LMI Approach to Robust H_∞/H_2 Controller Design with Regional Poles Constraint of a Pump-Motor System

The time domain guideposts requirements of a pump-motor system is transfered into a series of constraints which express the robust performance upper bound and regional poles limits of the closed loop system. Then the servo system control problem is transferred into the problem of robust performance optimizing under regional poles constrains described by linear matrix inequality （LMI）. These LMIs are easy to solve through the Matlab LMI-toolbox. Simulations indicate that the controller has excellent dynamic, static and disturbance rejection performance, and the control system is robust and has perfect H2 performance to the bounded external torque disturbance.

Regional pole assignment for uncertain delta-operator systems

The pole assignment in a specified disk by state feedback for uncertain delta-operator systems is studied. By making use of algebra Riccati equations, a sufficient and necessary condition of pole assignment for a kind of parameter uncertain delta-operator system in a specified disk by state feedback is presented. And the design method of state feedback controller is also developed. The proposed method can unify some previous related results of continuous and discrete time systems into the delta framework. The efficiency of the design method is illustrated by a numerical example.

Missile autopilot design based on robust LPV control

This paper proposes an effective algorithm to work out the linear parameter-varying (LPV) framework autopilot for the air defense missile so as to simultaneously guarantee the closed-loop system properties globally and locally, which evidently reduces the number of unknown variables and hence increases the computational efficiency. The notion of 'robust quadratic stability' is inducted to meet the global properties, including the robust stability and robust performance, while the regional pole placement scheme together with the adoption of a model matching structure is involved to satisfy the dynamic performance, including limiting the 'fast poles'. In order to reduce the conservatism, the full block multiplier is employed to depict the properties, with all specifications generalized in integral quadratic constraint frame and finally transformed into linear matrix inequalities for tractable solutions through convex optimization. Simulation results validate the performance of the designed robust LPV autopilot and the proposed framework control method integrating with the full block multiplier approach and the regional pole placement scheme, and demonstrate the efficiency of the algorithm. An efficient algorithm for the air defense missile is proposed to satisfy the required global stability and local dynamical properties by a varying controller according to the flight conditions, and shows sufficient promise in the computational efficiency and the real-time performance of the missile-borne computer system.

Assessing and Comparing Smallholders’Vulnerability to Climate Change among Countries in the Pan-Third Pole Region

A comprehensive assessment of climate change vulnerability is imperative for formulating effective adaptation strategies and advancing sustainable development goals.As one of the most climate-vulnerable regions globally,the Pan-Third Pole area lacks transnational vulnerability assessments,which poses a significant obstacle to efficient climate adaptation.This study conducted transnational comparisons based on primary micro-survey data collected uniformly across Nepal,Cambodia,Thailand,and Myanmar,which are all located in the Pan-Third Pole region.Evaluating and comparing the vulnerabilities employed an extended framework of climate change indicators.The findings reveal substantial variations in vulnerability among the countries,with Cambodia exhibiting the highest vulnerability,followed by Thailand,Myanmar,and Nepal in descending order,primarily due to differences in exposure.Household exposure to climate change also varied significantly.Sensitivity scores decreased in the order of Nepal>Cambodia>Thailand>Myanmar,with demographic factors,tap water accessibility,and land being the major contributors and sources of differentiation among the countries.Regarding adaptability,Thailand demonstrated the highest adaptability,with human and financial capital as the key differentiators.The outcomes underscore the need for tailored policy measures addressing the diverse vulnerabilities,including enhancing household disaster prevention and capital protection.Furthermore,targeted international investments are crucial for improving adaptability among smallholders in this unique region.

Off-farm income promotes energy transition in the Pan-Third Pole cross-national region

The Pan-Third Pole region comprises multiple nations affected by climate vulnerability and energy inequality,wherein promoting energy transitions in rural households would provide a path to combat climate change.Identifying the factors that drive rural household energy consumption and the transition is important.This study performed a micro-survey of 1060 rural households in five countries in the Pan-Third Pole region and empirically analyzed the relationships between off-farm income,energy consumption,and energy transitions.The off-farm income of rural households was found to have a significantly positive effect(p<0.01)on energy expenditure,indicating that energy expenditure increased with increasing off-farm income.Off-farm income has a significantly positive effect(p<0.01)on the proportion of commercial energy but a significantly negative effect on the proportion of noncommercial energy.These results indicate that increasing off-farm income can adjust the energy consumption structure of rural households.Furthermore,a robustness check by substituting independent variables,instrumental variable method(IV),and propensity score matching method(PSM)provided strong evidence to prove the robustness of the results.The heterogeneity analysis showed that the effects of off-farm income on energy expenditure and transitions differed among countries,off-farm income had no significant impact on energy expenditure in Cambodia and Myanmar,but it worked for China,Nepal,and Thailand.Finally,policy implications are proposed to promote energy transition in the Pan-Third pole region:providing more full-time or part-time off-farm employment opportunities,employment assistance or skill training by local governments;increasing the pace of infrastructure construction to solve energy inaccessibility;multiple measures to promote the education and environmental knowledge.