Fixed winch type ship lock traffic bridge lifting system and method based on balance shaft synchronization

Abstract

The invention discloses a fixed winch type ship lock traffic bridge lifting system and method based on balance shaft synchronization, and relates to the technical field of multi-driving-point control systems.The method comprises the following steps that displacement sensors and load sensors are arranged at at least two driving adjusting lifting points respectively; obtaining real-time height and load data of each lifting point; calculating a deviation value of each lifting point relative to a target reference value or a system average value, wherein the deviation value comprises a height deviation and a load deviation; when any deviation value exceeds a set threshold value, the PLC calculates a speed compensation value based on a current control gain parameter and outputs the speed compensation value to the driving execution unit through the motion control module; the problem of stress concentration is effectively relieved, the structural safety is greatly improved, and the service life is greatly prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of multi-drive-point control systems, and particularly to a fixed winch type ship lock traffic bridge lifting system and method based on balanced shaft synchronization. BACKGROUND

[0002] The current ship lock traffic bridge lifting system mainly faces the following challenges: in terms of synchronization accuracy, the traditional hydraulic synchronization method is significantly affected by environmental temperature and changes in pipeline resistance, resulting in inconsistent lifting height of multiple drive lifting points during simultaneous lifting, thereby generating a large displacement error, causing uneven stress and stress concentration on the bridge body, and affecting structural safety. SUMMARY

[0003] To solve the defects in the prior art, the present application provides a fixed winch type ship lock traffic bridge lifting system and method based on balanced shaft synchronization.

[0004] To solve the above technical problems, the present application provides the following technical solutions: The present application provides a fixed winch type ship lock traffic bridge lifting method based on balanced shaft synchronization, comprising the following steps: Displacement sensors and load sensors are arranged at at least two drive adjustment lifting points, the displacement sensors are used to detect the actual movement height of the lifting points in the vertical direction, the load sensors are used to detect the real-time load value borne by the lifting points, and the displacement sensors and load sensors are connected with a PLC controller through an industrial field bus interface; The displacement sensors and load sensors of all lifting points are data collected at a fixed sampling period to obtain real-time height and load data of each lifting point; Based on the real-time sampling data, a system deviation model is constructed to calculate the deviation amount of each lifting point relative to the target reference value or the system average value, the deviation amount including height deviation and load deviation; When any deviation amount exceeds a set threshold, the PLC controller calculates a speed compensation amount based on the current control gain parameter, and outputs the speed compensation amount to the drive execution unit through a motion control module.

[0005] The present application also provides a fixed winch type ship lock traffic bridge lifting system, which comprises: A central drive rack is internally provided with a double-output shaft reducer, the output shafts of which are respectively connected to rigid transmission shafts through gear couplings at both ends; The transmission shafts pass through the left and right winch racks along the transverse direction of the bridge body and are connected to the respective winch devices through winch couplings to achieve rigid power transmission; The each winding drum device leads several steel wire ropes, is guided to each automatic pulley structure through a fixed pulley, and is connected to the balance wheel mechanism at the end of the lifting point, and through the setting of two groups of side-by-side arranged central drive racks and winding machine racks, a symmetrical four-point suspension closed loop system is formed; The balance wheel mechanism is provided with a load sensor at the shaft center, and a displacement sensor is installed at the end of the winding drum, which is used for monitoring the height and load information in the lifting process in real time; The height and load data are collected and analyzed through the PLC controller, when any lifting point deviates, the variable frequency speed compensation instruction is calculated according to the deviation, and the four-point synchronous lifting control of the bridge body is realized.

[0006] The beneficial effects of the present application are: In the present application, the heights and loads of multiple lifting points are obtained at a fixed sampling period, and the deviation from the relative average value is calculated in real time, when any deviation exceeds the limit, the error feedback speed instruction compensation mechanism based on PLC operation is started, the maximum displacement error between the lifting points can be effectively eliminated, and this method is especially suitable for a multi-branch point long-span structure such as a ship lock traffic bridge. Compared with the traditional hydraulic synchronous method (which is easily affected by oil temperature and has large synchronous error), the present method can compress the synchronous deviation to millimeter level, effectively alleviate the stress concentration problem, and greatly improve the structural safety and service life. BRIEF DESCRIPTION OF DRAWINGS

[0007] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, and are used to explain the present application together with embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0008] Figure 1 It is a working flowchart of the fixed winding type ship lock traffic bridge lifting method based on the balance shaft synchronization of the present application.

[0009] Figure 2 It is a structural schematic diagram of the fixed winding type ship lock traffic bridge lifting system of the present application.

[0010] Figure 3 It is another structural schematic diagram of the fixed winding type ship lock traffic bridge lifting system of the present application.

[0011] In the figure: 1, central drive rack; 2, speed reducer; 3, shaft coupling; 4, transmission shaft; 5, winding machine rack; 6, winding drum device; 7, steel wire rope; 8, pulley structure; 9, balance wheel mechanism. DETAILED DESCRIPTION

[0012] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and do not limit the present application.

