| 摘要 |
<p>Electric motors (102) having controllable induced armature fields, such as induction motors and synchronous reluctance motors, are used in power assisted steering systems for motor vehicles. Power is conserved by tailoring induced armature fields or rotor flux in accordance with the speeds of motor vehicles including the power assisted steering system. In particular, one or more flux programs or maps are provided for the power assisted steering system with the flux map or program being accessed or addressed by means of the vehicle speed. During low speed operation of the motor vehicle, for example to perform parking manoeuvres where speeds are near zero and steering forces are near or at maximum, the rotor flux is programmed to maximum. For high speed operation, such as highway and rural motor vehicle operation, the rotor flux is programmed to a low value so that internal loss mechanisms in the power assist motor and motor controller are minimised yet provide sufficient rotor flux to meet steering needs such as lane changes, obstacle avoidance and the like. Various transition speeds and flux transition curves provide smooth transitions between high flux levels and low flux levels. <IMAGE></p> |
