JP2007030832A - Vehicle traveling motion controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly control a vehicle's traveling motion regardless of the operating condition of a roll rigidity changing apparatus by computing a desired yaw rate to an appropriate value while taking the operating condition of the roll rigidity changing apparatus into consideration. <P>SOLUTION: This vehicle traveling motion controller controls a front wheel side active stabilizer device 16 and a rear wheel side active stabilizer device 18 based on desired anti-roll moment Mat and the desired front-to-rear-wheel distribution ratio Rfr of roll rigidity (S80, 100-130). A stability factor Kh is computed in such a way that the stability factor gets higher as the desired roll rigidity distribution ratio Rfr of the front wheels to the rear wheels gets higher (S230). A desired yaw rate γt is computed based on the stability factor Kh, whereby the desired yaw rate γt is computed in such a manner to become smaller as the distribution ratio of roll rigidity to the rear wheels becomes higher (S310). The controlling driving force on each wheel is controlled so that the vehicle's yaw rate γ becomes equal to the desired yaw rate γt, whereby the vehicle's traveling motion is controlled (S320-340). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle travel motion control device that controls the braking / driving force of each wheel so that the yaw rate of the vehicle becomes a target yaw rate, and more specifically, a roll stiffness variable that increases or decreases the roll stiffness of the front wheel side or the rear wheel side. The present invention relates to a traveling motion control device for a vehicle including the device.

  As one of the travel motion control devices that control the travel motion of a vehicle such as an automobile, for example, as described in Patent Document 1 below, the target yaw rate of the vehicle is calculated based on the steering angle, and the yaw rate of the vehicle is calculated. 2. Description of the Related Art A traveling motion control device that stabilizes the traveling motion of a vehicle by controlling the braking force of each wheel so as to achieve a target yaw rate to suppress the spin state and the drift-out state is well known.

  Also, as one of the roll stiffness variable devices that increase or decrease the roll stiffness on the front wheel side or the rear wheel side to control the roll behavior during turning of a vehicle such as an automobile, a two-part stabilizer and a torsion bar of the stabilizer are relative to each other. In a situation where a high roll moment acts on the vehicle, such as when the vehicle is turning, the two torsion bars are rotated relative to each other by the actuator and applied to the vehicle. 2. Description of the Related Art Active stabilizer devices configured to increase the anti-roll moment are conventionally known.

According to the traveling motion control apparatus as described above, the vehicle yaw rate can be set to the target yaw rate by controlling the braking force of each wheel, so that the traveling stability of the vehicle is improved by suppressing the spin state and the drift-out state. In addition, according to the active stabilizer device, since the roll rigidity of the vehicle can be increased in a situation where a high roll moment acts on the vehicle, the vehicle can be compared with the case where the stabilizer is a normal stabilizer. It is possible to reduce the roll of the vehicle at the time of turning without deteriorating the ride comfort during the straight traveling of the vehicle and to improve the steering stability of the vehicle.
Japanese Patent No. 3178273

  In general, in a traveling motion control device that controls the braking force or driving force of each wheel so that the yaw rate of the vehicle becomes the target yaw rate, the target yaw rate has a stability factor that is set in advance along with the steering angle and the vehicle speed, as is well known. Calculated based on

  However, in a vehicle provided with a roll stiffness variable device that increases or decreases the roll stiffness on the front wheel side or the rear wheel side, the roll stiffness on the front wheel side or the rear wheel side changes due to the operation of the roll stiffness variable device. Stability factors also change.

  However, in the conventional running motion control device, since it is not considered that the stability factor of the vehicle changes due to the operation of the roll stiffness varying device, the target yaw rate is an appropriate value depending on the operation status of the roll stiffness varying device. Therefore, there is a problem that the traveling motion control by the traveling motion control device is not properly performed. This problem also occurs when the anti-roll moment increasing / decreasing device is an active suspension device that controls increasing / decreasing the contact load of each wheel.

  The present invention has been made in view of the above-described problems in a vehicle travel motion control device equipped with a roll stiffness variable device that increases or decreases the roll stiffness on the front wheel side or the rear wheel side like an active stabilizer device, The main object of the present invention is to appropriately control the running motion of the vehicle regardless of the operation status of the roll stiffness variable device by calculating the target yaw rate to an appropriate value in consideration of the operation status of the roll stiffness variable device. Is to do.

  According to the present invention, the main problem described above is the configuration of claim 1, that is, the target yaw rate setting means for setting the target yaw rate of the vehicle, and the braking / driving force of each wheel so that the yaw rate of the vehicle becomes the target yaw rate. In a vehicle travel motion control device having a braking / driving force control means for controlling and a roll stiffness variable device for increasing / decreasing the roll stiffness on the front wheel side or the rear wheel side, the target yaw rate setting means is adapted to the roll stiffness on the front wheel side. This is achieved by the vehicle travel motion control device characterized in that the higher the rear wheel roll stiffness ratio, the smaller the target yaw rate.

