Heavy-load lifting and positioning control device and control method for port equipment cranes

Abstract

This invention relates to the field of port crane equipment and automation control, specifically to a heavy-load lifting and positioning control device and method for port cranes; it includes a crane main beam, trolley frame, laser ranging component, status monitoring component, and controller module; the device combines a side-mounted laser rangefinder, an incremental photoelectric encoder at the drum end, and a dual-axis tilt sensor at the top of the hook to directly acquire various real-time operating states; its core is to directly collect real state quantities such as the absolute position of the trolley, the rotation angle of the lifting drum, and the swing angle of the hook to participate in control calculations, thereby achieving precise lifting and positioning of heavy loads; this invention eliminates the need for additional mechanical swing limiting mechanisms and complex nonlinear state observers, significantly reducing the structural complexity of the equipment, simplifying the system hardware architecture, and effectively reducing the computational burden on the controller.

Description

Technical Field

[0001] This invention relates to the field of port lifting equipment and automation control, specifically to a heavy-load lifting and positioning control device and control method for port equipment cranes. Background Technology

[0002] In the face of the heavy-load lifting environment of port equipment cranes, when the trolley carrying heavy loads moves and positions along the main beam track, the load suspended at the bottom of the wire rope will inevitably sway. In order to suppress the load sway and achieve precise docking at the target position, existing solutions generally adopt additional mechanical sway limiting mechanisms such as hydraulic anti-sway arms, or introduce complex nonlinear state observers into the control system to estimate the load sway and generate anti-sway compensation commands in combination with fixed empirical coefficients. Although this solution has a certain sway reduction and positioning capability, the additional mechanical mechanisms significantly increase the structural complexity of the equipment and reduce the inherent reliability of the mechanical system. At the same time, the algorithm calculation relying on complex nonlinear observers is heavy. Moreover, when using fixed empirical coefficients for compensation and control, it cannot adapt to the dynamic sway length changes caused by the hoisting drum winding and unwinding the wire rope, resulting in a decrease in compensation accuracy. This requires the trolley to perform repeated jogging operations at the positioning end, which seriously affects the operating performance of the equipment and leads to an extension of the positioning control cycle.

[0003] Therefore, how to accurately calculate the anti-sway compensation amount based on the dynamic changes of the pendulum length in real time and improve the stability of the crane's heavy load lifting and positioning without adding additional mechanical pendulum limiting mechanisms or relying on complex nonlinear observers has become an urgent technical problem to be solved. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a heavy-load lifting and positioning control device and control method for port equipment cranes. Specifically, the technical solution of the present invention is as follows: The port equipment crane's heavy-load lifting and positioning control device includes: The crane's main beam has parallel tracks laid on top; reflective targets are installed at the ends of the crane's main beam. The trolley frame is placed on the parallel track via its wheels; wherein, a lifting drum is provided on the top surface of the trolley frame, a steel wire rope is wound on the lifting drum, and a hook frame is suspended at the bottom end of the steel wire rope; A ranging component is disposed on the side of the vehicle frame; wherein, the ranging component includes a laser rangefinder, the optical axis of which is aligned with the reflective target; The status monitoring component includes an incremental photoelectric encoder and a dual-axis tilt sensor; wherein the incremental photoelectric encoder is connected to the non-drive end journal of the hoisting drum, and the dual-axis tilt sensor is disposed on the top horizontal plane of the hook frame; A controller is located inside the vehicle frame and connected to a frequency converter; wherein the controller controls the laser rangefinder, the incremental photoelectric encoder, the dual-axis tilt sensor and the frequency converter, and the frequency converter is connected to a walking motor that drives the walking wheels to rotate.

[0005] In some embodiments, the incremental photoelectric encoder is connected to the hoisting drum via a cross-slider type flexible coupling; The cross-slider type flexible coupling allows for an axial deviation of ±2mm and an angular deviation of ±1° to ±3°.

[0006] In some embodiments, the dual-axis tilt sensor is covered by a stainless steel protective housing; A polyurethane shock-absorbing pad is provided between the stainless steel protective shell and the hook frame.

[0007] In some embodiments, the stainless steel protective shell has a thickness of 1 mm to 4 mm, and the polyurethane shock-absorbing pad has a thickness of 0.5 mm to 3 mm.

[0008] In some embodiments, the outer cylindrical surface of the hoisting drum is machined with a helical rope groove; The steel wire rope is wound inside the spiral groove.

[0009] In some embodiments, the walking motor is fixed to the bottom of the vehicle frame; The output shaft of the walking motor is directly connected to the axle of the walking wheel via a single-stage gear reducer.

[0010] The control method for the heavy-load lifting and positioning control device of the port equipment crane includes: S1. Real-time acquisition of the rotation angle pulse signal of the incremental photoelectric encoder on the hoisting drum, calculation of the real-time winding length based on the rotation angle pulse signal, and calculation of the real-time swing length in combination with the pre-calibrated initial total length of the wire rope. S2. Obtain the reflected light signal of the laser rangefinder, calculate the current absolute position of the vehicle frame based on the reflected light signal using the time of light flight, and calculate the difference between the preset target position and the current absolute position to obtain the remaining running distance. S3. Based on the remaining running distance, calculate the basic running acceleration of the vehicle frame; S4. Obtain the tilt angle of the dual-axis tilt sensor in the direction of the vehicle's movement as the real-time swing angle; S5. Determine whether the absolute value of the real-time swing angle is greater than the preset vertical zero dead zone threshold. S6. When the real-time swing angle exceeds the preset vertical zero dead zone, the compensation acceleration is calculated based on the real-time swing angle and the real-time swing length, and the working state of the walking motor is controlled in combination with the basic running acceleration and the compensation acceleration; when the real-time swing angle does not exceed the preset vertical zero dead zone, the working state of the walking motor is controlled only based on the basic running acceleration.

[0011] In some implementations, step S1 includes: S101. Obtain the number of rotation angle pulses in the rotation angle pulse signal; S102. Calculate the real-time winding length based on the number of rotation angle pulses; S103. Based on the calculation result of the difference between the pre-calibrated initial total length of the wire rope and the real-time winding length, obtain the real-time swing length of the current system.

