CN1862232A - System and method for estimating side drift angle of motor vehicle - Google Patents

Abstract

The present invention relates to an automotive vehicle side slip angle estimation system and its estimating method. Said system includes wheel angular speed acquisition unit, steering wheel angle sensor and side slip angle estimation unit. The wheel angular speed acquisition unit includes right front wheel angular speed sensor, left front wheel angular speed sensor, right rear wheel angular speed sensor and left rear wheel angular speed sensor. The side slip angle estimation unit is electrically connected with the described wheel angular speed acquisition unit and steering wheel angle sensor.

Description

The estimating system of side drift angle of motor vehicle and method of estimation

Technical field

The present invention relates to a kind of estimating system and method for estimation of side drift angle of motor vehicle, belong to motor vehicle control field.

Background technology

The side drift angle of motor vehicle is a considerable parameter in the control of motor vehicle control stability, but often can not directly measure with sensor.Usually need utilize other relevant parameter of various sensor measurements, just can estimate the side drift angle of motor vehicle in conjunction with certain algorithm.

Provided the method for motor vehicle calculation side drift angle commonly used at U.S. Pat P 6681180.An embodiment of this patent comprises a GPS receiver (GPS receiver) 22, two antennas (antenna) 26 of being installed on the motorcar body (vehicle) 10 and 28 and gyroscope (gyroscope) 34.Antenna 26 receives satellite 16A and the carrier wave 20A of 16B and the speed V ' that 20B can determine the horizontal direction of motor vehicle.Utilize antenna 26 and antenna 28 can determine the position angle of motor vehicle (heading angle) ψ.Gyroscope 34 is used for the yaw velocity (yaw rate) of measuring machine motor-car.

If the position of antenna 26 is the A point, on the motorcar body arbitrarily the position of any be the P point, can obtain the speed that P is ordered by following formula so:

In the formula, V _PBe the velocity that P is ordered, V _A=V ' is the velocity that A is ordered, i.e. the speed that records of antenna 26, Be the angular velocity vector of motor vehicle, comprise yaw velocity (yaw rate) component, rate of pitch (pitch rate) component and roll velocity (roll rate) component,

It is the distance vector that A point and P are ordered.Usually rate of pitch component and roll velocity component can be ignored, and therefore only need gyroscope 34 measuring machine motor-car yaw velocities to get final product.Equally, the distance component of vertical direction also has been left in the basket, and only considers the projection of distance vector in surface level.

Because the angle ψ that exists between motor vehicle coordinate system x-y coordinate system and the earth coordinates X-Y coordinate system (being the position angle of motor vehicle) can record, the therefore speed V of ordering of the P under earth coordinates _PCan be converted into two components---the V on the motor vehicle coordinate system _x ^PAnd V _y ^P, V _x ^PBe V _PAt the projection of x axle, V _y ^PBe V _PProjection at the y axle.

Therefore side drift angle (sideslip angle) β of any 1 P on the motorcar body _PCan try to achieve by following formula:

${\mathrm{\β}}_P={\tan }^{-1}\left(\frac{V_y^P}{V_x^P}\right)---\left(2\right)$

With the two-wheeled vehicle model is example, and the side drift angle of establishing the vehicle body of front-wheel position is β _f, the side drift angle of the vehicle body of trailing wheel position is β _r, front wheel steering angle is δ, and trailing wheel can not turn to, and the side drift angle of front tyre is so

α _f＝β _f-δ (3)

The side drift angle of rear tyre is

α _r＝β _r (4)

Can record the side drift angle of motor vehicle as mentioned above, but this method needs the more expensive gyroscope of price, can't use on economical motor vehicle, therefore very unfavorable to the reduction of motor vehicle cost.

Summary of the invention

The estimating system and the method for estimation that the purpose of this invention is to provide a kind of lower-cost side drift angle of motor vehicle.

