CN102343912A - Method for estimating state during running process of automobile - Google Patents

Abstract

The invention discloses a method for estimating a state during a running process of an automobile. The method comprises the following steps: analyzing a driving feature of the automobile and establishing a motion model of the automobile; introducing a non-integrity constraint for establishing a velocity error estimating equation; estimating errors along side direction and vertical direction during the running process of the automobile on the basis of a velocity and three attitude angles of the automobile; and establishing a slip angle estimating equation of the automobile. The stability of the automobile during the running process can be judged according to the velocity error estimation and slip angle estimation. According to the method, the on-line detection for a front-wheel steering angle of a four-wheel automobile can be realized by utilizing the motion model of the automobile. By adopting the method for estimating the state during the running process of the automobile, the real-time calculation and monitoring for state parameters of the automobile during the running process can be realized, for supplying data reference to safety running of the automobile.

Description

Method for estimating state in a kind of vehicle traveling process

Technical field

The present invention relates to the method for estimating state in a kind of vehicle traveling process.

Background technology

Since vehicle sell parallel sail a period of time after, the front-wheel steering angle can because violent jolt, the chassis part wearing and tearing, to change chassis part, changing of tire etc. former thereby change.In case steering angle owing to any reason changes, just possibly produce such as abnormal tyre wearing and tearing, running out the way, consumption increase, bearing circle send out heavy, potential safety hazard such as vehicle is unstable.In addition, the estimation of sideslip angle has great importance for the horizontal Steady-State Control of automobile in the running car, and sideslip angle is excessive and tire can not provide enough friction force, can cause automobile that the accident of horizontal whipping even rollover takes place in big turning environment.Therefore, the accurate estimation of the horizontal speed of a motor vehicle and sideslip angle controls, realizes that with stable active safety is most important for the fault pre-alarming in the vehicle traveling process in the detection of front wheel steering angle and the vehicle traveling process.The detection of current automobile four-wheel location and deflection angle is adopted mostly and is turned on axle housing and the steering handwheel through special implement is fixed on, and belongs to the mode of static detection.In the process of running at high speed, owing to fault has taken place unpredictable situation, yet the mode of this static detection obviously can not satisfy the needs of realizing automobile active safety to automobile often, and fault-tolerance can not get ensureing, increased the danger of running car.

Summary of the invention

Technical matters to be solved by this invention is the method for estimating state that proposes in a kind of vehicle traveling process; Method for estimating state in this vehicle traveling process can calculate and monitor the state parameter in the vehicle traveling process in real time, for vehicle safety travel provides the data reference.

Technical solution of the present invention is following:

Method for estimating state in a kind of vehicle traveling process may further comprise the steps:

Step 1: set up vehicle motion model:

Set up truck carrier system of axes X _RY _RZ _R, select rear axle mid point M _rInitial point O as carrier coordinate system;

Selecting the right-hand lay of sensing automobile is X _RAxle is along automotive ordinate axis and to point to the direction that automobile advances be Y _RAxle, Z _RAxle sensing automobile zenith direction; Definition two-dimensional coordinate system X _IO _IY _I, make that this system of axes and navigation coordinate are the EO ' N planes of ENU, X _IPoint to east, Y _IEnergized north, X _IO _IY _IThe plane is the two-dimentional global coordinate system of automobile sport, and navigation coordinate is that ENU is the three-dimensional global coordinate system of automobile sport;

Vehicle motion model is expressed by following formula:

Be the pose vector of automobile back wheel in global coordinate system, v _yBe automobile back wheel speed, l is a wheelbase,

Be the virtual deflection angle of car load,

Direction of passage dish turn around parameters tester is measured, and θ is that the direction angle of automobile is a course angle;

Step 2: the state parameter in the vehicle traveling process is estimated

Described state parameter comprises estimating speed value v ' _y,

Automobile is that ENU is X at navigation coordinate _IY _IZ _IVelocity vector in the system is expressed as V _I=[v _e, v _n, v _u] ^T, v wherein _e, v _nAnd v _uEast orientation, north orientation and the sky of having represented carrier respectively are to speed;

V ' _y=sin θ cos ψ v _e+ cos θ cos ψ v _n+ sin ψ v _u, wherein ψ is pitch angle, wherein v _e, v _nAnd v _u, ψ and θ variable try to achieve through the measurement of GPS Integrated Navigation Instrument;

Passing judgment on the precision of estimating does

V wherein _yBe the automobile actual speed.

