This paper proposes new method for object reference which enables a person to find surrounding objects and develops a navigation system named CoCo. CoCo employs an ultrasonic directional speaker with a rotating base. Ultrasonic wave transmitted by an ultrasonic directional speaker is converted to audible sound when it reflects on floor, wall, or object. Based on this property, CoCo can emit aud...

Ultrasonic distance measurement using the pulse-echo method is based on the determination of the time of flight of ultrasonic waves. The pulse-compression technique, in which the cross-correlation function of a detected ultrasonic wave and a transmitted ultrasonic wave is obtained, is the conventional method used for improving the resolution of distance measurement. However, the calculation of ...

Air – coupled ultrasonic investigation possess a great potential for investigation of aerospace composite materials, because it avoids disadvantages caused by immersion or contact techniques. In the work the test sample of the GLARE3-3/2 composite material with artificial delamination type defect was investigated. Numerical and experimental investigations using focussed air – coupled ultrasonic...

A digitally controlled drive system was implemented in this study to control the speed and direction of a travelling-wave ultrasonic motor. The drive system, based on a 2-phase voltage-fed high-frequency serial-resonant inverter, uses the mechanical resonant frequency of an ultrasonic motor. A TMS320F243 digital signal processor was used to control an ultrasonic motor drive system. The speed co...

Ultrasonic compression wave propagation is sensitive to the physical state of particulate liquid suspensions – colloids and emulsions. It is possible to estimate dispersed particle size distribution (PSD) from measurements of wave attenuation and/or phase velocity as functions of frequency. It is also possible to detect and characterise dynamic phenomena such as flocculation, network formation ...

A double ultrasonic source has been shown to dramatically increase dispersion efficiency of carbon nanotubes. Thermal measurements of dispersing fluid only show temperature rises commensurate with the power levels of the two ultrasonic sources; which is validated by predictions of statistical energy analysis (SEA) based on wave superposition principles. In this paper, nonlinear wave resonance c...

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...

In part 21 of the tutorial series "Acoustofluidics--exploiting ultrasonic standing wave forces and acoustic streaming in microfluidic systems for cell and particle manipulation", we review applications of ultrasonic standing waves used for enhancing immunoassays and particle sensors. The paper covers ultrasonic enhancement of bead-based immuno-agglutination assays, bead-based immuno-fluorescenc...

Ultrasonic radiation forces can be used for non-intrusive manipulation and concentration of suspended micrometer-sized particles. For bioanalytical purposes, standing-wave ultrasound has long been used for rapid immuno-agglutination of functionalized latex beads. More recently, detection methods based on laser-scanning fluorometry and single-step homogeneous bead-based assays show promise for f...

Transmission loss and insertion loss measurements of building materials at audible frequencies are commonly made using plane wave tubes or as a panel between reverberant rooms. These measurements provide information for noise isolation control in architectural acoustics and in product development. Airborne ultrasonic sound transmission through common building materials has not been fully explor...