Vertical control for a mechanical model of the one-legged hopping machine

A vertical control algorithm is proposed for a one-legged hopping machine. It differs from previous control algorithms in three ways: (i) it uses a near inverse of the machine´s dynamics; (ii) it uses discrete-time output feedback, namely, the hopping heights of previous cycles (rather than continuous full state feedback); and (iii) it uses a more realistic model of the hopping machine mechanical components. Numerical simulations are used to assess the ability of the controlled machine to track a piecewise constant height trajectory. Specifically, the sensitivity of the design to deviations in the hopping machine´s parameters is studied