Artificial Eyes with Emotion and Light Responsive Pupils for Realistic Humanoid Robots

Abstract

This study employs a novel 3D engineered robotic eye system with dielectric elastomer actuator (DEA) pupils and a 3D sculpted and colourised gelatin iris membrane to replicate the appearance and materiality of the human eye. A camera system for facial expression analysis (FEA) was installed in the left eye, and a photo-resistor for measuring light frequencies in the right. Unlike previous prototypes, this configuration permits the robotic eyes to respond to both light and emotion proximal to a human eye. A series of experiments were undertaken using a pupil tracking headset to monitor test subjects when observing positive and negative video stimuli. A second test measured pupil dilation ranges to high and low light frequencies using a high-powered artificial light. This data was converted into a series of algorithms for servomotor triangulation to control the photosensitive and emotive pupil dilation sequences. The robotic eyes were evaluated against the pupillometric data and video feeds of the human eyes to determine operational accuracy. Finally, the dilating robotic eye system was installed in a realistic humanoid robot (RHR) and comparatively evaluated in a human-robot interaction (HRI) experiment. The results of this study show that the robotic eyes can emulate the average pupil reflex of the human eye under typical light conditions and to positive and negative emotive stimuli. However, the results of the HRI experiment indicate that replicating natural eye contact behaviour was more significant than emulating pupil dilation.

Modeling Neuroendocrine Autonomic Responses in Embodied Autonomous Robots

“…In the literature, some works have modeled autonomic processes to improve the involuntary behavior and responsiveness of robots. [26][27][28] Nevertheless, they do not consider the important regulation that neuroendocrine substances exert, only focus on one process (e.g., pupil size or blinking regulation), and lack a methodology and studies to shape more processes drawing on biology. This is a significant difference from our work, which presents a biologically inspired methodology to emulate five autonomic processes in a social robot.…”

“…Strathearn [27] 2021 Precise biological modeling of pupil size changes in robots as a response to stimuli.…”

“…Strathearn [ 27 ] designed mechatronic eyes for humanoid robots. The most relevant novelty of this study for our work is that it includes a self‐regulatory mechanism of pupil size that is responsive to the light level and the robot's emotions.…”

“…In this vein, few contributions have investigated how to regulate the expression of specific autonomic processes in robots, lacking a robust biological foundation that can be extended to modeling multiple processes simultaneously. [26][27][28] In addition, although there are works that address the mathematical representation and role of neuroendocrine substances on behavior, they do not take into account the role of autonomic processes on involuntary behavior, and instead, focus only on voluntary behavior. [29][30][31][32] Emulating the human periodic biological changes using circadian rhythms permits these systems to replicate human activity and daily dynamics.…”