**4. Implementation with neural networks instead of the knowledge base tuning rules**

The replacement of the rules that define the gains of PID controller based on the working point system is raised by a neural network whose inputs are the operation conditions of the plant, and as outputs it will have the parameters of PID controller (*K*, *Ti* and *Td*). The neural network used is a network type MLP (Multi Layer Perceptron) with a similar topology to the one shown in Figure 3.

**Figure 3.** Neuronal network structure

It is possible to raise several simple neural networks for each parameter instead of one, in which all of them have as input, the system conditions but the output is the controller parameter in each case.
