VLS
How it works
1) A vision-language model interprets the instruction and the scene, setting the task goal (WHAT to do). 2) A planner/orchestrator decomposes the task into a sequence of skills and retrieves the appropriate validated skills from the library. 3) Each skill performs a specific, repeatable action (HOW), often pre-tested in simulation and reality. 4) Skill outcomes are monitored (measurability), and the orchestrator corrects/continues the plan until the task is complete.
Problem solved
End-to-end VLA models can be unpredictable, hard to validate and error-prone out of distribution. VLS increases reliability, repeatability and testability by basing execution on pre-validated skills.
Components
Interprets the scene and language instruction, setting the task goal (WHAT to do).
Official
A collection of pre-validated, repeatable skills performing specific actions (HOW).
Official
Decomposes the task into skills, retrieves them from the library, composes them into a sequence and monitors execution.
Official
Implementation
Tasks needing skills outside the library are infeasible; covering the long tail is hard.
Wrong choice or ordering of skills breaks the task despite correct individual skills.
Each skill requires validation (sim + real) and maintenance, which scales expensively.
Evolution
Vision-Language-Action models (e.g. RT-2) establish the monolithic, end-to-end approach to robot control that VLS differentiates from.
Holiday Robotics promotes the Vision-Language-Skill architecture for the FRIDAY humanoid as a modular, validated alternative to end-to-end VLA (a $105M Series A).
Hyperparameters (configurable axes)
How fine-grained/complex individual skills are.
Number and coverage of validated skills.
How the task is decomposed and composed from skills (planning, LLM, rules).
Computational complexity
Time complexity: Zalezna od VLM (planowanie) + wybor/wykonanie umiejetnosci. Space complexity: O(VLM + biblioteka umiejetnosci).
Compute bottleneck
VLS effectiveness depends on task coverage by validated skills; library gaps (the long tail) and orchestration errors limit flexibility relative to end-to-end VLA. Validating skills (sim + real) is costly.
Execution paradigm
Skill selection depends on the task and scene.
The orchestrator conditionally selects skills from the library for a given task.
Parallelism
VLM planning and skill selection can be parallelized; in-task execution is sequential.
Hardware requirements
The vision-language (planning) layer benefits from GPU accelerators; skill execution can run on the robot's controllers/edge.