JP2008081008A - Vehicle behavior controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle behavior controller which can achieve proper driving force control even in an initial unstable state, and can improve the stability or turning performance of a vehicle by obtaining driving force controlled variables using real road surface reaction force torque having almost the same phase relationship as self-aligning torque. <P>SOLUTION: The vehicle behavior controller is provided with: a speed detection means for detecting a vehicle speed; a steering angle detection means for detecting a steering angle or a real steering angle; a real road surface reaction force torque detection means for detecting a real road surface reaction force torque to be generated between a tire and a road surface; and a reference road surface reaction force torque calculation means for calculating a reference road surface reaction force torque from the vehicle speed, the steering angle, and the gradient of the road surface reaction force torque to the steering angle. The driving force controlled variables of the driving force adjusting device are determined based on the detected real road surface reaction force torque and the reference road surface reaction force torque. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle behavior control device for improving stability and turning performance when a vehicle turns.

  As a conventional vehicle behavior control device for improving the stability and turning performance of a vehicle when turning, a technique for adjusting the driving force of each driving wheel by a driving force adjusting device to generate a turning force is disclosed. In the conventional technique, the driving force control amount is determined from the target value calculated from the equation of motion of the vehicle, the vehicle state quantity such as the lateral acceleration, the yaw rate (Patent Document 1, Patent Document 2), and the grip degree (Patent Document 3). It had been.

Japanese Patent No. 2770661 Japanese Patent No. 3423125 Japanese Patent Laid-Open No. 2005-112007 Japanese Patent No. 3590608 JP 2005-324737 A Steering system and maneuverability of automobiles (Kayaba Industry Co., Ltd., published by Sankaido, September 10, 1996) pages 149-202

  In such a vehicle behavior control device, driving is performed in a state where the cornering force characteristic with respect to the side slip angle of the front wheels loses linearity and the turning characteristic of the vehicle deteriorates (for the sake of convenience, hereinafter, an initial unstable state). There is a problem that the amount of force control cannot be determined, and the stability and turning performance of the vehicle cannot be improved by the driving force adjusting device. The reason for this is as follows.

  The characteristics of the self-aligning torque and the cornering force with respect to the side slip angle β of the wheel are as shown in FIG. 16 for a dry road surface with a high friction coefficient and as shown in FIG. 17 for an ice disk road surface with a low friction coefficient. The self-aligning torque increases substantially in proportion to the side slip angle β from the side slip angle 0 [deg] to β peak [deg], and decreases at a side slip angle higher than that. On the other hand, the cornering force increases approximately proportionally up to the vicinity of βpeak [deg], and when the side-slip angle exceeds that, the increasing rate decreases and saturates to a constant value (decreases on an ice surface).

According to Non-Patent Document 1, it can be seen from [Equation 1] and [Equation 2] that the yaw rate and lateral acceleration have a first-order lag relationship with respect to the cornering force.

γ Vehicle yaw rate I Moment of inertia about vertical axis of vehicle center of gravity F _f Cornering force of front wheel F _r Cornering force of rear wheel l _f Length from vehicle center of gravity to front wheel shaft axis l _r Length from vehicle center of gravity to rear wheel shaft axis G _y Lateral acceleration V Vehicle speed

FIG. 18 shows the time response of each state quantity when the steering angle is increased at a constant angular speed at a constant vehicle speed. In this case, the side slip angle increases with time, and the self-aligning torque of the front wheels reaches a peak value at _Tβpeak . Front wheel cornering force is increased substantially proportionally until _T βpeak, then reaches a peak value at T _Ff increasing rate gradually decreases and. Lateral acceleration, further delayed _T Gy than _{T Ff} for yaw _rate, until _{T Yaw} reaches almost proportionally increased _{T Gy,} saturated respectively _{T Yaw.}
The time when the T _βpeak side slip angle reaches the peak value T _{Ff The} time when the lateral force of the front wheel reaches the saturation value T _{Gy The} time when the lateral acceleration reaches the saturation value T _{Yaw The} time when the _Yaw rate reaches the saturation value.

