Method and device for controlling posture of lifting appliance of eight-rope crane

Abstract

The invention discloses an eight-rope crane lifting appliance attitude control method and device, and belongs to the technical field of crane control, an eight-rope suspension device for a crane is adopted, the eight-rope suspension device comprises a mounting seat, eight lifting suspensions, a lifting appliance and a control device, four connecting seats are hinged to the lifting appliance, and the lifting appliance is connected with the control device. The four connecting seats are uniformly arranged on four sides of the lifting appliance; the hoisting suspension comprises winches and rotary encoders, the eight winches and the control device are fixedly arranged on the mounting seat, and the eight rotary encoders are rotationally arranged on the mounting seat; the eight winches and the eight rotary encoders are electrically connected to the control device. The eight hoisting suspensions are uniformly arranged on the four sides of the mounting seat in pairs, steel wire ropes of any group of two winches are fixedly arranged on the same connecting seat, and the lifting appliance has the advantages that the operation of controlling the hoisting position of the lifting appliance is simpler and more convenient, and the stability of the lifting appliance in the process of lifting inclined goods is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of crane control, and specifically provides a method and device for controlling the attitude of a spreader of an eight-rope crane. Background Art

[0002] During the operation of automated equipment, it is often necessary to obtain the real-time position accuracy of relevant mechanisms to determine whether the motion state of the mechanisms is normal. Under the limitations of certain occasions and safety conditions, the method of using a rotary encoder is usually adopted. When the rotary encoder has a linear relationship with the actual position, the real-time target position can be calculated through common mathematical formulas.

[0003] However, in some cases, the relationship between the two is non-linear, such as in the case of a crane that suspends a spreader by winding a wire rope in a triangular shape. Almost all domestic eight-rope suspensions currently use a rough method to calculate the lifting position of the spreader, including methods such as segmented calibration or segmented ratios. The up and down movement of the spreader is controlled by directly controlling the rotation of the winch, and then the lifting position is judged by visual inspection or with the help of an auxiliary vision.

[0004] Due to the unevenness of the site flatness and the uneven loading of goods in the container, there is a certain angle between the installation planes of the container on the carrier and the spreader. This makes the angle between the two not decrease due to the reduction of the distance between the two during the lifting process, because the movement state of the spreader is in the vertical up and down direction. This makes it inconvenient to install the spreader inclined on the container during the installation of the spreader and the container.

[0005] For the above technical conditions, there are still defects: since the installation planes of the container and the spreader present an angle in space, during the process of the spreader carrying the container and lifting it off the carrier, due to the uneven tightness of the wire ropes on the spreader, when the container is lifted off the carrier, the container swings and sways, posing a safety risk.

[0006] Based on this, the present invention designs a method for controlling the attitude of a spreader of an eight-rope crane to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for controlling the attitude of a spreader of an eight-rope crane to solve the above technical problems.

[0008] To achieve the above object, the present invention provides the following technical solutions: An eight-rope suspension device for a crane is adopted. The eight-rope suspension device includes a mounting seat, eight hoisting suspensions, a spreader, and a control device. Four connecting seats are hinged on the spreader, and the four connecting seats are evenly arranged on the four sides of the spreader. The hoisting suspension includes a winch and a rotary encoder. The eight winches and the control device are fixedly arranged on the mounting seat, and the eight rotary encoders are rotatably arranged on the mounting seat. The eight winches and the eight rotary encoders are electrically connected to the control device. The eight hoisting suspensions are evenly arranged in pairs on the four sides of the mounting seat, and the steel wires of any two winches in a group are fixedly arranged on the same connecting seat. And the following steps are included: S1. According to the structural parameters of the eight-rope suspension device, form a height control table of the eight-rope suspension device and record it in the control device; S2. Manually remotely control the control device to control the movement of the spreader, so that the spreader moves up and down until one side of the spreader abuts against the upwardly inclined side of the container; S3. According to the spatial position of the spreader, the control device records the position information of the spreader and the recording signals of each rotary encoder at the current position; S4. Set the tilt angle and direction of the spreader, and generate a tilt angle control table of the spreader at the current position in real time and record it in the control device; S5. The control device continuously controls the eight winches to retract and release the steel wires, transmits the data to the control device, compares it with the control table, and then controls the telescopic amount of the steel wires of the winches to achieve closed-loop control of the spreader attitude; In step S1, the structural parameters include: the radius of the steel wire winding rotary encoder 、the center distance between two rotary encoders installed on the same side of the mounting seat , the node spacing of two steel wires fixed on the same connecting seat on the spreader , the distance A between two opposite groups of rotary encoders and the distance B between two opposite connecting seats; Denote the distance from the steel wire node to the plane where the eight rotary encoders are located as H. At this time, the value of the projection of the center distance between the node of any steel wire on the spreader and the rotary encoder of the same group of hoisting suspensions on the plane perpendicular to the axis of the rotary encoder ; The value of the projection of the rope length between the node of any steel wire on the spreader and the tangent point of the rotary encoder of the same group of hoisting suspensions on the plane perpendicular to the axis of the rotary encoder ; Then the rope length value between the node of any steel wire on the spreader and the tangent point of the rotary encoder of the same group of hoisting suspensions ; At this time, the chord length value from the tangent point of the wire rope around the rotary encoder to the tangent point in the vertical direction ; At this time, when the spreader is relative to the installation plane H of the eight rotary encoders, the length of the wire rope passing through the rotary encoder ; Generate a control table respectively for the length L of the wire rope passing through the eight rotary encoders as the wire rope node moves away from the plane H where the eight rotary encoders are located.

