An inclined berth ship large ring segment module vehicle underload avoidance transportation control method

Abstract

This invention discloses a method for underload avoidance transportation control of large-scale ship segment modular vehicles on inclined slipways, addressing the safety hazard caused by insufficient single-axle load during the transportation of large-scale ship segments using modular vehicles. The method includes: obtaining the estimated total weight of the large-scale ship segment to be transported and the total number of available axles on the modular vehicle; calculating the average load per axle; determining whether it is below a preset minimum safe load threshold; if below, implementing an "axle lifting" strategy, calculating the number of axles to be lifted to increase the load of the remaining working axles to the optimal load range; selecting the axle to be lifted and controlling the modular vehicle's hydraulic system to lift its tires off the ground; and, while maintaining the stability of the vehicle frame, using the remaining axles to complete the transportation of the large-scale ship segment from the assembly site to the inclined slipway. This invention solves the technical problem of "underload" in modular vehicles due to the relatively light weight of large-scale ship segments, enabling safe transportation of modular vehicles under optimal working conditions.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding technology, specifically to a method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways. Background Technology

[0002] In the shipbuilding industry, slipway cycle time is a key factor determining shipbuilding capacity. This issue is particularly prominent for shipyards that can only use inclined slipways. To alleviate slipway pressure, the large-scale ring-section assembly method has been introduced into shipbuilding. This method pre-assembles multiple sections into large-scale ring-sections in an assembly area outside the slipway. These sections are then transported to the inclined slipway for mounting and positioning using SPMT (Special Purpose Mounted Vehicle) modular vehicles. This transfers a large amount of welding and outfitting work from the slipway to the assembly area, enabling parallel operations and significantly shortening the slipway cycle time.

[0003] However, in practical engineering applications, modular vehicles face a unique technical challenge when transporting large sections of ships: although these sections are massive in size, their overall weight is often relatively light due to the characteristics of their hull structure. This load level leads to a long-neglected safety issue—"underloading" of the modular vehicle. After discussion and confirmation by external experts, it has been determined that insufficient load on a single axle of the modular vehicle is also unsafe, specifically manifested in the following ways: Insufficient tire grip: Low load reduces the normal pressure between the tire and the ground, decreasing the coefficient of friction. This can easily lead to tire slippage or even vehicle rollover during transport on sloped sections of a dock.

[0004] Reduced transport stability: Low load causes the overall center of gravity of the modular vehicle to rise relatively, which weakens its ability to resist rollover when turning or passing through uneven roads. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects in the prior art and provide a method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways.

[0006] To achieve the above objectives, the technical solution of the present invention is to design a transportation control method for avoiding underload of large circular section modular vehicles on inclined slipways, comprising the following steps: S1. After completing the assembly and welding of the large ring section of the ship at the assembly site, obtain the estimated total weight W of the large ring section and the total number of available axles N of the modular vehicles involved in transportation. The estimated total weight W should include the structural weight of the large ring section, the weight of the outfitting components, the weight of the welding materials, and an appropriate safety margin. The total number of available axles N is determined based on the actual number of modular vehicles and the number of axles per modular vehicle.

[0007] S2. Calculate the average load P on a single axis. _avg =W / N; This value represents the ideal load value evenly distributed across all axes, used to make a preliminary judgment on the overall load level.

[0008] S3. Determine the average load P of the single axis. _avg Is it less than the preset minimum safe load threshold P? _min The P _min The net load capacity of a single axle of the modular vehicle; the P _min It is an empirical value determined after comprehensively considering factors such as tire adhesion, minimum working pressure of the hydraulic system, and transportation stability.

[0009] S4. If P _avg <P _min Then, execute the axis lifting strategy: calculate the number M of axes to be lifted, such that M satisfies: W / (NM)≥P _min And W / (NM)≤P _max ,in P_max The rated maximum load capacity of a single axle of the modular vehicle; in this invention, based on the technical parameters of the modular vehicle and a large amount of actual ship transport test data, the P... _min The minimum net load capacity per axle is set at 12 tons, which translates to a minimum total load capacity per axle (including the vehicle's own weight, approximately 4.5 tons per axle) of 16.5 tons. Specific details for different modular vehicles P... _min They may be different.

