An Adaptive Underactuated Door Machine Swing Elimination and Overtravel Prevention System and Method

Abstract

The present invention discloses an adaptive under-actuated gantry crane anti-sway and anti-overtravel system and method, which relates to the technical field of cranes and includes: a software simulation platform and a hardware simulation platform; the hardware simulation platform is configured with a control system and a vision measurement module; the software simulation platform simulates the movement trajectory of transporting and hoisting goods in the working scenario where the real gantry crane is located, and constructs a control simulation model, an anti-sway model and an anti-overtravel model of the movement trajectory; the hardware simulation platform builds a gantry crane transportation model based on the size of the real gantry crane and its working scenario; the control system is connected to the software simulation platform for data communication, and controls the movement of the gantry crane transportation model based on the trajectory control parameters obtained from the control simulation model constructed by the software simulation platform, so as to simulate the real transportation situation of the gantry crane, and further complete the training and verification of the control simulation model, the anti-sway model and the anti-overtravel model. This system ensures the offset self-adaptability and transportation stability during transportation.

Description

Technical Field

[0001] The present invention relates to the technical field of cranes, and particularly to an adaptive under-actuated portal crane anti-sway and anti-overtravel system and method. Background Art

[0002] Portal cranes are widely used in bulk cargo ship unloading operations at seaports. During the normal operation of a portal crane, the completion of one operation cycle mainly relies on the luffing motion of the transport crane mechanism of the ship unloader and the hoisting and lowering motion of the rope controlled by the rope motor mechanism. Due to the inertia of each mechanism during acceleration and deceleration and the fact that the control system in the system cannot directly apply force or torque to change the degrees of freedom of each mechanism. This means that under the influence of inertia, the motion state of the suspended load during operation will lag behind or lead the motion of the mechanism, and this part of the lag or lead will cause the rope mechanism to swing reciprocally around the crane and the load to overtravel. In this case, it becomes very important to indirectly control these degrees of freedom through appropriate algorithms and technologies. Under the operating conditions of one cycle, if the swing angle and rising speed of the suspended load are not effectively controlled, the following problems will exist:

[0003] First, when the portal crane hoists or lowers goods, or moves the load horizontally, if the operation is improper, the goods and the connected rope may swing. The swing angle generated by the rope and the goods provides an initial disturbance to the system and generates inertial force, causing the suspended load to swing and finally stop swinging under the action of friction and wind resistance, but this process lasts for a long time.

[0004] Second, the hoisting and lowering equipment of the crane rope collides or overshoots when approaching the top position. In some cases, a rapidly rising load may be difficult to stop immediately due to inertia, resulting in a risk of collision with the top transport crane structure.

[0005] The above problems greatly reduce the operation efficiency and running safety of the portal crane.

[0006] Currently, there are already technical solutions for anti-sway and anti-overtravel of portal cranes. Some electronic control systems based on sensor feedback can real-time monitor the position and speed of the hook, and slow down or stop the movement of the hook by adjusting the speed and direction of the motor. Traditional mechanical limiters can limit the maximum stroke of the hook by physical contact to avoid overtravel.

[0007] Although certain achievements have been made in the prior art, there are still some deficiencies. On the one hand, the traditional electronic control system relying on fixed parameter settings lacks flexibility and performs poorly in the face of different load conditions or external environmental changes. On the other hand, the traditional mechanical limit method has a slow response speed and low accuracy, making it difficult to meet the requirements of high-speed and high-precision operations. In addition, these systems often cannot handle the influence of non-linear factors well, such as sudden wind changes or complex load characteristics, resulting in poor system robustness and inability to ensure long-term stable operation. Summary of the Invention

[0008] In view of this, the present invention aims to provide an adaptive under-actuated gantry crane anti-sway and anti-overtravel system and method to solve the problems of load sway and overtravel caused by factors such as load uncertainty, parameter changes, and external interference during the operation of the existing adaptive under-actuated gantry crane.

[0009] To this end, the present invention adopts the following technical solutions:

[0010] On the one hand, the present invention discloses an adaptive under-actuated gantry crane anti-sway and anti-overtravel system, including: a software simulation platform and a hardware simulation platform; the hardware simulation platform is configured with a control system and a vision measurement module;

[0011] The software simulation platform simulates the movement trajectory of transporting and hoisting goods in the working scenario where the real gantry crane is located, and constructs a control simulation model, an anti-sway model, and an anti-overtravel model of the movement trajectory;

[0012] The hardware simulation platform builds a gantry crane transportation model based on the size of the real gantry crane and its working scenario; the control system controls the movement of the gantry crane transportation model based on the trajectory control parameters obtained from the control simulation model constructed by the software simulation platform, realizing the simulation of the real transportation situation of the gantry crane and the training and verification of the anti-sway model and the anti-overtravel model;

[0013] The vision measurement module includes an industrial vision camera and a binocular vision system installed at the suspended safety position of the gantry crane model. The industrial vision camera is used to collect images of the hoisted goods and the suspended ropes, and the binocular vision system detects the length of the steel wire rope of the suspended load and the swing angle of the suspended rope based on the collected images;

[0014] Among them, the training and verification of the anti-sway model and the anti-overtravel model include:

[0015] The vision measurement module feeds back the detected length of the steel wire rope of the suspended load to the anti-overtravel model of the software simulation platform to obtain anti-overtravel control parameters, and the control system controls the movement of the gantry crane transportation model based on the anti-overtravel control parameters to prevent the goods from overtraveling or the rope retraction speed from being too slow and colliding with the obstacles on the transportation track;

[0016] The visual measurement module feeds back the detected swing angle of the suspension rope to the anti-swing model of the software simulation platform to obtain anti-swing control parameters, and the control system controls the movement of the gantry crane transportation model based on the anti-swing control parameters to prevent the swing angle of the suspension rope from being too large.

