Completed notes of the course

Pagina 1

Physiological control systems intro Servomechanism: tracking of a specified dynamic trajectory by a control action. The controller is a regulator and maintains the output y within specified limits. We can have two types of control systems: 1. Open loop: may perform complex behaviours but cannot compensate disturbances that are a-priori unknown. For example, a rain of sunshine for the heating system. This is what happens when you learn a gesture and you repeat it several times. If you have to run and you are - Trained: heart rate and heart pressure start to increase even before starting because you know what you are about to do. - Untrained: at a point you have to stop because you have not calibrated the effort 2. Closed loop: gives much more versatility, it can respond to any kind of disturbance. The controller does the correction between the output and the reference input we want. It provides - Feedback: a method for controlling a system by reinserting the results of its past performance, Wiener 1940 - cybernetics: control applied to biological and artificial systems, from Greek kubernetes, timoniere, Wiener 1940 - homeostasis: It is the fixity of the milieu interieur. All our physiology has one main goal, to keep the milieu interieur at its optimal level of ions, oxygen etc. first introduced by Claude Bernard in the 19th century Examples of closed loop in our body: - muscle stretch reflex: is very rapid as it involves only one synapsis in the spinal cord - Baroreflex Physiological control systems characteristics: - Versatility: the dynamics change around the working point. Integration of open and closed loop regulation strategies - Cross coupling: different contributions from interrelated systems. - Hierarchical: the reference of a feedback is moved by another higher…