Optimization-based Maneuver Planning for a Tractor-Trailer Vehicle in Complex Environments using Safe Travel Corridors - Hangjie Cen; Bai Li; Tankut Acarman; Youmin Zhang; Yakun Ouyang; Yiqun Dong (IEEE Intelligent Vehicles Symposium, IV 2021, Nagoya, Japan, July 11-17, 2021, 2021)