[0017] Further, a gantry crane transportation model is built, including:

[0018] Build a gantry crane model with an inverted T-shaped structure under scale reduction; the gantry crane model includes: a base, a main beam erected at the center of the base, and a cross beam stably installed on top of the main beam;

[0019] Install a lifting mechanism and a position sensor for monitoring the lifting height on the main beam;

[0020] Install a traveling mechanism under the cross beam that can move smoothly along the main beam to simulate the process of the gantry crane traveling along the dock track;

[0021] Fix a spreader simulation device on the cross beam, and the spreader simulation device can rotate and tilt freely to facilitate imitating various actions under real working conditions;

[0022] Install a force sensor to detect the interaction force between the spreader and the goods;

[0023] Install a sensor system for monitoring the motion state during operation at the connection between the top of the main beam and the spreader simulation device;

[0024] Configure a control system responsible for receiving data from the software simulation platform and adjusting the motor output according to the received data.

[0025] Further, build a dynamic model for simulating the motion trajectory of the gantry crane goods, including:

[0026] Determine the physical parameters of the gantry crane transportation model, and the physical parameters include: the mass of the gantry crane trolley 、 The length of the steel wire rope for suspending the load, the lifting driving force of the lifting rope, and the load swing angle;

[0027] Based on the physical parameters of the gantry crane transportation model, use the Lagrangian method to establish a non-linear dynamic model for simulating the motion trajectory of the gantry crane goods; the non-linear dynamic model includes: the component force of the lifting driving force of the lifting rope on the cross beam during the process of lifting the goods, and the Lagrangian equation of the lifting driving force of the lifting rope and the swing angle.

[0028] Further, build an anti-swing model, including:

[0029] Perform two-dimensional phase plane analysis on the non-linear dynamic model of the simulated gantry crane cargo movement trajectory, establish a swing elimination model under zero initial state based on the shaping algorithm, and obtain the relationship between the load swing angle and the crane displacement acceleration, as well as the maximum and minimum values of the load swing angle;

[0030] Among them, the relationship between the load swing angle and the crane displacement acceleration is:

[0031] ;

[0032] Among them, is the crane displacement acceleration, is the mass of the gantry crane trolley, is the load swing angle, is the acceleration due to gravity, is the mass of the goods, is the component force of the lifting driving force of the suspension rope on the cross beam;

[0033] The maximum and minimum values of the load swing angle are:

[0034] ;

[0035] Among them, is the maximum value of the load swing angle, is the minimum value of the load swing angle, is a constant, g is the acceleration due to gravity, is the initial value of the load swing angle, is the initial value of the load swing angular velocity;

[0036] Based on the maximum and minimum values of the load swing angle, determine the constraint conditions of the load swing angle; the constraint conditions of the load swing angle are: the maximum and minimum values of the load swing angle are respectively less than the preset angle.

[0037] Furthermore, the visual measurement module feeds back the detected swing angle of the suspension rope to the swing elimination model of the software simulation platform to obtain swing elimination control parameters, including:

[0038] Based on the swing angle of the suspension rope detected by the visual measurement module, use the relationship between the load swing angle and the crane displacement acceleration to obtain the crane displacement acceleration and whether the current swing angle direction is the same as or opposite to the crane movement direction;

[0039] The control system controls the movement of the gantry crane transportation model based on the swing elimination control parameters to prevent the swing angle of the suspension rope from being too large, including:

[0040] When the load swing angle does not meet the constraint conditions, if the current swing angle direction is the same as the crane movement direction, the acceleration of the crane running motor is increased; if the current swing angle direction is opposite to the crane movement direction, the acceleration of the crane running motor is decreased.

[0041] Furthermore, an anti-overhead-stroke model is constructed, including:

[0042] Stereo correction is performed on the left and right views of the goods transported by the gantry crane collected in real time by the binocular industrial vision camera in the vision measurement module to obtain the internal and external parameters of the binocular industrial vision camera; the internal and external parameters of the binocular industrial vision camera include: binocular baseline distance T , camera focal length f , reference point in the world coordinate system with the left camera as the reference , where the coordinate Z is used to represent the length of the wire rope suspending the load l ;

[0043] The X-direction components of the two image coordinate systems of the point projections on the left and right image planes are , and the left and right picture projection parallax d is obtained:

[0044] ;

[0045] Based on the left and right picture projection parallax d the wire rope ranging formula is obtained:

[0046] ;

[0047] Calculate the rising or falling distance of the wire rope at fixed-time sampling, and the speed :

[0048] ;

[0049] where k is a variable value;

[0050] ;

[0051] The constraint conditions need to be satisfied:

[0052] ;

[0053] where is the minimum wire rope movement speed, and is the maximum wire rope movement speed.

[0054] Further, the visual measurement module feeds back the detected wire rope length of the suspended load to the anti-overhead impact model of the software simulation platform to obtain anti-overhead impact control parameters, including:

[0055] Obtaining a rotational speed deviation based on the wire rope length of the suspended load detected by the visual measurement module - Or - ;

[0056] The control system controls the movement of the gantry crane transportation model based on the anti-overhead impact control parameters to prevent the goods from hitting the top or colliding with the obstacles on the transportation track due to too slow rope retracting speed, including:

[0057] When does not meet the constraint conditions, if is greater than , reduce the rotational speed of the rope movement motor with a rotational speed deviation of - , if is less than , increase the rotational speed of the rope movement motor with a rotational speed deviation of - .

