A Sensor Based on a Spherical Parallel Mechanism for the Measurement of Fluid Velocity: Physical Modelling and Computational Analysis

Abstract

In this article, a new method was developed to measure the velocity of a fluid using a sensor, based on the use of a spherical parallel mechanism with three degrees-of-freedom (DOF). This sensor transforms the kinetic energy of the fluid into potential energy by deforming the parallel mechanism. This deformation is due to the impact of the fluid on a sphere attached to the platform of the parallel mechanism. Through the acquisition of data from a sensor using an inertial measurement unit (IMU) in the sphere, an algorithm calculates the velocity and direction of the fluid. In this article, a mathematical model of the mechanism and an algorithm for correctly measuring the velocity and direction of the fluid is developed; this algorithm is tested through a simulation in the Adams software, and the MATLAB software is used to execute the algorithm. The results show that the algorithm calculates the velocity and the direction of the fluid correctly, demonstrating the technical feasibility of the sensor.

Dynamic Walking of a Legged Robot in Underwater Environments

“…Finally, the velocity of the fluid is calculated by the hydrodynamic Equation of the drag force. The theoretical explanation of this sensor is shown in the paper by the authors of [13] and the demonstration experiment is shown in the paper by the authors of [14].…”

“…For the demonstration of the proposed concepts, a prototype of a planar bipedal robot was developed with a hydraulic actuator and a mechanical sensor that measures the velocity of the fluid relative to the centre of mass of the robot. The theoretical foundation and experimental validation of the sensor are found in [13,14].…”

A Sensor Based on a Spherical Parallel Mechanism for the Measurement of Fluid Velocity: Experimental Development

“…The forces applied to the sphere due to the movement of the fluid are calculated by equation (6). The calculation has previously been explained in full detail [1].…”

“…In the article, ''A Sensor Based on a Spherical Parallel Mechanism for the Measurement of Fluid Velocity: Physical Modeling and Computational Analysis'' [1], the researchers proposed a flow sensor [1], [2] that was based on the spherical parallel mechanism with the 2 UPS + 1 RU configuration [3]. They developed a mathematic model and working algorithm for the sensor.…”

“…which it is possible to know the angles of the platform and the acceleration of the sphere by using the IMU. These angles and accelerations are input into the algorithm that was developed previously [1]. Moreover, the velocity and direction of the fluid were calculated by using the mathematic models and the dynamics of the parallel mechanism.…”