[0012] In some embodiments, the step of calculating the compensation acceleration based on the real-time swing angle and the real-time swing length when the real-time swing angle exceeds the preset vertical zero dead zone includes: S601. Based on the positive proportional relationship between the real-time swing angle and the constant gravitational acceleration, generate a basic recovery acceleration that reflects the recovery trend under heavy load. S602: Based on the preset compensation gain coefficient and real-time pendulum length, the basic recovery acceleration is adjusted, and the compensation acceleration is output.

[0013] In some embodiments, the step of controlling the operating state of the walking motor by combining the base running acceleration and the compensated acceleration includes: S603. Based on the basic running acceleration and the compensated acceleration, the final composite acceleration is obtained; S604. Calculate the target running speed based on the final composite acceleration; S605. The target running speed is converted into a frequency command and sent to the frequency converter to drive the walking motor to counteract the swaying tendency of the hook frame.

[0014] The present invention has the following beneficial effects: 1. The heavy-load lifting and positioning control device for port equipment cranes of the present invention achieves direct measurement of state variables by installing a laser rangefinder on the side of the trolley frame, connecting an incremental photoelectric encoder to the non-drive end of the lifting drum, and installing a dual-axis tilt sensor on the top of the hook frame. This structure eliminates the need for additional mechanical swing limiting mechanisms, significantly reducing the structural complexity of the equipment and improving the overall mechanical stability of the device. At the same time, it directly collects absolute position, drum rotation angle, and hook swing angle to participate in control calculations, eliminating the dependence on complex nonlinear state observers and effectively reducing the computational burden on the controller. 2. The control method of this invention calculates the real-time swing length based on the rotation angle pulse signal of the incremental photoelectric encoder, and directly converts the compensation acceleration into the real-time swing angle obtained by the dual-axis tilt sensor, and synthesizes it with the basic running acceleration to control the traveling motor. This method realizes the dynamic matching between the anti-sway compensation amount and the real-time swing length, replacing the traditional fixed empirical coefficient, effectively overcoming the problems of overcompensation of short ropes and undercompensation of long ropes that are easily caused when the hoisting drum winds up and unwinds the wire rope, improving the stability of the crane's heavy-load positioning, and greatly reducing the repeated jogging operations at the positioning end. Attached Figure Description

[0015] The following drawings, which illustrate embodiments of this application, are incorporated herein by reference and are used to understand this application. The drawings depict embodiments of this application and their descriptions, serving to explain the principles of this application. In the drawings, Figure 1 This is a schematic diagram of the overall external structure of the device; Figure 2 This is a structural diagram of the car frame; Figure 3 This is a structural diagram of the hook frame; Figure 4 This is a structural diagram of a walking motor; Figure 5 This is a flowchart of the method of the present invention.

[0016] In the diagram: 1. Crane main beam; 2. Parallel rail; 3. Reflective target; 4. Trolley frame; 5. Traveling wheels; 6. Lifting drum; 7. Wire rope; 8. Hook frame; 9. Distance measuring component; 10. Laser rangefinder; 11. Status monitoring component; 12. Incremental photoelectric encoder; 13. Dual-axis tilt sensor; 14. Controller; 15. Variable frequency drive; 16. Travel motor; 17. Cross-slider type flexible coupling; 18. Stainless steel protective shell; 19. Polyurethane shock-absorbing pad; 20. Spiral rope groove; 21. Single-stage gear reducer. Detailed Implementation

[0017] In the following description, numerous specific details are set forth to provide a more thorough understanding of this application. However, it will be apparent to those skilled in the art that embodiments of this application may be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described to avoid confusion with embodiments of this application.

[0018] Example 1: Combination Figure 1 As shown, the port equipment crane heavy load lifting and positioning control device includes: The crane main beam 1 has parallel rails 2 laid on top; and reflective targets 3 are installed at the ends of the crane main beam 1. The trolley frame 4 is placed on the parallel track 2 via the traveling wheels 5; the top surface of the trolley frame 4 is provided with a lifting drum 6, a steel wire rope 7 is wound on the lifting drum 6, and a hook frame 8 is suspended at the bottom end of the steel wire rope 7. The ranging component 9 is disposed on the side of the vehicle frame 4; wherein, the ranging component 9 includes a laser rangefinder 10, the optical axis of which is aligned with the reflective target 3; The status monitoring component 11 includes an incremental photoelectric encoder 12 and a dual-axis tilt sensor 13; wherein, the incremental photoelectric encoder 12 is connected to the non-drive end journal of the hoisting drum 6, and the dual-axis tilt sensor 13 is set on the top horizontal plane of the hook frame 8. The controller 14 is located inside the trolley frame 4 and is connected to the frequency converter 15; wherein, the controller 14 controls the laser rangefinder 10, the incremental photoelectric encoder 12, the dual-axis tilt sensor 13 and the frequency converter 15, and the frequency converter 15 is connected to the walking motor 16 that drives the walking wheels 5 to rotate. The heavy-load lifting and positioning control device for the port equipment crane adopts a main beam traveling structure. The main beam 1 of the crane is used to bear the trolley frame 4 and its heavy-load running load. The parallel rail 2 on the top of the main beam can be two steel rails with a spacing of 1.5m to 3.5m. The length of the rail is set from 10m to 80m according to the overall span of the machine. The reflective target 3 is fixed at the end of the main beam 1 of the crane, preferably installed at the reference end face in the extension direction of the rail, and is used to provide a stable absolute position reference to the laser rangefinder 10. The trolley frame 4 is placed on the parallel track 2 via four traveling wheels 5. At least two of the four traveling wheels 5 are connected to the traveling motor 16 for driving the trolley frame 4 to move back and forth along the track. The lifting drum 6 on the top surface of the trolley frame 4 is used to wind up and unwind the wire rope 7. The hook frame 8 at the bottom of the wire rope 7 is used to connect the load to be lifted. The laser rangefinder 10 in the ranging component 9 is arranged on the side of the trolley frame 4. Its optical axis is aligned with the reflective target 3 along the length of the main beam so as to continuously output the absolute position signal of the trolley frame 4 relative to the end of the main beam during the movement of the trolley. The incremental photoelectric encoder 12 in the status monitoring component 11 is installed at the non-drive end journal position of the hoisting drum 6 to collect the rotation angle pulses of the hoisting drum 6 and calculate the real-time winding length of the wire rope 7; the dual-axis tilt sensor 13 is installed on the top horizontal plane of the hook frame 8 to collect the real-time swing angle of the heavy load in the trolley running direction, and can simultaneously provide auxiliary attitude data perpendicular to the running direction for zero-position calibration during installation and commissioning; The controller 14 is located inside the trolley frame 4. Preferably, it is a programmable logic controller 14. The controller 14 is electrically connected to the laser rangefinder 10, the incremental photoelectric encoder 12, the dual-axis tilt sensor 13, and the frequency converter 15. The controller 14 collects, converts, and performs control calculations on the signals from the three types of sensors, and outputs the calculated speed or frequency command to the frequency converter 15. The frequency converter 15 adjusts the output speed of the walking motor 16 according to the command, so that the trolley frame 4 actively applies corresponding walking acceleration and deceleration according to the change of the swing angle of the hook frame 8 while performing positioning movement. This device does not add additional mechanical sway limiting mechanisms such as hydraulic anti-sway arms. Instead, it uses three types of physical quantities—absolute position, drum rotation angle, and hook swing angle—to control the movement, so that the same trolley movement mechanism can take into account both equipment operation performance and sway suppression requirements.

