Patent Application
20230166567
The present disclosure relates generally to work vehicles. More specifically, the present disclosure relates to control of axle lead ratio in vehicles.
One embodiment relates to a system than includes a hydraulic suspension system including a front suspension actuator, and a front suspension pressure sensor associated with the front suspension actuator; a tire inflation system; and one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: determine a dynamic weight based on information received from the front suspension pressure sensor of the hydraulic suspension system, determine a current front axle lead ratio based on the dynamic weight, determine a target front axle lead ratio, and control operation of the tire inflation system to adjust from the current front axle lead ratio to the target front axle lead ratio.
Another embodiment relates to an apparatus that includes one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: determine a dynamic weight based on information received from a suspension pressure sensor associated with a suspension actuator of a hydraulic suspension system, determine a rolling radius of a tire supported by the suspension actuator based on the dynamic weight, determine a current axle lead ratio based on the rolling radius, determine a target axle lead ratio, determine a target tire pressure change of the tire to adjust the current axle lead ratio to the target axle lead ratio, and control operation of a tire inflation system to implement the target tire pressure change.
Still another embodiment relates to a method that includes determining a dynamic weight based on information received from a suspension pressure sensor associated with a suspension actuator of a hydraulic suspension system, querying a lookup table using the dynamic weight and a current tire pressure received from a tire pressure sensor associated with a tire, returning a current rolling radius of the tire from the lookup table, determining a current axle lead ratio based on the returned current rolling radius, determining a target axle lead ratio, querying the lookup table using the dynamic weight and a target rolling radius associated with the target axle lead ratio, returning a target tire pressure of the tire from the lookup table, determining a target tire pressure change based on a target tire pressure and the current tire pressure to adjust the current axle lead ratio to the target axle lead ratio, and controlling operation of a tire inflation system to implement the target tire pressure change.
This summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices or processes described herein will become apparent in the detailed description set forth herein, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements.
Before turning to the figures, which illustrate certain exemplary embodiments in detail, it should be understood that the present disclosure is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.
According to an exemplary embodiment, a vehicle (e.g., a tractor) of the present disclosure includes front wheel and rear wheels, a hydraulic suspension system, and a central tire inflation system. A controller is structured to determine a current front axle lead ratio based on dynamic loading of the vehicle (e.g., during operation), and adjust tire pressures of front tires mounted on the front wheels and rear tires mounted on the rear wheels to achieve a target front axle lead ratio. Dynamic loading of the vehicle (e.g., while towing an implement) may result in a dynamic weight shift and an increased dynamic weight on the rear tires. The increased dynamic weight results in a reduced rolling radius of the rear tires and an increased front axle lead ratio. A front axle lead ratio larger than the target front axle lead ratio can result in increased front wheel slippage, increased rear wheel drag, and an overall decrease in tractive efficiency of the vehicle. Adjustment of the tire pressures can affect the tire rolling radius and therefore be used to control the front axle lead ratio and improve the tractive efficiency of the vehicle.
According to the exemplary embodiment shown in
According to an exemplary embodiment, the vehicle 10 is an off-road machine or vehicle. In some embodiments, the off-road machine or vehicle is an agricultural machine or vehicle such as a tractor, a telehandler, a front loader, a combine harvester, a grape harvester, a forage harvester, a sprayer vehicle, a speedrower, and/or another type of agricultural machine or vehicle. In some embodiments, the off-road machine or vehicle is a construction machine or vehicle such as a skid steer loader, an excavator, a backhoe loader, a wheel loader, a bulldozer, a telehandler, a motor grader, and/or another type of construction machine or vehicle. In some embodiments, the vehicle 10 includes one or more attached implements and/or trailed implements such as a front mounted mower, a rear mounted mower, a trailed mower, a tedder, a rake, a baler, a plough, a cultivator, a rotavator, a tiller, a harvester, and/or another type of attached implement or trailed implement.