[0013] Example one like Figure 1 As shown, the method for lifting a fixed winch-type ship lock traffic bridge based on synchronization of a balance shaft includes the following steps: Displacement sensors and load sensors are respectively arranged at at least two driving and adjusting lifting points. The displacement sensors are used to detect the actual vertical movement height of the lifting points, and the load sensors are used to detect the real-time load value borne by the lifting points. The displacement sensors and load sensors are both connected to the PLC controller via an industrial field bus interface. In this embodiment, the number of suspension points is set to four. Specifically, a dual-output shaft reducer is installed inside the central drive frame, and the two ends of its output shaft are connected to rigid transmission shafts. The transmission shafts pass through the left and right hoisting frames horizontally along the bridge body and are connected to their respective drum devices through drum couplings to achieve rigid power transmission. Each drum device leads out a number of steel wire ropes, which are guided to each automatic pulley structure through a fixed pulley. The end of the suspension point is connected to a balance wheel mechanism. Two sets of central drive frames and hoisting frames are arranged side by side, that is, four sets of suspension points are provided, thereby forming a symmetrical four-point suspension closed-loop system. The following sensors are arranged at each lifting point: Displacement sensor: uses an absolute encoder or laser rangefinder to detect the vertical movement height in real time; Load sensor: Use piezoelectric or strain gauge sensors to monitor the load in real time; The above sensor signals are connected to the PLC system through an industrial fieldbus interface (such as PROFINET, CANopen, EtherCAT, etc.) to ensure the real-time and reliable data transmission. At the same time, it is also necessary to ensure that the system has the ability to conduct high-frequency parallel sampling of multiple lifting points.

[0014] The displacement sensors and load sensors of all hanging points are used to collect data at a fixed sampling period to obtain the real-time height and load data of each hanging point; By setting a fixed sampling period (e.g. 10ms-50ms), the PLC will periodically collect the real-time height and load height of each hanging point. This sampling mechanism ensures that the system can obtain accurate multi-point status information while maintaining high-speed dynamic response, providing basic data for subsequent control.

[0015] A system deviation model is constructed based on real-time sampling data to calculate the deviation of each hanging point relative to the target reference value or the system average value, including the height deviation ΔH. i (t) and load deviation ΔF i (t); The core significance of this step is to achieve a quantitative evaluation of the current platform state and form an error feedback control quantity, preferably calculating the deviation of each hanging point relative to the average value of multiple hanging points.

[0016] When any deviation exceeds the set threshold, the PLC controller calculates the speed compensation based on the current control gain parameters and outputs it to the drive execution unit through the motion control module. The command is output to the driver through the motion control module (such as the motion control function of the PLC itself or an external servo control unit) to achieve precise fine-tuning of the lifting point speed.

[0017] The motion control module is composed of a rigid main control channel and a flexible auxiliary adjustment channel. The main control channel is used to ensure the overall structural support balance and is responsible for rough synchronization and platform stability. The auxiliary adjustment channel performs independent speed adjustment based on error feedback for each lifting point to eliminate inconsistencies caused by dynamic disturbances. This "rigid guarantee + flexible calibration" mode can significantly improve system robustness.

[0018] The PLC controller integrates an abnormality detection module. When an abnormality is detected, it enters a preset safety control mode to prevent equipment damage or system instability through drive limiting or emergency stop mechanism; Considering the high requirements of industrial control systems for stability and safety, a multi-dimensional abnormality detection module is embedded in the PLC, which has the following capabilities: sensor data mutation detection (such as instantaneous jump, distortion drift), communication interruption diagnosis (such as bus disconnection, response timeout), control chain closed loop disconnection identification (such as drive non-response, running over-range), emergency stop input monitoring and state locking mechanism; Once an abnormality is detected, the system will enter a safety control mode and automatically activate the following protection behaviors: speed limiting control or speed zero, triggering the "slow stop" or "mechanical locking" command of the driver, and sending alarm information to the upper system or remote terminal.

[0019] Among them, the method of the application is not only suitable for ship lock traffic bridge lifting system, but also suitable for other lifting systems, such as city bridge expansion joint replacement construction platform, high-precision heavy load assembly platform leveling platform, etc.

[0020] Further, the core of the system deviation model is to take the average value of all lifting points as the dynamic reference benchmark, and calculate the height deviation and load deviation of each lifting point respectively. The construction process of the system deviation model is as follows, First, the average height of all n lifting points is as follows: ; Selecting the average value as the reference benchmark can realize real-time and dynamic symmetry adjustment, adapt to non-uniform load or inconsistent lifting scenarios. The average value reflects the "target state" or "expected state" of the system, which is suitable for multi-point coordinated adjustment. Compared with fixed target value, it can better adapt to complex scenarios such as bridge body flexibility response and self-weight deviation; The height deviation ΔH i(t) is the measured height H of the i th driving lifting point at the t th moment i (t) is the absolute difference value of the average height of all n lifting points, which is shown as follows: ; The absolute value processing ensures that the deviation definition is not affected by the positive and negative directions, which is suitable for downstream control threshold judgment, ensures that the system judges with the maximum deviation as the criterion, and meets the safety design principle; The average load of all n lifting points is shown as follows: ; The load deviation ΔF i (t) is the real-time load value F carried by the lifting point i (t) is the absolute difference value of the average load of all n lifting points, which is shown as follows: .