[0019] Combination Figure 2 As shown, the incremental photoelectric encoder 12 is connected to the hoisting drum 6 via a cross-slider type flexible coupling 17; wherein, the cross-slider type flexible coupling 17 allows an axial deviation of ±2mm and an angular deviation of ±1° to ±3°. The incremental photoelectric encoder 12 is connected to the hoisting drum 6 by a cross-slider type flexible coupling 17. The cross-slider type flexible coupling 17 refers to a connecting part that is formed by the cooperation of the two end hubs and the middle slider to form a displacement compensation capability. Its function is to absorb installation errors and load-bearing micro-deformation while transmitting the rotation angle of the hoisting drum 6. When the lifting drum 6 is lifted under heavy load, the drum journal may experience axial movement and angular deviation within the preset tolerance range due to the force. If the incremental photoelectric encoder 12 is rigidly connected directly, the encoder input bearing is easily subjected to additional load, causing pulse jitter or mechanical damage. After adopting the cross-slider type flexible coupling 17, the allowable range of axial deviation is set to ±2mm, and the angular deviation can be set to ±1° to ±3°. In the embodiment of this application, ±1° is preferred. The preset angular deviation here refers to the maximum installation angle between the axis of the lifting drum 6 and the encoder input axis when the encoder angular displacement transmission accuracy and the coupling compensation capability are simultaneously met. Its physical meaning is to limit the upper limit of the coupling's absorption of drum load sway and installation error. The preset angle deviation can be determined according to the following logic: First, determine the possible actual deflection range based on the shaft end deflection of the hoisting drum 6 under rated load and maximum hoisting height conditions, bearing installation tolerance, and frame manufacturing and assembly tolerance; then, combine the allowable radial additional load, allowable angular error, and required pulse stability given by the encoder manufacturer, and select the angle value that will not cause overload of the encoder input shaft and can maintain continuous and stable pulse output as the preset angle deviation. If the measured installation deviation angle exceeds the preset angle deviation, it should be addressed by adjusting the coaxiality of the bracket or changing the coupling specifications to prevent the system from entering normal control operation. This structure ensures a stable angular displacement transmission relationship between the non-drive end journal of the hoisting drum 6 and the input shaft of the incremental photoelectric encoder 12, while reducing the additional bending moment caused by eccentricity. To ensure pulse conversion accuracy, the coupling transmission clearance is preferably controlled within 0.1 degrees, and the encoder resolution is preferably 5000 to 20000 pulses per revolution, with 10000 pulses per revolution selected in one embodiment. The technical effect of this connection is that the rotation angle measured by the encoder is closer to the actual angular displacement of the lifting drum 6, so that the real-time winding length calculated from the pulse signal meets the preset consistency requirements, reduces the deviation in the swing length calculation caused by the swing of the drum shaft end, and provides stable input conditions for subsequent compensation acceleration calculation.

[0020] Combination Figure 3 As shown, the dual-axis tilt sensor 13 is covered by a stainless steel protective shell 18; a polyurethane shock-absorbing pad 19 is provided between the stainless steel protective shell 18 and the hook frame 8. The dual-axis tilt sensor 13 is used to measure the tilt angle of the hook frame 8 relative to the direction of gravity. Its output is directly used by the controller 14 to determine whether the heavy load swings and the swing direction and amplitude. Since the hook frame 8 is easily affected by dust, water vapor, salt spray and transient impact during lifting, lowering and collision micro-vibration, the dual-axis tilt sensor 13 is equipped with a stainless steel protective shell 18 to provide dustproof, splashproof and mechanical abrasion protection. A polyurethane damping pad 19 is installed between the stainless steel protective shell 18 and the hook frame 8. The function of the polyurethane damping pad 19 is to weaken the transmission of high-frequency impacts from the instantaneous tension of the wire rope 7, the contact load of the hook, or the self-vibration of the equipment to the sensor base. After the dual-axis tilt sensor 13 is fixed to the top horizontal plane of the hook frame 8, the stainless steel protective shell 18 and the polyurethane damping pad 19 together form an external environment isolation and impact filtering structure, so that the swing angle signal collected by the sensor retains the low-frequency swing component under heavy load and reduces the high-frequency mechanical disturbance component. Since the control method of this application directly uses real-time swing angle and real-time swing length to calculate the compensation acceleration, the authenticity of the swing angle signal directly affects the compensation direction and compensation magnitude. After adopting the above protection structure, it helps to reduce false triggering compensation and over-compensation, and improve the consistency between the control command and the actual hook swing state.