[0009] The position information in step S3 includes the distance from the geometric center of the eight wire rope nodes to the plane where the eight rotary encoders are located , the rope length values recorded by the rotary encoders in the two lifting suspensions on one side of the spreader that abuts against the container , the rope length recorded by the rotary encoders in the two lifting suspensions opposite to the abutting side of the spreader , and the rope length recorded by the rotary encoders in the four lifting suspensions adjacent to the abutting side .

[0010] The input parameter of the spreader angle in step S4 is θ; At this time, as the inclination angle θ of the spreader increases, in order to keep one side of the spreader continuously abutting against the container, the rope length values recorded by the rotary encoders in the two lifting suspensions on one side of the spreader that abuts against the container ; When the inclination angle θ of the spreader increases, the rope length recorded by the rotary encoders in the two lifting suspensions opposite to the abutting side of the spreader ; When the inclination angle θ of the spreader increases, the rope length recorded by the rotary encoders in the four lifting suspensions adjacent to the abutting side + ; Then respectively , , along with Generate an angle control table from the data formed by the change

[0011] In step S5, the control device continuously controls the eight winches to take in and release the wire rope, transmits the data to the control device and compares it with the angle control table, and then controls the wire rope telescopic amount of the winches to achieve closed-loop control of the spreader attitude. The specific method is: the control device controls the eight winches to work, so that when the length of the wire rope changes, one side of the spreader can be kept abutting against the container stably in real time, and at the same time, the values of the rope lengths obtained by the eight rotary encoders are compared in real time with the inclination angle of the spreader during the movement Whether it is consistent with the numerical value recorded in the angle control table in the control device. If not, control any winch to decelerate or stop until the parameters of the two are consistent. After the spreader reaches the specified tilt angle and effectively fits with the container placed on the vehicle, lifting can be carried out.

[0012] According to one aspect of the embodiments of the present application, an eight-rope crane device is provided, including a control device and a calculation program stored in the control device. The control device executes the calculation program to implement the method for controlling the attitude of the spreader of an eight-rope crane according to any one of claims 1-5.

[0013] In summary, the present application has the following beneficial technical effects: By setting the spreader tilt angle as the control input, when any side of the spreader touches the container, using the position of the spreader at this time as the origin of the motion state, a non-linearly related angle control table between the rope lengths of the winches at different positions and the spreader tilt angle is constructed. By setting the tilt angle amount, the control device controls the eight winches to operate, and through real-time comparison of the change amount by eight rotary encoders, the control device performs closed-loop control on the winches, so that when lifting an inclined container, the working state of the winches is controlled by setting the tilt angle, and the control method for the spreader tilt angle is more convenient; at the same time, an angle control table of the rotary encoder at the current height is constructed, so that during the process of the eight winches controlling the movement of the spreader, through the corresponding relationship between the rope length L of the winches at different positions and the spreader tilt angle in the angle control table generated in real time, it is ensured that the steel ropes of the eight winches remain taut during the process of the spreader lifting the container, thus achieving the goal of solving the risk of shaking and swinging when the spreader lifts inclined goods, and improving the stability of the spreader when loading the container during the lifting of the inclined container. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0015] Figure 1 It is a flow chart of the method for calculating the real-time position of the crane spreader in the embodiments of the present invention.

[0016] Figure 2 It is a structural schematic diagram of the eight-rope suspension device in the embodiments of the present invention.

[0017] Figure 3Schematic diagram of any group of two lifting suspension installation parameters in step S1 of the embodiment of the present invention.

