Serial vs. quasi-serial manipulators: Comparison analysis of elasto-static behaviors

The paper deals with comparison of industrial manipulators of serial and quasi-serial architecture. It proposes a new methodology that is based on estimation of the robot accuracy for three typical manufacturing tasks that are optimally located within the robot workspace. To cover wide range of applications, the set of isotropic, quasi-isotropic and extended benchmark tasks are considered and relevant compliance errors are evaluated taking into account the end-effector deflections caused by the external forces. It is shown that regardless of the benchmark task, the serial manipulators are preferable for small and medium tasks while the quasi-serial ones’ better suit to large-dimensional tasks only. The proposed technique was applied to the architecture comparison analysis of 15 industrial robots of both serial and quasi-serial manipulators with similar working radius and payload about 200 kg.