Modeling of Tendon-Driven continuum robot for space applications

The application of continuum robots with flexible mechanical structures is becoming more widespread in the aerospace . These types of robots have recently used to inspect aircraft fuel tanks and space probes. In this paper, the kinematic behavior and working space of a one-segment continuum robot with a tendon mechanism is studied. The theory for kinematic analysis is the fixed curvature method which is the most effective for analyzing continuum robots especially in the case of weightlessness. Also, the amount of tension and bending of the secondary backbones of the continuum robot in the one-dimensional and three-dimensional were investigated as a time dependent functions. Results showed the rate of change of link lengths is about 39.1% increase of back link, and 17.8%, and 21.2% decrease in others with an initial length of 40 mm . Based on this results , it is possible to estimate the amount of tension and bending over a certain period for different types of materials. Additionally, the error of reaching to target point in the obtained optimal values of bending and rotation angles,equal to 67.35 and -40.89, was almost zero which shows the very high accuracy of model. Also, the results of the working spacecover the surface of the sphere of the working space with an accuracy of 1 mm, The obtained results increase accuracy of robot moving in environments with complex structures and limited spaces. The proposed model can be used as a base for continuum multi-part robots.