BI-DIRECTIONAL PNEUMATIC BRAIDED MUSCLE ACTUATOR

Problem

The main problem about the Mckibben artificial muscles is related to the response characteristics of the pneumatic muscle which are determined by the original configuration.

Our Technology and Solution

Pneumatic artificial muscles usually consist of a hollow cylindrical elastomeric chamber covered by an outer braided sleeve, consisting of fibres made of un-stretchable material and arranged in an anti-symmetric helical configuration. The hollow internal chamber and the braided sleeve are tightly sealed and attached to rigid end fittings, a passage is provided through one of these end fittings for pressurizing the elastic chamber. The mechanical work done is transferred to an external system through these end fittings. The working principle of the Bi-directional actuator is based on the traditional pneumatic muscles but some fundamental changes enables the user to change the initial braid fiber angle independently. Depending on the braid angle, the actuator is able to produce extension and contraction upon pressurization, moreover the ability to change the initial braid fiber angle enables the actuator to achieve variable stiffness at each point along the total stroke of the actuator, whereas the traditional pneumatic muscles lack this ability.

Advantages

The advantages of using this artificial pneumatic actuator are the high power/weight ratio, the force and the bi-directional motion and the possibility for obtaining maximum and variable rigidity at each point along the entire structure of the actuator. In addition, its use is compatible with human-machine interaction in terms of safety and it does not require a precise alignment during the installation phase thanks to its flexibility.

TRL