公开(公告)号：US10471952B2

公开(公告)日：2019-11-12

申请号：US16006690

申请日：2018-06-12

Applicant: Mazda Motor Corporation

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Daisuke Kofu ,  Akihiro Tatara ,  Naoki Nobutani

IPC: B60W30/02

Abstract: 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.

公开(公告)号：US11420618B2

公开(公告)日：2022-08-23

申请号：US16346570

申请日：2017-11-02

Applicant: MAZDA MOTOR CORPORATION

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Tetsushi Marutani ,  Naoki Nobutani ,  Daisuke Kofu ,  Akihiro Tatara

IPC: B60W30/188 ,  B60W30/02 ,  B60K17/348 ,  B60W10/06 ,  B60W10/119 ,  B60W10/14 ,  B60W40/064 ,  B60W40/068

Abstract: A driving force control device 1 for a vehicle V comprises: a D-μ map M1 defining a linear correlation between a driving stiffness D and a maximum road surface μ; a slip ratio calculation circuit 21 for calculating a slip ratio S of one of a pair of front road wheels 10L, 10R; a DS calculation circuit 22 for calculating the driving stiffness D corresponding to a value the slip ratio S calculated by the slip ratio calculation circuit 21; a maximum road surface μ calculation circuit 23 for assigning a value of the driving stiffness D calculated by the DS calculation circuit 22 to the D-μ map M1 to calculate the maximum road surface μ; and a driving force distribution circuit 24 for controlling a driving force, using a value of the maximum road surface μ calculated by the maximum road surface μ calculation circuit 23.

公开(公告)号：US10981572B2

公开(公告)日：2021-04-20

申请号：US16145526

申请日：2018-09-28

Applicant: Mazda Motor Corporation

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Akihiro Tatara ,  Tetsushi Marutani ,  Hideki Tani

IPC: B60W30/188

Abstract: 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.

公开(公告)号：US20180362021A1

公开(公告)日：2018-12-20

申请号：US16006690

申请日：2018-06-12

Applicant: Mazda Motor Corporation

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Daisuke Kofu ,  Akihiro Tatara ,  Naoki Nobutani

IPC: B60W30/02

CPC classification number: B60W30/02 ,  B60W2520/26 ,  B60W2520/28 ,  B60W2550/147 ,  B60W2720/26

Abstract: 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.

公开(公告)号：US10946863B2

公开(公告)日：2021-03-16

申请号：US16116808

申请日：2018-08-29

Applicant: Mazda Motor Corporation

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Akihiro Tatara ,  Keisuke Haruta

IPC: B60W40/13

Abstract: 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.

公开(公告)号：US20190100203A1

公开(公告)日：2019-04-04

申请号：US16145526

申请日：2018-09-28

Applicant: Mazda Motor Corporation

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Akihiro Tatara ,  Tetsushi Marutani ,  Hideki Tani

IPC: B60W30/188

Abstract: 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.

公开(公告)号：US20190061770A1

公开(公告)日：2019-02-28

申请号：US16116808

申请日：2018-08-29

Applicant: Mazda Motor Corporation

Inventor： Yasumasa Imamura ,  Yasushi Yagi ,  Akihiro Tatara ,  Keisuke Haruta

IPC: B60W40/13

Abstract: 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.