Walking driving control method for port container tire crane

Abstract

The invention belongs to the technical field of port machinery automation control, and relates to a port container tire crane walking driving control method. According to the method, the steering compensation amount and the differential compensation amount corresponding to the transverse deviation and the course angle deviation of the tire crane are calculated in real time through the state space grid mapping technology, meanwhile, the health state level of each tire is evaluated based on the tread depth and the accumulated running time, and a differential distribution strategy is constructed. Under the physical execution constraint condition, the compensation amount is distributed according to the principle that the tires in the high health state bear dominant distribution, the tires in the middle health state bear basic distribution, and the tires in the low health state bear auxiliary distribution or do not bear, and dual safety guarantee is carried out in combination with environment safety monitoring and a tire physical constraint verification mechanism. According to the method, the problems of low control precision, unbalanced tire wear and potential safety hazards caused by uneven tire states in the traveling process of the traditional tire crane are effectively solved, and the automatic guide precision and stability of the tire crane are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of port machinery automation control, and relates to a port container rubber-tyred gantry crane walking driving control method. BACKGROUND

[0002] The port container rubber-tyred gantry crane (referred to as the rubber-tyred gantry crane) is a key equipment for loading and unloading and handling containers in a container yard. However, due to its large size and unique walking mode, it is prone to deviation during movement and has a visual blind area. Therefore, the deviation correction ability and anti-collision safety during its walking directly determine the efficiency of the loading and unloading operation and the safety of the equipment operation. If the deviation correction ability is insufficient or the anti-collision system fails, there are safety and efficiency risks.

[0003] At present, the walking control of the rubber-tyred gantry crane is mainly achieved by external reference positioning and sensor monitoring to realize the deviation correction and anti-collision functions. For example, a kind of rubber-tyred gantry crane walking positioning deviation correction and anti-collision method is proposed in Chinese invention patent publication No. CN105438998A. The method installs a laser scanner on the front wheel support of the rubber-tyred gantry crane, installs a column on the center line of the passageway at the back of the rubber-tyred gantry crane lane, measures the distance between multiple adjacent columns and the distance and angle between the column plane and the direction of the rubber-tyred gantry crane to correct the deviation, and divides the detection range into a far zone, a middle zone and a near zone to realize hierarchical anti-collision control.

[0004] However, this method mainly focuses on the monitoring and positioning of the external environment, and does not take the health status of the tires of the rubber-tyred gantry crane into the walking driving control decision. In actual operation, the wear degrees of the tires of the rubber-tyred gantry crane are different, resulting in differences in their mechanical properties. A unified control instruction will cause the overloading and wear of the tires in poor condition, while the potential of the tires in good condition is not utilized, thereby affecting the walking accuracy, control stability and overall service life of the tires.

[0005] Further, since the method does not establish a dynamic correlation between the tire health status and the control allocation, the system cannot adaptively allocate the compensation amount according to the tire status under complex walking conditions. If the loads of the high and low state tires cannot be optimized in path tracking, the walking stability and deviation correction efficiency will be reduced, and the non-uniform wear of the tire group will be aggravated.

[0006] In addition, the method has limitations in anti-collision safety control. The control response does not consider the physical limits of the tire actuators. Since the state of each actuator cannot be comprehensively judged, the system can only adopt global emergency stop. This simple strategy not only interrupts the continuity of the operation, but also may cause the whole machine to oscillate due to the limit state of individual tires, which hides a safety hazard. SUMMARY

[0007] In view of this, in order to solve the problems raised in the background art, a port container rubber-tyred gantry crane walking driving control method is proposed.

[0008] The object of the present application can be achieved by the following technical solution: a port container tire crane walking driving control method, comprising: S1, based on the lateral deviation and the heading angle deviation of the tire crane relative to the preset path obtained in real time, determining the required steering compensation and differential compensation through state space grid mapping.

[0009] S2, based on the tread depth and cumulative running time of each tire, determining the health status grade of each tire.

[0010] S3, under the condition of meeting the physical execution constraints of each tire, taking the health status grade as the basis for distribution, distributing the steering compensation and differential compensation to the rotational speed and steering angle of each tire to generate the target steering angle and target speed change of each tire, so that the high health status tire undertakes the leading distribution, the medium health status tire undertakes the basic distribution, and the low health status tire undertakes the auxiliary distribution or no distribution.

