PROBLEM TO BE SOLVED: To provide a position control apparatus having a simple structure, with which the automatic height control, automatic tilling depth control and automatic inclination control of a tiller connected to a vehicle main body liftably and lowerably and inclinably to right and left are carried and when the vehicle main body runs in a non-tilling operation state in which the tiller is positioned lower than the highest rise position and higher than the ground surface, the tiller is prevented from being largely inclined despite the intention of an operator by the automatic inclination control.SOLUTION: The position control apparatus for carrying out an automatic height control, an automatic tilling depth control and an automatic inclination control has a constitution that when the speed v of the vehicle main body 50 is higher than a fixed threshold value of speed vS, the control precision of the automatic inclination control is relaxed and the threshold value of speed vS is changed depending upon a set height position hS.COPYRIGHT: (C)2007,JPO&INPIT【課題】車輌本体に対して昇降可能且つ左右に傾動可能に連結された耕耘機に対して自動高さ制御、自動耕深制御及び自動傾き制御を行う姿勢制御装置であって、前記耕耘機を最上昇位置よりは下方で且つ地面よりは上方に位置させた非耕耘作業状態での車輌本体の走行時に、前記自動傾き制御によって前記耕耘機が意に反して大きく傾動されることを防止し得る構造簡単な姿勢制御装置を提供する。【解決手段】自動高さ制御と自動耕深制御と自動傾き制御とを行うように構成された姿勢制御装置は、車輌本体50の車速vが所定の閾値車速vSより高速の場合には、自動傾き制御の制御精度を緩和させると共に、閾値車速vSを設定高さ位置hSに応じて変更するように構成されている。【選択図】図15
