A hoisting operation method and a master-slave collaborative hoisting system

Abstract

The present application provides a lifting operation method and a master-slave collaborative lifting system. The lifting operation method provided by the present application includes: obtaining the actual displacement and actual speed at the current moment; determining the expected displacement and expected speed at the current moment according to the operation path; determining the state error of the slave crane relative to the master crane according to the expected displacement, expected speed, actual displacement, actual speed, and the current inclination angle of the hoisted object relative to the horizontal plane; determining the command conversion rate of the slave crane according to the state error, and calculating the target expected speed of the slave crane at the next moment according to the actual speed and the command conversion rate; controlling the slave crane according to the target expected speed so that the slave crane follows the action of the master crane to achieve the purpose of collaborative lifting of the hoisted object. The lifting operation method and master-slave collaborative lifting system provided by the present application can reduce the error between the master and the slave through the command conversion rate, and can accurately realize the synchronous operation between the master and the slave.

Description

Technical Field

[0001] The present application relates to the technical field of cranes, and in particular to a hoisting operation method and a master-slave collaborative hoisting system. Background Art

[0002] Master-slave crane collaborative operation realizes the lifting tasks of heavy, long and complex objects that are difficult to complete with a single crane through the synchronous operation of multiple cranes. Master-slave crane collaborative operation has important application value in the fields of heavy equipment installation, bridge and high-rise building construction, large structure handling and assembly, emergency rescue and high-precision handling.

[0003] Accurately realizing the synchronous operation of master and slave cranes can not only greatly improve the construction efficiency, but also ensure the safety of construction. Therefore, how to accurately realize the synchronous operation of master and slave cranes has become a problem that needs to be solved urgently. Summary of the invention

[0004] In view of this, the present application provides a hoisting operation method and a master-slave collaborative hoisting system to accurately realize the synchronous operation of the master and slave cranes.

[0005] Specifically, the present application is implemented through the following technical solutions:

[0006] In a first aspect, the present application provides a hoisting operation method, which is applied to a slave crane in a master-slave cooperative hoisting system; the master-slave cooperative hoisting system also includes a master crane, and the master crane and the slave crane are initially located at their respective corresponding predetermined hoisting positions in an initial posture; the master crane is controlled by a driver to operate according to a pre-planned operation path; the method includes:

[0007] Get the actual displacement and actual speed at the current moment;

[0008] Determine the expected displacement and expected speed at the current moment according to the operation path;

[0009] Determine a state error of the slave crane relative to the master crane according to the expected displacement, the expected speed, the actual displacement, the actual speed, and the current inclination angle of the hoisted object relative to the horizontal plane; wherein the state error is related to the displacement, the speed, and the inclination angle of the hoisted object relative to the horizontal plane;

[0010] Determine the instruction conversion rate of the slave crane according to the state error, and calculate the target expected speed of the slave crane at the next moment according to the actual speed and the instruction conversion rate; wherein the target expected speed is equal to the product of the actual speed and the instruction conversion rate;

[0011] The slave crane is controlled according to the target desired speed so that the slave crane follows the action of the master crane to achieve the purpose of collaboratively lifting the hoisted object.

[0012] A second aspect of the present application provides a master-slave collaborative lifting system, the master-slave collaborative lifting system comprising a server, a master crane and a slave crane; wherein:

[0013] The server is used to respond to the lifting task set by the user and pre-plan the operation path between the starting lifting position and the ending lifting position according to the starting lifting position and the ending lifting position preset in the lifting task;

[0014] The server is further used to determine the predetermined lifting position and initial posture corresponding to the master crane, and the predetermined lifting position and initial posture corresponding to the slave crane according to the starting lifting position and the ending lifting position;

[0015] The server is further used to send the predetermined lifting position and initial posture corresponding to the main crane to the main crane, so that the main crane moves to the predetermined lifting position and initializes the posture to the initial posture;

[0016] The server is further used to send the predetermined lifting position and initial posture corresponding to the slave crane to the slave crane, so that the slave crane moves to the predetermined lifting position and initializes the posture to the initial posture;

[0017] The server is further used to send the operation path to the main crane, so that the main crane is controlled by the driver to perform the operation according to the operation path;

[0018] The server is further used to send the operation path to the slave crane;

[0019] The slave crane is used to operate according to any of the methods provided in the first aspect of the present application, so as to follow the action of the master crane and achieve the purpose of collaboratively lifting the hoisted object.

[0020] The hoisting operation method and master-slave collaborative hoisting system provided by the present application, on the one hand, by determining the state error of the slave crane relative to the master crane, and then determining the command conversion rate of the slave crane according to the state error, and calculating the target expected speed of the slave crane at the next moment according to the actual speed and the command conversion rate, so as to control the slave crane according to the target expected speed, in this way, by dynamically adjusting the command conversion rate, it is possible to flexibly respond to the error between the master and the slave, so as to determine the target expected speed through the command conversion rate, and then reduce the error between the master and the slave through the target expected speed, so that the slave can accurately follow the master, complete the synchronization and collaborative operation between the master and the slave, and ensure the smooth progress of the operation. On the other hand, when calculating the state error, the speed, displacement and the inclination angle of the hoisted object relative to the horizontal plane are comprehensively considered, so that the state difference between the slave and the master can be accurately evaluated, and then the slave can be accurately controlled based on this, so as to achieve accurate synchronization between the master and the slave.

