Robust sliding mode control with ESO for dual-control missile

This paper proposes a novel composite dual-control bycombing the integral sliding mode control （ISMC） method basedon the finite time convergence theory with extended state observer（ESO） for a tracking problem of a missile with tail fins and reactionjetcontrol system （RCS）. First, the ISMC method based on finitetime convergence is utilized to design the control law of tail fins andthe pulse control of RCS for the dual-control system, ensuring thesystem with rapid response and high accuracy of tracking. Then,ESO is employed for the estimation of aerodynamic disturbancesinfluenced by the airflow of thruster jets. With the characteristicof high accuracy estimation of ESO, the chattering free trackingperformance of the attack angle command and the robustnessof the control law are achieved. Meanwhile, the stability of thedual-control system is analyzed based on finite time convergencestability theorem and Lyapunov’s theorem. Finally, numerical simulationsdemonstrate the effectiveness of the proposed design.

BTT autopilot design for agile missiles with aerodynamic uncertainty

The approach to the synthesis of autopilot with aerody- namic uncertainty is investigated in order to achieve large maneu- verability of agile missiles. The dynamics of the agile missile with reaction-jet control system （RCS） are presented. Subsequently, the cascade control scheme based on the bank-to-turn （B-I-T） steering technique is described. To address the aerodynamic un- certainties encountered by the control system, the active distur- bance rejection control （ADRC） method is introduced in the autopi- lot design. Furthermore, a compound controller, using extended state observer （ESO） to online estimate system uncertainties and calculate derivative of command signals, is designed based on dynamic surface control （DSC）. Nonlinear simulation results show the feasibility of the proposed approach and validate the robust- ness of the controller with severe unmodeled dynamics.

A sequential continuous flow synthesis and purification process of calcium dibutyryladenosine cyclophosphate

Calcium dibutyryladenosine cyclophosphate is a widely used cardiovascular drug.The traditional batch synthesis process suffers from long reaction times,tedious operations,and unstable yields.Herein,a sequential continuous flow synthesis combined with a multistage in-line purification process of calcium dibutyryladenosine cyclophosphate was developed.The acylation reaction was completed in a continuous coil reactor at 160℃ in 20 min.And the high toxic solvent pyridine was replaced by acetonitrile.Furthermore,the multistage in-line purification process was integrated into the homemade 3D circular cyclone-type micromixer chip.Combining with the membrane phase separators,the residence time of the purification step was 30 s.The isolated yield of this sequential continuous process was 92%with 99%purity.

Two-step continuous flow process of sodium tanshinone ⅡA sulfonate using a 3D circular cyclone-type microreactor

A sustainable and practical process is presented for the direct synthesis of sodium tanshinone IIA sulfonate(STS).Our approach was inspired by the well-established and industrially applied batch synthetic route for STS production.We constructed a telescoped two-step continuous flow platform.This involved a continuous tanshinone IIA sulfonation and in-line salt formation.For the setup,we constructed a 3D circular cyclone-type microreactor using femtosecond laser micromachining.Compared to the 68%yield for 2 h in batch,the two-step continuous flow had an STS yield of 90%,achieved for a total residence time of<3.0 min under optimal conditions.The proposed continuous flow method vastly simplified the operation and improved procedural safety,while significantly reducing the required acid content and wastewater production.