This paper presents an innovative robotic mechanism for generating peristaltic motion for robotic locomotion systems. The designed underactuated peristaltic robot utilizes a minimum amount of electromechanical hardware. Such a minimal electromechanical design not only reduces the number of potential failure modes but also provides the robot design with great potential for scaling to larger and smaller applications. We performed several speed and force generation tests atop a variety of granular media. Our experiments show the effective design of robot mechanism where the robot can travel with a small input power (1.14W) at 6.0 mm/sec with 2.45 N force atop sand.

In this work, we consider the optimal path of a fixed-wing unmanned aerial vehicle (UAV) tracking a mobile surface target. One of the limitations of fixed-wing UAVs in tracking mobile targets is the lack of hovering capability when the target moves much slower than the minimum UAV speed, requiring the UAV maintain an orbit about the target. In this paper, we propose a method to find the optimal policy for fixed-wing UAVs to minimize the location uncertainty of a mobile target. Using a grid-based Markov Decision Process (MDP), we use an off-line policy iteration algorithm to find an optimal UAV path in a coarse discretized state space, followed by an on-line policy iteration algorithm that applies a finer grid MDP to the region of interest to find the final optimal UAV trajectory. We validate the proposed algorithm using computer simulations. Comparing the simulation results with other methods, we show that the proposed method has up to 13% decrease in error uncertainty than ones resulted using conventional methods.

This work presents the design, fabrication, capabilities, and obstacle traversal mechanics of MEDIC (Millirobot Enabled Diagnostic of Integrated Circuits), a small legged robot able to overcome a varied array of obstacles. MEDIC features a hull that keeps its body in contact with the ground at all times, and uses only four actuators to move forward, turn, mount obstacles, and move in reverse. The chassis is fabricated using a Smart Composite Microstructures (SCM) approach and the robot is actuated by coiled Shape Memory Alloy (SMA). MEDIC also features a camera which will be useful for navigation in the future.

Recent advances in small-scale flapping-wing micro aerial vehicles have extended the capabilities of flight control for a number of applications, such as intelligence, surveillance, and reconnaissance activities. In this work, we demonstrate autonomous flight control of a 13 gram ornithopter capable of flying toward a target without remote assistance. For autonomous flight control, we developed 1.0 gram control electronics integrated with a microcontroller, inertial and visual sensors, communication electronics, and motor drivers. We also developed a simplified aerodynamic model of ornithopter flight to reduce the order of the control system. With the aerodynamic model and the orientation estimation from on-board inertial sensors, we present flight control of an ornithopter capable of flying toward a target using onboard sensing and computation only. To this end, we developed a dead-reckoning algorithm to recover from the temporary loss of the target which can occur with a visual sensor with a narrow field of view. As a result, the 28 cm wing-span ornithopter flying toward a target landed within a radius of 0.5 m from the target with more than 85% success (N = 20).

Flapping-wing air vehicles can improve efficiency by running at resonance to reduce inertial costs of accelerating and decelerating the wings. For battery-powered, DC motor-driven systems with gears and cranks, the drive torque and velocity is a complicated function of battery voltage. Hence, resonant behavior is not as well defined as for flapping-wing systems with elastic actuators. In this paper, we analyze a resonant drive to reduce average battery power consumption for DC motor-driven flapping-wing robots. We derive a nondimensionalized analysis of the generic class of a motor-driven slider crank, considering motor and battery resistance. This analysis is used to demonstrate the benefits of efficient resonant drive on a 5.8 g flapping-wing robot and experiments showed a 30% average power reduction by integrating a tuned compliant element.