[0011] S4, performing safety verification on the distribution results of each tire.

[0012] Compared with the prior art, the present application has the following advantages: (1) the present application establishes a tire health status grading system based on tread depth and cumulative running time, and uses it as the basis for distribution of steering and differential compensation, solving the problem of one-size-fits-all control instructions caused by individual performance differences of tires. This method makes high health status tires undertake leading control tasks, and medium and low health status tires assist, achieving accurate matching of load and tire performance, which not only optimizes the walking accuracy and control stability of the whole machine, but also promotes the balanced wear of the tire group.

[0013] (2) The present application combines the environmental monitoring of laser radar and ultrasonic sensor with the physical constraint state feedback of tire actuator to construct a priority collaborative safety control mechanism, which preferentially executes anti-collision control when obstacles approach, and implements precise degradation strategy by combining mechanical limiting and motor current real-time monitoring, solving the problem of single global emergency stop causing work interruption and control oscillation, and achieving the balance effect of safety protection and work continuity. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0015] Figure 1 The present application is a port container tire crane walking driving control method.

[0016] Figure 2 The flow chart of the method for obtaining the steering compensation amount and the differential compensation amount in the application.

[0017] Figure 3 The flow chart of the method for obtaining the health state grade of each tire in the application. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the application will be clearly and completely described with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the application.

[0019] Please refer to Figure 1 As shown in the figure, the application provides a port container tire crane walking driving control method, comprising: S1, based on the lateral deviation and the heading angle deviation of the tire crane relative to the preset path obtained in real time, determining the required steering compensation amount and the differential compensation amount through state space grid mapping.

[0020] In an embodiment of the application, considering the stability and accuracy of the tire crane in maintaining the preset path during walking, the lateral deviation and the heading angle deviation are selected as the core control variables.

[0021] The lateral deviation directly reflects the position deviation degree of the tire crane relative to the preset path, and the heading angle deviation represents the degree of coincidence of the attitude direction of the tire crane and the tangent direction of the path. The two together constitute a complete state description of the path tracking control. Through the state space grid mapping method, the path tracking problem is converted into a real-time compensation problem of the state vector, so as to realize the correction of the walking trajectory of the tire crane.

[0022] Specifically, the lateral deviation is the vertical distance from the geometric center of the tire crane to the preset path, and the heading angle deviation is the included angle between the center line of the tire crane and the tangent direction of the preset path. The lateral deviation and the heading angle deviation are single numerical values at any control time.

[0023] Further, please refer to Figure 2 As shown in the figure, in order to realize the path tracking compensation control based on the above-mentioned lateral deviation and heading angle deviation, the corresponding steering compensation amount and differential compensation amount need to be obtained, and the method for obtaining the same comprises the following steps: S11, based on the maximum allowed lateral deviation and the maximum allowed heading angle deviation of the tire crane, a 5*5 state space grid is established.

[0024] Specifically, the method of establishing the 5x5 state space grid is as follows: first, define two coordinate axes of the state space: take the lateral deviation as the first dimension as the lateral deviation axis, and the value range is [-maximum allowed lateral deviation, +maximum allowed lateral deviation].

[0025] Take the heading angle deviation as the second dimension as the heading angle deviation axis, and the value range is [-maximum allowed heading angle deviation, +maximum allowed heading angle deviation], and the two dimensions together constitute a two-dimensional state space.

[0026] Divide the above-mentioned lateral deviation axis and heading angle deviation axis into five equally spaced interval levels respectively, and the interval levels of the lateral deviation axis are marked from left to right as [large negative deviation, small negative deviation, zero, small positive deviation, large positive deviation]; the interval levels of the heading angle deviation axis are marked from bottom to top as [large left deviation, small left deviation, zero, small right deviation, large right deviation].

[0027] Combine the two divided coordinate axes to form a 5x5 state space grid.

