Marc Freese

V-REP: A versatile and scalable robot simulation framework

From exploring planets to cleaning homes, the reach and versatility of robotics is vast. The integration of actuation, sensing and control makes robotics systems powerful, but complicates their simulation. This paper introduces a versatile, scalable, yet powerful general-purpose robot simulation framework called V-REP. The paper discusses the utility of a portable and flexible simulation framework that allows for direct incorporation of various control techniques. This renders simulations and simulation models more accessible to a general-public, by reducing the simulation model deployment complexity. It also increases productivity by offering built-in and ready-to-use functionalities, as well as a multitude of programming approaches. This allows for a multitude of applications including rapid algorithm development, system verification, rapid prototyping, and deployment for cases such as safety/remote monitoring, training and education, hardware control, and factory automation simulation.

Virtual robot experimentation platform V-REP: a versatile 3D robot simulator

From exploring planets to cleaning homes, the reach and versatility of robotics is vast. The integration of actuation, sensing and control makes robotics systems powerful, but complicates their simulation. This paper introduces a modular and decentralized architecture for robotics simulation. In contrast to centralized approaches, this balances functionality, provides more diversity, and simplifies connectivity between (independent) calculation modules. As the Virtual Robot Experimentation Platform (V-REP) demonstrates, this gives a smallfootprint 3D robot simulator that concurrently simulates control, actuation, sensing and monitoring. Its distributed and modular approach are ideal for complex scenarios in which a diversity of sensors and actuators operate asynchronously with various rates and characteristics. This allows for versatile prototyping applications including systems verification, safety/remote monitoring, rapid algorithm development, and factory automation simulation.

Endpoint Vibration Control of a Mobile Mine-Detecting Robotic Manipulator

The procedure for humanitarian land mine removal varies greatly. However, one central element is detecting and marking suspected mine locations using sensors such as trained dogs and metal detectors. This step is expensive, tedious, and dangerous. In order to improve the land mine detection process, a reliable, low-cost robotic manipulation system has been constructed. The system consists of long-reach manipulator mounted on a commercially available All-Terrain Vehicle. The system is capable of autonomously scanning for mines with different types of sensors. An electromagnetic induction metal detector is used in conjunction with ground-penetrating radar to detect metal and larger heterogeneities in the ground, i.e. mine detonators and mine casings, respectively. This sensor combination greatly reduces the number of false alarms over the traditional single-sensor approach. Given the long reach of the arm, the endpoint is susceptible to unwanted oscillations that corrupt the scanning information. This paper describes a control system that utilizes input shaping to improve endpoint tracking. The result is a system that generates high-quality sensor information for precise mine identification.

Bias-tolerant terrain following method for a field deployed manipulator

Manipulator operations are complicated by sensor noise, mechanical compliance, and system bias. These uncertainties are compounded in field environments, such as those encountered in humanitarian demining. By taking advantage of the generally flat and static structure of the terrain, a series of adaptive corrections and filters refine a sensed topographical model and generate a trajectory that is robust to inherent inaccuracies and modeling errors. Experimental testing on a mobile robot using stereo-vision as modeling sensor indicates that this method provides a tracking precision of plusmn5 mm on relatively flat ground. As such, it will keep the attached mine sensors close to the ground, improving effectiveness

Robotics-assisted demining with Gryphon

The threat and consequences of landmines have led to a multitude of alternative research activities in the field of demining. While mine sensor-focused research has been intensive, there has been relatively less attention given to the problem of automating the detection and removal procedure. Understandably, autonomous robot operation and interaction in unstructured field environments are difficult. This paper addresses this by presenting a robot meant to assist humanitarian demining by providing a cheap, fast, reliable and safe alternative to human deminers risking their lives on a daily basis. The robot, named Gryphon, is able to autonomously scan 2 m2 at a time with any type of mine sensor payload. It then presents acquired sensor images to the operator who selects which spots need further investigation or prodding. The robot then appropriately marks the terrain with paint or marking plates. Gryphon has been extensively field tested in Japan, Croatia and Cambodia.

