an embodiment. As noted above, the operator control system 110, 110′ may be considered to include the controller 120, 120′, the steering system 140, 140′ with one or more actuation devices 142, 142′, and one or more operator input devices 130, 130′. Generally, the actuation devices 142, 142′ discussed below may refer to any individual or combination of actuation devices and associated components that may be utilized to steer the motor grader 100 or wheel loader 100′, In this example, the operator input devices 130, 130′ include a joystick device 350 and the steering mode selection switch 136, 136′ (such as the steering mode selection switches 136, 136′ of FIG. 1A or 1B). The display device 172, 172′ (such as the display device 172, 172′ of FIG. 1A or 1B) may also form part of the operator control system 110, 110′.
In one example, the joystick device 350 may be incorporated into a larger operator control apparatus, such as one of the operator control apparatuses 132, 132′, 134, 134′, with numerous operator input mechanisms. However, for the purpose of steering the front wheels of the steering system 140, 140′ as part of the operator control system 110, 110′, the joystick device 350 is a single-axis joystick unit that may be pivoted to the left and right by the operator in order to steer the motor grader 100 (FIG. 1A) or the wheel loader 100′ (FIG. 1B). Generally, the joystick device 350 described below in reference to FIG. 3 may be implemented in any suitable manner; however, more specific example implementations are described below with reference to FIGS. 4, 5A, 5B, 6A-6C, and 7A-7C.
As shown, the joystick device 350 includes a joystick grip interface 352 mounted to a base or housing 354. The joystick grip interface 352 is a lever-type or shaft element with a first end engageable by an operator and a second end secured to pivot within the housing 354 about a pivot axis. The operator engages the joystick grip interface 352 along a range of motion to implement a desired steering or other actuation function of the motor grader 100 or the wheel loader 100′ as an operator steering input 370, as described below.
A feedback unit 356 is coupled to the joystick grip interface 352 or the base 354 in order to impart a feedback force in response to the operator manipulation of the joystick grip interface 352. As used herein, the term “feedback” refers to a force imparted on the joystick grip interface 352 in any form or for any purpose, including a force to counteract or resist operator manipulation or external forces, a force to maintain a position of the grip interface 352 in the absence of operator manipulation, or a force to center or reposition the grip interface 352 (e.g., to a neutral position or otherwise) in the absence of operator manipulation. In general, the feedback unit 356 applies the haptic feedback force or “feel” responsive to operator movements. The feedback force may be linear or non-linear and proportional to the force required to move the grip interface 352. As described below, the feedback unit 356 is commanded to apply the force in view of the steering control strategy.
The joystick device 350 further includes at least one control interface sensor 358 configured to collect various types of information associated with the operator steering input 370. In particular, with respect to the joystick grip interface 352, the control interface sensor 358 is configured to collect data associated with the position or displacement angle relative to a neutral position and the speed or angular velocity of the displacement (or derivations thereof), and in response, the control interface sensor 358 generates a corresponding signal in the form of an actuation request input 382. The actuation request input 382 is provided to the controller 120, 120′.
As introduced above, the operator input devices 130, 130′ further include the steering mode selection switch 136, 136′. The steering mode selection switch 136, 136′ is configured to receive an operator mode input 372 in which the operator selects between a velocity control mode implementing the velocity-based steering control strategy and a position control mode implementing the position-based steering control strategy. In response to the operator mode input 372, the steering mode selection switch 136, 136′ generates a corresponding signal in the form of a control mode selection input 380. The control mode selection input 380 is provided to the controller 120, 120′.
As such, the controller 120, 120′ may receive the control mode selection input 380 and actuation request input 382. With respect to the operator control system 110, 110′ of FIG. 3, the controller 120, 120′ may be organized as one or more functional units or modules 310, 320, and 330 (e.g., software, hardware, or combinations thereof). As can be appreciated, the modules 310, 320, 330 shown in FIG. 3 may be combined and/or further partitioned to carry out similar functions to those described herein. As an example, each of the modules 310, 320, 330 may be implemented with processing architecture such as a processor 302 and memory 304, as well as suitable communication interfaces. For example, the controller 120, 120′ may implement the modules 310, 320, 330 with the processor 302 based on programs or instructions stored in memory 304. In this example, the controller 120, 120′ includes a mode module 310, an actuation module 320, and a feedback module 330. In some embodiments, the feedback module 330 may be omitted, as described below.
As introduced above, the controller 120, 120′ is configured to receive the actuation request input 382 and the control mode selection input 380. In one embodiment, the mode module 310 receives the control mode selection input 380. The mode module 310 evaluates the control mode selection input 380, and in response, generates a control mode determination 312 that identifies the selected control mode represented in the control mode selection input 380. The control mode determination 312 is provided to the actuation module 320 and feedback module 330.
The actuation module 320 receives the actuation request input 382 and the control mode determination 312. The actuation module 320 evaluates the actuation request input 382 in view of the control mode determination 312. The actuation module 320 may access stored information that maps the actuation request input 382 to a work device operating command 390 according to the current control mode determination 312. Specifically, an actuation request input 382, when in the velocity control mode, is mapped to one or more work device operating commands 390 in order to implement a particular velocity; and an actuation request input 382, when in the position control mode, is mapped to a work device operating command 390 in order to implement a particular position. For example, in the velocity control mode, the actuation request input 382 is interpreted as a joystick grip interface input, and in response, the actuation module 320 may reference a stored map to determine a corresponding velocity command for one or more of the steering actuation devices 142, 142′ that results in an operator desired steering velocity. Such reference maps may include a collection of data in the form of tables, graphs, and/or equations. Similarly, in the position control mode, the actuation request input 382 based on the operator steering input 370 is interpreted as a joystick grip interface (or other operator interface) position input, and in response, the actuation module 320 may reference a stored map to determine a corresponding position command for one or more of the steering actuation devices 142, 142′ that results in an operator desired steering position.