[0028] It should be noted that when the lateral deviation or the heading angle deviation exceeds the range of the state space grid, it indicates that the tire crane has entered an abnormal serious deviation state, and the exceeding part is processed according to the boundary value in this state, and a system warning signal is immediately generated, which will be transmitted to the upper monitoring system.

[0029] S12, based on the grade division rule of lateral deviation and heading angle deviation, calculate the corresponding steering compensation and differential compensation for each grid node, and construct the steering compensation matrix and differential compensation matrix accordingly.

[0030] Wherein, the grade division rule is: (a) the larger the lateral deviation, the larger the steering compensation; when the lateral deviation direction is negative or positive, the steering compensation direction is consistent with it.

[0031] (b) the larger the heading angle deviation, the larger the differential compensation; when the yaw direction is left or right, the differential compensation direction is consistent with it.

[0032] (c) when the lateral deviation and the heading angle deviation are large at the same time, appropriately increase the two types of compensation to make the correction more rapid.

[0033] (d) when the lateral deviation or the heading angle deviation is in the small negative deviation, small positive deviation, small left deviation, or small right deviation, the compensation is taken at a moderate level, so that the control output changes smoothly in the case of slight deviation, and avoids sudden changes in compensation.

[0034] (e) when the lateral deviation and the heading angle deviation are both in the zero level, the compensation is taken at the minimum value, so that the control command naturally transitions in the state close to zero deviation, and avoids the appearance of compensation direction reversal or jitter.

[0035] (f) all compensation amounts are limited within the safe range allowed by the device.

[0036] It should be noted that the above classification rules establish the qualitative principle of control output, and the corresponding steering compensation amount and differential compensation amount of each node in the state space grid need to be calculated based on the rules.

[0037] Specifically, a weighted synthesis method based on preset coefficients is adopted, wherein: the steering compensation amount is obtained by multiplying the lateral deviation by a first preset coefficient and then superimposing the result of multiplying the heading angle deviation by a second preset coefficient; and the differential compensation amount is obtained by multiplying the heading angle deviation by a third preset coefficient and then superimposing the result of multiplying the lateral deviation by a fourth preset coefficient.

[0038] The values of the first to fourth preset coefficients are dynamically adjusted according to the classification rules.

[0039] For example, for a grid node with a lateral deviation level of positive large and a heading angle deviation level of right small, when calculating the steering compensation amount, the dominant coefficient, i.e., the first preset coefficient, takes a larger value of 0.5 because the lateral deviation level is large, and the auxiliary coefficient, i.e., the second preset coefficient, takes a smaller value of 0.1 because the heading angle deviation level is small.

[0040] When calculating the differential compensation amount, the dominant coefficient, i.e., the third preset coefficient, takes a smaller value of 0.2 because the heading angle deviation level is small, and the auxiliary coefficient, i.e., the fourth preset coefficient, takes a medium value of 0.3 because the lateral deviation level is large.

[0041] The specific values of all preset coefficients are obtained through parameter tuning experiments on simulation and physical platforms, and are iteratively optimized to minimize path tracking error.

[0042] S13, determine the position of the lateral deviation and the heading angle deviation in the state space grid through real-time acquisition, and calculate the real-time steering compensation amount and the differential compensation amount from the steering compensation matrix and the differential compensation matrix based on the bilinear interpolation algorithm.

[0043] Considering that the state space grid is discrete and the real-time acquired lateral deviation and heading angle deviation are continuous values, they may not exactly fall on the preset grid nodes. If the compensation amount of the nearest neighbor node is simply taken, it will cause the control output to have a step change.

[0044] Therefore, the bilinear interpolation algorithm, which is a numerical interpolation method on a two-dimensional grid, is used to achieve smooth transition of the compensation amount between adjacent grid nodes.

[0045] Specifically, according to the real-time detected lateral deviation value and the heading angle deviation value, a specific unit region in which the lateral deviation value and the heading angle deviation value are located in the state space grid is determined. The unit is surrounded by four nearest grid nodes, and the four nodes correspond to the boundary values of the grade interval division on the lateral deviation axis and the heading angle deviation axis, respectively.

[0046] From the constructed steering compensation matrix and the differential compensation matrix, the compensation amount values stored in the four nodes are read.