State parameter in the step 2 also comprises automobile lateral error estimated valve η _xWith vertical error estimated valve η _z:

$\left\{\begin{array}{c}{\mathrm{\η}}_x=(\cos \mathrm{\θ}\sin \mathrm{\γ}+\sin \mathrm{\θ}\sin \mathrm{\ψ}\sin \mathrm{\γ})v_e+(\cos \mathrm{\θ}\sin \mathrm{\ψ}\sin \mathrm{\γ}-\sin \mathrm{\ψ}\cos \mathrm{\γ})v_n-\cos \mathrm{\ψ}\sin \mathrm{\γ}{v}_u\\ {\mathrm{\η}}_z=(\cos \mathrm{\θ}\sin \mathrm{\γ}-\sin \mathrm{\θ}\sin \mathrm{\ψ}\cos \mathrm{\γ})v_e-(\cos \mathrm{\θ}\sin \mathrm{\ψ}\cos \mathrm{\γ}+\sin \mathrm{\θ}\sin \mathrm{\γ})v_n-\cos \mathrm{\ψ}\cos \mathrm{\γ}{v}_u\end{array}\right.$ Wherein, γ is a roll angle, η _xAnd η _zBe worth greatly more, show that the ruined degree of non-integrity constraint is high more, wherein roll angle γ tries to achieve through the GPS Integrated Navigation Instrument.

State parameter in the step 2 also comprises sideslip angle β,

l _rBe M _rThe distance of C, C is the centre of gravity of vehicle point,

Measure by the wheel steering parameter tester.

State parameter in the step 2 also comprises the front tyre deflection angle; The front tyre deflection angle comprises: interior front wheel steering angle

and outer front wheel steering angle

minimum turning radius when automobile dispatches from the factory are known, try to achieve

value according to

;

By the formula

obtained

d for the track, w is the width of the tire;

virtual steering angle and the front wheel

The relationship between

Utilize the corner φ of turn around parameters tester direction of measurement dish, through

Ask the virtual deflection angle of vehicle front Wherein, φ _MaxBe the maximum steering wheel angle of automobile, utilize again

With the vehicle motion model formula of considering sideslip angle Estimate the track T of running car ₃, utilize the GPS sensor in real time to draw the path of motion T of automobile ₄, compare T ₃And T ₄Degree of agreement to judge the route departure degree of automobile, it is wide that two trajector deviations exceed 2 tires, it is unusual to think that then motor turning angle mechanism takes place.

Parameter declaration:

θ is an intermediate quantity during model is set up, and can obtain this value through model, but can not be worth the substitution Model Calculation with this, and the base quantity of model is v _y, l and

Speed of a motor vehicle vy gets through speed of a motor vehicle instrumentation, and wheelbase l is a known quantity, deflection angle

Direction of passage dish parameter tester is tried to achieve, and then model can operate.

φ is a steering wheel angle, can directly be measured by the steering wheel angle tester;

is the virtual deflection angle of front-wheel; Promptly suppose the corner when the automotive ordinate axis direction has individual virtual tire, can direction of passage dish corner φ and formula 22 in reduction ratio k try to achieve;

is the foreign steamer deflection angle of vehicle front;

is the interior wheel deflection angle of vehicle front;

Among this paper several kinds of parameters ask for the order:

At first direction of passage dish slew test appearance records steering wheel angle φ, and then this is " actual measured value " can then can to try to achieve interior front wheel steering angle

and outer front-wheel

through formula

in the hope of " the virtual deflection angle of front-wheel "

in the automobile actual travel process;

Then through the minimum turning radius can find the car front wheel steering angle and the outer front wheel

" theoretical value ";

Through the contrast of actual " observed reading " and " standard value ", judge the motoring condition of automobile at last.Beneficial effect:

Method for estimating state in the vehicle traveling process of the present invention has the following advantages:

1) among the present invention with navigation coordinate system global coordinate system as automobile; For the motoring condition of automobile is introduced longitude, latitude and height value; And the speed of east, north, day three directions is equivalent; Can utilize external sensor to portray the motoring condition of automobile by actv., thereby when having avoided the automobile autonomous positioning, the shortcoming that sensor error can accumulate.

2) adopt indirect sensors that some parameters of automobile self are carried out On-line Estimation among the present invention, need automobile not stopped on the monitor station, adopt the direct method of measurement to detect then.The advantage that has that detection speed is fast, cost is low, can online detection, the active safety that helps realizing automobile with give warning in advance function.

3) vehicle motion model of setting up among the present invention is a R point with the automobile hind axle center not merely, carries out modeling and selected center of gravity of the automobile to put as a reference simultaneously.Go to the automobile Ordinary road simultaneously and, set up two models respectively, considered the factor of sideslip angle of vehicle, provided the method for estimation of sideslip angle, improved the particularity of vehicle motion model in two kinds of situation of deep camber travels down.

4) the present invention utilizes the mode of vehicle self original place rotation to carry out the fault detection of front-wheel steering locking angle, is suitable for not having equipment to be used for detecting in real time the situation of vehicle front deflection angle.

5) among the present invention car model is introduced non-integrity constrains, be used for estimating the size of the cross velocity error in the running car, pass judgment on the ruined degree of non-integrity constraint, and then can be used for estimating the state of vehicle '.The travel situation of the big expression automobile of error is comparatively complicated, and automobile chassis breaks down easily.

The present invention is the presence method of estimation in a kind of vehicle traveling process; Can remedy the shortcoming that automobile need stop and detect; Equipment Inspection has reduced the cost that detects by external sensor; Can improve the driving performance of automobile, increase the safety in the driving process, help ensureing chaufeur and passenger's safety.

Method for estimating state in the vehicle traveling process of the present invention is estimated to pass judgment on vehicle stability in the process of moving through speed course latitude error estimation, sideslip angle.The present invention can also utilize the kinematic model of automobile simultaneously, realizes the online detection of four-wheel automobile front wheel steering angle.The present invention utilizes external sensor equipment such as GPS/INS to estimate the state of running car; Has the advantage that cost is low, reliability is high; Can in the automobile normal running process, carry out real-time status and estimate, motoring condition comprises lateral error and side direction error and error estimate precision, Vehicle Side Slip Angle, front tyre deflection angle.The present invention can high efficiency, realize the motoring condition On-line Estimation cheaply, and provides estimated accuracy, helps improving the driving safety of automobile, for the active safety of realizing automobile provides the bottom service.

Description of drawings

Fig. 1 is automobile global coordinate system and local coordinate system scheme drawing among the present invention.

Fig. 2 is the horizontal model scheme drawing of automobile among the present invention when moving.

Fig. 3 is front-wheel steering locking angle method of inspection scheme drawing among the present invention.

Fig. 4 is the state estimation diagram of circuit in the vehicle traveling process among the present invention.

Fig. 5 among the present invention based on the automobile orbital radius calculated examples of kinematics model.

Fig. 6 is Vehicle Side Slip Angle calculated examples among the present invention.

Fig. 7 measures track and calculates track comparison diagram (unit: m) for GPS.

Fig. 8 is side direction error η _xWith vertical error η _zResult of calculation.

Fig. 9 is for estimating the speed of a motor vehicle, actual vehicle speed and error contrast thereof.

The specific embodiment

Below will combine accompanying drawing and specific embodiment that the present invention is explained further details:

Vehicle front deflection angle method of inspection and motoring condition method of estimation concrete steps are following:

The first step is set up vehicle motion model generally speaking.

Set up truck carrier system of axes X _RY _RZ _R, select rear axle mid point M _rInitial point O as carrier coordinate system.Selecting the right-hand lay of sensing automobile is X _RAxle is along automotive ordinate axis and to point to the direction that automobile advances be Y _RAxle, Z _RAxle sensing automobile zenith direction.Definition two-dimensional coordinate system X _IO _IY _I, make that this system of axes and navigation coordinate are the EO ' N planes of ENU, X _IPoint to east (E axle), Y _IEnergized north (N axle).Like this, X _IO _IY _IThe plane is the two-dimentional global coordinate system of automobile sport, and navigation coordinate is that ENU is the three-dimensional global coordinate system of automobile sport, and the system of axes scheme drawing is as shown in Figure 1.

As shown in Figure 2, wheelbase is l, and d is a wheelspan, and the vehicle commander is L, and overall width is W, and tyre width is w, and the car total mass is m.Front wheel steering angle comprises: the deflection angle

of the deflection angle of interior wheel foreign steamer is the virtual deflection angle of car load; Deflection angle when soon two front-wheels are regarded a wheel as can be measured by direction of passage dish turn around parameters tester.If centre of gravity of vehicle is the C point, M _rC and M _fThe distance of C is respectively l _rAnd l _f, and l=l is arranged _r+ l _f

Point I is the instantaneous center of turn of automobile; The minimum turning radius of automobile is

(distance between ID; In like manner

is distance between IA,

be distance between IB).Transverse slip does not take place during Vehicular turn, and four wheels all should rotate around an I.Therefore, have the relation that needs between

wheel turning angle

and

to satisfy to be:

If known, the minimum turning radius car

is the maximum front axle steering angle

is:

Definition M _rAt X _IO _IY _ICoordinate in the plane is (x _r, y _r), its position in ENU is by (B _r, L _r, H _r) expression, i.e. warp, latitude and height value.X _IO _IY _IAnd X _ROY _RBetween differential seat angle be the direction θ of automobile.Make ζ ^I=[x, y, θ] ^TFor automobile at X _IO _IY _IIn the pose vector.With quadrature rotation matrix R (θ) with two-dimensional coordinate system X _IOY _IBe mapped to two-dimensional coordinate system X _ROY _RIn, i.e. ζ ^R=R (θ) ζ ^I, otherwise ζ is arranged ^I=R (θ) ^-1ζ ^RWherein:

$R{\left(\mathrm{\θ}\right)}^{-1}=\left[\begin{array}{ccc}\cos \mathrm{\θ}& -\sin \mathrm{\θ}& 0\\ \sin \mathrm{\θ}& \cos \mathrm{\θ}& 0\\ 0& 0& 1\end{array}\right]---\left(3\right)$

If the car load speed of automobile is automobile back wheel speed v _y, along carrier coordinate system Y _RDirection.With M _rBe fixed point, in the Δ t time, the instantaneous distance of advancing of automobile is Δ s, then has

And by

Can get:

Relation between

is:

M _rThe pose vector do

M then _rAt global coordinate system X _IOY _IIn the pose equation of state be:

That is:

And then can be in the hope of the position of any time centre of gravity of vehicle C by formula (8).

$\left\{\begin{array}{c}{x}_c=x_r+l_r\cos \mathrm{\θ}\\ y_c=y_r+l_r\sin \mathrm{\θ}\end{array}\right.---\left(8\right)$

In second step, transverse state is estimated in the running car.