[0021] In addition, the hoisting operation method and the master-slave collaborative hoisting system provided by the present application, after controlling the slave crane according to the target expected speed, calculates the first lifting height of the slave crane, and then calculates the current lifting inclination angle of the hoisted object according to the first lifting height, so that the second lifting height of the master crane can be calculated according to the lifting inclination angle, and the hoisting compensation amount of the slave crane can be calculated according to the first lifting height and the second lifting height. In this way, the hoisting of the slave crane can be controlled to change the hoisting compensation amount to compensate for the balance of the hoisted object, so that the lifting inclination angle is equal to 90°. In this way, the master and slave cranes can be ensured to rise and fall synchronously, maintain the stable state of the hoisted object, reduce the risk and complexity of the operation, ensure the safety of the operation, and prevent the damage of the hoisted object caused by imbalance.

[0022] Furthermore, in the present application, the inner layer speed control and the outer layer displacement control can be realized through the double closed-loop PID control algorithm, and the purpose of precise control can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of a master-slave collaborative lifting system shown as an exemplary embodiment of the present application;

[0024] Figure 2 This is a schematic diagram showing an implementation principle of determining a predetermined lifting position of a master and slave crane according to an exemplary embodiment of the present application;

[0025] Figure 3 A flowchart of a first embodiment of the hoisting operation method provided in this application;

[0026] Figure 4 A flowchart of Embodiment 2 of the hoisting operation method provided in this application;

[0027] Figure 5This is a schematic diagram showing the implementation principle of winch compensation according to an exemplary embodiment of the present application;

[0028] Figure 6 A flowchart of Embodiment 3 of the hoisting operation method provided in this application;

[0029] Figure 7 An exemplary embodiment provided in the present application shows a schematic diagram of implementing the control of a slave crane according to a target desired speed. DETAILED DESCRIPTION

[0030] Here, exemplary embodiments are described in detail, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application.

[0031] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0032] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0033] Specific embodiments are given below to introduce the technical solution of the present application in detail.

[0034] The hoisting operation method provided in the present application is applied to a slave crane in a master-slave cooperative hoisting system. The master-slave cooperative hoisting system is briefly introduced below.

[0035] Specifically, the master-slave collaborative lifting system can be a master crane and a slave crane. Before the lifting begins, the master crane and the slave crane are initially located at their respective corresponding predetermined lifting positions in an initial posture. After the lifting begins, the master crane is controlled by the driver to operate according to the pre-planned operation path. The slave crane operates according to the lifting operation method provided in this application.

[0036] Specifically, Figure 1This is a schematic diagram of a master-slave collaborative lifting system shown in an exemplary embodiment of the present application. Figure 1 The structures of the master crane and the slave crane may be the same or different, and this embodiment does not limit this. It should be noted that the hoisting operation method provided in this embodiment is applied to the slave crane.

[0037] Furthermore, the predetermined lifting position refers to the position of the crane during operation.

[0038] It should be noted that the master-slave collaborative lifting system also includes a server, and the predetermined lifting position is determined by the server when receiving a lifting task set by a user, based on the starting lifting position and the ending lifting position preset in the lifting task.

[0039] The following describes how to determine the intended lifting position:

[0040] Specifically, Figure 2 This is a schematic diagram showing an implementation principle of determining the predetermined lifting position of the master and slave cranes according to an exemplary embodiment of the present application. Figure 2 In one possible implementation, the predetermined lifting position is determined by the following method:

[0041] (1) According to the preset starting lifting position A and ending lifting position B, a target line segment AB formed by the starting lifting position A and the ending lifting position B is determined.

[0042] It should be noted that the starting lifting position A refers to the initial position of the lifting object, and the ending lifting position B refers to the target position that the lifting object needs to reach. The starting lifting position A and the ending lifting position are set by the user according to actual needs, and are not limited in this embodiment.

[0043] (2) For each crane, according to a first constraint, searching for a target distance between a predetermined lifting position corresponding to the crane and the target line segment within the working range of the crane; wherein the first constraint is that the target distance is greater than the minimum working range of the crane and less than the maximum working range of the crane.

[0044] Specifically, for the convenience of explanation, the main crane is recorded as C, and the slave crane is recorded as D. For the main crane, the first constraint condition can be calculated using the following formula:

[0045] ,

[0046] in, Refers to the minimum working range of the main crane C;

[0047] It refers to the target distance from the predetermined lifting position corresponding to the main crane C to the target line segment;

[0048] Refers to the maximum working range of the main crane C.

