CN115848354A - Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels - Google Patents

Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels Download PDF

Info

Publication number
CN115848354A
CN115848354A CN202211436858.3A CN202211436858A CN115848354A CN 115848354 A CN115848354 A CN 115848354A CN 202211436858 A CN202211436858 A CN 202211436858A CN 115848354 A CN115848354 A CN 115848354A
Authority
CN
China
Prior art keywords
vehicle
rear wheel
angle
information
deflection
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202211436858.3A
Other languages
Chinese (zh)
Inventor
刘福星
刘应花
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Great Wall Motor Co Ltd
Original Assignee
Great Wall Motor Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Great Wall Motor Co Ltd filed Critical Great Wall Motor Co Ltd
Priority to CN202211436858.3A priority Critical patent/CN115848354A/en
Publication of CN115848354A publication Critical patent/CN115848354A/en
Pending legal-status Critical Current

Links

Images

Landscapes

  • Steering Control In Accordance With Driving Conditions (AREA)

Abstract

The present disclosure provides a vehicle control method, system, device, storage medium and vehicle based on rear wheels, comprising: acquiring vehicle information, and judging the deflection direction of a rear wheel according to the vehicle information to obtain the deflection direction of the rear wheel; obtaining front wheel steering angle information, and determining a first rear wheel deflection angle based on a vehicle mass center side deflection angle by using the front wheel steering angle information; determining a second rear wheel deflection angle based on the front wheel steering angle information and a vehicle yaw rate; weighting and calculating the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle; and controlling the rear wheels of the vehicle based on the rear wheel deflection direction and the rear wheel deflection angle. The method solves the problems that in the running process of the vehicle, due to factors such as overhigh speed or tire adhesion force change and the like, wheels slip, and the vehicle is under-steered or over-steered.

