Compliant Mechanism And Its Application In Bionic Jump Institutions

Compliant mechanisms are new mechanical devices that achieve some or all of their motion, force and energy via elastic deformation. These devices have good prospects in areas such as precision position, MEMS and smart structures due to their advantages such as elimination of friction and wear. This paper studies the theory and design method of compliant mechanisms systematically, on the basis of which, applies them to bionic kangaroo-hopping mechanism in order to solve related problems of energy conservation and dynamics.First of all, this paper presents the representation of flexural segments and compliant kinematic chain. Pseudo-rigid-body models of several common flexural segments are given and the formula of their equivalent spring stiffness and position of gyration center are deduced with elliptic integral solution. All above provide a foundation for the analysis and design of compliant mechanisms with the theory of rigid mechanisms.Due to the dual nature of compliant mechanisms, this paper analyses and designs bistable compliant mechanisms and constant-force output mechanisms with pseudo-rigid-body model method, and meanwhile discusses the requirements for four-bar mechanism to be bistable with potential energy, and puts forward energy storage characteristic. Then this paper researches on design method of compliant mechanisms based on structure optimization. Model and solution of single object function of continuum rigid structure with single load are studied, and implemented in MATLAB. When designing compliant mechanisms, one must account for both the kinematic requirements and the structure requirements stimulatingly. For which, the ratio of strain energy to mutual potential energy is posed as object function.This paper applies compliant mechanisms to bionic kangaroo-hopping mechanism and establishes its pseudo-rigid-body model. Dynamic differential equation is established with Kane method. The formulas of input torque at each joint and force acting on the ground and the approach to equivalent spring stiffness were presents. Finally, this paper calculates and analyses the rigid model and pseudo-rigid -body model respectively with an example. The results indicate that compliant mechanisms can solve problem of energy conservation and shake elimination tosome extent.This paper provides a reference to the design and application of compliant mechanisms and research on bionic hopping robots.