[0021] The stainless steel protective shell 18 has a thickness of 1mm to 4mm, and the polyurethane shock-absorbing pad 19 has a thickness of 0.5mm to 3mm. The thickness of the stainless steel protective shell 18 and the thickness of the polyurethane shock-absorbing pad 19 are preset according to the operating vibration level of the hook frame 8, the environmental impact level, and the allowable installation space of the sensor. The thickness of the stainless steel protective shell 18 can be selected from 1mm to 4mm. In the preferred embodiment of this application, a 2mm thick 304 stainless steel plate is bent and welded into a cover, which can ensure sufficient mechanical strength and will not increase the additional load on the hook frame 8 due to excessive weight of the shell. The thickness of the polyurethane shock-absorbing pad 19 can be selected from 0.5mm to 3mm. In the preferred embodiment, a 1mm thick polyurethane sheet is used. The hardness can be selected from Shore hardness of 60° to 85° to balance the buffering and vibration absorption capacity and installation stability. If the thickness of the protective shell is less than the preset lower limit, external abrasion or particle impact may cause the shell to deform and squeeze the sensor. If the thickness of the protective shell is greater than the preset upper limit, it will increase the non-working weight of the top of the hook frame 8 and change the local inertia distribution. If the thickness of the damping pad is less than the preset lower limit, the high-frequency impact attenuation will be insufficient; if the thickness of the damping pad is greater than the preset upper limit, the stiffness of the sensor mounting base will decrease, which may lead to low-frequency attitude lag. By presetting the thickness of the protective shell and the damping pad, the external protective structure of the sensor can maintain a suitable parameter match between strength, weight and vibration isolation, thereby ensuring that the swing angle measurement results can be stably used for real-time calculation of the controller 14.

[0022] The outer cylindrical surface of the hoisting drum 6 is machined with a spiral rope groove 20; wherein the wire rope 7 is wound inside the spiral rope groove 20; The outer cylindrical surface of the hoisting drum 6 is machined with a spiral rope groove 20. The spiral rope groove 20 is a guide groove continuously distributed along the axial direction of the drum. Its groove spacing matches the diameter of the wire rope 7 and is used to constrain the wire rope 7 to be evenly distributed along a predetermined path. After the wire rope 7 is wound in the spiral rope groove 20, the cross-over and local overlapping phenomena between winding layers are reduced. The unwinding length of the hoisting drum 6 at each revolution is closer to the theoretical circumference value, thereby improving the linear consistency of the winding length converted from the 12 pulses of the incremental photoelectric encoder. For the control method of this application, the real-time swing length is obtained by subtracting the real-time winding length from the initial total length of the wire rope 7. If the winding is irregular, the same number of encoder pulses may correspond to different actual rope release lengths, resulting in swing length estimation error. After setting the spiral rope groove 20, the radial stacking pattern of the wire rope 7 on the drum is more controllable, the real-time swing length calculation error is reduced, and the controller 14 can more accurately match the inherent swing characteristics of the current hook system when calculating the compensation acceleration based on the swing length. The spiral rope groove 20 can be a circular arc bottom groove or a V-shaped transition groove. The groove depth can be selected from 0.3 to 0.6 times the diameter of the wire rope 7, and the groove spacing can be selected from 1.02 to 1.10 times the diameter of the wire rope 7 to ensure that the wire rope 7 maintains stable guidance during lifting and lowering.

[0023] Combination Figure 4 As shown, a walking motor 16 is fixed at the bottom of the car frame 4; wherein, the output shaft of the walking motor 16 is directly connected to the axle of the walking wheel 5 through a single-stage gear reducer 21. The bottom of the trolley frame 4 is fixed with a travel motor 16. The travel motor 16 can be a three-phase AC asynchronous motor or a permanent magnet synchronous motor. The rated power is set from 3kW to 45kW according to the crane tonnage and the running resistance of the trolley. The output shaft of the travel motor 16 is directly connected to the axle of the travel wheel 5 through a single-stage gear reducer 21. The reduction ratio of the single-stage gear reducer 21 can be selected from 3 to 12, which is used to convert the higher speed of the motor into the axle speed suitable for the trolley to run along the track. By adopting a transmission relationship where a single-stage gear reducer 21 is directly connected to the wheel axle, the number of intermediate transmission components and additional clearances can be reduced, allowing the output frequency change of the variable frequency drive 15 to be reflected as the acceleration and deceleration changes of the traveling wheel 5 within a preset response time. Since the control method of this application needs to continuously adjust the combined result of the basic running acceleration and the compensation acceleration according to the real-time swing angle change, shortening the transmission chain can reduce the dynamic lag time of the command transmission to the mechanical response link, thereby improving the accuracy of the swing suppression control of the hook frame 8. The walking motor 16 is fixed to the bottom of the trolley frame 4 by bolts or welded supports. The reducer can be installed by flange connection or foot connection. The two ends of the wheel axle are supported on the trolley frame 4 by bearing seats. This structure makes the drive torque transmission path clear, reduces maintenance points, and facilitates the controller 14 to repeatedly adjust the moving speed of the trolley frame 4 according to frequency commands.

