RynnValue: Scaling Robotic Value Foundation Models with Temporal Distance
RynnValue is an open-source robotic value foundation model that scales to millions of instruction-conditioned clips by using temporal distance as a supervision target, outperforming preference-based methods in evaluation and significantly boosting real-world policy success without requiring explicit reward or progress annotations.
Original paper licensed under CC BY 4.0 (http://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Imagine you are trying to teach a robot how to cook a meal, but instead of giving it a recipe, you just say, "Make it good!" and hope it figures out the rest. This is the world of robot learning, a branch of science where engineers try to teach machines to move and interact with the physical world. The biggest hurdle isn't usually the robot's brain (its ability to move); it's the reward. In the world of AI, a "reward" is like a scorecard or a high-five that tells the robot, "Good job!" or "Try again." The problem is that giving a robot a perfect scorecard for every single move is incredibly hard. If the scorecard is too vague, the robot gets confused. If it's too specific to one task, the robot can't learn anything new. Scientists have been trying to build a "general-purpose" scorecard that works for any robot doing any task, but they've been stuck on how to create it without needing a human to manually grade every single attempt.
This is where a new idea called RynnValue comes in. Think of it as a new way to grade a robot's performance. Instead of asking, "How close are you to the finish line?" (which is hard to measure if the finish line looks different for every task), RynnValue asks, "How much time is left until you're done?" It treats the robot's journey like a countdown timer. If the robot is far from the goal, the timer is high. If it's close, the timer is low. The magic of this paper is that it shows you don't need a human to press a button and say "Good job" to create this timer. You can just look at the clock. If a video of a robot cooking starts at 10 minutes and ends at 0, the computer can automatically figure out that at the 5-minute mark, the robot had 5 minutes left. This simple trick allows the robot to learn from thousands of hours of videos without anyone needing to manually grade them.
The Problem: The "Progress" Trap
For a long time, scientists tried to teach robots by measuring "progress." Imagine a robot trying to stack blocks. A progress model would try to guess if the robot is 10% done, 50% done, or 90% done. But here's the catch: "50% done" looks totally different for stacking blocks than it does for pouring water. One robot might be halfway through by height, while another is halfway through by time. This makes it really hard to train a robot that can do many different things, because the definition of "progress" changes every time the task changes. It's like trying to teach a student math by saying "You're halfway there!" without ever telling them what the final answer is supposed to be.
The authors of this paper argue that this "progress" approach is a dead end. They say we need to stop trying to guess how far along a robot is and start counting down the time until the job is finished. They call this temporal distance. It's the "cost-to-go," or simply, "how much time do I have left?"
The Solution: RynnValue and the Magic Clock
The team at Alibaba's DAMO Academy and Hupan Lab built a model called RynnValue. Instead of trying to guess a progress percentage, RynnValue looks at a video of a robot and a text instruction (like "put the cup on the table") and predicts exactly how many seconds are left until the task is done.
Here is the clever part: they didn't need humans to write down "5 seconds left" for every video. They just used the timestamps already on the video files. If a video starts at 0:00 and the robot finishes at 0:10, the computer knows that at 0:05, the robot had 5 seconds left. This means they could train the model on a massive library of over 7,000 hours of robot videos—roughly 3 million clips—without needing a single human to manually grade them. It's like teaching a student to read by letting them watch thousands of movies with subtitles, rather than having a teacher grade every sentence they read.
The Sneaky Tricks (and How They Stopped Them)
You might think, "If the robot just learns to look at the clock, isn't that exploiting a shortcut?" The scientists were worried about this too. They knew that if they just showed the robot videos in order, the robot might learn a shortcut: "Oh, the 3rd frame in the video is always halfway done!" or "If the video is 10 seconds long, the middle is always 5 seconds left." The robot would stop looking at the actual robot arms and just guess based on the video's position.
To stop this, they added some "chaos" to the training:
- Random Sampling: They didn't show the robot the video in a straight line. They picked random moments from the video, so the robot couldn't guess the time based on the order of the frames.
- Shuffling: They sometimes showed the robot the video backwards or in a jumbled order. If the robot saw a "finished" state before a "start" state, it had to realize that the "finished" state was actually further away in time, forcing it to actually look at the picture of the robot, not just the order of the pictures.
- Isolation: They made sure the robot couldn't peek at the answers for the next frame while guessing the current one. It had to solve each moment on its own.
The Results: Does It Work?
The team tested RynnValue on a bunch of different robots and tasks it had never seen before. The results were surprisingly good.
- Ranking Tasks: When asked to rank different robot attempts from "best" to "worst," RynnValue got a score of 0.675. This was better than the previous best models that relied on humans manually grading the videos (which scored 0.655).
- Real-World Robots: They took the model and used it to teach real robots to do tricky tasks, like putting bread in a basket or moving a steak with a spatula.
- With RynnValue, the robots succeeded 72.5% of the time when learning online (while moving).
- Without it, using the old best methods, they only succeeded 52.5% of the time.
- In offline learning (learning from a database of past moves), RynnValue boosted success from 63.8% to 82.5%.
Why This Matters
The most exciting thing about this paper is that it suggests we don't need to be perfect at grading robots to teach them. We just need to know when they finished. By using the simple, automatic "clock" of time, RynnValue creates a universal language for robot rewards. It works for a robot with two arms, a robot with a wheel, or a robot with a hand, as long as we can tell when the job is done.
The authors are careful to note that this isn't a magic wand that solves every robot problem instantly. They found that for very tricky tasks requiring precise alignment (like putting a box in a drawer), the model still struggled a bit because the visual clues were confusing. But overall, they showed that temporal distance is a powerful, scalable way to teach robots. It turns the messy, hard problem of "what is a good move?" into the simple, solvable problem of "how much time is left?"
In short, RynnValue is like giving a robot a stopwatch instead of a report card. It turns the chaotic world of robot learning into a simple countdown, and it seems to be working better than the old ways.
Drowning in papers in your field?
Get daily digests of the most novel papers matching your research keywords — with technical summaries, in your language.