PROBLEM TO BE SOLVED: To provide an automatic steering system capable of efficiently making transition from a previous traveling route to a next traveling route and controlling turning.SOLUTION: An automatic steering system comprises: a first steering control unit which performs steering control for a first turning traveling which deviates from a previous traveling route Ls and heads for a next traveling route Ln； a second steering control unit which performs steering control for a second turning traveling which enters the next running route； a third steering control unit which performs steering control for transition traveling between the first turning traveling and the second turning traveling； a virtual turning circle calculation unit which calculates a virtual turning circle VC used as a target route of the second turning traveling； and a tangent calculation unit which calculates a tangent from a vehicle body reference point to the virtual turning circle VC in the first turning traveling as a target route of the transition traveling.SELECTED DRAWING: Figure 3【課題】前走行経路から次走行経路へ効率よく移行できる旋回制御が可能な自動操舵システムの提供。【解決手段】自動操舵システムは、前走行経路Ｌｓを離脱して次走行経路Ｌｎに向かう第１旋回走行のための操舵制御を行う第１操舵制御部と、次走行経路に進入する第２旋回走行のための操舵制御を行う第２操舵制御部と、第１旋回走行と第２旋回走行との間の移行走行のための操舵制御を行う第３操舵制御部と、第２旋回走行の目標経路として用いられる仮想旋回円ＶＣを算出する仮想旋回円算出部と、第１旋回走行における車体基準点から仮想旋回円ＶＣへの接線を、移行走行の目標経路として算出する接線算出部とを備える。【選択図】図３
