JP4169082B1 - Vehicle rollover prevention device - Google Patents

Abstract

In a vehicle rollover prevention device comprising a tractor and a trailer, the roll angle of the trailer can be accurately detected on the tractor head side.
Detecting the rear roll angle (RHr) of the tractor, estimating the total weight of the tractor and trailer (W _tortal ), estimating the load (W _fifth ) applied to the coupler connecting the tractor and trailer, and The roll stiffness (KHf, KHr) of the tractor front and rear axle suspensions is calculated. The tractor rear roll angle (RHr), total connection weight (W _tortal ), load (W _fifth ), roll stiffness of both suspensions (KHf, KHr), and predetermined torsional stiffness (KTtorsion) separately given ) And the trailer roll angle is estimated and output (R _OUT ). The trailer roll angle can also be estimated by adding the lateral acceleration (Gy) of the tractor.
[Selection] Figure 5

Description

  The present invention relates to a vehicle rollover prevention device, and more particularly to a tractor / trailer coupled vehicle connected by a coupler having no degree of freedom in the roll direction, and the risk of rollover is determined based on the trailer roll angle. It relates to the device.

  It is well known that automobiles (vehicles) behave outwardly when turning due to centrifugal force. For this reason, when the vehicle is suddenly turned and the force to tilt outward exceeds the ground contact force, the wheel inside the turn rises from the road surface and rolls over.

Therefore, it is performed to detect the roll angle of the vehicle and prepare for rollover prevention. Here, as a method of detecting the roll angle of the vehicle, (1) a method of calculating the roll angle of the vehicle from the difference between the left and right suspension strokes (for example, refer to Patent Document 1), and (2) the inclination of the vehicle body with respect to the road surface. A method for calculating the roll angle of the vehicle body from the detection output of the ground displacement meter using a directly detected ground displacement meter (see, for example, Patent Document 2), (3) A roll angle sensor for detecting the vehicle body inclination (tilt (See, for example, Patent Document 3) or (4) estimated acceleration calculated from vehicle speed and yaw rate and vehicle body Various methods have been proposed, such as a method of estimating a roll angle using an actual lateral acceleration obtained from a sensor attached to (see, for example, Patent Document 4).
Japanese Unexamined Patent Publication No. 60-252011 JP-A-6-297985 Japanese Utility Model Publication No. 3-110903 Japanese Patent Laid-Open No. 11-258260

  By the way, all of the means for detecting the roll angle described above are based on the premise that a sensor is attached to the vehicle body that is to detect the roll angle. However, in a vehicle in which a tractor and a trailer are connected, the tractor is changed depending on the time. Because it is separated from the trailer and connected to another trailer, when detecting the roll angle of the trailer on the tractor side, it is not always possible to assume that the sensor necessary for detecting the roll angle is mounted on the trailer. .

  Therefore, when a coupler (coupler) having no flexibility in the roll direction is used at the coupling portion between the tractor head and the trailer, it is conceivable to substitute the trailer roll angle with the roll angle of the tractor. Depending on the difference in the position of the front and rear of the cargo, it may not be possible to substitute.

  FIGS. 15 (1) and (2) show the rear roll angle characteristic A of the tractor and the rear roll angle characteristic B of the trailer when the position of the load is changed back and forth, respectively. As shown in Fig. 1 (1), when the load position is the front load, the roll angle of the tractor and trailer roll angle are almost the same value, but as shown in Fig. 2 (2), the load position is In the case of a product, the roll angle of the tractor is only smaller than the roll angle of the trailer, and the roll angle of the tractor cannot be used as a substitute for the roll angle of the trailer.

  For example, when the load is after-loading, if the roll angle of the tractor is used as a substitute for the trailer roll angle in the rollover prevention device that makes a determination using the roll angle, the tractor roll angle is not changed even if the trailer rollover risk is high. Since it is smaller than the trailer, it may be erroneously determined that the risk of rollover is low.

  The present invention has been made paying attention to the above-mentioned problems of the prior art, and an object of the present invention is to provide a connected vehicle rollover prevention device capable of accurately detecting the trailer roll angle on the tractor head side.

  In order to achieve the above object, a vehicle rollover prevention device according to the present invention is a vehicle rollover prevention device comprising a tractor and a trailer, and a tractor rear roll angle detection means for detecting a rear roll angle of the tractor, A total connection weight estimation means for estimating a total connection weight of the tractor and the trailer, a load estimation means for estimating a load received by a coupler connecting the tractor and the trailer, and calculating a roll rigidity of the front suspension of the tractor A tractor front shaft suspension roll stiffness calculation unit, a tractor rear shaft suspension roll stiffness calculation unit for calculating the roll stiffness of the rear suspension of the tractor, the tractor rear roll angle, the total connection weight, the load, and the front suspension. Based on the roll stiffness, the roll stiffness of the rear axle suspension, and the predetermined torsional stiffness of the trailer, the tray Characterized in that and a trailer roll angle estimation means for estimating a roll angle of.

  Here, the predetermined torsional rigidity of the trailer described above may be given from a trailer torsional rigidity input unit or stored in advance in the trailer roll angle estimating means.

  Further, the trailer roll angle estimation means obtains a trailer weight from the total connection weight and a known tractor weight, and calculates a ratio of the distance between the connection shaft and the front-rear center of gravity relative to the trailer wheel base from the trailer weight and the load. The trailer roll angle can be calculated based on the ratio, the tractor rear roll angle, both suspension roll stiffnesses, the trailer torsional stiffness, and the known tractor torsional stiffness.

