Method for operating electric tractor hitch, and system for implementing method

Abstract

Disclosed in one embodiment of the present invention is a system for operating an electric tractor hitch, comprising: a first sensing unit for generating a digital pulse corresponding to an input of a user; a calculation unit for determining any one of the ascent and the descent of the hitch on the basis of the characteristics of the generated digital pulse; a driving unit for driving an ascending proportional control solenoid and a descending proportional control solenoid on the basis of a result value determined by the calculation unit; and a cylinder hydraulic pressure increase / decrease unit, which increases or decreases hydraulic pressure in a cylinder according to the driving control of the driving unit so as to cause the hitch to ascend or descend.

Description

Method for operating a hitch of an electric tractor and a system for implementing the method

[0001] The present invention relates to a method for operating a hitch of a tractor, and more particularly, to a method for operating a hitch of an electric tractor that operates based on a motor and a system for implementing the method.

[0002] The input devices of existing tractors consisted of mechanical operating devices or switches directly connected to relays, so that when the operator operated a lever, the hydraulic pressure was mechanically opened and closed, or when the switch was operated, the relay was directly operated to control the implement and various parts. However, as time passed and users (operators) of tractors demanded high convenience, and due to issues with the arrangement and design of parts, various parts in the cabin were digitalized, the general trend is that frequently used control devices (input devices) are located on the armrest, and infrequently used setting devices are located on the IVI panel (In-Vehicle Infotainment panel).

[0003] In this way, various information operated by the worker is input to the controller inside the armrest (hereinafter referred to as “armrest controller”) through electrical signals (analog or digital signals), and this input signal is transmitted to various electronic modules (hydraulic controller, vehicle controller, motor controller, hitch controller, battery management controller, etc.) through vehicle communication (CAN communication). In addition, the characteristics of the work equipment that are not frequently used during work are set through the IVI panel, and this set information is also transmitted to various modules through vehicle communication.

[0004] Figure 1 is a schematic drawing showing an example of a mechanical operation method in a conventional tractor.

[0005] For example, referring to Fig. 1, when an operator operates a lever of a tractor, a valve is opened and closed by a mechanical connection, and as a result, the hydraulic pressure of the cylinder increases or decreases, thereby causing the tractor or the implement connected to the PTO (power take off) of the tractor to operate. Alternatively, when an operator operates a switch of the tractor, a voltage is generated across the switch, which operates a relay to supply power, and thus various lamps or electronic components turn on.

[0006] Meanwhile, in a traditional mechanical tractor, the hydraulic pressure is mechanically opened and closed as the operator (user) operates the lever, and the hydraulic pressure of the cylinder is varied, thereby raising or lowering the work piece (hitch).

[0007] Figure 2 is a schematic diagram showing the raising and lowering of the hitch in a conventional tractor.

[0008] On the other hand, in the case of electric tractors that are being mass-produced recently, when the user operates the lever, the controller (ECU) detects the movement of the lever and controls the solenoid accordingly to operate the hydraulic opening and closing, and as the hydraulic pressure of the cylinder changes, the work piece (hitch) is raised or lowered.

[0009] Figure 3 is a drawing for explaining an example of an electronic operating method used in a conventional electric tractor.

[0010] Referring to Figure 3, although there are some differences in the driving process, the electronic operation method employed in the electric tractor is substantially the same as that of a conventional mechanical tractor in that it uses a lever.

[0011] Figure 4 is a drawing for explaining the driving method of an electronic hitch operation lever system used in a conventional electric tractor.

[0012] Referring to FIG. 4, it can be seen that the electronic hitch operation lever system included in the existing electric tractor includes a first sensing unit, an operation unit, a driving unit, a cylinder hydraulic pressure increasing unit, and a second sensing unit.

[0013] The first sensing unit generally includes an analog sensor, has a limited operating angle, generates a sensing value within a range of 0 to 5 V depending on the user's operation, and converts this input value into a desired hitch height requirement (0% to 100%, 0% - lowest, 100% - highest) to receive the desired hitch position information from the user.

