Force-Based Robotic Imitation Learning: A Two-Phase Approach for Construction Assembly Tasks

Robots have shown enormous potential to alleviate repetitive, and dangerous tasks from human workers, such as assembly, infrastructure inspection, material handling and heavy rigging [4-6]. Integrating the artificial intelligence (AI) agent with a physical robotic system could further improve the precision, reliability, and consistency of operations with competent training [7, 8]. While AI-enabled robots excel in performing repetitive and predefined tasks, dexterous and complex tasks still pose a significant difficulty such as welding and pipe insertion [9, 10]. Training a robot to perform these dexterous tasks demands delicate manipulation and adaptive force control, which induces diversity and several potential actions leading to a substantial increase in the complexity of the learning process and resulting in slow convergence or lack of convergence [11] To tackle the challenges of learning in high-dimensional action spaces, Imitation Learning (IL) based methods are applied to leverage demonstrations from human experts or proficient use of human demonstrations as a form of instruction and reduce the size of action spaces that need to be explored [12-14]. Generative Adversarial Imitation Learning (GAIL)[15] could further address some key limitations of traditional IL by mitigating distributional shifts, thus enabling better exploration and performance in unseen states and generalizing better to new tasks [15].