Candidate: Nelson Walter da Silva Neto 
Program: UFSC / POSMEC
Date: November, 2021
Advisor: Victor Juliano De Negri (UFSC)
Abstract: Hydraulic actuators are used in several applications in industry due to their ability to work with large forces, low vibration and low inertia. Force control is widely used in industrial, mobile, aeronautic, and robotic applications, among others. In robotics, for example, the hydraulic system is used with force control in the interaction between the system and an unknown environment. Researchers often describe the importance of a flexible coupling between the actuator and the medium to isolate the system dynamics and have a stable and robust force output. This increased compliance is one way to solve the stability problems inherent in force control. The main objective is to present a methodology for calculating the volume and preload of accumulators in order to facilitate their sizing and selection for force control application. The sizing method is applied to a force control system using hydraulic accumulators in which the aim is to decrease the effective compressibility modulus of the hydraulic fluid and thus replace the elastic effect obtained when mechanical springs are used. Subsequently, the dynamic model of the system is elaborated and assembled on an experimental bench. Employing a PID control, simulation and experimental results are compared, proving the effectiveness of the proposed system for force control.
Reference: SILVA NETO, N. W. da. Metodologia de dimensionamento de acumuladores hidráulicos para controle de força. 2021. 82 p. Dissertação (Programa de Pós Graduação em Engenharia Mecânica) – Universidade Federal de Santa Catarina