Hybrid control: identification of two parameters

This video shows the execution of a new controller for the 4dof parallel robot. It is a hybrid controller that uses window-based least (WLS) squares or recursive least squares (RLS) for the identification of the robot’s parameters. In this case, by means RLS we estimate the first and second relevant parameters. The first relevant parameter corresponds basically to the mobile platform mass and the second relevant parameter represent the first inertia moment on X axis of the limb 1.

In order to verify the developed controller, some experiments have been carried out. For these experiments, the trajectories employed involve sinusoidal movements around the generalized coordinates (x, z, θ, ψ), wich sntail two hip flexion combined with flexion-extension of knee. Four pauses are introduced where the robot maintains the mobile platform horizontally in a fixed position, waiting for a payload to be placed (or removed) during 20 seconds. Starting with no payload (stage 1), a 25 kg payload is placed at instant t=100 s (stage 2) and moved away at t=220 s (stage 3). Afterwards, a 15 kg payload is placed at t=340 s (stage 4) and removed at instant t=460 s (stage 5).