SYSTEMS, METHODS AND NON-TRANSITORY COMPUTER-READABLE MEDIA FOR ACTIVE HYDRAULIC SYSTEM WARMUP

Description

FIELD OF THE DISCLOSURE

Some example embodiments provide systems, methods, and non-transitory computer-readable media for warming oil of a hydraulic system by pumping the oil though open center valves of the hydraulic system.

BACKGROUND

Heavy machines including, for example, dozers, loaders, excavators, motor graders, etc. typically comprise a number of hydraulic actuators to perform various functions. Actuators are fluidly connected to a pump on the machine that provides pressurized hydraulic oil to chambers within the actuators. As the pressurized hydraulic oil moves into or through the chambers, the pressure of the oil acts on hydraulic surfaces of the chambers to affect movement of the actuator and a connected implement (e.g., a work tool). When the pressurized oil is drained from the chambers it is returned to a low pressure tank on the machine.

SUMMARY

Some example embodiments provide improved systems, methods, and non-transitory computer-readable media that enables warming of hydraulic oil using existing open center valves of a hydraulic system.

Some example embodiments provide a system including a pump, a valve including an open center passage, the valve being configured to return a hydraulic oil flow received from the pump to a hydraulic reservoir through the open center passage when the valve is in a first position, and pass the hydraulic oil flow to an actuator when the valve is in a work position, and processing circuitry configured to cause the hydraulic system to determine whether a current temperature of hydraulic oil is less than or equal to a target temperature, cause a position of the valve to be set to the first position in response to determining that the current temperature of the hydraulic oil is less than or equal to the target temperature, and cause the pump to flow the hydraulic oil to the valve.

Some example embodiments provide a method including determining whether a current temperature of hydraulic oil is less than or equal to a target temperature, causing a position of a valve to be set to a first position in response to determining that the current temperature of the hydraulic oil is less than or equal to the target temperature, the valve including an open center passage, and the valve being configured to return a hydraulic oil flow received from a pump to a hydraulic reservoir through the open center passage when the valve is in the first position, and pass the hydraulic oil flow to an actuator when the valve is in a work position, and causing the pump to flow the hydraulic oil to the valve.

Some example embodiments provide a non-transitory computer-readable medium storing instructions that, when executed by at least one processor, cause the at least one processor to perform a method, the method includes determining whether a current temperature of hydraulic oil is less than or equal to a target temperature, causing a position of a valve to be set to a first position in response to determining that the current temperature of the hydraulic oil is less than or equal to the target temperature, the valve including an open center passage, and the valve being configured to return a hydraulic oil flow received from a pump to a hydraulic reservoir through the open center passage when the valve is in the first position, and pass the hydraulic oil flow to an actuator when the valve is in a work position, and causing the pump to flow the hydraulic oil to the valve.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the non-limiting embodiments herein may become more apparent upon review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are merely provided for illustrative purposes and should not be interpreted to limit the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. For the purposes of clarity, various dimensions of the drawings may have been exaggerated.

FIG. 1 illustrates a work vehicle, in accordance with some example embodiments;

FIG. 2 illustrates an Electro-Hydraulic (EH) system according to some example embodiments;

FIGS. 3A-3C illustrate a valve set to different positions according to some example embodiments;

FIG. 4 illustrates a control device for controlling the EH system of FIG. 3, according to some example embodiments; and

FIG. 5 illustrates a method of warming hydraulic oil, according to some example embodiments.

DETAILED DESCRIPTION

The performance and/or response of hydraulic systems vary according to a temperature of hydraulic oil used in the hydraulic systems. For example, the performance and/or response of the hydraulic systems may be reduced when the temperature of the hydraulic oil falls below a target temperature. This is particularly challenging in Electro-Hydraulic (EH) systems, where pilot passageways are restricted and susceptible to response differences with varying oil viscosities.

