Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Hiroyuki Urabe

Toru Takenaka

Takayuki Toyoshima

Hiroshi Kono

Keiyu Kin

Osamu Yano

Yoshihiro Mori

Toshiaki Matsuzawa

Shuji Shiraishi

Yukihiro Orimoto

Tomoya Ushimura

The present disclosure relates to a hub bracket structure wherein a hub bracket that connects a trailing arm and a hub includes a hub mounting surface, a front connecting surface that connects a front portion of the hub mounting surface and the trailing arm, and a rear connecting surface that connects a rear portion of the hub mounting surface and the trailing arm, each of the front connecting surface and the rear connecting surface is formed in a plate shape extending in up-down and vehicle width directions, and an angle formed by the hub mounting surface and the front connecting surface is greater than an angle formed by the hub mounting surface and the rear connecting surface.

Hub bracket structure

A hub bracket structure includes a hub bracket that connects a trailing arm and a hub carrier, wherein the hub bracket includes a bracket body that includes a mounting surface mounted with the hub carrier, and a rear connector that extends from the bracket body toward the trailing arm behind a ground contact point of a rear wheel, and the rear connector is extended to a position to overlap with a rear surface of the trailing arm in a front-rear direction and is joined to the rear surface of the trailing arm.

A road surface frictional coefficient estimating apparatus includes a device which determines a first estimated value of a to-be-compared external force acting on a vehicle due to the resultant force of road surface reaction forces using a determined frictional coefficient estimated value and the like, and a device which determines a second estimated value of the to-be-compared external force from the observed value of motional state amounts of the vehicle that define an inertial force corresponding to the to-be-compared external force. The estimated value of a road surface frictional coefficient is updated based on the difference between the first estimated value and the second estimated value. When the first estimated value and the second estimated value have opposite polarities, the updating of the estimated value of the road surface frictional coefficient based on the difference is not carried out.

Road surface frictional coefficient estimating apparatus

A road surface friction coefficient estimating device includes a means which finds a first estimated value Mnsp_estm of an external force to be compared (Sto S, S-), a means which finds a second estimated value Mnsp_sens (S-), and a plurality of increasing/decreasing manipulated variable determining means_k, each of which determines the increasing/decreasing manipulated variable &#x394;&#x3bc;_k of the friction coefficient estimated value on the basis of the first estimated value Mnsp_estm and the second estimated value Mnsp_sens, and updates the friction coefficient estimated value according to &#x394;&#x3bc;_k. The increasing/decreasing manipulated variable determining meansanddetermine &#x394;&#x3bc;and &#x394;&#x3bc;according to a deviation in filtering value between the first estimated value and the second estimated value, and the increasing/decreasing manipulated variable determining meansdetermines &#x394;&#x3bc;according to the deviation between the first estimated value and the second estimated value.

Road surface friction coefficient estimating device

A road surface frictional coefficient estimating apparatus has a device for determining a first estimated value of a yaw moment Mnsp_estm generated at an NSP of a vehicle due to the resultant force of road surface reaction forces acting on each wheel by using, for example, a frictional coefficient estimated value that has been determined, and a device for determining a second estimated value of a yaw moment Mnsp_sens generated at the NSP from the observed value of motional state amounts defining an inertial force moment at the NSP. The increasing/decreasing manipulated variable of the frictional coefficient estimated value is sequentially determined on an error (Mnsp_sens&#x2212;Mnsp_estm) such that the error is converged to zero, and the road surface frictional coefficient is updated on the basis of the increasing/decreasing manipulated variable.

A driving/braking force manipulation control input of a k-th wheel, which denotes one or more specific wheels among a plurality of wheels of a vehicle, is determined such that a required condition concerning a relationship among a road surface reaction force that may act from a road surface on the k-th wheel on the basis of the detected values or estimated values of a side slip angle and a friction characteristic of the k-th wheel, a feedback control input related to the driving/braking force of the k-th wheel for bringing a difference between a state amount of the vehicle and a reference state amount close to zero, a driving/braking force feedforward control input based on a drive manipulated variable supplied by a driver of the vehicle, and a k-th wheel driving/braking force manipulation control input is satisfied. This arrangement makes it possible to properly control a motion of an actual vehicle to a desired motion while properly considering the characteristics of a road surface reaction force acting from a road surface on a wheel.

Vehicle control device

An actual vehicle actuator operation control input and a model operation control input are determined by an FB distribution law such that the difference between a reference state amount determined in a vehicle model and an actual state amount of an actual vehicle approximates zero, and then an actuator device of the actual vehicle and the vehicle model are operated on the basis of the control inputs. The value of a parameter of the vehicle model set according to an actual vehicle motional state such that the attenuation property of a reference state amount when a drive manipulated variable is changed is higher than the attenuation property of an actual state amount. Accordingly, the actual vehicle actuator device is properly controlled independently of an actual vehicle motional state such that a state amount related to an actual vehicle motion approximates a vehicle state amount on a dynamic characteristic model.

A control input for operating an actual vehicle actuator and a control input for operating a vehicle model are determined by an FB distribution law based on a difference between a reference state amount determined by a vehicle model and an actual state amount of an actual vehicle such that the state amount error is approximated to zero, and then an actuator device of the actual vehicle and the model vehicle are operated based on the control inputs. The FB distribution law determines a control input for operating the model such that a state amount error is approximated to zero while restraining a predetermined restriction object amount from deviating from a permissible range. A vehicle control device capable of enhancing robustness against disturbance factors or their changes while performing operation control of actuators that is as suited to behaviors of an actual vehicle as possible is provided.

A driving/braking force manipulation control input of a k-th wheel, which denotes one or more specific wheels among a plurality of wheels of a vehicle, is determined such that a required condition concerning a relationship among a road surface reaction force that may act from a road surface on the k-th wheel on the basis of the detected values or estimated values of a road surface reaction force and a friction characteristic of the k-th wheel, a feedback control input related to the driving/braking force of the k-th wheel for bringing a difference between a state amount of the vehicle and a reference state amount close to zero, a driving/braking force feedforward control input based on a drive manipulated variable supplied by a driver of the vehicle, and a k-th wheel driving/braking force manipulation control input is satisfied.

Controller of vehicle

A basic required manipulated variable Mfbdmd_a is determined on the basis of a state amount error, which is the difference between a state amount of a motion of an actual vehicleand a reference state amount, then a driving/braking force manipulation control input Fxfbdmd_n of a wheel is determined on the basis of the above basic required manipulated variable. At this time, a change in a driving/braking force operation control input Fxdmd_n of a front wheel and a rear wheel, respectively, of a particular set is made to be proportional to a change in the basic required manipulated variable Mfbdmd_a, and the ratio (gain) of a change in Fxdmd_n with respect to a change in Mfbdmd_a is made to change on the basis of gain adjustment parameters, such as side slip angles &#x3b2;f_act and &#x3b2;r_act. This makes it possible to properly control a motion of the actual vehicle to a desired motion by properly manipulating a road surface reaction force acting on a front wheel of the vehicle and a road surface reaction force acting on a rear wheel.

An FB distribution ruledetermines an actual vehicle actuator operation control input and a vehicle model operation control input such that a difference between a reference state amount determined by a vehicle modeland an actual state amount of an actual vehicle(a state amount error) approximates to zero, and the control inputs are used to operate an actuator deviceof the actual vehicleand the vehicle model. In the FB distribution law, when an actual vehicle feedback required amount based on the state amount error exists in a dead zone, then an actual vehicle actuator operation control input is determined by using the required amount as a predetermined value. A vehicle model manipulated variable control input is determined such that a state amount error is brought close to zero, independently of whether an actual vehicle feedback required amount exists in a dead zone. This enhances linearity of a control system and also enhances the robustness against disturbance factors or changes therein while carrying out operation control of an actuator that suits a behavior of an actual vehicle as much as possible.

A control input for operating an actual vehicle actuator and a control input for operating a vehicle model are determined by an FB distribution law based on a state amount error which is a difference between a reference state amount determined by a vehicle model and an actual state amount of an actual vehicle such that the state amount error is approximated to zero. An actuator device of the actual vehicle and the model vehicle, respectively, are then operated based on the control inputs. The FB distribution law estimates an external force acting on the actual vehicle due to a control input for operating an actual vehicle actuator, and determines a control input for operating the vehicle model on the basis of the estimated value and a basic value of a control input for operating the vehicle model for approximating the state amount error to zero.

In a vehicle motion control system based on a target yaw rate scheme, a brake force computing unit brakes an outer front wheel in a controlled manner when a sign of the yaw rate has changed and the yaw rate increment has become equal to or greater than a threshold value after a counter steer action has been detected and the vehicle body slip angle has become equal to or greater than a threshold value. Thus, suppose that a vehicle travels a winding road and a counter steer action is taken. If the vehicle body slip angle and actual yaw rate increment exceed threshold values, the outer front wheel is braked. Therefore, even when the vehicle body slip angle reaches a maximum value and an attempt is made to reduce it again by a counter steer action in a similar manner as a swinging pendulum, because the increases in the yaw rate and actual yaw rate increment are predicted and monitored before the vehicle body slip angle reaches its maximum value, the vehicle is enabled to travel in a stable fashion.

Vehicle motion control system

In a system for computing a road surface frictional coefficient for controlling a motion of a vehicle, the road surface frictional coefficient is estimated according to the deviation of the estimated vehicle body fore-and-aft/lateral acceleration from the actually detected vehicle body fore-and-aft/lateral acceleration, instead of estimating it directly from the tire slip ratio so that the road surface frictional coefficient is prevented from being estimated substantially higher than it actually is. In particular, by judging a sudden change in the road surface frictional coefficient only when a change in the road surface frictional coefficient, in particular an increase in the frictional coefficient, has persisted for more than a prescribed time period, an error in the estimation of the road surface frictional coefficient can be minimized, and a favorable vehicle motion control based on the estimated road surface frictional coefficient can be ensured under all conditions.

System for computing a road surface frictional coefficient

The turning behavior state of a vehicle is determined by a determining device, by comparing a front wheel slip angle and a rear wheel slip angle calculated based on a lateral slip angle of a vehicle body by a wheel slip angle calculating device, with a front wheel slip angle limit value and a rear wheel slip angle limit value which are determined based on a vehicle speed detected by a vehicle speed detecting device and a friction coefficient presumed by a friction coefficient presuming device. Thus, even in a state in which the road surface friction coefficient is low, the turning behavior state of the vehicle can be detected precisely.

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Wako, Japan

Hiroyuki Urabe