Vehicle and control method thereof

Abstract

The invention discloses a vehicle and a control method thereof. The control method of the vehicle comprises the steps that the first target rotating speed of an oil pump motor and the first target opening degree of a first proportional valve are determined according to the first stroke of a lifting operation rod; when the actual height of the pallet fork reaches the first buffering range of the current-stage portal frame, the second target rotating speed of the oil pump motor is determined; when the actual height of the pallet fork reaches the first buffering range of the current-stage portal frame, the second target opening degree of the first proportional valve is determined according to the actual height of the pallet fork; determining a third target rotating speed of the oil pump motor according to the first target rotating speed, the second target rotating speed and the actual height of the fork, determining a final target rotating speed of the oil pump motor according to the first target rotating speed and the third target rotating speed, and controlling the oil pump motor to operate according to the final target rotating speed; and determining a first final target opening degree of the first proportional valve according to the first target opening degree and the second target opening degree, and controlling the opening degree of the first proportional valve according to the first final target opening degree.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control, and in particular to a vehicle and a control method thereof. Background Art

[0002] With the rapid development of vehicle technology, electric forklifts are being used more and more widely. In order to pick up and place goods at different heights, electric forklifts can be equipped with multiple gantries, such as a first-level gantry, a second-level gantry, and a third-level gantry. The first-level gantry is installed on the electric forklift, the second-level gantry is slidably connected to the inner side of the first-level gantry, the third-level gantry is slidably connected to the inner side of the second-level gantry, and the forks are set on the third-level gantry. When the required height is smaller, the first-level gantry, the second-level gantry, and the third-level gantry are stacked. When the required height is higher, the second-level gantry can be switched to, that is, the oil pump motor drives the second-level gantry to rise, and the second-level gantry drives the third-level gantry and the forks to rise. When a higher height is required, the third-level gantry can be switched to, that is, on the basis of the second-level gantry rising, the oil pump motor is controlled to drive the third-level gantry to rise, so that the forks can reach a higher height.

[0003] However, due to the different sizes of gantries of different levels, the working cross-sectional areas of the oil cylinders corresponding to gantries of different levels are different, which causes a sudden change in load and speed of the oil pump motor when switching gantries, causing severe vibration of the gantry. Summary of the Invention

[0004] The present invention provides a vehicle and a control method thereof, so as to solve the problem of severe mast shaking when the mast of the vehicle is switched.

[0005] According to one aspect of the present invention, a method for controlling a vehicle is provided, the vehicle comprising an n-stage mast, a cargo fork, a lifting operating lever, a controller, and an oil pump motor, the cargo fork being located on the n-stage mast, the m+1-stage mast being slidably connected to the m-stage mast, the oil pump motor being used to drive the mast and the cargo fork to move, a first proportional valve being provided on a first oil circuit of the oil pump motor, the controller being connected to the oil pump motor, the lifting operating lever, and the first proportional valve, respectively, and the vehicle control method being executed by the controller; wherein n is an integer greater than or equal to 2, and m is a positive integer;

[0006] The vehicle control method includes:

[0007] When the lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of the first proportional valve are determined according to a first stroke of the lifting operating lever;

[0008] When the actual height of the forks reaches the first buffer range of the current mast, the second target speed of the oil pump motor is determined based on the actual torque current of the oil pump motor corresponding to the current mast, and the no-load torque current and full-load torque current corresponding to the next mast; wherein the current mast is the mast with the smallest number of the masts with the highest height among the raised masts;

[0009] When the actual height of the fork reaches the first buffer range of the current mast, determining the second target opening of the first proportional valve according to the actual height of the fork;

[0010] determining a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the fork, determining a final target speed of the oil pump motor according to the first target speed and the third target speed, and controlling the operation of the oil pump motor according to the final target speed;

[0011] A first final target opening of the first proportional valve is determined according to the first target opening and the second target opening, and the opening of the first proportional valve is controlled according to the first final target opening.

[0012] Optionally, the vehicle further comprises a descending operating rod, a second proportional valve is provided on the second oil circuit of the oil pump motor, and the controller is connected to the descending operating rod and the second proportional valve respectively;

[0013] The vehicle control method further includes:

[0014] When the lowering operating lever is activated, determining a third target opening of the second proportional valve according to a second stroke of the lowering operating lever;

[0015] When the actual height of the fork reaches the second buffer range of the current mast, determining a fourth target opening of the second proportional valve according to the actual height of the fork;

[0016] A second final target opening of the second proportional valve is determined according to the third target opening and the fourth target opening, and the opening of the second proportional valve is controlled according to the second final target opening.

[0017] Optionally, determining the second target opening of the first proportional valve according to the actual height of the fork includes:

[0018] The second target opening of the first proportional valve is determined based on the actual height of the fork, the first preset opening, the second preset opening, the first starting height and the first ending height of the first buffer range; wherein the first ending height is the height of the switching point where the fork switches from the current level mast to the next level mast, and the first starting height is less than the first ending height.

[0019] Optionally, determining a first final target opening of the first proportional valve according to the first target opening and the second target opening includes:

[0020] The minimum value between the first target opening degree and the second target opening degree is used as the first final target opening degree.

[0021] Optionally, when the lifting operating lever is activated, the vehicle control method further includes:

[0022] When the actual height of the fork is less than the first starting height of the first buffer range of the current mast, the opening of the first proportional valve is controlled according to the first target opening, and the operation of the oil pump motor is controlled according to the first target speed;

[0023] When the actual height of the fork is greater than the first end height of the first buffer range of the current level mast and is less than the first starting height of the first buffer range corresponding to the next level mast, the opening of the first proportional valve is controlled according to the minimum value of the second preset opening and the first target opening, and the operation of the oil pump motor is controlled according to the minimum value of the first target speed and the second target speed.

[0024] Optionally, determining a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the fork, and determining a final target speed of the oil pump motor according to the first target speed and the third target speed includes:

[0025] Determine a first ratio of a difference between an actual height of the fork and a first starting height of a first buffer range of a current mast, and a difference between a first ending height of the first buffer range of the current mast and the first starting height;

[0026] determining a first product of a difference between the second target speed and the first target speed and the first ratio;

[0027] The sum of the first target speed and the first product is used as a third target speed, and the minimum value between the first target speed and the third target speed is used as the final target speed.

[0028] Optionally, determining the second target speed of the oil pump motor according to the actual torque current of the oil pump motor corresponding to the current-stage gantry, and the no-load torque current and full-load torque current corresponding to the next-stage gantry includes:

[0029] determining a second ratio of a difference between the actual torque current and the full-load torque current to a difference between the no-load torque current and the full-load torque current;

[0030] determining a second product of a difference between a second preset speed and the first preset speed and the second ratio;

[0031] The sum of the first preset rotational speed and the second product is used as the second target rotational speed.

[0032] Optionally, determining the fourth target opening of the second proportional valve according to the actual height of the fork includes:

[0033] Determining a third ratio of a difference between a second starting height of a second buffer range of a current-stage mast and the actual height of the fork, and a difference between the second starting height and a second ending height of the second buffer range of the current-stage mast; wherein the second starting height is the height of a switching point from a next-stage mast to the current-stage mast, and the second ending height is less than the second starting height;

[0034] determining a third product of a difference between a fourth preset opening and a third preset opening and the third ratio;

[0035] taking the sum of the third preset opening and the third product as the fourth target opening;

[0036] Determining the second final target opening of the second proportional valve according to the third target opening and the fourth target opening includes:

[0037] The minimum value between the third target opening degree and the fourth target opening degree is set as the second final target opening degree.

[0038] Optionally, when the lowering operating lever is activated, the vehicle control method further includes:

[0039] When the actual height of the fork is greater than the second starting height of the second buffer range of the current mast, controlling the opening of the second proportional valve according to the third target opening;

[0040] When the actual height of the fork is less than the second end height of the second buffer range of the current level mast, the opening of the second proportional valve is controlled according to the minimum value of the fourth preset opening and the third target opening; wherein the fourth preset opening is the target opening of the second proportional valve corresponding to the second end height of the second buffer range corresponding to the current level mast.

