ROAD SURFACE GRADIENT DETECTING DEVICE FOR VEHICLE

摘要

PURPOSE:To improve the shift control of an automatic transmission with no cost increase by detecting the gradient of the road surface on which is vehicle is running based on the difference between the longitudinal total acceleration and the running acceleration, and detecting the gradient of the road surface with a sensor not used for gradient detection in the past. CONSTITUTION:The vehicle speed obtained as the inverse number of the period T of the pulse signal detected by a vehicle speed sensor 6 is read out. The difference between this vehicle speed and the previous value of the vehicle speed is calculated to obtain the running acceleration alpha of a vehicle against the road surface. The longitudinal acceleration detection signal G is read out from a longitudinal acceleration sensor 1. When the vehicle is running on a flat road, G=alpha, when the longitudinal direction of the vehicle is inclined (gradient theta) from the horizontal direction on a slope, the vehicle longitudinal gravity acceleration component gsin theta is the difference between the vehicle longitudinal total acceleration G and the running acceleration alpha. The gradient theta of the road surface on which the vehicle is running can be obtained.