In the systems of automatic control in a feedback chain for formation of the operating signal the proportional integrated and differential (PID) regulator is used. After carrying out control of this element it is possible to raise its accuracy by 5-100 times of rather position regulator.
Instruction
1. Carry out control proportional PID-regulator components. Disconnect integrated and differential to a component or set to the maximum position an integration constant, and a differentiation constant – on a minimum.
2. Further put the required setting for SP and note a zone of the proportionality equal to zero. As a result the PID-regulator will perform functions of the on-off regulator. Take readings of transitional characteristic. To establish a zone of proportionality of temperature equal to fluctuation band: Pb=DT.
3. Changing valuethisindicator , find optimum control at which damped oscillations will have 5-6 periods. It is necessary to remember that with increase in a zone of proportionality, the residual mismatch and duration of transition processes increases. Further settings of the PID-regulator are intended to eliminate some errors and to bring the device to optimum level of work.
4. Adjust differential to the PID-regulator component if it is applied in your device. Change a differentiation time constant (ti = 0.2ґDt) until the schedule of fluctuations does not have 5-6 periods of attenuation. By means of given components damped oscillations are eliminated therefore the PID-regulator turns out static and dynamic accuracy.
5. Receive transitional characteristic after control proportional and differential PID-regulator components. Adjust an integration time constant so that to remove a residual mismatch between indicators of a setting and temperature which were established in a system. Specify the given indicator equal the delta of t in the beginning then change its value until you find such situation at which the schedule will have the way out on a setting.