[0049] Similarly, for the slave crane D, the first constraint can be calculated using the following formula:

[0050] ,

[0051] in, Refers to the minimum working range of crane D;

[0052] It refers to the target distance from the predetermined lifting position corresponding to the crane D to the target line segment;

[0053] Refers to the maximum working range of the slave crane D.

[0054] It should be noted that, refer to Figure 2 For a crane, the working range of the crane refers to the annular area between the circle with the crane position as the center and the crane's minimum working range as the radius and the circle with the crane position as the center and the crane's maximum working range as the radius. For example, Figure 2 The main crane C in the figure has a working range between the two red circles. For example, Figure 2 The heavy slave crane D has a working range within the area between the two green circles.

[0055] In this step, for each crane, according to the first constraint condition, the target distance between the predetermined lifting position corresponding to the crane and the target line segment is searched within the working range of the crane. Figure 2 , the target distance is not unique.

[0056] (3) Determine the perpendicular bisector of the target line segment.

[0057] (4) For each crane, the predetermined lifting position corresponding to the crane is determined on the perpendicular bisector according to the target distance between the predetermined lifting position corresponding to the crane and the target line segment AB.

[0058] It should be noted that, referring to the previous description, when searching for the target distance, the target distance is not unique. After searching for a target distance, the perpendicular bisector of the target line segment is drawn. and Determine the preset lifting positions for both cranes.

[0059] It should be noted that, refer to Figure 2 , Figure 2The illustrated embodiment only illustrates how to determine the predetermined lifting position when the structures of the master and slave cranes are different. In actual applications, when the structures of the master and slave cranes are the same, the predetermined lifting position can also be determined according to this method.

[0060] In addition, the initial position refers to the position of the crane when the crane starts to operate. In specific implementation, the initial position of the master and slave cranes can be determined according to the preset starting lifting position.

[0061] It should be noted that before starting the operation, the master and slave cranes are located at their respective corresponding predetermined lifting positions in their respective initial postures.

[0062] Furthermore, the pre-planned operation path is also determined by the server in advance according to the lifting task. The method for determining the pre-planned operation path will be described in detail in the following embodiments and will not be repeated here.

[0063] Figure 3 This is a flow chart of the first embodiment of the hoisting operation method provided in this application. Please refer to Figure 3 , the method provided in this embodiment may include:

[0064] S301, obtaining the actual displacement and actual speed at the current moment.

[0065] Specifically, the current posture can be obtained, and then the actual displacement and actual speed at the current moment can be calculated based on the current posture. It should be noted that the posture of the crane includes the position and posture of the crane, and its posture is characterized by arm length, rotation angle and elevation angle.

[0066] S302: Determine the expected displacement and expected speed at the current moment according to the operation path.

[0067] Before introducing the specific implementation principle of this step, the following is a brief introduction to the operation path planning method.

[0068] Specifically, in a possible implementation, the operation path can be pre-planned by coordinate discretization and joint space solution. Coordinate discretization refers to dividing a continuous path or space into a series of discrete points. Joint space solution refers to converting each discrete point on the path into the position and posture of the crane.

[0069] Optionally, in a possible implementation, a method for planning a pre-planned operation path includes:

[0070] (1) Select multiple intermediate points between a preset starting lifting position and an ending lifting position, and determine a sequence consisting of the starting lifting position, the multiple intermediate points, and the ending lifting position as a trajectory path.

[0071] Specifically, the middle point may be selected manually or automatically using an RRT search algorithm.

[0072] It should be noted that for complex working environments, segmented path planning can be performed by selecting multiple intermediate points, for example, two intermediate points (Xm1, Ym1, Zm1) and (Xm2, Ym2, Zm2) or multiple intermediate points are selected between the starting lifting position (X1, Y1, Z1) and the ending lifting position (X2, Y2, Z2). An exemplary embodiment of the present application is described according to the case of selecting two intermediate points, and the path formed by the target starting position → the first intermediate point → the second intermediate point → the ending lifting position is the trajectory path.

[0073] Combined with the above example, for example, in one possible implementation, the starting lifting position and the ending lifting position are (0, 0, 0) and (10, 10, 10) respectively, and the two intermediate points are selected as (5, 0, 5) and (5, 10, 5) respectively. Then the path formed by (0, 0, 0) → (5, 0, 5) → (5, 10, 5) → (10, 10, 10) is the trajectory path.

[0074] (2) For each point in the trajectory path, determine the posture of the crane at the point, and determine a posture sequence consisting of the postures of the crane at each trajectory point in the trajectory path as an alternative operation path.

[0075] Specifically, after selecting the middle point, the joint space solution can be performed to solve the position and posture of the crane at each trajectory point.

[0076] It should be noted that the posture is a parameter that describes the specific state of the crane in three-dimensional space, including the position and posture of the crane. The posture is characterized by arm length, rotation angle, and elevation angle. In this application, the arm length of the crane remains unchanged during operation.