[0021] Wherein, by accurately defining the lifting point height deviation ΔH i (t) and the load deviation ΔF i (t), the core is to compare each lifting point with the overall average state, rather than only referring to the target value, and to uniformly construct a system deviation model, which provides a mathematical basis for subsequent dynamic compensation control and is suitable for multi-lifting point flexible structures. Through the definition mechanism, dynamic deviation quantization can be performed, thereby supporting error-driven feedback control; The system deviation model realizes dynamic monitoring of the bridge body posture and stress by calculating the deviation of each lifting point from the system average state in real time, and provides input basis for subsequent speed compensation.

[0022] Further, the control gain parameters include a height error control gain coefficient K p and a load error control gain coefficient K f , the height error control gain coefficient and the load error control gain coefficient support dynamic self-adaptive adjustment, the initial values are obtained based on the platform structure response characteristics through offline identification, and are saved in the PLC parameter configuration area; The core of gain self-adaptive adjustment is to dynamically adjust the control gain based on the real-time feedback data of the system. In this embodiment, the system will monitor the height deviation ΔH i (t) and the load deviation ΔF i (t) of each lifting point in real time, and adjust the control gain coefficients K p and K f according to the change rate of these deviations. The design of this adjustment mechanism fully considers factors such as load changes, environmental influences, and mechanical wear under different working conditions, ensuring that in actual application, the system can be flexibly adjusted as needed to achieve the best synchronous control effect; During operation, the PLC controller continuously records the height deviation ΔH i (t) the load deviation ΔF i (t) the trend change within the continuous sampling period, and performs the following recursive adjustment operation every N periods: ; ; Where K p (t) represents the height error control gain coefficient at the current time t, which is related to the change rate of the height deviation ΔH i (t), in the case of high synchronization accuracy requirement, K p needs to have sufficient response speed to quickly adjust when a large deviation is detected, K p The initial setting range of K K f (t) represents the load error control gain coefficient at the current time t, which is related to the change rate of the load deviation ΔF i (t), the value of K f will be adjusted flexibly according to the change of the load to ensure that the system can cope with different load conditions and maintain stable operation, K f The initial setting range of K K p (t+Δt) represents the height error control gain coefficient at the next update, K f (t+Δt) represents the load error control gain coefficient at the next update, represents the change rate of the height deviation of the suspension point i with respect to time, represents the change rate of the load deviation of the suspension point i with respect to time, if the trend of the change rate is "error increases", the gain coefficient is automatically enhanced to increase the response speed, if the error tends to converge, the gain coefficient is automatically weakened to prevent overcompensation or oscillation, for example, if > 0 and increases, it means that the synchronization error is getting larger, the system automatically increases K p to quickly correct the deviation, similarly, when the load changes dramatically, increasing K f can adjust the traction force compensation faster.

[0023] γ1 represents the height error adjustment slope coefficient, which is used to control the sensitivity of height error gain adjustment, and γ2 represents the load error adjustment slope coefficient, which is used to control the sensitivity of load error gain adjustment. In the formula, γ1 and γ2 represent the sensitivity of the adjustment process. When γ1 is large, the system is more sensitive to height error changes and can quickly adjust the height synchronization state, but may cause system oscillation. When γ1 is small, the system response is relatively stable, but the adjustment speed is slow. Similarly, when γ2 is large, the system is more sensitive to load changes, which is suitable for working conditions with frequent load fluctuations. When γ2 is small, it is suitable for working conditions with relatively stable load.

[0024] Preferably, γ1 ∈ [0.02, 0.2]: the system response speed and oscillation risk need to be balanced, and γ2 ∈ [0.01, 0.1]: due to the slow change of load error, the sensitivity should be moderate; γ1 and γ2 can be calibrated through step response test, observing the stable time and overshoot of the system under different change rates, and optimizing to obtain that when the system response is fast, the coefficient takes a small value to avoid over-adjustment, and when the response is slow, the coefficient needs to be amplified to enhance the feedback adjustment rate. For example, in heavy load working conditions: the lifting force requirement is high, K f Automatic bias is large; When the height difference error increases: the system enhances the synchronization response, and automatically increases K p ; When the temperature rises / severe wear: due to slow mechanical response, γ1 can be appropriately increased to compensate for the delay.

[0025] In this embodiment, the initial value of K p is 0.8 (curve fitting of 200 bridge test runs, ΔH i response stable interval is located in [0.7, 0.9]), the initial value of K f is 0.3 (strong structural rigidity, load impact weight is less than height), the initial value of γ1 is 0.025, and the initial value of γ2 is 0.02.

