Multi-dimensional vehicle real-time roll-over warning method fusing steering intention

Abstract

The application provides a multi-dimensional vehicle real-time rollover warning method fusing steering intention, comprising the following steps: acquiring vehicle driving parameters of the vehicle at the current time, if the vehicle driving parameters meet the warning judgment condition, then executing the next step, wherein the vehicle driving parameters include real-time vehicle speed, steering wheel turning angle size, steering wheel turning angle speed, vehicle inclination angle, vehicle angular velocity and road adhesion coefficient; based on the vehicle driving parameters, dynamically matching the LTR dynamic threshold database to acquire the rollover warning threshold of the vehicle at the current time, and calculating the lateral load transfer rate of the vehicle at the current time; according to the lateral load transfer rate and the rollover warning threshold, calculating the rollover warning time of the vehicle at the current time, determining the rollover risk level based on the rollover warning time, taking the TTR as one of the judgment bases of the rollover warning and fusing the steering intention of the driver, so as to improve the accuracy and adaptability of the vehicle rollover warning, and it is of great significance to optimize the intervention time of the rollover prevention control.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vehicle rollover warning, in particular to a multi-dimensional vehicle real-time rollover warning method fusing steering intention. BACKGROUND

[0002] Vehicle rollover, as a typical instability accident with extremely high fatality rate, the accuracy and reliability of its warning system are crucial to improving the active safety performance of vehicles. The core of the warning system lies in building an evaluation index that can accurately represent the degree of rollover danger. Lateral-load Transfer Ratio (LTR) has become the most effective and widely used rollover warning evaluation index because it can directly reflect the transfer state of vertical load between left and right wheels and has clear physical meaning. Based on this, existing rollover warning technologies mostly use a fixed LTR threshold as the warning trigger condition. However, the vehicle dynamics behavior is influenced by multiple factors such as vehicle driving state speed and external environment. The application of a fixed LTR threshold as a warning trigger condition has certain limitations. In low-risk conditions, false positives may occur due to excessive sensitivity. In high-risk conditions such as high speed, low adhesion, or sharp turns, the warning may be delayed due to excessive conservatism, making it difficult to ensure sufficient reaction time.

[0003] To further optimize the LTR threshold, patent CN110040146A incorporates road surface parameters to make the LTR threshold adaptively adjust with vehicle speed and road surface environment. This method is suitable for both stumble-type and non-stumble-type rollovers. Patent CN115406669A considers the optimization of non-sprung mass LTR calculation and builds a fitting relationship between the warning threshold and vehicle speed and road adhesion coefficient. However, the above methods achieve dynamic threshold adjustment but do not incorporate the real-time steering intention (steering wheel angle and angular velocity) of the driver, resulting in the same warning value being used for both smooth and emergency steering conditions, which makes it difficult to actively predict and affects the accuracy and reliability in complex conditions.

[0004] In addition, LTR can only judge the current or short-term rollover risk of the vehicle and lacks reasonable prediction ability, making it difficult to ensure sufficient prevention time and having certain limitations. Therefore, scholars have proposed using Time to rollover (TTR) as one of the rollover evaluations to dynamically predict risks based on body roll angle or LTR threshold and set an upper limit for TTR to ensure prevention time. For example, patent CN119636689A calculates TTR based on roll angle, determines the risk level in combination with vehicle speed, and adopts different control strategies. However, the roll angle threshold varies with vehicle models and lacks universality. Patent CN202510168027.X calculates TTR based on LTR (fixed threshold of 1) and Zero Moment Point (ZMP), but at this time the wheels have already left the ground, making it impossible to provide early warning. However, such patents still fail to consider the steering intention of the driver, resulting in low accuracy of vehicle rollover warning. SUMMARY

[0005] The present application aims to provide a multi-dimensional vehicle real-time rollover warning method fusing steering intention, taking TTR as one of the evaluation basis for rollover warning and fusing the driver's steering intention, which is of great significance to improve the accuracy and adaptability of vehicle rollover warning and optimize the intervention time of rollover prevention control.

[0006] To achieve the above purpose, the technical scheme provides a multi-dimensional vehicle real-time rollover warning method fusing steering intention, comprising the following steps:

[0007] S1: obtaining the vehicle driving parameters of the vehicle at the current time, if the vehicle driving parameters meet the warning judgment condition, executing step S2, wherein the vehicle driving parameters include real-time vehicle speed, steering wheel angle, steering wheel angle speed, vehicle inclination angle, vehicle angular velocity and road adhesion coefficient;

[0008] S2: dynamically matching the LTR dynamic threshold database based on the vehicle driving parameters to obtain the rollover warning threshold of the vehicle at the current time, and calculating the lateral load transfer rate of the vehicle at the current time;

[0009] S3: calculating the rollover warning time of the vehicle at the current time according to the lateral load transfer rate and the rollover warning threshold, and determining the rollover risk level based on the rollover warning time.