[0041] Optionally, the fork is provided with an encoder, the encoder includes two output channels, the output channels are connected to the controller, and the mast is provided with a proximity switch;

[0042] The vehicle control method further includes:

[0043] When the fork is determined to be in the raised state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, the number of pulses output by the encoder is accumulated, and in each height determination cycle, the actual height of the fork is determined based on the accumulated number of pulses and a first preset correspondence; wherein the first preset correspondence is a correspondence between the number of pulses and the actual height when the height of the fork is less than the height of the proximity switch and the fork is in the raised state;

[0044] When the proximity switch is closed, the actual height of the fork is updated according to the height of the proximity switch, and the number of pulses output by the encoder is accumulated again from zero;

[0045] determining the actual height of the fork according to the accumulated number of pulses and a second preset correspondence; wherein the second preset correspondence is a correspondence between the number of pulses and the actual height when the height of the fork is greater than the height of the proximity switch and the fork is in a raised state;

[0046] When the fork is determined to be in a lowered state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, the number of pulses output by the encoder is cumulatively decremented, and in each height determination cycle, the actual height of the fork is determined based on the number of pulses obtained by the cumulative decrement and a third preset corresponding relationship; wherein the third preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is greater than the height of the proximity switch and the fork is in a lowered state;

[0047] When the proximity switch is closed, the actual height of the fork is updated according to the height of the proximity switch, and the number of pulses output by the encoder is decremented from zero;

[0048] The actual height of the fork is determined based on the number of pulses obtained by cumulative subtraction and a fourth preset corresponding relationship; wherein the fourth preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is less than the height of the proximity switch and the fork is in a lowered state.

[0049] Optionally, the vehicle control method further includes:

[0050] When the lifting operating lever or the lowering operating lever of the vehicle is activated, if the encoder outputs a pulse signal, it is determined that the encoder is faulty;

[0051] And / or, when the lifting operating lever is started, the speed of the oil pump motor is not zero, and the current of the oil pump motor is less than a preset current, if the encoder has no output, it is determined that the encoder is faulty.

[0052] Optionally, when determining that the fork is in the lifting state according to the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed and before accumulating the number of pulses output by the encoder, the method further includes:

[0053] controlling the lifting of the fork, determining the phase relationship between two pulse signals output by two output channels of an encoder corresponding to the lifting of the fork, and accumulating the number of pulses output by the encoder to determine the first preset corresponding relationship;

[0054] When the proximity switch is closed, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder is continuously accumulated until the torque current of the oil pump motor reaches a preset current, so as to determine the second preset corresponding relationship;

[0055] When it is determined that the fork is in the descending state according to the phase relationship between the two pulse signals output by the two output channels of the encoder, and before the proximity switch is closed, and before the number of pulses output by the encoder is decremented, the method further includes:

[0056] controlling the fork to descend, determining a phase relationship between two pulse signals output by two output channels of an encoder corresponding to the fork's descent, and accumulating and decrementing the number of pulses output by the encoder to determine the third preset corresponding relationship;

[0057] When the proximity switch is closed, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder is continuously decremented to determine the fourth preset corresponding relationship.

[0058] According to another aspect of the present invention, there is provided a vehicle comprising: an n-stage mast, a cargo fork, a lifting operating lever, a controller, and an oil pump motor;

[0059] The cargo fork is located on the nth-level mast, the m+1th-level mast is slidably connected to the mth-level mast, the oil pump motor is used to drive the mast and the cargo fork to move, a first proportional valve is provided in the first oil circuit of the oil pump motor, the controller is respectively connected to the oil pump motor, the lifting operating lever and the first proportional valve, and the controller is used to execute the vehicle control method described in any embodiment of the present invention; wherein n is an integer greater than or equal to 2, and m is a positive integer.

[0060] The technical solution of the embodiment of the present invention is that when the lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of the first proportional valve are determined according to the first stroke of the lifting operating lever. When the actual height of the fork reaches the first buffer range of the current mast, a second target speed of the oil pump motor is determined according to the actual torque current of the oil pump motor corresponding to the current mast, the no-load torque current and the full-load torque current corresponding to the next mast. A third target speed of the oil pump motor is determined according to the first target speed, the second target speed and the actual height of the fork. A final target speed of the oil pump motor is determined according to the first target speed and the third target speed. The operation of the oil pump motor is controlled according to the final target speed so that the actual height of the fork corresponds to the third target speed one-to-one, that is, the third target speed changes linearly with the actual height of the fork. When the third target speed is used as the final target speed of the oil pump motor, the speed of the oil pump motor can be linearly changed, so that the speed of the oil pump motor can change gradually, avoiding sudden changes in the speed of the oil pump motor, thereby achieving a buffering effect, avoiding severe shaking of the mast due to sudden changes in the speed of the oil pump motor, and facilitating improved vehicle stability. When the actual height of the fork reaches the first buffer range of the current mast, a second target opening of the first proportional valve is determined based on the actual height of the fork. A first final target opening of the first proportional valve is determined based on the first target opening and the second target opening. The opening of the first proportional valve is controlled based on the first final target opening. When the actual height of the fork reaches the first buffer range of the current mast, the actual height of the fork corresponds to the second target opening of the first proportional valve, i.e., the second target opening of the first proportional valve varies linearly with the actual height of the fork. The second target opening of the first proportional valve can be determined based on the actual height of the fork. Using the second target opening as the first final target opening allows the opening of the first proportional valve to gradually vary with the actual height of the fork when the actual height of the fork reaches the first buffer range corresponding to the current mast, thereby gradually varying the flow rate of the first oil circuit, and thereby gradually varying the lifting speed of the piston and the speed of the oil pump motor. This avoids sudden changes in the lifting speed of the piston and the speed of the oil pump motor, thereby achieving a buffering effect and preventing severe shaking of the mast caused by sudden changes in the speed of the oil pump motor and the lifting speed of the piston, thereby improving vehicle stability.

[0061] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 is a flow chart of a vehicle control method provided by an embodiment of the present invention;

[0064] Figure 2 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0065] Figure 3 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0066] Figure 4 is a flow chart of another vehicle control method provided by an embodiment of the present invention;

[0067] Figure 5 It is a structural schematic diagram of a vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0068] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0069] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0070] An embodiment of the present invention provides a method for controlling a vehicle, wherein the vehicle includes an n-level mast, a fork, a lifting operating lever, a controller, and an oil pump motor, wherein the fork is located on the n-level mast, the m+1-level mast is slidably connected to the m-level mast, the oil pump motor is used to drive the mast and the fork to move, a first proportional valve is provided on the first oil circuit of the oil pump motor, the controller is respectively connected to the oil pump motor, the lifting operating lever, and the first proportional valve, and the vehicle control method is executed by the controller; wherein n is an integer greater than or equal to 2, and m is a positive integer.

[0071] The vehicle includes n-stage gantries, or n gantries. A cargo fork is fixed to the n-stage gantries. The oil pump motor drives the gantries, which in turn drives the cargo forks. The m+1-stage gantries are slidably connected to the m-stage gantries, achieving a step-by-step connection of the gantries. For example, if n is 3, the first-stage gantries are mounted on the electric forklift, the second-stage gantries are slidably connected to the inside of the first-stage gantries, the third-stage gantries are slidably connected to the inside of the second-stage gantries, and the cargo forks are mounted on the third-stage gantries. The pipeline diameter of the m+1-stage gantries is smaller than that of the m-stage gantries, resulting in a smaller working cross-sectional area of ​​the oil cylinder of the m+1-stage gantries. A controller is connected to the oil pump motor to control its speed. For example, the first oil circuit is the lifting oil circuit, which supplies oil to the oil pump motor when the cargo forks are lifted. The controller controls whether the first proportional valve is open and the degree of opening of the first proportional valve, thereby controlling the flow rate in the first oil circuit. This flow rate is adapted to the speed of the oil pump motor, i.e., different speeds correspond to different flow rates. The lifting lever is the operating lever that controls the lifting of the forks. When the lifting lever is activated, it moves, and the travel of the lifting lever corresponds to the height of the forks.

[0072] Figure 1 This is a flow chart of a vehicle control method provided by an embodiment of the present invention, with reference to Figure 1 , the vehicle control method includes:

[0073] S101. When a lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of a first proportional valve are determined according to a first stroke of the lifting operating lever.

[0074] Specifically, the first stroke of the lifting operating lever corresponds to the first target speed of the oil pump motor. When the controller determines that the lifting operating lever is activated, it can obtain the first stroke of the lifting operating lever. Based on the correspondence between the first stroke and the first target speed and the first stroke, the first target speed of the oil pump motor can be determined. For example, if the range of the first stroke is 0%-100%, when the first stroke is 0%, the corresponding first target speed of the oil pump motor is 0, and when the first stroke is 100%, the corresponding first target speed of the oil pump motor is the maximum speed of the oil pump motor corresponding to the current mast. A linear relationship between the first stroke and the first target speed can be determined, and the first target speed of the oil pump motor can be determined by substituting the determined first stroke of the lifting operating lever into the linear relationship between the first stroke and the first target speed.

