A climbing robot design, using dry adhesion forces, has to be developed in order to maximize the effectiveness of the attachment system. In particular there are three main requirements for developing such a robot:
1. Maximize the attachment area.
2. Apply preload between vehicle and vertical surface for increasing the attaching force.
3. Use peel force during the detaching phase.
Two different vehicle concepts were developed. The first one is a wheg (wheel-leg) vehicle that uses legs with adhesive feet for climbing vertical surface. The second one is a tread based locomotive mechanism using a rubber belt in place of a chain tire.
In order to achieve good performances, an optimization analysis was performed. The properties of tail and the position of the center of the mass were optimized. Finite Element Methods (FEM) was chosen for solving and optimizing the over constrained model. In the FEM model, the climbing robots were schematized by means of three beam elements having null masses. The gravitational force was applied in the center of mass of the system.
The results of the optimization correspond to a vehicle having the same dimensions of the developed tank robot. The force varies changing the length and the rigidity of the tail of the model depicture. The attaching force has a monotone behavior with respect to the Young’s modulus but there is a local minimum for the tail length. The optimal tail length should be 0.12 meter long and the Young’s modulus should be the highest possible.
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