Control of a Hierarchical Team of Robots for Urban Search and Rescue

<p>Research teams worldwide are researching the application of robots for Urban Search and Rescue (USAR) operations and some are using teams of robots. The Mechatronics Research Group of Victoria University of Wellington is developing a low cost architecture of a team of USAR robots that is hierarchically structured and can operate autonomously. The objective of this thesis is to design the autonomous control system for the proposed architecture. The overall system design and combination of hardware and software solutions needs to be evaluated in a realistic environment. The project could not perform tests in a real environment and developed a realistic simulation environment instead to allow the evaluation of hardware and software constraints. This project successfully developed an incremental mapping algorithm which served as foundation for distributed path planning, and modified an existing navigation approach to cope with the main challenges of 3D operation environments. In order to deal with multiple robots, this thesis applied a centralised control mechanism and a combination of a global and local exploration strategy. This thesis contributes software solutions to operate the low cost robot architecture and identified weaknesses in the design of the middle tier of robots. The individual algorithms, and their combination in a major control system proved to be effective, but not without limitations. Consequently, this thesis suggests solutions to overcome some of these limitations.</p>

Control of a Hierarchical Team of Robots for Urban Search and Rescue

<p>Research teams worldwide are researching the application of robots for Urban Search and Rescue (USAR) operations and some are using teams of robots. The Mechatronics Research Group of Victoria University of Wellington is developing a low cost architecture of a team of USAR robots that is hierarchically structured and can operate autonomously. The objective of this thesis is to design the autonomous control system for the proposed architecture. The overall system design and combination of hardware and software solutions needs to be evaluated in a realistic environment. The project could not perform tests in a real environment and developed a realistic simulation environment instead to allow the evaluation of hardware and software constraints. This project successfully developed an incremental mapping algorithm which served as foundation for distributed path planning, and modified an existing navigation approach to cope with the main challenges of 3D operation environments. In order to deal with multiple robots, this thesis applied a centralised control mechanism and a combination of a global and local exploration strategy. This thesis contributes software solutions to operate the low cost robot architecture and identified weaknesses in the design of the middle tier of robots. The individual algorithms, and their combination in a major control system proved to be effective, but not without limitations. Consequently, this thesis suggests solutions to overcome some of these limitations.</p>

Determination of the inverse kinematics branches of solution based on joint coordinates for UR-like serial robot architecture

This paper introduces a classification of the inverse kinematics solutions (or robot postures) of six-degree-of-freedom serial robots with a geometry based on or similar to Universal Robots' arms. The solution of the inverse kinematics problem is first presented briefly and the equations required to classify the robot postures(branches) based on the joint coordinates are then introduced.

A Robot Architecture Using ContextSLAM to Find Products in Unknown Crowded Retail Environments

Grocery shoppers must negotiate cluttered, crowded, and complex store layouts containing a vast variety of products to make their intended purchases. This complexity may prevent even experienced shoppers from finding their grocery items, consuming a lot of their time and resulting in monetary loss for the store. To address these issues, we present a generic grocery robot architecture for the autonomous search and localization of products in crowded dynamic unknown grocery store environments using a unique context Simultaneous Localization and Mapping (contextSLAM) method. The contextSLAM method uniquely creates contextually rich maps through the online fusion of optical character recognition and occupancy grid information to locate products and aid in robot localization in an environment. The novelty of our robot architecture is in its ability to intelligently use geometric and contextual information within the context map to direct robot exploration in order to localize products in unknown environments in the presence of dynamic people. Extensive experiments were conducted with a mobile robot to validate the overall architecture and contextSLAM, including in a real grocery store. The results of the experiments showed that our architecture was capable of searching for and localizing all products in various grocery lists in different unknown environments.

