Insect Robots Designed

The mobility of animals, including many insects, is typically superior to current legged robots. This fact recommends the use of animal designs in robot. However, the reality of current technology often encourages engineers to use different designs for legged robots than those found in nature. Some robots use mechanisms to couple their joints for the purposes reducing the number of actuators of simplifying the control problem. Actuators are typically heavy and reducing their number can increase the payload or range of a robot.

When early legged robots were developed, computational limitations impeded the use of onboard computers to coordinate many joints. The ASV, Titan IV, and Dino are three of many robots that use pantograph mechanisms to uncouple the vertical and horizontal motions of their feet. Dante II used power screws to achieve large forces with small motors to save weight, but the resulted in slow movements. The K2T carab robot used cables, brakes and clutches to move its 17 joints with just 5 motors. RHEX is a recent robot that adheres to this strategy of simplified mechanical designs. It uses just one motor in each of its six legs to drive each foot in a circular path. It speeds each foot through its swing phase relative to its stance phase so that the robot can walk in insect gaits despite its simple mechanical design. Mechanical coupling and simplicity can ease the development of legged robots. However, the tradeoffs include reduced mobility.