Yisheng Guan

A Modular Biped Wall-Climbing Robot With High Mobility and Manipulating Function

High-rise tasks such as cleaning, painting, inspection, and maintenance on walls of large buildings or other structures require robots with climbing and manipulating skills. Motivated by these potential applications and inspired by the climbing motion of inchworms, we have developed a biped wall-climbing robot-W-Climbot. Built with a modular approach, the robot consists of five joint modules connected in series and two suction modules mounted at the two ends. With this configuration and biped climbing mode, W-Climbot not only has superior mobility on smooth walls, but also has the function of attaching to and manipulating objects equivalent to a “mobile manipulator.” In this paper, we address several fundamental issues with this novel wall-climbing robot, including system development, analysis of suction force, basic climbing gaits, overcoming obstacles, and transiting among walls. A series of comprehensive and challenging experiments with the robot climbing on walls and performing a manipulation task have been conducted to demonstrate its superior climbing ability and manipulation function. The analytical and experimental results have shown that W-Climbot represents a significant advancement in the development of wall-climbing robots.

Climbing gaits of a modular biped climbing robot

For high-rise work in fields such as agriculture, forestry and architecture, and inspired by the climbing motion of inchworms, chimpanzees, and sloths, we have developed a biped climbing robot - Climbot. Consisting of five 1-DOF joint modules in series and two special grippers at the ends, Climbot is capable of grasping objects and climbing poles, trees and trusses. In this paper, we first introduce this novel robot, and then present three climbing gaits. We perform simulation to illustrate, verify and compare the proposed climbing gaits.

Autonomous Pose Detection and Alignment of Suction Modules of a Biped Wall-Climbing Robot

Vacuum adsorption is a simple but effective attaching method widely used in many fields including robotic wall climbing. It is required that the sucker is aligned well with the target surface to form airtight chamber for vacuum generation. For applications in biped wall-climbing robots, automatically aligning the sucker with the wall is beneficial and important to enhance the efficiency and effectiveness of vacuum adsorption. Especially, such a function is essential for autonomous intelligent climbing. To this end, we propose a novel and low-cost approach to perform autonomous alignment of a sucker (suction module) based on noncontact sensors. We first develop a sensing system to detect the configuration of the swinging suction module with respect to the target surface, and then present an algorithm to compute the configuration transformation and control the robot to drive the suction cups toward the target surface with a well-aligned configuration for adherence. In this paper, the basic theory for autonomous pose detection and alignment of the suction module for wall climbing with a biped robot is presented. Specifically, the key configuration of the swinging suction module for adsorption is analyzed, and the pose detection model, the conditions for forming airtight chamber, and the autonomous alignment algorithm are introduced. Calibration of the sensing system and experiments with our biped wall-climbing robot W-Climbot is conducted. The results have verified the feasibility, effectiveness and applicability of the proposed sensing system, theoretical analysis and the algorithm for autonomous pose detection and alignment of the suction modules.

Development of novel robots with modular methodology

Modules have been widely used in the development of re-configurable robots and snake-like robots. Modular methodology can also be applied in design of other robots. To build robots flexibly and quickly with low costs, we have developed two basic joint modules and several functional modules including grippers, suckers and wheels/feet as end-effectors. In this paper, we introduce the development of these modules, and present several novel robots built using them. Specifically, we show how to use them to set up a manipulator, a 6-DoF biped walking robot, a wheeled mobile robot, a biped tree-climbing robot, and a biped wall-climbing robot. It has been shown that a few modules can easily spawn a variety of novel robots with modular methodology.

Climbot: A modular bio-inspired biped climbing robot

High-rise tasks in agriculture, forestry and building industry requires robots possessing climbing function. Motivated by these potential applications and inspired by the climbing motion of animals such as inchworms, we have developed a novel biped climbing robot - Climbot. Built with a modular approach, the robot consists of five 1-DoF joint modules connected in series and two special grippers mounted at the ends. With this configuration, Climbot is able not only to climb a variety of media, but also to grasp and manipulate objects, and hence is a “mobile” manipulator. In this paper, we first introduce the development of this novel robot, and then illustrate three climbing gaits based on the unique configuration of the robot. Experiments of climbing poles are carried out to verify the climbing functions and to demonstrate potential application of the proposed robot.