  According to the present invention, in order to effectively achieve the main problem described above, in the configuration of claim 1, the target yaw rate setting means sets the target yaw rate based on at least a stability factor, The higher the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side, the smaller the target yaw rate is increased by increasing the stability factor (configuration of claim 2).

  According to the present invention, in order to effectively achieve the main problems described above, in the configuration of claim 1 or 2, the roll stiffness varying device is provided on the front wheel side or the rear wheel side and is applied to the vehicle. An anti-roll moment increasing / decreasing device for increasing / decreasing the anti-roll moment to be generated is included (structure of claim 3).

  According to the present invention, the anti-roll moment increasing / decreasing device includes a front-wheel-side anti-roll moment increasing / decreasing device and a rear-wheel-side anti-roll according to the configuration of claim 3 in order to effectively achieve the above-mentioned main problems. It is comprised so that it may be a moment increase / decrease apparatus (structure of Claim 4).

  In general, in a vehicle equipped with a roll stiffness variable device that increases or decreases the roll stiffness on the front wheel side or the rear wheel side, the roll stiffness of the entire vehicle is increased or decreased by the operation of the roll stiffness variable device, and the rear wheel side relative to the front wheel side. The ratio of the roll stiffness also changes. In particular, when the ratio of the roll stiffness on the rear wheel side to the front wheel side becomes high, the turning state of the vehicle tends to be oversteered, so the target yaw rate of the vehicle is calculated based on a preset stability factor, and the yaw rate of the vehicle If the braking / driving force of each wheel is controlled by the braking / driving force control means so that the target yaw rate becomes the target yaw rate, the control amount of the braking / driving force control means becomes excessive, and the turning state of the vehicle tends to be oversteered.

  According to the first aspect of the present invention, the higher the ratio of the roll stiffness on the rear wheel side to the roll stiffness on the front wheel side, the smaller the target yaw rate, so the magnitude of the deviation between the vehicle yaw rate and the target yaw rate is large. The vehicle's turning state is excessive due to the excessive control amount of the braking / driving force control means when the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the rear wheel side is high. A steer state can be reliably prevented.

  According to the second aspect of the present invention, the target yaw rate is set based on at least the stability factor, and the stability factor is increased by increasing the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side. Since the yaw rate is reduced, the target is higher when the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side is higher than when the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side is lower. The magnitude of the yaw rate can be reliably reduced.

  According to the third aspect of the present invention, the roll stiffness varying device includes the anti-roll moment increasing / decreasing device that is provided on the front wheel side or the rear wheel side and increases or decreases the anti-roll moment applied to the vehicle. By increasing or decreasing the anti-roll moment applied to the vehicle on the wheel side, the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side can be reliably changed.

  According to the above configuration of the fourth aspect, the anti-roll moment increasing / decreasing device includes the front wheel side anti-roll moment increasing / decreasing device and the rear wheel side anti-roll moment increasing / decreasing device, so that the roll rigidity of the entire vehicle can be increased / decreased, The ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side is reliably changed by increasing or decreasing the anti-roll moment applied to the vehicle by the front wheel side anti-roll moment increasing / decreasing apparatus or the rear wheel side anti-roll moment increasing / decreasing apparatus. Can do.

[Preferred embodiment of problem solving means]
According to one preferred aspect of the present invention, in the configuration of claim 3 or 4, the anti-roll moment increasing / decreasing device includes an anti-roll moment applying means for applying an anti-roll moment to the vehicle, and a roll moment acting on the vehicle. And a control means for controlling the anti-roll moment applying means according to the estimated roll moment to increase or decrease the anti-roll moment applied to the vehicle (preferred aspect 1). .

  According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 1, the anti-roll moment applying means includes an active stabilizer having a two-divided stabilizer and an actuator for rotating the torsion bar of the stabilizer relative to each other. It is comprised so that it may contain (Preferred aspect 2).

  According to another preferable aspect of the present invention, in the configuration of the preferable aspect 1, the anti-roll moment applying means is configured to include an active suspension capable of increasing / decreasing a wheel support load (Preferable aspect 3). .

  According to another preferred aspect of the present invention, in the configurations of claims 1 to 4 and preferred aspects 1 to 3, when the roll stiffness variable device is abnormal, it is used for calculating a target yaw rate. The stability factor is configured to be set to a value equal to or greater than the value when the roll stiffness variable device is normal (Preferred aspect 4).

