Control method and device of arm assembly, storage medium, vehicle

Abstract

The application discloses a control method and device of an arm support assembly, a storage medium and a vehicle, and relates to the technical field of engineering machinery. The control method of the arm support assembly comprises the following steps: acquiring the deformation amount and the maximum allowable rotation angle of a terminal arm support in the arm support assembly, and acquiring the preset gravity center range and the actual gravity center range of the arm support assembly; in the case where the actual gravity center range exceeds the preset gravity center range, the arm support assembly is controlled based on the actual gravity center range to determine the arm support included angle adjustment amount between the terminal arm support and the adjacent arm support; in the case where the terminal arm support is determined to be in a deformation state based on the rotation angle change value and the maximum allowable rotation angle, the target adjustment angle is determined based on the maximum allowable rotation angle and the arm support included angle adjustment amount, so that the arm support assembly is controlled based on the target adjustment angle. The method can effectively solve the problem of excessive structural deformation of a single arm support, and improve the collaborative control ability of the safety of the arm support assembly.

Description

Technical Field

[0001] This application relates to the field of engineering machinery technology, and in particular to a control method for a boom assembly, a computer-readable storage medium, a vehicle, and a control device for a boom assembly. Background Technology

[0002] To ensure the safety of fire truck operations and improve firefighting efficiency, it is necessary to effectively control the impact of water cannon jet reaction force on the boom system in order to avoid excessive structural deformation or instability of the boom.

[0003] In related technologies, a control method based on the safe center of gravity range is used to cope with the reaction force of water cannons. This method monitors and adjusts the boom attitude to ensure that the virtual dynamic center of gravity of the boom assembly remains within a preset safe range when subjected to reaction forces, thereby preventing vehicle rollover or breakage of major structural components. However, this approach mainly focuses on the overall stability of the boom assembly, with its safety criterion concentrated on the center of gravity position. For boom systems composed of multiple boom sections, especially the lighter and relatively less rigid end boom section, its own structural deformation may exceed the safety limit, but its impact on the overall center of gravity of the boom assembly may be negligible. This makes it difficult for this control method to effectively monitor and suppress such excessive local deformation.

[0004] Therefore, under the existing control framework based on the overall center of gravity safety criterion, how to effectively monitor and coordinate the structural deformation of individual booms (especially end booms) while taking into account the overall stability of boom components has become an urgent technical problem to be solved. Summary of the Invention

[0005] This application aims to at least partially address one of the technical problems in related technologies. To this end, the first objective of this application is to propose a control method for a boom assembly. By acquiring the deformation (angle change value) of the end boom caused by the reaction force of the water cannon and its maximum permissible angle, and combining this with the preset and actual center of gravity ranges of the boom assembly before and after the reaction force, the method can, when it is determined that the end boom has deformed and the overall center of gravity safety is compromised, collaboratively consider the deformation limit of the boom structure and the center of gravity recovery requirements to determine the final target adjustment angle for boom control. Specifically, by introducing an independent deformation safety criterion for the end boom (comparison of deformation amount and maximum permissible angle), direct monitoring and limitation of the deformation of a single boom structure are achieved. Simultaneously, this criterion, combined with the center of gravity safety criterion (comparison of the actual center of gravity range and the preset range), ensures that the generation of control commands simultaneously considers both local structural strength safety and overall stability. This effectively solves the problem of excessive structural deformation that may occur in a single boom and improves the collaborative control capability for the safety of the boom assembly.

[0006] The second objective of this application is to provide a computer-readable storage medium.

[0007] The third objective of this application is to propose a vehicle.

[0008] The fourth objective of this application is to provide a control device for a boom assembly.

[0009] To achieve the above objectives, a first aspect of this application proposes a control method for a boom assembly. The method includes: obtaining the deformation amount and maximum permissible rotation angle of the end boom in the boom assembly, and obtaining a preset center of gravity range and an actual center of gravity range of the boom assembly, wherein the deformation amount is the rotation angle change value of the boom assembly caused by the reaction force of the water cannon, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon; when the actual center of gravity range exceeds the preset center of gravity range, determining an adjustment amount of the boom angle between the end boom and the adjacent boom based on the actual center of gravity range; when it is determined that the end boom is in a deformed state based on the rotation angle change value and the maximum permissible rotation angle, determining a target adjustment angle based on the maximum permissible rotation angle and the boom angle adjustment amount, and controlling the boom assembly based on the target adjustment angle.

[0010] According to the boom assembly control method of this application embodiment, the deformation amount and maximum allowable rotation angle of the end boom in the boom assembly are obtained, and the preset center of gravity range and actual center of gravity range of the boom assembly are also obtained. The deformation amount is the rotation angle change value of the boom assembly caused by the reaction force of the water cannon, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon. When the actual center of gravity range exceeds the preset center of gravity range, the boom angle adjustment amount between the end boom and adjacent booms is determined based on the actual center of gravity range. When the end boom is determined to be in a deformed state based on the rotation angle change value and the maximum allowable rotation angle, a target adjustment angle is determined based on the maximum allowable rotation angle and the boom angle adjustment amount, and the boom assembly is controlled based on the target adjustment angle. Therefore, this method can effectively solve the problem of excessive structural deformation that may occur in a single boom, and improve the collaborative control capability for the safety of the boom assembly.

[0011] In addition, the control method for the boom assembly according to the above embodiments of this application may also have the following additional technical features: According to one embodiment of this application, determining the maximum permissible rotation angle of the end boom includes: determining the maximum bending stress based on the boom structure safety factor; and determining the maximum permissible rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom.

[0012] According to one embodiment of this application, determining the maximum bending stress based on the boom structure safety factor includes: determining the allowable stress of the material based on the yield strength of the material used in the end boom and the boom structure safety factor, so as to use the allowable stress as the maximum permissible bending stress.

[0013] According to one embodiment of this application, determining the maximum permissible rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom includes: determining the moment of inertia and section modulus of the end boom based on the cross-sectional parameters, wherein the moment of inertia characterizes the end boom's ability to resist bending deformation, and the section modulus characterizes the bending bearing capacity of the end boom's cross-section; determining the theoretical bending deformation curve of the end boom under the maximum bending stress based on the product of the maximum bending stress and the section modulus, and the distance from the point of application of the water cannon reaction force on the end boom to the fixed end; determining the rotation limit value of the free end of the end boom relative to the fixed end based on the theoretical bending deformation curve, and determining the rotation limit value as the maximum permissible rotation angle.

[0014] According to one embodiment of this application, determining the target adjustment angle based on the maximum permissible turning angle and the boom angle adjustment amount includes: when the maximum permissible turning angle is greater than or equal to the boom angle adjustment amount, using the maximum permissible turning angle as the target adjustment angle; and when the maximum permissible turning angle is less than the boom angle adjustment amount, using the boom angle adjustment amount as the target adjustment angle.

[0015] According to one embodiment of this application, determining that the end boom is in a deformed state based on the angle change value and the maximum permissible angle includes: determining that the end boom is in a deformed state when the angle change value is greater than the maximum permissible angle.

[0016] According to one embodiment of this application, the method further includes: issuing a warning when it is determined that the end boom is in a deformed state.

[0017] To achieve the above objectives, a second aspect of this application provides a computer-readable storage medium having a program stored thereon that, when executed by a processor, implements the above-described control method for the boom assembly.

[0018] The computer-readable storage medium according to the embodiments of this application implements the above-described control method for the boom assembly during execution, which can effectively solve the problem of excessive structural deformation that may occur in a single boom and improve the coordinated control capability for the safety of the boom assembly.

[0019] To achieve the above objectives, a vehicle is provided in a third aspect of this application, including a memory, a processor, and a program stored in the memory and executable on the processor. When the processor executes the program, it implements the above-described control method for the boom assembly.

