Brightness Control

System

The experiments are set up with experimental panels in the profile frame. The controlled system or control loop is controlled with the Profi-CASSY and the measured values of interest are recorded.

Learning objectives

• Recognising basic control principles
• Management and fault control
• Handling Analysis and Simulation Software

Function

The light control path contains light sources for useful light and ambient light as well as a photo sensor. The LED light sources are controlled directly by the controller. An external actuator (power amplifier) is not required. Room light acts as an external disturbance variable on the controlled system through the focusing screen. Due to the relatively high cut-off frequencies of the opto-semiconductors, the light control path has a time behaviour like a fast PT1 system. The resulting system order is n = 1, there is only one significant energy store. Light control is mandatory in safety-critical rooms, e.g. in sports arenas or hospitals. A biological example is the up and down dimming function of the eye to adapt to different brightness levels (pupil).

Method

The equipment is equally suitable for demonstrations and student experiments. Experimental procedures are carried out using an electronic manual and the measurement files for CASSY Lab 2 and WinFACT. Plug & Play applies: the experiments start automatically after the measurement file is called up.

Target groups

Vocational training in electrical engineering in trade and industry and students specialising in automation technology and mechatronics. The course offers both introductory courses at a basic level as well as challenging topics for bachelor's programmes.

Topics

• Characteristic curve of the temperature controlled system
• Recording the step response
• Amount optimum, the substitute controlled system
• Technical controller
• Controller in the limit range
• Empirical dimensioning of controllers
• Controller design with known time constants of the controlled system
• Controller design by pole-zero compensation, KR determination in batch run
• Controller design through numerical optimisation
• Rule of thumb method
• Command and fault control with electronic controller
• Temperature control with software controller
• Temperature control with block-orientated PC simulation
• Temperature control with two-point controller, influence of hysteresis
• Two-point controller with delayed feedback
• Two-point controller with delayed feedback
• Temperature control with three-point controller
• Control loop modelling