  According to another preferred embodiment of the present invention, in the configuration of the preferred embodiment 4 described above, when the roll stiffness variable device changes from a normal state to an abnormal state, the stability provided for calculation of the target yaw rate. The factor is configured to gradually change from a value when the roll stiffness varying apparatus is in a normal state to a value when the roll stiffness varying apparatus is in an abnormal state (Preferable aspect 5).

  The present invention will now be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram showing one embodiment of a vehicle travel motion control device according to the present invention applied to a vehicle provided with an active stabilizer device on the front wheel side and the rear wheel side.

  In FIG. 1, 10 FL and 10 FR respectively indicate left and right front wheels that are driven wheels of the vehicle 12, and 10 RL and 10 RR respectively indicate left and right rear wheels that are drive wheels of the vehicle 12. The left and right front wheels 10FL and 10FR, which are also steered wheels, are driven in response to a steering wheel not shown in the drawing by the driver being steered by the driver by a power steering device not shown in the drawing. Steered through tie rods.

  An active stabilizer device 16 is provided between the left and right front wheels 10FL and 10FR, and an active stabilizer device 18 is provided between the left and right rear wheels 10RL and 10RR. The active stabilizer device 16 is integrally connected to a pair of torsion bar portions 16TL and 16TR extending coaxially with each other along an axis extending in the lateral direction of the vehicle, and to the outer ends of the torsion bar portions 16TL and 16TR, respectively. And a pair of arm portions 16AL and 16AR. The torsion bar portions 16TL and 16TR are supported by a vehicle body not shown in the drawing via brackets not shown in the drawing so as to be rotatable around their own axes. The arm portions 16AL and 16AR extend in the longitudinal direction of the vehicle so as to intersect the torsion bar portions 16TL and 16TR, respectively, and the outer ends of the arm portions 16AL and 16AR are respectively left and right through rubber bush devices not shown in the drawing. The front wheels 10FL and 10FR are connected to wheel support members or suspension arms.

  The active stabilizer device 16 has an actuator 20F between the torsion bar portions 16TL and 16TR. The actuator 20F rotates the pair of torsion bar portions 16TL and 16TR in opposite directions as necessary, so that when the left and right front wheels 10FL and 10FR bounce and rebound in opposite phases, the wheel bounces due to torsional stress. Then, the force to suppress rebound is changed, thereby increasing or decreasing the anti-roll moment applied to the vehicle at the position of the left and right front wheels, and variably controlling the roll rigidity of the vehicle on the front wheel side.

  Similarly, the active stabilizer device 18 has a pair of torsion bar portions 18TL and 18TR extending coaxially with each other along an axis extending in the lateral direction of the vehicle, and the outer ends of the torsion bar portions 18TL and 18TR, respectively. It has a pair of arm portions 18AL and 18AR connected together. The torsion bar portions 18TL and 18TR are respectively supported by a vehicle body not shown in the drawing via brackets not shown in the drawing so as to be rotatable around their own axes. The arm portions 18AL and 18AR extend in the longitudinal direction of the vehicle so as to intersect the torsion bar portions 18TL and 18TR, respectively, and the outer ends of the arm portions 18AL and 18AR are respectively left and right through rubber bushing devices not shown in the drawing. The rear wheels 10RL and 10RR are connected to wheel support members or suspension arms.

  The active stabilizer device 18 has an actuator 20R between the torsion bar portions 18TL and 18TR. The actuator 20R rotates the pair of torsion bar portions 18TL and 18TR in directions opposite to each other as necessary, so that when the left and right rear wheels 10RL and 10RR bounce and rebound in opposite phases, the torsional stress causes the wheel By changing the force to suppress bounce and rebound, the anti-roll moment applied to the vehicle at the positions of the left and right rear wheels is increased or decreased, and the roll rigidity of the vehicle on the rear wheel side is variably controlled.

  The active stabilizer devices 16 and 18 themselves do not form the gist of the present invention, and may have any configuration known in the art as long as the roll rigidity of the vehicle can be variably controlled. However, for example, the active stabilizer device described in Japanese Patent Application Laid-Open No. 2005-88722 according to the application of the present applicant, that is, an electric motor having a rotating shaft fixed to the inner end of one torsion bar portion and having a drive gear attached thereto, A driven gear fixed to the inner end of the other torsion bar portion and meshed with the drive gear. The drive gear and the driven gear transmit the rotation of the drive gear to the driven gear, but the rotation of the driven gear is transmitted to the drive gear. It is preferable that the active stabilizer device be a gear that does not.

  As shown, the actuators 20F and 20R of the active stabilizer devices 16 and 18 are controlled by an electronic control unit 24. Although not shown in detail in FIG. 1, each of the electronic control devices 24 has a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other by a bidirectional common bus and a drive. It may consist of a circuit.

