A method and device for controlling the lifting of a forklift fork, a forklift and a medium

Abstract

The present invention relates to the technical field of automatic control of forklifts, and discloses a lifting control method, device, forklift and medium for a forklift fork, wherein the method comprises: obtaining the current cargo weight; calculating the upper limit of the lifting height according to the current cargo weight; collecting the oil inlet and outlet volume of the forklift hydraulic cylinder, and calculating the lifting height of the fork according to the oil inlet and outlet volume; comparing the lifting height of the fork with the upper limit of the lifting height, and prohibiting the fork from continuing to rise when the lifting height of the fork increases to be equal to the upper limit of the lifting height. The present invention derives the lifting height of the fork through the oil inlet and outlet volume parameters of the forklift cylinder, thereby avoiding the interference of external auxiliary components on the sensor scanning signal, thereby realizing the fork height detection without adding external sensors, improving the detection accuracy, and reducing the production cost of the forklift.

Description

Technical Field

[0001] The present invention relates to the technical field of forklift automatic control, and in particular to a forklift fork lifting control method, device, forklift and medium. Background Art

[0002] At present, forklifts are widely used in all walks of life. The lifting height of forklifts is relatively high. However, when the lifting is overloaded, the center of gravity of the vehicle is unstable and the forklift may tip over, thus endangering personal safety. Therefore, how to flexibly control the lifting height of the forklift is the top priority to ensure the safe operation of the forklift. At present, in order to prevent lifting overload and reduce the possibility of tipping, the maximum lifting height of the fork is limited when the cargo is too heavy to solve the above problem. However, the lifting height of the fork is often measured by sensors, and there are many auxiliary parts such as gears and chains near the fork of the forklift, resulting in low accuracy of the height value measured by the sensor, which is inaccurate when judging whether the lifting height of the fork has reached the limit value. Summary of the invention

[0003] In view of this, the present invention provides a lifting control method and device for a forklift fork, a forklift and a medium to solve the problem of lifting overload.

[0004] In a first aspect, the present invention provides a lifting control method for a forklift fork, the method comprising: obtaining the current cargo weight; calculating the upper limit of the lifting height according to the current cargo weight; collecting the inlet and outlet oil volumes of the forklift hydraulic cylinder, and calculating the lifting height of the fork according to the inlet and outlet oil volumes; comparing the lifting height of the fork with the upper limit of the lifting height, and prohibiting the fork from continuing to rise when the lifting height of the fork increases to be equal to the upper limit of the lifting height.

[0005] In some optional embodiments, obtaining the current cargo weight includes: controlling the fork to lift the current cargo, and collecting the current lifting speed of the fork under preset oil pump current conditions; obtaining a first relationship model between the lifting speed and the cargo weight; inputting the current lifting speed into the first relationship model to obtain the output of the current cargo weight.

[0006] In some optional embodiments, a first relationship model between lifting speed and cargo weight is obtained, including: for different cargo weight samples, respectively collecting lifting speed samples when the fork lifts each cargo weight sample under preset oil pump current conditions; creating a first model training sample according to the correspondence between the cargo weight sample and the lifting speed sample; initializing and generating a first original network model; and training the first original network model using the first model training sample to obtain a first relationship model for predicting cargo weight based on the lifting speed.

[0007] In some optional embodiments, obtaining the current cargo weight also includes: controlling the fork to lift the current cargo, and collecting the current oil pump current of the hydraulic oil pump under preset uniform speed conditions; obtaining a second relationship model between the oil pump current and the cargo weight; inputting the current oil pump current into the second relationship model to obtain the output of the current cargo weight.

[0008] In some optional embodiments, a relationship model between oil pump current and cargo weight is obtained, including: for different cargo weight samples, respectively collecting oil pump current samples when the fork lifts each cargo weight sample under preset uniform speed conditions; creating a second model training sample according to the correspondence between the cargo weight sample and the oil pump current sample; initializing and generating a second original network model; and training the second original network model using the second model training sample to obtain a second relationship model for predicting cargo weight based on the oil pump current.

[0009] In some optional embodiments, the oil inlet and outlet volumes of the forklift hydraulic cylinder are collected, and the fork lifting height is calculated based on the oil inlet and outlet volumes, including: collecting the oil inlet and outlet volumes of the hydraulic cylinder; calculating the cross-sectional area of ​​the hydraulic cylinder; determining the change in oil height based on the oil inlet and outlet volumes and the cross-sectional area; determining the change in hydraulic cylinder stroke based on the change in oil height; and calculating the fork lifting height based on the initial height of the fork and the change in hydraulic cylinder stroke.