[0077] In specific implementation, the rotation angle and elevation angle can be calculated according to the position of each point in the trajectory path to obtain the position and posture of the crane at that point. The specific implementation principle and implementation process of calculating the rotation angle and elevation angle can be referred to the description in the relevant technology, which will not be repeated here.

[0078] For example, in an exemplary embodiment of the present application, the position and posture of the crane can be calculated through a known kinematic model and the position of the crane.

[0079] (3) Determine whether there is a collision on the alternative operation path by using a simulation experiment, and if there is a collision on the alternative operation path, execute again the step of selecting a plurality of intermediate points between the preset starting lifting position and the ending lifting position, and if there is no collision on the alternative operation path, determine the alternative operation path as the pre-planned operation path.

[0080] Specifically, if a collision occurs in the simulation, the trajectory planning is performed again; if no collision occurs in the simulation, the operation path is determined as the pre-planned operation path.

[0081] The specific implementation process of this step is introduced below. Referring to the previous description, the operation path is composed of a posture sequence. It can be understood that each posture in the posture sequence includes time information. In this step, the posture corresponding to the current moment is found from the operation path. The posture records the position and posture. Through the posture, the expected displacement and expected speed can be calculated. The specific implementation principle and implementation process of the calculation can be referred to the description in the relevant technology, which will not be repeated here.

[0082] S303. Determine a state error of the slave crane relative to the master crane based on the expected displacement, the expected speed, the actual displacement, the actual speed, and the current inclination angle of the hoisted object relative to the horizontal plane; wherein the state error is related to the displacement, the speed, and the inclination angle of the hoisted object relative to the horizontal plane.

[0083] It should be noted that the state error of the slave crane relative to the master crane is used to characterize the state difference of the slave crane relative to the master crane. The state error is a joint function based on displacement, speed and the inclination angle of the hoisted object relative to the horizontal plane.

[0084] In a possible implementation, the state error can be calculated according to the following formula:

[0085] ,

[0086] in, is the expected displacement;

[0087] is the actual displacement;

[0088] is the expected speed;

[0089] is the actual speed;

[0090] is the inclination angle of the hoisted object relative to the horizontal plane;

[0091] is the weight factor corresponding to the displacement;

[0092] is the weight factor corresponding to the speed;

[0093] is the weight factor corresponding to the inclination angle of the hoisted object relative to the horizontal plane.

[0094] It should be noted that , and The weight factor is set by the user according to actual needs. In this embodiment, its specific value is not limited. In specific implementation, the weight factor is adjusted according to the importance of displacement, speed and inclination angle and the actual working conditions. For example, in a possible implementation, the lifting operation needs to be completed as soon as possible and the speed is more concerned. In this case, the weight factor can be set as Increase appropriately and increase the working speed to complete the work as soon as possible.

[0095] S304. Determine the instruction conversion rate of the slave crane according to the state error, and calculate the target expected speed of the slave crane at the next moment according to the actual speed and the instruction conversion rate; wherein the target expected speed is equal to the product of the actual speed and the instruction conversion rate.

[0096] Specifically, the command conversion rate in the control system refers to the conversion ratio or factor from high-level control commands to actual execution commands. In specific applications, such as cylinder displacement control, the command conversion rate is the conversion of high-level control requirements (such as target position, speed or acceleration) into commands that can be actually executed by the actuator (such as the cylinder). These commands may include current, voltage, hydraulic pressure and other signals. The initial value of the command conversion rate is the initial state of the slave, which is set by the system initialization.

[0097] Specifically, in a possible implementation, when the state error exceeds a preset threshold, the command conversion rate of the slave crane is adjusted to reduce the state error. For example, in one embodiment, when adjusting the command conversion rate, the larger the state error, the smaller the command conversion rate.

[0098] It should be noted that the instruction conversion rate will be used to generate the target expected speed at the next moment to adjust the state of the slave crane, so as to reduce the state error between the master and slave cranes.

[0099] Optionally, in a possible implementation, the target expected speed may be calculated using the following formula:

[0100] ,

[0101] in, The target expected speed for the next moment;

[0102] K is the instruction conversion rate;

[0103] is the actual speed.

[0104] S305: Control the slave crane according to the target expected speed, so that the slave crane follows the action of the master crane to achieve the purpose of collaboratively lifting the hoisted object.

[0105] The specific implementation principle and process of controlling the slave crane according to the target desired speed will be described in detail in the following embodiments and will not be repeated here.

[0106] Optionally, in a possible implementation, the posture and environmental status of the hoisted object can be monitored in real time. When the hoisted object tilts or the two cranes move out of sync, manual interruption is set and the position is adjusted. When there is a risk of collision, manual interruption is performed and obstacle removal is prioritized.

[0107] It should be noted that, in the specific implementation, the entire process will provide real-time feedback and be repeated as needed until the system reaches the expected stable state and accuracy, or until a specific job is completed.

