Mapping opaque and confined environments such as caves and pipes is a challenging problem for mobile robots because sensor information is severely limited to the immediate proximity of the robot due to the extreme environmental conditions. The robot must also be flexible and agile in unstructured environments while still providing accurate pose estimation. This paper presents a solution to mapping a 2-dimensional tube by using only a snake robot's proprioceptive joint angle sensors. We assume that the tube is sufficiently smooth and that we know the tube width. We propose techniques for (1) pose estimation of a snake robot by using a self-posture motion model, (2) correcting error in pose estimation using only the snake's internal configuration over time, and (3) building environmental features using only self-occupancy and contact detection. Our goal is to use the minimal amount of sensor information possible to build an accurate spatial map of the environment. We have tested the proposed techniques in simulated environments and experimental results show that they are both effective and efficient for mapping tube environments. We plan to extend these techniques to deal with more complex confined environments beyond single-path tubes.

Superbot consists of Lego-like but autonomous robotic modules that can reconfigure into different systems for different tasks. Examples of configurable systems include rolling tracks or wheels (for efficient travel), spiders or centipedes (for climbing), snakes (for burrowing in ground), and climbers (for inspection and repair in space). This video shows several configurations and behaviors that are new for modular and reconfigurable robots. Each SuperBot module is a complete robotic system and has a power supply, micro- controllers, sensors, communication, three degrees of freedom, and six connecting faces (front, back, left, right, up and down) to dynamically connect to other modules. This design allows flexible bending, docking, and continuous rotation. A single module can move forward, back, left, right, flip-over, and rotate as a wheel. Modules can communication with each other for totally distributed control and can support arbitrary module reshuffling during their operation. The modules have both internal and external sensors for monitoring self-status and environmental parameters. They can form arbitrary configurations (graphs) and can control these configurations for different functionality such as locomotion, manipulation, and self-repair. This video shows the latest status the SuperBot modules and all these behaviors were made in just one week. The fact that SuperBot can achieve so much in so short a time demonstrates the unique value of modular, multifunctional and self-reconfigurable robots.

This paper presents a modular and reconfigurable robot for multiple locomotion modes based on reconfigurable modules. Each mode consists of characteristics for the environment type, speed, turning-ability, energy-efficiency, and recover ability from failures. The paper demonstrates this solution by the Superbot robot that combines advantages from MTRAN, CONRO and others. Experimental results, both in real robots and in simulation, have shown the validity of the approach and demonstrated the movements of forward, backward, turn, sidewinder, maneuver, and travel on batteries up to 500 meters on a flat terrain. In physics-based simulation, Superbot can perform as snake, caterpillar, insect, spider, rolling track, H-walker, etc., and move 1.0 meter/second on flat terrain with less than 6 W/module, and climb slopes of no less 40 degrees

Much work on self-reconfigurable robotics has been focused on motion planning and physical reconfiguration of the robot. Using the Superbot self-reconfigurable robot, we focus on the details of realizing locomotion gaits given that a single robot topology can be realized in a large number of different ways. That is, each module in the robot topology has 4 symmetric orientations that are functional and shape equivalent. Once a role is selected for each module, such as through the use of hormone-inspired control, each module's role is supplied with a gait template which then must be transformed to suit the local configurations of each module with respect to the global topology. We provide a theoretical framework for which this can be accomplished

This paper presents an experimental system for assembly in space. A weightless and frictionless environment is approximated using an air-hockey table where robots and structural components can float on the surface. The robots use fan propulsion to dock with components and assemble them together to make 2D structures. This system is designed to implement three key technologies for space self-assembly: 1) intelligent components with universal connectors, 2) a set of self-reconfigurable robots that fetch and assemble components, and 3) a distributed method for controlling the robotic-assembly process. An overview of the system's design and experimental results is presented.