[0024] Example 2: Combination Figure 5 As shown, the control method for the heavy-load lifting and positioning control device of the port equipment crane includes: S1. Real-time acquisition of the rotation angle pulse signal of the incremental photoelectric encoder 12 on the hoisting drum 6, real-time winding length calculated based on the rotation angle pulse signal, and real-time swing length calculated in combination with the pre-calibrated initial total length of the wire rope 7. S2. Acquire the reflected light signal of the laser rangefinder 10, calculate the current absolute position of the car frame 4 based on the reflected light signal using the time of light flight, and calculate the difference between the preset target position and the current absolute position to obtain the remaining running distance. S3. Based on the remaining running distance, calculate the basic running acceleration of the car frame 4; S4. Obtain the tilt angle of the dual-axis tilt sensor 13 in the direction of the vehicle's movement as the real-time swing angle; S5. Determine whether the absolute value of the real-time swing angle is greater than the preset vertical zero dead zone threshold. S6. When the real-time swing angle exceeds the preset vertical zero dead zone, the compensation acceleration is calculated based on the real-time swing angle and real-time swing length, and the working state of the walking motor 16 is controlled by combining the basic running acceleration and the compensation acceleration; when the real-time swing angle does not exceed the preset vertical zero dead zone, the working state of the walking motor 16 is controlled only based on the basic running acceleration. The control method operates in the controller 14 located inside the trolley frame 4. The scanning cycle of the controller 14 can be set from 5ms to 20ms to ensure that the dynamic data during the crane's movement can be continuously updated. In S1, the controller 14 reads the rotation angle pulse signal from the incremental photoelectric encoder 12, accumulates or decrements the number of pulses according to the encoder zero-position calibration value and the counting direction, calculates the real-time rotation angle of the hoisting drum 6, and obtains the real-time winding length according to the drum's geometric parameters; the controller 14 uses the initial total length of the wire rope 7 recorded during installation and commissioning as a known quantity, and obtains the real-time swing length by subtracting the real-time winding length from the initial total length of the wire rope 7. This real-time swing length represents the effective suspension length between the suspension point of the hook frame 8 and the approximate position of the center of gravity of the hook frame 8; In S2, the laser rangefinder 10 continuously emits laser light towards the reflective target 3 at the end of the main beam 1 of the crane. After receiving the reflected light signal, it calculates the optical path length using the time of flight of light and subtracts the fixed installation offset to obtain the current absolute position of the trolley frame 4. The controller 14 calculates the difference between the pre-input target position and the current absolute position to obtain the remaining running distance. The target position can be issued by the crane's host computer management system or pre-input by the operator through the human-machine interface terminal to the controller 14. In S3, the controller 14 plans the basic running acceleration based on the remaining running distance. This basic running acceleration reflects the driving requirements of the positioning task itself for the movement of the trolley. This planning process is essentially calling a preset motion trajectory planning model. The purpose of this motion trajectory planning model is to automatically generate basic motion commands that conform to the mechanical operating characteristics when the crane trolley approaches the target position, so as to achieve smooth deceleration and accurate positioning. In terms of logical structure, the model receives the remaining running distance as the input data stream, combines the pre-set maximum allowable running speed and allowable deceleration, determines the current movement stage of the car through distance threshold comparison logic, and outputs the basic running acceleration that matches the stage. In terms of physical relationships, this model represents the ideal kinematic process of a crane trolley smoothly transitioning from its current motion state to a target stopping state on a restricted track. The model can employ piecewise linear programming, constant acceleration deceleration programming, or S-shaped acceleration-deceleration programming. In one embodiment, when the remaining running distance is greater than the preset deceleration distance, the basic running acceleration is a positive set value during the acceleration phase and zero during the uniform speed phase. When the remaining running distance is less than the preset deceleration distance, the basic running acceleration decelerates according to a preset constant deceleration or the square root of the remaining running distance until the running speed is reduced to zero. For example, the maximum allowable operating speed is set to 1.5 m / s, and the preset deceleration distance is 3.0 m. When the remaining operating distance is 5.0 m, the basic operating acceleration output by the controller 14 remains at the positive set value or zero. When the remaining operating distance is reduced to 1.5 m, it is in the deceleration phase. The controller 14 dynamically adjusts the basic operating acceleration proportionally according to the ratio of the remaining operating distance to the preset deceleration distance, thereby achieving a smooth transition. The preset deceleration distance refers to the distance threshold set by the controller 14 to ensure that the trolley can smoothly transition from the current running speed to the allowable end approach speed between the current position and the target position. Its function is to serve as the basis for judging the basic running acceleration to switch from the acceleration segment to the deceleration segment. The preset deceleration distance can be preset according to the maximum allowable running speed, allowable deceleration, load level and track adhesion conditions, or it can be verified by no-load and rated load tests during the commissioning stage and the more conservative value is taken. The allowable deceleration can be set according to the braking capacity and anti-slip requirements of the trolley traveling mechanism, for example, 0.1 m / s² to 1.0 m / s²; the allowable end approach speed can be set according to the positioning accuracy requirements of the crane, for example, 0.05 m / s to 0.2 m / s. In S4, the controller 14 collects the tilt angle of the dual-axis tilt sensor 13 in the direction of the trolley's movement as the real-time swing angle. The sign of the swing angle is used to distinguish the left and right directions of the heavy load deviating from the vertical line. In S5, controller 14 compares the real-time swing angle with the vertical zero position. The vertical zero position can be obtained through no-load static calibration, and the zero-position dead zone can be set, for example... to To suppress frequent adjustments caused by minute measurement fluctuations; vertical zero position refers to the reference angle value output by the dual-axis tilt sensor 13 relative to the direction of gravity when the hook frame 8 is stationary and without continuous swing; When there are minor assembly errors in the hook frame 8, sensor mounting base, or protective structure, the reference angle value does not need to be strictly zero, but the calibration record value is used as the comparison reference; the zero dead zone refers to the allowable fluctuation range set around the vertical zero position. When the real-time swing angle enters this range, the controller 14 determines that it has not deviated from the vertical zero position, only performs position movement control, and does not trigger swing compensation; when the real-time swing angle exceeds this range, the controller 14 determines that there is effective swing and enters the compensation acceleration calculation process; In S6, when the real-time swing angle exceeds the preset vertical zero dead zone, the controller 14 calculates the compensation acceleration based on the real-time swing angle and real-time swing length, and combines the basic running acceleration with the compensation acceleration to generate control commands for the walking motor 16; when the real-time swing angle does not exceed the preset vertical zero dead zone, the controller 14 controls the walking motor 16 only based on the basic running acceleration, so that the trolley can complete the position movement task. This method unifies three measurable physical quantities—drum rotation angle, absolute position, and swing angle—for control calculations, without relying on complex state estimation models. It maintains the correspondence between the compensation amount and the current swing length even as the length of the wire rope 7 changes. To prevent control instability caused by data link anomalies, the controller 14 can also set validity checks for the real-time swing length, current absolute position, and real-time swing angle separately. When the encoder count exceeds the limit, the laser rangefinder continuously loses reflection, or the tilt angle signal changes abruptly beyond the preset rate of change, the controller 14 maintains or downgrades the output of the basic operating command and prohibits the use of abnormal data to participate in the compensation acceleration calculation, thereby keeping the data source, judgment conditions and control flow between each step clear; the preset rate of change can be preset according to the normal sampling noise of the dual-axis tilt angle sensor 13 and the maximum possible swing angular velocity under heavy load, for example, it can be set to 0.1° / ms to 0.5° / ms.

