A Cilia-inspired Closed-loop Sensor-actuator Array

© 2018, Jilin University. Cilia are finger-like cell-surface organelles that are used by certain varieties of aquatic unicellular organisms for motility, sensing and object manipulation. Initiated by internal generators and external mechanical and chemical stimuli, coordinated undulations of cilia lead to the motion of a fluid surrounding the organism. This motion transports micro-particles towards an oral cavity and provides motile force. Inspired by the emergent properties of cilia possessed by the pond organism P. caudatum, we propose a novel smart surface with closed-loop control using sensor-actuators pairings that can manipulate objects. Each vibrating motor actuator is controlled by a localised microcontroller which utilises proximity sensor information to initiate actuation. The circuit boards are designed to be plug-and-play and are infinitely up-scalable and reconfigurable. The smart surface is capable of moving objects at a speed of 7.2 millimetres per second in forward or reverse direction. Further development of this platform will include more anatomically similar biomimetic cilia and control

Global stability for distributed systems with changing contact states

Analyzes the global stability of distributed manipulation control schemes. The "programmable vector field" approach, which assumes that the system's control actions can be approximated by a continuous vector force field, is a commonly proposed scheme for distributed manipulation control. In practical implementations, the continuous control force field idealization must then be adapted to the specifics of the discrete physical actuator array. However, in Murphey and Burdick (2001) it was shown that when one takes into account the discreteness of actuator arrays and realistic models of the actuator/object contact mechanics, the controls designed by the continuous approximation approach can be unstable at the desired equilibrium configuration. We introduced a discontinuous feedback law that locally stabilizes the manipulated object at the equilibrium. However, the stability of this feedback law only holds in a neighborhood of the equilibrium. In this paper we show how to combine the programmable vector field approach and our local feedback stabilization law to achieve a globally stable distributed manipulation control system. Simulations illustrate the method

Proof-of-concept investigation of Active Velcro for smart attachment mechanisms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76230/1/AIAA-2001-1503-863.pd

Nonprehensile Dynamic Manipulation: A Survey

Nonprehensile dynamic manipulation can be reason- ably considered as the most complex manipulation task. It might be argued that such a task is still rather far from being fully solved and applied in robotics. This survey tries to collect the results reached so far by the research community about planning and control in the nonprehensile dynamic manipulation domain. A discussion about current open issues is addressed as well

Department of Computer Science Activity 1998-2004

This report summarizes much of the research and teaching activity of the Department of Computer Science at Dartmouth College between late 1998 and late 2004. The material for this report was collected as part of the final report for NSF Institutional Infrastructure award EIA-9802068, which funded equipment and technical staff during that six-year period. This equipment and staff supported essentially all of the department\u27s research activity during that period

Planning and control for microassembly of structures composed of stress-engineered MEMS microrobots

We present control strategies that implement planar microassembly using groups of stress-engineered MEMS microrobots (MicroStressBots) controlled through a single global control signal. The global control signal couples the motion of the devices, causing the system to be highly underactuated. In order for the robots to assemble into arbitrary planar shapes despite the high degree of underactuation, it is desirable that each robot be independently maneuverable (independently controllable). To achieve independent control, we fabricated robots that behave (move) differently from one another in response to the same global control signal. We harnessed this differentiation to develop assembly control strategies, where the assembly goal is a desired geometric shape that can be obtained by connecting the chassis of individual robots. We derived and experimentally tested assembly plans that command some of the robots to make progress toward the goal, while other robots are constrained to remain in small circular trajectories (orbits) until it is their turn to move into the goal shape. Our control strategies were tested on systems of fabricated MicroStressBots. The robots are 240–280 µm × 60 µm × 7–20 µm in size and move simultaneously within a single operating environment. We demonstrated the feasibility of our control scheme by accurately assembling five different types of planar microstructures

Force-Deflection Behavior of a Smart Attachment Mechanism

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77258/1/AIAA-2003-1638-430.pd