Loader driving stability analysis method and system

Abstract

The invention relates to a loader driving stability analysis method and system, and the method comprises four key links: real-time monitoring and critical threshold calculation, virtual potential field construction and threshold correction, unstable state determination and active intervention strategy, and the links form closed-loop control. The method effectively overcomes the defects of response lag and poor adaptability of a traditional method, and is characterized in that a critical dip angle threshold is dynamically adjusted, the critical dip angle threshold is corrected in real time through a virtual potential field, and key factors such as bucket load and wheel slippage are included into a stability evaluation system to correct the critical dip angle threshold through calculation of a mass potential barrier and a slippage vector. The stability limit of the loader under different road conditions and in different postures can be reflected more accurately, the hysteresis problem of a traditional fixed threshold value method is avoided, and finally, the bucket posture adjustment serves as a priority stability compensation means and is combined with speed adjustment, rapid response can be achieved at the initial stage of vehicle body instability, and the rollover risk is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of loaders, and in particular to a method and system for analyzing the driving stability of a loader. Background Art

[0002] As a crucial piece of equipment in the construction machinery sector, loaders face significant stability challenges in complex working conditions, particularly on slopes.

[0003] In actual operation, lateral slip under slope driving conditions is the most common and most dangerous form of instability. When the loader performs steering operations on an inclined road, due to the influence of the dynamic changes in the center of gravity position, a combined instability phenomenon of lateral slip and longitudinal rollover is very likely to occur.

[0004] Currently, the industry mainly improves driving stability by optimizing mechanical structure (such as lowering the center of gravity of the vehicle body) or adopting electronic stability systems (such as anti-rollover control algorithms). However, these methods have obvious limitations: mechanical structure optimization is limited by the design space and requires changes to the structure of the loader itself, making it difficult to adapt to changing working conditions; and existing electronic stability systems mostly rely on fixed threshold judgments, adjusting the output power only according to the size of the slope to control the speed of the loader. They are unable to dynamically adapt to the real-time state changes of the loader under different vehicle postures, resulting in control lag or misjudgment, affecting operating efficiency and safety. Summary of the Invention

[0005] To this end, the present invention proposes a loader driving stability analysis method and system. The core of this method is to dynamically adjust the critical inclination angle threshold. The critical inclination angle threshold is corrected in real time through a virtual potential field, which can more accurately reflect the stability limit of the loader under different road conditions and avoid the hysteresis problem of the traditional fixed threshold method. In addition, through the calculation of mass potential barriers and slip vectors, key factors such as bucket load and wheel slip are incorporated into the stability evaluation system to correct the critical inclination angle threshold. Finally, bucket posture adjustment is used as a priority stability compensation method, and combined with speed regulation, it can respond quickly in the early stage of vehicle body instability and reduce the risk of rollover.

[0006] To solve the above technical problems, the present invention provides a method for analyzing the driving stability of a loader, comprising the following steps:

[0007] Real-time monitoring of the loader's body inclination angle, combined with current road slope data, uses a dynamic balance algorithm to calculate the critical inclination angle threshold under current working conditions;

[0008] A virtual potential field is constructed based on the loader's body posture to dynamically correct the critical tilt angle threshold. The virtual potential field determines the potential field base plane based on the body's pitch and roll angles, calculates the mass distribution offset based on the loader's bucket angle and height, generates a corresponding mass barrier in the potential field, and derives a potential slip vector based on the speed difference between the driven and non-driven wheels to form the potential field gradient direction.

[0009] If the vehicle body tilt angle exceeds the corrected critical tilt angle threshold, it is determined to be in an unstable state;

[0010] When it is determined to be in an unstable state, the bucket rotation direction is first determined based on the potential field gradient direction, and the bucket rotation angle and height are determined based on the mass potential barrier. If it is still in this stable state, the loader's driving speed is gradually adjusted to match the loader's driving speed with the current road conditions.

[0011] In one embodiment of the present invention, the dynamic balancing algorithm simulates the center of gravity deviation trend of the loader at different slopes and gradually adjusts the critical inclination angle threshold so that it decreases as the slope increases and increases as the slope decreases;

[0012] In one embodiment of the present invention, the specific steps of dynamically correcting the critical tilt angle threshold include:

[0013] A three-dimensional coordinate system is established based on the potential field base plane, and the real-time monitored vehicle body tilt angle is projected onto the coordinate system;

[0014] According to the distribution position and strength of the mass barrier, a corresponding threshold correction is applied at the projection position, wherein the greater the mass barrier strength, the greater the correction;

[0015] The threshold offset compensation is performed along the potential field gradient direction. When the gradient direction is consistent with the vehicle body tilt direction, the correction amount is increased, and when the gradient direction is opposite, the correction amount is reduced.

[0016] In one embodiment of the present invention, the dynamically correcting critical tilt angle threshold further comprises: establishing a mapping relationship table between potential field parameters and threshold correction amounts, wherein:

[0017] For every 1 degree increase in the tilt angle of the potential field base plane, the critical tilt angle threshold decreases by 0.5 to 0.8 degrees;

[0018] For every level increase in mass barrier strength, the critical dip threshold decreases by 1 to 1.5 degrees;

[0019] When the angle between the potential field gradient direction and the vehicle body tilt direction is less than 30 degrees, the critical tilt angle threshold is reduced by 1.2 to 1.8 degrees.

[0020] In one embodiment of the present invention, the calculation of the mass distribution offset includes: obtaining material weight distribution data in the bucket, and calculating the offset vector of the material center of gravity relative to the vehicle body reference position in combination with the bucket lifting height and rotation angle.

[0021] In one embodiment of the present invention, the process of determining the potential field gradient direction further includes:

[0022] Monitor tire pressure data;

[0023] When the tire pressure on one side is abnormal, a compensation vector is applied in the direction of the potential field gradient on the corresponding drive wheel side. The size of the compensation vector is adjusted according to the degree of tire pressure deviation to correct the critical tilt angle threshold.

[0024] In one embodiment of the present invention, the determination of the bucket rotation direction includes: when a roll trend is detected, preferentially adjusting the bucket position in the opposite direction of the potential field gradient; when a pitch trend is detected, preferentially adjusting the bucket lifting height.

[0025] In one embodiment of the present invention, when an unstable state is determined, analyzing the severity level of the unstable state includes:

[0026] Level 1 instability: vehicle tilt exceeds the threshold by 5%-10%, and only the bucket position is adjusted;

[0027] Level 2 instability: When the vehicle body tilt exceeds the threshold by 10%-20%, the bucket position and driving speed are adjusted synchronously;

[0028] Level 3 instability: If the vehicle tilt angle exceeds the threshold by 20%, emergency braking will be performed immediately and an audible and visual alarm will be issued.

[0029] In one embodiment of the present invention, under wet and slippery road conditions, an additional tire slip ratio parameter is introduced:

[0030] Calculate the real-time slip rate through the wheel speed sensor;

[0031] When the slip rate continues to increase, the unstable state judgment is triggered in advance;

[0032] The road adhesion coefficient compensation vector is superimposed in the potential field gradient direction to correct the critical inclination angle threshold.

[0033] In order to solve the above technical problems, the present invention also provides a loader driving stability analysis system, comprising:

[0034] The tilt monitoring module is used to monitor the tilt angle of the loader in real time and collect the current road slope data;

[0035] A dynamic balance calculation module, connected to the tilt angle monitoring module, for calculating a critical tilt angle threshold under current working conditions using a dynamic balance algorithm;

[0036] A virtual potential field construction module is connected to the dynamic balance calculation module and is used to construct a virtual potential field according to the body posture of the loader to dynamically correct the critical tilt angle threshold, wherein:

[0037] The virtual potential field determines the potential field base plane based on the vehicle body pitch angle and roll angle; calculates the mass distribution offset based on the loader bucket angle and bucket height, and generates a corresponding mass potential barrier in the potential field; and derives the potential slip vector based on the speed difference between the drive wheel and the non-drive wheel to form the potential field gradient direction;

[0038] a stability determination module, connected to the virtual potential field construction module, for determining that the loader is in an unstable state when the vehicle body inclination angle exceeds the corrected critical inclination angle threshold;

[0039] The active adjustment module is connected to the stability determination module and is configured to perform the following operations when an unstable state is determined:

[0040] The bucket's rotation direction is determined based on the potential field gradient direction; the bucket's rotation angle and height are determined based on the mass potential barrier; and the loader's travel speed is gradually adjusted according to the severity of the unstable state to match the current road conditions.

[0041] The above technical solution of the present invention has the following advantages over the prior art:

[0042] The loader driving stability analysis method described in the present invention first calculates the critical inclination angle threshold value through a dynamic balance algorithm, so that it is adaptively adjusted as the slope changes, avoiding misjudgment caused by a fixed threshold value. Then, by constructing a virtual potential field, the critical inclination angle threshold value is corrected in real time by comprehensively considering the vehicle body posture, bucket load distribution and wheel slip trend, making the stability judgment more accurate. Finally, when an unstable state is detected, the system intelligently adjusts the bucket angle and height based on the potential field gradient direction, uses the bucket's mass distribution to compensate for the vehicle body offset, and adjusts the driving speed in stages to ensure a smooth transition to a safe state.

[0043] Compared with the prior art, the advantages of the present invention are:

[0044] 1. By using the virtual potential field to correct the critical inclination angle threshold in real time, the stability limit of the loader under different road conditions can be more accurately reflected, avoiding the hysteresis problem of the traditional fixed threshold method.

[0045] 2. By calculating the mass barrier and slip vector, key factors such as bucket load and wheel slip are incorporated into the stability assessment system, further improving the accuracy of stability determination.

[0046] 3. Active compensation control: First, bucket posture adjustment is used as a means of stability compensation. Finally, combined with speed graded adjustment, it can quickly respond to the initial stage of vehicle body instability and reduce the risk of rollover. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0048] Figure 1 is a flowchart of the steps of the loader driving stability analysis method of the present invention;

[0049] Figure 2 It is a flowchart of the specific implementation process of the dynamic correction of the critical tilt angle threshold of the present invention;

[0050] Figure 3 is a flowchart of the steps of incorporating tire pressure monitoring into the process of determining the potential field gradient direction of the present invention;

[0051] Figure 4 It is a structural block diagram of the hierarchical response mechanism processing of the present invention;

[0052] Figure 5 It is a structural block diagram of the loader driving stability analysis system of the present invention. DETAILED DESCRIPTION

[0053] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0054] Reference Figure 1 As shown, the present invention discloses a method for analyzing the driving stability of a loader, which is characterized by comprising the following steps:

[0055] Real-time monitoring of the loader's body inclination angle, combined with current road slope data, uses a dynamic balance algorithm to calculate the critical inclination angle threshold under current working conditions;

[0056] A virtual potential field is constructed based on the loader's body posture to dynamically correct the critical tilt angle threshold. The virtual potential field determines the potential field base plane based on the body's pitch and roll angles, calculates the mass distribution offset based on the loader's bucket angle and height, generates a corresponding mass barrier in the potential field, and derives a potential slip vector based on the speed difference between the driven and non-driven wheels to form the potential field gradient direction.

[0057] If the vehicle body tilt angle exceeds the corrected critical tilt angle threshold, it is determined to be in an unstable state;

[0058] When it is determined to be in an unstable state, the bucket rotation direction is first determined based on the potential field gradient direction, and the bucket rotation angle and height are determined based on the mass potential barrier. If it is still in this stable state, the loader's driving speed is gradually adjusted to match the loader's driving speed with the current road conditions.

[0059] The core technology of the loader driving stability analysis method described in the present invention lies in the construction of an intelligent evaluation system that responds to changes in the loader's operating state in real time. Unlike the traditional static threshold comparison method, this scheme realizes adaptive adjustment of the stability boundary and active intervention of instability trends through the organic combination of dynamic balance algorithm and virtual potential field technology.

[0060] The technical solution of the present invention includes four key links: real-time monitoring and critical threshold calculation, virtual potential field construction and threshold correction, unstable state judgment and active intervention strategy. These links form a closed-loop control, which effectively solves the defects of traditional methods such as delayed response and poor adaptability.

[0061] The first technical innovation of the present invention is reflected in the application of the dynamic balancing algorithm. The system monitors the inclination angle of the loader's body in real time and, combined with the road surface information obtained by the high-precision slope sensor, calculates the critical inclination angle threshold under the current working conditions. This step breaks through the limitations of the traditional fixed threshold method and enables the stability judgment standard to be dynamically adjusted as the working conditions change. Specifically, when the loader is on different slopes, its stability boundary will change significantly, and the static threshold cannot fully cover various working conditions. The dynamic balancing algorithm adopted by the present invention is based on the principles of mechanics and can calculate in real time the stability threshold that best suits the current actual situation, greatly improving the accuracy of judgment.

[0062] The construction of a virtual potential field is the second technical innovation of this invention. As mentioned above, the existing technology does not consider the impact of the loader's posture on its stability when analyzing the loader's stability. To address this problem, the inventors constructed a multi-dimensional virtual potential field based on the loader's body posture to further correct the critical tilt angle threshold. This potential field contains three key elements: the potential field base plane, the mass potential barrier, and the potential field gradient direction.

[0063] The potential field base plane is determined by the vehicle body's pitch and roll angles, reflecting the loader's current overall attitude benchmark. Determining the potential field base plane is the basis for constructing a virtual potential field, as it reflects the current road slope. The loader's stability on a ramp is directly related to the road slope. This method accurately estimates the inclination of the potential field base relative to the horizontal plane by integrating the vehicle body's pitch and roll angles, providing a reference coordinate system for subsequent analysis.

[0064] The mass barrier is a mapping of the mass distribution offset calculated using bucket angle and height data into the potential field. It accurately characterizes the impact of bucket position changes on the vehicle's center of gravity and stability. Unlike traditional fixed-position vehicle frames, the loader's mass distribution changes with the bucket's relative angle and position. This method combines bucket angle and height data to infer real-time changes in the center of gravity. In the virtual potential field, this mass distribution change manifests as a change in the barrier's height and shape, directly affecting the shape of the stability boundary. Through data calibration, the degree of influence of mass distribution on stability can be accurately reflected.

[0065] The potential field gradient direction is derived from the analysis of the speed difference between the driven and non-driven wheels, and can predict the direction of potential slip trends. Traditional methods typically only evaluate the magnitude of stability while ignoring the directional characteristics of instability. The present invention analyzes the speed difference between the driven and non-driven wheels to identify the potential slip direction and represents it as a gradient direction in the virtual potential field. This information is crucial for the subsequent generation of recommended operation vectors, enabling the system to provide accurate operational recommendations for instability trends in specific directions.

[0066] By coupling the three elements of the potential field base plane, the mass potential barrier and the potential field gradient direction, a dynamically evolving stability evaluation space is formed, which can further accurately reflect the stability state in combination with the current vehicle body posture.

[0067] Furthermore, the present invention, through gradient direction analysis in the virtual potential field, can predict potential slip risks even before the actual vehicle body inclination angle exceeds a safety threshold. Specifically, by monitoring the speed difference between the driven and non-driven wheels, the system can keenly capture tiny changes in traction distribution, which are often precursors to subsequent serious instability. When such subtle changes are detected, corresponding gradient directions are formed in the virtual potential field, providing a basis for subsequent decision-making. This predictive capability based on precursor characteristics enables the system to issue warnings several seconds in advance, leaving valuable reaction time for the driver or automatic control system.

[0068] The third technical innovation of this invention lies in its intervention strategy for unstable conditions. When the system detects that the vehicle body tilt angle exceeds a corrected critical threshold, a hierarchical intervention strategy is immediately triggered. Unlike traditional simple alarms, the intervention measures proposed in this invention are clearly directional and progressive. The system first determines the optimal rotation direction of the bucket based on the direction of the potential field gradient. This is equivalent to using the bucket as a balance regulator, offsetting the slip tendency by changing its position. The specific rotation angle and lifting height of the bucket are then determined based on the strength of the mass potential barrier, ensuring that the adjustment force is precisely matched to the degree of instability. Finally, the system gradually adjusts the driving speed according to the severity of the unstable state, forming a hierarchical, step-by-step intervention strategy for vehicle body posture adjustment and vehicle driving state. This strategy can restore the loader's stability in the shortest time and with the lowest operational cost, significantly improving the effectiveness of corrective measures.

[0069] Specifically, when the system detects an unstable state, it will first determine the optimal adjustment direction of the bucket based on the direction of the potential field gradient. If the predicted slip direction is to the left, the system may suggest swinging the bucket to the right to generate a counteracting torque. It then accurately calculates the angle and height to which the bucket needs to be rotated based on the strength of the mass potential barrier to ensure that the intervention force accurately matches the degree of instability. Finally, the system will gradually adjust the driving speed according to the severity of the unstable state to avoid the risk of secondary instability caused by sudden deceleration. Compared with traditional speed control methods, this multi-level, differentiated intervention strategy can achieve optimal stabilization with minimal impact on operating efficiency.

[0070] In this embodiment, a dynamic balance algorithm is used as the core method for calculating the critical inclination angle threshold. Its specific implementation is directly related to the accuracy and reliability of the entire stability analysis system. In order to clarify the specific working mechanism of the algorithm and its synergistic relationship with the overall technical solution, the dynamic balance algorithm is set to simulate the center of gravity deviation trend of the loader under different slopes, establish a dynamic model of the loader's center of gravity deviation, and dynamically adjust the critical inclination angle threshold by simulating the center of gravity change trend of the loader under different slopes in real time;

[0071] Specifically, the algorithm first collects the current slope data of the loader through sensors and establishes a correspondence model between the slope and the theoretical center of gravity position; then, based on the real-time motion state of the loader, including parameters such as the body vibration frequency and steering acceleration, the theoretical model is dynamically calibrated so that the model can accurately reflect the changes in the center of gravity under actual working conditions; finally, the critical inclination angle threshold at the current slope is output based on the calibrated model. This threshold will automatically decrease as the slope increases, and increase accordingly as the slope decreases.

[0072] The technical effects of this dynamic adjustment mechanism are reflected in three aspects: first, by establishing a correspondence model between slope and center of gravity position, the theoretical basis of threshold calculation is ensured to be scientific and reliable; second, by introducing real-time motion parameters for dynamic calibration, the algorithm can adapt to the actual operating status of the loader under different loads and road conditions, avoiding the problem of insufficient adaptability of fixed threshold algorithms under complex working conditions; finally, the dynamic change of threshold with slope enables the system to adopt more stringent stability control strategies in advance under high-risk conditions such as steep slopes, effectively preventing the occurrence of rollover accidents.

[0073] In this embodiment, the construction of virtual potential field is the core technical means of dynamically correcting the critical tilt angle threshold. Its specific implementation process directly affects the accuracy and real-time performance of stability judgment. In order to reveal the intrinsic mechanism between the virtual potential field and the critical tilt angle threshold and make the innovation of the entire technical solution clearer, reference is made to Figure 2 As shown, the inventors further disclosed the specific steps of dynamically correcting the critical tilt angle threshold:

[0074] The correction process first establishes a three-dimensional coordinate system based on the potential field base plane determined by the vehicle's pitch and roll angles. This step transforms the loader's spatial posture into a quantifiable mathematical model, providing a reference framework for subsequent precise calculations. By projecting the real-time monitored vehicle roll angle onto this coordinate system, a precise mapping between the actual physical state and the virtual potential field is achieved, ensuring the accuracy of subsequent correction calculations.

[0075] After obtaining the projection position, the system applies the corresponding threshold correction according to the distribution position and strength of the mass potential barrier. The correction effect of the mass potential barrier is reflected in the secondary adjustment of the projection coordinates. The system calculates the mass distribution offset based on the bucket angle and height data, and forms a mass potential barrier with directional and intensity characteristics in the virtual potential field. The position of this barrier in the three-dimensional coordinate system reflects the actual influence range of the center of gravity offset, and its intensity is proportional to the severity of the instability trend. The correction algorithm superimposes a vector component proportional to the strength of the mass potential barrier on the projection coordinates, so that the impact of the center of gravity offset on stability can be quantitatively evaluated; especially when the bucket lifts materials, the system will automatically increase the correction amount to reflect the risk brought by the upward shift of the center of gravity. This dynamic response mechanism solves the defect that the traditional method is insensitive to load changes.

[0076] Finally, the threshold offset compensation performed along the potential field gradient fully considers the potential slip trend reflected by the speed difference between the driven and non-driven wheels. When the gradient direction is consistent with the vehicle body tilt direction, it indicates that the slip trend exacerbates the instability risk. In this case, increasing the correction amount can provide early warning and take control measures. The opposite situation indicates that the slip trend helps to offset the tilt risk. Appropriately reducing the correction amount can avoid overly conservative control strategies.

[0077] This dynamic correction mechanism based on the synergistic effect of multiple factors ensures that the critical inclination angle threshold can accurately reflect the actual stability state of the loader in real time, providing a scientific basis for subsequent stability judgment and control decisions, thereby effectively solving the technical problem of insufficient adaptability of the traditional fixed threshold method under complex working conditions.

[0078] In this embodiment, in order to further achieve quantitative dynamic correction of the critical inclination angle threshold, a precise mapping relationship table between potential field parameters and threshold correction values ​​is established to provide a clear standard for parameter adjustment in actual engineering applications of virtual potential field theory. The establishment of this mapping relationship table is based on an in-depth mechanism analysis of the factors affecting loader stability, where:

[0079] When a loader travels on a slope, the inclination angle of the potential field's base plane directly reflects the fundamental impact of road slope on stability. Experimental data shows that for every 1-degree increase in base plane inclination, the loader's theoretical stability margin decreases by 0.6-0.9 degrees. The mapping table sets a threshold reduction range of 0.5-0.8 degrees, providing a safety margin while avoiding overly conservative judgments.

[0080] The graded correction mechanism for the mass barrier strength reflects a scientific assessment of the load distribution. After calculating the mass distribution offset based on the bucket angle and height data, the system quantifies it into multiple intensity levels, with each level corresponding to a threshold reduction of 1 to 1.5 degrees. This nonlinear relationship accurately simulates the actual impact of the center of gravity offset on stability. When the bucket lifts a heavy object, the mass barrier strength will jump by 2-3 levels, triggering a substantial reduction in the threshold, thereby providing an early warning of possible overturning risks.

[0081] The system further realizes the coupled correction of the potential field gradient direction and the body tilt angle. When the angle between the potential field gradient direction generated by the speed difference between the driving wheel and the non-driving wheel and the actual tilt direction of the body is less than 30 degrees, it indicates the existence of a synergistic effect that exacerbates instability. At this time, the mapping relationship table stipulates an additional threshold reduction of 1.2 to 1.8 degrees. This directional sensitivity correction can identify complex instability modes that are difficult to detect with traditional methods. For example, when lateral slip and longitudinal rollover trends overlap in the same direction, the system will activate the maximum correction amount to form multi-dimensional protection.

[0082] This quantitative correction mechanism based on the synergy of multiple parameters essentially breaks through the limitations of traditional empirical threshold settings. By establishing precise mathematical correspondences, it not only retains the adaptability of virtual potential field theory to complex working conditions, but also achieves the standardization and repeatability of control parameters. In practical applications, the mapping relationship table can be used to match parameters with loader models and operating environment characteristics to form a stability control solution that is both universal and targeted, providing reliable technical support for the intelligent development of construction machinery.

[0083] In this embodiment, the mass distribution offset is a key dynamic parameter affecting the stability of the loader. Its calculation accuracy directly determines the accuracy of the mass barrier in the virtual potential field. In actual engineering, the dynamic distribution of materials in the bucket directly affects the quantitative evaluation of the mass barrier. In order to accurately calculate the impact of the dynamic distribution of materials, the real-time weight distribution data of the materials is first obtained through the weight sensor installed on the bucket. This basic data acquisition link ensures the accuracy of the source of the calculation; then, combined with the bucket lifting height and rotation angle parameters measured by the high-precision angle sensor, a spatial geometric relationship model including the material position, bucket posture and vehicle body reference position is established; finally, based on the model, the offset vector of the material center of gravity relative to the vehicle body reference position is calculated. This vector result not only contains the offset distance information, but also retains the directional characteristics, providing complete dynamic load parameters for the subsequent construction of the virtual potential field.

[0084] Specifically, by obtaining material weight distribution data in real time instead of using estimated values, the authenticity of the calculation results is greatly improved, especially for unevenly distributed materials. The bucket lifting height and rotation angle are incorporated into the calculation model to accurately reflect the impact of bucket posture changes on the material center of gravity during operation, avoiding errors caused by static assumptions. The calculation result of the offset vector directly corresponds to the spatial coordinate system of the virtual potential field, realizing the precise conversion of physical parameters to the control model.

[0085] This refined method for calculating mass distribution offset fundamentally solves the problem of rough load parameter estimation in traditional stability control systems, enabling the virtual potential field to truly reflect the dynamic stability state of the loader during operation, and providing reliable input data for subsequent critical inclination angle threshold correction, thereby ensuring that the entire control system can still maintain high-precision stability judgment capabilities in complex operating environments.

[0086] In actual engineering, the inconsistent tire pressure on both sides of the loader will affect the speed difference, thereby affecting the accuracy of the potential field gradient direction determination. Therefore, incorporating tire pressure monitoring into the process of determining the potential field gradient direction can specifically solve the problem of inaccurate stability judgment of construction machinery under abnormal tire working conditions; Figure 3 As shown, the tire pressure data of each tire is monitored in real time through the pressure sensors installed in the tires. When the system detects abnormal tire pressure on one side, it immediately generates a compensation vector in the virtual potential field model with the opposite direction of the tire pressure deviation. The size of the compensation vector is dynamically adjusted according to the percentage of tire pressure deviation. The larger the deviation, the larger the compensation vector. Finally, this compensation vector is superimposed on the calculation result of the original potential field gradient direction to achieve targeted correction of the critical tilt angle threshold.

[0087] From a technical mechanism perspective, abnormal tire pressure will significantly change the contact characteristics between the tire and the ground, resulting in uneven distribution of driving force on both sides of the vehicle, which in turn affects the stability performance of the entire vehicle. Traditional control systems often ignore this important factor. In this embodiment, by introducing tire pressure data into the potential field gradient calculation in real time, the system can perceive the potential skid risk caused by uneven tire pressure in advance, and actively apply reverse compensation in the virtual potential field model, which is equivalent to pre-offsetting the instability factors caused by abnormal tire pressure at the algorithm level.

[0088] In this embodiment, when an unstable state is determined, the bucket rotation direction is first determined based on the direction of the potential field gradient, and the loader's instability mode is identified by real-time analysis of the potential field gradient characteristics. When the system detects an instability trend mainly caused by the roll moment, the control strategy prioritizes driving the bucket to move in the opposite direction of the potential field gradient. This design cleverly uses the reverse torque generated by the bucket mass to offset the roll trend. When the instability characteristics in the pitch direction are identified, the bucket lifting height is prioritized. By changing the vertical position of the bucket, the center of gravity height of the vehicle is adjusted, thereby improving longitudinal stability.

[0089] From the perspective of control mechanism, this differentiated treatment fully considers the differences in the dynamic characteristics of the loader under different instability modes: for the roll tendency, adjusting the horizontal position of the bucket can most directly generate the reverse torque to resist rollover; while for the pitch tendency, adjusting the bucket height can more effectively change the longitudinal weight distribution.

[0090] Reference Figure 4 As shown, the present application also introduces a hierarchical response mechanism in the active intervention strategy, which realizes the refined processing of unstable states and effectively solves the problem of insufficient adaptability of the "one-size-fits-all" response method in traditional control systems when dealing with different degrees of instability risks.

[0091] Specifically, the hierarchical control strategy first quantitatively assesses the severity of the unstable state based on the percentage range of the vehicle body tilt angle exceeding the critical threshold, and scientifically divides the risk level into three progressive levels:

[0092] When a level 1 instability condition is detected, meaning the vehicle body tilt exceeds a threshold of 5%-10%, only the mildest intervention, adjusting the bucket position, is used to compensate. This conservative strategy is suitable for conditions that slightly exceed the threshold and effectively corrects stability deviations while maximizing operational continuity.

[0093] When the vehicle reaches the second level of instability, meaning the vehicle body tilt exceeds a threshold of 10%-20%, coordinated control of bucket position adjustment and travel speed regulation is activated, creating a more powerful stability compensation effect through dual intervention.

[0094] For the most dangerous level 3 instability, when the vehicle body tilt angle exceeds the threshold of 20%, a full range of safety protection measures including emergency braking and sound and light alarms will be triggered.

[0095] The technical advantages of this hierarchical response mechanism are primarily reflected in three aspects: First, it matches control measures of corresponding strength to the degree of risk, avoiding the impact of excessive intervention on normal operations; second, a progressive control strategy provides the system with a multi-level safety line of defense, ensuring that the most appropriate response plan can be adopted at any risk level; and finally, clear grading standards make the entire control process more standardized and predictable, making it easier for operators to understand and cooperate with the system. In terms of control effectiveness, this hierarchical approach not only ensures operational efficiency under mildly unstable conditions, but also enables a quick and decisive response to serious dangers, achieving an optimal balance between safety and work efficiency.

[0096] This embodiment is specifically optimized for the unique operating condition of slippery roads. By incorporating a tire slip monitoring and compensation mechanism, it effectively addresses the lag in response of traditional stability control systems on low-adhesion surfaces. This technical solution first uses high-precision wheel speed sensors to calculate the slip rate of each tire in real time. If the system detects a sustained upward trend in slip rate, it triggers an instability detection preemptively, even if the vehicle body roll angle has not yet reached the theoretical threshold. This proactive judgment mechanism seizes valuable control opportunities. Simultaneously, based on real-time slip data, the system generates a compensation vector related to the road adhesion coefficient within the virtual potential field model. The magnitude of this compensation vector is proportional to the slip rate change, and its direction is correlated with the vehicle's motion trend. By superimposing this compensation vector on the original potential field gradient, the critical roll angle threshold is dynamically adjusted downward.

[0097] The low adhesion of slippery roads significantly reduces a loader's stability limit. Traditional systems, lacking direct perception of road conditions, often wait until the vehicle body exhibits a noticeable tilt before reacting. By monitoring tire slip rate in real time, a parameter that directly reflects road adhesion, the system can proactively detect risks and adjust control strategies accordingly. Specifically, when a continuous increase in slip rate is detected, indicating a loss of tire grip, triggering instability detection early can increase control response time. The compensation vector generated based on the slip rate simulates the impact of decreased road adhesion on vehicle stability at the algorithmic level, enabling the critical tilt angle threshold to match the actual load-bearing capacity of the current road surface in real time.

[0098] Reference Figure 5 As shown, in order to implement the above method, the present invention also discloses a loader driving stability analysis system, comprising:

[0099] The tilt monitoring module is used to monitor the tilt angle of the loader in real time and collect the current road slope data;

[0100] A dynamic balance calculation module, connected to the tilt angle monitoring module, for calculating a critical tilt angle threshold under current working conditions using a dynamic balance algorithm;

[0101] A virtual potential field construction module is connected to the dynamic balance calculation module and is used to construct a virtual potential field according to the body posture of the loader to dynamically correct the critical tilt angle threshold, wherein:

[0102] The virtual potential field determines the potential field base plane based on the vehicle body pitch angle and roll angle; calculates the mass distribution offset based on the loader bucket angle and bucket height, and generates a corresponding mass potential barrier in the potential field; and derives the potential slip vector based on the speed difference between the drive wheel and the non-drive wheel to form the potential field gradient direction;

[0103] a stability determination module, connected to the virtual potential field construction module, for determining that the loader is in an unstable state when the vehicle body inclination angle exceeds the corrected critical inclination angle threshold;

[0104] The active adjustment module is connected to the stability determination module and is configured to perform the following operations when an unstable state is determined:

[0105] The bucket's rotation direction is determined based on the potential field gradient direction; the bucket's rotation angle and height are determined based on the mass potential barrier; and the loader's travel speed is gradually adjusted according to the severity of the unstable state to match the current road conditions.

[0106] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0107] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0108] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0109] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0110] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for analyzing driving stability of a loader, characterized by: The following steps are involved: Real-time monitoring of the loader's body inclination angle, combined with current road slope data, uses a dynamic balance algorithm to calculate the critical inclination angle threshold under current working conditions; A virtual potential field is constructed based on the loader's body posture to dynamically correct the critical tilt angle threshold. The virtual potential field determines the potential field base plane based on the body's pitch and roll angles, calculates the mass distribution offset based on the loader's bucket angle and height, generates a corresponding mass barrier in the potential field, and derives a potential slip vector based on the speed difference between the driven and non-driven wheels to form the potential field gradient direction. If the vehicle body tilt angle exceeds the corrected critical tilt angle threshold, it is determined to be in an unstable state; When it is determined to be in an unstable state, the bucket rotation direction is first determined based on the potential field gradient direction, and the bucket rotation angle and height are determined based on the mass potential barrier. If it is still in this stable state, the loader's driving speed is gradually adjusted to match the loader's driving speed with the current road conditions.