From _Tβpeak , the vehicle is in an initial unstable state, and the turning characteristics of the vehicle deteriorate. However, even during the period from T _βpeak to T _Gy , T _Yaw , the lateral acceleration and yaw rate are linearly delayed with respect to the cornering force, so that linearity is maintained and the target value calculated by the vehicle equation of motion is Match. Therefore, in the methods of Patent Literature 1 and Patent Literature 2, an appropriate driving force control amount cannot be obtained even though the vehicle is in an initial unstable state, and the vehicle stability and turning performance are improved. I can't.

  On the other hand, in Patent Document 3, an estimated value of the grip degree is used. The grip degree itself exhibits the same characteristics as the cornering force, but since the lateral acceleration and yaw rate are used to estimate the grip degree, the estimated value of the grip degree has a phase lag relationship with the cornering force. it is conceivable that. Therefore, even with the method of Patent Document 3, an appropriate driving force control amount cannot be obtained even though the vehicle is in an initial unstable state, and the stability and turning performance of the vehicle cannot be improved.

  In addition to the above, the useful vehicle state quantity at the time of turning of the vehicle includes an actual road reaction torque generated between the tire and the road surface. The road surface reaction torque is a moment acting around the kingpin. It has the same phase relationship as the self-aligning torque acting around the vertical direction of the wheel, and shows similar characteristics to the skid angle. That is, from the side slip angle of 0 deg to near βpeak, it increases substantially proportionally to the side slip angle, and decreases at a side slip angle of more than that. As a technique paying attention to the characteristics of such road surface reaction torque, there are Patent Document 4 and Patent Document 5.

  In Patent Document 4, the road surface reaction force torque is estimated, and the steering angle δpeak at the peak of the estimated road surface reaction force torque is obtained. Then, with δpeak as the steering limit of the vehicle, the control output value of the vehicle behavior control device is changed in the direction of promoting the turning motion when the steering angle exceeds δpeak.

  However, in the above technology, since δpeak is updated using the increase / decrease relationship between the estimated road reaction torque and the steering angle, the amount of processing of the system increases when updating every control cycle, while the control is performed several times. When updating is performed every cycle, there is a problem that the accuracy of δpeak deteriorates. Further, when turning in an environment where the friction coefficient of the road surface changes suddenly, there is a problem that it is difficult to obtain an optimal δpeak because the road surface reaction torque changes rapidly.

  On the other hand, Patent Document 5 is a technique for detecting a vehicle state based on an estimated road reaction force torque and changing a control output value so that the vehicle behavior is stabilized. However, the technique does not mention means for calculating the control output value. In addition, both Patent Document 4 and Patent Document 5 are aimed at the stability of vehicle behavior, and there is a problem that it is impossible to improve the turning performance.

  The present invention has been made in view of the above problems, and determines the driving force control amount of the driving wheel based on the actual road surface reaction torque and the reference road surface reaction torque, thereby improving the stability of the vehicle during turning. The purpose is to improve the turning ability.

  The vehicle behavior control device according to the present invention is a vehicle behavior control device including a driving force adjusting device capable of adjusting the driving force of each driving wheel, and detects vehicle speed detecting means for detecting the vehicle speed and a steering angle or an actual steering angle. The reference road surface reaction from the steering angle detection means, the actual road surface reaction force torque detection means for detecting the actual road surface reaction torque generated between the tire and the road surface, and the gradient of the road surface reaction force torque with respect to the vehicle speed, the steering angle, and the steering angle. Reference road surface reaction torque calculating means for calculating force torque is provided, and a driving force control amount of the driving force adjusting device is determined based on the detected actual road surface reaction torque and the reference road surface reaction torque.

  According to the vehicle behavior control device of the present invention, by determining the driving force control amount based on the detected actual road surface reaction torque and the reference road surface reaction torque, the actual road surface having substantially the same phase relationship as the self-aligning torque. Since the driving force control amount is calculated using the reaction force torque, appropriate driving force control can be realized even when the vehicle is in an initial unstable state, and the stability and turning performance of the vehicle during turning can be improved. it can.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a vehicle behavior control apparatus according to Embodiment 1 of the present invention. In the figure, the vehicle state quantity detection unit 0401 includes a steering angle sensor 0402, a vehicle speed sensor 0403, and an actual road surface reaction force torque detection unit 0404 that detect a steering angle or an actual steering angle. The vehicle behavior control ECU 0405 includes a reference road surface reaction torque calculation unit 0406 and a control amount calculation unit 0407. In the vehicle behavior control ECU 0405, each detected value of the vehicle state quantity detection unit 0401 is input, and the left and right wheel driving force control amount is calculated by an algorithm described later. The vehicle behavior control unit 0412 includes a left and right wheel driving force adjustment device 0413. The left and right wheel driving force adjusting device adjusts the left and right driving forces with a control amount as an input. Note that the actual road surface reaction torque detection unit 0404 may detect the actual road surface reaction torque using a load cell or the like, or may estimate it using a known technique.

