Structural Motion Monitoring Using 9-Axis Sensing Modules with Wireless Communication Capability

Abstract

Dynamic motion monitoring is useful for many applications such as modal testing, mechanical design, vibration control, structural coupling and theoretical model modifications. New sensing systems and sensing techniques for both translational and rotational motion are always in great need. This paper present two compact and portable motion sensing systems to monitor the dynamic behavior of complicated structures. Each system consists of a 9-axis sensing module and a control computer.As the sensing modules implement signal filtering, analogue to digital conversion and motion analysis on chip, no additional signal amplifiers are necessary. The modules get their power supply from the USB (Universal Serial Bus) port of the computer without involvement of extra power unit. The same cable for the sensor power supply serves to transfer the measured data from the module to the computer thus no oscilloscope is needed. The elimination of sensor power unit, amplifiers and oscilloscope greatly simplifies the measurement system and makes on-site motion monitoring much more convenient, especially when the accessible space is limited. The inertial loading and local stiffening effects introduced by conventional sensors are also reduced. In addition, for cases where the cable connection between the module and the computer is difficult or even impossible, wireless transmission modules can be incorporated into the system to form a wireless measurement system. Through experiments, it is found that the wireless data maintain their quality even after passing through a few concrete walls when wireless transmission distance is more than 60 meters. activity by its nature (Kongsberg Maritime 2016). In order to undertake tasks such as wave height monitoring or using cranes during rough weather, roll, pitch, yaw motion needs to be measured. Traditional sensors like Motion Reference Units (MRUs) though can provide accurate measurement; they are complex, expensive and big in size. New sensors or sensing systems with high reliability and low cost are in great demand for large-scale industrial deployment.Traditional IMUs like Honeywell and Sagem are used in many applications for navigation, control and human environment interaction (Yuan et al. 2014, Ren et al. 2014. With AHRS (attitude and heading reference system), it is possible to get similar performance in a smaller package which can caters for more applications, such as antenna and camera stabilization, small unmanned vehicles and even hand-held applications.In this paper, structural motion measurement systems based on 9-Axis MEMS (Micro Electro Mechanical Sensor) sensing modules are developed. Attitude sensing modules JY-901 and GY953 are used in monitoring the translational acceleration and rotational motion of structures. Wireless transmission modules may be incorporated into the measurement system when the cable connection between the module and the computer is difficult or even impossible. The measured motion data give us insight into how the structures work and provide usefu...

MEMS accelerometers for mechanical vibrations analysis: a comprehensive review with applications

“…The MPU-5060 can be used in many applications; for example, reference [96] presents a solution on how to generate a power for marine wireless sensors using underwater motion energy; in [97] a damage detection method is made based on autoregressive model (AR) and damage-sensitive features (DSFs); reference [98] proposes the development of a sensing system that uses the Arduino platform and a MPU-5060 accelerometer; and in [99] two compact and portable motion sensing systems to monitor the dynamic behavior of complicated structures are presented.…”