[0058] On the other hand, the present invention also provides an adaptive under-actuated gantry crane anti-sway and anti-overhead impact method. The method uses the above-mentioned adaptive under-actuated gantry crane anti-sway and anti-overhead impact system for anti-sway and anti-overhead impact. The method includes the following steps:

[0059] Step 1: Simplify the actual gantry crane transportation process to obtain the simulated parameters of the gantry crane transportation process under proportional scaling;

[0060] Step 2: Simulate the movement trajectory of transporting and hoisting goods in the working scenario where the real gantry crane is located based on the simulated parameters of the gantry crane transportation process under proportional scaling, and construct a control simulation model, an anti-sway model and an anti-overhead impact model of the movement trajectory;

[0061] Step 3: Build a gantry crane transportation model based on the simulated parameters of the gantry crane transportation process under proportional scaling, combined with the size of the real gantry crane and its working scenario;

[0062] Step 4: Control the movement of the gantry crane transportation model with the trajectory control parameters obtained from the control simulation model to realize the simulation of the real transportation situation of the gantry crane;

[0063] Step 5: Training and verification of the anti-sway model and the anti-overhead impact model, including:

[0064] The industrial vision camera collects images of the hoisted cargo and the suspension rope in real time, and the binocular vision system detects the length of the wire rope hanging the load and the swing angle of the suspension rope based on the collected images;

[0065] Feeding back the detected length of the wire rope of the hanging load to the anti-collision model to obtain the anti-collision control parameters, and controlling the movement of the gantry crane transport model based on the anti-collision control parameters to prevent the cargo from collide with the transport track obstacles due to the slow rope collection speed;

[0066] Feeding back the detected swing angle of the suspension rope to the anti-swing model to obtain the anti-swing control parameter, and controlling the movement of the portal crane transport model based on the anti-swing control parameter to prevent the suspension rope from swinging too much;

[0067] Step 6: Apply the trained and verified control simulation model, sway elimination model and top impact prevention model to the actual adaptive under-actuated door crane to achieve sway elimination and top impact prevention of the actual adaptive under-actuated door crane.

[0068] Furthermore, based on the simulated parameters of the gantry crane transportation process under proportional scaling, the motion trajectory of the gantry crane in transporting hoisted cargo in the actual working scene is simulated, and a control simulation model, a swing elimination model and a top impact prevention model of the motion trajectory are constructed, including:

[0069] Determine the target trajectory that the door-to-door aircraft needs to follow to deliver the goods;

[0070] Based on the time required to complete the entire movement with the actual driving force obtained, define the position the system should be in at each moment and determine the speed at each position; define the change in acceleration to ensure the smoothness of the movement;

[0071] Set the number of continuous state variables, the number of discrete state variables, the number of outputs, and the number of inputs;

[0072] The reference shaping algorithm uses cubic spline interpolation in S-curve trajectory planning to smooth the changes in crane motion acceleration;

[0073] Use minimum beat control to transfer the system from one state to another in the shortest time and reduce overshoot;

[0074] Pre-oscillation compensation is performed before the action starts, introducing a small pre-oscillation to offset the swing caused by the subsequent action and make the model more stable.

[0075] Furthermore, the actual gantry crane transportation process is simplified, including: simplifying the actual gantry crane transportation process into a process without initial speed, first accelerating to the maximum speed and then to the stable speed from the feeding point to the picking point, and then decelerating to 0m / s to the picking point.

[0076] The beneficial effects of the present invention are as follows: through the collaborative action of the software simulation platform and the hardware simulation platform, the accurate simulation and optimized control of the transportation process of the gantry crane are realized. On the one hand, the motion trajectory control, anti-swing and anti-overhead models constructed by the software simulation platform provide a theoretical basis for the efficient operation of the gantry crane; on the other hand, the hardware simulation platform combines with the vision measurement module to collect the image information of the goods and ropes in real time, and feeds it back to the simulation platform for model training and verification to ensure the accuracy and adaptability of the control parameters. The introduction of the vision measurement module enables the system to monitor the length of the steel wire rope and the swing angle of the suspension rope in real time, and then accurately adjust the control parameters to effectively prevent the goods from hitting the top or colliding with obstacles, and avoid excessive swing angles of the suspension rope. This innovative method combining virtual simulation and actual measurement not only improves the operation efficiency and safety of the gantry crane, but also enhances the robustness and adaptability of the system, reduces the accident risk caused by operation errors or environmental interference, and provides an efficient and reliable solution for the transportation of gantry cranes in complex operating environments such as ports. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0078] Figure 1 Shows the scaling model after processing the actual data in the embodiment of the present invention;

[0079] Figure 2 Shows the schematic diagram of the two-dimensional simplification of the actual gantry crane in the embodiment of the present invention;

[0080] Figure 3 Shows the schematic diagram of the binocular ranging principle in the embodiment of the present invention;

[0081] Figure 4 Shows the flowchart of an adaptive underactuated gantry crane anti-swing and anti-overhead method in the embodiment of the present invention;

[0082] Figure 5 Shows the control flowchart of the implementation principle of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0083] To enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the 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 of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0084] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or are inherent to these processes, methods, products, or devices.

