33 research outputs found
NASA NDE Applications for Mobile MEMS Devices and Sensors
NASA would like new devices and sensors for performing nondestructive evaluation (NDE) of aerospace vehicles. These devices must be small in size/volume, mass, and power consumption. The devices must be autonomous and mobile so they can access the internal structures of aircraft and spacecraft and adequately monitor the structural health of these craft. The platforms must be mobile in order to transport NDE sensors for evaluating structural integrity and determining whether further investigations will be required. Microelectromechanical systems (MEMS) technology is crucial to the development of the mobile platforms and sensor systems. This paper presents NASA s needs for micro mobile platforms and MEMS sensors that will enable NDE to be performed on aerospace vehicles
Development of micromechanics for micro-autonomous systems (ARL-MAST CTA Program)
We envision situational awareness developed through warfighters deployment of a system of diverse mobile, communicating platforms that cooperate to provide full coverage of interior and exterior spaces. The goal of the ARL-MAST Center on Microsystem Mechanics is to perform the fundamental research that will enable flying and ambulating platforms to achieve the required mobility for the proposed missions and environments. In this paper the fundamental issues and challenges associated with achieving this goal will be discussed
Reasons, Robots and The Extended Mind
A suitable project for the new Millenium is to radically reconfigure our image of human rationality. Such a project is already underway, within the Cognitive Sciences, under the umbrellas of work in Situated Cognition, Distributed and De-centralized Cogition, Real-world Robotics and Artificial Life1. Such approaches, however, are often criticized for giving certain aspects of rationality too wide a berth. They focus their attention on on such superficially poor cousins as âadaptive behaviourâ, âecologically sound perception-action routinesâ, âfast and frugal heuristicsâ and âfast, fluent real-time real-world action controlâ2. Is this robbery or revelation? Has 'embodied, embedded' cognitive science simply lost sight of the very phenomena it was meant to explain? Or are we finally seeing rationality aright, as fully continous with various forms of simpler, ecologically situated, adaptive response?
I distinguish two ways of developing the 'embodied, embedded' approach. The first, which does indeed threaten to lose sight of the key targets, is fully committed to a doctrine of biological cognitive incrementalism according to which full-scale human rationality is reached, rather directly, by some series of tweaks to basic biological modes of adaptive response. The second depicts human capacities for advanced reason as at best the indirect products of such a process. Such capacities, it is argued, depend heavily upon the effects of a special kind of hybridization in which human brains enter into an increasingly potent cascade of genuinely symbiotic relationships with knowledge-rich artifacts and technologies. This latter approach, I finally suggest, does better justice to our peculiar profile, which combines deep biological continuity with an equally deep cognitive discontinuity
Simplifying robotic locomotion by escaping traps via an active tail
Legged systems offer the ability to negotiate and climb heterogeneous terrains, more so than their wheeled counterparts \cite{freedberg_2012}. However, in certain complex environments, these systems are susceptible to failure conditions. These scenarios are caused by the interplay between the locomotor's kinematic state and the local terrain configuration, thus making them challenging to predict and overcome. These failures can cause catastrophic damage to the system and thus, methods to avoid such scenarios have been developed. These strategies typically take the form of environmental sensing or passive mechanical elements that adapt to the terrain. Such methods come at an increased control and mechanical design complexity for the system, often still being susceptible to imperceptible hazards. In this study, we investigated whether a tail could serve to offload this complexity by acting as a mechanism to generate new terradynamic interactions and mitigate failure via substrate contact. To do so, we developed a quadrupedal C-leg robophysical model (length and width = 27 cm, limb radius = 8 cm) capable of walking over rough terrain with an attachable actuated tail (length = 17 cm). We investigated three distinct tail strategies: static pose, periodic tapping, and load-triggered (power) tapping, while varying the angle of the tail relative to the body. We challenged the system to traverse a terrain (length = 160 cm, width = 80 cm) of randomized blocks (length and width = 10 cm, height = 0 to 12 cm) whose dimensions were scaled to the robot. Over this terrain, the robot exhibited trapping failures independent of gait pattern. Using the tail, the robot could free itself from trapping with a probability of 0 to 0.5, with the load-driven behaviors having comparable performance to low frequency periodic tapping across all tested tail angles. Along with increasing this likelihood of freeing, the robot displayed a longer survival distance over the rough terrain with these tail behaviors. In summary, we present the beginning of a framework that leverages mechanics via tail-ground interactions to offload limb control and design complexity to mitigate failure and improve legged system performance in heterogeneous environments.M.S
