A magnetostrictive system in industrial automation doesn't typically convert vibrations directly into electrical power, but rather utilizes the magnetostrictive effect for position sensing and control applications. The magnetostrictive effect is the property of certain materials to change their shape in response to an applied magnetic field, or conversely, to generate a magnetic field in response to a mechanical deformation.
In industrial automation, a magnetostrictive sensor is often used to precisely measure the position of a moving component, such as a piston or rod in a hydraulic or pneumatic cylinder. Here's how it works:
Basic Principle: The magnetostrictive sensor consists of a magnetostrictive waveguide (usually a rod) made from a magnetostrictive material, typically an alloy containing iron. The sensor is positioned alongside the moving component whose position needs to be measured.
Magnetic Pulse Generation: The sensor contains a coil of wire that generates a short-duration magnetic pulse along the magnetostrictive waveguide. This pulse generates a torsional strain wave that travels along the waveguide in both directions.
Interaction with Moving Component: When the torsional strain wave encounters the interface between the magnetostrictive waveguide and the moving component (e.g., piston or rod), it induces a torsional stress in the waveguide at that point.
Return Wave Detection: A sensing element, often a magnetostrictive pickup coil, is placed along the magnetostrictive waveguide to detect the returning torsional strain wave that reflects back from the moving component. The interaction between the torsional stress and the magnetic field induces an electrical pulse in the pickup coil.
Position Calculation: The time it takes for the torsional strain wave to travel to the moving component and back is measured. Since the wave speed is constant for a given material, this time can be used to accurately determine the position of the moving component relative to the sensor.
Output Signal: The output signal from the magnetostrictive sensor is an electrical pulse or a series of pulses that corresponds to the measured position. This information can be sent to a control system for precise position control or monitoring purposes.
In summary, a magnetostrictive system in industrial automation doesn't convert vibrations into electrical power. Instead, it utilizes the magnetostrictive effect to accurately measure the position of moving components through the generation and detection of torsional strain waves. The technology is valuable in applications where high accuracy and reliability in position sensing are crucial, such as in hydraulic systems, pneumatic systems, and other industrial machinery.