Multi-sensor fusion type lifting air bag system capable of automatically regulating pressure

Abstract

The invention provides a multi-sensor fusion type lifting air bag system capable of automatically adjusting pressure, and relates to the technical field of underwater operation. The lifting air bag system comprises an air bag immersed in water, a pressure sensor (capable of detecting the absolute pressure in the air bag in real time) is arranged in the air bag, a lifting structure used for lifting a heavy object is arranged on the air bag, a depth sensor (capable of detecting the absolute depth of the heavy object underwater in real time) is arranged on the lifting structure, and the air bag lifts together with the heavy object when inflated. When the air bag is closed, the internal pressure is not changed, and the air bag with the heavy object is suspended in water. The synchronous ascending / descending speed of the air bag and the heavy object can be dynamically regulated and controlled according to the absolute pressure and the absolute depth, so that the air bag with the heavy object stably and accurately ascends / descends to the target position and hovers, overshoot of a traditional scheme is avoided, reliability is high, dependence on manual judgment and operation is avoided, the response speed is high, and the safety is high. And the control efficiency of underwater weight lifting can be improved.

Description

Technical Field

[0001] This application relates to the field of underwater operation technology, and in particular to a multi-sensor fusion lifting airbag system with automatic pressure adjustment. Background Technology

[0002] In related technologies, there are many ways to implement underwater heavy objects (such as aquaculture cages, underwater operation machinery, etc.) lifting (including surfacing, diving and suspending) systems. For example, winches can directly pull up / lower heavy objects by winding and unwinding cables; airbags can adjust their buoyancy by inflating and deflating air; and mechanical floats can adjust their buoyancy by injecting / discharging ballast water. Lifting and lowering heavy objects can be achieved by adjusting buoyancy. However, the control effect of underwater heavy object lifting and lowering remains unsatisfactory, mainly due to the following issues: The winch is cumbersome, the cable is greatly affected by water currents and poses a risk of entanglement and breakage, and its response speed is slow with limited control precision, making it difficult to achieve precise and stable static hovering of heavy objects underwater; Mechanical floats have complex structures, are susceptible to seawater corrosion and biofouling, have high maintenance costs, and provide lag and insufficient precision in controlling underwater heavy object lifting and lowering, failing to meet the stringent stability requirements of precision underwater operations; Airbags lack reliable pressure safety protection mechanisms, and over-inflation or increased external water pressure during descent can easily lead to airbag rupture / explosion; Airbags use a simple pneumatic adjustment method, which makes their volume prone to sudden changes, resulting in unstable lifting and lowering of underwater heavy objects and even impacts on the object. Furthermore, this simple pneumatic adjustment method lacks monitoring of the airbag's movement. Predictive and damping control methods often suffer from overshoot (underwater objects are prone to overshoot due to inertia when approaching the target depth), leading to repeated oscillations around the target depth and failing to meet the stringent stability requirements of precision underwater operations. Furthermore, the mobilization and descent of underwater objects relies on a single type of sensor (such as a depth gauge or pressure gauge), and the system's reliability decreases when the sensor is interfered with or malfunctions. Controlling the mobilization and descent solely based on the object's depth deviation underwater cannot detect or suppress the object's speed, which is one of the root causes of unstable control and overshoot. Finally, the mobilization and descent control relies on manual judgment and operation, resulting in slow response times and an inability to respond in real-time to dynamic environmental factors such as water flow and density changes, reducing the control efficiency and increasing the burden and risk of errors for operators. Summary of the Invention

[0003] This application provides a multi-sensor fusion lifting airbag system with automatic pressure adjustment, which aims to solve the problem of poor control effect of underwater heavy object lifting systems in related technologies.

[0004] To address the aforementioned drawbacks of related technologies, this application provides an automatically pressure-adjustable multi-sensor fusion lifting airbag system. This system includes an airbag, a main pipe, an inflation pipe, an exhaust pipe, a multi-way valve, a regulating valve, an air supply device, a control device, a floating platform, a depth sensor, and a pressure sensor. The floating platform floats on the water surface. The air supply device and control device are both located on the floating platform. The airbag is submerged in water and has a lifting structure for hoisting heavy objects. One end of the main pipe, inflation pipe, and exhaust pipe are connected to the multi-way valve. The other end of the main pipe is connected to the airbag via the regulating valve. The other end of the inflation pipe is connected to the air supply device. The other end of the exhaust pipe extends out of the water surface and is located on the floating platform. The pressure sensor is located inside the airbag, and the depth sensor is located on the lifting structure. The multi-way valve, regulating valve, air supply device, pressure sensor, and depth sensor are all communicatively connected to the control device. The airbag has an inflation process during ascent, an exhaust process during descent, and a pressure-maintaining process during hovering. Specifically, the pressure sensor is used to detect the absolute pressure inside the airbag in real time. The depth sensor is used to detect the absolute depth of the heavy object underwater in real time. The control device is used to: during inflation, control the multi-way valve to connect the main pipe to the inflation pipe and control the air supply device to deliver compressed air into the inflation pipe; during deflation and pressure holding, control the air supply device to stop delivering compressed air into the inflation pipe, and during deflation, control the multi-way valve to connect the main pipe to the deflation pipe, and during pressure holding, control the opening of the regulating valve to be zero; and during inflation and deflation, dynamically control the opening of the regulating valve according to the absolute pressure and absolute depth.

[0005] In some implementation schemes, when the opening of the regulating valve is dynamically controlled based on absolute pressure and absolute depth, the control device is used to: estimate the depth of the weight underwater based on the absolute pressure to obtain the estimated depth; fuse the absolute depth and the estimated depth to obtain the optimal depth; perform differential calculation on the optimal depth to obtain the instantaneous velocity of the weight; calculate the depth deviation between the optimal depth and the target depth of the weight underwater; and dynamically control the opening of the regulating valve based on the depth deviation and the instantaneous velocity.

