Soft soil foundation shallow solidification system and construction method
By combining BeiDou positioning and intelligent control system, precise positioning and uniform mixing of sludge solidification construction are achieved, solving the problem of difficult quality control, improving construction efficiency and quality, and reducing dependence on operators.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CCCC ROAD & BRIDGE SPECIAL ENG
- Filing Date
- 2025-12-26
- Publication Date
- 2026-05-12
Smart Images
Figure CN122013750A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of geotechnical engineering and foundation treatment technology. More specifically, this invention relates to a shallow solidification system and construction method for soft soil foundations. Background Technology
[0002] Silt solidification technology is increasingly used to treat shallow, soft soil foundations such as silt. A pre-prepared solidifying agent solution is injected into the silt via grouting pumps and pipelines, and then continuously stirred by an excavator equipped with a powerful mixing head. This mixing and reaction of the silt and solidifying agent increases soil strength and improves the foundation's bearing capacity. Compared to conventional excavation and replacement methods, this technology is both economical and efficient.
[0003] However, the existing sludge solidification treatment methods are inconsistent in quality and greatly affected by the operators' work. Existing testing shows significant issues such as incomplete mixing, excessive mixing, and uneven mixing at the construction site. During the operation, workers inevitably experience visual and mental fatigue due to prolonged repetitive actions, resulting in insufficient solidification depth, unmixed areas creating blank work zones, excessive grouting in areas with long dwell times, and insufficient grouting in areas with short dwell times, severely impacting construction quality. This also makes quality control difficult and standardized construction impossible. Soft soil foundation treatment is a hidden project, and sludge solidification requires time to develop strength, making real-time quality inspection impossible. If quality inspection fails, rework is difficult and severely impacts the construction schedule. Summary of the Invention
[0004] The purpose of this invention is to provide a shallow solidification system and construction method for soft soil foundations. By utilizing the BeiDou positioning system and intelligent control system in synergy, and through precise positioning and grid management of the three-dimensional coordinates of the construction site, as well as unmanned automated control of the excavator, the excavator can complete the prescribed actions along a preset path. This enables quantitative spraying and timed mixing of the solidifying agent within each grid unit of the construction area, ensuring the stability of the solidification material and the uniformity of mixing. This achieves standardized construction of shallow solidification for soft soil foundations, ensuring both construction quality and improving construction efficiency.
[0005] The technical solution adopted by the present invention to solve this technical problem is: a shallow solidification system for soft soil foundation, comprising: a management platform, an intelligent excavator, a grouting unit, and a positioning and communication unit; The management platform is used to generate a three-dimensional coordinate grid covering the construction site and an automated construction path for the intelligent excavator based on the boundary data of the construction site, the mechanical parameters of the excavator and the mixing head, and the target curing depth. The intelligent excavator includes an excavator body, a mixing head mounted on the excavator body, a sensor group for sensing the spatial position and attitude of the mixing head, and a motion control module for receiving instructions from the management platform. The grouting unit is used to deliver a curing agent slurry prepared according to a preset ratio to the mixing head; The positioning and communication unit includes a Beidou positioning module and a 5G communication module, which are used to realize the real-time accurate positioning of the intelligent excavator and establish a data communication link between the management platform and the intelligent excavator. The system is configured such that the management platform controls the intelligent excavator through the positioning and communication unit, causing it to move according to the automated construction path, and controls the mixing head to perform quantitative spraying and timed mixing operations at designated grid points on the three-dimensional coordinate grid.
[0006] As a further aspect of the present invention, the sensor group includes at least one of the following: a Beidou receiver, an angle sensor installed on the boom and arm of an excavator, an angle sensor installed on the mixing head, a lidar, and a high-definition camera.
[0007] As a further aspect of the present invention, the three-dimensional coordinate grid includes a longitudinal large grid divided by a longitudinal large grid spacing L, and longitudinal small grids and transverse small grids determined by the length and width (l, b) of the mixing head within each longitudinal large grid; the automated construction path is a sequential path of construction point by point along the center line of the transverse small grid, and after completing one transverse small grid line, moving longitudinally to the next transverse small grid line to continue construction. When moving laterally and longitudinally to an adjacent construction position, the system controls the moving distance of the mixing head to be (b - s) or (l - s), where s is the preset overlap width of adjacent curing areas.