[0010] If P _avg ≥P _min If the load level is within a safe range, transportation can proceed according to normal procedures without the need to lift the shaft.

[0011] If P _avg <P _min If so, it indicates a risk of "underloading" and the subsequent axis lifting strategy must be implemented.

[0012] The calculation principle is: after lifting M shafts, the average load on the remaining shafts should be increased to the preset optimal load range, that is, simultaneously satisfying the requirements of not being lower than the minimum safe load threshold and not being higher than the maximum rated load capacity.

[0013] S5. Select M axes from the N available axes as the axes to be lifted, and control the hydraulic suspension system of the control module vehicle to lift the tires of the M axes off the ground so that they are off the ground and do not participate in the load-bearing. The route selection rules should follow these principles: (1) Symmetry principle: The axis to be lifted should be symmetrically distributed in both the longitudinal and transverse directions about the center of gravity of the large ring segment, so as to ensure that the resultant force of the remaining axis coincides with or deviates very little from the center of gravity of the segment.

[0014] (2) Principle of left-right balance: The modular vehicles involved in transportation are divided into left and right groups, and the number of axles lifted by the left and right groups must be equal. For example, when M=4, 2 axles are lifted by each side; when M=12, 6 axles are lifted by each side.

[0015] (3) Priority to the middle principle: Since the center of gravity of the large ring section is usually located in the middle of the length of the section, the axis is selected from the middle area of ​​the module vehicle queue for lifting first, so that the axis of the remaining work is distributed on both sides of the center of gravity, and the number of axis on both sides is as equal as possible.

[0016] (4) Uniform distribution principle: When multiple modular vehicles are rigidly connected in parallel on one side, the number of shafts lifted on each modular vehicle is the same, and the lifting positions are symmetrically distributed in the middle of the modular vehicle.

[0017] After selecting the axle to be lifted, the control system sends a command to the hydraulic suspension system of the modular vehicle, controlling the hydraulic cylinders of the M axles to retract, raising their tires approximately 50mm off the ground. At this point, these M axles are completely off the ground, bearing no load, and only move with the frame. The remaining NM axles remain grounded, bearing the entire weight of the large ring section.

[0018] During the lifting operation, the control system monitors the pitch and roll angles of the chassis platform in real time using tilt sensors. When a change in chassis attitude is detected (such as chassis tilting due to the lifting of part of the axle), the hydraulic suspension height on the unlifted axle is automatically adjusted to keep the chassis platform level at all times. This ensures the stability of the large ring section and avoids additional stress or deformation of the section structure due to sudden changes in attitude.

[0019] S6. While maintaining the overall stability of the modular vehicle frame platform, the remaining NM axis lines are used to support the large ring segment, and the segment is transported from the assembly site to the inclined platform for mounting and positioning along a predetermined transportation path.

[0020] The transportation routes include: Horizontal sections within the main group's training grounds; A transportation channel connecting the main assembly area and the inclined slipway; The variable-gradient sections of the inclined slipway include a second inclined section with a gradient of 1:22 and a first inclined section with a gradient of 1:40 or 1:32.

[0021] During transportation, the following control measures will be implemented: (1) Speed ​​control: The travel speed is strictly controlled at ≤1km / h to ensure smooth transportation.

[0022] (2) Adaptive slope: When the modular vehicle enters a slope area, the electronic control system of the modular vehicle automatically calculates and adjusts the lifting height of the hydraulic suspension of each working axis according to the preset slope data or real-time sensor signals, so that the chassis platform always remains horizontal and ensures that the large ring section travels smoothly on the slope channel.

