CN116513209A - Vehicle speed estimation method under driving and emergency braking conditions - Google Patents

Vehicle speed estimation method under driving and emergency braking conditions Download PDF

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Publication number
CN116513209A
CN116513209A CN202310213731.3A CN202310213731A CN116513209A CN 116513209 A CN116513209 A CN 116513209A CN 202310213731 A CN202310213731 A CN 202310213731A CN 116513209 A CN116513209 A CN 116513209A
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China
Prior art keywords
speed
vehicle
center line
longitudinal
shaft center
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宫新乐
黄晋
李星宇
钟志华
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Tsinghua University
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Tsinghua University
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion
    • B60W40/105—Speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W40/00—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models
    • B60W40/10—Estimation or calculation of non-directly measurable driving parameters for road vehicle drive control systems not related to the control of a particular sub unit, e.g. by using mathematical models related to vehicle motion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W50/00—Details of control systems for road vehicle drive control not related to the control of a particular sub-unit, e.g. process diagnostic or vehicle driver interfaces
    • B60W2050/0001—Details of the control system
    • B60W2050/0002—Automatic control, details of type of controller or control system architecture
    • B60W2050/0004—In digital systems, e.g. discrete-time systems involving sampling
    • B60W2050/0005—Processor details or data handling, e.g. memory registers or chip architecture
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/60—Other road transportation technologies with climate change mitigation effect
    • Y02T10/72—Electric energy management in electromobility

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  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Mathematical Physics (AREA)
  • Human Computer Interaction (AREA)
  • Regulating Braking Force (AREA)

Abstract

The application relates to a vehicle speed estimation method under driving and emergency braking conditions. The method comprises the following steps: determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle, determining the first shaft center line speed according to the shaft center line speed and the braking condition of the driven wheels in each wheel, and estimating the longitudinal speed of the vehicle according to the first shaft center line speed; wherein the longitudinal speed is a speed in a direction parallel to the vehicle running direction. The accuracy of the estimated longitudinal speed of the vehicle can be improved by adopting the method.

Description

Vehicle speed estimation method under driving and emergency braking conditions
Technical Field
The application relates to the technical field of vehicle control, in particular to a vehicle speed estimation method under driving and emergency braking conditions.
Background
In order to improve the active safety of a vehicle during driving, it is necessary to measure and monitor a state parameter during driving of the vehicle, in particular, a vehicle longitudinal speed is an important parameter of an active safety control system of the vehicle, wherein the vehicle longitudinal direction is a direction parallel to the driving direction of the vehicle, and thus, it is necessary to measure and monitor the vehicle longitudinal speed.
In the conventional technology, the longitudinal speed of a vehicle is estimated mainly by acquiring the longitudinal acceleration of the vehicle and integrating the longitudinal acceleration of the vehicle.
However, the conventional method has a problem in that the accuracy of the estimated vehicle longitudinal speed is low.
Disclosure of Invention
In view of the foregoing, it is desirable to provide a vehicle speed estimation method that can improve the accuracy of estimated vehicle longitudinal speed in driving and emergency braking conditions.
In a first aspect, the present application provides a vehicle speed estimation method for driving and emergency braking conditions.
The method comprises the following steps:
determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
determining a first axle centerline speed based on each of the axle centerline speeds and a braking condition of a driven wheel in each of the wheels;
estimating a longitudinal speed of the vehicle from the first shaft centerline speed; wherein the longitudinal speed is a speed in a direction parallel to the vehicle running direction.
In one embodiment, the estimating the longitudinal speed of the vehicle from the first shaft centerline speed includes:
a longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and state information of a brake antilock braking system of the vehicle.
In one embodiment, if the status information of the antilock brake system indicates that the antilock brake system is in a non-activated state; the estimating the longitudinal speed of the vehicle based on the first shaft centerline speed and state information of a brake antilock braking system of the vehicle includes:
a longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
In one embodiment, if the status information of the antilock brake system indicates that the antilock brake system is in an activated state; the estimating the longitudinal speed of the vehicle based on the first shaft centerline speed and state information of a brake antilock braking system of the vehicle includes:
determining a longitudinal speed of the anti-lock brake system in a non-activated state as an initial longitudinal speed of the vehicle;
determining an intermediate longitudinal speed of the vehicle based on the initial longitudinal speed and a longitudinal acceleration of the vehicle;
determining the longitudinal speed according to the intermediate longitudinal speed and the second shaft centerline speed; the second shaft centerline speed is a maximum shaft centerline speed of the shaft centerline speeds.
In one embodiment, the determining the longitudinal speed from the intermediate longitudinal speed and the second shaft centerline speed includes:
comparing the intermediate longitudinal speed with the second shaft center line speed to obtain a comparison result;
if the comparison result indicates that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle;
and if the comparison result indicates that the intermediate longitudinal speed is greater than or equal to the second shaft center line speed, determining the intermediate longitudinal speed as the longitudinal speed.
In one embodiment, said determining a first axle centerline speed based on each of said axle centerline speeds and a braking condition of a driven wheel in each of said wheels comprises:
and if the driven wheels are not braked, determining the average value of the shaft center line speeds corresponding to the driven wheels as the first shaft center line speed.
And if the driven wheels are braked, determining the maximum shaft center line speed in the shaft center line speeds as the first shaft center line speed.
And if any driven wheel in the driven wheels is not braked, determining the shaft center line speed corresponding to the non-braked driven wheel as the first shaft center line speed.
In a second aspect, the present application further provides a vehicle speed estimation device for driving and emergency braking conditions, the device comprising:
the first determining module is used for determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
the second determining module is used for determining the first shaft center line speed according to the shaft center line speeds and the braking conditions of driven wheels in the wheels;
an estimation module for estimating a longitudinal speed of the vehicle from the first shaft centerline speed; wherein the longitudinal speed is a speed in a direction parallel to the vehicle running direction.