[0108] The hoisting operation method provided in this embodiment, on the one hand, determines the state error of the slave crane relative to the master crane, and then determines the command conversion rate of the slave crane based on the state error, and calculates the target expected speed of the slave crane at the next moment based on the actual speed and the command conversion rate, so as to control the slave crane according to the target expected speed. In this way, by dynamically adjusting the command conversion rate, it is possible to flexibly respond to the error between the master and the slave, so as to determine the target expected speed through the command conversion rate, and then reduce the error between the master and the slave through the target expected speed, so that the slave can accurately follow the master, complete the synchronization and collaborative operation between the master and the slave, and ensure the smooth progress of the operation. On the other hand, when calculating the state error, the speed, displacement and the inclination angle of the hoisted object relative to the horizontal plane are comprehensively considered, so that the state difference between the slave and the master can be accurately evaluated, and then the slave can be accurately controlled based on this to achieve accurate synchronization between the master and the slave.

[0109] It should be noted that after controlling the slave crane according to the target expected speed, there may be a problem of tilting of the hoisted object, that is, it may still be impossible to accurately achieve precise synchronization between the slave crane and the master crane. Further, in order to achieve precise synchronization between the slave crane and the master crane, the present application also provides a winch compensation method to achieve precise synchronization between the slave and the master. The winch compensation method provided by the present application is introduced below.

[0110] Figure 4 This is a flow chart of Example 2 of the lifting operation method provided in this application. Figure 5 This is a schematic diagram showing the implementation principle of winch compensation according to an exemplary embodiment of the present application. Figure 4 and Figure 5The method provided in this embodiment is based on the above embodiment, and after controlling the slave crane according to the target expected speed, the method further includes:

[0111] S401, calculating a first lifting height of the slave crane according to a shortening amount of the hoist of the slave crane, a boom length of the slave crane, a first elevation angle before the slave crane lifts, and a second elevation angle after the slave crane lifts.

[0112] For details, please refer to Figure 5 ,Depend on Figure 5 It can be seen that the master and slave satisfy the following relationship during the collaborative lifting process:

[0113] ,

[0114] in, is the current height of the main crane;

[0115] is the current height from the crane;

[0116] is the initial height of the main crane;

[0117] is the initial height from the crane;

[0118] Second lifting height for main crane;

[0119] For the first lifting height from the crane;

[0120] is the lifting inclination angle of the hoisting object;

[0121] d is the vertical distance between the main crane's hoisting wire and the slave crane's hoisting wire;

[0122] is the first elevation angle before lifting from the crane;

[0123] is the second elevation angle after lifting from the crane;

[0124] L2 is the arm length of the slave crane;

[0125] x1 is the shortening of the winch of the main crane;

[0126] x2 is the shortening amount from the hoist of the crane.

[0127] It should be noted that the first elevation angle and the second elevation angle before and after lifting by the crane refer to the angle formed between the boom of the crane and the horizontal plane.

[0128] Specifically, referring to the previous introduction, it can be seen that the shortening amount of the winch of the crane satisfies the following relationship:

[0129] ,

[0130] in, For the first lifting height from the crane;

[0131] x2 is the shortening of the winch from the crane;

[0132] L2 is the arm length of the slave crane;

[0133] is the first elevation angle before lifting from the crane;

[0134] It is the second elevation angle after lifting from the crane.

[0135] Therefore, according to the above relationship, in specific implementation, the first lifting height can be calculated according to the following formula:

[0136] .

[0137] S402: Calculate a current lifting inclination angle of the hoisted object according to the first lifting height, the arm length, the first elevation angle, and the second elevation angle.

[0138] It should be noted that the lifting inclination angle of the hoisted object refers to the inclination angle of the hoisted object relative to the horizontal plane during the hoisting process.

[0139] Specifically, referring to the above description, the second elevation angle after lifting from the crane satisfies the following relationship:

[0140] ,

[0141] in, is the lifting inclination angle of the hoisting object;

[0142] L2 is the arm length of the slave crane;

[0143] For the first lifting height from the crane;

[0144] is the first elevation angle before lifting from the crane;

[0145] It is the second elevation angle after lifting from the crane.

[0146] In specific implementation, based on the above relationship, the lifting inclination angle can be calculated according to the following formula:

[0147] .

[0148] S403: Calculate a second lifting height of the main crane according to the lifting inclination angle, the vertical distance between the hanging wire of the main crane and the hanging wire of the slave crane, and the first lifting height.

[0149] Specifically, referring to the previous description, the lifting inclination angle of the hoisted object satisfies the following relationship:

[0150] ,

[0151] in, Second lifting height for main crane;

[0152] is the first lifting height from the crane;

[0153] d is the vertical distance between the main crane's hoisting wire and the slave crane's hoisting wire;

[0154] It is the lifting inclination angle of the hoisting object.

[0155] In specific implementation, the second lifting height can be calculated according to the following formula:

[0156] .

[0157] S404. Calculate a hoisting compensation amount of the slave crane according to the first lifting height and the second lifting height; wherein the hoisting compensation amount is equal to a difference between the second lifting height and the first lifting height.