[0075] Different masts have different sizes, and the maximum speeds of their corresponding motors vary. For example, the maximum speed of the oil pump motor for a level-one mast is the maximum speed marked at the factory. The maximum speed of the oil pump motor for the m+1th level mast is lower than the maximum speed of the oil pump motor for the mth level mast. The current mast is the mast with the smallest number of masts among the masts that have been raised, with the highest height. For example, n is 3. When all masts are stacked together, that is, when all masts are in their initial state, that is, when all masts are not raised, that is, when all masts are at the same height, the current mast is the primary mast (i.e., the first-level mast). When switching to the secondary mast (i.e., the second-level mast), that is, after the oil pump motor drives the secondary mast to rise, the secondary mast drives the tertiary mast (i.e., the third-level mast) and the forks to rise, the secondary mast and the tertiary mast are at the same height, the mast with the highest height among the raised masts is the secondary mast and the tertiary mast, and the mast with the smallest number of the masts among the highest raised masts is the secondary mast, that is, the current mast is the secondary mast. In some embodiments, for example, the mast height refers to the height of the mast bottom or the height of the mast top, which is not limited here.

[0076] Specifically, the first stroke of the lifting operating lever corresponds to the first target opening of the first proportional valve. The first stroke can be substituted into the preset correspondence between the first stroke and the first target opening, thereby determining the first target opening of the first proportional valve according to the first stroke.

[0077] S102. When the actual height of the forks reaches the first buffer range of the current-level mast, determine the second target speed of the oil pump motor according to the actual torque current of the oil pump motor corresponding to the current-level mast, the no-load torque current and the full-load torque current corresponding to the next-level mast; wherein the current-level mast is the mast with the smallest level among the masts with the highest height among the raised masts.

[0078] Each mast corresponds to a first buffer range, which extends from a first starting height to a first ending height. The first ending height is the height of the forks at a switching point, which is the point at which the mast switches from the current mast to the next mast, i.e., at the switching point, the next mast completes lifting. The first starting height can be less than the first ending height, for example, the first starting height can be 70% of the first ending height, or the first starting height can be 80% of the first ending height, or the first starting height can be 90% of the first ending height, although this embodiment is not limited thereto.

[0079] The next-level gantry is the current-level gantry plus one. For example, if the current-level gantry is the m-th gantry, the next-level gantry is the m+1-th gantry. The maximum height that the next-level gantry can reach is greater than the maximum height that the current-level gantry can reach.

[0080] Specifically, the torque current of the oil pump motor corresponds to its speed. Because the diameters of the pipelines on different masts vary, the flow rates through these pipelines vary, resulting in different speeds and torque currents for the oil pump motor on different masts. When switching to the current mast, the oil pump motor operates based on the actual torque current. When switching from the current mast to the next mast, the oil pump motor operates based on the torque current corresponding to the next mast. The torque current corresponding to the next mast is greater than or equal to the full-load torque current corresponding to the next mast, and less than or equal to the no-load torque current corresponding to the next mast. The no-load torque current corresponding to the next mast is the torque current of the oil pump motor for the next mast when the forks are raised without load. The full-load torque current corresponding to the next mast is the torque current of the oil pump motor for the next mast when the forks are raised with full load. A full-load fork means the forks have reached the rated load indicated at the factory. The full-load torque current and no-load torque current for each mast can be preset.

[0081] Specifically, the second target speed of the oil pump motor is determined according to the actual torque current of the oil pump motor corresponding to the current-level gantry, the no-load torque current and the full-load torque current corresponding to the next-level gantry, so that the second target speed is related to the actual torque current corresponding to the current-level gantry, the no-load torque current corresponding to the next-level gantry and the full-load torque current corresponding to the next-level gantry. The actual torque current of the oil pump motor corresponding to the current-level gantry is related to the load of the fork, so that the second target speed can be determined according to the load of the fork, and the second target speed can be determined in combination with the load change, so that the speed of the oil pump motor can be adjusted under different load conditions to reduce the vibration of the gantry, that is, under different load conditions, the vibration of the gantry can be reduced, and the vehicle can be better controlled.

[0082] S103: When the actual height of the fork reaches the first buffer range of the current mast, determine the second target opening of the first proportional valve according to the actual height of the fork.

[0083] Specifically, the fork is equipped with a wire encoder, and the pulse signal output by the wire encoder can be used to determine the actual height of the fork. When the actual height of the fork reaches the first buffer range of the current mast, the actual height of the fork corresponds to the second target opening of the first proportional valve. That is, when the actual height of the fork reaches the first buffer range of the current mast, the second target opening of the first proportional valve varies linearly with the actual height of the fork. The second target opening of the first proportional valve can then be determined based on the actual height of the fork. Consequently, when the actual height of the fork reaches the first buffer range corresponding to the current mast, the opening of the first proportional valve can gradually vary with the actual height of the fork, thereby gradually varying the flow rate in the first oil circuit. This facilitates a gradual change in the lifting speed of the piston, preventing sudden changes in the piston's lifting speed, thereby achieving a buffering effect and preventing severe mast vibration caused by sudden changes in the piston's lifting speed, thereby improving vehicle stability. Furthermore, the flow rate in the first oil circuit can be made to correspond to the speed of the oil pump motor.

[0084] S104: Determine a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the forks; determine a final target speed of the oil pump motor according to the first target speed and the third target speed; and control the operation of the oil pump motor according to the final target speed.

[0085] Specifically, the third target speed of the oil pump motor is determined according to the first target speed, the second target speed and the actual height of the fork, so that the third target speed is a value between the first target speed and the second target speed, and the third target speed is related to the actual height of the fork. When the operation of the oil pump motor is controlled according to the third target speed, the speed of the oil pump motor can be gradually changed to the second target speed.

[0086] When the actual height of the forks reaches the first buffer range of the current mast, the actual height of the forks corresponds to the third target speed, meaning the third target speed varies linearly with the actual height of the forks. Using the third target speed as the final target speed for the oil pump motor allows the speed of the oil pump motor to vary linearly, gradually changing and avoiding sudden changes in speed. This provides a buffering effect, preventing severe mast vibration caused by sudden changes in speed, and improving vehicle stability.

[0087] The final target speed of the oil pump motor is determined based on the first target speed and the third target speed. For example, the minimum value of the first target speed and the third target speed can be used as the final target speed, so that the final target speed of the oil pump motor can be smaller and closer to the target speed of the oil pump motor corresponding to the next-level mast, thereby ensuring that the speed of the oil pump motor will not suddenly change when the fork height reaches the switching point, avoiding violent shaking of the mast due to sudden changes in the speed of the oil pump motor, and helping to improve the stability of the vehicle.

[0088] S105 : Determine a first final target opening of the first proportional valve according to the first target opening and the second target opening, and control the opening of the first proportional valve according to the first final target opening.

[0089] Among them, if the diameter of the oil circuit corresponding to the next-level gantry is smaller than the diameter of the oil circuit corresponding to the current-level gantry, the opening of the first proportional valve corresponding to the next-level gantry is smaller than the opening of the oil circuit corresponding to the current-level gantry.

[0090] Specifically, the first final target opening of the first proportional valve is determined based on the first target opening and the second target opening. For example, the minimum of the first target opening and the second target opening can be used as the first final target opening. This can make the first final target opening of the oil pump motor smaller and closer to the opening of the first proportional valve corresponding to the next-level mast. The opening of the first proportional valve is related to the speed of the oil pump motor, thereby further ensuring that when the fork height reaches the switching point, the speed of the oil pump motor and the lifting speed of the piston will not suddenly change. This further avoids severe shaking of the mast caused by sudden changes in the speed of the oil pump motor and the lifting speed of the piston, which is beneficial to improving vehicle stability. In this way, the shaking problem of the mast can be effectively avoided when the forks are raised and the mast is switched.

