Electric power steering device, control device for electric power steering device, and program
AssigneeHitachi Astemo, Ltd.
InventorKyoichi Tagami
Life of this patent
Estimating the term…
Abstract
An electric power steering device 100 includes: an electric motor 110 configured to apply a driving force to steer a wheel in response to operation of a steering wheel; and a control device 10 configured to perform control of drive of the electric motor by estimating a degree of sloping in a transverse direction of a roadway on which a vehicle travels, determining, based on the estimated degree of sloping, a correction current for correcting a target current required for the electric motor to generate the driving force, and correcting the target current with the correction current.
Claims9
An electric power steering device comprising:
- an electric motor configured to apply a driving force to steer a wheel in response to operation of a steering wheel;
- and
- a control unit configured to perform control of drive of the electric motor by estimating a degree of sloping in a transverse direction of a roadway on which a vehicle travels, determining, based on the estimated degree of sloping, a correction current for correcting a target current required for the electric motor to generate the driving force, and correcting the target current with the correction current, wherein
- the control unit is configured to:
- determine conditions of a road surface of the roadway and change the control according to the determined conditions of the road surface;
- and
- perform the control when the road surface is paved, and not to perform the control in response to determining that the road surface is unpaved when a number of times where a differential value for an indicator representing the degree of sloping is greater than a predetermined first threshold exceeds a second threshold during a unit of time.
A control device for an electric power steering device, the control device comprising:
- a slope estimator configured to estimate a degree of sloping in a transverse direction of a roadway on which a vehicle travels;
- a road surface determiner configured to determine conditions of a road surface of the roadway;
- a correction current determiner configured to determine, based on the conditions of the road surface of the roadway determined by the road surface determiner and the estimated degree of sloping, a correction current for correcting a target current required for an electric motor to generate a driving force;
- and
- a target current determiner configured to determine the target current based on the determined correction current, wherein
- the road surface determiner is configured to determine that the road surface is unpaved when a number of times where a differential value for an indicator representing the degree of sloping is greater than a predetermined first threshold exceeds a second threshold during a unit of time, and determine that the road surface is paved when the number of times does not exceed the second threshold during the unit of time, and
- the correction current determiner is configured to determine the correction current based on the estimated degree of sloping when the road surface is paved, and set the correction current to 0 when the road surface is unpaved.
Dependencies are inferred from the claim text.