The detection of weak signals has been widely used in communication, radar and other fields. The detection of weak signals in the background of strong noise is an important research hotspot of modern information theory, and prompts people to explore and study new theories and new methods of weak signal detection. The device takes Holmes-type Duffing mapping as the research object, and uses the Lyapunov exponent as the criterion for chaos identification. The chaotic critical value of the equation is changed from chaotic state to periodic state. Whether it contains the detection algorithm of the target signal, the signal detection for the unknown frequency and the Holmes-type Duffing system is improved by the sliding mode variable structure control method in the control theory. The simulation results show that the improved chaotic Duffing system can effectively suppress the noise and detect the frequency of the weak signal through the power spectrum of the system.
The dependence of flow volume on the pressure difference between the ports of a U-tube was determined for both laminar and turbulent flows of a magnetic fluid. The results showed that the dependence was linear in the case of laminar flow but was non-linear in the case of turbulent flow. In addition, the inductance and the voltage difference across two coils around the arms of the U-tube were calculated. The voltage difference was proportional to the flow volume and inversely proportional to the square of the coil length. These theoretical and experimental results demonstrate that the design of magnetic-fluid-based flow sensors is feasible. magnetic fluid, flow, sensor, inductance
Citation:Hao R C, Li D C. Theoretical and experimental study on magnetic-fluid-based flow sensors.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.