Manipulating cables is challenging for robots because of the infinite degrees of freedom of the cables and frequent occlusion by the gripper and the environment. These challenges are further complicated by the dexterous nature of the operations required for cable routing and assembly, such as weaving and inserting, hampering common solutions with vision-only sensing. In this paper, we propose to integrate tactile-guided low-level motion control with high-level vision- based task parsing for a challenging task: cable routing and assembly on a reconfigurable task board. Specifically, we build a library of tactile-guided motion primitives using a fingertip GelSight sensor, where each primitive reliably accomplishes an operation such as cable following and weaving. The overall task is inferred via visual perception given a goal configuration image, and then used to generate the primitive sequence. Experiments demonstrate the effectiveness of individual tactile- guided primitives and the integrated end-to-end solution, sig- nificantly outperforming the method without tactile sensing. Our reconfigurable task setup and proposed baselines provide a benchmark for future research in cable manipulation.

This paper proposes a Magneto Rheological linear clutch for use in human safe robotic applications. The force transmitted to the links of the robot must be precisely controlled for any manipulator if it has to be operated safely alongside humans. The traditional approaches to this problem is using various compliant actuating schemes like Series Elastic Actuators, Joint Torque Control etc. Research on the usage of smart materials that change their properties on application of electrical or magnetic fields for human safe robots have gained momentum recently. Studies on the feasibility of Magneto-Rheological actuators has been done already. This paper introduces a MR clutch which can control the force transmitted by a linear actuator. The electromechanical model of the linear clutch has been developed, implemented in hardware, and tested using a prototype one Degree of Freedom arm. The design of the clutch is detailed and the performance is characterized thorough a series of experiments. The results suggest that the linear clutch serves well for the precise force control of a linear actuator.