[0008] As a further aspect of the present invention, the management platform is also used to determine the amount of solidifying material added per unit volume of sludge. Content of curing material per unit volume of slurry The construction time t at a single point and the volume parameters of the gridded construction are used to calculate and control the spraying speed of the mixing head at a single point.
[0009] As a further aspect of the present invention, the grouting unit includes a curing agent storage tank, a screw conveyor, a fully automatic grouting machine, a grouting pump, and a grout pipe connected in sequence, and the grout pipe is connected to the stirring head.
[0010] As a further aspect of the present invention, the system is configured to control the construction action of the mixing head at a single grid point as follows: maintaining a vertical posture, sinking at a uniform speed to the target curing depth, and then lifting at a uniform speed to the ground, and this sinking and lifting cycle is performed multiple times.
[0011] The present invention also provides a method for shallow solidification construction of soft soil foundation using the system, comprising the following steps: S1. Site Measurement and Modeling: Use Beidou RTK to measure the boundary of the construction site, and input the boundary data, mechanical parameters of the excavator and mixing head, and target solidification depth into the management platform. The management platform will then generate a three-dimensional coordinate grid and an automated construction path. S2. Equipment positioning and initialization: Move the intelligent excavator to the initial construction position, install the mixing head, and connect the grouting unit; S3. Grid-based unmanned construction: The management platform controls the intelligent excavator through the positioning and communication unit, so that it moves according to the automated construction path and arrives at each grid point in sequence; at each point, the mixing head is controlled to maintain a vertical posture, perform quantitative grouting and execute sinking and lifting mixing actions; S4. Area overlap and continuous construction: After completing the construction of the current longitudinal large grid area, use the solidified area as a construction platform, control the intelligent excavator to move to the next adjacent longitudinal large grid area, repeat step S3, until the construction of the entire site is completed.
[0012] As a further aspect of the present invention, in step S1, the mechanical parameters include at least the length and width (l, b) of the mixing head, and the division of the three-dimensional coordinate grid is based on the longitudinal large grid spacing L determined by the excavator boom extension, and the longitudinal small grid spacing and the transverse small grid spacing determined by the length and width (l, b) of the mixing head.
[0013] As a further aspect of the present invention, in step S3, the velocity v of the quantitative spraying is calculated using the following formula: Where h is the target curing depth. The amount of solidifying material added per unit volume of sludge. t represents the content of solidifying material in a unit volume of grout, and t is the time required for the excavator to complete construction at one point. The sinking and lifting mixing action includes: controlling the mixing head to sink from the ground at a uniform speed to the designed curing depth, and then lifting it back to the ground at the same speed. This process is repeated 2 to 5 times. When moving between adjacent points in the horizontal direction, the moving distance is (b - s), where s is the horizontal overlap width; when moving to the next horizontal grid line after completing one horizontal small grid line in the vertical direction, the moving distance is (l - s), where s is the vertical overlap width. The horizontal overlap width and the vertical overlap width are the same, and s is not less than 10cm.
[0014] As a further aspect of the present invention, during the sinking and lifting of the stirring head in step S3, the management platform constructs and executes an integrated attitude dynamic stabilization control strategy, specifically including: a) Real-time status monitoring: Continuously receive data from the tilt sensor installed on the stirring head, and estimate the angular velocity of the stirring head in real time by calculating the tilt change rate. The tilt angle and angular velocity together constitute the real-time status feedback quantity for attitude closed-loop control. b) Feedforward compensation: Based on the preset excavator kinematics model, according to the real-time motion parameters of the boom and arm, the attitude change of the mixing head caused by its motion is predicted in advance, and feedforward control commands are generated to the excavator motion control module to actively counteract its influence before the attitude change occurs.