Description

Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels
Technical Field
The present disclosure relates to the field of vehicle control technologies, and in particular, to a method, a system, a device, a storage medium, and a vehicle for controlling a vehicle based on rear wheels.
Background
In the running process of a vehicle, particularly in the running process of a curve, due to factors such as overhigh speed or tire adhesion force change, wheels slip, the problem of insufficient or over-steering of the vehicle is easy to occur, the vehicle is out of control, and safety accidents are caused.
In view of this, how to avoid the problem of understeer or oversteer of the vehicle and improve driving stability and safety becomes an important research problem.
Disclosure of Invention
In view of the above, the present disclosure is directed to a method, a system, a device, a storage medium and a vehicle for controlling a vehicle based on rear wheels, so as to solve the problem of understeer or oversteer when the vehicle is steered.
In view of the above object, a first aspect of the present disclosure provides a rear wheel-based vehicle control method, the method including:
acquiring vehicle information, and judging the deflection direction of a rear wheel according to the vehicle information to obtain the deflection direction of the rear wheel;
obtaining front wheel steering angle information, and determining a first rear wheel deflection angle based on a vehicle mass center side deflection angle by using the front wheel steering angle information;
determining a second rear wheel deflection angle based on the front wheel steering angle information and a vehicle yaw rate;
weighting the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle;
and controlling the rear wheels of the vehicle based on the rear wheel deflection direction and the rear wheel deflection angle.
Based on the same inventive concept, a second aspect of the present disclosure proposes a rear wheel-based vehicle control system, comprising:
the information acquisition module is configured to acquire vehicle information and judge the deflection direction of the rear wheel according to the vehicle information to obtain the deflection direction of the rear wheel;
an angle calculation module configured to obtain front wheel steering angle information with which a first rear wheel yaw angle is determined based on a vehicle centroid slip angle; determining a second rear wheel deflection angle based on the front wheel steering angle information and the vehicle yaw rate;
a rear wheel control module configured to control a rear wheel of a vehicle based on the rear wheel yaw direction and the rear wheel yaw angle.
Based on the same inventive concept, a third aspect of the present disclosure proposes an electronic device comprising a memory, a processor and a computer program stored on the memory and executable by the processor, the processor implementing the method as described above when executing the computer program.
Based on the same inventive concept, a fourth aspect of the present disclosure proposes a non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the method as described above.
Based on the same inventive concept, a fifth aspect of the present disclosure provides a vehicle, which includes the vehicle-mounted function bit complementing system of the second aspect or the electronic device of the third aspect or the storage medium of the fourth aspect.
As can be seen from the foregoing, the present disclosure provides a rear wheel-based vehicle control method, which determines the deflection direction of a rear wheel based on acquired vehicle information, improves the accuracy of the determination, and further improves the stability of a vehicle; the rear wheel deflection angle is obtained by weighting and calculating a first rear wheel deflection angle obtained based on the vehicle mass center side deflection angle and a second rear wheel deflection angle obtained based on the vehicle yaw velocity, two important parameters of the vehicle mass center side deflection angle and the vehicle yaw velocity are considered in the rear wheel deflection angle calculation process, and the calculation result is more accurate; the rear wheels of the vehicle are controlled based on the deflection direction of the rear wheels and the deflection angle of the rear wheels, and the rear wheels of the vehicle are correspondingly adjusted through the scheme under the condition that the vehicle is under-steered or over-steered, so that the steering condition of the vehicle is controlled, and the stability of the vehicle and the driving safety are improved.
Drawings
In order to more clearly illustrate the technical solutions in the present disclosure or related technologies, the drawings needed to be used in the description of the embodiments or related technologies are briefly introduced below, and it is obvious that the drawings in the following description are only embodiments of the present disclosure, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a flow chart of a rear wheel based vehicle control method according to an embodiment of the present disclosure;
FIG. 2 is a first partial flowchart of an embodiment of the present disclosure in another application scenario;
FIG. 3 is a second partial flowchart of an embodiment of the present disclosure in another application scenario;
FIG. 4 is a block diagram of a rear wheel based vehicle control system according to an embodiment of the present disclosure;
fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the disclosure.
Detailed Description
For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.
It is to be noted that technical terms or scientific terms used in the embodiments of the present disclosure should have a general meaning as understood by those having ordinary skill in the art to which the present disclosure belongs, unless otherwise defined. The use of "first," "second," and similar terms in the embodiments of the disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item preceding the word comprises the element or item listed after the word and its equivalent, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.
As described above, there is a problem that, during running of a vehicle, particularly during running on a curve, wheels slip due to factors such as an excessively high vehicle speed and a change in tire adhesion, and the vehicle is under-steered or over-steered.
Based on the above description, the present embodiment proposes a rear wheel-based vehicle control method, as shown in fig. 1, the method including:
step 101, obtaining vehicle information, and judging the deflection direction of the rear wheel according to the vehicle information to obtain the deflection direction of the rear wheel.
In specific implementation, vehicle information is acquired, wherein the vehicle information comprises vehicle basic information and vehicle running information, and the vehicle basic information comprises at least one of the following information: vehicle mass or vehicle tire information, the vehicle operation information including at least one of: vehicle corner information, vehicle running speed or vehicle gear information. Judging the deflection direction of the rear wheels according to the vehicle information to obtain a rear deflection direction, judging to obtain a vehicle state according to the vehicle information, and determining the reverse deflection of the rear wheels and the front wheels of the vehicle in response to the fact that the vehicle is in an understeer state; in response to the vehicle being in an oversteer condition, the rear wheels of the vehicle are determined to be co-steered with the front wheels. According to the scheme, the deflection direction of the rear wheel is judged based on the acquired vehicle information, the judgment accuracy is improved, meanwhile, the deflection angle of the rear wheel is obtained based on the deflection direction of the rear wheel and subsequent calculation, the adjustment of vehicle deflection is completed by adjusting the rear wheel of the vehicle, and the stability of the vehicle in the driving process is improved.
Step 102, front wheel steering angle information is obtained, and a first rear wheel deflection angle is determined based on a vehicle mass center side deflection angle by means of the front wheel steering angle information.
In specific implementation, the vehicle front wheel steering angle information is obtained through a vehicle steering wheel, the vehicle front wheel steering angle information comprises a vehicle front wheel deflection angle, and a vehicle mass center side deflection angle function is calculated and obtained based on a vehicle two-degree-of-freedom model algorithm. And calculating the deflection angle of the rear wheel according to the deflection angle of the front wheel of the vehicle and the side deflection angle function of the mass center of the vehicle to obtain a first rear wheel deflection angle. According to the scheme, the vehicle mass center side slip angle function is calculated and obtained according to a vehicle two-degree-of-freedom model algorithm, the first vehicle rear wheel deflection angle is calculated and obtained based on the obtained front wheel deflection angle and the calculated vehicle mass center side slip angle function, the calculation result is more accurate, the control of the vehicle rear wheels is achieved together with the rear wheel deflection direction obtained in the step, and the driving safety is improved.
And 103, determining a second rear wheel deflection angle based on the front wheel steering angle information and the vehicle yaw rate.
In specific implementation, a vehicle yaw velocity function is calculated and obtained based on a vehicle two-degree-of-freedom model algorithm. And obtaining a calculated rear wheel deflection angle according to the vehicle front wheel deflection angle and the vehicle yaw velocity function, and obtaining a second rear wheel deflection angle. According to the scheme, the vehicle yaw velocity function is calculated according to the vehicle two-degree-of-freedom model algorithm, the second rear wheel deflection angle is calculated based on the obtained front wheel deflection angle and the calculated vehicle yaw velocity function, and the calculation result is more accurate.
And 104, weighting the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.
In specific implementation, when the vehicle runs, preferably when the vehicle runs in a steering manner, due to the influence of a centripetal force, a tire of the vehicle is added with a cornering force, so that a tire cornering angle is generated, and further a yaw rate and a centroid cornering angle of the whole vehicle are influenced. Through the scheme, two parameters of the mass center side slip angle and the vehicle yaw velocity are considered in the calculation process of the deflection angle of the rear wheel, the calculation result is more accurate, the control of the rear wheel of the vehicle is realized together with the deflection direction of the rear wheel obtained in the step, the driving stability is improved, and the safety risk is reduced.
And 105, controlling the rear wheels of the vehicle based on the rear wheel deflection direction and the rear wheel deflection angle.
When the method is specifically implemented, the deflection direction of the rear wheel and the deflection angle of the rear wheel are sent to a controller, and the controller controls the rear wheel of the vehicle based on control information, wherein the control information comprises the deflection direction of the rear wheel and the deflection angle of the rear wheel, so that the driving smoothness is improved, and the safety risk in driving is reduced.
By the scheme, the deflection direction of the rear wheel is judged based on the acquired vehicle information, so that the judgment accuracy is improved, and the stability of the vehicle is further improved; the rear wheel deflection angle is obtained by carrying out weighted calculation on a first rear wheel deflection angle obtained based on the vehicle mass center side deflection angle and a second rear wheel deflection angle obtained based on the vehicle yaw velocity, two important parameters of the vehicle mass center side deflection angle and the vehicle yaw velocity are considered in the rear wheel deflection angle calculation process, and the calculation result is more accurate; the rear wheels of the vehicle are controlled based on the deflection direction of the rear wheels and the deflection angle of the rear wheels, and the rear wheels of the vehicle are correspondingly adjusted through the scheme under the condition that the vehicle is under-steered or over-steered, so that the steering condition of the vehicle is controlled, and the stability of the vehicle and the driving safety are improved.
In some embodiments, step 101 specifically includes:
step 1011, obtaining vehicle information, and calculating the slip rate or slip ratio of the vehicle wheels according to the vehicle information.
In specific implementation, vehicle information is acquired through a sensor, and the vehicle information comprises wheel speed, rolling radius of a tire, longitudinal vehicle speed, gear information, vehicle acceleration information and the like. The vehicle comprises a wheel speed sensor and a vehicle speed sensor, the wheel speed sensor is used for collecting the wheel speed of the vehicle, the vehicle speed sensor is used for collecting the longitudinal vehicle speed of the vehicle, a tire rolling radius map is obtained according to a rotary drum experiment, the tire rolling radius is determined according to the tire pressure and the vehicle speed information of the vehicle, and the slip rate of the vehicle wheel is calculated according to the following formula:
K=(u-ω·R)/u
wherein K is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle;
calculating the slip rate of the vehicle wheels by the formula:
S=(ω·R-u)/(ω·R)
where S is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.
Through the scheme, the slip rate or the slip rate of the vehicle wheel is calculated and is used for subsequently judging the deflection direction of the rear wheel, so that the judgment is more accurate.
Step 1012, in response to at least one of the vehicle front wheel slip ratio satisfying the first threshold range or the vehicle rear wheel slip ratio satisfying the second threshold range or the vehicle rear wheel slip ratio satisfying the third threshold range or the vehicle rear wheel slip ratio satisfying the fourth threshold range, determining that the vehicle is in an understeer state and the rear wheel deflection direction is in a reverse deflection with respect to the front wheels.
During specific implementation, the slip rate or the slip rate of the vehicle wheels is calculated, when the slip rate of at least one front wheel of the vehicle meets a first threshold range or the slip rate meets a second threshold range and the slip rate of a rear wheel of the vehicle meets a third threshold range or the slip rate meets a fourth threshold range, the vehicle is determined to be in an insufficient steering state, the deflection direction of the rear wheel is determined to be in reverse deflection with the front wheel, after the deflection angle of the rear wheel is obtained through calculation in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction in reverse deflection with the front wheel and the deflection angle of the rear wheel, the sliding out of the head of the vehicle along the tangential direction of an arc line is avoided, and potential safety hazards are reduced.
For example, if the first threshold range is greater than or equal to 10%, the second threshold range is less than or equal to-10%, the third threshold range is equal to or equal to 10%, and the fourth threshold condition is that the slip ratio is less than or equal to-10%, then at least one vehicle has a front wheel slip ratio of greater than or equal to 10% or a slip ratio of less than or equal to-10%, and a rear wheel slip ratio of equal to 10% or a slip ratio of less than or equal to-10%, it is determined that the vehicle is in an understeering state, and the rear wheel deflection direction is in a direction opposite to the front wheel deflection direction.
And 1013, in response to that at least one vehicle rear wheel slip ratio meets a first threshold range or the slip ratio meets a second threshold range, and when the vehicle front wheel slip ratio meets a third threshold range or the slip ratio meets a fourth threshold range, determining that the vehicle is in an oversteer state, and the rear wheel deflection direction is in the same direction as the front wheel deflection.
During specific implementation, the slip rate or the slip ratio of the vehicle wheels is calculated, the vehicle is determined to be in an oversteering state in response to the fact that the slip rate of at least one rear wheel of the vehicle meets a first threshold range or the slip ratio meets a second threshold range and the slip rate of a front wheel of the vehicle meets a third threshold range or the slip ratio meets a fourth threshold range, the deflection direction of the rear wheel is determined to be in the same direction as that of the front wheel, so that after the deflection angle of the rear wheel is calculated in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction in the same direction as that of the front wheel and the deflection angle of the rear wheel, the sliding out of the tangential direction of the rear extension arc line of the vehicle is avoided, and potential safety hazards are reduced.
For example, the first threshold range is 10% or more, the second threshold range is-10% or less, the third threshold range is 10% or more, and the fourth threshold condition is that the slip ratio is-10% or less, then at least one vehicle rear wheel slip ratio is 10% or more or less-10% or less, the front wheel slip ratio is 10% or less-10%, and the vehicle is determined to be in an oversteer state, where the rear wheel deflection direction is the same as the front wheel deflection direction.
In some embodiments, step 1011 specifically includes:
in step 1011A, the vehicle state is determined according to the vehicle information.
In specific implementation, vehicle information is acquired, wherein the vehicle information comprises vehicle running information, vehicle gear information and the like, and the current running state of the vehicle is judged according to the acquired vehicle information, wherein the vehicle running state comprises a driving state or a braking state.
And step 1011B, in response to determining that the vehicle state is a driving state, determining the slip rate of the vehicle wheels according to the vehicle information.
In specific implementation, according to the vehicle running state, in response to the fact that the vehicle running state is determined to be the driving state, the slip rate of the vehicle wheel is calculated according to the information of the wheel speed of the vehicle wheel, the rolling radius of the tire, the longitudinal vehicle speed and the like.
And step 1011C, in response to determining that the vehicle state is a braking state, determining the slip rate of the vehicle wheel according to the vehicle information.
In specific implementation, the vehicle running state comprises a driving state and a braking state; and in response to determining that the vehicle running state is a braking state, calculating the slip rate of the vehicle wheel according to the information of the wheel speed of the vehicle wheel, the rolling radius of the tire, the longitudinal vehicle speed and the like.
By the scheme, the corresponding slip rate or slip ratio is calculated according to different vehicle states, the calculated amount is reduced, the calculation speed is increased, the corresponding control operation on the vehicle wheels can be realized in a shorter time, and the driving safety is improved.
In some embodiments, step 1011A specifically includes:
in step 1011Aa, vehicle acceleration information and gear information are acquired.
During specific implementation, vehicle acceleration information and gear information are obtained through a vehicle internal sensor, and a vehicle state is judged according to the vehicle acceleration information and the gear information, wherein the vehicle state refers to states of a vehicle under different accelerations and different gears, and includes one of the following states: a forward drive state, a forward braking state, a reverse braking state, or a reverse drive state.
And a step 1011Ab of judging the vehicle state according to the vehicle acceleration information and the gear information.
In specific implementation, the direction of the vehicle acceleration pointing to the vehicle head is a positive value, the direction pointing to the vehicle tail is a negative value, and the vehicle state is determined to be a forward driving state in response to the fact that the gear information is a forward gear and the acceleration information is a positive value; in response to the fact that the gear information is a forward gear and the acceleration information is a negative value, determining that the vehicle state is a forward braking state; in response to the fact that the gear information is a reverse gear and the acceleration information is a positive value, determining that the vehicle state is a reverse braking state; and determining that the vehicle state is a reverse driving state in response to the fact that the gear information is a reverse gear and the acceleration information is a negative value.
According to the scheme, the vehicle state is judged according to the acquired vehicle acceleration information and the acquired vehicle gear information, the slip ratio or slip ratio of the vehicle is calculated according to the judged vehicle state, so that the deflection direction of the rear wheel of the vehicle is judged, the judgment result is more accurate, the vehicle steering is adjusted based on the deflection direction of the rear wheel and the deflection angle of the rear wheel obtained in the subsequent step, and the stability and safety of vehicle operation are improved.
In some embodiments, step 102 comprises: acquiring front wheel steering angle information, and processing the front wheel steering angle information based on a rear wheel steering angle relation function determined by a vehicle mass center side slip angle to obtain a first rear wheel steering angle; and the rear wheel steering angle relation function is obtained according to a vehicle two-degree-of-freedom model algorithm.
In specific implementation, vehicle front wheel steering angle information is obtained through a vehicle steering wheel, the vehicle front wheel steering angle information comprises a vehicle front wheel deflection angle, and the vehicle front wheel deflection angle is processed based on a rear wheel steering angle relation function determined by a vehicle mass center side deflection angle to obtain a first rear wheel deflection angle; and calculating a two-degree-of-freedom model algorithm of the vehicle to obtain the rear wheel steering angle relation function.
In some embodiments, before step 102, the method specifically further includes:
and 1021, obtaining a vehicle mass center slip angle function according to a vehicle two-degree-of-freedom model algorithm, wherein the vehicle mass center slip angle function comprises a plurality of parameter information, and the mass center slip angle is one of the plurality of parameter information.
In the concrete implementation, when the vehicle is in steering driving, the smaller the centroid slip angle is, the smaller the tire sideslip tendency is, and the better the steering stability is. The vehicle operation information comprises the longitudinal vehicle speed, the lateral vehicle speed, the vehicle yaw rate, the vehicle mass center slip angle and the like of the vehicle, and a vehicle mass center slip angle function is obtained based on a vehicle two-degree-of-freedom model algorithm according to the vehicle operation information. The vehicle mass center slip angle function at least comprises the following parameter information: vehicle mass center slip angle, vehicle mass center slip angular velocity, vehicle lateral speed, vehicle acceleration. The vehicle mass center side slip angle function is obtained through calculation according to the scheme, and the rear wheel side slip angle is obtained through calculation according to the function, so that the vehicle is controlled, the side slip trend of the tire is weakened, and the driving smoothness is improved.
In some embodiments, step 1021 specifically includes:
based on a vehicle two-degree-of-freedom model algorithm, a vehicle mass center slip angle function is obtained and expressed as:
Figure BDA0003947183160000091
wherein m is the mass of the whole vehicle, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, and k 1 Yaw stiffness, k, of the front axle 2 Is the cornering stiffness of the rear axle, delta 1 For front wheel deflection angle, delta 2 For rear wheel deflection angle, I z Is the rotational inertia of the whole vehicle.
And 1022, determining that the plurality of parameter information meet preset conditions, and determining the rear wheel steering angle relation function according to the vehicle mass center side slip angle function.
In specific implementation, according to the obtained vehicle mass center side slip angle function, when the parameter information meets the preset condition, a rear wheel steering angle relation function is obtained.
Through the scheme, the rear wheel steering angle relation function is calculated through the vehicle mass center side deflection angle function, so that the first rear wheel deflection angle can be calculated in the subsequent step process.
In some embodiments, step 1022 specifically includes:
based on the vehicle centroid side slip angle function, the plurality of parameter information meeting preset conditions comprises: the centroid slip angle is zero and the acceleration is zero; determining a rear wheel steering relationship function expressed as:
Figure BDA0003947183160000092
wherein, delta 2 | β=0 Is the first rear wheel deflection angle, beta is the centroid slip angle,
Figure BDA0003947183160000093
is the acceleration.
Based on the vehicle centroid side slip angle function, the plurality of parameter information meeting preset conditions comprises: the centroid slip angle is zero, the yaw angle velocity change rate is zero, and the acceleration is zero; determining a rear wheel steering angle relationship function expressed as:
Figure BDA0003947183160000094
and step 1023, calculating according to the rear wheel steering angle relation function to obtain a first rear wheel deflection angle.
During specific implementation, a centroid slip angle function is obtained based on vehicle operation information and a vehicle two-degree-of-freedom algorithm, a rear wheel steering angle relation function is obtained in response to the fact that parameters in the formula meet preset conditions, and a first rear wheel deflection angle is obtained through calculation according to a front wheel deflection angle. According to the scheme, the rear wheel steering angle relation function is obtained through calculation, the first rear wheel deflection angle is obtained according to the function and the front wheel deflection angle, the accuracy of the calculated first rear wheel deflection angle is improved, the rear wheel of the vehicle is controlled together with the rear wheel deflection direction obtained through the step, and the stability of the vehicle is improved.