  Further, as shown in FIG. 1, the braking force of the left and right front wheels 10FL, 10FR and the left and right rear wheels 10RL, 10RR is applied by the hydraulic circuit 30 of the braking device 28 to the braking pressures of the corresponding wheel cylinders 32FL, 32FR, 32RL, 32RR. It is controlled by controlling. Although not shown in the drawing, the hydraulic circuit 30 includes a reservoir, an oil pump, various valve devices, etc., and the braking pressure of each wheel cylinder is normally determined by the amount of depression of the brake pedal 34 and the depression of the brake pedal 34 by the driver. In accordance with the pressure of the master cylinder 36 driven in response to the braking force, the oil pump and various valve devices are controlled by the electronic control device 38 for controlling the braking force as required, so that the brakes by the driver Control is performed regardless of the depression amount of the pedal 34.

  Although not shown in detail in FIG. 1, the electronic control device 38 for controlling the braking force also includes a microcomputer and a drive circuit. The microcomputer includes, for example, a CPU, a ROM, a RAM, an input / output port device, and the like. And these may be of a general configuration connected to each other by a bidirectional common bus.

  As shown in FIG. 1, the electronic control unit 24 has a signal indicating the vehicle lateral acceleration Gy from the lateral acceleration sensor 25 and the actual rotation angle φF of the actuators 20F and 20R detected by the rotation angle sensors 26F and 26R. A signal indicating φR is input. On the other hand, the electronic control unit 38 has a signal indicating the vehicle yaw rate γ detected by the yaw rate sensor 40, a signal indicating the vehicle speed V detected by the vehicle speed sensor 42, and a signal indicating the steering angle θ detected by the steering angle sensor 44. A signal indicating the master cylinder pressure Pm is input from the pressure sensor 46, and a signal indicating the corresponding wheel braking pressure (wheel cylinder pressure) Pbi (i = fl, fr, rl, rr) is input from the pressure sensors 48FL to 48RR. Is done.

  The electronic control units 24 and 38 exchange signals with each other as necessary. Further, the lateral acceleration sensor 25, the rotation angle sensors 26F and 26R, the yaw rate sensor 40, and the steering angle sensor 44 are respectively set to positive values generated when the vehicle turns to the left, the vehicle lateral acceleration Gy, the rotation angles φF and φR, the vehicle yaw rate γ, The steering angle θ is detected.

  The electronic control unit 24 estimates the roll moment acting on the vehicle based on the lateral acceleration Gy of the vehicle, calculates the target roll stiffness of the front and rear wheels, and cancels the roll moment according to the flowchart shown in FIG. Based on the roll moment and the target roll stiffness, the target rotation angles φFt and φRt of the actuators 20F and 20R of the active stabilizer devices 16 and 18 are calculated so that the moment increases, and the rotation angles φF and φR of the actuators 20F and 20R respectively correspond. Control is performed to achieve the target rotation angles φFt and φRt, thereby reducing the roll of the vehicle when turning.

  Accordingly, the active stabilizer devices 16 and 18 function as a front wheel side and rear wheel side anti-roll moment applying device that applies an anti-roll moment to the vehicle on the front wheel side and the rear wheel side, respectively. The active stabilizer devices 16 and 18, the electronic control device 26, the lateral acceleration sensor 60, and the like function as an anti-roll moment increasing / decreasing device that increases the anti-roll moment and reduces the roll of the vehicle when an excessive roll moment acts on the vehicle. To do.

  Further, the electronic control unit 24 determines whether or not an abnormality that cannot generate the required anti-roll moment has occurred in the anti-roll moment increasing / decreasing device including the active stabilizer devices 16, 18, and the like. A signal indicating whether an abnormality has occurred and the target roll stiffness ratio of the front and rear wheels is output to the electronic control unit 38.

  Note that the determination itself of whether or not the anti-roll moment increasing / decreasing device including the active stabilizer devices 16, 18 and the like itself is not a gist of the present invention. Therefore, the determination is performed in an arbitrary manner known in the art. You may be broken.

  For example, when signφf is a sign of the rotation angle φf of the actuator 20F of the active stabilizer device 16, a rotation angle deviation Δφf represented by signφf (φft−φf) is calculated, and the rotation angle deviation Δφf is greater than or equal to a reference value Δφfo. It may be determined whether or not the active stabilizer device 16 is abnormal by determining whether or not the active stabilizer device 18 is abnormal. In the same manner, it may be determined whether or not the active stabilizer device 18 is abnormal. In this case, the reference value Δφfo (and Δφro) may be a constant, but the magnitude of the lateral acceleration Gy of the vehicle or the estimated lateral acceleration Gyh of the vehicle estimated based on the steering angle θ and the vehicle speed V is large. It may be variably set based on the magnitude of the lateral acceleration Gy or the estimated lateral acceleration Gyh of the vehicle so as to increase.

