Vertical lifting control method and system of electric reach stacker

Abstract

The invention discloses a vertical lifting control method and system for an electric reach stacker, and belongs to the technical field of hoisting equipment. The vertical lifting control method of the electric reach stacker comprises the steps that if a vertical lifting instruction is received, the initial extension distance and the initial lifting angle of the electric reach stacker at the initial moment are determined; calculating the radius of a target lifting appliance according to the initial extension distance, the initial lifting angle and the equipment structure parameters; calculating a lifting appliance radius error at the current moment according to the target lifting appliance radius and the actual lifting appliance radius; processing based on a fuzzy proportional control algorithm according to the radius error of the lifting appliance to obtain lifting control information; carrying out PID (Proportion Integration Differentiation) control algorithm processing according to the radius error of the lifting appliance to obtain telescopic control information; the lifting proportional valve is controlled according to the lifting control information, and the telescopic proportional valve is controlled according to the telescopic control information. According to the invention, the electric reach stacker can be controlled to automatically perform vertical lifting motion on the premise of ensuring efficiency and precision.

Description

Technical Field

[0001] The present application relates to the technical field of lifting equipment, and in particular to a vertical lifting control method and system for an electric reach stacker. Background Art

[0002] Electric reach stacker is a reach stacker driven by electricity. It is also called container reach stacker, container reach crane or reach crane. It is a mobile lifting equipment used for loading and unloading containers.

[0003] At present, when performing vertical lifting operations, operators need to frequently switch the pitch and telescopic movements of the crane arm in order to accurately lift the container to the specified position; the above process is complex to operate, and the work efficiency and accuracy are low.

[0004] Therefore, how to control the electric reach stacker to automatically perform vertical lifting movements while ensuring efficiency and accuracy is a technical problem that technical personnel in this field currently need to solve. Summary of the invention

[0005] The purpose of the present application is to provide a vertical lifting control method and system for an electric reach stacker, which can control the electric reach stacker to automatically perform vertical lifting movements while ensuring efficiency and accuracy.

[0006] In order to solve the above technical problems, the present application provides a vertical lifting control method of an electric reach stacker, comprising:

[0007] If a vertical lifting instruction is received, determining an initial extension distance and an initial lifting angle of the electric reach stacker at an initial time; wherein the initial time is the time when the vertical lifting instruction is received;

[0008] Calculate a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters;

[0009] Determine an actual spreader radius at a current moment, and calculate a spreader radius error at a current moment according to the target spreader radius and the actual spreader radius;

[0010] Processing based on the fuzzy proportional control algorithm is performed according to the spreader radius error to obtain lifting control information;

[0011] Processing the PID control algorithm according to the spreader radius error to obtain telescopic control information;

[0012] The lifting proportional valve is controlled according to the lifting control information, and the telescopic proportional valve is controlled according to the telescopic control information, so that the lifting device of the electric front crane performs vertical lifting movement.

[0013] Optionally, calculating a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters includes:

[0014] Determine the horizontal distance of the hinge points, the vertical distance of the hinge points and the wheelbase according to the structural parameters of the equipment; wherein the horizontal distance of the hinge points is the distance between the upper hinge point and the rear hinge point in the horizontal direction under the reference state, and the vertical distance of the hinge points is the distance between the upper hinge point and the rear hinge point in the vertical direction under the reference state; the reference state is a state where the lifting angle is equal to 0 and the extension distance of the telescopic arm is equal to 0, the upper hinge point is the hinge point between the inner arm of the telescopic arm and the sling, and the rear hinge point is the hinge point between the outer arm of the telescopic arm and the vehicle body;

[0015] The initial reference angle and the initial hinge point distance are calculated according to the initial extension distance, the hinge point horizontal distance and the hinge point vertical distance; wherein the initial reference angle is the angle between the target straight line and the horizontal direction at the initial moment, the target straight line is the line connecting the upper hinge point and the rear hinge point, and the initial hinge point distance is the distance between the upper hinge point and the rear hinge point at the initial moment;

[0016] The target spreader radius is calculated according to the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase.

[0017] Optionally, calculating the target spreader radius according to the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase includes:

[0018] Substituting the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase into the spreader radius calculation formula to obtain the target spreader radius;

[0019] The calculation formula of the spreader radius is: , represents the target spreader radius, represents the initial hinge distance, Indicates the initial lifting angle, represents the initial reference angle, Indicates wheelbase.

[0020] Optionally, processing based on a fuzzy proportional control algorithm is performed according to the spreader radius error to obtain lifting control information, including:

[0021] Substituting the spreader radius error into an opening calculation formula based on a fuzzy proportional control algorithm to obtain a first opening value;

[0022] Wherein, the opening calculation formula is: ; Indicates the first opening value, Indicates the handle opening, Indicates the spreader radius error, Indicates the maximum absolute value of the spreader radius error, Indicates the reference opening value, min means the minimum value, and max means the maximum value;

[0023] Correspondingly, controlling the lifting proportional valve according to the lifting control information includes:

[0024] The opening of the lifting proportional valve or the lowering proportional valve is adjusted according to the first opening value; wherein the lifting proportional valve is used to control the lifting of the telescopic arm, and the lowering proportional valve is used to control the lowering of the telescopic arm.

[0025] Optionally, before substituting the spreader radius error into the opening calculation formula based on the fuzzy proportional control algorithm, the method further includes:

[0026] The corresponding reference opening value is determined according to the angle interval of the current lifting angle at the current moment.

[0027] Optionally, a PID control algorithm is processed according to the spreader radius error to obtain telescopic control information, including:

[0028] Calculate the second opening value using the PID control formula;

[0029] Wherein, the PID control formula is:

[0030] ;

[0031] Indicates the second opening value, represents the proportional gain, Indicates the spreader radius error at the current moment, represents the integral gain, Represents the cumulative sum of all spreader radius errors, represents the differential gain, Indicates the spreader radius error at the last moment;

[0032] Correspondingly, controlling the telescopic proportional valve according to the telescopic control information includes:

[0033] The opening of the extension proportional valve and / or the retraction proportional valve is adjusted according to the second opening value; wherein the extension proportional valve is used to control the extension of the telescopic arm, and the retraction proportional valve is used to control the retraction of the telescopic arm.

[0034] Optionally, the second opening value is calculated using a PID control formula, including:

[0035] Determining the instruction type of the vertical lift instruction;

[0036] If the instruction type is a vertical lifting instruction, the second opening value is calculated using the first PID control formula;

[0037] If the instruction type is a vertical descent instruction, the second opening value is calculated using the second PID control formula;

[0038] Wherein, the first PID control formula is:

[0039] ; Indicates the lifting proportional gain, Indicates the hoisting integral gain, Represents the lifting differential gain; the second PID control formula is: ; represents the decreasing proportional gain, Indicates decreasing integral gain, Indicates decreasing differential gain.