FIG. 2 is a flowchart showing a control procedure according to the first embodiment. In the figure, the control is started when the ignition of the vehicle is turned on and a current is supplied to the vehicle behavior control device (step S0501, hereinafter simply referred to as S0501. The other steps are also the same). The vehicle state quantity detection unit 0401 detects the steering angle δ, the vehicle speed V, and the actual road surface reaction torque T _align (S0502). Subsequently, the reference road surface reaction force torque is calculated by the reference road surface reaction torque calculation unit 0406 using the steering angle δ and the vehicle speed V as inputs (S0503). As shown in FIG. 3, the reference road surface reaction torque calculation unit 0406 inputs the vehicle speed V to KalignMap (road surface reaction torque gradient characteristic) 0601 and obtains K _align (the gradient of road reaction torque against the steering angle). The reference road surface reaction torque T _{align_ref} is _obtained by multiplying the steering angle δ.
T _{align_ref} = K _align × δ [Formula 3]
Here, KalignMap 0601 may store characteristics obtained by a running test in advance in a memory of a microcomputer, or may use characteristics analyzed online.

With the actual road surface reaction force torque T _align , the reference road surface reaction force torque T _{align_ref} , and the vehicle speed V as inputs, the control output value calculation unit 0407 calculates left and right wheel driving force control output values (S0504). First, a road surface reaction torque deviation T _{align_err} is obtained by taking the difference between the reference road surface reaction torque T _{align_ref} and T _align (S0505).
T _{align_err} = T _{align_ref} −T _align [Formula 4]

The deviation conversion unit 0408 calculates a converted yaw rate deviation γ _{err_trq} by converting the road surface reaction force torque deviation T _{align_err} into a yaw rate deviation (S0506). In this calculation, as shown in FIG. 4, the road surface reaction torque deviation T _{align_err} is multiplied by a conversion coefficient 0701 obtained from the vehicle speed V, the vehicle wheel base l, the stability factor A, and K _align . The wheel base 1 is a value unique to the vehicle, and a value stored in the memory of the microcomputer is used. As for the stability factor A, a value calculated in advance may be stored in the memory of the microcomputer, or may be obtained online.

[式６]は車両の運動方程式（二輪モデル）から求められた式であり、従来技術における目標ヨーレートに相当すると考えられる。 According to Non-Patent Document 1, when the differential value of the side slip angle of the vehicle and the differential value of the yaw rate γ are small, the relationship between the yaw rate and the steering angle δ is as follows.

[Expression 6] is an expression obtained from the equation of motion (two-wheel model) of the vehicle, and is considered to correspond to the target yaw rate in the prior art.

Ｔ_{align_reｆ}は理論上の路面反力トルクであるのに対し、Ｔ_alignは実際の路面反力トルクであることから、上式のヨーレートは車両に発生している実ヨーレートに相当すると考えられる。 On the other hand, when T _{align_ref} in [Expression 6] is replaced with T _align , the following expression is obtained.

T _{align_ref} is a theoretical road reaction torque, whereas T _align is an actual road reaction torque. Therefore, it is considered that the above yaw rate corresponds to the actual yaw rate generated in the vehicle.

γ_{tgt_trq}：基準路面反力トルクから求めた目標ヨーレート
γ_{real_trq}：実路面反力トルクから求めた実ヨーレート
γ_{err_trq}：路面反力トルク偏差から求めた変換ヨーレート偏差 To summarize the above, the relationship between the reference road surface reaction torque, the actual road surface reaction torque and the yaw rate is as follows.