  On the other hand, the electronic control unit 38 sets the vehicle stability factor Kh according to whether or not an abnormality has occurred in the anti-roll moment increasing / decreasing device and the target roll stiffness ratio of the front and rear wheels, according to the flowchart shown in FIG. The target yaw rate γt of the vehicle is calculated based on the vehicle steering angle θ, the vehicle speed V, and the stability factor Kh, and the deviation Δγ between the actual yaw rate (detected yaw rate) γ detected by the yaw rate sensor 40 and the target yaw rate γt is calculated. By calculating, based on the yaw rate deviation Δγ, calculating the target braking pressure Pti of each wheel for setting the yaw rate deviation Δγ to 0, and controlling the braking device 28 so that the braking pressure Pi of each wheel becomes the target braking pressure Pti. Control of braking force for vehicle running motion control is executed.

  Next, the control routine of the active stabilizer device achieved by the electronic control device 24 in the first embodiment will be described with reference to the flowchart shown in FIG. The control according to the flowchart shown in FIG. 2 is started by closing an ignition switch not shown in the figure, and is repeatedly executed at predetermined time intervals.

  First, in step 10, a signal indicating the vehicle speed V detected by the vehicle speed sensor 42 is read, and in step 20, it is determined whether or not the front wheel active stabilizer device 16 is normal. When an affirmative determination is made, the process proceeds to step 50. When a negative determination is made, the process proceeds to step 30.

  In step 30, the control of the front wheel active stabilizer device 16 is stopped, so that the operation is stopped. In step 40, the flag Fsf is set to 2 and the flag Fsf is 2. A signal is transmitted to the electronic control unit 38.

  In step 50, it is determined whether or not the rear wheel active stabilizer device 18 is normal. If an affirmative determination is made, the flag Fsf is set to 0 and the flag Fsf is set in step 60. When a signal indicating 0 is transmitted to the electronic control unit 38 and a negative determination is made, in step 70, the flag Fsf is set to 1 and the signal indicating that the flag Fsf is 1 is electronically controlled. Transmitted to the device 38.

  In step 80, the target anti-roll moment Mat is calculated based on the lateral acceleration Gy of the vehicle so that the target anti-roll moment Mat increases as the lateral acceleration Gy of the vehicle increases. The target anti-roll moment Mat may be calculated based on the estimated lateral acceleration Gyh of the vehicle calculated based on the vehicle speed V and the steering angle θ, and is calculated based on the lateral acceleration Gy and estimated lateral acceleration Gyh of the vehicle. Also good.

  In step 90, it is determined whether or not the flag Fsf is 0, that is, whether or not both the front wheel active stabilizer device 16 and the rear wheel active stabilizer device 18 are normal, and a negative determination is made. When the determination is made, the process proceeds to step 140. When the determination is affirmative, the process proceeds to step 100.

  In step 100, a front roll target roll stiffness distribution ratio Rsft (0 <Rsft <1) is calculated in a manner known in the art, and a signal indicating the front roll target roll stiffness distribution ratio Rsft is obtained. It is transmitted to the electronic control unit 38.

In step 110, the target anti-roll moment Maft for the front wheels and the target anti-roll moment Mart for the rear wheels are calculated according to the following equations 1 and 2, respectively.
Maft = Rsdt · Mat (1)
Mart = (1-Rsdt) Mat (2)

  In step 120, the target rotational angles φft and φrt of the actuators 20F and 20R of the active stabilizer devices 16 and 18 are calculated based on the front wheel target anti-roll moment Maft and the rear wheel target anti-roll moment Mart, respectively. In this case, the rotation angles φf and φr of the actuators 20F and 20R are controlled to be the target rotation angles φft and φrt, respectively.

  Next, a control routine for the vehicle running motion by controlling the braking force achieved by the electronic control unit 38 in the embodiment will be described with reference to the flowchart shown in FIG. Note that the control according to the flowchart shown in FIG. 3 is also started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.

  First, in step 210, a signal indicating the vehicle speed V detected by the vehicle speed sensor 42 is read, and in step 220, it is determined whether or not the flag Fsf is 0, that is, an active stabilizer device for the front wheels. It is determined whether both the 16 and the rear wheel active stabilizer device 18 are normal. If a negative determination is made, the process proceeds to step 240. If an affirmative determination is made, the process proceeds to step 230.

  In step 230, the target front / rear wheel distribution ratio Rfr = (1-Rsft) / Rsft is calculated as the ratio of the rear wheel target roll rigidity distribution ratio (1-Rsft) to the front wheel target roll rigidity distribution ratio Rsft. In addition, the stability factor used for calculating the target yaw rate γt of the vehicle based on the target front / rear wheel distribution ratio Rfr of the roll stiffness so that the stability factor Kh increases as the target front / rear wheel distribution ratio Rfr of the roll rigidity increases. Kh is calculated, and then the routine proceeds to step 270.