[0026] The setting of these coefficients is based on the dynamic characteristics and response speed requirements of the system. Through real-time tracking of the deviation change rate, the control gain can be adjusted in time under different load changes and motion states, avoiding system instability caused by excessive adjustment or lag adjustment.

[0027] Gain adjustment process: Real-time data acquisition: the system acquires the height deviation and load deviation of each lifting point, and calculates the deviation change rate of each lifting point combined with the real-time processing capability of the PLC controller. The gain adjustment amount is calculated: based on the change rate of the deviation, the gain is adjusted by a formula, and gamma 1 and gamma 2 in the formula represent the sensitivity of the adjustment process, which can be optimized according to the requirements and characteristics of the system; Output adjustment instruction: the PLC controller outputs the speed compensation instruction to the driving execution unit in real time according to the adjusted gain value, so as to adjust the lifting speed of each lifting point and ensure the synchronization of the entire bridge.

[0028] The gain adaptive adjustment mechanism of the present application is designed to effectively solve the synchronization error and load change problems that may occur in the actual operation of the four-point synchronous lifting system. Since the working environment and load of each lifting point will change dynamically over time, the traditional fixed gain control method cannot ensure the best synchronization accuracy and stability under various working conditions. The introduction of the gain adaptive adjustment mechanism can adjust the control gain in real time according to the feedback data of the system, thereby optimizing the response speed and stability of the entire synchronous lifting system.

[0029] In the practical application of the present application, the gain adaptive adjustment mechanism can cope with various working condition changes. For example, when the bridge lifting system is in a heavy load state, the load deviation may be large, and the system can speed up the response to load changes by increasing K f When the bridge lifting process is affected by temperature changes or mechanical wear, the height deviation may be large, and the system can enhance the height adjustment accuracy by increasing K p .

[0030] Further, the PLC controller adopts a main cycle and auxiliary cycle parallel mechanism; The main cycle is used to execute the control algorithm main loop, including deviation calculation, speed instruction generation and data archiving; The main cycle is the main execution process of system control, and its period is generally set to T m =100ms, and the specific functions include: Control core algorithm operation: that is, dynamic calculation of height deviation ΔH i (t) and load deviation ΔF i (t); Speed instruction generation: generate frequency converter speed compensation instruction V adj according to the joint compensation strategy; Historical data archiving and trend modeling: used for subsequent gain coefficient adaptive update; Main control link coordination output: complete the driving control task scheduling under the unified time rhythm.

[0031] The auxiliary cycle is used to perform the following real-time self-checking tasks: displacement sensor and load sensor data mutation detection, bus communication state monitoring, driver running state diagnosis, and emergency stop signal listening and logic response; The auxiliary cycle is a fast and light control self-checking mechanism, and the cycle setting is usually T s =10 ms, and the high frequency ensures that the system quickly captures abnormal states. The main functions are as follows:

[0032] Real-time sensor mutation detection: mutation amplitude identification of displacement and load sampling values; Communication link integrity detection: bus signal state and frame rate stability monitoring; Execution unit state prediction: check the working state of the frequency converter, encoder and other execution units; Emergency stop logic monitoring: high-priority interrupt response strategy ensures that the system can quickly enter the safe mode; Feedback filtering and redundancy activation: dynamic switching judgment is performed on the redundant channel.

[0033] The traditional PLC cycle period design is single, and lacks high-frequency state detection capability, resulting in delayed response to sudden risks (such as sensor distortion and cable disconnection), which cannot meet the requirements of structural safety and control stability in the bridge lifting scene, and the single cycle main program cannot consider both compensation instructions and system monitoring requirements, task scheduling conflicts, especially in the complex structure arrangement of the middle part of the bridge and the dense real-time detection demand, which can easily cause system overload, missed detection and other problems.

[0034] Therefore, the present application proposes a PLC control architecture based on a main auxiliary dual cycle parallel task mechanism, in order to achieve coordination and improvement between control accuracy, system stability and response real-time.

[0035] The "main auxiliary cycle asynchronous parallel architecture" proposed by the present application achieves the following effects: Improve response real-time: high-frequency 10ms auxiliary cycle ensures that abnormal states are captured in the first time; Ensure stable operation of the main control task: the main cycle control calculation is not interrupted by the state detection task, improving the calculation certainty; Improve safety and redundancy response capability: abnormal state trigger signals can be processed by the auxiliary cycle interrupt mechanism to achieve system emergency stop, with high fault tolerance; Adapt to complex ship lock bridge application scenarios: in the face of long-time operation, multi-point control and serious structure dynamic deviation, the mechanism has strong adaptability and deployment flexibility.

[0036] In the system of the present application, the specific working steps of the algorithm are as follows: Every T s =10 ms cycle, the auxiliary task reads the original data from the absolute value encoder and load sensor; into the main task (every T m =100 ms), complete: height mean and load mean calculation, height deviation ΔHi (t) With load deviation ΔF i (t) Calculate; If the threshold is exceeded, the subsequent operation steps are performed.

