Device for improving vehicle behavior when steering

Abstract

The drive torque of a motor for driving a vehicle wheel, as shown in (a), during the period between the start of steering t1 and an instant t2 when a prescribed interval TM1s has passed, is controlled so as to be a value which is temporarily increased from the intended motor torque by just the amount indicated by the solid line waveform in (a); and during the period between t2 and an instant t4 when a prescribed interval TM2s has passed, the drive torque of a motor for driving a vehicle wheel is controlled so as to be a value which is temporarily decreased from the intended motor torque by just the amount indicated by the solid line waveform in (a). In the t1 - t2 interval (initial stage) of (c), the turning moment becomes large according to the difference between the turning moment of the turning direction of the outer wheel Mout and the turning moment (restoring moment) of the turning direction of the inner wheel Min. The increment in the yaw rate promptly rises in the initial stage of the instant t1 - t2 as indicated by a solid line in (b), in accordance with the increase in the apparent lateral force caused by the increase in the turning moment, thus the yaw rate is caused to rise without delay, and thereby it is possible to greatly improve the steering response (initial turning characteristics) of the vehicle.

Description

technical field [0001] The present invention relates to a device for improving the steering behavior of a vehicle capable of driving wheels with driving force from a power source when turning, that is, steering response and roll behavior. Background technique [0002] Recently, in order to reduce fuel consumption, fuel-efficient tires with low rolling resistance are used in vehicles, and the sprung weight on the upper side of the suspension device of the vehicle tends to increase due to the addition of fuel consumption countermeasures, etc., and the need to install large-capacity batteries for this purpose. . [0003] The use of fuel-efficient tires means that the coefficient of friction with the road surface becomes smaller, and the increase in sprung weight means that the suspension travel becomes larger. [0004] Both the decrease in the coefficient of friction of the road surface and the increase in the suspension stroke have the effect of reducing the steering response...

AI Technical Summary

Problems solved by technology

[0009] However, as described above, in measures to increase the mounting rigidity of the suspension or increase the vibration damping force of the shock absorber, the spring constant of the suspension becomes large, and new problems related to vibration and noise arise.

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