In a third aspect, the present application also provides a computer device. The computer device comprises a memory storing a computer program and a processor implementing the method of the first aspect described above when executing the computer program.
In a fourth aspect, the present application also provides a computer-readable storage medium. The computer readable storage medium has stored thereon a computer program which, when executed by a processor, implements the method of the first aspect described above.
In a fifth aspect, the present application also provides a computer program product. The computer program product comprises a computer program which, when executed by a processor, implements the method according to the first aspect described above.
According to the vehicle speed estimation method for driving and emergency braking conditions, firstly, the shaft center line speed corresponding to each wheel is determined according to the wheel speed of each wheel of a vehicle, so that the first shaft center line speed is determined according to the shaft center line speed and the braking condition of the driven wheels in each wheel, and further the longitudinal speed parallel to the running direction of the vehicle can be estimated according to the first shaft center line speed; in addition, as the braking conditions of the driven wheels in each wheel are considered in the process of determining the first shaft center line speed, different first shaft center line speeds can be determined according to different braking conditions, so that the first shaft center line speeds corresponding to different braking conditions in a vehicle braking scene can be considered more comprehensively, and the accuracy of the longitudinal speed of the vehicle estimated according to the first shaft center line speeds is further improved.
Drawings
FIG. 1 is a diagram of an application environment for a method of estimating vehicle speed for driving and emergency braking conditions in one embodiment;
FIG. 2 is a flow chart of a method of estimating vehicle speed for driving and emergency braking conditions in one embodiment;
FIG. 3 is a schematic diagram of a vehicle model in one embodiment;
FIG. 4 is a flow chart of a method for estimating vehicle speed for driving and emergency braking conditions in another embodiment;
FIG. 5 is a flow chart of a method for estimating vehicle speed for driving and emergency braking conditions in another embodiment;
FIG. 6 is a flow chart of a method for estimating vehicle speed for driving and emergency braking conditions in another embodiment;
FIG. 7 is a block diagram of a vehicle speed estimation device for driving and emergency braking conditions in one embodiment;
FIG. 8 is a block diagram of a vehicle speed estimation device for driving and emergency braking conditions in another embodiment.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.
In order to improve the safety performance of the vehicle during running, a series of safety control systems such as an anti-lock braking system (Antilock Brake System, ABS) and a traction control system are arranged on the vehicle, and the safety control systems can effectively improve the steering stability of the vehicle and avoid traffic accidents, but the implementation of the safety systems is seriously dependent on more accurate vehicle state parameters. In general, vehicle state parameters are obtained during the running of a vehicle through various vehicle-mounted sensors, such as wheel speeds, steering angles, longitudinal accelerations of the vehicle, longitudinal speeds of the vehicle, etc., wherein the longitudinal direction of the vehicle is a direction parallel to the running direction of the vehicle, and the longitudinal speeds of the vehicle directly affect the performance of the vehicle stability control system, so that accurate and reliable longitudinal speed information of the vehicle is an important parameter of the performance of the vehicle stability control system.
However, the sensor for measuring the longitudinal speed of the vehicle is expensive and the problem of reliability of the signal is not completely solved, and thus it is difficult to obtain it directly by measurement. The current method for acquiring the longitudinal speed of the vehicle is to integrate the longitudinal acceleration of the vehicle by a direct integration method to acquire the longitudinal speed of the vehicle, and the method is simple, but integrates signal noise and zero offset measured by an acceleration sensor, so that the accumulated error is larger and larger, and the estimated longitudinal speed of the vehicle has the problem of lower accuracy. Based on this, the present application proposes a vehicle speed estimation method capable of improving driving and emergency braking conditions of an estimated vehicle longitudinal speed accuracy.
The vehicle speed estimation method under the driving and emergency braking conditions can be applied to an application environment shown in fig. 1. Fig. 1 provides a computer device, which may be a server, whose internal structure may be as shown in fig. 1. The computer device includes a processor, a memory, and a network interface connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database of the computer device is used to store speed data in the emergency braking scenario of the vehicle. The network interface of the computer device is used for communicating with an external terminal through a network connection. The computer program, when executed by the processor, implements a method for estimating vehicle speed for driving and emergency braking conditions.
In one embodiment, as shown in fig. 2, a method for estimating a vehicle speed under driving and emergency braking conditions is provided, which is applicable not only to a normal driving condition of a vehicle but also to an emergency braking scene of the vehicle, and the method is applied to the computer device in fig. 1 for illustration, and includes the following steps:
S201, determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle.
The wheel speed of each wheel refers to the speed of the wheel rotation, the axle center refers to the center line of the tread of the left and right tires in the same transverse direction of the vehicle, the linear speed refers to the speed when any point on the wheel performs circular motion on a fixed axle, and the axle center line speed refers to the speed when the left and right tires in the same transverse direction perform circular motion on the center line between the left and right tires.
In this embodiment, the wheel speed of each wheel may be measured by the vehicle-mounted sensor, so that the measured wheel speed of each wheel may be converted into a corresponding shaft center line speed by a geometric conversion method, and optionally, the shaft center line speed may be a front shaft center line speed or a rear shaft center line speed. Taking a four-wheel vehicle as an example, if the vehicle is designed to drive front wheels, the left and right front wheels are driving wheels, and the left and right rear wheels are driven wheels, the central line speed of a front shaft corresponding to each wheel can be determined according to the wheel speed of each wheel of the vehicle; if the vehicle is in a rear wheel driving design, the left and right rear wheels are driving wheels, and the left and right front wheels are driven wheels, so that the central line speed of the rear axle corresponding to each wheel can be determined according to the wheel speed of each wheel of the vehicle.