[0018] Figure 4 Schematic diagram of the rope length parameter when the spreader is tilted in step S4 of the embodiment of the present invention.

[0019] In the attached drawings, the list of components represented by each reference numeral is as follows: 1. Mounting base; 2. Lifting suspension; 3. Spreader; 4. Control device; 5. Connecting seat; 6. Winch; 7. Rotary encoder. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] The following is a further detailed description of the present application in conjunction with the attached Figures 1-4 This application will be further described in detail below.

[0022] A method for controlling the attitude of the spreader 3 of an eight-rope crane adopts an eight-rope suspension device for a crane. The eight-rope suspension device includes a mounting base 1, eight lifting suspensions 2, a spreader 3 and a control device 4. Four connecting seats 5 are hinged on the spreader 3, and the four connecting seats 5 are evenly arranged on the four sides of the spreader 3; the lifting suspension 2 includes a winch 6 and a rotary encoder 7.

[0023] Eight winches 6 and the control device 4 are fixedly arranged on the mounting base 1, and eight rotary encoders 7 are rotatably arranged on the mounting base 1; the eight winches 6 and the eight rotary encoders 7 are electrically connected to the control device 4.

[0024] Eight lifting suspensions 2 are evenly arranged in pairs on the four sides of the mounting base 1, and the steel wires of any group of two winches 6 are fixedly arranged on the same connecting seat 5.

[0025] In this embodiment, the control device 4 is a single-chip microcomputer, and the specific model and brand are not limited.

[0026] In a method for controlling the attitude of the spreader 3 of an eight-rope crane in this embodiment, the following steps are included: S1. According to the structural parameters of the eight-rope suspension device, form a height control table of the eight-rope suspension device and record it in the control device 4; S2. Manually remotely control the control device 4 to further control the movement of the spreader 3, so that the spreader 3 moves up and down until one side of the spreader 3 abuts against one side of the container that is tilted upward; S3, according to the spatial position of the spreader 3, the control device 4 records the position information of the spreader 3 at the current position and the recording signals of each rotary encoder 7; S4, setting the inclination angle and direction of the spreader 3, generating a real-time angle control table of the spreader 3 at the current position and recording it in the control device 4; S5, the control device 4 continuously controls the eight hoists 6 to retract and release the wire ropes, and after transmitting the data to the control device 4, the data is compared with the control table, and then the hoists 6 are controlled to control the extension and retraction amount of the wire ropes to achieve closed-loop control of the posture of the sling 3.

[0027] In this embodiment, the structural parameters in step S1 include: the radius of the wire rope rotation encoder , the center distance between the two rotary encoders 7 installed on the same side of the mounting seat 1 , the node spacing of the two steel wire ropes fixed on the same connection seat 5 on the sling 3 , the distance A between the two opposite sets of rotary encoders 7 and the distance B between the two opposite connecting seats 5; The distance between the wire rope node and the plane where the eight rotary encoders 7 are located is H. At this time, the projection value of the center distance between any wire rope node on the sling 3 and the rotary encoder 7 of the same group of lifting suspension 2 on the plane perpendicular to the axis of the rotary encoder 7 is ; The value of the projection of the rope length between the node of any steel wire rope on the sling 3 and the tangent point of the rotary encoder 7 of the same group of lifting suspension 2 on the plane perpendicular to the axis of the rotary encoder 7 ; Then the rope length value of the node of any wire rope on the sling 3 and the tangent point of the rotary encoder 7 of the same group of lifting suspension 2 is ; At this time, the chord length of the wire rope from the tangent point of the rotary encoder 7 to the tangent point in the vertical direction is ; At this time, when the lifting device 3 is installed relative to the eight rotary encoders 7, the length of the steel wire rope passing through the rotary encoder 7 is ; Generate control tables for the change of the length L of the steel wire ropes passed by the eight rotary encoders 7 as the steel wire rope nodes move away from the plane H where the eight rotary encoders 7 are located.

[0028] In this embodiment, the position information in step S3 includes the distance between the geometric center of the eight wire rope nodes and the plane where the eight rotary encoders 7 are located. , the rope length value recorded by the rotary encoder 7 in the two lifting suspensions on one side of the spreader 3 on the container , the rope length recorded by the rotary encoder 7 in the two lifting suspensions opposite to the contact side of the sling 3 , the rope lengths recorded by the rotary encoders 7 in the four lifting suspensions adjacent to the abutting edge .