According to an exemplary embodiment, the cab 30 is configured to provide seating for an operator (e.g., a driver, etc.) of the vehicle 10. In some embodiments, the cab 30 is configured to provide seating for one or more passengers of the vehicle 10. According to an exemplary embodiment, the operator interface 40 is configured to provide an operator with the ability to control one or more functions of and/or provide commands to the vehicle 10 and the components thereof (e.g., turn on, turn off, drive, turn, brake, engage various operating modes, raise/lower an implement, etc.). The operator interface 40 may include one or more displays and one or more input devices. The one or more displays may be or include a touchscreen, a LCD display, a LED display, a speedometer, gauges, warning lights, etc. The one or more input device may be or include a steering wheel, a joystick, buttons, switches, knobs, levers, an accelerator pedal, a brake pedal, etc.
According to an exemplary embodiment, the driveline 50 is configured to propel the vehicle 10. As shown in
As shown in
As shown in
As shown in
In some embodiments, the driveline 50 includes a plurality of prime movers 52. By way of example, the driveline 50 may include a first prime mover 52 that drives the front tractive assembly 70 and a second prime mover 52 that drives the rear tractive assembly 80. By way of another example, the driveline 50 may include a first prime mover 52 that drives a first one of the front tractive elements 78, a second prime mover 52 that drives a second one of the front tractive elements 78, a third prime mover 52 that drives a first one of the rear tractive elements 88, and/or a fourth prime mover 52 that drives a second one of the rear tractive elements 88. By way of still another example, the driveline 50 may include a first prime mover that drives the front tractive assembly 70, a second prime mover 52 that drives a first one of the rear tractive elements 88, and a third prime mover 52 that drives a second one of the rear tractive elements 88. By way of yet another example, the driveline 50 may include a first prime mover that drives the rear tractive assembly 80, a second prime mover 52 that drives a first one of the front tractive elements 78, and a third prime mover 52 that drives a second one of the front tractive elements 78. In such embodiments, the driveline 50 may not include the transmission 56 or the transfer case 58.
As shown in
According to an exemplary embodiment, the braking system 100 includes one or more brakes (e.g., disc brakes, drum brakes, in-board brakes, axle brakes, etc.) positioned to facilitate selectively braking (i) one or more components of the driveline 50 and/or (ii) one or more components of a trailed implement. In some embodiments, the one or more brakes include (i) one or more front brakes positioned to facilitate braking one or more components of the front tractive assembly 70 and (ii) one or more rear brakes positioned to facilitate braking one or more components of the rear tractive assembly 80. In some embodiments, the one or more brakes include only the one or more front brakes. In some embodiments, the one or more brakes include only the one or more rear brakes. In some embodiments, the one or more front brakes include two front brakes, one positioned to facilitate braking each of the front tractive elements 78. In some embodiments, the one or more front brakes include at least one front brake positioned to facilitate braking the front axle 76. In some embodiments, the one or more rear brakes include two rear brakes, one positioned to facilitate braking each of the rear tractive elements 88. In some embodiments, the one or more rear brakes include at least one rear brake positioned to facilitate braking the rear axle 86. Accordingly, the braking system 100 may include one or more brakes to facilitate braking the front axle 76, the front tractive elements 78, the rear axle 86, and/or the rear tractive elements 88. In some embodiments, the one or more brakes additionally include one or more trailer brakes of a trailed implement attached to the vehicle 10. The trailer brakes are positioned to facilitate selectively braking one or more axles and/or one more tractive elements (e.g., wheels, etc.) of the trailed implement.
As shown in
The pneumatic system 150 includes a central tire inflation system 154 that is coupled to tire pressure units 158 associated with each tractive element 78, 88 to increase or decrease tire pressure. In some embodiments, the tire inflation system 154 includes an air compressor, an accumulator, and/or other components. In some embodiments, the tire pressure units 158 include a pneumatic valve and/or an assembly providing pressurized air to the interior of the tractive elements 78, 88 while the vehicle 10 is in use.