Existing devices and methods for warming hydraulic oil involve adding components to the hydraulic systems such as, additional valves, flushing circuits, throttles, etc. Such additional and/or specialized components increase the complexity, manufacturing costs and/or physical size of the hydraulic systems. However, some example embodiments provide improved devices and methods for warming hydraulic oil as discussed further below.

FIG. 1 illustrates a work vehicle, in accordance with some example embodiments.

Referring to FIG. 1, depicted is a left side view of a work vehicle 100. The work vehicle 100 is illustrated as a hydraulic excavator 100a, including a chassis or frame 14, and traction members (e.g., crawler tracks 18) for supporting and propelling the frame 14 along a surface. In some example embodiments, the frame 14 includes a platform that is rotatable relative to the tracks 18 about a vertical axis 20. The excavator 100a may further include an operator cab 22 and/or a boom 30 supported on the frame 14. A tool or work attachment (e.g., a bucket 34) may be coupled to an end of the boom 30. The excavator 100a may also include a drive system having a prime mover or engine (not shown), motors (not shown) for driving the tracks 18, and/or motors (not shown) for pivoting the platform about the axis 20. In some example embodiments, the motors may be hydraulic motors. Although the work vehicle 100 is illustrated and described as the excavator 100a, it is understood that the work vehicle 100 may have a different form, such as a loader, a dozer, a motor grader, a scraper, or another type of construction, mining, agricultural, or utility machine. Also, although the work attachment is illustrated and described as the bucket 34, it is understood that the work attachment may have a different form, such as an auger, a breaker, a ripper, a grapple, or some other type of attachment for digging, breaking, handling, carrying, dumping or otherwise engaging dirt or other material. In addition, the work attachment may be detachable from the boom 30 to permit another type of work attachment to be coupled to the boom 30.

In the illustrated example, the boom 30 includes a primary member or hoist portion 38 pivotably coupled to the frame 14, and an arm or stick portion 42 pivotably coupled to an end of the hoist portion 38. The work attachment 34 is pivotably coupled to an end of the stick portion 42. The excavator 100a may include actuators such as hydraulic cylinders 46 for actuating or moving the bucket 34, the hoist portion 38, and the stick portion 42 relative to one another and relative to the frame 14. For example, the actuators may include a first actuator 46a for actuating or moving the hoist portion 38, a second actuator 46b for actuating or moving the stick portion 42 and a third actuator 46c for actuating or moving the bucket 34. According to some example embodiments, the actuators, boom 30 and/or traction members discussed in connection with FIG. 1 are merely examples and some example embodiments are not limited thereto. For example, according to some example embodiments, the work vehicle 100 may include different actuators, a different boom 30 and/or different traction members from those discussed in connection with FIG. 1. Also, one or more components discussed in connection with FIG. 1 may be omitted, and/or one or more other components added, according to some example embodiments.

FIG. 2 illustrates an Electro-Hydraulic (EH) system according to some example embodiments.

Referring to FIG. 2, an EH system 300 may include a pump 310, a valve 320, an actuator 330 and/or a hydraulic reservoir 340. According to some example embodiments, the EH system 300 may include a pressure sensor 360 (e.g., a pressure transducer) positioned, for example, between the pump 310 and the valve 320, but some example embodiments are not limited thereto. The pump 310 may be an EH-controlled pump. For example, the pump 310 may be an Electronic Displacement Control (EDC) pump, and a flow rate of the pump 310 may be controlled using a first EH solenoid 312. Each of the pump 310, the valve 320, the actuator 330 and the hydraulic reservoir may be connected through hydraulic lines 350, 352, 354 and 356 carrying hydraulic oil. Although FIG. 2 illustrates only a single pump 310, a single valve 320 and a single actuator 330, some example embodiments are not limited thereto. According to some example embodiments, the EH system 300 may include an additional pump(s) 310, an additional valve(s) 320 and/or an additional actuator(s) 330. According to some example embodiments, the actuator 330 may be used to implement each of the first actuator 46a, the second actuator 46b and the third actuator 46c discussed in connection with FIG. 1. According to some example embodiments, the EH system 300 may be partially or entirely included on the work vehicle 100, but some example embodiments are not limited thereto and at least one or more elements of the EH system 300 may be external to the work vehicle 100.

