Vehicle rollover warning method and device based on ltr and roll energy weighting

Abstract

The application provides a vehicle rollover early warning method and device based on LTR and roll energy weighting, which comprises the following steps: acquiring the lateral load transfer rate and roll energy of the vehicle at the current time; presetting a static energy threshold based on the vehicle mass, wheel tread and vehicle center of mass height, taking the ratio of the roll energy to the static energy threshold as the roll energy index at the current time; calculating the roll energy weight coefficient and the lateral load transfer rate weight coefficient, and weighting and calculating the comprehensive rollover index; presetting a comprehensive rollover threshold, and performing vehicle rollover early warning when the comprehensive rollover index is greater than the comprehensive rollover threshold. The scheme takes the absolute value of the roll angle acceleration as the basis for adjusting and calculating the dynamic weight coefficient, automatically takes the lateral load transfer rate evaluation as the main factor in the smooth driving and initial roll stage, automatically increases the roll energy weight when the roll is intensified or a sudden lateral impact is encountered, simultaneously considers the two rollover instability modes of the non-tripping type and the tripping type, and improves the real-time performance and accuracy of the early warning.

Description

Technical Field

[0001] This application relates to the field of vehicle rollover warning, and in particular to a vehicle rollover warning method and device based on LTR and rollover energy weighting. Background Technology

[0002] Vehicle rollovers are mainly divided into two categories: non-tripping rollovers and tripping rollovers. The former is often caused by driver error, such as excessive speed or sharp steering while turning, resulting in excessive centrifugal force and causing the vehicle to roll over. The latter refers to rollovers caused by external factors, including vertical impacts from the road surface and changes in road gradient. Determining the timing of active rollover prevention control based on pre-set rollover evaluation indicators is of great significance for conducting research on active rollover prevention control for vehicles.

[0003] For non-tripping rollovers, common rollover warning indicators mainly include the Rollover Index (RI), Lateral Load Transfer Rate (LTR), and Time to Rollover (TTR). Among them, the Lateral Load Transfer Rate can intuitively present the dynamic distribution of vertical loads on both sides of the wheels and is the most universal and efficient core indicator in the field of rollover warning. Based on the core position of LTR, how to dynamically match the warning threshold with the current driving environment has become an important research direction in the field of rollover prevention control. For example, the patent application No. 202210941393.0 considers optimizing LTR calculation with unsprung mass and constructs a fitting relationship between the warning threshold and vehicle speed and road adhesion coefficient; however, the core limitation of LTR is that the vertical load of the wheels is difficult to measure directly and at low cost on mass-produced vehicles, and as a pure state feedback indicator, it lacks forward-looking predictive ability. When LTR reaches the critical danger threshold, the time left for the chassis actuator to respond is extremely limited, making it difficult to cope with sudden rollover situations. For trip-over rollovers, existing rollover warning indicators mainly include energy-based evaluation indicators (RPER), generalized rollover index (GRI), and vertical load change rate, such as the roll energy stability index Ei proposed in patent application number 202110156321.0. This index is no longer limited to kinematic parameters, but calculates the ratio of the vehicle's real-time instability energy to its static rollover energy, and introduces the coupling coefficient between steering and vehicle speed. This energy index has higher accuracy and foresight than simply measuring the LTR, but it usually relies on complex vehicle dynamics models and a large number of vehicle parameters that are difficult to identify online, resulting in complex algorithm implementation and high calibration costs. At the same time, most existing studies design warning indicators for a single rollover mechanism, lacking a classification and differentiated evaluation mechanism for trip-over and non-trip-over rollovers. When the causes of vehicle rollover change, a unified risk assessment indicator cannot balance the accuracy and real-time performance of the warning, and is prone to false alarms, missed alarms, or unreasonable timing of control intervention.

[0004] To better adapt to the switching between trip-and-fall and non-trip-and-fall rollover scenarios, existing methods often employ single-type indicators or fixed-weight fusion strategies, making it difficult to dynamically adjust the evaluation mechanism based on changes in rollover inducing factors. This results in insufficient applicability in complex road environments. Therefore, there is an urgent need to propose a comprehensive rollover risk assessment method that can identify vehicle rollover characteristics in real time and dynamically adjust the evaluation mechanism based on rollover inducing factors, thus taking into account both trip-and-fall and non-trip-and-fall instability modes. Summary of the Invention

[0005] This application provides a vehicle rollover warning method and device based on LTR and roll energy weighting. The method calculates dynamic roll energy weighting coefficient and lateral load transfer rate weighting coefficient based on the absolute value of roll angle acceleration. During stable driving and the initial roll, the method automatically prioritizes lateral load transfer rate evaluation. When the roll intensifies or a sudden lateral impact occurs, the method automatically increases the roll energy weighting. At the same time, it takes into account both non-tripping and tripping rollover instability modes, thereby improving the real-time performance, robustness and accuracy of the warning.