[0014] The operation unit can compare the hitch height request from the first sensing unit with the actual current position input from the hitch position sensor to determine whether the hitch is raised or lowered.

[0015] The driving unit can drive the proportional control solenoid for rising or the proportional control solenoid for falling depending on the rising or falling determined by the operating unit.

[0016] The cylinder hydraulic pressure increase / decrease unit increases / decrease the hydraulic pressure inside the cylinder according to proportional control solenoid control, thereby causing the hitch to rise or lower.

[0017] The second sensing unit includes an analog position sensor (0V to 5V) to determine and digitize the actual position of the current hitch, and can output the position of the hitch as a value between 0% and 100% depending on the value of the position sensor.

[0018] That is, the electronic hitch operation lever system as shown in Fig. 4 operates on the principle of receiving the user's hitch request position as an absolute value (0 to 5 V) from the first sensing unit and controlling the raising / lowering of the work machine based on the user's request value.

[0019] The problem with the electronic hitch lever system is that there is a high possibility of risk of personal injury or other accidents due to the unintentional raising / lowering of the lever by the driver. For example, if the user has the tractor ignition turned off and the lever is accidentally operated and the tractor ignition is then turned back on, the controller (ECU) recognizes the current value of the sensing unit (electronic lever), judges this to be the user's intention to operate, and controls the solenoid valve. As a result, there is a possibility of a personal injury or accident if the hitch suddenly rises or lowers as soon as the ignition is turned on.

[0020] The technical problem to be solved by the present invention is to provide a method for operating a hitch of an electric tractor and a method implemented by the system.

[0021] According to one embodiment of the present invention for solving the above technical problem, a system for operating a hitch of an electric tractor comprises: a first sensing unit for generating a digital pulse corresponding to a user's input; a calculation unit for determining either raising or lowering of the hitch based on a characteristic of the generated digital pulse; a driving unit for driving a proportional control solenoid for raising and a proportional control solenoid for lowering based on a result value determined by the calculation unit; and a cylinder hydraulic pressure increasing / decreasing unit for causing raising or lowering of the hitch by increasing or decreasing hydraulic pressure in a cylinder according to driving control of the driving unit.

[0022] According to another embodiment of the present invention for solving the above technical problem, a method for operating a hitch of an electric tractor comprises: a step of generating a digital pulse corresponding to a user's input; a step of determining one of raising and lowering of the hitch based on a characteristic of the generated digital pulse; a step of driving a proportional control solenoid for raising and a proportional control solenoid for lowering based on a result value of one of the determined raising and lowering; and a step of causing raising or lowering of the hitch by increasing or decreasing a hydraulic pressure in a cylinder according to the driving control.

[0023] One embodiment of the present invention can provide a computer-readable recording medium storing a program for executing the above method.

[0024] According to the present invention, an electric tractor with improved safety can be provided.

[0025] Figure 1 is a schematic drawing showing an example of a mechanical operation method in a conventional tractor.

[0026] Figure 2 is a schematic diagram showing the raising and lowering of the hitch in a conventional tractor.

[0027] Figure 3 is a drawing for explaining an example of an electronic operating method used in a conventional electric tractor.

[0028] Figure 4 is a drawing for explaining the driving method of an electronic hitch operation lever system used in a conventional electric tractor.

[0029] FIG. 5 is a block diagram showing an example of an electric tractor to which one embodiment of the present invention is applied.

[0030] Fig. 6 is a block diagram showing an example of an electric tractor electric system that is an improvement on the electric tractor electric system described in Fig. 5.

[0031] Figure 7 is a block diagram showing an example of a communication security system for an electric tractor.

[0032] FIG. 8 is a drawing for explaining an electronic hitch operation dial system as another embodiment of the present invention.

[0033] FIG. 9 is a drawing for explaining the driving method of an electronic hitch operation dial system used in an electric tractor according to the present invention.