[0091] The technical solution of this embodiment is that when the lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of the first proportional valve are determined based on the first stroke of the lifting operating lever. When the actual height of the fork reaches the first buffer range of the current mast, a second target speed of the oil pump motor is determined based on the actual torque current of the oil pump motor corresponding to the current mast, the no-load torque current, and the full-load torque current corresponding to the next mast. A third target speed of the oil pump motor is determined based on the first target speed, the second target speed, and the actual height of the fork. A final target speed of the oil pump motor is determined based on the first target speed and the third target speed. The operation of the oil pump motor is controlled based on the final target speed, so that the actual height of the fork corresponds to the third target speed one-to-one, that is, the third target speed changes linearly with the actual height of the fork. When the third target speed is used as the final target speed of the oil pump motor, the speed of the oil pump motor can be linearly changed, so that the speed of the oil pump motor can change gradually, avoiding sudden changes in the speed of the oil pump motor, thereby achieving a buffering effect, avoiding severe shaking of the mast due to sudden changes in the speed of the oil pump motor, and improving vehicle stability. When the actual height of the fork reaches the first buffer range of the current mast, a second target opening of the first proportional valve is determined based on the actual height of the fork. A first final target opening of the first proportional valve is determined based on the first target opening and the second target opening. The opening of the first proportional valve is controlled based on the first final target opening. When the actual height of the fork reaches the first buffer range of the current mast, the actual height of the fork corresponds to the second target opening of the first proportional valve, i.e., the second target opening of the first proportional valve varies linearly with the actual height of the fork. The second target opening of the first proportional valve can be determined based on the actual height of the fork. Using the second target opening as the first final target opening allows the opening of the first proportional valve to gradually vary with the actual height of the fork when the actual height of the fork reaches the first buffer range corresponding to the current mast, thereby gradually varying the flow rate of the first oil circuit, and thereby gradually varying the lifting speed of the piston and the speed of the oil pump motor. This avoids sudden changes in the lifting speed of the piston and the speed of the oil pump motor, thereby achieving a buffering effect and preventing severe shaking of the mast caused by sudden changes in the speed of the oil pump motor and the lifting speed of the piston, thereby improving vehicle stability.

[0092] Based on the above technical solution, the vehicle optionally further includes a lowering operating lever, a second proportional valve is provided on the second oil circuit of the oil pump motor, and a controller is connected to the lowering operating lever and the second proportional valve, respectively. The lowering operating lever is an operating lever for controlling the lowering of the cargo fork. When the lowering operating lever is activated, the lowering operating lever moves, and the travel of the lowering operating lever corresponds to the height of the cargo fork. For example, the second oil circuit is a lowering oil circuit, i.e., a pipeline for returning oil when the cargo fork is lowered. The controller can control whether the second proportional valve is open and the opening degree of the second proportional valve, thereby controlling the flow rate in the second oil circuit, and further controlling the lowering speed of the piston rod and the lowering speed of the cargo fork.

[0093] Figure 2 is a flow chart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 2 , the vehicle control method includes:

[0094] S201. When a lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of the first proportional valve are determined according to a first stroke of the lifting operating lever.

[0095] S202. When the actual height of the fork reaches the first buffer range of the current-level gantry, determine the second target speed of the oil pump motor according to the actual torque current of the oil pump motor corresponding to the current-level gantry, the no-load torque current and the full-load torque current corresponding to the next-level gantry; wherein the current-level gantry is the gantry with the smallest level among the gantry with the highest height among the raised gantry.

[0096] S203: When the actual height of the fork reaches the first buffer range of the current mast, determine the second target opening of the first proportional valve according to the actual height of the fork.

[0097] S204: Determine a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the forks; determine a final target speed of the oil pump motor according to the first target speed and the third target speed; and control the operation of the oil pump motor according to the final target speed.

[0098] S205 : Determine a first final target opening of the first proportional valve according to the first target opening and the second target opening, and control the opening of the first proportional valve according to the first final target opening.

[0099] S206 : When the lowering operating lever is activated, determine a third target opening of the second proportional valve according to the second stroke of the lowering operating lever.

[0100] Specifically, the second stroke of the lowering operating lever has a corresponding relationship with the third target opening of the second proportional valve. The second stroke can be substituted into the preset corresponding relationship between the second stroke and the third target opening, thereby determining the third target opening of the second proportional valve according to the second stroke.

[0101] S207: When the actual height of the fork reaches the second buffer range of the current mast, determine a fourth target opening of the second proportional valve according to the actual height of the fork.

[0102] Each mast has a corresponding second buffer range, which extends from the second starting height to the second ending height. The second starting height is the height of the forks at the switching point, which is the point where the next mast switches to the current mast. That is, at this switching point, the next mast completes its descent. For example, if the current mast is the mth mast, the next mast is the m+1th mast. The second ending height is lower than the second starting height.

[0103] Specifically, when the actual height of the fork reaches the second buffer range of the current mast, the actual height of the fork corresponds to the fourth target opening of the second proportional valve. That is, when the actual height of the fork reaches the second buffer range of the current mast, the fourth target opening of the second proportional valve varies linearly with the actual height of the fork. Therefore, the fourth target opening of the second proportional valve can be determined based on the actual height of the fork. Thus, when the actual height of the fork reaches the second buffer range corresponding to the current mast, the opening of the second proportional valve can gradually vary with the actual height of the fork. For example, as the height decreases, the opening of the second proportional valve gradually increases. This allows the flow rate in the second oil circuit to gradually change, allowing the fork's descent speed to gradually change, avoiding sudden changes in the fork's descent speed, thereby achieving a buffering effect and preventing severe shaking of the mast, which is beneficial for improving vehicle stability.

[0104] In this way, after the next-level gantry switches to the current-level gantry (the m+1-level gantry switches to the m-level gantry), the opening of the second proportional valve will not increase instantaneously, thereby ensuring that the lowering speed of the fork will not increase instantaneously, avoiding violent shaking of the gantry when the fork is lowered, which is beneficial to improving the stability of the vehicle.

[0105] It should be noted that when the forks are lowered, they descend based on gravity, rather than the torque current provided by the controller to control the speed of the oil pump motor. Therefore, by controlling the opening of the second proportional valve, the flow rate in the second oil circuit can be controlled, thereby controlling the movement speed of the piston and, consequently, the speed of the forks' descent.

[0106] S208 : Determine a second final target opening of the second proportional valve according to the third target opening and the fourth target opening, and control the opening of the second proportional valve according to the second final target opening.

[0107] Specifically, when the actual height of the forks reaches the second buffer range of the current mast, the second final target opening of the second proportional valve is determined based on the third and fourth target openings. For example, the minimum of the third and fourth target openings can be used as the second final target opening. This can reduce the second final target opening of the second proportional valve and bring it closer to the opening of the second proportional valve corresponding to the next mast, further ensuring that the speed of the forks does not change suddenly when the forks reach the switching point. This effectively prevents mast vibration when the forks are lowered and the masts are switched.

[0108] Based on the above technical solutions, optionally, determining the second target opening of the first proportional valve according to the actual height of the fork includes:

[0109] The second target opening of the first proportional valve is determined according to the actual height of the fork, the first preset opening, the second preset opening, the first starting height and the first ending height of the first buffer range; wherein the first ending height is the height of the switching point where the fork switches from the current level mast to the next level mast, and the first starting height is less than the first ending height.

[0110] Among them, the second preset opening is the preset target opening of the first proportional valve corresponding to the first end height corresponding to the current level mast, and the first preset opening is the preset target opening of the first proportional valve corresponding to the first starting height corresponding to the current level mast.

[0111] For example, the actual height of the fork is , the second preset opening is , the first preset opening is , the first starting height is , the first ending height is , then the second target opening for In this way, the second target opening of the first proportional valve changes linearly with the actual height of the forks. When the actual height of the forks reaches the first buffer range corresponding to the current mast, the opening of the first proportional valve can gradually change with the actual height of the forks, thereby gradually changing the flow rate of the first oil circuit and gradually changing the lifting speed of the piston, thereby avoiding sudden changes in the lifting speed of the piston, thereby achieving a buffering effect and avoiding violent shaking of the mast caused by sudden changes in the lifting speed of the piston, which is beneficial to improving the stability of the vehicle.

[0112] Based on the above technical solutions, optionally, determining a first final target opening of the first proportional valve according to the first target opening and the second target opening includes:

[0113] The minimum value between the first target opening degree and the second target opening degree is used as the first final target opening degree.

[0114] Specifically, the controller can periodically determine the actual height of the forks, and thus periodically determine the second target opening. Each time the second target opening is determined, the first target opening is compared with the second target opening. If the first target opening is greater than the second target opening, the second target opening is used as the first final target opening. If the first target opening is less than the second target opening, the first target opening is used as the first final target opening. If the first target opening is equal to the second target opening, either the first target opening or the second target opening can be used as the first final target opening. This allows the first final target opening of the oil pump motor to be smaller, closer to the opening of the first proportional valve corresponding to the next mast. This further ensures that the oil pump motor speed and piston lifting speed do not abruptly change when the forks reach the switching point. This further prevents severe mast vibration caused by sudden changes in the oil pump motor speed and piston lifting speed, thereby improving vehicle stability. This effectively prevents mast vibration during fork lifting and mast switching.

