Actuator

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A rotary actuator, the axis of which drives an electric motor, here together with the controller as an integrated unit in the same housing

As actuator , also actuator (English: actuator ), usually are technical drive units referred to an electrical signal a physical (from the control computer commands issued) into mechanical movements or changes in variables such as pressure or temperature implement and thus actively interfere with the controlled process.

The associated technical discipline is actuator technology .

application areas

In measuring, control and regulation technology, actuators are the counterpart to sensors in relation to signal converters and form the final control elements in a control loop . During a control process, they convert the signals into effects - through mechanical work in motion control - with which the controlled variable is influenced. An example is opening and closing a valve or a ventilation flap.

In robotics , the term effector is often used synonymously instead of actuator . The last element of a kinematic chain is then also referred to as the end effector . In the case of a robot, this actuator or effector is used, for example, to grasp and process objects and thus creates an effect.

In sub-areas of mechatronics , such as actuators or linear technology , electromechanical drives , for example for lifting and adjustment systems, are used, which are generally referred to as actuators. The stepper motor of the read / write head of a hard disk or the compensating carriage for a stationary pendulum also represent an actuator. When controlling the process, a distinction is made between an open and a closed control loop .

Actuator of a hard disk drive

Actor principles

Developments in actuators that react to changes in certain environmental variables with defined actuator effects originate from the field of new materials. You can use it to replace electrical control systems with a single element. Actuators based on shape memory alloys and expansion elements are temperature-sensitive and are used in temperature controllers, for example . Shape memory alloy actuators create new possibilities and offer advantages u. a. in terms of installation space and weight, e.g. For example, flat bending actuators in which shape memory alloy wires are integrated into a fiber-reinforced plastic composite can achieve a deflection in the range of a few millimeters to several centimeters, depending on their size.

Smart hydrogels are used, among other things, for chemostats that automatically regulate pH , ion or substance concentrations .

See also

literature

  • Daniel J. Jendritza: Technical use of new actuators . expert, Renningen 2008, ISBN 978-3-8169-2765-5 .
  • H. Janocha: Actuators - Basics and Applications . Springer, Berlin 2004, ISBN 3-540-61564-4 .
  • Clarence W. De Silva: Sensors and actuators - control systems instrumentation . CRC Pr., Boca Raton 2007, ISBN 978-1-4200-4483-6 .
  • John R. Brauer: Magnetic actuators and sensors . Wiley-Interscience, Hoboken 2006, ISBN 0-471-73169-2 .
  • Actuators - machines modeled on muscles . In: Naturwissenschaftliche Rundschau . No. 12 , 2005, ISSN  0028-1050 , p. 654 .
  • B. Schröer: Actuators in microsystem technology. In: Sensor magazine. 1992, ISSN  0179-9592 , No. 1, 23-25, No. 2, pp. 10-13.

Web links

Commons : Actuators  - collection of images, videos and audio files

Individual evidence

  1. ↑ Foil-based miniature actuator: "Crocodile" with shape memory. February 26, 2018, accessed June 27, 2019 (German).
  2. ↑ Shape memory actuators enable new freedom with minimal installation space and minimal weight. Retrieved November 22, 2019 .