A scheme to improve the structure of electromagnetic flow sensor is put forward in this paper, which can effectively solve the slurry noise problem when electromagnetic flowmeter measures slurry fluid. The electromagnetic flow sensor used for measuring slurry fluid has slurry noise interference in the measurement signal. At present, the method of increasing the excitation frequency of electromagnetic flow sensor is widely used to overcome slurry noise. However, high excitation frequency will lead to poor stability of zero point. In view of the shortcomings of existing methods, this paper studies the method of improving sensor structure to overcome slurry noise. Firstly, according to the mechanism of slurry noise, an improved scheme for the installation position of the measuring electrode of electromagnetic flow sensor is proposed, which can greatly reduce the probability of solid particles of slurry fluid colliding with the measuring electrode; Then, the relevant research results of bubble dynamics theory are applied to optimize the improvement scheme, and the improvement scheme is determined, through calibration, it is concluded that the improved sensor can reach the accuracy level of 1.0; Finally, through slurry measurement experiments, it is verified that the improved electromagnetic flow sensor can effectively overcome slurry noise.

Through systematic analysis of the structural characteristics and invulnerability of spider web, this paper explores the possibility of combining the advantages of spider web such as network robustness and invulnerability with farmland wireless sensor network. A universally applicable definition and mathematical model of artificial spider web structure are established. The comparison between artificial spider web and traditional networks is discussed in detail. The simulation result shows that the networking structure of artificial spider web is better than that of traditional networks in terms of improving the overall reliability and invulnerability of communication system. A comprehensive study on the advantage characteristics of spider web has important theoretical and practical significance for promoting the invulnerability research of farmland wireless sensor network.

The output signal of the electromagnetic flowmeter measuring the slurry flow will be disturbed by the slurry noise. It is necessary to study the characteristics of slurry noise in order to reduce the interference. The methodology for the estimation of the slurry noise power spectrum based on the ARMA model is presented in this paper, and the relation among the slurry noise, the velocity, and the concentration is obtained by means of the methodology above according to the1/fcharacteristics of the slurry noise. The results by computer simulation experiment show that if the concentration or flow velocity is increased, then slurry noise power spectral density curve in the logarithmic coordinate system will move to the upper right; if the concentration or flow velocity is reduced, then slurry noise power spectral density curve in the logarithmic coordinate system will move to the lower left.

This paper addresses the challenges of cooperative formation control and prescribed-time tracking for networked quadrotor UAVs under speed and input saturation constraints. A hierarchical control framework including position formation layer and attitude tracking layer is proposed, which achieves full drive control of an underactuated UAV formation system by introducing the expected tracking Euler angle. For the outer-loop position control, a distributed consensus protocol with restricted state and control inputs is designed to ensure formation stability with customizable spacing and bounded velocity. The inner-loop attitude control employs a prescribed-time sliding mode attitude controller (PTSMAC) integrated with a prescribed-time extended state observer (PTESO), enabling rapid convergence within user-defined time and compensating for unmodeled dynamics, wind disturbances, and actuator saturation. The effectiveness of the proposed algorithm was demonstrated through Lyapunov stability. Comparative simulations show that the proposed method has significant advantages in high-precision formation control, convergence time, and input saturation.

In this paper, the robust finite-time control for impact angle guidance of missile dynamic system with uncertainties is investigated by combining linear extended state observer (LESO) and adaptive non-singular fast terminal sliding mode method. Specially for dealing with existing uncertainties including time-varying parametric perturbation and nonparametric disturbances in high order line-of-sight rates and target acceleration, a robust LESO strategy is proposed for designing sliding mode-based impact angle guidance, which can guarantee that estimation error converges to the neighborhood of the origin in finite-time. Based on the proposed LESO framework, an adaptive non-singular fast terminal sliding mode guidance law is considered for realizing interception of maneuvering targets, which can guarantee asymptotically stability of the system. Simulation results are shown for confirming effectiveness of the proposed guidance strategy of this paper. Compared with former methods, accuracy of estimation is increased by nearly two times, and miss distance is reduced by nearly two times.