[0010] In some optional embodiments, determining the hydraulic cylinder stroke change according to the oil height change includes: obtaining the number of forklift cylinders; and calculating the hydraulic cylinder stroke change according to the ratio of the oil height change to the number of forklift cylinders.

[0011] In a second aspect, the present invention provides a lifting control device for a forklift fork, the device comprising: a weight detection module for obtaining the current cargo weight; a height upper limit calculation module for calculating the lifting height upper limit based on the current cargo weight; a lifting height calculation module for collecting the inlet and outlet oil volumes of the forklift hydraulic cylinder, and calculating the lifting height of the fork based on the inlet and outlet oil volumes; an overload detection module for comparing the lifting height of the fork with the upper limit of the lifting height, and prohibiting the fork from continuing to rise when the lifting height of the fork increases to be equal to the upper limit of the lifting height.

[0012] In a third aspect, the present invention provides a forklift, comprising: a fork, a hydraulic cylinder, a flow meter, a fuel tank, a hydraulic oil pump, an oil pump controller, and a vehicle controller; the hydraulic cylinder is mechanically connected to the fork, the hydraulic cylinder is connected to the fuel tank through a pipeline, the flow meter and the hydraulic oil pump are both arranged in the pipeline, the oil pump controller is electrically connected to the hydraulic oil pump, the oil pump controller is used to control the operation of the hydraulic oil pump, the vehicle controller is communicatively connected to the oil pump controller, and is used to control the operation of the oil pump controller, the vehicle controller is also communicatively connected to the flow meter, and the vehicle controller is used to execute a computer program, thereby executing any one of the methods provided in the first aspect.

[0013] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to cause a computer to execute the method of the first aspect or any corresponding embodiment thereof.

[0014] The technical solution provided by the present invention has the following advantages:

[0015] The present invention is based on obtaining the current cargo weight in real time during the process of the forklift lifting the cargo, and then calculating the upper limit of the lifting height according to the current cargo weight based on the load curve when the forklift is produced. Afterwards, the present invention collects the oil inlet and outlet volume of the forklift hydraulic cylinder, and calculates the lifting height of the fork according to the oil inlet and outlet volume parameters of the forklift cylinder; then compares the lifting height of the fork with the upper limit of the lifting height, and when the lifting height of the fork is equal to the upper limit of the lifting height, the fork is prohibited from continuing to rise. The lifting height of the fork is derived by the oil inlet and outlet volume parameters of the forklift cylinder, which avoids the interference of external auxiliary components on the sensor scanning signal, thereby realizing the fork height detection without adding external sensors, improving the detection accuracy, and reducing the production cost of the forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 is a schematic flow chart of a method for controlling the lifting of a forklift fork according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of a flow chart of a lifting control device for a forklift fork according to an embodiment of the present invention;

[0019] Figure 3 It is a schematic diagram of the hardware structure of a forklift according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution 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 described embodiments are 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 those skilled in the art without creative work are within the scope of protection of the present invention.

[0021] According to an embodiment of the present invention, an embodiment of a lifting control method for a forklift fork is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0022] In this embodiment, a method for controlling the lifting of a forklift fork is provided. Figure 1 1 is a flow chart of a method for controlling the lifting of a forklift fork according to an embodiment of the present invention, and the flow chart includes the following steps:

[0023] Step S101, obtaining the current cargo weight;

[0024] Step S102, calculating the upper limit of the lifting height according to the current cargo weight;

[0025] Step S103, collecting the oil inlet and outlet volumes of the forklift hydraulic cylinder, and calculating the fork lift height based on the oil inlet and outlet volumes;

[0026] Step S104, comparing the lifting height of the fork with the upper limit of the lifting height, and when the lifting height of the fork increases to be equal to the upper limit of the lifting height, the fork is prohibited from further rising.

[0027] Specifically, during the process of lifting cargo with a cargo fork, the present invention obtains the current cargo weight in real time, and then calculates the upper limit of the lifting height according to the current cargo weight based on the load curve when the forklift is produced.

