Detecting Grain Flow Rate Using a Laser Scanner

Detecting and measuring mass flow is fundamental to many applications in agricultural engineering. Material handling, food processing, fertilizer spreading, and yield monitoring in combines are examples where mass flow measurement is needed. Methods for measuring material flow have used load cells, optical sensors, radiometric sensors, and many other techniques. The objective of this study was to develop a system to measure material (grain) flow using a laser line scanner. A laser line scanner measures the distance between the sensor and objects based on the time-of-flight principle. In this study, it was used to measure grain flowing from a stationary bin. A sliding gate at the bottom of the bin was used to adjust the grain flow. Experiments were conducted at six grain flow rates with three replications. The results showed the ability to detect the grain flow and measure grain flow rates up to approximately 5 kg s^-1 for 45 cm of flow width (with R² = 0.97). Measurement of flow rates greater than 5 kg s^-1 was not possible. We found a linear relationship between grain flow rate and the RMSE of the laser line scanner signal (R² = 0.91).