Brightness Control

 System
The experiments are set up with experiment plates in profile frames. The controlled system or control circuit are activated with the Profi-CASSY and the relevant measurement values recorded.

Objectives

• Get familiar with the basic principles of controllers
• Setpoint and disturbance control
• Handle analysis and simulation software

Function
Light control systems contain light sources for usable and disturbance light as well as a photo sensor. The LED light sources are activated directly with the controller. An external control element (power amplifier) is not necessary. The diffusing screen spatially influences the controlled system as an external disturbance variable. Influenced by the relatively high limit frequencies of the opto semiconductors, the light control system has a time response similar to a fast PT1 system. The resulting system order is n = 1; there is only one main energy store. Light control is required for rooms where light is critical to safety, such as in sports arenas or hospitals. One biological example would be the ability of the eye to adapt to different levels of brightness (pupils).

Method
The equipment is ideal for demonstration and students' experiments. The tests were carried out with an electronic manual and the data files for CASSY Lab 2 and WinFACT. It is true Plug & Play: The measurement starts automatically after loading the data file.

Target groups
Students completing vocational training in electrical engineering for industry and students of automation engineering and mechatronics are the target group. The course offers introductory experiments that are very simple and also addresses difficult topics for bachelor-level studies.

Topics

• Characteristic curve for the temperature controlling system
• Recording the jump response
• Optimal amount, replacement controlled system
• Technical controller
• Controller in the limit range
• Empirical tuning of controllers
• Control unit design with known time constants for the controlled system
• Controller design zero-pole compensation, KP determination in batch run
• Control unit design through numerical optimization
• Rule of thumb method
• Setpoint and disturbance control with electronic controllers
• Temperature regulation with a software controller
• Temperature controlling with block-oriented PC simulation
• Temperature control with two-point controller, influence of hysteresis
• Two-point controller with delayed feedback
• Two-point controller with delayed weakening feedback
• Temperature regulation with three-point controller
• Control circuit modelling

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