  That is, the trailer roll angle estimating means calculates the weight of the trailer including the load from the estimated value of the total connection weight and the known tractor weight. Further, the load applied to the tractor from the trailer through the coupler (coupler) is estimated, and the ratio of the distance between the connecting shaft and the trailer center of gravity center position to the trailer wheel base is obtained from the trailer weight and the fifth wheel load obtained by the calculation. The tractor roll angle is estimated based on the known tractor torsional rigidity in addition to the ratio of the trailer center of gravity position, the obtained tractor rear roll angle, both suspension roll rigidity, and the trailer torsional rigidity. In this case, items relating to the lateral acceleration are omitted.

Further, the trailer roll angle estimation means obtains a trailer weight from the total connected weight and a known tractor weight, and calculates a ratio of the distance between the connecting shaft and the front-rear center of gravity relative to the trailer wheel base from the trailer weight and the load. , Based on the ratio, the tractor rear roll angle, the suspension suspension rigidity, the trailer torsional rigidity, the known tractor wheelbase and the distance between the tractor front shaft and the connecting shaft, the connecting shaft, the distance between the tractor rear shaft and the tractor torsional rigidity. The trailer roll angle can also be calculated. Also in this case, items relating to the lateral acceleration are omitted.

Further, a lateral acceleration detecting means for detecting a lateral acceleration of the tractor is further provided, and the lateral acceleration, a known weight on the tractor spring, and a height of the tractor spring upper center of gravity from the roll axis are added to the calculation of the trailer roll angle. You can also.

  The trailer wheel base is, for example, a distance from the position of the connecting shaft to the position of the single trailer shaft or the intermediate position of the plurality of trailer shafts.

  Furthermore, the present invention can also include means for determining a rollover risk based on the trailer roll angle, means for issuing an alarm based on the determination result, or means for performing rollover suppression control based on the determination result. It is.

  In the present invention, the roll angle can be replaced with a roll angular velocity or a roll angular acceleration. In that case, the roll angular velocity estimation device and trailer roll angular acceleration estimation device can be operated.

  According to the present invention, it becomes possible to estimate the roll angle of the trailer with higher accuracy than before without adding a sensor for detecting the roll angle to the trailer. When applied, it is possible to more accurately determine the trailer rollover risk and contribute to safe driving.

  In addition, in Japanese Patent Application No. 2007-21727 by the present applicant, a map of a ratio of a coupler-trailer center-of-gravity distance to a trailer wheel base (LCGratio) and a roll correction coefficient is obtained in advance, and a trailer roll angle is estimated using this map. However, the present invention does not require the above map, and as a result, an accurate trailer roll angle can be calculated in a vehicle in which the spring constant such as air suspension changes from time to time.

General configuration example of a connected vehicle applied to the present invention: FIGS. 1 to 4
The semi-trailer type connected vehicle has a configuration as shown in FIG. 1, and receives a vertical load (fifth wheel load) W _fifth at the front portion of the trailer 300 by a coupler 200 attached to the tractor 100. The position of the center of gravity CG combining the load and trailer 300 differs depending on the load loading position even if the load weight is the same, so the fifth wheel load W _fifth and the trailer shaft load W _rr also differ from time to time. . This difference in load distribution is considered to be a factor that causes the tractor 100 and the trailer 300 to have different roll states during turning.

Here, the case where there are a plurality of trailer shafts is shown in FIGS. 2 to 4. The example of FIG. 2 is the case of one tractor rear shaft and two trailer shafts, and the example of FIG. 3 is the tractor rear shaft two axes. In the case of 2 trailer shafts, the example of FIG. 4 shows the case of 2 trailer shafts and 3 trailer shafts. In these cases, the total of the trailer shaft loads is the trailer shaft load _Wrr, and the trailer shaft side base point of the trailer wheel base L _trailer is the intermediate position of the plurality of shafts. L _f represents the distance between the coupling axis of the coupler 200 and the trailer center of gravity CG, and L _r represents the distance between the trailer center of gravity CG and the intermediate position of the trailer axis. L _Hf is the distance between the front shaft of the tractor and the connecting shaft of the coupler 200, L _Hr is the distance between the connecting shaft of the coupler 200 and the rear shaft of the tractor, and L _Head is the wheelbase of the tractor 100 (L _Hf + L _Hr ) Respectively.

Overall configuration of the embodiment: FIG.
As shown in FIG. 5, the configuration of the embodiment is as follows: tractor rear roll angle detection unit 1, connected total weight estimation unit 2, fifth wheel load estimation unit 3, tractor lateral acceleration detection unit 4, tractor front shaft suspension roll stiffness calculation unit 5 The tractor rear shaft suspension roll stiffness calculation unit 6, the tractor torsional stiffness input unit 7, the trailer roll angle estimation unit 8, the rollover risk determination unit 9, and the rollover risk warning unit 10 are included. These are equipped on the tractor 100 side. Hereinafter, each part will be described.

Description of each part of Example
1) Tractor rear roll angle detector: Fig. 6
In the tractor rear roll angle detection unit 1, as shown in FIG. 6 (1), stroke sensors 13 and 14 for measuring the relative displacement between the sprung and unsprung are attached to the left and right of the rear suspensions 11 and 12 of the tractor 100, respectively. The roll angle calculation unit 15 that has input the measurement value obtains the sprung roll angle RHr by the following equation.

ここで、h_LH：左側相対変位、h_RH：右側相対変位、Tread_sensor：ストロークセンサ取付けスパン、である。

Here, h _LH : left side relative displacement, h _RH : right side relative displacement, Tread _sensor : stroke sensor mounting span.

  In addition, since the roll angle until the tire rises is not large, the roll angle RHr may be obtained by approximating the following equation.