[0020] The vehicle according to the embodiments of this application, by executing the above-described control method for the boom assembly, can effectively solve the problem of excessive structural deformation that may occur in a single boom, and improve the coordinated control capability for the safety of the boom assembly.

[0021] To achieve the above objectives, a fourth aspect of this application provides a control device for a boom assembly. The device includes: an acquisition module, configured to acquire the deformation and maximum permissible rotation angle of the end boom in the boom assembly, and to acquire a preset center of gravity range and an actual center of gravity range of the boom assembly, wherein the deformation is the rotation angle change value of the boom assembly caused by the reaction force of the water cannon, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon; a determination module, configured to determine an adjustment amount of the boom angle between the end boom and an adjacent boom based on the actual center of gravity range when the actual center of gravity range exceeds the preset center of gravity range; and a control module, configured to determine a target adjustment angle based on the maximum permissible rotation angle and the boom angle adjustment amount when the end boom is determined to be in a deformed state based on the rotation angle change value and the maximum permissible rotation angle, so as to control the boom assembly based on the target adjustment angle.

[0022] According to the control device for the boom assembly in this application embodiment, the acquisition module is used to acquire the deformation amount and maximum allowable rotation angle of the end boom in the boom assembly, and to acquire the preset center of gravity range and actual center of gravity range of the boom assembly. The deformation amount is the rotation angle change value caused by the reaction force of the water cannon on the boom assembly, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon. The determination module is used to determine the boom angle adjustment amount between the end boom and adjacent booms based on the actual center of gravity range when the actual center of gravity range exceeds the preset center of gravity range. The control module is used to determine the target adjustment angle based on the maximum allowable rotation angle and the boom angle adjustment amount when the end boom is determined to be in a deformed state based on the rotation angle change value and the maximum allowable rotation angle, and to control the boom assembly based on the target adjustment angle. Therefore, this device can effectively solve the problem of excessive structural deformation that may occur in a single boom, and improve the coordinated control capability for the safety of the boom assembly.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] Figure 1This is a flowchart of a control method for a boom assembly according to an embodiment of this application.

[0025] Figure 2 This is a flowchart illustrating a control method for a boom assembly according to a specific example of this application.

[0026] Figure 3 This is a block diagram of a vehicle according to an embodiment of this application.

[0027] Figure 4 This is a block diagram of a control device for a boom assembly according to an embodiment of this application. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0029] In the safety control of the boom assembly of a high-lift fire truck, to address the stability challenges posed by the water cannon's reaction force, a commonly used control method is to adjust the posture based on the overall safe range of the boom assembly's center of gravity. Specifically, the center of gravity of the assembly is calculated by obtaining the tilt angle of each boom section, and the influence of the water cannon's reaction force is superimposed to calculate a virtual dynamic center of gravity position. Its basic working principle is that when the virtual center of gravity position is determined to exceed the preset safe range, the angle between adjacent boom sections is adjusted to bring the center of gravity back to the safe area, thereby preventing the vehicle from overturning. Its widespread application is mainly due to its ability to provide a relatively clear safety criterion and adjustment logic from an overall stability perspective.

[0030] However, when this solution is applied to multi-section booms, especially in structures where the end boom section is relatively lightweight and slender, its control effect is not ideal. A fundamental contradiction lies in the fact that, in order to optimize its overall stability control, its single center of gravity safety criterion inevitably impairs the ability to monitor and protect against local structural deformations, and may even lead to structural damage risks to the boom itself. Specifically, when the end boom undergoes significant bending deformation under the reaction force of the water cannon, its impact on the center of gravity of the entire boom assembly is negligible due to its small mass proportion, and the center of gravity safety criterion may not trigger an adjustment command. However, at this time, the actual stress of the end boom may have approached or exceeded the material yield limit, posing a risk of plastic deformation or fracture.

[0031] Through in-depth analysis, the inventors discovered that the root causes of the aforementioned contradictions are multifaceted: From a mechanical perspective, the boom assembly is a continuous elastic system. The internal forces and deformations generated by the water cannon reaction force within the system are unevenly distributed, with the end boom being the weakest link in terms of stress and deformation. Furthermore, the overall center of gravity reflects the average position of the system's center of mass, and the two are not physically equivalent. From a control perspective, the control objective of the existing solution (keeping the center of gravity within the frame) does not correspond one-to-one with the risks that need to be prevented (local stress exceeding limits). Using overall indicators as proxy variables for local dangerous conditions inherently leads to monitoring failures. Moreover, from a design perspective, blindly increasing the boom cross-sectional dimensions to improve overall stiffness to address this monitoring blind spot incurs negative costs in terms of weight, cost, and mobility. These factors collectively limit the performance ceiling of the existing solution while ensuring all-around operational safety.

[0032] To address the aforementioned issues, this application proposes a control method for boom assemblies. By introducing an independent structural deformation safety criterion for the end boom and performing parallel monitoring and coupled decision-making with the traditional overall center of gravity safety criterion, the risk identification and decision-making processes in the safety control logic are improved. This effectively enhances the protection against local structural overload deformation and avoids the risk of hidden structural damage due to monitoring gaps without significantly sacrificing the original overall anti-tipping safety. In other words, it provides a control method that integrates both local deformation and overall offset safety parameters to solve the problem that existing solutions cannot effectively prevent excessive bending deformation of the end boom in long boom and high reaction force operation scenarios, achieving a technical effect that balances overall stability and local structural safety under complex working conditions.

[0033] In one embodiment of this application, the control system corresponding to the control method can be deployed in the control unit of a high-rise fire truck, typically including a sensor group, a controller, and actuators. The sensor group is used to collect status information, and may include, but is not limited to: angle sensors installed at each boom hinge point or specific location to measure the relative angle between booms or the absolute tilt angle of the boom; flow and pressure sensors installed at the water cannon outlet, or force sensors directly installed at the boom end to acquire or calculate the water cannon reaction force; optionally, strain gauges (for directly measuring deformation) may also be included installed on the end boom. The controller can be the vehicle's existing vehicle controller, a dedicated boom control PLC (Programmable Logic Controller), or an embedded processor. It receives data from the sensor group, executes the control method of this application, and generates control commands. The actuators mainly refer to the hydraulic cylinders that drive the movement of each boom and their corresponding electro-hydraulic proportional valves or servo valves. The angle adjustment commands issued by the controller are ultimately converted into control signals for the corresponding cylinders, changing the angle between booms by pushing or pulling the cylinders, thereby adjusting the boom posture.

[0034] The following description, with reference to the accompanying drawings, outlines a control method for a boom assembly, a computer-readable storage medium, a vehicle, and a control device for a boom assembly, as proposed in embodiments of this application.

[0035] Figure 1 This is a flowchart of a control method for a boom assembly according to an embodiment of this application.

[0036] like Figure 1 As shown, the control method for the boom assembly in this application embodiment may include the following steps: S1, obtain the deformation and maximum allowable rotation angle of the end boom in the boom assembly, and obtain the preset center of gravity range and actual center of gravity range of the boom assembly. The deformation is the change in rotation angle caused by the reaction force of the water cannon on the boom assembly, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon.

[0037] Specifically, when controlling the boom assembly, the deformation and maximum permissible rotation angle of the end boom are first obtained, along with the preset and actual center of gravity ranges of the boom assembly. The purpose of obtaining the deformation of the end boom is to monitor its structural response in real time under the reaction force of the water cannon. Deformation is a key input parameter for assessing the safety of a local structure. In this application, "deformation" specifically refers to the change in rotation angle caused by the reaction force of the water cannon on the boom assembly. That is, it measures the difference between the current actual attitude angle of the end boom and its expected attitude angle when not subjected to the water cannon reaction force (or under a theoretical rigid model).

