Patent attributes
Kinematic parameters of a parallel kinematic machine can be estimated with high precision considering thermal displacement and error of a measuring device, in addition to deformation error caused by self-weight of each component. A DBB device is used when end effectors of a parallel kinematic mechanism machine are positioned at plural positions and in plural postures. In the DBB device, a plurality of support bars are provided with rigid balls on the both ends. One of the balls is fixed on a table and the other ball is provided with an end effector. The position, posture, and distance from a fixed position are measured and based on the measured value kinematic parameters are estimated. In estimating the kinematic parameters, any of deformation error caused by self-weight of each component, thermal displacement of each component, error of a measuring device are added for computation by linear approximation.