SollWert

Sollwert is a term used in control engineering to denote the target or reference value that a process variable should reach. It represents the desired state of the system, while the actual measured value is called the Istwert. The difference between Sollwert and Istwert creates the control error that a regulator aims to minimize.

In a closed-loop control system, the controller computes a manipulated variable to drive the process toward the Sollwert. Feedback from sensors is used to monitor the Istwert, and the control action is adjusted to reduce the deviation between Istwert and Sollwert. This concept applies across many domains, such as temperature regulation, pressure control, motor speed, and robotic positioning.

The Sollwert can be static or dynamic. A static setpoint remains constant, while a dynamic setpoint changes over time according to a schedule or trajectory, such as a ramp, step change, or predefined profile. Setpoints may be provided by human operators, higher-level automation systems, or automated scheduling algorithms. In complex systems, multiple setpoints or setpoint profiles may exist for different operating phases.

Practical considerations include actuator limits, safety constraints, and potential for instability or overshoot if setpoints are changed abruptly. Techniques such as rate limiting, integral windup protection, and filtering may be applied to the setpoint signal. In some control strategies, setpoints are complemented by feedforward terms to improve responsiveness.

In German-language engineering usage, Sollwert corresponds to the English term setpoint or target value. It is central to PID controllers, sequence control, and process automation, and appears in instrumentation standards and engineering practice.