γ _{tgt_trq} : Target yaw rate obtained from reference road reaction torque γ _{real_trq} : Actual yaw rate obtained from actual road reaction torque γ _{err_trq} : Conversion yaw rate deviation obtained from road reaction torque deviation

変換ヨーレート偏差γ_{err_trq}を得る。 From the above relationship, the conversion coefficient 0701 is _obtained for the road surface reaction torque deviation T _{align_err} .

A conversion yaw rate deviation γ _{err_trq} is obtained.

比例制御部と微分制御部の出力和が目標γ増分Ｔ_γとして出力される。 Next, the calculation amount T _γ is calculated using the converted yaw rate deviation γ _{err_trq} as an input. FIG. 5 shows the configuration of the proportional control unit 0409, and FIG. 6 shows the configuration of the differential control unit 0410.
The converted yaw rate deviation proportional value K ₁ γ _{err_trq} is obtained by multiplying the converted yaw rate deviation γ _{err_trq} by K ₁ which is the proportional gain 0801 (S0507). Further, the converted yaw rate deviation γ _{err_trq} is input to the differentiator 0901 and multiplied by K ₂ which is the differential gain 0902, thereby converting the converted yaw rate deviation differential value.

The output sum of the proportional control unit and the differential control unit is output as the target γ increment T _γ .

The calculation amount converter 0411 converts the target γ increment T _γ to the left and right wheel driving force control amount C _out (S0510). In this transformation, the target gamma increment T _gamma as shown in Figure 7, the vehicle speed V, the wheel base l in the vehicle, the stability factor A, front wheel cornering power K _f, the rear wheel cornering power K _r, of the vehicle The tread length l _tred is multiplied by the conversion coefficient 1001 obtained from the tire radius R.
The front wheel cornering power K _f , the rear wheel cornering power K _r , the vehicle tread length l _tred , and the tire radius R are vehicle-specific values, and values stored in the memory of the microcomputer are used.

In the vehicle turning left as shown in FIG. 8, it is assumed that the force F _diff is applied to the right rear wheel due to the driving force difference. At this time, the moment M _diff around the center of gravity generated by the driving force difference is expressed as follows. As shown in FIG. 8, L is the center of gravity and the length of the rear wheel to the rear wheel axis.

但し、 β：車両重心の横滑り角 ｍ：車両の質量
[式１２]は車両横向きの運動方程式、[式１３]は車両重心回りの運動方程式である。 By adding [Expression 11] to the relational expression of the moment acting around the center of gravity of the two-wheel model (Non-patent Document 1), which is the basic equation of motion of the vehicle, the equation of motion including the driving force difference is as follows.

Where β: side slip angle of vehicle center of gravity m: vehicle mass
[Expression 12] is an equation of motion in the lateral direction of the vehicle, and [Expression 13] is an equation of motion around the center of gravity of the vehicle.

Ｔ_γ＝Δγとすることで、所望の車両状態を得るためのＦ_diffが導かれる。Ｆ_diffにタイヤの半径Ｒを乗算することで、左右輪駆動力制御量Ｃ_out＝Ｆ_diff×Ｒが求められる。 From [Equation 14], the increment Δγ of the yaw rate generated by the driving force difference F _diff is as follows.

By setting T _γ = Δγ, F _diff for obtaining a desired vehicle state is derived. By multiplying F _diff by the tire radius R, the left and right wheel driving force control amount C _out = F _diff × R is obtained.

The vehicle behavior control unit 0412 drives the left and right wheel driving force control device 0413 based on the control amount C _out (S0511). The vehicle behavior apparatus repeats S0502 to S0511 for each control period of the vehicle behavior control ECU 0405 until the ignition of the vehicle is turned off (S0512). When the ignition of the vehicle is turned off and no current is supplied to the vehicle behavior control device, the control of the vehicle behavior control device ends (S0513).

  As described above, since the driving force control amount is determined with substantially the same phase relationship as the self-aligning torque by determining the driving force control amount based on the detected actual road surface reaction force torque and the reference road surface reaction force torque, the vehicle Appropriate driving force control is realized even when is in the initial unstable state. Even in the initial unstable state immediately before the cornering force is saturated, it is possible to determine an appropriate control amount for the left and right wheel driving force adjusting device, thereby improving the stability and turning performance of the vehicle. In particular, the stability and turning performance of the vehicle during accelerated turning performed near the exit of the turning circuit can be improved. In the first embodiment, for simplification of description, the driving force is adjusted for the left and right wheels of the rear wheel, but the driving force of each driving wheel may be adjustable.