A position of the valve 320 may be controlled using a second EH solenoid 322. In scenarios in which the EH system 300 includes a plurality of valves 320, a respective position of each of the plurality of valves 320 may be controlled using a corresponding second EH solenoid 322. The valve 320 may be set to a plurality of different positions including at least a neutral position and one or more work positions. When the valve 320 is set to the neutral position, the valve 320 disconnects the actuator 330 from the flow of hydraulic oil pumped by the pump 310 such that the actuator 330 does not move the boom 30 (e.g., any among the first actuator 46a or the hoist portion 38, the second actuator 46b or the stick portion 42, and/or the third actuator 46c or the bucket 34). Specifically, the valve 320 includes an open center passage 324, and when the valve 320 is set to the neutral position the flow of hydraulic oil enters the open center passage 324 through a first hydraulic line 350 and returns to the hydraulic reservoir 340 through a second hydraulic line 352 after exiting the open center passage. Alternatively, when the valve 320 is set to a work position, the flow of the hydraulic oil passes through the valve 320 to the actuator 330 via one among the third or fourth hydraulic lines 354 or 356, enables the actuator 330 to move the boom 30 (e.g., any among the first actuator 46a or the hoist portion 38, the second actuator 46b or the stick portion 42, and/or the third actuator 46c or the bucket 34), and returns via the other among the third or fourth hydraulic lines 354 or 356. In scenarios in which the EH system 300 includes a plurality of valves 320, each of the plurality of valves 320 may be set to a respective position among the neutral position or the one or more work positions. According to some example embodiments, every respective valve 320 among a plurality of valves 320 may be configured to (1) return a hydraulic oil flow to the hydraulic reservoir 340, and/or (2) pass the hydraulic oil flow to a corresponding actuator 330, based on a position of the of the respective valve 320 (e.g., the neutral position or the one or more work positions), but some example embodiments are not limited thereto.

FIGS. 3A-3C illustrate a valve set to different positions according to some example embodiments.

Referring to FIGS. 2 and 3A, the valve 320 is illustrated as being set to the neutral position. In the neutral position, an entry port 325 and an exit port 326 of the open center passage 324 are aligned to match the first hydraulic line 350 and the second hydraulic line 352, respectively. Accordingly, in the neutral position hydraulic oil flow restriction at the connections between the entry port 325 with the first hydraulic line 350, and between the exit port 326 and the second hydraulic line 352, are minimized or relatively low (particularly as compared to the intermediate position discussed below).

Referring to FIGS. 2 and 3B, the valve 320 is illustrated as being set to a work position. In the work position, an entry port 336 and an exit port 337 of a work passage 335 are aligned to match the first hydraulic line 350 and the second hydraulic line 352, respectively. Accordingly, in the work position hydraulic oil flow restriction at the connections between the entry port 336 with the first hydraulic line 350, and between the exit port 337 and the second hydraulic line 352, are minimized or relatively low (particularly as compared to the intermediate position discussed below).

Referring back to FIG. 2, some example embodiments provide improved devices and methods for warming hydraulic oil. For example, by setting the valve 320 to the neutral position, the open center passage 324 creates a restriction to the flow of the hydraulic oil. This restriction increases the oil pressure at an outlet of the pump 310, and thereby increases a pressure drop across an inlet and an outlet of the open center passage 324 that causes the hydraulic oil to warm. Accordingly, the improved devices and methods enable warming of the hydraulic oil without the incorporation of additional and/or specialized components (e.g., additional valves, flushing circuits, throttles, etc.). Therefore, the improved devices and methods overcome the deficiencies of the existing devices and methods to at least reduce the complexity, manufacturing costs and/or physical size of hydraulic systems relative to those of the existing devices and methods. According to some example embodiments, in scenarios in which the EH system 300 includes a plurality of valves 320, hydraulic oil warming may be performed by setting only a single one, two or more, or all among the plurality of valves 320 to the neutral position.