[0040] Optionally, after receiving the vertical lift command, the method further includes:

[0041] Determine the minimum motor speed required for the electric reach crane's lifting device to perform vertical lifting movement, and control the pump motor according to the minimum motor speed; wherein the pump motor is used to provide hydraulic oil to the lifting proportional valve and the telescopic proportional valve.

[0042] Optionally, determining the initial extension distance and initial lifting angle of the electric reach stacker at the initial moment includes:

[0043] The initial extension distance and the initial lifting angle of the electric reach crane at the initial moment are determined by using a length and angle sensor; wherein the length and angle sensor is installed on the telescopic arm of the electric reach crane.

[0044] The present application also provides a vertical lifting control system for an electric reach stacker, the system comprising:

[0045] A measuring module, for determining an initial extension distance and an initial lifting angle of the electric reach stacker at an initial moment if a vertical lifting instruction is received; wherein the initial moment is a moment when the vertical lifting instruction is received;

[0046] A target determination module, used for calculating a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters;

[0047] An error calculation module, used to determine the actual spreader radius at the current moment, and calculate the spreader radius error at the current moment according to the target spreader radius and the actual spreader radius;

[0048] A first processing module is used to perform processing based on a fuzzy proportional control algorithm according to the spreader radius error to obtain lifting control information;

[0049] A second processing module is used to process the PID control algorithm according to the spreader radius error to obtain telescopic control information;

[0050] The control module is used to control the lifting proportional valve according to the lifting control information, and to control the telescopic proportional valve according to the telescopic control information, so that the lifting device of the electric front crane can perform vertical lifting movement.

[0051] The present application provides a vertical lifting control method for an electric reach crane. After receiving a vertical lifting instruction, the present solution calculates the target spreader radius according to the initial extension distance, initial lifting angle and equipment structural parameters at the time of receiving the vertical lifting instruction; the actual spreader radius at the current moment is compared with the target spreader radius to obtain the spreader radius error. The present application combines the spreader radius error with a fuzzy proportional control algorithm to obtain lifting control information; the PID control algorithm is also processed according to the spreader radius error to obtain telescopic control information; the spreader of the electric reach crane can be controlled to perform vertical lifting according to the above lifting control information and telescopic control information. Through the fuzzy logic of the above fuzzy proportional control algorithm, the present application can dynamically adjust the control strategy according to the degree of spreader radius error, thereby improving the adaptability and robustness of the lifting control; the present application also uses the PID control algorithm for telescopic control. It can be seen that the present application can automatically control the electric reach crane to perform vertical lifting under the premise of ensuring efficiency and accuracy by comprehensively using fuzzy proportional control and PID control algorithms, combined with real-time error monitoring and proportional valve control. The present application also provides a vertical lifting control system for an electric reach crane, which has the above beneficial effects and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0053] Figure 1 A flow chart of a vertical lifting control method of an electric reach stacker provided in an embodiment of the present application;

[0054] Figure 2 A schematic diagram of the structure of an electric reach stacker provided in an embodiment of the present application;

[0055] Figure 3A signal acquisition block diagram of a control system for an electric reach stacker provided in an embodiment of the present application;

[0056] Figure 4 A schematic diagram of the appearance of a control handle provided in an embodiment of the present application;

[0057] Figure 5 A flow chart of a vertical lifting control program provided in an embodiment of the present application;

[0058] Figure 6 A flow chart of a vertical descent control program provided in an embodiment of the present application. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0060] See below Figure 1 , Figure 1 A flow chart of a vertical lifting control method for an electric reach stacker provided in an embodiment of the present application.

[0061] Specific steps may include:

[0062] S101: If a vertical lifting instruction is received, determining an initial extension distance and an initial lifting angle of the electric reach stacker at an initial moment;

[0063] Among them, this embodiment can be applied to the vehicle control unit (VCU) of the electric reach stacker. The above-mentioned vertical lifting instruction can be an instruction input by other equipment or the control handle of the reach stacker, and the vertical lifting instruction can be a vertical lifting instruction or a vertical descent instruction. The vertical lifting instruction is used to indicate that the electric reach stacker currently needs to control the spreader to perform vertical lifting movement, that is, to control the spreader to rise or fall while maintaining the spreader radius unchanged. The spreader radius refers to: the horizontal distance between the spreader center and a fixed part of the electric reach stacker (such as the front wheel center or the rotation center).

[0064] If a vertical lifting command is received, it means that the lifting device needs to be controlled to perform lifting and lowering movements while keeping the current lifting device radius unchanged. The application can set the moment of receiving the vertical lifting command as the initial moment, set the extension distance of the electric reach crane at the initial moment as the initial extension distance, and set the lifting angle of the electric reach crane at the initial moment as the initial lifting angle.

[0065] The electric reach stacker includes a body, a telescopic arm and a sling. The extension distances (such as initial extension distance and actual extension distance) described in this document are all extension distances of the telescopic arm relative to a reference state. The lifting angles (such as initial lifting angle and actual lifting angle) described in this document are all lifting angles of the telescopic arm relative to a reference state. The reference state is a state where the sling is at the lowest point and the length of the telescopic arm is the shortest.

[0066] As a feasible implementation mode, this embodiment can use a length-angle sensor to determine the initial extension distance and the initial lifting angle of the electric reach crane at the initial moment; wherein, the length-angle sensor is installed on the telescopic arm of the electric reach crane.

[0067] After receiving the vertical lifting instruction, the minimum motor speed required for the electric front crane's lifting device to perform vertical lifting movement can also be determined, and the pump motor can be controlled according to the minimum motor speed so that the speed of the pump motor is greater than or equal to the minimum motor speed; wherein the pump motor is used to provide hydraulic oil to the lifting proportional valve and the telescopic proportional valve.

[0068] S102: Calculating a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters;

[0069] Before this step, there may be an operation of obtaining equipment structural parameters, which are structural parameters of the electric reach stacker. The target spreader radius can be obtained by performing trigonometric calculation based on the initial extension distance, initial lifting angle and equipment structural parameters. The target spreader radius is the spreader radius of the electric reach stacker at the initial moment; in response to the vertical lifting command, the spreader needs to be controlled to maintain the target spreader radius and perform lifting and lowering movements.

