CN109591806B

CN109591806B - Rollover early warning method and device, storage medium and vehicle

Info

Publication number: CN109591806B
Application number: CN201811544046.4A
Authority: CN
Inventors: 魏恒; 高小丽; 程海松; 戴彪; 刘壬生; 邱东; 陈辉; 潘高强
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2018-12-17
Filing date: 2018-12-17
Publication date: 2021-03-23
Anticipated expiration: 2038-12-17
Also published as: CN109591806A

Abstract

The invention discloses a rollover warning method, a rollover warning device, a storage medium and a vehicle, wherein the method comprises the following steps: acquiring displacement sensor data and speed information of a vehicle to be early-warned; determining the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information; and determining a comparison result of the transverse load transfer rate and a set early warning value, and prompting the comparison result according to a set rollover danger level. The scheme of the invention can solve the problem that rollover accidents are easy to occur during control such as turning and lane changing during high-speed running of the multi-axle commercial vehicle, so that the safety is poor, and the effect of improving the safety is achieved.

Description

Rollover early warning method and device, storage medium and vehicle

Technical Field

The invention belongs to the technical field of automobiles, and particularly relates to a rollover early warning method and device, a storage medium and a vehicle, in particular to a method and device for realizing a rollover prevention early warning system of a multi-axle air suspension vehicle based on a wheel speed difference load transfer rate model, a storage medium and a vehicle.

Background

The vehicle turns on one's side is a serious road traffic accident, turns on one's side the accident more easily to the passenger-cargo vehicle that the barycenter is high, and along with the demand of load, multiaxis commercial car is more and more, when controlling such as turn and lane change when going at a high speed, very easily takes place the accident of turning on one's side.

We generally use the lateral load transfer rate LTR as a rollover threshold for the rollover warning system. Wherein LTR ═ F_L-F_R)/(F_L+F_R) I.e., the difference between the vertical loads of the left and right tires of the vehicle divided by the sum of the vertical loads.

Existing threshold models based on LTR are mainly classified into three categories: (1) a wheel speed difference LTR threshold model (refer to wheel speed difference LTR threshold models disclosed in documents CN103569087B, CN103569087A, CN202481078U, etc.); (2) a suspension deformation LTR threshold model (refer to a suspension deformation LTR threshold model disclosed in CN104476999A and the like); (3) the rollover dynamics LTR threshold model (refer to S.Selim et al.A. method for the design of robust roller preservation controllers for automatic approaches). As shown in fig. 8: the idea of calculating the transverse load transfer rate by the wheel speed difference is to eliminate the influence of the wheel speed difference of the turning by using two factors of the wheel speed difference in the turning motion so as to obtain the load transfer of the inner tire and the outer tire.

When the vehicle turns, the rotating speeds of the inner tire and the outer tire are different, and the outer tire travels a larger distance in the same time. The automobile is provided with a differential device, the differential device is arranged between a transmission shaft and a half shaft, and the running stability of the automobile is ensured due to different rotating speeds of wheels on different road surfaces and different steering conditions. When the vehicle is driving around a turn, the inner wheel will have a different speed than the outer wheel to prevent unstable driving, which is done on conventional vehicles by a mechanical differential. The motion law of the mechanical differential is as follows: the sum of the rotational speeds of the two side drive wheels is always equal to twice the rotational speed of the differential case, regardless of turning or straight running. The common symmetrical bevel gear differential mechanism has small internal friction torque, and can be considered to be that torque on two sides is always evenly distributed no matter whether the rotating speeds of left and right driving wheels are equal or not, the distribution ratio is satisfactory to the running state of a vehicle when the vehicle runs on a good road surface in a straight line or a turning way, but the running working condition of the vehicle is complicated and changeable, and no differential mechanism can meet the functional requirements under all road conditions.

The difference in wheel speed due to the difference in turning radius. When the wheel is turned, the inner side wheel slips, the outer side wheel slips, the ground generates opposite forces on the driving wheel, the forces act on the half shaft gear, the planetary gear rotates to accelerate the rotation of the outer side half shaft gear and decelerate the rotation of the inner side half shaft gear in order to ensure that the wheels roll, and therefore the rotating speeds of the wheels on two sides are different. Thus, under the action of the differential, when the road adhesion coefficients are the same, the vehicle can automatically adjust the rotating speeds of the left wheel and the right wheel according to different turning radiuses.

Besides the wheel speed difference caused by the turning radius, the load transfer of the vehicle causes the load difference of the left and right side tires, and further causes the rolling radius difference, and under the condition that the vehicle speed is fixed, the wheel speed of the side with the increased load is larger than that of the side with the decreased load. In the process of keeping the whole automobile forward, the load transfer of each shaft can bring about the difference of the rotating speed, and further represents the deformation of the tire. Therefore, the load transfer is obtained by obtaining the rotating speed difference caused by load transfer through the rotating speed difference of the whole vehicle and the turning rotating speed difference.

Disclosure of Invention

The invention aims to provide a rollover warning method, a rollover warning device, a rollover warning storage medium and a vehicle, aiming at overcoming the defects that rollover accidents are easy to happen during control such as turning and lane changing when a multi-axle commercial vehicle runs at a high speed and the safety is poor in the prior art, and achieving the effect of improving the safety.

The invention provides a rollover early warning method, which comprises the following steps: acquiring displacement sensor data and speed information of a vehicle to be early-warned; determining the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information; and determining a comparison result of the transverse load transfer rate and a set early warning value, and prompting the comparison result according to a set rollover danger level.

Optionally, acquiring the displacement sensor data and the speed information of the vehicle to be early-warned includes: acquiring displacement sensor data and speed information from an ABS (anti-lock braking system) system and an active suspension system of a vehicle to be pre-warned; or acquiring the data of the displacement sensor of the vehicle to be pre-warned detected by the displacement sensor and the speed information of the vehicle to be pre-warned detected by the sensor; or acquiring the displacement sensor data and the speed information of the vehicle to be early-warned, which are fed back by the vehicle electronic system.

Optionally, determining a lateral load transfer rate of the vehicle to be warned according to the displacement sensor data and the speed information includes: constructing a wheel speed difference LTR threshold model of a vehicle with more than two axles in advance; and calculating the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information by utilizing a pre-constructed wheel speed difference LTR threshold model of the vehicle with more than two axles.

Optionally, a wheel speed difference LTR threshold model of the vehicle with two or more axles is constructed in advance, including: determining the speed difference of load transfer wheels of the vehicles with more than two axles, and determining the total spring load of the vehicles with more than two axles; determining load transfer of each axle of the vehicles with more than two axles by combining the radial rigidity of the wheels of the vehicles with more than two axles and the speed difference of the load transfer wheels to obtain total load transfer; and calculating to obtain the speed difference of the load transfer wheel according to the total sprung load and the total load transfer.

Optionally, the speed information includes: at least one of rotational speed, vehicle speed, lateral acceleration information, and wheel speed information; determining a load transfer wheel speed differential for a vehicle having more than two axles, comprising: obtaining wheel speed information of wheels on the left side and the right side of each axle of a vehicle with more than two axles, and calculating to obtain an average rotating speed and a total wheel speed difference; calculating to obtain an instantaneous turning radius according to the speed and the lateral acceleration of the vehicle with more than two axles, and calculating to obtain a steering wheel speed difference generated by the instantaneous turning radius according to the average rotating speed; and subtracting the speed difference of the steering wheel from the total wheel speed difference to obtain the speed difference of the load transfer wheel.

Optionally, determining the total sprung load of the vehicle for more than two axles comprises: acquiring displacement sensor data and unsprung loads of a vehicle with more than two axles; the displacement sensor data comprising: the initial height of the air spring, the working area of the air spring and the displacement of the air spring; determining the spring load of the vehicle with more than two axles according to the data of the displacement sensors; and determining the total sprung load of the vehicle with more than two axles according to the sprung load and the unsprung load.

