The degrees of freedom (DOF) of a kinematic chain is defined as the number of parameters that determine its configuration. In a system comprising n rigid bodies, the total DOF is calculated as 6n, where n represents the number of moving bodies. The formula for mobility is expressed as M=6(N-1), with N being the total count of moving bodies plus one fixed body. This definition clarifies the distinction between a kinematic chain and a mechanism, emphasizing the role of fixed links in determining mobility.
PREREQUISITESMechanical engineers, robotics designers, and students studying kinematics who seek to understand the principles governing the motion and configuration of mechanical systems.
Wikipedia.org said:The degrees of freedom, or mobility, of a kinematic chain is the number of parameters that define the configuration of the chain.[2][5] A system of n rigid bodies moving in space has 6n degrees of freedom measured relative to a fixed frame. This frame is included in the count of bodies, so that mobility does not depend on link that forms the fixed frame. This means the degree-of-freedom of this system is M=6(N-1), where N=n+1 is the number of moving bodies plus the fixed body.