A new bionically inspired approach to increase positioning accuracy of robotic systems

In state of the art robotics, high positioning accuracy is achieved by using solid and stiff components as well as powerful drive units which have no backlash. In contrast, human beings are able to achieve remarkable high positioning accuracy despite of low mass, low power consumption and relatively simple mechanics. One approach to obtain this accuracy is to temporarily create additional supporting structures by interacting with the direct environment, e.g. supporting the heel of the hand on a table for writing. This article deals with the essential idea of applying this method correspondingly into the field of robotics. It points out advantages and disadvantages as well as possibilities to realize this method in different scenarios. With simplified conditions, the influence of propping up on the stiffness and hence on the positioning accuracy is examined using different simulation models. It turns out that blocking of even one degree of freedom in one direction, can lead to a significant improvement regarding stiffness and therefore positioning accuracy. This approach could be used in diverse applications e.g. deburring with an industrial robot or in a humanoid robot to increase the reliability of a process or to reduce cost of components.