[0006] In some implementations, when estimating the depth of a weight underwater based on absolute pressure, the control device is used to calculate the depth using formula H. p =(P ab -P at ) / (ρ×g) is used to estimate the depth of the object underwater, H p To estimate the depth, P ab For absolute pressure, P at ρ is atmospheric pressure, ρ is the density of water, and g is the acceleration due to gravity.

[0007] In some implementations, when fusing absolute depth and estimated depth data, the control device is used to fuse absolute depth and estimated depth based on complementary filtering or Kalman filtering algorithms.

[0008] In some implementation schemes, when dynamically controlling the opening of the regulating valve based on the depth deviation and instantaneous motion speed, the control device is used to: perform PID calculation on the depth deviation to obtain the basic control quantity of the regulating valve opening; generate a damping control quantity of the regulating valve opening based on the speed feedback algorithm and the instantaneous motion speed, wherein the damping control quantity is proportional to the magnitude of the instantaneous motion speed and opposite in direction; predict the control quantity of the regulating valve opening based on the rate of change of the depth deviation using a feedforward control algorithm to obtain the feedforward control quantity of the regulating valve opening; add the basic control quantity, the damping control quantity, and the feedforward control quantity to obtain the total control quantity of the regulating valve opening, and control the opening of the regulating valve based on the total control quantity.

[0009] In some implementations, when a damping control quantity is generated based on a velocity feedback algorithm and instantaneous motion velocity, the control device is used to: [follow formula O] d =-K d ×V c Calculate the damping control quantity for the valve opening; where, O d K is the damping control variable. d V is the preset damping coefficient. c It represents the instantaneous velocity.

[0010] In some implementations, when the feedforward control quantity is predicted based on the feedforward control algorithm and the rate of change of depth deviation, the control device is used to: [according to formula O] f =K f ×(de / dt) calculates the feedforward control quantity for the valve opening; where, O f K represents the feedforward control variable. f denoted by , e represents the preset feedforward coefficient, t represents time, and de / dt represents the rate of change of the depth deviation.

[0011] In some implementations, the control device is also used to compare the absolute pressure with a preset pressure threshold in real time, and to execute preset safety measures when the absolute pressure exceeds the preset pressure threshold.

[0012] In some implementations, the airbag is equipped with an air nozzle, and the main pipe is connected to the airbag through the air nozzle.

[0013] In some implementations, the air nozzles include multiple ones located at different positions in the airbag. One end of the main pipe is connected to a multi-way valve via a regulating valve, and the other end branches and is connected to the airbag via multiple air nozzles.

[0014] The lifting airbag system provided in this application includes an airbag, a main pipe, an inflation pipe, an exhaust pipe, a multi-way valve, a regulating valve, an air supply device, a control device, a floating platform, a depth sensor, and a pressure sensor. The floating platform floats on the water surface. The air supply device and the control device are both located on the floating platform. The airbag is submerged in water and has a lifting structure for hoisting heavy objects. One end of the main pipe, the inflation pipe, and the exhaust pipe are connected to the multi-way valve. The other end of the main pipe is connected to the airbag through the regulating valve. The other end of the inflation pipe is connected to the air supply device. The other end of the exhaust pipe extends out of the water surface and is located on the floating platform. The pressure sensor is located inside the airbag, and the depth sensor is located on the lifting structure. The multi-way valve, the regulating valve, the air supply device, the pressure sensor, and the depth sensor are all communicatively connected to the control device. The pressure sensor can detect the absolute pressure inside the airbag in real time, and the depth sensor can detect the absolute depth of the heavy object underwater in real time. The airbag has an inflation process when rising, an exhaust process when descending, and a pressure holding process when hovering. In practical applications, when the airbag is inflating, the control device activates the multi-way valve to connect the main pipe to the inflation pipe and controls the air supply device to deliver compressed air into the inflation pipe. The compressed air entering the inflation pipe flows sequentially through the multi-way valve and the main pipe into the airbag, thereby increasing the airbag's buoyancy and causing the airbag to rise with the weight. When the airbag is deflated, the air supply device stops delivering compressed air into the inflation pipe, and the control device activates the multi-way valve to connect the main pipe to the exhaust pipe. The compressed air inside the airbag is then discharged to the outside through the main pipe, the multi-way valve, and the exhaust pipe, thereby reducing the airbag's buoyancy and causing the airbag to deflate. The airbag descends with the weight. When the airbag is in the pressure-holding process, the control device will control the opening of the regulating valve to zero. At this time, the inflation pipe and the deflation pipe are disconnected from the main pipe, so no new compressed air will enter the airbag, and the compressed air in the airbag will not be discharged. The pressure in the airbag remains unchanged, keeping it suspended in the water with the weight. Regardless of whether the airbag is in the inflation or deflation process, the control device can dynamically control the opening of the regulating valve according to the absolute pressure in the airbag and the absolute depth of the weight underwater, thereby dynamically controlling the flow rate (velocity) of compressed air entering and leaving the airbag when it rises / falls, and thus dynamically controlling the speed of the airbag when it rises / falls. Therefore, the lifting and lowering of underwater heavy objects in this application does not rely on a single type of sensor as in traditional solutions. Instead, it integrates pressure and depth sensors. Furthermore, it can dynamically adjust the speed of the airbag and the heavy object during synchronous ascent / descent based on the absolute pressure inside the airbag and the absolute depth of the heavy object underwater. This not only provides higher reliability but also allows the airbag to smoothly and accurately rise / fall to the target position and hover, avoiding overshoot in traditional solutions and thus meeting the stringent stability requirements of precision underwater operations. In addition, the lifting and lowering of underwater heavy objects in this application does not rely on manual judgment and operation but is entirely controlled automatically by the control device. This results in a fast response speed, ultimately improving the control efficiency of lifting and lowering underwater heavy objects and reducing the burden and error risk for operators. Attached Figure Description

[0015] To more clearly illustrate the related technologies or the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the related technologies or the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application, and not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A schematic diagram of the structure of a first type of lifting airbag system provided in the embodiments of this application;

[0017] Figure 2 Another structural schematic diagram of the first type of lifting airbag system provided in the embodiments of this application;

[0018] Figure 3 This is a schematic diagram of the airbag and its internal structure provided in the embodiments of this application;

[0019] Figure 4 This is a schematic diagram of the structure of a second type of lifting airbag system provided in an embodiment of this application.

