Soft robotic drummer uses tricks for better multi-bounce drum rolls
Multi-bounce Drum Roll with Optimized Active Tricks to Leverage Soft Embodiment
Robotics
Summary
Accurate and fast drum rolls need a drumstick to bounce multiple times per strike, which is hard for robots. This paper shows how a soft robotic drummer can use the body's stretchiness along with special motion tricks to get more bounces and keep the sound loud. One trick pulls the stick after hitting to increase rebounds, and another adds tiny shakes to keep the drum volume steady. The authors used smart trial-and-error tuning methods to find the best ways to do this. Their results show that soft robots can perform drum rolls better than stiff ones by combining softness and clever motion.
soft roboticsmulti-bounce techniquedrum rollelasticityBayesian optimizationrobotic drummingactuator tricksacoustic efficiencyend-effector
Authors
Naoto Yamanaka, Takanori Jin, Taisuke Kobayashi
Abstract
This paper presents a soft robotic drummer for accurate and efficient drum rolls. High-frequency drum rolls require the "multi-bounce technique," where a drumstick bounces multiple times with a single stroke. In robotic reproduction of this technique, the body's elasticity is key, while the fine motion during the stroke is also crucial for maximizing the potential of that elasticity. Therefore, we design two tricks: i) Tap-Pull (TP) trick to increase the number of rebounds by adding a pulling motion after impact; and ii) Micro-Pulse (MP) trick to keep the drumming volume by injecting small oscillations during the stroke. Due to the nonlinear complexity of soft embodiment, both tricks are efficiently tuned using Bayesian optimization in a data-driven manner for accomplishing the respective objectives quantified. We evaluated the optimized behaviors with soft and rigid end-effectors. As a result, the soft TP achieved the highest bounce count (12.25 per stroke) with uniform intervals. The soft MP suppressed the volume decay, yielding 6.8-times higher acoustic efficiency compared to the rigid MP. These results indicate that the proposed tricks with the combination of elasticity and optimization can make robots play excellent drum rolls.