なおロール角検出部1はこれに限らず、他の方法を用いても良い。例えば、図6(2)に示すように、トラクタフレーム上に取り付けられたロールレートセンサ16で計測されるロール角速度の値をロール角演算部15に与え、ここで積分してロール角RH_rを求めても良い。

The roll angle detector 1 is not limited to this, and other methods may be used. For example, as shown in FIG. 6 (2), the roll angular velocity value measured by the roll rate sensor 16 mounted on the tractor frame is given to the roll angle calculation unit 15, where it is integrated to obtain the roll angle RH _r . You may ask.

2) Consolidated total weight estimation unit: Fig. 7
As shown in FIG. 7 (1), the connected total weight estimation unit 2 includes an accelerator opening sensor 21, an engine speed sensor 22, a vehicle longitudinal acceleration sensor 23, and a calculation unit 24.

The calculation unit 24 obtains the engine torque by referring to the accelerator opening and the engine speed from the accelerator opening sensor 21 and the engine speed sensor 22 and a map stored in the calculation unit 24 in advance, and determines the vehicle longitudinal acceleration. The vehicle speed is obtained by integrating the longitudinal acceleration of the vehicle from the sensor 23. From these engine torque, longitudinal acceleration, and vehicle speed, the _total connected weight W _total consisting of the tractor 100, the trailer 300, and the load is obtained as follows.

  First, assuming that the running resistance of the vehicle is Tf, the calculation formula of the running resistance is expressed by the following formula.

Tf = μW _total + ρAV ² + (α / g) (W _total + ΔW _total ) + W _total sinθ (3)
Here, μ: rolling resistance, W _total : _total connection weight, ρ: air resistance coefficient, A: vehicle front projected area, ΔW _total : rotating part equivalent inertia weight, α: acceleration / deceleration, sinθ: road surface gradient, V: vehicle Speed, g: Gravity acceleration. Among them, the rolling resistance μ, the road surface gradient sinθ, and the vehicle speed V are values that change depending on the situation, but the other values are vehicle specific values (vehicle specifications).

Therefore, the running resistance Tf is measured every minute time ΔT. Here, if the current running resistance is Tf0, the running resistance after ΔT is Tf1, and if there is no change in the road surface condition at the minute time ΔT, the rolling resistance μW _total and the gradient resistance W _total sinθ are equal at both times, The following equation is obtained.

Tf0 = μW _total + ρAV0 ² + (α0 / g) (W _total + ΔW _total ) + W _total sinθ (4)
Tf1 = μW _total + ρAV1 ² + (α1 / g) (W _total + ΔW _total ) + W _total sinθ (5)
Next, when the difference between Expression (4) and Expression (5) is calculated, the following expression is obtained.

Tf0−Tf1 = ρA (V0 ² −V1 ² ) + (α0−α1) (W _total + ΔW _total ) / g (6)
From this equation (6), the following equation is obtained.

W _total + ΔW _total = g [Tf0−Tf1−ρA (V0 ² −V1 ² )] / (α0−α1) (7)
Further, the [Delta] W _total, when a 0.1 W _total as an example, the left side of the above equation (7) the following equation is obtained because the _{W total + 0.1W total = 1.1W total} .

W _total = g [Tf0−Tf1−ρA (V0 ² −V1 ² )] / 1.1 (α0−α1) (8)
On the other hand, assuming that the engine torque obtained by the calculation unit 24 at each time point of Equation (4) and Equation (5) is Te0 and Te1, respectively, and the driving force of the wheels is T0 and T1, respectively, T0 and T1 are respectively Given in.

T0 = (Te0 · GT · GF · η) / R (9)
T1 = (Te1, GT, GF, η) / R (10)
Here, GT: transmission gear ratio, GF: final reduction ratio, η: transmission efficiency, and R: tire radius. These are eigenvalues (specifications of the vehicle) of the vehicle.

Since the vehicle travels in a state where the running resistance Tf and the driving forces T0 and T1 are balanced, T0 and T1 in Equation (9) and Equation (10) are substituted for Tf0 and Tf1 in Equation (8), respectively. By doing so, the _total connected weight W _total can be detected and estimated for every minute time ΔT during traveling.

In addition, about a connection gross weight estimation method, you may use not only this but another method. For example, as shown in FIG. 7 (2), the brake pressure sensor 25 for each wheel of the tractor, the pressure sensor 26 for the trailer brake, and the vehicle longitudinal acceleration sensor 23 are provided, and the calculation unit 27 calculates the _total connection weight W _total as follows. Can do.

  There is a relationship of the following equation between the deceleration (acceleration in the front-rear direction) α acting on the vehicle and the braking force F at that time.

F = W _total (α / g) ... Formula (11)
From this equation (11), the following equation is obtained.

W _total = F (g / α) (12)
The braking force F is shown as a function of the brake coefficient B and the brake air pressure P. Specifically, the brake force F is obtained from the following formula using the brake coefficients Bf, Br, Bt of the front wheels, the rear wheels, and the trailer and the brake air pressures Pf, Pr, Pt.

F = Bf · Pf + Br · Pr + Bt · Pt (= B · P) (13)
By substituting the braking force F of equation (13) into equation (12), the _total connection weight W _total can be calculated and estimated.

3) Fifth wheel load estimator: Fig. 8
As shown in FIG. 8 (1), the fifth wheel load estimation unit 3 includes a pressure sensor 31 that measures the air spring internal pressure of each wheel in the tractor 100 in a coupled vehicle in which the tractor 100 is configured by an air suspension. The measurement value of the measured internal pressure is sent to the calculation unit 32, and thus the fifth wheel load W _fifth is estimated and calculated.

  First, the air spring load Fi (i: each tractor wheel) of each wheel of the tractor 100 is the product of the air spring internal pressure Pi and the effective sectional area Ai of the air spring previously stored in the calculation unit 32 as shown in the following equation. Can be obtained.