[0025] Step S1 includes: S101, obtaining the number of rotation angle pulses in the rotation angle pulse signal; S102. Calculate the real-time winding length based on the number of rotation angle pulses; S103. Based on the calculation result of the difference between the pre-calibrated initial total length of the wire rope 7 and the real-time winding length, obtain the real-time swing length of the current system. In S101, the controller 14 receives the A-phase and B-phase signals output by the incremental photoelectric encoder 12 through the high-speed counting input port, identifies the rotation direction of the hoisting drum 6 according to the phase relationship, and adds the pulse increment in the current sampling period to the total pulse count value to obtain the rotation angle pulse count. In S102, the controller 14 pre-stores the circumference conversion coefficient of the hoisting drum 6. The circumference conversion coefficient represents the winding length of the wire rope 7 corresponding to a unit pulse. The calculation method is to divide the effective circumference length of the hoisting drum 6 by the total number of pulses per revolution of the encoder. When the effective diameter of the hoisting drum 6 is 0.40m and the encoder resolution is 10,000 pulses per revolution, the circumference conversion coefficient can be taken as approximately 0.0001256m / pulse. The controller 14 multiplies the number of rotation angle pulses with the circumference conversion coefficient to obtain the real-time winding length since the initial reference position. For the effective diameter change that may be caused by multi-layer winding, a correction coefficient can be set according to the number of wire rope 7 layers in the equipment parameter table. The controller 14 switches the corresponding circumference conversion coefficient according to the current number of layers to improve the length conversion accuracy. In S103, the controller 14 uses the initial total length of the wire rope 7 measured during the installation and commissioning phase as a fixed reference value. This initial total length of the wire rope 7 can be the total length of the rope laid out when the hook frame 8 is at the reference height. Subtracting the real-time winding length from the initial total length of the wire rope 7 yields the current real-time swing length. If the real-time winding length exceeds the initial total length of the wire rope 7, the controller 14 will output a limiting signal and use zero lower limit protection to prevent invalid data with negative swing length. After the above decomposition steps, the source of the real-time swing length is clear and verifiable, which facilitates parameter setting by those skilled in the art based on the drum size, encoder specifications, and the total length of the wire rope 7.

[0026] When the real-time swing angle exceeds the preset vertical zero dead zone, the steps for calculating the compensation acceleration based on the real-time swing angle and real-time swing length include: S601. Based on the positive proportional relationship between the real-time swing angle and the constant gravitational acceleration, a basic recovery acceleration that reflects the recovery trend under heavy load is generated. S602. Based on the preset compensation gain coefficient and real-time pendulum length, the basic recovery acceleration is adjusted, and the compensation acceleration is output. When the real-time swing angle exceeds the preset vertical zero dead zone, the controller 14 performs a compensation acceleration conversion. This conversion process is essentially based on a preset linearized pendulum anti-sway model. The purpose of this linearized pendulum anti-sway model is to quickly and stably estimate the compensation acceleration required to suppress the swing of the hook frame 8 using the real-time measured swing angle and pendulum length without relying on a complex nonlinear observer. Logically, the model receives the real-time swing angle and real-time pendulum length as input data streams, generates a unit mass restoration term through the basic restoring force calculation stage, and outputs the compensation acceleration through the pendulum length scaling stage. In terms of physical relationships, this model characterizes the dynamic balance between the restoring torque generated by gravity and the compensating inertial torque generated by the motion of the trolley frame 4 when the hook frame 8 and the heavy load are abstracted as an ideal pendulum system under a small angle of deflection. In S601, the controller 14 reads the real-time swing angle, which is calculated using radians. If the dual-axis tilt sensor 13 outputs an angle value, the controller 14 first converts it to a radian value. The controller 14 multiplies the real-time swing angle by the gravitational acceleration constant, which can be 9.8 m / s² or 9.81 m / s², thereby obtaining the foundation recovery acceleration. This item reflects the unit mass recovery trend when the heavy load tends to the vertical equilibrium position under the action of gravity. In S602, the controller 14 divides the basic recovery acceleration by the real-time pendulum length to obtain the compensation acceleration. The direction of the compensation acceleration corresponds to the direction of the real-time pendulum angle and is used to generate an inertial effect that cancels out the swing through the trolley frame 4. According to the approximate relationship of small-angle swing, the larger the swing angle or the shorter the pendulum length, the larger the absolute value of the compensation acceleration; the smaller the swing angle or the longer the pendulum length, the smaller the absolute value of the compensation acceleration. To illustrate with a specific quantitative simulation example: Assuming that the real-time swing angle measured by the dual-axis tilt sensor 13 is 0.05 radians during the current control cycle, and the constant of gravitational acceleration is taken as 9.8 m / s², then the basic recovery acceleration is 0.05 multiplied by 9.8 equals 0.49 m / s². If the real-time pendulum length calculated from the encoder data is 10.0m, and a preset compensation gain coefficient of 1.0m is introduced, then the compensation acceleration is 0.49 divided by 10.0, multiplied by the preset compensation gain coefficient of 1.0m, which equals 0.049m / s². Similarly, if the preset compensation gain coefficient remains unchanged at 1.0m, and the real-time pendulum length is shortened to 5.0m, then the compensation acceleration increases to 0.49 divided by 5.0, which equals 0.098m / s². The calibration logic for the preset compensation gain coefficient is as follows: obtain the maximum allowable anti-sway output torque of the crane trolley under no-load and rated full-load conditions and the acceleration and deceleration limit threshold of the travel motor, combine the mechanical damping characteristics of the hook frame under the corresponding conditions to conduct a step response test, and lock the peak value of the coefficient that does not cause motor overload and makes the anti-sway overshoot converge within the set error range as the compensation gain coefficient. The calculation process is completed within one scan cycle through basic arithmetic instructions, ensuring the programmable implementation and real-time processing capability of the control algorithm. To ensure stable operation of the equipment, the controller 14 can set a limit value for the compensation acceleration, with a limit range of 0.05m / s² to 1.50m / s², and can also set a rate of change limit to prevent sudden changes in the output of the walking motor 16 due to instantaneous measurement jumps. By directly using the real-time pendulum length as a divisor in the calculation, the same pendulum angle corresponds to different compensation accelerations under different rope lengths, thereby ensuring that the control quantity is consistent with the dynamic characteristics of the current hook system. This avoids situations where the compensation quantity exceeds the preset compensation upper limit under short rope conditions and falls below the preset compensation lower limit under long rope conditions when using fixed empirical coefficients. Specifically, the input data for this step comes from the real-time pendulum length output by S1 and the real-time pendulum angle output by S4. The controller 14 first performs angle unit unification, and then performs sign preservation processing, that is, retains the positive and negative signs of the real-time pendulum angle to distinguish the direction of swing. The unit mass recovery term is calculated according to the linear relationship of small angles, and then divided by the real-time pendulum length and multiplied by the preset compensation gain coefficient to obtain the compensation acceleration. Therefore, the result of this conversion process includes not only the compensation magnitude, but also the compensation direction. In this embodiment, the basic recovery acceleration is used to describe the intermediate calculation quantity obtained by converting the gravity recovery trend. Its essence is the unit mass recovery term, rather than the mechanical force value that must be measured separately. The purpose of using this intermediate quantity is to first convert the pendulum angle information into a quantity corresponding to the gravity recovery trend, and then combine it with the pendulum length to complete the compensation amount scaling. After the controller 14 obtains the compensation acceleration, it directly transmits the result to the acceleration synthesis step S601. If the real-time pendulum length is lower than the preset minimum effective pendulum length, the controller 14 will use the preset minimum effective pendulum length to substitute into the calculation or directly limit the compensation acceleration to prevent the calculated compensation amount from exceeding the preset control limit due to the denominator being lower than the preset minimum effective pendulum length. The preset minimum effective pendulum length can be set during the commissioning stage based on the minimum working height of the hook frame 8, the number of turns of the wire rope 7, and the dimensions of the drum structure. For example, it can be set to 0.3m to 1.5m to ensure that the compensation calculation remains stable under short rope conditions.