[0023] (3) Load monitoring: The actual load on each working axis is monitored in real time by pressure sensors installed on each axis. If the actual load on a certain axis exceeds P... _max If the actual load on a certain axis is lower than P, an overload alarm will be issued and transportation will be suspended; _min If the load is too high, an underload alarm will be issued and the operator will be prompted to check.

[0024] (4) Attitude monitoring: Continuously monitor the attitude of the frame and dynamically adjust the suspension height of each axle when passing through uneven road surfaces or areas with varying slopes to keep the frame level.

[0025] Optionally, in step S3, the preset minimum safe load threshold P _min Specifically, the net load capacity per axle is 12 tons, or the total load capacity per axle is 16.5 tons; the total load capacity per axle includes the tare weight of the modular vehicle body corresponding to the axle. This value is determined for the modular vehicles used by this shipyard.

[0026] Furthermore, in step S4, the method for determining the number M of shafts to be lifted is as follows: calculate the target number of working shafts N. _target =ceil(W / P _opt ), where P _opt The preset optimal single-axis load value, and P _min ≤ P_opt ≤P _max Then M = NN _target If the calculated result M is odd, it is rounded up to an even number to ensure that the number of axes lifted by the module vehicles on the left and right sides is symmetrical.

[0027] Optionally, the optimal single-axis load value P _opt The setting is to keep the load percentage of each axis in the range of 40% to 80%.

[0028] Furthermore, in step S5, the specific method for selecting the axle to be lifted is as follows: the modular vehicles involved in the transportation are divided into left and right groups, and the number of axles lifted by the left and right groups is equal; within each group, the axle is selected from the middle area first, so that the remaining working axles are symmetrically distributed before and after the center of gravity of the large ring section; when multiple modular vehicles are rigidly connected in parallel on one side, the number of axles lifted on each modular vehicle is the same, and the lifting positions are symmetrically distributed in the middle on that modular vehicle.

[0029] Furthermore, in step S6, maintaining the overall posture stability of the modular vehicle frame platform specifically includes: during the process of lifting part of the axis, monitoring the pitch angle and roll angle of the frame platform in real time through tilt sensors; when the change in the frame posture is detected to exceed a preset threshold, automatically adjusting the hydraulic suspension height on the unlifted axis to restore the frame platform to a horizontal state, ensuring that the large ring section does not undergo structural deformation during transportation.

[0030] Furthermore, in step S6, the transportation route includes a passage from the main assembly site to the inclined platform, which includes a horizontal section and a variable-slope section of the inclined platform; when the modular vehicle travels on the variable-slope section, the electronic control system on the modular vehicle automatically adjusts the lifting height of each working axis according to the real-time slope.

[0031] Furthermore, it also includes a pre-weighing verification step: before performing the axle lifting operation, the actual weight of the large ring section is measured using the weighing system on the modular vehicle to obtain the actual total weight W. _actual If |W _actual -W| / W>5%, then based on W _actual Recalculate the number of axes M that need to be lifted to ensure that the lifting plan matches the actual weight.

[0032] Furthermore, it also includes a transportation monitoring step: during transportation, pressure sensors installed on each axis are used to monitor the actual load of each working axis in real time; if the actual load of a certain axis exceeds P... _max If the actual load on a certain axis is lower than P, an overload alarm will be issued and transportation will be suspended; _min If the load is not cleared, an underload alarm will be issued and the operator will be prompted to check; transportation can only continue after the alarm is cleared.

[0033] The advantages and beneficial effects of this invention are as follows: This invention is the first to recognize that the low single-axis load caused by the large volume and medium weight of large ship segments also poses a serious safety hazard, filling a technological gap. It proposes a reverse-thinking solution of actively lifting the axis, thereby increasing the single-axis load by actively reducing the number of stressed axes, solving the problem of safe transportation under low-load conditions. This solution requires no additional equipment or material investment; it can be achieved solely through control strategy optimization, at zero cost.