Fi = Ai · Pi (14)
Therefore, the sprung load W _{Tractor_all} including the _fifth wheel load W _fifth of the tractor 100 is obtained by the following equation.

W _{Tractor_all} = ΣFi
= ΣAi · Pi (15)
The fifth wheel load W _fifth is represented by the following equation by subtracting the sprung load W _{Tractor_0} for a single tractor vehicle stored in advance in the calculation unit 32 from the tractor sprung load W _{Tractor_all} obtained in Equation (15). Can be requested.

W _fifth = W _{Tractor_all} −W _{Tractor_0}・ ・ ・ Equation (16)
Alternatively, as another fifth wheel load estimation method, since the mounting position of the coupler 200 is substantially above the rear shaft of the tractor 100, the air spring internal pressure sensor 31 is mounted only on the rear shaft air spring, _Substituting i for each wheel on the rear axle of the tractor, W _{Tractor_all} for the sprung load on the rear axle, and W _{Tractor_0} for the sprung load on the rear axle for a single tractor vehicle, and calculating equations (14) to (16). Thus, the fifth wheel load W _fifth may be obtained.

As another fifth wheel load estimation method, for example, in a tractor vehicle using a metal spring as a suspension, each tractor wheel is provided with a suspension stroke sensor 33 as shown in FIG. Can be sent to the calculation unit 34 to calculate the fifth wheel load W _fifth . The load Fi (i: each tractor wheel) applied to the spring of each wheel of the tractor is a function fi of the spring deflection amount Hi measured by the suspension stroke sensor 33.

Fi = fi (Hi) (17)
For example, in the case of a linear spring with a constant spring constant ki, the following equation is obtained.

Fi ＝ ki ・ Hi ・ ・ ・ Formula (18)
Therefore, the sprung load W _{Tractor_all} including the _fifth wheel load W _fifth of the tractor is obtained by the following equation.

W _{Tractor_all} = ΣFi
= Σfi (Hi) ・ ・ ・ Formula (19)
The fifth wheel load W _fifth can be _obtained by subtracting the sprung load W _{Tractor_0} for a single tractor vehicle, which is stored in advance in the calculation unit 34, from the tractor sprung load W _{Tractor_all} obtained by Expression (19).

W _fifth = W _{Tractor_all} −W _{Tractor_0} (20)
Similarly to the above method using the air suspension internal pressure, the suspension stroke sensor 33 is attached only to the suspension of the tractor rear shaft, i is the wheel on the tractor rear shaft, W _{Tractor_all} is the sprung load applied to the rear shaft, W _{Tractor_0} The fifth wheel load W _fifth may be obtained by calculating the equation (17) to the equation (20) by replacing the above with the sprung load of the rear shaft when a single tractor is used.

4) Tractor lateral acceleration detector: Fig. 9
The tractor lateral acceleration detection unit 4 detects the tractor lateral acceleration value Gy by the lateral acceleration sensor 41 attached to the tractor 100 as shown in FIG. 9 (1), and the signal processing unit 42 removes noise by a low-pass filter or the like. .

  The tractor lateral acceleration detection method is not limited to the above method, and other methods may be used. For example, as shown in FIG. 9 (2), the tractor 100 is provided with a steering angle sensor 43 and a vehicle speed sensor 44, and an output value from each sensor is sent to the lateral acceleration calculation unit 45.

  The lateral acceleration calculation unit 45 calculates the lateral acceleration Gy from the following equation using the steering angle δ and the vehicle speed V obtained from the sensors 43 and 44.

ここで、L_Head:トラクタ100のホイールベース、Gr:操舵角δに対する前輪実舵角の比であり、予め横加速度演算部45に記憶させておく。

Here, L _{Head is} the wheel base of the tractor 100, Gr is the ratio of the front wheel actual steering angle to the steering angle δ, and is stored in advance in the lateral acceleration calculation unit 45.

5) Tractor front wheel suspension roll stiffness calculator: Fig. 10
As shown in FIG. 10 (1), the tractor front wheel suspension roll stiffness calculation unit 5 measures the air spring internal pressure in each wheel of the tractor front shaft for a vehicle in which the front shaft of the tractor 100 is formed of an air suspension. 51, which is configured to send the measured internal pressure to the front shaft roll stiffness estimation calculation unit 52.

  In this front shaft roll rigidity estimation calculation unit 52, the spring constant Kfsp of the air spring is calculated by referring to a map showing the relationship between the air spring internal pressure and the air spring spring constant stored in advance using the sent air suspension pressure. To do. The roll stiffness Kφfsp by the air spring is calculated from the following equation from the spring constant Kfsp of the air spring.

ここで、dfsp:トラクタ前軸スプリングトレッドであり、予め推定演算部52に記憶させておく。このエアスプリングによるロール剛性Kφfspと予め記憶させている前軸サスペンションスタビライザのロール剛性Kφfstbとの和を前軸サスペンションのロール剛性KHfとして算出し、トレーラロール角推定部8に送る。

Here, dfsp: tractor front shaft spring tread, which is stored in the estimation calculation unit 52 in advance. The sum of the roll stiffness Kφfsp of the air spring and the roll stiffness Kφfstb of the front axle suspension stabilizer stored in advance is calculated as the roll stiffness KHf of the front axle suspension and sent to the trailer roll angle estimation unit 8.

KHf = Kφfsp + Kφfspb (23)
If the spring constant Kfsp is assumed to be constant, for example, because the tractor front shaft suspension is composed of a metal spring, the roll stiffness KHf of the front shaft suspension is obtained and stored in advance, and the value is always stored. You may make it send to the trailer roll angle estimation part 8 (refer FIG. 10 (2)).