Side drift angle of motor vehicle estimating system provided by the invention comprises angular speed of wheel collecting unit 20, steering wheel angle sensor 50, wherein also comprise side drift angle estimation unit 60, described angular speed of wheel collecting unit 20 comprises off-front wheel angular-rate sensor 21, the near front wheel angular-rate sensor 22, off hind wheel angular-rate sensor 23, left rear wheel angular-rate sensor 24; Described side drift angle estimation unit 60 is electrically connected with described angular speed of wheel collecting unit 20 and steering wheel angle sensor 50.A kind of employing system of the present invention carries out the side drift angle of motor vehicle estimation approach, comprising:

(1) carries out the collection of each sensor signal, gather off-front wheel angular velocity w from the off-front wheel angular-rate sensor ₁, gather the near front wheel angular velocity w from the near front wheel angular-rate sensor ₂, gather off hind wheel angular velocity w from the off hind wheel angular-rate sensor ₃, gather left rear wheel angular velocity w from the left rear wheel angular-rate sensor ₄, gather steering wheel angle φ from steering wheel angle sensor;

(2) according to the steering angle sigma of formula (1) calculating front wheels of motor-vehicles, wherein, k is the steering reduction gear ratio;

δ＝/k (1)

(3) calculate intermediate variable a, b and c according to formula (2), (3), (4), wherein, T is the wheel for motor vehicle distance;

a＝sinδ， (2)

b＝cosδ， (3)

$c=\frac{w_3-w_4}{T}---\left(4\right)$

(4) calculate off-front wheel side drift angle α according to formula (5), (6) ₁With the near front wheel side drift angle α ₂

${\mathrm{\α}}_1=\frac{{\mathrm{bw}}_1-w_3}{{\mathrm{aw}}_1}---\left(5\right)$

${\mathrm{\α}}_2=\frac{{\mathrm{bw}}_2-w_4}{{\mathrm{aw}}_2}---\left(6\right)$

(5) calculate off hind wheel side drift angle α according to formula (7), (8) ₃With left rear wheel side drift angle α ₄, wherein, L is the motor vehicle wheelbase.

${\mathrm{\α}}_3=\frac{{\mathrm{bw}}_1{\mathrm{\α}}_1+{\mathrm{aw}}_1-\mathrm{cL}}{w_3}---\left(7\right)$

${\mathrm{\α}}_4=\frac{{\mathrm{bw}}_2{\mathrm{\α}}_2+{\mathrm{aw}}_2-\mathrm{cL}}{w_4}---\left(8\right)$

System provided by the invention and employing native system are estimated the method for side drift angle of motor vehicle, have saved expensive gyroscope, and the cost of motor vehicle calculation side drift angle is descended.Particularly, on motor vehicle, need not add any hardware, it can be applied on economical motor vehicle, solve the problem that side drift angle of motor vehicle needs expensive device of calculating with ABS and ESP.

Description of drawings

Fig. 1 is the composition synoptic diagram according to side drift angle of motor vehicle estimating system of the present invention;

Fig. 2 is the synoptic diagram of the kinematic relation of expression four-wheeled vehicle;

Fig. 3 is the side drift angle estimating system structural representation of expression four-wheeled vehicle;

Fig. 4 is that expression side drift angle estimation unit carries out the step that side drift angle is estimated.

Embodiment

The invention will be further described below in conjunction with the drawings and specific embodiments:

According to side drift angle of motor vehicle estimating system provided by the invention, as shown in Figure 1, comprise angular speed of wheel collecting unit 20, steering wheel angle sensor 50, wherein also comprise side drift angle estimation unit 60, described angular speed of wheel collecting unit 20 comprises off-front wheel angular-rate sensor 21, the near front wheel angular-rate sensor 22, off hind wheel angular-rate sensor 23, left rear wheel angular-rate sensor 24; Described steering wheel angle sensor 50 is used for direction of measurement dish rotational angle; Described side drift angle estimation unit 60 is electrically connected with described angular speed of wheel collecting unit 20 and steering wheel angle sensor 50, is used to calculate side drift angle of motor vehicle.