[0115] On the basis of the above technical solutions, Figure 3 This is a flow chart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 3 , the vehicle control method includes:

[0116] S301. When a lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of the first proportional valve are determined according to a first stroke of the lifting operating lever.

[0117] S302, determining whether the actual height of the fork is less than the first starting height of the first buffer range of the current mast, if so, executing step S303; if not, executing step S304.

[0118] S303 : Control the opening of the first proportional valve according to the first target opening, and control the operation of the oil pump motor according to the first target speed.

[0119] Specifically, when the actual height of the fork is greater than the first end height of the first buffer range of the previous mast and is less than the first starting height of the first buffer range of the current mast, the opening of the first proportional valve is controlled according to the first target opening, and the operation of the oil pump motor is controlled according to the first target speed, so that when the actual height of the fork is less than the first starting height of the first buffer range of the current mast, the speed of the oil pump motor can be higher to meet the first target speed and first target opening corresponding to the lifting operating lever, thereby avoiding the fork rising too slowly.

[0120] S304: Determine whether the actual height of the fork is greater than the first end height of the first buffer range of the current mast. If not, execute step S305; if so, execute step S309.

[0121] S305. Determine the second target speed of the oil pump motor based on the actual torque current of the oil pump motor corresponding to the current-level gantry, the no-load torque current and the full-load torque current corresponding to the next-level gantry; wherein, the current-level gantry is the gantry with the smallest number of levels among the gantry with the highest height among the raised gantry.

[0122] S306: When the actual height of the fork reaches the first buffer range of the current mast, determine the second target opening of the first proportional valve according to the actual height of the fork.

[0123] S307: Determine a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the forks; determine a final target speed of the oil pump motor according to the first target speed and the third target speed; and control the operation of the oil pump motor according to the final target speed.

[0124] S308 : Determine a first final target opening of the first proportional valve according to the first target opening and the second target opening, and control the opening of the first proportional valve according to the first final target opening.

[0125] S309. When the actual height of the fork is greater than the first end height of the first buffer range of the current mast and less than the first starting height of the first buffer range corresponding to the next mast, the opening of the first proportional valve is controlled according to the minimum value between the second preset opening and the first target opening, and the operation of the oil pump motor is controlled according to the minimum value between the first target speed and the second target speed.

[0126] Specifically, the diameter of the oil circuit of the next-level mast is smaller than that of the oil circuit of the current-level mast. The second preset opening is the target opening of the first proportional valve corresponding to the first end height of the current-level mast. When the actual height of the forks is greater than the first end height of the first buffer range of the current-level mast and less than the first starting height of the first buffer range of the next-level mast, the opening of the first proportional valve is controlled based on the minimum of the second preset opening and the first target opening, so that after switching to the next-level mast, the opening of the first proportional valve is smaller, consistent with the smaller diameter oil circuit. Furthermore, the operation of the oil pump motor is controlled based on the minimum of the first target speed and the second target speed, so that the speed of the oil pump motor is adapted to the opening of the first proportional valve, that is, the speed of the oil pump motor is adapted to the flow rate of the oil circuit.

[0127] Based on the above technical solutions, optionally, determining a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the forks, and determining a final target speed of the oil pump motor according to the first target speed and the third target speed includes:

[0128] Step a1: Determine a first ratio of a difference between an actual height of the fork and a first starting height of a first buffer range of a current mast, and a difference between a first ending height and a first starting height of the first buffer range of the current mast.

[0129] For example, the actual height of the fork is , when the first starting height of the first buffer range of the current mast is , when the first end height of the first buffer range of the current mast is , then the difference between the actual height of the fork and the first starting height of the first buffer range of the current mast is , when the difference between the first end height and the first starting height of the first buffer range of the current mast is , then the first ratio is .

[0130] Step a2: Determine a first product of a difference between the second target speed and the first target speed and the first ratio.

[0131] For example, the first target speed is , the second target speed is , then the difference between the second target speed and the first target speed is , then the first product is .

[0132] Step a3: taking the sum of the first target speed and the first product as the third target speed, and taking the minimum value between the first target speed and the third target speed as the final target speed.

[0133] Exemplarily, the third target speed for , so that within the first buffer range corresponding to the current-level mast, the third target speed changes linearly with the actual height of the forks. When the third target speed is used as the final target speed of the oil pump motor, the speed of the oil pump motor can be changed linearly, so that the speed of the oil pump motor can change gradually, avoiding sudden changes in the speed of the oil pump motor, thereby achieving a buffering effect. Taking the minimum value of the first target speed and the third target speed as the final target speed, the final target speed of the oil pump motor can be made smaller, closer to the target speed of the oil pump motor corresponding to the next-level mast, thereby further ensuring that the speed of the oil pump motor will not suddenly change when the forks reach the switching point, further avoiding violent shaking of the mast caused by sudden changes in the speed of the oil pump motor, and helping to improve the stability of the vehicle.

[0134] On the basis of the above technical solutions, optionally, determining the second target speed of the oil pump motor according to the actual torque current of the oil pump motor corresponding to the current-stage gantry, the no-load torque current and the full-load torque current corresponding to the next-stage gantry includes:

[0135] Step b1: Determine a second ratio of a difference between the actual torque current and the full-load torque current to a difference between the no-load torque current and the full-load torque current.

[0136] The actual torque current of the oil pump motor corresponding to the current mast is the actual torque current of the oil pump motor before the switch. The difference between the actual torque current and the full-load torque current is the actual torque current of the oil pump motor corresponding to the current mast minus the torque current of the oil pump motor corresponding to the next mast when the oil pump motor is fully loaded. The difference between the no-load torque current and the full-load torque current is the torque current of the oil pump motor corresponding to the next mast when the oil pump motor is no-load minus the torque current of the oil pump motor corresponding to the next mast when the oil pump motor is fully loaded.

[0137] For example, the actual torque current of the oil pump motor corresponding to the current mast is , the full load torque current of the oil pump motor corresponding to the next level gantry , the no-load torque current corresponding to the next-level gantry is , then the second ratio is .

[0138] When the actual torque current of the oil pump motor corresponding to the current-stage mast is related to the load of the fork, the proportion of the torque current corresponding to the load of the fork can be determined by determining the second ratio.

[0139] Step b2: Determine a second product of a difference between the second preset speed and the first preset speed and the second ratio.

[0140] Specifically, the second preset speed is a preset target speed of the oil pump motor corresponding to the next mast when the fork is lifted with no load. The first preset speed is a preset target speed of the oil pump motor corresponding to the next mast when the fork is lifted with full load.

[0141] For example, the first preset speed is , the second preset speed is , the difference between the second preset speed and the first preset speed is , then the second product is .

[0142] Step b3: taking the sum of the first preset speed and the second product as the second target speed.

[0143] For example, the second target speed is ,but In this way, the second target speed can be determined according to the load of the fork, and the second target speed can be determined in combination with the load change, so that the speed of the oil pump motor can be adjusted under different load conditions to reduce the vibration of the mast. That is, the vibration of the mast can be reduced under different load conditions, and the vehicle can be better controlled.

[0144] Based on the above technical solutions, optionally, determining the fourth target opening of the second proportional valve according to the actual height of the fork includes:

[0145] Step c1, determine a third ratio of the difference between the second starting height of the second buffer range of the current level gantry and the actual height of the fork, and the difference between the second starting height and the second ending height of the second buffer range of the current level gantry; wherein the second starting height is the height of the switching point from the next level gantry to the current level gantry, and the second ending height is less than the second starting height.

[0146] When the fork is lowered, the next-level gantry is switched to the current-level gantry. For example, if the current-level gantry is the m-th-level gantry, the next-level gantry is the m+1-th-level gantry.

[0147] For example, the actual height of the fork is , when the second starting height of the second buffer range of the current mast is , when the second end height of the second buffer range of the current mast is , then the difference between the second starting height of the second buffer range of the current mast and the actual height of the fork is The difference between the second starting height and the second ending height of the second buffer range of the current mast is , then the second ratio is .

[0148] Step c2: Determine a third product of a difference between the fourth preset opening and the third preset opening and the third ratio.