6) Tractor rear shaft suspension roll stiffness calculator: Fig. 11
In the tractor rear shaft suspension roll stiffness calculating section 6, as shown in FIG. 11 (1), a pressure sensor 61 for measuring the air spring internal pressure in each wheel of the tractor rear shaft for a vehicle in which the tractor rear shaft is constituted by an air suspension. The measured value of the measured internal pressure is sent to the rear shaft roll stiffness estimation calculation unit 62. The rear shaft roll stiffness estimation calculation unit 62 calculates the spring constant Krsp of the air spring using the sent air suspension pressure with reference to a previously stored map showing the relationship between the air spring internal pressure and the air spring spring constant. To do. The roll stiffness Kφrsp by the air spring is calculated from the following equation from the spring constant Krsp of the air spring.

ここで、drsp:トラクタ後軸スプリングトレッドであり、予め推定演算部62に記憶させておく。このエアスプリングによるロール剛性Kφrspと予め記憶させている後軸サスペンションスタビライザのロール剛性Kφrstbとの和を後軸サスペンションのロール剛性KHrとして算出し、トレーラロール角推定演算部に送る。

Here, drsp: tractor rear shaft spring tread, which is stored in the estimation calculation unit 62 in advance. The sum of the roll stiffness Kφrsp by the air spring and the roll stiffness Kφrstb of the rear axle suspension stabilizer stored in advance is calculated as the roll stiffness KHr of the rear axle suspension, and sent to the trailer roll angle estimation calculation unit.

KHr = Kφrsp + Kφrspb (25)
If the tractor rear shaft suspension is composed of a metal spring, etc., and the spring constant can be considered to be constant, the roll stiffness KHr of the rear shaft suspension is obtained and stored in advance, and this value is always stored in the trailer roll. You may make it send to the angle estimation part 8 (refer FIG. 11 (2)).

7) Trailer torsional rigidity input part In the trailer torsional rigidity input part 7, the torsional rigidity KTtorsion of the trailer is manually input using a numeric keypad, dial, or a selection switch from several types.

  The trailer torsional rigidity input means is not limited to this, and other methods may be used. For example, as disclosed in JP-A-6-144303, various methods such as a method of reading from a memory installed in a trailer and storing the specifications of the trailer, and storing a typical trailer torsional rigidity value in advance. The trailer torsional rigidity may be acquired with For this reason, the trailer torsional rigidity input portion 7 is shown by a dotted line.

8) Trailer roll angle estimation unit: Fig. 12 and Fig. 13
The trailer roll angle estimation unit 8 estimates the trailer roll angle according to the flowchart shown in FIG. The processing content of each step of the flowchart is as follows.

 Step S1: When the key SW is ON, the tractor rear roll angle RHr is first obtained from the tractor rear roll angle detection unit 1.

Step S2: Obtain an estimated value W _total of the connected total weight from the connected total weight estimation unit 2.

Step S3: Obtain an estimated value W _fifth of the _fifth wheel load from the fifth wheel load estimation unit 3.

Step S4: a known weight W _tractor of the tractor 100 stored in the estimation unit 8 in advance,
The trailer weight W _trailer including the load is calculated from the acquired combined total weight W _total by the following equation.

W _trailer ＝ W _total −W _tractor・ ・ ・ Formula (26)
-Step S5: When the trailer weight W _trailer calculated by the equation (26) is very small and the following equation (27) holds, it is determined that the trailer 300 is not connected, and the trailer roll angle estimation calculation is not performed. Proceed to step S10.

W _trailer <α (α is a positive constant smaller than the trailer empty vehicle weight) (27)
The determination in equation (27) may be performed by the following equation using the estimated value W _fifth of the _fifth wheel load as shown in the following equation instead of the trailer weight W _trailer .

W _fifth <β (β is a positive constant smaller than the fifth wheel load when trailer-coupled idle)
... Formula (28)
Step S6: The trailer weight W _trailer can be considered as the sum of the _fifth wheel load W _fifth and the trailer shaft load W _rr as shown in the following equation.

W _trailer = W _fifth + W _rr・ ・ ・ Formula (29)
Here, as described above, if the distance between the connecting shaft and the trailer center of gravity is L _f and the trailer wheel base is L _trailer , the following equation is established from the balance of forces.

L _f · W _trailer ＝ L _trailer · W _rr・ ・ ・ Formula (30)
When the ratio of the distance Lf between the connecting shaft and the trailer center of gravity to the trailer wheel base L _trailer is L _CGratio , this ratio L _CGratio is obtained from the following equations from equations (29) and (30).

・ステップS7：
ステップS6で求めたL_CGratio、トラクタ後部ロール角検出部1で求めたロール角RHr、横加速度検出部4で求めた横加速度Gy、トラクタ前軸サスロール剛性演算部5で求めた前軸サスロール剛性KHf、トラクタ後軸サスロール剛性演算部6で求めた後軸サスロール剛性KHr、トレーラねじり剛性入力部7から入力されたトレーラねじり剛性値KTtorsionを用いて次式からトレーラ300のロール角推定値RTCGを求める。

・ Step S7:
L _CGratio obtained in step S6, roll angle RHr obtained by tractor rear roll angle detection unit 1, lateral acceleration Gy obtained by lateral acceleration detection unit 4, front shaft suspension roll stiffness KHf obtained by tractor front shaft suspension roll stiffness calculation unit 5 The roll angle estimation value RTCG of the trailer 300 is obtained from the following equation using the rear shaft suspension roll stiffness KHr obtained by the tractor rear shaft suspension roll stiffness calculation unit 6 and the trailer torsion stiffness value KTtorsion inputted from the trailer torsion stiffness input unit 7.