[0034] Figure 10 is a diagram schematically showing an example of a hitch operation method according to the present invention.

[0035] According to one embodiment of the present invention for solving the above technical problem, a system for operating a hitch of an electric tractor comprises: a first sensing unit for generating a digital pulse corresponding to a user's input; a calculation unit for determining either raising or lowering of the hitch based on a characteristic of the generated digital pulse; a driving unit for driving a proportional control solenoid for raising and a proportional control solenoid for lowering based on a result value determined by the calculation unit; and a cylinder hydraulic pressure increasing / decreasing unit for causing raising or lowering of the hitch by increasing or decreasing hydraulic pressure in a cylinder according to driving control of the driving unit.

[0036] In the above system, a second sensing unit may be further included that outputs a numerical value between 0% and 100% for the position of the hitch caused to rise or fall by the cylinder hydraulic pressure increasing / decreasing unit.

[0037] In the above system, the first sensing unit may include a dial-shaped input unit that selectively receives only clockwise or counterclockwise input from the user.

[0038] In the above system, the characteristic of the digital pulse may be the number of digital pulses generated in proportion to the user's input.

[0039] According to another embodiment of the present invention for solving the above technical problem, a method for operating a hitch of an electric tractor comprises: a step of generating a digital pulse corresponding to a user's input; a step of determining one of raising and lowering of the hitch based on a characteristic of the generated digital pulse; a step of driving a proportional control solenoid for raising and a proportional control solenoid for lowering based on a result value of one of the determined raising and lowering; and a step of causing raising or lowering of the hitch by increasing or decreasing a hydraulic pressure in a cylinder according to the driving control.

[0040] One embodiment of the present invention can provide a computer-readable recording medium storing a program for executing the above method.

[0041] The present invention is capable of various modifications and embodiments. Specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, as well as the methods for achieving them, will become clearer with reference to the embodiments described in detail below, along with the drawings. However, the present invention is not limited to the embodiments disclosed below and can be implemented in various forms.

[0042] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. When describing with reference to the drawings, identical or corresponding components are given the same drawing reference numerals, and redundant descriptions thereof will be omitted.

[0043] In the following examples, the terms first, second, etc. are not used in a limiting sense, but are used for the purpose of distinguishing one component from another.

[0044] In the examples below, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0045] In the following examples, terms such as “include” or “have” mean that a feature or component described in the specification is present, and do not preclude the possibility that one or more other features or components may be added.

[0046] In some embodiments, where the implementation is otherwise feasible, a particular process sequence may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0047] FIG. 5 is a block diagram showing an example of an electric tractor to which one embodiment of the present invention is applied.

[0048] The electric tractor according to the present invention uses a different power source than a traditional mechanical tractor. A mechanical tractor essentially includes an internal combustion engine, and a clutch and transmission unit for driving and controlling the engine. However, the electric tractor according to the present invention is different in that it receives power from a drive motor rather than an engine, and thus does not include a clutch or transmission unit. Furthermore, the drive motor of the electric tractor is powered by a battery, unlike a traditional tractor that requires diesel fuel to operate the engine.

[0049]

[0050] Table 1 shows the names and functions of a plurality of sub-modules constituting an electric tractor according to the present invention. Referring to Table 1, an electric tractor according to an embodiment of the present invention may include a vehicle control unit (VCU), a cluster (CLU), an infotainment (INF), an armrest controller (MPU), a power distribution unit (PDU), a low voltage direct current converter (LDC), a battery management controller (BMS), an on-board battery charger (OBC), a thermal management controller (TMS), a drive motor controller (MCU1), a hydraulic controller (PCU), and a PTO motor controller (MCU2).

[0051] The modules described in Table 1 are examples of sub-modules that may be included in an electric tractor. Therefore, depending on the embodiment, the electric tractor may include a greater number of modules than the sub-modules described in Table 1, or may be implemented in a form that includes a smaller number of modules. For example, although omitted in Table 1, a reducer may be additionally coupled to the drive motor and the PTO motor, and the battery may further include an inverter for converting power output from the battery.