[0037] Further, the threshold includes a maximum threshold value ε H for the height deviation, and a maximum threshold value ε F for the load deviation. When the height deviation ΔH i > ε H and the load deviation ΔF i ≤ ε F , independent compensation based on the height deviation is performed, indicating that there is a vertical height anomaly at this point, but the load does not fluctuate significantly, which may be caused by wear or local jamming of the mechanism. At this time, the system performs independent compensation based on the height deviation to adjust the speed of the winch to gradually restore the average height. When the load deviation ΔF i > ε F and the height deviation ΔH i ≤ ε H , independent compensation based on the load deviation is performed, indicating that the lifting height is consistent, but there is an abnormal stress concentration in the structure due to the abnormal force at the lifting point. At this time, a separate compensation strategy based on the load deviation is adopted to unload / load the lifting point by changing its movement trend to relieve stress. When both the height deviation ΔH i and the load deviation ΔF i exceed the threshold, it indicates that both the position and the force of the lifting point are significantly abnormal, and joint compensation is performed. ; Where V adji represents the speed compensation required for the i-th lifting point. This expression couples the height and load into a linear combination of speed commands, achieving synchronous dynamic adjustment of the attitude and load.

[0038] According to the structural stiffness analysis and measured data, 10mm is close to the critical deformation limit of the structure, therefore, the ε H in the present application can be 10mm, when the deviation is > 10mm, the structure has a detectable attitude deflection and needs to be adjusted. Preferably, the maximum threshold value for the load deviation is 5%Q, where Q is the design rated load of the lifting point, for example, Q=100kN, and the deviation threshold is 5kN.

[0039] Application scenario example: In the lifting operation of the ship lock traffic bridge, the bridge deck will be tilted or "tilted" if a lifting point is lifted / descended first due to uneven self-weight distribution of the bridge deck structure or wind load, which may further induce structural fatigue and even steel wire rope rupture if no dynamic correction is made at this time; Control process: The bridge is started to lift, and the heights of the four lifting points are initially approximately consistent; A lifting point deviates due to the difference in steel wire rope pretightening force, and the system calculates ΔH i = 16 mm, and ΔF i = 6.1%Q; The PLC determines that the set threshold is exceeded, and enters the compensation state; V adj is calculated, and the speed of the winch of the deviated lifting point is started to be finely adjusted; After about 200 ms, the lifting points are restored to be synchronized, and the error falls back to less than 5 mm.

[0040] The process can be cyclically executed, and the dynamic balance in the lifting process is ensured through closed loop each cycle.

[0041] Further, the displacement sensor is an absolute value encoder with power failure memory function, which records the last height value before power failure after abnormal power failure; The absolute value encoder (Absolute Encoder) adopted in the application is different from the ordinary incremental encoder and has the following core characteristics: Power failure memory: built-in EEPROM memory, which can permanently retain the last encoding data after power failure; High resolution: matched with synchronous lifting requirements, 16-bit SSI interface is selected; Interface compatibility: supporting PLC (such as Siemens S7-1500) standard industrial bus protocol (such as PROFINET or SSI), ensuring real-time performance and anti-interference ability; Environmental adaptability: IP67 protection level, suitable for typical ship lock operating environments such as heat and humidity, oil stains, and high dust. These characteristics make it an optimal solution for maintaining continuous synchronization control in a power failure state.

[0042] The PLC controller reads all the encoding values when it is powered on again, and adjusts the zero offset uniformly through the reference height calibration algorithm; In order to ensure that the system can still maintain the flatness of the bridge deck and the four-point symmetry state after power failure recovery, the following height reference calibration algorithm is designed in the PLC: First, record the last power-on encoding value H i old of each lifting point i as the actual height of the last sampling before power failure; after power-on again, read the EEPROM storage value in the current encoder , provide the actual mechanical displacement of the power-off data retention; The difference between the two is: ; Where ΔH i zero is the zero offset of the current hanging point i, indicating the height reference drift caused by power failure, ranging from ±2 to 10mm; Marriage calibration logic as follows: First, optionally, with the left front hanging point (marked as i = 1) as the reference, establish a global reference datum: ; Where, is the offset datum for the global reference hanging point; For all hanging points i, adjust uniformly to: ; Where H i new is the new height after calibration, that is, the corrected height value after calculation, used for the next step control starting reference.

[0043] The entire system design to ensure "even if a sudden power failure can quickly restore synchronous control state", the following is the actual operation in the step-by-step process: Sudden power failure occurs: Hanging point stop running, control PLC power failure, absolute value encoder immediately write the current position to EEPROM (non-volatile storage), the last height value (H i old ) in the RAM buffer of the PLC automatically power failure retention.

