A Training Utility for Estimating the Bowling Speed of a Cricketer Using Accelerometer Data

Abstract

This prototype system known as the Wearable Instantaneous Ball Speed Estimator (WIBASE) was designed to measure the bowling speed of a cricketer during training. When fast bowlers are training, coaches have to assess their ability to bowl consistently fast balls even when they are required to perform long bowling spells, hence the need for reliable, accessible and affordable equipment for measuring their bowling speed cannot be over emphasised. The WIBASE seeks to fill in this gap. It is made up of two hardware components; a computer and a wrist-worn electronic board that houses among other components, a 3-dimensional (3D) acceleration sensor. The system tracks the three-axis acceleration generated by the movement of the arm when delivering the ball and stores these values. The raw sensor data from three different sensors namely accelerometer, gyroscope and magnetometer is processed by a Digital Motion Processor (DMP) on the board in a process known as Sensor Fusion before it is sent via Bluetooth to the computer. The computer runs a Python script that receives the filtered acceleration which consists of both static acceleration and dynamic acceleration. The acceleration is numerically integrated over a minute period of time around the release point using the Trapezoidal method of integrating numerical data to derive the speed of the cricket bowler. The results obtained from the three sets of experiments that were conducted show that the WIBASE can track the 3D acceleration of the hand when bowling, derive the speed of the bowlers and display the speed on a computer while logging all the data into a file.