[0006] In a first aspect, embodiments of this application provide a method for vehicle rollover warning based on LTR and roll energy weighting, the method comprising:

[0007] Obtain the lateral load transfer rate and roll energy of the vehicle at the current moment, wherein the roll energy is the sum of the vehicle's roll kinetic energy and roll potential energy; Based on the vehicle's mass, track width, and center of gravity height, a static energy threshold is preset, and the ratio of roll energy to the static energy threshold is used as the roll energy index at the current moment. Obtain the absolute value of the vehicle's roll angle acceleration at the current moment, calculate the roll energy weighting coefficient based on the absolute value of the roll angle acceleration, and obtain the lateral load transfer rate weighting coefficient based on the roll energy weighting coefficient; The sum of the weighted result of the lateral load transfer rate weighting coefficient on the absolute value of the lateral load transfer rate and the weighted result of the roll energy weighting coefficient on the roll energy index is used as the comprehensive rollover index. A preset comprehensive rollover threshold is set, and a vehicle rollover warning is issued when the comprehensive rollover index exceeds the comprehensive rollover threshold.

[0008] Secondly, embodiments of this application provide a vehicle rollover warning device based on LTR and roll energy weighting, comprising: The acquisition module is used to acquire the lateral load transfer rate and roll energy of the vehicle at the current moment, wherein the roll energy is the sum of the roll kinetic energy and roll potential energy of the vehicle. The roll energy index calculation module presets a static energy threshold based on the vehicle's mass, track width, and center of gravity height, and uses the ratio of roll energy to the static energy threshold as the roll energy index at the current moment. The dynamic weight allocation module is used to obtain the absolute value of the vehicle's roll angle acceleration at the current moment, calculate the roll energy weight coefficient based on the absolute value of the roll angle acceleration, and obtain the lateral load transfer rate weight coefficient based on the roll energy weight coefficient. The comprehensive rollover index calculation module uses the weighted result of the lateral load transfer rate weighting coefficient on the absolute value of the lateral load transfer rate and the weighted result of the roll energy weighting coefficient on the roll energy index as the comprehensive rollover index. The early warning module has a preset comprehensive rollover threshold. When the comprehensive rollover index is greater than the comprehensive rollover threshold, a vehicle rollover warning is issued.

[0009] Thirdly, embodiments of this application provide an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor is configured to run the computer program to execute a vehicle rollover warning method based on LTR and roll energy weighting.

[0010] Fourthly, embodiments of this application provide a readable storage medium storing a computer program, which, when executed by a processor, implements a vehicle rollover warning method based on LTR and roll energy weighting.

[0011] The main contributions and innovations of this invention are as follows: This application defines the sum of roll kinetic energy and roll potential energy as roll energy, which comprehensively reflects the energy accumulation trend during vehicle rollover from an energy perspective. Compared with a single roll motion parameter, it can detect the development trend of rollover risk earlier. This application uses the absolute value of roll angle acceleration as the basis for calculating dynamic roll energy weight coefficient and lateral load transfer rate weight coefficient. During stable driving and the initial stage of rollover, the lateral load transfer rate is automatically used as the main evaluation factor. When the rollover intensifies or a sudden lateral impact is encountered, the roll energy weight is automatically increased. At the same time, it takes into account both non-tripping and tripping rollover instability modes, improving the real-time performance, robustness and accuracy of the warning. This application calculates the weighted sum of the absolute value of lateral load transfer rate and roll energy index with the corresponding dynamic weight coefficient to obtain a comprehensive rollover index. A unified comprehensive rollover threshold is preset. When the index exceeds the threshold, a rollover warning is triggered. Combined with the dynamic weight mechanism, it adapts to different driving conditions. Compared with the fixed weight fusion strategy, it improves the adaptability of the warning in complex road environments and effectively reduces false alarms and missed alarms.

[0012] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0013] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a flowchart of a vehicle rollover warning method based on LTR and roll energy weighting according to an embodiment of this application; Figure 2 This is a schematic diagram illustrating the construction of a four-degree-of-freedom vehicle dynamics model according to an embodiment of this application; Figure 3 This is a schematic diagram of dynamic weight allocation under normal driving conditions according to an embodiment of this application; Figure 4 This is a schematic diagram of the overall rollover index fluctuation under normal driving conditions according to an embodiment of this application; Figure 5 This is a schematic diagram of dynamic weight allocation under extreme driving conditions according to an embodiment of this application; Figure 6 This is a schematic diagram of the comprehensive rollover index fluctuation under extreme driving conditions according to an embodiment of this application; Figure 7 This is a schematic diagram of dynamic weight allocation under a tripping-type rollover condition according to an embodiment of this application; Figure 8 This is a schematic diagram of the overall rollover index fluctuation under a tripping-type rollover condition according to an embodiment of this application; Figure 9 This is a structural block diagram of a vehicle rollover warning device based on LTR and roll energy weighting according to an embodiment of this application; Figure 10 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of this application. Detailed Implementation

[0014] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with one or more embodiments of this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of one or more embodiments of this specification as detailed in the appended claims.

[0015] It should be noted that the steps of the corresponding methods are not necessarily performed in the order shown and described in this specification in other embodiments. In some other embodiments, the methods may include more or fewer steps than described in this specification. Furthermore, a single step described in this specification may be broken down into multiple steps in other embodiments; and multiple steps described in this specification may be combined into a single step in other embodiments.

[0016] Example 1 This application provides a vehicle rollover warning method based on LTR and roll energy weighting. This scheme uses the absolute value of roll angle acceleration as the adjustment criterion to calculate dynamic roll energy weighting coefficients and lateral load transfer rate weighting coefficients. During stable driving and the initial stage of rollover, the lateral load transfer rate is automatically prioritized for evaluation. When rollover intensifies or a sudden lateral impact occurs, the roll energy weighting is automatically increased. Simultaneously, it considers both non-tripping and tripping rollover instability modes, improving the real-time performance, robustness, and accuracy of the warning. Specifically, refer to... Figure 1 The method includes: Obtain the lateral load transfer rate and roll energy of the vehicle at the current moment, wherein the roll energy is the sum of the vehicle's roll kinetic energy and roll potential energy; Based on the vehicle's mass, track width, and center of gravity height, a static energy threshold is preset, and the ratio of roll energy to the static energy threshold is used as the roll energy index at the current moment. Obtain the absolute value of the vehicle's roll angle acceleration at the current moment, calculate the roll energy weighting coefficient based on the absolute value of the roll angle acceleration, and obtain the lateral load transfer rate weighting coefficient based on the roll energy weighting coefficient; The sum of the weighted result of the lateral load transfer rate weighting coefficient on the absolute value of the lateral load transfer rate and the weighted result of the roll energy weighting coefficient on the roll energy index is used as the comprehensive rollover index. A preset comprehensive rollover threshold is set, and a vehicle rollover warning is issued when the comprehensive rollover index exceeds the comprehensive rollover threshold.

[0017] In the current embodiment, a vehicle inertial coordinate system is constructed with the vehicle's center of mass as the origin, the longitudinal axis as the x-axis, and the lateral axis as the y-axis. Within the vehicle inertial coordinate system, longitudinal motion equations are constructed for translation along the x-axis, lateral motion equations for translation along the y-axis, yaw motion equations for rotation along the z-axis, and roll motion equations for rotation along the x-axis. A four-degree-of-freedom vehicle dynamics model is constructed, which includes longitudinal motion equations, lateral motion equations, yaw motion equations, and roll motion equations. Based on the four-degree-of-freedom vehicle dynamics model, vehicle motion parameters are obtained, and the lateral load transfer rate and roll energy are calculated by combining the vehicle motion parameters with the vehicle's own parameters.

[0018] Specifically, the schematic diagram for constructing a four-degree-of-freedom vehicle dynamics model is as follows: Figure 2 As shown, the formula for the longitudinal motion equation is expressed as follows:

[0019] The equation of lateral motion is expressed as follows:

[0020] The equation of motion for yaw is expressed as:

[0021] The equation for roll motion is expressed as follows:

[0022] in, For the overall vehicle quality, For the sprung mass, It is the acceleration due to gravity. These are the distances from the vehicle's center of gravity to the front and rear axles, respectively. The wheelbase is the distance between the wheels. The height of the center of mass of the sprung mass. and These are the vehicle's roll inertia and yaw inertia, respectively. The vehicle roll angle, This is the equivalent roll stiffness of the suspension. This is the equivalent roll damping of the suspension. and These are the longitudinal and lateral speeds of the entire vehicle, respectively. and These are the longitudinal and lateral accelerations of the entire vehicle, respectively. Let yaw rate be the vehicle's angular velocity. Let yaw acceleration be the acceleration of the vehicle. The longitudinal force acting on the left front wheel. The left front wheel is subjected to a lateral force; The longitudinal force acting on the right front wheel. The right front wheel is subjected to a lateral force; The longitudinal force acting on the left rear wheel. The left rear wheel is subjected to a lateral force; The longitudinal force acting on the right rear wheel. The right rear wheel is subjected to a lateral force. For the front wheel steering angle, The angular velocity is the roll rate. This is the roll angle acceleration.

[0023] In the current embodiment, sensor parameters are acquired through various types of sensors in the vehicle. These sensor parameters include real-time vehicle speed, steering wheel angle data, lateral velocity, body roll angle, roll rate, roll acceleration, and road adhesion coefficient, among other multi-dimensional parameters. The sensor data is then substituted into a four-degree-of-freedom vehicle dynamics model to obtain vehicle motion parameters. Additionally, the vehicle's original body parameters at the time of manufacture are acquired as the vehicle's own parameters. Based on these vehicle parameters and the vehicle motion parameters, the lateral load transfer rate and roll energy are calculated.

[0024] Specifically, the vehicle speed is obtained in real time through Hall effect wheel speed sensing. The wheel speed sensor uses Hall elements to cause a change in magnetic field when the toothed ring that rotates with the wheel passes by, generating a pulse voltage proportional to the wheel speed. The control unit then calculates the wheel speed by calculating the number of pulses per unit time, and then combines it with the wheel rolling radius to finally calculate the real-time vehicle speed.

[0025] When the vehicle sideslips or turns, the microelectromechanical sensors in the vehicle's inertial unit generate microstructural deformation and Coriolis force, causing changes in electrical parameters and generating corresponding voltage signals. The control unit then uses filtering and analog-to-digital conversion to obtain the real-time lateral acceleration of the center of gravity and the yaw rate around the vertical axis. Combined with the front wheel steering angle command provided by the steering wheel angle sensor and the longitudinal vehicle speed calculated by the wheel speed sensor as reference inputs, the extended Kalman filter is used for closed-loop data fusion to dynamically eliminate the cumulative drift error of the sensors and the interference of tire nonlinear characteristics, and finally to estimate the accurate real-time lateral speed of the vehicle.

[0026] Specifically, the MEMS gyroscope sensor in the vehicle's inertial measurement unit uses a tiny internal mass to cause changes in the microstructure capacitance when the vehicle rolls or pitches, generating a weak voltage signal proportional to the rotation rate. The control unit then filters and converts this signal from analog to digital to obtain the real-time vehicle roll angular velocity. Combined with the gravitational acceleration component obtained from the triaxial accelerometer as a reference, the angular velocity is integrated over time using data fusion algorithms such as Kalman filtering to dynamically eliminate accumulated drift errors, ultimately calculating the accurate real-time vehicle roll angle. Simultaneously, the electronic control unit performs discrete differential calculations on the acquired real-time roll angular velocity signal per unit time to calculate the vehicle's roll angular acceleration.

[0027] In the current embodiment, the lateral load transfer rate of the vehicle at the current moment is calculated based on the vehicle roll angle and the vehicle roll angular velocity. The formula for calculating the lateral load transfer rate is as follows:

[0028] in, The lateral load transfer rate at the current moment. This is the equivalent roll stiffness of the suspension. This is the equivalent roll damping of the suspension. The vehicle's roll rate. The vehicle roll angle, For the overall vehicle quality, It is the acceleration due to gravity. This refers to the wheel track.

[0029] Specifically, the lateral load transfer ratio (LTR) represents the ratio of the difference in vertical load between the left and right wheels of a vehicle to the total load. Its normal range is between -1 and 1. When the LTR approaches 0, it indicates that the load distribution on the left and right wheels of the vehicle is uniform and the vehicle is in a stable driving state. When the absolute value of the LTR increases to 1, it indicates that the vertical load on one side of the vehicle's wheel has dropped to 0, the wheel on that side has lifted off the ground, and the vehicle is about to roll over.

[0030] In the current embodiment, the formula for calculating the roll kinetic energy is expressed as:

[0031] The formula for calculating the roll potential energy is expressed as:

[0032] in, For tilting kinetic energy, For the tilt potential energy, The moment of inertia is the tilting motion. The angular velocity is the roll rate. For the overall vehicle quality, The lateral speed of the entire vehicle, It is the acceleration due to gravity. For the height of the vehicle's center of gravity, This refers to the vehicle's roll angle.

[0033] The formula for the tilt energy is expressed as:

[0034] in, For tilt energy, For tilting kinetic energy, This is the potential energy for tilting.

[0035] Specifically, roll potential energy reflects the accumulation of a vehicle's gravitational potential energy as the roll angle changes, while roll kinetic energy reflects the change in kinetic energy during the roll motion. The combination of the two can fully reflect the overall trend of energy accumulation during a vehicle rollover, and can detect the development trend of rollover risk earlier than a single roll parameter.

[0036] In the current embodiment, when the vehicle is about to overturn, the vehicle's center of gravity will shift to directly above the wheel contact point. Once this boundary is crossed, gravity will cause the vehicle to overturn. The preset formula for the static energy threshold is:

[0037]

[0038] in, The static energy threshold, For the overall vehicle quality, It is the acceleration due to gravity. For the height of the vehicle's center of gravity, The height of the vehicle's center of gravity above the ground when it is directly above the wheel's contact point. This refers to the wheel track.

[0039] Specifically, the static energy threshold characterizes the critical energy value in the critical state of vehicle rollover. When the accumulated tilt energy of the vehicle exceeds this threshold, the gravitational potential energy will drive the vehicle to tilt further, eventually causing rollover instability.

[0040] The formula for the tilt energy index is:

[0041] in, The tilt energy index, For tilt energy, This is the static energy threshold.

[0042] Specifically, the theoretical normal range of the roll energy index is 0 to 1. When the roll energy index is less than 1, the roll energy of the vehicle is lower than the static energy threshold, so it will not roll over. When the roll energy index is greater than 1, it indicates that the current roll energy of the vehicle has exceeded the static energy threshold, and the risk of rollover is high.

[0043] In the current embodiment, the absolute value of the roll angle acceleration can characterize the rate of change of the vehicle's roll motion. The larger the absolute value, the more drastic the change in the vehicle's roll state, and the higher the risk of the vehicle becoming unstable and rolling over. Since the lateral load transfer rate and roll energy have different characterizing capabilities at different rollover stages, a dynamic weighting method based on the logistic function is used to calculate the roll energy weighting coefficient based on the absolute value of the roll angle acceleration. The formula for obtaining the roll energy weighting coefficient is as follows:

[0044] in, This is the tilt energy weighting coefficient. This is the weighting adjustment coefficient. This is the absolute value of the roll angle acceleration. The weighting conversion threshold is used to characterize the roll angle acceleration value when the lateral load transfer rate is comparable to the contribution of roll energy to rollover risk.

[0045] Furthermore, since the sum of the roll energy weighting coefficient and the lateral load transfer rate weighting coefficient is 1, the formula for obtaining the lateral load transfer rate weighting coefficient based on the roll energy weighting coefficient is expressed as:

[0046] in, This is the weighting coefficient for the lateral load transfer rate.

[0047] In other words, in this scheme, as the absolute value of the roll angle acceleration increases, the roll energy weighting coefficient... Gradually increase, while the weighting coefficient of the lateral load transfer rate... Gradually decreasing the weight of the roll angle acceleration has the advantage that in the early stages of roll, the absolute value of the roll angle acceleration is relatively small. At this time, the lateral load transfer rate can more accurately reflect the current load transfer status of the vehicle. Giving it a higher weight can more accurately reflect the early rollover risk. When the roll trend of the vehicle intensifies and the absolute value of the roll angle acceleration increases, the roll energy accumulation is close to the critical threshold. At this time, giving the roll energy a higher weight can more sensitively capture the rollover instability trend caused by energy accumulation.

[0048] Specifically, when a vehicle is in a stable driving state, the roll angle acceleration is relatively small. The value is close to 0. At this point, the vehicle mainly faces non-tripping rollover risk, and the rollover process is relatively slow. The comprehensive evaluation index mainly relies on the lateral load transfer rate for risk assessment to ensure the stability and accuracy of the evaluation results. As the vehicle's tilting motion gradually intensifies, A sustained increase indicates that the vehicle may be under severe external excitation conditions such as extreme cornering or curb impact, resulting in a significant abrupt change in body roll motion. In this case, the lateral load transfer rate only increases rapidly after significant body roll and load transfer, thus exhibiting a certain response lag. Roll energy, however, reflects the instability energy accumulated during rollover development and can characterize the increasing trend of rollover risk earlier. Therefore, with... As the load increases, the weight of the roll energy index in the comprehensive evaluation index gradually increases, while the weight of the lateral load transfer rate decreases accordingly. This shifts the evaluation result from primarily relying on the lateral load transfer rate to primarily relying on roll energy. This dynamic weight allocation method ensures the stability of risk assessment under normal vehicle driving conditions while improving the system's early warning capability and response speed to sudden dangerous situations such as tripping-induced rollovers, thereby enhancing the predictive effect on vehicle rollover trends. This continuous dynamic weight adjustment mechanism avoids the abrupt weight changes that occur during condition switching in traditional fixed weight allocation methods, achieving adaptive fusion of lateral load transfer rate and roll energy, and improving the real-time performance, robustness, and accuracy of vehicle rollover warnings.

[0049] In the current embodiment, the formula for calculating the comprehensive rollover index is:

[0050] in, To calculate the overall rollover index, This is the weighting coefficient for the lateral load transfer rate. For lateral load transfer rate, This is the tilt energy weighting coefficient. The tilt energy index.

[0051] In this scheme, the overall rollover threshold is preset to 0.7. Specifically, when the overall rollover index is less than 0.7, it is determined that the current rollover risk of the vehicle is within a controllable range. At this time, the vehicle system does not execute the dynamic control of the chassis layer to avoid interfering with the driver's control intentions and to ensure driving smoothness. When the overall rollover index is not less than 0.7, it is determined that the vehicle is in a high-risk instability state, and is about to or has already experienced a tendency for the side wheels to leave the ground. At this time, the system immediately activates the vehicle's active safety execution program and prepares to issue targeted control commands according to the rollover type.

[0052] In some other embodiments, a sports utility vehicle (SUV) is used as an example to illustrate the technical logic of this solution. The specific simulation vehicle parameter table is shown in Table 1: Table 1 Simulation Vehicle Parameter Table Vehicle mass m (kg) 1862 <![CDATA[sprung mass m s (kg)]]> 1592 <![CDATA[yaw moment of inertia I z (kg·m 2 )]]> 3100 <![CDATA[Roll moment of inertia I x (kg·m 2 )]]> 614 Distance a (m) from the center of mass to the front axle 1.18 Distance b (m) from the center of mass to the rear axle 1.77 Total height of the centroid h (m) 0.91 <![CDATA[Sprung mass centroid height h s (m)]]> 1 Wheelbase B (m) 1.575 <![CDATA[Equivalent roll stiffness of suspension K φ (N·m / rad)]]> 187500 <![CDATA[Suspension equivalent roll damping C φ (N·m / rad)]]> 11422 In this embodiment, to improve the robustness of the warning system in complex driving environments, test conditions covering multiple extreme scenarios were first designed based on vehicle dynamics simulation. Extensive closed-loop dynamics simulation analysis was conducted for different conditions, including normal driving (such as straight driving and smooth lane changes), extreme steering (such as hook-type and double lane change conditions), and vehicle tripping (such as side impact from a curb). Statistical analysis of the peak roll angle acceleration distribution under different conditions revealed that the roll angle acceleration under normal driving and general steering conditions is below 150 deg / s², while the roll-over condition under tripping is typically significantly higher than this value. Therefore, 150 deg / s² was selected as the weighting transformation threshold.

[0053] To verify the effectiveness of the early warning method proposed in this invention, simulation tests were conducted on typical operating conditions of vehicles under different rollover risk states. During the simulation, the system automatically adjusted the weight distribution of the lateral load transfer rate and roll energy index based on the vehicle's real-time roll angle acceleration, and calculated the comprehensive rollover index R to evaluate the vehicle's current rollover risk level. Analysis of the variation law of the comprehensive rollover index under different operating conditions verified that the dynamic weight adjustment mechanism proposed in this invention can take into account both non-tripping and tripping rollover instability modes, achieving accurate identification of vehicle rollover risk.

[0054] For stable driving conditions, in the simulation test, the target vehicle performed normal lane changes at a speed of 72 km / h on the road, with the steering wheel angle maintained within 30° and the steering wheel angular velocity at 30° / s². The absolute value of the roll acceleration fluctuated only between 5deg / s² and 12deg / s², far below the set weight conversion threshold. The dynamic weight allocation diagram under normal driving conditions is shown below. Figure 3 As shown, by Figure 3 It can be seen that the weighting coefficient of lateral load transfer rate under normal driving conditions is... It accounts for a very large proportion, close to 1. Under this high weighting distribution, the lateral load transfer rate of the wheel vertical load dominates the comprehensive rollover index, and the comprehensive rollover index R remains stable within 0.35, that is, the comprehensive rollover index remains within the safe range. The schematic diagram of the comprehensive rollover index under normal driving conditions is shown below. Figure 4 As shown.

[0055] For extreme driving conditions, to verify the accuracy of the system's warning for non-tripping rollovers, a simulation environment was used to simulate a hook-like extreme test. The target vehicle performed emergency avoidance maneuvers and continuous reverse steering maneuvers at a high initial speed of 72 km / h. Under this extreme maneuver, the vehicle's lateral dynamic response was extremely drastic, with a significant change in the roll angle acceleration. The sensors detected that the absolute value of the roll angle acceleration rapidly increased and remained below 160 deg / s². The dynamic weight distribution diagram under extreme driving conditions is shown below. Figure 5 As shown, It continuously decreased to 0.42, while the comprehensive rollover index fluctuation diagram under extreme driving conditions is shown in the figure below. Figure 6 As shown, by Figure 6 It can be seen that when the vehicle makes its first extreme turn under extreme driving conditions, the comprehensive rollover index has exceeded 0.7, and it has entered a high-risk rollover warning state.

[0056] In addition, for the tripping-type rollover scenario, this example simulates a vehicle rolling over after hitting a curb. When the outer wheel contacts the curb, the vehicle experiences a sudden lateral impact, causing a drastic change in the vehicle's tilt motion state within a very short time. The tilt angle acceleration rapidly increases and exceeds the preset weight conversion threshold. The dynamic weight allocation diagram for a vehicle rolling over after hitting a curb is shown below. Figure 7 As shown, by Figure 7 It can be seen that at approximately 2.2 seconds, It quickly jumped from near 0 to near 1, and The synchronous decrease to near 0 indicates that the system has shifted its focus in assessing rollover risk from load transfer status to rollover energy status. As the impact gradually weakens, It quickly fell back again. It regained dominance, achieving dynamic switching of weights; and the diagram illustrating the fluctuation of the comprehensive rollover index under tripping-type rollover conditions is shown below. Figure 8 As shown, in Figure 8 As can be seen, at about 2.5 seconds, R rises rapidly and exceeds the warning threshold of 0.7, with the peak value approaching 1. The system immediately enters a high-risk rollover warning state. Although R drops somewhat afterward, it remains at a high level during the rollover development stage. The results show that the proposed dynamic weight allocation strategy can capture the vehicle instability trend in a timely manner in the early stage of a tripping rollover, effectively improving the sensitivity of rollover risk assessment and the real-time performance of warnings.

[0057] Example 2 Based on the same concept, referencing Figure 9 This application also proposes a vehicle rollover warning device based on LTR and roll energy weighting, comprising: The acquisition module is used to acquire the lateral load transfer rate and roll energy of the vehicle at the current moment, wherein the roll energy is the sum of the roll kinetic energy and roll potential energy of the vehicle. The roll energy index calculation module presets a static energy threshold based on the vehicle's mass, track width, and center of gravity height, and uses the ratio of roll energy to the static energy threshold as the roll energy index at the current moment. The dynamic weight allocation module is used to obtain the absolute value of the vehicle's roll angle acceleration at the current moment, calculate the roll energy weight coefficient based on the absolute value of the roll angle acceleration, and obtain the lateral load transfer rate weight coefficient based on the roll energy weight coefficient. The comprehensive rollover index calculation module uses the weighted result of the lateral load transfer rate weighting coefficient on the absolute value of the lateral load transfer rate and the weighted result of the roll energy weighting coefficient on the roll energy index as the comprehensive rollover index. The early warning module has a preset comprehensive rollover threshold. When the comprehensive rollover index is greater than the comprehensive rollover threshold, a vehicle rollover warning is issued.

[0058] Example 3 This embodiment also provides an electronic device, see reference. Figure 10 It includes a memory 402 and a processor 401, the memory 402 storing a computer program and the processor 401 being configured to run the computer program to perform the steps in any of the above method embodiments.

[0059] Specifically, the processor 401 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0060] The memory 402 may include a mass storage device for data or instructions. For example, and not limitingly, the memory 402 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), flash memory, an optical disk drive, a magneto-optical disk drive, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 402 may include removable or non-removable (or fixed) media. Where appropriate, the memory 402 may be internal or external to a data processing device. In a particular embodiment, the memory 402 is non-volatile memory. In a particular embodiment, the memory 402 includes read-only memory (ROM) and random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable read-only memory (PROM), an erasable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), an electrically alterable read-only memory (EAROM), or flash memory, or a combination of two or more of these. Where appropriate, the RAM can be Static Random-Access Memory (SRAM) or Dynamic Random-Access Memory (DRAM). DRAM can be Fast Page Mode Dynamic Random Access Memory (FPMDRAM), Extended Data Out Dynamic Random Access Memory (EDODRAM), Synchronous Dynamic Random-Access Memory (SDRAM), etc.

[0061] The memory 402 can be used to store or cache various data files that need to be processed and / or communicated, as well as possible computer program instructions executed by the processor 401.

[0062] The processor 401 reads and executes computer program instructions stored in the memory 402 to implement any of the vehicle rollover warning methods based on LTR and roll energy weighting in the above embodiments.

[0063] Optionally, the electronic device may further include a transmission device 403 and an input / output device 404, wherein the transmission device 403 is connected to the processor 401 and the input / output device 404 is connected to the processor 401.

[0064] The transmission device 403 can be used to receive or send data via a network. Specific examples of the network described above may include wired or wireless networks provided by the communication provider of the electronic device. In one example, the transmission device includes a Network Interface Controller (NIC), which can connect to other network devices via a base station to communicate with the Internet. In another example, the transmission device 403 may be a Radio Frequency (RF) module used for wireless communication with the Internet.

[0065] The input / output device 404 is used to input or output information. In this embodiment, the input information may be the vehicle's lateral load transfer rate and roll energy, etc., and the output information may be the vehicle's comprehensive rollover index, etc.

[0066] Optionally, in this embodiment, the processor 401 can be configured to perform the following steps via a computer program: Obtain the lateral load transfer rate and roll energy of the vehicle at the current moment, wherein the roll energy is the sum of the vehicle's roll kinetic energy and roll potential energy; Based on the vehicle's mass, track width, and center of gravity height, a static energy threshold is preset, and the ratio of roll energy to the static energy threshold is used as the roll energy index at the current moment. Obtain the absolute value of the vehicle's roll angle acceleration at the current moment, calculate the roll energy weighting coefficient based on the absolute value of the roll angle acceleration, and obtain the lateral load transfer rate weighting coefficient based on the roll energy weighting coefficient; The sum of the weighted result of the lateral load transfer rate weighting coefficient on the absolute value of the lateral load transfer rate and the weighted result of the roll energy weighting coefficient on the roll energy index is used as the comprehensive rollover index. A preset comprehensive rollover threshold is set, and a vehicle rollover warning is issued when the comprehensive rollover index exceeds the comprehensive rollover threshold.

[0067] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementations, and will not be repeated here.

[0068] Generally, various embodiments can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects of the invention can be implemented in hardware, while others can be implemented by firmware or software executed by a controller, microprocessor, or other computing device, but the invention is not limited thereto. Although various aspects of the invention may be shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, by way of non-limiting example, these blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0069] Embodiments of the present invention can be implemented by computer software, which may be executable by a data processor of a mobile device, such as a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also referred to as program products) including software routines, applets, and / or macros can be stored in any device-readable data storage medium, and they include program instructions for performing specific tasks. The computer program product may include one or more computer-executable components configured to perform the embodiments when the program is run. The one or more computer-executable components may be at least one piece of software code or a portion thereof. Additionally, it should be noted in this respect that, as Figure 10 Any box in the logical flow can represent a program step, or interconnected logic circuits, boxes and functions, or a combination of program steps and logic circuits, boxes and functions. Software can be stored on physical media such as memory chips or blocks of storage implemented within a processor, magnetic media such as hard disks or floppy disks, and optical media such as DVDs and their data variants, CDs, etc. The physical medium is a non-transient medium.

