Kinematic accuracy analysis of serial manipulator based on POE formula

In the kinematic calibration of robots, an essential step is to develop an error model. Recently, the product of exponentials (POE) due to its singularity-free property has been widely used in the calibration. However, the previous error models based on POE are of linear kind. In this paper, to investigate the applicability of the liner model, a second order error model is established. Based on the error model, the corresponding statistical models are developed and applied for the Puma 560. It is found that the linear error model is adequately accurate for most practical manipulations.