[0047] For the lateral deviation direction, a relative position ratio of the current deviation value in the interval in the direction is calculated to obtain a lateral weight coefficient; similarly, for the heading angle deviation direction, a relative position ratio of the current deviation value in the interval in the direction is calculated to obtain a heading angle weight coefficient. The two weight coefficients are both dimensionless values and are located in [0, 1].

[0048] By using the compensation amount values of the above four nodes and combining the two weight coefficients calculated, a real-time compensation amount under the current deviation state is finally obtained through linear weighted fusion.

[0049] S2, based on the tread depth and the cumulative running time of each tire, the health state grade of each tire is determined.

[0050] In an embodiment of the present application, considering that the tires will have different performance differences due to different degrees of wear during long-term operation, the tread depth sensor data and the cumulative running time counter data installed on each tire are obtained for evaluation. The tread depth is a direct physical parameter representing the remaining grip capacity and safety margin of the tire, and the cumulative running time comprehensively reflects the material fatigue aging degree and historical load condition of the tire.

[0051] Based on the two key data, a median-based comparison method is used to divide the tire health state into three grades: high, medium and low.

[0052] Further, referring to Figure 3 As shown in the figure, the method for obtaining the health state grade of each tire is to calculate the median of all tread depths and cumulative running times, and if the number of tires is even, to take the average of the two middle values.

[0053] According to the medians of the tread depths and the cumulative running times, the health state grade of each tire is determined according to the following rules: High health state tire: the tire with a tread depth greater than or equal to the median of all tire tread depths and a cumulative running time less than or equal to the median of all tire cumulative running times, indicating that it has good grip and long remaining service life, and is suitable for bearing the main control load.

[0054] Low health state tire: tire with tread depth less than the median value of all tire tread depths and cumulative running time greater than the median value of all tire cumulative running times, indicating that its grip is significantly reduced and the degree of aging is high, and should avoid bearing excessive load.

[0055] Medium health state tire: tire other than high health state tire and low health state tire.

[0056] S3, under the condition of meeting the physical execution constraints of each tire, the steering compensation and the differential compensation are allocated to the speed and the steering angle of each tire according to the health state level, the target steering angle and the target speed change of each tire are generated, the high health state tire bears the leading allocation, the medium health state tire bears the basic allocation, and the low health state tire bears the auxiliary allocation or no allocation.

[0057] In an embodiment of the present application, considering the physical constraints such as mechanical limit and motor current of the tire, the feasibility and safety need to be considered in load distribution, and walking driving control is realized through hierarchical allocation and real-time verification.

[0058] Further, considering that the extreme steering demand of the tire crane may exceed the bearing capacity of the mechanical structure under complex working conditions, in order to avoid overload damage of the steering mechanism and the risk of walking instability caused thereby, the physical constraint condition is met in the following way: the real-time state of the mechanical limit switch of the steering mechanism of each tire is obtained, and when the mechanical limit switch is triggered, the maximum allowed target steering angle of the tire is limited to the maximum allowed angle of the physical structure.

[0059] At the same time, the current value of the driving motor of each tire is collected in real time through the current sensor, and when it is detected that the current value exceeds the rated current of the motor, the target speed change of the tire is immediately set to zero, and the overcurrent protection mechanism is started to prevent overload damage of the motor and ensure that the system operates within the physical safety boundary.

[0060] Further, the specific method of allocating the steering compensation is: if there are multiple high health state tires, the part of the steering compensation greater than the average allocation is allocated to all high health state tires, and the remaining part is allocated to non-high health state tires.

[0061] If there is only a single high health state tire, the part of the steering compensation greater than the allocation of other single tires is allocated to the high health state tire, and the remaining part is allocated to the medium health state tire, and the low health state tire does not bear the steering compensation.

[0062] If there is no high health state tire but there is a medium health state tire, the part of the steering compensation greater than the average allocation is allocated to the medium health state tire, and the remaining part is allocated to the low health state tire.

[0063] If all the tires are low health state tires, the steering compensation amount is evenly distributed to each tire.

[0064] Further, the specific method of distributing the differential compensation amount is that, if there are high health state tires, each high health state tire is allocated a differential compensation amount greater than the average distribution amount of all tires, and each non-high health state tire is allocated a differential compensation amount less than the average distribution amount.