2. The method for analyzing loader driving stability according to claim 1, characterized in that: The dynamic balancing algorithm simulates the center of gravity deviation trend of the loader under different slopes and gradually adjusts the critical inclination angle threshold so that it decreases as the slope increases and increases as the slope decreases.

3. The method for analyzing loader driving stability according to claim 1, wherein: The specific steps of dynamically correcting the critical tilt angle threshold include: A three-dimensional coordinate system is established based on the potential field base plane, and the real-time monitored vehicle body tilt angle is projected onto the coordinate system; According to the distribution position and strength of the mass barrier, a corresponding threshold correction is applied at the projection position, wherein the greater the mass barrier strength, the greater the correction; The threshold offset compensation is performed along the potential field gradient direction. When the gradient direction is consistent with the vehicle body tilt direction, the correction amount is increased, and when the gradient direction is opposite, the correction amount is reduced.

4. The method for analyzing loader driving stability according to claim 2, wherein: The dynamically correcting critical tilt angle threshold value further includes: establishing a mapping relationship table between potential field parameters and threshold correction amounts, wherein: For every 1 degree increase in the tilt angle of the potential field base plane, the critical tilt angle threshold decreases by 0.5 to 0.8 degrees; For every level increase in mass barrier strength, the critical dip threshold decreases by 1 to 1.5 degrees; When the angle between the potential field gradient direction and the vehicle body tilt direction is less than 30 degrees, the critical tilt angle threshold is reduced by 1.2 to 1.8 degrees.

5. The method for analyzing loader driving stability according to claim 1, wherein: The calculation of the mass distribution offset includes: obtaining the weight distribution data of the material in the bucket, and calculating the offset vector of the center of gravity of the material relative to the reference position of the vehicle body in combination with the bucket lifting height and rotation angle.

6. The method for analyzing loader driving stability according to claim 1, characterized in that: The process of determining the potential field gradient direction further includes: Monitor tire pressure data; When the tire pressure on one side is abnormal, a compensation vector is applied in the direction of the potential field gradient on the corresponding drive wheel side. The size of the compensation vector is adjusted according to the degree of tire pressure deviation to correct the critical tilt angle threshold.

7. The method for analyzing loader driving stability according to claim 1, characterized in that: The determination of the bucket rotation direction includes: when a roll trend is detected, the bucket position is preferentially adjusted in the opposite direction of the potential field gradient; when a pitch trend is detected, the bucket lifting height is preferentially adjusted.

8. The method for analyzing loader driving stability according to claim 1, wherein: When an unstable state is determined, analyzing the severity level of the unstable state includes: Level 1 instability: vehicle tilt exceeds the threshold by 5%-10%, and only the bucket position is adjusted; Level 2 instability: When the vehicle body tilt exceeds the threshold by 10%-20%, the bucket position and driving speed are adjusted synchronously; Level 3 instability: If the vehicle tilt angle exceeds the threshold by 20%, emergency braking will be performed immediately and an audible and visual alarm will be issued.

9. The method for analyzing loader driving stability according to claim 1, wherein: Under wet and slippery road conditions, the tire slip rate parameter is additionally introduced: Calculate the real-time slip rate through the wheel speed sensor; When the slip rate continues to increase, the unstable state judgment is triggered in advance; The road adhesion coefficient compensation vector is superimposed in the potential field gradient direction to correct the critical inclination angle threshold.

10. A loader driving stability analysis system, characterized by: include: The tilt monitoring module is used to monitor the tilt angle of the loader in real time and collect the current road slope data; A dynamic balance calculation module, connected to the tilt angle monitoring module, for calculating a critical tilt angle threshold under current working conditions using a dynamic balance algorithm; A virtual potential field construction module is connected to the dynamic balance calculation module and is used to construct a virtual potential field according to the body posture of the loader to dynamically correct the critical tilt angle threshold, wherein: The virtual potential field determines the potential field base plane based on the vehicle body pitch angle and roll angle; calculates the mass distribution offset based on the loader bucket angle and bucket height, and generates a corresponding mass potential barrier in the potential field; and derives the potential slip vector based on the speed difference between the drive wheel and the non-drive wheel to form the potential field gradient direction; a stability determination module, connected to the virtual potential field construction module, for determining that the loader is in an unstable state when the vehicle body inclination angle exceeds the corrected critical inclination angle threshold; The active adjustment module is connected to the stability determination module and is configured to perform the following operations when an unstable state is determined: The bucket's rotation direction is determined based on the potential field gradient direction; the bucket's rotation angle and height are determined based on the mass potential barrier; and the loader's travel speed is gradually adjusted according to the severity of the unstable state to match the current road conditions.

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