[0028] One optional method is to install a pressure sensor on the fork and calculate the current cargo weight based on the pressure parameters caused by the cargo on the pressure sensor when lifting the cargo. Because the maximum lifting height of cargo with different weights is also different, there is a load curve relationship H between the two. max =m*W, input the current cargo weight W into the load curve relationship H max =m*W, and then calculate the upper limit of lifting height H according to the load relationship max , where m represents the coefficient of the relationship between the cargo weight and the upper limit of the lifting height. The above load curve relationship H max = m*W is a relationship model obtained from the load test during forklift production. For example, when the cargo is 2 tons, the fork can be lifted to the maximum stroke, but when the cargo is 3 tons, it is recommended that the fork only be lifted to 60% of the maximum stroke. If it continues to rise, there is a high risk of tipping. The load curve relationship is the known data obtained when the forklift is produced, so the fitting process of the load curve relationship is not repeated. To prevent overloading, when the fork lift reaches the upper limit of the lift height H max Automatically stops lifting.

[0029] Afterwards, the present invention collects the oil inlet and outlet volume of the forklift hydraulic cylinder in real time, which can be measured by a flow meter installed in the pipeline between the hydraulic cylinder and the oil tank, and then calculates the lifting height of the fork according to the oil inlet and outlet parameters of the forklift cylinder. Finally, the lifting height of the fork is compared with the upper limit of the lifting height. When the lifting height of the fork increases to the upper limit of the lifting height and is equal to it, the fork is prohibited from continuing to rise. If the lifting height of the fork does not increase to the upper limit of the lifting height, it can continue to rise, or if the lifting height of the fork drops from a position exceeding the upper limit of the lifting height, it is allowed to drop.

[0030] The lifting height of the forklift is deduced by the oil inlet and outlet parameters of the forklift cylinder, avoiding the interference of external auxiliary components on the sensor scanning signal. Therefore, the fork height detection is realized without adding external sensors, the detection accuracy is improved, and the production cost of the forklift is reduced.

[0031] In some optional implementations, the above step S101 includes:

[0032] Step a1, controlling the fork to lift the current cargo, and collecting the current lifting speed of the fork under the preset oil pump current condition;

[0033] Step a2, obtaining a first relationship model between lifting speed and cargo weight;

[0034] Step a3, input the current lifting speed into the first relationship model to obtain the output current cargo weight.

[0035] Specifically, the present invention provides a method for measuring the weight of cargo without the need for an additional pressure sensor. For a forklift to lift cargo, if the cargo is heavier, the forklift needs to output oil stably to lift the cargo stably. The stable output of oil requires a stable speed of the hydraulic oil pump. In order to overcome the greater gravity of the cargo, the hydraulic oil pump needs a larger oil pump current to maintain a stable speed. If the hydraulic oil pump only works with a fixed current, the force generated by the rotation of the hydraulic oil pump is difficult to overcome the resistance, which will cause the hydraulic oil pump to rotate slower, thereby causing the lifting speed of the cargo to slow down. Therefore, there is a certain mapping relationship between the lifting speed and the weight of the cargo. Since the mapping relationship is often nonlinear, it is also necessary to fit the model. The present invention uses a first relationship model to fit the mapping relationship, which can be a cubic polynomial, a quartic polynomial, etc. When fitting the first relationship model, a large number of paired lifting speed samples and cargo weight samples are obtained. These samples are all collected under the preset oil pump current conditions, and then the functional relationship is fitted through the acquired samples to obtain the first relationship model.

[0036] Afterwards, in actual application, this embodiment first controls the fork to slowly lift the cargo with a preset oil pump current, measures or calculates the current lifting speed of the fork by means of a speed sensor, gear speed detection, etc., and then inputs the measured current lifting speed into the first relationship model to calculate the current cargo weight. After obtaining the current cargo weight, the oil pump current is increased to make the fork lift the cargo quickly.

[0037] The method provided by the embodiment of the present invention provides a way to measure the weight of goods without using a pressure sensor. The weight of goods can be calculated only by the speed of the fork, which is applicable in scenarios where it is inconvenient to install a pressure sensor on the fork.

[0038] In some optional implementations, the above step a2 includes:

[0039] Step a21, for different cargo weight samples, respectively collecting lifting speed samples when the cargo fork lifts each cargo weight sample under the preset oil pump current condition;

[0040] Step a22, creating a first model training sample according to the correspondence between the cargo weight sample and the lifting speed sample;

[0041] Step a23, initializing and generating a first original network model;

[0042] Step a24, training the first original network model using the first model training sample to obtain a first relationship model for predicting the weight of the cargo according to the lifting speed.