  In step 240, it is determined whether or not the flag Fsf is 1, that is, whether or not the front wheel active stabilizer device 16 is normal and the rear wheel active stabilizer device 18 is abnormal. Is performed, the stability factor Kh used for calculating the target yaw rate γt of the vehicle is set to Kh1 in step 250, and then the process proceeds to step 270. If the determination is negative, the vehicle is determined in step 260. After the stability factor Kh used for the calculation of the target yaw rate γt is set to Kh2, the routine proceeds to step 270.

  In this case, the stability factors Kh1 and Kh2 may be constant values set in advance, and the stability factors calculated when both the front wheel active stabilizer device 16 and the rear wheel active stabilizer device 18 are normal. When Kh is Kh0, the stability factors Kh1 and Kh2 are values greater than or equal to Kh0. The stability factor Kh2 is larger than the stability factor Kh1. That is, the magnitude relationship between these stability factors is Kh0 ≦ Kh1 <Kh2.

  In step 270, it is determined whether or not the vehicle is turning based on the steering angle θ or the like. If a negative determination is made, the process proceeds to step 310. If an affirmative determination is made, the process proceeds to step 280. .

  In step 280, it is determined whether or not the flag Fsf has changed, that is, whether or not the front wheel active stabilizer device 16 or the rear wheel active stabilizer device 18 has changed normally or abnormally. When the determination is made, the process proceeds to step 300. When the negative determination is made, the process proceeds to step 290.

  In step 290, it is determined whether or not asymptotic processing of the stability factor Kh in step 300 to be described later is completed. If an affirmative determination is made, the process proceeds to step 310, and a negative determination is made. Sometimes, in step 300, the stability factor Kh asymptotic processing is performed so that the value of the stability factor Kh used for the calculation of the target yaw rate γt gradually changes from the value before the change of the flag Fsf to the value after the change of the flag Fsf. After that, go to step 310.

In step 310, H is the wheel base, Rg is the steering gear ratio, the reference yaw rate γe is calculated according to the following equation 3 based on the vehicle speed V, the steering angle θ, and the stability factor Kh, and T is the time constant. Then, the target yaw rate γt of the vehicle is calculated according to the following equation 4 using s as a Laplace operator. The reference yaw rate γe may be calculated in consideration of the lateral acceleration Gy of the vehicle so as to consider the dynamic yaw rate.
γe = V · (θ / Rg) / {(1 + KhV ² ) H} (3)
γt = γe / (1 + Ts) (4)

  In step 320, a deviation Δγ between the yaw rate γ and the target yaw rate γt is calculated. In step 330, the target braking pressure Pti of each wheel for setting the yaw rate deviation Δγ to 0 based on the yaw rate deviation Δγ is determined in the present technology. The vehicle is controlled by controlling the braking device 28 so that the braking pressure Pi of each wheel becomes the target braking pressure Pti calculated in step 290 in step 340. The control of the braking force for the running motion control is executed.

  Thus, according to the illustrated embodiment, when the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18 are normal, the steps 20, 50, 80 of the control routine of the active stabilizer device shown in FIG. In step 80 and steps 100 to 130, an affirmative determination is made, and at least a part of the roll moment acting on the vehicle is exerted by the anti-roll moment applied to the vehicle by the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18. Accordingly, the roll of the vehicle when the vehicle turns is effectively suppressed.

  Further, according to the illustrated embodiment, when the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18 are normal, step 220 of the control routine of the vehicle traveling motion by controlling the braking force shown in FIG. In step 230, a target front / rear wheel distribution ratio Rfr = (1-Rsft) / Rsft of the roll rigidity is calculated based on the front roll target roll rigidity distribution ratio Rsft, and the roll rigidity of the roll rigidity is calculated. The vehicle stability factor Kh is calculated based on the roll stiffness target front / rear wheel distribution ratio Rfr so that the higher the target front / rear wheel distribution ratio Rfr, the greater the stability factor Kh used for calculating the target yaw rate γt.

  Therefore, according to the illustrated embodiment, when the front wheel side active stabilizer device 16 and the rear wheel side anti-roll moment increasing / decreasing device 18 are normal, the stability factor Kh increases as the roll rigidity target front / rear wheel distribution ratio Rfr increases. Since the stability factor Kh is calculated based on the target stiffness distribution ratio Rfr of the roll stiffness, the front and rear wheels of the roll stiffness by the control of the front wheel side active stabilizer device 16 and the rear wheel side anti-roll moment increasing / decreasing device 18 are calculated. The target yaw rate γt can be calculated to an optimal value according to the distribution ratio, which can cause the vehicle turning state to become oversteered or understeered due to control of the vehicle's running motion. Can be reliably prevented, and this effectively stabilizes the running movement of the vehicle. Can.