[0015] This invention offers at least the following beneficial effects: By introducing an intelligent control system based on BeiDou high-precision positioning and 5G communication, it transforms the traditional construction mode, which relies on manual experience and judgment, into a standardized process driven by data and executed automatically. This system ensures precise positioning and vertical operation of the mixing head on a preset three-dimensional grid, and achieves quantitative and timed spraying of the curing agent slurry, fundamentally eliminating issues such as missed mixing, re-mixing, and uneven mixing. The direct result is a significant improvement in the overall uniformity and bearing capacity reliability of the foundation solidification treatment. Simultaneously, unmanned automated construction greatly reduces reliance on skilled operators, minimizing quality fluctuations and safety risks caused by personnel fatigue, and significantly improving construction efficiency. Furthermore, the digital recording of the entire process provides traceable data for construction quality, greatly facilitating project management and post-assessment, and offering a practical solution for the intelligent and standardized upgrading of soft soil foundation treatment.
[0016] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description
[0017] Figure 1 is a schematic diagram of the composition of the shallow solidification system for soft soil foundation of the present invention; Figure 2 is a schematic diagram of the system unit area coverage of the present invention; Figure 3 is a front view of the mechanical parameters of the stirring head used in the system of the present invention; Figure 4 is a side view of the mechanical parameters of the stirring head used in the system of the present invention; Figure 5 is a schematic diagram of the construction sequence of the present invention; Figure 6 is a schematic diagram of the overlapping of the curing construction area of the present invention; Figure 7 is a schematic diagram of the excavator's body posture and automatic movement during the construction process of the present invention.
[0018] Among them, 1-management platform, 2-positioning and communication unit, 3-intelligent excavator, 4-curing agent storage tank, 5-screw conveyor, 6-fully automatic pulping machine, 7-slurry pipe, 8-grouting pump. Detailed Implementation
[0019] The present invention will now be described in detail and completely with reference to the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be particularly noted that the technical solutions and features provided in various parts of the present invention, including the following description, can be combined with each other without conflict.
[0020] Furthermore, the embodiments of the present invention described below are generally only some, not all, of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.
[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The specific implementation process is as follows: like Figures 1-7As shown, this invention provides a shallow solidification system for soft soil foundations, comprising: a management platform 1, an intelligent excavator 3, a grouting unit, and a positioning and communication unit 2; the management platform 1 is used to generate a three-dimensional coordinate grid covering the construction site and an automated construction path for the intelligent excavator 3 based on the boundary data of the construction site, the mechanical parameters of the excavator and the mixing head, and the target solidification depth; the intelligent excavator 3 includes an excavator body, a mixing head mounted on the excavator body, a sensor group for sensing the spatial position and attitude of the mixing head, and a motion control module for receiving commands from the management platform 1; The grouting unit is used to deliver the curing agent slurry prepared according to a preset ratio to the mixing head; the positioning and communication unit 2 includes a Beidou positioning module and a 5G communication module, used to realize the real-time precise positioning of the intelligent excavator 3 and establish a data communication link between the management platform 1 and the intelligent excavator 3; wherein, the system is configured such that: the management platform 1 controls the intelligent excavator 3 through the positioning and communication unit 2, so that it moves according to the automated construction path, and controls the mixing head to perform quantitative grouting and timed mixing operations at the specified grid points of the three-dimensional coordinate grid.
[0022] Before construction begins, technicians operate surveying instruments equipped with Beidou RTK positioning devices to precisely map the soft soil foundation site to be treated, determining the precise boundaries of the construction area. This boundary data is uploaded to the system's remote management platform 1. Simultaneously, the mechanical parameters of the specific excavator model used in the construction, such as its boom span and swing radius, as well as the specific length and width dimensions of the mixing head, are also input into the management platform 1. Based on these input site and mechanical data, the management platform 1 software automatically plans a finely divided three-dimensional coordinate grid covering the entire construction area on a digitized construction area map. This grid not only defines each precise point requiring mixing but also plans the optimal sequence and path for the excavator to move from one point to the next, forming a complete automated construction route.
