Search

Permanent magnet synchronous linear motor (PMSLM) is a linear motion device, which has the characteristics of simple structure, low loss, high precision, repeatability, large stroke, and simple maintenance. Simultaneously, due to its feature of non-linearity, time-varying, strong coupling, and external load uncertainty, a speed disturbance control method base on sliding mode control of PMSLM is proposed in this paper. The method of sliding mode control uses the power function to smooth the processing. It replaces the symbolic function based on the exponential approach method; therefore, the buffeting of the conventional sliding mode can be well suppressed by this method. When considering different disturbances, the simulation proves that the sliding mode control system can overcome the influence of system parameter changes and external disturbances. Therefore, the control of the PMSLM can be achieved. Meanwhile, the simulation results show that the proposed new sliding mode approach rate can better suppress chattering compared with the traditional approach rate. Additionally, the stability of the system and anti-interference is improved.

In the fields of physics, mathematics, communication, control, biology, etc., chaos is widely used, and it plays an important role in modern science and technology. In this paper, a new seven-dimensional hyperchaotic system is proposed and some related features of the hyperchaotic system are analyzed, including equilibrium stability, dissipation, bifurcation and Lyapunov exponent. The results show that the proposed hyperchaotic system exhibits hyperchaotic, chaotic, quasi-periodic and periodic dynamic behaviors. The seven-dimensional hyperchaotic system is implemented through experiments, and the phase diagrams of the circuit simulation are consistent with those of the numerical simulation, which verifies the physical realization of the hyperchaotic system. In view of chaos in some important fields, such as communication security and complex systems, the seven-dimensional hyperchaotic system is applied to signal encryption and decryption circuit design. Firstly, the proposed seven-dimensional hyperchaotic system is scaled and transformed into a hyperchaotic system that is easy to implement. Then an improved chaotic circuit module design is adopted. Finally, the seven-dimensional hyperchaotic circuit is designed to form a hyperchaotic secure communication circuit. The electronic circuit realizes the confidential communication and its experimental results prove the effectiveness of the designed scheme.