According to some example embodiments, the second EH solenoid 322 may set the valve 320 to an intermediate position during a warming operation. For example, the intermediate position may be a position between the neutral position and a work position. When the valve 320 transitions from the neutral position to a work position, the center passage begins to be restricted before the hydraulic oil is able to pass through the valve 320 into the third or fourth hydraulic line 354 or 356. This position at which the area of the open center passage 324 is reduced, causing the above-mentioned restriction, without the hydraulic oil being able to pass through the valve 320 into the third or fourth hydraulic line 354 or 356 may be referred to herein as the intermediate position. In the intermediate position, the amount of restriction across the open center passage 324 is increases relative to that provided in the neutral position, and thus, the pressure drop across the open center passage 324 in the intermediate position is likewise increased relative to that provided in the neutral position. This increase in the pressure drop across the open center passage 324 causes the hydraulic oil to warm faster than when the valve 320 is in the neutral position. Accordingly, in examples in which the valve 320 is set to the intermediate position during a warming operation, faster hydraulic oil warming is enabled without the incorporation of additional and/or specialized components (e.g., additional valves, flushing circuits, throttles, etc.). According to some example embodiments, in scenarios in which the EH system 300 includes a plurality of valves 320, hydraulic oil warming may be performed by setting only a single one, two or more, or all among the plurality of valves 320 to the intermediate position.

Referring to FIGS. 2 and 3C, the valve 320 is illustrated as being set to the intermediate position. In the neutral position, the entry port 325 and the exit port 326 of the open center passage 324 are shifted in the direction of the work passage 335 relative to the positioning of the neutral position. Accordingly, the entry port 325 and the exit port 326 are only partly aligned with the first hydraulic line 350 and the second hydraulic line 352, respectively. In the intermediate position, the path of the hydraulic oil flow is further restricted entry port 325 and the exit port 326 due to the partial alignment with the first hydraulic line 350 and the second hydraulic line 352, respectively. This further restriction increases the pressure drop across the open center passage 324 relative to that provided in the neutral position.

According to some example embodiments, additionally or alternatively to performing hydraulic oil warming by setting the position of the valve 320 to one of the neutral position or the intermediate position, hydraulic oil warming may be performed by setting a flow rate of the pump 310. An amount of thermal energy transferred to the hydraulic oil corresponds to both the pressure drop across the valve 320 and the flow rate of the hydraulic oil. Accordingly, hydraulic oil warming may be performed by increasing the flow rate of the pump 310 in addition to, or as an alternative to, the setting of the position of the valve to the neutral position or the intermediate position. Accordingly, in some example embodiments, hydraulic oil warming is enabled by controlling a flow rate of the pump 310 without the incorporation of additional and/or specialized components (e.g., additional valves, flushing circuits, throttles, etc.).

As noted above, the intermediate position of the valve 320 is a position at which the area of the open center passage 324 is reduced without the hydraulic oil being able to pass through the valve 320 into the third or fourth hydraulic line 354 or 356. However, various implementations of the EH system 300 are possible, and in implementations in which setting the valve 320 to the intermediate position without the hydraulic oil being able to pass through the valve 320 into the third or fourth hydraulic line 354 or 356 is impossible or difficult, additional solutions may be provided to enable the warming operation.

According to some example embodiments, for example, prior to setting the valve 320 to the intermediate position, the boom 30 (e.g., any among the first actuator 46a or the hoist portion 38, the second actuator 46b or the stick portion 42, and/or the third actuator 46c or the bucket 34) may be placed against a stop rendering movement of the boom 30 impossible or difficult. In so doing, the hydraulic oil flow would be forced across the open center passage 324 resulting in the pressure drop without risking movement of the boom 30. Additionally or alternatively, according to some example embodiments, a dedicated valve 320 that is not configured to pass hydraulic oil to an actuator 330 may be used to perform the warming operation using the open center passage 324 of the dedicated valve 320 (e.g., set to either the neutral position or the intermediate position). Additionally or alternatively, according to some example embodiments, the valve 320 may be manufactured such that a range of positions, in which hydraulic oil flow across the open center passage 324 is restricted without the hydraulic oil being able to pass through the valve 320 into the third or fourth hydraulic line 354 or 356, is increased.