Shown in Figure 2 is the kinematic relation of four-wheeled vehicle, and the implication of each symbol representative is as follows among the figure

The X-axis of X---motor vehicle, promptly motor vehicle is vertical,

The Y-axis of Y---motor vehicle, promptly motor vehicle is horizontal,

The steering angle of δ---front-wheel,

α ₁---the off-front wheel side drift angle,

α ₂---the near front wheel side drift angle,

α ₃---the off hind wheel side drift angle,

α ₄---the left rear wheel side drift angle,

V ₁---the speed of off-front wheel wheel center,

V _1x---the longitudinal velocity of off-front wheel wheel center, i.e. the speed V of off-front wheel wheel center ₁Component on X-axis,

V _1y---the transverse velocity of off-front wheel wheel center, i.e. the speed V of off-front wheel wheel center ₁Component on Y-axis,

V _1w---the speed V of off-front wheel wheel center ₁Component on the off-front wheel wheel plane,

V ₂---the speed of the near front wheel wheel center,

V _2x---the longitudinal velocity of the near front wheel wheel center, i.e. the speed V of the near front wheel wheel center ₂Component on X-axis,

V _2y---the transverse velocity of the near front wheel wheel center, i.e. the speed V of the near front wheel wheel center ₂Component on Y-axis,

V _2w---the speed V of the near front wheel wheel center ₂Component on the near front wheel wheel plane,

V ₃---the speed of off hind wheel wheel center,

V _3w=V _3x---the speed V of off hind wheel wheel center ₃Component on the off hind wheel wheel plane equals the speed V of off hind wheel wheel center ₃Component on X-axis, i.e. the longitudinal velocity of off hind wheel wheel center,

V _3y---the transverse velocity of off hind wheel wheel center, i.e. the speed V of off hind wheel wheel center ₃Component on Y-axis,

V ₄---the speed of left rear wheel wheel center,

V _4w=V _4x---the speed V of left rear wheel wheel center ₄Component on the left rear wheel wheel plane equals the speed V of left rear wheel wheel center ₄Component on X-axis, the i.e. longitudinal velocity of left rear wheel wheel center

V _4y---the transverse velocity of left rear wheel wheel center, i.e. the speed V of left rear wheel wheel center ₄Component on Y-axis,

The wheelspan of T---left and right wheels, its value can obtain from the operation instructions of motor vehicle, and can pre-deposit in the storer of motor vehicle,

L---the wheelbase of front and back axletree, its value can obtain from the operation instructions of motor vehicle, and can pre-deposit in the storer of motor vehicle,

W _r---the yaw velocity of motor vehicle.

As shown in Figure 3, the next door of the off-front wheel 11 of four-wheel automobile, the near front wheel 12, off hind wheel 13 and left rear wheel 14 is separately installed with off-front wheel angular-rate sensor 21, the near front wheel angular-rate sensor 22, off hind wheel angular-rate sensor 23 and left rear wheel angular-rate sensor 24.On the turning-bar 40 of bearing circle 30 steering wheel angle sensor 50 is installed.Angular speed of wheel sensor 21,22,23 and 24 is sent to side drift angle estimation unit 60 with the wheel 11,12,13 that collects and 14 tach signal; Steering wheel angle sensor 50 also is sent to side drift angle estimation unit 60 with the steering wheel angle signal that collects.Side drift angle estimation unit 60 with the side drift angle value output of each wheel of automobile of estimating, is controlled the control stability of automobile, thereby is guaranteed that automobile has good maneuvering performance after all signals of input are handled and calculated.

When driver's steering wheel rotation 30, the near front wheel 11 of motor vehicle and off-front wheel 12 all can turn over an angle.If the angle that bearing circle rotates is φ, between the steering angle sigma of it and front wheels of motor-vehicles following relation is arranged so

δ＝/k (1)

In the formula, the corner of φ---bearing circle,

The reduction gear ratio of k---steering.

Steering wheel angle sensor 50 can be measured the corner φ of motor vehicle steering wheel, and the reduction gear ratio k of motor vehicle steering system can obtain from the operation instructions of motor vehicle, and this value can pre-deposit in the storer of motor vehicle.Can obtain the steering angle sigma of front wheels of motor-vehicles by the corner φ that measures motor vehicle steering wheel according to formula (1).