Cognitive Wearable Robotics for Autism Perception Enhancement

Autism spectrum disorder (ASD) is a serious hazard to the physical and mental health of children, which limits the social activities of patients throughout their lives and places a heavy burden on families and society. The developments of communication techniques and artificial intelligence (AI) have provided new potential methods for the treatment of autism. The existing treatment systems based on AI for children with ASD focus on detecting health status and developing social skills. However, the contradiction between the terminal interaction capability and availability cannot meet the needs for real application scenarios. At the same time, the lack of diverse data cannot provide individualized care for autistic children. To explore this robot-based approach, a novel AI-based first-view-robot architecture is proposed in this article. By providing care from the first-person perspective, the proposed wearable robot overcomes the difficulty of the absence of cognitive ability in the third-view of traditional robotics and improves the social interaction ability of children with ASD. The first-view-robot architecture meets the requirements of dynamic, individualized, and highly immersed interaction services for autistic children. First, the multi-modal and multi-scene data collection processes of standard, static, and dynamic datasets are introduced in detail. Then, to comprehensively evaluate the learning ability of children with ASD through mental states and external performances, a learning assessment model with emotion correction is proposed. Besides, a wearable robot-assisted environment perception and expression enhancement mechanism for children with ASD is realized by reinforcement learning, which can be adapted to interactive environments with optimal action policies. An interactive testbed for children with ASD treatments is demonstrated and experimental cases for test subjects are presented. Last, three open issues are discussed from data processing, robot designing, and service responding perspectives.

A 3D Machine Vision-Enabled Intelligent Robot Architecture

In this paper, the principle of camera imaging is studied, and the transformation model of camera calibration is analyzed. Based on Zhang Zhengyou’s camera calibration method, an automatic calibration method for monocular and binocular cameras is developed on a multichannel vision platform. The automatic calibration of camera parameters using human-machine interface of the host computer is realized. Based on the principle of binocular vision, a feasible three-dimensional positioning method for binocular target points is proposed and evaluated to provide binocular three-dimensional positioning of target in simple environment. Based on the designed multichannel vision platform, image acquisition, preprocessing, image display, monocular and binocular automatic calibration, and binocular three-dimensional positioning experiments are conducted. Moreover, the positioning error is analyzed, and the effectiveness of the binocular vision module is verified to justify the robustness of our approach.

Optimizing the Rigid or Compliant Behavior of a Novel Parallel-Actuated Architecture for Exoskeleton Robot Applications

The purpose of this work is to optimize the rigid or compliant behavior of a new type of parallel-actuated robot architecture developed for exoskeleton robot applications. This is done in an effort to provide those that utilize the architecture with the means to maximize, minimize, or simply adjust its stiffness property so as to optimize it for particular tasks, such as augmented lifting or impact absorption. This research even provides the means to produce non-homogeneous stiffness properties for applications that may require non-homogeneous dynamic behavior. In this work, the new architecture is demonstrated in the form of a shoulder exoskeleton. An analytical stiffness model for the shoulder exoskeleton is created and validated experimentally. The model is then used, along with a method of bounded nonlinear multi-objective optimization to configure the parallel substructures for desired rigidity, compliance or nonhomogeneous stiffness behavior. The stiffness model and its optimization can be applied beyond the shoulder to any embodiment of the new parallel architecture, including hip, wrist and ankle robot applications. In order to exemplify this, we present the rigidity optimization for a theoretical hip exoskeleton.

An Estimator for the Kinematic Behaviour of a Mobile Robot Subject to Large Lateral Slip

In this paper, the effects of wheel slip compensation in trajectory planning for mobile tractor-trailer robot applications are investigated. Firstly, a kinematic model of the proposed robot architecture is marked out, then an experimental campaign is done to identify if it is possible to kinematically compensate trajectories that otherwise would be subject to large lateral slip. Due to the close connection to the experimental data, the results shown are valid only for Epi.q, the prototype that is the main object of this manuscript. Nonetheless, the base concept can be usefully applied to any mobile robot subject to large lateral slip.