Optionally, determining load transfer for each axle of the vehicle at the two or more axles in combination with the wheel radial stiffness of the vehicle at the two or more axles and the load transfer wheel speed differential comprises: calculating effective rolling radii of the vehicles with more than two axles according to the average rotating speed of the rotating speeds of the wheels on the left side and the right side of each axle of the vehicles with more than two axles and the vehicle speeds of the vehicles with more than two axles; calculating the tire rolling radius difference of the left and right wheels of each axle of the vehicle with more than two axles according to the effective rolling radius and the speed difference of the load transfer wheels; and calculating load transfer of each shaft of the vehicles with more than two shafts by combining the radial rigidity of the wheels of the vehicles with more than two shafts and the rolling radius difference of the tires.

Optionally, the prompting of the comparison result according to a set rollover risk level includes: if the steering wheel of the vehicle to be early-warned turns left, the vehicle to be early-warned tilts right, and the transverse load transfer rate is smaller than the set early-warning value, the rollover dangerous state indicating needle hits the left side of the indicating area; or if the steering wheel of the vehicle to be pre-warned turns right, the vehicle to be pre-warned inclines left, and the transverse load transfer rate is greater than the set pre-warning value, the rollover danger state indicating needle is driven to the right side of the indicating area.

Optionally, wherein the rollover risk level of the rollover risk state and the magnitude of the difference between the lateral load transfer rate and the set warning value are in a positive correlation relationship; and/or grading prompt is carried out on different rollover danger levels of the rollover danger state by at least one of set prompt information of color, pattern and sound and light.

In another aspect, the invention provides a rollover warning device, which includes: the system comprises an acquisition unit, a pre-warning unit and a warning unit, wherein the acquisition unit is used for acquiring displacement sensor data and speed information of a vehicle to be pre-warned; the determining unit is used for determining the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information; the determining unit is further used for determining a comparison result of the transverse load transfer rate and a set early warning value, and prompting the comparison result according to a set rollover danger level.

Optionally, the acquiring unit acquires the displacement sensor data and the speed information of the vehicle to be warned, and includes: acquiring displacement sensor data and speed information from an ABS (anti-lock braking system) system and an active suspension system of a vehicle to be pre-warned; or acquiring the data of the displacement sensor of the vehicle to be pre-warned detected by the displacement sensor and the speed information of the vehicle to be pre-warned detected by the sensor; or acquiring the displacement sensor data and the speed information of the vehicle to be early-warned, which are fed back by the vehicle electronic system.

Optionally, the determining unit determines a lateral load transfer rate of the vehicle to be warned according to the displacement sensor data and the speed information, and includes: constructing a wheel speed difference LTR threshold model of a vehicle with more than two axles in advance; and calculating the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information by utilizing a pre-constructed wheel speed difference LTR threshold model of the vehicle with more than two axles.

Optionally, the determining unit constructs in advance a wheel speed difference LTR threshold model of the vehicle having two or more axles, including: determining the speed difference of load transfer wheels of the vehicles with more than two axles, and determining the total spring load of the vehicles with more than two axles; determining load transfer of each axle of the vehicles with more than two axles by combining the radial rigidity of the wheels of the vehicles with more than two axles and the speed difference of the load transfer wheels to obtain total load transfer; and calculating to obtain the speed difference of the load transfer wheel according to the total sprung load and the total load transfer.

Optionally, the speed information includes: at least one of rotational speed, vehicle speed, lateral acceleration information, and wheel speed information; the determination unit determines a load transfer wheel speed difference of a vehicle having two or more axles, including: obtaining wheel speed information of wheels on the left side and the right side of each axle of a vehicle with more than two axles, and calculating to obtain an average rotating speed and a total wheel speed difference; calculating to obtain an instantaneous turning radius according to the speed and the lateral acceleration of the vehicle with more than two axles, and calculating to obtain a steering wheel speed difference generated by the instantaneous turning radius according to the average rotating speed; and subtracting the speed difference of the steering wheel from the total wheel speed difference to obtain the speed difference of the load transfer wheel.

Optionally, the determining unit determines a total sprung load of the vehicle at two or more axles, including: acquiring displacement sensor data and unsprung loads of a vehicle with more than two axles; the displacement sensor data comprising: the initial height of the air spring, the working area of the air spring and the displacement of the air spring; determining the spring load of the vehicle with more than two axles according to the data of the displacement sensors; and determining the total sprung load of the vehicle with more than two axles according to the sprung load and the unsprung load.

Optionally, the determining unit determines load transfer of each axle of the two or more axles in combination with the wheel radial stiffness of the two or more axles and the load transfer wheel speed difference, including: calculating effective rolling radii of the vehicles with more than two axles according to the average rotating speed of the rotating speeds of the wheels on the left side and the right side of each axle of the vehicles with more than two axles and the vehicle speeds of the vehicles with more than two axles; calculating the tire rolling radius difference of the left and right wheels of each axle of the vehicle with more than two axles according to the effective rolling radius and the speed difference of the load transfer wheels; and calculating load transfer of each shaft of the vehicles with more than two shafts by combining the radial rigidity of the wheels of the vehicles with more than two shafts and the rolling radius difference of the tires.

Optionally, the determining unit prompts the comparison result according to a set rollover risk level, including: if the steering wheel of the vehicle to be early-warned turns left, the vehicle to be early-warned tilts right, and the transverse load transfer rate is smaller than the set early-warning value, the rollover dangerous state indicating needle hits the left side of the indicating area; or if the steering wheel of the vehicle to be pre-warned turns right, the vehicle to be pre-warned inclines left, and the transverse load transfer rate is greater than the set pre-warning value, the rollover danger state indicating needle is driven to the right side of the indicating area.

In accordance with the above apparatus, a further aspect of the present invention provides a vehicle comprising: the rollover early warning device is described above.

In accordance with the above method, a further aspect of the present invention provides a storage medium comprising: the storage medium has stored therein a plurality of instructions; the instructions are used for being loaded by the processor and executing the rollover warning method.

In accordance with the above method, a further aspect of the present invention provides a vehicle comprising: a processor for executing a plurality of instructions; a memory to store a plurality of instructions; the instructions are stored in the memory, and loaded and executed by the processor.

According to the scheme, the rollover warning function is realized by using the wheel speed difference LTR threshold model of the multi-axle vehicle and based on the wheel speed difference LTR rollover warning system of the ABS system, the cost is low, the integration level is high, the rollover warning processing process is greatly simplified, and the safety is improved.

Further, according to the scheme of the invention, the wheel speed difference threshold value is calculated by tire deformation based on the first LTR principle, rollover warning is carried out on commercial vehicles with various axle numbers, and the method is good in universality and convenient to integrate into the existing automobile electronic system.

Furthermore, the scheme of the invention can be realized by directly using wheel speed information on a vehicle provided with the ABS and only needing an additional acceleration sensor or obtaining lateral acceleration information from other vehicle electronic systems on the vehicle not provided with the ABS, and has low cost and good use convenience.

Furthermore, according to the scheme of the invention, the wheel speed difference LTR of the multi-axle vehicle is modeled, so that the rollover early warning system is generally suitable for vehicles with various axle numbers, and has the advantages of good universality and high reliability.

Furthermore, according to the scheme of the invention, the rollover prevention early warning system based on the wheel speed difference only needs the displacement sensor data and the lateral acceleration information of the conventional ABS system and the conventional active suspension system, and the rollover prevention early warning system is convenient and simple to implement, low in cost and high in reliability.