[0085] An adaptive under-actuated door machine anti-swing and anti-overtravel system is provided in an embodiment of the present invention, including: a software simulation platform and a hardware simulation platform; where:

[0086] The software simulation platform is used to obtain the action data under normal track operation from the actual door machine angle and the actual database of the hoist rope driving force, first establish a closed-loop control model through a shaping algorithm and a non-dynamic formula, simulate the XZ trajectory model of the front and back swing in a two-dimensional coordinate, as well as the associated motion speed and acceleration under the change of the hoist rope length, and perform a simulation of the real situation. In addition, the software simulation platform also constructs an anti-swing model and an anti-overtravel model to achieve anti-swing and anti-overtravel of the adaptive under-actuated door machine.

[0087] The hardware simulation platform establishes a simulated door machine transportation model, which is a scaled model after processing the actual data (as Figure 1 shown), simulates the actual motion parameters, conducts indoor simulations of the acceleration time and the swing angle, reasonably scales the mass of the actual crane and the associated grab and the above speed and other parameters, so that under the proportional scaling, the motion state of the object is similar to the actual situation, especially the swing angle is the same, which is convenient for anti-sway testing when applied to the actual situation.

[0088] The hardware simulation platform is configured with a control system and a vision measurement module. The control system is connected to the software simulation platform for data communication. The motion of the gantry crane transportation model is controlled by the trajectory control parameters obtained from the control simulation model built based on the software simulation platform, realizing the simulation of the actual transportation situation of the gantry crane and the training and verification of the anti-swing model and the anti-overtravel model.

[0089] The vision measurement module includes an industrial vision camera and a binocular vision system installed at the suspended safety position on the gantry crane model. The industrial vision camera is used to collect images of the hoisted goods and the suspended ropes. The binocular vision system detects the length of the steel wire rope of the suspended load and the swing angle of the suspended rope based on the collected images;

[0090] The training and verification of the anti-swing model and the anti-overtravel model include: The vision measurement module is connected to the software simulation platform for data communication. The detected length of the steel wire rope of the suspended load is fed back to the anti-overtravel model of the software simulation platform to obtain anti-overtravel control parameters. The control system controls the motion of the gantry crane transportation model based on the anti-overtravel control parameters to prevent the goods from overtraveling or the rope retraction speed from being too slow and colliding with the obstacles on the transportation track; The vision measurement module feeds back the detected swing angle of the suspended rope to the anti-swing model of the software simulation platform to obtain anti-swing control parameters. The control system controls the motion of the gantry crane transportation model based on the anti-swing control parameters to prevent the swing angle of the suspended rope from being too large.

[0091] The above adaptive underactuated gantry crane anti-swing and anti-overtravel system consists of three links when in use, including: a software simulation link, a hardware simulation link, and a vision measurement feedback link.

[0092] The simulation software platform uses a closed-loop control shaping algorithm to simulate the pick-up trajectory of the gantry crane in the two-dimensional XZ axis, and at the same time conducts simulations on the hardware simulation platform to ensure that its motion ratio is consistent with the actual gantry crane, and strictly controls the similarity between its swing angle and the actual swing angle, maximizing the simulation of the actual transportation situation. Finally, an anti-sway model is added for anti-sway processing, and an anti-overtravel model is added for anti-overtravel processing.

[0093] The vision measurement feedback link uses a binocular industrial camera to capture images of the goods and telescopic pictures, detects the length of the steel wire rope of the suspended load and the swing angle of the suspended rope. The obtained data is used for data adjustment of the simulation software platform. Finally, a control system is used for motor control, and the hardware simulation platform is used to realize the training and verification of the anti-sway model and the anti-overtravel model, and finally used for the actual adaptive underactuated gantry crane anti-sway and anti-overtravel.

[0094] The following is a specific description of the anti-sway model:

[0095] The two-dimensional plane schematic diagram is as Figure 2As shown below. First, through reasonable assumptions, the Newtonian mechanics analysis of the gantry crane trolley under different initial conditions is carried out. The system space model is simplified to a two-dimensional plane space through decoupling analysis, and only the movement of the gantry crane trolley in the XZ axis is analyzed, so as to establish a mathematical model for anti-sway of the gantry crane.

[0096] Among them, is the mass of the gantry crane trolley, is the length of the wire rope for the suspended load, is the driving force for lifting the wire rope, is the swing angle of the load. The gantry crane trolley only moves in the X-axis direction, and its position coordinate can be expressed as . The load can move in the XOZ plane, and the position coordinate can be expressed as ( ), and the relationship with the position coordinate of the gantry crane trolley is:

[0097] ;

[0098] The speed relationship between the load and the hoisting trolley:

[0099] ;

[0100] By analyzing the energy of the bridge gantry crane system, the Lagrangian equation is established and solved to obtain the mathematical model of the bridge gantry crane system. The kinetic energy of the gantry crane system includes the kinetic energy of the gantry crane trolley and the kinetic energy of the load. The structure of the gantry crane trolley has no influence on the system motion state, and at the same time, the gantry crane trolley only moves in the X-axis, so the kinetic energy of the trolley is:

[0101] ;

[0102] The gantry crane load swings in the XOZ plane, so its speed is composed of the speeds in the X and Z directions as :

[0103] ;

[0104] Among them, the speeds of the gantry crane load in the X and Z directions are respectively , .