[0034] By increasing the single-axle load to the optimal working range (40%-80% load percentage), the adhesion between the tires and the ground is significantly increased, effectively preventing the modular vehicle from slipping or skidding on sloping sections. Simultaneously, the working environment of the hydraulic system is improved, extending the equipment's service life and significantly enhancing the safety of slope-adjustable transport on inclined platforms.

[0035] This invention provides a systematic calculation method to determine the optimal number of lifting axes, and combines the principle of symmetry to select the line, ensuring that the resultant force application point of the remaining axes is precisely matched with the center of gravity of the large ring segment, thus avoiding new risks caused by off-center loading. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the modular vehicle structure of the present invention; Figure 2 This is a schematic diagram of the structure of the 30C main module vehicle of the present invention when it carries the axle for transportation; Figure 3 This is a top view of the multiple modular vehicles of the present invention; Figure 4 This is a schematic diagram of the structure of the 30E main module vehicle of the present invention when it carries the axle for transportation. Detailed Implementation

[0037] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0038] This embodiment describes in detail the entire process of identifying the risk of "underloading" and performing the "lifting part of the axis" operation when transporting the 30C section of an 8300t general cargo ship using modular vehicles by applying the method of the present invention.

[0039] I. Project Background A shipyard undertook a batch construction task of 8300t general cargo ships. To shorten the slipway cycle, the large-scale ring-section assembly method was adopted for construction. The cargo hold area was divided into four large ring sections: 30A, 30B, 30C, and 30E. After assembly and welding were completed at the assembly site, the sections were transported to the inclined slipway by modular vehicles for mounting and positioning.

[0040] The 30C main section is composed of segments 306 (left / right), 307, 524, 534, and 602, with external dimensions of 19.8m (length) × 22.8m (width) × 10.3m (height). The theoretical weight of the main section structure is 282 tons. Considering outfitting components, welding materials, and safety margins, the estimated total weight is W = 310 tons.

[0041] The transportation equipment is configured as follows: 2 power units (PPU) + 4 6-axle modular vehicles, that is, the left group has 2 6-axle modular vehicles rigidly connected in parallel, and the right group has 2 6-axle modular vehicles rigidly connected in parallel, with a total number of available axles N=24 axles.

[0042] Modular vehicle technical parameters: Rated maximum load capacity P per axle _max =40 tons; single-axle vehicle body weight 4.5 tons; based on modular vehicle technical data and expert advice, the minimum safe net load P for a single axle is... _min=12 tons (corresponding to a total load capacity of 16.5 tons).

[0043] II. Identification of Underload Risk (corresponding steps S1-S3) Calculate the average net load on a single axle: P _avg_net =W / N=310 tons / 24 axles=12.92 tons / axle This value is slightly above the minimum safety threshold of 12 tons / axis, and superficially appears to be within the safe range. However, further analysis by the project team revealed the following risk factors: (1) The center of gravity of the entire section is not absolutely centered. According to calculations, the coordinates of the center of gravity of the 30C section are approximately (X=FR118+589, Y=224, Z=3741), with lateral and longitudinal eccentricities. In actual transportation, the load on the end axis farther from the center of gravity will be lower than the average value.

[0044] (2) The two power units (PPUs) weigh approximately 14 tons in total. Their weight is borne by the axis closest to the power unit, which further exacerbates the uneven force distribution.

[0045] (3) Using finite element analysis software to simulate transportation conditions, stress analysis was performed on the scheme where all 24 axles were grounded. The results showed that the actual net load of some axles located at the edges of both ends of the main section was only 9-10 tons, which is lower than the minimum safety threshold of 12 tons.

[0046] In summary, the transportation of the 30C section has a clear risk of "underloading," and the axle lifting strategy of this invention must be implemented.

[0047] III. Calculation of the number of axes to be lifted (corresponding to step S4) Set the optimal single-axis net load P _opt =18 tons / axis (corresponding to a load percentage of 45%).

