Continuously variable transmission (cvt) ratio control

A vehicle includes an engine with an associated engine-speed sensor, and wheels each having a respective wheel-speed sensor. The vehicle also includes a continuously variable transmission (CVT) coupled to the engine and configured to operate at variable input-to-output ratios. At least one controller is programmed to reduce the operating ratio of the CVT in response to the engine-speed sensor indicating the engine is operating at idle speed and the wheel-speed sensor indicating the velocity is approximately zero. This provides less noise, vibration and harshness in the vehicle due to the reduced ratio that is possible during conditions in which a vehicle launch in that reduced ratio may not be acceptable. 公开了种无级变速器传动比控制。提供种车辆，所述车辆包括具有相关联的发动机速度传感器的发动机以及均具有各自的车轮速度传感器的车轮。车辆还包括连接到发动机并被构造成以可变的输入输出传动比运转的无级变速器。至少个控制器被配置成：响应于发动机速度传感器指示发动机以怠速转速运转且车轮速度传感器指示车轮转速大约为零，减小无级变速器的运转传动比。由于在减小传动比可能是不被接受的车辆起步的状况期间减小传动比是可能的，因此这在车辆中提供减小的噪声、振动和声振粗糙度。