[0020] The markings in the above figures represent: 1-airbag, 2-main pipe, 3-inflation pipe, 4-exhaust pipe, 5-multi-way valve, 6-regulating valve, 7-air supply device, 8-control device, 9-floating platform, 10-pressure sensor, 20-lifting structure, 30-air nozzle, 40-display device, 50-alarm device. Detailed Implementation

[0021] While winches, airbags, and mechanical floats can all raise and lower heavy objects underwater, their control over this process remains unsatisfactory. This is mainly due to the following issues: winches are bulky, their cables are highly susceptible to water currents and pose risks of entanglement and breakage, and they suffer from slow response times and limited control precision, making it difficult to achieve precise and stable static hovering of heavy objects underwater; mechanical floats have complex structures, are susceptible to seawater corrosion and biofouling, have high maintenance costs, and their control over raising and lowering of heavy objects is lagging and lacks precision, failing to meet the stringent stability requirements of precision underwater operations; airbags lack reliable pressure safety protection mechanisms, and over-inflation or increased external water pressure during descent can easily lead to airbag rupture / explosion; airbags use simple pneumatic adjustment methods, making their volume prone to sudden changes, resulting in unstable raising and lowering of heavy objects underwater, and even causing impacts. The current dynamic adjustment method lacks prediction and damping control of the airbag's motion state, leading to frequent overshoot (underwater objects are prone to overshoot due to inertia when approaching the target depth), causing repeated oscillations of the object around the target depth, which is difficult to meet the stringent stability requirements of precision underwater operations. The lifting and lowering of underwater objects relies on a single type of sensor (such as a depth gauge or pressure gauge), and the system's reliability decreases when the sensor is interfered with or malfunctions. Controlling the lifting and lowering of the object solely based on its depth deviation underwater cannot sense or suppress the object's speed, which is one of the root causes of unstable control and overshoot. The control of underwater object lifting and lowering relies on manual judgment and operation, resulting in slow response times and an inability to respond in real time to dynamic environmental factors such as water flow and density changes, ultimately reducing the control efficiency of underwater object lifting and lowering and increasing the burden on operators and the risk of errors. In view of this, this application proposes an automatically pressure-adjustable multi-sensor fusion lifting airbag system in the embodiments below to solve the above-mentioned drawbacks of the related technologies.

[0022] To make the objectives, technical solutions, and advantages of this application more apparent and understandable, this application will be clearly and completely described below in conjunction with its embodiments and corresponding drawings. Throughout, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. It should be understood that the embodiments of this application described below are only for explaining this application and are not intended to limit this application. That is, all other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. Furthermore, the technical features involved in the various embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0023] Please see Figures 1-4 , Figure 1 This is a structural schematic diagram of the first type of lifting airbag system. Figure 2 This is another structural diagram of the first type of lifting airbag system. Figure 3 This is a schematic diagram of the airbag and its internal structure. Figure 4 This is a schematic diagram of the second type of lifting airbag system. This embodiment provides an automatically pressure-adjustable multi-sensor fusion lifting airbag system, including an airbag 1, a main pipe 2, an inflation pipe 3, an exhaust pipe 4, a multi-way valve 5, a regulating valve 6, an air supply device 7, a control device 8, a floating platform 9, a depth sensor (not shown), and a pressure sensor 10. The floating platform 9 is used to float on the water surface. The air supply device 7 and the control device 8 are both located on the floating platform 9. The airbag 1 is used to be submerged in water. The airbag 1 is equipped with a lifting structure 20 for lifting heavy objects. The main pipe 2, inflation pipe 3, and exhaust pipe are also included. One end of the main pipe 4 is connected to the multi-way valve 5, the other end of the main pipe 2 is connected to the airbag 1 through the regulating valve 6, the other end of the inflation pipe 3 is connected to the air supply device 7, the other end of the exhaust pipe 4 extends out of the water surface and is set on the floating platform 9, the pressure sensor 10 is set inside the airbag 1, the depth sensor is set on the hoisting structure 20, the multi-way valve 5, the regulating valve 6, the air supply device 7, the pressure sensor 10 and the depth sensor are respectively connected to the control device 8, and the airbag 1 has an inflation process when rising, an exhaust process when descending and a pressure holding process when hovering.

[0024] In this embodiment, pressure sensor 10 is used to detect the absolute pressure inside airbag 1 in real time. Depth sensor is used to detect the absolute depth of the weight underwater in real time. Control device 8 is used to: control multi-way valve 5 to connect main pipe 2 to inflation pipe 3 during inflation, and control air supply device 7 to supply compressed air into inflation pipe 3; control air supply device 7 to stop supplying compressed air into inflation pipe 3 during deflation and pressure holding processes, and control multi-way valve 5 to connect main pipe 2 to deflation pipe 4 during deflation, and control the opening of regulating valve 6 to zero during pressure holding processes; and dynamically control the opening of regulating valve 6 according to absolute pressure and absolute depth during inflation and deflation processes.

