PROBLEM TO BE SOLVED: To enable a smooth transition from a manual travel mode to an automatic travel mode.SOLUTION: A vehicle has: an automatic travel mode 81 enabling an automatic travel by a control part 30 controlling steering drive means, engine revolution control means and transmission means and a manual travel mode 80 enabling a travel of a body in accordance with a manual operation. The control part is connected to an auto-manual changeover switch 71 for changing over between the automatic travel mode 81 and manual travel mode 80. Further, when the auto-manual changeover switch 71 is changed from manual to auto, the control part 30 changes to an automatic travel ready mode under a condition where a vehicle speed is equal to or less than a set speed, a steering device is at a substantial straight position, forward-reverse changeover means is neutral, no operation is performed on clutch pedal 16, brake pedal 15 and parking lever 39, a secondary transmission device is at a low speed position, no abnormality exists, and an engine revolution is equal to or higher than a set number of revolution, and then changes to the automatic travel mode 81, starting an automatic travel, under a condition where all data necessary for the automatic travel is put together.COPYRIGHT: (C)2014,JPO&INPIT【課題】手動走行モードから自動走行モードへスムーズに移行できるようにする。【解決手段】操舵駆動手段と、エンジン回転制御手段及び変速手段を制御部30にて、制御して自動走行可能とする自動走行モード81と、人為的操作に応じて前記機体の走行を可能とする手動走行モード80と、自動走行モード81と手動走行モード80を切り換える自動・手動切換スイッチ71が接続され、制御部30は、自動・手動切換スイッチ71が手動から自動に切り換えられると、車速が設定速度以下、かつ、操舵装置が略直進位置、かつ、前後進切換手段が中立、かつ、クラッチペダル16、ブレーキペダル15、パーキングレバー39が操作されていない、かつ、副変速装置が低速位置、かつ、異常がなく、かつ、エンジン回転数が設定回転数以上の場合、自動走行準備モードに切り換わり、自動走行にかかる必要なデータがそろうと、自動走行モード81となり自動走行が開始される。【選択図】図4