Embodiment 2. FIG.
FIG. 9 is a block diagram showing the configuration of the vehicle behavior control apparatus according to the second embodiment. In contrast to the vehicle behavior control apparatus of the first embodiment, the vehicle state detection unit 1214 and the control amount correction unit 1215 are provided in the second embodiment. The control amount correction unit 1215 corrects the control amount C _out calculated in S0510 of FIG. 2, and outputs the correction control quantity R _out.

FIG. 10 is a flowchart showing a control procedure according to the second embodiment. The vehicle state detection unit 1214 detects the generated tire force F _{r_out} of the non-turning rear wheel and the tire force limit LF _{r_out} of the non-turning rear wheel (S1301, S1302). In addition, about these vehicle state quantities, you may detect using a sensor and you may use the patent document 3 and other well-known calculating means.

A value F _s obtained by adding the generated tire force F _{r_out} of the rear wheel and F _diff for obtaining the desired vehicle state obtained in S0510 in FIG. 2 is compared with the tire force limit LF _{r_out} of the rear wheel outside the turn. (S1303).
When F _s <LF _{r_out} (S1303), R _out = C _out is output to the vehicle behavior control unit 1212 (S1304). When F _s > LF _{r_out} (S1303), R _out = LF _{r_out−} F _{r_out} is output to the vehicle behavior control unit 1212 (S1305).

The vehicle behavior control unit 1212 drives the left and right wheel driving force adjusting device 1213 based on the correction control amount _Rout . In this way, by correcting the driving force control amount according to the vehicle state amount, the driving force control when the vehicle behavior limit is exceeded is suppressed, and an unstable state due to excessive driving force control is avoided. In the second embodiment, the vehicle state detection unit corrects the control amount based on the generated tire force of the non-turning rear wheel and the tire force limit of the non-turning rear wheel. However, the vehicle state amount such as the yaw rate or the lateral acceleration is used. The control amount may be corrected based on the above.

Embodiment 3 FIG.
FIG. 11 is a block diagram showing the configuration of the vehicle behavior control apparatus according to the third embodiment. In contrast to the vehicle behavior control device of the second embodiment, in the third embodiment, a power detection unit 1416 that detects the output of the power unit of the vehicle, a control amount calculation unit 1417, a transmission device 1418, and front and rear wheel driving force adjustment devices. 1419 and a braking force control device 1420 are provided. In the third embodiment, the control amount for each device of the vehicle behavior control unit 1412 is obtained using the correction control amount _Rout obtained in the second embodiment as the target driving force control amount.

In a vehicle in which each wheel of the vehicle does not have a power source, the torque of the power source is distributed to each wheel. Hereinafter, it is considered that no loss occurs in power transmission. The torque of the power source T _e, a transmission ratio R _g of the driving force of the torque and the vehicle power source, 1-R to the drive distribution ratio of the front and rear wheels _tr: When R _tr, the rear wheel drive torque T _r Is given by
T _r = T _e × R _g × R _tr [Formula 16]
If this driving force is distributed to the left and right wheels at a distribution ratio 1-R _y : R _y , the rear wheel driving torque difference T _dr is expressed by the following equation.
T _dr = T _r × R _y −T _r × (1−R _y )
= T _e × R _g × R _tr × (2R _y −1) [Formula 17]

In FIG. 11, the correction control amount R _out is the target left and right wheel driving force difference, and by setting T _dr = R _out , the left and right wheel driving force distribution ratio, transmission ratio, and front and rear wheel driving that can achieve the target driving force difference. The power distribution ratio can be obtained. The control amount correction unit 1414 outputs the correction control amount R _out and corresponds to the target left and right wheel driving force difference calculating means. Note that the target left / right wheel driving force difference may be achieved by a combination of several transmission ratios and distribution ratios. FIG. 12 shows an example of a procedure for determining this combination.

