Modeling and identification of pneumatic actuators

Pneumatic actuators are mechanically simple and robust, have good energetic properties due to air compressibility, and are relatively cheap. Despite these advantages they are difficult to control - pressure dynamics have typical timescales on the order of 100ms, and this delay can severely cripple simplistic control approaches. The solution is to use a model-based controller with a good model of the pressure dynamics. Here we present a general parametric model of these dynamics based on both a theoretical analysis and an empirical study with a humanoid robot.