Towards Connecting Control to Perception: High-Performance Whole-Body Collision Avoidance Using Control-Compatible Obstacles

One of the most important aspects of autonomous systems is safety. This includes ensuring safe human-robot and safe robot-environment interaction when autonomously performing complex tasks or in collaborative scenarios. Although several methods have been introduced to tackle this, most are unsuitable for real-time applications and require carefully hand-crafted obstacle descriptions. In this work, we propose a method combining high-frequency and real-time self and environment collision avoidance of a robotic manipulator with low-frequency, multimodal, and high-resolution environmental perceptions accumulated in a digital twin system. Our method is based on geometric primitives, so-called primitive skeletons. These, in turn, are information-compressed and real-time compatible digital representations of the robot's body and environment, automatically generated from ultra-realistic virtual replicas of the real world provided by the digital twin. Our approach is a key enabler for closing the loop between environment perception and robot control by providing the millisecond real-time control stage with a current and accurate world description, empowering it to react to environmental changes. We evaluate our whole-body collision avoidance on a 9-DOFs robot system through five experiments, demonstrating the functionality and efficiency of our framework.Comment: Accepted for publication at 2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2023

Glutathione Restricts Serine Metabolism to Preserve Regulatory T Cell Function

Regulatory T cells (Tregs) maintain immune homeostasis and prevent autoimmunity. Serine stimulates glutathione (GSH) synthesis and feeds into the one-carbon metabolic network (1CMet) essential for effector T cell (Teff) responses. However, serine’s functions, linkage to GSH, and role in stress responses in Tregs are unknown. Here, we show, using mice with Treg-specific ablation of the catalytic subunit of glutamate cysteine ligase ( Gclc), that GSH loss in Tregs alters serine import and synthesis and that the integrity of this feedback loop is critical for Treg suppressive capacity. Although Gclc ablation does not impair Treg differentiation, mutant mice exhibit severe autoimmunity and enhanced anti-tumor responses. Gclc-deficient Tregs show increased serine metabolism, mTOR activation, and proliferation but downregulated FoxP3. Limitation of cellular serine in vitro and in vivo restores FoxP3 expression and suppressive capacity of Gclc-deficient Tregs. Our work reveals an unexpected role for GSH in restricting serine availability to preserve Treg functionality