Therefore, according to the scheme of the invention, the rollover warning function is realized by utilizing the wheel speed difference LTR threshold model of the multi-axle vehicle and the wheel speed difference LTR rollover warning system based on the ABS system, and the problem that rollover accidents are easy to occur and the safety is poor when the multi-axle commercial vehicle is operated and controlled during turning, lane changing and the like in the prior art is solved, so that the defects of poor safety, complex processing process and high cost in the prior art are overcome, and the beneficial effects of good safety, simple processing process and low cost are realized.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic flow chart of a rollover warning method according to an embodiment of the present invention;

FIG. 2 is a schematic flow chart illustrating an embodiment of determining a lateral load transfer rate of a vehicle to be pre-warned based on the displacement sensor data and the speed information in the method of the present invention;

FIG. 3 is a schematic flow chart illustrating an embodiment of pre-constructing a wheel speed difference LTR threshold model of a vehicle with more than two axles according to the method of the present invention;

FIG. 4 is a schematic flow chart illustrating one embodiment of the method of the present invention for determining a load transfer wheel speed differential for a vehicle having more than two axles;

FIG. 5 is a schematic flow chart illustrating one embodiment of determining the total sprung load for a vehicle having more than two axles according to the method of the present invention;

FIG. 6 is a schematic flow chart diagram illustrating one embodiment of determining load transfer for each axle of a vehicle having more than two axles in the method of the present invention;

fig. 7 is a schematic structural diagram of a rollover warning device according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a wheel speed difference calculation for lateral load transfer rate;

FIG. 9 is a schematic diagram illustrating changes in the height and load of a membrane air spring according to an embodiment of the rollover warning method of the present invention;

FIG. 10 is a schematic diagram of a wheel speed difference LTR threshold model according to an embodiment of the rollover warning method of the present invention;

fig. 11 is a wheel speed difference LTR rollover warning algorithm according to an embodiment of the rollover warning method of the present invention, where (a) is a rollover warning flow diagram, and (b) is a rollover warning indication diagram;

fig. 12 is a schematic structural diagram of a wheel speed difference LTR rollover warning system according to an embodiment of the rollover warning method of the present invention.

The reference numbers in the embodiments of the present invention are as follows, in combination with the accompanying drawings:

102-an obtaining unit; 104 — a determination unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, a rollover warning method is provided, as shown in fig. 1, which is a schematic flow chart of an embodiment of the method of the present invention. The rollover early warning method can comprise the following steps: step S110 to step S130.

At step S110, displacement sensor data and speed information of the vehicle to be warned are acquired.

Optionally, the acquiring of the displacement sensor data and the speed information of the vehicle to be warned in step S110 may include any one of the following acquiring situations.

A first acquisition scenario: and acquiring the data and the speed information of the displacement sensors of the ABS system and the active suspension system of the vehicle to be early warned.

A second acquisition scenario: and acquiring the data of the displacement sensor of the vehicle to be pre-warned, which is detected by the displacement sensor additionally arranged on the vehicle to be pre-warned, and the speed information of the vehicle to be pre-warned, which is detected by the sensor additionally arranged on the vehicle to be pre-warned.

A third acquisition scenario: and acquiring the displacement sensor data and the speed information of the vehicle to be early-warned, which are fed back by other vehicle electronic systems except the vehicle to be early-warned.

Therefore, the displacement sensor data and the speed information of the vehicle to be subjected to early warning are acquired in multiple modes, the displacement sensor data and the speed information of multiple vehicles can be conveniently and flexibly acquired, rollover early warning of the multiple vehicles is achieved, and the vehicle to be subjected to early warning is good in universality and high in reliability.

At step S120, a lateral load transfer rate of the vehicle to be warned is determined according to the displacement sensor data and the speed information.

Optionally, with reference to a schematic flow chart of an embodiment of determining the lateral load transfer rate of the vehicle to be warned according to the displacement sensor data and the speed information in the method of the present invention shown in fig. 2, a specific process of determining the lateral load transfer rate of the vehicle to be warned according to the displacement sensor data and the speed information in step S120 may include: step S210 and step S220.

In step S210, a wheel speed difference LTR threshold model of the vehicle with two or more axles is constructed in advance. Wherein, more than two axles can include: two axes, and more than two axes.

For example: the wheel speed difference LTR of a multi-axle (including two axles) vehicle is modeled, so that the rollover early warning system is generally suitable for vehicles with various axles.

More optionally, the specific process of pre-constructing the wheel speed difference LTR threshold model of the two or more axles in step S210 may further be described with reference to a flowchart of an embodiment of pre-constructing the wheel speed difference LTR threshold model of the two or more axles in the method of the present invention shown in fig. 3, and may include: step S310 to step S330.

Step S310 determines the load transfer wheel speed difference of the vehicle for two or more axles, and determines the total sprung load of the vehicle for two or more axles.

Further alternatively, the specific process of determining the difference between the load transfer wheel speeds of the two or more vehicles in step S310 may be further described with reference to a flowchart of an embodiment of determining the difference between the load transfer wheel speeds of the two or more vehicles in the method of fig. 4, and may include: step S410 to step S430.

Step S410, the speed information may include: at least one of rotational speed, vehicle speed, lateral acceleration information, and wheel speed information; and obtaining wheel speed information of wheels on the left side and the right side of each axle of the vehicle with more than two axles, and calculating to obtain the average rotating speed and the total wheel speed difference. The wheel speed information is wheel angular velocity information, and may be obtained from the ABS. The vehicle speed and the lateral acceleration information can be other basic vehicle information.

And step S420, calculating to obtain an instantaneous turning radius according to the vehicle speed and the lateral acceleration of the vehicle with more than two axles, and calculating to obtain the steering wheel speed difference generated by the instantaneous turning radius according to the average rotating speed.

And step S430, subtracting the speed difference of the steering wheel from the total wheel speed difference to obtain the speed difference of the load transfer wheel.

Therefore, the load transfer wheel speed difference is calculated according to the wheel speed information of the left wheel and the right wheel of each axle of the vehicle with more than two axles, the calculation mode is simple and convenient, and the calculation result is accurate.

Further alternatively, the specific process of determining the total sprung load of the two or more axles in step S310 may further be described with reference to a flowchart of an embodiment of determining the total sprung load of the two or more axles in the method of fig. 5, where the specific process may include: step S510 to step S530.

Step S510, displacement sensor data and unsprung loads of the vehicle with two or more axles are acquired. The displacement sensor data may include: air spring initial height, air spring working area, and air spring displacement.

For example: the displacement of each air spring is read in real time, the load of the whole vehicle can be accurately estimated, the influence of rolling radius caused by the elimination of steering radius difference is considered, and the calculated wheel speed difference LTR is more accurate.

And step S520, determining the spring load of the vehicle with more than two axles according to the displacement sensor data.

Step S530, determining the total spring load of the vehicle with more than two axles according to the spring load and the unsprung load.

For example: by using the calculation mode of the nonlinear stiffness of the load of the air spring, the change of the spring load of the whole vehicle can be updated in time, and the accurate calculation of the transverse load transfer rate is ensured; and the deformation amount of load transfer of each shaft is obtained by using the wheel rotation speed difference, and then the deformation amount of load transfer of the whole vehicle is obtained by superposition. Such as: according to the load of a single air spring, the load of all the air springs, namely the spring load of the whole vehicle can be obtained. Any load variation of the vehicle between empty and full load can be calculated according to a formula, only data values of displacement sensors of each air spring of the vehicle are needed. If the air spring suspension is automatically adjusted in height, the automatic adjustment unit ECU records and provides a displacement change value x before each automatic adjustment. After the vehicle is turned off, it returns to the original design height h.

