# 4. Primary elements of the systems during the simulation

The simulation system is carried out on a block diagram which may consist of the following main elements:

**1. Dynamic element**(DE) is shown in Figure 3.

Figure 3. Designation dynamic link to the scheme of the system

Under the dynamic element refers to an object with the transfer function W(p), which is fed to the input of the impact of U, and the output is formed by the reaction of Y on the input action. The transfer function (1) with the characteristics of a and b is a differential equation relating the input (polynomial of order m) and output (polynomial of degree n), with the order m must not exceed the order of n (the condition of physical realizability):

(1) |

After that, the input U and Y output signals taken out of the bracket, and the operator is replaced by formal differentiation operator p corresponding degree.

The output of the dynamic element is calculated by the formula (2):

The output of the dynamic element is calculated by the formula (2):

(2) |

**2. Gain element**(GE) is presented in Figure 4.

Figure 4. The reinforcement element system in the scheme

The reinforcement element performs multiplication of the input signal U to the magnitude of K. The output signal Y of the amplifying unit is calculated by the formula (3):

(3) |

**3. Summing element**(SE) is shown in Figure 5.

Figure 5. Summing element in scheme of the system

Summing element performs addition of the input signals with respective U marks and generates an output signal Y, which in this case can be calculated by the formula (4):

(4) |

**4.**Nonlinear element

**(NE) is shown in Figure 6.**

Figure 6. The non-linear element in the scheme of the system

Nonlinear element produces non-linear transformation of the functions of NE input U, the result of which is the output signal Y (5):

Figure 7. Exposure to the scheme of the system

(5) |

**5. External element**(EE) is not an internal component of the system is indicated by the arrow direction (see Figure 7) to the input of U, are exposed to these impacts G.Figure 7. Exposure to the scheme of the system