To target left and right wheel driving force difference R _out to check whether achievable only left and right wheel driving force adjustment, relative to [Expression 17], the torque T _e and the maximum left and right wheel driving force distribution ratio maxR _y of the power source, current front-rear wheel driving force distribution ratio CR _tr, enter the current transmission ratio CR _g, and calculates the left and right wheel driving force difference M _y achievable (S1501). And comparing the M _y and R _out (S1502), in the case of M _y> R _out are the control amounts as S1503 (left and right wheel driving force control amount, front-rear wheel driving force controlled variable transmission ratio) set the To do.

For _{M y <R out (S1502)} , in order to target the right and left wheel drive force difference R _out to check whether achievable with the left and right wheel driving force adjustment and front and rear wheel drive force adjustment, the power source with respect to [Expression 17] torque T _e and the maximum left and right wheel driving force distribution ratio maxR _y, the maximum front-rear wheel driving force distribution ratio maxR _tr, enter the current transmission ratio CR _g, and calculates an achievable left and right wheel driving force difference _M y_tr (S1504 ). And comparing the M _{Y_tr} and R _out (S1505), in the case of _M y_tr> R _out are the control amounts as S1506 (left and right wheel driving force control amount, front-rear wheel driving force controlled variable transmission ratio) set the To do.

If _{My_tr} <R _out (S1505), the left / right driving force is checked to see if the target left / right wheel driving force difference R _out can be achieved only by adjusting the left / right wheel driving force adjustment, front / rear wheel driving force adjustment, and transmission ratio adjustment. which is the difference relative to the [equation 18], and the input torque T _e and the maximum left and right wheel driving force distribution ratio maxR _y of the power source, the maximum front-rear wheel driving force distribution ratio maxR _tr, the maximum transmission ratio CR _g, achievable The left and right wheel driving force difference _{My_tr_g} is calculated (S1507). And comparing the M _{Y_tr_g} and R _out (S1508), the control amount as S1509 in the case of _M y_tr_g> R _out to set the (left and right wheel driving force control amount, front-rear wheel driving force controlled variable transmission ratio) .

[式１１]と同様に考えることで、所望の車両挙動を実現するために必要な制動力を求めることができる。この時、左右輪駆動力配分比、前後輪駆動力配分比、伝達比については、現在の制御量を用いても良いし、S1509で設定される制御量を用いても良い。 In the case of _{M y_tr_g <R out (S1508)} , to control the braking force (S1510). As shown in FIG. 13, the moment M _b around the center of gravity generated when the braking force F _b is applied to the turning inner wheel is as follows.

By considering in the same manner as [Equation 11], it is possible to obtain the braking force necessary to realize the desired vehicle behavior. At this time, for the left and right wheel driving force distribution ratio, the front and rear wheel driving force distribution ratio, and the transmission ratio, the current control amount may be used, or the control amount set in S1509 may be used.

  In this way, by controlling the left and right wheel driving force control amount, the front and rear wheel driving force control amount and the transmission ratio based on the output of the power unit and the target left and right wheel driving force difference, the left and right wheel driving force control device alone can Even when the left and right wheel driving force difference cannot be achieved, the absolute amount of rear wheel driving torque to be distributed increases, so that the target left and right wheel driving force difference can be achieved. On the other hand, by controlling the braking force, even if the left and right wheel driving force control device alone cannot achieve the target left and right wheel driving force difference, a force opposite to the driving direction is generated. Can be achieved.

  In the third embodiment, for simplicity of explanation, the vehicle has one power source. However, the power source may be a vehicle with one front wheel and one rear wheel. Further, although the braking force control apparatus controls the braking force of the rear wheels in the turn, the braking force of the four wheels may be controllable.

Embodiment 4 FIG.
FIG. 14 is a block diagram showing the configuration of the vehicle behavior control apparatus according to the fourth embodiment. In contrast to the vehicle behavior control device of the third embodiment, the fourth embodiment includes a steering assist device 1721, and the road surface reaction force detector 1704 is configured in the steering assist device. The steering assist device is a device that assists the driver's steering torque by generating assist torque by motor control. The road surface reaction force detection unit 1704 includes a steering torque detection unit 1722, an assist torque detection unit 1723, and a filter 1724. The road surface reaction force detection unit 1704 estimates the actual road surface reaction force torque with the above-described configuration, and outputs the estimated actual road surface reaction force torque ETalign.