[0052] An electric tractor according to one embodiment of the present invention can perform essentially the same function as a conventional mechanical tractor or hybrid tractor. For example, an implement, such as a baler, may be connected to the rear side of an electric tractor according to one embodiment of the present invention, and the baler, powered by the PTO of the electric tractor, may operate in a manner that generates bales according to the direction in which the electric tractor moves.

[0053] Referring to FIG. 5, it can be seen that an electric tractor according to an embodiment of the present invention includes an input unit (210), an armrest controller (220), an IVI panel (230), a hydraulic controller (240), a vehicle controller (250), a motor controller (260), and a battery management controller (270). Since FIG. 5 exemplarily shows sub-modules that may be included in an electric tractor, an electric tractor according to the present invention may include more or fewer sub-modules than those shown in FIG. 5, depending on the embodiment.

[0054] First, after the user gets on the electric tractor, he / she can input to the input unit (210). The input unit (210) can be any one of a button, a switch, and a lever on the electric tractor, and can also be in the form of multiple buttons, multiple switches, or multiple levers. When the user inputs to the input unit (210), the user's input can be transmitted to the armrest controller (220) in the form of an analog signal or a digital signal. The armrest controller (220) is a controller that oversees the control of the armrest, and can perform the function of converting the user's input into a control signal and transmitting it to a lower module described below.

[0055] The IVI panel (230) can convert a user's touch input into a digital control signal and transmit it to the sub-modules of the electric tractor. The IVI panel (230) performs the function of generating a control signal in parallel with the armrest controller (220) and transmitting it to the sub-modules of the electric tractor.

[0056] The hydraulic controller (240) is a module that controls a hydraulic motor included in an electric tractor. Here, the hydraulic motor is a device that generates power by injecting high pressure generated by a hydraulic pump into an operating shaft.

[0057] The vehicle controller (250) can perform a function of comprehensively controlling various electronic modules included in the electric tractor.

[0058] The motor controller (260) can perform the function of controlling the drive motor among the drive motor, hydraulic motor, and PTO motor included in the electric tractor.

[0059] The battery management controller (270) can perform a function of comprehensively managing and controlling the remaining capacity, output voltage, and fault status of the battery of the electric tractor.

[0060] An electric tractor such as that in Fig. 5, unlike a traditional mechanical tractor, has a modularized configuration according to function, and accordingly, the part that receives a signal reflecting the user's operating intention is an armrest controller or an IVI panel, and the armrest controller or IVI panel transmits the processed signals to an external drive controller through a vehicle network (typically, CAN communication) to generate physical movement.

[0061] However, when transmitting signals using a communication protocol used in an electric tractor, the signals have characteristics that make them easy to debug, so instead of normal control signals generated by a user's operation, an arbitrary control signal generated through an unauthorized external device may cause the electric tractor or a work machine connected to the electric tractor to operate incorrectly, and therefore, there is a need to prevent this.

[0062] Fig. 6 is a block diagram showing an example of an electric tractor electric system that is an improvement on the electric tractor electric system described in Fig. 5.

[0063] More specifically, the electric tractor electrical system illustrated in FIG. 6 refers to a system that further includes a communication security system (500) in addition to the electric tractor electrical system described in FIG. 5. That is, the input unit (210), armrest controller (220), IVI panel (230), hydraulic controller (240), vehicle controller (250), motor controller (260), and battery management controller (270) of FIG. 5 can correspond identically to the input unit (410), armrest controller (420), IVI panel (430), hydraulic controller, vehicle controller, motor controller, and battery management controller of FIG. 6, respectively.

[0064] The communication security system (500) according to the present invention is composed of a transmitter (510) and a receiver (520, 530, 540, 550).

[0065] First, the transmitter (510) performs the function of processing the control signal received from the armrest controller (420) or the IVI panel (430) according to a preset communication protocol and processing standard and transmitting the processed signal to at least one module. The transmitter (510) may be placed adjacent to the armrest controller (420) and the IVI panel (430) so as to be able to directly receive the control signal received from the armrest controller (420) or the IVI panel (430).