[0048] Calculate the target number of working axes: N _target =ceil(W / P _opt =ceil(310 / 18) =ceil(17.22)≈18 axis Theoretically, the number of shafts that need to be lifted is: M _theory =NN _target =24-18=6 axis lines The project team further optimized and calculated the load parameters under different lifting schemes: Taking into account transportation stability, safety margin, and ease of operation, the project team decided to adopt a four-axle lifting scheme. This scheme increases the net load per axle from 12.92 tons to 15.50 tons, an increase of 20%, with a load percentage of 50%, which is within the optimal working range of the modular vehicle (40%-80%).

[0049] IV. Select the axis to be lifted and perform the lifting operation (corresponding to step S5). As attached Figure 1 , 2 As shown in Figure 3, the modular vehicle is configured as follows: Left vehicle group: Modular car L1 (6 axles), modular car L2 (6 axles), rigidly connected in parallel. Right car group: Modular car R1 (6 axles), modular car R2 (6 axles), rigidly connected in parallel. The axle numbers from the front of the left train set to the end of the right train set are L1-1 to L1-6 (first train set), L2-1 to L2-6 (second train set), R1-1 to R1-6, and R2-1 to R2-6.

[0050] Route selection scheme (M=4, 2 axes suspended on each side): Left car group: Lift the middle L1-4 axle from the L1 module car; lift the middle L2-3 axle from the L2 module car. Figure 2 The red wheel in the middle is the wheel where the lifting axle is located. Right car group: Lift the middle R1-4 axle from the R1 module car; lift the middle R2-3 axle from the R2 module car.

[0051] This route selection scheme satisfies: Symmetrical left and right: Each of the left and right train sets lifts 2 axles. Symmetrical front and back: The lifting axis is distributed front and back of the center of gravity. Evenly distributed: Each modular vehicle lifts the two central axles. The control system sends commands to the hydraulic suspension cylinders on the corresponding axes, raising the tires on those axes approximately 50mm off the ground. During the lifting process, tilt sensors monitor the frame's attitude in real time. When a slight tilt is detected in the frame due to the lifting of part of the axes, the system automatically adjusts the suspension height of the remaining working axes to keep the frame level at all times.

[0052] Ultimately, the remaining 20 axes (10 on each side) were grounded for load bearing. Pressure sensor readings showed that the net load of each working axis was stable within the range of 14.5-16.5 tons, with an average of 15.5 tons, fully meeting safety requirements, and the force distribution was better than the 24-axis all-grounding scheme.

[0053] V. Transportation Execution and Results (Corresponding Step S6) After the axis lifting operation is completed, the modular vehicle carrying the 30C main section departs from the assembly site and proceeds along the predetermined route to the inclined slipway.

[0054] Transportation route parameters: Overall venue: Level road Transportation access road: paved surface, 45m wide The section with varying gradients at the inclined ship dock: successively passing through the second gradient section (1:22) and the first gradient section (1:40). Travel speed: ≤1km / h, monitored by dedicated personnel throughout the journey.

[0055] On gradient sections, the modular vehicle's electronic control system automatically adjusts the suspension height of each axle based on gradient sensor data to maintain a level chassis. With the single-axle load increased to 15.5 tons (a 20% increase over the original plan), tire traction is significantly enhanced. Drivers reported good grip and no signs of slippage or rolling back when driving and braking on 1:22 and 1:40 gradient slopes.

[0056] The pressure sensor monitoring data showed that the load fluctuation range of all working axes was within ±1.5 tons, and no underload or overload alarms were triggered.

[0057] Compared with the traditional transportation method that does not adopt the solution of this invention (all 24 axles are grounded, and the load on the side axles is only 9-10 tons), after adopting the "lifting 4 axles" solution of this invention: the average load on a single axle is increased by 20%; the tire adhesion is increased by about 20% (the coefficient of friction μ is proportional to the normal pressure); the working pressure of the hydraulic system enters the optimal range; and the transportation safety and equipment operating status are significantly improved.

