Abstract
In recognition of the growing environmental awareness of customers, the automotive industry is researching and developing various types of electrically powered vehicles. These include vehicles equipped with in-wheel motors, i.e., motor units that are installed inside the wheels of the vehicle. Because this layout allows more effective use of interior space and due to the potential dynamic performance benefits of using in-wheel motors, this type of vehicle is attracting close attention.
Vehicles equipped with in-wheel motors are capable of independent driving and braking force control of each wheel. Furthermore, in addition to yaw motion control, vehicles equipped with in-wheel motors can potentially control the motion of the sprung mass as effectively as an active suspension system due to the large vertical suspension reaction force generated during driving. Based on this mechanism, this paper describes a method for independently controlling yaw, roll, and pitch moment by driving force distribution control. It also proposes a decoupling method that cancels out the dynamic coupling effect between each motion and a control method at the limit of tire adhesion. The following details also include an analysis of these methods and the results of actual-vehicle verification.
KEYWORDS – in-wheel motor, vehicle dynamics, electric control, steering response control, sprung mass control