[0027] The steps for controlling the operating state of the walking motor 16 by combining the basic running acceleration and the compensated acceleration include: S603. Based on the synthesis of the basic running acceleration and the compensated acceleration, the final composite acceleration is obtained; S604. Calculate the target running speed based on the final composite acceleration; S605, convert the target running speed into a frequency command and send it to the frequency converter 15 to drive the walking motor 16 to counteract the swaying tendency of the hook frame 8. In S603, controller 14 algebraically adds the basic running acceleration planned based on the remaining running distance to the compensated acceleration calculated based on the real-time swing angle and real-time swing length, obtaining the final composite acceleration. The basic running acceleration is used to meet the displacement requirements of the trolley reaching the target position, and the compensated acceleration is used to suppress the swing of the hook frame 8. Together, they determine the acceleration and deceleration states that the trolley frame 4 should execute within the current control cycle. To avoid insufficient deceleration due to the basic running acceleration and compensated acceleration being in opposite directions at the positioning end, a dynamic attenuation weight coefficient is introduced into the compensated acceleration when the remaining running distance is less than the preset end safety distance. The updated calculation formula for the final composite acceleration at this time is: ,in, Represents the final composite acceleration. Represents basic operational acceleration. Represents compensated acceleration, This represents the dynamic decay weighting coefficient. The calculation logic for this weighting coefficient is as follows: In the formula The current remaining running distance, A pre-set safe distance at the end point is defined and limited within the control logic. The maximum value is 1. Through this dynamic attenuation strategy, as the vehicle approaches the target position, the system linearly reduces the intervention weight of anti-sway compensation as the remaining distance decreases, and the basic operation deceleration takes the lead in stopping the action. This effectively eliminates the overshoot risk caused by the direct superposition of acceleration and deceleration commands, and ensures the stability and reliability of the positioning end control. In S604, controller 14 performs discrete integration on the final composite acceleration according to a set sampling period. The target running speed can be updated in such a way that the target running speed of the current period is equal to the target running speed of the previous period plus the final composite acceleration multiplied by the sampling period. Its discrete integral relationship can be expressed as:

[0028] in, The target operating speed for the current cycle, The target operating speed for the previous cycle, For the final synthesis acceleration of the current cycle, The sampling period; This serves as the current sampling sequence step index in the discrete control algorithm. To ensure operational safety, the controller 14 sets an upper and lower speed limit for the target operating speed. The upper speed limit can be set from 0.2 m / s to 3.0 m / s according to the crane specifications. A low-speed approximation limit can also be superimposed when approaching the target position. In S605, the controller 14 converts the target running speed into the corresponding motor speed based on the diameter of the traveling wheel 5, the gear ratio of the reducer, and the rated speed of the traveling motor 16. Then, it converts the speed into the frequency command of the frequency converter 15 and outputs it to the frequency converter 15. The frequency converter 15 adjusts the frequency and voltage of the three-phase AC power output to the traveling motor 16 according to the frequency command, and drives the traveling wheel 5 to perform corresponding acceleration and deceleration along the track of the crane main beam 1. In terms of data flow and interaction, the controller 14 and the frequency converter 15 preferably use an industrial fieldbus for communication and interaction. The controller 14 encapsulates the converted frequency command into a standard message format and sends it to the frequency converter 15 in a periodic data exchange manner. After parsing the message, the frequency converter 15 immediately updates the output frequency of the inverter, ensuring that the data flow of the command transmission is clear and seamless. Since the target running speed is obtained by the final synthesized acceleration integral, the control quantity of the walking motor 16 has a clear numerical correspondence with the position movement requirement and the swing suppression requirement. The control link, from sensor sampling, parameter conversion, acceleration synthesis to frequency command output, can be directly implemented by those skilled in the art. This method enables the trolley frame 4 to not only reduce its running speed when approaching the target position, but also to synchronously correct the walking trend according to the actual swing state of the hook frame 8, thereby reducing the number of repeated jogs at the positioning end.