[0043] Specifically, the present invention takes into account that a neural network is a natural nonlinear model, and has a strong fitting ability for nonlinear mapping relationships, which is better than high-order polynomials. Therefore, the first relationship model provided by the present invention can be implemented using a neural network model. The first original network model before parameter adjustment is obtained, such as a BP neural network model. The present invention only takes this as an example and is not limited to this. Afterwards, a cargo weight sample of known weight is obtained, and for different cargo weight samples, a forklift lifting experiment is performed under the preset oil pump current condition, and the lifting speed samples when the fork lifts each cargo weight sample are collected respectively. Afterwards, the collected cargo weight samples and lifting speed samples are paired as the first model training samples, and the first original network model is trained by the neural network. The trained first relationship model can output the corresponding cargo weight by inputting the lifting speed, thereby realizing the prediction of the cargo weight. The first relationship model provided by the embodiment of the present invention is implemented based on the neural network technology, and has a stronger nonlinear expression ability, thereby improving the accuracy of predicting the cargo weight.

[0044] In some optional implementation manners, the above step S101 further includes:

[0045] Step b1, controlling the fork to lift the current cargo, and collecting the current oil pump current of the hydraulic oil pump under a preset uniform speed condition;

[0046] Step b2, obtaining a second relationship model between the oil pump current and the cargo weight;

[0047] Step b3, input the current oil pump current into the second relationship model to obtain the output current cargo weight.

[0048] Specifically, for a forklift lifting goods, if the goods are heavier, the forklift needs to stably lift the goods and the oil output needs to be stable. The stable output of oil requires the hydraulic oil pump to have a stable speed. Therefore, in order to overcome the greater gravity of the goods, the hydraulic oil pump needs to have a larger oil pump current to maintain a stable speed. If the hydraulic oil pump only works with a fixed current, the force generated by the rotation of the hydraulic oil pump is difficult to overcome the resistance, which will cause the hydraulic oil pump to rotate slower, thereby causing the lifting speed of the goods to slow down. Therefore, if you want to maintain a uniform and stable lifting condition, there is a certain mapping relationship between the weight of the goods and the oil pump current of the hydraulic oil pump. The heavier the goods, the larger the oil pump current is required. Since the mapping relationship is often nonlinear, it is also necessary to fit the model. The present invention uses a second relationship model to fit the mapping relationship, which can be a cubic polynomial, a quartic polynomial, etc. When fitting the second relationship model, a large number of paired oil pump current samples and cargo weight samples are obtained. These samples are all collected under preset uniform speed conditions, and then the second relationship model is obtained by fitting the function relationship of the acquired samples. Through the embodiment of the present invention, another method for measuring the weight of goods without the need for an additional pressure sensor is provided, and the oil pump current is an electrical parameter and can be collected without any sensor, further reducing the cost of forklift production.

[0049] In some optional implementation manners, the above step b2 includes:

[0050] Step b21, for different cargo weight samples, respectively collect oil pump current samples when the cargo fork lifts each cargo weight sample under a preset uniform speed condition;

[0051] Step b22, creating a second model training sample according to the correspondence between the cargo weight sample and the oil pump current sample;

[0052] Step b23, initializing and generating a second original network model;

[0053] Step b24, training the second original network model using the second model training sample to obtain a second relationship model for predicting cargo weight based on oil pump current.

[0054] Specifically, the training method and principle of the second relationship model are the same as those of the first relationship model, except that the lifting speed samples in the model training samples are replaced with oil pump current samples under the same lifting speed conditions. Therefore, the principle description of training the second relationship model in the embodiment of the present invention can refer to the steps of the first relationship model mentioned above, and will not be repeated here.

[0055] In some optional implementation manners, the above step S103 includes:

[0056] Step c1, collecting the oil inlet and outlet volumes of the hydraulic cylinder;

[0057] Step c2, calculating the cross-sectional area of ​​the hydraulic cylinder;

[0058] Step c3, determining the oil height change according to the oil inlet and outlet volume and the cross-sectional area;

[0059] Step c4, determining the change in the stroke of the hydraulic cylinder according to the change in the oil height;

[0060] Step c5, calculating the lifting height of the fork according to the initial height of the fork and the change in the stroke of the hydraulic cylinder.

