摘要

This paper presents a new static mathematical model of a type of pneumatic artificial muscle (PAM). Generally, there are three main kinds of PAM, of which the braided fibre-reinforced PAM is most common. The PAM produced by Festo Company (abbreviated as FMPAM in this paper) and McKibben muscle all belong to the category of braided fibre-reinforced PAM. However, the structure of FMPAM is different from that of McKibben muscle. In FMPAM, elastic material (elastomer) and braided reinforced fibres are mixed together. A quasi finite element method based on certain assumptions is suggested to derive the mathematic model via the elasticity principle of virtual work, in which the grid of every braided fibre is regarded as an element. By using such a method, it is possible to consider the elasticity of the braided fibres. Finally, a simplification and a compensation item are introduced to the static mathematical model. An experimental facility is set up to determine the tension-pressure-length character of the FMPAM in a quasi static experiment. The experimental results show that the new mathematical model developed in this paper can shed light on the static or quasi static character of FMPAM.