Development and Performance Assessment of Real-time Rotational Speed Measurement System for Agricultural Application

Rotational speed is one of the most important parameters in the performance of any system. It becomes more vital when the rotational speed measurement is required on real-time basis. Measurement of rotational speed has a crucial role in automation of agricultural machineries for various purposes. The existing real-time speed measurement systems are susceptible to the varying working environment. Therefore, it was necessary to study the performance of available sensor. In this study four different sensors (inductive proximity, Infrared (IR), Hall effect and optical proximity sensors) were tested in three different working environments (indoor, outdoor and outdoor dusty condition) for two different spacings (2 and 5 mm) between sensors and target. A laboratory setup was developed to test the performance of the sensors in terms of percentage deviation in rotational speeds measurement compared to actual values. The values were recorded in Secure Digital (SD) card and analysed using full factorial design. The means of the different levels were compared using Tukey’s (b) method. There was significant difference in sensor response for different conditions. The percentage of deviation in speed for Hall effect, inductive proximity, IR and optical proximity sensors varied from 0.55 to 1.03, 1.20 to 32.29, 21.37 to 100.00 and 35.18 to 99.98%, respectively. The study concluded that the Hall effect sensor was more suitable for rotational speed measurement than the other sensors without being affected by working environment.