In some embodiments, step 103 specifically includes:
step 1031, the size of the centroid slip angle is the ratio of the lateral speed to the longitudinal speed, the yaw rate change rate is zero, the acceleration is zero, and the rear wheel deflection angle is zero, and based on the vehicle centroid slip angle function, the vehicle yaw rate function is determined:
Figure BDA0003947183160000101
and calculating according to the vehicle yaw rate function to obtain an ideal yaw rate, wherein the ideal yaw rate is represented as:
Figure BDA0003947183160000102
wherein, K is a stable factor,
Figure BDA0003947183160000103
Figure BDA0003947183160000104
for ideal yaw rate, L is the wheelbase, L = a + b.
And 1032, performing operation processing on the deflection angle of the rear wheel of the vehicle according to the ideal yaw velocity to obtain a second deflection angle of the rear wheel.
In specific implementation, the ideal yaw rate is obtained through calculation according to the yaw rate function, and the actual vehicle yaw rate is obtained through acquisition of vehicle sensors. And calculating to obtain a second rear wheel deflection angle according to the vehicle yaw velocity and the ideal yaw velocity, wherein the obtained calculation result is more accurate, the control of the rear wheel deflection angle is more accurate, the accuracy is improved, the rear wheel deflection is controlled together with the rear wheel deflection direction obtained in the step, and the driving safety is improved.
In some embodiments, step 1032 specifically includes:
and performing calculation processing on the vehicle yaw rate and the ideal yaw rate to obtain a second rear wheel deflection angle, which is expressed as:
Figure BDA0003947183160000111
wherein, delta 2 | ω Is the second rear wheel deflection angle, K ω For the preset yaw-rate feedback control coefficient,
Figure BDA0003947183160000112
is the desired yaw rate.
In some embodiments, step 104 specifically includes:
weighting the first rear wheel deflection angle and the second rear wheel deflection angle for calculation to obtain a rear wheel deflection angle, which is expressed as:
δ 2 Total =ξ 12 | β=022
ξ 12 =1
Wherein, delta 2 total Angle of rear wheel turning, xi 1 And xi 2 Are weight coefficients.
During the running process of the vehicle, preferably when the vehicle runs on a curve, the front wheel state comprises an uncontrolled state or a non-uncontrolled state.
The method comprises the steps of obtaining the stress information of a vehicle tire, determining that a front wheel of the vehicle is in an out-of-control state when the stress of the tire breaks through a friction circle, executing the steps of the embodiment, and adjusting the deflection of the vehicle by adjusting the deflection direction of a rear wheel of the vehicle and the deflection angle of the rear wheel.
And when the stress of the tire does not break through the friction circle, determining that the front wheel of the vehicle is in a non-runaway state, executing the steps of the embodiment, and adjusting the deflection of the vehicle by adjusting the deflection direction of the rear wheel of the vehicle and the deflection angle of the rear wheel. Alternatively, the first and second electrodes may be,
when the stress of the tire does not break through the friction circle, the front wheel of the vehicle is determined to be in a non-runaway state, the steps of the following embodiment are executed, and the deflection of the vehicle is adjusted by adjusting the front wheel and the rear wheel of the vehicle, and the method comprises the following steps:
and step 10A, acquiring an actual deflection angle of a front wheel, performing operation processing on the actual deflection angle of the front wheel to obtain an expected deflection angle of the front wheel, and controlling the front wheel of the vehicle according to the expected deflection angle of the front wheel.
In specific implementation, the acquired vehicle information includes an actual deflection angle of the front wheel, a front wheel steering angle control coefficient is acquired, and the expected deflection angle of the front wheel is obtained by performing operation processing on the actual deflection angle of the front wheel and the front wheel steering angle control coefficient. The actual deflection angle of the front wheel is the deflection angle of the current front wheel of the vehicle obtained through a steering wheel; the front wheel steering angle control coefficient is a coefficient reflecting the relation between the actual steering angle of the front wheel and the expected steering angle of the front wheel, can be obtained by looking up a table, and is related to the vehicle speed and the average slip ratio of the front wheel of the vehicle or the average slip ratio of the front wheel; the desired yaw angle of the front wheels is a yaw angle required for the front wheels when the front wheels are controlled in order to ensure the stability of the vehicle when the vehicle is steered.
And step 10B, adjusting the rear wheels of the vehicle, wherein the adjusting step is the same as the step of the embodiment.
Based on the same inventive concept, in response to the vehicle being in a driving state, another embodiment of the present disclosure in an application scenario is shown in fig. 2, and includes:
in step 201, vehicle information is acquired.
In specific implementation, vehicle information is monitored and obtained through an Electronic Control Unit (ECU), and the vehicle information includes vehicle basic information, vehicle running information, vehicle front wheel steering angle information and the like, wherein the vehicle basic information includes vehicle mass, vehicle tire information and the like, the vehicle running information includes vehicle steering angle information, vehicle running speed, vehicle gear information and the like, and the vehicle front wheel steering angle information is obtained through a steering wheel. By means of the scheme, the rear wheel deflection direction is judged in the subsequent steps based on the acquired vehicle information, and the judgment accuracy is improved.
And step 202, judging vehicle gear information.
During specific implementation, vehicle gear information is acquired through a vehicle internal sensor, wherein the gear information comprises a forward gear (D gear) and a reverse gear (R gear), and a basis is made for subsequent judgment of the deflection direction of the rear wheel of the vehicle.
And step 203, judging the running state of the vehicle according to the longitudinal acceleration information of the vehicle.
In specific implementation, the vehicle comprises a vehicle speed sensor, the vehicle speed sensor is used for collecting the longitudinal vehicle speed of the vehicle, the longitudinal acceleration of the vehicle is calculated according to the obtained longitudinal vehicle speed of the vehicle, and the vehicle running state is judged according to the longitudinal acceleration information of the vehicle, wherein the vehicle running state comprises a driving state and a braking state. According to the scheme, the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle, and in the subsequent step, the slip rate of the vehicle wheels is calculated in response to the fact that the running state of the vehicle is a driving state; and responding to the fact that the vehicle running state is a braking state, calculating the slip rate of the vehicle wheels for subsequent judgment of the deflection direction of the rear wheels of the vehicle.
Step 204, calculating the slip rate of the vehicle wheel.
In specific implementation, vehicle information is acquired through a sensor, and the vehicle information comprises wheel speed, rolling radius of a tire, longitudinal vehicle speed, gear information, vehicle acceleration information and the like. The vehicle comprises a wheel speed sensor and a vehicle speed sensor, the wheel speed sensor is used for collecting the wheel speed, the vehicle speed sensor is used for collecting the longitudinal vehicle speed of the vehicle, a tire rolling radius map is obtained according to a rotary drum experiment, and the tire rolling radius is determined according to the tire pressure and the vehicle speed information of the vehicle. And calculating the slip rate or the slip rate of the vehicle wheels according to the vehicle information, and judging the deflection direction of the rear wheels according to the calculated slip rate. Calculating the slip rate of the vehicle wheels by the formula:
S=(ω·R-u)/(ω·R)
where S is the slip of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.
And step 205, judging the deflection direction of the rear wheel according to the slip ratio of the vehicle wheel.
In specific implementation, the vehicle state is judged according to the slip ratio of the vehicle wheels obtained through calculation, wherein the vehicle state refers to the running state of the vehicle in the current state and comprises an understeer state and an oversteer state. According to the scheme, the deflection direction of the rear wheel is judged through the slip ratio obtained through calculation, the control of the rear wheel of the vehicle is realized together with the deflection angle of the rear wheel obtained in the following step, the judgment result is more accurate, and the driving safety is improved.
In some embodiments, step 205 specifically includes:
step 2051, in response to calculating the slip ratio of the front wheel of at least one vehicle to be less than or equal to-10% and then calculating the slip ratio of the rear wheel of at least one vehicle to be less than or equal to-10%, determining that the vehicle is in an understeer state and the deflection direction of the rear wheel is in a direction opposite to that of the front wheel.
In specific implementation, by judging that the slip ratio of the vehicle wheels is satisfied, the slip ratio of at least one front wheel of the vehicle is calculated to be less than or equal to minus 10%, then the slip ratio of at least one rear wheel of the vehicle is calculated to be less than or equal to minus 10%, the vehicle is determined to be in an understeer state, the deflection direction of the rear wheel is determined to be the reverse deflection with the front wheel, so that the deflection angle of the rear wheel is obtained through calculation in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction of the reverse deflection with the front wheel and the deflection angle of the rear wheel, the slipping-out of the head of the vehicle along the tangential direction of an arc line is avoided, and potential safety hazards are reduced.
And step 2052, in response to that the slip ratio of the rear wheel of at least one vehicle is calculated to be less than or equal to-10%, and then the slip ratio of the front wheel of at least one vehicle is calculated to be less than or equal to-10%, the vehicle is determined to be in an oversteered state, and the deflection direction of the rear wheel is determined to be the same as that of the front wheel.
During specific implementation, by judging that the slip rates of the vehicle wheels meet, the slip rate of at least one rear wheel of the vehicle is calculated to be less than or equal to-10%, then the slip rate of at least one front wheel of the vehicle is calculated to be less than or equal to-10%, the vehicle is determined to be in an oversteered state, the deflection direction of the rear wheel is determined to be deflected in the same direction as the front wheel, so that the deflection angle of the rear wheel is calculated in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction deflected in the same direction as the front wheel and the deflection angle of the rear wheel, the tangential direction sliding of a rear extension arc line of the vehicle is avoided, and potential safety hazards are reduced.
And step 2053, determining the deflection direction of the rear wheel according to the slip rate of the vehicle wheel.
In specific implementation, the deflection direction of the rear wheel of the vehicle is judged through the slip ratio of the vehicle wheel obtained through calculation, wherein the deflection direction comprises the deflection in the direction opposite to the front wheel and the deflection in the same direction as the front wheel. Determining the deflection direction of the rear wheels to be the reverse deflection of the front wheels in response to judging that the vehicle is in an understeer state according to the slip rate of the vehicle wheels; and in response to the fact that the vehicle is judged to be in an oversteer state according to the slip rate of the vehicle wheels, the deflection direction of the rear wheels is determined to be the same as the deflection direction of the front wheels, and the judgment result is more accurate.
And step 206, acquiring the deflection angle of the front wheel.
In specific implementation, the vehicle front wheel steering angle information is obtained through a vehicle steering wheel, and the vehicle front wheel steering angle information contains the vehicle front wheel deflection angle for subsequent calculation of the rear wheel deflection angle.
In some embodiments, step 206 specifically includes:
step 2061, a first rear wheel deflection angle is obtained based on the ideal centroid slip angle.