The work device operating command 390 generated by the actuation module 320 is provided to the steering system 140, 140′, such as one or more of the steering actuation devices 142, 142′, as introduced above. For example, the work device operating command 390 may correspond to valve positions to operate the actuation devices 142, 142′ to a specified position or velocity. Accordingly, the steering system 140, 140′ implements the work device operating command 390 for the control mode determination 312, thereby enabling steering operation with steering inputs 370 according to a desired or preferred steering control strategy.
In some embodiments, the actuation module 320 may receive additional input data (not shown) from various sensors, systems, or other modules on-board or off-board of the motor grader 100 or wheel loader 100′. Such additional input may include information associated with the actuation devices 142, 142′ (e.g., cylinder positions, tank volumes, fluid pressures, etc.). The actuation module 320 may further evaluate the actuation request input 382 in view of the additional input to provide an appropriate operating command 390.
In some examples, the mode module 310 may further provide the control mode determination 312 to the display device 172, 172′. This enables a visual indication to the operator of the present steering control mode.
The mode module 310 further provides the control mode determination 312 to the feedback module 330. The feedback module 330 also receives the actuation request input 382. In turn, the feedback module 330 may actively generate an appropriate feedback command 392 in response to the actuation request input 382 according to the control mode determination 312 for the feedback unit 356 of the joystick device 350. In one example, the feedback module 330 may access stored information that maps the actuation request input 382 in view of the control mode determination 312 to an associated feedback force response as a feedback command 392. Specifically, an actuation request input 382, when in the velocity control mode, is mapped to one or more feedback commands 392 in order to implement a particular feedback force according to a velocity-based steering control strategy; and an actuation request input 382, when in the position control mode, is mapped to one or more feedback commands 392 in order to implement a particular feedback force according to a position-based steering control strategy. Such reference maps may include a collection of data in the form of tables, graphs, and/or equations.
Upon receipt, the feedback unit 356 applies a force to the joystick grip interface 352 according to the feedback command 392. As a result, the steering control mode dictates the nature of the feedback force generated by the feedback unit 356 on the joystick grip interface 352.
In some examples, the feedback module 330 may be omitted. In those embodiments, the feedback force may be applied passively to the joystick device 350, e.g., without active control. Additional details regarding the feedback unit 356, including example mechanisms for applying the feedback force, are provided below.
In this manner, the operator control system 110, 110′ enables the operator to select a steering mode and provide steering inputs, and in response, the controller 120, 120′ implements these inputs to appropriately control the steering system 140, 140′. The controller 120, 120′ may additionally generate the appropriate feedback force at the joystick device 350 according to the selected mode.
In various embodiments of the operator control system 110, 110′ described above, the velocity-based and position-based steering control strategies may be implemented according to various types of operator input devices and associated feedback responses. For example, the operator input devices may be implemented in an active system in which a motor generates an appropriate feedback response; a passive system in which mechanical components generate the feedback response; and a semi-active system that includes implementation characteristics of a passive system and an active system. Examples are provided below with reference to FIGS. 4, 5A, 5B, 6A-6C, and 7A-7C. Additionally, as noted above, although the operator control system 110, 110′ is primarily described in the context of steering, corresponding strategies may be utilized with other actuation operations.
Reference is made to FIG. 4, which is an active (or full-active) feedback force joystick device 400. In one embodiment, the joystick device 400 is an electromechanical joystick device. The joystick device 400 of FIG. 4 may be considered one of the operator input devices 130 of the operator control system 110, 110′ discussed above with reference to FIGS. 1A, 1B, 2, and 3.
The joystick device 400 includes a joystick grip interface (or joystick shaft) 410 that extends between a first end 412 configured for engagement by the operator to a second end within a housing or base member. Although not shown, the second end of the joystick grip interface 410 is pivotally coupled to a positioning motor 430 via any suitable linkage arrangement, such as gimbal arm, pivot bearing, bearing mount, gear arrangements, and the like.
A positioning motor 430, such as a servo motor, is operatively coupled to the joystick grip interface 410 via various mechanisms such that a desired force and/or velocity can be applied to the control joystick grip interface 410 having a magnitude that is a function of the torque and/or velocity of a motor drive shaft (not shown).
One or more electromechanical or optical position sensors 440 (schematically shown) are operatively coupled to the joystick grip interface 410 to determine the position of the joystick grip interface 410. Examples of such sensors 440 include rotary or linear potentiometers, optical encoders, and linear displacement voltage transducers (LDVTs).
In FIG. 4, the joystick grip interface 410 is in a neutral or center position. During operation, a force applied by the operator pivots the joystick grip interface 410 relative to the steering axis, and thus pivots a linkage arrangement to cause rotation of the drive shaft of the motor 430. The amount of rotation imparted to drive shaft may be sensed by sensors 440 that output a corresponding signal representing an actuation request signals (e.g., actuation request input 382 of FIG. 3).
Additionally, the motor 430 is configured to generate a feedback force applied to the joystick grip interface 410 in response according to command signals (e.g., feedback command 392 of FIG. 3). In particular, the motor 430 applies a feedback force in order to move or resist movement of the joystick grip interface 410. The motor 430 may implement the variable feedback force according to the selected control mode, e.g., either the velocity-based steering control strategy in the velocity control mode or the position-based steering control strategy in the position control mode.
As examples, in the velocity control mode, the feedback force curve remains centered, regardless of the position of the joystick grip interface 410. As such, as the joystick grip interface 410 is moved further from the center, the motor 430 applies an increasing feedback force to the joystick grip interface 410 in an opposing direction, although typically less than the force required to move the joystick grip interface 410. Moreover, the feedback force from the motor 430 functions to re-center the joystick grip interface 410 after the operator releases the joystick grip interface 410. Based on the feedback commands, the feedback force may be linearly or non-linearly proportional to the force required to move the joystick grip interface 410.
In the position control mode, the feedback force curve follows the position of the joystick grip interface 410. As such, as the joystick grip interface 410 completes a movement, the feedback force applied by the motor 430 operates to maintain the position of the joystick grip interface 410 associated with the operator input. As introduced above, the motor 430 may additionally provide a feedback force in view of the speed of the operator input according to the reaction time of the steering system (e.g., steering system 140 of FIG. 1A, as well as steering system 140′ of FIG. 1B). In particular, if the joystick grip interface 410 is moved quickly, the motor 430 may apply a relatively strong resisting feedback force to the joystick grip interface 410. The resisting feedback force reflects the ability of the steering system to implement the actuation request input. Otherwise, the steering system may not be able to “keep up” with the inputs at the joystick grip interface 410.
In some examples, the feedback force applied by the motor 430 may have characteristics of both the velocity-based steering command strategy and the position-based steering command strategy regardless of the current steering control mode in order to improve the function of the joystick device 400. For example, in the velocity control mode, the motor 430 operates to provide some stabilizing feedback force to the joystick grip interface 410 upon returning to the neutral position. Otherwise, the joystick grip interface 410 may undesirably oscillate upon returning to the neutral position. Similarly, in the position control mode, the motor 430 operates to provide some stabilizing feedback force on the joystick grip interface 410, even when the joystick grip interface 410 has been released by the operator. Otherwise, the weight of the joystick grip interface 410 may cause unwanted movement. Instead, the feedback force of the motor 430 may automatically account for the weight of the joystick grip interface 410 such that when the interface 410 is released, it stays in the position. However, the selected mode designates which strategy dominates the applicable feedback force.
Reference is now made to FIGS. 5A-5B, 6A-6C, and 7A-7C, which are different views of a passive (or full-passive) feedback force joystick device 500. The joystick device 500 may be considered one of the operator input devices 130, 130′ of the operator control system 110, 110′ discussed above with reference to FIGS. 1A, 1B, 2, and 3. In this example, the joystick device 500 is incorporated with a steering mode selection switch 510, which may correspond to the steering mode selection switch 136 also discussed above with reference to FIGS. 1A, 1B, 2, and 3.
Initially referring to FIG. 5A, the joystick device 500 includes a joystick grip interface 530 that extends between a first end 532 configured for engagement by the operator to a second end 534 within a housing or base member 536. The second end 534 of the joystick grip interface 530 is pivotally coupled to a pivot collar 540 to pivot about a pivot axis 542.
The joystick device 500 further includes a feedback unit 550 that functions to provide velocity-based feedback force and position-based feedback force on the joystick grip interface 530 based on operator selections from the steering mode selection switch 510. In particular, the feedback unit 550 includes a velocity-based feedback pack 560 and a position-based feedback pack 570, as described in greater detail below. The feedback packs 560, 570 discussed below are merely examples on the numerous types of feedback mechanisms that may be implemented according to the embodiments discussed herein.
The joystick device 500 additionally includes one or more sensors 580. As the joystick grip interface 530 pivots about the pivot axis 542, the sensor 580 collects information associated with one or more of the position and velocity of the joystick grip interface 530, including the position and the velocity resulting from the operator input on the joystick grip interface 530, which results in the actuation request input (e.g., input 382 of FIG. 3). As described in greater detail below, the sensor 580 additionally collects information associated with the operator mode selection on the steering mode selection switch 510. The sensor 580 provides the actuation request input and the operator strategy selection input to an operator system controller (e.g., the controller 120, 120′), as described above. In one example, the sensor 580 includes one or more of a rotary hall effect sensor, a reed switch, or a hall effect sensor.
The steering mode selection switch 510 includes an operator engagement interface, such as a knob 512, coupled to a rod 514 terminating at a cam 516. The cam 516 has a gear engagement that is coupled to an engagement rod 520. As a result of this arrangement, twisting of the knob 512 operates to shift the engagement rod 520 along the pivot axis 542 back and forth (i.e., to the left and right in FIG. 5A). In effect, the engagement rod 520 is a link between the switch 510 and the velocity-based feedback pack 560 and the position-based feedback pack 570. As noted above, the knob 512 may be surrounded by indicia reflecting knob positions corresponding the respective modes
The engagement rod 520 has a first end 522 coupled to a cam 516, a center portion 524 that extends through the housing 536 of the joystick device 500, and an end portion 526 positioned in one of the velocity-based feedback pack 560 or the position-based feedback pack 570, depending on the position of the steering mode selection switch 510. As described below, the engagement rod 520 may have at least two positions corresponding to the position of the steering mode selection switch 510, including: a first position (as shown in FIG. 5A) in which the end portion 526 is positioned in the velocity-based feedback pack 560; and a second position (as shown in FIG. 5B) in which the end portion 526 is positioned in the position-based feedback pack 570.
The engagement rod 520 has a first set of splines (or teeth) 525 arranged on the center portion 524 that extend through the pivot collar 540. The pivot collar 540 has internal splines or teeth 544 that engage the splines 525 of the engagement rod 520. Regardless of the position of the engagement rod 520, the splines 525 of the engagement rod 520 mesh with the splines 544 of the pivot collar 540. As a result, when the interface 530 pivots about the pivot axis 542, the engagement rod 520 pivots with the interface 530. The splined arrangement enables the engagement rod 520 to slide relative to the pivot collar 540 while maintaining the pivoting engagement.
The engagement rod 520 has a set of teeth (or splines) 527 (as shown in FIGS. 6A-6C, 7A-7C) on the end portion 526. The other portions of the engagement rod 520, including the center portion 524 immediately proximate to the end portion 526, may be cylindrical or other cross-sectional shapes that have smaller cross-sectional areas than the teeth 527 on the end portion 526. As described below, the teeth 527 of the end portion 526 of the engagement rod 520 selectively engage the velocity-based feedback pack 560 or the position-based feedback pack 570 such that the selected pack 560, 570 may impose a force on the joystick grip interface 530 via the engagement rod 520 and the pivot collar 540.
Reference is now made to FIGS. 6A-6C, which are cross-sectional views of the joystick device 500 through line 6-6 of FIG. 5A, particularly through the velocity-based feedback pack 560. In FIG. 6A, the joystick grip interface 530 is in a neutral position; in FIG. 6B, the joystick grip interface 530 has been moved leftward; and in FIG. 6C, the joystick grip interface 530 has been moved rightward.
As shown, the velocity-based feedback pack 560 is a centering spring pack and includes a centering spring 610 on a pivot bracket 630 pivotally mounted on a planar rear wall 632 within a housing 602 and a stationary bracket 670 fixedly mounted to the housing 602. In this example, the pivot bracket 630 includes a first (or cylindrical) wall element 640 and second (or U-shaped) wall element 650.
The cylindrical wall element 640 of the pivot bracket 630 is pivotally coupled to the rear wall 632 and generally cylindrical to define a passageway 642 therethrough that aligns with a corresponding passageway through the rear wall 632. The cylindrical wall element 640 includes a plurality of internal teeth (or splines) 644 that circumscribe the passageway 642. As shown, when the mode selection switch 510 is in the position corresponding to the velocity control mode, the teeth 527 on the engagement rod 520 engage the teeth 644 of the cylindrical wall element 640 for rotational engagement, as discussed in greater detail below.
The U-shaped wall element 650 of pivot bracket 630 is pivotally coupled to the rear wall 632 and is formed with a curved section 652, a first wall leg 654, and a second wall leg 656. The curved section 652 surrounds, but is spaced apart from, a portion of the cylindrical wall element 640. The first wall leg 654 extends linearly from one end of the curved section 652 and the second wall leg 656 extends linearly from the other end of the curved section 652. The first and second wall legs 654, 656 are parallel to each other. The U-shaped wall element 650 is fixed to the cylindrical wall element 640 to pivot therewith.
In this embodiment, the stationary bracket 670 extends between side walls 604, 606 of the housing 602. The stationary bracket 670 is generally parallel to the rear wall 632 and spaced axially apart from the wall elements 640, 650, 660 of the pivot bracket 630. The stationary bracket 670 include pins or stops 672, 674 that extend axially toward the rear wall 632 on either side of the centering spring 610.
The centering spring 610 is formed by a center coil 612, a first spring leg 614 extending linearly from a first end of the center coil 612, and second spring leg 616 extending linearly from a second end of the center coil 612. As shown, the center coil 612 is wrapped around the cylindrical wall element 640, in between the cylindrical wall element 640 and the U-shaped wall element 650. The spring 610 is fixedly engaged to the cylindrical wall element 640. In the neutral position, the first and second spring legs 614, 616 extend parallel to one another, along the first and second wall legs 654, 656, respectively.
Accordingly, when the operator desires to implement a steering function in a velocity control mode, the operator rotates the knob 512 to a position representing the velocity control mode. When the knob 512 is rotated into the position corresponding to the velocity control mode, the engagement rod 520 is translated by the rod 514 and cam 516. Upon movement or repositioning of the engagement rod 520, the sensor 580 determines the position of the engagement rod 520 and sends a control mode selection input (e.g., input 380) to the controller 120, 120′, as discussed above. Upon the linear translation of the engagement rod 520 into the position reflected by the knob 512 for the velocity control mode, the teeth 527 at the end portion 526 of the engagement rod 520 mesh with the teeth 644 in the cylindrical wall element 640 of the pivot bracket 630 of the velocity-based feedback pack 560. In this position, the center portion 524 (FIG. 5) of the engagement rod 520 extends through a passageway (discussed below) in the position-based feedback pack 570 such that the engagement rod 520 is not engaged with the position-based feedback pack 570.
Because the engagement rod 520 is engaged with the velocity-based feedback pack 560, the joystick device 500 behaves in an operator-accustomed manner for a velocity-based steering control strategy, as discussed below. As shown in FIG. 6A, in a neutral position, the joystick grip interface 530 is positioned in a vertical orientation, although the neutral position may correspond to other angles relative to the ground plane in other embodiments based on the shape of the interface 530, ergonomics, or other considerations. As noted above, when the joystick grip interface 530 and thus the velocity-based feedback pack 560 are in the neutral position, the first and second spring legs 614, 616 of the spring 610 are parallel to one another and respectively engage the stops 672, 674 of the stationary bracket 670, which maintain the spring 610 and thus, the pivot bracket 630, engagement rod 520, pivot collar 540, and joystick grip interface 530 in the generally neutral position according to a centering equilibrium of the spring force.
During an operator steering input in a leftward direction, the force applied by the operator moves the joystick grip interface 530 to an angle offset from the vertical, as shown in FIG. 6B. During this pivoting movement, the splined connection between the pivot collar 540 and the engagement rod 520 causes the engagement rod 520 to rotate. As noted above, movement of the engagement rod 520 is sensed by the sensor 580 for the generation of a corresponding actuation request input (e.g., input 382 of FIG. 3) to the controller 120. In response and since the velocity control mode has been selected, the controller 120 generates an operating command (e.g., command 390 of FIG. 3) that moves the steering actuation devices (e.g., devices 142, 142′) at a rate of change corresponding to a rate of change of the actuation request input (e.g., input 370) on the joystick device 500.
Moreover, as discussed above, movement of the joystick grip interface 530 results in corresponding movement within the velocity-based feedback pack 560. In particular, pivoting of the joystick grip interface 530 results in the pivoting of the pivot bracket 630 (e.g., via the pivot collar 540 and engagement rod 520). As the pivot bracket 630 pivots, the first wall leg 654 of the U-shaped wall element 650 presses the first spring leg 614 of the spring 610 in the pivoting direction on the other side of the pivot axis 542 (e.g., to the right in FIG. 6B), while the first stop 672 maintains the position of the second spring leg 616 of the spring 610. This results in the spring 610 being placed under compression, thereby generating a resistance force in the direction opposite to the pivoting direction. The resistance force is transferred through the pivot bracket 630, through the splined connection to the engagement rod 520, and through the collar 540 to the joystick grip interface 530, such that the resistance force provides a feedback force to the operator. Typically, the feedback force is consistent with the feel of the joystick grip interface 530 in a velocity-based steering control strategy.
When operator pressure is no longer being applied to the joystick grip interface 520, the force of the spring 610 at the first spring leg 614 of the spring 610 presses the first wall leg 654 of the U-shaped wall element 650 such that the pivot bracket 630 returns to the neutral position. As a result, the engagement rod 520 rotates, which in turn pivots the joystick grip interface 530 back into the neutral position.
Referring briefly to FIG. 6C, a similar operation occurs in the opposite direction when then joystick grip interface 530 is moved by the operator in the right direction. Movement of the joystick grip interface 530 is interpreted according to the velocity control mode and the spring 610 imparts an appropriate feedback force. Subsequently, upon release, the spring 610 returns the pivot bracket 630 and thus the joystick grip interface 530 back into the neutral position.
Accordingly, the configuration of the velocity-based feedback pack 560 with the spring 610 provides haptic behavior is consistent with the velocity-based steering control strategy. Elements other than the coil spring 610 may be provided, such as gas springs, air springs, or similar elements.
Reference is now made to FIGS. 7A-7C, which are cross-sectional views of the joystick device 500 through line 7-7 of FIG. 5A, particularly through the position-based feedback pack 570. In FIG. 7A, the joystick grip interface 530 is in a neutral position; in FIG. 7B, the joystick grip interface 530 has been moved leftward; and in FIG. 7C, the joystick grip interface 530 has been moved rightward.
As shown, the position-based feedback pack 570 is a friction damping pack and includes a position-maintaining, friction-based dampening device formed by one or more fixed plates 710 and one or more pivot plates 720, each mounted on a housing 702. The plates 710, 720 may be arranged in a stacked and/or abutting configuration such that adjacent planar surfaces of the plates 710, 720 abut against and frictionally engage one another. Each plate 710, 720 defines a passageway 722 (one of which is shown) respectively aligned with one another. The passageways 722 through the pivot plates 720 includes a plurality of internally extending teeth or splines 724, and the passageways (not shown) through the fixed plates 710 are larger than the passageways 722 through the pivot plates 720. As a result, the teeth 527 on the engagement rod 520 are configured to engage the teeth 724 of the pivot plates 720 for rotational engagement, while the engagement rod 520 passes through the fixed plates 710 unencumbered.
Accordingly, when an operator desires to implement a steering function in a position control mode, the operator rotates the knob 512 to a position representing the position control mode. When the knob 512 is rotated into the position corresponding to the position control mode, the engagement rod 520 is translated by the rod 514 and cam 516. Upon movement or repositioning of the engagement rod 520, the sensor 580 determines the position of the engagement rod 520 and sends a control mode selection input (e.g., input 380) to the controller 120, 120′, as discussed above. Upon the linear translation of the engagement rod 520 into the position reflected by the knob 512 for the position control mode, the teeth 527 at the end the end portion 526 of the engagement rod 520 mesh with the teeth 724 of the pivot plates 720 of the position-based feedback pack 570, as depicted in FIGS. 7A-7C.
Because the engagement rod 520 is engaged with the position-based feedback pack 570, the joystick device 500 behaves in an operator-accustomed manner for position-based steering control strategies. As shown in FIG. 7A, in a neutral position, the joystick grip interface 530 is positioned in a vertical orientation, although the neutral position may correspond to other angles relative to the ground plane in other embodiments.
Regardless of the position of the joystick grip interface 530, the plates 710, 720 abut one another and apply a mutual friction force to resist movement. When the joystick grip interface 530 is moved (e.g., from neutral in FIG. 7A to the left as shown in FIG. 7B or to the right as shown in FIG. 7C), the engagement rod 520 also pivots.
As noted above, movement of the engagement rod 520 is sensed by the sensor 580 for the generation of a corresponding actuation request input (e.g., input 382 of FIG. 3) to the controller 120. In response and since the position control mode has been selected, the controller 120 generates an operating command (e.g., command 390 of FIG. 3) that that moves the steering actuation devices (e.g., devices 142, 142′) into a position corresponding to a position of the actuation request input (e.g., input 370) on the joystick device 500.
Moreover, as discussed above, movement of the joystick grip interface 530 results in corresponding movement within the position-based feedback pack 570. In particular, pivoting of the joystick grip interface 530 results in a force imparted on the pivot plates 720 via engagement of the engagement rod 520 and the pivot plates 720. When sufficient force is placed on the joystick grip interface 530, the friction force between the abutting plates 710, 720 is overcome and the pivot plates 720 move relative to the fixed plates 710. The friction force from abutting plates 710, 720 provides resistance as a feedback force for the operator at the joystick grip interface 530 (e.g., through the engagement rod 520 and collar 540). Typically, the feedback force is consistent with the feel of the joystick grip interface 530 in a position-based steering control strategy. When operator pressure is no longer being applied to the joystick grip interface 530, the friction force between abutting plates 710, 720 maintains this position, and thus, the position of the joystick grip interface 530.
In some examples, a detent arrangement 726 may be implemented to provide a haptic indication of a center or neutral position. For example, a detent arrangement 726 may be cooperating detents on one or more of the plates 710, 720 such that a “click” or neutral position may be sensed by the operator. Other mechanisms indicating the neutral position may be provided, including spring arrangements, ball arrangements, and the like.
Accordingly, the configuration of the position-based feedback pack 570 with the friction plates 710, 720 provides haptic behavior is consistent with the position-based steering control strategy. Position-maintaining elements other than the plates 710, 720 may be provided in other embodiments.
Generally, the joystick device 400 of FIG. 4 may be considered an active system in which the motor (e.g., motor 430) generates the feedback response, and the joystick device 500 of FIGS. 5A, 5B, 6A-6C, and 7A-7C may be considered a passive system in which passive elements (e.g., the spring 610 and plates 710, 720) generate the feedback response. However, in some embodiments, a joystick device may be provided as a semi-active system that includes characteristics of both active systems and passive systems.
In one such semi-active embodiment, the joystick device may include a partial electro-mechanical joystick device with a positioning motor and a centering spring, each coupled to a joystick grip interface. For example, the positioning motor may be similar to the motor 430 described above with reference to FIG. 4 and the centering spring may be similar to the positioning spring 610 described above with reference FIGS. 5A, 5B, and 6A-6C. As such, the positioning spring may be coupled to a pivot bracket that engages an engagement rod coupled to the joystick grip interface, as described above, and the pivot bracket may further have teeth that engage a drive shaft of a motor. As above, a steering mode selection switch may be provided to indicate the desired mode to the controller and the actuation request inputs from the joystick device are interpreted accordingly.
Regarding application of a feedback force, typically in such an arrangement according to a velocity control mode, the motor is not used and the device operates such as described above with the device of FIG. 4 utilizing the feedback force of the coil spring. In effect, the positioning motor may be locked in a center position. In the position control mode, the motor is actively controlled according to position-based position control strategy such that a feedback force is applied to the joystick grip interface through the pivot bracket or housing. When the operator releases the joystick grip interface, the motor may maintain the position of the joystick grip interface. Moreover, the motor may be actively controlled to resist movement of the joystick grip interface at too fast a speed that would overtax the steering system, thereby providing a haptic feel to the operator that the joystick grip interface is being moved too fast.
Accordingly, the operator control system may selectively implement one of two operator control strategies for steering a work vehicle, namely, a velocity-based steering control strategy and a position-based steering control strategy. In response to the operator selection that the velocity-based steering control strategy is to be used, the joystick device acts in accordance with how the operator is accustomed to a joystick device operating under the velocity-based steering control strategy and the work vehicle responds accordingly. In response to the operator selection that the position-based steering control strategy is to be used, the joystick device acts in accordance with how the operator is accustomed to a joystick device operating under the position-based steering control strategy and the work vehicle responds accordingly.
Also, the following examples are provided, which are numbered for easier reference:
1. A control system for a work vehicle having one or more actuation devices, the control system comprising: an operator input device configured to receive operator input from an operator of the work vehicle; and a controller operatively connected to the operator input device and to the one or more actuation devices, the controller configured to: receive a control mode selection input including a position control mode selection input or a velocity control mode selection input; receive an actuation request input from the operator input device; determine an operating command corresponding to the actuation request input from the operator input device according to the control mode selection input; and issue the operating command to the one or more actuation devices.
2. The control system of example 1, wherein, in the position control mode, the operating command includes an instruction to move the one or more actuation devices to a position corresponding to a position corresponding to the actuation request input from the operator input device; and wherein, in the velocity control mode, the operating command includes an instruction to move the one or more actuation devices at a rate of change corresponding to the position of the actuation request input from the operator input device.
3. The control system of example 1, wherein the operator input device includes a grip interface having a range of motion for transmitting the operator input to the operator input device.
4. The control system of example 3, wherein the operator input device is an electro-mechanical joystick device having a feedback motor coupled to the grip interface; and wherein the controller is further configured to: determine a feedback command corresponding to movement of the grip interface associated with the actuation request according to the control mode selection input; and issue the feedback command to the feedback motor.
5. The control system of example 4, wherein, in the position control mode, the feedback command includes an instruction to the feedback motor to maintain a position of the grip interface associated with at least one of the actuation request input and the position of the one or more actuation devices; and wherein, in the velocity control mode, the feedback command includes an instruction to the feedback motor to re-center the grip interface following the actuation request input.
6. The control system of example 5, wherein, in the velocity control mode, the feedback command includes an instruction to the feedback motor to provide a counteracting force resisting movement of the grip interface that is less than or equal to a force required to move the grip interface, wherein the counteracting force is linearly or non-linearly proportional to the force required to move the grip interface.
7. The control system of example 3, wherein the operator input device is a partial electro-mechanical joystick device having a positioning motor and a centering spring both coupled to the grip interface; wherein, in the position control mode, the controller is further configured to determine a position command corresponding to movement of the grip interface associated with the actuation request input; and wherein, in the velocity mode, the positioning motor is locked in a center position.
8. The control system of example 3, wherein the operator input device is a mechanical joystick having a position-maintaining device, a centering device or both the position-maintaining device and the centering device; wherein the position-maintaining device is configured to maintain a position of the grip interface after movement associated with the actuation request input; and wherein the centering device is configured to center the grip interface after movement associated with the actuation request input.
9. The control system of example 8, wherein the position-maintaining device is a friction and damper device; and wherein the centering device is a centering spring.
10. The control system of example 10, wherein the operator input device includes a selection switch; and further comprising: a sensor configured to detect a position of the selection switch and provide the control mode selection input to the controller.
11. The control system of example 10, wherein the operator input device includes a link coupled to the selection switch and to either the position-maintaining device or the centering device.
12. The control system of example 11, wherein the operator input device includes both the position-maintaining device and the centering device; and wherein movement of the selection switch causes movement of the link to selectively couple to either the position-maintaining device or the centering device.
13. A control system for a work vehicle having one or more actuation devices, the control system comprising: an operator input device configured to receive operator input from an operator of the work vehicle, wherein the operator input device includes a grip interface having a range of motion for transmitting the operator input to the operator input device; a controller operatively connected to the operator input device and to the one or more actuation devices, the controller configured to: receive a control mode selection input including a mode selection input as a position control mode or a velocity control mode; receive an actuation request input from the operator input device; determine an operating command corresponding to the actuation request input from the operator input device according to the control mode selection input; and issue the operating command to the one or more actuation devices; wherein, in the position control mode, the operating command includes an instruction to move the one or more actuation devices to a position corresponding to a position corresponding to the actuation request input from the operator input device; and wherein, in the velocity control mode, the operating command includes an instruction to move the one or more actuation devices at a rate of change corresponding to the position of the actuation request input from the operator input device.
14. The control system of example 13, wherein the operator input device is an electro-mechanical joystick having a feedback motor coupled to the grip interface; and wherein the controller is further configured to: determine a feedback command corresponding to movement of the grip interface associated with the actuation request input according to the control mode selection input; and issue the feedback command to the feedback motor, wherein, in the position control mode, the feedback command includes an instruction to the feedback motor to maintain a position of the grip interface associated with the actuation request input; and wherein, in the velocity control mode, the feedback command includes an instruction to the feedback motor to re-center the grip interface following the actuation request input and to provide a counteracting force resisting movement of the grip interface that is less than a force required to move the grip interface, wherein the counteracting force is linearly or non-linearly proportional to the force required to move the grip interface.
15. The control system of example 13, wherein the operator input device includes a mode selection switch; and wherein the control system further comprises a sensor configured to detect a position of the mode selection switch and provide the control mode selection input to the controller, wherein the operator input device is a mechanical joystick having a friction dampening device and a spring centering device; wherein the friction dampening device is configured to maintain a position of the grip interface after movement associated with the actuator request; and wherein the spring centering device is configured to center the grip interface after movement associated with the actuator request, and wherein movement of the mode selection switch causes movement of the link to selectively couple to either the position-maintaining device or the centering device.
As used herein, unless otherwise limited or modified, lists with elements that are separated by conjunctive terms (e.g., “and”) and that are also preceded by the phrase “one or more of” or “at least one of” indicate configurations or arrangements that potentially include individual elements of the list, or any combination thereof. For example, “at least one of A, B, and C” or “one or more of A, B, and C” indicates the possibilities of only A, only B, only C, or any combination of two or more of A, B, and C (e.g., A and B; B and C; A and C; or A, B, and C).
As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Embodiments of the present disclosure may be described herein in terms of functional and/or logical block components and various processing steps. It should be appreciated that such block components may be realized by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, an embodiment of the present disclosure may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, logic elements, look-up tables, or the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that embodiments of the present disclosure may be practiced in conjunction with any number of systems, and that the loader described herein is merely one example embodiment of the present disclosure.
For the sake of brevity, conventional techniques related to signal processing, data transmission, signaling, control, and other functional aspects of the systems (and the individual operating components of the systems) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent example functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in an embodiment of the present disclosure.
As will be appreciated by one skilled in the art, certain aspects of the disclosed subject matter can be embodied as a method, system (e.g., a work vehicle control system included in a work vehicle), or computer program product. Accordingly, certain embodiments can be implemented entirely as hardware, entirely as software (including firmware, resident software, micro-code, etc.) or as a combination of software and hardware (and other) aspects. Furthermore, certain embodiments can take the form of a computer program product on a computer-usable storage medium having computer-usable program code embodied in the medium. Any suitable computer usable or computer readable storage or signal medium can be utilized.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. Explicitly referenced embodiments herein were chosen and described in order to best explain the principles of the disclosure and their practical application, and to enable others of ordinary skill in the art to understand the disclosure and recognize many alternatives, modifications, and variations on the described example(s). Accordingly, various embodiments and implementations other than those explicitly described are within the scope of the following claims.

Claims

What is claimed is:

1. A control system for a work vehicle having one or more actuation devices, the control system comprising:

an operator input device configured to receive operator input from an operator of the work vehicle; and

a controller operatively connected to the operator input device and to the one or more actuation devices, the controller configured to:

receive a control mode selection input including a position control mode selection input or a velocity control mode selection input;

receive an actuation request input from the operator input device;

determine an operating command corresponding to the actuation request input from the operator input device according to the control mode selection input; and

issue the operating command to the one or more actuation devices.

2. The control system of claim 1,

wherein, in the position control mode, the operating command includes an instruction to move the one or more actuation devices to a position corresponding to a position corresponding to the actuation request input from the operator input device; and

wherein, in the velocity control mode, the operating command includes an instruction to move the one or more actuation devices at a rate of change corresponding to the position of the actuation request input from the operator input device.

3. The control system of claim 1, wherein the operator input device includes a grip interface having a range of motion for transmitting the operator input to the operator input device.

4. The control system of claim 3, wherein the operator input device is an electro-mechanical joystick device having a feedback motor coupled to the grip interface; and

wherein the controller is further configured to:

determine a feedback command corresponding to movement of the grip interface associated with the actuation request according to the control mode selection input; and

issue the feedback command to the feedback motor.

5. The control system of claim 4, wherein, in the position control mode, the feedback command includes an instruction to the feedback motor to maintain a position of the grip interface associated with at least one of the actuation request input and the position of the one or more actuation devices; and

wherein, in the velocity control mode, the feedback command includes an instruction to the feedback motor to re-center the grip interface following the actuation request input.

6. The control system of claim 5, wherein, in the velocity control mode, the feedback command includes an instruction to the feedback motor to provide a counteracting force resisting movement of the grip interface that is less than or equal to a force required to move the grip interface.

7. The control system of claim 6, wherein the counteracting force is linearly or non-linearly proportional to the force required to move the grip interface.

8. The control system of claim 3, wherein the operator input device is a partial electro-mechanical joystick device having a positioning motor and a centering spring both coupled to the grip interface;

wherein, in the position control mode, the controller is further configured to determine a position command corresponding to movement of the grip interface associated with the actuation request input; and

wherein, in the velocity mode, the positioning motor is locked in a center position.

9. The control system of claim 3, wherein the operator input device is a mechanical joystick having a position-maintaining device, a centering device or both the position-maintaining device and the centering device;

wherein the position-maintaining device is configured to maintain a position of the grip interface after movement associated with the actuation request input; and

wherein the centering device is configured to center the grip interface after movement associated with the actuation request input.

10. The control system of claim 9, wherein the position-maintaining device is a friction and damper device; and

wherein the centering device is a centering spring.

11. The control system of claim 9, wherein the operator input device includes a selection switch; and further comprising:

a sensor configured to detect a position of the selection switch and provide the control mode selection input to the controller.

12. The control system of claim 11, wherein the operator input device includes a link coupled to the selection switch and to either the position-maintaining device or the centering device.

13. The control system of claim 12, wherein the operator input device includes both the position-maintaining device and the centering device; and

wherein movement of the selection switch causes movement of the link to selectively couple to either the position-maintaining device or the centering device.

14. A control system for a work vehicle having one or more actuation devices, the control system comprising:

an operator input device configured to receive operator input from an operator of the work vehicle;

receive a control mode selection input including a mode selection input as a position control mode or a velocity control mode;

receive an actuation request input from the operator input device;

issue the operating command to the one or more actuation devices;

15. The control system of claim 14, wherein the operator input device includes a grip interface having a range of motion for transmitting the operator input to the operator input device.

16. The control system of claim 15, wherein the operator input device is an electro-mechanical joystick having a feedback motor coupled to the grip interface; and

wherein the controller is further configured to:

determine a feedback command corresponding to movement of the grip interface associated with the actuation request input according to the control mode selection input; and

issue the feedback command to the feedback motor,

wherein, in the position control mode, the feedback command includes an instruction to the feedback motor to maintain a position of the grip interface associated with at least one of the actuation request input and the position of the one or more actuation devices; and

17. The control system of claim 16, wherein, in the velocity control mode, the feedback command includes an instruction to the feedback motor to provide a counteracting force resisting movement of the grip interface that is less than or equal to a force required to move the grip interface; and

wherein the counteracting force is linearly or non-linearly proportional to the force required to move the grip interface.

18. The control system of claim 15, wherein the operator input device is a mechanical joystick having a friction dampening device, a spring centering device or both the friction dampening device and the spring centering device;

wherein the friction dampening device is configured to maintain a position of the grip interface after movement associated with the actuator request; and

wherein the spring centering device is configured to center the grip interface after movement associated with the actuator request.

19. The control system of claim 18, wherein the operator input device includes a mode selection switch; and further comprising:

a sensor configured to detect a position of the mode selection switch and provide the control mode selection input to the controller.

20. The control system of claim 19, wherein the operator input device includes both the position-maintaining device and the centering device; and

wherein movement of the mode selection switch causes movement of the link to selectively couple to either the position-maintaining device or the centering device.