Jonathan E. Clark

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Robots to date lack the robustness and performance of even the simplest animals when operating in unstructured environments. This observation has prompted an interest in biomimetic robots that take design inspiration from biology. However, even biomimetic designs are compromised by the complexity and fragility that result from using traditional engineering(More)
The design of legged robots has long drawn on nature for inspiration. However, few of these robots exhibit the speed and robustness seen in even the simplest of animals. This paper presents the design and fabrication of a novel class of six-legged running robots based on biologically-inspired functional principles. We first describe recent findings in(More)
We describe the design features that underlie the operation of iS-prawl, a small (0.3 kg) autonomous, bio-inspired hexapod that runs at 15 body-lengths/second (2.3 m/s). These features include a tuned set of leg compliances for efficient running and a light and flexible power transmission system. This transmission system permits high speed rotary power to(More)
Biomechanical studies suggest that animals' abilities to tune their effective leg compliance in response to changing terrain conditions plays an important role in their agile, robust locomotion. However, despite growing interest in leg compliance within the robotics literature, little experimental work has been reported on tunable passive leg compliance in(More)
Traditional legged runners and climbers have relied heavily on gait generators in the form of internal clocks or reference trajectories. In contrast, here we present physical experiments with a fast, dynamical, vertical wall climbing robot accompanying a stability proof for the controller that generates it without any need for an additional internal clock(More)
This paper describes the inspiration, design, analysis, implementation of and experimentation with the first dynamical vertical climbing robot. Biologists have proposed a pendulous climbing model that abstracts remarkable similarities in dynamic wall scaling behavior exhibited by radically different animal species. We study numerically a version of that(More)
Simple mathematical models or 'templates' of locomotion have been effective tools in understanding how animals move and have inspired and guided the design of robots that emulate those behaviors. This paper describes a recently proposed biologically-based template for dynamic vertical climbing, and evaluates the feasibility of adapting it to build a(More)
Recent developments in legged robotics have found that constant stiffness passive compliant legs are an effective mechanism for enabling dynamic locomotion. In spite of its success, one of the limitations of this approach is reduced adaptability. The final leg mechanism usually performs optimally for a small range of conditions such as the desired speed,(More)
The present work investigates the effect of rolling contact during stance phase in running by relating the variation of foot curvature radii to running efficiency, stability and forward speed. Both a conservative reduced-order running model and one with a simple motor and friction model are used to simulate running with a rolling foot. We find that having a(More)
Humans and animals adapt their leg impedance during running for both internal(e.g. loading) and external(e.g. surface) changes. In this paper we examine the relationship between leg stiffness and the speed and stability of dynamic legged locomotion. We utilize a torque-driven reduced-order model of running based on a successful family of running robots to(More)