During specific implementation, a vehicle mass center slip angle function is calculated and obtained based on a vehicle two-degree-of-freedom model algorithm, and a calculated rear wheel deflection angle is obtained according to the vehicle front wheel deflection angle and the vehicle mass center slip angle function, so that a first rear wheel deflection angle is obtained. According to the scheme, the vehicle mass center slip angle function is calculated according to a vehicle two-degree-of-freedom model algorithm, the first vehicle rear wheel deflection angle is calculated based on the obtained front wheel deflection angle and the calculated vehicle mass center slip angle function, the calculation result is more accurate, the control of the rear wheels of the vehicle is realized together with the rear wheel deflection direction obtained in the step, and the driving safety is improved.
Step 2062, a second rear wheel yaw angle is obtained based on the ideal yaw rate.
In specific implementation, a vehicle yaw velocity function is calculated and obtained based on a vehicle two-degree-of-freedom model algorithm. And obtaining a calculated rear wheel deflection angle according to the vehicle front wheel deflection angle and the vehicle yaw velocity function, and obtaining a second rear wheel deflection angle. According to the scheme, the vehicle yaw velocity function is calculated according to the vehicle two-degree-of-freedom model algorithm, the second rear wheel deflection angle is calculated based on the obtained front wheel deflection angle and the calculated vehicle yaw velocity function, and the calculation result is more accurate.
And step 207, performing weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.
In specific implementation, when the vehicle runs, preferably when the vehicle runs in a steering manner, due to the influence of a centripetal force, a tire of the vehicle is added with a cornering force, so that a tire cornering angle is generated, and further a yaw rate and a centroid cornering angle of the whole vehicle are influenced. According to the scheme, two important parameters of the mass center side slip angle and the vehicle yaw velocity of the vehicle are considered in the calculation process of the deflection angle of the rear wheel, the mass center side slip angle and the vehicle yaw velocity of the vehicle are controlled to be in a stable working interval, and the control of the rear wheel of the vehicle is realized together with the deflection direction of the rear wheel obtained in the above step, so that the driving stability is improved, and the safety risk is reduced.
And 208, controlling the rear wheels of the vehicle according to the deflection direction of the rear wheels and the deflection angle of the rear wheels.
When the method is specifically implemented, the deflection direction of the rear wheel and the deflection angle of the rear wheel are sent to a controller, and the controller controls the rear wheel of the vehicle based on control information, wherein the control information comprises the deflection direction of the rear wheel and the deflection angle of the rear wheel, so that the driving smoothness is improved, and the safety risk in driving is reduced.
Based on the same inventive concept, in response to the vehicle being in a braking state, another embodiment of the present disclosure in an application scenario is shown in fig. 3, and includes:
in step 301, vehicle information is acquired.
In specific implementation, vehicle information is monitored and obtained through an Electronic Control Unit (ECU), and the vehicle information includes vehicle basic information, vehicle running information, vehicle front wheel steering angle information and the like, wherein the vehicle basic information includes vehicle mass, vehicle tire information and the like, the vehicle running information includes vehicle steering angle information, vehicle running speed, vehicle gear information and the like, and the vehicle front wheel steering angle information is obtained through a steering wheel. According to the scheme, the subsequent steps are used for judging the deflection direction of the rear wheel based on the acquired vehicle information, so that the judgment accuracy is improved.
Step 302, vehicle gear information is judged.
During specific implementation, the gear information of the vehicle is acquired through a vehicle internal sensor, wherein the gear information comprises a forward gear (D gear) and a reverse gear (R gear), and a basis is made for subsequent judgment of the deflection direction of the rear wheel of the vehicle.
And step 303, judging the running state of the vehicle according to the longitudinal acceleration information of the vehicle.
In specific implementation, a vehicle speed sensor is arranged in the vehicle, the longitudinal vehicle speed of the vehicle is acquired through the vehicle speed sensor, the longitudinal acceleration of the vehicle is calculated according to the acquired longitudinal vehicle speed of the vehicle, and the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle, wherein the running state of the vehicle comprises a driving state and a braking state. According to the scheme, the running state of the vehicle is judged according to the longitudinal acceleration information of the vehicle, and in the subsequent step, the slip rate of the vehicle wheels is calculated in response to the fact that the running state of the vehicle is a driving state; and responding to the fact that the vehicle running state is a braking state, calculating the slip rate of the vehicle wheels for subsequent judgment of the deflection direction of the rear wheels of the vehicle.
Step 304, calculating the slip rate of the vehicle wheel.
In specific implementation, vehicle information is acquired through a sensor, and the vehicle information comprises wheel speed, rolling radius of a tire, longitudinal vehicle speed, gear information, vehicle acceleration information and the like. The vehicle comprises a wheel speed sensor and a vehicle speed sensor, the wheel speed sensor is used for collecting the wheel speed, the vehicle speed sensor is used for collecting the longitudinal vehicle speed of the vehicle, a tire rolling radius map is obtained according to a rotary drum experiment, and the tire rolling radius is determined according to the tire pressure and the vehicle speed information of the vehicle. And calculating the slip rate or slip ratio of the vehicle wheels according to the vehicle information, and judging the deflection direction of the rear wheels according to the calculated slip rate. Calculating the slip ratio of the vehicle wheel by the following formula:
K=(u-ω·R)/u
where K is the slip ratio of the vehicle tire, ω is the wheel speed of the vehicle tire, R is the rolling radius of the vehicle tire, and u is the longitudinal speed of the vehicle.
And 305, judging the deflection direction of the rear wheel according to the slip rate of the vehicle wheel.
In specific implementation, the vehicle state is judged according to the calculated slip rate of the vehicle wheels, wherein the vehicle state refers to the running state of the vehicle in the current state and comprises an understeer state and an oversteer state. According to the scheme, the deflection direction of the rear wheel is judged through the slip rate obtained through calculation, the control of the rear wheel of the vehicle is realized together with the deflection angle of the rear wheel obtained in the following step, the judgment result is more accurate, and the driving safety is improved.
In some embodiments, step 305 specifically includes:
step 3051, in response to calculating that at least one of the slip ratio of the front wheels of the vehicle is equal to or greater than 10% and the slip ratio of the rear wheels of the vehicle is equal to 10%, determining that the vehicle is in an understeer state and the yaw direction of the rear wheels is in a reverse yaw direction with respect to the front wheels.
During specific implementation, by judging that the slip rates of the vehicle wheels are met, the slip rate of at least one front wheel of the vehicle is more than or equal to 10%, and the slip rate of a rear wheel of the vehicle is equal to 10%, the vehicle is determined to be in an under-steering state, the deflection direction of the rear wheel is determined to be in reverse deflection with the front wheel, so that the deflection angle of the rear wheel is obtained through calculation in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction in reverse deflection with the front wheel and the deflection angle of the rear wheel, the slipping of the head of the vehicle in the tangential direction of a delay arc line is avoided, and potential safety hazards are reduced.
And step 3052, in response to calculating that the slip ratio of at least one rear wheel of the vehicle is greater than or equal to 10% and the slip ratio of a front wheel of the vehicle is equal to 10%, determining that the vehicle is in an oversteer state and the deflection direction of the rear wheel is in the same direction as that of the front wheel.
During specific implementation, by judging that the slip rates of the vehicle wheels are met, the slip rate of at least one rear wheel of the vehicle is more than or equal to 10%, and the slip rate of a front wheel of the vehicle is equal to 10%, the vehicle is determined to be in an oversteer state, the deflection direction of the rear wheel is determined to be deflected in the same direction as that of the front wheel, so that the deflection angle of the rear wheel is obtained through calculation in the subsequent step process, the rear wheel is controlled to be adjusted according to the deflection direction deflected in the same direction as that of the front wheel and the deflection angle of the rear wheel, the sliding out of the tail of the vehicle in the tangential direction of the extension arc line is avoided, and potential safety hazards are reduced.
And step 3053, determining the deflection direction of the rear wheel according to the slip ratio of the vehicle wheel.
In specific implementation, the deflection direction of the rear wheel of the vehicle is judged through the slip ratio of the vehicle wheel obtained through calculation, wherein the deflection direction comprises the deflection in the direction opposite to the front wheel and the deflection in the same direction with the front wheel. Determining the deflection direction of the rear wheels to be the reverse deflection of the front wheels in response to judging that the vehicle is in an understeer state according to the slip rate of the wheels of the vehicle; and in response to the judgment that the vehicle is in an oversteer state according to the slip rate of the vehicle wheels, determining the deflection direction of the rear wheels to be the same as that of the front wheels, and obtaining a more accurate judgment result.
And step 306, acquiring a front wheel deflection angle.
In specific implementation, the vehicle front wheel steering angle information is obtained through a vehicle steering wheel, and the vehicle front wheel steering angle information contains the vehicle front wheel deflection angle for subsequent calculation of the rear wheel deflection angle.
In some embodiments, step 306 specifically includes:
step 3061, a first rear wheel deflection angle is obtained based on the ideal centroid slip angle.
During specific implementation, a vehicle mass center slip angle function is calculated and obtained based on a vehicle two-degree-of-freedom model algorithm, and a calculated rear wheel deflection angle is obtained according to the vehicle front wheel deflection angle and the vehicle mass center slip angle function, so that a first rear wheel deflection angle is obtained. According to the scheme, the vehicle mass center side slip angle function is calculated and obtained according to a vehicle two-degree-of-freedom model algorithm, the first vehicle rear wheel deflection angle is calculated and obtained based on the obtained front wheel deflection angle and the calculated vehicle mass center side slip angle function, the calculation result is more accurate, the control of the vehicle rear wheels is achieved together with the rear wheel deflection direction obtained in the step, and the driving safety is improved.
Step 3062, a second rear wheel deflection angle is obtained based on the ideal yaw rate.
In specific implementation, a vehicle yaw velocity function is calculated and obtained based on a vehicle two-degree-of-freedom model algorithm. And obtaining a calculated rear wheel deflection angle according to the vehicle front wheel deflection angle and the vehicle yaw velocity function, and obtaining a second rear wheel deflection angle. According to the scheme, the vehicle yaw velocity function is calculated according to the vehicle two-degree-of-freedom model algorithm, the second rear wheel deflection angle is calculated based on the obtained front wheel deflection angle and the calculated vehicle yaw velocity function, and the calculation result is more accurate.
And 307, performing weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.
In specific implementation, when the vehicle runs, preferably when the vehicle runs in a steering manner, due to the influence of a centripetal force, a tire of the vehicle is added with a cornering force, so that a tire cornering angle is generated, and further a yaw rate and a centroid cornering angle of the whole vehicle are influenced. According to the scheme, two important parameters of the mass center side slip angle and the vehicle yaw velocity of the vehicle are considered in the calculation process of the deflection angle of the rear wheel, the mass center side slip angle and the vehicle yaw velocity of the vehicle are controlled to be in a stable working interval, and the control of the rear wheel of the vehicle is realized together with the deflection direction of the rear wheel obtained in the above step, so that the driving stability is improved, and the safety risk is reduced.
