Honda Motor Co., Ltd.

Kyohei Sakagami

Masamichi Harada

Hirohiko Totsuka

Makito Nakasone

Shigeji Nakano

Masato Shigenaga

A travel control system for a vehicle provided with a drive source, a wheel having a wheel body connected to the drive source via a power transmission member and a tire mounted on the wheel body, and a braking device for braking the wheel includes: an estimation unit configured to estimate a tire torsional stiffness and a road surface friction coefficient based on at least the rotation speed of the drive source, the rotation speed of the wheel body, the vehicle body speed, and the torque applied to the wheel body; and a control unit configured to control at least one of the drive source and the braking device such that the tire does not exceed an adhesion limit derived from the tire torsional stiffness and the road surface friction coefficient.

Travel control system and travel control method

A travel control system for a vehicle includes: an external environment recognizing unit that recognizes an obstacle around the vehicle; a tire parameter estimation unit that estimates a tire parameter of a tire of the vehicle; and a travel plan unit that sets a travel route, an amount of acceleration and deceleration, and an amount of turning based on the obstacle and the tire parameter. The travel plan unit sets the travel route, the amount of acceleration and deceleration, and the amount of turning so as to suppress an excess amount of a slip ratio of the tire relative to an adhesion limit slip ratio while avoiding approach to the obstacle.

In a control unit of a hydraulic control device, a vehicle state grasping unit grasps a vehicle state of a vehicle, and an output determination unit determines whether an operation point depending on the vehicle state that is decided by an operation point decision unit is over a discharging capability limit line. A pump controller stops a second pump or decreases a rotation number if the output determination unit determines that the operation point is over the discharging capability limit line.

Hydraulic control device

In a hydraulic control device, a hydraulic sensor is provided on an intake side of a second pump where first oil is taken in and a line pressure sensor is provided on a discharging side of the second pump where the second oil is discharged. A control unit controls driving of the second pump by controlling a motor on the basis of an output pressure detected by the output pressure sensor or a line pressure detected by the line pressure sensor.

A compression control device for a continuously variable transmission is provided in which the compression control device that controls the compression of either one of shaft elements of the continuously variable transmission calculates a slip state matrix from an amplitude ratio between a variable component of a rotational speed of the input shaft and a variable component of a rotational speed of the output shaft, a phase lag that is an indicator of difference in phase between a variable component of the rotational speed of the input shaft and a variable component of the rotational speed of the output shaft, and a gear ratio between the input shaft and the output shaft, estimates a power transmission state among the input shaft element, the output shaft element, and the power transmission element based on an eigenvalue sequence calculated from the slip state matrix, and controls compression.

Compression control device for continuously variable transmission

An abnormality determination device for a continuously variable transmission is provided in which since the abnormality determination device which calculates a compression stiffness of a metal belt from an amplitude ratio between a variable component of the rotational speed of an input shaft and a variable component of the rotational speed of an output shaft, a phase lag that is an indicator of the difference in phase between a variable component of the rotational speed of the input shaft and a variable component of the rotational speed of the output shaft, and a belt pitch radius of a drive pulley or a driven pulley, and determines whether a metal ring has broken by comparing the compression stiffness of the metal belt with a preset reference compression stiffness.

Abnormality determination device for continuously variable transmission

A compression control device for a continuously variable transmission is provided in which when estimating the torque ratio, which is the ratio of the actually transmitted torque relative to the maximum transmittable torque of the continuously variable transmission, based on the transmission characteristics for transmitting the given variable component of the input shaft to the output shaft via an endless belt, a slip identifier, which is an indicator for the ratio of the amplitude of the variable component between the input shaft and the output shaft, or a phase lag, which is an indicator for difference in phase of the variable component, is used. It is possible to improve the control responsiveness and reduce the computation load of the control device and to improve the power transmission efficiency of the continuously variable transmission while preventing the endless belt thereof from slipping.

When estimating a torque ratio, which is the ratio of an actually transmitted torque relative to the maximum transmittable torque of a continuously variable transmission, based on the transmission characteristics for transmitting a given variable component of an input shaft element to an output shaft element via a frictional element, since the torque ratio is estimated from a slip identifier, an indicator for difference in amplitude of a variable component between the two elements, or a phase lag, an indicator for difference in phase of the variable component between the two elements, it is possible to estimate the torque ratio, which is closely related to the power transmission efficiency of the continuously variable transmission, with good precision, thus improving the power transmission efficiency. Moreover, since the torque ratio is estimated from the slip identifier or the phase lag, it is possible to minimize the number of sensors necessary for estimation.

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Wako, Japan

Kyohei Sakagami