A feasible, portable and low-cost detection technique for train track misalignment was proposed. Currently, the detection of orientation movement of train along a flat head rail focuses on using different combination of optical sensor, accelerometer and gyro sensors, separated at several compartment and parts of the train. However, due to high implementation cost and complexity, these systems could not be widely implemented in all of the passenger-loaded compartments train and not suitable to switch from one platform to another, as it requires complex mounted installations. Hence, a MEMS-based Inertia Measurement Unit (IMU) was proposed to be implemented as an alternative low-cost and portable detection solution. The primary objective focuses on identifying potential misaligned track section through tri-axis Euler angles and tri-axis acceleration of the train. Equipped with an onboard Arduino ATMega328 microcontroller, the IMU was programmed through Arduino IDE by using USB-to-UART converter. Direction-cosine-matrix (DCM) algorithm was also implemented to detect and correct numerical error for the gyroscope via reference data from accelerometer. Practical implementation had also being conducted on both car and passenger-loaded train. These data were extracted onto PC for storage and post-processing via MATLAB. The measurements were analyzed and presented with discussion on track characteristics, train motion and noise. Also, analysis through the frequency spectrum over time provides insight onto possible misalignment region. The overall measurement analysis showed good correlation between actual track features and IMU sensor data