[0066] Next, the receiving terminals (520, 530, 540, 550) are each included in at least one module, and perform a function of receiving the processed control signal transmitted by the transmitting terminal (510) and restoring it to correspond to a processing standard. When the processed control signal is restored by the receiving terminal (520, 530, 540, 550), the operation of the lower modules (in FIG. 4, the hydraulic controller, the vehicle controller, the motor controller, and the battery management controller) including the receiving terminal can be controlled according to the restored control signal.

[0067] External equipment (440) refers to unauthorized equipment that is not included in the communication security system (500) of the electric tractor according to the present invention. The external equipment (440) may generate an unauthorized control signal that may disrupt the operation of at least one of the hydraulic controller, the vehicle controller, the motor controller, and the battery management controller, and the external equipment (440) may transmit the generated unauthorized control signal to at least one of the hydraulic controller, the vehicle controller, the motor controller, and the battery management controller through a communication protocol identical to the communication protocol used in the electric tractor.

[0068] In a conventional electric tractor, when external equipment (440) intervenes, there was no way to prevent unauthorized control signals from the external equipment (440) from being transmitted to the lower modules (hydraulic controller, vehicle controller, motor controller, and battery management controller) of the electric tractor. However, according to the communication security system (500) according to the present invention, the receiving end (520, 530, 540, 550) can determine that the unauthorized control signals from the external equipment (440) are inappropriate control signals, thereby maximizing the security of the electric tractor.

[0069] Figure 7 is a block diagram showing an example of a communication security system for an electric tractor.

[0070] Referring to FIG. 7, it can be seen that the communication security system (500) according to the present invention includes a transmitter (510) and receivers (520, 530, 540, 550). Although a total of four receivers (520, 530, 540, 550) are illustrated in FIG. 7, this is because the number of sub-modules in FIG. 6, which is 4, is matched for convenience of explanation. Therefore, it will be sufficiently understood by those skilled in the art that, depending on the embodiment, the number of receivers included in the communication security system (500) may be less than or more than 4.

[0071] Below, the explanation will be given with reference to Fig. 5.

[0072] The transmitter (510) can process the control signal of the armrest controller (420) or the IVI panel (430) according to a preset communication protocol and processing standard and transmit the processed signal to at least one module. In one embodiment, the communication protocol may be the SAE (Society of Automotive Engineers) J1939 standard.

[0073] Hereinafter, a signal processed in accordance with the communication protocol and processing standard at the transmitter (510) will be referred to as a "processed control signal." The processed control signal refers to a control signal that is converted in a manner that not only complies with the standards stipulated in the communication protocol, but also additionally complies with the processing standard (transformation standard) built into the transmitter (510).

[0074] When the processed control signal follows the J1939 standard, the processed control signal uses a single simple data link layer, has six subfields encoded as a 29-bit CAN identifier, and can contain data for priority, extended data page, data page, protocol format, and protocol-specific source address.

[0075]

[0076] Table 2 tabulates the 29-bit CAN identifiers included in the processed control signals. In Table 2, P indicates the message priority, EDP and DP constitute four different pages, one of which is reserved for ISO 15765-3, PF and PS define the parameter group number and destination address, and SA indicates the source address of the controller application, respectively.

[0077] Processed control signals according to the J1939 standard can have one of three message sizes: 3 bytes, 8 bytes, and variable-length bytes, in addition to the 29-bit CAN identifier. Of these, setting a message size to 8 bytes has the advantage of maximizing the amount of network data, allowing for more efficient use of network bandwidth. In other words, if 8 bytes are allocated to the message size of a processed control signal, data transmission can be achieved through a single CAN frame.

[0078] As described above, in the present invention, it is assumed that 8 bytes are allocated to the message size of the processed control signal, so that network bandwidth can be used efficiently.

