Rheological Based Hibrid Hyper-Redundant Robot - Design

Hyper-redundant robots are designed to work in space with restrictions. From the point of view of the mobility of the discrete hyper-redundant robots, two constructive types are consecrated. With extreme mobility (element level actuating), a solution that requires actuators in each joint, to the detriment of weight and hence the length. With a large length (actuators in the base, and traction cables), a solution that increases the length of the robot against the mobility. In this paper, the authors propose a joint actuating solution that solves this problem. The proposed actuating system is a hybrid structure, based on pneumatic control with an electrorheological element. It made of a pneumatic actuation with kinematics and dynamics fully controllable based by a structure with an electrorheological stop valve. Also, the proposed electrorheological stop-valve solution reduces the limitations imposed on the fields of application of electro-rheological fluids, limitations due to the high voltage supply, of the KV order. The voltage required for the proposed structure is in the order of tens of volts what the recommends robot even for use in the medical field. It also drastically reduces the complexity and size of the power supply and control system needed for this type of actuator system. The proposed solution allows the action to joint-level for hyper-redundant robots of any length (infinitely long robots) due to the very good force/weight ratio of the system of the actuators. Due to this particularity (length), these robots can be used in various domains, with different motion strategies being applied to different robot segment, depending on the topology of the field.