[0061] Specifically, the method for measuring the lifting height of the fork provided by the present invention first needs to collect the inlet and outlet oil volume of the hydraulic cylinder. The inlet and outlet oil volume specifically includes the inlet and outlet oil volume of the hydraulic cylinder. In this embodiment, the inlet and outlet oil volume specifically refers to the volume of the inlet and outlet oil. The inlet and outlet oil volume can be counted by a flow meter set in the hydraulic pipeline, or calculated by the number of revolutions of the oil pump. For example, it is known that the oil pump displacement per revolution of the hydraulic oil pump is r. Assuming that the oil pump rotates N times during the lifting time, the amount of oil passing through the hydraulic oil pump is Q=K. y *N*r, that is, the total oil intake of the hydraulic cylinder, where K y It represents the efficiency coefficient of the oil pump, and the total oil output can be directly counted by the flow meter.

[0062] Since the diameter parameter of the hydraulic cylinder is known at the factory, the radius can be determined by the diameter of the hydraulic cylinder, and the cross-sectional area S of the hydraulic cylinder can be calculated by multiplying the square of the radius parameter and π.

[0063] Afterwards, the ratio of the oil intake and the cross-sectional area of ​​the hydraulic cylinder is calculated to determine the height to which the oil rises in the hydraulic cylinder when the hydraulic cylinder intakes oil, or the height to which the oil drops in the hydraulic cylinder when the cylinder discharges oil is determined by calculating the ratio of the oil output. Finally, the heights of the oil rising and falling in the hydraulic cylinder are added together to obtain the change in oil height, so that the change in oil output height can be determined based on the oil intake and output and the cross-sectional area.

[0064] In addition, when the change in the oil height in the hydraulic cylinder is determined, the distance the cylinder is extended can be calculated through the change in the oil height. For example, when a single cylinder is used, the change in the oil height is equal to the change in the hydraulic cylinder stroke. When multiple cylinders are used, the change in the hydraulic cylinder stroke is equal to the change in the hydraulic cylinder stroke divided by the number of cylinders. The specific steps are as follows.

[0065] Step d1, obtaining the number of forklift cylinders;

[0066] Step d2, calculating the change in the stroke of the hydraulic cylinder according to the ratio of the change in oil height to the number of forklift cylinders.

[0067] For example, assuming that a forklift has two cylinders, the total oil intake calculated by the oil pump revolutions is Q, then the hydraulic cylinder stroke change H1 = Q / (2S), where S represents the cross-sectional area of ​​the hydraulic cylinder.

[0068] It should be noted that, in general, the fork is not directly lifted by the hydraulic cylinder. The hydraulic cylinder is placed in the middle of the chain connecting the forklift and the fork. When the hydraulic cylinder is raised, it is equivalent to folding the chain in two. For every centimeter the hydraulic cylinder rises, the chain is fixed at one end, so the other end rises by two centimeters. Therefore, the change in the fork lifting height is twice the change in the hydraulic cylinder stroke. Therefore, when calculating the fork lifting height by the initial height of the fork and the change in the hydraulic cylinder stroke, the change in the hydraulic cylinder stroke needs to be doubled. For example, assuming that the initial height is 0 by default, the fork lifting height H2 = 2*H1. That is, after the change in the fork lifting height is determined, the initial height of the fork is known, and the accurate fork lifting height can be calculated by summing the two.

[0069] Through the technical solution provided by the embodiment of the present invention, the lifting height of the fork is calculated through the physical parameters of the cylinder and the oil volume, realizing a method for measuring the lifting height of the fork by pure software, reducing the use of sensors, improving the detection accuracy and reducing the production cost of the forklift.

[0070] In this embodiment, a lifting control device for a forklift fork is also provided, which is used to implement the above-mentioned embodiments and preferred embodiments, and will not be repeated hereafter. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0071] This embodiment provides a lifting control device for a forklift fork, such as Figure 2 As shown, including:

[0072] The weight detection module 201 is used to obtain the current weight of the goods;

[0073] The upper limit height calculation module 202 is used to calculate the upper limit of the lifting height according to the current cargo weight;

[0074] The lifting height calculation module 203 is used to collect the oil inlet and outlet of the forklift hydraulic cylinder and calculate the lifting height of the fork according to the oil inlet and outlet;

[0075] The overload detection module 204 is used to compare the lifting height of the fork with the upper limit of the lifting height, and when the lifting height of the fork increases to be equal to the upper limit of the lifting height, the fork is prohibited from continuing to rise.

