A flying robot is localized using ultrasonic sensor network distributed on the ground. This requires localization of sensor nodes first. In absence of RF link between target and sensors, weighted Multi-Dimensional Scaling (MDS) with Gradient Descent is used to localize the sensors from outlier free data obtained from generating a locally linear manifold. After initialization, an Extended Kalman...

Multi-mode techniques reduce scanning times in ultrasonic systems, as they allow transducers in a sensor to simultaneously emit and receive without interference. In order to implement these techniques, it is necessary to encode each transducer’s emission. The use of orthogonal pairs of Golay sequences associated with different emitters avoids crosstalk among them. However, these sequences imply...

Introduction The nondestructive, in-situ testing of early-age concrete properties is a crucial point for the progress of many construction projects in the building sector. The application of such techniques can establish e.g. the earliest possible form removal from concrete construction elements, thereby opening highways to traffic or releasing prestress from steel reinforcement with greatest e...

We theoretically and experimentally demonstrate a fiber-optic ultrasonic sensor system based on a fiber-ring laser whose cavity consisting of a regular fiber Bragg grating (FBG) and a tunable optical band-pass filter (TOBPF). The FBG is the sensing element and the TOBPF is used to set the lasing wavelength at a point on the spectral slope of the FBG. The ultrasonic signal is detected by the var...

Currently, vehicles are often equipped with active safety systems to reduce the risk of accidents, many of which occur in the urban environments. The most popular include Antilock Braking Systems (ABS), Traction Control and Stability Control. All these systems employ different types of sensors to constantly monitor the conditions of the vehicle, and respond in an emergency situation. In this pa...

Rice is a food crop commodity that produces rice which plays an important role in the economic life of Indonesia. as staple very difficult to replace by other staples. This study aims determine results design internet-based monitoring system for field irrigation and soil pH with Thinger.io. The tools used this are Node MCU ESP8266, Ultrasonic Sensor HC-SR04, Soil Sensor, Servo Motor (MicroServo...

Characterization of flaws of weld bead is imperative for high-quality welding. Methods of weld bead inspection include radiographic, ultrasonic and vision inspection. However, such methods are costly and time consuming. The proposed sensor is light, low-cost and fast. This paper summarizes our work on weld bead monitoring and defect detection using an electromagnetic sensor. Measurements are ac...