For example, a rear-wheel drive design vehicle is shown in FIG. 3, which is a schematic diagram of a vehicle model, wherein the direction of the line segment AB is the horizontal direction of the front wheel of the vehicle, r is the wheel radius, L is the distance between the front axle and the rear axle, and B f B is the wheel distance between the left and right front wheels r Is the tread between the left and right rear wheels. According to the vehicle model schematic diagram, the central line speed of the rear axle corresponding to each wheel of the vehicle can be obtained as follows:
in the formula, v 1 、v 2 、v 3 、v 4 The center line speeds of the rear axle are respectively changed by the left front wheel, the right front wheel, the left rear wheel and the right rear wheel of the vehicle; omega 1 、ω 2 、ω 3 、ω 4 Wheel speeds of a left front wheel, a right front wheel, a left rear wheel and a right rear wheel of the vehicle respectively, and omega is the yaw rate of the vehicle.
S202, determining the first shaft center line speed according to the shaft center line speeds and the braking condition of driven wheels in each wheel.
The driven wheel braking condition refers to a braking state corresponding to the driven wheel in the vehicle braking process, and the braking state can be braking or non-braking optionally; the first shaft center line speed refers to a shaft center line speed that best meets an actual braking condition in a vehicle braking process, and optionally, the first shaft center line speed may be a maximum shaft center line speed in the shaft center line speeds, may be a minimum shaft center line speed in the shaft center line speeds, or may be an average value of the shaft center line speeds.
In this embodiment, different first shaft center line speeds corresponding to different braking conditions may be determined according to the braking conditions of each driven wheel and according to each shaft center line speed, and illustratively, taking a four-wheel vehicle as an example, the braking conditions of the driven wheels may be that both driven wheels are not braked, one driven wheel is not braked, both driven wheels are braked, and as an alternative implementation manner, if the braking conditions of the driven wheels are that both driven wheels are not braked, the shaft center line speed corresponding to the larger driven wheel may be determined as the first shaft center line speed.
S203, estimating the longitudinal speed of the vehicle according to the first shaft central line speed; the longitudinal speed is a speed in a direction parallel to the vehicle traveling direction.
Wherein the longitudinal speed of the vehicle may represent a real-time speed of the vehicle in a direction parallel to the direction of travel of the vehicle during travel or during braking. Alternatively, in the present embodiment, the first shaft center line speed may be determined as the longitudinal speed of the vehicle, or the first shaft center line speed may be set as the initial longitudinal speed of the vehicle, and the longitudinal speed of the vehicle may be estimated from the initial longitudinal speed of the vehicle and the real-time running speed of the vehicle and the real-time acceleration of the vehicle.
According to the vehicle speed estimation method for driving and emergency braking conditions, firstly, the shaft center line speed corresponding to each wheel is determined according to the wheel speed of each wheel of a vehicle, so that the first shaft center line speed is determined according to the shaft center line speed and the braking condition of the driven wheels in each wheel, and then the longitudinal speed parallel to the running direction of the vehicle can be estimated according to the first shaft center line speed; in addition, as the braking conditions of the driven wheels in each wheel are considered in the process of determining the first shaft center line speed, different first shaft center line speeds can be determined according to different braking conditions, so that the first shaft center line speeds corresponding to different braking conditions in a vehicle braking scene can be considered more comprehensively, and the accuracy of the longitudinal speed of the vehicle estimated according to the first shaft center line speeds is further improved.
In the above scenario of estimating the longitudinal speed of the vehicle based on the first shaft center line speed, it is necessary to determine the anti-lock braking state information of the vehicle first, and then estimate the longitudinal speed of the vehicle based on the anti-lock braking state information of the vehicle. In one embodiment, the step S203 includes: the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and the state information of the vehicle's anti-lock braking system.
The anti-lock braking system of the vehicle is a system for preventing the wheels from being locked by sliding the wheels with small amplitude while braking in order to ensure that the wheels are not locked under the condition of emergency braking, and optionally, the state information of the anti-lock braking system of the vehicle can be in a non-starting state or a starting state.
In a vehicle braking scenario, the anti-lock braking system of the vehicle may automatically control the magnitude of braking force of the brake during braking of the vehicle, determine the locking state of the wheels according to the speed signals of the wheels, so that the wheels are not locked and are in a rolling and sliding state (the sliding rate is about 20%) so as to ensure that the adhesion between the wheels and the ground is at a maximum value. In particular, at the time of starting the antilock brake system, the vehicle is dithered, and the longitudinal speed of the vehicle is greatly changed, so that it is necessary to determine different estimation methods of the longitudinal speed of the vehicle according to the starting state of the antilock brake system.
In an alternative embodiment, if the state information of the anti-lock brake system of the vehicle indicates that the anti-lock brake system is in the non-activated state, the "estimating the longitudinal speed of the vehicle based on the first shaft centerline speed and the state information of the anti-lock brake system of the vehicle" includes: the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
The Kalman filtering algorithm is an algorithm for optimally estimating the system state by utilizing a linear system state equation and through system input and output observation data, and can realize the estimation and prediction of the real-time running state. The state equation of the system in the Kalman filtering algorithm is:
X(K+1)＝AX(k)+Bu(K)+W(k)
the observation state equation of the system is as follows:
Z(K)＝CX(k)+V(k)
where X (k) is a state quantity at the time of system k,v ref(k) a is the vehicle speed at the time of k of the system e (k) The deviation of the acceleration signal of the vehicle at the moment k; u (k) is the system input, U (k) =a x0 (k) The method comprises the steps of carrying out a first treatment on the surface of the The process noise at the moment W (k) is k, and the process noise is Gaussian white noise with the average value of 0; z (k) is the observed quantity of the moment of the system k, Z (k) =v ｗｒ (ｋ)，ｖ ｗｒ (k) The wheel speed signal obtained in the step 2 is obtained; the observed noise at time V (k) is k, and is gaussian white noise with the average value of 0; A. b, C is a parameter matrix, wherein ∈ >t s Is the sampling instant.
In this embodiment, the longitudinal speed of the vehicle in the non-activated state of the antilock brake system may be estimated by a kalman filter algorithm, and the estimation process may be expressed by the following formula:
state prediction:
X(k|k-1)＝AX(k-1|k-1)+BU(k)
error covariance prediction:
P(k|k-1)＝AP(k-1|k-1)A T +Q
kalman gain:
state estimation correction:
X(k|k)＝X(k|k-1)+K(k)[Z(k)-HX(k|k-1)]
error covariance estimation correction:
P(k|k)＝[I-K(k)H]P(k|k-1)
wherein X (k|k-1) is the result of the k moment predicted by the state at the (k-1) moment; x (k-1|k-1) is the optimal result in the state at time (k-1); p (k|k-1) is the covariance matrix corresponding to X (k|k-1); p (k-1|k-1) is the corresponding covariance matrix of the corresponding X (k-1|k-1); a is that T Representing the transpose matrix of A; q is the variance of the process noise W (k); k (K) is Kalman filtering gain; h is a conversion matrix from state quantity to observed quantity; h T Representing the transpose matrix of H; r is the variance of the observed noise V (k); x (k|k) is the optimal estimate at time k.
It should be noted that, different braking conditions of the driven wheels of the vehicle correspond to different first shaft center line speeds, and the kalman filtering method can estimate vehicle longitudinal speeds corresponding to different braking conditions of the vehicle.
According to the embodiment, when the vehicle braking anti-lock braking system is in a non-starting state, the longitudinal speed of the vehicle is estimated by adopting a Kalman filtering algorithm, different braking conditions of the vehicle can be fully considered, so that the longitudinal speed of the vehicle can be estimated to be more in line with the actual braking condition of the vehicle, and the accuracy of the estimated longitudinal speed of the vehicle is further improved.
In another alternative embodiment, as shown in fig. 4, if the state information of the antilock brake system indicates that the antilock brake system is in the activated state, "estimate the longitudinal speed of the vehicle based on the first shaft centerline speed and the state information of the antilock brake system of the vehicle" includes:
s301, determining a longitudinal speed of the vehicle when the antilock brake system is in a non-activated state as an initial longitudinal speed of the vehicle.
When the anti-lock brake system is in a start state, the wheel speed of the vehicle fluctuates in succession, so that the longitudinal speed of the vehicle needs to be estimated by adopting an adaptive slope method, and the estimation process can be expressed according to the following formula:
in the method, in the process of the invention,estimating a longitudinal speed of the vehicle for an adaptive slope method; v 0 Is the initial longitudinal speed of the brake anti-lock system when in a starting state; a, a x The longitudinal acceleration of the vehicle can be obtained through measurement of an on-board sensor; t is the sampling time.
It will be appreciated that the influence factors of the adaptive slope method include an initial longitudinal speed and a longitudinal acceleration, wherein the longitudinal acceleration of the vehicle is directly measured by the vehicle-mounted sensor, and the initial longitudinal speed may be determined by the longitudinal speed of the vehicle corresponding to the last moment when the antilock braking system is in the inactive state, or may be determined by the longitudinal speed of the vehicle corresponding to any moment when the antilock braking system is in the inactive state.
The starting conditions of the adaptive slope method are as follows: a, a x <a thre1 Wherein a is thre1 Is a preset threshold value of the longitudinal acceleration of the vehicle, namely, if the anti-lock braking system is braked in the scene of vehicle braking, a state information tableAnd if the anti-lock braking system is in a starting state and the braking acceleration is smaller than a preset threshold value, the longitudinal speed of the vehicle can be estimated by adopting an adaptive slope method.
S302, determining the middle longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle.
In the present embodiment, in the case where the start condition of the adaptive slope method is satisfied, the intermediate longitudinal speed of the vehicle can be estimated by the adaptive slope method:
in the method, in the process of the invention,v is the intermediate longitudinal speed of the vehicle 1 For braking the longitudinal speed of the vehicle, a) corresponding to the last moment when the antilock braking system is in the inactive state x For longitudinal acceleration, t is the sampling time.
S303, determining the longitudinal speed according to the middle longitudinal speed and the second shaft center line speed; the second shaft centerline speed is the maximum shaft centerline speed among the shaft centerline speeds.
It will be appreciated that in estimating the longitudinal speed of the vehicle using the adaptive slope method, since the longitudinal speed of the vehicle is in the process of continuously changing, as the braking time increases, there may be a deviation in the estimated longitudinal speed of the vehicle, based on which it is necessary to correct the influence factor in the adaptive slope method, wherein the vehicle longitudinal acceleration is obtained by directly measuring the vehicle-mounted sensor, and therefore, the deviation can be reduced by resetting the initial longitudinal speed, the reset condition of the initial longitudinal speed being:
In the formula, v' i，max Is the maximum axle center speed among the axle center speeds of the vehicleThe degree of the heat dissipation,is the intermediate longitudinal speed of the vehicle. The initial longitudinal speed may be reset when the intermediate longitudinal speed is less than the maximum shaft centerline speed.
In this embodiment, the determined intermediate longitudinal speed may be compared with the second axis center line speed, and whether to reset the initial longitudinal speed in the adaptive slope method is determined according to the comparison result, if the initial longitudinal speed is reset, the vehicle longitudinal speed needs to be estimated again according to the reset initial longitudinal speed; if the initial longitudinal speed is not reset, continuing to estimate the longitudinal speed of the vehicle according to the initial longitudinal speed which is not reset.
Alternatively, in this embodiment, the initial longitudinal speed after the reset may be used, and the longitudinal speed of the vehicle may be continuously re-estimated by using the adaptive slope method:
in the method, in the process of the invention,for estimated longitudinal speed of the vehicle, v' i，max For initial longitudinal speed after reset, a x For longitudinal acceleration, t is the sampling time.
According to the embodiment, when the anti-lock braking system of the vehicle is in the starting state, the longitudinal speed of the vehicle is estimated by adopting the self-adaptive slope method according to the change condition of the wheel speed when the anti-lock braking system is started, so that the signal drift phenomenon occurring when the anti-lock braking system is started can be eliminated, and the initial longitudinal speed in the self-adaptive slope method is reset according to the change rule of the longitudinal speed of the vehicle in the vehicle braking process, so that the reset initial longitudinal speed is closer to the actual braking condition of the vehicle, and the accuracy of the estimated longitudinal speed of the vehicle is further improved.
In this embodiment, by estimating the longitudinal speed of the vehicle according to the first shaft center line speed and the state information of the anti-lock braking systems of the vehicle, the accuracy of the estimated longitudinal speed of the vehicle under the state information of the different anti-lock braking systems of the vehicle can be improved on the basis of the first shaft center line speed with higher stability; in addition, the longitudinal speed of the vehicle is estimated by adopting an estimation method which is closer to the actual braking condition of the vehicle under the state information of different braking anti-lock systems of the vehicle, so that the accuracy of the estimated longitudinal speed of the vehicle is further improved.
In the above-described scenario of resetting the initial longitudinal speed, it may be determined whether to reset the initial longitudinal speed by comparing the magnitudes of the intermediate longitudinal speed and the second axis centerline speed. In one embodiment, as shown in fig. 5, S303 includes:
s401, comparing the middle longitudinal speed with the second shaft center line speed to obtain a comparison result.
Optionally, in this embodiment, the difference value between the intermediate longitudinal speed and the second axis center line speed may be calculated, and a comparison result between the intermediate longitudinal speed and the second axis center line speed may be determined according to the calculation result; the comparison result of the intermediate longitudinal speed and the second axis center line speed may also be determined according to the calculation result by calculating the ratio of the intermediate longitudinal speed to the second axis center line speed, and the embodiment is not limited to a specific comparison method.
And S402, if the comparison result shows that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle.
In an alternative embodiment, the difference value is calculated between the intermediate longitudinal speed and the second axis center line speed, if the calculation result is a positive number, which indicates that the intermediate longitudinal speed is smaller than the second axis center line speed, then it is indicated that the estimated longitudinal speed of the current vehicle deviates from the actual braking condition of the vehicle, the initial longitudinal speed of the adaptive slope method needs to be reset, the second axis center line speed can be determined to be a new initial longitudinal speed, and the intermediate longitudinal speed of the vehicle is estimated according to the new initial longitudinal speed after the reset.
It will be appreciated that in a vehicle braking scenario, when the vehicle's anti-lock brake system is in an activated state, the second axle centerline speed, i.e., the maximum axle centerline speed of the axle centerline speeds, may be taken as the initial longitudinal speed of the adaptive slope method, thereby estimating the longitudinal speed of the vehicle.
S403, if the comparison result indicates that the intermediate longitudinal speed is greater than or equal to the second shaft center line speed, determining the intermediate longitudinal speed as the longitudinal speed.
It will be appreciated that in a vehicle braking scenario, the longitudinal speed of the vehicle is continuously decreasing as the braking time increases, and if the comparison indicates that the intermediate longitudinal speed is greater than or equal to the second axis centerline speed, it is indicated that the current longitudinal speed of the vehicle corresponds to the actual braking situation of the vehicle, and therefore, the current estimated intermediate longitudinal speed may be determined as the longitudinal speed of the vehicle.
In this embodiment, a comparison result is obtained by comparing the intermediate longitudinal speed with the second axis center line speed, if the comparison result indicates that the intermediate longitudinal speed is smaller than the second axis center line speed, the second axis center line speed is determined to be a new initial longitudinal speed, the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle is performed back, and if the comparison result indicates that the intermediate longitudinal speed is greater than or equal to the second axis center line speed, the intermediate longitudinal speed is determined to be the longitudinal speed, so that in a vehicle braking scene, the braking condition of the vehicle can be judged in real time according to a preset reset condition of the initial longitudinal speed, and errors of the determined initial longitudinal speed can be reduced, and the accuracy of the estimated vehicle longitudinal speed is improved.
In the above scenario where the first shaft centerline speed is determined based on the shaft centerline speeds and the braking conditions of the driven wheels in each wheel, different braking conditions correspond to different first shaft centerline speeds. In one embodiment, as shown in fig. 6, S202 includes:
s501, if none of the driven wheels is braked, determining an average value of the shaft center line speeds corresponding to the driven wheels as the first shaft center line speed.
In this embodiment, if none of the driven wheels is braked, an average value of the rear axle center line speeds corresponding to the two driven wheels may be used as the first axle center line speed to represent the axle center line speed closest to the current real running condition of the vehicle.
In this embodiment, if both the driven wheels are not braked, an average value of the rear axle center line speeds corresponding to the two driven wheels may be used as the first axle center line speed to represent the current running condition of the vehicle.
S502, when the driven wheels are braked, the largest shaft center line speed among the shaft center line speeds is determined as the first shaft center line speed.
In this embodiment, if the driven wheels are braked, it is indicated that the rotational speed of the driven wheels is in a state in which the rotational speed continuously decreases when the vehicle is in a braking scenario, and therefore, the maximum shaft center line speed among the shaft center line speeds may be determined as the first shaft center line speed.
For example, taking a rear-drive four-wheel vehicle as an example, taking two front wheels of the vehicle as driven wheels, if both driven wheels brake and the axle center line speed corresponding to the left front wheel is greater than the axle center line speeds corresponding to the other three wheels, the rear axle center line speed of the left front wheel can be determined as the first axle center line speed.
If any one of the driven wheels is not braked, the shaft center line speed corresponding to the non-braked driven wheel is determined as the first shaft center line speed at S503.
In this embodiment, if any one of the driven wheels is not braked, it is indicated that the vehicle is in a braking scenario, and the shaft center line speed corresponding to one of the driven wheels does not start to decrease, so that the shaft center line speed corresponding to the non-braked driven wheel may be determined as the first shaft center line speed.
For example, in a four-wheel vehicle driven at a rear position, two front wheels of the vehicle are used as driven wheels, and if a left front wheel of the two driven wheels is not braked, a rear axle center line speed corresponding to the left front wheel is determined as a first axle center line speed.
In this embodiment, different first shaft center line speeds can be determined according to different braking conditions of the driven wheels, and influences of the braking conditions of different wheels in a vehicle braking scene on the longitudinal speed of the vehicle are fully considered, so that accuracy of the estimated longitudinal speed of the vehicle can be improved.
For the convenience of understanding of those skilled in the art, the following describes in detail the method for estimating vehicle speed in driving and emergency braking conditions provided in the present application, which may include:
s1, acquiring wheel speed signals of all wheels of a vehicle according to an on-board sensor.
S2, converting the wheel speed of each wheel into the shaft center line speed of the vehicle through a set conversion method.
And S3, if the driven wheels are not braked, determining the average value of the shaft center line speeds corresponding to the driven wheels as a first shaft center line speed.
And S4, if any driven wheel is not braked, determining the shaft center line speed corresponding to the non-braked driven wheel as the first shaft center line speed.
And S5, if the driven wheels are braked, determining the maximum shaft center line speed among the shaft center line speeds as a first shaft center line speed.
S6, estimating the longitudinal speed of the vehicle according to the Kalman filtering method and the determined first shaft center line speed when the anti-lock braking system is in a non-starting state.
S7, when the anti-lock braking system is in a starting state, estimating the longitudinal speed of the vehicle according to the self-adaptive slope method and the longitudinal speed of the vehicle corresponding to the last moment when the anti-lock braking system is in a non-starting state.
It should be understood that, although the steps in the flowcharts related to the above embodiments are sequentially shown as indicated by arrows, these steps are not necessarily sequentially performed in the order indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least some of the steps in the flowcharts described in the above embodiments may include a plurality of steps or a plurality of stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of the steps or stages is not necessarily performed sequentially, but may be performed alternately or alternately with at least some of the other steps or stages.
Based on the same inventive concept, the embodiment of the application also provides a driving and emergency braking condition vehicle speed estimating device for realizing the driving and emergency braking condition vehicle speed estimating method. The implementation of the solution provided by the device is similar to that described in the above method, so the specific limitation in the embodiments of the vehicle speed estimation device for driving and emergency braking conditions provided below may be referred to the limitation of the vehicle speed estimation method for driving and emergency braking conditions hereinabove, and will not be repeated here.
In one embodiment, as shown in FIG. 7, there is provided a vehicle speed estimation apparatus for driving and emergency braking conditions, comprising: a first determination module 10, a second determination module 11 and an estimation module 12, wherein:
the first determining module 10 is configured to determine a shaft center line speed corresponding to each wheel according to a wheel speed of each wheel of the vehicle.
A second determining module 11 for determining the first shaft centerline speed based on the shaft centerline speeds and the braking conditions of the driven wheels in each wheel.
An estimation module 12 for estimating a longitudinal speed of the vehicle based on the first shaft centerline speed; the longitudinal speed is a speed in a direction parallel to the vehicle traveling direction.
The vehicle speed estimation device for driving and emergency braking conditions provided in this embodiment may implement the above method embodiment, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, as shown in fig. 8, the estimation module 12 includes: an estimation unit 121, wherein:
an estimating unit 121 for estimating a longitudinal speed of the vehicle based on the first shaft center line speed and state information of a brake antilock brake system of the vehicle.
The vehicle speed estimation device for driving and emergency braking conditions provided in this embodiment may implement the above method embodiment, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, please continue to refer to fig. 8, if the state information of the antilock braking system indicates that the antilock braking system is in the non-activated state, the estimating unit 121 is configured to: the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
The vehicle speed estimation device for driving and emergency braking conditions provided in this embodiment may implement the above method embodiment, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, please continue to refer to fig. 8, if the state information of the antilock braking system indicates that the antilock braking system is in the activated state, the estimating unit 121 is configured to: determining a longitudinal speed of the brake antilock system in a non-activated state as an initial longitudinal speed of the vehicle; determining an intermediate longitudinal speed of the vehicle based on the initial longitudinal speed and the longitudinal acceleration of the vehicle; determining a longitudinal speed according to the intermediate longitudinal speed and the second shaft centerline speed; the second shaft centerline speed is the maximum shaft centerline speed among the shaft centerline speeds.
The vehicle speed estimation device for driving and emergency braking conditions provided in this embodiment may implement the above method embodiment, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, please continue to refer to fig. 8, the estimation unit 121 is configured to compare the intermediate longitudinal speed with the second axis centerline speed to obtain a comparison result; if the comparison result shows that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to execute the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle; if the comparison indicates that the intermediate longitudinal speed is greater than or equal to the second shaft centerline speed, the intermediate longitudinal speed is determined to be the longitudinal speed.
The vehicle speed estimation device for driving and emergency braking conditions provided in this embodiment may implement the above method embodiment, and its implementation principle and technical effects are similar and will not be described herein.
In one embodiment, please continue to refer to fig. 8, the first determining module 10 includes a first determining unit 101, a second determining unit 102, and a third determining unit 103, wherein:
The first determining unit 101 is configured to determine, as the first shaft center line speed, an average value of shaft center line speeds corresponding to the driven wheels if none of the driven wheels is braked.
The second determining unit 102 is configured to determine the maximum shaft center line speed among the shaft center line speeds as the first shaft center line speed when the driven wheels are braked.
And a third determining unit 103, configured to determine, if any one of the driven wheels is not braked, a shaft center line speed corresponding to the non-braked driven wheel as the first shaft center line speed.
The vehicle speed estimation device for driving and emergency braking conditions provided in this embodiment may implement the above method embodiment, and its implementation principle and technical effects are similar and will not be described herein.