FIG. 15 is a diagram showing the principle of road surface reaction torque estimation. Torque acting on the steering shaft, where T _hdl is the steering torque detected by the steering torque detector 1722, T _assist is the assist torque detected by the assist torque detector 1723, and T _dist is the disturbance torque such as friction of the steering shaft The relationship of T _align is given by the following equation.
T _align + T _dist = T _hdl + T _assist
T _align = T _hdl + T _assist −T _dist [Formula 19]
Therefore, as shown in FIG. 14, the estimated actual road surface reaction force torque ET _align can be obtained by inputting the sum of the steering torque and the assist torque to a filter that cancels the influence of the disturbance torque. About a filter, you may obtain | require from the characteristic of the disturbance torque calculated | required previously, and patent document 5 and other well-known techniques may be used.

  Thus, in a vehicle including a steering assist device, the actual road surface reaction torque can be estimated by including a steering torque detector, an assist torque detector, and a filter. The steering torque detection unit and the assist torque detection unit are normally configured in a steering assist device in order to obtain appropriate assist torque, and the filter can be implemented by software. Therefore, the road surface reaction force detecting means can be realized without using a sensor or the like, and the cost required for the configuration of the vehicle behavior device can be reduced and the system configuration can be simplified.

  In the fourth embodiment, control amount correction, transmission ratio control, front / rear ratio control, braking force control, and actual road surface reaction force torque estimation are added to the first embodiment. A desired effect can be obtained by providing these alone or several of them. For example, by providing only transmission ratio control, the absolute amount of rear wheel drive torque distributed can be increased, and excessive drive force control suppression can be achieved by combining control amount correction and actual road surface reaction force torque estimation. Cost reduction and system configuration can be simplified.

1 is a block diagram showing a configuration of a vehicle behavior control apparatus according to Embodiment 1 of the present invention. 3 is a flowchart illustrating a control procedure according to the first embodiment. FIG. 5 is a diagram showing a calculation means of a reference road surface reaction torque calculation unit according to the first embodiment. FIG. 6 is a diagram showing a configuration of a deviation conversion unit that converts road reaction force torque deviation into yaw rate deviation according to the first embodiment. FIG. 3 is a diagram showing a configuration of a proportional control unit according to the first embodiment. FIG. 3 is a diagram showing a configuration of a differential control unit according to the first embodiment.

FIG. 3 is a diagram illustrating a configuration of a calculation amount conversion unit according to the first embodiment. FIG. 5 is a diagram showing a relationship of yaw moment generated by a driving force difference according to the first embodiment. It is a block diagram which shows the structure of the vehicle behavior control apparatus by Embodiment 2. 10 is a flowchart illustrating a control procedure according to the second embodiment. FIG. 10 is a block diagram illustrating a configuration of a vehicle behavior control device according to a third embodiment. 12 is a flowchart illustrating a control procedure of a control amount calculation unit in the third embodiment.

FIG. 10 is a diagram showing a relationship of yaw moment generated by braking force in the third embodiment. It is a block diagram which shows the structure of the vehicle behavior control apparatus by Embodiment 4. FIG. 10 is a diagram showing a relationship of torque acting on a steering shaft according to a fourth embodiment. It is a figure which shows the relationship of the self-aligning torque and cornering force with respect to the skid angle (beta) in a dry road surface. It is a figure which shows the relationship of the self-aligning torque and cornering force with respect to the skid angle (beta) in an ice board road surface. It is a figure which shows the time characteristic of the various vehicle state quantities when the steering angle is increased at a constant angular velocity at a constant vehicle speed.

Explanation of symbols

0401 Vehicle state quantity detection unit 0402 Rudder angle sensor
0403 Vehicle speed sensor 0404 Actual road surface reaction torque detector
0405 Vehicle behavior control ECU 0406 Reference road surface reaction torque calculation unit
0407 Control amount calculation unit 0408 Deviation conversion unit
0409 Proportional control unit 0410 Differential control unit
0411 Complexity conversion unit 0412 Vehicle behavior control unit
0413 Left and right wheel drive force adjustment device 0601 KalignMap
0701 Conversion coefficient 0801 Proportional gain