[0023] During construction, the equipment on site works in concert. The intelligent excavator 3 serves as the execution terminal for automated tasks. It has been modified to include a high-precision Beidou positioning receiver, tilt sensors for sensing the angles of the boom and arm, and another set of tilt sensors directly mounted on the mixing head. These sensors form the nerve endings that sense the spatial position and real-time attitude of the mixing head. The excavator's own hydraulic and electronic control systems integrate a dedicated motion control module capable of receiving and executing commands from a distance. Simultaneously, an independent grouting unit is located at the edge of the site. This unit includes a silo storing powdered hardener, automatic weighing and conveying equipment, a fully automatic slurry mixer 6 that mixes the hardener and water in a preset ratio to form a slurry, and a high-pressure grouting pump 8 responsible for conveying the slurry. The slurry is continuously delivered to the mixing head on the excavator through pipelines.
[0024] The management platform 1 maintains real-time two-way communication with the intelligent excavator 3 on-site via a wireless communication network. Construction commands are issued from the platform, and the excavator's positioning and attitude data are transmitted back in real time. Based on the pre-calculated construction path, the platform issues movement commands to the excavator. The excavator then automatically travels to the first designated grid point. Upon arrival, the platform comprehensively processes BeiDou positioning data and data from various tilt sensors on the excavator body to calculate precise adjustment commands, guiding the excavator's motion control module to operate the boom and arm, ensuring the mixing head is precisely aligned with the center of the point and adjusted to a strictly vertical position. Next, the platform issues commands to the grouting unit to initiate quantitative grouting, while simultaneously controlling the excavator to allow the mixing head to begin drilling into the ground at a constant speed until the preset solidification depth is reached, and then it is lifted back to the surface at the same speed. This sinking and lifting mixing process can be repeated several times according to the design. After the work at one point is completed, the platform directs the excavator to automatically move to the next grid point. The distance traveled is precisely calculated to ensure sufficient overlap between adjacent mixing areas, thus preventing missed mixing. This cycle continues until the construction of the entire area is completed.
[0025] In another technical solution, the sensor group includes at least one of the following: a Beidou receiver, tilt sensors mounted on the excavator's boom and forearm, a tilt sensor mounted on the mixing head, a lidar, and a high-definition camera. A Beidou satellite positioning receiver is installed on the top of the excavator's cab to continuously report the excavator's horizontal position. High-precision tilt sensors are installed at key joints of the excavator's boom and forearm to detect every minute pitch change of the boom in real time. A dedicated tilt sensor is also securely installed on the mixing head body, which is deep underground and in direct contact with the silt. This sensor directly measures the tilt angle of the mixing head itself, providing the most direct evidence of whether it remains vertical. Furthermore, depending on requirements, a lidar can be added to the excavator to scan the surrounding terrain, or a high-definition camera can be configured to assist in monitoring the overall site conditions. All the data collected by these sensors is transmitted in real time and continuously to a remote system management platform 1 via a wireless network through a built-in data acquisition module. The platform fuses and calculates fragmented information from different sources (such as location and multiple angles) to accurately reproduce the real-time position and precise posture of the mixing head in three-dimensional space on the background screen. This invention completely eliminates the blind spots in the construction process through this multi-dimensional direct sensing, providing an unreliable sensing basis for subsequent automated and precise control.
[0026] In another technical solution, the three-dimensional coordinate grid includes a longitudinal large grid divided by a longitudinal large grid spacing L, and longitudinal small grids and transverse small grids determined by the length and width (l, b) of the mixing head within each longitudinal large grid; the automated construction path is a sequential path of construction point by point along the center line of the transverse small grid, and after completing one transverse small grid line, moving longitudinally to the next transverse small grid line to continue construction. When moving laterally and longitudinally to adjacent construction positions, the system controls the movement distance of the mixing head to be (b - s) or (l - s), where s is the preset overlap width of adjacent solidification areas. It should be noted that the horizontal and vertical small grids are virtual two-dimensional coordinate grids divided on the construction site plane by the management platform 1 before construction, based on the mixing head size and overlap requirements. The mixing point is the intersection of the center lines of the horizontal and vertical small grids; this intersection is used to precisely locate the center position of each mixing point. The solidification area refers to the actual area of soil affected and reinforced after a complete sinking-lifting mixing operation at a single mixing point (such as points 1# and 2#). It is a three-dimensional area, which can be approximated as a cuboid with length × width × depth centered on the mixing head. Its planar dimensions (length and width) are determined by the mechanical dimensions of the mixing head itself.