[0105] The kinetic energy of the crane load can be obtained as:

[0106] ;

[0107] Among them, the displacement speed of the gantry crane trolley is . The total kinetic energy of the system is:

[0108] ;

[0109] The potential energy is:

[0110] ;

[0111] For a two - dimensional under - actuated crane system, there are three generalized coordinate variables, namely . is the displacement of the crane trolley , is the displacement in the direction of the crane wire rope , is the swing angle of the crane load . is the generalized non - conservative force of the system. L is the Lagrangian operator of the system, ;

[0112] where T represents the kinetic energy in the crane system, that is, the sum of the kinetic energies of the crane trolley and the crane load. U represents the potential energy of the crane system during the movement. Establish the Lagrangian equation and obtain:

[0113] ;

[0114] According to:

[0115] ;

[0116] Obtain the Lagrangian equation for the component force of the lifting driving force cross - beam along the wire rope direction with respect to the motion along the wire rope :

[0117] ;

[0118] Establish the Lagrangian equation with respect to the motion direction of the wire rope l using the generalized coordinate variable in the direction of the wire rope movement:

[0119] ;

[0120] For the swing angle θ , establish the generalized Lagrangian equation:

[0121] ;

[0122] Obtain the non - linear dynamic equation of the under - actuated crane system moving in the XOZ plane as:

[0123] ;

[0124] Based on the system mathematical model, establish the state - space equation, verify the stability and controllability of the system, and analyze the relationship between the load swing state, the initial state, and the acceleration through the phase - plane method:

[0125] ;

[0126] Obtain the spatial expression correlation coefficient:

[0127] ;

[0128] Denote as 4 The unit matrix of 4, 0 represents the zero matrix.

[0129] Perform a phase-plane analysis of the image algorithm of the second-order system on the dynamic equation of the gantry crane system. When the swing angle of the pendulum motion is less than 10°, the swing period T is only related to the rope length, T = , so the natural frequency = , Substitute into the rearranged formula:

[0130] ;

[0131] When the acceleration of the crane system is constant and positive, the swing angle of the crane load will be at a maximum of , a minimum of , and with as the period starting from the point and performing periodic motion clockwise along the circular trajectory of the phase plane, is a constant.

[0132] ;

[0133] Under the initial conditions of the load, when there is no driving force, the input and the resistance input satisfy:

[0134] ;

[0135] Then the pendulum motion in the initial state satisfies:

[0136] ;

[0137] The radius of the phase-plane circle is obtained as = , and the starting point of the periodic motion is obtained :

[0138] ;

[0139] It is further interpreted that the initial swing angle of the crane load is ), and the swing angular velocity is , the periodic motion of the crane trolley with an acceleration of a. It further provides a theoretical basis for realizing the anti-sway of the crane shaping input in a non-zero initial state.

[0140] The following is a specific description of the anti-overtravel model:

[0141] Use the software simulation platform MATLAB to calibrate the left and right cameras separately, and then perform stereo rectification to obtain the accurate internal and external parameters of the cameras and the binocular baseline distance of the binocular camera device , the camera focal length , the reference point in the world coordinate system with the left camera as the reference , such as Figure 3 shown, where the coordinate Z can be used for the length of the wire rope suspending the load , calculate the rising or falling distance of the rope and speed . The X-direction components of the two image coordinate systems of the point projection on the left and right image planes are , and the parallax of the left and right screen projections is obtained :

[0142] ;

[0143] The rope ranging formula is obtained:

[0144] ;

[0145] The change in the rope length is obtained by fixed-time sampling, and the change value is set as k =0,1,2

[0146] ;

[0147] The speed expression relationship is obtained:

[0148] .

[0149] Simulate installing a DS-2CD3367WDP2V2-L binocular industrial vision camera at the safe position of the model suspension on the rotary skip loader. Use a real-time binocular vision system based on FPGA algorithm and stereo matching algorithm to detect the change in the rising distance and swing angle of the suspended goods. Use MATLAB to calibrate the left and right cameras separately, and then perform binocular calibration to obtain the accurate internal and external parameters of the cameras. Finally, use the Bouguet algorithm to complete the stereo rectification of the left and right views of the binocular camera.

[0150] Before the formal installation of the system, the hardware simulation link of the present invention needs to be constructed and trained through actual data and the initial closed-loop model, and then feedback needs to be obtained through the return value of visual measurement.

[0151] As shown Figure 5 in the figure, the working principle of the present invention mainly depends on the anti-sway model, the anti-overhead model and the simulation of actual data collection. Then, the anti-sway treatment is carried out on the actual acceleration and deceleration of the gantry crane transportation by detecting the sway angle as the output, and the anti-overhead treatment is carried out on the actual rope release and retraction speed and acceleration of the load by measuring the movement speed and acceleration of the load. The anti-sway model and the anti-overhead model that can predict the normal working state are trained through a large number of normal events in the database. When the gantry crane is working, the visual measurement module composed of DS-2CD3367WDP2V2-L binocular industrial vision cameras works, and the initial data is transmitted as input to the anti-sway model of the control system based on the shaping algorithm and the angle measurement of the industrial camera. If the sway angle of the load exceeds the preset angle (such as 10 degrees) with respect to the central vertical line, the acceleration of the crane needs to be adjusted, and the adjustment signal is transmitted to the crane movement motor in the control system configured by the hardware simulation platform, and the control motor is controlled through the feedback signal. If the sway angle of the load does not exceed the specified angle range, the existing motion state is maintained. The anti-overhead model is based on the visual measurement module to detect the length of the wire rope of the suspended load. According to the collected continuous distance data, the rotational speed deviation is obtained -[[-]] or -[[-]] ; When does not meet the constraint conditions ( The constraint conditions to be met are: ; Among them, is the minimum rope movement speed, is the maximum rope movement speed.) When entering this link, a response feedback is given to the rope movement motor of the hardware control system (if is greater than , the rotational speed of the rope movement motor is reduced with a rotational speed deviation of -[[-]] , if is less than , the rotational speed of the rope movement motor is increased with a rotational speed deviation of -[[-]] ).