[0044] System power-up start: PLC power-on self-test, start and four drive hanging points of the bus communication, read from each encoder its EEPROM stored before power failure position , while extracting H i old ; Calculate the zero offset: Calculate the zero offset ΔH i zero of each hanging point i, this step reveals "whether the actual bridge displacement during power failure", and whether the hanging points remain synchronized; Reference hanging point calibration: Establish a global reference datum and correct all hanging points to the offset datum to obtain the new height H i new after calibration, this step is equivalent to "eliminate global deviation and keep relative height consistent"; System restart preparation: H i new The synchronization control module of the PLC is compared with the original set target position to calculate ΔH i , the fine compensation controller is started, and V adj is calculated for the slow start and resynchronization process. System starts lifting action: All lifting points are based on the new starting height, and synchronous lifting is performed, and the system dynamically corrects the deviation in real time to achieve millimeter-level control accuracy.

[0045] Further, the height change rate dH i / dt of the i-th lifting point and the load change rate dF i / dt of the i-th lifting point are calculated in each sampling period, and if the height change rate dH i / dt exceeds the maximum allowable threshold β H or the load change rate dF i / dt exceeds the maximum allowable threshold β F , the amplitude limiting compensation mode is entered, and the speed is limited before output: The maximum change rate is limited by the speed limiting proportion coefficient α max and the abnormal value is time-stamped for subsequent diagnosis.

[0046] In the ship lock traffic bridge synchronous lifting system solved by the present application, the bridge body structure is huge (span 9.5m) and the load is uneven, and the four lifting points must be kept in high-precision synchronization to prevent stress concentration, but even if a rigid transmission shaft is introduced to achieve preliminary synchronization, it cannot completely avoid the dynamic deviation caused by load mutation, local slip or sensor noise.

[0047] Especially in the following two working conditions, it is easy to cause system instability or mechanical damage: High rate of height change (dH i / dt): It may cause a point on the bridge body to rise or fall quickly, inducing local structure fatigue; High rate of load change (dF i / dt): It may be caused by sudden slip of the winding drum, local instability of the steel wire rope, or redistribution of the force on the lifting point.

[0048] The traditional control method mainly focuses on the size of the deviation itself, and lacks effective constraint on the deviation "change rate", making it difficult to achieve compatibility of high-speed response and control stability. Therefore, the present application sets up a "change rate amplitude limiting compensation mechanism" as a dynamic protection logic patch module in the PLC control.

[0049] Among them, the maximum allowable threshold β HThe preferred value of the maximum allowable threshold β of the height change rate is 5 mm / s (deduced reversely from the encoder sampling rate (100 Hz) and the maximum speed of the drum driving (50 mm / s), and the limit value is set to 10% thereof), and the maximum allowable threshold β of the load change rate F The preferred value of the speed limiting proportion coefficient α is 2% Q / s (deduced based on the maximum dynamic load floating amplitude allowed by the structure not exceeding ±5% of the rated load), and the speed limiting proportion coefficient α max The preferred value is 0.6-0.8, which ensures a balance between response performance and safety stability. max When α = 0.7, the average stable time of the system is the shortest, and the oscillation is the lowest.

[0050] When the theoretical compensation speed before speed change is V adj , if the height change rate dH i / dt and the load change rate dF i / dt do not exceed the threshold, the control output speed is still V adj , if the height change rate dH i / dt exceeds the maximum allowable threshold β of the height change rate H , or the load change rate exceeds the maximum allowable threshold β of the load change rate F , the control output speed V cmd is: ; Wherein, sgn(·) is a sign function, which determines the limiting direction.

[0051] Further, two groups of displacement sensors and load sensors are arranged at each driving adjustment lifting point, and each group of sensors is connected to the PLC controller through an independent channel. The data of the two groups of displacement sensors and load sensors are collected simultaneously in a sampling period, and the consistency comparison is performed by the PLC controller to calculate the deviation δ sync , if the deviation δ sync exceeds the set value δ max , the following steps are performed: The current lifting point compensation is zeroed; The channel is marked as invalid and switched to backup; The next cycle is automatically recalibrated.

[0052] The stable operation and accurate data collection of the precision sensors are the key basis for realizing closed-loop synchronous control. Sensor failure will directly cause error feedback misalignment, and then cause structural imbalance, and induce safety accidents. Therefore, the present application sets two groups of displacement sensors and load sensors at each driving lifting point.

[0053] The load sensor is preferably a bridge load cell, and the accuracy is preferably 0.5% F.S. The comparison tolerance is set to 4 times thereof, i.e. δ max = 2.0% Q. The precision of the displacement sensor is 0.1 mm, and the threshold range delta of the displacement sensor can be set max ±3 mm.

[0054] In a typical 9.5 m span traffic bridge synchronous lifting application: Four lifting points are arranged at the ends of the bridge on both sides, and two groups of sensors (8 sampling sensors) are installed at each lifting point. The PLC compares the redundant data at a period of 10 ms, realizes 100 times of synchronous checking per second, and if it is detected that a channel fails, the system completes channel switching and deviation zeroing within 10 ms, and the next period is re-modeled deviation to avoid triggering unnecessary compensation commands due to false data, and to ensure that the bridge body is symmetrically stressed and smoothly lifted.