以下に、上記の各変数及びこの連結車両の諸元値を列挙する（一部は後述する。）。

Below, the above-mentioned variables and the specification values of this connected vehicle are listed (some will be described later).

× RHf: Tractor front roll angle ○ RHr: Tractor rear roll angle × RC: Tractor coupler roll angle ◎ L _Head : Tractor wheelbase (= L _Hf + L _Hr )
◎ L _Hf : Distance between tractor front shaft and connecting shaft ◎ L _Hr : Distance between connecting shaft and tractor rear shaft 〇 KHf: Roll rigidity of tractor front shaft suspension 〇 KHr: Roll rigidity of tractor rear shaft suspension ◎ KHtorsion: Tractor front -Rear torsional rigidity 〇 KHtorsion_f: Tractor front part-Coupler torsional rigidity 〇 KHtorsion_r: Coupler part-tractor rearward torsional rigidity ◎ mH: Weight on tractor spring △ mT: Mass on trailer spring ◎ hH: Roll on center of gravity on tractor spring Height from axis △ hT: Height of trailer spring center of gravity from roll axis 〇 Gy: Lateral acceleration 〇 RTCG: Trailer center of gravity roll angle △ RTf: Trailer front roll angle × RTr: Trailer rear roll angle × L _trailer : Trailer wheelbase (= L _Tf + L _Tr )
× L _Tf : Distance between connecting shaft and trailer center of gravity × L _Tr : Trailer center of gravity-distance between trailer shafts △ KT: Roller shaft suspension rigidity ◎ KTtorsion: Trailer front-rear torsional rigidity ○ KTtorsion_f: Trailer front-trailer Center of gravity torsional rigidity 〇 KTtorsion_r: Torsional rigidity between the center of gravity of the trailer and the rear of the trailer The attached symbols have the following meanings.

◎: Known vehicle specification value, previously stored in trailer roll angle estimation unit 〇: Derived by formula or other means △: Not necessary but described for convenience ×: Eliminated in calculation process Since the torsional rigidity KHtorsion of the tractor 100 is usually smaller than the torsional rigidity KTtorsion of the trailer 300, the fourth term on the right side regarding the lateral acceleration Gy is omitted. The trailer roll angle estimated value RTCG may be obtained from the following equation (33). In this case, the tractor lateral acceleration detection unit 4 in the configuration example of FIG. 5 may be omitted.

さらに、カプラー200はトラクタ100の後軸のほぼ真上に設置されていることから、トラクタカプラー部とトラクタ後部とを一体と考えることもできる。その場合、L_Hr=0(L_Head=L_Hf)となるため、次式からトレーラロール角推定値RTCGを求めてもよい。

Furthermore, since the coupler 200 is installed almost directly above the rear shaft of the tractor 100, the tractor coupler portion and the tractor rear portion can be considered as one body. In this case, since L _Hr = 0 (L _Head = L _Hf ), the trailer roll angle estimated value RTCG may be obtained from the following equation.

また、上記の式(32)と同様、横加速度Gyに関する項を省略して、次式からトレーラロール角推定値RTCGを求めてもよい。この場合も、図5の構成例にあるトラクタ横加速度検出部4は省略してよい。

Similarly to the above equation (32), the term relating to the lateral acceleration Gy may be omitted, and the trailer roll angle estimated value RTCG may be obtained from the following equation. Also in this case, the tractor lateral acceleration detection unit 4 in the configuration example of FIG. 5 may be omitted.

・ステップS8：ステップS7で求めたトレーラロール角推定値RTCGをロール角出力値R_OUTとする。

Step S8: The trailer roll angle estimated value RTCG obtained in step S7 is set as the roll angle output value R _OUT .

Step S9: The tractor roll angle value RHr is set as the roll angle output value R _OUT .

Derivation Process of Expression (32) and Expression (34) Here, the derivation process of Expression (32) and Expression (34) will be described below.

  Now, as shown in FIG. 13, the tractor 100 is divided into three rigid bodies in the front-rear direction in the front part 101, the coupler part 102, and the rear part 103, and the trailer 300 in the front part 301, the center of gravity part 302, and the rear part 303, Consider a model in which the three-part rigid body is connected by a torsion spring with a degree of freedom in the roll direction, and consider the balance of moments in the roll direction during steady circle turning. Here, it is assumed that the sprung mass mH of the tractor 100 is concentrated on the tractor front portion 101 and the trailer sprung mass mT is concentrated on the trailer center of gravity 302. Further, since a coupler having no degree of freedom in the roll direction is considered, it is assumed that the tractor coupler portion 102 and the trailer front portion 301 move integrally in the roll direction. Further, since there is a connection angle Ψ between the tractor 100 and the trailer 300, the relationship between the roll angle Rc of the tractor coupler section 102 and the roll angle RTf of the trailer front section 301 is expressed by the following equation (36), where θT is the pitch angle of the trailer vehicle body. Although the connection angle is small except at low speeds, the influence of the connection angle is ignored here, and the following equation (37) is considered.

    RC = RTf ・ cos (Ψ) + θT ・ sin (Ψ) (36)

トラクタカプラー部102とトラクタ100の前後を結ぶねじりばねのねじり剛性は、それぞれ次式のように表される。

The torsional rigidity of the torsion spring connecting the tractor coupler portion 102 and the front and rear of the tractor 100 is expressed by the following equations, respectively.

また、同様にトレーラ重心部とトレーラの前後を結ぶねじりばねのねじり剛性をそれぞれ次式のように表すことができる。

Similarly, the torsional rigidity of the torsion spring connecting the center of gravity of the trailer and the front and rear of the trailer can be expressed by the following equations, respectively.