And 308, controlling the rear wheels of the vehicle according to the rear wheel deflection direction and the rear wheel deflection angle.
When the method is specifically implemented, the deflection direction of the rear wheel and the deflection angle of the rear wheel are sent to a controller, and the controller controls the rear wheel of the vehicle based on control information, wherein the control information comprises the deflection direction of the rear wheel and the deflection angle of the rear wheel, so that the driving smoothness is improved, and the safety risk in driving is reduced.
Based on the same inventive concept, corresponding to the method of any embodiment, the disclosure also provides a vehicle control system based on the rear wheels.
Referring to fig. 4, fig. 4 is a rear wheel-based vehicle control system of an embodiment, including:
the information acquisition module 401 is configured to acquire vehicle information, and determine a rear wheel deflection direction according to the vehicle information to obtain a rear wheel deflection direction;
an angle calculation module 402 configured to obtain front wheel steering angle information with which a first rear wheel yaw angle is determined based on a vehicle centroid slip angle; determining a second rear wheel deflection angle based on the front wheel steering angle information and a vehicle yaw rate;
a rear wheel control module 403 configured to control the rear wheels of the vehicle based on the rear wheel yaw direction and the rear wheel rudder angle.
In some embodiments, the angle calculation module 402 specifically includes:
the function calculation unit is configured to obtain a vehicle mass center slip angle function according to a vehicle two-degree-of-freedom model algorithm, wherein the vehicle mass center slip angle function comprises a plurality of pieces of parameter information, and the mass center slip angle is one of the plurality of pieces of parameter information;
a function calculation unit configured to determine that the plurality of parameter information satisfy a preset condition, and determine the rear wheel steering angle relation function according to the vehicle centroid slip angle function;
a first angle calculation unit configured to calculate a first rear wheel deflection angle from the rear wheel steering angle relation function;
and the second angle calculation unit is configured to obtain a vehicle yaw velocity function based on a vehicle two-degree-of-freedom model algorithm, and perform operation processing on the vehicle rear wheel deflection angle according to the yaw velocity function to obtain a second rear wheel deflection angle.
A rear wheel angle calculation unit configured to perform weighted calculation on the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle.
In some embodiments, the function calculating unit specifically includes:
a function calculation subunit configured to derive a vehicle centroid slip angle function, expressed as:
Figure BDA0003947183160000191
wherein m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, and k 1 Yaw stiffness, k, of the front axle 2 Is the cornering stiffness of the rear axle, delta 1 For front wheel deflection angle, delta 2 For rear wheel deflection angle, I z Is the rotational inertia of the whole vehicle.
A relation function calculation subunit configured to calculate, based on the vehicle centroid slip angle function, the plurality of pieces of parameter information satisfying a preset condition including: the centroid slip angle is zero and the acceleration is zero; determining a rear wheel steering angle relationship function expressed as:
Figure BDA0003947183160000192
wherein, delta 2 | β=0 Is the first rear wheel deflection angle, beta is the centroid slip angle,
Figure BDA0003947183160000193
is the acceleration;
based on the vehicle centroid side slip angle function, the plurality of parameter information meeting preset conditions comprises: the centroid slip angle is zero, the yaw angle speed change rate is zero, and the acceleration is zero; determining a rear wheel steering relationship function expressed as:
Figure BDA0003947183160000201
in some embodiments, the second angle calculating unit specifically includes:
a function calculation subunit configured to determine a vehicle yaw rate function based on the vehicle centroid yaw angle function, the magnitude of the centroid yaw angle being a ratio of the lateral velocity to the longitudinal velocity, the yaw rate change rate being zero, the acceleration being zero, and the rear wheel yaw angle being zero:
Figure BDA0003947183160000202
obtaining an ideal yaw rate according to the vehicle yaw rate function, wherein the ideal yaw rate is represented as:
Figure BDA0003947183160000203
wherein, K is a stable factor,
Figure BDA0003947183160000204
Figure BDA0003947183160000205
an ideal yaw rate, L being the wheelbase, L = a + b;
and the angle calculation subunit is configured to perform operation processing on the deflection angle of the rear wheel of the vehicle according to the ideal yaw velocity to obtain a second rear wheel deflection angle.
In some embodiments, the angle calculation subunit is specifically configured to perform an arithmetic processing on the vehicle yaw rate and the ideal yaw rate to obtain a second rear-wheel steering angle, expressed as:
Figure BDA0003947183160000206
wherein, delta 2 | ω Is the second rear wheel deflection angle, K ω For the preset yaw-rate feedback control coefficient,
Figure BDA0003947183160000207
is the desired yaw rate. />
In some embodiments, the rear wheel angle calculation unit specifically includes:
a weighting calculation subunit configured to calculate the first rear wheel yaw angle and the second rear wheel yaw angle by weighting, resulting in a rear wheel yaw angle, expressed as:
δ 2 Total =ξ 12 | β=022
ξ 12 =1
Wherein, delta 2 total Angle of rear wheel turning, xi 1 And xi 2 Are weight coefficients.
For convenience of description, the above devices are described as being divided into various modules by functions, and are described separately. Of course, the functionality of the various modules may be implemented in the same one or more pieces of software and/or hardware in practicing the present disclosure.
The apparatus in the foregoing embodiment is used to implement the corresponding mapper file processing method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which are not described herein again.
Based on the same inventive concept, corresponding to any embodiment of the method, the present disclosure further provides an electronic device, which includes a memory, a processor, and a computer program stored on the memory and running on the processor, wherein the processor executes the program to implement the rear-wheel-based vehicle control method according to any embodiment of the method.
Fig. 5 is a schematic diagram illustrating a more specific hardware structure of an electronic device according to this embodiment, where the electronic device may include: a processor 1010, a memory 1020, an input/output interface 1030, a communication interface 1040, and a bus 1050. Wherein the processor 1010, memory 1020, input/output interface 1030, and communication interface 1040 are communicatively coupled to each other within the device via bus 1050.
The processor 1010 may be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an Application Specific Integrated Circuit (ASIC), or one or more Integrated circuits, and is configured to execute related programs to implement the technical solutions provided in the embodiments of the present disclosure.
The Memory 1020 may be implemented in the form of a ROM (Read Only Memory), a RAM (Random Access Memory), a static Memory device, a dynamic Memory device, or the like. The memory 1020 may store an operating system and other application programs, and when the technical solution provided by the embodiments of the present specification is implemented by software or firmware, the relevant program codes are stored in the memory 1020 and called to be executed by the processor 1010.
The input/output interface 1030 is used for connecting an input/output module to input and output information. The i/o module may be configured as a component in a device (not shown) or may be external to the device to provide a corresponding function. The input devices may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output devices may include a display, a speaker, a vibrator, an indicator light, etc.
The communication interface 1040 is used for connecting a communication module (not shown in the drawings) to implement communication interaction between the present device and other devices. The communication module can realize communication in a wired mode (such as USB, network cable and the like) and also can realize communication in a wireless mode (such as mobile network, WIFI, bluetooth and the like).
Bus 1050 includes a path that transfers information between various components of the device, such as processor 1010, memory 1020, input/output interface 1030, and communication interface 1040.
It should be noted that although the above-mentioned device only shows the processor 1010, the memory 1020, the input/output interface 1030, the communication interface 1040 and the bus 1050, in a specific implementation, the device may also include other components necessary for normal operation. In addition, those skilled in the art will appreciate that the above-described apparatus may also include only those components necessary to implement the embodiments of the present description, and not necessarily all of the components shown in the figures.
The electronic device of the foregoing embodiment is used to implement a corresponding rear-wheel-based vehicle control method in any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which are not described again here.
Based on the same inventive concept, corresponding to any of the above-described embodiment methods, the present disclosure also provides a non-transitory computer-readable storage medium storing computer instructions for causing the computer to execute the rear-wheel-based vehicle control method according to any of the above-described embodiments.
Computer-readable media of the present embodiments, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed by a computing device.
The storage medium of the above embodiment stores computer instructions for causing the computer to execute the method for controlling a vehicle based on a rear wheel according to any of the above embodiments, and has the advantages of corresponding method embodiments, which are not described herein again.
Based on the same inventive concept, corresponding to the method of any embodiment, the application further provides a vehicle, which includes the vehicle control system based on the rear wheels, or the electronic device, or the storage medium in the embodiment, and the vehicle device implements the vehicle control method based on the rear wheels in any embodiment.
The vehicle of the foregoing embodiment is used for implementing the vehicle control method based on the rear wheel according to any of the foregoing embodiments, and has the beneficial effects of the corresponding method embodiment, which are not described again here.
Those of ordinary skill in the art will understand that: the discussion of any embodiment above is meant to be exemplary only, and is not intended to intimate that the scope of the disclosure, including the claims, is limited to these examples; within the idea of the present disclosure, also technical features in the above embodiments or in different embodiments may be combined, steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present disclosure as described above, which are not provided in detail for the sake of brevity.
In addition, well-known power/ground connections to Integrated Circuit (IC) chips and other components may or may not be shown in the provided figures for simplicity of illustration and discussion, and so as not to obscure the embodiments of the disclosure. Furthermore, devices may be shown in block diagram form in order to avoid obscuring embodiments of the present disclosure, and this also takes into account the fact that specifics with respect to implementation of such block diagram devices are highly dependent upon the platform within which the embodiments of the present disclosure are to be implemented (i.e., specifics should be well within purview of one skilled in the art). Where specific details (e.g., circuits) are set forth in order to describe example embodiments of the disclosure, it should be apparent to one skilled in the art that the embodiments of the disclosure can be practiced without, or with variation of, these specific details. Accordingly, the description is to be regarded as illustrative instead of restrictive.
While the present disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art in light of the foregoing description. For example, other memory architectures, such as Dynamic RAM (DRAM), may use the discussed embodiments.
The disclosed embodiments are intended to embrace all such alternatives, modifications and variances which fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalents, improvements, and the like that may be made without departing from the spirit or scope of the embodiments of the present disclosure are intended to be included within the scope of the disclosure.