Therefore, the total sprung load is calculated according to the displacement sensor data and the unsprung load of the vehicle with more than two axles, the calculation mode is simple and convenient, and the calculation result is accurate.

And step S320, determining the load transfer of each axle of the vehicle with more than two axles by combining the radial rigidity of the wheels of the vehicle with more than two axles and the speed difference of the load transfer wheels to obtain the total load transfer.

Still alternatively, the concrete process of determining the load transfer of each axle of the vehicle with two or more axles in step S320 by combining the wheel radial stiffness of the vehicle with two or more axles and the load transfer wheel speed difference may further be described with reference to a flowchart of an embodiment of determining the load transfer of each axle of the vehicle with two or more axles in the method shown in fig. 6, and may include: step S610 to step S630.

In step S610, the effective rolling radii of the two or more vehicles are calculated according to the average rotation speed of the rotation speeds of the left and right wheels of each axle of the two or more vehicles and the vehicle speeds of the two or more vehicles.

And S620, calculating the tire rolling radius difference of the left wheel and the right wheel of each axle of the vehicle with more than two axles according to the effective rolling radius and the load transfer wheel speed difference.

And step S630, calculating and obtaining the load transfer of each shaft of the vehicles with more than two shafts by combining the radial rigidity of the wheels of the vehicles with more than two shafts and the rolling radius difference of the tires.

Therefore, load transfer is calculated according to wheel speed information of vehicles on the left side and the right side of each axle of the vehicles with more than two axles and by combining the radial rigidity of the wheels of the vehicles with more than two axles and the rolling radius difference of the tires, and the load transfer calculation method is good in calculation accuracy and high in reliability.

And step S330, calculating to obtain a load transfer wheel speed difference according to the total sprung load and the total load transfer.

Therefore, the load transfer wheel speed difference and the total spring load of the vehicle with more than two shafts are respectively determined, the total load transfer is further determined according to the load transfer wheel speed difference and the radial rigidity of the wheels, the load transfer wheel speed difference is calculated according to the total load transfer and the total spring load, the calculation mode is simple and convenient, and the calculation result is accurate.

Step S220, calculating the transverse load transfer rate (namely LTR) of the vehicle to be pre-warned according to the displacement sensor data and the speed information by utilizing a wheel speed difference LTR threshold model of the vehicle with more than two pre-constructed axles.

Therefore, the transverse load transfer rate of the vehicle to be pre-warned is calculated by constructing the wheel speed difference LTR threshold model of the vehicle with more than two axles and further utilizing the wheel speed difference LTR threshold model of the vehicle with more than two axles based on the acquired displacement sensor data and speed information, so that the calculation mode of the transverse load transfer rate of the vehicle to be pre-warned is simple and convenient, and the calculation result is reliable.

In step S130, a comparison result between the lateral load transfer rate and a set warning value is determined, and the comparison result is prompted according to the set rollover risk level, so as to prompt the driver of the current rollover risk level of the vehicle to be warned, thereby implementing rollover warning of the vehicle to be warned.

For example: can utilize the poor LTR threshold value model of wheel speed of multiaxis vehicle, based on the poor LTR early warning system that turns on one's side of wheel speed of ABS system, realize the high early warning function that turns on one's side of with low costs integrated level. Such as: the rollover warning method can be used for carrying out rollover warning on commercial vehicles with various shaft numbers, and based on the first LTR principle, the wheel speed difference threshold value calculation is realized through tire deformation; wheel speed information can be used directly on a vehicle equipped with an ABS; the method can be realized by only needing an additional acceleration sensor or obtaining lateral acceleration information from other vehicle electronic systems, and is convenient to integrate into the existing automobile electronic systems. That is to say, the rollover-prevention early warning system based on the wheel speed difference only needs the displacement sensor data and the lateral acceleration information of the conventional ABS system and the conventional active suspension system, and is convenient and simple to implement.

For example: as shown in fig. 11, the rotation speeds of the left and right wheels of each axle of the vehicle are known in real time, the average rotation speed and the total wheel speed difference are calculated, the instantaneous turning radius is calculated according to the vehicle speed and the lateral acceleration, the steering wheel speed difference is further obtained, the steering wheel speed difference is reduced through the total wheel speed difference, the load transfer wheel speed difference is obtained, the load transfer is further obtained through the radial rigidity of the wheels, the load transfer of each axle is overlapped, the current spring load is calculated according to the air spring, the current value of the transverse load transfer rate is obtained, and the judgment is carried out according to the designed danger level, so that the driver is prompted to turn over the danger degree sideways.

Therefore, the lateral load transfer rate of the vehicle to be pre-warned is determined according to the displacement sensor data and the speed information of the vehicle to be pre-warned, the comparison result of the lateral load transfer rate and the set pre-warning value is further determined, the comparison result is prompted according to the rollover danger level, rollover pre-warning of the vehicle to be pre-warned is achieved, and the safety of vehicle operation is improved.

And the rollover danger level of the rollover dangerous state and the amplitude of the difference between the transverse load transfer rate and the set early warning value form a positive correlation relationship.

Therefore, the rollover danger level of the rollover dangerous state and the lateral load transfer rate and the amplitude of the difference between the set early warning values are in positive correlation, the rollover dangerous state can be accurately determined, and the rollover early warning sensitivity and reliability are better.

Optionally, the step S130 may prompt the comparison result according to the set rollover risk level, and any one of the following prompting situations may be included.

The first prompting scenario: and if the steering wheel of the vehicle to be early-warned turns left, the vehicle to be early-warned tilts right, and the transverse load transfer rate is smaller than the set early-warning value, the rollover dangerous state indicating needle hits the left side of the indicating area.

The second prompting scenario: and if the steering wheel of the vehicle to be pre-warned turns right, the vehicle to be pre-warned inclines left, and the transverse load transfer rate is greater than the set pre-warning value, the rollover dangerous state indicating needle hits the right side of the indicating area.

For example: the method comprises the steps that the vehicle side-tipping state disclosed by the model is indicated by an instrument indication mode, the intuitive feeling of a driver is met, when the steering wheel turns left, the vehicle inclines right, LTR is less than 0, the side-tipping dangerous state indicator is hit to the left side, and the side-tipping dangerous state indicator is positively correlated with the amplitude; on the contrary, when the steering wheel turns right, the severity of the rollover risk of the vehicle is the same as that shown by the pointer.

From this, through the suggestion mode of multiform, the user that can make things convenient for the difference to look over the demand looks over, is favorable to promoting flexibility and the variety of suggestion when the early warning of turning on one's side.

And grading prompting is carried out on different rollover danger levels of the rollover danger state by at least one of set prompting information of color, pattern and sound and light.

For example: the rollover dangerous states in the instrument indication are classified into three types, safety, second-level obvious color early warning (such as second-level yellow early warning) and third-level obvious color early warning (such as third-level red early warning) are achieved, the early warning critical value can be customized and taught according to different vehicle types, the lower critical value can be correspondingly set when vehicles with higher centroids and lower inherent rollover threshold values are matched, and the safety requirements of different vehicle types are met.

Therefore, different rollover danger levels are graded and prompted through different prompting information, rollover early warning prompting can be performed more accurately, and the method is strong in intuition and good in humanization.

Through a large amount of experimental verifications, adopt the technical scheme of this embodiment, through the poor LTR threshold value model of wheel speed that utilizes the multiaxis vehicle, based on the poor LTR early warning system that turns on one's side of wheel speed of ABS system, realize the early warning function of turning on one's side, with low costs and the integrated level is high, has simplified the processing procedure of the early warning of turning on one's side greatly and has promoted the security.

