Work vehicle with joystick and pedal propel control system

Abstract

A work machine having a first actuator and a second actuator for moving a work tool in a first direction and a second direction and having ground engaging mechanisms for supporting a frame of the machine and for propelling and steering the frame along a ground surface, includes a controller that can switch between a working and travel modes. In the working mode, the controller is configured to use a command signal of a first hand control to regulate a forwards or backwards propel speed and steering of the ground engaging mechanisms, and a command signal from the second hand control to control movement of the work tool. In the travel mode, the controller is configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the single-acting foot control to regulate the propel speed of the ground engaging mechanisms, and is configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms.

Description

FIELD OF THE DISCLOSURE

[0001] The present disclosure generally relates to an apparatus and system for controlling a work vehicle and, more specifically, to an apparatus and system that can switch between different joystick and a foot control operational patterns for controlling the work tool and propel functions of a work vehicle.BACKGROUND

[0002] Work machines, such as those in the construction and forestry industries, include different operator interfaces through which the operator inputs commands to control and operate multiple work machine functions. For instance, a machine may include one or more work implements for performing a specific task. Such work machines can be designed to receive commands from an operator through an interface for controlling the machine to move the work tool and the work machine relative to a subject work piece, such as a ground surface or other object to be manipulated. The machine may have different controls for performing the specific task. Conventional machines, for example, may include a steering wheel, joystick, foot pedal, push buttons, dials, switches, levers, and the like for controllably moving the machine by propelling and steering the machine and its work tool along a ground surface, or by adjusting the position of the work tool relative to a main frame of the work machine. Some work tools and implements can include actuators and motors that can be powered, such as power saws, drills, augers, mills, hammers and lifts. Accordingly, where applicable, the operator interface can include controls, such as buttons, levers, switches and dials to control power delivery to such implements located on separate displays and consoles or can conveniently be positioned on joysticks or steering wheels.

[0003] A machine operator often uses two or more of the controls for operating the machine. This requires the operator to be well-trained and cognizant of his or her surroundings. With so many different controls, the operator must operate the machine in a safe manner. Moreover, most machines only have a single operator to control all of the functions thereof. In some instances, the machine operator may be using both hands to control joysticks, levers, etc. Here, if a machine operator wants to adjust throttle, trigger a switch, or readjust a machine setting, the operator would have to release one hand from a joystick or other control to complete the desired task. This can cause the machine to operate at less than optimal performance and with lower productivity. Depending on the circumstances, it may also be inconvenient to the operator to release or stop one machine control in order to change or adjust a second machine control.

[0004] Some work machines, such as skid steer loaders, have conventionally heavily relied on hand controls, such as joysticks, as interfaces for operators to input commands to control and operate the machine's work tool, steering and propel functions. An operator can input commands through a joystick by pushing a handle of the joystick away from a central position in forwards, backwards, left, right, or oblique directions. Joysticks can be spring loaded to provide a biasing force returning the joystick to a central neutral position which an operator must overcome when actuating the joystick. Steering and propel functions can include moving the work machine forwards or backwards along a ground surface, while steering functions can include turning the machine, i.e., rotating the work machine, as viewed from above, either when stationary or as it moves forwards or backwards. Steering and propel functions can be controlled using a first joystick. Work tool functions can include adjusting the position of the work tool relative to the work machine frame, which can include raising, lowering, or pivoting the work tool (such as a bucket or auger) relative to the frame. These work tool functions can be controlled using a second joystick. An operator can control such work machines to propel forward by displacing the first joystick in a forwards direction against the centralizing biasing force of the spring loaded joystick. Hand controls such as joysticks can be advantageous for providing an operator the versatility to provide fine motion control of the work machine when a job demands small and accurate work tool motion as well as rapid and large work machine movements when work permits.

[0005] Propelling the work machine for long periods, such as when roading a skid steer loader to a distant field on a farm or other worksite, can be fatiguing because the joystick requires constant manual manipulation against joystick's bias spring. Hand fatigue can be dangerous as it can prevent an operator from accurately and reliably actuating the joystick. Hand fatigue may require an operator to pause and stop the roading the work machine to rest the hand, delaying the progress of work. A need therefore exists for a work machine control interface that permits hand control of propel functions when an operator uses a work machine controlling and operating work tools and a safer less fatiguing propel control system for roading or propelling the work machine over extended periods.SUMMARY OF THE DISCLOSURE

[0006] In one embodiment, a work machine with a switchable machine control pattern includes a work tool movably coupled to a frame of the work machine. The work tool can be coupled to first actuator configured to move the work tool in a first direction and coupled to a second actuator configured to move the work tool in a second direction. The frame can be supported on ground engaging mechanisms for propelling and steering the frame along a ground surface.

[0007] The work machine can also include a controller configured switch between a working mode and a travel mode, and communicatively coupled to receive operator command signals from a first hand control, a second hand control, a single-acting foot control. In the working mode, the controller can be configured to use a command signal responsive to a forward or a reverse actuation of the first hand control to regulate a forwards or backwards propel speed of the ground engaging mechanisms. Controller can be configured also to use a command signal responsive to a left or right actuation of the first hand control to regulate the steering of the ground engaging mechanisms in a corresponding left or right direction, and command signals from the second hand control to control movement of the work tool. In the travel mode, the controller can be configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the single-acting foot control to regulate the propel speed of the ground engaging mechanisms. Also in the travel mode, the controller can be configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms. The first hand control can be a joystick and foot control can be a single acting foot pedal.

[0008] According to one alternative, in the travel mode the controller can be configured to receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from the forward or reverse actuation of the first hand control. In addition, the controller can be configured to operate the first actuator and the second actuator to move the work tool in response to command signals responsive to the forward, reverse, left or right actuation of the second hand control.

[0009] According to another alternative, work machine can further include a console coupled to the controller. The console can be configured to receive an operator command to switch the controller between the working mode and the travel mode.

[0010] According to yet another alternative, work machine can further include an engine having an adjustable engine speed coupled to drive a variable displacement hydraulic pump having a pump output, and a valve block that selectively couples the pump output to a drive motor. The controller can be configured to adjust the engine speed and vary a displacement of the hydraulic pump to control the drive motor speed in response to the foot control command signal.

[0011] A second embodiment provides a control system for switching between a working mode and a travel mode on a work machine. The control system includes a controller operatively coupled to operate a first actuator configured to move a work tool coupled the work machine in a first direction, operatively coupled to operate a second actuator configured to move the work tool in a second direction. The controller is also operatively coupled to operate a plurality of ground engaging mechanisms to propel the work machine along a ground surface. The controller is configured switch between a working mode and a travel mode, the controller communicatively coupled to receive operator command signals from a first hand control, a second hand control, and a foot control. In the working mode, the controller is configured to use a command signal responsive to a forward or a reverse actuation of the first hand control to regulate a forwards or backwards propel speed of the ground engaging mechanisms, a command signal responsive to a left or right actuation of the first hand control to regulate steering of the ground engaging mechanisms in a corresponding left or right direction, and command signals from the second hand control to control movement of first actuator and second actuator. In the travel mode, the controller is configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the foot control to regulate the propel speed of the ground engaging mechanisms, and is configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms. The foot control can be a single-acting foot pedal.

[0012] According to one option of the second embodiment, the first hand control can be a joystick. According to a further option, the controller can receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from a joystick console. According to an alternative option, in the travel mode, the controller can be configured to receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from the forward or reverse actuation of the first hand control.

[0013] According to a further option of the second embodiment, the controller can operate the first actuator and the second actuator to move the work tool in response to command signals responsive to the forward, reverse, left or right actuation of the second hand control. According to a alternative option of the second embodiment, the control system can include a console coupled to the controller. The console can be configured to receive an operator command to switch the controller between the working mode and the travel mode.

[0014] The control system of the second embodiment can also include an engine having an adjustable engine speed coupled to drive a variable displacement hydraulic pump having a pump output, and a valve block that selectively couples the pump output to a drive motor. The controller can be configured to adjust the engine speed and vary a displacement of the hydraulic pump to control the drive motor speed in response to the foot control command signal.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a left side view of an example of work vehicle which is a skid steer loader, with drive wheels and a bucket.

[0016] FIG. 2 is a schematic view of mechanical, hydraulic, and control systems of an exemplary work machine.

[0017] FIG. 3 is schematic view of a first pattern for controlling the operation of the exemplary work vehicle of FIG. 2.

[0018] FIG. 4 is schematic view of a second pattern for controlling the operation of the exemplary work vehicle of FIG. 2.

[0019] FIG. 5 is an example of a foot pedal usable in one embodiment of the work machine of FIG. 1.

[0020] FIG. 6A is a side view of a joystick usable in one embodiment of the work machine of FIG. 1.

[0021] FIG. 6B is a tope view of a joystick usable in one embodiment of the work machine of FIG. 1.DETAILED DESCRIPTION

[0022] The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

[0023] Referring to FIG. 1, an exemplary embodiment of a machine, such as a skid steer loader 100, is shown. The skid steer 100 can be provided with a ground engaging mechanism for moving along the ground. In FIG. 1, the ground engaging mechanism can include wheels, such as front wheels 102 and rear wheels 104 coupled to a left side and a right side of a frame 116 of the skid steer 100 and support the frame above a ground surface. In another aspect, however, the ground-engaging mechanism can be a drive track disposed on each side of frame 116 of skid steer 100. An operator can manipulate controls to drive wheel 104 and optionally wheel 102 to propel the frame 116 along the ground surface. Additionally, the operator can manipulate controls to drive the wheels on the right or left side of frame 116 at different speeds to steer the machine 100 in a conventional skid steer fashion. For example, by driving left wheel 104 forwards slower, or backwards, relative to right wheels 104, the operator can steer the machine 100 to the left when driving forwards, or rotate it counterclockwise as viewed from above. Conversely, by driving right wheels 104 forwards slower or backwards relative to left wheels 104, the operator can steer the machine 100 to the right when driving forwards, or rotate it clockwise as viewed from above. The machine 100 can be further provided with a work tool or implement, such as loader bucket 106, movably coupled to frame 116 via a pair of boom arms. A boom arm 108 can be positioned on each side of the machine 100. The boom arms 108 can be coupled to the machine 100 by a linkage mechanism 110.

[0024] The loader bucket 106 is pivotally coupled to a forward portion of boom arms 108. A bucket tilt hydraulic cylinder 114 extends between the bucket 106 and the boom arms 108 for controlling the tilted orientation of the bucket 106 with respect to the boom arms 108. The operator can extend a piston in the tilt cylinder 114 to pivot the bucket 106 forward for dumping the contents therefrom or can retract the piston to pivot the bucket 106 upward or curl bucket 106 to scoop and hold material in the bucket 106. The boom arms 108 and linkage mechanism 110, which couples the boom arms 108 to the frame 116, can be substantially the same on both the left and right sides of the machine 100. A boom hydraulic cylinder 118 can be coupled between the boom arm 108 on each of the left and right side and the frame 116. Each boom cylinder 118 can be controlled to extend to raise the boom arm 108 and bucket 106 or retracted to lower the boom arm 108 and bucket 106. Machine 100 can include a cab assembly 112 which can have a seat where a machine operator can sit to access and manipulate an operator interface. The operator interface can include consoles, display screens, levers, joysticks and similar devices for controlling operating functions of machine 100.

[0025] FIG. 2 is a schematic diagram of one embodiment of work machine 100 showing how mechanical, hydraulic, and control systems of the work machine 100 can be interconnected. In FIG. 2, the work machine 100 includes an internal combustion engine 202 coupled to drive a hydraulic pump 204. Optionally, engine 202 can be coupled to multiple pumps adapted to drive different work machine hydraulic systems. Hydraulic pump 204 can be a variable displacement hydraulic pump which can be controlled to vary its displacement to adjust the flow rate of hydraulic fluid it pumps for a given engine drive speed. Hydraulic fluid pumped from an output of hydraulic pump 204 flows through input hydraulic line 218 to an input of valve block 206. Valve block 206 can include electrohydraulic solenoid valves which can be selectively opened or closed, as well as electrohydraulic variable flow proportional solenoid valves which each can controlled to vary the flow rate of hydraulic fluid passing through the valve. Controller 210 can actuate the electrohydraulic valves to permit the flow of hydraulic fluid from the input of valve block 206 to output hydraulic lines 220 connected at output ports of valve block 206. Thus, controller 210 can selectively start and stop actuation of a connected hydraulic device, such as a motor or actuator, by opening or closing electrohydraulic solenoid valves. Alternatively, controller 210 can adjust the flow rate of hydraulic fluid through an electrohydraulic variable flow proportional solenoid valve to control speed connected hydraulic devices actuate.

[0026] Output hydraulic lines 220 can connect the output ports to left and right side front or rear drive motors 212, 214, to hydraulic boom cylinder 118 and tilt cylinder 114. Generally, in such skid steer loaders 100, only one pair of wheels are driven by motors and, therefore skid steer 100 may only include rear drive motors 214 or front drive motors 212. However, in some embodiments, skid steer loader 100 can include front and rear drive motors 212, 214 as shown in FIG. 2. As shown in dashed lines, controller 210 can be operatively coupled via electric wires, such as control lines 216, to control the operation of the engine 202, hydraulic pump 204, valve block 206 and, as a further option (not shown in FIG. 2), drive motors 212, 214. Controller 210 can further indirectly operate actuators 114, 118, and motors 212, 214 by controlling the flow of hydraulic fluid into valve block 206 through hydraulic line 218, and by controlling the flow of hydraulic fluid from valve block 206 to the actuators and motors through hydraulic lines 220. Controller 210 can also be communicatively coupled to receive operator commands from operator interface 208. Operator interface 208 can include one or more hand controls or joysticks, foot controls or foot pedals, display screens, and consoles with buttons, switches, dials, or levers. Using operator interface 208 an operator can input commands to control the operation of the work machine 100. An operator can also receive information relating to the operating state of the work machine through operator interface 208. Operator interface 208 can be located in cab assembly 112. Controller 210 can be configured to receive operator commands from operator interface 208 and transmit control signals to control the operation of the engine 202, hydraulic pump 204, valve block 206 and drive motors 212, 214. Thus, controller 210 can regulate the operation of work tool 106 as well as the backwards and forwards propel and steering functions of work machine 100.

[0027] FIGS. 6A and 6B are, respectively side and top views of an exemplary joystick 600 that can be used in the present disclosure. Joystick 600 can include a joystick handle 602 that is pivotably coupled to joystick base 604. Joystick handle can include buttons, switches, dials, or levers 612 in a joystick console 606 that can be configured to transmit command signals to controller 210 to control features and systems of work machine 100. As shown in FIG. 6B, joystick 600 can be actuated when an operator displaces handle 602 in a forward direction 608a, a reverse direction 608b, a left direction 610a or a right direction 610b and can generate a command signal transmitted to controller 210 in response to displacement in these directions or, optionally, in response to displacement in a combination of these directions.

[0028] In a working mode, controller 210 can receive and interpret operator commands from operator interface 208 to operate work machine 100 according to the arrangement shown in FIG. 3. The working mode can be designed to facilitate operator's manipulation and use of the working machine's work tool or implement and movement of work machine 100 to accomplish a job. In FIG. 3, first control pattern 300 includes a first hand control or joystick 302 and a second hand control or joystick 304. The first control pattern 300 can be referred to as a “hand control pattern” since both hands of the operator are required to control the machine 100. The first joystick 302 may be disposed on the left side of the cab 112 and controlled by an operator's left hand, while the second joystick 304 may be disposed on the right side of the cab 112 and controlled by the operator's right hand. In this particular pattern 300, the first joystick 302 can operably control the steer and propel functions of the machine 100 and the second joystick 304 can operably control the boom arms 108 and bucket 106.

[0029] For instance, the first joystick 302 can control both the steering and propel functions for both of the left side and right side of the machine 100. The first joystick 302 can be actuated in a forward direction 306 to control the forward speed of left and right wheels 102, 104 to propel the machine 100 forward. The first joystick 302 can be actuated in a backward direction 308 to control the reverse speed of left and right wheels 102, 104 to propel the machine 100 backwards. In addition, machine 100 can be steered in a counterclockwise direction by controllably moving the first joystick 302 in a left direction 310. Similarly, machine 100 can be steered in a clockwise direction by moving the first joystick 302 in a right direction 312.

[0030] Machine 100 can be propelled in a forward direction and turned in a counterclockwise direction by moving the first joystick 302 in a forward-left direction 314. Similarly, the machine 100 can be propelled in a forward direction and turned in a clockwise direction by moving the first joystick 302 in a forward-right direction 318. To propel the machine 100 in reverse and rotate in a counterclockwise direction, the first joystick 302 is moved in a reverse-right direction 320, whereas the machine 100 moves in reverse and rotates clockwise by moving the first joystick 302 in a reverse-right direction 316.

[0031] An operator can control the steer and propel functions of the machine 100 via the first joystick 302 with one hand, the operator can control the boom arms 108 and bucket 106 with the other hand. For example, the boom arms 108 can be lowered by moving the second joystick 304 in a forward direction 322. The boom arms 108 can be raised by moving the second joystick 304 in a reverse direction 324. As for bucket 106, it can be pivoted upwards and raised to a curl position by moving the second joystick 304 in a left direction 326. If the operator wants to dump the contents from the bucket 106, the operator can do so by moving the second joystick 304 in a right direction 328 to pivot bucket 106 in a downward direction to dump the bucket's contents.

[0032] The joysticks in machine 100 can include sensors that measure the forward, reverse, left, and right position of the joystick handle and generate command signals responsive to the position of the joystick handle in each direction. The joysticks can transmit these command signals to a machine controller which can be configured to operate various machine components and features based on each signal. For example, an operator can actuate joystick 302 to control steer and propel functions of machine 100. Optionally, joystick 302 can generate signals representing the handle's displacement in each direction can vary with the corresponding distance of displacement for each signal. As a further option, at least one characteristic of at least one of the signals can vary in proportion to the displacement distance. The signals can be transmitted to a controller configured to interpret the signal as an operator command specifying how the controller 210 should operate actuators, work tools, or other devices that the operator is to control. Controller 210 can be configured with a program or code stored in a memory associated with controller 210 to respond to the command signals received from the operator interface 208 by transmitting control signals to operate the machine's mechanical and hydraulic systems in accordance with a first set of rules which represent a first pattern 300.

[0033] Operators may need to drive machine 100 over long distances and drive for extended periods, such as when driving from a workshop or parking facility to a remote work location or field on a farm where machine 100 will be used to work. Driving for such extended periods would conventionally require the operator to continuously actuate the joysticks that command forward travel, such as included in first hand control 302. Constant actuation of such joysticks can cause an operator unnecessary arm fatigue, which can be unpleasant, distracting, and dangerous. Accordingly, using operator commands received through operator interface 208, controller 210 is switchable from a working mode to a travel mode. In the travel mode, controller 210 can be configured to receive an operator command to switch from the first pattern 300 in which the controller 210 responds to operator commands it receives from the operator interface 208 based on a first set of rules, to a second pattern 400, shown in FIG. 4. In the second pattern 400, controller 210 responds to operator commands it receives from the operator interface 208 to operate the work machine 100 in accordance with a second set of rules. The second set of rules specify how controller 210 responds to command signals from a foot pedal for controlling propel speed as well as different rules for responding to hand control command signals and other commands from operator interface 208.

[0034] When switched to the second pattern 400, as shown in FIG. 4, operator interface 208 in cab 112 can include a right foot control or pedal 404 and optionally a left foot control or pedal 402 for controlling the propel speed of work machine 100. Right foot pedal 404 can preferably be a single-acting foot pedal which permits an operator to depress the pedal with operator's right foot and modulate actuation of the pedal over long periods while minimizing operator fatigue. Right foot pedal 404 can be biased by a spring so that the pedal returns to a fully raised or extended position unless actuated or depressed by the operator using a foot, for example. Foot pedal 404 can be designed to produce a propel speed command signal responsive to the amount the foot pedal 404 is depressed. Thus, an operator can actuate foot pedal 404 by depressing or moving pedal 404 in a forward direction 418 to control the propel speed of the work machine 100. FIG. 5 is a side view of an exemplary single-acting foot pedal 404 with a foot plate 502 hinged to a base plate 504 via hinge 500 at or near a lower end of foot pedal 404. A spring biases foot plate 502 to pivot to its uppermost stationary position 506 unless foot pedal 404 is actuated. An operator can actuate foot pedal 404 by using a foot to press downward against foot plate502 and overcome bias spring to pivot foot plate 502 through actuation angle 508 towards base plate 504. At full actuation, foot plate 502 is pivoted down to its lowermost maximum propel speed position 510.

[0035] When controller 210 is switched to use the second pattern 400, second joystick 408 of second pattern 400 can retain the same functionality as the second joystick 304 of first pattern 300. For example, boom arms 108 can be lowered by moving the second joystick 408 in a forward direction 430. The boom arms 108 can be raised by moving the second joystick 408 in a reverse direction 428. Bucket 106 can be pivoted upwards and raised to a curl position by moving the second joystick 408 in a left direction 424. An operator can move second joystick 408 in a right direction 426 to pivot bucket 106 in a downward direction to dump the bucket's contents.

[0036] First joystick 406 of second pattern 400 can retain the steering functionality of first joystick 302 so that machine 100 can be steered in a counterclockwise direction by controllably moving the first joystick 406 in a left direction 420. Similarly, machine 100 can be steered in a clockwise direction by moving the first joystick 406 in a right direction 422. However, when using the second pattern 400, controller 210 does not use the command signal produced by forward or backward actuation of first joystick 406 to control the forward and reverse propel speed of left and right wheels 102, 104. Instead, controller 210 receives a propel speed command signal from a foot pedal, such as right foot pedal 404 which specifies the speed, but not direction, at which controller 210 drives the work machine's ground engaging mechanisms which, in work machine 100 are front wheels 102 and rear wheels 104. Controller 210 receives a separate propel direction command signal from operator interface 208 which specifies whether controller 210 drives the work machine's ground engaging mechanisms in a forwards or reverse direction.

[0037] The propel direction command signal can be generated by an operator momentarily actuating first joystick 406 forwards or backwards to toggle the controller 210 between forwards, reverse, and neutral propel directions. In a neutral propel direction, controller 210 can disconnect the engine from the ground engaging mechanisms so that work vehicle remains stationary irrespective of engine speed and irrespective of left or right actuation 420, 422 of first joystick 406. An operator can command controller 210 to set a forward propel direction by a substantial forward actuation 410 of first joystick 406 by, for example momentarily displacing first joystick 406 by 50% or more of its maximum forward displacement and releasing the joystick to return to its neutral position. Similarly, from neutral propel direction, an operator can command controller 210 to a reverse propel direction by a substantial backward actuation 412 of first joystick 406 by, for example momentarily displacing first joystick 406 by 50% or more of its maximum backward displacement and releasing the joystick to return to its neutral position. Once controller 210 is in a forward propel direction or reverse propel direction, an operator can return controller 210 to a neutral propel direction by substantial actuation of joystick 406 in the opposite direction.

[0038] Although the embodiment described above uses the first joystick 406 to set the propel direction, those skilled in the art will understand that other input devices in the operator interface 208 can be used to receive operator input and generate a propel direction command signal. For example, controller 210 can be configured to receive a propel direction command signal from left hand foot pedal 402 which an operator can actuate by foot. Left hand foot pedal 402 can be designed to transmit a propel direction command signal in response to an operator momentarily actuating left hand foot pedal 402 by a substantial displacement, e.g., 50% of maximum foot pedal displacement in a forwards direction 414 or backwards direction 416 to toggle the controller 210 between forwards, reverse, and neutral propel directions, as described with first joystick 406. Alternatively in some embodiments, buttons, switches, dials, or levers 612 in joystick console 606 can be configured to generate command signals that toggle the controller 210 between forwards, reverse, and neutral propel directions. As a further alternative, operator interface can include other switches, levers, or consoles, preferably conveniently placed near to joysticks 406, 408 designed to receive operator input to select a propel direction.

[0039] As previously explained, in response to receiving command signals from operator interface 208 based on commands an operator inputs via hand controls, foot pedals, switches and consoles, for example, controller 210 transmits control signals to various components of the work machine 100 to implement the received operator commands. Although controller 210 uses different rules to interpret command signals from operator interface 208 when switched to the first pattern 300 as compared with the second pattern 400, controller 210 controls operation of engine 202, hydraulic pump 204, valve block 206 and drive motors 212, 214 in a similar manner irrespective of which control pattern it is configured to implement. The following describes the control signals controller 210 transmits when switched to the second pattern 400.

[0040] When controller 210 is set to the neutral propel direction, an operator can begin to propel and steer machine 100 forward by a substantial forward actuation 410 of first joystick 406 to set controller 210 to a forward propel direction. Operator can then actuate foot pedal 404 in the forward direction 418 to command controller 210 to drive front and rear wheels 102, 104 to drive forward at the speed set by the propel speed command signal actuation of foot pedal 404. Controller 210 can be configured to control engine speed by manual operator control or automatically. Under manual engine speed control, operator interface 208 can include a switch, console or similar interface through which operator can set engine speed. Based on the speed the operator has set, controller 210 transmits a control signal to hydraulic pump 204 to adjust the hydraulic pump's displacement to produce sufficient flow of hydraulic fluid to power drive motors 212, 214 at the commanded speed. Additionally, controller 210 transmits control signals to open selected electrohydraulic valves in valve block 206 to transmit flow of hydraulic fluid to drive motors 212, 214.

[0041] Under automatic engine speed control, controller 210 can be configured to adjust engine speed according to a target metric. For example, controller 210 can adjust engine speed to minimize fuel consumption, to maximize engine power output, to maximize engine torque output or to some other measurable target that controller 210 may set, optionally based on operator inputs or operational commands. Controller 210 can then transmit control signals to coordinate the operation engine 202 and pump 204 by adjusting engine speed and pump displacement accordingly, for example. As with manual engine control, with automatic engine control controller 210 can be configured to transmit control signals to open selected electrohydraulic valves in valve block 206 to transmit flow of hydraulic fluid to drive motors 212, 214. As a further alternative, work machine 100 can include variable displacement drive motors 212, 214. In such cases, controller 210 can be configured to vary the displacement of the drive motors 212, 214 to adjust their drive speeds for a given flow rate of hydraulic fluid from valve block 206.

[0042] According to a further option, controller 210 can coordinate operation of the engine 202 and hydraulic pump 204 so that when engine 202 is running with the foot pedal in its stationary position 506 controller 210 sets engine 202 speed to 1300 rpm and adjusts hydraulic pump 204 and valve block 206 to bring and hold work machine stationary at zero propel speed. As an operator actuates foot pedal 404 and progressively depresses foot plate 502 through a larger actuation angle 508 controller 210 operates engine 202 at an increased engine speed and proportionally increases propel speed. With foot plate 502 at the maximum propel speed position 510, controller 210 operates engine 202 at 2700 rpm and adjusts hydraulic pump 204, valve block 206 and to drive motors 212, 214 to propel work machine 100 at its maximum propel speed.

[0043] Controller 210 can be configured to transmit left or right steering control signals to valve block 206 and, optionally, to drive motors 212, 214 that are appropriately configured variable displacement drive motors upon receiving left or right steering command signals from first actuator 406. In response to a left steering command signal, controller 210 can transmit a control signal to appropriate electrohydraulic valves in valve block 206 to retard or reverse the drive speed of the left side drive motors 212, 214 relative to the right side drive motors 212, 214. In response to a right steering command signal, controller 210 can transmit a control signal to appropriate electrohydraulic valves in valve block 206 to retard or reverse the drive speed of the right side drive motors 212, 214 relative to the left side drive motors 212, 214. Where drive motors 212, 214 are appropriately configured variable displacement drive motors, controller 210 can transmit control signals to the drive motors to adjust the displacement, and hence drive speed, of the left and right side drive motors.

[0044] Whether switched to use the first pattern 300 or the second pattern 400, controller 210 interprets the command signal it receives from a forward actuation 430 of second joystick 408 as a command to lower boom arms 108 and the command signal it receives from a reverse actuation 428 of joystick 408 as a command to raise boom arms 108. In response, controller 210 can transmit a control signal to hydraulic pump 204 to adjust the pump's displacement to pump hydraulic fluid at a sufficient flow rate to extend boom cylinder 118 and raise the boom arm 108 at the commanded speed. Under automatic engine speed control, controller 210 can be configured to adjust engine speed to the target value and coordinate operation of engine 202 and hydraulic pump 204. Additionally, in response to the raise or lower boom arm command, controller 210 can open electrohydraulic valves in valve block 206 to permit flow of hydraulic fluid from hydraulic pump 204 to flow into and extend or retract boom cylinder 118, as commanded. Controller 210 interprets the command signal it receives from a left actuation 424 of second joystick 408 as a command to pivot bucket 106 upwards and the command signal it receives from a right actuation 426 of joystick 408 as a command to pivot bucket 106 in a downward direction to dump the bucket's contents. In response, controller 210 can transmit a control signal to hydraulic pump 204 to adjust the pump's displacement to pump hydraulic fluid at a sufficient flow rate to extend or retract tilt cylinder 114 and pivot bucket 106 at the commanded speed. Under automatic engine speed control, controller 210 can be configured to adjust engine speed to the target value and coordinate operation of engine 202 and hydraulic pump 204. Additionally, in response to the curl or dump command, controller 210 can open electrohydraulic valves in valve block 206 to permit flow of hydraulic fluid from hydraulic pump 204 to flow into and extend or retract tilt cylinder 114, as commanded.

[0045] While exemplary embodiments incorporating the principles of the present disclosure have been described hereinabove, the present disclosure is not limited to the described embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.

[0046] Thus, it is seen that the apparatus and methods of the present disclosure readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the disclosure have been illustrated and described for present purposes, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present disclosure as defined by the appended claims. Each disclosed feature or embodiment may be combined with any of the other disclosed features or embodiments.

Examples

Embodiment Construction

[0022]The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

[0023]Referring to FIG. 1, an exemplary embodiment of a machine, such as a skid steer loader 100, is shown. The skid steer 100 can be provided with a ground engaging mechanism for moving along the ground. In FIG. 1, the ground engaging mechanism can include wheels, such as front wheels 102 and rear wheels 104 coupled to a left side and a right side of a frame 116 of the skid steer 100 and support the frame above a ground surface. In another aspect, however, the ground-engaging mechanism can be a drive track disposed on each side of frame 116 of skid steer 100. An operator can manipulate controls to drive wheel 104 and optionally wheel 1...

FIELD OF THE DISCLOSURE

[0001] The present disclosure generally relates to an apparatus and system for controlling a work vehicle and, more specifically, to an apparatus and system that can switch between different joystick and a foot control operational patterns for controlling the work tool and propel functions of a work vehicle.BACKGROUND

[0002] Work machines, such as those in the construction and forestry industries, include different operator interfaces through which the operator inputs commands to control and operate multiple work machine functions. For instance, a machine may include one or more work implements for performing a specific task. Such work machines can be designed to receive commands from an operator through an interface for controlling the machine to move the work tool and the work machine relative to a subject work piece, such as a ground surface or other object to be manipulated. The machine may have different controls for performing the specific task. Conventional machines, for example, may include a steering wheel, joystick, foot pedal, push buttons, dials, switches, levers, and the like for controllably moving the machine by propelling and steering the machine and its work tool along a ground surface, or by adjusting the position of the work tool relative to a main frame of the work machine. Some work tools and implements can include actuators and motors that can be powered, such as power saws, drills, augers, mills, hammers and lifts. Accordingly, where applicable, the operator interface can include controls, such as buttons, levers, switches and dials to control power delivery to such implements located on separate displays and consoles or can conveniently be positioned on joysticks or steering wheels.

[0003] A machine operator often uses two or more of the controls for operating the machine. This requires the operator to be well-trained and cognizant of his or her surroundings. With so many different controls, the operator must operate the machine in a safe manner. Moreover, most machines only have a single operator to control all of the functions thereof. In some instances, the machine operator may be using both hands to control joysticks, levers, etc. Here, if a machine operator wants to adjust throttle, trigger a switch, or readjust a machine setting, the operator would have to release one hand from a joystick or other control to complete the desired task. This can cause the machine to operate at less than optimal performance and with lower productivity. Depending on the circumstances, it may also be inconvenient to the operator to release or stop one machine control in order to change or adjust a second machine control.

[0004] Some work machines, such as skid steer loaders, have conventionally heavily relied on hand controls, such as joysticks, as interfaces for operators to input commands to control and operate the machine's work tool, steering and propel functions. An operator can input commands through a joystick by pushing a handle of the joystick away from a central position in forwards, backwards, left, right, or oblique directions. Joysticks can be spring loaded to provide a biasing force returning the joystick to a central neutral position which an operator must overcome when actuating the joystick. Steering and propel functions can include moving the work machine forwards or backwards along a ground surface, while steering functions can include turning the machine, i.e., rotating the work machine, as viewed from above, either when stationary or as it moves forwards or backwards. Steering and propel functions can be controlled using a first joystick. Work tool functions can include adjusting the position of the work tool relative to the work machine frame, which can include raising, lowering, or pivoting the work tool (such as a bucket or auger) relative to the frame. These work tool functions can be controlled using a second joystick. An operator can control such work machines to propel forward by displacing the first joystick in a forwards direction against the centralizing biasing force of the spring loaded joystick. Hand controls such as joysticks can be advantageous for providing an operator the versatility to provide fine motion control of the work machine when a job demands small and accurate work tool motion as well as rapid and large work machine movements when work permits.

[0005] Propelling the work machine for long periods, such as when roading a skid steer loader to a distant field on a farm or other worksite, can be fatiguing because the joystick requires constant manual manipulation against joystick's bias spring. Hand fatigue can be dangerous as it can prevent an operator from accurately and reliably actuating the joystick. Hand fatigue may require an operator to pause and stop the roading the work machine to rest the hand, delaying the progress of work. A need therefore exists for a work machine control interface that permits hand control of propel functions when an operator uses a work machine controlling and operating work tools and a safer less fatiguing propel control system for roading or propelling the work machine over extended periods.SUMMARY OF THE DISCLOSURE

[0006] In one embodiment, a work machine with a switchable machine control pattern includes a work tool movably coupled to a frame of the work machine. The work tool can be coupled to first actuator configured to move the work tool in a first direction and coupled to a second actuator configured to move the work tool in a second direction. The frame can be supported on ground engaging mechanisms for propelling and steering the frame along a ground surface.

[0007] The work machine can also include a controller configured switch between a working mode and a travel mode, and communicatively coupled to receive operator command signals from a first hand control, a second hand control, a single-acting foot control. In the working mode, the controller can be configured to use a command signal responsive to a forward or a reverse actuation of the first hand control to regulate a forwards or backwards propel speed of the ground engaging mechanisms. Controller can be configured also to use a command signal responsive to a left or right actuation of the first hand control to regulate the steering of the ground engaging mechanisms in a corresponding left or right direction, and command signals from the second hand control to control movement of the work tool. In the travel mode, the controller can be configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the single-acting foot control to regulate the propel speed of the ground engaging mechanisms. Also in the travel mode, the controller can be configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms. The first hand control can be a joystick and foot control can be a single acting foot pedal.

[0008] According to one alternative, in the travel mode the controller can be configured to receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from the forward or reverse actuation of the first hand control. In addition, the controller can be configured to operate the first actuator and the second actuator to move the work tool in response to command signals responsive to the forward, reverse, left or right actuation of the second hand control.

[0009] According to another alternative, work machine can further include a console coupled to the controller. The console can be configured to receive an operator command to switch the controller between the working mode and the travel mode.

[0010] According to yet another alternative, work machine can further include an engine having an adjustable engine speed coupled to drive a variable displacement hydraulic pump having a pump output, and a valve block that selectively couples the pump output to a drive motor. The controller can be configured to adjust the engine speed and vary a displacement of the hydraulic pump to control the drive motor speed in response to the foot control command signal.

[0011] A second embodiment provides a control system for switching between a working mode and a travel mode on a work machine. The control system includes a controller operatively coupled to operate a first actuator configured to move a work tool coupled the work machine in a first direction, operatively coupled to operate a second actuator configured to move the work tool in a second direction. The controller is also operatively coupled to operate a plurality of ground engaging mechanisms to propel the work machine along a ground surface. The controller is configured switch between a working mode and a travel mode, the controller communicatively coupled to receive operator command signals from a first hand control, a second hand control, and a foot control. In the working mode, the controller is configured to use a command signal responsive to a forward or a reverse actuation of the first hand control to regulate a forwards or backwards propel speed of the ground engaging mechanisms, a command signal responsive to a left or right actuation of the first hand control to regulate steering of the ground engaging mechanisms in a corresponding left or right direction, and command signals from the second hand control to control movement of first actuator and second actuator. In the travel mode, the controller is configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the foot control to regulate the propel speed of the ground engaging mechanisms, and is configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms. The foot control can be a single-acting foot pedal.

[0012] According to one option of the second embodiment, the first hand control can be a joystick. According to a further option, the controller can receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from a joystick console. According to an alternative option, in the travel mode, the controller can be configured to receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from the forward or reverse actuation of the first hand control.

[0013] According to a further option of the second embodiment, the controller can operate the first actuator and the second actuator to move the work tool in response to command signals responsive to the forward, reverse, left or right actuation of the second hand control. According to a alternative option of the second embodiment, the control system can include a console coupled to the controller. The console can be configured to receive an operator command to switch the controller between the working mode and the travel mode.

[0014] The control system of the second embodiment can also include an engine having an adjustable engine speed coupled to drive a variable displacement hydraulic pump having a pump output, and a valve block that selectively couples the pump output to a drive motor. The controller can be configured to adjust the engine speed and vary a displacement of the hydraulic pump to control the drive motor speed in response to the foot control command signal.BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a left side view of an example of work vehicle which is a skid steer loader, with drive wheels and a bucket.

[0016] FIG. 2 is a schematic view of mechanical, hydraulic, and control systems of an exemplary work machine.

[0017] FIG. 3 is schematic view of a first pattern for controlling the operation of the exemplary work vehicle of FIG. 2.

[0018] FIG. 4 is schematic view of a second pattern for controlling the operation of the exemplary work vehicle of FIG. 2.

[0019] FIG. 5 is an example of a foot pedal usable in one embodiment of the work machine of FIG. 1.

[0020] FIG. 6A is a side view of a joystick usable in one embodiment of the work machine of FIG. 1.

[0021] FIG. 6B is a tope view of a joystick usable in one embodiment of the work machine of FIG. 1.DETAILED DESCRIPTION

[0022] The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

[0023] Referring to FIG. 1, an exemplary embodiment of a machine, such as a skid steer loader 100, is shown. The skid steer 100 can be provided with a ground engaging mechanism for moving along the ground. In FIG. 1, the ground engaging mechanism can include wheels, such as front wheels 102 and rear wheels 104 coupled to a left side and a right side of a frame 116 of the skid steer 100 and support the frame above a ground surface. In another aspect, however, the ground-engaging mechanism can be a drive track disposed on each side of frame 116 of skid steer 100. An operator can manipulate controls to drive wheel 104 and optionally wheel 102 to propel the frame 116 along the ground surface. Additionally, the operator can manipulate controls to drive the wheels on the right or left side of frame 116 at different speeds to steer the machine 100 in a conventional skid steer fashion. For example, by driving left wheel 104 forwards slower, or backwards, relative to right wheels 104, the operator can steer the machine 100 to the left when driving forwards, or rotate it counterclockwise as viewed from above. Conversely, by driving right wheels 104 forwards slower or backwards relative to left wheels 104, the operator can steer the machine 100 to the right when driving forwards, or rotate it clockwise as viewed from above. The machine 100 can be further provided with a work tool or implement, such as loader bucket 106, movably coupled to frame 116 via a pair of boom arms. A boom arm 108 can be positioned on each side of the machine 100. The boom arms 108 can be coupled to the machine 100 by a linkage mechanism 110.

[0024] The loader bucket 106 is pivotally coupled to a forward portion of boom arms 108. A bucket tilt hydraulic cylinder 114 extends between the bucket 106 and the boom arms 108 for controlling the tilted orientation of the bucket 106 with respect to the boom arms 108. The operator can extend a piston in the tilt cylinder 114 to pivot the bucket 106 forward for dumping the contents therefrom or can retract the piston to pivot the bucket 106 upward or curl bucket 106 to scoop and hold material in the bucket 106. The boom arms 108 and linkage mechanism 110, which couples the boom arms 108 to the frame 116, can be substantially the same on both the left and right sides of the machine 100. A boom hydraulic cylinder 118 can be coupled between the boom arm 108 on each of the left and right side and the frame 116. Each boom cylinder 118 can be controlled to extend to raise the boom arm 108 and bucket 106 or retracted to lower the boom arm 108 and bucket 106. Machine 100 can include a cab assembly 112 which can have a seat where a machine operator can sit to access and manipulate an operator interface. The operator interface can include consoles, display screens, levers, joysticks and similar devices for controlling operating functions of machine 100.

