Limits...
Climbing with adhesion: from bioinspiration to biounderstanding.

Cutkosky MR - Interface Focus (2015)

Bottom Line: In parallel, advances in fabrication methods and materials are allowing us to engineer artificial structures with similar properties.The resulting robots become useful platforms for testing hypotheses about which principles are most important.Taking gecko-inspired climbing as an example, we show that the process of extracting principles from animals and adapting them to robots provides insights for both robotics and biology.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering , Stanford University , Stanford, CA 94305 , USA.

ABSTRACT
Bioinspiration is an increasingly popular design paradigm, especially as robots venture out of the laboratory and into the world. Animals are adept at coping with the variability that the world imposes. With advances in scientific tools for understanding biological structures in detail, we are increasingly able to identify design features that account for animals' robust performance. In parallel, advances in fabrication methods and materials are allowing us to engineer artificial structures with similar properties. The resulting robots become useful platforms for testing hypotheses about which principles are most important. Taking gecko-inspired climbing as an example, we show that the process of extracting principles from animals and adapting them to robots provides insights for both robotics and biology.

No MeSH data available.


If the weight of the robot is evenly distributed (a) between the upper and lower limbs, the front limb has a small margin of safety against detaching from the surface. Controlling the upper limb to carry a larger percentage of the load (b) provides a greater overall margin of safety.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4590421&req=5

RSFS20150015F5: If the weight of the robot is evenly distributed (a) between the upper and lower limbs, the front limb has a small margin of safety against detaching from the surface. Controlling the upper limb to carry a larger percentage of the load (b) provides a greater overall margin of safety.

Mentions: The proportional nature of the adhesion also leads to some possibly non-intuitive results. Figure 5 shows a small gecko or robot climbing a vertical wall using a diagonal gait with one upper and one lower foot in contact at each step. Because the centre of mass is located a small distance away from the wall surface, the upper foot, shown in green, must produce adhesion (Fn < 0) to keep the gecko from falling backward off the wall. The blue lower limb, in contrast, is pressed gently into the wall (Fn > 0). If we plot the corresponding forces with respect to the adhesion limits, it is clear that the green dot corresponding to the upper limb, initially at position (a) in force space, is closer to the edge of the safe region than the blue dot associated with the lower limb. This situation matches our intuition that the upper limb is more likely to fail and may suggest a control approach that tends to ‘favour’ the upper limb by loading it gently and supporting most of the weight with the lower limb. But, this is precisely the wrong strategy! Instead, the gecko or robot should pull harder with its front limbs, so that it has more adhesion with which to work. The result is shown by moving the forces from (a) to (b) in the figure, so that both feet have an equal safety margin with respect to the limits of adhesion and sliding.Figure 5.


Climbing with adhesion: from bioinspiration to biounderstanding.

Cutkosky MR - Interface Focus (2015)

If the weight of the robot is evenly distributed (a) between the upper and lower limbs, the front limb has a small margin of safety against detaching from the surface. Controlling the upper limb to carry a larger percentage of the load (b) provides a greater overall margin of safety.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4590421&req=5

RSFS20150015F5: If the weight of the robot is evenly distributed (a) between the upper and lower limbs, the front limb has a small margin of safety against detaching from the surface. Controlling the upper limb to carry a larger percentage of the load (b) provides a greater overall margin of safety.
Mentions: The proportional nature of the adhesion also leads to some possibly non-intuitive results. Figure 5 shows a small gecko or robot climbing a vertical wall using a diagonal gait with one upper and one lower foot in contact at each step. Because the centre of mass is located a small distance away from the wall surface, the upper foot, shown in green, must produce adhesion (Fn < 0) to keep the gecko from falling backward off the wall. The blue lower limb, in contrast, is pressed gently into the wall (Fn > 0). If we plot the corresponding forces with respect to the adhesion limits, it is clear that the green dot corresponding to the upper limb, initially at position (a) in force space, is closer to the edge of the safe region than the blue dot associated with the lower limb. This situation matches our intuition that the upper limb is more likely to fail and may suggest a control approach that tends to ‘favour’ the upper limb by loading it gently and supporting most of the weight with the lower limb. But, this is precisely the wrong strategy! Instead, the gecko or robot should pull harder with its front limbs, so that it has more adhesion with which to work. The result is shown by moving the forces from (a) to (b) in the figure, so that both feet have an equal safety margin with respect to the limits of adhesion and sliding.Figure 5.

Bottom Line: In parallel, advances in fabrication methods and materials are allowing us to engineer artificial structures with similar properties.The resulting robots become useful platforms for testing hypotheses about which principles are most important.Taking gecko-inspired climbing as an example, we show that the process of extracting principles from animals and adapting them to robots provides insights for both robotics and biology.

View Article: PubMed Central - PubMed

Affiliation: Department of Mechanical Engineering , Stanford University , Stanford, CA 94305 , USA.

ABSTRACT
Bioinspiration is an increasingly popular design paradigm, especially as robots venture out of the laboratory and into the world. Animals are adept at coping with the variability that the world imposes. With advances in scientific tools for understanding biological structures in detail, we are increasingly able to identify design features that account for animals' robust performance. In parallel, advances in fabrication methods and materials are allowing us to engineer artificial structures with similar properties. The resulting robots become useful platforms for testing hypotheses about which principles are most important. Taking gecko-inspired climbing as an example, we show that the process of extracting principles from animals and adapting them to robots provides insights for both robotics and biology.

No MeSH data available.