The control system 200 is arranged in communication with the hydraulic suspension system 130 and the tire inflation system 154 and receives signals from a sensor array 210 including suspension sensors 204 and tire pressure sensors 208. The suspension sensors 204 are positioned to monitor a rod side pressure and a head side pressure of the suspension actuators 134 and send a signal to the control system 200 indicative of hydraulic pressures at rod-side and head-side of the suspension actuator 134. The tire pressure sensors 208 are positioned to monitor the tire pressure and send a signal to the control system 200 indicative of the tire pressure.
An adaptive tire pressure control system is provided for the vehicle 10 and includes the hydraulic suspension system 130, the tire inflation system 154, and the control system 200. In some embodiments, the vehicle 10 is a mechanical front-wheel drive tractor. In some embodiments, the vehicle 10 is a four-wheel drive tractor or a vehicle 10 switchable between front wheel drive, rear wheel drive, and/or four wheel drive.
A front axle lead ratio Z is determined using the following equation:
Where Vtf is a front wheel theoretical ground speed, Vtr is a rear wheel theoretical ground speed, Zf is a front wheel transmission ratio, Zr is a rear wheel transmission ratio, Rf is a front wheel rolling radius, and Rr is a rear wheel rolling radius. The front wheel transmission ratio Zf and the rear wheel transmission ratio Zr are fixed, and variations in tire inflation pressure and wheel vertical load impact the front wheel rolling radius Rf and the rear wheel rolling radius Rr. The inflation pressure of the front wheels 78 and the rear wheels 88 can be changed via the tire inflation system 154 to manipulate the front axle lead ratio Z.
When the vehicle 10 travels without a tractive load, that is, without an implement (e.g., a trailer, a grain cart, a cultivator, etc.), an ideal situation from tractive efficiency (i.e., a ratio of drawbar power to axle power) perspective is that the front wheels 78 and the rear wheels 88 have zero slip, and therefore the slip related power loss is zero (i.e., a tractive efficiency of 1).
When the front axle lead ratio Z is greater than zero percent (0%) the vehicle experiences front wheel slip and rear wheel skid and a front wheel slip force, or driving force, is opposed by a rear wheel skid force, or resistance force, so that the total longitudinal force on the vehicle 10 is zero. Tractive power loss occurs due to the kinematic discrepancy between the front wheels 78 and the rear wheels 88. As the front axle lead ratio Z increases, a power loss, tire wear, and fuel consumption will increase as well.
It is desirable that the front wheels 78 will experience zero skid (i.e., minimized skidding) in order to maintain steering controllability. Alternatively, excessive front axle lead ratios Z will increase the front wheel slip and results in increased rear wheel digging.
When the vehicle 10 travels with a tractive load such as a drawbar implement, a hitched implement, a trailer, or a grain cart, and the front axle lead ratio Z is greater than zero, the front wheels 78 have a higher slip and the rear wheels 88 have a lower slip. Because the tractive efficiency of the wheels 78, 88 is a function of slip, the front wheels 78 of a higher slip and the rear wheels 88 of a lower slip may not result in an optimal wheel tractive efficiency together, and consequently the overall vehicle tractive efficiency will not reach an optimal value.
Dynamic tractive loads cause dynamic tractor weight transfer from the front axle 76 to rear axle 86. The greater the tractive load, the greater the weight transfer from the front axle 76 to the rear axle 86. Typically, front tires mounted on the front wheels 78 and rear tires mounted on the rear wheels 88 are inflated based on static load on the wheel 78, 88. The reduced front wheel load caused by tractive loads results in an increased front wheel rolling radius Rf, and a decreased rear wheel rolling radius Rr. The dynamic weight transfer, as a result of dynamic tractive load, can further increase the kinematic discrepancy and the front axle lead ratio Z (lead-lag ratio), between front wheels 78 and rear wheels 88, and consequently impact the tractive efficiency of the vehicle 10.
This disclosure includes systems and methods for controlling tire inflation in order to adapt to tractive load variations for optimal tractive efficiency. The systems and methods inflate the tires to a baseline front tire pressure and a baseline rear tire pressure under static front axle weight and rear axle weight. During work with an implement, the systems and methods calculate tractor dynamic weight, and then adaptively adjust inflation pressures of front tires and/or rear tires to manage the front axle lead ratio Z and achieve an improved tractive efficiency.
Referring now to
In one configuration, the control system 222 is embodied as machine or computer-readable media that is executable by a processor, such as processor 216. As described herein and amongst other uses, the machine-readable media facilitates performance of certain operations to enable reception and transmission of data. For example, the machine-readable media may provide an instruction (e.g., command, etc.) to, e.g., acquire data. In this regard, the machine-readable media may include programmable logic that defines the frequency of acquisition of the data (or, transmission of the data). The computer readable media may include code, which may be written in any programming language including, but not limited to, Java or the like and any conventional procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program code may be executed on one processor or multiple remote processors. In the latter scenario, the remote processors may be connected to each other through any type of network (e.g., CAN bus, etc.).
In another configuration, the control system 222 is embodied as hardware units, such as electronic control units. As such, the control system 222 may be embodied as one or more circuitry components including, but not limited to, processing circuitry, network interfaces, peripheral devices, input devices, output devices, sensors, etc. In some embodiments, the control system 222 may take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (IC), discrete circuits, system on a chip (SOCs) circuits, microcontrollers, etc.), telecommunication circuits, hybrid circuits, and any other type of “circuit.” In this regard, the control system 222 may include any type of component for accomplishing or facilitating achievement of the operations described herein. For example, a circuit as described herein may include one or more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, and so on). The control system 222 may also include programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like. The control system 222 may include one or more memory devices for storing instructions that are executable by the processor(s) of the control system 222. The one or more memory devices and processor(s) may have the same definition as provided below with respect to the memory device 218 and processor 216. In some hardware unit configurations, the control system 222 may be geographically dispersed throughout separate locations in the vehicle 10. Alternatively and as shown, the control system 222 may be embodied in or within a single unit/housing, which is shown as the controller 200.
In the example shown, the controller 200 includes the processing circuit 212 having the processor 216 and the memory device 218. The processing circuit 212 may be structured or configured to execute or implement the instructions, commands, and/or control processes described herein with respect to control system 222. The depicted configuration represents the control system 222 as machine or computer-readable media. However, as mentioned above, this illustration is not meant to be limiting as the present disclosure contemplates other embodiments where the control system 222, or at least one circuit of the control system 222, is configured as a hardware unit. All such combinations and variations are intended to fall within the scope of the present disclosure.
The hardware and data processing components used to implement the various processes, operations, illustrative logics, logical blocks, modules and circuits described in connection with the embodiments disclosed herein (e.g., the processor 216) may be implemented or performed with a general purpose single- or multi-chip processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, or, any conventional processor, or state machine. A processor also may be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. In some embodiments, the one or more processors may be shared by multiple circuits (e.g., the control system 222 may comprise or otherwise share the same processor which, in some example embodiments, may execute instructions stored, or otherwise accessed, via different areas of memory). Alternatively or additionally, the one or more processors may be structured to perform or otherwise execute certain operations independent of one or more co-processors. In other example embodiments, two or more processors may be coupled via a bus to enable independent, parallel, pipelined, or multi-threaded instruction execution. All such variations are intended to fall within the scope of the present disclosure.
The memory device 218 (e.g., memory, memory unit, storage device) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present disclosure. The memory device 218 may be communicably connected to the processor 216 to provide computer code or instructions to the processor 216 for executing at least some of the processes described herein. Moreover, the memory device 218 may be or include tangible, non-transient volatile memory or non-volatile memory. Accordingly, the memory device 218 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein.