[0010] Compared with the prior art, the technical scheme has the following characteristics and beneficial effects:

[0011] 1. The present application comprehensively considers the parameters of road adhesion coefficient, vehicle speed, steering wheel angle and steering wheel angle speed, breaks through the limitation of the existing rollover warning technology which only relies on vehicle speed and road adhesion coefficient, can accurately distinguish operation scenes such as smooth steering and emergency steering, and makes up for the defects of insufficient warning accuracy and reliability under complex working conditions.

[0012] 2. The present application takes the dynamic LTR threshold as the judgment condition, calculates TTR combined with the first-order change rate of LTR, can quantify the required time to trigger warning under the current state and change trend, more directly reflects the risk urgency, provides accurate intervention time for the subsequent active rollover prevention control, and according to the TTR interval, divides the risk level, matches the controllable differential braking measures, realizes the targeted rollover prevention control, and effectively improves the driving safety. DETAILED DESCRIPTION

[0013] Figure 1 is the flowchart of the multi-dimensional vehicle real-time rollover warning method fusing steering intention of the present application.

[0014] Figure 2 is the logic diagram based on the vehicle driving parameters meeting the warning judgment condition.

[0015] Figure 3 is a schematic diagram of a lateral vehicle dynamics model.

[0016] Figure 4 is a schematic diagram of a four-degree-of-freedom vehicle dynamics model.

[0017] Figure 5 is a decision logic diagram of a vehicle rollover warning time.

[0018] Figure 6 is a decision logic diagram of a risk level.

[0019] Figure 7 is a logic diagram of differential braking control.

[0020] Figure 8 is a structural schematic diagram of an electronic device. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0022] It should be noted that: in other embodiments, the steps of the corresponding method are not necessarily performed in the order shown and described in the present specification. In some other embodiments, the steps included in the method can be more or less than described in the present specification. In addition, a single step described in the present specification can be divided into multiple steps for description in other embodiments; and multiple steps described in the present specification can also be combined into a single step for description in other embodiments.

[0023] Embodiment one

[0024] As shown in Figure 1 The present scheme provides a multi-dimensional vehicle real rollover warning method fusing steering intention, comprising the following steps:

[0025] S1: obtaining the vehicle driving parameters of the vehicle at the current time, if the vehicle driving parameters meet the warning judgment condition, executing step S2, wherein the vehicle driving parameters include real-time vehicle speed, steering wheel angle size, steering wheel angle speed, vehicle inclination angle, vehicle angular velocity and road adhesion coefficient;

[0026] S2: dynamically matching the LTR dynamic threshold database based on the vehicle driving parameters to obtain the rollover warning threshold of the vehicle at the current time, and calculating the lateral load transfer rate of the vehicle at the current time;

[0027] S3: calculating the rollover early warning time of the vehicle at the current moment according to the lateral load transfer rate and the rollover early warning threshold, and determining the rollover risk level based on the rollover early warning time.

[0028] The step S1 of the scheme comprehensively considers many vehicle driving parameters such as real-time vehicle speed, steering wheel angle size, steering wheel angle speed, vehicle inclination angle, vehicle angular velocity, and road adhesion coefficient to make early warning initial judgment, in particular, the steering wheel angle size and the steering wheel angle speed are used as the steering intention of the driver, which breaks through the limitation of the existing rollover early warning technology that only relies on vehicle speed and road adhesion coefficient, can accurately distinguish operation scenes such as smooth steering and emergency steering, and makes up for the defects of insufficient warning accuracy and reliability under complex working conditions.

[0029] In step S1, the real-time vehicle speed is obtained in real time by a wheel speed sensor, the steering wheel angle size and the steering wheel angle speed are obtained in real time by a steering force and angle sensor, the vehicle inclination angle and the vehicle angular velocity are obtained in real time by a dynamic inclination sensor, and the road adhesion coefficient is calculated by a road adhesion coefficient estimation unit.

[0030] Specifically, the real-time vehicle speed is obtained in real time by a wheel speed sensor, and the number of wheel rotation turns and frequency are detected in real time by a Hall wheel speed sensor installed at the hub of each wheel of the vehicle, and the real-time vehicle speed is calculated in combination with the rolling radius of the wheel.

