π MAROKO133 Eksklusif ai: ByteDance Introduces Astra: A Dual-Model Architecture fo
The increasing integration of robots across various sectors, from industrial manufacturing to daily life, highlights a growing need for advanced navigation systems. However, contemporary robot navigation systems face significant challenges in diverse and complex indoor environments, exposing the limitations of traditional approaches. Addressing the fundamental questions of “Where am I?”, “Where am I going?”, and “How do I get there?”, ByteDance has developed Astra, an innovative dual-model architecture designed to overcome these traditional navigation bottlenecks and enable general-purpose mobile robots.
Traditional navigation systems typically consist of multiple, smaller, and often rule-based modules to handle the core challenges of target localization, self-localization, and path planning. Target localization involves understanding natural language or image cues to pinpoint a destination on a map. Self-localization requires a robot to determine its precise position within a map, especially challenging in repetitive environments like warehouses where traditional methods often rely on artificial landmarks (e.g., QR codes). Path planning further divides into global planning for rough route generation and local planning for real-time obstacle avoidance and reaching intermediate waypoints.
While foundation models have shown promise in integrating smaller models to tackle broader tasks, the optimal number of models and their effective integration for comprehensive navigation remained an open question.
ByteDance’s Astra, detailed in their paper “Astra: Toward General-Purpose Mobile Robots via Hierarchical Multimodal Learning” (website: https://astra-mobility.github.io/), addresses these limitations. Following the System 1/System 2 paradigm, Astra features two primary sub-models: Astra-Global and Astra-Local. Astra-Global handles low-frequency tasks like target and self-localization, while Astra-Local manages high-frequency tasks such as local path planning and odometry estimation. This architecture promises to revolutionize how robots navigate complex indoor spaces.
Astra-Global: The Intelligent Brain for Global Localization
Astra-Global serves as the intelligent core of the Astra architecture, responsible for critical low-frequency tasks: self-localization and target localization. It functions as a Multimodal Large Language Model (MLLM), adept at processing both visual and linguistic inputs to achieve precise global positioning within a map. Its strength lies in utilizing a hybrid topological-semantic graph as contextual input, allowing the model to accurately locate positions based on query images or text prompts.
The construction of this robust localization system begins with offline mapping. The research team developed an offline method to build a hybrid topological-semantic graph G=(V,E,L):
- V (Nodes): Keyframes, obtained by temporal downsampling of input video and SfM-estimated 6-Degrees-of-Freedom (DoF) camera poses, act as nodes encoding camera poses and landmark references.
- E (Edges): Undirected edges establish connectivity based on relative node poses, crucial for global path planning.
- L (Landmarks): Semantic landmark information is extracted by Astra-Global from visual data at each node, enriching the map’s semantic understanding. These landmarks store semantic attributes and are connected to multiple nodes via co-visibility relationships.
In practical localization, Astra-Global’s self-localization and target localization capabilities leverage a coarse-to-fine two-stage process for visual-language localization. The coarse stage analyzes input images and localization prompts, detects landmarks, establishes correspondence with a pre-built landmark map, and filters candidates based on visual consistency. The fine stage then uses the query image and coarse output to sample reference map nodes from the offline map, comparing their visual and positional information to directly output the predicted pose.
For language-based target localization, the model interprets natural language instructions, identifies relevant landmarks using their functional descriptions within the map, and then leverages landmark-to-node association mechanisms to locate relevant nodes, retrieving target images and 6-DoF poses.
To empower Astra-Global with robust localization abilities, the team employed a meticulous training methodology. Using Qwen2.5-VL as the backbone, they combined Supervised Fine-Tuning (SFT) with Group Relative Policy Optimization (GRPO). SFT involved diverse datasets for various tasks, including coarse and fine localization, co-visibility detection, and motion trend estimation. In the GRPO phase, a rule-based reward function (including format, landmark extraction, map matching, and extra landmark rewards) was used to train for visual-language localization. Experiments showed GRPO significantly improved Astra-Global’s zero-shot generalization, achieving 99.9% localization accuracy in unseen home environments, surpassing SFT-only methods.