[0025] In other words, in practical applications, when the airbag 1 is inflating, the control device 8 controls the valve core of the multi-way valve 5 to connect the main pipe 2 to the inflation pipe 3, and controls the air supply device 7 to supply compressed air into the inflation pipe 3. The compressed air entering the inflation pipe 3 flows into the airbag 1 through the multi-way valve 5 and the main pipe 2 in sequence, thereby increasing the buoyancy of the airbag 1 and causing the airbag 1 to rise with the weight. When the airbag 1 is deflated, the air supply device 7 stops supplying compressed air into the inflation pipe 3, and the control device 8 controls the valve core of the multi-way valve 5 to connect the main pipe 2 to the exhaust pipe 4. The compressed air in the airbag 1 is discharged to the outside through the main pipe 2, the multi-way valve 5, and the exhaust pipe 4 in sequence, thereby reducing the buoyancy of the airbag 1. The buoyancy of the airbag 1 causes it to descend with the weight. When the airbag 1 is in the pressure-holding process, the control device 8 controls the opening of the regulating valve 6 to zero. At this time, the inflation pipe 3 and the exhaust pipe 4 are disconnected from the main pipe 2, so no new compressed air enters the airbag 1, and the compressed air in the airbag 1 will not be discharged. The pressure in the airbag 1 remains unchanged, allowing it to suspend with the weight in the water. Regardless of whether the airbag 1 is in the inflation or deflation process, the control device 8 can dynamically control the opening of the regulating valve 6 according to the absolute pressure in the airbag 1 and the absolute depth of the weight underwater, thereby dynamically controlling the flow rate (velocity) of compressed air entering and leaving the airbag 1 when it rises / falls, and thus dynamically controlling the speed of the airbag 1 when it rises / falls.

[0026] In this embodiment, the airbag 1 is made of a high-strength, corrosion-resistant, and highly airtight flexible material (such as polyurethane coated fabric, rubber composite material, etc.), and its pressure-bearing capacity needs to be designed according to the maximum depth of the heavy object's descent. Furthermore, the airbag 1 is equipped with an air nozzle 30, which serves as the inlet and outlet for compressed air on the airbag 1; that is, the main pipe 2 is connected to the airbag 1 through the air nozzle 30. Of course, the inlet and outlet for compressed air on the airbag 1 is not limited to one. In other embodiments, the air nozzle 30 may include multiple nozzles, each located at a different position on the airbag 1. In this case, one end of the main pipe 2 is connected to the multi-way valve 5 through the regulating valve 6, and the other end branches and is connected to the airbag 1 through multiple air nozzles 30 respectively. It is understood that when there are multiple air nozzles 30, the airbag 1 has multiple inlets and outlets for compressed air, thus achieving uniformity and speed in airbag inflation / deflation, avoiding localized stress concentration or uneven deformation of the airbag 1 caused by single-point air intake / deflation, and also improving the redundancy of the lifting airbag system.

[0027] In this embodiment, the control device 8 uses any device commonly used in the art that has control and data processing and analysis functions, such as a small computer, a microcontroller, an industrial control computer (IPC), a programmable logic controller (PLC), and a distributed control system (DCS). The specific device can be selected according to actual needs, and this embodiment does not limit it to a single device. For example, the control device 8 in this embodiment uses a PLC control cabinet. Based on this, in addition to the structure described above, the lifting airbag system also includes a display device 40 that is connected to the control device 8. The display device 40 can be installed on the floating platform 9, on the PLC control cabinet, or by hand (such as a mobile phone, tablet computer, or laptop computer) by the operator. The specific choice can be made according to actual needs, and this embodiment does not limit it to a single device. The display device 40 is mainly used to provide visual operation and monitoring. It can display various parameters during the operation of the lifting airbag system, such as the default opening degree of the regulating valve 6, the target depth of the weight underwater, the absolute depth of the weight, the absolute pressure inside the airbag 1, the valve status of the multi-way valve 5, and the current opening degree of the regulating valve 6. In addition, the operator can issue commands to the control device 8 through the display device 40, and can also set the lifting airbag system to manual or automatic mode. When it is necessary to debug and maintain the lifting airbag system, it can be set to manual mode.

[0028] In this embodiment, the multi-way valve 5 is a solenoid valve, such as a two-position three-way solenoid valve; the regulating valve 6 is an electric valve with air flow regulation function commonly used in the art. The air supply device 7 can use air sources commonly used in the art, such as air compressors, air pumps, high-pressure air cylinders, etc., which can be selected according to actual needs, and this embodiment does not limit it to a single one. Of course, common components such as switching valves, pressure reducing valves, and filters can be installed on the air filling pipe 3 between the air supply device 7 and the multi-way valve 5. This is a relatively mature technology in the art, so this embodiment will not describe it in detail.

[0029] As can be seen from the above, the lifting and lowering of underwater heavy objects in this embodiment does not rely on a single type of sensor as in traditional solutions. Instead, it integrates a pressure sensor 10 and a depth sensor. Furthermore, it can dynamically adjust the speed of the airbag 1 and the heavy object as they rise / fall synchronously based on the absolute pressure inside the airbag 1 and the absolute depth of the heavy object underwater. This not only provides higher reliability but also allows the airbag 1 to rise / fall smoothly and accurately with the heavy object to the target position and hover, avoiding overshoot in traditional solutions. This meets the stringent stability requirements of precision underwater operations. In addition, the lifting and lowering of underwater heavy objects in this embodiment does not rely on manual judgment and operation but is completely automatically controlled by the control device 8. The response speed is fast, which ultimately improves the control efficiency of lifting and lowering underwater heavy objects and reduces the burden and error risk of operators.

[0030] In some embodiments, the specific process by which the control device 8 dynamically controls the opening of the regulating valve 6 based on absolute pressure and absolute depth is as follows: the depth of the weight underwater is estimated based on the absolute pressure to obtain the estimated depth; the absolute depth and the estimated depth are fused to obtain the optimal depth; the optimal depth is differentiated to obtain the instantaneous velocity of the weight; the depth deviation between the optimal depth and the target depth of the weight underwater is calculated; and the opening of the regulating valve 6 is dynamically controlled based on the depth deviation and the instantaneous velocity.

