Group Control of Mobile Robots for More Efficient Searches – Verification of Semi-Autonomous Trajectory Tracking Motions in Irregular Ground Environment –

After the occurrence of a disaster, it is critical to perform rapid and accurate searching operations in the large disaster area. It is efficient to perform such operations using multiple mobile exploration robots. Accordingly, we focus on cooperative cruising in a disaster environment and propose the trajectory tracking control method for a semi-autonomous search robot. We apply a robot operating system (ROS) to execute the trajectory tracking control using two mobile exploration robots. In this paper, we describe the trajectory tracking control using gravity potential method and the results of a cooperative cruising experiment in an uneven terrain environment.

Telerobotic Control System to Enhance Rescue Operations for Arm-Equipped Tracked Vehicle HELIOS IX

This paper focuses on a telerobotic system in which an operator executes tasks by operating an arm-equipped tracked vehicle, HELIOS IX. It is necessary to develop an assisting sensor system, teleoperation system, and semi-autonomous robot motions to enhance teleoperationability, because HELIOS IX has many DOFs and unique mechanisms. To realize this development, the authors discuss the required specifications of the sensors, teleoperation system, and semi-autonomous motion planning. First, the sensor system for assistance and teleoperation system are described. Next, terrain-adaptive, tracked locomotion with no additional sensors is explained and verified through terrain traversing experiments. Then, the authors discuss the telerobotic system for the door opening task, a system based on Shared Autonomy, and demonstrate that HELIOS IX can successfully perform the door opening task. Finally, we describe what we have learned and the problems involved in the development of the telerobotic system of the HELIOS IX rescue robot.

Design of Large Motion Range and Heavy Duty 2-DOF Spherical Parallel Wrist Mechanism

Wrist mechanisms are important elements of robotic arms because they significantly affect the arm’s handling ability. Although various wrist mechanisms have been developed to date, a mechanism with a compact structure, a wide range of motion and a large load capacity has not yet been realized. Thus, in this paper, we propose 2-DOF Spherical Parallel (2DSP) mechanism, a heavy-duty wrist mechanism with a large motion range, and clarify its features both analytically and experimentally. The 2DSP mechanism is driven by a 2-DOF spherical parallel mechanism and is supported by a universal joint located at its center. This structure allows the 2DSP mechanism to realize a large motion range and load capacity and simplifies its kinematic analysis. Based on this analysis, we clarify the design process to maximize the motion range and propose a preferable structure of passive joints from the viewpoint of load capacity and production cost. We also describe the detailed design of a 2DSP mechanism for a rescue robot we developed previously and verify the feasibility of the proposed mechanism.

Robust Global Localization Using Laser Reflectivity

Global localization, which determines an accurate global position without prior knowledge, is a fundamental requirement for a mobile robot. Map-based global localization gives a precise position by comparing a provided geometric map and current sensory data. Although 3D range data is preferable for 6D global localization in terms of accuracy and reliability, comparison with large 3D data is quite timeconsuming. On the other hand, appearance-based global localization, which determines the global position by comparing a captured image with recorded ones, is simple and suitable for real-time processing. However, this technique does not work in the dark or in an environment in which the lighting conditions change remarkably. We herein propose a two-step strategy, which combines map-based global localization and appearance-based global localization. Instead of camera images, which are used for appearance-based global localization, we use reflectance images, which are captured by a laser range finder as a byproduct of range sensing. The effectiveness of the proposed technique is demonstrated through experiments in real environments.