[0038] One specific implementation method is to directly measure the angle change using an angle sensor installed at the root of the end boom or at the hinge point with an adjacent boom. For example, the change in the angle sensor reading can be compared before and after the water cannon is activated. This direct measurement method allows for quick and intuitive acquisition of deformation information without the need for complex intermediate calculations.

[0039] More generally, the methods for obtaining deformation are not limited to direct angle measurement. For example, they may include, but are not limited to: measuring the strain distribution by multiple strain gauges mounted on the end boom and then calculating the end rotation angle based on beam bending theory in mechanics of materials; or, identifying the displacement of specific marked points on the end boom using a vision system and then calculating the rotation angle; or, measuring the angular velocity of the end boom using a high-precision inertial measurement unit and integrating it to obtain the attitude change. All these methods can achieve the higher-level function of obtaining information characterizing the degree of deformation of the end boom structure.

[0040] In a specific example, an angle sensor is installed at the root hinge point of the end boom to measure the relative angle of that boom section with respect to the preceding boom section. The controller stores reference angle values ​​for each sensor when the water cannon is off and the boom system is in a balanced state without external load. When the water cannon is activated and generates reaction force, the controller reads the real-time angle of the sensor and subtracts it from the stored reference value; the difference is taken as the deformation (angle change). Those skilled in the art will understand that if the reference value is a theoretically calculated value, it can also be directly compared with the theoretical value. Furthermore, the sampling frequency of the deformation can be adjusted between 10Hz and 100Hz according to control requirements, and different filtering algorithms such as mean filtering and low-pass filtering can be used for the rate of change.

[0041] It should be noted that obtaining accurate deformation requires knowing or accurately estimating the state without external load. In some embodiments, an instantaneous reference can be obtained by briefly shutting down the water cannon, or online prediction can be performed using a high-precision attitude estimation model. This feature provides the most direct input data for subsequent judgment of whether the boom is in a dangerous deformation state. Furthermore, in this application, a boom assembly refers to any mechanical structural component formed by multiple boom sections connected by hinge points, capable of changing its spatial attitude and end position by adjusting the relative angles between the boom sections. For example, it may include, but is not limited to, multi-section straight or folding boom structures for aerial spray fire trucks, telescopic or articulated boom structures for engineering machinery, or combinations thereof. The end boom specifically refers to the boom section located at the farthest end of the boom assembly, used to directly or indirectly support the end effector (such as a water cannon) and thus directly bears the reaction force generated by the end effector. For example, it may include, but is not limited to, the last boom section in a multi-section boom, the boom section in the boom assembly where the water cannon is installed, or the boom section determined by force analysis to be most affected by the reaction force. The preset center of gravity range refers to a theoretically safe area for the center of gravity of the boom assembly, calculated based on its current posture (angle, length, and mass distribution of each boom segment) when it is not subjected to water cannon reaction force, to ensure the overall stability of the boom assembly. For example, it may include, but is not limited to, the geometric region formed by the center of gravity position and its allowable offset range calculated according to a static model under the assumption of an ideal rigid boom. The actual center of gravity range specifically refers to the actual position and dynamic range of the center of gravity of the boom assembly after it has been subjected to water cannon reaction force, with the actual deformation of the end boom (such as changes in rotation angle) as a correction parameter. For example, it may include, but is not limited to, the dynamic center of gravity position and its distribution range obtained by superimposing the change in center of mass position caused by boom deformation onto the theoretical center of gravity. Deformation refers to the degree of shape change of the end boom due to external forces (mainly water cannon reaction force). Its core function is to characterize the degree to which the structure deviates from its original stress-free state. Specifically, it can refer to the angular change (angular deformation) of the end boom relative to its theoretical rigid position, measured by an angle sensor, or it can encompass the linear displacement (deflection) of a specific point on the boom, measured and calculated by strain gauges. For example, in one embodiment, "deformation" specifically refers to the angle through which the end boom axis rotates relative to its theoretical axis in a vertical or horizontal plane. The maximum permissible angle in this application is a pre-calculated or calibrated static or quasi-static parameter, which can be calculated and stored in the controller according to the boom model before the vehicle leaves the factory, or it can be refreshed according to the actual extension length before each operation.

[0042] In other words, the feature of obtaining the preset and actual center of gravity ranges of the boom assembly aims to inherit and integrate the input parameters of traditional center of gravity safety control to maintain overall stability control capabilities. The preset center of gravity range is the safe working area calculated based on the vehicle's own parameters (such as outrigger span and vehicle center of gravity) and the boom's unloaded posture. The actual center of gravity range is the real-time estimated position or state of the combined center of gravity of the boom assembly and the vehicle body after being subjected to the reaction force of the water cannon. Obtaining the preset center of gravity range can be achieved by pre-storing a safety boundary data table for different boom assembly postures (angles between each boom) in the controller, or by real-time calculation through geometric and mechanical models. Obtaining the actual center of gravity range requires comprehensively considering the known parameters of the current boom posture angles, the mass and center of gravity positions of each boom and water cannon, and the magnitude and direction of the water cannon reaction force. Through mechanical calculations, the position of the system's center of gravity after loading is obtained. That is, determining whether the actual center of gravity range exceeds the preset center of gravity range means determining whether the real-time center of gravity position has crossed the preset safety boundary.

[0043] S2, when the actual center of gravity range exceeds the preset center of gravity range, determine the adjustment amount of the boom angle between the end boom and the adjacent boom based on the actual center of gravity range. The preset center of gravity range can be determined according to the actual situation.

[0044] Specifically, the relationship between the actual center of gravity range and the preset center of gravity range is assessed. If the actual center of gravity range exceeds the preset range, it indicates that the actual center of gravity has deviated from the safe operating area, posing a risk of overturning or structural failure. When determining the adjustment amount of the boom angle between the end boom and adjacent booms based on the actual center of gravity range, the deformation direction, deformation degree, and vector characteristics of the center of gravity offset must be comprehensively considered. For example, if the change in angle in the vertical plane manifests as an upward or downward tilt in the pitch direction, and the actual center of gravity range deviates outward along the boom extension direction beyond the preset threshold, then the boom angle adjustment should prioritize reducing the pitch angle between the end boom and adjacent booms, causing the end boom to retract and reduce the lever arm length. If the change in angle in the horizontal plane manifests as a left-right sway, and the actual center of gravity range deviates laterally beyond the safety boundary, then the boom angle adjustment needs to simultaneously correct the horizontal rotation angle and pitch angle, using a composite adjustment of spatial attitude to bring the center of gravity projection back into the preset center of gravity range. When calculating the specific adjustment value, a local coordinate system with the adjacent boom hinge points as the origin can be established. The coordinate values ​​of the actual center of gravity position are compared with the boundary equation of the preset center of gravity range. The minimum angle adjustment required to return the center of gravity to the safe area is solved by inverse kinematics. This adjustment amount must meet the response speed and execution accuracy constraints of the boom hydraulic drive system to avoid secondary vibration or impact load caused by excessive adjustment.

[0045] The feature "determines the boom angle adjustment amount based on the actual center of gravity range when the actual center of gravity range exceeds the preset center of gravity range" performs a judgment and preliminary calculation of the overall stability dimension. For example, based on the direction and magnitude of the current center of gravity offset, it can calculate which boom sections need to be adjusted by how many degrees to bring them back to a safe range. This calculated adjustment amount is the boom angle adjustment amount, which is a suggested angle adjustment value aimed at restoring overall stability.

[0046] S3, when the end boom is determined to be in a deformed state based on the angle change value and the maximum allowable angle, the target adjustment angle is determined based on the maximum allowable angle and the boom angle adjustment amount, so as to control the boom assembly based on the target adjustment angle.

[0047] Specifically, after obtaining the angle change value and the maximum permissible angle, it is possible to determine whether the end boom is in a deformed state based on these values. For example, the relationship between the angle change value and the maximum permissible angle can be used to determine whether the end boom is in a deformed state. If the angle change value is greater than the maximum permissible angle, it indicates that the end boom has undergone structural deformation, posing a risk of overturning or structural failure. In this case, the attitude adjustment mechanism needs to be activated immediately to restore the stability of the boom system. More generally, being in a deformed state can be a Boolean value (yes / no) or a value representing the degree of danger (e.g., mild, moderate, severe). The judgment logic is not limited to a simple "greater than". For example, it can be determined as a "warning state" when the deformation reaches 80% of the maximum permissible angle, and a "dangerous deformation state" when it reaches 100%. These variations can all achieve the function of risk identification.

[0048] After determining the maximum turning angle and boom angle adjustment amount, the target adjustment angle can be determined based on these two values. For example, the opening degree can be determined according to a pre-defined relationship. For instance, by pre-determining the relationship between the maximum allowable turning angle and the boom angle adjustment amount, the target adjustment angle can be determined directly by calling the relationship after the maximum allowable turning angle and boom angle adjustment amount are determined. Furthermore, the strategy for determining the target adjustment angle is not limited to simply taking the maximum value. For example, it could be a weighted sum of the two values, or an angle that simultaneously optimizes two objective functions within an allowable adjustment range. After determining the target adjustment angle, the controller generates corresponding control commands. These commands need to be converted into control signals for the hydraulic actuators, driving the cylinders to change the angle between the end boom and adjacent booms, thus achieving attitude adjustment. The adjustment direction is usually to reduce the current angle, causing the boom to move towards a more retracted and stable posture, reducing the lever arm of the water cannon reaction force, thereby reducing the bending moment on the end boom and the overall overturning moment.

[0049] Therefore, when the reaction force generated by the water cannon spray acts on the end boom, if the boom angle is too large, the lever arm of the reaction force will increase significantly, resulting in a large bending moment at the root of the end boom and creating an unfavorable overturning moment for the entire vehicle. By reducing the boom angle in time, the lever arm of the reaction force can be shortened, directly reducing the bending stress on the end boom and preventing plastic deformation or fatigue damage to the local structure due to overload. At the same time, adjusting the boom posture towards the retracted direction can lower the center of gravity of the entire vehicle, improve the moment balance, significantly reduce the overturning moment, and improve the overall stability during operation. By monitoring the angle between the end boom and adjacent booms in real time and automatically triggering posture adjustment when the angle reaches the maximum allowable angle, the risk of structural instability caused by excessive boom extension can be effectively prevented. This active control method based on angle monitoring transforms traditional passive protection into active prevention, enabling the boom assembly to maintain optimal mechanical state under complex working conditions, extending the service life of the structure and providing reliable protection for the safety of aerial work. In addition, this control method can achieve rapid response without human intervention, making it particularly suitable for emergency scenarios such as fire fighting, and can minimize equipment risks while ensuring spraying effect.

[0050] According to one embodiment of this application, determining the maximum permissible rotation angle of the end boom includes: determining the maximum bending stress based on the boom structure safety factor; and determining the maximum permissible rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom.

[0051] Specifically, when determining the maximum permissible rotation angle of the end boom, the maximum bending stress can be determined based on the boom structure safety factor. This maximum bending stress is not the ultimate strength of the boom material, but rather an allowable stress value derived by comprehensively considering the material's yield strength, fatigue life reserve, and dynamic load impact coefficient. The boom structure safety factor is typically set according to relevant national standards or industry specifications. For special equipment such as fire trucks undertaking emergency rescue missions, considering the complexity of operating conditions and the severity of failure consequences, the safety factor is often set at an upper limit or even higher. The maximum bending stress that the structure can withstand during its service life can be obtained by dividing the material's yield strength by this safety factor. This value ensures that the elastic deformation of the boom under rated load is within a controllable range and also provides a necessary safety margin for unexpected overload situations.

[0052] After obtaining the maximum bending stress, the maximum allowable rotation angle needs to be calculated further by combining the cross-sectional parameters of the end boom. The cross-sectional parameters of the end boom include geometric characteristics such as the moment of inertia and section modulus, which directly determine the boom's ability to resist bending deformation. According to the bending normal stress formula in mechanics of materials, the maximum bending stress is directly proportional to the bending moment and inversely proportional to the section modulus. When the boom is in a horizontally extended state, the bending moment at the root of the end boom is the largest, which is determined by the boom's self-weight, end load, and boom angle. By establishing a boom mechanical model and using the maximum bending stress as a constraint, the corresponding critical angle can be solved, which is the maximum allowable rotation angle. In the specific calculation process, the boom needs to be simplified as a cantilever beam structure, considering the coupling effect between multiple boom sections. Iterative solutions are then performed using the principle of virtual work or the finite element method to ultimately determine the optimal rotation angle threshold that satisfies both strength requirements and the operating range.

[0053] Furthermore, determining the maximum permissible turning angle requires comprehensive consideration of multiple constraints, including the stroke limit of the boom luffing cylinder, the mechanical interference boundary between adjacent booms, and the overall vehicle stability boundary. When the turning angle threshold calculated based on bending strength conflicts with other constraints, the minimum value should be taken as the final maximum permissible turning angle to ensure that the control strategy can be effectively executed under all operating conditions. This optimization method under multiple constraints makes the maximum permissible turning angle both a hard boundary for structural safety and a decision-making basis for the intelligent control system, providing a precise trigger threshold for subsequent automatic attitude adjustment.

[0054] Therefore, the maximum allowable rotation angle determined by the comprehensive optimization method under the above-mentioned multi-constraint conditions can effectively solve the problem of overly conservative or overly aggressive rotation angle settings caused by single strength constraints in traditional boom control. On the one hand, mechanical calculations with bending strength as the core ensure the structural safety of the boom under extreme working conditions, avoiding plastic deformation or fatigue damage caused by excessive rotation angle; on the other hand, the integration of cylinder stroke, mechanical interference, and stability boundary constraints makes the rotation angle threshold more closely match the actual operating scenario, maximizing the boom's working space while ensuring safety.

[0055] According to one embodiment of this application, determining the maximum bending stress based on the boom structure safety factor includes: determining the allowable stress of the material based on the yield strength of the material used in the end boom and the boom structure safety factor, so as to use the allowable stress as the maximum permissible bending stress.

[0056] Specifically, when determining the maximum bending stress based on the boom structure safety factor, the allowable stress of the material can first be determined based on the yield strength of the material used in the end boom and the boom structure safety factor. The allowable stress reflects the maximum stress level that the material can withstand under a specific safety factor and is a fundamental parameter for structural strength design. In practical engineering applications, the end boom is usually made of high-strength alloy steel or composite materials, and its yield strength can be obtained through material performance tests or standard specifications. Directly using the calculated allowable stress as the maximum allowable bending stress means that in the subsequent calculation of the maximum allowable rotation angle, the bending stress of the end boom must not exceed this threshold under any working condition. This approach simplifies the engineering calculation process while ensuring the consistency of the safety margin. When the water cannon sprays at maximum flow rate, the reaction force is transmitted to each boom section through the end boom, forming a bending moment distributed along the boom length. Through finite element analysis or analytical calculation methods, a mapping relationship between the boom rotation angle and the maximum bending stress can be established, and then the critical rotation angle value that satisfies the strength constraints can be derived.

[0057] It is worth noting that allowable stress is also used to evaluate the design control stress of the end boom under the reaction force of the water cannon. The determination of the design control stress also needs to consider the influence of dynamic effects. Pressure pulsations and fluid impacts occur during water cannon spraying, causing the reaction force to exhibit periodic fluctuations. Therefore, based on static calculations, a dynamic load factor is usually introduced to correct the allowable stress, or an equivalent static load method is used to convert the dynamic reaction force into a static load with the same damage effect. This dynamic strength verification method can more accurately reflect the stress response of the boom in actual operation, avoiding potential failure risks caused by neglecting dynamic amplification effects.

[0058] For example, if the end boom material is Q460 high-strength steel with a yield strength of 460 MPa, and a safety factor of 2.0 is selected based on factors such as the load spectrum and importance of the operation, then the allowable stress is 230 MPa. This allowable stress is determined as the design control stress for assessing the strength and safety of the boom, i.e., the maximum bending stress. This step links the macroscopic "safety factor" with the microscopic "material strength," ensuring that the starting point for the threshold calculation is scientific and conforms to engineering specifications.

[0059] This simplifies the safety assessment process under complex dynamic loads and fundamentally ensures the structural integrity and reliability of the boom assembly throughout the entire high-pressure water cannon operation cycle.

[0060] According to one embodiment of this application, determining the maximum permissible rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom includes: determining the moment of inertia and section modulus of the end boom based on the cross-sectional parameters, wherein the moment of inertia is used to characterize the end boom's ability to resist bending deformation, and the section modulus is used to characterize the bending bearing capacity of the end boom section; determining the theoretical bending deformation curve of the end boom under the maximum bending stress based on the product of the maximum bending stress and the section modulus, and the distance from the point of application of the water cannon reaction force on the end boom to the fixed end; determining the limit value of the rotation angle of the free end of the end boom relative to the fixed end based on the theoretical bending deformation curve, and determining the limit value of the rotation angle as the maximum permissible rotation angle.

[0061] Specifically, the cross-sectional parameters include the moment of inertia and section modulus. For common box-shaped, circular tube-shaped, or I-shaped cross-sections, these parameters can be directly calculated based on the cross-sectional dimensions (such as length and width). When determining the maximum allowable rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom, the moment of inertia and section modulus of the end boom are first determined based on the cross-sectional parameters. The moment of inertia characterizes the end boom's ability to resist bending deformation, while the section modulus characterizes the bending load-bearing capacity of the end boom section, determining the magnitude of the bending moment the section can withstand under a specific bending stress level. Subsequently, based on the product of the maximum bending stress and the section modulus, the maximum bending moment that the end boom can withstand under the ultimate state can be calculated. Combining the distance from the point of application of the water cannon reaction force on the end boom to the fixed end, i.e., the lever arm length, the theoretical bending deformation curve of the end boom under the ultimate bending moment can be derived from the relationship between the bending moment and the lever arm. This curve describes the deflection distribution law of the end boom at each cross-section from the fixed end to the free end, reflecting the overall deformation mode of the boom under the ultimate load.

[0062] Furthermore, by performing differential operations or geometric analysis on the theoretical bending deformation curve, the slope of the tangent at the free end of the curve is obtained. This slope is the limit value of the rotation angle of the free end of the end boom relative to the fixed end. Determining this limit value as the maximum allowable rotation angle means that in actual operation, as long as the real-time monitored rotation angle of the end boom does not exceed this threshold, the maximum bending stress of the boom can be ensured to always be within the allowable stress range, thereby fundamentally guaranteeing the structural safety of the boom. This calculation process organically combines the strength theory in mechanics of materials with structural deformation analysis, realizing an effective conversion from stress control to deformation monitoring, and providing a precise theoretical basis for subsequent real-time safety control based on rotation angle thresholds.

[0063] In a specific example, after obtaining the moment of inertia I and section modulus W of the section, and obtaining the maximum bending stress σ_max and section modulus W, the ultimate bending moment M_max = σ_max that the critical section of the boom (usually the root) can withstand can be obtained. W. However, the maximum allowable rotation angle is the end rotation angle, and its calculation requires knowing the load information. Assuming the water cannon reaction force F acts at the end, and the lever arm is L, then the actual root bending moment is FL. When the actual bending moment reaches the ultimate bending moment M_max, the material stress reaches the allowable stress. At this time, the corresponding end rotation angle can be obtained through the beam bending deformation formula. For the cantilever beam under concentrated force model, the end rotation angle θ = (F L^2) / (2 E I). Simultaneously, the limiting state has FL = M_max = σ_max. W. Let F = σ_max Substituting W / L into the angle formula, we get θ_lim=(σ_max) W L) / (2 E (I) For a specific cross-section, W / I is often related to the cross-section height h (e.g., for a rectangular cross-section, W / I = 2 / h). Therefore, the final θ_lim can be expressed as a function related to the allowable stress σ_max of the material, the boom span L, the material elastic modulus E, and the cross-section height h. This calculation process closely integrates cross-section geometry, material mechanical properties, and stress models, and the derived maximum allowable rotation angle has a clear physical meaning.

[0064] Assuming the end boom has a rectangular hollow cross-section with an outer height h = 0.3m and an elastic modulus E = 210GPa, and based on the previously calculated σ_max = 230MPa, and assuming a lever arm L = 6m, θ_lim can be obtained by substituting into the formula. Those skilled in the art will understand that the above calculation is based on a simplified cantilever beam model with concentrated load. In practical applications, the water cannon reaction force may not be a purely concentrated force, and the boom may have a variable cross-section or be locally reinforced. In such cases, finite element analysis software can be used for more accurate calculations, or the calculation model can be modified to include distributed loads, multiple concentrated forces, or the influence of shear deformation can be considered. The calculation formula can also be in other equivalent forms, such as formulas derived based on the strain energy method. Furthermore, the safety factor for the boom structure is not limited to 2.0 and can be selected within a reasonable range of 1.5 to 3.0 according to different safety level standards (such as national standards and enterprise standards). The allowable stress can also be determined by dividing the tensile strength by a larger safety factor.

[0065] Therefore, by monitoring the water cannon reaction force in real time and dynamically calculating the boom's limit attitude angle, the boom can automatically adjust to the optimal working posture under different working conditions. This avoids both the limitation of the working range caused by an overly conservative posture and the risk of structural overload caused by an overly aggressive posture. This real-time feedback-based control method significantly improves the adaptability and reliability of the boom assembly, enabling it to cope with complex and ever-changing actual operating environments. Furthermore, the control method proposed in this application has good versatility and scalability. This method is not only applicable to standard boom structures, but can also be adapted to boom products of different specifications and uses by adjusting material parameters, safety factors, and calculation models.

[0066] According to one embodiment of this application, determining the target adjustment angle based on the maximum permissible turning angle and the boom angle adjustment amount includes: when the maximum permissible turning angle is greater than or equal to the boom angle adjustment amount, taking the maximum permissible turning angle as the target adjustment angle; when the maximum permissible turning angle is less than the boom angle adjustment amount, taking the boom angle adjustment amount as the target adjustment angle.

[0067] Specifically, when determining the target adjustment angle based on the maximum permissible rotation angle and the boom angle adjustment amount, the relationship between these two factors can be assessed. If the maximum permissible rotation angle is greater than or equal to the boom angle adjustment amount, the maximum permissible rotation angle is used as the target adjustment angle. Conversely, if the maximum permissible rotation angle is less than the boom angle adjustment amount, the boom angle adjustment amount is used as the target adjustment angle. In other words, when the maximum permissible rotation angle is greater than or equal to the boom angle adjustment amount, it indicates that the boom structure has sufficient safety margin under the current working conditions and can fully respond to the attitude adjustments required by control commands. In this case, using the maximum permissible rotation angle as the target adjustment angle can fully utilize the boom's working space and maximize operational efficiency. Conversely, when the maximum permissible rotation angle is less than the boom angle adjustment amount, it means that adjusting according to the original plan would exceed the structure's safe bearing capacity. In this case, using the boom angle adjustment amount as the target adjustment angle effectively limits the adjustment requirements, ensuring that the boom always operates within the safety boundaries. This dual-judgment mechanism embodies the core idea of ​​proactive safety control: on the one hand, it dynamically identifies the safety status of the current operating condition by comparing two key parameters in real time; on the other hand, it automatically selects a more conservative control strategy based on the comparison result, forming hardware-level safety redundancy. It should be noted that the "target adjustment angle" here may, in specific implementation, be expressed as directly using this value, or it may be expressed as the result of optimization calculations with this value as the constraint boundary, depending on the trajectory planning algorithm used.

[0068] In short, the maximum value of the two is taken as the final target adjustment angle Δθ_target = max(θ_lim, Δθ_cg), where Δθ_cg is the angle adjustment amount required to correct the center of gravity. The principle behind this decision-making logic is that the maximum permissible rotation angle θ_lim is the theoretical limit reference value for the adjustment angle required to control deformation within a safe range, based on material strength (e.g., how many degrees of springback are needed to bring the stress below the allowable value). Δθ_cg, on the other hand, is the angle adjustment required to restore the center of gravity to its original position, based on overall stability. Taking the maximum value means that the final adjustment action will satisfy the more stringent requirement (i.e., the larger adjustment range required). If the deformation safety requirement is an adjustment of 5 degrees and the center of gravity safety requirement is an adjustment of 3 degrees, then an adjustment of 5 degrees is made, which satisfies both deformation control (more stringent) and the center of gravity adjustment requirement (because the adjustment range is larger). Conversely, if the center of gravity safety requirement is an adjustment of 7 degrees and the deformation safety requirement is an adjustment of 4 degrees, then an adjustment of 7 degrees is made, which, while restoring the center of gravity, will also necessarily correct the deformation to a greater extent.

[0069] Those skilled in the art will understand that maximizing the value is the core of the decision-making process. In some variations, the maximum value can be multiplied by a coefficient slightly greater than 1 (e.g., 1.1) to provide additional safety margin. Alternatively, different priority weights can be assigned to the two input values, but when the final angle command is expressed, it is still equivalent to using a more stringent constraint value. Furthermore, the objects of comparison and selection are not limited to the original values, but can also be filtered or processed values.

[0070] Therefore, by employing the aforementioned decision-making logic that takes the largest value, this preferred solution can quickly and decisively determine the final angle command to be executed between the structural safety angle limit and the angle adjustment required for center of gravity stability. This further helps to solve the problem of potentially ambiguous or conflicting control commands under multiple safety constraints, thereby synergistically strengthening the overall technical effect of the present invention's integrated dual-criteria control. It is foreseeable that when this decision-making logic is used in combination with the aforementioned parameter acquisition and state judgment features, a complete and robust safety control chain from perception and judgment to decision-making will be formed.

[0071] According to one embodiment of this application, determining that the end boom is in a deformed state based on the angle change value and the maximum permissible angle includes: determining that the end boom is in a deformed state when the angle change value is greater than the maximum permissible angle.

[0072] Specifically, when determining that the end boom is in a deformed state based on the angle change value and the maximum permissible angle, the relationship between the angle change value and the maximum permissible angle is judged. If the angle change value is greater than the maximum permissible angle, it indicates that the actual deformation of the end boom has exceeded the preset safety threshold. At this point, the end boom is immediately determined to be in a deformed state, and the corresponding safety control response is triggered. This judgment logic is simple and clear, avoiding complex intermediate calculations or fuzzy interval judgments, ensuring that decisions can be made quickly when structural safety is threatened.

[0073] It should be noted that in practical engineering applications, considering the impact of sensor measurement noise and environmental vibration interference, an auxiliary confirmation mechanism can be introduced into the basic judgment logic mentioned above to avoid misjudgment. For example, it can be required that the angle change value is greater than the maximum allowable angle for several consecutive control cycles, or cross-verification can be performed by combining the boom vibration frequency characteristics, before the deformation state can be finally confirmed. Although this delayed confirmation strategy sacrifices extremely short response time, it significantly reduces the probability of false triggering caused by instantaneous interference and improves the overall reliability of the control system.

[0074] Therefore, through the deformation determination mechanism based on the change in rotation angle and the maximum allowable rotation angle, this embodiment of the application achieves real-time, accurate monitoring and rapid response to the structural status of the end boom. On the one hand, the direct size comparison judgment logic significantly reduces computational complexity, enabling the control system to complete status identification within milliseconds, meeting the real-time requirements of high-dynamic operation scenarios in construction machinery. On the other hand, the optional auxiliary confirmation mechanism effectively filters out false signals caused by sensor noise and environmental interference through multi-cycle verification or cross-analysis of vibration characteristics, keeping the false alarm rate within an acceptable range for engineering applications, while balancing judgment accuracy and system robustness. This hierarchical and progressive judgment strategy ensures safe response speed under extreme working conditions and improves operational stability in daily operations through an adaptive confirmation process, providing reliable technical assurance for the long-term safe service of the boom assembly.

[0075] According to one embodiment of this application, the control method for the boom assembly further includes: issuing a warning when it is determined that the end boom is in a deformed state.

[0076] Specifically, as an additional safety feature, a warning can be issued when the end boom is found to be deformed. The warning can take several forms. For example, a prominent red icon and text "End boom deformation exceeds limits!" can be displayed on the multi-function display screen in the fire truck cab; simultaneously, a rapid alarm sound can be emitted. Alternatively, the warning information can be sent to a remote control or rear command platform via the vehicle bus, expanding the alarm range. The warning information can include the exceeded value, the time of occurrence, and suggested actions (such as "The system is automatically adjusting" or "Please reduce the water cannon flow").

[0077] In summary, in a specific example, the controller continuously compares the real-time deformation θ_actual measured by the angle sensor with the stored maximum allowable rotation angle θ_lim. When the condition θ_actual > θ_lim is met, a flag representing the "deformation state" is set to "true". Simultaneously, the controller sends a predefined pre-alarm message to the instrument panel via the CAN bus, triggering an audible and visual alarm. Those skilled in the art will understand that the trigger threshold for the alarm is not necessarily strictly equal to θ_lim; a lead time can be set, for example, when θ_actual > 0.9. A primary warning (yellow alert) is triggered when θ_lim is reached, and a higher-level warning (red alert with automatic intervention) is triggered when θ_actual > θ_lim. Warning methods are not limited to sound and light; they can also include haptic feedback (steering wheel vibration) or remote network notifications.

[0078] Therefore, by adopting the aforementioned clear judgment criteria and linking them with early warning functions, this preferred solution enables intuitive and timely human-machine interaction regarding the safety status of the end-cap boom structure. This further helps improve the operator's situational awareness of hidden structural risks, adding a layer of human supervision to the automatic control system, thereby synergistically enhancing the overall technical effect of this invention in improving operational safety. This early warning feature can be combined with all the aforementioned control steps to form a composite safety system that includes automatic control and human monitoring.

[0079] To more specifically illustrate the technical effects of the present invention, a dynamic description is provided below in conjunction with a typical fire extinguishing application scenario.

[0080] Suppose a high-rise fire truck arrives at a fire scene to extinguish a fire on the middle floor of a high-rise building. The operator extends and levels the vehicle's outriggers and begins operating the boom. The boom assembly (e.g., containing 5 telescopic boom sections) gradually extends from its retracted state and is adjusted to a position with a longer horizontal extension distance to bring the water cannon closer to the fire. At this point, the end boom (the 5th boom section) is fully extended. After the boom's position stabilizes, the operator activates the water cannon for high-flow-rate spraying. The enormous reaction force generated by the high-pressure water jet instantly acts on the water cannon mounting point on the end boom. Initially, the water cannon reaction force causes elastic bending deformation of the end boom, and the angle sensor detects a deformation (angle change) of 2.5 degrees. The controller retrieves the maximum permissible angle θ_lim of the end boom in the current position from memory. This value has been pre-calculated as 5.0 degrees based on the boom extension length, material parameters, etc. Since 2.5 degrees < 5.0 degrees, the controller initially determines that the end boom is not in a deformation hazard state (the deformation status indicator is false).

[0081] Meanwhile, the controller calculates the actual center of gravity of the vehicle under load based on the boom angles, mass parameters, and water cannon reaction force. It is found that due to the relatively long horizontal extension of the boom and the large water cannon reaction force, the calculated actual center of gravity projection is close to the boundary of the stable area formed by the outriggers, but has not exceeded the preset safe center of gravity range. Therefore, the center of gravity shift did not trigger the adjustment conditions.

[0082] At this point, both safety dimensions are within safe limits, the system does not issue adjustment commands, and the boom maintains its current posture and continues spraying. The operator observes a slight droop at the boom tip (corresponding to a 2.5-degree deformation), but the system displays everything as normal.

[0083] As the firefighting progressed, the fire situation changed, necessitating a further increase in water cannon flow to improve extinguishing efficiency. This increased flow led to a greater reaction force (F) from the water cannon. This increased reaction force exacerbated the deformation of the end boom, with the deformation measured by sensors gradually increasing to 5.2 degrees, exceeding the maximum permissible angle of 5.0 degrees. The controller immediately set the deformation status flag to true and displayed a red warning on the cab display: "Warning: End boom deformation exceeds limit!" Simultaneously, the increased reaction force also exacerbated the vehicle's center of gravity shift. The controller recalculated and found that the actual center of gravity projection had slightly exceeded the preset safety range. The center of gravity shift also triggered adjustment conditions. Due to the simultaneous anomalies in both the deformation and center of gravity shift states, the controller entered an adjustment decision process. First, based on the magnitude and direction of the current center of gravity shift, it calculated that to restore center of gravity stability, the angle between the end boom and the adjacent boom needed to be reduced by Δθ_cg = 3.0 degrees. Then, the controller made the final decision. It compares the safety limit angle θ_lim (5.0 degrees) required to suppress deformation with the adjustment amount Δθ_cg (3.0 degrees) required to restore the center of gravity. According to the principle of taking the larger value, the target adjustment angle Δθ_target=max(5.0,3.0)=5.0 degrees.

[0084] The controller then generates control commands and sends them to the electro-hydraulic proportional valve of the hydraulic cylinder driving the end boom, instructing it to reduce the angle between the end boom and the middle boom by 5.0 degrees. The cylinder begins to actuate, and the boom posture changes slowly. As the angle decreases, the water cannon position is pulled back, which shortens the lever arm L of the water cannon reaction force on the end boom, thereby rapidly reducing the bending stress and deformation of the end boom. On the other hand, it also causes the center of gravity of the entire boom assembly to retract towards the vehicle body, helping the actual center of gravity position return to a safe range.

[0085] During the adjustment process, the operator could see the warning message still in effect, but the system status displayed "Automatic Adjustment in Progress." A few seconds later, the adjustment was complete. Sensor feedback showed that the deformation of the end boom had decreased to below 1.0 degree, far below the 5.0-degree limit; simultaneously, system calculations showed that the actual center of gravity had returned to a safe range. The warning message automatically dissipated, and the display screen returned to a green safe status. Although the water cannon's range was slightly shortened due to the boom retraction, it could still effectively cover the fire source, and the safety of the entire work platform was doubly guaranteed.

[0086] In this scenario, the present invention significantly improves the safety of the boom system of fire trucks while pursuing high-flow, long-range fire extinguishing efficiency. Traditional methods relying solely on center-of-gravity control may only adjust by 3.0 degrees when deformation reaches 5.2 degrees and the center of gravity just exceeds the limit. Although the center of gravity is stabilized, the deformation of the end boom remains in a dangerously high-stress state (after the 5.2-degree adjustment, there may still be a residual deformation of 2.2 degrees, which may still exceed the allowable stress). The present invention, by introducing deformation criteria and a maximum value decision, forces a 5.0-degree adjustment, completely unloading the deformation stress below a safe level. This proactively prevents potential fatigue damage or sudden failure of local structures, achieving a technical effect that balances overall stability and local structural safety.

[0087] The following is combined with Figure 2 The method described in this application is used to describe the method.

[0088] As a specific example, the control method for the boom assembly of this application may include the following steps: S101, obtain the deformation amount and maximum allowable rotation angle of the end boom in the boom assembly, and obtain the preset center of gravity range and actual center of gravity range of the boom assembly. The deformation amount is the rotation angle change value caused by the reaction force of the water cannon on the boom assembly, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon.

[0089] S102, determine whether the change in angle is greater than the maximum allowable angle. If yes, proceed to step S103; if no, proceed to step S101.

[0090] S103, confirm that the end boom is in a deformed state.

[0091] S104. Determine whether the actual center of gravity range exceeds the preset center of gravity range. If yes, proceed to step S105; if no, proceed to step S101.

[0092] S105, determine the adjustment amount of the boom angle between the end boom and the adjacent boom based on the actual center of gravity range.

[0093] S106, Determine whether the maximum permissible turning angle is greater than or equal to the boom angle adjustment amount. If yes, proceed to step S107; if no, proceed to step S109.

[0094] S107, use the maximum permissible turning angle as the target adjustment angle.

[0095] S108 controls the boom assembly by adjusting the angle based on the target.

[0096] S109, take the boom angle adjustment amount as the target adjustment angle, and proceed to step S108.

[0097] In summary, the control method for the boom assembly according to the embodiments of this application obtains the deformation amount and maximum permissible rotation angle of the end boom in the boom assembly, and obtains the preset center of gravity range and actual center of gravity range of the boom assembly. The deformation amount is the rotation angle change value caused by the reaction force of the water cannon on the boom assembly, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon. When the actual center of gravity range exceeds the preset center of gravity range, the adjustment amount of the boom angle between the end boom and adjacent booms is determined based on the actual center of gravity range. When the end boom is determined to be in a deformed state based on the rotation angle change value and the maximum permissible rotation angle, a target adjustment angle is determined based on the maximum permissible rotation angle and the boom angle adjustment amount, and the boom assembly is controlled based on the target adjustment angle. Therefore, this method can effectively solve the problem of excessive structural deformation that may occur in a single boom, and improve the collaborative control capability for the safety of the boom assembly.

[0098] Corresponding to the above embodiments, this application also proposes a computer-readable storage medium.

[0099] The computer-readable storage medium of this application embodiment stores a program that, when executed by a processor, implements the above-described control method for the boom assembly.

[0100] According to the computer-readable storage medium of the embodiments of this application, by executing the above-described control method for the boom assembly, the problem of excessive structural deformation that may occur in a single boom can be effectively solved, and the collaborative control capability for the safety of the boom assembly can be improved.

[0101] Corresponding to the above embodiments, this application also proposes a vehicle.

[0102] like Figure 3 As shown, the vehicle 200 in this embodiment may include: a memory 210, a processor 220, and a program stored in the memory 210 and executable on the processor 220. When the processor 220 executes the program, it implements the above-described control method for the boom assembly.

[0103] The vehicle according to the embodiments of this application, by executing the above-described control method for the boom assembly, can effectively solve the problem of excessive structural deformation that may occur in a single boom, and improve the coordinated control capability for the safety of the boom assembly.

[0104] Corresponding to the above embodiments, this application also proposes a control device for a boom assembly.

[0105] like Figure 4 As shown, the control device 100 for the boom assembly in this embodiment includes: an acquisition module 110, a determination module 120, and a control module 130.