[0031] The steering wheel angle size and the steering wheel angle speed are obtained in real time by a steering force and angle sensor, the steering force and angle sensor is integrated at the steering column, and the optical encoding technology is used to capture the change of the light signal when the steering shaft rotates, to convert the mechanical angle into a digital signal, and at the same time, the steering wheel angle speed is calculated in real time by the ratio of the angle difference to the time interval in the adjacent sampling period, to identify the steering intention of the driver in the “small angle slow steering” (smooth working condition) and “large angle fast steering” (emergency working condition).

[0032] The vehicle inclination angle and the vehicle angular velocity are obtained in real time by a dynamic inclination sensor, the dynamic inclination sensor is installed at the vehicle body frame directly above the center of mass of the vehicle, and the data fusion algorithm of the micro-electromechanical system technology combined with the gyroscope and the accelerometer is used to output the inclination angle and the inclination angular velocity of the vehicle around the horizontal axis in real time, to effectively capture the tendency of the vehicle to roll in the curve, lane change or uneven road working condition.

[0033] The road adhesion coefficient The road adhesion coefficient is calculated by a road adhesion coefficient estimation unit, and is obtained by combining the wheel speed difference collected by a wheel speed sensor, the lateral acceleration collected by a lateral acceleration sensor (integrated with a dynamic inclination sensor), and a tire magic formula model, and by using Kalman filtering to inversely calculate the adhesion capability of the current road.

[0034] The present scheme introduces the steering wheel angle and the steering wheel angle speed to represent the driving intention of the driver, and determines whether the driver operation belongs to dangerous steering based on the steering wheel angle and the steering wheel angle speed.

[0035] Specifically, the contents of the early warning judgment condition are as follows:

[0036] When the real-time vehicle speed is not greater than the low vehicle speed threshold, the early warning judgment condition is not met, and it is determined that the vehicle steering does not have a rollover risk, i.e., the rollover early warning does not need to be started.

[0037] When the real-time vehicle speed is greater than the low vehicle speed threshold but not greater than the high vehicle speed threshold, and the steering wheel steering is not greater than the high steering size threshold or the steering wheel angle speed is not greater than the high steering speed threshold, the early warning judgment condition is not met, and it is determined that the vehicle belongs to a stable steering condition, and the early warning judgment condition is not met.

[0038] When the real-time vehicle speed is greater than the high vehicle speed threshold, and the steering wheel steering is not greater than the low steering size threshold or the steering wheel angle speed is not greater than the low steering speed threshold, the early warning judgment condition is not met, and it is determined that the vehicle belongs to a stable steering condition, and the early warning judgment condition is not met.

[0039] It should be noted that when the real-time vehicle speed is not greater than the low vehicle speed threshold, the vehicle lateral inertia force is small, and the rollover risk is extremely low, so the early warning judgment is not needed; when the real-time vehicle speed is greater than the low vehicle speed threshold but not greater than the high vehicle speed threshold, it is a medium-speed driving, and if the steering wheel steering is not greater than the high steering size threshold or the steering wheel angle speed is not greater than the high steering speed threshold, it represents that the driver is in a stable steering condition, and the early warning judgment is not needed; when the real-time vehicle speed is greater than the high vehicle speed threshold, it is a high-speed driving, and the sensitivity to vehicle rollover is improved.

[0040] In a specific embodiment, as shown in Figure 2 the early warning judgment condition is as follows:

[0041] (1) If the real-time vehicle speed ≤ 50 km / h, the vehicle steering does not have a rollover risk, and it is determined that the rollover early warning does not need to be started;

[0042] (2) If 50 km / h < v < 90 km / h, if the steering wheel angle size ≤ 100° or the angle speed ≤ 0.5 rad / s, the early warning judgment condition is not met. ≤ 180° / s, it belongs to the stable steering working condition, and it is determined that the rollover warning is not needed; otherwise, it belongs to the emergency steering working condition, and it is determined that the rollover warning is needed.

[0043] (3) If > 90 km / h, at this time, it belongs to high-speed driving, and if the steering wheel angle size ≤ 60° or the steering wheel angle speed ≤ 120° / s, it belongs to the stable steering working condition, and it is determined that the rollover warning is not needed; otherwise, it belongs to the emergency steering working condition, and it is determined that the rollover warning is needed.

[0044] The step S2 of the scheme is based on the LTR dynamic threshold database constructed based on massive simulation, and the warning threshold is adaptively adjusted according to the real-time vehicle driving parameters including the real-time steering intention of the driver.

[0045] Specifically, in the step S2, the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size and the steering wheel angle speed are used to dynamically match the LTR dynamic threshold database to obtain the rollover warning threshold of the vehicle at the current moment.

