A Robust Orientation System for Inclinometer With Full-Redundancy in Heavy Industry

Abstract

In the heavy industry, high-quality inclinometer has been required in terms of accuracy, stability, and safety function for durable use in harsh environments. This paper proposes a robust orientation system for industrial inclinometer based on Microelectromechanical Systems (MEMS) accelerometer. An industrial motor (Vexta) is used as an oriental reference. The STM microcontroller (MCU) has the role of memorizing the inclination sent from the motor with the corresponding acceleration into a Lookup Table (LUT) by using Flash memory. The full redundancy included dual accelerometers and MCUs to enhance the safety function for the operating system via two inclination channels. The support from the Low-pass filter and the zero-offset compensation for temperature change contribute to the measurement precision. For industrial applications, Control Area Network open (CANopen) is used as an embedded network communication system. Both static and dynamic cases were tested to verify the behavior of the inclination sensor. The designed structure provides high efficiency for inclinometer performance with accuracy ±0.2° and the stability is always guaranteed thanks to safety function. The designed inclinometer was used for a real excavator to verify its stability and operating performance. The project was carried out at the ’Sensor System’ in Italy, an industrial company in the inclinometer field.