Vehicle receives the restriction of both direction in motion process: if ground does not take place to break away or jump out of, then the vehicle ground speed the side direction of car body and with car body axis normal, the velocity projections pointed on the roof direction be zero.For the vehicle of cruising on road, do not break away basically, or it is very little to break away, wheel is close proximity to ground all the time, exists in the reality and takeoffs and skid, and can regard it as noise.Make V _R=[v _x, v _y, v _z] ^TFor automobile at X _RY _RZ _RIn velocity vector, if the hypothesis vehicle can not takeoff from ground, can not skid on the ground, be i.e. vehicle vertical direction (Z _RAxle) speed v _zBe 0, perpendicular to working direction (Y _RAxle) speed v _xBe 0, so the velocity vector of automobile can be expressed as V _R=[0, v _y, 0] ^T(the v here _yBe the speed of vehicle miles counter)

Yet automobile is in the middle of actual motion, because the vibration of automobile or sideslip, these constrain in a way and all have been destroyed.Consider the ruined situation of non-integrity constraint, promptly have: v _x-η _x=0 and v _z-η _z=0, η _xAnd η _zBe noise.Can find out that the power of noise has been represented the ruined degree of the non-integrity constraint of automobile.

Automobile is ENU (X at navigation coordinate _IY _IZ _ISystem) velocity vector in can be expressed as V _I=[v _e, v _n, v _u] ^T, v wherein _e, v _nAnd v _uEast orientation, north orientation and the sky of having represented carrier respectively are to speed.Utilize (the X of navigation coordinate system _IY _IZ _ISystem) to carrier coordinate system (X _RY _RZ _RSystem) attitude transition matrix

Can get

Wherein, θ is a yaw angle, and ψ is a pitch angle, and γ is a roll angle.(variable v _e, v _n, v _uAnd θ, ψ, γ can try to achieve through the GPS Integrated Navigation Instrument)

And then can get:

$\left[\begin{array}{c}{\mathrm{\η}}_x\\ v_y\\ {\mathrm{\η}}_z\end{array}\right]=C_n^b\left[\begin{array}{c}{v}_e\\ v_n\\ v_u\end{array}\right]---\left(9\right)$

Further calculating can get:

$\left\{\begin{array}{c}{\mathrm{\η}}_x=(\cos \mathrm{\θ}\sin \mathrm{\γ}+\sin \mathrm{\θ}\sin \mathrm{\ψ}\sin \mathrm{\γ})v_e+(\cos \mathrm{\θ}\sin \mathrm{\ψ}\sin \mathrm{\γ}-\sin \mathrm{\ψ}\cos \mathrm{\γ})v_n-\cos \mathrm{\ψ}\sin \mathrm{\γ}{v}_u\\ {\mathrm{\η}}_z=(\cos \mathrm{\θ}\sin \mathrm{\γ}-\sin \mathrm{\θ}\sin \mathrm{\ψ}\cos \mathrm{\γ})v_e-(\cos \mathrm{\θ}\sin \mathrm{\ψ}\cos \mathrm{\γ}+\sin \mathrm{\θ}\sin \mathrm{\γ})v_n-\cos \mathrm{\ψ}\cos \mathrm{\γ}{v}_u\end{array}\right.---\left(10\right)$

v _y＝sinθcosψv _e+cosθcosψv _n+sinψ _v (11)

It is thus clear that we can be according to v _e, v _n, v _uAnd the attitude angle information calculations goes out noise η _xAnd η _zThereby, estimate car behaviour (as: automobile lateral error estimated valve η _xWith vertical error estimated valve η _z).Through the v ' that estimates _yThe value, and with automobile actual speed v _yCompare, the precision of passing judgment on estimation does Precision is high more, the horizontal lateral deviation error estimate of automobile η _xWith vertical error estimated valve η _zCredible more.

In the 3rd step, the cross side drift angle is estimated in the running car.

The car model of setting up in the first step is kinematic model (at the less road driving of curvature) generally speaking, speed of a motor vehicle v _yAlong automotive ordinate axis direction (Y _RAxle).Advance on ring road yet work as automobile, the observation speed that this moment, C was ordered is not along the automotive ordinate axis direction, but and Y _RA differential seat angle β is arranged, and definition β is the sideslip angle of automobile, and this moment, the course angle λ of automobile was: the course angle during automobile normal running is θ; When break away taking place, can produce angle of side slip β, this moment automobile single-piece course angle be normal value θ and β and; Making it is λ, promptly has:

λ＝θ+β (12)

At Δ ICM _fIn, have following formula (13) to set up:

And then can get:

Abbreviation can get:

At Δ ICM _rIn, have following formula to set up:

$\frac{\sin \mathrm{\β}}{l_r}=\frac{1}{\mathrm{\ρ}}---\left(16\right)$

That is:

$\sin \mathrm{\β}=\frac{l_r}{\mathrm{\ρ}}---\left(17\right)$

By (15) and (17) Shi Kede:

The computing formula of sideslip angle β (19) is as follows:

This moment, the kinematic model formula (7) of automobile considered that the factor of sideslip angle should be revised as:

The 3rd step revised kinematics model in the automobile actual travel process, had increased the sideslip angle factor.Automobile can estimate the sideslip angle β of automobile in the process of moving in real time.The sideslip angle of automobile is the another important state in the vehicle traveling process, and the side slip angle β that accurately estimates automobile has great importance for the horizontal Steady-State Control of automobile.

The 4th step, the detection of running car front tyre deflection angle.

Automobile is in going for a long time, and the accurate coupling of steering wheel angle and tire deflection angle has vital function for the horizontal Steady-State Control of automobile.Therefore before going, need detect the front-wheel steering locking angle.Adopt the mode of vehicle self original place rotation to carry out among the present invention.As shown in Figure 3; Select a level ground; At first the bearing circle conter clockwise " is killed " (making deflection angle or

maximum), keep low speed driving in the original place.

is known for minimum turning radius when automobile dispatches from the factory, and can be worth in the hope of

according to formula (2).Under the low speed situation,, can calculate the path of motion T of automobile according to the kinematic model (7) and the initial position coordinate of automobile ₁And can draw out automobile actual motion track T accurately by the GPS sensor ₂, compare T ₁And T ₂Degree of agreement so that pass judgment on the particularity of kinematic model (7).

By the formula (1) can be obtained

and then the

can be obtained

empathy can be obtained

and

Shown in Figure 3 is the track of automobile sport, four concentrically ringed radiuses of measured automobiles track, from outside be designated as r inward respectively ₁, r ₂, r ₃And r ₄Next with

of the derivation of equation with compare; Thereby calculate the actual value of front-wheel steering locking angle (front wheel steering angle is taken turns deflection angle

and foreign steamer deflection angle

in comprising) and the deviation between the theoretical value; And then whether the state that can estimate vehicle steering mechanism is normal, and its value and deviation should meet the technical index that vehicle manufacturer provides.

According to the regulation among standard GB 18565-2001 " commerial vehicle Combination property require and the method for inspection " and the GB7258-2004 " self-propelled vehicle safe in operation engineering factor ": " minimum turning diameter of vehicle; former foreign steamer track line of centers is base measurement, and its value must not be greater than 24m.The steering locking angle of wheel flutter should meet the relevant technologies condition of this fixed car of former factory rules and regulations.Therefore, measure value 2r ₁Represent the steering hardware mal greater than 24m, can be through formula (2) by r ₁Inverse is tried to achieve steering locking angle

The Specification that its value and deviation must meet vehicle when dispatching from the factory.When the standard value that provides when testing result and manufacturer has than mistake, explain that fault has appearred in steering hardware or suspension system.

The 5th step, the state estimation in the vehicle traveling process.

Utilize the turn around parameters tester, corner and these two dynamical parameteies of vehicle front deflection angle

that can the direction of measurement dish.The input computing machine also utilizes vehicle motion model formula (19) and (20 of setting up in the 3rd step), can in vehicle traveling process, estimate the track T that goes ₃, utilize the GPS sensor can draw the estimation T of automobile in real time ₄, compare T ₃And T ₄Degree of agreement can judge the route departure degree of automobile.

Utilize the formula (10) in second step, can estimate the cross velocity error η in the running car _xWith vertical velocity error η _zSize, precision is evaluated through formula (21).

η _xAnd η _zBe worth greatly more, show that the ruined degree of non-integrity constraint is high more.

Automobile in the process of moving, sideslip angle can be estimated through formula (19) in real time.Provide below

Concrete calculated examples.

Embodiment 1:

With homemade Changfeng cheetah CFA6470MA cross-country car is example, and its parameter is seen table 1.

Principal parameter (the unit: mm) of table 1CFA6470MA cross-country car

Can try to achieve deflection angle according to the vehicle parameter in the table 1 and formula (1) and (2) is 24.786 °; In like manner can get

is 33.093 ° (steering locking angles), and then can to get virtual corner

be 28.393 °.Further can calculate

and be 5901.2mm; is 4071.2mm, and

is 4899.0mm.Each radius of Theoretical Calculation is as shown in Figure 5.

The comparison of table 2 orbital radius observed reading and theoretical value

During the automobile pivot stud, outmost turns automobile track is measured, data are seen table 2; Minimum turning radius is 6195.7mm; It is 35.2607 ° that inverse gets the automobile steering locking angle: and theoretical turn radius is 6500mm, desirable steering locking angle is 33 °, error is 304.3mm; Error meets the correlation technique index in 2 motor tire wide regions.

The comparison diagram of track that Fig. 7 draws for gps data and kinematics formula to calculating track, Fig. 8 are the side direction error η that calculates _xWith vertical velocity error η _zSize, Fig. 9 is for estimating speed of a motor vehicle v ' _y, actual vehicle speed v _y, and error v _y-v ' _yFig. 8 black line is seen in contrast.The result of calculation of Vehicle Side Slip Angle shown in the table 3, average Vehicle Side Slip Angle are 0.59 degree.Table 4 is the status data statistics, actual vehicle speed with estimate speed of a motor vehicle error average out to 3.9m/s, the estimated accuracy aviation value is about 70%, can degree of precision draw the error estimate that obtains among Fig. 8.Side direction error η during running car _xBe 0.0271m/s, vertical error η _zBe about 0.1978m/s, standard deviation is 0.1915, and the experiment route is comparatively steady.

Aforementioned calculation result shows that this instance is chosen in comparatively smooth playground, ground to carry out, and the ground drying does not have tangible lateral deviation to take place, and automobile is along the circle orbiting motion.

Table 3 Vehicle Side Slip Angle test figures

Status data statistical value in table 4 vehicle '

Embodiment 2

The automobile sport that proposed among the present invention learn in the model important parameters be the virtual deflection angle of front-wheel

but its value direction of passage dish slew test appearance measure; At first measuring the angle that bearing circle rotates is φ, then its with the deflection angle

of vehicle front between relation is

wherein k be the reduction ratio of automobile steering system.And the k value can obtain from the automotive technology index.In the vehicle index that has, there is not the reduction ratio parameter, also can be through test determination, measuring method is: the maximum steering wheel angle φ after this car bearing circle is killed _Max, then through trying to achieve deflection angle according to minimum turning radius in the table 1 and formula (2) Be 0.5192 (29.751 °), can get by formula (1)

Be 0.7449 (42.680 °).

is steering locking angle at this moment, then can get reduction ratio and be:

Claims (5)

1. the method for estimating state in the vehicle traveling process is characterized in that, may further comprise the steps:

Step 1: set up vehicle motion model:

Set up truck carrier system of axes X _RY _RZ _R, select rear axle mid point M _rInitial point O as carrier coordinate system;

Selecting the right-hand lay of sensing automobile is X _RAxle is along automotive ordinate axis and to point to the direction that automobile advances be Y _RAxle, Z _RAxle sensing automobile zenith direction; Definition two-dimensional coordinate system X _IO _IY _I, make that this system of axes and navigation coordinate are the EO ' N planes of ENU, X _IPoint to east, Y _IEnergized north, X _IO _IY _IThe plane is the two-dimentional global coordinate system of automobile sport, and navigation coordinate is that ENU is the three-dimensional global coordinate system of automobile sport;