[0027] In another technical solution, the management platform 1 is also used to determine the amount of solidifying material added per unit volume of sludge. Content of curing material per unit volume of slurry The system calculates and controls the grouting speed of the mixing head at a single point by considering the construction time (t) at a single location and the volume parameters of the gridded construction. This embodiment elevates the grouting process to a precise dosage control based on model calculations. During the design phase before construction begins, technicians determine the required mass of solidifying material per unit volume of sludge and the content of solidifying material in the grout mix through indoor experiments. These key parameters, along with the mixing head size and designed solidification depth, are input into the management platform 1. When the system performs mixing construction at a single point, the management platform 1 no longer issues a simple binary command to start the pump. Instead, it calculates a precise theoretical grouting flow rate in real time based on the volume of soil covered by the mixing head in one operation, the designed dosage of solidifying agent, the grout concentration, and the planned total time to complete mixing at that point. This calculated value is converted into a precise speed control command for the variable grouting pump 8. During the grouting process, the system is not simply set and then ignored; instead, it monitors the actual operating status of the pump in real time to ensure that its output stably follows the theoretical value. By correlating the amount of grout sprayed with the soil volume and construction time at that point, this invention ensures that the amount of solidifying material received in each standard grid cell is strictly in accordance with the design, thereby guaranteeing the uniformity of the spatial distribution of the solidifying material from the source and providing a guarantee for the formation of a foundation with consistent strength.
[0028] In another technical solution, the grouting unit includes a curing agent storage tank 4, a screw conveyor 5, a fully automatic grouting machine 6, a grouting pump 8, and a grout pipe 7 connected in sequence. The grout pipe 7 is connected to the mixing head. The system begins with a large curing agent powder storage tank, from which the powder is stably and quantitatively conveyed to the next stage via the screw conveyor 5 at its bottom. The powder is fed into a fully automatic grouting machine 6, while a predetermined amount of water is simultaneously injected through a water pipe. Inside the grouting machine, the powder and water are thoroughly and uniformly mixed according to a preset water-to-solid ratio using mechanical stirring or high-speed jet stirring to form a homogeneous and stable grout. The prepared grout is immediately injected into the grouting pump 8, which is connected to the outlet of the grouting machine. The entire process, from powder discharge to grout spraying, is carried out in closed pipelines and equipment, achieving unmanned operation and centralized control. This continuous supply chain ensures that the grout supplied to the mixing head is always accurately proportioned, uniformly mixed, and stably supplied, providing a reliable guarantee for precise front-end construction and making long-term automated continuous operation possible.
[0029] In another technical solution, the system is configured to control the construction action of the mixing head at a single grid point as follows: maintaining a vertical posture, sinking at a uniform speed to the target curing depth, and then lifting at a uniform speed to the ground, and this sinking and lifting cycle is performed multiple times.
[0030] This embodiment also provides a method for shallow solidification construction of soft soil foundation using the system, including the following steps: S1. Site Measurement and Modeling: Use Beidou RTK to measure the boundary of the construction site, and input the boundary data, mechanical parameters of the excavator and mixing head, and target solidification depth into management platform 1. Management platform 1 will then generate a three-dimensional coordinate grid and an automated construction path. S2. Equipment positioning and initialization: Move the intelligent excavator 3 to the initial construction position, install the mixing head, and connect the grouting unit; S3. Grid-based unmanned construction: The management platform 1 controls the intelligent excavator 3 through the positioning and communication unit 2, so that it moves according to the automated construction path and arrives at each grid point in sequence; at each point, the mixing head is controlled to maintain a vertical posture, perform quantitative grouting and execute sinking and lifting mixing actions; S4. Area overlap and continuous construction: After completing the construction of the current longitudinal large grid area, use the solidified area as a construction platform, control the intelligent excavator 3 to move to the next adjacent longitudinal large grid area, repeat step S3, until the construction of the entire site is completed.