Biological Practices and Fields, Missing Pieces of the Biomimeticsâ Methodological Puzzle
Facing current biomimetics impediments, recent studies have supported the integration within biomimetic teams of a new actor having biological knowledge and know-how. This actor is referred to as the âbiomimeticianâ in this article. However, whereas biology is often considered a homogenous whole in the methodological literature targeting biomimetics, it actually gathers fundamentally different fields. Each of these fields is structured around specific practices, tools, and reasoning. Based on this observation, we wondered which knowledge and know-how, and so biological fields, should characterize biomimeticians. Following the design research methodology, this article thus investigates the operational integration of two biological fields, namely ecology and phylogenetics, as a starting point in the establishment of the biomimeticianâs biological tools and practices. After a descriptive phase identifying specific needs and potential conceptual bridges, we presented various ways of applying biological expertise during biomimetic processes in the prescriptive phase of the study. Finally, we discussed current limitations and future research axes
Models for reinforcement learning and design of a soft robot inspired by Drosophila larvae
Designs for robots are often inspired by animals, as they are designed mimicking animalsâ
mechanics, motions, behaviours and learning. The Drosophila, known as the
fruit fly, is a well-studied model animal. In this thesis, the Drosophila larva is studied
and the results are applied to robots. More specifically: a part of the Drosophila larvaâs
neural circuit for operant learning is modelled, based on which a synaptic plasticity
model and a neural circuit model for operant learning, as well as a dynamic neural network
for robot reinforcement learning, are developed; then Drosophila larvaâs motor
system for locomotion is studied, and based on it a soft robot system is designed.
Operant learning is a concept similar to reinforcement learning in computer science,
i.e. learning by reward or punishment for behaviour. Experiments have shown
that a wide range of animals is capable of operant learning, including animal with only
a few neurons, such as Drosophila. The fact implies that operant learning can establish
without a large number of neurons. With it as an assumption, the structure and dynamics
of synapses are investigated, and a synaptic plasticity model is proposed. The
model includes nonlinear dynamics of synapses, especially receptor trafficking which
affects synaptic strength. Tests of this model show it can enable operant learning at the
neuron level and apply to a broad range of NNs, including feedforward, recurrent and
spiking NNs.
The mushroom body is a learning centre of the insect brain known and modelled
for associative learning, but not yet for operant learning. To investigate whether it participates
in operant learning, Drosophila larvae are studied with a transgenic tool by
my collaborators. Based on the experiment and the results, a mushroom body model
capable of operant learning is modelled. The proposed neural circuit model can reproduce
the operant learning of the turning behaviour of Drosophila larvae.
Then the synaptic plasticity model is simplified for robot learning. With the simplified
model, a recurrent neural network with internal neural dynamics can learn to
control a planar bipedal robot in a benchmark reinforcement learning task which is
called bipedal walker by OpenAI. Benefiting efficiency in parameter space exploration
instead of action space exploration, it is the first known solution to the task with reinforcement
learning approaches.
Although existing pneumatic soft robots can have multiple muscles embedded in
a component, it is far less than the muscles in the Drosophila larva, which are well-organised
in a tiny space. A soft robot system is developed based on the muscle pattern
of the Drosophila larva, to explore the possibility to embed a high density of muscles
in a limited space. Three versions of the body wall with pneumatic muscles mimicking
the muscle pattern are designed. A pneumatic control system and embedded control
system are also developed for controlling the robot. With a bioinspired body wall will
a large number of muscles, the robot performs lifelike motions in experiments