[0031] Specifically, the control device 8 can be based on formula H p =(P ab -P at The formula ) / (ρ×g) is used to estimate the depth of the object underwater; where H is the weight of the object. p To estimate the depth, P ab For absolute pressure, P at Here, ρ is atmospheric pressure, ρ is water density, and g is gravitational acceleration. Furthermore, the control device 8 can fuse the absolute depth and estimated depth based on complementary filtering or Kalman filtering algorithms to obtain the optimal depth. It is understood that complementary filtering and Kalman filtering algorithms are both commonly used and technically mature data fusion algorithms in this field, and this application will not elaborate further on them. The calculation of the optimal depth will be illustrated below using only the complementary filtering algorithm as an example.

[0032] The core of the complementary filtering algorithm is to "leverage strengths and avoid weaknesses." It utilizes the frequency characteristic differences between the pressure sensor 10 and the depth sensor, allocating their contributions to the fusion result through weighted coefficients. The depth sensor's advantages are that it directly outputs absolute depth and has good low-frequency stability (e.g., small error during static hovering), but its dynamic response is slow (e.g., large instantaneous fluctuations during water flow impacts and noticeable high-frequency noise). The pressure sensor 10's advantages are fast dynamic response (pressure changes can be captured in real time and it has good high-frequency characteristics), but it is easily affected by changes in water temperature and density (e.g., density fluctuations due to temperature differences at different depths and drift errors in the low-frequency range). For the pressure sensor 10 and the depth sensor, their frequencies are complementary. The absolute depth from the depth sensor is suitable for a low-frequency reference, while the estimated depth from the pressure sensor 10 is suitable for correcting high-frequency fluctuations.

[0033] The general formula for the complementary filtering algorithm is H. f =α×H p +(1-α)×H d H f H represents the optimal depth. dThe absolute depth is represented by α, and the weighting coefficient is 0 < α < 1. In static scenarios (such as when airbag 1 is hovering and the depth of the object changes slowly), α is set to 0.3~0.4 to increase the weight of the absolute depth (utilizing its low-frequency stability) and reduce the drift effect of pressure conversion. In dynamic scenarios (such as when airbag 1 is rapidly rising and falling and the depth of the object changes rapidly), α is set to 0.6~0.7 to increase the weight of the estimated depth (utilizing its high-frequency fast response) and reduce errors caused by the dynamic lag of the depth sensor. In practical applications, the system synchronously collects absolute and estimated depths at a fixed sampling period (e.g., 100 m / s). After each sampling, α is determined based on the dynamic / static nature of the current scene and substituted into the general formula to calculate the optimal depth. Then, the optimal depth of the previous moment is used as a reference. If the deviation between the current optimal depth and the optimal depth of the previous moment exceeds a set value (e.g., 0.05 m), α is fine-tuned (e.g., increasing the weight of the absolute depth when the deviation is large) to avoid abrupt changes in the fusion result of the absolute and estimated depths. Furthermore, the rate of change of estimated depth (dH) can be calculated. p When the estimated depth change rate exceeds a preset threshold (e.g., 0.1 m / s), α is automatically increased; conversely, when the estimated depth change rate is less than the preset threshold, α is decreased.

[0034] In some embodiments, the process by which the control device 8 dynamically controls the opening of the regulating valve 6 based on the depth deviation and instantaneous motion speed is as follows: A PID calculation is performed on the depth deviation to obtain the basic control quantity for the opening of the regulating valve 6; a damping control quantity for the opening of the regulating valve 6 is generated based on a speed feedback algorithm and according to the instantaneous motion speed, wherein the damping control quantity is proportional to the magnitude of the instantaneous motion speed and opposite in direction; a feedforward control quantity for the opening of the regulating valve 6 is obtained by predicting the control quantity based on the rate of change of the depth deviation using a feedforward control algorithm; the basic control quantity, the damping control quantity, and the feedforward control quantity are added together to obtain the total control quantity for the opening of the regulating valve 6, and the opening of the regulating valve 6 is controlled according to the total control quantity. It should be noted that PID algorithms, speed feedback, and feedforward control are all relatively mature technologies in the field, therefore, this application will not describe them in detail, and only a brief description will be given below.

[0035] The basic control quantity, damping control quantity, and feedforward control quantity are essentially all signal values ​​used to control the opening of regulating valve 6. The opening of regulating valve 6 directly affects the flow rate of gas entering or exiting airbag 1, thus affecting the buoyancy of airbag 1 and its rising and falling state. The magnitude of the basic control quantity determines the direction and amplitude of the adjustment of the opening of regulating valve 6. For example, when the basic control quantity is positive and large, it means that the absolute depth is less than the target depth, and the system needs to increase the buoyancy of airbag 1. At this time, the control device 8 will control the regulating valve 6 to increase its opening, thereby allowing more gas to fill airbag 1 and make it rise. When the basic control quantity is negative and large in absolute value, it means that the absolute depth is greater than the target depth, and the system needs to reduce the buoyancy of airbag 1. The control device 8 will control the regulating valve 6 to increase its opening to expel gas and make airbag 1 descend. In other words, by continuously adjusting the basic control quantity (adjusting the opening of regulating valve 6) according to the deviation between the optimal depth and the target depth, the weight gradually approaches and stabilizes at the target depth.

[0036] Control device 8 can be based on formula O d =-K d ×V c Calculate the damping control value for the opening degree of regulating valve 6, O d K is the damping control variable. d V is a preset damping coefficient (a positive number, experimentally calibrated, such as 0.5~2). c The instantaneous velocity is represented by a positive value (positive value indicates rising, negative value indicates falling). The damping control value is a signal value that is proportional to the magnitude of the instantaneous velocity and opposite in direction. Its core function is to suppress the excessively fast movement of airbag 1 through "reverse damping force" to avoid depth overshoot caused by inertia (such as the weight passing through the target depth when rising or the weight falling below the target depth when falling).

[0037] The damping control amount is equivalent to applying dynamic resistance to the inflation and deflation process of airbag 1: if airbag 1 rises rapidly (V c If the value is positive and relatively large, and the damping control value is negative and relatively large, the inflation force of airbag 1 will be weakened (e.g., reducing the opening of regulating valve 6) to prevent the heavy object from rising too quickly and exceeding the target depth; if airbag 1 descends rapidly (V c When the damping control quantity is negative and has a large absolute value, and the damping control quantity is positive and large, the exhaust force of airbag 1 will be weakened (e.g., the opening of regulating valve 6 during exhaust will be reduced), to prevent the heavy object from falling too quickly and breaking through the target depth. Furthermore, regarding the coordination between the damping control quantity and the basic control quantity, taking the movement of airbag 1 from shallow water to the target depth (deeper) as an example: In the initial stage, the depth deviation is large (optimal depth < target depth), the basic control quantity is positive and large, and the control device 8 controls the regulating valve 6 to open to a large degree, thereby inflating airbag 1 and accelerating its ascent (V... c (Increase); as the weight gets closer to the target depth, the depth deviation decreases, the basic control quantity decreases, but Vc The pressure is still relatively high (due to inertia). At this point, the damping control quantity is negative and has a large absolute value (opposite to the upward speed of the heavy object). After the basic control quantity and the damping control quantity are superimposed, the total control quantity decreases, the inflation force on airbag 1 weakens, and airbag 1 decelerates as it rises with the heavy object. Finally, when the depth deviation is approximately zero, the basic control quantity, instantaneous motion speed, and damping control quantity are all approximately zero, and airbag 1 reaches the target depth and hovers stably there.

[0038] Control device 8 can be based on formula O f =K f The feedforward control quantity for the opening degree of regulating valve 6 is calculated using ×(de / dt). f K represents the feedforward control variable. f This represents the preset feedforward coefficient (a positive number, calibrated experimentally, such as 0.3~1), and e represents the depth deviation (e=H). s -H f H s (where t represents time, de / dt represents the rate of change of depth deviation). It can be understood that the core of feedforward control is the proactive prediction based on the rate of change of depth deviation. By analyzing the rate of change of depth deviation, it outputs a control quantity (i.e., feedforward control quantity) that matches the disturbance trend in advance, thereby offsetting the adjustment delay caused by system inertia or lag. The rate of change of depth deviation reflects the dynamic trend of depth deviation. When de / dt > 0, it indicates that the depth deviation is increasing (e.g., the airbag 1 rises slower than expected, and the difference between the absolute depth and the target depth becomes larger). At this time, the feedforward control quantity is positive, and the control device 8 increases the inflation force of airbag 1 in advance (or decreases the deflation force) to compensate for the system response lag and prevent the depth deviation from expanding further. When de / dt < 0, it indicates that the depth deviation is decreasing (e.g., airbag 1 rises too fast and is approaching the target depth). The feedforward control quantity is negative, and the control device 8 decreases the inflation force of airbag 1 in advance (or increases the deflation force) to suppress the overshoot caused by inertia. When de / dt = 0, it indicates that the depth deviation is stable (airbag 1 is in a steady state or moving at a constant speed). The calculation of de / dt is often based on discrete sampling data and approximated by the difference method, i.e., de / dt = [e(k) - e(k-1)] / T, where T is the sampling period, k is the current time, and k-1 is the previous time.

[0039] Regarding the coordination of feedforward control, damping control, and basic control, taking the lifting of a heavy object from 5m to 10m as an example: In the initial stage, e=5m (large depth deviation), de / dt=0 (just starting), V c=0, the basic control quantity is positive and large (inflation of the dominant airbag 1), the feedforward and damping control quantities are both zero (no trend), the total control quantity = the basic control quantity, the control device 8 controls the regulating valve 6 to a large opening, and the airbag 1 accelerates upward; in the intermediate stage, e = 3m, de / dt = -0.2m / s (depth deviation decreases), V c =0.8m / s (airbag 1 rises rapidly), the basic control quantity is positive and decreasing (due to the reduction in depth deviation), the feedforward control quantity is negative (due to de / dt < 0, deceleration is initiated early), the damping control quantity is negative (opposite to the rising speed of airbag 1, braking), the total control quantity = basic control quantity + feedforward control quantity + damping control quantity, the control device 8 controls the regulating valve 6 to reduce the opening, and airbag 1 decelerates and rises; when airbag 1, carrying the weight, approaches the target depth, e = 0.5m, de / dt = -0.1m / s (depth deviation decreases slowly), V c =0.3m / s, the basic control quantity is positive and small (fine adjustment), the feedforward control quantity is negative and small (predicting that the target depth will be reached and reducing force in advance), the damping control quantity is negative and small (slight braking), the total control quantity = basic control quantity + feedforward control quantity + damping control quantity ≈ 0, the regulating valve 6 is close to closing, and the airbag 1 smoothly reaches the target depth with the weight and hovers.

[0040] In summary, the opening degree of regulating valve 6 (0~100%) directly determines the inflation and deflation flow rate of airbag 1 (the larger the opening degree, the faster the gas enters and exits airbag 1). The control of the opening degree of regulating valve 6 requires the integration of feedforward control, damping control, and basic control. The basic control eliminates static errors by comparing the current depth deviation with historical depth deviations, ensuring that the heavy object can ultimately reach the target depth accurately (this is the key to solving the "accuracy" problem). The damping control suppresses overshoot caused by inertia based on instantaneous motion speed (this is the key to solving the "stability" problem). The feedforward control intervenes in advance by using the rate of change of depth deviation to compensate for system response lag (this is the key to solving the "speed" problem). In short, the feedforward control quantity, damping control quantity, and basic control quantity are algebraically superimposed (directly added) to form a total control quantity that balances accuracy, stability, and response speed. Its numerical range corresponds to the opening ratio of regulating valve 6 (for example, if the total control quantity is 60%, then regulating valve 6 is opened by 60%). Its core value lies in the fact that through the complementarity and balance of multi-dimensional adjustment, the lifting airbag system can not only respond quickly to depth requirements in complex underwater environments, but also smoothly approach the target depth, ultimately achieving high-precision hovering control of heavy objects.

