This report details the implementation of distance measurement system using ultrasonic waves. As the human ear audible range is in between 20 Hz to 20 kHz, it is insensitive to ultrasonic waves that falls beyond that range, and hence, the ultrasound waves can be used for applications in the project is to known the distance from obstacle to blind person. And it heard blind person by using android application which programmed by microcontroller. They are widely used as range centimeters and proximity detectors on road and also in the parking assistance systems. The distance can be measured using pulse-echo and phase-measurement method. In this project, the switch is used to know particular instant of distance. When switch is pressed signal fed to controller, microcontroller is interfaced to Bluetooth and it send to android phone and then distance is heard to blind person on android app. The measurement unit uses pulses over continuous signal in the transmission frequency range of ultrasonic transducers. The signal is transmitted by an ultrasonic transducer, reflected by an obstacle and received by another transducer wherein the signal is detected. The time delay of the transmitted and the received signal corresponds to the distance between the system and the obstacle.
The techniques of distance measurement using ultrasonic in air include continuous-wave and pulse-echo technique. In the pulse-echo method, a burst of pulses is sent through the transmission medium and is reflected by an object kept at a specified distance. The time taken for the pulse to propagate from the transmitter to the receiver is proportional to the distance of the object. In this project, an ultrasonic module is interfaced to the microcontroller, and an ultrasonic transducer comprising of a transmitter and receiver are also used. The transmitted waves are reflected back from the object and received by the transducer. The total time taken from sending the waves to the receiving end is calculated by taking into consideration the velocity of the sound. Then, the distance is calculated by a program running on the microcontroller and displayed on an LCD screen interfaced to the microcontroller.
The power supply consists of a step-down transformer 230/12V, which steps down the voltage to 12V AC. This is converted to DC using a Bridge rectifier. The ripples are removed using a capacitive filter, and it is then regulated to +5V using a voltage regulator 7805, which is required for the operation of the microcontroller and other components.
The scope of the project in future can be heightened by using high-frequency transducers to make it fit for medical applications like ultrasound machine.
- This project implement distance measurement using ultrasonic wave
- Microcontroller program is used to calculate the distance
- Bluetooth is interfaced to controller it sends signal to android app.
- Ultrasonic Sensor
- LCD Display