定常状態のそれぞれの部位毎にロール方向のモーメントの釣り合いを考えると次のようになる。

Considering the balance of moments in the roll direction for each part in the steady state, it is as follows.

・ Tractor front 101:
When in steady state, moment to increase roll angle due to lateral acceleration acting on mass on tractor spring (mH ・ Gy ・ hH), moment to keep horizontal roll angle by suspension (KHf ・ RHf) and Since the torsional moment (KHtorsion_f · (RHf-RC)) due to the roll angle difference between the tractor front part 101 and the tractor coupler part 102 is in a balanced state, the following equation is established.

KHtorsion_f ・ (RHf-RC) + KHf ・ RHf = mH ・ Gy ・ hH ・ ・ ・ Formula (42)
・ Tractor rear 103:
When in steady state, the moment to keep the roll angle by suspension (KHr ・ RHr) and the torsional moment (KHtorsion_r ・ (RHr-RC)) due to the roll angle difference between tractor rear part 103 and tractor coupler part 102 are balanced. Since it is in a state, the following equation holds.

KHtorsion_r ・ (RHr-RC) + KHr ・ RHr = 0 ・ ・ ・ Formula (43)
・ Tractor coupler 102 (= Trailer front 301):
When in steady state, the torsional moment (KHtorsion_f ・ (RC-RHf)) due to the roll angle difference between the tractor front part 101 and the tractor coupler part 102, the torsional moment (KHtorsion_r (RC-RHr)) and the torsional moment (KTtorsion_f · (RC-RTCG)) due to the roll angle difference between the trailer front portion 301 and the trailer center of gravity 302 are in the balanced state.

KHtorsion_f ・ (RC-RHf) + KHtorsion_r ・ (RC-RHr) + KTtorsion_f ・ (RC-RTCG) = 0
... Formula (44)
-Trailer center of gravity 302:
When in steady state, moment to increase roll angle due to lateral acceleration acting on trailer spring mass (mH ・ Gy ・ hH), torsional moment due to roll angle difference between trailer front 301 and trailer center of gravity 302 (KTtorsion_f (RTCG-RC)), and the torsional moment (KTtorsion_r · (RTCG-RTr)) due to the roll angle difference between the trailer rear portion 303 and the trailer center of gravity 302 is in a balanced state.

KTtorsion_f ・ (RTCG-RC) + KTtorsion_r ・ (RTCG-RTr) = mT ・ Gy ・ hT ・ ・ ・ Formula (45)
-Trailer rear 303:
When in a steady state, the moment to maintain the roll angle by the suspension (KTr / RTr) and the torsional moment (KTtorsion_r · (RTr-RTCG)) due to the roll angle difference between the trailer rear part 303 and the trailer center of gravity 302 are balanced. Since it is in a state, the following equation holds.

KT ・ RTr + KTtorsion_r ・ (RTr-RTCG) = 0 ・ ・ ・ Formula (46)
The above formula (32) can be derived by summarizing the above formula for the roll angle RTCG of the trailer center of gravity position.

Further, since the coupler is installed almost directly above the tractor rear portion 103, the tractor coupler portion 102 and the tractor rear portion 103 can be considered as one body. In that case, L _Hr = 0 (L _Head = L _Hf ), and the above equation (34) can be derived.

9) Roll-over risk judgment unit The roll-over risk judgment unit 9 has a roll-over risk when the relationship between the roll angle output value R _out from the trailer roll angle estimation unit 8 and the roll-over risk judgment threshold R _threshold satisfies the following equation: A rollover danger signal is sent to the rollover danger warning unit 10 when it is determined that the value is high.

| R _OUT | ＞ R _threshold・ ・ ・ Formula (47)
10) Rollover danger warning unit When the rollover danger warning unit 10 receives a rollover danger signal, it warns the driver with an alarm lamp, sound, etc.

  As shown in FIG. 14, a rollover suppression control unit 20 is provided instead of the rollover danger warning unit 10, and when a rollover danger signal is received, the vehicle brakes and engine are controlled to decelerate the vehicle and suppress rollover. It is good also as a structure.

Variation:
The roll angle can be replaced with a roll angular velocity or a roll angular acceleration. In this case, the roll angular velocity estimation device and trailer roll angular acceleration estimation device can be operated.

  For example, in the above embodiment, when the roll angular velocity estimation device of the trailer 300 is used, the roll angle calculation unit is replaced with the roll angular velocity calculation unit in the configuration of FIG. 6 (1). The roll angular velocity is obtained by differentiating the roll angle obtained in (2). Alternatively, the measurement value of the roll rate sensor is output as it is to the trailer roll angular velocity estimation calculation unit in the configuration of FIG. 2 (2), and the roll angle in the other components is replaced with the roll angular velocity.

  In this way, the trailer roll angular velocity estimation device can be used, and the estimated roll angular velocity of the trailer is used to make a rollover risk determination. If there is a risk of rollover, an alarm is issued or the vehicle is decelerated. Control and suppress rollover.

  It should be noted that the present invention is not limited to the above-described embodiments, and it is apparent that various modifications can be made by those skilled in the art based on the description of the scope of claims.