[0070] S103: determining an actual spreader radius at a current moment, and calculating a spreader radius error at a current moment according to the target spreader radius and the actual spreader radius;

[0071] Among them, after receiving the vertical lifting command, the spreader can be controlled to rise or fall. The spreader radius changes during the process of rising or falling. The present application can be controlled through the relevant operations of S103-S106 to maintain the spreader radius and thus achieve vertical lifting.

[0072] This step can obtain the actual spreader radius at the current moment, and calculate the spreader radius error at the current moment according to the target spreader radius and the actual spreader radius. Specifically, this embodiment can determine the actual extension distance and actual lifting angle of the electric reach stacker at the current moment, and calculate the actual spreader radius according to the actual extension distance, the actual lifting angle and the equipment structure parameters.

[0073] S104: performing processing based on a fuzzy proportional control algorithm according to the spreader radius error to obtain lifting control information;

[0074] Among them, this embodiment can use the fuzzy proportional control algorithm to convert the spreader radius error into a fuzzy value, and then infer the fuzzy value and the preset fuzzy rule library to obtain the fuzzy control output, and convert the fuzzy control output into lifting control information.

[0075] The lifting control information is information for controlling the lifting of the telescopic arm. In this embodiment, the electric reach stacker uses a lifting proportional valve to control the lifting of the telescopic arm, so the lifting control information is information for describing the opening of the lifting proportional valve. The telescopic arm includes an inner arm and an outer arm, the inner arm is connected to the spreader, and the outer arm is connected to the vehicle body. The lifting of the telescopic arm is the lifting of the spreader.

[0076] S105: Processing the PID control algorithm according to the spreader radius error to obtain telescopic control information;

[0077] Among them, according to the spreader radius error, the PID control algorithm processes the error signal through three links: proportion (P), integration (I), and differentiation (D), and dynamically generates telescopic control information.

[0078] The telescopic control information is information for controlling the telescopic arm's telescopic extension. In this embodiment, the electric reach stacker uses a telescopic proportional valve to control the telescopic arm's telescopic extension. Therefore, the telescopic control information is information for describing the opening of the telescopic proportional valve.

[0079] S106: Control the lifting proportion valve according to the lifting control information, and control the telescopic proportion valve according to the telescopic control information, so that the lifting device of the electric reach stacker performs vertical lifting movement.

[0080] Among them, the lifting proportional valve includes an ascending proportional valve and a descending proportional valve, and this step can control the ascending proportional valve or the descending proportional valve according to the lifting control information; the telescopic proportional valve includes an extending proportional valve and a retracting proportional valve, and this step can control the extending proportional valve and / or the retracting proportional valve according to the telescopic control information. The above method can effectively control the lifting angle and extension length of the telescopic arm to ensure that the sling can perform vertical lifting movement.

[0081] This embodiment provides a vertical lifting control method for an electric front crane. After receiving a vertical lifting instruction, this scheme calculates the target sling radius according to the initial extension distance, initial lifting angle and equipment structure parameters at the time of receiving the vertical lifting instruction; the actual sling radius at the current moment is compared with the target sling radius to obtain the sling radius error. This embodiment combines the sling radius error with a fuzzy proportional control algorithm to obtain lifting control information; it also processes the PID control algorithm according to the sling radius error to obtain telescopic control information; according to the above lifting control information and telescopic control information, the sling of the electric front crane can be controlled to perform vertical lifting movement. Through the fuzzy logic of the above fuzzy proportional control algorithm, this embodiment can dynamically adjust the control strategy according to the degree of the sling radius error, thereby improving the adaptability and robustness of the lifting control; this embodiment also uses the PID control algorithm for telescopic control. It can be seen that this embodiment can automatically control the electric front crane to perform vertical lifting movement while ensuring efficiency and accuracy by comprehensively using fuzzy proportional control and PID control algorithms, combined with real-time error monitoring and proportional valve control.

[0082] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of an electric reach crane provided in an embodiment of the present application, in which A represents a rear hinge point, F represents a rear wheel force fulcrum (i.e., the projection of the rear wheel center in the vertical direction), and E represents a front wheel force fulcrum (i.e., the projection of the front wheel center in the vertical direction). represents the vehicle wheelbase (i.e. the distance between the front and rear wheels), COG represents the radius of the spreader, and D represents the upper hinge point. Indicates the lifting angle. Indicates the extension distance, Indicates the horizontal distance of the hinge point (i.e. the horizontal distance from the hinge point at the rear of the telescopic arm to the hinge point on the sling when it is fully retracted). Indicates the vertical distance of the hinge point (i.e. the vertical distance from the rear hinge point of the telescopic arm to the hinge point on the sling when it is fully retracted). , , is a constant parameter. The upper hinge point is the hinge point between the inner arm of the telescopic arm and the sling, and the rear hinge point is the hinge point between the outer arm of the telescopic arm and the vehicle body. The horizontal distance of the hinge points is: the distance between the upper hinge point and the rear hinge point in the horizontal direction under the reference state; the vertical distance of the hinge points is: the distance between the upper hinge point and the rear hinge point in the vertical direction under the reference state; the reference state is the state where the lifting angle is equal to 0 and the extension distance of the telescopic arm is equal to 0.

[0083] As a further introduction to the above embodiment, the target spreader radius can be calculated in the following manner:

[0084] Step A1: Determine the horizontal distance of the hinge point according to the equipment structure parameters , vertical distance from hinge point and wheelbase ;

[0085] Step A2: According to the initial extension distance , the horizontal distance of the hinge point The vertical distance from the hinge point Calculate the initial reference angle The distance from the initial hinge point ;

[0086] The initial reference angle is the angle between the target straight line and the horizontal direction at the initial moment, and the target straight line is the line connecting the upper hinge point and the rear hinge point; that is, the initial reference angle is the angle between the line connecting the upper hinge point and the rear hinge point and the horizontal direction at the initial moment. The initial hinge point distance is the distance between the upper hinge point and the rear hinge point at the initial moment.

[0087] The calculation formula for the initial reference angle is: .

[0088] The calculation formula for the initial hinge distance is: .

[0089] Step A3: Based on the initial reference angle , the initial hinge distance , the initial lifting angle and the wheelbase , calculate the target spreader radius .

[0090] Specifically, in this step, the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase may be substituted into the spreader radius calculation formula to obtain the target spreader radius;

[0091] The calculation formula of the spreader radius is: , represents the target spreader radius, represents the initial hinge distance, Indicates the initial lifting angle, represents the initial reference angle, represents wheelbase, and cos represents cosine function.

