Angle measurement on a flat surface using high frequency ultrasonic pulse

Ultrasonic waves are most commonly used to measure the presence of an object and its distance from the source using time of flight concept. These are pulses of sound waves that have frequency range higher than the human hearing range. In this paper, we will discuss the measurement of the tilt angle of a robot with respect to a flat base using ultrasonic waves and time of flight concept [2]. An Arduino platform was used with Atmel328P as the processing microcontroller chipset which will then compute the angle of tilt using the distance calculated from an ultrasonic sound transmitter and a receiver using coordinate geometry and trigonometric functions. A combination of gyroscope and accelerometer is also used to find the true tilt angle of the apparatus and then it is compared with the angle readings obtained from the ultrasonic sensor system. A high response time and low delay is necessary for instantaneous angle measurement. Hence, gyroscope-based angles have been used as a reference to adjust filter parameters to decrease error and noise at every iteration.