The various modules in the vehicle speed estimation device for driving and emergency braking conditions described above may be implemented in whole or in part by software, hardware, and combinations thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.
In one embodiment, a computer device is provided comprising a memory and a processor, the memory having stored therein a computer program, the processor when executing the computer program performing the steps of:
Determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
determining a first shaft centerline speed based on the shaft centerline speeds and the braking conditions of the driven wheels in each wheel;
estimating a longitudinal speed of the vehicle based on the first shaft centerline speed; the longitudinal speed is a speed in a direction parallel to the vehicle traveling direction.
In one embodiment, the processor when executing the computer program further performs the steps of:
the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and the state information of the vehicle's anti-lock braking system.
In one embodiment, the processor when executing the computer program further performs the steps of:
if the state information of the anti-lock braking system indicates that the anti-lock braking system is in a non-starting state; the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
In one embodiment, the processor when executing the computer program further performs the steps of:
if the state information of the anti-lock braking system indicates that the anti-lock braking system is in a starting state; determining a longitudinal speed of the brake antilock system in a non-activated state as an initial longitudinal speed of the vehicle;
Determining an intermediate longitudinal speed of the vehicle based on the initial longitudinal speed and the longitudinal acceleration of the vehicle;
determining a longitudinal speed according to the intermediate longitudinal speed and the second shaft centerline speed; the second shaft centerline speed is the maximum shaft centerline speed among the shaft centerline speeds.
In one embodiment, the processor when executing the computer program further performs the steps of:
comparing the middle longitudinal speed with the second shaft center line speed to obtain a comparison result;
if the comparison result shows that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to execute the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle;
if the comparison indicates that the intermediate longitudinal speed is greater than or equal to the second shaft centerline speed, the intermediate longitudinal speed is determined to be the longitudinal speed.
In one embodiment, the processor when executing the computer program further performs the steps of:
if the driven wheels are not braked, determining an average value of shaft center line speeds corresponding to the driven wheels as a first shaft center line speed;
if the driven wheels are braked, determining the maximum shaft center line speed in the shaft center line speeds as a first shaft center line speed;
If any one of the driven wheels is not braked, the shaft center line speed corresponding to the non-braked driven wheel is determined to be the first shaft center line speed.
In one embodiment, a computer readable storage medium is provided having a computer program stored thereon, which when executed by a processor, performs the steps of:
determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
determining a first shaft centerline speed based on the shaft centerline speeds and the braking conditions of the driven wheels in each wheel;
estimating a longitudinal speed of the vehicle based on the first shaft centerline speed; the longitudinal speed is a speed in a direction parallel to the vehicle traveling direction.
In one embodiment, the computer program when executed by the processor further performs the steps of:
the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and the state information of the vehicle's anti-lock braking system.
In one embodiment, the computer program when executed by the processor further performs the steps of:
if the state information of the anti-lock braking system indicates that the anti-lock braking system is in a non-starting state; the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
In one embodiment, the computer program when executed by the processor further performs the steps of:
if the state information of the anti-lock braking system indicates that the anti-lock braking system is in a starting state; determining a longitudinal speed of the brake antilock system in a non-activated state as an initial longitudinal speed of the vehicle;
determining an intermediate longitudinal speed of the vehicle based on the initial longitudinal speed and the longitudinal acceleration of the vehicle;
determining a longitudinal speed according to the intermediate longitudinal speed and the second shaft centerline speed; the second shaft centerline speed is the maximum shaft centerline speed among the shaft centerline speeds.
In one embodiment, the computer program when executed by the processor further performs the steps of:
comparing the middle longitudinal speed with the second shaft center line speed to obtain a comparison result;
if the comparison result shows that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to execute the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle;
if the comparison indicates that the intermediate longitudinal speed is greater than or equal to the second shaft centerline speed, the intermediate longitudinal speed is determined to be the longitudinal speed.
In one embodiment, the computer program when executed by the processor further performs the steps of:
if the driven wheels are not braked, determining an average value of shaft center line speeds corresponding to the driven wheels as a first shaft center line speed;
if the driven wheels are braked, determining the maximum shaft center line speed in the shaft center line speeds as a first shaft center line speed;
if any one of the driven wheels is not braked, the shaft center line speed corresponding to the non-braked driven wheel is determined to be the first shaft center line speed.
In one embodiment, a computer program product is provided comprising a computer program which, when executed by a processor, performs the steps of:
determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
determining a first shaft centerline speed based on the shaft centerline speeds and the braking conditions of the driven wheels in each wheel;
estimating a longitudinal speed of the vehicle based on the first shaft centerline speed; the longitudinal speed is a speed in a direction parallel to the vehicle traveling direction.
In one embodiment, the computer program when executed by the processor further performs the steps of:
the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and the state information of the vehicle's anti-lock braking system.
In one embodiment, the computer program when executed by the processor further performs the steps of:
if the state information of the anti-lock braking system indicates that the anti-lock braking system is in a non-starting state; the longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
In one embodiment, the computer program when executed by the processor further performs the steps of:
if the state information of the anti-lock braking system indicates that the anti-lock braking system is in a starting state; determining a longitudinal speed of the brake antilock system in a non-activated state as an initial longitudinal speed of the vehicle;
determining an intermediate longitudinal speed of the vehicle based on the initial longitudinal speed and the longitudinal acceleration of the vehicle;
determining a longitudinal speed according to the intermediate longitudinal speed and the second shaft centerline speed; the second shaft centerline speed is the maximum shaft centerline speed among the shaft centerline speeds.
In one embodiment, the computer program when executed by the processor further performs the steps of:
comparing the middle longitudinal speed with the second shaft center line speed to obtain a comparison result;
if the comparison result shows that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to execute the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle;
If the comparison indicates that the intermediate longitudinal speed is greater than or equal to the second shaft centerline speed, the intermediate longitudinal speed is determined to be the longitudinal speed.