FIG. 4 illustrates a control device for controlling the EH system of FIG. 3, according to some example embodiments. Referring to FIG. 4, a control device 400 may include a processor 410, a memory 420, a communication device 430, a temperature sensor 440, a user interface (UI) 450 and/or a movement detector 460. The processor 410 may control overall operation of the control device 400 and may be implemented using processing circuitry. The term ‘processing circuitry,’ as used in the present disclosure, may refer to, for example, hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc. According to some example embodiments, the control device 400 may be partially or entirely included in the EH system 300, but some example embodiments are not limited thereto and at least one or more elements of the control device 400 may be external to the EH system 300.

The processor 410 may store and/or retrieve data to and/or from the memory 420 (e.g., programming instructions for execution by the processor 410, operational data generated by the processor 410, etc.). The processor 410 may communicate, and/or control, the communication device 430 and/or the UI 450.

The memory 420 may be a tangible, non-transitory computer-readable medium, such as a Random Access Memory (RAM), a flash memory, a Read Only Memory (ROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk, a removable disk, a Compact Disk (CD) ROM, any combination thereof, or any other form of storage medium known in the art. The memory 420 may store data and/or instructions for retrieval by, for example, the processor 410.

The communication device 430 may include a transmitter, a receiver and/or a transceiver. The communication device 430 may output one or more control signals, provided by the processor 410, to the first EH solenoid 312 and/or the second EH solenoid 322. In scenarios in which the EH system 300 includes a plurality of valves 320, the communication device 430 may output the one or more control signals to one or more the second EH solenoids 322. The communication device 430 may receive a pressure value from the pressure sensor 360 and provide the pressure value to the processor 410. The communication device 430 may communicate with the first EH solenoid 312, the second EH solenoid(s) 322 and/or the pressure sensor 360 via any wired and/or wireless communication method that would be known to a person having ordinary skill in the art.

The temperature sensor 440 may detect a temperature of the hydraulic oil of the EH system 300 and provide the temperature (may also be referred to herein as a temperature value) to the processor 410. The temperature sensor 440 may be implemented using any sensor capable of detecting the temperature of hydraulic oil that would be known to a person having ordinary skill in the art.

The UI 450 may include one or more devices for communicating information to, and/or receiving information from, an operator of the work vehicle 100. For example, the UE 450 may receive a command from the operator to initiate a warming mode and provide an indication of the command to the processor 410. Also, the UI 450 may receive information from the processor 410 (e.g., a hydraulic oil temperature value, a hydraulic oil pressure value, etc.) and display an indication of the information on a screen of the UI 450. Additionally or alternatively, the UI 450 may communicate the information received from the processor 410 audibly (e.g., via a speaker of the UI 450), haptically (e.g., via a piezoelectric actuator of the UI 450), etc. According to some example embodiments, the control device 400 may not include the UI 450. For example, the warming operations discussed herein may be performed as a background process without interaction from the operator.

The movement detector 460 may provide the processor 410 with information regarding whether the boom 30 (e.g., any among the first actuator 46a or the hoist portion 38, the second actuator 46b or the stick portion 42, and/or the third actuator 46c or the bucket 34) is moving. According to some example embodiments, the movement detector 460 may receive commands (provided by the operator by, for example, moving a joystick of the work vehicle 100), for moving the boom 30, sent to the EH system 300. In such examples, the movement detector 460 may provide the processor 410 with a movement signal when the boom 30 is being moved (or a non-movement when the boom 30 is not being moved). According to some example embodiments, the movement detector 460 may detect when at least one valve 320 is positioned to flow hydraulic oil to at least one actuator 330. In such examples, the movement detector 460 may provide the processor 410 with the movement signal while the hydraulic oil is flowing to the at least one actuator 330 (or the non-movement in circumstances in which hydraulic oil is not flowing to any actuator 330). According to some example embodiments, operations performed by the movement detector 460 may be implemented using processing circuitry. According to some example embodiments the movement detector 460 may be implemented by the processor 410.

FIG. 5 illustrates a method of warming hydraulic oil, according to some example embodiments. According to some example embodiments, the method may be performed by the processor 410.

Referring to FIG. 5, in operation 502, the method may include determining whether to perform a hydraulic oil warming operation. For example, the processor 410 may determine whether a temperature of the hydraulic oil of the EH system 300 (e.g., obtained by the temperature sensor 440) is greater than a target temperature. In response to determining that the temperature of the hydraulic oil of the EH system 300 is less than or equal to the target temperature (“Yes” in operation 502), the method may advance to operation 504. Otherwise, in response to determining that the temperature of the hydraulic oil of the EH system 300 is greater than the target temperature (“No” in operation 502), the method may repeat operation 502 after a certain period of time, but some example embodiments are not limited thereto.

According to some example embodiments, operation 502 may be initiated in response to receiving a command from an operator of the work vehicle via the UI 450. In such circumstances, in response to determining that the temperature of the hydraulic oil of the EH system 300 is greater than the target temperature (“No” in operation 502), the method may end and/or output a notification (e.g., indicating that the hydraulic oil warming operation has not been performed because temperature of the hydraulic oil is above the target temperature) to the UI 450 rather than repeat operation 502.

According to some example embodiments, operation 502 may be initiated in response to determining (by the processor 410) that the work vehicle 100 has been idle for a threshold period of time (e.g., 60 seconds) or more. The work vehicle 100 may be interpreted as being idle when the boom 30 (e.g., any or all among the first actuator 46a or the hoist portion 38, the second actuator 46b or the stick portion 42, and/or the third actuator 46c or the bucket 34) is not being moved. In such examples, the method of FIG. 5 may be performed as illustrated until the processor 410 detects that the work vehicle 100 is no longer idle (e.g., based on a signal received from the movement detector 460) at which point the method may promptly end without performing any additional operation(s) of the method. After the method has been ended under these circumstances, operation 502 may be reinitiated in response to determining that the work vehicle 100 has again been idle for the threshold period of time or more.

According to some example embodiments, operation 502 may include determining the target temperature. For example, the target temperature may differ among different implementations of the EH system 300 and/or different types of hydraulic oil used in the EH system 300. The processor 410 may obtain (e.g., via information stored in the memory 420, etc.), or be provided (e.g., via a transmission received through the communication device 430 from an external source, via an input through the UI 450 provided by the operator, etc.), such information about the current implementation of the EH system 300 and/or the current type of hydraulic oil in use in the EH system 300, and may determine (e.g., calculate) the target temperature using any corresponding algorithm that would be known to a person having ordinary skill in the art.

In operation 504, the method may include controlling the second EH solenoid 322 to position the valve 320 in one of the neutral position or the intermediate position. For example, the processor 410 may generate a control signal configured to trigger the second EH solenoid 322 to set the position of the valve 320 to the neutral position or the intermediate position, and transmit the control signal to the second EH solenoid 322 via the communication device 430. In scenarios in which the EH system 300 includes a plurality of valves 320, the processor 410 may generate, and transmit, a respective control signal for (and to) a single one, two or more, or all among the plurality of valves 320.

According to some example embodiments, the processor 410 may determine whether to position the valve 320 in the neutral position or the intermediate position based on a difference between a current temperature of the hydraulic oil and the target temperature. For example, in response to determining that the current temperature of the hydraulic oil is within a threshold temperature range of the target temperature, the processor 410 may position the valve in the neutral position. Alternatively, in response to determining that the current temperature of the hydraulic oil is not within the threshold temperature range of the target temperature, the processor 410 may position the valve in the intermediate position in order to warm the hydraulic oil at a faster rate. In such cases, the processor 410 may also reposition the valve 320 from the intermediate position to the neutral position in response to determining that the current temperature of the hydraulic oil has warmed sufficiently to bring the current temperature within the threshold temperature range.