[0158] In specific implementation, the winch compensation amount can be calculated according to the following formula:

[0159] .

[0160] S405, controlling the hoisting change of the slave crane, that is, the hoisting compensation amount, to compensate for the balance of the hoisted object so that the hoisting inclination angle is equal to 90°.

[0161] Specifically, refer to Figure 5 When the hoisted object tilts, the winch compensation can be used to compensate for the balance of the hoisted object, so that the lifting angle is equal to 90°, that is, the hoisted object is kept balanced in the horizontal direction, so as to accurately achieve synchronization between the master and the slave, and ensure the safety of the operation.

[0162] The method provided in this embodiment, after controlling the slave crane according to the target expected speed, calculates the first lifting height of the slave crane, and then calculates the current lifting inclination angle of the hoisted object according to the first lifting height, so that the second lifting height of the master crane can be calculated according to the lifting inclination angle, and the hoisting compensation amount of the slave crane can be calculated according to the first lifting height and the second lifting height. In this way, the hoisting of the slave crane can be controlled to change the hoisting compensation amount to compensate for the balance of the hoisted object, so that the lifting inclination angle is equal to 90°, so that the master and slave cranes can be ensured to rise and fall synchronously, maintain the stable state of the hoisted object, reduce the risk and complexity of the operation, ensure the safety of the operation, and prevent the damage of the hoisted object caused by imbalance.

[0163] Figure 6 This is a flow chart of the third embodiment of the hoisting operation method provided in this application. Please refer to Figure 6 The method provided in this embodiment is based on the above embodiment, wherein the control of the slave crane according to the target expected speed includes:

[0164] S601. Calculate a target expected displacement of a cylinder of a hydraulic system of the slave crane according to the target expected speed.

[0165] The specific implementation principle and implementation process of this step can be found in the description of the relevant technology and will not be repeated here.

[0166] S602: Calculate a PID control output according to the target expected displacement and the actual displacement of the oil cylinder based on a PID control algorithm.

[0167] In specific implementation, the error between the target expected displacement and the actual displacement of the cylinder can be calculated, and then based on the error between the two, the PID control algorithm can be used to calculate the PID control output.

[0168] Figure 7 This is a schematic diagram showing an implementation principle of controlling a slave crane according to a target desired speed, provided as an exemplary embodiment of the present application. Figure 7 PID controller 1 can be used to calculate the PID control output. In specific implementation, the target expected displacement and the actual displacement of the cylinder are input into PID controller 1, and PID controller 1 outputs the PID control output.

[0169] S603, converting the PID control output into the expected displacement of the main valve core of the hydraulic system, and generating a control current signal of the pilot valve of the hydraulic system based on the PID control algorithm according to the expected displacement of the main valve core and the actual displacement of the main valve core.

[0170] For details, see Figure 7The conversion module can be used to convert the PID control output into the desired displacement of the main valve core of the hydraulic system. The working principle of the conversion module can be found in the description of the related art, which will not be repeated here.

[0171] Furthermore, after the desired displacement of the main valve core is obtained through conversion, a control current signal of the pilot valve of the hydraulic system can be generated based on the desired displacement of the main valve core and the actual displacement of the main valve core and based on a PID control algorithm.

[0172] In specific implementation, the displacement error can be calculated based on the expected displacement of the main valve core and the actual displacement of the main valve core, and then the control current signal of the pilot valve can be calculated based on the displacement error using the PID control algorithm.

[0173] See also Figure 7 , you can use Figure 7 The PID controller 2 in the control circuit is used to calculate the control current signal of the pilot valve. In specific implementation, the expected displacement of the main valve core and the actual displacement of the main valve core are input into the PID controller 2, and the controller 2 outputs the control current signal of the pilot valve.

[0174] It should be noted that the main valve core can be set in a specific position to allow oil flow to enter and exit the cylinder at a predetermined rate. The linear variable differential transformer LVDT (LVDT) is physically connected to the main valve core and can monitor the position changes of the main valve core in real time.

[0175] When the main valve core moves, the position change detected by the LVDT is converted into an electrical signal, which reflects the actual displacement of the main valve core.

[0176] S604. Use the control current signal to control the pilot valve to achieve the purpose of controlling the opening of the pilot valve, so that the opening change of the pilot valve causes the opening change of the main valve core, and then the opening change of the main valve core causes the flow of the cylinder to change, thereby causing the arm of the slave crane to move.

[0177] Specifically, after the pilot valve is controlled by the current signal, the opening of the pilot valve changes. Further, when the opening of the pilot valve changes, the opening of the main valve core changes. Further, when the opening of the main valve core changes, the flow of the oil cylinder changes. When the flow of the oil cylinder changes, the arm of the crane moves.