[0065] If there are no high health state tires but there are medium health state tires, the average distribution amount of the differential compensation amount on all tires is calculated.

[0066] Each medium health state tire is allocated a differential compensation amount greater than the average distribution amount, each low health state tire is allocated a differential compensation amount less than the average distribution amount, and the sum of the distribution amounts of all tires is ensured to equal the differential compensation amount.

[0067] If all the tires are low health state tires, the differential compensation amount is equally distributed to each tire.

[0068] It should be noted that if the number of tires is 1, the tire is considered as a high health state tire and is allocated all the steering compensation amount or the differential compensation amount.

[0069] Due to the complex and variable port operation environment, there is a risk of personnel, equipment and other obstacles invading the tire crane walking path. In order to ensure safe operation, during the distribution of the steering compensation amount and the differential compensation amount, environmental safety control also needs to be performed in parallel, specifically including: The laser radar and ultrasonic sensor are used to monitor the environment around the tire crane in real time, and the distance of the nearest obstacle is obtained by scanning and monitoring the dynamic environment around the tire crane in real time through the laser radar and ultrasonic sensor array installed on the main body of the tire crane.

[0070] The distance of the obstacle is compared with the preset safety threshold value, and when the distance of any obstacle is lower than the safety threshold value, the distribution of the steering compensation amount and the differential compensation amount is immediately interrupted, and an anti-collision control instruction is generated and sent to the actuator. The anti-collision control instruction includes an emergency stop instruction or a deceleration to a safe speed instruction.

[0071] The safety threshold value is determined by following the mandatory requirements for the safety distance of industrial vehicles in the port equipment safety specification.

[0072] When the distance of all directions of the obstacle is continuously higher than the safety threshold value for a preset recovery duration, the system automatically recovers the normal distribution and execution of the steering compensation amount and the differential compensation amount.

[0073] S4, safety verification is performed on the distribution results of each tire.

[0074] Since the tire crane is physically limited by mechanical structure, motor performance, etc. in actual operation, directly allocating compensation according to the health state may cause individual tires to exceed their execution capacity, thereby causing equipment damage or control instability. Therefore, a safety check needs to be performed on the allocation results of each tire to ensure that the final control instructions of each tire are within its physical execution capacity.

[0075] Further, the safety check is specifically: obtaining the mechanical limit switch state of each tire steering mechanism and the real-time current value of the driving motor.

[0076] When the target steering angle of any tire causes the mechanical limit switch of the tire to trigger, the target steering angle is truncated to the maximum allowed value that does not trigger the limit switch, and the excess part is reallocated to the tires that do not trigger the limit switch in order of health state level from high to low, ensuring that the steering action does not exceed the mechanical structure bearing capacity, while preferentially using tires with better health state to share the additional load.

[0077] When the target speed change of any tire causes the real-time current value to exceed the rated current value, the target speed change of the tire is proportionally reduced so that the current value does not exceed the rated current value, and the reduced part is evenly distributed among tires of the same health state level, preventing motor overload and damage, while load balancing among tires of the same level avoids transferring too much load to a single tire.

[0078] Wherein the proportion is the ratio of the rated current value of the motor to the real-time current value before the overrun occurs.

[0079] When there are still tires triggering the mechanical limit switch or current overrun after the above reallocation, expand the allocation range, allocate the compensation in proportion to all tires that do not trigger the constraint in order of health state level from high to low, to ensure operation within the physical safety boundary and prevent system failure due to local overload.

[0080] When the number of reallocations reaches a preset threshold (such as 5 times) and all physical constraint conditions are still not met, start the system-level protection mechanism: proportionally reduce the overall steering compensation and differential compensation to reduce control demand; at the same time, generate a system degradation operation signal to make the tire crane continue to work in a conservative mode; and send a tire maintenance warning to the operator to prompt timely repair or replacement of the problem tire.

[0081] Considering that personnel and equipment safety is the highest priority principle of port operations, the real-time and reliability of the anti-collision control must be prioritized over the allocation and check process of the tire target steering angle and speed change.