[0029] This application has been described through the above embodiments; however, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit this application to the described embodiments. Those skilled in the art will understand that many more variations and modifications can be made based on the teachings of this application, and all such variations and modifications fall within the scope of protection claimed in this application.

Claims

1. A heavy-load lifting and positioning control device for port equipment cranes, characterized in that, include: The crane main beam (1) has parallel rails (2) laid on top; wherein, the end of the crane main beam (1) is provided with reflective targets (3); The trolley frame (4) is placed on the parallel track (2) by the walking wheels (5); wherein, the top surface of the trolley frame (4) is provided with a lifting drum (6), a steel wire rope (7) is wound on the lifting drum (6), and a hook frame (8) is suspended at the bottom end of the steel wire rope (7). A ranging component (9) is disposed on the side of the vehicle frame (4); wherein the ranging component (9) includes a laser rangefinder (10), the optical axis of which is aligned with the reflective target (3). The status monitoring component (11) includes an incremental photoelectric encoder (12) and a dual-axis tilt sensor (13); wherein the incremental photoelectric encoder (12) is connected to the non-drive end journal of the hoisting drum (6), and the dual-axis tilt sensor (13) is disposed on the top horizontal surface of the hook frame (8); The controller (14) is located inside the car frame (4) and connected to the frequency converter (15); wherein the controller (14) controls the laser rangefinder (10), the incremental photoelectric encoder (12), the dual-axis tilt sensor (13) and the frequency converter (15), and the frequency converter (15) is connected to the walking motor (16) that drives the walking wheel (5) to rotate.

2. The heavy-load lifting and positioning control device for port equipment cranes according to claim 1, characterized in that, The incremental photoelectric encoder (12) is connected to the hoisting drum (6) via a cross-slider type flexible coupling (17); wherein the cross-slider type flexible coupling (17) allows an axial deviation of ±2mm and an angular deviation of ±1° to ±3°.

3. The heavy-load lifting and positioning control device for port equipment cranes according to claim 1, characterized in that, The dual-axis tilt sensor (13) is covered by a stainless steel protective shell (18); wherein a polyurethane shock-absorbing pad (19) is provided between the stainless steel protective shell (18) and the hook frame (8).

4. The heavy-load lifting and positioning control device for port equipment cranes according to claim 3, characterized in that, The stainless steel protective shell (18) has a thickness of 1 mm to 4 mm, and the polyurethane shock-absorbing pad (19) has a thickness of 0.5 mm to 3 mm.

5. The heavy-load lifting and positioning control device for port equipment cranes according to claim 1, characterized in that, The outer cylindrical surface of the hoisting drum (6) is machined with a spiral rope groove (20); wherein the wire rope (7) is wound in the spiral rope groove (20).

6. The heavy-load lifting and positioning control device for port equipment cranes according to claim 1, characterized in that, The bottom of the vehicle frame (4) is fixed with the walking motor (16); wherein the output shaft of the walking motor (16) is directly connected to the axle of the walking wheel (5) through a single-stage gear reducer (21).

7. A control method, applied to the heavy-load lifting and positioning control device for port equipment cranes as described in claim 1, characterized in that, include: S1. Real-time acquisition of the rotation angle pulse signal of the incremental photoelectric encoder (12) on the lifting drum (6), real-time winding length calculated based on the rotation angle pulse signal, and real-time swing length calculated in combination with the pre-calibrated initial wire rope (7) total length. S2. Obtain the reflected light signal of the laser rangefinder (10), calculate the current absolute position of the car frame (4) based on the reflected light signal using the time of light flight, and calculate the difference between the preset target position and the current absolute position to obtain the remaining running distance. S3. Based on the remaining running distance, the basic running acceleration of the car frame (4) is obtained; S4. Obtain the tilt angle of the dual-axis tilt sensor (13) in the direction of the vehicle's movement as the real-time swing angle; S5. Determine whether the absolute value of the real-time swing angle is greater than the preset vertical zero dead zone threshold. S6. When the real-time swing angle exceeds the preset vertical zero dead zone threshold, the compensation acceleration is calculated based on the real-time swing angle and the real-time swing length, and the working state of the walking motor (16) is controlled in combination with the basic running acceleration and the compensation acceleration; when the real-time swing angle does not exceed the preset vertical zero dead zone threshold, the working state of the walking motor (16) is controlled only based on the basic running acceleration.

8. The control method according to claim 7, characterized in that, Step S1 includes: S101. Obtain the number of rotation angle pulses in the rotation angle pulse signal; S102. Calculate the real-time winding length based on the number of rotation angle pulses; S103. Based on the difference between the pre-calibrated initial total length of the wire rope (7) and the real-time winding length, obtain the real-time swing length of the current system.

9. The control method according to claim 7, characterized in that, When the real-time swing angle exceeds the preset vertical zero dead zone threshold, the step of calculating the compensation acceleration based on the real-time swing angle and the real-time swing length includes: S601. Based on the positive proportional relationship between the real-time swing angle and the constant gravitational acceleration, generate a basic recovery acceleration that reflects the recovery trend under heavy load. S602: Based on the preset compensation gain coefficient and real-time pendulum length, the basic recovery acceleration is adjusted, and the compensation acceleration is output.

10. The control method according to claim 7, characterized in that, The steps of controlling the operating state of the walking motor (16) by combining the basic running acceleration and the compensated acceleration include: S603. Based on the basic running acceleration and the compensated acceleration, a final composite acceleration is obtained; wherein, when the remaining running distance is less than a preset end safety distance, a dynamic attenuation weighting coefficient is introduced into the compensated acceleration. According to the formula The final synthesized acceleration is obtained; wherein, Represents the final composite acceleration. Represents basic operational acceleration. Represents the compensation acceleration, and the dynamic attenuation weighting coefficient It is the ratio of the remaining running distance to the end-of-line safety distance, with a maximum value of 1; S604. Calculate the target running speed based on the final composite acceleration; S605. The target running speed is converted into a frequency command and sent to the frequency converter (15) to drive the walking motor (16) to counteract the swaying tendency of the hook frame (8).

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