According to the embodiment of the invention, the invention further provides a rollover warning device corresponding to the rollover warning method. Referring to fig. 7, a schematic diagram of an embodiment of the apparatus of the present invention is shown. This early warning device of turning on one's side can include: an acquisition unit 102 and a determination unit 104.

In an optional example, the obtaining unit 102 may be configured to obtain displacement sensor data and speed information of a vehicle to be warned. The specific functions and processes of the acquiring unit 102 are referred to in step S110.

Optionally, the obtaining unit 102 obtains the displacement sensor data and the speed information of the vehicle to be warned, which may include any one of the following obtaining situations.

A first acquisition scenario: the obtaining unit 102 may be further configured to obtain displacement sensor data and speed information from an ABS system and an active suspension system of a vehicle to be warned.

A second acquisition scenario: the obtaining unit 102 may be further configured to obtain data of a displacement sensor of the vehicle to be pre-warned, which is detected by a displacement sensor additionally disposed on the vehicle to be pre-warned, and speed information of the vehicle to be pre-warned, which is detected by a sensor additionally disposed on the vehicle to be pre-warned.

A third acquisition scenario: the obtaining unit 102 may be further configured to obtain the displacement sensor data and the speed information of the vehicle to be pre-warned, which are fed back by the vehicle electronic systems other than the vehicle to be pre-warned.

In an optional example, the determining unit 104 may be configured to determine a lateral load transfer rate of the vehicle to be warned according to the displacement sensor data and the speed information. The specific function and processing of the determination unit 104 are referred to in step S120.

Optionally, the determining unit 104 determines the lateral load transfer rate of the vehicle to be warned according to the displacement sensor data and the speed information, and may include:

the determination unit 104 may be further configured to pre-construct a wheel speed difference LTR threshold model of the vehicle with more than two axles. The specific function and processing of the determination unit 104 are also referred to in step S210.

More optionally, the determining unit 104 pre-constructs a wheel speed difference LTR threshold model of the vehicle with more than two axles, which may include:

the determination unit 104 may be further configured to determine a difference between load transfer wheel speeds of two or more vehicles, and determine a total sprung load of the two or more vehicles. The specific function and processing of the determination unit 104 are also referred to in step S310.

Still further alternatively, the determining unit 104 may determine the load transfer wheel speed difference of the vehicle with two or more axles, and may include:

the speed information may include: at least one of rotational speed, vehicle speed, lateral acceleration information, and wheel speed information. The determining unit 104 may be further configured to obtain wheel speed information of left and right wheels of each axle of the vehicle with more than two axles, and calculate an average rotation speed and a total wheel speed difference. The specific function and processing of the determination unit 104 are also referred to in step S410.

The determining unit 104 may be further configured to calculate an instantaneous turning radius according to the vehicle speed and the lateral acceleration of the vehicle with more than two axles, and calculate a steering wheel speed difference generated by the instantaneous turning radius according to the average rotation speed. The specific function and processing of the determination unit 104 are also referred to step S420.

The determining unit 104 may be further configured to subtract the total wheel speed difference from the steering wheel speed difference to obtain a load transfer wheel speed difference. The specific function and processing of the determination unit 104 are also referred to in step S430.

Still further alternatively, the determining unit 104 may determine the total sprung load of the vehicle for two or more axles, and may include:

the determination unit 104 may be further configured to obtain displacement sensor data and unsprung loads of a vehicle having two or more axles. The displacement sensor data may include: air spring initial height, air spring working area, and air spring displacement. The specific function and processing of the determination unit 104 are also referred to in step S510.

The determination unit 104 may be further configured to determine sprung loads of the two or more vehicles based on the displacement sensor data. The specific function and processing of the determination unit 104 are also referred to in step S520.

The determining unit 104 may be further configured to determine a total sprung load of the vehicle at two or more axes based on the sprung load and the unsprung load. The specific function and processing of the determination unit 104 are also referred to in step S530.

The determining unit 104 may be further configured to determine load transfer of each axle of the two or more axles by combining the radial stiffness of the wheels of the two or more axles and the load transfer wheel speed difference, so as to obtain total load transfer. The specific function and processing of the determination unit 104 are also referred to in step S320.

Still further alternatively, the determining unit 104 may determine load transfer of each axle of the two or more axles by combining the wheel radial stiffness of the two or more axles and the load transfer wheel speed difference, and may include:

the determining unit 104 may be further configured to calculate effective rolling radii of the two or more vehicles according to an average rotation speed of rotation speeds of left and right wheels of each axle of the two or more vehicles and a vehicle speed of the two or more vehicles. The specific function and processing of the determination unit 104 are also referred to in step S610.

The determining unit 104 may be further configured to calculate, according to the effective rolling radius and the load transfer wheel speed difference, a tire rolling radius difference between left and right wheels of each axle of the two or more vehicles. The specific function and processing of the determination unit 104 are also referred to in step S620.

The determining unit 104 may be further configured to calculate load transfer of each axis of the two or more vehicles by combining the radial stiffness of the wheel of the two or more vehicles and the rolling radius difference of the tire. The specific function and processing of the determination unit 104 are also referred to in step S630.

The determining unit 104 may be further specifically configured to calculate a load transfer wheel speed difference according to the total sprung load and the total load transfer. The specific function and processing of the determination unit 104 are also referred to in step S330.

The determining unit 104 may be further configured to calculate, according to the displacement sensor data and the speed information, a lateral load transfer rate of the vehicle to be pre-warned by using a pre-constructed wheel speed difference LTR threshold model of the vehicle with more than two axles. The specific function and processing of the determination unit 104 are also referred to in step S220.

In an optional example, the determining unit 104 may be further configured to determine a comparison result between the lateral load transfer rate and a set warning value, and prompt the comparison result according to a set rollover risk level to prompt a driver of a rollover risk level of a vehicle to be warned, so as to realize rollover warning of the vehicle to be warned. The specific function and processing of the determination unit 104 are also referred to in step S130.

Optionally, the determining unit 104 may prompt the comparison result according to a set rollover risk level, which may include any one of the following prompting situations.

The first prompting scenario: the determining unit 104 may be further specifically configured to, if the steering wheel of the vehicle to be pre-warned turns left, the vehicle to be pre-warned tilts right, and the lateral load transfer rate is smaller than the set pre-warning value, hit the rollover risk indicator on the left side of the indication area.

The second prompting scenario: the determining unit 104 may be further specifically configured to, if the steering wheel of the vehicle to be pre-warned turns right, the vehicle to be pre-warned tilts left, and the lateral load transfer rate is greater than the set pre-warning value, hit the rollover risk indicator on the right side of the indication area.

Since the processes and functions implemented by the apparatus of this embodiment substantially correspond to the embodiments, principles and examples of the method shown in fig. 1 to fig. 6, the description of this embodiment is not detailed, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.

Through a large number of tests, the technical scheme provided by the invention realizes the calculation of the wheel speed difference threshold value through the tire deformation based on the LTR first principle, performs rollover early warning on commercial vehicles with various axle numbers, has good universality and is convenient to integrate into the existing automobile electronic system.

According to the embodiment of the invention, the invention further provides a vehicle corresponding to the rollover warning device. The vehicle may include: the rollover early warning device is described above.

In an optional embodiment, according to the scheme of the invention, a wheel speed difference LTR threshold model of the multi-axle vehicle can be utilized, and a rollover warning function with low cost and high integration level can be realized based on a wheel speed difference LTR rollover warning system of an ABS system.

Therefore, the scheme of the invention can be used for carrying out rollover early warning on commercial vehicles with various axle numbers, and the calculation of the wheel speed difference threshold value is realized by tire deformation based on the first LTR principle; wheel speed information may be used directly on a vehicle equipped with an ABS. The scheme of the invention is simple to apply, and can be realized only by an additional acceleration sensor or by obtaining lateral acceleration information from other vehicle electronic systems; the technology has low cost and is convenient to be integrated into the existing automobile electronic system.