[0058] Example 2: Underload Avoidance Control During the Transportation of Section 30E of an 8300t General Cargo Ship This embodiment describes another example of applying the method of the present invention in the transportation of the 30E main section.

[0059] I. Project Background Section 30E is located at the bow and consists of nine sections: 308, 309, 622, 632, 525, 535, 801, 804, and 805. Its external dimensions are 21.8m × 22.8m × 9.95m. The estimated total weight is W = 226 tons.

[0060] The same modular vehicle configuration as the 30C main section is adopted: 2 PPU + 4 6-axle modular vehicles, N=24 axles.

[0061] II. Identification of Underload Risk Calculate the average net load on a single axle: P _avg_net =226 tons / 24 axles = 9.42 tons / axle This value is significantly lower than the minimum safe net load threshold of 12 tons, a decrease of 21.5%, posing a serious risk of underloading. If all 24 axles are grounded during transport, not only will the load on the side axles be extremely low (estimated at only 6-7 tons), but the load on the central axle will also be below the safe threshold, resulting in severely insufficient tire adhesion and a very high risk of slippage on sloping sections. Therefore, the axle lifting strategy of this invention must be implemented.

[0062] III. Calculation of the number of shafts to be lifted Set the optimal single-axis net load P _opt =18 tons / axis.

[0063] Calculate the target number of working axes: N _target =ceil(226 / 18)=ceil(12.56)=13 axis Theoretically, the number of shafts that need to be lifted is: M _theory =24-13=11 axis Since 11 is an odd number, to ensure left-right symmetry, it is rounded up to M=12 for the axis. However, the project team further calculated different lifting schemes: Taking all factors into consideration: Lifting scheme with 8 axes: The remaining 16 axes will operate, with a net load of 14.13 tons per axis, representing a load percentage of 46.6%. Between the 10-axis lifting scheme and the 12-axis lifting scheme, the number of working axes is smaller, which increases the pressure on the ground. Under the condition of meeting the single-axis load value, the scheme with fewer lifting axes should be selected first.

[0064] After thorough evaluation, the project team decided to adopt an 8-axle lifting scheme (4 axes on each side). This scheme increases the net load per axle from 9.42 tons to 14.13 tons, an increase of 50%, with a load percentage of 46.6%, which is within the good working condition range of the modular vehicle. It also maintains a sufficient number of working axes, moderate ground pressure, and good transportation stability.

[0065] IV. Selecting the axis to be lifted As attached Figure 4 As shown, the route selection scheme (M=8, 4 axes suspended on each side): Left vehicle group: L1 module vehicle lifts L1-3 and L1-4 axles; L2 module vehicle lifts L2-1 and L2-4 axles; Right car group: R1 module car lifts the R1-3 and R1-4 axles; R2 module car lifts the R2-1 and R2-4 axles.

[0066] This route selection scheme satisfies: Symmetrical: Each of the left and right train sets lifts 4 axles. Evenly distributed: Each modular vehicle lifts the four central axles. Calculations show that the resultant force application point of the remaining 16 working axes deviates from the center of gravity of the 30E section by less than 2%, indicating a good stress state.

[0067] V. Transportation Implementation and Results After performing the 8-axis lifting operation, the modular vehicle transported the 30E main section. The pressure sensors showed that the net load of each working axis was stable in the range of 13.5-15.0 tons, with an average of 14.13 tons, which fully meets the minimum safe load requirements.

[0068] During transportation on the sloped section of the shipyard, the tire adhesion was greatly enhanced due to the increased single-axle load of 14.13 tons. The vehicle performed stably on the slope, with no signs of slippage or rollback.

[0069] Compared with the traditional transportation method (all 24 axles are grounded, and the load on a single axle is only 9.42 tons) that does not adopt the solution of this invention, the "lifting 8 axles" solution of this invention results in: an average load on a single axle increased by 50%; tire adhesion increased by about 50%; the load on each axle entered the safe range, completely eliminating the risk of underloading; 16 working axles were retained, the ground pressure was moderate, and the impact on the hardened road surface and the slipway structure was small; and the subsequent loading and positioning operations were successfully completed.

