Cartesian spline interpolation for industrial robots

We describe an algorithm for interpolation of positions by a rational spline motion. A reparameterization of the resulting motion is applied in order to achieve the desired distribution of the velocity. For the ease of presentation we discuss trapezoidal velocity profiles, i.e. piecewise constant and linear velocity distribution. The method can be generalized to more general velocity profiles. The whole spline scheme possesses some special features which make it a suitable tool for the control of industrial robots.