[0055] Example two Reference Figures 2-3 The application also provides a fixed winch type ship lock traffic bridge lifting system, which comprises: A central drive rack 1 is internally provided with a double-output shaft reducer 2, and the output shafts of the double-output shaft reducer 2 are respectively connected to rigid transmission shafts 4 through gear couplings 3 at both ends. The transmission shafts 4 pass through the left and right two winch racks 5 along the transverse direction of the bridge body and are connected to the respective drum devices 6 through drum couplings 3, so as to realize rigid power transmission. Each drum device 6 leads out a plurality of steel wire ropes 7, which are guided to the respective automatic pulley structures 8 through fixed pulleys, and the end of the lifting point is connected to the balance wheel mechanism 9. Two groups of central drive racks 1 and winch racks 5 are arranged side by side, thereby forming a symmetric four-point suspension closed loop system. The balance wheel mechanism 9 is provided with a load sensor at the shaft center, and the drum end is provided with a displacement sensor, which is used for monitoring the height and load information in the lifting process in real time. The height and load data are collected and analyzed by the PLC controller, and when any lifting point deviates, the variable frequency speed compensation instruction is calculated according to the deviation, so as to realize four-point synchronous lifting control of the bridge body.

[0056] The material of the transmission shaft 4 is 42CrMo forged steel, and the quenched and tempered hardness is HB240-280. The gear coupling 3 is preferably a CLZ12 type gear coupling 3. The drum device 6 adopts a drum body made of Q355B steel plate with a δ=26 mm, and the end shaft is made of 45 steel. The CO2 gas protection welding forms a full penetration weld, and the ultrasonic flaw detection verifies that the compressive strength σy=91.3 MPa, and the safety factor reaches 2.59. The load sensor (precision 0.5% F.S.) is arranged in the suspension shaft of the balance wheel mechanism, and the load of the four suspension points (F1-F4) is monitored in real time. The SSI interface absolute encoder (displacement sensor) is arranged at the end of the drum shaft, the sampling period is 10 ms, the resolution is 0.01 mm, and the height (H1-H4) of each suspension point is collected.

[0057] Through the rigid transmission chain of the double-output reducer 2, the transmission shaft 4 and the drum coupler 3, the mechanical synchronization accuracy is 99.2%, and the synchronization error of more than 50 mm caused by the change of oil temperature and the pressure drop of the pipeline of the hydraulic system is eliminated. In addition, a three-rack coaxial transmission structure of a single motor driving a double-winch machine can be used, and the total height is only 3.2 m (the traditional hydraulic scheme needs to be greater than or equal to 5 m), which is suitable for harsh working conditions with a navigation net height of less than 15 m. A double motor can also be used, and the double motor drives the corresponding winch (double motor structure). Figure 3 The specific structure is not described again.

[0058] Further, from the perspective of system reliability, there is a high risk of leakage in the long-term operation of the hydraulic system, and the safety margin of the common steel wire rope 7 hoisting mechanism is insufficient, which is difficult to meet the long-period and high-reliability operation requirements of key infrastructure.

[0059] Therefore, the system is also provided with a visual monitoring unit for collecting video images of the steel wire rope 7, and further identifying the broken wire condition of the steel wire rope 7. Preferably, when the visual monitoring unit (industrial camera) detects that the broken wire rate is greater than 5% in real time, an alarm stop is triggered. The visual monitoring unit identifies the broken wire condition of the steel wire rope 7 as the prior art, and the structure and working principle are not described again.

[0060] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not used to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A fixed hoist type ship lock traffic bridge lifting method based on balanced axle synchronization, characterized in that, The method comprises the following steps: Displacement sensors and load sensors are arranged at at least two driving adjustment lifting points respectively, the displacement sensors are used to detect the actual movement height of the lifting points in the vertical direction, and the load sensors are used to detect the real-time load value borne by the lifting points, and the displacement sensors and the load sensors are connected with a PLC controller through an industrial field bus interface; Data of the displacement sensors and the load sensors of all the lifting points are collected at a fixed sampling period to obtain real-time height and load data of each lifting point; A system deviation model is constructed based on the real-time sampling data, and a deviation amount of each lifting point relative to a target reference value or a system average value is calculated, the deviation amount including a height deviation and a load deviation; When any deviation amount exceeds a set threshold value, the PLC controller calculates a speed compensation amount based on a current control gain parameter, and outputs the speed compensation amount to a driving execution unit through a motion control module; The control gain parameters include a height error control gain coefficient K p and a load error control gain coefficient K f The height error control gain coefficient K p and the load error control gain coefficient K f Support dynamic self-adaptive adjustment, the initial value is obtained by offline identification based on the platform structure response characteristics, and is saved in the PLC parameter configuration area; The threshold value includes a maximum threshold value ε of height deviation allowance H and a maximum threshold value ε of load deviation allowance F ; when the height deviation AH i > ε H and the load deviation AF i ≤ ε F an independent compensation based on the height deviation is performed; When the load deviation ΔF i > ε F and the height deviation ΔH i ≤ ε H , the independent compensation based on the load deviation is performed; When the height deviation AH i When the load deviation AF i When both the height deviation AH and the load deviation AF exceed the threshold values, joint compensation is performed: ； where V adji represents the velocity compensation amount required for the i-th hoist point.

2. The equilibrium axis synchronization based fixed hoist type ship lock transit bridge lifting method according to claim 1, characterized in that, The average of the sampling heights of all n lifting points is as follows: ； the height deviation AH i (t) is the measured height H of the i-th driving lifting point at the t-th time i (t) is the absolute difference value between the i-th driving lifting point and the mean value of the sampling heights of all n lifting points, which is expressed as follows: ； The average of the sampling loads of all n lifting points is as follows: ； said load deviation AF i (t) is the real-time load value F carried by the lifting point i (t) is the absolute difference value between the real-time load value F carried by the lifting point and the average value of the load of all n lifting points, and is expressed as follows: 。 3. The equilibrium axis synchronization based fixed hoist type lock transit bridge lifting method according to claim 2, characterized in that, In operation, the PLC controller continuously records the height deviation ΔH i (t) the load deviation ΔF i (t) the trend over successive sampling periods, and performs the following recursive adjustment operation every N periods: ； ； wherein K p (t) represents the altitude error control gain coefficient at the current time t, K f (t) represents the load error control gain coefficient at the current time t, K p (t+Δt) represents the altitude error control gain coefficient at the next update, K f (t+Δt) represents the load error control gain coefficient at the next update, K represents the rate of change of the altitude deviation of the hoisting point i with respect to time, represents the rate of change of the load deviation of the hoisting point i with respect to time, γ1 represents the altitude error adjustment slope coefficient, and γ2 represents the load error adjustment slope coefficient.

4. The balanced axle synchronization based fixed hoist type ship lock transit bridge lifting method according to claim 1, characterized in that, The PLC controller adopts a main cycle and an auxiliary cycle parallel mechanism; The main cycle is used to execute a control algorithm main loop, including deviation calculation, speed instruction generation and data archiving; The auxiliary cycle is used to execute the following real-time self-checking tasks: displacement sensor and load sensor data mutation detection, bus communication state monitoring, driver running state diagnosis and emergency stop signal listening and logic response.

5. The balanced axle synchronization based fixed hoist type ship lock transit bridge lifting method according to claim 1, characterized in that, The displacement sensor is an absolute value encoder with power failure memory function, which records the last height value before power failure after abnormal power failure; The PLC controller reads all the code values when re-powered, and adjusts the zero offset uniformly through a reference height calibration algorithm.

6. The balanced axle synchronization based fixed hoist type ship lock transit bridge lifting method according to claim 3, characterized in that, Calculate the height change rate dH of the i-th hanging point in each sampling period i / dt and the load change rate dF of the i-th hanging point i / dt, if the height change rate is dH i / dt exceeds the maximum allowable threshold β H Or load change rate dF i / dt exceeds the maximum allowable threshold β F , enter the limit compensation mode, and limit the speed before output: The maximum rate of change is limited by a rate limiting proportionality coefficient a max Limits and outliers are time-stamped for subsequent diagnostics.

7. The balanced axle synchronization based fixed hoist type ship lock transit bridge lifting method according to claim 1, characterized in that, Two groups of displacement sensors and load sensors are arranged at each driving adjustment lifting point, and each group of sensors is connected with the PLC controller through an independent channel; Two groups of displacement sensors and load sensors are simultaneously collected in a sampling period, and consistency comparison is performed by a PLC controller to calculate the deviation value δ sync If the deviation value δ sync exceeds the set value δ max , the following steps are performed: The current lifting point compensation is zeroed; The channel marker is switched to the backup in failure; The next cycle is automatically recalibrated.

8. A fixed hoist type lock bridge lifting system for implementing the fixed hoist type lock bridge lifting method based on synchronization of counterbalance axes according to any one of claims 1 to 7, characterized in that, The system comprises: A central drive rack is internally provided with a double-output-shaft reducer, the output shafts of the reducer are respectively connected with rigid transmission shafts through gear couplings at both ends of the output shafts; The transmission shafts pass through left and right hoist racks along the bridge body in the transverse direction and are connected with respective drum devices through drum couplings to realize rigid power transmission; Each drum device leads out a plurality of steel wire ropes, which are guided to respective automatic pulley structures through fixed pulleys, and the end of the lifting point is connected to a balance wheel mechanism, and two groups of the central drive racks and the hoist racks are arranged side by side to form a symmetrical four-point suspension closed loop system; A load sensor is installed at the shaft center of the balance wheel mechanism, and a displacement sensor is installed at the end of the drum to monitor the height and load information in the lifting process in real time; The PLC controller collects and analyzes the height and load data, calculates a variable frequency speed regulation compensation instruction according to the deviation amount when any lifting point deviates, and realizes four-point synchronous lifting control of the bridge body.

9. The fixed hoist ship lock vehicular bridge lifting system of claim 8, wherein, The system is also provided with a visual monitoring unit for collecting video images of the steel wire ropes to identify the wire breaking condition of the steel wire ropes.

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