[0092] As a further introduction to the above embodiment, the current spreader radius can be calculated in the following way:

[0093] Step B1: Determine the horizontal distance of the hinge point according to the equipment structure parameters , vertical distance from hinge point and wheelbase ;

[0094] Step B2: According to the current extension distance , the horizontal distance of the hinge point The vertical distance from the hinge point Calculate the current reference angle Distance from current hinge point ;

[0095] The current reference angle is the angle between the target straight line and the horizontal direction at the current moment, and the target straight line is the line connecting the upper hinge point and the rear hinge point; that is, the current reference angle is the angle between the line connecting the upper hinge point and the rear hinge point and the horizontal direction at the current moment. The current hinge point distance is the distance between the upper hinge point and the rear hinge point at the current moment.

[0096] The calculation formula for the current reference angle is: .

[0097] The calculation formula for the current hinge distance is: .

[0098] Step B3: Based on the current reference angle , the current hinge distance , the current lifting angle and the wheelbase , calculate the current spreader radius , arctan represents the inverse tangent function.

[0099] Specifically, in this step, the current reference angle, the current hinge point distance, the current lifting angle and the wheelbase may be substituted into the spreader radius calculation formula to obtain the current spreader radius; the spreader radius calculation formula is: , Indicates the current spreader radius, Indicates the current hinge distance, Indicates the current lifting angle. Indicates the current reference angle.

[0100] As a further introduction to the above embodiment, the lifting control information can be obtained by processing based on the fuzzy proportional control algorithm in the following manner: the sling radius error is substituted into the opening calculation formula based on the fuzzy proportional control algorithm to obtain a first opening value; the lifting control information includes the first opening value.

[0101] Wherein, the opening calculation formula is:

[0102] ; Indicates the first opening value, Indicates the handle opening, Indicates the spreader radius error, Indicates the maximum absolute value of the spreader radius error, Indicates the reference opening value, min indicates the minimum value, and max indicates the maximum value.

[0103] After obtaining the first opening value, the opening of the lifting proportional valve or the lowering proportional valve can be adjusted according to the first opening value; wherein the lifting proportional valve is used to control the lifting of the telescopic arm, and the lowering proportional valve is used to control the lowering of the telescopic arm. The lifting and lowering of the telescopic arm in this article substantially refers to the lifting and lowering of the sling connected to the telescopic arm.

[0104] Furthermore, before substituting the spreader radius error into the opening calculation formula based on the fuzzy proportional control algorithm, the corresponding reference opening value can also be determined according to the angle interval of the current lifting angle at the current moment.

[0105] This embodiment can divide the value range of the current lifting angle into multiple angle intervals, and set a corresponding reference opening value for each angle interval. The instruction types of vertical lifting instructions include vertical lifting instructions and vertical descent instructions. Further, this embodiment can also set a corresponding reference opening value for each angle interval and the corresponding instruction type. The above-mentioned handle opening includes the lifting handle opening and the descent handle opening. If the instruction type is a vertical lifting instruction, the lifting handle opening is used, and if the instruction type is a vertical descent instruction, the descent handle opening is used.

[0106] The number of the above angle intervals can be any value, so the reference opening values ​​include but are not limited to the following:

[0107] (1) If the current lifting angle is greater than 0 degrees and less than or equal to 35 degrees, and the command type is a vertical lifting command, the reference opening value = ;

[0108] (2) If the current lifting angle is greater than 35 degrees and less than or equal to 60 degrees, and the command type is a vertical lifting command, the reference opening value = ;

[0109] (3) If the current lifting angle is greater than 0 degrees and less than or equal to 35 degrees, and the command type is a vertical descent command, the reference opening value = ;

[0110] (4) If the current lifting angle is greater than 35 degrees and less than or equal to 60 degrees, and the command type is a vertical descent command, the reference opening value = .

[0111] As a further introduction to the above embodiment, in this embodiment, the second opening value may be calculated using a PID control formula; and the telescopic control information includes the above second opening value.

[0112] Wherein, the PID control formula is:

[0113] ;

[0114] Indicates the second opening value, represents the proportional gain, Indicates the spreader radius error at the current moment, represents the integral gain, Represents the cumulative sum of all spreader radius errors, represents the differential gain, Indicates the spreader radius error at the last moment;

[0115] After obtaining the second opening value, the opening of the extension proportional valve and / or the retraction proportional valve can be adjusted according to the second opening value; wherein the extension proportional valve is used to control the extension of the telescopic arm, and the retraction proportional valve is used to control the retraction of the telescopic arm.

[0116] Specifically, the process of calculating the second opening value using the PID control formula includes: determining the instruction type of the vertical lifting instruction; if the instruction type is a vertical lifting instruction, calculating the second opening value using the first PID control formula; if the instruction type is a vertical descent instruction, calculating the second opening value using the second PID control formula;

[0117] Wherein, the first PID control formula is:

[0118] ; Indicates the lifting proportional gain, Indicates the hoisting integral gain, Indicates the lifting differential gain;

[0119] The second PID control formula is:

[0120] ; represents the decreasing proportional gain, Indicates decreasing integral gain, Indicates decreasing differential gain.

[0121] The process described in the above embodiment is explained below through an embodiment in actual application.

[0122] The current vertical lifting control strategy of electric reach stackers is to either use the controller to control the pitch and telescopic movements of the boom according to the value of the long angle sensor using the PID control principle to achieve the vertical lifting function of the spreader, or to achieve the vertical lifting function of the spreader by maintaining the pitch and telescopic movements at the same level or by adopting open-loop control according to the value of the long angle sensor, and only adjusting the other movement. The above-mentioned electric reach stackers are specially designed for 20-foot and 40-foot containers, and are mainly used for stacking containers and horizontal transportation within the yard. They are important equipment for stacking and loading and unloading containers in docks, ports, railway yards and other places.

[0123] The existing vertical lifting technology uses the method of maintaining or open-loop control for one action and using PID control for the action in one direction, which will slow down the vertical lifting action, fail to fully exert the performance of the machine, and reduce efficiency. If the PID control method is used for both pitch and telescopic actions at the same time, it will lead to difficulty in adjusting parameters. The problem that PID parameters of different models cannot be universal will consume a lot of manpower in debugging parameters, and the labor cost is too high.

[0124] In response to the defects existing in the above-mentioned related technologies, this embodiment provides an electric reach stacker vertical lifting control solution that combines debugging fuzzy proportional control and PID control, which can solve the problem of frequent adjustment of handle movements during the vertical lifting of container reach stackers, thereby improving the vehicle's operating feel and performance level.

