The structure design of an autonomous/remote underwater vehicle, Intelligence Ocean I(IO-I), capable of operating in ROV or AUV mode and acquiring marine environment information and its own status data are outlined first in this paper. The dynamics equations of underwater vehicles in horizontal and vertical are given to describe the movement of an underwater vehicle, taking the gravity, buoyancy, thrust and hydrodynamic force into account. Furthermore, in order to realize high precision automatic control of robot, the fuzzy control algorithm which belongs to the intelligent control is combined with the cascade PID control algorithm to realize an modified underwater vehicle control algorithm, which improves the applicability of the control algorithm and reduces the difficulty and workload of parameter adjustment. The proposed control algorithm is recognized in numerical simulations as well as in experimental tests which confirm the good performance of the controller and the prototype. INDEX TERMS Unmanned underwater vehicle, dynamics modeling, motion control, PID controller.

A polarized light sensor is applied to the front-end detection of a biomimetic polarized light navigation system, which is an important part of analyzing the atmospheric polarization mode and realizing biomimetic polarized light navigation, having received extensive attention in recent years. In this paper, biomimetic polarized light navigation in nature, the mechanism of polarized light navigation, point source sensor, imaging sensor, and a sensor based on micro nano machining technology are compared and analyzed, which provides a basis for the optimal selection of different polarized light sensors. The comparison results show that the point source sensor can be divided into basic point source sensor with simple structure and a point source sensor applied to integrated navigation. The imaging sensor can be divided into a simple time-sharing imaging sensor, a real-time amplitude splitting sensor that can detect images of multi-directional polarization angles, a real-time aperture splitting sensor that uses a light field camera, and a real-time focal plane light splitting sensor with high integration. In recent years, with the development of micro and nano machining technology, polarized light sensors are developing towards miniaturization and integration. In view of this, this paper also summarizes the latest progress of polarized light sensors based on micro and nano machining technology. Finally, this paper summarizes the possible future prospects and current challenges of polarized light sensor design, providing a reference for the feasibility selection of different polarized light sensors.

No abstract

Fruit grading is an important step in postharvest processing. Based on the images of oranges, we can get those characters that describe the size and color of them. Then 16 features were used to grade the oranges. To the best of our knowledge, this is the first work that used the mean value of R, G, B, H, S, I and the variance of R, G, B, H, S, I together as parameters, and graded the oranges through Bayes inference method. Experimental result shows that our method is competitive.