Make-An-Agent: A Generalizable Policy Network Generator with Behavior-Prompted Diffusion

Can we generate a control policy for an agent using just one demonstration of desired behaviors as a prompt, as effortlessly as creating an image from a textual description? In this paper, we present Make-An-Agent, a novel policy parameter generator that leverages the power of conditional diffusion models for behavior-to-policy generation. Guided by behavior embeddings that encode trajectory information, our policy generator synthesizes latent parameter representations, which can then be decoded into policy networks. Trained on policy network checkpoints and their corresponding trajectories, our generation model demonstrates remarkable versatility and scalability on multiple tasks and has a strong generalization ability on unseen tasks to output well-performed policies with only few-shot demonstrations as inputs. We showcase its efficacy and efficiency on various domains and tasks, including varying objectives, behaviors, and even across different robot manipulators. Beyond simulation, we directly deploy policies generated by Make-An-Agent onto real-world robots on locomotion tasks. Project page: https://cheryyunl.github.io/make-an-agent/

Paper

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Peer review

Reviewer YLrf4/10 · confidence 4/52024-07-07

Summary

Make-An-Agent is a novel policy network generator that uses conditional diffusion models to create control policies based on a single demonstration of desired behaviors. By encoding behavior trajectories into embeddings, Make-An-Agent generates latent policy parameter representations that are decoded into functional policy networks. This method, trained on a dataset of policy parameters and their corresponding trajectories, excels in generating versatile and scalable policies across various tasks, including unseen ones, using few-shot demonstrations. Its robustness and efficiency are demonstrated in both simulation and real-world environments, highlighting its ability to produce high-performing policies even from noisy inputs. This approach bypasses traditional behavior modeling, instead leveraging the inherent correlations in agent behaviors to optimize policy generation without the need for further fine-tuning.

Strengths

1. The paper introduces a novel method that uses conditional diffusion models for policy generation, a significant shift from traditional policy learning methods. 2. Make-An-Agent demonstrates the ability to generate effective policies for a wide range of tasks by conditioning on behavior embeddings, showcasing scalability across different domains. 3. The diffusion-based generator exhibits strong generalization capabilities, producing proficient policies even for unseen behaviors and unfamiliar tasks. 4. The method can generate diverse and resilient policy parameters, maintaining high performance under environmental variability and with noisy input data. 5. The effectiveness of Make-An-Agent is validated not only in simulations but also in real-world robotics, highlighting its practical applicability and efficiency.

Weaknesses

While the paper demonstrates the method's effectiveness in various tasks, a more extensive evaluation across a broader range of environments and conditions could provide a more comprehensive assessment of its robustness and versatility. The performance of the generated policies heavily relies on the quality of the input demonstrations, which might not always be optimal or available in all scenarios. The model might overfit to the specific types of tasks and behaviors seen during training, potentially reducing its effectiveness in truly novel and diverse environments.

Questions

How does Make-An-Agent perform when faced with tasks that are vastly different from those it was trained on? Are there any specific limitations in task diversity that the model struggles with? What are the computational requirements for training and deploying Make-An-Agent? How does its efficiency compare to traditional reinforcement learning and other policy generation methods? How sensitive is the method to the quality of the behavior demonstrations? What happens if the demonstrations contain suboptimal or noisy behaviors? Can the approach be scaled to more complex tasks and larger environments? What modifications, if any, would be needed to handle such scalability? What are the contributions of the individual components of the method, such as the autoencoder, contrastive learning for behavior embedding, and the diffusion model? Are there ablation studies that show the impact of each component on the overall performance? What challenges were encountered during the deployment of the generated policies onto real-world robots? How were these challenges addressed? The paper mentions robustness to noisy trajectories, but to what extent can the model handle extreme levels of noise or inaccuracies in the demonstrations?

Rating

4

Confidence

4

Soundness

3

Presentation

2

Contribution

2

Limitations

The training process for the autoencoder and diffusion model is likely to be resource-intensive, potentially limiting accessibility for researchers with limited computational resources. The effectiveness of the generated policies is heavily reliant on the quality of the input demonstrations. Poor or suboptimal demonstrations could adversely affect the performance of the generated policies. The evaluation might be limited to specific tasks and environments. A broader range of experiments would be needed to fully assess the model's robustness and versatility across various domains and conditions. While the method shows promise in the tested domains, its scalability to more complex tasks and larger environments is not fully explored. Handling such scalability might require further modifications and optimizations. There is a risk that the model might overfit to the types of tasks and behaviors seen during training, which could reduce its effectiveness in truly novel and diverse environments. While the method has shown success in real-world robotics, the transition from simulation to real-world applications can introduce unforeseen challenges and complexities that need to be addressed comprehensively. The paper may lack thorough ablation studies to understand the contributions of individual components of the method, such as the autoencoder, behavior embeddings, and diffusion model. Although the method claims robustness to noisy trajectories, the extent to which it can handle extreme levels of noise or inaccuracies in the input demonstrations is not fully detailed. The sensitivity of the model to various hyperparameters and the process of tuning these parameters for optimal performance is not extensively covered, which can be crucial for practical implementations.