For example: the first principle is the nature, intrinsic nature, or definition of things. This means that the solution is considered from the definition, i.e. from the essence of the LTR meaning; in distinction to other derived solutions (e.g. LTR models based on kinetic models) derived under certain principles or theorems.

In an alternative example, considering that the existing rollover thresholds are set for a two-axle vehicle, the number of axles of a commercial vehicle is very common in order to increase the load. Therefore, the invention models the wheel speed difference LTR of a multi-axle (including two axles) vehicle, so that the rollover warning system is generally suitable for vehicles with various axles.

Optionally, the displacement of each air spring is read in real time, the load of the whole vehicle can be estimated accurately, the influence of rolling radius caused by removing the steering radius difference is considered, and the calculated wheel speed difference LTR is more accurate.

Optionally, the rollover-prevention early warning system based on the wheel speed difference only needs displacement sensor data and lateral acceleration information of the conventional ABS system and the conventional active suspension system, and is convenient and simple to implement.

Optionally, the vehicle roll state disclosed by the model is indicated by using an instrument indication mode, the intuitive feeling of a driver is met, when the steering wheel turns left, the vehicle turns right, LTR <0, the roll-over dangerous state indicator needle is hit to the left side and is positively correlated with the amplitude; on the contrary, when the steering wheel turns right, the severity of the rollover risk of the vehicle is the same as that shown by the pointer.

Optionally, rollover danger states in instrument indication are classified into three categories, safety, secondary obvious color early warning (such as secondary yellow early warning) and tertiary obvious color early warning (such as tertiary red early warning), the early warning critical value can be customized according to different vehicle types, vehicles with higher centroids and lower inherent rollover threshold values can be correspondingly set to lower critical values when being matched, and safety requirements of different vehicle types are met.

According to the scheme, the calculation mode of the nonlinear stiffness of the load of the air spring is used, the change of the spring load of the whole vehicle can be updated in time, and the accurate calculation of the transverse load transfer rate is guaranteed; and the deformation amount of load transfer of each shaft is obtained by using the wheel rotation speed difference, and then the deformation amount of load transfer of the whole vehicle is obtained by superposition.

In an alternative embodiment, the implementation of the solution of the present invention can be illustrated with reference to the examples shown in fig. 9 to 12.

As shown in fig. 9, since the unsprung mass is substantially constant, but the sprung mass varies from person to person and from load to load, it is necessary to estimate the load using an air spring model for sprung mass detection.

Considering the membrane type air spring load at the initial position, the effective air pressure in the air spring is p at a certain moment_eTo do soInitial position gas pressure p_e0From the thermodynamic equation, one can obtain:

and because the equivalent area of the membrane type air spring is approximately unchanged, V is obtained₀＝A_eh and V ═ A_e(h + x), then the load of the individual air springs is:

according to the load of a single air spring, the load of all the air springs, namely the spring load of the whole vehicle can be obtained. Any load variation of the vehicle between empty and full load can be calculated according to a formula, only data values of displacement sensors of each air spring of the vehicle are needed. If the air spring suspension is automatically adjusted in height, the automatic adjustment unit ECU records and provides a displacement change value x before each automatic adjustment. After the vehicle is turned off, it returns to the original design height h.

Table 1: variable symbol table for calculating spring load of air spring suspension

As shown in fig. 10, other effects of the rotational speed difference may be caused by an imbalance in initial loading of the vehicle or a difference in wheel air pressure and additional mechanical or electronic control of the wheel speed due to a difference in differential type (normal differential and limited slip differential) of the drive shaft. We make the following assumptions for the model:

(1) the driving road is flat and the adhesion coefficient is balanced, namely, the influence of the differential and the additional operation of the vehicle by a driver caused by wet road surface, muddy road surface, pothole road surface and the like is neglected.

(2) The vehicle is initially loaded evenly and the tire specifications, tire wear and tire pressure are the same on the left and right sides of the vehicle.

(3) The wheel speed difference between the vehicle drive axle and the non-drive axle is only affected by the turning radius and load transfer.

(4) The driver performs normal turning, accelerating, and braking driving operations.

As shown in fig. 10, the load transfer rate model based on the wheel speed difference is defined according to the lateral load transfer rate: LTR ═ F_L-F_R)/(F_L+F_R). The measurement of the denominator is simple, and the measuring method can be carried out by utilizing the factory quality and monitoring the tire pressure; the calculation of the molecules needs to be monitored, and the deformation quantity of the most intuitive left and right tires is used for monitoring. The difference in deformation of the tires is caused by load transfer, and at a given vehicle speed, the wheel speed and the effective rolling radius of the tire are inversely proportional, and the change in load causes a change in the effective radius, which in turn affects the speed. Make the rolling radius r at no load₀Then the actual rolling radius is r_a＝r₀- δ. Knowing the radial stiffness K of the tyre_TiThe change in load can be obtained from the change in rolling radius.

When only the wheel speed difference caused by steering is considered, the load transfer is not considered, so that the approximate tire rolling radius is approximately unchanged. Vehicle speed V and lateral acceleration a_y，R＝V²/a_yAnd V is the average vehicle speed. The rotational speed of each wheel can be averaged to obtain the real-time V. The tire behaves like a spring, assuming equal radial spring rates for the wheels, K_L＝K_RWhen the load is uniformly distributed to the left and right sides, the amount of deformation of the tire is the same, and when the wear and inflation pressure of the left and right tires are close to each other, r is_L＝r_RThe rotational speeds of the left and right wheels are equal when the vehicle is running straight, omega_Li＝ω_Ri。

When the vehicle turns, the difference in the rotational speeds of the wheels is affected by two factors. The first being steering speed difference, i.e. travelling with the outer wheels at the same timeThe distance is far from the inner wheel, as shown in fig. 10, when the wheel turns left, the rotation speed of the right wheel increases, the rotation speed of the left wheel decreases, and omega_Li<ω_Ri(ii) a Conversely, when turning to the right, ω_Li>ω_Ri. The second factor is load transfer, which is from the inside to the outside wheels due to the roll moment during steering, as shown by the right wheel load F in FIG. 10_RiIncrease of r_RiDecrease, omega_RiIncreased, and left side wheel load F_LiDecrease of r_LiIncrease of omega_LiDecrease, omega_Li<ω_Ri(ii) a Otherwise, when turning right, ω_RiDecrease, omega_LiIncrease of omega_Li>ω_Ri。

In order to obtain the difference in the rotational speeds of the left and right side wheels due to the lateral load transfer, it is necessary to subtract the difference in rotational speed due to steering. Δ ω_t(L-R)iFor i-th shaft steering speed difference, Δ ω_l(L-R)iTransferring a differential rotational speed for the i-th shaft load, equal to Δ ω_(L-R)i-Δω_t(L-R)i. Based on the model assumptions, we finally get the following equation 3.

Wherein

F_ASFor the load-carrying capacity of a single air spring suspension (see equation 2), (F)_AS)_jFor the jth air spring suspension to carry the load, n total axles, the total sprung load is

Table 2: symbol table of wheel speed difference LTR rollover threshold model

The derivation process of equation 3 can be seen in the following equation of load transfer rate based on the difference between rotational speeds:

during steering, the instantaneous turning radius is

R＝a_y/ω²＝V²/a_y (A.1)

Instantaneous turning radius of the inner and outer wheels is

R_L＝R-T/2；R_R＝R+T/2 (A.2)

The wheel speed is proportional to the turning radius

The above variables can be measured, and the i-th axle steering wheel speed difference exists

So as to obtain the speed difference of the i-th shaft transverse load transfer wheel,

Δω_l,(L-R)i＝Δω_(L-R)i-Δω_t,(L-R)i (A.5)

the wheel speed and the rolling radius are inversely proportional,

thus obtaining the rolling radius difference caused by load transfer

Wherein r is_iAnd ω_iThe average rolling radius of the i-th axis and the average wheel rotation speed are provided with the deformation amount of the rolling radius of the actual tire, K_TiThe radial rigidity of the tire on the ith axis is obtained, so that the vertical load of the tire on the left side and the right side is only different

The load transfer rate is obtained by substituting all the above calculation formulas

When the radial stiffness and the speed and lateral acceleration are known, only the measured rotational speed is determined.