According to some example embodiments, in scenarios in which the EH system 300 includes a plurality of valves 320, the processor 410 may determine many valves 320 among the plurality of valves 320 to position in the neutral position or the intermediate position based on a difference between a current temperature of the hydraulic oil and the target temperature. For example, the processor 410 may position a greater quantity of valves 320 in the neutral or intermediate position in response to determining that the current temperature of the hydraulic oil is not within a threshold temperature range of the target temperature. In another example, the processor 410 may determine a difference between the current temperature and the target temperature and position a quantity of valves 320 to the neutral or intermediate position proportional to the difference between the current temperature and the target temperature (e.g., using a fixed association(s) recorded in the memory 420, using a function stored in the memory 420, etc.). In so doing, the processor 410 may warm the hydraulic oil at a faster rate in circumstances in which the current temperature of the hydraulic oil is substantially colder than the target temperature. Also, according to some example embodiments, the processor may control both the quantity of valves 320 positioned, and whether the each of the positioned valves 320 is set to the neutral position or the intermediate position, according to the difference between the current temperature and the target temperature. In such cases, the processor 410 may also reposition one or more of the valves 320 from the intermediate position to the neutral position in response to determining that the current temperature of the hydraulic oil has warmed, reducing the difference between the current temperature and the target temperature.

According to some example embodiments, in implementations of the EH system 300 in which setting the valve 320 to the intermediate position without the hydraulic oil being able to pass through the valve 320 into the third or fourth hydraulic line 354 or 356 is impossible or difficult, an additional operation may be performed between operations 502 and 504. Specifically, this additional operation may include outputting a notification to the operator (e.g., via the UI 450) instructing the operator to place the boom 30 (e.g., any among the hoist portion 38, the stick portion 42 and/or the bucket 34) against a stop so as to render movement of the boom 30 impossible or difficult. In such examples, the method may advance to operation 504 only in response to receiving an indication (e.g., via the UI 450) from the operator indicating that the placement of the boom 30 has been successfully completed.

In operation 506, the method may include controlling the first EH solenoid 312 to set a selected flow rate of the pump 310. For example, the processor 410 may select a desired flow rate of the pump 310, generate a control signal configured to trigger the first EH solenoid 312 to set the selected flow rate, and transmit the control signal to the first EH solenoid 312 via the communication device 430. According to some example embodiments, the processor 410 may selected the desired flow rate according to a difference between a current temperature of the hydraulic oil and the target temperature of the hydraulic oil. For example, the processor 410 may select a flow rate that is proportional to the difference between the current temperature and the target temperature (e.g., using a fixed association(s) recorded in the memory 420, using a function stored in the memory 420, etc.). In so doing, the processor 410 may warm the hydraulic oil at a faster rate in circumstances in which the current temperature of the hydraulic oil is substantially colder than the target temperature. According to some example embodiments, the processor 410 may control the flow rate of the pump 310 with reference to a current pressure (e.g., provided by the pressure sensor 360) in order to maintain a desired pressure in the EH system 300.

According to some example embodiments, the processor 410 may control one or more among the flow rate of the pump 310, the position of the valve(s) 320 (e.g., the neutral position or the intermediate position) and/or the quantity of the valves 320 so positioned to enable hydraulic oil warming. According to some example embodiments, as discussed above, the processor 410 may select a flow rate of the pump 310, the position of the valve(s) 320 and/or the quantity of the valves 320 based on the difference between the current temperature and the target temperature (e.g., using one or more fixed associations recorded in the memory 420, using one or more functions stored in the memory 420, etc.) to increase a rate of hydraulic oil warming in circumstances in which the current temperature of the hydraulic oil is substantially colder than the target temperature. In an example, the processor 410 may set the valve 320, or all of the plurality of valves 320, to the neutral position in operation 504, and control the flow rate of the pump 310 in operation 506 to achieve a desired rate of hydraulic oil warming based on the neutral positioning of the valve(s) 320. In an example, the processor 410 set the valve 320, or a selected quantity among the plurality of valves 320, to the intermediate position to achieve a desired rate of hydraulic oil warming in operation 504 (based on a standard or default flow rate), and select the standard or default flow rate of the pump 310 in operation 506.

