Animated Cassie: A Dynamic Relatable Robotic Character

Animated Cassie: A Dynamic Relatable Robotic Character

To improve human-robot interaction, robots should incite emotion in humans besides executing tasks. Such types of robots as bipedal robots can move and convey emotion with lots of agility and success. A recent paper on suggests how a bipedal robot, Cassie Cal, can perform emphatic motions and make an impression of having a personality.

Image credit: Zhongyu Li, Christine Cummings and Koushil Sreenath / arXiv:2009.02846

The behavior with emotional attributes is created on a 3D animation suite. Then, the animated motions are translated to be feasible by a real-world robot. To perform complex motions, a novel walking controller is proposed. A library of motions corresponding to different emotions is created. Furthermore, a story where the robot chases a moving laser point is created. During experimental tests, it was verified that people can recognize the emotions of Cassie and follow the story, while the robot maintained balance and smoothly performed the transitions between standing and walking states.

Creating robots with emotional personalities will transform the usability of robots in the real world. As previous emotive social robots are mostly based on statically stable robots whose mobility is limited, this paper develops an animation to real world pipeline that enables dynamic bipedal robots that can twist, wiggle, and walk to behave with emotions. First, an animation method is introduced to design emotive motions for the virtual robot character. Second, a dynamics optimizer is used to convert the animated motion to dynamically feasible motion. Third, real time standing and walking controllers and an automaton are developed to bring the virtual character to life. This framework is deployed on a bipedal robot Cassie and validated in experiments. To the best of our knowledge, this paper is one of the first to present an animatronic dynamic legged robot that is able to perform motions with desired emotional attributes. We term robots that use dynamic motions to convey emotions as Dynamic Relatable Robotic Characters.