Navigation technology is an essential ability for the survival and development of animal and human. Desert ants Cataglyphis are able to explore their desert habitat for hundreds of meters while foraging and return back to their nest precisely and in a straight line. For deriving direction information, these animals use the pattern of polarized light in the sky, which arises due to scattering of sunlight in the atmosphere. The polarization sensitivity mechanisms of the ants' compound eye are analyzed. A novel bionic navigation sensor is constructed. The work principle of the sensor is discussed. A novel algorithm of the direction angle calculation is presented. The merits of the new algorithm are discussed in detail. The angle output experiment of the navigation sensor is performed under different light conditions. The normalization output curve is obtained, and the angle output error is given with our algorithm. The experiment result indicates that the new angle algorithm is feasible and effective.

This paper aims to develop a novel attitude determination system aided by polarization sensor. An improved heading angle function is derived using the perpendicular relationship between directions of E-vector of linearly polarized light and solar vector in the atmospheric polarization distribution model. The Extended Kalman filter (EKF) with quaternion differential equation as a dynamic model is applied to fuse the data from sensors. The covariance functions of filter process and measurement noises are deduced in detail. The indoor and outdoor tests are conducted to verify the validity and feasibility of proposed attitude determination system. The test results showed that polarization sensor is not affected by magnetic field, thus the proposed system can work properly in environments containing the magnetic interference. The results also showed that proposed system has higher measurement accuracy than common attitude determination system and can provide precise parameters for Unmanned Aerial Vehicle (UAV) flight control. The main contribution of this paper is implementation of the EKF for incorporating the self-developed polarization sensor into the conventional attitude determination system. The real-world experiment with the quad-rotor proved that proposed system can work in a magnetic interference environment and provide sufficient accuracy in attitude determination for autonomous navigation of vehicle.

Many animals exploit polarized light in order to calibrate their magnetic compasses for navigation. For example, some birds are equipped with biological magnetic and celestial compasses enabling them to migrate between the Western and Eastern Hemispheres. The Vikings' ability to derive true direction from polarized light is also widely accepted. However, their amazing navigational capabilities are still not completely clear. Inspired by birds' and Vikings' ancient navigational skills. Here we present a combined real-time position method based on the use of polarized light and geomagnetic field. The new method works independently of any artificial signal source with no accumulation of errors and can obtain the position and the orientation directly. The novel device simply consists of two polarized light sensors, a 3-axis compass and a computer. The field experiments demonstrate device performance.

Azimuth information obtained from a polarization pattern in the sky provides many organisms like insects and birds with the ability to navigate. The aim of this study is to investigate the azimuth method to measure the solar meridian from the pattern of the Angle of E vector (AOE) when it is partially obscured and disturbed. The model of the sky polarization pattern projected onto an imaging sensor is analyzed. The projection characteristic of the solar meridian is proved to be a straight line passing through the principal point, which is composed of pixels with the E-vector orientation 90° in the AOE map. Based on the mutation feature of the gradient amplitude of E-vector orientation 90° and occlusion without mutation on the solar meridian, a robust gradient amplitude and binary integration (GABI) azimuth method for a polarization imaging sensor is proposed. Then, the feasibility and robustness of this method are verified via numerical simulation and outdoor experiments, and the results show that when branches and buildings shield more than 80% of AOE map, the azimuth measurement method remains effective. The accuracy of azimuth is 0.417° (σ). This indicates that the azimuth can be effectively measured, even in the presence of occlusion and interference.