Flea inspired catapult mechanism with active energy storage and release for small scale jumping robot

Abstract

Fleas have a unique catapult mechanism with a special muscle configuration. Energy is stored in an elastic material, resilin, and the extensor muscle. Force is applied by the extensor muscle to generate a torque. Energy is released as a small triggering muscle reverses the direction of the aforementioned torque. A flea can jump 150 times its body length using this elastic catapult mechanism. In this paper, a flea-inspired catapult mechanism is presented. This mechanism can be categorized as an active storage and active release elastic catapult. Owing to its unique stiffness change characteristic, a shape-memory-alloy coil spring actuator enables the mimicking of the flea's catapult mechanism. Two types of flea-inspired jumping mechanisms were developed for verifying the feasibility of applying the concept to an efficient jumping robot. The first prototype has a flea-like appearance and the second is simplified to contain just the essential components of the flea-inspired catapult mechanism. The two prototypes are 20-mm-and 30-mm-long and can jump 64 cm and 120 cm, respectively. This unique catapult mechanism can be used not only for jumping robots but also for other small-sized robots to generate fast-releasing motion.

Role of compliant leg in the flea-inspired jumping mechanism

“…Additionally, the slippage problem must be resolved in order to obtain more precise experimental results. Finally, symmetric jumping mechanisms [2,3] should be implemented to eliminate rotation of the robot body. This rotation make analysis difficult and usually occurs owing to reaction forces not passing through the center of mass.…”

“…To achieve high jumping height, a variety of mechanisms are employed, such as an escapement mechanism using a cam or gear [4][5][6][7], snap-through buckling [8], torque-reversal [1][2][3], one-way bearing [9], an inchworm motor [10] and chemical energy [11]. To maximize takeoff speed, more powerful actuators, large energy storages, and robust robot frames have been used.…”

Design, Optimization, and Experiment on a Bioinspired Jumping Robot with a Six-Bar Leg Mechanism Based on Jumping Stability

“…e average jumping height and jumping distance were 99.1 and 72.7 cm on a smooth surface, respectively. With the development of material science, the integration of the 1DOF mechanism and flexible materials has also been studied [21,22]. Compared with the four-bar mechanism, the six-and eightbar mechanisms have more complex structures, but more abundant motion can be achieved [23].…”

A Novel Locust-inspired Jumping Robot Driven by Pneumatic Muscle Actuators

“…Jumping motions have obvious advantages in uneven physiognomy or rugged environment compared to crawl and walking mode. Therefore, many jumping robots have been being developed in recent years [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. M Kovač et.al proposed a novel spherical robot with the function of jump, recovery and orienting itself [1].…”