Fig. 11 is a rollover warning algorithm based on wheel speed difference LTR. According to the model hypothesis of the algorithm and the calculation formula 2 and the calculation formula 3, the rotating speeds of the left wheel and the right wheel of each axle of the vehicle are required to be known in real time, the average rotating speed and the total wheel speed difference are calculated, the instantaneous turning radius is calculated according to the vehicle speed and the lateral acceleration, the steering wheel speed difference is further obtained by subtracting the steering wheel speed difference from the total wheel speed difference, the load transfer is further obtained through the radial rigidity of the wheels, the load transfer of each axle is superposed, the current spring load is calculated according to the air spring, the current value of the transverse load transfer rate is obtained, the judgment is carried out according to the designed danger level, and the side overturning danger degree of the driver is prompted.

In fig. 11, for the implementation of equation 3, the information of the existing ABS is fully utilized, and the required load transfer wheel speed difference is obtained by using the relationship between two influencing factors (turning and load transfer) of the wheel speed difference, so as to obtain load transfer.

The displacement of each air spring is read in real time, the load of the whole vehicle can be estimated accurately, the influence of rolling radius caused by rejecting steering radius difference is considered, and the calculated wheel speed difference LTR is more accurate; and the rollover-prevention early warning system based on the wheel speed difference only needs the displacement sensor data and the lateral acceleration information of the conventional ABS system and the conventional active suspension system, and is convenient and simple to implement. Fig. 12 is a structural diagram of a wheel speed difference LTR rollover warning system.

In an optional specific example, the load transfer rate threshold model based on the wheel speed difference is selected, compared with the existing threshold method, the model is low in cost, and can be directly integrated in an ABS system or other vehicle electronic determination units provided with the ABS system, so that the usability of the method is greatly improved.

The invention is based on a rollover early warning system of wheel speed difference LTR, and is characterized in that the wheel speed difference LTR is calculated. According to the model hypothesis of the algorithm and a calculation formula 3, the rotating speeds of the left wheel and the right wheel of each axle of the vehicle are required to be known in real time, the average rotating speed and the total wheel speed difference are calculated, the instantaneous turning radius is calculated according to the vehicle speed and the lateral acceleration, further the steering wheel speed difference is obtained, the steering wheel speed difference is reduced through the total wheel speed difference, the load transfer wheel speed difference is obtained, further the load transfer is obtained through the radial rigidity of the wheels, the load transfer of each axle is superposed, and then the current value of the transverse load transfer rate is obtained.

Comparing the currently calculated dynamic threshold with a set rollover threshold of the vehicle, wherein the set rollover threshold is usually smaller than 1, and an alarm threshold proportion can be set according to the vehicle to be matched, and the thresholds of 50% and 70% shown in fig. 11 are set as reference thresholds; and finally, an alarm display part is set, and according to the definition of the load transfer rate, the vehicle load is transferred to the left side when the steering wheel turns right, the indicated value of LTR points to the right side, and the violent operation is more, the higher the rollover risk is, the more intuitively the driver can prompt, the driver can conveniently standardize the driving behavior of the driver, and the rollover accident can be avoided. Otherwise, continuously monitoring the wheel speed difference, and calculating LTR to repeat the above process.

In the scheme of the present invention, a flow chart of an algorithm is shown in fig. 11, a schematic diagram of a system structure is shown in fig. 12, and algorithm application requires attention:

(1) the ABS vehicle is modified to read the data of wheel speed, otherwise, the wheel speed sensor is installed.

(2) The mounting position of the lateral acceleration sensor should be near the centroid position, and the calculated turning radius may be deviated due to the long size of the commercial vehicle.

(3) Under the condition that the wheel speed difference is not obvious in turning, the error may be larger than the actual value;

(4) the radial stiffness of the tire, if chosen to be fixed, may introduce additional errors.

In an alternative specific example, the sensor device may be an integrated vehicle shared data sensor or may be a separate sensor device.

In an alternative specific example, the microprocessor may be a micro-computing center, a microprocessor, an MCU, or the like.

In an alternative embodiment, the effective areas of the same size air springs may be approximately all equal, and the radial stiffness of the same size tires may be approximately equal.

In an alternative embodiment, the threshold judgment ratio can be customized according to different vehicle types.

Since the processes and functions implemented by the vehicle of this embodiment substantially correspond to the embodiments, principles and examples of the apparatus shown in fig. 7, the description of this embodiment is not given in detail, and reference may be made to the related descriptions in the foregoing embodiments, which are not repeated herein.

Through a large number of tests, the technical scheme of the invention can be used for directly using wheel speed information on a vehicle provided with the ABS and obtaining lateral acceleration information on a vehicle not provided with the ABS only by an additional acceleration sensor or from other vehicle electronic systems, and has low cost and good use convenience.

According to the embodiment of the invention, the invention further provides a storage medium corresponding to the rollover warning method. The storage medium may include: the storage medium has stored therein a plurality of instructions; the instructions are used for being loaded by the processor and executing the rollover warning method.

Since the processing and functions implemented by the storage medium of this embodiment substantially correspond to the embodiments, principles, and examples of the methods shown in fig. 1 to fig. 6, details are not described in the description of this embodiment, and reference may be made to the related descriptions in the foregoing embodiments, which are not described herein again.

Through a large number of tests, the rollover warning system is generally applicable to vehicles with various axles by modeling the wheel speed difference LTR of the multi-axle vehicle by adopting the technical scheme of the invention, and has good universality and high reliability.

According to the embodiment of the invention, the invention further provides a vehicle corresponding to the rollover warning method. The vehicle may include: a processor for executing a plurality of instructions; a memory to store a plurality of instructions; the instructions are stored in the memory, and loaded and executed by the processor.

Since the processes and functions implemented by the vehicle of the present embodiment substantially correspond to the embodiments, principles and examples of the method shown in fig. 1 to fig. 6, the description of the present embodiment is not detailed, and reference may be made to the related descriptions in the foregoing embodiments, which are not repeated herein.

Through a large number of tests, the technical scheme of the invention is adopted, and the rollover-prevention early warning system based on the wheel speed difference only needs the displacement sensor data and the lateral acceleration information of the conventional ABS system and the conventional active suspension system, so that the rollover-prevention early warning system is convenient and simple to implement, low in cost and high in reliability.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A rollover warning method is characterized by comprising the following steps:

acquiring displacement sensor data and speed information of a vehicle to be early-warned; the displacement sensor data of the vehicle to be early-warned comprises: displacement sensor data of the active suspension system; the speed information includes: wheel speed information and vehicle speed information;

determining the transverse load transfer rate of the vehicle to be early-warned according to the displacement sensor data and the speed information, and comprising the following steps: constructing a wheel speed difference LTR threshold model of a vehicle with more than two axles in advance; calculating the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information by utilizing a pre-constructed wheel speed difference LTR threshold model of the vehicle with more than two axles; wherein, construct the wheel speed difference LTR threshold value model of the vehicle more than the diaxon in advance, include: determining the speed difference of load transfer wheels of the vehicles with more than two axles, and determining the total spring load of the vehicles with more than two axles; determining load transfer of each axle of the vehicles with more than two axles by combining the radial rigidity of the wheels of the vehicles with more than two axles and the speed difference of the load transfer wheels to obtain total load transfer; calculating to obtain a load transfer wheel speed difference according to the total sprung load and the total load transfer;

and determining a comparison result of the transverse load transfer rate and a set early warning value, and prompting the comparison result according to a set rollover danger level.