The suspension control circuit 226 is structured to actively control the hydraulic suspension system 130 via the communications interface 250 to raise, lower, level, or otherwise adjust the orientation of the vehicle 10. In some embodiments, the suspension control circuit 226 controls operation of pumps, valves, and other control components of the hydraulic suspension system 130 including the suspension actuator 134.
The hydraulic pressure circuit 230 is structured to receive signals from the suspension sensors 204 associated with the suspension actuators 134, and determine hydraulic pressures. The hydraulic pressure circuit 230 also determines a front axle weight and a rear axle weight based on the hydraulic pressures at rod side and head side of each suspension actuator 134. In some embodiments, the hydraulic pressure circuit 230 records the head side hydraulic cylinder pressures and the rod side pressures of the front suspension actuators 134 via the suspension sensors 204 while vehicle 10 is not moving and determines a cylinder force. The hydraulic pressure circuit 230 then determines a static front axle weight FWS(i) and a static rear axle weight RWS(i) that is supported by the suspension actuators 134 based on the cylinder force while the vehicle 10 is stationary.
The dynamic weight circuit 234 is structured to determine dynamic weights during travel or field operation. A dynamic front axle weight FWD is determined by the dynamic weight circuit 234 based on the hydraulic pressure of each suspension actuator 134 recorded over time to determine a mean value of pressures. The dynamic front axle weight FWD is based on the mean value. In some embodiments, the dynamic front axle weight FWD is determined based on the mean hydraulic pressure values of the front suspension actuators 134 only. The determined dynamic front axle weight FWD is then used to determine a dynamic weight transfer based on a comparison of the dynamic front axle weight FWD in field operation with the static front axle weight FWS(i) determined while the vehicle 10 is stationary. In some embodiments, the dynamic weight circuit 234 determines a dynamic rear axle weight RWD is determined based on the hydraulic pressure of each suspension actuator 134 recorded over time to determine a mean value of pressures. The dynamic rear axle weight RWD is based on the mean value. In some embodiments, the dynamic rear axle weight RWD is determined based on the mean hydraulic pressure values of the rear suspension actuators 134 only. In some embodiments, the dynamic front axle weight FWD and the dynamic rear axle weight RWD are determined together based on the mean values of pressures measured at all of the suspension actuators 134.
The tire pressure circuit 238 is structured to receive information from the tire inflation system 154 including the tire pressure units 158 and the tire pressure sensors 208. The tire pressure circuit 238 determines current tire pressures for each of the tires 78, 88 of the vehicle 10 and also stores a number of front tires 78 and a number of rear tires 88. In some embodiments, the number of front tires 78 and the number of rear tires 88 is preprogrammed, received from a user, or automatically detected. The tire pressure circuit 238 is also structured to control deflation or inflation of individual tires 78, 88 via the tire inflation system 154 including the tire pressure units 158. The tire pressure circuit 238 is structured to inflate the front tires 78 to a baseline front tire inflation pressure Pf, and a baseline rear tire inflation pressure Pr, determine current tire pressures, and to inflate and/or deflate the front tires 78 and rear tires 88 to updated pressures during operation of the vehicle 10.
The rolling radius circuit 242 is structured to determine a tire rolling radius for each tire 78, 88 based on the current tire inflation pressures and tire vertical load (e.g., the static front axle weight FWS(i), the static rear axle weight RWS(i), the dynamic front axle weight FWD, and the dynamic rear axle weight RWD). In some embodiments, the relationship between the tire rolling radius and tire parameters can be captured via equations, algorithms, models, etc. In some embodiments, a test method can be used to calibrate the tire rolling radius RR(I,j) of the front tires 78 and the rear tires 88 based on the front wheel loads (e.g., FWS(i)), the rear wheel loads (e.g., RWS(i)), and tire inflation pressures. As shown in
The wheel lead circuit 246 is structured to receive the front wheel transmission ratio Zf, the rear wheel transmission ratio Zr, the front tire inflation pressure Pf and the rear tire inflation pressure Pr from the tire pressure circuit 238, the static front axle weight FWS(i) and the static rear weight RWS(i) from the hydraulic pressure circuit 230, and the front tire rolling radius Rf and the rear tire rolling radius Rr from the rolling radius circuit 242. The wheel lead circuit 246 determines a front to rear lead-lag ratio Zb, as follows:
Due to the dynamic weight transfer during operation of the vehicle 10, the front and rear tire rolling radii change over time. The front axle lead ratio Z, is calculated iteratively and tire pressures are adjusted to maintain a desirable front axle lead ratio Z. The front axle lead ratio Z is optimized via the controller 200 for maximum tractive performance by adjusting the front tire pressure, the rear tire pressure, or both pressures.
The controller 200 carries out the tasks of data recording and weight transfer estimation, and stores at least the following information: the tractor static front weight FWS, and static rear weight RWS, the front tire rolling radius table and rear tire rolling radius table, the baseline front tire pressure Pf and rear tire pressure Pr, the number of front tires and number of rear tires, and the front weight supported by the front suspension actuators 134. After the estimation of the dynamic weight transfer, the controller 200 determines a tire pressure adjustment (e.g., inflation or deflation) needed for optimal tractive efficiency by using the stored information. The tire inflation pressure adjustments are executed through the tire inflation system 154.
As shown in
At step 308, the process of recording information is started. A start command can be received from a user input (e.g., via a button, a command entered through a human-machine-interface, etc.), automatically prompted by action (e.g., attachment of a drawbar implement, engagement of an accessory, etc.), or otherwise initiated. In some embodiments, a continuous execution of the method 300 is engaged once a start recording command is received. In some embodiments, the time period for recording includes a limited number of executions which is terminated by a stop recording command (see for example step 340).
At step 312, the controller 200 receives and records the static front weight FWS and the static rear weight RWS via the hydraulic pressure circuit 230, the front tire rolling radius Rf and the rear tire rolling radius Rr by querying lookup tables via the rolling radius circuit 242, and the baseline front tire pressure Pf and the baseline rear tire pressure Pf via the tire pressure circuit 238.
At step 316, the dynamic weight circuit 234 determines the dynamic front axle weight FWD and the dynamic rear axle weight RWD. In some embodiments, the dynamic weight circuit 234 determines dynamic weights at each tractive element 78, 88 (e.g., wheel/tire) at each set of tractive elements 78, 88 (e.g., a set of two wheels/tires on a left side of the vehicle 10 and a set of two wheels/tires or a right side of the vehicle 10 are determined as individual dynamic weights). Within this disclosure a dynamic weight may refer to a dynamic weight of an entire axle, an individual tractive element 78, 88 (e.g., a wheel/tire), or a subset of tractive elements 78, 88 (e.g., a group of wheels/tires). In some embodiments, a dynamic weight shift or a dynamic weight transfer is determined at step 316 by comparing the dynamic front weight FWD with the static front weight FWS determined earlier in step 312.
At step 320, the current front axle lead ratio Z is determined by the controller 200. The tire rolling radius circuit 242 determines the front rolling radius Rf and the rear rolling radius Rr based on the tables discussed above. In some embodiments, the rolling radius circuit 242 may include a machine learning engine that receives tire pressures, dynamic weights, static weights, hydraulic pressures, and/or other inputs and determines the front rolling radius Rf and the rear rolling radius Rr using a deep neural network, a neural network, reinforcement learning, or another machine learning architecture. The front rolling radius Rf and the rear rolling radius Rr, and front and rear transmission ratios Zf and Zr (received from the drivetrain 50 for example) are then used by the wheel lead circuit 246 to determine the current front axle lead ratio Z.
At step 324, the wheel lead circuit 246 determines a target lead ratio. In some embodiments, the target lead ratio is user defined (e.g., selected from a menu, graphical user interface, human machine interface, buttons, dials, etc.). In some embodiments, the controller 200 recognizes operating conditions and an operational mode automatically (e.g., towing an implement, travelling over a road, travelling in mud, etc.) and automatically selects a target lead ratio corresponding to the operating conditions. In some embodiments, the operational modes include a travel mode for travelling on a road or another level surface while the vehicle is relatively unloaded (e.g., not pulling an engaged implement such as a cultivator or a loaded wagon). In some embodiments, the target front axle lead ratio Z equals 1.0 (i.e., a 0% front wheel lead) while operating in the travel mode. In some embodiments, operational modes include a field mode for operation in a field or while towing or otherwise utilizing an implement. In some embodiments, the target front axle lead ratio Z is optimized for optimal tractive efficiency (e.g., a 1% front wheel lead or a target front axle lead ratio Z of 1.01) while operating in the field mode. In some embodiments, operational modes are not used and the target front axle lead ratio Z is set based on detected activities. For example, in some embodiments, the target lead ratio desirably provides zero front wheel lead (i.e., the front axle lead ratio Z equals 1.0) while travelling over a road or relatively level path, and/or the target lead ratio desirably provides an optimal front axle lead ratio while towing an implement or when operating in slippery conditions (e.g., mud, etc.).
At step 328, the tire pressure circuit 238 determines a front tire pressure change and a rear tire pressure change to achieve the target lead ratio. In some embodiments, the target front tire pressure change and rear tire pressure change are achieved by reverse look up using the rolling radius tables along with the dynamic weights, and the static weights and the target lead ratio. In some embodiments, a machine learning engine can be used to correlate, learn, and determine tire pressures corresponding to the target lead ratio during operation of the vehicle 10.
At step 332, the controller 200 commands the tire inflation system 154 to implement the front tire pressure change and the rear tire pressure change to achieve the target lead ratio as determined by the tire pressure circuit 238.
At step 336, the controller 200 checks to determine if the tire pressure of each tire 78, 88 is stable. If the pressures are not stable, the method 300 returns to step 332 and the tires are inflated/deflated to the desired pressures.
At step 340, the controller 200 determines if the time period of recording has been met. If not, the method 300 returns to step 312 and the method 300 continues to adjust the tire inflation pressure to achieve the target lead ratio. If the time period of recording has been achieved, then the method 300 stops at step 344 and normal operation of the vehicle 10 continues without the method 300 continually running.
When the vehicle 10 travels without a tractive load and both the front axle 76 and the rear axle 86 of the vehicle 10 are engaged, that is, without an implement or a trailer or grain cart, etc., an ideal situation from tractive efficiency perspective is that both the front tractive elements 78 and the rear tractive elements 88 have zero slip, and therefore the slip related power loss is zero. In situations of front wheel lead (e.g., a positive front axle lead ratio Z), the front tractive elements 78 slip, and the rear tractive elements 88 skid. The front slip force, or driving force, is opposed by the rear skid force, or resistance force, so that the total longitudinal force on the vehicle 10 is zero. Tractive power loss occurs due to the kinematic discrepancy between front and rear wheels. The greater the speed lead or lag, the greater the power loss and tire wear. The fuel consumption of the vehicle 10 increases as the front axle lead ratio Z increases. It is desirable that front wheel will not skid in order to maintain steering controllability, and excessive front wheel lead (e.g., the front axle lead ratio Z) will increase the front wheel slip and results in rear wheel digging. When the vehicle 10 travels with a tractive load such as a drawbar implement, a hitched implement, a trailer, or a grain cart, in a situation of front wheel lead, the front wheels have a higher slip and the rear wheels have a lower slip. Because the tractive efficiency of a wheel is a function of its slip, the front wheels of a higher slip and the rear wheels of a lower slip may not result in an optimal wheel tractive efficiency together, and consequently the overall vehicle tractive efficiency will not reach an optimal value. Dynamic tractive load causes dynamic tractor weight transfer from front axle to rear axle. The greater the tractive load, the greater the weight transfer. In general, a tire is inflated to the pressures based on static load on the wheel. The reduced front wheel load causes the front tire rolling radius, Rf, to increase, and at the same time the heavier rear wheel load causes the rear tire rolling radius, Rr, to decrease. The dynamic weight transfer, as a result of dynamic tractive load, can further increase the kinematic discrepancy and the front axle lead ratio Z, between front and rear wheels, and consequently impact the tractive efficiency of the tractor.
