What is an actuator that is positioned based on a controller's output called?

The term for an actuator that is positioned based on a controller's output is best described by a pneumatic valve actuator. This type of actuator utilizes compressed air to operate a valve, allowing for precise control of fluid flow or pressure in a system. The actuator receives signals from a control system, which dictate the position of the valve. This interaction makes it ideal for applications where precise adjustments are necessary based on feedback from various sensors and control logic.

In many industrial applications, pneumatic valve actuators are commonly used because they can operate quickly and can be finely adjusted based on the requirements of the system being controlled. The reliance on a controller's output means the actuator must be responsive and reliable, ensuring that the desired position is achieved promptly.

While other options like servo motors and stepper motors also act based on control inputs, they are not specifically categorized as pneumatic valve actuators. Similarly, hydraulic actuators use fluid pressure but are not limited to the function of controlling valves. This makes the pneumatic valve actuator the most appropriate descriptor for this type of system.