持ち上げておろすと進む機構（Lift-Lower-Propel Mechanism; LLPM）は，八幡浜の三瀬医院の院長，片山均が命名した，シンプルな構造でスムーズに前進するための機構です．

What is LLPM?

The Lift-Lower-Propel Mechanism (LLPM) is a mechanism that moves forward by lifting and lowering. It was named by Hitoshi Katayama, the director of Mise Clinic in Yawatahama, and is designed to achieve smooth forward motion with a simple structure.

LLPMは，胴と脚，それらを繋ぐ股関節から成ります．胴か脚には、脚が前後に振れすぎないようにするためのストッパーが1-2個取り付けられています．

Structure of the LLPM

The LLPM consists of a body, legs, and joints connecting them. One or two stoppers are attached to the body or legs to prevent excessive forward and backward movement of the legs.

1. 持ち上げる：機構全体を持ち上げることで，脚と地面の摩擦が減少します．

2. 機構下部の前進：股関節を支点として、脚（機構下部）が重心に従って前に移動（揺動）します。

3. おろす：持ち上げた機構を再びおろすことで、脚と地面の摩擦が増加します。

4. 機構上部の前進：脚と地面の接点を支点として、胴（機構上部）が前に移動（揺動）します。

5. 繰り返し：この動作を繰り返すことで、持ち上げておろす動きにより前進を続けます。

このプロセスにより、機構は効果的に前進します。

Working Mechanism

1. Lifting: The entire mechanism is lifted, reducing friction between the legs and the ground.

2. Forward movement of the lower part: The legs (lower part) move forward by swinging around the joint as the center of gravity shifts.

3. Lowering: The mechanism is lowered again, increasing friction between the legs and the ground.

4. Forward movement of the upper part: The body (upper part) moves forward by swinging around the contact point between the legs and the ground.

5. Repetition: Repeating these actions allows the mechanism to continue moving forward.

Through this process, the mechanism effectively moves forward.