[0031] In another technical solution, in step S1, the mechanical parameters include at least the length and width (l, b) of the mixing head. The division of the three-dimensional coordinate grid is based on the longitudinal large grid spacing L determined by the excavator boom span, and the longitudinal small grid spacing and transverse small grid spacing determined by the length and width (l, b) of the mixing head. Before the management platform 1 performs the critical grid division and path generation calculations, the specific mechanical parameters of the excavator and mixing tool, which are the main execution entities, must be used as core input conditions. These parameters include at least the dimensions of the mixing head body, i.e., its effective length and width for cutting soil. Simultaneously, the farthest and nearest working boundaries that the mixing head can reach when the excavator's boom and arm are fully extended at the current position are also crucial in determining the rationality of the planning. The platform software uses the dimensions of the mixing head as the basic unit to determine the spacing of the longitudinal and transverse small grids that constitute the fine texture of the construction surface. At the same time, based on the effective boom span of the excavator, the spacing of the longitudinal large grids that facilitate equipment movement and relocation is determined. The resulting grid system has small grid units that match the actual working range of the mixing head, ensuring no blind spots in coverage; its large grid division is perfectly adapted to the working radius of the excavator, so that after the equipment completes all the work in a large grid, it only needs to move its position once to start the efficient construction of the next grid. This ensures that the generated automated construction path is not only optimal, but also executable and efficient.
[0032] In another technical solution, in step S3, the velocity v of the quantitative spraying is calculated using the following formula: Where h is the target curing depth. The amount of solidifying material added per unit volume of sludge. t represents the content of solidifying material in a unit volume of slurry, and t represents the time required for the excavator to complete construction at one point. The sinking and lifting mixing action includes: controlling the mixing head to sink uniformly from the ground to the designed solidification depth, and then lifting it uniformly back to the ground at the same speed. This process is repeated 2 to 5 times, preferably 3 times. When moving between adjacent points laterally, the moving distance is (b - s), where s is the lateral overlap width; when moving to the next lateral grid line after completing one lateral small grid line longitudinally, the moving distance is (l - s), where s is the longitudinal overlap width. The lateral overlap width and the longitudinal overlap width are the same, and s is not less than 10cm. In this embodiment, for slurry control, the system uses a clear formula to link five key variables: the size of the mixing head, the designed depth, the amount of solidifying agent, the slurry concentration, and the planned single-point operation time, dynamically calculating the precise slurry flow rate required for the current point, and controlling the pump operation accordingly. Regarding the mixing action, it clearly defines uniform sinking-uniform lifting as a standard cycle, and specifies the number of cycles as a pre-set, fixed, small-range value, completely eliminating arbitrariness. For the equipment's movement step length, it stipulates a clear calculation logic: the lateral movement distance equals the mixing head width minus a fixed overlap width; the longitudinal movement distance equals the mixing head length minus the same overlap width. This overlap width is explicitly limited to a specific value of no less than ten centimeters, ensuring that adjacent mixing zones are both tightly connected and do not excessively overlap. These specific parameters and calculation rules are transformed into control benchmarks for each specific action of the construction equipment, thereby fundamentally preventing the possibility of quality fluctuations caused by ambiguous operating parameters.
[0033] In another technical solution, during the sinking and lifting of the stirring head in step S3, the management platform 1 constructs and executes an integrated attitude dynamic stabilization control strategy, specifically including: a) Real-time Status Monitoring: The system continuously receives data from the tilt sensor mounted on the stirring head and estimates the angular velocity of the stirring head in real time by calculating the tilt angle change rate. The tilt angle and angular velocity together constitute the real-time status feedback quantity for attitude closed-loop control. In this embodiment, the angular velocity is the rate of change of angle, which can be estimated by differentiating the change of tilt angle measured by the tilt sensor over time. Specifically, the real-time tilt angle data output by the tilt sensor can be used to calculate its difference relative to time to obtain an approximate value of the angular velocity. Considering that the sensor data may be noisy, appropriate filtering or smoothing can be used, such as using a low-pass filter or a Kalman filter, to improve the accuracy of the estimation.
[0034] b) Feedforward Compensation: Based on a pre-set excavator kinematic model, and according to the real-time motion parameters of the boom and arm, the system proactively predicts the changes in the mixer head's attitude caused by their movement, and generates feedforward control commands to the excavator's motion control module to actively counteract the effects of these attitude changes before they occur. Specifically: A kinematic model of the excavator is established, treating the boom and arm as two rigid connecting rods, with the mixing head fixed at the end of the arm. A kinematic chain from the excavator's rotation center to the end of the mixing head is established using the boom length L1, arm length L2, and joint hinge point positions.