[0046] The LTR dynamic threshold database of the scheme records the relationship between the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size, the steering wheel angle speed and the rollover warning threshold, so that the rollover warning threshold can be determined in the LTR dynamic threshold database according to the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size and the steering wheel angle speed.

[0047] The construction method of the LTR dynamic threshold database is as follows:

[0048] An inertial coordinate system is established, and a four-degree-of-freedom vehicle dynamics model is constructed according to the force received by the vehicle on the x-axis, the y-axis and the z-axis, wherein the four-degree-of-freedom dynamics model includes the longitudinal motion, the lateral motion, the yaw motion and the roll motion of the vehicle;

[0049] The real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size and the steering wheel angle speed are input as variables into the four-degree-of-freedom vehicle dynamics model, the “fishhook steering” test working condition is simulated to induce vehicle rollover, the value of the 0.1 lateral load transfer rate before the vehicle rollover reaches the 1 lateral load transfer rate is taken as the rollover warning threshold, if the vehicle does not rollover, the rollover warning threshold is 1, and the rollover warning thresholds under different real-time vehicle speeds, road adhesion coefficients, steering wheel angle sizes and steering wheel angle speeds are integrated to form the LTR dynamic threshold database.

[0050] For example, Figure 3 and Figure 4As shown, the inertial coordinate system XOY is established with the vehicle mass center position of the current vehicle as the origin O, with the longitudinal axis direction of the vehicle as the x axis, and with the lateral axis direction of the vehicle as the y axis, and the mechanical equilibrium equation is established according to the forces received by the vehicle in the four directions of the x axis, the y axis and the z axis as follows:

[0051] Longitudinal motion:

[0052] ;

[0053] Lateral motion:

[0054] ;

[0055] Yaw motion:

[0056] ;

[0057] Roll motion:

[0058] ;

[0059] Wherein m is the mass of the whole vehicle, m s is the sprung mass, g is the acceleration of gravity, a and b are the distances from the mass center of the whole vehicle to the front and rear axles, g is the acceleration of gravity, B is the wheelbase, h s is the height of the mass center of the sprung mass, I x and I z are the roll moment of inertia and the yaw moment of inertia of the whole vehicle, is the inclination angle of the vehicle, is the equivalent roll stiffness of the suspension, is the equivalent roll damping of the suspension, v x and v y are the longitudinal and lateral speeds of the whole vehicle, a x and a y are the longitudinal and lateral accelerations of the whole vehicle, is the yaw angular velocity of the vehicle, f xfl is the longitudinal force received by the left front wheel, f yfl is the lateral force received by the left front wheel; f xfr is the longitudinal force received by the right front wheel, f yfr is the lateral force received by the right front wheel; f xrl is the longitudinal force received by the left rear wheel, f yrl is the lateral force received by the left rear wheel; f xrr is the longitudinal force received by the right rear wheel, f yrr is the lateral force received by the right rear wheel.

[0060] After the four-degree-of-freedom vehicle dynamics model is constructed, the relationship between the vehicle rollover early warning threshold and the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size, and the steering wheel angle speed is obtained in advance through dynamic simulation.

[0061] Specifically, the road adhesion coefficient is increased from 0.1 to 1 by a set difference, the real-time vehicle speed is increased from a low vehicle speed threshold to 120 km / h by a set difference, and different steering wheel angle sizes and steering wheel angle speeds are set to obtain the lateral load transfer rate under different vehicle driving parameters. It should be noted that the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size, and the steering wheel angle speed are controlled by a single variable to obtain the lateral load transfer rate under different vehicle driving parameters, that is, in the case where any three parameters of the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size, and the steering wheel angle speed are fixed, the remaining one parameter is adjusted as a variable.

[0062] In some specific embodiments, the road adhesion coefficient is increased from 0.1 to 1 by 0.05, and the real-time vehicle speed is increased from 50 km / h by 10 km / h.

[0063] In the CarSim / Simulink joint simulation platform, the four-degree-of-freedom vehicle dynamics model simulates the “fishhook steering” test condition to induce vehicle rollover, so as to obtain the vehicle rollover condition under different real-time vehicle speeds, road adhesion coefficients, steering wheel angle sizes, and steering wheel angle speeds. If the vehicle does not rollover, the rollover early warning threshold LTR th is defined as 1, and if the vehicle rollover occurs, the value of the lateral load transfer rate of 0.1 before the lateral load transfer rate reaches 1 is taken as the rollover early warning threshold LTR th .

