tailieunhanh - Mobile Robots Navigation 2008 Part 2

Tham khảo tài liệu 'mobile robots navigation 2008 part 2', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 28 Mobile Robots Navigation center axis is Z the angle along the cone-wise plane from the line OA to an arbitrary position C is 0 the rotating angle of the cone-wise plane around the Z-axis is Ọ the angle between the line of vision ray axis and the ground is Y and the inclined angle of the mother line is Yo. We can obtain next formulas from the above geometrical relation cos Ọ cos 20 sin Ọ cos Y- Y0 sin 20 3a 3b If we assume the relation Y Y0 we can get Ọ 20 . 4 In the above relation the angle 0 means the angle of the polarizing plane based on the line OA. Hence we can extend the polarizing angle 0 in the range of 180 deg to the rotating angle of the cone-wise plane Ọ in the range of 360 deg . Since both angles are one-to-one correspondence we can determine the azimuth angle uniquely. When the sharpness of the cone-wise plane is the angle Y0 the extending shape of the cone-wise plane is determined uniquely as shown in Fig. 2. and we can get the next relation Yo 30 deg . 5 Then we can show that the rotating angle of the cone-wise plane around the Z-axis can be modulated as the angle of the polarizing plane around the ray axis. That is if we set a light source inside the cone-wise polarizer and observe from outside the cone-wise plane the angle of the observed polarizing plane is proportional to the rotating angle of the cone-wise plane. expansion form e-vector plane Fig. 2. 3-D conic structure made by flexible linear polarizer Optical Azimuth Sensor for Indoor Mobile Robot Navigation 29 Compensation of Discontinuity There is an adhered part that is parallel to the mother line in the manufactured cone-wise polarizer structurally. If we use a single cone-wise polarizer sensing information is discontinuous and influenced polarizing properties at the junction. So we use two cone-wise polarizers as shown in Fig. 3. and assign them at distorted angles each other for compensating discontinuity. cone 1 evector e O B cone 2 D D O e-vector plane E f Í Ị B V X. _ w e e. n