  According to the illustrated embodiment, when the front wheel side active stabilizer device 16 is normal, but when the rear wheel side active stabilizer device 18 is abnormal, an affirmative determination is made at step 20, and steps 50 and 90 are performed. In step 80 and steps 140 to 160, the operation of the rear wheel side active stabilizer device 18 is stopped, and the anti-roll moment applied to the vehicle by the front wheel side active stabilizer device 16 is determined. The roll moment acting on the vehicle is at least partially offset, thereby suppressing the roll of the vehicle when the vehicle is turning.

  In this case, the magnitude of the anti-roll moment applied to the vehicle by the front wheel side active stabilizer device 16 is determined by the front wheel side active stabilizer device 16 when the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18 are normal. It is smaller than the magnitude of the anti-roll moment applied to the vehicle.

  When the rear wheel side active stabilizer device 18 is normal, but the front wheel side active stabilizer device 16 is abnormal, a negative determination is made at step 20, and at step 30, the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 16 are determined. The operation of the wheel side active stabilizer device 18 is stopped, and the anti-roll moment is not applied to the vehicle by the rear wheel side active stabilizer device 18, which causes the roll rigidity on the rear wheel side to be excessive and the vehicle to turn excessively. An oversteer state is reliably prevented.

  A signal indicating the flag Fsf is transmitted to the electronic control unit 38 in steps 40, 60, and 70 regardless of whether the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18 are normal. Thus, information on whether or not the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18 are normal is transmitted to the electronic control device 38. When the front wheel side active stabilizer device 16 and the rear wheel side active stabilizer device 18 are normal, a signal indicating the target roll stiffness distribution ratio Rsft of the front wheels is transmitted to the electronic control unit 38 in step 100.

  On the other hand, when the front wheel side active stabilizer device 16 is normal but the rear wheel side active stabilizer device 18 is abnormal, a negative determination is made at step 220 and an affirmative determination is made at step 240. In step 250, the stability factor Kh used for the calculation of the target yaw rate γt is set to Kh1 equal to or higher than Kh0. When the rear wheel side active stabilizer device 18 is normal but the front wheel side active stabilizer device 16 is abnormal, a negative determination is made in steps 220 and 240, and in step 260, the target yaw rate γt is calculated. The provided stability factor Kh is set to Kh2 which is larger than Kh1.

  In step 310, the target yaw rate γt of the vehicle is calculated based on the vehicle speed V, the steering angle θ, and the stability factor Kh. In steps 320 to 340, each wheel is controlled so that the yaw rate γ of the vehicle becomes the target yaw rate γt. Power is controlled.

  Therefore, according to the illustrated embodiment, when the front wheel side active stabilizer device 16 or the rear wheel side active stabilizer device 18 is abnormal, the stability factor Kh is larger than that when the two active stabilizer devices are normal. Since the magnitude of the target yaw rate γt is reduced, the magnitude of the deviation Δγ between the vehicle yaw rate γ and the target yaw rate γt can be reliably reduced, thereby controlling the braking force control amount. Therefore, it is possible to reliably prevent the turning state of the vehicle from being oversteered due to the excessive amount of the vehicle.

  Further, according to the illustrated embodiment, when the front wheel side active stabilizer device 16 is normal, but the rear wheel side active stabilizer device 18 is abnormal, the stability factor Kh is set to Kh1 equal to or higher than Kh0, The side active stabilizer device 18 is normal, but when the front wheel side active stabilizer device 16 is abnormal, the stability factor Kh is set to Kh2 larger than Kh1, so the front wheel side active stabilizer device 16 and the rear wheel side active The magnitude of the target yaw rate γt can be reduced optimally depending on which of the stabilizer devices 18 is abnormal.

  Further, according to the illustrated embodiment, when the front wheel side active stabilizer device 16 or the rear wheel side anti-roll moment increasing / decreasing device 18 changes from a normal state to an abnormal state, the stability provided for calculation of the target yaw rate γt. The front wheel side active stabilizer device 16 or the rear wheel side anti-roll moment increasing / decreasing device 18 is more abnormal than the factor Kh when the front wheel side active stabilizer device 16 or the rear wheel side anti-roll moment increasing / decreasing device 18 is in a normal state. In steps 270 to 290, asymptotic processing of the stability factor Kh is performed so as to gradually change to the value at the state.

  Therefore, when the front wheel side active stabilizer device 16 or the rear wheel side anti-roll moment increasing / decreasing device 18 changes from a normal state to an abnormal state, the stability factor Kh changes suddenly, and the target yaw rate γt changes suddenly. Thus, it is possible to reliably prevent the control amount of the braking force of each wheel for controlling the traveling motion of the vehicle from abruptly changing and the sudden variation in the traveling motion of the vehicle resulting from this. it can.