[0064] The discrete data points obtained through a large number of simulations are integrated, and the four input variables (real-time vehicle speed, road adhesion coefficient, steering wheel angle size, and steering wheel angle speed) and the corresponding rollover early warning thresholds are constructed into a structured four-dimensional lookup table, i.e., a LTR dynamic threshold database, by MATLAB. It should be noted that the remaining rollover early warning thresholds not in the four-dimensional lookup table can be obtained by linear interpolation.

[0065] In addition, the lateral load transfer rate of the vehicle at the current time is calculated based on the vehicle inclination angle and the vehicle angular velocity, and the calculation formula is as follows:

[0066]

[0067] wherein is the vehicle inclination angle, is the equivalent roll stiffness of the suspension, and for the equivalent roll damping of the suspension, vehicle angular velocity m is the mass of the vehicle, g is the acceleration of gravity, and B is the wheel base.

[0068] The step S3 of the scheme calculates the rollover early warning time of the vehicle at the current time according to the lateral load transfer rate and the rollover early warning threshold, and the step S3 of the scheme calculates the rollover early warning time in combination with the first order change rate of the lateral load transfer rate, which can quantify the required time for triggering the early warning under the current state and the change trend.

[0069] Specifically, as shown in Figure 5 , the first order change rate of the lateral load transfer rate is calculated, if the lateral load transfer rate is less than the rollover early warning threshold and the first order change rate of the lateral load transfer rate is equal to 0, then the rollover early warning time is 2s; if the lateral load transfer rate is greater than the rollover early warning threshold and the first order change rate of the lateral load transfer rate is equal to 0s, then the rollover early warning time is 0; if the first order change rate of the lateral load transfer rate is not 0, the difference between the rollover early warning threshold and the lateral load transfer rate and the quotient of the first order change rate of the lateral load transfer rate are calculated as the rollover early warning time.

[0070] Specifically, the formula for calculating the rollover early warning time of the vehicle at the current time according to the lateral load transfer rate and the rollover early warning threshold is as follows:

[0071] ;

[0072] wherein is the first order change rate of the lateral load transfer rate, is the lateral load transfer rate, is the rollover early warning threshold.

[0073] The rollover early warning time calculated by the scheme can directly reflect the urgency of the rollover risk, if the rollover early warning time is smaller, it means that the vehicle has a greater rollover risk in the current dynamic state; the upper limit value of the rollover early warning time is set to 2, which means that the vehicle does not have a rollover risk; the lower limit value of the rollover early warning time is set to 0, which means that the vehicle has a great rollover risk. The detailed description of the upper limit value and the lower limit value of the rollover early warning time is as follows:

[0074] (1) When the vehicle is in a stable driving state, for example, straight-line driving at a constant speed, its body posture is stable, and the load on the left and right sides hardly transfers, so the lateral load transfer rate is close to 0, and since there is no tendency to exacerbate the roll, the change rate is also close to 0. In this case, since the denominator in the calculation formula tends to 0, the value of the rollover early warning time tends to infinity, in order to facilitate calculation, the value of the rollover early warning time in this case is set to the upper limit value of 2s, which means that the vehicle does not have a rollover risk at present.

[0075] (2) When the lateral load transfer rate reaches the rollover early warning threshold and continues to increase, and the system has not yet taken intervention measures, at this time the first order change rate of the lateral load transfer rate is greater than 0, at this time the value of the rollover early warning time is negative, in order to facilitate early warning, the value of the rollover early warning time in this case is set to the lower limit value 0s, indicating that this moment is the latest moment for the anti-rollover control strategy to intervene, if the system has not yet taken intervention measures at this time, the vehicle will roll over.

[0076] Further, as shown in Figure 6 , the present scheme determines the rollover risk level based on the rollover early warning time, if the rollover early warning time is equal to 2s, the risk level is defined as 0; if the rollover early warning time is less than 2s and not less than 1s, the risk level is defined as 1; if the rollover early warning time is less than 1s and greater than or equal to 0, the risk level is defined as 2.

[0077] That is:

[0078] (1) If TTR=2, at this time the vehicle has no rollover risk, the output risk level is 0;

[0079] (2) If , at this time the vehicle has a small rollover risk, the output risk level is 1;

[0080] (3) If 0≤TTR<1, at this time the vehicle has a large rollover risk, the output risk level is 2, and the rollover early warning ends.

[0081] In addition, the multi-dimensional vehicle real-time rollover early warning method of the present scheme fusing steering intention additionally includes the step: S4: realizing differentiated differential braking control based on the risk level.

[0082] As shown in Figure 7 , if the risk level is 0, no differential braking control is performed; if the risk level is 1, low-intensity differential braking control is performed; if the risk level is 2, high-intensity differential braking control is performed. In addition, the present scheme inputs the intensity level of differential braking into the wheel braking force calculation unit to calculate the required braking force of each wheel, and outputs the braking force by EMB to realize differential braking anti-rollover control.

