This paper presents work by researchers at The Florida Institute for Human and Machine Cognition (IHMC) on the DARPA funded Learning Locomotion program. This program started in 2005 and finished in 2009. The goal of the Learning Locomotion program was to develop control algorithms for autonomous traversal of large, irregular obstacles by an unmanned quadrupedal robot. The program was designed to allow multiple teams to compete for the fastest speeds across the terrain boards using identical hardware. Terrain sensing and localization issues were eliminated by providing a high resolution height map of the terrain as well as real time pose information of the robot on the terrain. The objective for each trial was to reach the goal position as fast as possible.

The IHMC Mobility Assist Exoskeleton is a robotic suit that a user can wear for strength augmentation or gait generation. This first generation exoskeleton prototype focuses on providing walking assistance to persons with lower extremity paralysis. The main goal is to successfully enable a person that cannot walk without assistance to walk in a straight line a distance of 15 feet. When in disable assist mode this prototype will rely on the user to provide balance control, and thus an external means for balancing will be required, such as crutches or a walker. Power and control is off board and supplied to the Exoskeleton by means of a tether. Rotary Series Elastic Actuators (RSEAs), which have high force fidelity and low impedance were designed to power the joints. This paper describes the design, test results, future work and potential applications of the exoskeleton.

This video highlights work to date on the Yobotics-IHMC lower body humanoid robot. The robot is a twelve degree-of-freedom robot with force controllable series elastic actuators at each degree of freedom. Control algorithms utilize virtual model control, and foot placement is determined using capture regions. The robot can recover from moderate disturbances and walk on flat ground. Ongoing work is focused on improving robustness to disturbances, walking more quickly and efficiently, and walking over rough terrain.

We present a controller for a quadrupedal robot statically walking on known rough terrain. The controller has both deliberative and reactive components for task specific control issues, such as impassable terrain and unmodeled foot slippage. The controller architecture supports multiple gaits, and we present both a stable omnidirectional gait and a faster directional gait. The robot successfully negotiates obstacles up to 7.5 cm (ap40% leg length) tall and navigates over rocky terrain.

We present several biologically inspired concept designs and feasibility analyses for underwater swimming exoskeletons. These designs are biologically inspired, based on observations of dolphins, sea turtles, and penguins. Biologically inspired designs have the advantages of stealth, maneuverability, and a natural interface when compared to propeller driven underwater propulsion devices. We present a lower body concept, based on dolphin locomotion and an upper body concept based on sea turtle and penguin locomotion. The dolphin based concept has the advantages of using the wearer's most powerful muscle groups, of being the most natural to swim with, and of leaving the user's hands free for other tasks. The sea-turtle based concept has the advantage of novelty and may have appeal as a recreational device. We predict that with actuation and energy storage components available today, an exoskeleton that produces a cruising speed of over 1 m/s and a top speed of over 1.5 m/s is feasible. We estimate that cruising at 1 m/s can be achieved with less than 504 Watts power consumption, which translates into 2.4 kg of off-the-shelf silver-zinc batteries per hour of operation.