[0029] In this embodiment, the angle input parameter of the spreader 3 in step S4 is θ; At this time, as the tilt angle θ of the spreader 3 increases, in order to keep one side of the spreader 3 continuously abutting on the container, the rope length values recorded by the rotary encoders 7 in the two lifting suspensions on one side of the spreader 3 abutting on the container ; When the rotary encoders 7 in the two lifting suspensions opposite to the abutting edge of the spreader 3 increase with the tilt angle θ of the spreader 3, record the rope length ; When the rotary encoders 7 in the four lifting suspensions adjacent to the abutting edge increase with the tilt angle θ of the spreader 3, the recorded rope length + ; Then respectively , , along with The data formed by the change generates an angle control table.

[0030] In this embodiment, in step S5, the control device 4 continuously controls the eight winches 6 to wind and unwind the steel wire ropes, and after transmitting the data to the control device 4, compares it with the angle control table, and then controls the telescopic amount of the steel wire ropes of the winches 6 to achieve closed-loop control of the attitude of the spreader 3. The specific method is: the control device 4 controls the eight winches 6 to work, so that when the rope length of the steel wire rope changes, one side of the spreader 3 can be abutted on the container in real time to maintain stability. At the same time, the rope length values obtained by the eight rotary encoders 7 are compared in real time, and whether it is consistent with the tilt angle of the spreader 3 during the movement in the angle control table recorded by the control device 4. If not, control any winch 6 to decelerate or stop until the parameters of the two are consistent, and after the spreader 3 reaches the specified tilt angle, it effectively forms a fit with the container placed on the carrier, and then lifting can be carried out.

[0031] In the embodiment of the present application, an eight-rope crane device is provided, including a control device 4 and a calculation program stored in the control device 4. The control device 4 executes the calculation program to implement a method for controlling the attitude of the spreader 3 of an eight-rope crane. Compared with the related technology, it can be realized that: input the structural parameters of the eight-rope crane device into the control device 4, and through the calculation program, a corresponding table of the recorded values of the rotary encoders 7 at each position and the tilt angle of the spreader 3 can be obtained. When controlling the tilt angle of the spreader 3, a closed-loop control is performed on the winch 6 through the control device 4 and the rotary encoder 7.

[0032] The mounting base 1 is fixedly arranged at the top of the crane. When the container is shipped and transferred by the lifting appliance 3, a point on the lifting appliance 3 abuts against the upwardly inclined side of the container. By setting the inclination angle of the lifting appliance 3 as the control input and taking the position of the lifting appliance 3 at this time as the origin of the motion state, the rope lengths of the hoists 6 at different positions and the inclination angle of the lifting appliance 3 are used to construct a non-linear correlation angle control table. By setting the inclination angle, the control device 4 controls the eight hoists 6 to operate. After the eight rotary encoders 7 compare the change amounts in real time, the control device 4 performs closed-loop control on the hoists 6, so that when hoisting the inclined container, the working state of the hoist 6 is controlled by setting the inclination angle, and the control method of the inclination angle of the lifting appliance 3 is more convenient. At the same time, an angle control table of the rotary encoder 7 at the current height is constructed, so that during the process of the eight hoists 6 controlling the movement of the lifting appliance 3, the corresponding relationship between the rope length L of the hoists 6 at different positions and the inclination angle of the lifting appliance 3 in the angle control table generated in real time is used to ensure that the steel ropes of the eight hoists 6 are kept in a taut state during the process of the lifting appliance 3 hoisting the container, thereby achieving the goal of solving the risk of shaking and swinging when the lifting appliance 3 hoists the inclined goods, and improving the stability of the lifting appliance 3 during the process of loading the inclined container.

[0033] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inner", "front", "center", "both ends", etc. is the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention.

[0034] In the present invention, unless otherwise clearly defined and limited, the terms "installation", "setting", "connection", "fixation", "swivel connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An attitude control method for an eight-rope crane spreader, characterized in that: An eight-rope suspension device for a crane is adopted. The eight-rope suspension device includes a mounting seat, eight hoisting suspensions, a spreader, and a control device. Four connecting seats are hinged on the spreader, and the four connecting seats are evenly arranged on the four sides of the spreader; each hoisting suspension includes a winch and a rotary encoder. The eight winches and the control device are fixedly arranged on the mounting seat, and the eight rotary encoders are rotatably arranged on the mounting seat; the eight winches and the eight rotary encoders are electrically connected to the control device; the eight hoisting suspensions are evenly arranged in groups of two on the four sides of the mounting seat, and the steel wires of any two winches in a group are fixedly arranged on the same connecting seat; and the following steps are included: S1. According to the structural parameters of the eight-rope suspension device, an eight-rope suspension device height control table is formed and recorded in the control device; S2. Manually remotely control the control device to control the movement of the spreader, so that the spreader moves up and down until one side of the spreader abuts against one side of the container that slopes upward; S3. According to the spatial position where the spreader is located, the control device records the position information of the spreader and the recording signals of each rotary encoder at the current position; S4. Set the tilt angle and direction of the spreader, and generate a spreader angle control table at the current position in real time and record it in the control device; S5. The control device continuously controls the eight winches to retract and release the steel wires, transmits the data to the control device, compares it with the control table, and then controls the telescopic amount of the steel wires of the winches to realize the closed-loop control of the spreader attitude.