[0083] As described above, the multi-dimensional vehicle real-time rollover early warning method of the present scheme fusing steering intention considers the vehicle real-time LTR / TTR rollover early warning method of the driver's steering intention, which can solve the problem in the prior art that the early warning threshold is fixed or only changes with vehicle speed and road surface, and cannot identify the driver's steering intention, resulting in early warning lag or false reporting. Compared with the fixed early warning threshold, the present scheme can make an early rollover warning, leaving more reaction time for the anti-rollover control of the vehicle, thereby effectively improving the driving safety.

[0084] The following provides a specific example for illustration:

[0085] The vehicle model used in this application to construct the LTR dynamic threshold database is a sport utility vehicle (SUV). The specific simulation vehicle parameters are shown in Table 1.

[0086] Table 1 Simulation Vehicle Parameter Table

[0087] .

[0088] The road surface adhesion coefficient μ is set to increase from 0.1 to 1 in increments of 0.05, and the vehicle speed V... x All speeds increase from 50 km / h to 120 km / h in increments of 10 km / h, and are adjusted according to the steering wheel angle. and steering wheel angular velocity The different conditions are divided into 4 different groups:

[0089] Working condition 1: Corner size 90°, angular velocity 300° / s;

[0090] Working condition 2: Corner size 150°, angular velocity 300° / s;

[0091] Operating Condition 3: Corner Size 90°, angular velocity 200° / s;

[0092] Operating Condition 4: Corner Size 150°, angular velocity It is 200° / s.

[0093] The process of constructing the LTR dynamic threshold database through offline simulation is as follows: By combining four key input variables—vehicle speed, road adhesion coefficient, steering wheel angle, and steering velocity—the "fishhook steering" test condition is simulated to induce vehicle rollover, and the vehicle rollover warning threshold (LTR) is accurately determined for each combination of conditions. th For test scenarios involving vehicle rollover, the definition is... The LTR value 0.1 seconds before the vehicle first reaches 1 is the rollover warning threshold. If the vehicle will not rollover, the rollover warning threshold is recorded as 1. The simulation data were then processed to obtain the following four sets of dynamic LTR thresholds for different operating conditions, as shown in Tables 2 to 5:

[0094] Table 2. Dynamic Thresholds of LTR under Operating Condition 1

[0095] .

[0096] Table 3. Dynamic Threshold Table of LTR under Operating Condition 2

[0097] .

[0098] Table 4 LTR dynamic threshold table under working condition 3

[0099] .

[0100] Table 5 LTR dynamic threshold table under working condition 4

[0101] .

[0102] From the LTR dynamic threshold tables obtained from Tables 2 to 5, it can be seen that the larger the road adhesion coefficient and the larger the steering angle speed of the vehicle, the more likely it is to roll over, and therefore four groups of working conditions are designed to verify the optimization effect of the rollover warning threshold under the condition that the steering wheel steering angle is 120° and the steering angle speed is 240° / s, and the road adhesion coefficients and vehicle speeds of the four groups of working conditions are 0.9 and 85 km / h, 0.9 and 95 km / h, 0.95 and 85 km / h, and 0.95 and 95 km / h, respectively. The rollover warning threshold before optimization is a fixed value of 0.85, and the rollover warning threshold after optimization is obtained according to the LTR dynamic threshold table of the present scheme. The comparison results of the rollover warning threshold before and after optimization are shown in Table 6:

[0103] Table 6 Comparison results of rollover warning threshold before and after optimization

[0104] .

[0105] Further, the optimization effect of the rollover warning time and the rollover time under the condition that the steering wheel steering angle is 120° and the steering angle speed is 240° / s is also verified for the four groups of different vehicle speeds and road adhesion coefficients, wherein the latest rollover warning intervention time before optimization is the time corresponding to the TTR value of 0 obtained by setting the LTRth as a fixed value of 0.85, i.e., the ratio of the difference between the LTR fixed value of 0.85 and the current LTR to the first-order change rate of the LTR, and the latest rollover warning intervention time after optimization is the time corresponding to the TTR value of 0 obtained by setting the LTRth as a dynamic threshold according to the present scheme. The rollover time is the time corresponding to the TTR value of 0 obtained by setting the LTRth as 1, and the comparison results of the rollover warning time before and after optimization are shown in Table 7:

[0106] .