[0076] In some optional implementations, the weight detection module 201 includes:

[0077] The first parameter acquisition unit is used to control the fork to lift the current cargo and to collect the current lifting speed of the fork under the preset oil pump current condition;

[0078] A first relationship model acquisition unit, used to acquire a first relationship model between the lifting speed and the cargo weight;

[0079] The first weight calculation unit is used to input the current lifting speed into the first relationship model to obtain the output current cargo weight.

[0080] In some optional implementations, the first relationship model acquisition unit includes:

[0081] The speed sample collection unit is used to collect lifting speed samples of the fork when lifting each cargo weight sample under the preset oil pump current condition for different cargo weight samples;

[0082] A first training sample unit, used to create a first model training sample according to the correspondence between the cargo weight sample and the lifting speed sample;

[0083] A first original model unit, used for initializing and generating a first original network model;

[0084] The first training unit is used to train the first original network model using the first model training sample to obtain a first relationship model for predicting the weight of the cargo according to the lifting speed.

[0085] In some optional implementations, the weight detection module 201 further includes:

[0086] The second parameter acquisition unit is used to control the fork to lift the current cargo and to collect the current oil pump current of the hydraulic oil pump under a preset uniform speed condition;

[0087] A second relationship model acquisition unit, used to acquire a second relationship model between the oil pump current and the cargo weight;

[0088] The second weight calculation unit is used to input the current oil pump current into the second relationship model to obtain the output current cargo weight.

[0089] In some optional implementations, the second relationship model acquisition unit includes:

[0090] The current sample collection unit is used to collect the oil pump current samples when the fork lifts each cargo weight sample under the preset uniform speed condition for different cargo weight samples;

[0091] A second training sample unit, used to create a second model training sample according to the correspondence between the cargo weight sample and the oil pump current sample;

[0092] A second original model unit, used for initializing and generating a second original network model;

[0093] The second training unit is used to train the second original network model using the second model training sample to obtain a second relationship model for predicting the cargo weight according to the oil pump current.

[0094] In some optional implementations, the lifting height calculation module 203 includes:

[0095] The oil inlet and outlet volume collection unit is used to collect the oil inlet and outlet volumes of the hydraulic cylinder;

[0096] Cylinder cross-sectional area calculation unit, used to calculate the cross-sectional area of ​​the hydraulic cylinder;

[0097] An oil height calculation unit is used to determine the oil height change according to the oil inlet and outlet volume and the cross-sectional area;

[0098] The oil cylinder stroke calculation unit is used to determine the change in the hydraulic cylinder stroke according to the change in the oil height;

[0099] The lifting height calculation unit is used to calculate the lifting height of the fork according to the initial height of the fork and the change in the stroke of the hydraulic cylinder.

[0100] In some optional embodiments, the cylinder stroke calculation unit includes:

[0101] The cylinder quantity acquisition unit is used to obtain the number of forklift cylinders;

[0102] The stroke calculation subunit is used to calculate the change in the stroke of the hydraulic cylinder according to the ratio of the change in oil height and the number of forklift cylinders.

[0103] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0104] The embodiment of the present invention further provides a forklift, such as Figure 3As shown, it includes: a fork, a hydraulic cylinder, a flow meter, a fuel tank, a hydraulic oil pump, an oil pump controller, and a vehicle controller; the hydraulic cylinder is mechanically connected to the fork, the hydraulic cylinder is connected to the fuel tank through a pipeline, the flow meter and the hydraulic oil pump are both arranged in the pipeline, the oil pump controller is electrically connected to the hydraulic oil pump, the oil pump controller is used to control the operation of the hydraulic oil pump, the vehicle controller is communicatively connected to the oil pump controller, and is used to control the operation of the oil pump controller, the vehicle controller is also communicatively connected to the flow meter, and the vehicle controller is used to execute a computer program, thereby executing the method provided in the above method embodiment.

[0105] The vehicle controller may include one or more processors, memories, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed in the computer device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system).

[0106] The processor may be a central processing unit, a network processor or a combination thereof. The processor may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0107] The memory stores instructions executable by at least one processor, so that the at least one processor executes the method shown in the above embodiment.