0902 Differential gain 1001 Conversion factor
1212 Vehicle behavior control unit 1213 Left and right wheel driving force adjustment device
1214 Vehicle state detection unit 1215 Control amount correction unit
1412 Vehicle behavior control unit 1416 Power detection unit
1417 Control amount calculation unit 1418 Transmission
1419 Front and rear wheel drive force adjustment device 1420 Braking force control device
1704 Road reaction force detector 1721 Steering assist device
1722 Steering torque detector 1723 Assist torque detector
1724 filters

Claims (9)

In a vehicle behavior control device including a driving force adjusting device capable of adjusting the driving force of each driving wheel,
Vehicle speed detection means for detecting the vehicle speed;
Steering angle detection means for detecting the steering angle or the actual steering angle;
An actual road surface reaction force torque detecting means for detecting an actual road surface reaction torque generated between the tire and the road surface;
Reference road surface reaction force torque calculating means for calculating a reference road surface reaction force torque from the vehicle speed, the steering angle, and the gradient of the road surface reaction force torque with respect to the steering angle,
A vehicle behavior control device characterized in that a driving force control amount of the driving force adjusting device is determined based on the detected actual road surface reaction force torque and the reference road surface reaction force torque.   2. The vehicle behavior control device according to claim 1, further comprising vehicle state detection means for detecting a vehicle state, wherein the driving force control amount is corrected based on the vehicle state. A steering assist device that generates assist torque by motor control and assists the steering torque of the driver;
Steering torque detection means for detecting the steering torque of the driver;
An assist torque detecting means for detecting an assist torque generated by the steering assist device;
A filter that removes torque components other than road surface reaction torque from the sum of the steering torque detected by the steering torque detection means and the assist torque detected by the assist torque detection means;
The vehicle behavior control device according to claim 1 or 2, wherein the actual road surface reaction force torque detecting means detects an actual road surface reaction force torque based on an output of the filter.   4. The vehicle behavior control device according to claim 1, wherein the driving force adjusting device adjusts the driving force of the left and right wheels based on a left and right wheel driving force control amount. 5. . The driving force adjusting device includes:
Power detection means for detecting the output of the power section of the vehicle;
Target left and right wheel driving force difference calculating means for calculating a target driving force difference between the left and right wheels;
Front and rear wheel drive force adjustment device capable of adjusting the front and rear wheel drive force based on the front and rear wheel drive force control amount
5. The vehicle behavior control device according to claim 4, wherein a left / right wheel driving force control amount and a front / rear wheel driving force control amount are determined based on an output of the power unit and a target left / right wheel driving force difference. The driving force adjusting device includes:
Power detection means for detecting the output of the power section of the vehicle and target left and right wheel driving force difference calculating means for calculating a target driving force difference between the left and right wheels;
It has a transmission that changes the transmission ratio of power and converts it into driving force,
5. The vehicle behavior control device according to claim 4, wherein a left / right wheel driving force control amount and a transmission ratio are determined based on an output of the power unit and a target left / right wheel driving force difference. The driving force adjusting device includes:
Power detection means for detecting the output of the power section of the vehicle;
Target left and right wheel driving force difference calculating means for calculating a target driving force difference between the left and right wheels;
It has a braking force control device that can adjust the braking force of each wheel,
5. The vehicle behavior control device according to claim 4, wherein a left / right wheel driving force control amount and a braking force of each wheel are determined based on an output of the power unit and a target left / right wheel driving force difference. The driving force adjusting device includes:
Power detection means for detecting the output of the power section of the vehicle;
Target left and right wheel driving force difference calculating means for calculating a target driving force difference between the left and right wheels;
Front / rear wheel driving force adjustment device that can adjust the driving force of the front and rear wheels based on the front / rear wheel driving force control amount, a transmission that changes the power transmission ratio to convert to driving force, and the braking force of each wheel can be adjusted Including any two or more of the braking force control devices;
Based on the output of the power unit and the target left / right wheel driving force difference, the right / left wheel driving force control amount, the front / rear wheel driving force control amount, the power transmission ratio, and the braking force of each wheel 5. The vehicle behavior control device according to claim 4, wherein the control amount is determined.   4. The vehicle behavior control device according to claim 1, wherein the driving force adjusting device adjusts the driving force of the front and rear wheels based on a front and rear wheel driving force control amount. 5. .

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