[0107] The comparison results of Table 6 and Table 7 show that the greater the road adhesion coefficient μ and the faster the vehicle speed Vx, the higher the risk of vehicle rollover, which is consistent with the vehicle dynamics characteristics, i.e. a higher adhesion coefficient allows a greater lateral force to be generated without side slipping, but this in turn increases the likelihood of the vehicle "stumbling" and rolling over. Therefore, considering the rollover warning threshold at different vehicle speeds, road adhesion coefficients, steering wheel angle sizes and steering wheel angle speed sizes can provide more reaction time for vehicle rollover prevention control. In addition, under the set four working conditions, compared with the fixed warning threshold 0.85, the optimized dynamic threshold is reduced by 0.0902, 0.1294, 0.1279 and 0.1544 respectively under the same vehicle speed and road adhesion coefficient conditions. This smaller threshold brings earlier warning time, so that the latest intervention time is advanced by 0.03s, 0.04s, 0.04s and 0.046s respectively. For a high-center SUV vehicle, the rollover process only occurs in an instant under extreme conditions, and these tens of milliseconds of advance are crucial, providing an opportunity for the driver's correction operation or the intervention of the vehicle active safety system.

[0108] Embodiment Three

[0109] The embodiment also provides an electronic device, referring to Figure 8 including a memory 404 and a processor 402, the memory 404 stores a computer program, and the processor 402 is configured to run the computer program to perform the steps in any one of the above method embodiments. The memory 404 can be used to store or cache various data files required for processing and / or communication, and the computer program instructions executed by the processor 402.

[0110] The processor 402 realizes the multi-dimensional vehicle real-time rollover warning method of fusion steering intention in any one of the above embodiments by reading and executing the computer program instructions stored in the memory 404.

[0111] Optionally, the above electronic device can further include a transmission device 406 and an input / output device 408, wherein the transmission device 406 is connected with the above processor 402, and the input / output device 408 is connected with the above processor 402. The transmission device 406 can be used to receive or send data via a network. The input / output device 408 is used to input or output information. In the embodiment, the input information can be vehicle driving parameters, etc., and the output information can be rollover warning time, rollover warning threshold or rollover risk level, etc.

[0112] Optionally, in the embodiment, the above processor 402 can be configured to execute the following steps by computer program:

[0113] S1: acquiring a vehicle driving parameter of the vehicle at the current time, and if the vehicle driving parameter meets a pre-warning judgment condition, performing step S2, wherein the vehicle driving parameter comprises a real-time vehicle speed, a steering wheel angle size, a steering wheel angle speed, a vehicle inclination angle, a vehicle angular speed, and a road adhesion coefficient;

[0114] S2: dynamically matching the LTR dynamic threshold database based on the vehicle driving parameter to acquire a rollover pre-warning threshold of the vehicle at the current time, and calculating a lateral load transfer rate of the vehicle at the current time;

[0115] S3: calculating a rollover pre-warning time of the vehicle at the current time according to the lateral load transfer rate and the rollover pre-warning threshold, and determining a rollover risk level based on the rollover pre-warning time.

[0116] It should be noted that the specific examples in the embodiments can refer to the examples described in the above embodiments and optional implementation manners, and the embodiments will not be described here.

[0117] Generally, various embodiments can be implemented in hardware or special-purpose circuitry, software, logic or any combination thereof. Some aspects of the application can be implemented in hardware, while other aspects can be implemented by firmware or software executed by a controller, microprocessor or other computing device, but the application is not limited thereto. Although various aspects of the application can be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein can be implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0118] Embodiments of the application can be implemented by computer software executable by a data processor of the mobile device such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and / or macros, can be stored in any apparatus-readable data storage medium and they include program instructions to implement specific tasks. The program product can include one or more computer-executable components which, when executed by the data processor, perform one or more of the steps of the disclosed embodiments. The one or more computer-executable components can be at least one software code or a portion thereof. Further in this regard, it should be noted that any blocks of the logical flow of the figures can represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software can be stored on such physical media as memory chips, or memory blocks implemented in the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media are non-transitory media.