The magnitude of angular velocity w that angular speed of wheel sensor 21,22,23 and 24 measures ₁, w ₂, w ₃And w ₄Expression, they are respectively and V so _1w, V _2w, V _3wAnd V _4wFollowing relation is arranged

$\left\{\begin{array}{c}{V}_{1w}=w_1\mathrm{<figure-callout\; id="2w"\; label="r\; V"\; filenames="A20051006933600171.png"\; state="\{\{state\}\}">r</figure-callout>}& \\ V_{}{}_{2w}=w_{2}r\\ V_{3w}=w_{3}r\\ V_{4w}=w_{4}r\end{array}\right.---\left(2\right)$

In the formula, the rolling radius of r---wheel.

Like this, utilize formula (2), the magnitude of angular velocity w of each wheel that the angular- rate sensor 21,22,23 and 24 by each wheel measures ₁, w ₂, w ₃And w ₄, just can be in the hope of each wheel center speed V ₁, V ₂, V ₃And V ₄Component V on its wheel plane _1w, V _2w, V _3wAnd V _4w

Can obtain the wheel center speed V of two front-wheels of motor vehicle thus ₁, V ₂

$\left\{\begin{array}{c}{V}_1=\frac{V_{1w}}{{\cos \mathrm{\&alpha;}}_1}\\ V_2=\frac{{\mathrm{<figure-callout\; id="2w"\; label="V"\; filenames="A20051006933600171.png"\; state="\{\{state\}\}">V</figure-callout>}}_{2w}}{\cos {\mathrm{\&alpha;}}_2}\end{array}\right.---\left(3\right)$

Further can obtain the longitudinal velocity V of two front-wheels of motor vehicle _1x, V _2xWith transverse velocity V _1y, V _2y

$\left\{\begin{array}{c}{V}_{1x}{=V}_1\cos ({\mathrm{\&alpha;}}_1+\mathrm{\&delta;})\\ V_{2x}=V_2\cos ({\mathrm{\&alpha;}}_2+\mathrm{\&delta;})\\ V_{1y}=V_1\sin ({\mathrm{\&alpha;}}_1+\mathrm{\&delta;})\\ V_{2y}=V_2\sin ({\mathrm{\&alpha;}}_2+\mathrm{\&delta;})\end{array}\right.---\left(4\right)$

The transverse velocity V of two trailing wheels of motor vehicle _3y, V _4yAlso can in the hope of

$\left\{\begin{array}{c}{V}_{3y}{=V}_{3w}\tan {\mathrm{\&alpha;}}_3\\ {\mathrm{<figure-callout\; id="4y"\; label="V"\; filenames="A20051006933600171.png"\; state="\{\{state\}\}">V</figure-callout>}}_{4y}=V_{4w}\tan {\mathrm{\&alpha;}}_4\end{array}\right.---\left(5\right)$

According to kinematic relation, the yaw velocity of motor vehicle can be tried to achieve by following formula

$w_r=\frac{V_{3x}-V_{4x}}{T}---\left(6\right)$

Because

$\left\{\begin{array}{c}{V}_{3x}=V_{3w}\\ V_{4x}=V_{4w}\end{array}\right.---\left(7\right)$

So can be write as after bringing formula (2) and formula (7) into formula (6)

$w_r=\frac{w_{3}r-w_{4}r}{T}---\left(8\right)$

According to the kinematic relation of motor vehicle, can list following equation

$\left\{\begin{array}{c}{V}_{1x}=V_{3x}\\ V_{2x}-=V_{4x}\\ V_{1y}-V_{3y}={\mathrm{Lw}}_r\\ V_{2y}-{\mathrm{<figure-callout\; id="4y"\; label="V"\; filenames="A20051006933600171.png"\; state="\{\{state\}\}">V</figure-callout>}}_{4y}={\mathrm{Lw}}_r\end{array}\right.---\left(9\right)$

Bringing formula (2), formula (3), formula (4) and formula (5) into formula (9) gets

$\left\{\begin{array}{c}\frac{w_{1}r\cos ({\mathrm{\&alpha;}}_1+\mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_1}{=w}_{3}r\\ \frac{w_{2}r\cos ({\mathrm{\&alpha;}}_2+\mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_2}=w_{4}r\\ \frac{w_{1}r\sin ({\mathrm{\&alpha;}}_1+\mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_1}-w_{3}r\tan {\mathrm{\&alpha;}}_3={\mathrm{Lw}}_r\\ \frac{w_{2}r\sin ({\mathrm{\&alpha;}}_2+\mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_2}-w_{4}r\tan {\mathrm{\&alpha;}}_4={\mathrm{Lw}}_r\end{array}\right.---\left(10\right)$

