Performance analysis and nonlinear calibration of GP2Y0A21 infrared distance sensor using MATLAB

Abstract

Infrared distance sensors are widely used in robotics and automation due to their low cost and small size. However, their output voltage versus distance characteristic is highly nonlinear and sensitive to target reflectivity. This paper presents a systematic performance analysis of the GP2Y0A21 sensor within its effective range of 10–80 cm. An automatic data acquisition system based on MATLAB is developed to measure the static characteristics. A physically motivated inverse model d=k⁄V +b is proposed for calibration. Experimental results show that the proposed model reduces the measurement error from ±3.5 cm (linear approximation) to within ±0.8 cm. The influence of target color and material is quantitatively analyzed, and a simple calibration routine is provided. The method is suitable for both teaching and engineering applications. In summary, this work: (a) evaluates the sensor’s static performance; (b) quantifies the influence of target color and material; (c) proposes a simple inverse calibration model; (d) provides anopen-source MATLAB routine.