[0035] Real-time motion parameters are obtained: The swing angle of the upper arm is acquired in real time through tilt sensors installed at the joints of the upper arm and forearm. and the swing angle of the forearm And the angular velocity is obtained by calculating its rate of change.
[0036] Calculate the end-effector disturbances, including positional and tilt disturbances. The positional disturbance is determined geometrically; the position (x, y) of the stirring head end can be expressed as... and The function. When or Minor changes At that time, the expected change in end position can be calculated by differentiating the kinematic equations. .
[0037] In tilt disturbances, if the agitator head is rigidly installed, its tilt angle is usually directly related to the forearm's posture. Therefore, changes in the forearm angle... This will directly lead to the expected change in the tilt angle of the stirring head. Simultaneously, the movement of the boom... It can also affect the spatial orientation of the stirring head through geometric coupling, thereby affecting its tilt angle relative to the vertical direction.
[0038] Feedforward commands are generated, converting the calculated expected attitude changes into compensation commands for the excavator's motion control module. For example, to counteract the forward tilt of the mixing head caused by the lowering of the boom, the boom cylinder can be instructed in advance to make fine adjustments to keep the mixing head vertical.
[0039] The above implementation constructs an integrated attitude stabilization control method that combines forward prediction and real-time correction. The system not only continuously reads real-time angle data from the tilt sensor mounted on the mixing head, but also estimates the angular velocity at which the mixing head is tilting or returning to center by analyzing the trend of these angle data over time. This combination of angle and angular velocity constitutes a precise profile of the mixing head's current motion state, serving as the core feedback basis for fine-tuning the system. A precise kinematic model of the excavator is pre-embedded within the system. While the mixing head is operating, the system monitors the motion parameters of the excavator's boom and forearm in real time, such as their swing angle and speed. Using this boom motion data, the system can immediately calculate, through the built-in model, the angle and direction of the boom's lowering action or the forearm's retraction action's impact on the mixing head's attitude in the next instant. Based on this calculated prediction, the system immediately generates a corresponding feedforward compensation command in the opposite direction and sends it in advance to the excavator's motion control module. The purpose of this instruction is to command the excavator's hydraulic system to make a subtle, pre-emptive adjustment so that the disturbance force caused by the movement of the boom or arm is precisely canceled out when it actually acts on the mixing head.
[0040] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.
Claims
1. A shallow solidification system for soft soil foundations, characterized in that, include: Management platform, intelligent excavator, grouting unit, and positioning and communication unit; The management platform is used to generate a three-dimensional coordinate grid covering the construction site and an automated construction path for the intelligent excavator based on the boundary data of the construction site, the mechanical parameters of the excavator and the mixing head, and the target curing depth. The intelligent excavator includes an excavator body, a mixing head mounted on the excavator body, a sensor group for sensing the spatial position and attitude of the mixing head, and a motion control module for receiving instructions from the management platform. The grouting unit is used to deliver a curing agent slurry prepared according to a preset ratio to the mixing head; The positioning and communication unit includes a Beidou positioning module and a 5G communication module, which are used to realize the real-time accurate positioning of the intelligent excavator and establish a data communication link between the management platform and the intelligent excavator. The system is configured such that the management platform controls the intelligent excavator through the positioning and communication unit, causing it to move according to the automated construction path, and controls the mixing head to perform quantitative spraying and timed mixing operations at designated grid points on the three-dimensional coordinate grid.
2. The shallow solidification system for soft soil foundations as described in claim 1, characterized in that, The sensor group includes at least one of the following: a Beidou receiver, tilt sensors mounted on the excavator boom and arm, tilt sensors mounted on the mixing head, a lidar, and a high-definition camera.