Area Chair kGqK2024-08-13

Required Action: Please Respond to the Author Rebuttal

Dear Reviewer YLrf, As the Area Chair for NeurIPS 2024, I am writing to kindly request your attention to the authors' rebuttal for the paper you reviewed. The authors have provided additional information and clarifications in response to the concerns raised in your initial review. Your insights and expertise are invaluable to our decision-making process, and we would greatly appreciate your assessment of whether the authors' rebuttal adequately addresses your questions or concerns. Please review the rebuttal and provide feedback. Your continued engagement ensures a fair and thorough review process. Thank you for your time and dedication to NeurIPS 2024. Best regards, Area Chair, NeurIPS 2024

Authorsrebuttal2024-08-13

Eagerly awaiting your valuable feedback Reviewer YLrf (for the final 12 hours)

Dear Reviewer YLrf, As the discussion period draws to a close in 12 hours, we are delighted to have received positive feedback from the other four reviewers and are very eager to ensure that our response has adequately addressed your concerns as well. We believe that the clarification in our paper would solve your concerns on input demonstrations/overfitting/computational cost/ablation/robustness, along with the additional results and discussions in rebuttal could solve your questions regarding experiments/scalability/real-world deployment. We deeply appreciate your contribution to the community through your review. Your insights are valuable to us. We eagerly await your response. Warm Regards, Paper 8467 Authors

Reviewer 8Q7F5/10 · confidence 4/52024-07-11

Summary

This paper proposes a novel approach to generate policy parameters based on the behavior through diffusion models. The paper leverages the autoencoder to map the parameters of the policy to latent representations. The model demonstrates remarkable generalization abilities on unseen tasks with few-shot demonstrations.

Strengths

* The method is novel. The paper learns behavior embeddings from agent behaviors to capture environmental dynamics and information about tasks. And it leverages such behavior embeddings as conditions for the parameter generation. * The empirical results are rich and strong. The paper evaluates the model across three environments (two simulations and one real world) and shows strong generalization performance on unseen tasks and for unseen robots. * This paper also presents well including figures and written structures.

Weaknesses

* The generated policies seem unstable. The generation by diffusion models are diverse but not stable. And the paper doesn't make sure the generated policies are good enough. And the experiments compare the best or top 5 generated policies. How to evaluate which policy is best? Does it require testing all policies and finding which one is best? In C.2, the paper shows the qualification rate of generated policies. The qualification rates are very weak (mostly less than 0.1) on unseen tasks except "drawer close". It's not practical. What if using expert demonstrations? * Some settings of experiments seem unreasonable. Why fix the initial locations during the training stage and finetuning/adaptation? This might make the baselines or generated policies only work on fixed initial locations. Similarly, why choose highly sub-optimal trajectories? If so, it may use offline RL approaches to finetune the baselines. * Lack of details of baselines. How to finetune the multi-task RL with fixed trajectories (10/50/100)?

Questions

* See weakness. * What are the states or what would happen after the first success time? Does the env stop if the task is succeeded?

Rating

5

Confidence

4

Soundness

3

Presentation

3

Contribution

2

Limitations

* The paper has provided several limitations. The paper only generates parameters for simple linear layers. And the learned behavior embeddings are also important.

Authorsrebuttal2024-08-10

Dear Reviewer 8Q7F, Thank you for your time and effort in reviewing our work and providing insightful feedback. > Collecting data from fix locations and highly sub-optimal would hugely hurt the baselines' performance. In our rebuttal results, we have demonstrated that our method not only excels in suboptimal data but also significantly outperforms all baselines when using expert demonstrations with random initialization. It's important to note that our method is not an imitation learning approach. Offline replay datasets are widely used in the evaluation of offline RL and meta RL, which is why we selected this evaluation metric. We fully agree with your suggestion and will include experiments using expert demonstrations in the appendix to fairly compare our method with meta IL baselines. > It's expensive and unsafe to evaluate the policy (like real-world) while it's simpler to collect expert demonstrations with teleoperation systems. In real-robot experiments as mentioned in our paper, we utilize the IsaacGym simulator to collect policies and trajectories and also evaluate generated policies before deploying them on the real robot, which ensures that we conduct evaluations at a relatively low cost. There is no contradiction between using simulation for initial evaluation and using expert demonstrations for generation. If optimal real-world data is available, using it to generate policies would certainly be preferable. Our experiments aim to demonstrate that policies generated and evaluated in simulation can still yield excellent results in real-world scenarios. > About real-world experiments, the paper seems only to provide some visualizations. What about the success rate and other baselines. Thank you for your suggestions. Real-world visualization is the most straightforward way to observe the performance of policies, especially since designing success rate metrics for real-robot locomotion tasks is challenging as shown in prior works. Additionally, none of the baselines we listed include real-world experiments, and the network sizes used in those baselines are not applicable to real-robot scenarios. We evaluate our generated policies against offline RL methods in low-speed testing and high-speed testing following [1]. The results demonstrate that the policies generated by our method exhibit better stability and performance on real robots. | Low-Speed Testing | IQL | BC | