Sensing and Control for Robotic Fish Locomotion
Richard Mason, Joel Burdick

We are studying issues in fluid mechanics, nonlinear control, and sensing that are necessary for the development of self-propelled robot fish. (full report)

Set-Valued Analysis for Switching Systems
Todd Murphey, Joel W. Burdick

Conventional nonholonomic motion planning and control theories do not directly apply to "overconstrained vehicles,'' such as the Sojourner vehicle of the Mars Pathfinder mission. This research investigates some basic issues that are necessary to build a motion planning and control framework for this potentially important class of mobile robots. A power dissipation approach is used to model the governing equations of overconstrained vehicles that move quasi-statically. These equations are shown to be switched hybrid systems. Standard notions, such as the Lie bracket, are extended to these switched systems. We then develop a controllability test for such systems. We explore motion planning primitives in the context of simplified examples. Another application area is that of distributed manipulation, where parts are being oriented by a large array of actuators. Here, too, the issues of discrete behavior as the part traverses different contact states plays a large role in analyzing stability. (full report)

Actuated Surgical Endoscopes for Minimally Invasive Surgery
Hans D. Hoeg, Joel W. Burdick, A. B. Slatkin

Our effort is aimed at developing articulated surgical endoscopes that can access the interior of the human body in a minimally invasive manner for the purposes of visualization, diagnosis and therapeutic intervention. We have specifically focused on design and construction of scopes for use in brain surgery and gastrointestinal procedures. (full report)

Distributed Collective Building of Two-Dimensional Structures Using Autonomous Robots
Kjerstin Easton, Alcherio Martinoli, Rodney Goodman

Using autonomous robots to build three-dimensional structures is a distant goal, but the first step in approaching collective building is to construct two-dimensional architectures. Using a team of miniature Khepera robots with manipulation and vision capabilities, we will implement a building technique modeled after qualitative stigmergic construction mechanisms used by social insects. This technique will allow the robots to communicate building instructions through modifications to the local environment, avoiding dependence on explicit robot-to-robot communication and lending itself to implementation with any number of robots. (full report)

Optimal Task Allocation and Distributed Sensing in Collective Autonomous Robotics
William Agassounon, Alcherio Martinoli, Rodney Goodman

Our research aims at studying two particular topics within the Collective Robotics field, these are the division of labor and the dynamic task allocation. The Swarm Intelligence approach can be applied to fully distributed systems that consist of several autonomous decision making entities working together with minimal communication and local perception to complete one or several tasks. Our approach is inspired by biological systems such as colonies of social insects (ants, bees, termites, etc) in which the collective behavior often emerges from a series of local agent-to-agent and agent-to-environment interactions. We are developing response threshold-based algorithms for optimal task allocation and probabilistic models that provide accurate forecast of the resulting collective behavior. Finally, one of the main strengths of this project is the attempt to create a theoretical framework for real embedded systems provided with threshold allocation mechanisms. These systems are therefore analyzed at several implementation levels, from analytical probabilistic models to real robots experiments through embodied sensor-based simulators. (full report)

Distributed Plume Tracing
Adam T. Hayes, Alcherio Martinoli, Owen Holland, Rodney M. Goodman

The objective of this project is to study biologically inspired algorithms which enable a robot or group of robots to track an odor plume to its source, with an appropriate combination of speed, efficiency, reliability, and accuracy. Research is conducted at three levels: non-embodied point simulations, embodied sensor-based simulations, and real robots. The simulations use sensors and actuators which are based on the capabilities of the real robots, and plume information is derived from empirical data files recorded from real plumes or realistic plume simulators. In simulation we explore the performance of various families of simple algorithms, as well as the potential for automated parameter tuning and on-line learning. We assess the most promising algorithms on real robots, which are equipped with Caltech olfactory sensors, anemometric devices, and simple communication systems. (full report)

Evolving Robust, Collective Patrolling Behavior Using Genetic Algorithms
Joseph Chen, Alcherio Martinoli, Rodney M. Goodman

Evolution is a powerful force. Harvester ants have successfully evolved to efficiently patrol their territory for different type of events (food items, enemy intrusion, etc.). The goal of this project is to study how effective and robust patrolling behavior can be evolved first in embodied, sensor-based simulations and then in real robot experiments. We will use evolutionary techniques (Genetic Algorithms, GA) for exploring the individual control parameters that play a crucial role in the team patrolling performance. In order to better understand the required individual and group capabilties for effective patrolling, we will test the influence of individual navigation capabilities and different fitness functions. We will also note whether any interesting collective behavior develops if the robots are allowed to directly communicate at each encounter, without introducing any type of stigmergic mechanism (e.g. pheromones). (full report)

Swarm Intelligence and Traffic Safety
Philip Tsao, Alcherio Martinoli, Rodney M. Goodman

An automotive controller that complements the driving experience must work to avoid collisions, enforce a smooth trajectory, and deliver the vehicle to the intended destination as quickly as possible. Unfortunately, satisfying these requirements with traditional methods proves intractable at best and forces us to consider biologically-inspired techniques such as Swarm Intelligence. A controller is currently being designed in a robot simulation program with the goal of implementing the system in real hardware to investigate these biologically-inspired techniques and to validate the results. (full report)