1 is a schematic side view of a connected vehicle including a general tractor and trailer (in the case of one trailer shaft and one trailer shaft). FIG. 1 is a schematic side view of a connected vehicle including a general tractor and a trailer (in the case of a tractor rear shaft of one axis and a trailer shaft of two axes). FIG. 1 is a schematic side view of a connected vehicle including a general tractor and a trailer (in the case of two trailer shafts and two trailer shafts). FIG. 2 is a schematic side view of a connected vehicle including a general tractor and a trailer (in the case of two tractor rear shafts and three trailer shafts). It is the block diagram which showed the structure of the Example of the vehicle rollover prevention apparatus which concerns on this invention. FIG. 6 is a diagram schematically showing a structure of a tractor rear roll angle detection unit shown in FIG. FIG. 6 is a block diagram showing a configuration of a connected total weight estimation unit shown in FIG. FIG. 6 is a block diagram showing a configuration of a fifth wheel load estimating unit shown in FIG. FIG. 6 is a block diagram showing a configuration of a tractor lateral acceleration detection unit shown in FIG. FIG. 6 is a block diagram showing a configuration of a tractor front shaft suspension roll stiffness calculation unit shown in FIG. FIG. 6 is a block diagram showing a configuration of a tractor rear shaft suspension roll stiffness calculation unit shown in FIG. FIG. 6 is a calculation flowchart of the trailer roll angle estimation unit shown in FIG. It is the figure which modeled the roll motion of the connection vehicle. It is the block diagram which showed the modification of this invention. It is the graph which showed the roll angle characteristic of the tractor and the trailer at the time of an actual vehicle running test (step steering).

Explanation of symbols

1 Tractor rear roll angle detector
2 Consolidated total weight estimation unit
3 Fifth wheel load estimation section
4 Tractor lateral acceleration detector
5 Tractor front wheel suspension roll stiffness calculator
6 Tractor rear wheel suspension roll stiffness calculator
7 Trailer torsional rigidity input section
8 Trailer roll angle estimation unit
9 Rollover risk judgment section
10 Roll-over danger warning section
11,12 Rear suspension
13,14 Suspension stroke sensor
15 Roll angle calculator
16 Roll rate sensor
20 Rollover suppression control unit
21 Accelerator position sensor
22 Engine speed sensor
23 Vehicle longitudinal acceleration sensor
24,27 Calculation unit
25 Tractor wheel brake pressure sensor
26 Trailer brake pressure sensor
31 Tractor wheel air suspension pressure sensor
32,34 Calculation unit
33 Tractor wheel suspension stroke sensor
41 Tractor lateral acceleration sensor
42 Signal processor
43 Steering angle sensor
44 Vehicle speed sensor
45 Tractor lateral acceleration calculator
51 Tractor front wheel air suspension pressure sensor
52 Front axis roll stiffness estimation calculator
53 Tractor front shaft suspension rigidity
61 Tractor rear wheel air suspension pressure sensor
62 Rear axis roll stiffness estimation calculation unit
63 Tractor rear shaft suspension roll rigidity
100 tractors
200 coupler
300 trailers
CG trailer center of gravity In the figure, the same reference numerals indicate the same or corresponding parts.

Claims (9)

A vehicle rollover prevention device comprising a tractor and a trailer,
A tractor rear roll angle detecting means for detecting a rear roll angle of the tractor;
A total connection weight estimating means for estimating a total connection weight of the tractor and the trailer;
Load estimating means for estimating a load received by the coupler connecting the tractor and the trailer;
A tractor front shaft suspension roll stiffness calculation unit for calculating the roll stiffness of the front shaft suspension of the tractor;
A tractor rear shaft suspension roll stiffness calculation unit for calculating the roll stiffness of the rear shaft suspension of the tractor;
Trailer for estimating the roll angle of the trailer based on the rear roll angle of the tractor, the total connection weight, the load, the roll rigidity of the front axle suspension, the roll rigidity of the rear axle suspension, and the predetermined torsional rigidity of the trailer. Roll angle estimation means;
A vehicle rollover prevention device characterized by comprising: In claim 1,
A vehicle rollover prevention device, wherein a predetermined torsional rigidity of the trailer is given from a trailer torsional rigidity input unit or stored in advance in the trailer roll angle estimating means. In claim 1 or 2,
The trailer roll angle estimation means obtains a trailer weight from the total connection weight and a known tractor weight, calculates a ratio of the distance between the connection shaft and the front and rear center of gravity relative to the trailer wheel base from the trailer weight and the load, and the ratio The trailer roll angle is calculated based on the tractor rear roll angle, both suspension roll stiffness, trailer torsion stiffness, and known tractor torsion stiffness, and a vehicle rollover prevention device. In claim 1 or 2,
The trailer roll angle estimation means obtains a trailer weight from the total weight of the connection and a known tractor weight, calculates a ratio of a distance between the connecting shaft and the front-rear center of gravity relative to the trailer wheel base from the trailer weight and the load, ratio and the tractor rear roll angle and both Sasuroru rigidity and the trailer torsional stiffness, as well known tractor wheel base and tractor front axle - the connecting shaft distance and the connecting shaft - the trailer based on the center distance and the tractor torsional stiffness after tractor A rollover prevention device for a vehicle characterized by calculating a roll angle. In claim 3 or 4,
The apparatus further comprises a lateral acceleration detecting means for detecting a lateral acceleration of the tractor, and adds the lateral acceleration, a known weight on the tractor spring, and a height from the roll axis of the tractor spring center of gravity to the calculation of the trailer roll angle. A vehicle rollover prevention device. In any one of claims 3 to 5,
A vehicle rollover prevention device, wherein the trailer wheel base is a distance from a position of a connecting shaft to a position of a single trailer shaft or an intermediate position of a plurality of trailer shafts. In any one of Claims 1-6,
A vehicle rollover prevention device, further comprising: means for determining a rollover risk based on the trailer roll angle; and means for issuing an alarm based on the determination result. In any one of Claims 1-6,
An apparatus for preventing a rollover of a vehicle, further comprising means for determining a rollover risk based on the trailer roll angle, and means for performing a rollover suppression control based on the determination result. In any one of Claims 1-8,
A rollover prevention device for a vehicle, characterized by using a roll angular velocity or a roll angular acceleration instead of the roll angle.

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