Astra-Local: The Intelligent Assistant for Local Planning
Astra-Local acts as the intelligent assistant for Astra’s high-frequency tasks, a multi-task network capable of efficiently generating local paths and accurately estimating odometry from sensor data. Its architecture comprises three core components: a 4D spatio-temporal encoder, a planning head, and an odometry head.
The 4D spatio-temporal encoder replaces traditional mobile stack perception and prediction modules. It begins with a 3D spatial encoder that processes N omnidirectional images through a Vision Transformer (ViT) and Lift-Splat-Shoot to convert 2D image features into 3D voxel features. This 3D encoder is trained using self-supervised learning via 3D volumetric differentiable neural rendering. The 4D spatio-temporal encoder then builds upon the 3D encoder, taking past voxel features and future timestamps as input to predict future voxel features through ResNet and DiT modules, providing current and future environmental representations for planning and odometry.
The planning head, based on pre-trained 4D features, robot speed, and task information, generates executable trajectories using Transformer-based flow matching. To prevent collisions, the planning head incorporates a masked ESDF loss (Euclidean Signed Distance Field). This loss calculates the ESDF of a 3D occupancy map and applies a 2D ground truth trajectory mask, significantly reducing collision rates. Experiments demonstrate its superior performance in collision rate and overall score on out-of-distribution (OOD) datasets compared to other methods.
The odometry head predicts the robot’s relative pose using current and past 4D features and additional sensor data (e.g., IMU, wheel data). It trains a Transformer model to fuse information from different sensors. Each sensor modality is processed by a specific tokenizer, combined with modality embeddings and temporal positional embeddi…
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π Sumber: syncedreview.com
π MAROKO133 Hot ai: Google Apologizes for Sending the Worst Push Notification You
Disaster tends to strike when you let automated systems distribute news, especially on sensitive topics.
The latest case in point: how Google’s automated news alerts accidentally ended up throwing more fuel onto an already hurtful racial slur controversy that unfolded at the BAFTA awards this weekend.
As Deadline reported, Google pushed out a notification linking to an article with the headline, “How the Tourette’s Fallout Unfolded at the BAFTA Film Award.” The problem was the message appended to the notification, which prompted readers to “see more on n****rs.”
The blunder became viral after Instagram influencer Danny Price posted a screenshot of the alert to his followers, calling it “absolutely f**ked.”
“What an interesting Black History month this has turned out to be,” Price wrote.
Google apologized for the slur after the incident gained news coverage.
“We’re very sorry for this mistake. We’ve removed the offensive notification and are working to prevent this from happening again,” a spokesperson told media outlets.
Understandably, the error prompted fiery discussions online about the irresponsibility of allowing AI systems to report and repackage the news. But Google claims that no AI was involved in the blunder.
In a clarification provided by Deadline after it originally reported the notification was AI-generated, Google told the paper that its systems “recognized a euphemism for an offensive term on several web pages, and accidentally applied the offensive term to the notification text.”
“This system error did not involve AI,” the company emphasized. “Our safety filters did not properly trigger, which is what caused this.”
Nonetheless, the criticisms of AI butting its way into journalism aren’t unwarranted. When Apple launched an AI feature that summarized headlines in 2024, it falsely told users that Luigi Manione had shot himself, and other lies, leading to the BBC filing a formal complaint against the tech giant after the tool repeatedly butchered its stories. Last December, the Washington Post deployed an AI-generated feature for creating personalized podcasts that summarized its stories, which immediately invented and misattributed quotes, among other mistakes.
Google, whose non-chatbot models are notorious for producing outrageous hallucinations, has itself been guilty of similar blunders, too. Last month, its Google Discover feed was caught showing users sensationalized AI-generated headlines that replaced the publication’s original headline, The Verge found.
More on Google: Googleβs AI Insists That Next Year Is Not 2027
The post Google Apologizes for Sending the Worst Push Notification You Can Possibly Imagine appeared first on Futurism.
π Sumber: futurism.com
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