[0149] Among them, the third preset opening is the preset target opening of the second proportional valve corresponding to the second starting height of the second buffer range corresponding to the current level gantry, and the fourth preset opening is the preset target opening of the second proportional valve corresponding to the second ending height of the second buffer range corresponding to the current level gantry.

[0150] For example, the third preset opening is , the fourth preset opening is , then the third product is .

[0151] Step c3: taking the sum of the third preset opening and the third product as the fourth target opening.

[0152] For example, the fourth target opening is ,but In this way, when the actual height of the forks reaches the second buffer range of the current mast, the fourth target opening of the second proportional valve changes linearly with the actual height of the forks, thereby causing the flow rate of the second oil circuit to change gradually, and the speed of the oil pump motor to change gradually, avoiding sudden changes in the speed of the oil pump motor, thereby achieving a buffering effect.

[0153] Optionally, determining a second final target opening of the second proportional valve according to the third target opening and the fourth target opening includes:

[0154] The minimum value between the third target opening degree and the fourth target opening degree is set as the second final target opening degree.

[0155] Specifically, the controller can periodically determine the actual height of the fork, and thus periodically determine the fourth target opening. After determining the fourth target opening each time, the minimum value of the third target opening and the fourth target opening is used as the second final target opening. The second final target opening of the oil pump motor can be made smaller and closer to the opening of the second proportional valve corresponding to the next-level mast, thereby further ensuring that the speed of the oil pump motor will not change suddenly when the fork height reaches the switching point.

[0156] On the basis of the above technical solutions, Figure 4 This is a flow chart of another vehicle control method provided by an embodiment of the present invention. Optionally, refer to Figure 4 , the vehicle control method includes:

[0157] S401. When the lifting operating lever is activated, determine a first target speed of the oil pump motor and a first target opening of the first proportional valve according to a first stroke of the lifting operating lever.

[0158] S402. When the actual height of the fork reaches the first buffer range of the current-level gantry, the second target speed of the oil pump motor is determined according to the actual torque current of the oil pump motor corresponding to the current-level gantry, the no-load torque current and the full-load torque current corresponding to the next-level gantry; wherein the current-level gantry is the gantry with the smallest level among the gantry with the highest height among the raised gantry.

[0159] S403: When the actual height of the fork reaches the first buffer range of the current mast, determine the second target opening of the first proportional valve according to the actual height of the fork.

[0160] S404: Determine a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the forks; determine a final target speed of the oil pump motor according to the first target speed and the third target speed; and control the operation of the oil pump motor according to the final target speed.

[0161] S405 : Determine a first final target opening of the first proportional valve according to the first target opening and the second target opening, and control the opening of the first proportional valve according to the first final target opening.

[0162] S406: When the lowering operating lever is activated, determine a third target opening of the second proportional valve according to the second stroke of the lowering operating lever.

[0163] S407: Determine whether the actual height of the fork is greater than the second starting height of the second buffer range of the current mast. If so, execute step S408; if not, execute step S409.

[0164] S408: Control the opening of the second proportional valve according to the third target opening.

[0165] Specifically, when the forks have not yet descended to the second buffer range under the current mast, the opening of the second proportional valve is controlled based on the third target opening corresponding to the stroke of the lowering lever, thereby adapting the lowering speed of the forks to the stroke of the lowering lever. For example, the greater the stroke of the lowering lever, the greater the opening of the second proportional valve, and the greater the lowering speed of the forks. Thus, the opening of the second proportional valve is controlled based on the third target opening, ensuring that the forks do not descend too slowly.

[0166] S409: Determine whether the actual height of the fork is less than the second end height of the second buffer range of the current mast. If not, execute step S410; if so, execute step S412.

[0167] S410: When the actual height of the fork reaches the second buffer range of the current mast, determine a fourth target opening of the second proportional valve according to the actual height of the fork.

[0168] S411 : Determine a second final target opening of the second proportional valve according to the third target opening and the fourth target opening, and control the opening of the second proportional valve according to the second final target opening.

[0169] S412. When the actual height of the fork is less than the second end height of the second buffer range of the current mast, the opening of the second proportional valve is controlled according to the minimum value between the fourth preset opening and the third target opening; wherein the fourth preset opening is the target opening of the second proportional valve corresponding to the second end height of the second buffer range corresponding to the current mast.

[0170] Specifically, under the current level mast, when the actual height of the fork is less than the second end height of the second buffer range of the current level mast, it indicates that the mast switching is completed, and the opening of the second proportional valve is controlled according to the minimum value of the fourth preset opening and the third target opening, so that the opening of the second proportional valve is smaller, thereby avoiding a large increase in the opening of the second proportional valve, and further avoiding a large increase in the descending speed of the fork, thereby ensuring the stable descent of the fork.

[0171] Based on the above technical solutions, the following describes a method for determining the actual height of the fork, but this does not limit the present application.

[0172] Optionally, the forks are equipped with an encoder with two output channels connected to a controller, and a proximity switch is provided on the mast. The encoder can be a wire-pull encoder, with both output channels capable of outputting pulse signals to the controller. The mast is equipped with a proximity switch at a known height, which closes when the forks reach the switch.

[0173] Optionally, the vehicle control method further includes:

[0174] Step d1: When the fork is determined to be in the raised state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, the number of pulses output by the encoder is accumulated, and in each height determination cycle, the actual height of the fork is determined based on the accumulated number of pulses and a first preset corresponding relationship; wherein the first preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is less than the height of the proximity switch and the fork is in the raised state.

[0175] The phase relationship between the two pulse signals output by the two output channels of the encoder corresponds to the state of the fork. For example, the two output channels include a first output channel and a second output channel, and the two pulse signals include a first pulse signal and a second pulse signal. The first output channel outputs the first pulse signal, and the second output channel outputs the second pulse signal. For example, when the phase of the first pulse signal leads the phase of the second pulse signal, the fork is in the raised state; when the phase of the first pulse signal is delayed behind the phase of the second pulse signal, the fork is in the lowered state. Alternatively, when the phase of the first pulse signal leads the phase of the second pulse signal, the fork is in the lowered state; when the phase of the first pulse signal is delayed behind the phase of the second pulse signal, the fork is in the raised state. This is not limited in this embodiment.

[0176] The controller may periodically determine the actual height of the forks, that is, determine the actual height of the forks once in each height determination cycle.

[0177] Specifically, when determining that the forks are in the raised state, before the proximity switch closes, that is, when the forks have not yet reached the height of the proximity switch, i.e., when the forks are less than the height of the proximity switch, the number of pulses output by the encoder is accumulated from zero. Specifically, the number of pulses is incremented by one for each valid level (high or low) detected. This accumulation can be performed on either the first or second output channel, although this is not limited herein. During each height determination cycle, the actual height of the forks is determined based on the accumulated number of pulses and a first preset correspondence. This allows the actual height of the forks to be determined when the height is less than the height of the proximity switch, facilitating the determination of the third target speed of the oil pump motor, the second target opening of the first proportional valve, and the fourth target opening of the second proportional valve based on the actual height of the forks.

[0178] Step d2: When the proximity switch is closed, the actual height of the fork is updated according to the height of the proximity switch, and the number of pulses output by the encoder is accumulated again from zero.

[0179] Specifically, when the proximity switch is closed, it indicates that the actual height of the fork reaches the height of the proximity switch. The actual height of the fork is updated according to the height of the proximity switch, making the determined actual height more accurate, realizing the calibration of the actual height of the fork, and avoiding the accumulation of errors caused by the accumulation of pulse numbers.

[0180] Re-accumulate the number of pulses output by the encoder from zero, that is, restart the accumulation of pulses to avoid the continuous accumulation of pulses, which will cause the actual height of the fork to have an increasing error.

[0181] Step d3: Determine the actual height of the fork based on the accumulated number of pulses and a second preset corresponding relationship; wherein the second preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is greater than the height of the proximity switch and the fork is in the raised state.

[0182] Specifically, after the fork continues to rise from the proximity switch, after restarting to accumulate the number of pulses, in each height determination cycle, the actual height of the fork can be determined according to the accumulated number of pulses and the second preset corresponding relationship.

[0183] Step d4: When the fork is determined to be in the lowered state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, the number of pulses output by the encoder is decremented, and in each height determination cycle, the actual height of the fork is determined based on the number of pulses obtained by the decrement and a third preset corresponding relationship; wherein the third preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is greater than the height of the proximity switch and the fork is in the lowered state.