Vehicle motion model is expressed by following formula:

Be the pose vector of automobile back wheel in global coordinate system, v _yBe automobile back wheel speed, l is a wheelbase,

Be the virtual deflection angle of car load, Direction of passage dish turn around parameters tester is measured, and θ is that the direction angle of automobile is a course angle;

Step 2: the state parameter in the vehicle traveling process is estimated

Described state parameter comprises estimating speed value v ' _y,

Automobile is that ENU is X at navigation coordinate _IY _IZ _IVelocity vector in the system is expressed as V _I=[v _e, v _n, v _u] ^T, v wherein _e, v _nAnd v _uEast orientation, north orientation and the sky of having represented carrier respectively are to speed;

V ' _y=sin θ cos ψ v _e+ cos θ cos ψ v _n+ sin ψ v _u, wherein ψ is pitch angle, wherein v _e, v _nAnd v _u, ψ and θ variable try to achieve through the measurement of GPS Integrated Navigation Instrument;

Passing judgment on the precision of estimating does

V wherein _yBe the automobile actual speed.

2. the method for estimating state in the vehicle traveling process according to claim 1 is characterized in that, the state parameter in the step 2 also comprises automobile lateral error estimated valve η _xWith vertical error estimated valve η _z:

$\left\{\begin{array}{c}{\mathrm{\η}}_x=(\cos \mathrm{\θ}\sin \mathrm{\γ}+\sin \mathrm{\θ}\sin \mathrm{\ψ}\sin \mathrm{\γ})v_e+(\cos \mathrm{\θ}\sin \mathrm{\ψ}\sin \mathrm{\γ}-\sin \mathrm{\ψ}\cos \mathrm{\γ})v_n-\cos \mathrm{\ψ}\sin \mathrm{\γ}{v}_u\\ {\mathrm{\η}}_z=(\cos \mathrm{\θ}\sin \mathrm{\γ}-\sin \mathrm{\θ}\sin \mathrm{\ψ}\cos \mathrm{\γ})v_e-(\cos \mathrm{\θ}\sin \mathrm{\ψ}\cos \mathrm{\γ}+\sin \mathrm{\θ}\sin \mathrm{\γ})v_n-\cos \mathrm{\ψ}\cos \mathrm{\γ}{v}_u\end{array}\right.$

Wherein, γ is a roll angle, η _xAnd η _zBe worth greatly more, show that the ruined degree of non-integrity constraint is high more, wherein roll angle γ tries to achieve through the GPS Integrated Navigation Instrument.

3. the method for estimating state in the vehicle traveling process according to claim 2 is characterized in that the state parameter in the step 2 also comprises sideslip angle β,

l _rBe M _rThe distance of C, C is the centre of gravity of vehicle point,

Measure by the wheel steering parameter tester.

4. the method for estimating state in the vehicle traveling process according to claim 3; It is characterized in that; State parameter in the step 2 also comprises the front tyre deflection angle; The front tyre deflection angle comprises: interior front wheel steering angle and outer front wheel steering angle

minimum turning radius when automobile dispatches from the factory

are known, try to achieve

value according to

;

By the formula

obtained

d as a track, w is the width of the tire;

virtual steering angle and the front wheel

The relationship between

5. the method for estimating state in the vehicle traveling process according to claim 4 is characterized in that,

Utilize the corner φ of turn around parameters tester direction of measurement dish, through

Ask the virtual deflection angle of vehicle front

Wherein, φ _MaxBe the maximum steering wheel angle of automobile, utilize again

With the vehicle motion model formula of considering sideslip angle

Estimate the track T of running car ₃, utilize the GPS sensor in real time to draw the path of motion T of automobile ₄, compare T ₃And T ₄Degree of agreement to judge the route departure degree of automobile, it is wide that two trajector deviations exceed 2 tires, it is unusual to think that then motor turning angle mechanism takes place.

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