[0079]

[0080] Table 3 intuitively illustrates an example of a control signal transmitted to a submodule in a signal using an 8-byte data size according to the J1939 standard. Referring to Table 3, it can be seen that the control commands constituting the control signal are divided and arranged into a total of 7 in the space allocated to a total of 8 bytes. Since Table 3 illustrates an example of a control signal according to the conventional J1939 standard, the same level of security as that of the present invention cannot be expected.

[0081]

[0082] Table 4 is a table that intuitively shows an example of a 'processed control signal' generated by a transmitter (510) in a communication security system (500) according to the present invention. Referring to Table 4, it can be seen that the control commands constituting the 'processed control signal' are divided into a total of 6 and arranged in a space where a total of 8 bytes are allocated, and a CRC (Cyclical Redundancy Check) is allocated to the last byte space, 'Byte7'. The standard required to generate a processed control signal as shown in Table 4 is called a 'processing standard' in the present invention, and there are various embodiments of the processing standard. In the present invention, the processing standard is established on the premise that the message size of the control signal is 8 bytes, and therefore, the processing standard has the characteristic of depending on the communication protocol.

[0083] The receiver receives the processed control signal, restores it to correspond to the processing standard, and controls the sub-module including the receiver using the restored result, and induces the device corresponding to the sub-module to operate appropriately. As illustrated in Fig. 6, the number of receivers is equal to the number of sub-modules, and one receiver corresponds to each sub-module. For example, if the receiver that received the processed control signal is a receiver included in a hydraulic control unit (PCU), after the processed control signal is restored according to the processing standard, the hydraulic control unit (PCU) operates according to the control command included in the processed control signal, and as a result, the amount or size of the hydraulic pressure corresponding to the hydraulic control unit (PCU) can be determined.

[0084] In the present invention, the transmitter (510) and the receiver (520, 530, 540, 550) may basically include the same processing criteria. The transmitter (510) may utilize the processing criteria to generate a processed control signal, and the receiver (520, 530, 540, 550) may utilize the processing criteria to receive and restore the processed control signal.

[0085] As an example, when a transmitter (510) generates and transmits a processed control signal by assigning a fixed CRC value to Byte7 through a processing standard, a receiver (520, 530, 540, 550) receives the processed control signal and checks the CRC value assigned to Byte7, thereby checking the integrity of the data, and only if it passes, induces the lower module including the receiver to be controlled through the control command in Byte0 to Byte6. In this embodiment, the processing standard may include information on the fixed CRC value and information on 8, which is the byte number to which the CRC value is assigned.

[0086] As another example, the CRC value may not be a fixed value, but may be a variable value that changes depending on the remaining six control commands. In the present embodiment, when the transmitter (510) generates a processed control signal through a processing reference and transmits it to the receiver, any one of the receivers (520, 530, 540, 550) that receives the processed control signal can check the CRC value in the processed control signal and determine whether the confirmed CRC value is a value that can be normally derived by the remaining six control commands. The receiver that receives the processed control signal can determine that the integrity of the processed control signal is recognized only if the confirmed CRC value and the calculated CRC value normally derived by the remaining six control commands are the same. In the present embodiment, the processing reference may include not only the byte number to which the CRC value is assigned, but also a series of formulas for calculating the calculated CRC value by combining the six control commands.

[0087] As another example, the processing criteria may be set differently for each of the multiple sub-modules that the receiver includes. For example, when the transmitter (510) transmits a processed control signal, the first receiver (520) can restore the CRC according to the first processing criteria to determine the integrity, and the second receiver (530) can restore the CRC according to the second processing criteria to determine the integrity. That is, the transmitter (510) can determine which sub-module the processed control signal will reach, and then process it differently for each determined sub-module, thereby inducing the CRC to be restored normally only in the sub-modules where the processed control signal should normally reach.

[0088] In addition, the transmitter (510) can generate a processed control signal by combining at least one of the above-described embodiments, and the specific method for this has already been described, so it will be omitted.