[0125] The vehicle controller controls the pitching action of the boom based on the closed-loop fuzzy proportional control algorithm according to the value of the length and angle sensor, and controls the telescopic action of the boom based on the PID control algorithm. The vehicle controller automatically adjusts the pitching angle and telescopic length of the boom according to the calculated spreader radius (COG) deviation value, thereby realizing the vertical lifting and lowering of the boom spreader. In the entire algorithm strategy, the maximum absolute value of the allowable radius error is introduced , PID parameters for vertical lifting ( , , ), PID parameters for vertical descent ( , , ), the maximum opening value of the lifting proportional valve during vertical lifting , , the maximum opening value of the descending proportional valve when descending vertically , , the minimum speed required for the pump motor to rise and fall vertically Twelve adjustable parameters, which can be set by the administrator through an interactive instrument, adjust the accuracy and efficiency of the vertical lift function.

[0126] See also Figure 3 , Figure 3 A control system signal acquisition block diagram of an electric reach crane provided in an embodiment of the present application, the electric reach crane includes a vehicle controller VCU, a joystick J, a length angle sensor ACQ, an interactive instrument (also known as an interactive bus instrument) P, a lifting proportional valve (i.e., a boom lifting proportional valve) Y1, a lowering proportional valve (i.e., a boom lowering proportional valve) Y2, an extending proportional valve (i.e., a boom extending proportional valve) Y3, a retracting proportional valve (i.e., a boom retracting proportional valve) Y4, and a pump motor controller MCU.

[0127] The electric reach stacker may also include a pump motor. A vertical lift control button is integrated on the operating handle, and the handle communicates with the VCU via a bus.

[0128] The target speed and the current motor speed r can be transmitted between the vehicle controller VCU and the pump motor controller MCU. The joystick J can transmit the joystick direction, joystick opening and vertical lifting enable signal to the vehicle controller VCU. Figure 4 , Figure 4 This is a schematic diagram of the appearance of a joystick provided in an embodiment of the present application, showing a vertical lifting switch of the joystick.

[0129] The vehicle controller controls the speed of the pump motor and the operating current of the boom proportional valves Y1~Y4 by comprehensively analyzing the angle, length and status of the joystick, and combines the parameters set by the instrument to achieve vertical lifting and lowering of the boom hoist; the bus instrument, joystick, ACQ sensor, vehicle controller and motor controller exchange information through the CAN bus.

[0130] The administrator can set adjustable parameters 1, 2, 3, ..., n on the interactive instrument P. For example, the adjustable parameters include:

[0131] Maximum absolute value of the allowable spreader radius error ;

[0132] PID parameters for vertical lifting (lifting proportional gain , Lifting integral gain , Lifting differential gain );

[0133] PID parameters for vertical descent (descent proportional gain , reduce the integral gain , decrease the differential gain );

[0134] Maximum opening value of the lifting proportional valve during vertical lifting , ;

[0135] Maximum opening value of the descending proportional valve during vertical descent , ;

[0136] Minimum speed required for the pump motor to rise and fall vertically .

[0137] The accuracy and efficiency of system operation are adjusted through the twelve adjustable parameters mentioned above.

[0138] This embodiment provides a method for controlling the vertical lifting of an electric reach stacker, which specifically includes the following steps:

[0139] Step B1: The controller obtains the customer-set adjustable parameters through the instrument, including the maximum absolute value of the allowable spreader radius error. , PID parameters for vertical lifting ( , , ), PID parameters for vertical descent ( , , ), the maximum opening value of the lifting proportional valve during vertical lifting , , the maximum opening value of the descending proportional valve when descending vertically , , the minimum speed required for the pump motor to rise and fall vertically .

[0140] In this embodiment, the values ​​of the above parameters are as follows:

[0141] =200mm, =0.55, =0.2, =0, =0.6, =0.2, =1, =70%, =60%, =30%, =60%, =1000rpm.

[0142] Step B2: The vehicle controller obtains the distance of the telescopic arm by collecting data from the length angle sensor ACQ (m) and the angle of the boom lifting The distance that the telescopic arm extends is And the angle value of the boom lifting It can be measured in real time by calibrating the length and angle sensor installed on the telescopic arm.

[0143] Step B3: The vehicle controller calculates the angle between the straight line from the hinge point D on the sling to the rear hinge point A and the horizontal line of the rear hinge point A. :

[0144] .

[0145] Step B4: The vehicle controller calculates the straight-line distance from the hinge point D on the sling to the rear hinge point A :

[0146] .

[0147] Step B5: The vehicle controller substitutes the results of steps B3 and B4 into the calculation of the horizontal distance between the center of the spreader and the center of the front wheel. :

[0148] ;

[0149] In the formula, wheelbase (m), vertical distance from the rear hinge point of the telescopic arm to the upper hinge point of the sling (m) and the horizontal distance from the rear hinge point of the telescopic arm to the hinge point on the sling when it is fully retracted (m) is the structural parameter of the front loader; the distance the telescopic arm extends (m) and the angle of the boom lifting (°) is a variable parameter obtained by the length and angle sensor.

[0150] In this embodiment, the values ​​of the above parameters are as follows:

[0151] ;

[0152] ;

[0153] .

[0154] Step B6: The vehicle controller determines the data status of the joystick. If the vertical lifting switch signal on the handle is 1 and an ascending state command is issued, the vertical lifting control program of step B7 is entered; if the vertical lifting switch signal on the handle is 1 and a descending state command is issued, the vertical descending control program of step B8 is entered. If the vertical lifting switch signal is 0, the vehicle enters the normal working state, that is, normal lifting and descending actions are performed at this time, and the control of the vertical lifting algorithm is not performed.

[0155] Step B7: The process of the vertical lifting control program is as follows: the vehicle controller obtains the opening degree of the handle when lifting according to the handle signal The VCU controls the pump motor through the pump motor controller MCU to follow the minimum speed required for vertical lifting. Run. The VCU register records the current telescopic arm extension distance of the spreader through the length angle sensor ACQ when the vertical lift button is pressed And the angle value of the boom lifting , substitute into step B5 to calculate the target spreader radius value , calculate the real-time error value of the spreader radius :

[0156] .

[0157] The vehicle controller controls the opening of the lifting proportional valve Y1 during lifting The calculation is as follows:

[0158] ;

[0159] In the formula It is the maximum opening value allowed by the lifting proportional valve when the boom angle is within the range of 0 to 35 degrees during vertical lifting. It is the maximum opening value allowed by the lifting proportional valve when the boom angle is within the range of 35 to 60 degrees during vertical lifting. is the maximum absolute value of the allowable radius error.

[0160] The vehicle controller adopts PID control method to control the opening of the telescopic proportional valves Y3 and Y4 of the telescopic cylinder of the boom during lifting. The calculation is as follows:

[0161] ;

[0162] In the above formula is the lifting proportional gain, is the lifting integral gain; is the lifting differential gain; , are the spreader radius errors at the current sampling moment and the last sampling moment respectively; It is the cumulative sum of all radius errors between the current moment and the past moments.

[0163] Step B8: The process of the vertical descent control program is as follows: the vehicle controller obtains the opening degree of the handle when it descends according to the handle signal The VCU controls the pump motor through the pump motor controller MCU to follow the minimum speed required for vertical lifting. The VCU register records the current telescopic arm extension distance of the spreader obtained through the ACQ sensor when the vertical lift button is pressed. And the angle value of the boom lifting , substitute into step B5 to calculate the target spreader radius value , and then calculate the real-time error value of the spreader radius :

[0164] .

[0165] The vehicle controller controls the opening of the descending proportional valve Y2 during lifting The calculation is as follows:

[0166] ;

[0167] In the formula It is the maximum opening value allowed by the descending proportional valve when the boom angle is within the range of 0 to 35 degrees during vertical descent. It is the maximum opening value allowed by the descending proportional valve when the boom angle is within the range of 35 to 60 degrees during vertical descent. is the maximum absolute value of the allowable radius error.

[0168] The vehicle controller adopts PID control method to control the opening of the telescopic proportional valves Y3 and Y4 of the telescopic cylinder of the boom during descent. The calculation is as follows:

[0169] ;

[0170] In the formula To decrease the proportional gain, To decrease the integral gain; To decrease the differential gain; , are the spreader radius errors at the current sampling moment and the last sampling moment respectively; It is the cumulative sum of all radius errors between the current moment and the past moments.

[0171] The It is the maximum opening value allowed by the lifting proportional valve when the boom angle is within the range of 0 to 35 degrees during vertical lifting. It is the maximum opening value allowed by the lifting proportional valve when the boom angle is within the range of 35 to 60 degrees during vertical lifting. It is the maximum opening value allowed by the descending proportional valve when the boom angle is within the range of 0 to 35 degrees during vertical descent. The maximum opening value allowed for the descending proportional valve when the boom angle is within the range of 35 to 60 degrees during vertical descent. These four parameters are determined by analyzing the mathematical boundary conditions of the boom extension distance, lifting distance, and descending distance. The agreement on these four parameters ensures the success rate of the PID control of the telescopic direction proportional valve and reduces the difficulty of PID tuning.

[0172] See also Figure 5 , Figure 5 A flowchart of a vertical lifting control program provided in an embodiment of the present application specifically includes the following steps:

[0173] Step C1: The vehicle controller obtains the joystick direction and opening data , arm extension distance , boom lifting angle, PID parameter value during vertical lifting, and allowable error value of the spreader radius , Maximum opening value allowed by the lifting proportional valve during vertical lifting and .

[0174] Step C2: Determine whether the vertical lifting function is triggered; if so, proceed to step C3; if not, end the process.

[0175] Step C3: Determine whether the handle is in the lifting state; if so, proceed to step C4; if not, end the process.

[0176] Step C4: The vehicle controller controls the vehicle according to the handle opening , the obtained parameters are used to calculate the real-time spreader radius COG and the target spreader radius when the vertical lift button is pressed .

[0177] Step C5: The controller calculates the real-time error value of the spreader radius .

[0178] Step C6: The controller is based on the error value The PID algorithm is used to control the opening of the telescopic proportional valves Y3 and Y4 in real time.

[0179] Step C7: The controller calculates the opening value of the lifting proportional valve Y1 according to the result of the telescopic valve PID setting and the current boom lifting angle value.

[0180] See also Figure 6 , Figure 6 A flowchart of a vertical descent control program provided in an embodiment of the present application specifically includes the following steps:

[0181] Step D1: The vehicle controller obtains the direction and opening data of the joystick , arm extension distance , boom lifting angle, PID parameter value during vertical descent, and allowable error value of the spreader radius , Maximum opening value allowed for the descending proportional valve during vertical descent and .

[0182] Step D2: Determine whether the vertical lifting function is triggered; if so, proceed to step C3; if not, end the process.

[0183] Step D3: Determine whether the handle is in the descending state; if so, proceed to step C4; if not, end the process.

[0184] Step D4: The vehicle controller controls the vehicle according to the handle opening , the obtained parameters are used to calculate the real-time spreader radius COG and the target spreader radius when the vertical lift button is pressed .

[0185] Step D5: The controller calculates the real-time error value of the spreader radius .

[0186] Step D6: The controller is based on the error value The PID algorithm is used to control the opening of the telescopic proportional valves Y3 and Y4 in real time.

[0187] Step D7: The controller calculates the opening value of the descending proportional valve Y2 according to the result of the telescopic valve PID setting and the current boom lifting angle value.

[0188] This embodiment controls the lifting or lowering proportional valve by a joint control method based on the boom lifting angle and the sling radius deviation range value. It can automatically correct and adjust the vertical lifting or lowering speed according to the PID setting result of the boom extension and retraction action, thereby maximizing the working efficiency of the vertical lifting function while greatly reducing the difficulty of PID setting in the extension and retraction direction.

[0189] The above control strategy introduces the maximum opening value of the lifting proportional valve during vertical lifting. , The maximum opening value of the proportional valve when descending vertically , A control method of controlling the boom lifting proportional valve and the boom lowering proportional valve in sections by the boom lifting angle is proposed. These four parameters are agreed upon to ensure the success rate of PID control of the telescopic direction proportional valve and further reduce the difficulty of PID setting in the telescopic direction.

[0190] In the above control strategy, different PID parameter setting values ​​are used for the control of telescopic proportional valves for vertical lifting and vertical descent ( , , , , , ), which increases the adaptability of this embodiment to different vehicle models.

[0191] The above control strategy introduces the maximum absolute value of the allowable spreader radius error When the deviation value exceeds the limit, the opening value of the extension proportional valve Y3 can be limited to 0, ensuring the lower limit of the debugging accuracy and avoiding the impact on the next row of containers due to unstable debugging accuracy or emergencies.

[0192] An embodiment of the present application provides a vertical lifting control system for an electric reach stacker, the system may include:

[0193] A measuring module, for determining an initial extension distance and an initial lifting angle of the electric reach stacker at an initial moment if a vertical lifting instruction is received; wherein the initial moment is a moment when the vertical lifting instruction is received;

[0194] A target determination module, used for calculating a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters;

[0195] An error calculation module, used to determine the actual spreader radius at the current moment, and calculate the spreader radius error at the current moment according to the target spreader radius and the actual spreader radius;

[0196] A first processing module is used to perform processing based on a fuzzy proportional control algorithm according to the spreader radius error to obtain lifting control information;

[0197] A second processing module is used to process the PID control algorithm according to the spreader radius error to obtain telescopic control information;

[0198] The control module is used to control the lifting proportional valve according to the lifting control information, and to control the telescopic proportional valve according to the telescopic control information, so that the lifting device of the electric front crane can perform vertical lifting movement.