According to some example embodiments, the processor 410 may only select the flow rate of the pump 310 that is less than or equal to a maximum flow rate (e.g., an upper limit flow rate). For example, the processor 410 may obtain (e.g., via information stored in the memory 420, etc.), or be provided (e.g., via a transmission received through the communication device 430 from an external source, via an input through the UI 450 provided by the operator, etc.), the maximum flow rate (the upper limit flow rate), or information sufficient to determine the maximum flow rate (the upper limit flow rate). The maximum flow rate (the upper limit flow rate) may reflect a maximum (or upper limit) noise level. Accordingly, the information sufficient to determine the maximum flow rate (the upper limit flow rate) may include an indication of a noise level (e.g., a decibel value). The processor 410 may determine (e.g., calculate) the maximum flow rate (the upper limit flow rate) (e.g., using the information sufficient to determine the maximum flow rate (the upper limit flow rate)) using any corresponding algorithm or function that would be known to a person having ordinary skill in the art. Also, the amount of noise produced by the EH system 300 may be based on both the flow rate of the pump 310 and the temperature of the hydraulic oil. Accordingly, the processor 410 may determine (e.g., calculate) the maximum flow rate (the upper limit flow rate), or adjust the obtained the maximum flow rate (the upper limit flow rate) based on the current temperature of the hydraulic oil.

According to some example embodiments, operation 506 may be performed until the current temperature of the hydraulic oil becomes greater than the target temperature, at which point the method ends.

The various operations of methods described above may be performed by any suitable device capable of performing the operations, such as the processing circuitry discussed above. For example, as discussed above, the operations of methods described above may be performed by various hardware and/or software implemented in some form of hardware (e.g., processor, ASIC, etc.).

The software may comprise an ordered listing of executable instructions for implementing logical functions, and may be embodied in any “processor-readable medium” for use by or in connection with an instruction execution system, apparatus, or device, such as a single or multiple-core processor or processor-containing system.

The blocks or operations of a method or algorithm and functions described in connection with some example embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a tangible, non-transitory computer-readable medium (e.g., the memory 420).

According to some example embodiments, the memory 420 may each be a tangible, non-transitory computer-readable medium, such as a Random Access Memory (RAM), a flash memory, a Read Only Memory (ROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), registers, a hard disk, a removable disk, a Compact Disk (CD) ROM, any combination thereof, or any other form of storage medium known in the art.

Some example embodiments may be described with reference to acts and symbolic representations of operations (e.g., in the form of flow charts, flow diagrams, data flow diagrams, structure diagrams, block diagrams, etc.) that may be implemented in conjunction with units and/or devices discussed in more detail below. Although discussed in a particular manner, a function or operation specified in a specific block may be performed differently from the flow specified in a flowchart, flow diagram, etc. For example, functions or operations illustrated as being performed serially in two consecutive blocks may actually be performed concurrently, simultaneously, contemporaneously, or in some cases be performed in reverse order.

It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it may be directly connected or coupled to the other element or intervening elements may be present. As used herein the term “and/or” includes any and all combinations of one or more of the associated listed items.

Although terms of “first” or “second” may be used to explain various components (or parameters, values, etc.), the components (or parameters, values, etc.) are not limited to the terms. These terms should be used only to distinguish one component from another component. For example, a “first” component may be referred to as a “second” component, or similarly, and the “second” component may be referred to as the “first” component. Expressions such as “at least one of” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or any variations of the aforementioned examples.