[0152] In another embodiment, the present invention provides a method for anti-sway and anti-overhead when using the above anti-sway and anti-overhead system to hoist and transport goods in various aspects of the scene by a gantry crane or other hoisting machinery. As shown Figure 4 in the figure, the specific steps are as follows:

[0153] Step 1: Simplify the actual transportation process of the gantry crane to obtain the simulation parameters of the gantry crane transportation process under proportional scaling;

[0154] Specifically, the actual gantry crane transportation process is simplified to the process of starting from no initial speed, accelerating to the maximum speed, reaching a stable speed, and then decelerating to 0m / s to the picking point.

[0155] Step 2: Based on the simulated parameters of the gantry crane transportation process under scaled conditions, the motion trajectory of the gantry crane in transporting hoisted cargo in the actual working scenario is simulated, and a control simulation model, a swing elimination model, and an anti-top impact model of the motion trajectory are constructed;

[0156] Among them, the shaping algorithm is used in the control simulation model to obtain the simulated motion trajectory and the motion parameters under the time angle such as the speed of the crane and the grab;

[0157] Specifically, the software simulation model is constructed using the simulink module in MATLAB according to the actual factory setting values. Step 2 specifically includes:

[0158] Step 2-1, determine the target trajectory that the door-to-door crane needs to execute to transport the goods;

[0159] Specifically, firstly, the task that the door-to-door crane needs to perform in transporting goods is clarified, that is, the path from the starting point to the end point; this target trajectory can be a straight line, a curve, or a path of any other shape.

[0160] Step 2-2: Based on the time required to complete the entire movement using the actual driving force obtained, define the position the system should be in at each moment and determine the speed at each position; define the change in acceleration to ensure the smoothness of the movement.

[0161] Step 2-3, set the number of continuous state variables, the number of discrete state variables, the number of outputs, and the number of inputs;

[0162] Here it is assumed that there are only two input signals, representing the control input (such as the torque or force of the motor), and the direct feedthrough flag, 0 means that the output does not directly depend on the current input (that is, the output will not immediately reflect the change of the input), the number of sampling times, 0 means inheriting the default sampling time, and converting the set sizes object to a simsizes object and assigning it to sys; at the same time, the initial state vector is set, where all 6 states are initialized, and actual application needs to be adjusted according to specific circumstances.

[0163] Step 2-4: Use the shaping algorithm to smooth the acceleration changes and avoid sudden changes using cubic spline interpolation in S-curve trajectory planning.

[0164] Step 2-5: Use minimum beat control to transfer the system from one state to another in the shortest time and reduce overshoot.

[0165] Step 2-6: Perform pre-oscillation compensation before the action starts, introducing a small pre-oscillation to counteract the swing caused by the subsequent action and make the model more stable.

[0166] Step 2-7: Establish the dynamic model of the system through a PID controller, including physical parameters such as mass, moment of inertia, and friction coefficient, in order to accurately predict the behavior of the system.

[0167] Step 2-8: Repeat Steps 2-4 and 2-7 until the optimal trajectory algorithm result is obtained.

[0168] Step 3: Based on the simulation parameters of the gantry crane transportation process under proportional scaling, build a gantry crane transportation model in combination with the size and working scenario of the actual gantry crane.

[0169] Specifically, according to the actual size of the gantry crane, a stable base frame is built using steel structure materials. The base should be wide enough to support the weight of the entire simulation platform and ensure that it does not displace during operation. A main beam is erected at the center of the base, which is the core part of the inverted T-shaped structure. The height of the main beam should be equivalent to that of the actual gantry crane to ensure that its working height can be accurately simulated. A cross beam is installed on top of the main beam to form a stable T-shaped structure. The connection between the cross beam and the main beam must be firm and reliable to prevent loosening caused by vibration. A lifting mechanism is installed on the main beam, usually realized by an electric hoist or a hydraulic cylinder. The lifting mechanism should be equipped with limit switches and emergency braking devices to ensure operation safety. At the same time, position sensors are also installed to monitor the lifting height in real time. A traveling mechanism is installed below the cross beam, including rails and traveling wheels. The traveling mechanism should be able to move smoothly along the main beam to simulate the process of the gantry crane traveling along the dock rails. The traveling wheels should have good wear resistance and load-bearing capacity, and an encoder is installed to record the traveling distance. A spreader simulation device, such as a grab or a hook, is fixed on the cross beam. The spreader simulation device should be able to rotate and tilt freely to facilitate imitating various actions under real working conditions. In addition, force sensors are installed to detect the interaction force between the spreader and the goods. An industrial vision camera and a sensor system are installed to monitor the vibration, tilt and other states of the simulation platform during operation. These sensors should be installed at key positions, such as the top of the main beam and the connection of the spreader, to ensure that motion information can be comprehensively captured. A control system is configured, mainly including components such as a control board, a motor driver, and a data acquisition card. The control system is responsible for receiving data from the sensors and adjusting the motor output according to the preset control algorithm to achieve precise control of the simulation platform. At the same time, a suitable software interface also needs to be developed or selected to facilitate the operator to monitor and adjust parameters. Finally, system debugging is carried out. First, the functions of each subsystem (such as the lifting mechanism, the traveling mechanism, etc.) are tested separately, and after confirmation, the overall linkage test is carried out. During this process, attention should be paid to observing whether there are abnormal noises, vibrations and other situations, and relevant components should be adjusted in time. After debugging, a detailed operation manual and maintenance guide also need to be formulated to ensure the long-term stable operation of the simulation platform and flexible configuration to meet the operation requirements of other industrial lifting machines.