2. The method of claim 1, wherein obtaining displacement sensor data and speed information for a vehicle to be pre-warned comprises:

acquiring displacement sensor data and speed information from an ABS (anti-lock braking system) system and an active suspension system of a vehicle to be pre-warned;

or,

acquiring displacement sensor data of a vehicle to be pre-warned detected by a displacement sensor and speed information of the vehicle to be pre-warned detected by the sensor;

or,

and acquiring the displacement sensor data and the speed information of the vehicle to be early warned, which are fed back by the vehicle electronic system.

3. The method of claim 1, wherein the speed information comprises: at least one of rotational speed, vehicle speed, lateral acceleration information, and wheel speed information;

determining a load transfer wheel speed differential for a vehicle having more than two axles, comprising:

obtaining wheel speed information of wheels on the left side and the right side of each axle of a vehicle with more than two axles, and calculating to obtain an average rotating speed and a total wheel speed difference;

calculating to obtain an instantaneous turning radius according to the speed and the lateral acceleration of the vehicle with more than two axles, and calculating to obtain a steering wheel speed difference generated by the instantaneous turning radius according to the average rotating speed;

and subtracting the speed difference of the steering wheel from the total wheel speed difference to obtain the speed difference of the load transfer wheel.

4. A method according to any one of claims 1-3, wherein determining the total sprung load of a vehicle having more than two axles comprises:

acquiring displacement sensor data and unsprung loads of a vehicle with more than two axles; the displacement sensor data comprising: the initial height of the air spring, the working area of the air spring and the displacement of the air spring;

determining the spring load of the vehicle with more than two axles according to the data of the displacement sensors;

and determining the total sprung load of the vehicle with more than two axles according to the sprung load and the unsprung load.

5. A method according to any of claims 1-3, wherein determining the load transfer for each axle of a vehicle having more than two axles in combination with the wheel radial stiffness of the vehicle having more than two axles and the load transfer wheel speed difference comprises:

calculating effective rolling radii of the vehicles with more than two axles according to the average rotating speed of the rotating speeds of the wheels on the left side and the right side of each axle of the vehicles with more than two axles and the vehicle speeds of the vehicles with more than two axles;

calculating the tire rolling radius difference of the left and right wheels of each axle of the vehicle with more than two axles according to the effective rolling radius and the speed difference of the load transfer wheels;

and calculating load transfer of each shaft of the vehicles with more than two shafts by combining the radial rigidity of the wheels of the vehicles with more than two shafts and the rolling radius difference of the tires.

6. The method of claim 4, wherein determining load transfer for each axle of the two or more axles in combination with the wheel radial stiffness of the two or more axles and the load transfer wheel speed differential comprises:

7. The method according to any one of claims 1-3 and 6, wherein prompting the comparison result according to a set rollover risk level comprises:

if the steering wheel of the vehicle to be early-warned turns left, the vehicle to be early-warned tilts right, and the transverse load transfer rate is smaller than the set early-warning value, the rollover dangerous state indicating needle hits the left side of the indicating area;

or,

and if the steering wheel of the vehicle to be pre-warned turns right, the vehicle to be pre-warned inclines left, and the transverse load transfer rate is greater than the set pre-warning value, the rollover dangerous state indicating needle hits the right side of the indicating area.

8. The method of claim 4, wherein prompting the comparison result according to a set rollover risk level comprises:

or,

9. The method of claim 5, wherein prompting the comparison result according to a set rollover risk level comprises:

or,

10. The method of claim 7, wherein,

the rollover danger level of the rollover dangerous state and the amplitude of the difference between the transverse load transfer rate and the set early warning value are in positive correlation;

and/or the presence of a gas in the gas,

and grading and prompting different rollover danger levels of the rollover danger states by at least one prompting message of set colors, patterns and sound and light.

11. The method of claim 8 or 9, wherein,

and/or the presence of a gas in the gas,

12. The utility model provides a rollover warning device which characterized in that includes:

the system comprises an acquisition unit, a pre-warning unit and a warning unit, wherein the acquisition unit is used for acquiring displacement sensor data and speed information of a vehicle to be pre-warned; the displacement sensor data of the vehicle to be early-warned comprises: displacement sensor data of the active suspension system; the speed information includes: wheel speed information and vehicle speed information;

the determining unit is used for determining the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information, and comprises the following steps: constructing a wheel speed difference LTR threshold model of a vehicle with more than two axles in advance; calculating the transverse load transfer rate of the vehicle to be pre-warned according to the displacement sensor data and the speed information by utilizing a pre-constructed wheel speed difference LTR threshold model of the vehicle with more than two axles; wherein the determination unit previously constructs a wheel speed difference LTR threshold model of the vehicle having two or more axles, including: determining the speed difference of load transfer wheels of the vehicles with more than two axles, and determining the total spring load of the vehicles with more than two axles; determining load transfer of each axle of the vehicles with more than two axles by combining the radial rigidity of the wheels of the vehicles with more than two axles and the speed difference of the load transfer wheels to obtain total load transfer; calculating to obtain a load transfer wheel speed difference according to the total sprung load and the total load transfer;

the determining unit is further used for determining a comparison result of the transverse load transfer rate and a set early warning value, and prompting the comparison result according to a set rollover danger level.

13. The apparatus according to claim 12, wherein the acquiring unit acquires the displacement sensor data and the speed information of the vehicle to be pre-warned, comprising:

or,

14. The apparatus of claim 12, wherein the speed information comprises: at least one of rotational speed, vehicle speed, lateral acceleration information, and wheel speed information;

the determination unit determines a load transfer wheel speed difference of a vehicle having two or more axles, including:

15. The apparatus according to any one of claims 12-14, wherein the determining unit determines the total sprung load of the vehicle for two or more axles, including:

16. The apparatus according to any one of claims 12-14, wherein the determining unit determines the load transfer of each axle of the vehicle having more than two axles in combination with the wheel radial stiffness of the vehicle having more than two axles and the load transfer wheel speed difference, comprises:

17. The apparatus of claim 15, wherein the determining unit determines load transfer for each axle of the two or more axles in conjunction with the wheel radial stiffness and the load transfer wheel speed differential for the two or more axles comprises:

18. The apparatus according to any one of claims 12 to 14 and 17, wherein the determining unit prompts the comparison result according to a set rollover risk level, and comprises:

or,

19. The apparatus according to claim 15, wherein the determining unit prompts the comparison result according to a set rollover risk level, and comprises:

or,

20. The apparatus according to claim 16, wherein the determining unit prompts the comparison result according to a set rollover risk level, and comprises:

or,

21. The apparatus of claim 18, wherein,

and/or the presence of a gas in the gas,

22. The apparatus of claim 19 or 20, wherein,

and/or the presence of a gas in the gas,

23. A vehicle, characterized by comprising: the rollover warning device according to any one of claims 12-22.

24. A storage medium having a plurality of instructions stored therein; the plurality of instructions for being loaded by a processor and executing the rollover warning method as recited in any one of claims 1-11.

25. A vehicle, characterized by comprising:

a processor for executing a plurality of instructions;

a memory to store a plurality of instructions;

wherein the plurality of instructions are stored by the memory and loaded and executed by the processor to perform the rollover warning method according to any one of claims 1-11.