[0184] Specifically, when determining that the forks are in the lowered state, before the proximity switch is closed, that is, when the height of the forks is higher than the height of the proximity switch, the number of pulses output by the encoder is subtracted from the number of pulses after the last accumulation. Specifically, the number of pulses is reduced by one each time a valid level is detected. The number of pulses output by the first output channel can be subtracted, or the number of pulses output by the second output channel can be subtracted, without limitation. In each height determination cycle, the actual height of the forks when the height is higher than the height of the proximity switch is determined based on the number of pulses obtained by the subtraction and a third preset correspondence.

[0185] Step d5: When the proximity switch is closed, the actual height of the fork is updated according to the height of the proximity switch, and the number of pulses output by the encoder is decremented from zero.

[0186] Specifically, when the proximity switch is closed, it indicates that the actual height of the fork reaches the height of the proximity switch. The actual height of the fork is updated according to the height of the proximity switch, making the determined actual height more accurate, realizing the calibration of the actual height of the fork, and avoiding the error accumulation caused by the cumulative decrease of the number of pulses.

[0187] Step d6: Determine the actual height of the fork based on the number of pulses obtained by cumulative subtraction and a fourth preset corresponding relationship; wherein the fourth preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is less than the height of the proximity switch and the fork is in a lowered state.

[0188] Specifically, starting from the height of the proximity switch, the number of pulses is decremented from zero. In each height determination cycle, the actual height of the fork can be determined based on the decremented number of pulses and a fourth preset corresponding relationship.

[0189] On the basis of the above technical solutions, in order to accurately determine the actual height of the fork, it is necessary to perform fault detection on the encoder. The fault detection method is described below, but it does not limit the present application.

[0190] Optionally, the vehicle control method further includes:

[0191] When the vehicle's lifting or lowering operating lever is activated, if the encoder outputs a pulse signal, it is determined that the encoder is faulty;

[0192] And / or, when the lifting operating lever is activated, the speed of the oil pump motor is not zero, and the current of the oil pump motor is less than a preset current, if the encoder has no output, it is determined that the encoder is faulty.

[0193] Specifically, when the vehicle's lifting operating lever or lowering operating lever is started, if the encoder outputs a pulse signal, it is determined that the channel in which the encoder does not output the pulse signal is faulty, that is, it is determined that the channel in which the pulse signal is not output is disconnected, that is, it is determined that the encoder is faulty, and a first prompt message can be issued to facilitate timely maintenance.

[0194] The preset current is the torque current of the oil pump motor when the forks reach their maximum height. The forks reach their maximum height when all masts are fully raised. When the forks reach their maximum height, the oil pump motor is unloaded, causing the torque current to accumulate and increase, reaching the maximum preset current.

[0195] When the lifting operating lever is started, the speed of the oil pump motor is not zero, and the current of the oil pump motor is less than the preset current, that is, when the fork is in the lifting process and has not reached the maximum height, if the encoder has no output, that is, both output channels of the encoder do not output pulse signals, it is determined that both channels of the encoder are broken, determining that the encoder is faulty, and a second prompt message can be issued to facilitate timely maintenance.

[0196] On the basis of the above technical solutions, the following describes the method for determining the first preset correspondence relationship, the second preset correspondence relationship, the third preset correspondence relationship, and the fourth preset correspondence relationship, but this does not limit the present application.

[0197] Optionally, when determining that the fork is in the lifting state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed and before accumulating the number of pulses output by the encoder, the method further includes:

[0198] Step e1, controlling the lifting of the fork, determining the phase relationship between the two pulse signals output by the two output channels of the corresponding encoder when the fork is lifted, and accumulating the number of pulses output by the encoder to determine a first preset corresponding relationship.

[0199] Specifically, when the vehicle is not in use, the controller controls the forks to lift unloaded from their initial (lowest) position. This means that all masts are raised starting from the first mast level. During the lifting process, the controller captures two pulse signals from the encoder's two output channels and stores the phase relationship between the two pulse signals. This stores the phase relationship between the two pulse signals corresponding to the fork lift. Furthermore, the number of pulses output by the encoder is accumulated starting from zero. Based on the accumulated pulse count and the measured fork height, the corresponding relationship between the pulse count and the actual fork height is determined, which becomes the first preset relationship.

[0200] Step e2: When the proximity switch is closed, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder is continuously accumulated until the torque current of the oil pump motor reaches a preset current, so as to determine a second preset corresponding relationship.

[0201] Specifically, when the proximity switch is closed, that is, the actual height of the fork is raised to the height of the proximity switch, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder continues to be accumulated. According to the accumulated number of pulses and the measured height of the fork, the corresponding relationship between the number of pulses and the actual height of the fork is determined, which is the second preset corresponding relationship.

[0202] Optionally, when it is determined that the fork is in the descending state according to the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, before the number of pulses output by the encoder is decremented, the method further includes:

[0203] Step f1: Control the fork to descend, determine the phase change relationship of the encoder pulse number corresponding to the fork descending, and decrement the pulse number output by the encoder to determine a third preset corresponding relationship.

[0204] Specifically, when the vehicle is not in use, the controller controls the forks to descend from their highest position, i.e., all masts descend starting from the nth mast. During this descent, the controller obtains two pulse signals output by the encoder's two output channels and stores the phase relationship between the two pulse signals. This stores the phase relationship between the two pulse signals corresponding to the fork's descent. Furthermore, the number of pulses output by the encoder is decremented from the last accumulated value. Based on the decremented pulse number and the measured fork height, the corresponding relationship between the pulse number and the actual fork height is determined, which becomes the third preset correspondence.

[0205] Step f2: when the proximity switch is closed, clear the number of pulses output by the encoder and continue to decrement the number of pulses output by the encoder to determine a fourth preset corresponding relationship.

[0206] Specifically, when the proximity switch is closed, that is, the actual height of the fork is raised to the height of the proximity switch, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder continues to be decremented. According to the decremented number of pulses and the measured height of the fork, the corresponding relationship between the number of pulses and the actual height of the fork is determined, which is the fourth preset corresponding relationship.

[0207] An embodiment of the present invention further provides a vehicle, Figure 5 This is a schematic diagram of the structure of a vehicle provided by an embodiment of the present invention, with reference to Figure 5 , the vehicle includes: an n-level mast 501, a cargo fork 502, a lifting operating lever 503, a controller 504 and an oil pump motor 505;

[0208] The fork 502 is located on the n-th level gantry 501, the m+1-th level gantry is slidably connected to the m-th level gantry, the oil pump motor 505 is used to drive the gantry 501 and the fork 502 to move, and a first proportional valve 506 is provided on the first oil circuit of the oil pump motor 505. The controller 504 is respectively connected to the oil pump motor 505, the lifting operating lever 503 and the first proportional valve 506. The controller 504 is used to execute the vehicle control method provided by any embodiment of the present invention; wherein n is an integer greater than or equal to 2, and m is a positive integer.

[0209] like Figure 5 As shown, for example, if n is 3, the first-level gantry 501 (1) can be connected to the front of the vehicle, the second-level gantry 501 (2) is slidably connected to the inner side of the first-level gantry 501 (1), and the third-level gantry 501 (3) is slidably connected to the inner side of the second-level gantry 501 (2).

[0210] The controller 504 is used to execute the vehicle control method provided by any embodiment of the present invention. Therefore, the controller of this embodiment has the same beneficial effects as the vehicle control method provided by any embodiment of the present invention, which will not be repeated here.

[0211] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0212] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A vehicle control method, characterized in that: The vehicle includes an n-level mast, a cargo fork, a lifting operating lever, a controller, and an oil pump motor, wherein the cargo fork is located on the n-level mast, the m+1-level mast is slidably connected to the m-level mast, the oil pump motor is used to drive the mast and the cargo fork to move, a first proportional valve is provided in a first oil circuit of the oil pump motor, the controller is respectively connected to the oil pump motor, the lifting operating lever, and the first proportional valve, and the vehicle control method is executed by the controller; wherein n is an integer greater than or equal to 2, and m is a positive integer; The vehicle control method includes: When the lifting operating lever is activated, a first target speed of the oil pump motor and a first target opening of the first proportional valve are determined according to a first stroke of the lifting operating lever; When the actual height of the forks reaches the first buffer range of the current mast, the second target speed of the oil pump motor is determined based on the actual torque current of the oil pump motor corresponding to the current mast, and the no-load torque current and full-load torque current corresponding to the next mast; wherein the current mast is the mast with the smallest number of the masts with the highest height among the raised masts; When the actual height of the fork reaches the first buffer range of the current mast, determining the second target opening of the first proportional valve according to the actual height of the fork; determining a third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the fork, determining a final target speed of the oil pump motor according to the first target speed and the third target speed, and controlling the operation of the oil pump motor according to the final target speed; A first final target opening of the first proportional valve is determined according to the first target opening and the second target opening, and the opening of the first proportional valve is controlled according to the first final target opening.