[0170] Step 4: Control the movement of the gantry crane transportation model with the trajectory control parameters obtained from the control simulation model to simulate the actual transportation situation of the gantry crane.

[0171] Specifically, the control simulation model is converted into a PLC program to control the rotation parameters of the hardware platform for testing.

[0172] Step 5: Train and verify the anti-sway model and the anti-overhead model.

[0173] Specifically, it includes: an industrial vision camera collects images of the hoisted goods and the suspension ropes in real time, and a binocular vision system detects the length of the steel wire rope of the suspended load and the swing angle of the suspension rope based on the collected images.

[0174] The detected length of the steel wire rope of the suspended load is fed back to the anti-overtravel model to obtain anti-overtravel control parameters, and the movement of the gantry crane transportation model is controlled based on the anti-overtravel control parameters to prevent the goods from overtraveling or colliding with obstacles on the transportation track due to too slow rope retraction speed.

[0175] The detected swing angle of the suspension rope is fed back to the swing elimination model to obtain swing elimination control parameters, and the movement of the gantry crane transportation model is controlled based on the swing elimination control parameters to prevent the swing angle of the suspension rope from being too large.

[0176] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive under-actuated door crane anti-sway and anti-top-impact system, characterized in that: include: Software simulation platform and hardware simulation platform; The hardware simulation platform is configured with a control system and a visual measurement module; The software simulation platform simulates the motion trajectory of transporting hoisted goods in the working scene of the real gantry crane, and constructs a control simulation model, a swing elimination model and an anti-top impact model of the motion trajectory; The hardware simulation platform builds a portal machine transportation model based on the size of the actual portal machine and its working scene; the control system controls the movement of the portal machine transportation model based on the trajectory control parameters obtained from the control simulation model built by the software simulation platform, so as to simulate the actual transportation situation of the portal machine and train and verify the anti-sway model and the anti-top impact model; The visual measurement module includes an industrial visual camera and a binocular visual system installed in a suspended safety position on the portal machine model, wherein the industrial visual camera is used to collect images of the hoisted cargo and the suspension rope, and the binocular visual system detects the length of the steel wire rope of the suspended load and the swing angle of the suspension rope based on the collected images; The training and verification of the anti-sway model and the anti-top-impact model include: The visual measurement module feeds back the detected wire rope length of the hanging load to the anti-collision model of the software simulation platform to obtain the anti-collision control parameters. The control system controls the movement of the gantry crane transport model based on the anti-collision control parameters to prevent the cargo from collide with the transport track obstacles due to the slow rope collection speed. The visual measurement module feeds back the detected swing angle of the suspension rope to the anti-swing model of the software simulation platform to obtain the anti-swing control parameters. The control system controls the movement of the gantry crane transport model based on the anti-swing control parameters to prevent the suspension rope from swinging too much. Among them, the dynamic model of the simulated door crane cargo movement trajectory is constructed, including: Determine the physical parameters of the portal crane transport model, including: the mass of the portal crane trolley 、 The length of the wire rope that suspends the load, the driving force of the rope to lift it, and the load swing angle; Based on the physical parameters of the portal crane transportation model, a nonlinear dynamic model for simulating the movement trajectory of the portal crane cargo is established using the Lagrangian method; the nonlinear dynamic model includes: the Lagrangian equations of the crossbeam component of the lifting driving force of the lifting rope, the lifting driving force of the lifting rope and the swing angle during the lifting of the cargo; Among them, building a swing elimination model includes: The nonlinear dynamic model of the simulated gantry crane cargo motion trajectory is analyzed in two-dimensional phase plane, and a swing elimination model based on the shaping algorithm is established under the zero initial state to obtain the relationship between the load swing angle and the crane displacement acceleration as well as the maximum and minimum values ​​of the load swing angle. Among them, the relationship between the load swing angle and the crane displacement acceleration is: ； in, is the crane displacement acceleration, For the quality of the portal crane trolley, is the load swing angle, is the acceleration due to gravity, For the quality of goods, It is the beam force component of the lifting driving force of the rope; The maximum and minimum values ​​of the load swing angle are: ； in, is the maximum load swing angle, is the minimum load swing angle, is a constant, g is the acceleration due to gravity, is the initial value of the load swing angle, is the initial value of the load swing angular velocity; Based on the maximum and minimum values ​​of the load swing angle, determining the constraint condition of the load swing angle; the constraint condition of the load swing angle is: the maximum and minimum values ​​of the load swing angle are respectively less than the preset angle; Among them, the construction of the anti-top model includes: The left and right views of the cargo transported by the gate machine collected in real time by the binocular industrial vision camera in the visual measurement module are stereo corrected to obtain the internal and external parameters of the binocular industrial vision camera; the internal and external parameters of the binocular industrial vision camera include: binocular baseline distance T , Camera focal length f , the reference point in the world coordinate system with the left camera as the reference , where the coordinate Z represents the length of the wire rope that suspends the load l ; The component of the X direction in the two image coordinate systems of the point projection on the left and right image planes is , get the projection parallax of the left and right images d : ； Based on the parallax of left and right screen projection d The rope distance measurement formula is obtained: ； Calculate the rope ascent or descent distance under fixed time sampling ,speed : ； Among them, k is the change value; ； The constraints must be met: ； in, is the minimum rope speed, is the maximum rope movement speed.

