Study on the singularity of a planar five-bar mechanism

Jacobian matrix of a planar five-bar mechanism is deduced and the posture of a planar five-bar mechanism is given when the mechanism locates in singularity position. By analyzing the determinant of Jacobian matrix det (J) of a planar five-bar mechanism, the methods to avoid singularity are presented. When det (J) = 0, singularity can be avoided by making the real path far from the boundary of work space; When det (J) → ∞, singularity can be avoided by selecting suitable dimensions of the mechanism, by selecting suitable mechanism posture or by ensuring that the real path doesn't go through the singularity path. A set of software is developed to simulate the singularity path and it provides the basis for the design of a five-bar mechanism.