[0082] Therefore, when generating the anti-collision control instruction, the environmental safety control is preferentially executed, the safety check is suspended, the quick response capability and decision certainty of the control system in the emergency are ensured, when the distribution is resumed, that is, when the environmental safety control is released and all the obstacle distances continuously exceed the safety threshold for 5-10 seconds, the safety check is reactivated and the distribution process is continuously executed based on the distribution state before the interruption.

[0083] To sum up, the application firstly calculates the steering compensation and differential compensation required by the tire crane based on the lateral deviation and the heading angle deviation through the state space grid mapping method; secondly, the health state grades of the tires are scientifically evaluated in combination with the tread depths and the cumulative running times of the tires; and then, the differentiated load distribution strategy based on the health state is realized under the condition of meeting the physical execution constraints, so that the high-health-state tires bear the leading distribution, the medium-health-state tires bear the basic distribution, and the low-health-state tires bear the auxiliary distribution or are exempted from the distribution; and simultaneously, the safe and stable operation of the system in the complex port environment is ensured through the double protection mechanism of the environmental safety control and the execution safety check.

[0084] Those skilled in the art can appreciate that the algorithm steps of each example described in combination with the embodiments disclosed herein can be realized in electronic hardware or in combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0085] In addition, each functional module in each embodiment of the present application can be integrated in one processing module, or each module can exist physically alone, or two or more modules can be integrated in one module.

[0086] The above is merely specific implementation of the present application, but the protection scope of the present application is not limited thereto, any skilled person in the art can easily think of changes or replacements within the technical range disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

[0087] Finally, the above is merely the preferred embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method of controlling the travel drive of a port container rubber-tired crane, characterized by, The method comprises the following steps: S1. Based on the lateral deviation and the heading angle deviation of the tire crane relative to the preset path, the required steering compensation and differential compensation are determined by state space grid mapping; S2. Based on the tread depth and the cumulative running time of each tire, the health status level of each tire is determined; S3. Under the condition of meeting the physical execution constraints of each tire, the steering compensation and differential compensation are allocated to the rotation speed and steering angle of each tire according to the health status level, and the target steering angle and target speed change of each tire are generated, so that the high health status tire undertakes the leading allocation, the medium health status tire undertakes the basic allocation, and the low health status tire undertakes the auxiliary allocation or no allocation; S4. The allocation results of each tire are subjected to safety verification.

2. The port container tire crane traveling drive control method according to claim 1, characterized in that, When the method of claim 1 is executed, it further comprises environmental safety control, specifically comprising: The laser radar and ultrasonic sensor are used to monitor the environment around the tire crane in real time, and the distance of the obstacles is obtained; The distance of the obstacles is compared with the preset safety threshold; When any obstacle distance is lower than the safety threshold, the allocation of the steering compensation and the differential compensation is immediately interrupted, and the anti-collision control instruction including the emergency stop instruction or the deceleration to safety speed instruction is generated and sent to the execution mechanism; When all obstacle distances are continuously higher than the safety threshold for a predetermined time, the allocation and execution of the steering compensation and the differential compensation are resumed.

3. The port container tire crane traveling drive control method according to claim 1, characterized by, The lateral deviation and the heading angle deviation are specifically: The vertical distance from the geometric center of the tire crane to the preset path is taken as the lateral deviation, and the included angle between the center line of the tire crane and the tangent direction of the preset path is taken as the heading angle deviation, and the lateral deviation and the heading angle deviation are single values at any control time.

4. The port container tire crane traveling drive control method of claim 1, wherein, The method for obtaining the steering compensation and the differential compensation is: Based on the maximum allowed lateral deviation and the maximum allowed heading angle deviation of the tire crane, a state space grid is established; Based on the grade division rule of the lateral deviation and the heading angle deviation, the corresponding steering compensation and differential compensation of each grid node are calculated, and the steering compensation matrix and the differential compensation matrix are constructed accordingly; The real-time lateral deviation and the heading angle deviation are used to determine the position of the tire crane in the state space grid, and the real-time steering compensation and differential compensation are calculated from the steering compensation matrix and the differential compensation matrix based on the bilinear interpolation algorithm.