As utilized herein with respect to numerical ranges, the terms “approximately,” “about,” “substantially,” and similar terms generally mean +/−10% of the disclosed values, unless specified otherwise. As utilized herein with respect to structural features (e.g., to describe shape, size, orientation, direction, relative position, etc.), the terms “approximately,” “about,” “substantially,” and similar terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.
It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).
The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with one another, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.
References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the figures. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.
The present disclosure contemplates methods, systems, and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.
Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above. Such variation may depend, for example, on the software and hardware systems chosen and on designer choice. All such variations are within the scope of the disclosure. Likewise, software implementations of the described methods could be accomplished with standard programming techniques with rule-based logic and other logic to accomplish the various connection steps, processing steps, comparison steps, and decision steps.
The term “client or “server” include all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, or combinations, of the foregoing. The apparatus may include special purpose logic circuitry, e.g., a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). The apparatus may also include, in addition to hardware, code that creates an execution environment for the computer program in question (e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them). The apparatus and execution environment may realize various different computing model infrastructures, such as web services, distributed computing and grid computing infrastructures.
The systems and methods of the present disclosure may be completed by any computer program. A computer program (also known as a program, software, software application, script, or code) may be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program may be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program may be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.
The processes and logic flows described in this specification may be performed by one or more programmable processors executing one or more computer programs to perform actions by operating on input data and generating output. The processes and logic flows may also be performed by, and apparatus may also be implemented as, special purpose logic circuitry (e.g., an FPGA or an ASIC).
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing actions in accordance with instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data (e.g., magnetic, magneto-optical disks, or optical disks). However, a computer need not have such devices. Moreover, a computer may be embedded in another device (e.g., a vehicle, a Global Positioning System (GPS) receiver, etc.). Devices suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including by way of example semiconductor memory devices (e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks). The processor and the memory may be supplemented by, or incorporated in, special purpose logic circuitry.
To provide for interaction with a user, implementations of the subject matter described in this specification may be implemented on a computer having a display device (e.g., a CRT (cathode ray tube), LCD (liquid crystal display), OLED (organic light emitting diode), TFT (thin-film transistor), or other flexible configuration, or any other monitor for displaying information to the user. Other kinds of devices may be used to provide for interaction with a user as well; for example, feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback).
Implementations of the subject matter described in this disclosure may be implemented in a computing system that includes a back-end component (e.g., as a data server), or that includes a middleware component (e.g., an application server), or that includes a front end component (e.g., a client computer) having a graphical user interface or a web browser through which a user may interact with an implementation of the subject matter described in this disclosure, or any combination of one or more such back end, middleware, or front end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include a LAN and a WAN, an inter-network (e.g., the Internet), and peer-to-peer networks (e.g., ad hoc peer-to-peer networks).
It is important to note that the construction and arrangement of the vehicle 10 and the systems and components thereof (e.g., the driveline 50, the braking system 100, the control system 200, etc.) as shown in the various exemplary embodiments is illustrative only. Additionally, any element disclosed in one embodiment may be incorporated or utilized with any other embodiment disclosed herein.