[0089] In the above manner, according to the communication security system of the present invention, encryption of control signals exposed on a communication network is possible, thereby preventing arbitrary manipulation using external equipment, and thus the security of the entire electric tractor system can be significantly enhanced.

[0090] FIG. 8 is a drawing for explaining an electronic hitch operation dial system as another embodiment of the present invention.

[0091] Referring to FIG. 8, it can be seen that the electronic hitch operation dial system according to the present invention has a completely different appearance from the existing hitch operation system implemented as a lever. The user can cause the hitch to rise or fall by rotating the first sensing unit implemented in the form of a dial clockwise or counterclockwise. Here, the dial is not an input unit that maintains a fixed input state like a lever, but operates as a type of sensor that generates a digital pulse in proportion to the user's input, thereby resulting in an electronic hitch operation dial system that is much safer than the existing hitch operation lever system.

[0092] FIG. 9 is a drawing for explaining the driving method of an electronic hitch operation dial system used in an electric tractor according to the present invention.

[0093] Referring to Fig. 9, it can be seen that the electronic hitch operation dial system includes a first sensing unit (910), a calculation unit (920), a driving unit (930), a cylinder hydraulic pressure increasing unit (940), and a second sensing unit (950). According to an embodiment, the electronic hitch operation dial system of Fig. 9 can be implemented in a form physically included in the input unit, the armrest system, and the hydraulic control unit (PCU) described in Figs. 5 and 6.

[0094] First, the first sensing unit (910) generally uses an encoder sensor, and the operating range can be infinitely operated in the clockwise / counterclockwise direction, and two pulse signals with different phases can be generated depending on the direction in which the dial is operated. For example, when the dial is operated clockwise, the phase is opposite to that when it is operated counterclockwise. This digital pulse signal is not generated when there is no user operation, and only when there is a user operation on the dial, at least one pulse is generated depending on the magnitude of the operation. For example, if one pulse is generated as the dial moves clockwise, the current hitch position is raised by 1%, and if 10 pulses are detected, the current hitch position is raised by 10%.

[0095] The operation unit (920) can compare the hitch height request from the first sensing unit (910) with the actual current position input from the hitch position sensor to determine whether the hitch is raised / lowered.

[0096] The driving unit (930) can drive the proportional control solenoid for rising or the proportional control solenoid for falling according to the rising or falling determined by the calculating unit (920).

[0097] The cylinder hydraulic pressure increase / decrease unit (940) increases / decrease the hydraulic pressure inside the cylinder according to proportional control solenoid control, thereby inducing the hitch to rise or lower.

[0098] The second sensing unit (950) includes an analog position sensor (0 V to 5 V) to determine and digitize the actual position of the current hitch, and can output the position of the hitch as a value between 0% and 100% according to the value of the position sensor.

[0099] That is, the electronic hitch operation lever system as shown in Fig. 4 operates on the principle of receiving the user's hitch request position as an absolute value (0 to 5 V) from the first sensing unit and controlling the raising / lowering of the work machine based on the user's request value.

[0100] Figure 10 is a diagram schematically showing an example of a hitch operation method according to the present invention.

[0101] Since the method according to FIG. 10 can be implemented by an electric tractor including the electronic hitch operation dial system (900) described in FIG. 9, a description overlapping with the description through FIG. 9 will be omitted below.

[0102] The first sensing unit (910) can generate a digital pulse corresponding to the user's input (S1010).

[0103] The operation unit (920) can determine the rise / fall of the hitch based on the characteristics of the digital pulse (S1030).

[0104] The driving unit (930) can drive the proportional control solenoid for raising / lowering based on the determined result value (S1050).

[0105] The cylinder hydraulic pressure increase / decrease unit (940) can increase / decrease the hydraulic pressure inside the cylinder according to the driving control to cause the hitch to rise / lower (S1070).