[0199] This embodiment provides a vertical lifting control method for an electric front crane. After receiving a vertical lifting instruction, this scheme calculates the target sling radius according to the initial extension distance, initial lifting angle and equipment structure parameters at the time of receiving the vertical lifting instruction; the actual sling radius at the current moment is compared with the target sling radius to obtain the sling radius error. This embodiment combines the sling radius error with a fuzzy proportional control algorithm to obtain lifting control information; it also processes the PID control algorithm according to the sling radius error to obtain telescopic control information; according to the above lifting control information and telescopic control information, the sling of the electric front crane can be controlled to perform vertical lifting movement. Through the fuzzy logic of the above fuzzy proportional control algorithm, this embodiment can dynamically adjust the control strategy according to the degree of the sling radius error, thereby improving the adaptability and robustness of the lifting control; this embodiment also uses the PID control algorithm for telescopic control. It can be seen that this embodiment can automatically control the electric front crane to perform vertical lifting movement while ensuring efficiency and accuracy by comprehensively using fuzzy proportional control and PID control algorithms, combined with real-time error monitoring and proportional valve control.

[0200] Furthermore, the process of the target determination module calculating the target spreader radius according to the initial extension distance, the initial lifting angle and the equipment structure parameters includes:

[0201] Determine the horizontal distance of the hinge point, the vertical distance of the hinge point and the wheelbase according to the equipment structure parameters; wherein the horizontal distance of the hinge point is the distance between the upper hinge point and the rear hinge point in the horizontal direction under the reference state, and the vertical distance of the hinge point is the distance between the upper hinge point and the rear hinge point in the vertical direction under the reference state; the reference state is a state where the lifting angle is equal to 0 and the extension distance of the telescopic arm is equal to 0, the upper hinge point is the hinge point between the inner arm of the telescopic arm and the sling, and the rear hinge point is the hinge point between the outer arm of the telescopic arm and the vehicle body; calculate the initial reference angle and the initial hinge point distance according to the initial extension distance, the horizontal distance of the hinge point and the vertical distance of the hinge point; wherein the initial reference angle is the angle between the target straight line and the horizontal direction at the initial moment, the target straight line is the line connecting the upper hinge point and the rear hinge point, and the initial hinge point distance is the distance between the upper hinge point and the rear hinge point at the initial moment; calculate the target sling radius according to the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase.

[0202] Further, the process of calculating the target spreader radius by the target determination module according to the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase includes:

[0203] Substituting the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase into the spreader radius calculation formula to obtain the target spreader radius;

[0204] The calculation formula of the spreader radius is: , represents the target spreader radius, represents the initial hinge distance, Indicates the initial lifting angle, represents the initial reference angle, Indicates wheelbase.

[0205] Furthermore, the first processing module performs processing based on the fuzzy proportional control algorithm according to the spreader radius error to obtain the lifting control information, including: substituting the spreader radius error into the opening calculation formula based on the fuzzy proportional control algorithm to obtain a first opening value;

[0206] Wherein, the opening calculation formula is: ; Indicates the first opening value, Indicates the handle opening, Indicates the spreader radius error, Indicates the maximum absolute value of the spreader radius error, Indicates the reference opening value, min means the minimum value, and max means the maximum value;

[0207] Correspondingly, the process in which the control module controls the lifting proportional valve according to the lifting control information includes: adjusting the opening of the lifting proportional valve or the lowering proportional valve according to the first opening value; wherein the lifting proportional valve is used to control the lifting of the telescopic arm, and the lowering proportional valve is used to control the lowering of the telescopic arm.

[0208] Furthermore, the first processing module is also used to determine the corresponding reference opening value according to the angle interval of the current lifting angle at the current moment before substituting the spreader radius error into the opening calculation formula based on the fuzzy proportional control algorithm.

[0209] Furthermore, the second processing module performs PID control algorithm processing according to the spreader radius error to obtain the telescopic control information, and the process includes: calculating the second opening value by using the PID control formula;

[0210] Wherein, the PID control formula is: ;

[0211] Indicates the second opening value, represents the proportional gain, Indicates the spreader radius error at the current moment, represents the integral gain, Represents the cumulative sum of all spreader radius errors, represents the differential gain, Indicates the spreader radius error at the last moment;

[0212] Correspondingly, the process in which the control module controls the telescopic proportional valve according to the telescopic control information includes: adjusting the opening of the extension proportional valve and / or the retraction proportional valve according to the second opening value; wherein the extension proportional valve is used to control the extension of the telescopic arm, and the retraction proportional valve is used to control the retraction of the telescopic arm.

[0213] Further, the process of the second processing module calculating the second opening value using the PID control formula includes: determining the instruction type of the vertical lifting instruction; if the instruction type is a vertical lifting instruction, calculating the second opening value using the first PID control formula; if the instruction type is a vertical descent instruction, calculating the second opening value using the second PID control formula;

[0214] Wherein, the first PID control formula is:

[0215] ; Indicates the lifting proportional gain, Indicates the hoisting integral gain, Indicates the lifting differential gain;

[0216] The second PID control formula is:

[0217] ; represents the decreasing proportional gain, Indicates decreasing integral gain, Indicates decreasing differential gain.

[0218] Furthermore, it also includes:

[0219] The motor control module is used to determine the minimum motor speed required for the electric front crane to perform vertical lifting movement after receiving the vertical lifting instruction, and control the pump motor according to the minimum motor speed; wherein the pump motor is used to provide hydraulic oil to the lifting proportional valve and the telescopic proportional valve.

[0220] Furthermore, the process of the measurement module determining the initial extension distance and initial lifting angle of the electric reach stacker at the initial moment includes:

[0221] The initial extension distance and the initial lifting angle of the electric reach crane at the initial moment are determined by using a length and angle sensor; wherein the length and angle sensor is installed on the telescopic arm of the electric reach crane.

[0222] Since the embodiments of the system part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the system part, which will not be repeated here.

[0223] The present application also provides a storage medium on which a computer program is stored, and when the computer program is executed, the steps provided in the above embodiment can be implemented. The storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0224] The present application also provides an electronic device, which may include a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps provided in the above embodiment may be implemented. Of course, the electronic device may also include various network interfaces, power supplies and other components.

[0225] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of this application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of this application.