[0106] The acquisition module 110 is used to acquire the deformation and maximum permissible rotation angle of the end boom in the boom assembly, and to acquire the preset center of gravity range and the actual center of gravity range of the boom assembly. The deformation is the change in rotation angle caused by the reaction force of the water cannon, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon. The determination module 120 is used to determine the adjustment amount of the boom angle between the end boom and adjacent booms based on the actual center of gravity range when the actual center of gravity range exceeds the preset center of gravity range. The control module 130 is used to determine the target adjustment angle based on the maximum permissible rotation angle and the boom angle adjustment amount when the end boom is determined to be in a deformed state, based on the change in rotation angle and the maximum permissible rotation angle, so as to control the boom assembly based on the target adjustment angle.

[0107] According to one embodiment of this application, the determining module 120 determines the maximum permissible rotation angle of the end boom, specifically for: determining the maximum bending stress based on the boom structure safety factor; and determining the maximum permissible rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom.

[0108] According to one embodiment of this application, the determining module 120 determines the maximum bending stress based on the boom structure safety factor, specifically used to: determine the allowable stress of the material based on the yield strength of the material used in the end boom and the boom structure safety factor, and use the allowable stress as the maximum allowable bending stress.

[0109] According to one embodiment of this application, the determining module 120 determines the maximum allowable rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom. Specifically, it is used to: obtain the cross-sectional moment of inertia and section modulus of the end boom, wherein the cross-sectional moment of inertia is used to characterize the end boom's ability to resist bending deformation, and the section modulus is used to characterize the bending bearing capacity of the end boom section; determine the theoretical bending deformation curve of the end boom under the maximum bending stress based on the product of the maximum bending stress and the section modulus, and the distance from the point of application of the water cannon reaction force on the end boom to the fixed end; determine the rotation angle limit value of the free end of the end boom relative to the fixed end based on the theoretical bending deformation curve, and determine the rotation angle limit value as the maximum allowable rotation angle.

[0110] According to one embodiment of this application, the determining module 120 determines the target adjustment angle based on the maximum permissible turning angle and the boom angle adjustment amount, specifically used for: when the maximum permissible turning angle is greater than or equal to the boom angle adjustment amount, taking the maximum permissible turning angle as the target adjustment angle; when the maximum permissible turning angle is less than the boom angle adjustment amount, taking the boom angle adjustment amount as the target adjustment angle.

[0111] According to one embodiment of this application, the determining module 120 determines that the end boom is in a deformed state based on the angle change value and the maximum allowable angle, specifically used to: determine that the end boom is in a deformed state when the angle change value is greater than the maximum allowable angle.

[0112] According to one embodiment of this application, the control module 130 is further configured to: issue a warning reminder when it is determined that the end boom is in a deformed state.

[0113] It should be noted that for details not disclosed in the control device of the boom assembly in the embodiments of this application, please refer to the details disclosed in the control method of the boom assembly in the embodiments of this application, which will not be repeated here.

[0114] According to the control device for the boom assembly in this application embodiment, the acquisition module is used to acquire the deformation amount and maximum allowable rotation angle of the end boom in the boom assembly, and to acquire the preset center of gravity range and actual center of gravity range of the boom assembly. The deformation amount is the rotation angle change value caused by the reaction force of the water cannon on the boom assembly, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon. The determination module is used to determine the boom angle adjustment amount between the end boom and adjacent booms based on the actual center of gravity range when the actual center of gravity range exceeds the preset center of gravity range. The control module is used to determine the target adjustment angle based on the maximum allowable rotation angle and the boom angle adjustment amount when the end boom is determined to be in a deformed state based on the rotation angle change value and the maximum allowable rotation angle, and to control the boom assembly based on the target adjustment angle. Therefore, this device can effectively solve the problem of excessive structural deformation that may occur in a single boom, and improve the coordinated control capability for the safety of the boom assembly.

[0115] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0116] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0117] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0118] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0119] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0120] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A control method for a boom assembly, characterized in that, The method includes: Obtain the deformation and maximum allowable rotation angle of the end boom in the boom assembly, and obtain the preset center of gravity range and actual center of gravity range of the boom assembly, wherein the deformation is the rotation angle change value of the boom assembly caused by the reaction force of the water cannon, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the reaction force of the water cannon. If the actual center of gravity range exceeds the preset center of gravity range, the adjustment amount of the boom angle between the end boom and the adjacent boom is determined based on the actual center of gravity range; When the end boom is determined to be in a deformed state based on the angle change value and the maximum permissible angle, a target adjustment angle is determined based on the maximum permissible angle and the boom angle adjustment amount, so as to control the boom assembly based on the target adjustment angle.

2. The control method for the boom assembly according to claim 1, characterized in that, Determining the maximum permissible angle of rotation of the end boom includes: The maximum bending stress is determined based on the safety factor of the boom structure. The maximum permissible rotation angle is determined based on the maximum bending stress and the cross-sectional parameters of the end boom.

3. The control method for the boom assembly according to claim 2, characterized in that, The determination of the maximum bending stress based on the boom structure safety factor includes: The allowable stress of the material is determined based on the yield strength of the material used in the end boom and the safety factor of the boom structure, so that the allowable stress is used as the maximum allowable bending stress.

4. The control method for the boom assembly according to claim 2, characterized in that, Determining the maximum permissible rotation angle based on the maximum bending stress and the cross-sectional parameters of the end boom includes: The moment of inertia and section modulus of the end boom are determined based on the cross-sectional parameters, wherein the moment of inertia is used to characterize the ability of the end boom to resist bending deformation, and the section modulus is used to characterize the bending bearing capacity of the end boom section. Based on the product of the maximum bending stress and the section modulus, and the distance from the point of application of the water cannon reaction force on the end boom to the fixed end, the theoretical bending deformation curve of the end boom under the maximum bending stress is determined. The rotation limit value of the free end of the end boom relative to the fixed end is determined based on the theoretical bending deformation curve, and the rotation limit value is determined as the maximum allowable rotation angle.

5. The control method for the boom assembly according to claim 1, characterized in that, Determining the target adjustment angle based on the maximum permissible rotation angle and the boom angle adjustment amount includes: If the maximum permissible rotation angle is greater than or equal to the boom angle adjustment amount, the maximum permissible rotation angle shall be taken as the target adjustment angle; If the maximum permissible turning angle is less than the boom angle adjustment amount, the boom angle adjustment amount shall be taken as the target adjustment angle.

6. The control method for the boom assembly according to claim 1, characterized in that, Determining that the end boom is in a deformed state based on the angle change value and the maximum permissible angle includes: If the change in rotation angle is greater than the maximum permissible rotation angle, the end boom is determined to be in a deformed state.

7. The control method for the boom assembly according to claim 6, characterized in that, The method further includes: If the end boom is found to be in a deformed state, a warning is issued.

8. A computer-readable storage medium, characterized in that, It stores a program that, when executed by a processor, implements the control method for the boom assembly according to any one of claims 1-7.

9. A vehicle, characterized in that, include: A memory, a processor, and a program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the control method for the boom assembly according to any one of claims 1-7.

10. A control device for a boom assembly, characterized in that, The device includes: The acquisition module is used to acquire the deformation amount and maximum allowable rotation angle of the end boom in the boom assembly, and to acquire the preset center of gravity range and actual center of gravity range of the boom assembly, wherein the deformation amount is the rotation angle change value of the boom assembly under the action of the water cannon reaction force, and the actual center of gravity range is the center of gravity range of the boom assembly after being subjected to the water cannon reaction force. The determining module is used to determine the adjustment amount of the boom angle between the end boom and the adjacent boom based on the actual center of gravity range when the actual center of gravity range exceeds the preset center of gravity range; The control module is used to determine a target adjustment angle based on the maximum allowable angle and the boom angle adjustment amount when the end boom is determined to be in a deformed state based on the angle change value and the maximum allowable angle, so as to control the boom assembly based on the target adjustment angle.

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