Claims (13)

1. A rear wheel based vehicle control method, comprising:
acquiring vehicle information, and judging the deflection direction of a rear wheel according to the vehicle information to obtain the deflection direction of the rear wheel;
obtaining front wheel steering angle information, and determining a first rear wheel deflection angle based on a vehicle mass center side deflection angle by using the front wheel steering angle information;
determining a second rear wheel deflection angle based on the front wheel steering angle information and a vehicle yaw rate;
weighting the first rear wheel deflection angle and the second rear wheel deflection angle to obtain a rear wheel deflection angle;
and controlling the rear wheels of the vehicle based on the rear wheel deflection direction and the rear wheel deflection angle.
2. The method of claim 1, wherein the obtaining front wheel steering angle information, using the front wheel steering angle information to determine a first rear wheel steering angle based on a vehicle center of mass slip angle, comprises:
acquiring front wheel steering angle information, and processing the front wheel steering angle information based on a rear wheel steering angle relation function determined by a vehicle mass center side slip angle to obtain a first rear wheel steering angle; and the rear wheel steering angle relation function is obtained according to a vehicle two-degree-of-freedom model algorithm.
3. The method of claim 2, wherein processing the front wheel steering angle information based on a rear wheel steering angle relationship function determined from a vehicle center of mass slip angle to obtain a first rear wheel steering angle further comprises:
obtaining a vehicle mass center slip angle function according to a vehicle two-degree-of-freedom model algorithm, wherein the vehicle mass center slip angle function comprises a plurality of parameter information, and the mass center slip angle is one of the plurality of parameter information;
and determining that the plurality of parameter information meet preset conditions, and determining the rear wheel steering angle relation function according to the vehicle mass center side slip angle function.
4. The method of claim 3, wherein the deriving the vehicle centroid slip angle function according to the vehicle two degree of freedom model algorithm comprises:
based on the vehicle two-degree-of-freedom model algorithm, a vehicle mass center side slip angle function is obtained and expressed as:
Figure FDA0003947183150000021
wherein m is the vehicle mass, a is the distance from the center of mass to the front axle, b is the distance from the center of mass to the rear axle, and k 1 Yaw stiffness, k, of the front axle 2 Is the cornering stiffness of the rear axle, delta 1 For front wheel deflection angle, delta 2 For rear wheel deflection angle, I z Is the rotational inertia of the whole vehicle, u is the longitudinal vehicle speed, v is the lateral vehicle speed,
Figure FDA0003947183150000025
is the vehicle acceleration, beta is the vehicle centroid slip angle, omega r For vehicle yaw rate>
Figure FDA0003947183150000026
Is the rate of change of the yaw rate of the vehicle.
5. The method of claim 4, wherein the determining that the plurality of parameter information satisfies a preset condition, the determining the rear wheel steering angle relationship function according to the vehicle center of mass and side slip angle function comprises:
the plurality of parameter information satisfying the preset condition includes: the centroid slip angle is zero and the acceleration is zero; determining the rear wheel steering angle relation function according to the vehicle mass center side slip angle function, and expressing as:
Figure FDA0003947183150000022
wherein, delta 2 | β=0 Is the first rear wheel deflection angle, beta is the centroid slip angle,
Figure FDA0003947183150000024
is the acceleration.
6. The method of claim 4, wherein determining that the plurality of parameter information satisfies a preset condition, determining the rear wheel steering angle relationship function according to the vehicle centroid slip angle function comprises:
the plurality of parameter information satisfying the preset condition includes: the centroid slip angle is zero, the yaw angle speed change rate is zero, and the acceleration is zero; determining the rear wheel steering angle relation function according to the vehicle mass center side slip angle function, and expressing as:
Figure FDA0003947183150000023
7. the method of claim 4, wherein determining a second rear-wheel steering angle based on the front-wheel steering angle information and a vehicle yaw rate comprises:
based on the size of the mass center slip angle as the ratio of the lateral speed to the longitudinal speed, the change rate of the yaw angle speed is zero, the acceleration is zero and the deflection angle of the rear wheel is zero; determining a vehicle yaw rate function according to the vehicle mass center side slip angle function:
Figure FDA0003947183150000031
obtaining an ideal yaw rate according to the vehicle yaw rate function, wherein the ideal yaw rate is represented as:
Figure FDA0003947183150000032
wherein, K is a stable factor,
Figure FDA0003947183150000033
Figure FDA0003947183150000034
an ideal yaw rate, L being the wheelbase, L = a + b;
and processing the deflection angle of the rear wheel of the vehicle according to the ideal yaw velocity to obtain a second rear wheel deflection angle.
8. The method of claim 7, wherein processing the vehicle rear wheel yaw angle from the desired yaw rate to obtain a second rear wheel yaw angle comprises:
processing said vehicle yaw rate and said ideal yaw rate to obtain a second rear wheel yaw angle, expressed as:
Figure FDA0003947183150000035
wherein, delta 2 | ω Is the second rear wheel deflection angle, K ω For the preset yaw-rate feedback control coefficient,
Figure FDA0003947183150000036
is the desired yaw rate.
9. The method of claim 1, wherein weighting the first rear wheel yaw angle and the second rear wheel yaw angle to obtain a rear wheel yaw angle comprises:
weighting the first rear wheel deflection angle and the second rear wheel deflection angle for calculation to obtain a rear wheel deflection angle, which is expressed as:
δ 2 Total =ξ 12 | β=022
ξ 12 =1
Wherein, delta 2 Total Is the angle of deflection of the rear wheel, xi 1 And xi 2 Are weight coefficients.
10. A rear wheel based vehicle control system, comprising:
the information acquisition module is configured to acquire vehicle information and judge the deflection direction of the rear wheel according to the vehicle information to obtain the deflection direction of the rear wheel;
an angle calculation module configured to obtain front wheel steering angle information, determine a first rear wheel yaw angle based on a vehicle centroid slip angle using the front wheel steering angle information; determining a second rear wheel deflection angle based on the front wheel steering angle information and the vehicle yaw rate;
a rear wheel control module configured to control a rear wheel of a vehicle based on the rear wheel yaw direction and the rear wheel yaw angle.
11. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing a rear wheel based vehicle control method as claimed in any one of claims 1 to 9 when executing the program.
12. A non-transitory computer-readable storage medium storing computer instructions for causing a computer to perform the rear wheel-based vehicle control method of any one of claims 1 to 9.
13. A vehicle comprising the rear-wheel-based vehicle control system of claim 10 or the electronic device of claim 11 or the computer-readable storage medium of claim 12.
CN202211436858.3A 2022-11-16 2022-11-16 Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels Pending CN115848354A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202211436858.3A CN115848354A (en) 2022-11-16 2022-11-16 Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202211436858.3A CN115848354A (en) 2022-11-16 2022-11-16 Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels

Publications (1)

Publication Number Publication Date
CN115848354A true CN115848354A (en) 2023-03-28

Family

ID=85663809

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202211436858.3A Pending CN115848354A (en) 2022-11-16 2022-11-16 Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels

Country Status (1)

Country Link
CN (1) CN115848354A (en)

Similar Documents

Publication Publication Date Title
EP2203340B1 (en) Vehicle body speed estimating device
CN102202949A (en) Device and method for estimating frictional condition of ground surface with which vehicle is in contact
JP6328841B1 (en) Control device and steering device
CN114771530A (en) Vehicle steering control method and device, vehicle and storage medium
JP5919889B2 (en) Vehicle attitude control device
WO2020043198A1 (en) Vehicle control method and device
JP5251177B2 (en) Vehicle running state estimation device
JPWO2012131952A1 (en) Vehicle driving force control device
JP6577850B2 (en) Vehicle control apparatus and vehicle control method
JP6674769B2 (en) Vehicle control device and vehicle control method
CN115848354A (en) Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels
JP6428497B2 (en) Vehicle control device
KR20170136765A (en) Steering control apparatus and steering control method, and steering-state determination apparatus therefor
CN115675445A (en) Vehicle control method, system, equipment, storage medium and vehicle based on rear wheels
CN105752059A (en) Vehicle stability control method
CN115675636A (en) Control method and system for front wheel and rear wheel, electronic device, storage medium and vehicle
CN115675634A (en) Control method and system for front wheel and rear wheel, electronic device, storage medium and vehicle
CN115675635A (en) Control method and system for front wheel and rear wheel, electronic device, storage medium and vehicle
JP6237105B2 (en) Vehicle control device
KR101355351B1 (en) Vehicle Touque Distribution Control Apparatus and Controlling Method
JP5251176B2 (en) Vehicle running state estimation device
JP6560522B2 (en) Vehicle control apparatus and vehicle control method
CN113830075B (en) Vehicle stability control method, device, electronic device, and medium
JP2002173012A (en) Behavior control device for vehicle
JP2008260439A (en) Vehicle behavior control unit and vehicle behavior control method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination