A Novel Skylight Orientation Sensor for Autonomous Navigation

<a></a>The angle of the polarization (AOP) and the degree of polarization (DOP) of the scattered skylight are symmetrically distributed concerning the solar meridian. Based on the symmetry of the skylight polarization distribution pattern, this paper proposes a novel skylight orientation sensor consists of a camera, an S-waveplate, and a linear polarizer. The skylight orientation sensor is using the image polarization encoding capability of the S-waveplate and the linear polarizer to convert the skylight polarization information into the image’s symmetry axis extraction, which has the advantages of no resolution loss and instantaneous field of view error. The symmetry axis in the image is consistent with the solar meridian. Therefore, the angle between the solar meridian and the skylight orientation sensor reference axis can be obtained without calculating the polarization information, which is also beneficial for real-time performance. The angle measurement accuracy and uncertainty of the skylight orientation sensor are verified by numerical simulation and outdoor experiments. The results demonstrate that the skylight orientation sensor has good application potential in autonomous navigation.

A Novel Skylight Orientation Sensor for Autonomous Navigation

<a></a>The angle of the polarization (AOP) and the degree of polarization (DOP) of the scattered skylight are symmetrically distributed concerning the solar meridian. Based on the symmetry of the skylight polarization distribution pattern, this paper proposes a novel skylight orientation sensor consists of a camera, an S-waveplate, and a linear polarizer. The skylight orientation sensor is using the image polarization encoding capability of the S-waveplate and the linear polarizer to convert the skylight polarization information into the image’s symmetry axis extraction, which has the advantages of no resolution loss and instantaneous field of view error. The symmetry axis in the image is consistent with the solar meridian. Therefore, the angle between the solar meridian and the skylight orientation sensor reference axis can be obtained without calculating the polarization information, which is also beneficial for real-time performance. The angle measurement accuracy and uncertainty of the skylight orientation sensor are verified by numerical simulation and outdoor experiments. The results demonstrate that the skylight orientation sensor has good application potential in autonomous navigation.

Rancang Bangun Aplikasi Jam Tangan Pranata Laboratorium Pendidikan dengan Kemampuan Waterpas Tiga Dimensi untuk Mengatur Sambungan Modul Uji Pembebanan Motor

When testing the loading of an electric machine, we often experience problems in finding a tool to see the precision of the connection between the shaft of an electric machine. Shaft connections that are not straight and not right in the middle can damage the shaft of the rotating engine and the engine being rotated. This research is the development of previous research that uses Android phone as a tool. By reading the value of the orientation sensor on an android phone, we can measure the angle of rotation on the x, y and z axes. The Watpasdroid application will display the value on each axis. This application has also been used in the Electric Driving Laboratory at the Surabaya State Electronic Polytechnic (PENS), to check the connection (coupling) between an electric motor and a magnetic load (dynamo meter). The size of a cellphone that is still too large is sometimes become a problem if the surface being measured is narrow. So we uses a wristband-shaped watch module that already has a gyro sensor and can be programmed according to our need. The size is almost 1/12 of ordinary cellphones. The M5Stick-C module is used to compare the gyro reading value displayed by the wristband. To test the quality of motor joint which flatness checks have been assisted by using a wristband, a thermal observation camera is used. This application, does not rule out, can be used in other laboratories for the purpose of checking the plane levelness or equality in two dimensions or three dimensions.

A Novel Position and Orientation Sensor for Indoor Navigation Based on Linear CCDs

The position and orientation of a mobile agent, such as robot or drone, etc., should be estimated in a timely way during operation in the structured indoor environment, so as to ensure the security and efficiency of task execution. Concerning the problem that the position and orientation are often estimated separately by different kinds of sensors in the off-the-shelf methods, we design a novel position orientation sensor (POS). The POS consists of four pairs of linear charge-coupled devices (CCDs) and cylindrical lenses, which can estimate the 3D coordinate of the anchor in the POS’s field of view. After detecting at least three anchors in its field of vision sequentially, the Rodrigues coordinate transformation algorithm is utilized to estimate the position and orientation of POS simultaneously. Meanwhile, the position and orientation are estimated at the receiver side. Hence there is no privacy concern associated with this system. The architecture of the proposed POS is symmetrical and redundant, even if one of the linear CCDs or cylindrical lens malfunctions, the whole system could still work normally. The proposed method is cost-effective and easily extends to a wide range. The numerical simulation demonstrates the feasibility and high accuracy of the proposed method, and it outperforms the off-the-shelf methods.

Design of Autonomous Quadcopter Using Orientation Sensor with Variations in Load Fulcrum Point

In designing the quadcopter, the main focus is stability and balance. Thus, in the more specific implementation, for example for aerial photography, a quadcopter can also be used as a load carrier. To be able to balance the quadcopter equipped with an orientation sensor on the controller, the orientation sensor includes a gyroscope sensor, accelerometer, and magnetometer. For this reason, it is necessary to have an autonomous stabilizer mechanism that can make the quadcopter stay in a stable and balanced condition even with the additional load. Furthermore, in this research, we will discuss how to determine the PID set points for quadcopter balance that can be tested on loads with different fulcrums. The test is limited to the condition of the quadcopter being hovered for pitch and roll angles. Based on the testing results, it can be concluded that there is a stability response in the Quadcopter. It can be seen from the RMS value obtained that it is by the steady-state tolerance of 2% -5% of the setpoint. Then, the Quadcopter can carry the maximum load with different fulcrums; 950g for fulcrum in the middle of the quadcopter, 580g for the load is placed 6 cm from the middle of the quadcopter, and 310g if the load is placed on one motor.