W-Climbot: A modular biped wall-climbing robot

Although a large number of wall-climbing robots have been developed in the past decades, most of them suffer from shortcomings such as poor ability to omni-directional locomotion, lower capability to transit between walls and to negotiate obstacles on the walls. To overcome these drawbacks, we have developed a novel biped wall-climbing robot - W-Climbot using modularization method. Consisting of an arm as the main body and two vacuum suckers at the two ends, W-Climbot has great mobility on walls and potential manipulation function. In this paper, the development of W-Climbot is briefly introduced, and then the suction force model for suction module design is presented. The superior ability to transit between walls and to traverse and step over obstacles is analyzed. Experiments are carried out to verify the effectiveness of the system design and to demonstrate basic features of the novel robot.

1-DoF robotic joint modules and their applications in new robotic systems

Modules have been widely used in development of various robots including re-configurable robots and snake-like robots. To build robotic systems more flexibly and quickly with low costs of manufacturing and maintenance, we have developed two basic types, which are called T-type and I-type, of robotic joint modules with one degree of freedom for general purpose. The modules are designed to be compact, light-weighted and self-contained. A variety of robotic systems may be constructed easily using these modules. In this paper, the mechanical design, the control system including the hardware and software of the joint modules are described. In addition, the conceptual design of a few novel robots is presented, showing how new robots can be built using these basic joint modules in practical applications. The new robots include a bio-inspired robot that can climb poles, trusses and trees, a biped walking robot with only six active joints, and a two-wheeled mobile robot with a caster.

An efficient visual loop closure detection method in a map of 20 million key locations

An important problem in robot simultaneous localization and mapping (SLAM) is loop closure detection. Recent studies of the problem have led to successful development of methods that are based on images captured by the robot. These methods tackle the issue of efficiency through data structures such as indexing and hierarchical (tree) organization of the image data that represent the robot map. In this paper, we offer an alternative approach and present a novel method for visual loop-closure detection. Our approach uses an extremely simple image representation, namely, a down-sampled binarized version of the original image, combined with a highly efficient image similarity measure - mutual information. As a result, our method is able to perform loop closure detection in a map with 20 million key locations in about 2.38 seconds on a commodity computer. The excellent performance of our method in terms of its low complexity and accuracy in experiments establishes it as a promising solution to loop closure detection in large-scale robot maps.

An intelligent environmental monitoring system based on autonomous mobile robot

Monitoring indoor environmental state of large communication rooms, warehouses and power stations is an important task. Based on mobile robotics, we have developed an intelligent environmental monitoring system. In this system, a mobile robot carrying a number of sensors autonomously navigates and dynamically sample the environmental data including the temperature, humidity and airflow velocity. The system outputs the environmental parameters in appropriate modes such as clouds. In this paper, we present the development of this monitoring system, its working principle and application effectiveness. It has been shown how a mobile robot can be used to as a novel application in industry environments.

Workspace Generation for Multifingered Manipulation

In this paper, we propose a novel numerical approach and algorithm to compute and visualize the workspace of a multifingered hand manipulating an object. Based on feasibility analysis of grasps, the proposed approach uses an optimization technique to first compute discretely the position boundary of the grasped object and then calculate the rotation ranges of the object at specified positions within the boundary. In other words, workspace generation with the approach is fulfilled by obtaining reachable boundaries of the grasped object in the sense of both position and orientation, and the discrete boundary points are computed by a series of optimization models. Unlike in workspace generation of other robotic systems where only geometric and kinematic parameters of the robots are considered, all factors including geometric, kinematic and force-related factors that affect the workspace of a hand–object system can be taken into account in our approach to generate the workspace of multifingered manipulation. Since various constraints can be integrated into the optimization models, our method is general and complete, with adaptability to various grasps and manipulations. Workspace generation with the approach in both planar and spatial cases are illustrated with examples. The approach provides an effective and general solution to the long-term open and challenging problem of workspace generation of multifingered manipulation. Part of the work has been published in the Proceedings of IEEE/RSJ IROS2008 and IEEE/ASME AIM2008.