[0070] Example 3: Modular Vehicle Hydraulic Control System and Sensor Configuration This embodiment describes the hardware configuration of the control system for implementing the method of the present invention.

[0071] The system includes: (1) Central Controller (ECU): A PLC or embedded industrial computer is used as the core of the system for calculation and control. It receives data from various sensors, executes the calculation method of this invention, and issues instructions to the hydraulic system.

[0072] (2) Data acquisition module: Connected to the central controller, it allows input of parameters such as the estimated weight of the total section and the axle configuration via a touch screen or host computer. This module can also be connected to the weighbridge or the weighing system interface of the modular vehicle to realize automatic weighing data reading (pre-weighing verification function).

[0073] (3) Axis lifting planning module: Embedded in the central controller, it plans the lifting based on the input W, N and preset P. _min P _opt It automatically calculates the number M of axes that need to be lifted and, in conjunction with preset line selection rules (symmetry, centering, uniformity), generates specific axis lifting schemes, displaying the status (grounding / lifting) of each axis in a graphical interface.

[0074] (4) Hydraulic control module: This includes a hydraulic pump station, proportional control valve group, and control lines connected to the hydraulic suspension cylinders of each axis. The central controller sends PWM control signals to the proportional valves of the corresponding axes according to the axis lifting scheme, achieving precise tire lifting control (accuracy ±5mm). Simultaneously, it acquires real-time load data for each axis through pressure sensors, forming a closed-loop control system.

[0075] (5) Attitude monitoring module: including dual-axis tilt sensors (accuracy ±0.1°) mounted on the frame to monitor pitch and roll angles in real time. When the lifting axis causes the frame attitude change to exceed a preset threshold (e.g., ±0.5°), the central controller automatically calculates the compensation amount and adjusts the suspension height of the remaining working axis through the hydraulic control module to restore the frame to a horizontal position.

[0076] (6) Load monitoring module: Consists of pressure sensors on each axis, with a range of 0-60MPa and an accuracy of 0.5. It continuously monitors the actual load on the working axis during transportation. When the load on any axis exceeds the set threshold, it sends an alarm signal to the central controller.

[0077] (7) Alarm module: Receives alarm commands from the central controller and issues audible and visual alarms (red flashing + buzzer for overload, yellow flashing + intermittent buzzer for underload) to alert operators. Simultaneously, the central controller can automatically reduce vehicle speed or trigger emergency braking according to preset logic.

[0078] (8) Display module: A 10-inch industrial touch screen is used to display the load data (numerical value + bar chart) of each axis, the attitude of the frame (pitch angle / roll angle value + analog instrument), vehicle speed, direction of travel and other key information in real time for operators to monitor.

[0079] Running example (30C main segment): The operator inputs the following into the data acquisition module: total section weight 310 tons, number of axles 24. The system automatically calculates and displays: P _avg =12.92 tons, lower than P _min Boundary values ​​indicate that a lifting operation is recommended. The operator selects the "Automatic Optimization" mode. The axle lifting planning module automatically calculates the M=4 scheme and generates a route selection diagram. After operator confirmation, the system automatically executes: the hydraulic control module controls the lifting of four axles (L1-4, L2-3, R1-4, R2-3) 50mm off the ground. The attitude monitoring module displays a 0.3° change in the chassis pitch angle and a 0.1° change in the roll angle. The system automatically adjusts the suspension height of the remaining 20 axles to compensate, restoring the chassis to a level position. During transportation, the load monitoring module shows that the load on all working axles remains stable within the range of 14.5-16.5 tons, without triggering any alarms. The transportation task is successfully completed.