[0025] FIG. 2 is a schematic diagram of one embodiment of work machine 100 showing how mechanical, hydraulic, and control systems of the work machine 100 can be interconnected. In FIG. 2, the work machine 100 includes an internal combustion engine 202 coupled to drive a hydraulic pump 204. Optionally, engine 202 can be coupled to multiple pumps adapted to drive different work machine hydraulic systems. Hydraulic pump 204 can be a variable displacement hydraulic pump which can be controlled to vary its displacement to adjust the flow rate of hydraulic fluid it pumps for a given engine drive speed. Hydraulic fluid pumped from an output of hydraulic pump 204 flows through input hydraulic line 218 to an input of valve block 206. Valve block 206 can include electrohydraulic solenoid valves which can be selectively opened or closed, as well as electrohydraulic variable flow proportional solenoid valves which each can controlled to vary the flow rate of hydraulic fluid passing through the valve. Controller 210 can actuate the electrohydraulic valves to permit the flow of hydraulic fluid from the input of valve block 206 to output hydraulic lines 220 connected at output ports of valve block 206. Thus, controller 210 can selectively start and stop actuation of a connected hydraulic device, such as a motor or actuator, by opening or closing electrohydraulic solenoid valves. Alternatively, controller 210 can adjust the flow rate of hydraulic fluid through an electrohydraulic variable flow proportional solenoid valve to control speed connected hydraulic devices actuate.

[0026] Output hydraulic lines 220 can connect the output ports to left and right side front or rear drive motors 212, 214, to hydraulic boom cylinder 118 and tilt cylinder 114. Generally, in such skid steer loaders 100, only one pair of wheels are driven by motors and, therefore skid steer 100 may only include rear drive motors 214 or front drive motors 212. However, in some embodiments, skid steer loader 100 can include front and rear drive motors 212, 214 as shown in FIG. 2. As shown in dashed lines, controller 210 can be operatively coupled via electric wires, such as control lines 216, to control the operation of the engine 202, hydraulic pump 204, valve block 206 and, as a further option (not shown in FIG. 2), drive motors 212, 214. Controller 210 can further indirectly operate actuators 114, 118, and motors 212, 214 by controlling the flow of hydraulic fluid into valve block 206 through hydraulic line 218, and by controlling the flow of hydraulic fluid from valve block 206 to the actuators and motors through hydraulic lines 220. Controller 210 can also be communicatively coupled to receive operator commands from operator interface 208. Operator interface 208 can include one or more hand controls or joysticks, foot controls or foot pedals, display screens, and consoles with buttons, switches, dials, or levers. Using operator interface 208 an operator can input commands to control the operation of the work machine 100. An operator can also receive information relating to the operating state of the work machine through operator interface 208. Operator interface 208 can be located in cab assembly 112. Controller 210 can be configured to receive operator commands from operator interface 208 and transmit control signals to control the operation of the engine 202, hydraulic pump 204, valve block 206 and drive motors 212, 214. Thus, controller 210 can regulate the operation of work tool 106 as well as the backwards and forwards propel and steering functions of work machine 100.

[0027] FIGS. 6A and 6B are, respectively side and top views of an exemplary joystick 600 that can be used in the present disclosure. Joystick 600 can include a joystick handle 602 that is pivotably coupled to joystick base 604. Joystick handle can include buttons, switches, dials, or levers 612 in a joystick console 606 that can be configured to transmit command signals to controller 210 to control features and systems of work machine 100. As shown in FIG. 6B, joystick 600 can be actuated when an operator displaces handle 602 in a forward direction 608a, a reverse direction 608b, a left direction 610a or a right direction 610b and can generate a command signal transmitted to controller 210 in response to displacement in these directions or, optionally, in response to displacement in a combination of these directions.

[0028] In a working mode, controller 210 can receive and interpret operator commands from operator interface 208 to operate work machine 100 according to the arrangement shown in FIG. 3. The working mode can be designed to facilitate operator's manipulation and use of the working machine's work tool or implement and movement of work machine 100 to accomplish a job. In FIG. 3, first control pattern 300 includes a first hand control or joystick 302 and a second hand control or joystick 304. The first control pattern 300 can be referred to as a “hand control pattern” since both hands of the operator are required to control the machine 100. The first joystick 302 may be disposed on the left side of the cab 112 and controlled by an operator's left hand, while the second joystick 304 may be disposed on the right side of the cab 112 and controlled by the operator's right hand. In this particular pattern 300, the first joystick 302 can operably control the steer and propel functions of the machine 100 and the second joystick 304 can operably control the boom arms 108 and bucket 106.

[0029] For instance, the first joystick 302 can control both the steering and propel functions for both of the left side and right side of the machine 100. The first joystick 302 can be actuated in a forward direction 306 to control the forward speed of left and right wheels 102, 104 to propel the machine 100 forward. The first joystick 302 can be actuated in a backward direction 308 to control the reverse speed of left and right wheels 102, 104 to propel the machine 100 backwards. In addition, machine 100 can be steered in a counterclockwise direction by controllably moving the first joystick 302 in a left direction 310. Similarly, machine 100 can be steered in a clockwise direction by moving the first joystick 302 in a right direction 312.

[0030] Machine 100 can be propelled in a forward direction and turned in a counterclockwise direction by moving the first joystick 302 in a forward-left direction 314. Similarly, the machine 100 can be propelled in a forward direction and turned in a clockwise direction by moving the first joystick 302 in a forward-right direction 318. To propel the machine 100 in reverse and rotate in a counterclockwise direction, the first joystick 302 is moved in a reverse-right direction 320, whereas the machine 100 moves in reverse and rotates clockwise by moving the first joystick 302 in a reverse-right direction 316.

[0031] An operator can control the steer and propel functions of the machine 100 via the first joystick 302 with one hand, the operator can control the boom arms 108 and bucket 106 with the other hand. For example, the boom arms 108 can be lowered by moving the second joystick 304 in a forward direction 322. The boom arms 108 can be raised by moving the second joystick 304 in a reverse direction 324. As for bucket 106, it can be pivoted upwards and raised to a curl position by moving the second joystick 304 in a left direction 326. If the operator wants to dump the contents from the bucket 106, the operator can do so by moving the second joystick 304 in a right direction 328 to pivot bucket 106 in a downward direction to dump the bucket's contents.

[0032] The joysticks in machine 100 can include sensors that measure the forward, reverse, left, and right position of the joystick handle and generate command signals responsive to the position of the joystick handle in each direction. The joysticks can transmit these command signals to a machine controller which can be configured to operate various machine components and features based on each signal. For example, an operator can actuate joystick 302 to control steer and propel functions of machine 100. Optionally, joystick 302 can generate signals representing the handle's displacement in each direction can vary with the corresponding distance of displacement for each signal. As a further option, at least one characteristic of at least one of the signals can vary in proportion to the displacement distance. The signals can be transmitted to a controller configured to interpret the signal as an operator command specifying how the controller 210 should operate actuators, work tools, or other devices that the operator is to control. Controller 210 can be configured with a program or code stored in a memory associated with controller 210 to respond to the command signals received from the operator interface 208 by transmitting control signals to operate the machine's mechanical and hydraulic systems in accordance with a first set of rules which represent a first pattern 300.

[0033] Operators may need to drive machine 100 over long distances and drive for extended periods, such as when driving from a workshop or parking facility to a remote work location or field on a farm where machine 100 will be used to work. Driving for such extended periods would conventionally require the operator to continuously actuate the joysticks that command forward travel, such as included in first hand control 302. Constant actuation of such joysticks can cause an operator unnecessary arm fatigue, which can be unpleasant, distracting, and dangerous. Accordingly, using operator commands received through operator interface 208, controller 210 is switchable from a working mode to a travel mode. In the travel mode, controller 210 can be configured to receive an operator command to switch from the first pattern 300 in which the controller 210 responds to operator commands it receives from the operator interface 208 based on a first set of rules, to a second pattern 400, shown in FIG. 4. In the second pattern 400, controller 210 responds to operator commands it receives from the operator interface 208 to operate the work machine 100 in accordance with a second set of rules. The second set of rules specify how controller 210 responds to command signals from a foot pedal for controlling propel speed as well as different rules for responding to hand control command signals and other commands from operator interface 208.

[0034] When switched to the second pattern 400, as shown in FIG. 4, operator interface 208 in cab 112 can include a right foot control or pedal 404 and optionally a left foot control or pedal 402 for controlling the propel speed of work machine 100. Right foot pedal 404 can preferably be a single-acting foot pedal which permits an operator to depress the pedal with operator's right foot and modulate actuation of the pedal over long periods while minimizing operator fatigue. Right foot pedal 404 can be biased by a spring so that the pedal returns to a fully raised or extended position unless actuated or depressed by the operator using a foot, for example. Foot pedal 404 can be designed to produce a propel speed command signal responsive to the amount the foot pedal 404 is depressed. Thus, an operator can actuate foot pedal 404 by depressing or moving pedal 404 in a forward direction 418 to control the propel speed of the work machine 100. FIG. 5 is a side view of an exemplary single-acting foot pedal 404 with a foot plate 502 hinged to a base plate 504 via hinge 500 at or near a lower end of foot pedal 404. A spring biases foot plate 502 to pivot to its uppermost stationary position 506 unless foot pedal 404 is actuated. An operator can actuate foot pedal 404 by using a foot to press downward against foot plate502 and overcome bias spring to pivot foot plate 502 through actuation angle 508 towards base plate 504. At full actuation, foot plate 502 is pivoted down to its lowermost maximum propel speed position 510.

[0035] When controller 210 is switched to use the second pattern 400, second joystick 408 of second pattern 400 can retain the same functionality as the second joystick 304 of first pattern 300. For example, boom arms 108 can be lowered by moving the second joystick 408 in a forward direction 430. The boom arms 108 can be raised by moving the second joystick 408 in a reverse direction 428. Bucket 106 can be pivoted upwards and raised to a curl position by moving the second joystick 408 in a left direction 424. An operator can move second joystick 408 in a right direction 426 to pivot bucket 106 in a downward direction to dump the bucket's contents.

[0036] First joystick 406 of second pattern 400 can retain the steering functionality of first joystick 302 so that machine 100 can be steered in a counterclockwise direction by controllably moving the first joystick 406 in a left direction 420. Similarly, machine 100 can be steered in a clockwise direction by moving the first joystick 406 in a right direction 422. However, when using the second pattern 400, controller 210 does not use the command signal produced by forward or backward actuation of first joystick 406 to control the forward and reverse propel speed of left and right wheels 102, 104. Instead, controller 210 receives a propel speed command signal from a foot pedal, such as right foot pedal 404 which specifies the speed, but not direction, at which controller 210 drives the work machine's ground engaging mechanisms which, in work machine 100 are front wheels 102 and rear wheels 104. Controller 210 receives a separate propel direction command signal from operator interface 208 which specifies whether controller 210 drives the work machine's ground engaging mechanisms in a forwards or reverse direction.

[0037] The propel direction command signal can be generated by an operator momentarily actuating first joystick 406 forwards or backwards to toggle the controller 210 between forwards, reverse, and neutral propel directions. In a neutral propel direction, controller 210 can disconnect the engine from the ground engaging mechanisms so that work vehicle remains stationary irrespective of engine speed and irrespective of left or right actuation 420, 422 of first joystick 406. An operator can command controller 210 to set a forward propel direction by a substantial forward actuation 410 of first joystick 406 by, for example momentarily displacing first joystick 406 by 50% or more of its maximum forward displacement and releasing the joystick to return to its neutral position. Similarly, from neutral propel direction, an operator can command controller 210 to a reverse propel direction by a substantial backward actuation 412 of first joystick 406 by, for example momentarily displacing first joystick 406 by 50% or more of its maximum backward displacement and releasing the joystick to return to its neutral position. Once controller 210 is in a forward propel direction or reverse propel direction, an operator can return controller 210 to a neutral propel direction by substantial actuation of joystick 406 in the opposite direction.

[0038] Although the embodiment described above uses the first joystick 406 to set the propel direction, those skilled in the art will understand that other input devices in the operator interface 208 can be used to receive operator input and generate a propel direction command signal. For example, controller 210 can be configured to receive a propel direction command signal from left hand foot pedal 402 which an operator can actuate by foot. Left hand foot pedal 402 can be designed to transmit a propel direction command signal in response to an operator momentarily actuating left hand foot pedal 402 by a substantial displacement, e.g., 50% of maximum foot pedal displacement in a forwards direction 414 or backwards direction 416 to toggle the controller 210 between forwards, reverse, and neutral propel directions, as described with first joystick 406. Alternatively in some embodiments, buttons, switches, dials, or levers 612 in joystick console 606 can be configured to generate command signals that toggle the controller 210 between forwards, reverse, and neutral propel directions. As a further alternative, operator interface can include other switches, levers, or consoles, preferably conveniently placed near to joysticks 406, 408 designed to receive operator input to select a propel direction.

[0039] As previously explained, in response to receiving command signals from operator interface 208 based on commands an operator inputs via hand controls, foot pedals, switches and consoles, for example, controller 210 transmits control signals to various components of the work machine 100 to implement the received operator commands. Although controller 210 uses different rules to interpret command signals from operator interface 208 when switched to the first pattern 300 as compared with the second pattern 400, controller 210 controls operation of engine 202, hydraulic pump 204, valve block 206 and drive motors 212, 214 in a similar manner irrespective of which control pattern it is configured to implement. The following describes the control signals controller 210 transmits when switched to the second pattern 400.

[0040] When controller 210 is set to the neutral propel direction, an operator can begin to propel and steer machine 100 forward by a substantial forward actuation 410 of first joystick 406 to set controller 210 to a forward propel direction. Operator can then actuate foot pedal 404 in the forward direction 418 to command controller 210 to drive front and rear wheels 102, 104 to drive forward at the speed set by the propel speed command signal actuation of foot pedal 404. Controller 210 can be configured to control engine speed by manual operator control or automatically. Under manual engine speed control, operator interface 208 can include a switch, console or similar interface through which operator can set engine speed. Based on the speed the operator has set, controller 210 transmits a control signal to hydraulic pump 204 to adjust the hydraulic pump's displacement to produce sufficient flow of hydraulic fluid to power drive motors 212, 214 at the commanded speed. Additionally, controller 210 transmits control signals to open selected electrohydraulic valves in valve block 206 to transmit flow of hydraulic fluid to drive motors 212, 214.

[0041] Under automatic engine speed control, controller 210 can be configured to adjust engine speed according to a target metric. For example, controller 210 can adjust engine speed to minimize fuel consumption, to maximize engine power output, to maximize engine torque output or to some other measurable target that controller 210 may set, optionally based on operator inputs or operational commands. Controller 210 can then transmit control signals to coordinate the operation engine 202 and pump 204 by adjusting engine speed and pump displacement accordingly, for example. As with manual engine control, with automatic engine control controller 210 can be configured to transmit control signals to open selected electrohydraulic valves in valve block 206 to transmit flow of hydraulic fluid to drive motors 212, 214. As a further alternative, work machine 100 can include variable displacement drive motors 212, 214. In such cases, controller 210 can be configured to vary the displacement of the drive motors 212, 214 to adjust their drive speeds for a given flow rate of hydraulic fluid from valve block 206.

[0042] According to a further option, controller 210 can coordinate operation of the engine 202 and hydraulic pump 204 so that when engine 202 is running with the foot pedal in its stationary position 506 controller 210 sets engine 202 speed to 1300 rpm and adjusts hydraulic pump 204 and valve block 206 to bring and hold work machine stationary at zero propel speed. As an operator actuates foot pedal 404 and progressively depresses foot plate 502 through a larger actuation angle 508 controller 210 operates engine 202 at an increased engine speed and proportionally increases propel speed. With foot plate 502 at the maximum propel speed position 510, controller 210 operates engine 202 at 2700 rpm and adjusts hydraulic pump 204, valve block 206 and to drive motors 212, 214 to propel work machine 100 at its maximum propel speed.

[0043] Controller 210 can be configured to transmit left or right steering control signals to valve block 206 and, optionally, to drive motors 212, 214 that are appropriately configured variable displacement drive motors upon receiving left or right steering command signals from first actuator 406. In response to a left steering command signal, controller 210 can transmit a control signal to appropriate electrohydraulic valves in valve block 206 to retard or reverse the drive speed of the left side drive motors 212, 214 relative to the right side drive motors 212, 214. In response to a right steering command signal, controller 210 can transmit a control signal to appropriate electrohydraulic valves in valve block 206 to retard or reverse the drive speed of the right side drive motors 212, 214 relative to the left side drive motors 212, 214. Where drive motors 212, 214 are appropriately configured variable displacement drive motors, controller 210 can transmit control signals to the drive motors to adjust the displacement, and hence drive speed, of the left and right side drive motors.

[0044] Whether switched to use the first pattern 300 or the second pattern 400, controller 210 interprets the command signal it receives from a forward actuation 430 of second joystick 408 as a command to lower boom arms 108 and the command signal it receives from a reverse actuation 428 of joystick 408 as a command to raise boom arms 108. In response, controller 210 can transmit a control signal to hydraulic pump 204 to adjust the pump's displacement to pump hydraulic fluid at a sufficient flow rate to extend boom cylinder 118 and raise the boom arm 108 at the commanded speed. Under automatic engine speed control, controller 210 can be configured to adjust engine speed to the target value and coordinate operation of engine 202 and hydraulic pump 204. Additionally, in response to the raise or lower boom arm command, controller 210 can open electrohydraulic valves in valve block 206 to permit flow of hydraulic fluid from hydraulic pump 204 to flow into and extend or retract boom cylinder 118, as commanded. Controller 210 interprets the command signal it receives from a left actuation 424 of second joystick 408 as a command to pivot bucket 106 upwards and the command signal it receives from a right actuation 426 of joystick 408 as a command to pivot bucket 106 in a downward direction to dump the bucket's contents. In response, controller 210 can transmit a control signal to hydraulic pump 204 to adjust the pump's displacement to pump hydraulic fluid at a sufficient flow rate to extend or retract tilt cylinder 114 and pivot bucket 106 at the commanded speed. Under automatic engine speed control, controller 210 can be configured to adjust engine speed to the target value and coordinate operation of engine 202 and hydraulic pump 204. Additionally, in response to the curl or dump command, controller 210 can open electrohydraulic valves in valve block 206 to permit flow of hydraulic fluid from hydraulic pump 204 to flow into and extend or retract tilt cylinder 114, as commanded.

[0045] While exemplary embodiments incorporating the principles of the present disclosure have been described hereinabove, the present disclosure is not limited to the described embodiments. Instead, this application is intended to cover any variations, uses, or adaptations of the disclosure using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this disclosure pertains and which fall within the limits of the appended claims.

[0046] Thus, it is seen that the apparatus and methods of the present disclosure readily achieve the ends and advantages mentioned as well as those inherent therein. While certain preferred embodiments of the disclosure have been illustrated and described for present purposes, numerous changes in the arrangement and construction of parts and steps may be made by those skilled in the art, which changes are encompassed within the scope and spirit of the present disclosure as defined by the appended claims. Each disclosed feature or embodiment may be combined with any of the other disclosed features or embodiments.

Examples

Embodiment Construction

[0022]The embodiments of the present disclosure described below are not intended to be exhaustive or to limit the disclosure to the precise forms in the following detailed description. Rather, the embodiments are chosen and described so that others skilled in the art may appreciate and understand the principles and practices of the present disclosure.

[0023]Referring to FIG. 1, an exemplary embodiment of a machine, such as a skid steer loader 100, is shown. The skid steer 100 can be provided with a ground engaging mechanism for moving along the ground. In FIG. 1, the ground engaging mechanism can include wheels, such as front wheels 102 and rear wheels 104 coupled to a left side and a right side of a frame 116 of the skid steer 100 and support the frame above a ground surface. In another aspect, however, the ground-engaging mechanism can be a drive track disposed on each side of frame 116 of skid steer 100. An operator can manipulate controls to drive wheel 104 and optionally wheel 1...

Claims

1. A work machine having a switchable machine control pattern comprising:a work tool movably coupled to a frame of the work machine, to a first actuator configured to move the work tool in a first direction, and to a second actuator configured to move the work tool in a second direction, wherein the frame is supported on ground engaging mechanisms for propelling and steering the frame along a ground surface;a controller configured switch between a working mode and a travel mode, the controller communicatively coupled to receive operator command signals from a first hand control, a second hand control, and a single-acting foot control;wherein in the working mode, the controller is configured to use a command signal responsive to a forward or a reverse actuation of the first hand control to regulate a forwards or backwards propel speed of the ground engaging mechanisms, a command signal responsive to a left or right actuation of the first hand control to regulate the steering of the ground engaging mechanisms in a corresponding left or right direction, and command signals from the second hand control to control the first and second actuator, andwherein in the travel mode, the controller is configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the single-acting foot control to regulate the propel speed of the ground engaging mechanisms, and is configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms.

2. The work machine of claim 1, wherein the first hand control is a joystick.

3. The work machine of claim 2, wherein in the travel mode, the controller is configured to receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from the forward or reverse actuation of the first hand control.

4. The work machine of claim 1, wherein the controller operates the first actuator and the second actuator to move the work tool in response to command signals responsive to the forward, reverse, left or right actuation of the second hand control.

5. The work machine of claim 1 further comprising a console coupled to the controller, the console configured to receive an operator command to switch the controller between the working mode and the travel mode.

6. The work machine of claim 1, wherein the foot control is a single-acting foot pedal.

7. The work machine of claim 1 further comprising,an engine having an adjustable engine speed coupled to drive a variable displacement hydraulic pump having a pump output, anda valve block that selectively couples the pump output to a drive motor,wherein the controller is configured to adjust the engine speed and vary a displacement of the hydraulic pump to control the drive motor speed in response to the foot control command signal.

8. A control system for switching between a working mode and a travel mode on a work machine, the control system comprising:a controller operatively coupled to operate a first actuator configured to move a work tool coupled the work machine in a first direction, operatively coupled to operate a second actuator configured to move the work tool in a second direction, operatively coupled to operate a plurality of ground engaging mechanisms to propel the work machine along a ground surface;wherein the controller is configured to switch between a working mode and a travel mode, and the controller communicatively coupled to receive operator command signals from a first hand control, a second hand control, and a foot control,wherein in the working mode, the controller is configured to use a command signal responsive to a forward or a reverse actuation of the first hand control to regulate a forwards or backwards propel speed of the ground engaging mechanisms, a command signal responsive to a left or right actuation of the first hand control to regulate steering of the ground engaging mechanisms in a corresponding left or right direction, and command signals from the second hand control to control movement of first actuator and second actuator, andwherein in the travel mode, the controller is configured to switch from using the forward or reverse actuation of the first hand control to using a foot control command signal responsive to an actuation of the foot control to regulate the propel speed of the ground engaging mechanisms, and is configured to receive a propel direction command signal, separate from the foot control, to control the forward or reverse propel direction of the ground engaging mechanisms.

9. The control system of claim 8, wherein the first hand control is a joystick.

10. The control system of claim 9, wherein the controller receives the propel direction command signal to switch between a forward, reverse, or neutral propel direction from a joystick console.

11. The control system of claim 9, wherein in the travel mode, the controller is configured to receive the propel direction command signal to switch between a forward, reverse, or neutral propel direction from the forward or reverse actuation of the first hand control.

12. The control system of claim 8, wherein the controller operates the first actuator and the second actuator to move the work tool in response to command signals responsive to the forward, reverse, left or right actuation of the second hand control.

13. The control system of claim 8 further comprising a console coupled to the controller, the console configured to receive an operator command to switch the controller between the working mode and the travel mode.

14. The control system of claim 8, wherein the foot control is a single-acting foot pedal.

15. The control system of claim 8 further comprising,an engine having an adjustable engine speed coupled to drive a variable displacement hydraulic pump having a pump output, anda valve block that selectively couples the pump output to a drive motor,wherein the controller is configured to adjust the engine speed and vary a displacement of the hydraulic pump to control the drive motor speed in response to the foot control command signal.

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