2. The adaptive under-actuated door crane anti-sway and anti-top-impact system according to claim 1 is characterized in that: Build a door-to-door transport model, including: A proportionally scaled inverted T-shaped portal machine model is constructed; the portal machine model comprises: a base, a main beam erected at the center of the base, and a crossbeam firmly installed on the top of the main beam; Install a lifting mechanism and a position sensor for monitoring the lifting height on the main beam; A traveling mechanism is installed under the crossbeam, which can move smoothly along the main beam to simulate the process of the gantry crane traveling along the dock track; A sling simulation device is fixed on the crossbeam, and the sling simulation device can rotate and tilt freely so as to simulate various actions under real working conditions; Install force sensors to detect the interaction force between the spreader and the cargo; A sensor system for monitoring the motion status during operation is installed on the top of the main beam and at the connection of the spreader simulation device; The configuration is responsible for receiving data from the software simulation platform and adjusting the control system of the motor output according to the received data.

3. The adaptive under-actuated door crane anti-sway and anti-top-impact system according to claim 1, characterized in that: The visual measurement module feeds back the detected swing angle of the suspension rope to the anti-swing model of the software simulation platform to obtain anti-swing control parameters, including: Based on the swing angle of the suspension rope detected by the visual measurement module, the relationship between the load swing angle and the crane displacement acceleration is used to obtain the crane displacement acceleration and whether the current swing angle direction is in the same direction or in the opposite direction of the crane movement direction; The control system controls the movement of the portal crane transport model based on the anti-sway control parameter to prevent the suspension rope from swinging too much, including: When the load swing angle does not meet the constraint conditions, if the current swing angle direction is in the same direction as the crane movement direction, the acceleration of the crane running motor is increased; if the current swing angle direction is in the opposite direction to the crane movement direction, the acceleration of the crane running motor is reduced.

4. The adaptive under-actuated door crane anti-sway and anti-top-impact system according to claim 1, characterized in that: The visual measurement module feeds back the detected length of the wire rope of the suspended load to the anti-top impact model of the software simulation platform to obtain the anti-top impact control parameters, including: Based on the length of the wire rope of the suspended load detected by the visual measurement module, the speed deviation is obtained. - or - ; The control system controls the movement of the portal crane transport model based on the anti-collision control parameter to prevent the cargo from collide with the transport track obstacle due to the slow rope collection speed, including: when If the constraints are not met, Greater than ,by - The speed deviation reduces the rope motion motor speed. Less than ,by - The speed deviation increases the rope motion motor speed.

5. An adaptive under-actuated door machine anti-sway and anti-top-impact method, characterized in that: The method uses an adaptive under-actuated door machine sway elimination and top impact prevention system as described in any one of claims 1 to 4 to eliminate sway and prevent top impact, and the method comprises the following steps: Step 1: Simplify the actual door-to-door crane transportation process and obtain the simulation parameters of the door-to-door crane transportation process under proportional scaling; Step 2: Based on the simulated parameters of the gantry crane transportation process under scaled conditions, the motion trajectory of the gantry crane in transporting hoisted cargo in the actual working scenario is simulated, and a control simulation model, a swing elimination model, and an anti-top impact model of the motion trajectory are constructed; Step 3: Based on the simulated parameters of the portal crane transportation process under scale, the portal crane transportation model is built in combination with the size of the actual portal crane and its working scene; Step 4: Using the trajectory control parameters obtained by the control simulation model to control the movement of the portal crane transportation model, so as to simulate the actual transportation situation of the portal crane; Step 5: Training and verification of the anti-sway model and anti-top-impact model, including: The industrial vision camera collects images of the hoisted cargo and the suspension rope in real time, and the binocular vision system detects the length of the wire rope hanging the load and the swing angle of the suspension rope based on the collected images; Feeding back the detected length of the wire rope of the hanging load to the anti-top impact model to obtain the anti-top impact control parameters, and controlling the movement of the gantry crane transport model based on the anti-top impact control parameters to prevent the cargo from hitting the top or the rope collection speed from being too slow and colliding with obstacles on the transport track; Feeding back the detected swing angle of the suspension rope to the anti-swing model to obtain the anti-swing control parameter, and controlling the movement of the portal crane transport model based on the anti-swing control parameter to prevent the suspension rope from swinging too much; Step 6: Apply the trained and verified control simulation model, sway elimination model and top impact prevention model to the actual adaptive under-actuated door crane to achieve sway elimination and top impact prevention of the actual adaptive under-actuated door crane.

6. The method for preventing swing and top impact of an adaptive under-actuated door crane according to claim 5 is characterized in that: Based on the simulated parameters of the gantry crane transportation process under scaled conditions, the motion trajectory of the gantry crane in transporting hoisted goods in the actual working scenario is simulated, and the control simulation model, swing elimination model and top impact prevention model of the motion trajectory are constructed, including: Determine the target trajectory that the door-to-door aircraft needs to follow to deliver the goods; Based on the time required to complete the entire movement with the actual driving force obtained, define the position the system should be in at each moment and determine the speed at each position; define the change in acceleration to ensure the smoothness of the movement; Set the number of continuous state variables, the number of discrete state variables, the number of outputs, and the number of inputs; The reference shaping algorithm uses cubic spline interpolation in S-curve trajectory planning to smooth the changes in crane motion acceleration; Use minimum beat control to transfer the system from one state to another in the shortest time and reduce overshoot; Pre-oscillation compensation is performed before the action starts, introducing a small pre-oscillation to offset the swing caused by the subsequent action and make the model more stable.

7. The method for preventing swing and top impact of an adaptive under-actuated door crane according to claim 5, characterized in that: Simplifying the actual gantry crane transportation process includes: simplifying the actual gantry crane transportation process to a process without initial speed, first accelerating to the maximum speed and then to the stable speed from the feeding location to the picking point, and then decelerating to 0m / s to the picking point.

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