  Further, according to the illustrated embodiment, it is determined in step 270 whether or not the vehicle is turning, and asymptotic processing of the stability factor Kh is performed by steps 280 to 300 only when the vehicle is turning. Therefore, even if the target yaw rate γt changes due to the change of the stability factor Kh, there is no risk that the running motion of the vehicle will change suddenly. Can be prevented.

  Although the present invention has been described in detail with reference to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.

  For example, in the above-described embodiment, the anti-roll moment is increased by the active stabilizer device to increase or decrease the roll rigidity of the vehicle. Any means known in the art that can increase or decrease the load may be used.

  In the above-described embodiment, the front and rear wheel distribution ratio Rfr of the target roll rigidity is calculated based on the target roll rigidity distribution ratio Rsft of the front wheel, and the target yaw rate γt is calculated as the front and rear wheel distribution ratio Rfr of the target roll rigidity is higher. The stability factor Kh of the vehicle is calculated on the basis of the front and rear wheel distribution ratio Rfr of the target roll stiffness so that the stability factor Kh provided to the vehicle is increased, but the rotation angle φf of the actuators 20F and 20R and The front / rear wheel distribution ratio of roll rigidity is calculated based on φr, and the stability factor Kh is calculated based on the front / rear wheel distribution ratio of roll rigidity so that the stability factor Kh increases as the front / rear wheel distribution ratio of roll rigidity increases. It may be modified as follows.

  In the above-described embodiment, when it is determined in step 20 that the front wheel active stabilizer device 16 is abnormal, the control of the front wheel active stabilizer device 16 is stopped in step 30. The operation is stopped, and a negative determination is made in step 240, so that in step 260, the stability factor Kh used for calculating the target yaw rate γt of the vehicle is set to Kh2. When it is determined that the front wheel active stabilizer device 16 is abnormal, it is determined whether or not the rear wheel active stabilizer device 18 is abnormal, and the front wheel and rear wheel active stabilizer devices are abnormal. If the determination is made, the control may be modified such that the control of the running motion of the vehicle by the control of the braking force is stopped.

  In the above-described embodiment, when the front wheel side active stabilizer device 16 or the rear wheel side anti-roll moment increasing / decreasing device 18 changes from a normal state to an abnormal state, an asymptotic process of the stability factor Kh is performed. However, this asymptotic process may be omitted.

  In the above-described embodiment, whether or not the active stabilizer device is normal is determined based on the rotation angle of the actuators 20F and 20R, but the torque of the torsion bar portion is detected. The determination may be made based on the relationship between the detected torque and the control command value for the actuator of the active stabilizer device.

  In the above-described embodiment, the control of the running motion of the vehicle is performed by controlling the braking force of each wheel, but the braking force and driving force of each wheel are controlled. May be modified to be executed.

It is a schematic block diagram showing one embodiment of a vehicle travel motion control device according to the present invention applied to a vehicle provided with an active stabilizer device on the front wheel side and the rear wheel side. It is a flowchart which shows the control routine of the active stabilizer apparatus in an Example. It is a flowchart which shows the control routine of the running motion of the vehicle in an Example.

Explanation of symbols

16, 18 Active stabilizer device 24, 26 Electronic control device 25 Lateral acceleration sensor 26F, 26R Rotation angle sensor 28 Braking device 40 Yaw rate sensor 42 Vehicle speed sensor 44 Steering angle sensor

Claims (4)

  Target yaw rate setting means for setting the target yaw rate of the vehicle, braking / driving force control means for controlling the braking / driving force of each wheel so that the yaw rate of the vehicle becomes the target yaw rate, and roll rigidity on the front wheel side or the rear wheel side is increased or decreased. In the vehicle running motion control apparatus having the roll stiffness variable device, the target yaw rate setting means reduces the target yaw rate as the ratio of the roll stiffness on the rear wheel side to the roll stiffness on the front wheel side is higher. A vehicle movement control apparatus characterized by the above.   The target yaw rate setting means sets the target yaw rate based on at least a stability factor, and increases the stability factor by increasing the stability factor as the ratio of the roll rigidity on the rear wheel side to the roll rigidity on the front wheel side increases. The vehicle travel motion control device according to claim 1, wherein the size is reduced.   3. The vehicle according to claim 1, wherein the roll stiffness varying device includes an anti-roll moment increasing / decreasing device that is provided on a front wheel side or a rear wheel side and increases / decreases an anti-roll moment applied to the vehicle. Traveling motion control device. 4. The vehicle travel motion control device according to claim 3, wherein the anti-roll moment increasing / decreasing device comprises a front wheel side anti-roll moment increasing / decreasing device and a rear wheel side anti-roll moment increasing / decreasing device.

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