Through the development in the past 20 years

the flexible mechanism has become a important branch of modern mechanisms and is widely applied in such fields as precision engineering and robotics.A flexible mechanism is a new mechanism which uses the elastic deformation of its flexible elements to transfer movement

force

or energy.The use of flexible members always makes it difficult to distinguish joints from links

which causes that the concept of degree of freedom for flexible mechanisms is different from that of rigid-body mechanisms.Based on Pseudo-rigid-body model

the definition of the two degree of freedom of a flexible mechanism and relevant corollaries are given

and calculation method of degree of freedom for flexible mechanism is analyzed.