3. The shallow solidification system for soft soil foundations as described in claim 1, characterized in that, The three-dimensional coordinate grid includes a longitudinal large grid divided by a longitudinal large grid spacing L, and longitudinal small grids and transverse small grids determined by the length and width (l, b) of the mixing head within each longitudinal large grid; the automated construction path is a sequential path that constructs point by point along the center line of the transverse small grid, and after completing one transverse small grid line, moves longitudinally to the next transverse small grid line to continue construction. When moving laterally and longitudinally to an adjacent construction position, the system controls the moving distance of the mixing head to be (b - s) or (l - s), where s is the preset overlap width of adjacent curing areas.
4. The shallow solidification system for soft soil foundations as described in claim 1, characterized in that, The management platform is also used to determine the amount of solidification material to be added per unit volume of sludge. Content of curing material per unit volume of slurry The construction time t at a single point and the volume parameters of the gridded construction are used to calculate and control the spraying speed of the mixing head at a single point.
5. The shallow solidification system for soft soil foundations as described in claim 1, characterized in that, The grouting unit includes a curing agent storage tank, a screw conveyor, a fully automatic grouting machine, a grouting pump, and a grout pipe connected in sequence, with the grout pipe connected to the stirring head.
6. The shallow solidification system for soft soil foundations as described in any one of claims 1 to 5, characterized in that, The system is configured to control the construction action of the mixing head at a single grid point as follows: maintaining a vertical posture, sinking at a uniform speed to the target curing depth, and then lifting at a uniform speed to the ground, and this sinking and lifting cycle is performed multiple times.
7. The method for shallow solidification construction of soft soil foundation according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Site Measurement and Modeling: Use Beidou RTK to measure the boundary of the construction site, and input the boundary data, mechanical parameters of the excavator and mixing head, and target solidification depth into the management platform. The management platform will then generate a three-dimensional coordinate grid and an automated construction path. S2. Equipment positioning and initialization: Move the intelligent excavator to the initial construction position, install the mixing head, and connect the grouting unit; S3. Grid-based unmanned construction: The management platform controls the intelligent excavator through the positioning and communication unit, so that it moves according to the automated construction path and arrives at each grid point in sequence; at each point, the mixing head is controlled to maintain a vertical posture, perform quantitative grouting and execute sinking and lifting mixing actions; S4. Area overlap and continuous construction: After completing the construction of the current longitudinal large grid area, use the solidified area as a construction platform, control the intelligent excavator to move to the next adjacent longitudinal large grid area, repeat step S3, until the construction of the entire site is completed.
8. The construction method as described in claim 7, characterized in that, In step S1, the mechanical parameters include at least the length and width (l, b) of the mixing head, and the division of the three-dimensional coordinate grid is based on the longitudinal large grid spacing L determined by the excavator boom extension, and the longitudinal small grid spacing and the transverse small grid spacing determined by the length and width (l, b) of the mixing head.
9. The construction method as described in claim 8, characterized in that, In step S3, the velocity v of the quantitative spraying is calculated using the following formula: Where h is the target curing depth. The amount of solidifying material added per unit volume of sludge. t represents the content of solidifying material in a unit volume of grout, and t is the time required for the excavator to complete construction at one point. The sinking and lifting mixing action includes: controlling the mixing head to sink from the ground at a uniform speed to the designed curing depth, and then lifting it back to the ground at the same speed. This process is repeated 2 to 5 times. When moving between adjacent points in the horizontal direction, the moving distance is (b - s), where s is the horizontal overlap width; when moving to the next horizontal grid line after completing one horizontal small grid line in the vertical direction, the moving distance is (l - s), where s is the vertical overlap width. The horizontal overlap width and the vertical overlap width are the same, and s is not less than 10cm.
10. The construction method as described in claim 7, characterized in that, During the sinking and lifting of the stirring head in step S3, the management platform constructs and executes an integrated attitude dynamic stabilization control strategy, specifically including: a) Real-time status monitoring: Continuously receive data from the tilt sensor installed on the stirring head, and estimate the angular velocity of the stirring head in real time by calculating the tilt change rate. The tilt angle and angular velocity together constitute the real-time status feedback quantity for attitude closed-loop control. b) Feedforward compensation: Based on the preset excavator kinematics model, according to the real-time motion parameters of the boom and arm, the attitude change of the mixing head caused by its motion is predicted in advance, and feedforward control commands are generated to the excavator motion control module to actively counteract its influence before the attitude change occurs.