A Review of Active Mechanical Driving Principles of Spherical Robots <s> Pressurized Air Bladders <s> The authors have designed and constructed a new type of actuation for a spherical robot. The proposed actuation system consists of a large number of individually inflatable rubber bladders covering a sphere. Inflation of one or more of these bladders imparts a moment to the sphere and coordinated inflation results in a directed motion. Further, the authors introduce a scheme for steering the robot by correctly selecting the proper bladders to inflate so that motive force is developed in a specified direction. The control scheme utilizes a passively rolling inner vehicle with a directional, remotely positioned light source that causes valves housed within the sphere to inflate the designated bladders through optical commutation. <s> BIB001 </s> A Review of Active Mechanical Driving Principles of Spherical Robots <s> Pressurized Air Bladders <s> This paper presents investigations toward the development of an inflated deformable rolling rover. The proposed novel locomotion system could find potential future use, for example, in scouting and exploration missions. The manufacturing procedure used to fabricate a preliminary prototype is presented in this paper. The prototype consists of a rigid frame and four dielectric elastomer actuator (DEA) sectors, which give the prototype a spherical shape. Analytical models are proposed to predict the electromechanical behavior of the DEA sectors and to estimate their effect on the prototype's dynamics. These models are validated through an experimental procedure. <s> BIB002
A basic deformable spherical rover is proposed by M. Artusi BIB002 . The outer shell consists of four dielectric elastomer actuators sections, which can be transformed by applying an electric field. Transformation of the sections in sequence will cause the robot to roll. K. Wait proposes a similar, yet more advanced idea that utilizes pressurized air bladders. The robot is extremely similar to a soccer ball where each pentagonal section of the outer sphere can inflate and deflate BIB001 . Each section of the outer sphere is actually an elastomer bladder that can be filled with air. Depending on which sections are filled with air, the sphere can be pushed along a path as shown in Figure 14 . Ingeniously, this type of system can provide holonomic movements. Multiple bladders can be inflated allowing for a various directions of travel. Figure 14 . Soccer ball type robot movement BIB001 . Figure 15 . Breakaway view of the soccer ball robot BIB001 . A notable outcome resulting from this research is the design of the control method, which is for the most part non-computational when compared with the previously discussed designs. Inside of the soccer ball shell there is another spherical robot altogether, designed extremely similar to the hamster ball and IDU design discussed in Section 2. On the rear of the control disc, which is inside the inner shell (shown in Figure 15 , there is a high power LED. Each of the pentagonal bladders is equipped with a photo diode. As the control disc moves via radio control, the LED shines on the photo diodes of the bladders, inflating the proper bladders and thus moving the robot.