[0226] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A vertical lifting control method for an electric reach stacker, characterized in that: include: If a vertical lifting instruction is received, determining an initial extension distance and an initial lifting angle of the electric reach stacker at an initial time; wherein the initial time is the time when the vertical lifting instruction is received; Calculate a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters; Determine an actual spreader radius at a current moment, and calculate a spreader radius error at a current moment according to the target spreader radius and the actual spreader radius; Processing based on the fuzzy proportional control algorithm is performed according to the spreader radius error to obtain lifting control information; Processing the PID control algorithm according to the spreader radius error to obtain telescopic control information; The lifting proportional valve is controlled according to the lifting control information, and the telescopic proportional valve is controlled according to the telescopic control information, so that the lifting device of the electric front crane performs vertical lifting movement.

2. The vertical lifting control method of the electric reach stacker according to claim 1, characterized in that: Calculating a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters includes: Determine the horizontal distance of the hinge points, the vertical distance of the hinge points and the wheelbase according to the structural parameters of the equipment; wherein the horizontal distance of the hinge points is the distance between the upper hinge point and the rear hinge point in the horizontal direction under the reference state, and the vertical distance of the hinge points is the distance between the upper hinge point and the rear hinge point in the vertical direction under the reference state; the reference state is a state where the lifting angle is equal to 0 and the extension distance of the telescopic arm is equal to 0, the upper hinge point is the hinge point between the inner arm of the telescopic arm and the sling, and the rear hinge point is the hinge point between the outer arm of the telescopic arm and the vehicle body; The initial reference angle and the initial hinge point distance are calculated according to the initial extension distance, the hinge point horizontal distance and the hinge point vertical distance; wherein the initial reference angle is the angle between the target straight line and the horizontal direction at the initial moment, the target straight line is the line connecting the upper hinge point and the rear hinge point, and the initial hinge point distance is the distance between the upper hinge point and the rear hinge point at the initial moment; The target spreader radius is calculated according to the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase.

3. The vertical lifting control method of the electric reach stacker according to claim 2, characterized in that: Calculating the target spreader radius according to the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase includes: Substituting the initial reference angle, the initial hinge point distance, the initial lifting angle and the wheelbase into the spreader radius calculation formula to obtain the target spreader radius; The calculation formula of the spreader radius is: , represents the target spreader radius, represents the initial hinge distance, Indicates the initial lifting angle, represents the initial reference angle, Indicates wheelbase.

4. The vertical lifting control method of the electric reach stacker according to claim 1, characterized in that: According to the spreader radius error, a fuzzy proportional control algorithm is used to process and obtain lifting control information, including: Substituting the spreader radius error into an opening calculation formula based on a fuzzy proportional control algorithm to obtain a first opening value; Wherein, the opening calculation formula is: ; Indicates the first opening value, Indicates the handle opening, Indicates the spreader radius error, Indicates the maximum absolute value of the spreader radius error, Indicates the reference opening value, min means the minimum value, and max means the maximum value; Correspondingly, controlling the lifting proportional valve according to the lifting control information includes: The opening of the lifting proportional valve or the lowering proportional valve is adjusted according to the first opening value; wherein the lifting proportional valve is used to control the lifting of the telescopic arm, and the lowering proportional valve is used to control the lowering of the telescopic arm.

5. The vertical lifting control method of the electric reach stacker according to claim 4, characterized in that: Before substituting the spreader radius error into the opening calculation formula based on the fuzzy proportional control algorithm, it also includes: The corresponding reference opening value is determined according to the angle interval of the current lifting angle at the current moment.

6. The vertical lifting control method of the electric reach stacker according to claim 1, characterized in that: The PID control algorithm is processed according to the spreader radius error to obtain telescopic control information, including: Calculate the second opening value using the PID control formula; Wherein, the PID control formula is: ; Indicates the second opening value, represents the proportional gain, Indicates the spreader radius error at the current moment, represents the integral gain, Represents the cumulative sum of all spreader radius errors, represents the differential gain, Indicates the spreader radius error at the last moment; Correspondingly, controlling the telescopic proportional valve according to the telescopic control information includes: The opening of the extension proportional valve and / or the retraction proportional valve is adjusted according to the second opening value; wherein the extension proportional valve is used to control the extension of the telescopic arm, and the retraction proportional valve is used to control the retraction of the telescopic arm.

7. The vertical lifting control method of the electric reach stacker according to claim 6, characterized in that: The second opening value is calculated using the PID control formula, including: Determining the instruction type of the vertical lift instruction; If the instruction type is a vertical lifting instruction, the second opening value is calculated using the first PID control formula; If the instruction type is a vertical descent instruction, the second opening value is calculated using the second PID control formula; Wherein, the first PID control formula is: ; Indicates the lifting proportional gain, Indicates the hoisting integral gain, Represents the lifting differential gain, and the second PID control formula is: ; represents the decreasing proportional gain, Indicates decreasing integral gain, Indicates decreasing differential gain.

8. The vertical lifting control method of the electric reach stacker according to claim 1, characterized in that: After receiving the vertical lift command, it also includes: Determine the minimum motor speed required for the electric reach crane's lifting device to perform vertical lifting movement, and control the pump motor according to the minimum motor speed; wherein the pump motor is used to provide hydraulic oil to the lifting proportional valve and the telescopic proportional valve.

9. The vertical lifting control method of the electric reach stacker according to claim 1, characterized in that: Determine the initial reach and initial lifting angle of the electric reach stacker at the initial moment, including: The initial extension distance and the initial lifting angle of the electric reach crane at the initial moment are determined by using a length and angle sensor; wherein the length and angle sensor is installed on the telescopic arm of the electric reach crane.

10. A vertical lifting control system for an electric reach stacker, characterized in that: include: A measuring module, for determining an initial extension distance and an initial lifting angle of the electric reach stacker at an initial moment if a vertical lifting instruction is received; wherein the initial moment is a moment when the vertical lifting instruction is received; A target determination module, used for calculating a target spreader radius according to the initial extension distance, the initial lifting angle and equipment structural parameters; An error calculation module, used to determine the actual spreader radius at the current moment, and calculate the spreader radius error at the current moment according to the target spreader radius and the actual spreader radius; A first processing module is used to perform processing based on a fuzzy proportional control algorithm according to the spreader radius error to obtain lifting control information; A second processing module is used to process the PID control algorithm according to the spreader radius error to obtain telescopic control information; The control module is used to control the lifting proportional valve according to the lifting control information, and to control the telescopic proportional valve according to the telescopic control information, so that the lifting device of the electric front crane can perform vertical lifting movement.

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