[0080] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways, characterized in that, Includes the following steps: S1. After completing the assembly and welding of the large ring section of the ship at the assembly site, obtain the estimated total weight W of the large ring section and the total number of available axles N of the modular vehicles involved in the transportation. S2, calculate single axis average load P _avg = W / N; S3. Determine the average load P of the single axis. _avg Is it less than the preset minimum safe load threshold P? _min The P _min The net load capacity of a single axle of the modular vehicle; S4. If P _avg <P _min Then, execute the axis lifting strategy: calculate the number M of axes to be lifted, such that M satisfies: W / (NM)≥P _min And W / (NM)≤P _max ,in P_max This refers to the rated maximum load capacity of a single axle of the modular vehicle. S5. Select M axes from the N available axes as the axes to be lifted, and control the hydraulic suspension system of the control module vehicle to lift the tires of the M axes off the ground so that they are off the ground and do not participate in the load-bearing. S6. While maintaining the overall stability of the modular vehicle frame platform, the remaining NM axis lines are used to support the large ring segment, and the segment is transported from the assembly site to the inclined platform for mounting and positioning along a predetermined transportation path.

2. The method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, In step S3, the preset minimum safe load threshold P _min Specifically, the net load capacity of a single axle is 12 tons, or the total load capacity of a single axle is 16.5 tons; the total load capacity of a single axle includes the self-weight of the module vehicle body corresponding to the axle.

3. The method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, In step S4, the method for determining the number M of shafts to be lifted is as follows: calculate the target number of working shafts N. _target =ceil(W / P _opt ), where P _opt The preset optimal single-axis load value, and P _min ≤ P_opt ≤P _max Then M = NN _target If the calculated result M is odd, it is rounded up to an even number to ensure that the number of axes lifted by the module vehicles on the left and right sides is symmetrical.

4. The method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, The optimal single-axis load value P _opt The setting is to keep the load percentage of each axis in the range of 40% to 80%.

5. The method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, In step S5, the specific method for selecting the axle to be lifted is as follows: the modular vehicles involved in the transportation are divided into left and right groups, and the number of axles lifted by the left and right groups is equal; within each group, the axle is selected from the middle area first, so that the remaining working axles are symmetrically distributed before and after the center of gravity of the large ring section; when multiple modular vehicles are rigidly connected in parallel on one side, the number of axles lifted on each modular vehicle is the same, and the lifting positions are symmetrically distributed in the middle on that modular vehicle.

6. The method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, In step S6, maintaining the overall stability of the modular vehicle frame platform specifically includes: during the process of lifting part of the axis, the pitch angle and roll angle of the frame platform are monitored in real time by tilt sensors; when the change in the frame attitude is detected to exceed a preset threshold, the hydraulic suspension height on the unlifted axis is automatically adjusted to restore the frame platform to a horizontal state, ensuring that the large ring section does not undergo structural deformation during transportation.

7. The method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, In step S6, the transportation route includes a passage from the main assembly site to the inclined platform, which includes a horizontal section and a variable-slope section of the inclined platform. When the modular vehicle travels on the variable-slope section, the electronic control system on the modular vehicle automatically adjusts the lifting height of each working axis according to the real-time slope.

8. A method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, It also includes a pre-weighing verification step: before performing the axle lifting operation, the actual weight of the large ring section is measured using the weighing system on the modular vehicle to obtain the actual total weight W. _actual If |W _actual -W| / W>5%, then based on W _actual Recalculate the number of axes M that need to be lifted to ensure that the lifting plan matches the actual weight.

9. A method for underload avoidance transportation control of large circular section modular vehicles on inclined slipways according to claim 1, characterized in that, It also includes a transportation monitoring step: during transportation, the actual load on each working axis is monitored in real time using pressure sensors installed on each axis; if the actual load on a certain axis exceeds P... _max If the actual load on a certain axis is lower than P, an overload alarm will be issued and transportation will be suspended; _min If the load is not cleared, an underload alarm will be issued and the operator will be prompted to check; transportation can only continue after the alarm is cleared.

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