2. The attitude control method of an eight-rope crane spreader according to claim 1, wherein: In step S1, the structural parameters include: the radius of the wire rope rotation encoder , the center distance between two rotary encoders installed on the same side of the mounting base , the node spacing between two wire ropes fixed on the same connecting seat on the spreader , the distance A between two sets of opposite rotary encoders and the distance B between two opposite connecting seats; Let the distance from the wire rope node to the plane where the eight rotary encoders are located be H. At this time, the projection value on the plane perpendicular to the axis of the rotary encoder of the center distance between any wire rope node on the spreader and the rotary encoder of the same group of hoisting suspensions ; The value of the projection on the plane perpendicular to the axis of the rotary encoder of the rope length between the node of any steel wire rope on the lifting appliance and the tangent point of the same set of lifting suspensions ; The rope length value between the node of any steel wire rope on the sling and the tangent point of the rotary encoder for the same group of hoisting suspensions ; At this time, the chord length value from the tangent point where the steel wire rope winds around the rotary encoder to the tangent point in the vertical direction ; At this time, when the spreader is relative to the eight rotary encoder mounting planes H, the length of the wire rope passing through the rotary encoder ; respectively generate a control table of the length L of the wire rope passing through the eight rotary encoders as the wire rope node moves away from the plane H where the eight rotary encoders are located.

3. A method for controlling the attitude of an eight-rope crane spreader according to claim 2, characterized in that: The position information in step S3 includes the distances of the geometric centers of the eight wire rope nodes relative to the plane where the eight rotary encoders are located , the rope length values recorded by the rotary encoders in two of the lifting suspensions that abut on one side of the spreader against the container , the rope lengths recorded by the rotary encoders in two of the lifting suspensions opposite to the abutting side of the spreader , the rope lengths recorded by the rotary encoders in four of the lifting suspensions adjacent to the abutting side .

4. A method for controlling the attitude of an eight-rope crane spreader according to claim 3, characterized in that: In step S4, the input parameter of the spreader angle is θ; At this time, as the inclination angle θ of the spreader increases, in order to keep one side of the spreader in contact with the container continuously, the rope length values recorded by the rotary encoders in the two lifting suspensions on the side of the spreader in contact with the container ; When the rotary encoders in the two lifting suspensions opposite to the edges in contact with the spreader increase with the increase of the spreader tilt angle θ, record the rope length ; When the rotary encoder in the four lifting suspensions adjacent to the abutting edge records the rope length as the inclination angle θ of the spreader increases + ; Then, respectively, , , along with the data generated as it changes to form an angle control table.

5. A method for controlling the attitude of an eight-rope crane spreader according to claim 3, characterized in that: An attitude control method for an eight-rope crane spreader according to claim 4, characterized in that: in step S5, the control device continuously controls the eight winches to retract and extend the steel wire ropes, transmits the data to the control device, compares it with the angle control table, and then controls the telescopic amount of the steel wire ropes of the winches to achieve closed-loop control of the spreader attitude. The specific method is as follows: The control device controls the eight winches to work so that when the rope length of the steel wire rope changes, one side of the spreader can be in contact with the container in real time to maintain stability. At the same time, the numerical values of the rope lengths obtained by the eight rotary encoders are compared in real time with the tilt angle of the spreader during movement Is it consistent with the numerical values recorded in the angle control table in the control device? If not, control any winch to decelerate or stop until the parameters of the two are consistent. After the spreader reaches the specified tilt angle and effectively fits with the container placed on the vehicle, lifting can be carried out.

6. The attitude control method of an eight-rope crane spreader according to claim 3, characterized in that: An eight-rope crane device, including a control device and a calculation program stored in the control device, is characterized in that: the control device executes the calculation program to realize the method for controlling the attitude of an eight-rope crane spreader according to any one of claims 1-5.

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