Bucky gel actuator is a novel electro-active polymer (EAP), which is a low-voltage driven dry soft actuator. Its device has a bimorph structure with polymer-supported bucky gel electrodes and a polymer-supported ionic gel electrolyte. It can be fabricated by layer-by-layer casting, to form any shape easily. Some of the EAP materials can be used as a sensor as well as an actuator. If sensor function and actuator function exist in a same device, both function can be integrated with keeping the advantages of functional polymeric material. Miniature actuator-sensor systems and feedback control systems can be constructed; therefore, possibility of application can be expanded. In this paper, we verify the sensor device property of bucky gel devices. Based on the experiment, the relationship between an output signal and a deformation is investigated, and an estimation method of a deformation is demonstrated.

A bucky gel actuator is a novel electro-active polymer (EAP), which is a low-voltage-driven dry soft actuator. In addition, the bucky gel device generates electromotive force when bending and then ...

This paper reports experimental evaluation results of a time variant disturbance observer based on the LuGre friction model for friction compensation. The observer is designed from state space expressions of a controlled plant with the LuGre model that is locally-linearized every sampling period. Thus, observer gains derived from the linearized model become time variant ones as a function of velocity. Parameters of the LuGre model were experimentally identified for a linear stage driven by a ball screw with an AC motor, i.e., a controlled plant. To show the validity of the proposed method, experiments using the controlled plant were conducted to evaluate tracking errors for positioning control with and without the proposed disturbance observer. From the experimental results, it has been confirmed that the proposed disturbance observer can eliminate influence of the friction and is effective to improve positioning accuracy.

In this study, trajectory-tracking control for a lizard-inspired single-actuated robot (LISA) is implemented using a novel morphology. A high degree of reproducibility is obtained between the results of kinematic analysis and the behavior of the actual robot. Several 1-degree-of-freedom (DOF)-driven robots have been proposed. However, the application of these robots is severely restricted because of their inherent morphology limitations. LISA is a multilegged robot that can overcome these disadvantages and propel and turn with 1-DOF. In this study, we formulate the kinematics, such as the turning angle and stride length, of LISA. Furthermore, a unique robot coordinate is defined to enable the symmetrical representation of critical robot state quantities. Next, a trajectory-tracking control system based on the proportional-integral-derivative (PID) control is designed, and it is verified by both experiments and numerical simulations. Finally, the results of the experiments and numerical simulations are quantitatively compared according to the root mean square, and the reproducibility of the kinematics analysis and the behavior of the actual system are discussed. This study makes the following contributions: (1) The morphology of LISA facilitates analytical results with only kinematic analysis, which is considerably simpler than dynamics analysis. (2) LISA achieved sufficiently good kinematic performance for the required motions. Experiments revealed that the designed trajectory-tracking control system allows for LISA to appropriately track several types of trajectories.

The purpose of this paper is to design a lizard-inspired robot driven by a single actuator. Lizard-inspired robots in previous studies had the issue of slippage of their supporting legs. To overcome this issue, a lizard-inspired robot consisting of a four-bar linkage mechanism was designed. The purpose of this paper was achieved through three processes. The first process was kinematic analysis, where the turning angle and stride length of the robot were analyzed. The kinematic analysis results were verified via numerical simulations. The second process was the design and fabrication of the robot. For the robot’s design, both a shuffle-walking method utilizing a claw-shaped leg mechanism and a sliding-rod mechanism for equipping the actuator on the robot’s own coordinates were designed. The third process was experimental verification. The first experimental result was that the claw-shaped leg mechanism was capable of generating an 85.26 N difference in the static frictional force in the longitudinal direction. The other three experimental results were that the robot was capable of driving with 3.51%, 3.16%, and 3.53% error compared to the kinematic analyses, respectively.

This paper presents a robot design competition called ‘IDC Robocon’ as an effective tool for engineering education. The International Design Contest (IDC) Robocon competition has several benefits in creating a meaningful design experience for undergraduate engineering students and includes an international flavour as participants of the competition hail from all around the world. The problem posed to the contestants is to design, build and test mobile robots that are capable of accomplishing a task. A primary goal of the competition is to provide undergraduates with a meaningful design experience with an emphasis on mechanical design, electronic circuits and programming. It is hoped that by placing the emphasis on the design, the course will encourage more undergraduates to go into the field of engineering design. This paper presents the latest 2015 IDC Robocon (the 26th edition) in detail and discusses course of events and results in terms of the educational experience. In this competition, a simulated space problem of cleaning the debris from orbit is proposed for the latest IDC Robocon competition. Teams, comprising of students from multiple countries work together to develop robotic systems to compete with each other in collecting the foam balls and delivering them to the rotating the holder.