Stair climbable hexapod walking robot (1st report. Design and control of hexapod walking robot with fixed gait, 'MELCRAB-1,' and design of self contained hexapod walking robot with semi-fixed gait, 'MELCRAB-2.')

Two prototype hexapod walking robots were developed. One is called MELCRAB-1, a hexapod walking robot with fixed gait, which is capable to go straight forwards or backwards over stair steps or rough terrains. The other is called MELCRAB-2, a self-contained hexapod walking robot with semi fixed gait, which can go straight forwards and backwards on rough terrains including stairs and turn to the right or to the left. MELCRAB-1 is one third scale size prototype for MELCRAB-2, and they made the methodology of geometric design of hexapod walking machine for going up and down stairs. A special linkage mechanism was used to make the leg motion to walk on a flat floor. A new actuation category, 'MDA: Motion Decoupled Actuation,' was proposed additionally to 'GDA: Gravitationally Decoupled Actuation.' MELCRAB-1 succeeded to go up and down stairs, and evidenced the MDA makes it easy to make control program adaptive to rough terrains. MELCRAB-2 succeeded to be constructed as a self-contained walking robot with DC motor actuator system powered by electric batteries. It owed to the effect to make the weight lighter by MDA.