Design considerations for an earth based flexible robotic system

The problems of designing a robot with joint and link flexibility are discussed. The relationship between the deflection of the robot under gravity is correlated with the fundamental frequency of vibration. Different types of link geometry are considered, evaluating the flexibility potential of different materials. Some general conclusions and guidelines for constructing a flexible robot are given. It is found that, for maximum flexibility with minimum stiffness, the best material choice for the links is titanium. Some aluminium alloys may be inexpensive alternatives, but the fatigue characteristics of aluminium are unacceptable in most applications. Coiled springs give very little stiffness in comparison to their strength, but their weight makes them unusable in all but planar applications