bangbangregelingen

Bangbangregelingen, commonly referred to as bang-bang control, describe a family of control strategies in which the controller output switches abruptly between two extreme values (on and off) rather than taking intermediate levels. The controlled variable is compared to a target or threshold, and the actuator is driven to its maximum or minimum limit. To avoid rapid switching from small disturbances, a hysteresis or deadband is often included, creating a range where no switching occurs until the deviation exceeds the threshold.

Principle and characteristics: The control law selects either the maximum or minimum actuation based on the system state, yielding a discontinuous, nonlinear response. This approach is well suited to simple systems where fast, robust reaction is prioritized and precise modeling is impractical. It is easy to implement with relays or basic digital controllers and tends to be tolerant of parameter variations.

Applications: Bang-bang regulation is common in heating and cooling systems (thermostats), motor control (on/off drives), basic power regulation, and other situations where a binary actuator is sufficient. It is also found in certain automotive or aerospace actuators and in educational demonstrations of discrete control.

Advantages and limitations: The method is simple, inexpensive, and fast to respond, with good robustness to disturbances. However, it offers limited regulation precision, possible steady-state error without appropriate hysteresis, and a risk of high-frequency switching (chattering) near thresholds. Mechanical wear and energy inefficiency can also be concerns in some applications.

Design considerations: Choosing the hysteresis width is key to balancing switching frequency and regulation accuracy. In digital implementations, a Schmitt trigger or similar deadband logic is often used to reduce chatter and noise-induced switching.

See also: Bang-bang control, hysteresis, relay control, Schmitt trigger, thermostat.