Look Ahead Cruise Control: Road Slope Estimation and Control Sensitivity

Look ahead cruise control is a relatively new concept. It deals with the possibility of making use of recorded road slope data in combination with GPS, inorder to improve vehicle cruise control. This thesis explores the possibility ofestimating road slope as well as investigating the sensitivity of two look aheadcontrollers, with respect to errors in estimation of mass, wheel radius and roadslope. A filter using GPS and standard vehicle sensors is used for estimation ofroad slope. The filter is robust to losses in data since redundant information isavailable. Possible errors in estimation caused by the filter are identified. Two previously published look ahead controllers using different strategies tocontrol a heavy vehicle are investigated. A description of controller behaviourin perfect conditions is presented. Sensitivity analysis is performed identifyingerroneous control behaviour inflicted by errors in the used vehicle model androad slope. Further, effects on controllers caused by errors in road slope estimation estimation are detected. Conclusions about the two look ahead strategiesare drawn