In one embodiment, the computer program when executed by the processor further performs the steps of:
if the driven wheels are not braked, determining an average value of shaft center line speeds corresponding to the driven wheels as a first shaft center line speed;
if the driven wheels are braked, determining the maximum shaft center line speed in the shaft center line speeds as a first shaft center line speed;
if any one of the driven wheels is not braked, the shaft center line speed corresponding to the non-braked driven wheel is determined to be the first shaft center line speed.
Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, database, or other medium used in the various embodiments provided herein may include at least one of non-volatile and volatile memory. The nonvolatile Memory may include Read-Only Memory (ROM), magnetic tape, floppy disk, flash Memory, optical Memory, high density embedded nonvolatile Memory, resistive random access Memory (ReRAM), magnetic random access Memory (Magnetoresistive Random Access Memory, MRAM), ferroelectric Memory (Ferroelectric Random Access Memory, FRAM), phase change Memory (Phase ChangeMemory, PCM), graphene Memory, and the like. Volatile memory can include random access memory (Random Access Memory, RAM) or external cache memory, and the like. By way of illustration, and not limitation, RAM can be in the form of a variety of forms, such as Static Random access memory (Static Random access memory AccessMemory, SRAM) or dynamic Random access memory (Dynamic Random Access Memory, DRAM), and the like. The databases referred to in the various embodiments provided herein may include at least one of relational databases and non-relational databases. The non-relational database may include, but is not limited to, a blockchain-based distributed database, and the like. The processors referred to in the embodiments provided herein may be general purpose processors, central processing units, graphics processors, digital signal processors, programmable logic units, quantum computing-based data processing logic units, etc., without being limited thereto.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.

Claims (10)

1. A method of estimating vehicle speed for driving and emergency braking conditions, the method comprising:
determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
determining a first axle centerline speed based on each of the axle centerline speeds and a braking condition of a driven wheel in each of the wheels;
estimating a longitudinal speed of the vehicle from the first shaft centerline speed; wherein the longitudinal speed is a speed in a direction parallel to the vehicle running direction.
2. The method of claim 1, wherein estimating the longitudinal speed of the vehicle from the first shaft centerline speed comprises:
a longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and state information of a brake antilock braking system of the vehicle.
3. The method of claim 2, wherein the antilock braking system is in a non-activated state if the status information of the antilock braking system indicates that the antilock braking system is in a non-activated state; the estimating the longitudinal speed of the vehicle based on the first shaft centerline speed and state information of a brake antilock braking system of the vehicle includes:
a longitudinal speed of the vehicle is estimated based on the first shaft centerline speed and a Kalman filtering algorithm.
4. The method of claim 2, wherein if the status information of the antilock brake system indicates that the antilock brake system is in an activated state; the estimating the longitudinal speed of the vehicle based on the first shaft centerline speed and state information of a brake antilock braking system of the vehicle includes:
determining a longitudinal speed of the anti-lock brake system in a non-activated state as an initial longitudinal speed of the vehicle;
Determining an intermediate longitudinal speed of the vehicle based on the initial longitudinal speed and a longitudinal acceleration of the vehicle;
determining the longitudinal speed according to the intermediate longitudinal speed and the second shaft centerline speed; the second shaft centerline speed is a maximum shaft centerline speed of the shaft centerline speeds.
5. The method of claim 4, wherein said determining said longitudinal speed from said intermediate longitudinal speed and a second axis centerline speed comprises:
comparing the intermediate longitudinal speed with the second shaft center line speed to obtain a comparison result;
if the comparison result indicates that the intermediate longitudinal speed is smaller than the second shaft center line speed, determining the second shaft center line speed as a new initial longitudinal speed, and returning to the step of determining the intermediate longitudinal speed of the vehicle according to the initial longitudinal speed and the longitudinal acceleration of the vehicle;
and if the comparison result indicates that the intermediate longitudinal speed is greater than or equal to the second shaft center line speed, determining the intermediate longitudinal speed as the longitudinal speed.
6. The method of any one of claims 1-5, wherein determining the first axle centerline speed based on each of the axle centerline speeds and a braking condition of the driven wheels in each of the wheels includes:
If the driven wheels are not braked, determining an average value of shaft center line speeds corresponding to the driven wheels as the first shaft center line speed;
if the driven wheels are braked, determining the maximum shaft center line speed in the shaft center line speeds as the first shaft center line speed;
and if any driven wheel in the driven wheels is not braked, determining the shaft center line speed corresponding to the non-braked driven wheel as the first shaft center line speed.
7. A vehicle speed estimation device for driving and emergency braking conditions, the device comprising:
the first determining module is used for determining the corresponding shaft center line speed of each wheel according to the wheel speed of each wheel of the vehicle;
the second determining module is used for determining the first shaft center line speed according to the shaft center line speeds and the braking conditions of driven wheels in the wheels;
an estimation module for estimating a longitudinal speed of the vehicle from the first shaft centerline speed; wherein the longitudinal speed is a speed in a direction parallel to the vehicle running direction.
8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor implements the steps of the method of any of claims 1 to 6 when the computer program is executed.
9. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 6.
10. A computer program product comprising a computer program, characterized in that the computer program, when being executed by a processor, implements the steps of the method of any of claims 1 to 6.
CN202310213731.3A 2023-02-28 2023-02-28 Vehicle speed estimation method under driving and emergency braking conditions Pending CN116513209A (en)

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Application Number Priority Date Filing Date Title
CN202310213731.3A CN116513209A (en) 2023-02-28 2023-02-28 Vehicle speed estimation method under driving and emergency braking conditions

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310213731.3A CN116513209A (en) 2023-02-28 2023-02-28 Vehicle speed estimation method under driving and emergency braking conditions

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CN116513209A true CN116513209A (en) 2023-08-01

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