Utilize triangle formula formula (10) can be rewritten as

$\left\{\begin{array}{c}\frac{w_1(\cos {\mathrm{\&alpha;}}_1\cos \mathrm{\&delta;}-\sin {\mathrm{\&alpha;}}_1\sin \mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_1}{=w}_3\\ \frac{w_2({\cos \mathrm{\&alpha;}}_2\cos \mathrm{\&delta;}-\sin {\mathrm{\&alpha;}}_2\sin )}{\cos {\mathrm{\&alpha;}}_2}=w_4\\ \frac{w_{1}r(\sin {\mathrm{\&alpha;}}_1\cos \mathrm{\&delta;}+\cos {\mathrm{\&alpha;}}_1\sin \mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_1}-w_{3}r\tan {\mathrm{\&alpha;}}_3={\mathrm{Lw}}_r\\ \frac{w_{2}r(\sin {\mathrm{\&alpha;}}_2\cos \mathrm{\&delta;}+\cos {\mathrm{\&alpha;}}_2\sin \mathrm{\&delta;})}{\cos {\mathrm{\&alpha;}}_2}-w_{4}r\tan {\mathrm{\&alpha;}}_4={\mathrm{Lw}}_r\end{array}\right.---\left(11\right)$

Because side drift angle α ₁, α ₂, α ₃And α ₄All very little, so the trigonometric function of side drift angle can be done approximate processing, formula (11) can be similar to and be write as so

$\left\{\begin{array}{c}{w}_1\cos \mathrm{\&delta;}-w_1{\mathrm{\&alpha;}}_1\sin \mathrm{\&delta;}=w_3\\ w_2\cos \mathrm{\&delta;}-w_2{\mathrm{\&alpha;}}_2\sin \mathrm{\&delta;}=w_4\\ w_{1}r{\mathrm{\&alpha;}}_1\cos \mathrm{\&delta;}+w_{1}r\sin \mathrm{\&delta;}-w_{3}r{\mathrm{\&alpha;}}_3={\mathrm{Lw}}_r\\ w_{2}r{\mathrm{\&alpha;}}_2\cos \mathrm{\&delta;}+w_{2}r\sin \mathrm{\&delta;}-w_{4}r{\mathrm{\&alpha;}}_4={\mathrm{Lw}}_r\end{array}\right.---\left(12\right)$

Bring formula (1) and formula (8) into formula (12)

Because the angular velocity w of each wheel 11,12,13 and 14 ₁, w ₂, w ₃And w ₄Can measure by the angular- rate sensor 21,22,23 and 24 of each wheel, steering wheel angle φ can be measured by steering wheel angle sensor 50, the wheelspan T of motor vehicle, wheelbase L and steering retarded velocity k all can obtain in the operation instructions by motor vehicle, just can calculate the side drift angle α of each wheel of motor vehicle so according to formula (13) ₁, α ₂, α ₃And α ₄

From formula (13), it can also be seen that, calculate the side drift angle α of each wheel of motor vehicle ₁, α ₂, α ₃And α ₄Be the rolling radius r that does not need to know wheel, therefore,, write formula (13) as following form in order to reduce the operation times in side drift angle of motor vehicle estimating system 60

$\left\{\begin{array}{ccc}{\mathrm{bw}}_1-{\mathrm{aw}}_1{\mathrm{\&alpha;}}_1=w_3& 10& (14-1)\\ {\mathrm{bw}}_2-{\mathrm{aw}}_2{\mathrm{\&alpha;}}_2=w_4& & (14-2)\\ {\mathrm{bw}}_1{\mathrm{\&alpha;}}_1+{\mathrm{aw}}_1-{w_3\mathrm{\&alpha;}}_3=\mathrm{cL}& & (14-3)\\ {\mathrm{bw}}_2{\mathrm{\&alpha;}}_2+{\mathrm{aw}}_2-w_4{\mathrm{\&alpha;}}_4=\mathrm{cL}& & (14-4)\end{array}\right.---\left(14\right)$

