Mazda Motor Corporation

Jtekt Corporation

Akihiro Tatara

Yasushi Yagi

Daisuke Kofu

Yasumasa Imamura

Ryohei Shigeta

Tomohiro Nozu

Go Nagayama

Akira Kodama

Naoki Nobutani

Tetsushi Marutani

Keisuke Haruta

Hideki Tani

Yagi Yasushi

A driving force control devicefor a vehicle V comprises: a D-&#x3bc; map Mdefining a linear correlation between a driving stiffness D and a maximum road surface &#x3bc;; a slip ratio calculation circuitfor calculating a slip ratio S of one of a pair of front road wheelsL,R; a DS calculation circuitfor calculating the driving stiffness D corresponding to a value the slip ratio S calculated by the slip ratio calculation circuit; a maximum road surface &#x3bc; calculation circuitfor assigning a value of the driving stiffness D calculated by the DS calculation circuitto the D-&#x3bc; map Mto calculate the maximum road surface &#x3bc;; and a driving force distribution circuitfor controlling a driving force, using a value of the maximum road surface &#x3bc; calculated by the maximum road surface &#x3bc; calculation circuit

Driving force control method and system for vehicle

A method of controlling driving force of a vehicle includes estimating a first maximum road surface frictional coefficient based on a driving stiffness defined by a micro slip ratio and driving force of drive wheels, in a first driving state where the vehicle travels straight at a constant acceleration, estimating a second maximum road surface frictional coefficient based on a steering reaction force detected by an electric power steering device, in a second driving state different from the first state and where the vehicle is steered, estimating a third maximum road surface frictional coefficient to be a given value in a third driving state different from the first and second states and where an outdoor air temperature is above a determination temperature, and controlling the driving force to settle within a friction circle defined by each of the highest frictional coefficients and a ground contact load of the drive wheels.

Method of controlling driving force of vehicle

A wheel load estimation method of a four-wheel drive vehicle driven by a rotational driving device comprises a correlation relationship setting step for previously setting a correlation relationship between a total weight and at least one of the front wheel load and the rear wheel load by variously changing a movable load of the vehicle, a total vehicle weight computation step for calculating a current total vehicle weight from an output torque of the rotational driving device and a longitudinal acceleration of the vehicle corresponding to the output torque, and a wheel load estimation step for estimating the wheel load of at least a driving wheel from the correlation relationship and the total vehicle weight.

Wheel load estimation method for four-wheel drive vehicle

A method of controlling a driving force of a four-wheel drive vehicle includes causing a control unit to acquire a vehicle speed, a lateral acceleration, a driving force of a wheel, a road surface friction coefficient, and a ground contact load of the wheel when the vehicle is traveling, determine whether a road surface is rough based on the acquired road surface condition, correct, when the road surface is determined to be rough, the load of the wheel, by applying thereto a load change rate set according to the roughness, predict a slip occurrence of the wheel by comparing a product of the corrected load and the road surface friction coefficient to a total force of the driving force and a lateral force caused by a lateral acceleration in cornering, and reduce, when the slip occurrence is predicted, the driving force so as to prevent the slip occurrence.

Method of controlling driving force

A driving force distribution control device, which is mounted on a vehicle including an engine configured to generate driving force for the vehicle, a transmission device configured to shift rotation of an output shaft of the engine by transmission ratios, and a driving force transmission system capable of transmitting output of the transmission device to main drive wheels and auxiliary drive wheels, includes: a control device configured to, when a rotational speed of the output shaft of the engine is in a range in which abnormal sound of the driving force transmission system due to pulsation of the driving force can be generated, set a torque value to a value capable of reducing the abnormal sound depending on the driving force; and a driving force transmitting device configured to transmit driving force depending on the set value to the auxiliary drive wheels.

Driving force distribution control device and four-wheel-drive vehicle

A road surface frictional coefficient estimation device includes: a first straight travel determination unit configured to determine whether or not a vehicle travels straight based on a rotational speed difference between a plurality of wheels of the vehicle; a second straight travel determination unit configured to determine whether or not the vehicle travels straight based on a steering angle of the vehicle; a selection unit configured to select one of determination results of the first straight travel determination unit and the second straight travel determination unit; and a frictional coefficient estimation unit configured to estimate a frictional coefficient of a road surface on which the vehicle travels when the one of the determination results selected by the selection unit indicates that the vehicle travels straight.

Road surface frictional coefficient estimation device, driving force distribution control device and four-wheel-drive vehicle

A driving force distribution control device mounted on a vehicle including an engine, a transmission device, a clutch engaging an output shaft of the engine with an input shaft of the transmission device, and a driving force transmission system capable of transmitting output of the transmission device to main and auxiliary drive wheels, includes: a control device obtaining a torque value to be transmitted to the auxiliary drive wheels, the control device reducing the torque value for a predetermined time when the vehicle is in a stopped state or in a state where a vehicle speed of the vehicle is lower than a predetermined value, and an increasing speed of engaging force of the clutch is equal to or greater than a predetermined value; and a driving force transmitting device transmitting torque depending on the obtained torque value to the auxiliary drive wheels.

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Aki-gun, Japan

Akihiro Tatara