Advanced Robotics

Yonekura, Kenta; Kim, Chyon Hae; Nakadai, Kazuhiro; Tsujino, Hiroshi; Yokoi, Kazuhito

doi: 10.1080/01691864.2015.1031280pmid: N/A

Effective rhythm expression (ERE) from a robot to a human performing a multi-modal physical-cooperation (MMPC) task was accomplished. During MMPC, the participant and the robot can exchange various rhythms between themselves. To accomplish ERE, it is important to appropriately select the modalities in which the robot expresses its desired rhythm. Accordingly, a hypothesis that selecting the visual rhythm for RE prevents MMPC was tested and confirmed. This hypothesis was preliminarily confirmed in regard to MMPC between two humans. Moreover, to confirm the hypothesis in regard to human–robot cooperation, an experimental system (including a rope-turning robot) was developed. This experimental system allowed experimenters to evaluate the synchronization during MMPC between a human and a robot by measuring the norm of angular velocities. The results of several experiments (namely, a comparison of norms), in which several combinations of visual and auditory rhythmic stimuli were presented to the subjects, strongly supported the hypothesis.

Onat, Altan; Ozkan, Metin

doi: 10.1080/01691864.2015.1014836pmid: N/A

This paper presents an approach for the trajectory tracking control of nonholonomic wheeled mobile robots (WMR) by combining one of the existing adaptive control methods and multiple identification models. The overall system includes two types of controllers in the control scheme. A kinematic controller developed by using kinematic model produces the required linear and angular velocities of the robot for tracking a reference trajectory. These required velocities are used to calculate the torques using an adaptive dynamic controller with multiple models. The proposed method uses the multiple models of the WMR for the identification of the dynamic parameters and performs switching between the given models. The models used in the identification are identical, except for the initial estimates of the parameters. By using an adaptive dynamic controller with multiple models of the WMR, enhancement in transient response is obtained. Stability analysis of the overall system is given, and simulation results are presented to demonstrate the effective performance of the adaptive control by using multiple models approach.

Staicu, Stefan

doi: 10.1080/01691864.2015.1023219pmid: N/A

Matrix relations for kinematics and dynamics analysis of a spatial two-module Stewart-based hybrid parallel robot are established in this paper. Knowing the relative motions of two moving platforms, the inverse dynamics problem is solved based on a set of recursive explicit equations. Finally, compact results and graphs of simulation for the input forces and powers of all actuators are obtained.

Lee, Jong-won; Kim, Hyogon; Jang, Jaeho; Park, Sangdeok

doi: 10.1080/01691864.2015.1040067pmid: N/A

In the field of robotics, mechanical power transmission systems are fundamental and critical components. In recent years, hydrostatic transmission systems (HSTs) have begun to receive attention as power transmission systems for robotic applications. The primary goal of this study is to identify the inherent properties of HSTs. In this article, we first introduce experimental methods for determining the characteristics of HSTs and then discuss the experimental results. Our findings from the experiments suggest that the commercial external gear pump in an HST cannot entirely convert mechanical power to hydraulic power because of its internal leakage and friction behavior. These physical behaviors are mathematically modeled and experimentally identified. It is also found that a long transmission line not only results in low-pressure rise rates but also flow friction loss. We strongly believe that the results discussed in this article will provide helpful guidance for the design and control of robotic systems.