In the formula, a=sin δ, (15)

b＝cosδ， (16)

Wherein δ is tried to achieve by formula (1) δ=/k,

$c=\frac{w_3-w_4}{T}.---\left(17\right)$

Further as can be seen, can directly obtain the side drift angle α of off-front wheel 11 from formula (14-1) ₁Come, in like manner also can directly obtain the side drift angle α of the near front wheel 12 by (14-2) ₂

${\mathrm{\&alpha;}}_1=\frac{{\mathrm{bw}}_1-w_3}{{\mathrm{aw}}_1}---\left(18\right)$

${\mathrm{\&alpha;}}_2=\frac{{\mathrm{bw}}_2-w_4}{{\mathrm{aw}}_2}---\left(19\right)$

Obtain the side drift angle α of off hind wheel 13 and left rear wheel 14 again by formula (14-3) and formula (14-4) ₃And α ₄

${\mathrm{\&alpha;}}_3=\frac{{\mathrm{bw}}_1{\mathrm{\&alpha;}}_1+{\mathrm{aw}}_1-\mathrm{cL}}{w_3}---\left(20\right)$

${\mathrm{\&alpha;}}_4=\frac{{\mathrm{bw}}_2{\mathrm{\&alpha;}}_2+{\mathrm{aw}}_2-\mathrm{cL}}{w_4}---\left(21\right)$

Side drift angle of motor vehicle estimating system provided by the invention, wherein said side drift angle estimation unit are used for according to each wheel 11,12,13 that receives and 14 angular velocity w ₁, w ₂, w ₃And w ₄And the wheelspan T of the preset parameter motor vehicle of motor vehicle, wheelbase L and steering retarded velocity k, by formula (1), formula (15)-Shi (21) calculates side drift angle of motor vehicle.

Side drift angle of motor vehicle estimating system provided by the invention, wherein, described side drift angle estimation unit is for carrying out the single-chip microcomputer of calculation side drift angle algorithm.It can be ECU (electronic control unit) in the car load control or the single-chip microcomputer among the ABS, and does not need additionally to acquire any hardware, only need get final product in the program that the side drift angle estimation unit loads operation calculation side drift angle algorithm.

In disposing the motor vehicle of ABS, do not need to dispose again the angular speed of wheel collecting unit, do not need to dispose again steering wheel angle sensor at the motor vehicle that disposes ESP.

Side drift angle of motor vehicle estimating system provided by the invention, wherein said angular speed of wheel collecting unit are preferably off-front wheel angular-rate sensor, the near front wheel angular-rate sensor, off hind wheel angular-rate sensor and the left rear wheel angular-rate sensor in the ABS of the motor vehicle that disposes ABS.

Side drift angle of motor vehicle estimating system provided by the invention, wherein said steering wheel angle sensor be preferably dispose the ESP motor vehicle in the steering wheel angle sensor of ESP.

Wherein, the calculation procedure that is loaded in the calculation side drift angle algorithm routine in the side drift angle estimation unit 60 as shown in Figure 4.

When step S100, begin the execution algorithm program.

Enter step S110 subsequently, motor vehicle parameter wheelbase L, wheelspan T and steering reduction gear ratio k are carried out initialization, the data of initialization values from store the motor vehicle storer in advance into obtain.This step only need be carried out once.

In step S120, carry out the collection of each sensor signal, obtain w1 from off-front wheel angular-rate sensor 21, obtain w2 from the near front wheel angular-rate sensor 22, obtain w3 from off hind wheel angular-rate sensor 23, obtain w4 from left rear wheel angular-rate sensor 24, also obtain φ from steering wheel angle sensor 50.

In step S 130, calculate the steering angle sigma of front wheels of motor-vehicles according to formula (1).

In step S140, calculate a, b and c according to formula (15), formula (16) and formula (17).

In step S150, calculate off-front wheel side drift angle α 1 and the near front wheel side drift angle α 2 according to formula (18) and formula (19).

In step S160, calculate off hind wheel side drift angle α 3 and left rear wheel side drift angle α 4 according to formula (20) and formula (21).