5. The port container tire crane travel drive control method of claim 1, wherein, The method for obtaining the health status level of each tire is: The tread depth sensor data and the cumulative running time counter of each tire are read; The medians of all tread depths and cumulative running times are calculated, and if the number of tires is even, the average of the two middle values is taken; According to the medians of the tread depth and the cumulative running time, the health status level of each tire is determined according to the following rules: High health status tire: the tire with the tread depth greater than or equal to the median of all tire tread depths and the cumulative running time less than or equal to the median of all tire cumulative running times; Low health status tire: the tire with the tread depth less than the median of all tire tread depths and the cumulative running time greater than the median of all tire cumulative running times; Medium health state tire: other tires except high health state tires and low health state tires.

6. The port container tire crane travel drive control method of claim 1, wherein, The physical execution constraint conditions of each tire are specifically: Obtaining the real-time state of the mechanical limit switch of each tire steering mechanism, when the mechanical limit switch is triggered, the maximum allowable target steering angle of the tire is limited to the maximum allowable angle of the physical structure of the steering mechanism; Obtaining the real-time current value of each tire driving motor, when the real-time current value exceeds the rated current value marked on the nameplate of the motor, the maximum allowable target speed change of the tire is set to zero.

7. The port container tire crane travel drive control method of claim 1, wherein, The specific method of distributing the steering compensation amount in S3 is: If there are multiple high health state tires, the part of the steering compensation amount greater than the average distribution amount is distributed to all high health state tires, and the remaining part is distributed to non-high health state tires; If there is only a single high health state tire, the part of the steering compensation amount greater than the distribution amount of other single tires is distributed to the high health state tire, and the remaining part is distributed to medium health state tires, and the low health state tire does not bear the steering compensation; If there is no high health state tire but there are medium health state tires, the part of the steering compensation amount greater than the average distribution amount is distributed to the medium health state tires, and the remaining part is distributed to the low health state tires; If all tires are low health state tires, the steering compensation amount is evenly distributed to each tire.

8. The port container tire crane travel drive control method of claim 1, wherein, The specific method of distributing the differential compensation amount in S3 is: If there are high health state tires, each high health state tire is allocated a differential compensation amount greater than the average distribution amount of all tires, and each non-high health state tire is allocated a differential compensation amount less than the average distribution amount; If there are no high health state tires but there are medium health state tires, the average distribution amount of the differential compensation amount on all tires is calculated; Each medium health state tire is allocated a differential compensation amount greater than the average distribution amount, each low health state tire is allocated a differential compensation amount less than the average distribution amount, and the sum of the distribution amounts of all tires is ensured to equal the differential compensation amount; If all tires are low health state tires, the differential compensation amount is equally distributed to each tire.

9. The port container tire crane travel drive control method of claim 1, wherein, The safety check on the distribution results of each tire includes: Obtaining the state of the mechanical limit switch of each tire steering mechanism and the real-time current value of the driving motor; When the target steering angle of any tire causes the mechanical limit switch of the tire to trigger, the target steering angle is truncated to the maximum allowable value that does not trigger the limit switch, and the excess part is redistributed to the tires that do not trigger the limit switch in the order from high to low health state level; When the target speed change amount of any tire causes the real-time current value to exceed the rated current value, the target speed change amount of the tire is proportionally reduced so that the current value does not exceed the rated current value, and the reduced part is evenly distributed among the tires of the same health state level; When there are still tires triggering the mechanical limit switch or the current exceeding the rated current value after redistribution, the compensation amount is proportionally distributed among the tires that do not trigger the constraint in the order from high to low health state level, to ensure that the load of each tire does not exceed its maximum allowable value; When the number of reassignments reaches a preset threshold and all physical constraint conditions are still not met, the overall steering compensation and differential compensation are scaled down, a system degradation operation signal is generated, and a tire maintenance warning is sent to the operator.

10. The port container tire crane travel drive control method of claim 9, wherein, The performing the safety check further includes: When the anti-collision control instruction is generated, the environmental safety control is preferentially performed, the performing the safety check is suspended, when the allocation is resumed, the performing the safety check is reactivated, and the allocation process is continued based on the allocation state before the interruption.

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