[0041] In some embodiments, regardless of whether the airbag 1 is in the inflation, deflation, or pressure-holding process, the control device 8 can compare the absolute pressure with a preset pressure threshold in real time and execute preset safety measures when the absolute pressure exceeds the preset pressure threshold. Based on this, in addition to the structure described above, the lifting airbag system also includes an alarm device 50 and an emergency exhaust valve connected to the control device 8. The emergency exhaust valve is located on the airbag 1, and the alarm device 50 can be located on the floating platform 9 or on the PLC control cabinet. It is understood that when the absolute pressure inside the airbag 1 exceeds the preset pressure threshold, the control device 8 can control the alarm device 50 to issue audible and visual alarms, and can also display relevant alarm information on the display device 40, thereby reminding personnel to intervene promptly.

[0042] As at least one embodiment, the preset pressure threshold includes a first preset pressure threshold and a second preset pressure threshold. The first preset pressure threshold is less than the second preset pressure threshold. When the absolute pressure inside the airbag 1 exceeds the first preset pressure threshold, it indicates that the absolute pressure inside the airbag 1 is relatively high. At this time, the control device 8 can control the alarm device 50 to emit a yellow light and sound an alarm, and can also control the valve core of the multi-way valve 5 to connect the main pipe 2 to the exhaust pipe 4, so that the airbag 1 can be vented, thereby achieving controllable pressure reduction. When the absolute pressure inside the airbag 1 exceeds the second preset pressure threshold, it indicates that the absolute pressure inside the airbag 1 is close to the pressure that would cause the airbag 1 to burst. At this time, the control device 8 controls the alarm device 50 to emit a red light and sound an alarm, and can also control the valve core of the multi-way valve 5 to connect the main pipe 2 to the exhaust pipe 4, and control the emergency exhaust valve to open, thereby quickly expelling the compressed air inside the airbag 1 and preventing the airbag 1 from bursting.

[0043] The above embodiments are merely preferred implementations of this application and are not the only limitations on the lifting airbag system. Those skilled in the art can flexibly customize the system based on the above embodiments and the actual application scenario. It is understood that through the implementation of the above embodiments of this application, a lifting airbag system is constructed using airbag 1, main pipe 2, inflation pipe 3, exhaust pipe 4, multi-way valve 5, regulating valve 6, air supply device 7, control device 8, floating platform 9, depth sensor, and pressure sensor 10. The floating platform 9 floats on the water surface, and the air supply device 7 and control device 8 are both mounted on the floating platform 9. Airbag 1 is submerged in water and has a lifting structure 20 for hoisting heavy objects. One end of the main pipe 2, inflation pipe 3, and exhaust pipe 4 are respectively connected to the multi-way valve 5, and the other end of the main pipe 2 is connected to the regulating valve. 6 is connected to the airbag 1, the other end of the inflation pipe 3 is connected to the air supply device 7, the other end of the exhaust pipe 4 extends out of the water surface and is set on the floating platform 9, the pressure sensor 10 is set inside the airbag 1, the depth sensor is set on the hoisting structure 20, the multi-way valve 5, the regulating valve 6, the air supply device 7, the pressure sensor 10 and the depth sensor are respectively connected to the control device 8. The pressure sensor 10 can detect the absolute pressure inside the airbag 1 in real time, and the depth sensor can detect the absolute depth of the heavy object underwater in real time. The airbag 1 has an inflation process when rising, an exhaust process when descending and a pressure holding process when hovering. In practical applications, when the airbag 1 is inflating, the control device 8 controls the valve core of the multi-way valve 5 to connect the main pipe 2 to the inflation pipe 3, and controls the air supply device 7 to supply compressed air into the inflation pipe 3. The compressed air entering the inflation pipe 3 flows into the airbag 1 through the multi-way valve 5 and the main pipe 2 in sequence, thereby increasing the buoyancy of the airbag 1 and causing the airbag 1 to rise with the weight. When the airbag 1 is deflated, the air supply device 7 stops supplying compressed air into the inflation pipe 3, and the control device 8 controls the valve core of the multi-way valve 5 to connect the main pipe 2 to the exhaust pipe 4. The compressed air in the airbag 1 is discharged to the outside through the main pipe 2, the multi-way valve 5, and the exhaust pipe 4 in sequence, thereby reducing the buoyancy of the airbag 1. The airbag 1 descends with the weight. When the airbag 1 is in the pressure-holding process, the control device 8 controls the opening of the regulating valve 6 to zero. At this time, the inflation pipe 3 and the exhaust pipe 4 are disconnected from the main pipe 2, so no new compressed air enters the airbag 1, and the compressed air in the airbag 1 will not be discharged. The pressure in the airbag 1 remains unchanged, keeping it suspended in the water with the weight. Regardless of whether the airbag 1 is in the inflation or deflation process, the control device 8 can dynamically control the opening of the regulating valve 6 according to the absolute pressure in the airbag 1 and the absolute depth of the weight underwater, thereby dynamically controlling the flow rate (velocity) of compressed air entering and leaving the airbag 1 when it rises / falls, and thus dynamically controlling the speed of the airbag 1 when it rises / falls.Therefore, the lifting and lowering of underwater heavy objects in this application does not rely on a single type of sensor as in traditional solutions. Instead, it integrates a pressure sensor 10 and a depth sensor. Furthermore, it can dynamically adjust the speed of the airbag 1 and the heavy object during synchronous ascent / descent based on the absolute pressure inside the airbag 1 and the absolute depth of the heavy object underwater. This not only provides higher reliability but also allows the airbag 1 to smoothly and accurately rise / fall to the target position and hover, avoiding overshoot in traditional solutions and thus meeting the stringent stability requirements of precision underwater operations. In addition, the lifting and lowering of underwater heavy objects in this application does not rely on manual judgment and operation but is completely automatically controlled by the control device 8. This results in a fast response speed, ultimately improving the control efficiency of lifting and lowering underwater heavy objects and reducing the burden and error risk for operators.