2. The method according to claim 1, characterized in that The vehicle further includes a descending operating rod, a second proportional valve is provided on the second oil circuit of the oil pump motor, and the controller is connected to the descending operating rod and the second proportional valve respectively; The vehicle control method further includes: When the lowering operating lever is activated, determining a third target opening of the second proportional valve according to a second stroke of the lowering operating lever; When the actual height of the fork reaches the second buffer range of the current mast, determining a fourth target opening of the second proportional valve according to the actual height of the fork; A second final target opening of the second proportional valve is determined according to the third target opening and the fourth target opening, and the opening of the second proportional valve is controlled according to the second final target opening.

3. The method according to claim 1, characterized in that Determining the second target opening of the first proportional valve according to the actual height of the fork includes: The second target opening of the first proportional valve is determined based on the actual height of the fork, the first preset opening, the second preset opening, the first starting height and the first ending height of the first buffer range; wherein the first ending height is the height of the switching point where the fork switches from the current level mast to the next level mast, and the first starting height is less than the first ending height.

4. The method according to any one of claims 1 to 3, characterized in that Determining a first final target opening of the first proportional valve according to the first target opening and the second target opening includes: The minimum value between the first target opening degree and the second target opening degree is used as the first final target opening degree.

5. The method according to claim 3, characterized in that When the lifting operating lever is activated, the vehicle control method further includes: When the actual height of the fork is less than the first starting height of the first buffer range of the current mast, the opening of the first proportional valve is controlled according to the first target opening, and the operation of the oil pump motor is controlled according to the first target speed; When the actual height of the fork is greater than the first end height of the first buffer range of the current level mast and is less than the first starting height of the first buffer range corresponding to the next level mast, the opening of the first proportional valve is controlled according to the minimum value of the second preset opening and the first target opening, and the operation of the oil pump motor is controlled according to the minimum value of the first target speed and the second target speed.

6. The method according to any one of claims 1 to 3, characterized in that The determining of the third target speed of the oil pump motor according to the first target speed, the second target speed, and the actual height of the fork, and determining the final target speed of the oil pump motor according to the first target speed and the third target speed includes: Determine a first ratio of a difference between an actual height of the fork and a first starting height of a first buffer range of a current mast, and a difference between a first ending height of the first buffer range of the current mast and the first starting height; determining a first product of a difference between the second target speed and the first target speed and the first ratio; The sum of the first target speed and the first product is used as a third target speed, and the minimum value between the first target speed and the third target speed is used as the final target speed.

7. The method according to any one of claims 1 to 3, characterized in that The determining the second target speed of the oil pump motor according to the actual torque current of the oil pump motor corresponding to the current-stage mast, the no-load torque current and the full-load torque current corresponding to the next-stage mast includes: determining a second ratio of a difference between the actual torque current and the full-load torque current to a difference between the no-load torque current and the full-load torque current; determining a second product of a difference between a second preset speed and the first preset speed and the second ratio; The sum of the first preset rotational speed and the second product is used as the second target rotational speed.

8. The method according to claim 2, characterized in that Determining the fourth target opening of the second proportional valve according to the actual height of the fork includes: Determining a third ratio of a difference between a second starting height of a second buffer range of a current-stage mast and the actual height of the fork, and a difference between the second starting height and a second ending height of the second buffer range of the current-stage mast; wherein the second starting height is the height of a switching point from a next-stage mast to the current-stage mast, and the second ending height is less than the second starting height; determining a third product of a difference between a fourth preset opening and a third preset opening and the third ratio; taking the sum of the third preset opening and the third product as the fourth target opening; Determining the second final target opening of the second proportional valve according to the third target opening and the fourth target opening includes: The minimum value between the third target opening degree and the fourth target opening degree is set as the second final target opening degree.

9. The method according to claim 2, characterized in that When the lowering operating lever is activated, the vehicle control method further includes: When the actual height of the fork is greater than the second starting height of the second buffer range of the current mast, controlling the opening of the second proportional valve according to the third target opening; When the actual height of the fork is less than the second end height of the second buffer range of the current level mast, the opening of the second proportional valve is controlled according to the minimum value of the fourth preset opening and the third target opening; wherein the fourth preset opening is the target opening of the second proportional valve corresponding to the second end height of the second buffer range corresponding to the current level mast.

10. The method according to any one of claims 1 to 3, characterized in that The fork is provided with an encoder, the encoder includes two output channels, the output channels are connected to the controller, and the mast is provided with a proximity switch; The vehicle control method further includes: When the fork is determined to be in the raised state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, the number of pulses output by the encoder is accumulated, and in each height determination cycle, the actual height of the fork is determined based on the accumulated number of pulses and a first preset correspondence; wherein the first preset correspondence is a correspondence between the number of pulses and the actual height when the height of the fork is less than the height of the proximity switch and the fork is in the raised state; When the proximity switch is closed, the actual height of the fork is updated according to the height of the proximity switch, and the number of pulses output by the encoder is accumulated again from zero; determining the actual height of the fork according to the accumulated number of pulses and a second preset correspondence; wherein the second preset correspondence is a correspondence between the number of pulses and the actual height when the height of the fork is greater than the height of the proximity switch and the fork is in a raised state; When the fork is determined to be in a lowered state based on the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed, the number of pulses output by the encoder is cumulatively decremented, and in each height determination cycle, the actual height of the fork is determined based on the number of pulses obtained by the cumulative decrement and a third preset corresponding relationship; wherein the third preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is greater than the height of the proximity switch and the fork is in a lowered state; When the proximity switch is closed, the actual height of the fork is updated according to the height of the proximity switch, and the number of pulses output by the encoder is decremented from zero; The actual height of the fork is determined based on the number of pulses obtained by cumulative subtraction and a fourth preset corresponding relationship; wherein the fourth preset corresponding relationship is the corresponding relationship between the number of pulses and the actual height when the height of the fork is less than the height of the proximity switch and the fork is in a lowered state.

11. The method according to claim 10, characterized in that The vehicle control method further includes: When the lifting operating lever or the lowering operating lever of the vehicle is activated, if the encoder outputs a pulse signal, it is determined that the encoder is faulty; And / or, when the lifting operating lever is started, the speed of the oil pump motor is not zero, and the current of the oil pump motor is less than a preset current, if the encoder has no output, it is determined that the encoder is faulty.

12. The method according to claim 10, characterized in that When the fork is determined to be in the lifting state according to the phase relationship between the two pulse signals output by the two output channels of the encoder, before the proximity switch is closed and before the number of pulses output by the encoder is accumulated, the method further includes: controlling the lifting of the fork, determining the phase relationship between two pulse signals output by two output channels of an encoder corresponding to the lifting of the fork, and accumulating the number of pulses output by the encoder to determine the first preset corresponding relationship; When the proximity switch is closed, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder is continuously accumulated until the torque current of the oil pump motor reaches a preset current, so as to determine the second preset corresponding relationship; When it is determined that the fork is in the descending state according to the phase relationship between the two pulse signals output by the two output channels of the encoder, and before the proximity switch is closed, and before the number of pulses output by the encoder is decremented, the method further includes: controlling the fork to descend, determining a phase relationship between two pulse signals output by two output channels of an encoder corresponding to the fork's descent, and accumulating and decrementing the number of pulses output by the encoder to determine the third preset corresponding relationship; When the proximity switch is closed, the number of pulses output by the encoder is cleared, and the number of pulses output by the encoder is continuously decremented to determine the fourth preset corresponding relationship.

13. A vehicle, characterized in that: include: N-level mast, forks, lifting operating lever, controller and oil pump motor; The fork is located on the nth-level gantry, the m+1th-level gantry is slidably connected to the mth-level gantry, the oil pump motor is used to drive the gantry and the fork to move, and a first proportional valve is provided in the first oil circuit of the oil pump motor. The controller is respectively connected to the oil pump motor, the lifting operating lever and the first proportional valve, and the controller is used to execute the vehicle control method described in any one of claims 1 to 12; wherein n is an integer greater than or equal to 2, and m is a positive integer.

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