[0178] For details, please refer to Figure 7 , referring to the above description, in this embodiment, when controlling the slave crane according to the target desired speed, a double closed-loop control idea is adopted, specifically:

[0179] (1) In the closed loop 1 process, a control current signal of the pilot valve is generated according to the expected displacement of the main valve core and the actual displacement obtained by the LVDT. The pilot valve is controlled by the control current signal, and then the opening of the main valve core changes due to the opening change of the pilot valve. The opening change of the main valve core causes the flow rate of the cylinder to change. Finally, the flow rate change of the cylinder causes the arm movement of the variable amplitude mechanism.

[0180] (2) In the closed loop 2 process, the target displacement of the cylinder is obtained, and the expected displacement of the main valve core is determined based on the target displacement and the actual displacement of the cylinder.

[0181] The method provided in this embodiment can realize the speed control of the inner layer and the displacement control of the outer layer through the double closed-loop PID control algorithm, and can achieve the purpose of precise control.

[0182] Compared with the hoisting operation method provided above, the present application also provides a master-slave collaborative hoisting system. The master-slave collaborative hoisting system provided by the present application is briefly introduced below:

[0183] The present application provides a master-slave collaborative lifting system, which includes a server, a master crane and a slave crane; wherein:

[0184] The server is used to respond to the lifting task set by the user and pre-plan a pre-planned operation path between the starting lifting position and the ending lifting position according to the starting lifting position and the ending lifting position preset in the lifting task;

[0185] The server is further used to determine the predetermined lifting position and initial posture corresponding to the master crane, and the predetermined lifting position and initial posture corresponding to the slave crane according to the starting lifting position and the ending lifting position;

[0186] The server is further used to send the predetermined lifting position and initial posture corresponding to the main crane to the main crane, so that the main crane moves to the predetermined lifting position and initializes the posture to the initial posture;

[0187] The server is further used to send the predetermined lifting position and initial posture corresponding to the slave crane to the slave crane, so that the slave crane moves to the predetermined lifting position and initializes the posture to the initial posture;

[0188] The server is further used to send the pre-planned operation path to the main crane, so that the main crane is controlled by the driver to operate according to the pre-planned operation path;

[0189] The server is further used to send the pre-planned operation path to the slave crane;

[0190] The slave crane is used to operate according to the method described in any one of the embodiments provided in the present application, so as to follow the action of the master crane and achieve the purpose of collaboratively lifting the hoisted object.

[0191] The specific implementation principle of this step can be found in the introduction of the previous embodiment and will not be repeated here.

[0192] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A hoisting operation method, characterized in that: The hoisting operation method is applied to a slave crane in a master-slave cooperative hoisting system; the master-slave cooperative hoisting system also includes a master crane, and the master crane and the slave crane are initially located at their respective corresponding predetermined hoisting positions in an initial posture; The main crane is controlled by a driver to operate according to a pre-planned operation path; the method comprises: Get the actual displacement and actual speed at the current moment; Determine the expected displacement and expected speed at the current moment according to the operation path; Determine a state error of the slave crane relative to the master crane according to the expected displacement, the expected speed, the actual displacement, the actual speed, and the current inclination angle of the hoisted object relative to the horizontal plane; wherein the state error is related to the displacement, the speed, and the inclination angle of the hoisted object relative to the horizontal plane; Determine the instruction conversion rate of the slave crane according to the state error, and calculate the target expected speed of the slave crane at the next moment according to the actual speed and the instruction conversion rate; wherein the target expected speed is equal to the product of the actual speed and the instruction conversion rate; The slave crane is controlled according to the target desired speed so that the slave crane follows the action of the master crane to achieve the purpose of cooperatively lifting the hoisted object.

2. The method according to claim 1, characterized in that After controlling the slave crane according to the target desired speed, the method further includes: Calculating a first lifting height of the slave crane according to a shortening amount of the hoist of the slave crane, a boom length of the slave crane, a first elevation angle before the slave crane is lifted, and a second elevation angle after the slave crane is lifted; Calculating a current lifting inclination angle of the hoisted object according to the first lifting height, the arm length, the first elevation angle, and the second elevation angle; Calculating a second lifting height of the main crane according to the lifting inclination angle, a vertical distance between a hanging line of the main crane and a hanging line of the slave crane, and the first lifting height; Calculating a hoisting compensation amount of the slave crane according to the first hoisting height and the second hoisting height; wherein the hoisting compensation amount is equal to a difference between the second hoisting height and the first hoisting height; The hoisting of the slave crane is controlled to change the hoisting compensation amount to compensate for the balance of the hoisted object so that the hoisting inclination angle is equal to 90°.

3. The method according to claim 1, characterized in that: The controlling the slave crane according to the target desired speed comprises: Calculating a target expected displacement of a cylinder of a hydraulic system of the slave crane according to the target expected speed; Calculating a PID control output based on the target expected displacement and the actual displacement of the oil cylinder and based on a PID control algorithm; Converting the PID control output into a desired displacement of a main valve core of the hydraulic system, and generating a control current signal of a pilot valve of the hydraulic system based on a PID control algorithm according to the desired displacement of the main valve core and the actual displacement of the main valve core; The control current signal is used to control the pilot valve to achieve the purpose of controlling the opening of the pilot valve, so that the opening change of the pilot valve causes the opening change of the main valve core, and then the opening change of the main valve core causes the flow of the cylinder to change, thereby causing the arm of the slave crane to move.

