Measurement and modeling of a flexible manipulator for vibration control using five-segment S-curve motion

Abstract

User designed manipulators are widely used in industry as a part of automation. The design of lighter robotic arms is required for less energy consumption. Joints, structural features, and payload affect the dynamic behavior of manipulators. Even if the arms have sufficient structural rigidity, joints, or payloads further increase their flexibility. These factors should be considered at the design stage. Flexibility causes vibrations, and these vibrations negatively affect robot repeatability and processing speed. Reducing the vibration levels of flexible manipulators is an attractive issue for engineers and researchers. Accurate estimation of the mathematical model of flexible manipulators increases the success of vibration control. In this paper, the modeling and experiments for vibration control of a single-axis flexible curved manipulator with payload are considered. The experimental system is introduced to collect vibration responses synchronously at the tip of the curved manipulator for angular velocity input. The mathematical model of the manipulator is estimated using the continuous-time system identification (CTSI) method with a black-box model based on the experimental input/output (I/O) signals. A five-segment S-curve motion input based on the modal parameters is designed to suppress residual vibrations. Vibration control is successfully performed for different deceleration times of the designed S-curve motion input. The results showed that the residual vibrations from experiments and predicted models matched well for different cases depending on payload, angular position, and motion time.

Command smoothing-proxy sliding mode control of hydraulic servo system considering structural flexibility

“…Besides, trajectory planning based on dynamic analysis and virtual control force are demonstrated and validated in Shi et al 14 and Lei et al 15 respectively. A five-segment S-curve motion input based on the modal parameters is designed in Malgaca and Lo¨k 16 to suppress residual vibrations. Vibration control is successfully performed for different deceleration times of the designed S-curve motion input.…”

Analysis of an actively controlled composite box manipulator without external actuator

“…Besides, the dynamic model of a flexible manipulator placed piezoelectric actuator/sensor on its surface was defined by Orszulik and Shan 37 with a genetic algorithm. Malgaca and Lök 38 identified a curved manipulator with the black-box identification approach via an experimental test rig. Lou et al 39 proposed a reduced-order transfer function of a flexible manipulator with piezoelectric actuators and strain sensors to determine precisely the system model, and an inertia element is added to the identified model, which is matched well with experimental studies.…”