Vehicle steering apparatus, method and non-transitory computer readable medium

摘要

According to a relaxation length compensation torque computation section 54 of a vehicle steering apparatus 100, a relaxation length compensation torque is computed based on (1) a front wheel actual steering angular velocity computed from a motor rotation angular velocity input by a front wheel actual steering angular velocity computation section 52, and based on (2) a transfer function that is (a) expressed using a difference between a road surface reaction torque model and a referential reaction torque model and that is (b) determined according to a vehicle velocity input by a vehicle velocity sensor 20. A power steering controller 58 adds the relaxation length compensation torque to an assistance torque, and controls an EPS motor 3 so as to generate the assistance torque to which the relaxation length compensation torque has been added. The relaxation length compensation torque is thereby computed with good precision, enabling high handling performance to be achieved.

主权项

1. A vehicle steering apparatus comprising:
a vehicle velocity detection unit that detects a vehicle velocity; a state amount detection unit that detects a front wheel actual steering angle state amount of a vehicle; a computation unit that computes a relaxation length compensation torque based on
(1) a transfer function that is (a) expressed using a difference between a road surface reaction torque model that considers dynamic characteristics of tires according to a relaxation length to derive a first road surface reaction torque based on the front wheel actual steering angle state amount, and a referential reaction torque model that does not consider the dynamic characteristics of tires according to the relaxation length to derive a second road surface reaction torque based on the front wheel actual steering angle state amount, and that (b) expresses a relaxation length compensation torque that is a steering torque predetermined according to the vehicle velocity detected by the vehicle velocity detection unit to compensate for the relaxation length for the front wheel actual steering angle state, and(2) the front wheel actual steering angle state amount detected by the state amount detection unit; a summing unit that adds the relaxation length compensation torque computed by the computation unit to an assistance torque of electrical power steering; and a steering torque control unit that controls so as to generate the assistance torque that has been summed by the summing unit.