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The purpose of this paper is to estimate aircraft roll angle and rate gyro biases using aircraft kinematics with GPS and low‐quality rate gyros.

The proposed method is motivated by observing the fact that, in typical flight applications with transport, reconnaissance, or surveillance missions, the aircraft flies along relaxed flight paths, and the associated aircraft motion can be considered as the sum of the coordinated flight, low‐frequency motion and non‐coordinated, high‐frequency motion. The proposed scheme utilizes the coordinated flight kinematics to form the relatively simple, low‐order Kalman filter that estimates the aircraft roll attitude and rate gyro biases.

The associated frequency analysis reveals that, for the estimation in the relatively low‐frequency region, the method relies primarily on GPS with the help of coordinated flight kinematics in removing the bias effect from the low‐quality rate gyros. Also, for the estimation in the high‐frequency region the method relies mainly on the numerical integration of the rate gyro for the roll attitude, which enables a high‐bandwidth estimation.

The proposed method is not suitable for flight manoeuvres where a non‐coordinated flight, such as steady heading sideslip, is sustained for a long period of time.

The proposed method has been implemented in a small UAV. The associated flight tests and simulations indicate that the new method has a potential to be used as a backup or a replacement for other complex conventional methods for many flight applications.

This paper has been the first to promote the estimation method that combines aircraft kinematics with GPS and low‐quality rate gyros.

Customers in an Internet shopping environment actually play dual roles. One is the role as a customer in a shopping place, and the other is the role as a user of information technology. In both cases, the level of satisfaction is of great concern. In this vein, a way of measuring the satisfaction level that takes both roles into account is needed. However, in past research indexes for consumer satisfaction and indexes for user information satisfaction have been developed separately in the fields of marketing and management information systems. Because of this lack of interaction between the two streams of research, an index for electronic commerce consumers that has its base in the dual roles has not been developed and tested. In this research, an instrument for measuring electronic commerce consumer satisfaction was proposed and validated using a sample of over 400 customers. The relationship between the index and consumers’ purchasing intention was also examined.

To solve the shortcomings of existed search and rescue drones, search and rescue the trapped people trapped in earthquake ruins, underwater and avalanches quickly and accurately, this paper aims to propose a four-axis eight-rotor rescue unmanned aerial vehicle (UAV) which can carry a radar life detector. As the design of propeller is the key to the design of UAV, this paper mainly designs the propeller of the UAV at the present stage.

Based on the actual working conditions of UAVs, this paper preliminarily estimated the load of UAVs and the diameters of propellers and designed the main parameters of propellers according to the leaf element theory and momentum theory. Based on the low Reynolds number airfoil, this paper selected the airfoil with high lift drag ratio from the commonly used low Reynolds number airfoils. The chord length and twist angle of propeller blades were calculated according to the Wilson method and the maximum wind energy utilization coefficient and were optimized by the Asymptotic exponential function. The aerodynamic characteristics of the designed single propeller and coaxial propeller under different installation pitch angles and different installation distances were analyzed.

The results showed that the design of coaxial twin propellers can increase the load capacity by about 1.5 times without increasing the propeller diameter. When the installation distance between the two propellers was 8 cm and the tilt angle was 15° counterclockwise, the aerodynamic characteristics of the coaxial propeller were optimal.

The novelty of this work came from the conceptual design of the new rescue UAV and its numerical optimization using the Wilson method combined with the maximum wind energy utilization factor and the exponential function. The aerodynamic characteristics of the common shaft propeller were analyzed under different mounting angles and different mounting distances.