4. The method according to claim 1, characterized in that The planning method of the pre-planned operation path includes: Selecting a plurality of intermediate points between a preset starting lifting position and an ending lifting position, and determining a sequence consisting of the starting lifting position, the plurality of intermediate points and the ending lifting position as a trajectory path; For each point in the trajectory path, determine the posture of the crane at the point, and determine a posture sequence consisting of the postures of the crane at each trajectory point in the trajectory path as an alternative operation path; A simulation experiment is used to determine whether there is a collision in the alternative working path. When there is a collision in the alternative working path, the step of selecting multiple intermediate points between the preset starting lifting position and the ending lifting position is performed again. When there is no collision in the alternative working path, the alternative working path is determined as the pre-planned working path.

5. The method according to claim 1, characterized in that The predetermined lifting position is determined by the following method: According to the preset starting lifting position and ending lifting position, determining a target line segment formed by the starting lifting position and the ending lifting position; For each crane, according to a first constraint condition, a target distance between a predetermined lifting position corresponding to the crane and the target line segment is searched within the working range of the crane; wherein the first constraint condition is that the target distance is greater than the minimum working range of the crane and less than the maximum working range of the crane; Determine the perpendicular bisector of the target line segment; For each crane, the predetermined lifting position corresponding to the crane is determined on the perpendicular midline according to the target distance between the predetermined lifting position corresponding to the crane and the target line segment.

6. The method according to claim 1, characterized in that Determining the state error of the slave crane relative to the master crane according to the expected displacement, the expected speed, the actual displacement, the actual speed, and the current inclination angle of the hoisted object relative to the horizontal plane includes: The state error is calculated according to the following formula: ， Among them, the is the expected displacement; Said is the actual displacement; Said is the expected speed; Said is the actual speed; Said is the current inclination angle of the hoisted object relative to the horizontal plane; Said is the weight factor corresponding to the displacement; Said is the weight factor corresponding to the speed; Said is the weight factor corresponding to the inclination angle of the hoisted object relative to the horizontal plane.

7. The method according to claim 2, characterized in that The calculating the first lifting height of the slave crane according to the winch shortening amount of the slave crane, the arm length of the slave crane, the first elevation angle before the slave crane is hoisted, and the second elevation angle after the slave crane is hoisted includes: The first lifting height is calculated according to the following formula: ， Among them, the For the first lifting height from the crane; Said The shortening from the winch of the crane; Said is the arm length of the crane; Said is the first elevation angle before lifting from the crane; Said It is the second elevation angle after lifting from the crane.

8. The method according to claim 2 or 7, characterized in that: Calculating a current lifting inclination angle of the hoisted object according to the first lifting height, the arm length, the first elevation angle, and the second elevation angle includes: The lifting inclination angle is calculated according to the following formula: ， Among them, the It is the current lifting tilt angle of the hoisted object; Said is the arm length of the crane; Said For the first lifting height from the crane; Said is the first elevation angle before lifting from the crane; Said It is the second elevation angle after lifting from the crane.

9. The method according to claim 2, characterized in that: The calculating the second lifting height of the main crane according to the lifting inclination angle, the vertical distance between the hanging wire of the main crane and the hanging wire of the slave crane, and the first lifting height comprises: The second lifting height is calculated according to the following formula: ， Among them, the Second lifting height for main crane; Said is the first lifting height from the crane; Said d is the vertical distance between the suspension wire of the main crane and the suspension wire of the slave crane; Said It is the current lifting tilt angle of the hoisted object.

10. A master-slave collaborative lifting system, characterized in that: The master-slave collaborative lifting system comprises a server, a master crane and a slave crane; wherein, The server is used to respond to the lifting task set by the user and pre-plan the operation path between the starting lifting position and the ending lifting position according to the starting lifting position and the ending lifting position preset in the lifting task; The server is further used to determine the predetermined lifting position and initial posture corresponding to the master crane, and the predetermined lifting position and initial posture corresponding to the slave crane according to the starting lifting position and the ending lifting position; The server is further used to send the predetermined lifting position and initial posture corresponding to the main crane to the main crane, so that the main crane moves to the predetermined lifting position and initializes the posture to the initial posture; The server is further used to send the predetermined lifting position and initial posture corresponding to the slave crane to the slave crane, so that the slave crane moves to the predetermined lifting position and initializes the posture to the initial posture; The server is further used to send the operation path to the main crane, so that the main crane is controlled by the driver to perform the operation according to the operation path; The server is further used to send the operation path to the slave crane; The slave crane is used to operate according to the method described in any one of claims 1 to 9 to follow the action of the master crane to achieve the purpose of collaboratively lifting the hoisted object.

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