Study on Self-excitation On-Off Drive Controled Hopping Robot without Absolute Position Sensor Arm

The hopping and jumping miniature robot without an absolute position sensor for the body was developed in this study. The machine is constitued with a vibration system by springs such as muscles, and excited with the on-off drive controled self-excitation for absorbtion of the effect of perturbation on the motion. The flight absolute body position and velocity can be estimated from relative position deta between the body and leg with an internal sensor. In the instant of landing, the relative value equals to the absolute value. The absolute position of the body is calculated by sum of the relative position value at landing as the base position value and the relative measuring position over the next flight motion. This idea had successful in loose the machine from restraint of the position measuring sensor arm, and delivered of the complite free flight body. The base value of the absolute body position is renewed every landing, therfore, the body position error doesn't increase and the steady-state motion must possibly continue. The machine is excited with a linear solenoide and it's motion is measured by twin strain gauges as the internal relative displacement sensor in the 1st trial. For direction and posture control, the body is inclined by draw of steel chips pasted with 4 assistant legs for magnets on the body. This robot was named the spider type based on it's configulation and behavior. The experimental results agreed approximately with results of the theoretical analysis. In the case of jumping, the theoretical solution couldn't be discovered in the conditions of the experimental apparatus, but the existence of the notion was confirmed in experiment. An octopus type hopping robot will also study to expand the widely applications in future.