Claims

1. A multi-dimension vehicle real-time roll-over warning method fusing steering intention, characterized in that, The method comprises the following steps: S1: acquiring vehicle driving parameters of the vehicle at the current time, and if the vehicle driving parameters meet the pre-warning judgment condition, executing step S2, wherein the vehicle driving parameters include real-time vehicle speed, steering wheel angle size, steering wheel angle speed, vehicle inclination angle, vehicle angular velocity, and road adhesion coefficient; S2: dynamically matching the LTR dynamic threshold database based on the vehicle driving parameters to acquire the vehicle rollover pre-warning threshold at the current time, and calculating the lateral load transfer ratio of the vehicle at the current time, wherein the construction method of the LTR dynamic threshold database is as follows: An inertial coordinate system is established, and a four-degree-of-freedom vehicle dynamics model is constructed according to the mechanical equilibrium equation of the vehicle in the x-axis, y-axis and z-axis directions, wherein the four-degree-of-freedom dynamics model includes the longitudinal motion, lateral motion, yaw motion and roll motion of the vehicle; The real-time vehicle speed, road adhesion coefficient, steering wheel angle size and steering wheel angle speed are input as variables into the four-degree-of-freedom vehicle dynamics model, a "fishhook steering" test condition is simulated to induce vehicle rollover, and if the vehicle rolls over, the value of the lateral load transfer ratio at 0.1 before the lateral load transfer ratio reaches 1 is taken as the rollover pre-warning threshold, and if the vehicle does not roll over, the rollover pre-warning threshold is 1, and the rollover pre-warning thresholds under different real-time vehicle speeds, road adhesion coefficients, steering wheel angle sizes and steering wheel angle speeds are integrated to form the LTR dynamic threshold database; S3: calculating the vehicle rollover pre-warning time at the current time according to the lateral load transfer ratio and the rollover pre-warning threshold, and determining the rollover risk level based on the rollover pre-warning time.

2. The multi-dimension vehicle real-time rollover warning method fusing steering intention according to claim 1, characterized in that, The real-time vehicle speed is acquired in real time by a wheel speed sensor, the steering wheel angle size and the steering wheel angle speed are acquired in real time by a steering force angle sensor, the vehicle inclination angle and the vehicle angular velocity are acquired in real time by a dynamic inclination angle sensor, and the road adhesion coefficient is calculated by a road adhesion coefficient estimation unit.

3. The multi-dimension vehicle real-time rollover warning method fusing steering intention according to claim 1, characterized in that, When the real-time vehicle speed is not greater than the low vehicle speed threshold, the pre-warning judgment condition is not met; when the real-time vehicle speed is greater than the low vehicle speed threshold but not greater than the high vehicle speed threshold, and the steering wheel steering is not greater than the high steering size threshold or the steering wheel angle speed is not greater than the high steering speed threshold, the pre-warning judgment condition is not met; when the real-time vehicle speed is greater than the high vehicle speed threshold, and the steering wheel steering is not greater than the low steering size threshold or the steering wheel angle speed is not greater than the low steering speed threshold, the pre-warning judgment condition is not met.

4. The multi-dimension vehicle real-time rollover warning method fusing steering intention according to claim 1, characterized in that, The LTR dynamic threshold database is dynamically matched based on the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size and the steering wheel angle speed to acquire the vehicle rollover pre-warning threshold at the current time.

5. The multi-dimension vehicle real-time rollover warning method fusing steering intention according to claim 1, characterized in that, The relationship between the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size, the steering wheel angle speed and the rollover pre-warning threshold is recorded in the LTR dynamic threshold database, so that the rollover pre-warning threshold can be determined in the LTR dynamic threshold database according to the real-time vehicle speed, the road adhesion coefficient, the steering wheel angle size and the steering wheel angle speed.

6. The multi-dimension vehicle real-time rollover warning method fusing steering intention according to claim 1, characterized in that, A first order change rate of the lateral load transfer ratio is calculated, if the lateral load transfer ratio is less than the rollover early warning threshold and the first order change rate of the lateral load transfer ratio is equal to 0, the rollover early warning time is 2s; if the lateral load transfer ratio is greater than the rollover early warning threshold and the first order change rate of the lateral load transfer ratio is equal to 0, the rollover early warning time is 0; if the first order change rate of the lateral load transfer ratio is not equal to 0, a difference value between the rollover early warning threshold and the lateral load transfer ratio and a quotient value of the first order change rate of the lateral load transfer ratio are calculated as the rollover early warning time.

7. The multi-dimension vehicle real-time rollover warning method fusing steering intention according to claim 6, characterized in that, A rollover risk level is determined based on the rollover early warning time, if the rollover early warning time is equal to 2s, the risk level is defined as 0; if the rollover early warning time is less than 2s and not less than 1s, the risk level is defined as 1; If the rollover early warning time is less than 1s and not less than 0, the risk level is defined as 2.

8. The multi-dimension vehicle real-time roll-over warning method fusing steering intention according to claim 1, wherein, The method further comprises S4: realizing differentiated differential braking control based on the risk level. 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 multi-dimensional vehicle real-time rollover early warning method of fusing steering intention according to any one of claims 1 to 8. The memory stores a computer program, and the processor is configured to run the computer program to execute the multi-dimensional vehicle real-time rollover early warning method of fusing steering intention according to any one of claims 1 to 8.

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