Turn back to step S120 subsequently and gather next sensor signal constantly, carry out the calculating of a new round.When returning, also in step S170, side drift angle α 1, α 2, α 3 and the α 4 that calculates exported.

According to side drift angle of motor vehicle estimating system of the present invention and method of estimation, what can not need costliness just can obtain side drift angle of motor vehicle as inertia devices such as gyroscopes, on automobile with ABS and ESP system, can not need to add any hardware and sensor and just can realize the function of this side drift angle estimating system, saved cost greatly, made it possess the possibility of on existing economical-type automobile, popularizing.

Claims (7)

1. side drift angle of motor vehicle estimating system comprises: the angular speed of wheel collecting unit, and steering wheel angle sensor wherein, also comprises the side drift angle estimation unit; The angular speed of wheel collecting unit comprises off-front wheel angular-rate sensor, the near front wheel angular-rate sensor, off hind wheel angular-rate sensor and left rear wheel angular-rate sensor; The side drift angle estimation unit is electrically connected with described angular speed of wheel collecting unit and steering wheel angle sensor.

2. side drift angle of motor vehicle estimating system according to claim 1, wherein, described angular speed of wheel collecting unit is included in off-front wheel angular-rate sensor, the near front wheel angular-rate sensor, off hind wheel angular-rate sensor and the left rear wheel angular-rate sensor of ABS in the motor vehicle that disposes ABS.

3. side drift angle of motor vehicle estimating system according to claim 1, wherein, described steering wheel angle sensor is the steering wheel angle sensor that disposes the ESP in the motor vehicle of ESP.

4. side drift angle of motor vehicle estimating system according to claim 1, wherein, described side drift angle estimation unit is for carrying out the single-chip microcomputer of calculation side drift angle algorithm.

5. side drift angle of motor vehicle estimating system according to claim 4, wherein, described side drift angle estimation unit is for carrying out the electronic control unit of calculation side drift angle algorithm.

6. side drift angle of motor vehicle estimating system according to claim 4, wherein, described side drift angle estimation unit is the single-chip microcomputer that disposes the execution calculation side drift angle algorithm among the ABS in the motor vehicle of ABS.

7. method that adopts the described side drift angle estimating system of claim 1 to estimate side drift angle of motor vehicle, this method comprises:

(1) carries out the collection of each sensor signal, gather off-front wheel angular velocity w1 from the off-front wheel angular-rate sensor, gather the near front wheel angular velocity w2 from the near front wheel angular-rate sensor, gather off hind wheel angular velocity w3 from the off hind wheel angular-rate sensor, gather left rear wheel angular velocity w4 from the left rear wheel angular-rate sensor, gather steering wheel angle φ from steering wheel angle sensor;

(2) according to the steering angle sigma of formula (1) calculating front wheels of motor-vehicles, wherein, k is the steering reduction gear ratio;

δ＝/k (1)

(3) calculate intermediate variable a, b and c according to formula (2), (3), (4), wherein, T is the wheel for motor vehicle distance;

a＝sinδ， (2)

b＝cosδ， (3)

$c=\frac{w_3-w_4}{T}---\left(4\right)$

(4) calculate off-front wheel side drift angle α according to formula (5), (6) ₁With the near front wheel side drift angle α ₂

${\mathrm{\&alpha;}}_1=\frac{{\mathrm{bw}}_1-w_3}{{\mathrm{aw}}_1}---\left(5\right)$

${\mathrm{\&alpha;}}_2=\frac{{\mathrm{bw}}_2-w_4}{{\mathrm{aw}}_2}---\left(6\right)$

(5) calculate off hind wheel side drift angle α according to formula (7), (8) ₃With left rear wheel side drift angle α ₄, wherein, L is the motor vehicle wheelbase.

${\mathrm{\&alpha;}}_3=\frac{{\mathrm{bw}}_1{\mathrm{\&alpha;}}_1+{\mathrm{aw}}_1-\mathrm{cL}}{w_3}---\left(7\right)$

${\mathrm{\&alpha;}}_4=\frac{{\mathrm{bw}}_2{\mathrm{\&alpha;}}_2+{\mathrm{aw}}_2-\mathrm{cL}}{w_4}---\left(8\right)$

Images