During the process of aircraft design, the mathematical model of pilot control behavior characteristics is always used to predict aircraft flying qualities （FQ）. This is one of the important methods to avoid pilot-aircraft adverse coupling. In order to study the FQ criterion based on closed-loop pilot-aircraft systems, first, an experimental database is built, which includes 40 aircraft dynamics configurations and the corresponding flight simulation results. Second, the mathematical pilot models with a set of different aircraft configurations are obtained by this experimental database. Then, two FQ criteria, Neal-Smith criterion and Moscow Aviation Institute （MAI） criterion, are analyzed. And the relationship between the FQ level evaluated by actual pilot and the parameters of closed-loop pilot-aircraft systems is studied. Finally, an improved criterion of aircraft FQ is built based on the above two criteria. This new criterion is further used to predict FQ for four new aircraft dynamics configurations, and the prediction results verify its accuracy and practicability.
With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system （MAS） is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the pro