[0070] Those skilled in the art should understand that the technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0071] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A vehicle roll-over warning method based on LTR and roll energy weighting, characterized in that, The method comprises the following steps: obtaining the lateral load transfer rate and the roll energy of the vehicle at the current moment, the roll energy being the sum of the roll kinetic energy and the roll potential energy of the vehicle; presetting a static energy threshold value based on the vehicle mass, the wheelbase and the vehicle center of mass height, and taking the ratio of the roll energy to the static energy threshold value as the roll energy index at the current moment; obtaining the absolute value of the roll angle acceleration of the vehicle at the current moment, calculating the roll energy weight coefficient based on the absolute value of the roll angle acceleration, and obtaining the lateral load transfer rate weight coefficient based on the roll energy weight coefficient; taking the sum of the weighted result of the lateral load transfer rate weight coefficient on the absolute value of the lateral load transfer rate and the weighted result of the roll energy weight coefficient on the roll energy index as the comprehensive rollover index; presetting a comprehensive rollover threshold value, and performing vehicle rollover warning when the comprehensive rollover index is greater than the comprehensive rollover threshold value.

2. The vehicle roll-over warning method based on LTR and roll energy weighting according to claim 1, characterized in that, A vehicle inertia coordinate system is constructed with the vehicle center of mass position as the origin, the longitudinal axis direction as the x-axis and the lateral direction as the y-axis, a longitudinal motion equation moving along the x-axis direction, a lateral motion equation moving along the y-axis direction, a yaw motion equation rotating along the z-axis direction and a roll motion equation rotating along the x-axis direction are constructed in the vehicle inertia coordinate system, a four-degree-of-freedom vehicle dynamics model comprising the longitudinal motion equation, the lateral motion equation, the yaw motion equation and the roll motion equation is constructed, and vehicle motion parameters are obtained based on the four-degree-of-freedom vehicle dynamics model, the lateral load transfer rate and the roll energy are calculated by combining the vehicle motion parameters with the vehicle parameters.

3. The vehicle roll-over warning method based on LTR and roll energy weighting according to claim 1, characterized in that, The sum of the roll energy weight coefficient and the lateral load transfer rate weight coefficient is 1.

4. The vehicle roll-over warning method based on LTR and roll energy weighting of claim 1, wherein, The formula for calculating the roll kinetic energy is: wherein, is the roll kinetic energy, is the roll moment of inertia, is the roll angular velocity, is the vehicle mass, is the vehicle lateral velocity.

5. The vehicle roll-over warning method based on LTR and roll energy weighting according to claim 1, wherein, The formula for calculating the roll potential energy is: wherein, is the roll potential, is the total vehicle mass, is the gravitational acceleration, is the vehicle center of mass height, is the vehicle roll angle.

6. The vehicle roll-over warning method based on LTR and roll energy weighting of claim 1, wherein, The formula for calculating the roll energy weight coefficient is: wherein, is a roll energy weight coefficient, is a weight adjustment coefficient, is a roll angle absolute value, is a weight conversion threshold.

7. The vehicle roll-over warning method based on LTR and roll energy weighting of claim 1, wherein, The preset formula for the static energy threshold value is: wherein is a static energy threshold, is the total vehicle mass, is the gravitational acceleration, is the vehicle center of mass height, is the height of the center of mass to the ground when the center of mass is turned to be directly above the wheel contact patch, is the wheel track.

8. A vehicle roll-over warning device based on LTR and roll energy weighting, characterized by, comprises: an obtaining module, configured to obtain the lateral load transfer rate and the roll energy of the vehicle at the current moment, the roll energy being the sum of the roll kinetic energy and the roll potential energy of the vehicle; a roll energy index calculation module, configured to preset a static energy threshold value based on the vehicle mass, the wheelbase and the vehicle center of gravity height, and take the ratio of the roll energy to the static energy threshold value as the roll energy index at the present moment; a dynamic weight distribution module, configured to obtain the absolute value of the roll angle acceleration of the vehicle at the current moment, calculate the roll energy weight coefficient based on the absolute value of the roll angle acceleration, and obtain the lateral load transfer rate weight coefficient based on the roll energy weight coefficient; a comprehensive rollover index calculation module, configured to take the sum of the weighted result of the lateral load transfer rate weight coefficient on the absolute value of lateral load transfer rate and the weighted result of the roll energy weight coefficient on the roll energy index, as the comprehensive rollover index; a warning module, configured to preset a comprehensive rollover threshold value, and perform vehicle rollover warning when the comprehensive rollover index is greater than the comprehensive rollover threshold value; 9.An electronic device comprising a memory and a processor, the electronic device characterized by, the memory stores a computer program, and the processor is configured to run the computer program to execute the vehicle rollover warning method based on the LTR and the roll energy weight of any one of claims 1-7.

10. A readable storage medium, characterized by, The readable storage medium stores a computer program, and the computer program is executed by the processor to realize the vehicle rollover warning method based on LTR and roll energy weighting according to any one of claims 1-7.

Images