GRADE ANGLE ESTIMATION SYSTEM BASED ON THREE-DIMENSIONAL MAP DATA

A grade angle estimation system for estimating a grade angle of a roadway that a vehicle is driving along includes one or more controllers. The one or more controllers include one or more processors that execute instructions to receive three-dimensional map data of the roadway and measurements indicating a grade angle of the roadway collected by an inertial measurement unit (IMU). The one or more controllers determine an IMU-based grade angle based on the measurements received by the IMU and compare an absolute value of the IMU-based grade angle with a threshold grade value. In response to determining the absolute value of the IMU-based grade angle is greater than the threshold grade value, the one or more controllers set the grade angle equal to the IMU-based grade angle.