[0044] It should be noted that the several embodiments shown above in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should also be noted that in the textual description of this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply such an actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements may include not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus; and, without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] Furthermore, those skilled in the art can implement or use this application by practicing the several embodiments shown above. Various modifications to the embodiments shown above will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments not shown without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the several embodiments shown above, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-sensor fusion lifting airbag system with automatic pressure adjustment, characterized in that, The system includes an airbag, a main pipe, an inflation pipe, an exhaust pipe, a multi-way valve, a regulating valve, an air supply device, a control device, a floating platform, a depth sensor, and a pressure sensor. The floating platform floats on the water surface. The air supply device and the control device are both located on the floating platform. The airbag is submerged in water and has a lifting structure for hoisting heavy objects. One end of the main pipe, the inflation pipe, and the exhaust pipe are respectively connected to the multi-way valve. The other end of the main pipe is connected to the airbag through the regulating valve. The other end of the inflation pipe is connected to the air supply device. The other end of the exhaust pipe extends out of the water surface and is located on the floating platform. The pressure sensor is located inside the airbag, and the depth sensor is located on the lifting structure. The multi-way valve, the regulating valve, the air supply device, the pressure sensor, and the depth sensor are all communicatively connected to the control device. The airbag has an inflation process during ascent, an exhaust process during descent, and a pressure-holding process during hovering. The pressure sensor is used to detect the absolute pressure inside the airbag in real time; the depth sensor is used to detect the absolute depth of the weight underwater in real time; the control device is used for: During the inflation process, the multi-way valve is controlled to connect the main pipe to the inflation pipe, and the air supply device is controlled to deliver compressed air into the inflation pipe. During the exhaust process and the pressure holding process, the air supply device is controlled to stop supplying compressed air into the inflation pipe, and during the exhaust process, the multi-way valve is controlled to connect the main pipe to the exhaust pipe, and during the pressure holding process, the opening degree of the regulating valve is controlled to be zero; during the inflation process and the exhaust process, the opening degree of the regulating valve is dynamically controlled according to the absolute pressure and the absolute depth.

2. The lifting airbag system according to claim 1, characterized in that, When the opening of the regulating valve is dynamically controlled based on the absolute pressure and the absolute depth, the control device is used to: The estimated depth is obtained by estimating the depth of the weight underwater based on the absolute pressure. The absolute depth and the estimated depth are fused to obtain the optimal depth. The instantaneous velocity of the weight is obtained by performing a differential operation on the optimal depth; Calculate the depth deviation between the optimal depth and the target depth of the weight underwater; The opening degree of the regulating valve is dynamically controlled based on the depth deviation and the instantaneous motion speed.

3. The lifting airbag system according to claim 2, characterized in that, When estimating the depth of the weight underwater based on the absolute pressure, the control device is used to: According to formula H p =(P ab -P at The depth of the weight underwater is estimated by H / (ρ×g); where H is the weight of the weight. p For the estimated depth, P ab P is the absolute pressure. at ρ is atmospheric pressure, ρ is the density of water, and g is the acceleration due to gravity.

4. The lifting airbag system according to claim 2, characterized in that, When performing data fusion on the absolute depth and the estimated depth, the control device is used to: The absolute depth and the estimated depth are fused based on complementary filtering or Kalman filtering algorithms.

5. The lifting airbag system according to claim 2, characterized in that, When the opening of the regulating valve is dynamically controlled based on the depth deviation and the instantaneous movement speed, the control device is used to: Perform PID calculations on the depth deviation to obtain the basic control quantity for the opening of the regulating valve; The damping control quantity of the regulating valve opening is generated based on the speed feedback algorithm and the instantaneous motion speed. The damping control quantity is proportional to the magnitude of the instantaneous motion speed and opposite in direction. Based on the feedforward control algorithm and predicting the control quantity of the regulating valve opening according to the rate of change of the depth deviation, the feedforward control quantity of the regulating valve opening is obtained. The basic control quantity, the damping control quantity, and the feedforward control quantity are added together to obtain the total control quantity, and the opening degree of the regulating valve is controlled according to the total control quantity.

6. The lifting airbag system according to claim 5, characterized in that, When generating the damping control value for the opening of the regulating valve, the control device is used to: According to formula O d =-K d ×V c Calculate the damping control value of the valve opening; where, O d K is the damping control quantity. d V is the preset damping coefficient. c The instantaneous velocity is denoted as .

7. The lifting airbag system according to claim 5, characterized in that, When predicting the feedforward control value for the opening of the regulating valve, the control device is used to: According to formula O f =K f ×(de / dt) calculates the feedforward control quantity for the opening of the regulating valve; Among them, O f K represents the feedforward control quantity. f Here, e represents the preset feedforward coefficient, t represents time, and de / dt represents the rate of change of the depth deviation.

8. The lifting airbag system according to claim 1, characterized in that, The control device is also used to execute preset safety measures when the absolute pressure is greater than a preset pressure threshold.

9. The lifting airbag system according to claim 1, characterized in that, The airbag is equipped with an air nozzle, and the main pipe is connected to the airbag through the air nozzle.

10. The lifting airbag system according to claim 9, characterized in that, The air nozzles include multiple ones, which are located at different positions of the airbag; one end of the main pipe is connected to the multi-way valve through the regulating valve, and the other end branches and is connected to the airbag through multiple air nozzles respectively.

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