Terrain Modeling and Following Using a Compliant Manipulator for Humanitarian Demining Applications

Operations with flexible, compliant manipulators over large workspaces relative to the manipulator are complicated by noise, vibration, and measurement bias. These difficulties are compounded in unstructured environments, such as those encountered in humanitarian demining. By taking advantage of the static structure of the terrain and the manipulator’s fundamental mechanical characteristics, a series of adaptive corrections and filters refine noisy topographical measurements. These filters along with a shaped actuation scheme can generate smooth and well-controlled trajectories that allow for terrain surface following. Experimental testing was performed on a field robot with a compliant, 3 m long hybrid manipulator and a stereo vision system. The proposed method provides a vertical tracking precision of ±5 mm on a variety of ground clearings, with tip scanning speeds of up to 0.5 m/s. As such, it can agilely move the attached sensor(s) through precise scanning trajectories that are very close to the ground. This method improves overall detection and generation of precise maps of suspected mine locations.

Development of Deminer-Assisting Robotic Tools at Tokyo Institute of Technology

Robot operation and interaction in unstructured environment is difficult. The problem becomes even more difficult if the environment is hazardous, presents a potentially wide temperature range, and is subject to rain, dust and other natural factors. Such conditions are typical in minefields. Current demining technology is slow, costly and dangerous, and has virtually not evolved in the last 60 years except for heavy and armoured soil-digging machines that are limited to well-conditioned terrain. Assisting human deminers in the mine searching task, or giving them better means of protection during the dangerous task of soil prodding and mine neutralization is challenging. However it is worth pursuing this goal: not only will deminers benefit from the development, but the demining industry itself will benefit from it with eventually faster paces, more efficient detection and removal rates, and this at reduced costs. The Tokyo Institute of Technology started developing robotic tools and machines for humanitarian demining more than a decade ago. The first steps were performed literally, with a quadruped walking robot named TITAN VIII (cf. Figure 1) that was able to adapt its gait to navigate on difficult terrain and use one of its legs as a manipulator to scan the soil for mines, cut vegetation or even dig the ground [Hirose & Kato, 1998; Kato & Hirose, 2001]. A sophisticated system including a tool-changer and tele-operation functionality allowed the robot to perform the most dangerous tasks without proximate assistance of humans. Scenarios in which one of the robot’s legs was blown off by accidentally stepping onto a mine were overcome by appropriately readjusting its walking gait for 3 legs. Other research institutions and laboratories have followed into Tokyo Institute of Technology’s footsteps by developing legged robots for humanitarian demining; one example is COMET-1 [Nonami et al., 2000], a 6-legged walking robot equipped with several cameras, an attitude control sensor mechanism, and 6 small metal detectors integrated into the extremity of each leg. Another legged example is the pneumatic multisensor demining robot [Rachkov et al., 2005], that can be equipped with a metal detector, an infrared detector and a chemical explosive sensor for mine detection. Source: Humanitarian Demining: Innovative Solutions and the Challenges of Technology, Book edited by: Maki K. Habib, ISBN 978-3-902613-11-0, pp. 392, February 2008, I-Tech Education and Publishing, Vienna, Austria O pe n A cc es s D at ab as e w w w .in te hw eb .c om

Development of Teleoperated Landmine Detection Buggy GRYPHON for Practical Humanitarian Demining Tasks

Millions of anti-personnel mines (AP-mines, for short) have been laid in many parts of the world in wartime without considering their posterior safe removal. Not only AP-mines, but almost all sorts of unexploded ordnance (UXO) that remain buried in the ground, do not loose the potential to blast even long after war and conflicts are over, and kill or main thousands of people every year. Most of the victims of these explosive remnants of the war are not the military, none the deminers, but innocent civilians.