[0108] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0109] The memory may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0110] The computer device also includes a communication interface, which is used for the computer device to communicate with other devices or a communication network.

[0111] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0112] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0113] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for controlling the lifting of a forklift fork, characterized in that: The method comprises: Get the current cargo weight; Calculate the upper limit of the lifting height according to the current cargo weight; Collect the oil inlet and outlet volume of the forklift hydraulic cylinder, and calculate the lifting height of the fork according to the oil inlet and outlet volume; The fork lifting height is compared with the lifting height upper limit, and when the fork lifting height increases to be equal to the lifting height upper limit, the fork is prohibited from continuing to rise.

2. The method according to claim 1, characterized in that The obtaining of the current cargo weight includes: Control the fork to lift the current cargo, and collect the current lifting speed of the fork under the preset oil pump current condition; Obtaining a first relationship model between lifting speed and cargo weight; The current lifting speed is input into the first relationship model to obtain the output of the current cargo weight.

3. The method according to claim 2, characterized in that The first relationship model of obtaining the lifting speed and the cargo weight includes: For different cargo weight samples, the lifting speed samples of the cargo fork when lifting each cargo weight sample are collected under the preset oil pump current condition; Creating a first model training sample according to the correspondence between the cargo weight sample and the lifting speed sample; Initialize and generate a first original network model; The first original network model is trained using the first model training samples to obtain the first relationship model for predicting cargo weight according to the lifting speed.

4. The method according to claim 1, characterized in that: The obtaining of the current cargo weight also includes: Control the fork to lift the current cargo and collect the current oil pump current of the hydraulic oil pump under the preset uniform speed condition; Obtaining a second relationship model between the oil pump current and the cargo weight; The current oil pump current is input into the second relationship model to obtain the current cargo weight as output.

5. The method according to claim 4, characterized in that The relationship model of obtaining the oil pump current and the cargo weight includes: For different cargo weight samples, the oil pump current samples are collected when the fork lifts each cargo weight sample under the preset uniform speed condition; Creating a second model training sample according to the correspondence between the cargo weight sample and the oil pump current sample; Initialize and generate a second original network model; The second original network model is trained using the second model training samples to obtain the second relationship model for predicting cargo weight based on oil pump current.

6. The method according to claim 1, characterized in that The collecting of the oil inlet and outlet of the forklift hydraulic cylinder and calculating the lifting height of the fork according to the oil inlet and outlet include: Collect the oil volume in and out of the hydraulic cylinder; Calculate the cross-sectional area of ​​the hydraulic cylinder; Determine the oil height change according to the oil inlet and outlet volumes and the cross-sectional area; Determine the change in the stroke of the hydraulic cylinder according to the change in the oil height; The lifting height of the fork is calculated by the initial height of the fork and the change in the stroke of the hydraulic cylinder.

7. The method according to claim 6, characterized in that Determining the hydraulic cylinder stroke change according to the oil height change includes: Get the number of forklift cylinders; The change in stroke of the hydraulic cylinder is calculated according to the ratio of the change in oil height to the number of the forklift cylinders.

8. A lifting control device for a forklift fork, characterized in that: The device comprises: Weight detection module, used to obtain the current weight of goods; A height upper limit calculation module, used to calculate the upper limit of the lifting height according to the current cargo weight; A lifting height calculation module is used to collect the oil inlet and outlet volumes of the forklift hydraulic cylinder and calculate the lifting height of the fork according to the oil inlet and outlet volumes; The overload detection module is used to compare the lifting height of the fork with the upper limit of the lifting height, and when the lifting height of the fork increases to be equal to the upper limit of the lifting height, prohibit the fork from continuing to rise.

9. A forklift, characterized in that: include: Forks, hydraulic cylinders, flow meters, fuel tanks, hydraulic oil pumps, oil pump controllers, vehicle controllers; The fork is mechanically connected to the hydraulic cylinder, the hydraulic cylinder is connected to the oil tank through a pipeline, the flow meter and the hydraulic oil pump are both arranged in the pipeline, the oil pump controller is electrically connected to the hydraulic oil pump, the oil pump controller is used to control the operation of the hydraulic oil pump, the whole vehicle controller is communicatively connected to the oil pump controller, and is used to control the operation of the oil pump controller, the whole vehicle controller is also communicatively connected to the flow meter, and the whole vehicle controller is used to execute a computer program, thereby executing the method provided in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the method according to any one of claims 1 to 7.

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