[0106] The electric tractor according to the present invention is driven by an electronic hitch control dial method that requires a relative position value calculated based on the characteristics of a digital pulse, rather than an electronic hitch control lever that requires an absolute position value in the armrest system, thereby fundamentally preventing accidents that may cause personal injury or property damage due to rapid rise / fall of the hitch before and after starting the electric tractor.

[0107] The embodiments of the present invention described above may be implemented in the form of a computer program that can be executed through various components on a computer, and such a computer program may be recorded on a computer-readable medium. At this time, the medium may include a magnetic medium such as a hard disk, a floppy disk, and a magnetic tape, an optical recording medium such as a CD-ROM and a DVD, a magneto-optical medium such as a floptical disk, and a hardware device specifically configured to store and execute program instructions, such as a ROM, a RAM, a flash memory, etc.

[0108] Meanwhile, the computer program may be specifically designed and constructed for the present invention, or may be one known and available to those skilled in the computer software field. Examples of computer programs may include not only machine language code, such as that generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

[0109] The specific implementations described in the present invention are exemplary embodiments and do not limit the scope of the present invention in any way. For the sake of brevity, descriptions of conventional electronic components, control systems, software, and other functional aspects of the systems may be omitted. In addition, the lines connecting or connecting members between components illustrated in the drawings are merely representative of functional connections and / or physical or circuit connections, and may be replaced or represented as various additional functional connections, physical connections, or circuit connections in an actual device. In addition, unless specifically mentioned as “essential,” “important,” etc., a component may not be absolutely necessary for the application of the present invention.

[0110] The use of the term "above" and similar referential terms in the specification of the present invention (especially in the claims) may refer to both singular and plural. Furthermore, if a range is described in the present invention, it includes inventions that apply individual values ​​within the range (unless otherwise stated), and is equivalent to describing each individual value constituting the range in the detailed description of the invention. Finally, unless the order of the steps constituting the method according to the present invention is explicitly stated or otherwise stated to the contrary, the steps may be performed in any appropriate order. The present invention is not necessarily limited by the order in which the steps are described. The use of all examples or exemplary terms (e.g., "for example," etc.) in the present invention is merely intended to illustrate the present invention in detail, and the scope of the present invention is not limited by the examples or exemplary terms, unless otherwise defined by the claims. Furthermore, those skilled in the art will appreciate that various modifications, combinations, and variations can be made within the scope of the appended claims or their equivalents, depending on design conditions and factors.

Claims

1. As a hitch operation system for an electric tractor, A first sensing unit that generates a digital pulse corresponding to a user's input; A calculation unit that determines either the rise or fall of the hitch based on the characteristics of the generated digital pulse; A driving unit that drives the ascending proportional control solenoid and the descending proportional control solenoid based on the result value determined by the above operation unit; and A hitch operation system for an electric tractor, comprising a cylinder hydraulic pressure increasing / decreasing unit that causes the hitch to rise or fall by increasing or decreasing the hydraulic pressure in the cylinder according to the driving control of the above driving unit.

2. In paragraph 1, A hitch operation system for an electric tractor, further comprising a second sensing unit that outputs a position of the hitch, which has been raised or lowered by the cylinder hydraulic pressure increasing / decreasing unit, as a value between 0% and 100%.

3. In paragraph 1, The above first sensing unit, An electric tractor hitch operation system including a dial-type input unit that selectively receives only clockwise or counterclockwise input from the user.

4. In paragraph 1, The characteristics of the above digital pulse are: A hitch operation system for an electric tractor, the number of digital pulses generated being proportional to the user's input.

5. As a hitch operation method for an electric tractor, A step of generating a digital pulse corresponding to a user's input; A step of determining either rising or falling of the hitch based on the characteristics of the generated digital pulse; A step of driving a proportional control solenoid for rising and a proportional control solenoid for falling based on the result value of either the rising or falling determined above; and A method for operating a hitch of an electric tractor, comprising: a step of causing the hitch to rise or fall by increasing or decreasing the hydraulic pressure in the cylinder according to the above driving; 6. A computer-readable recording medium storing a program for executing the method according to Article 5.

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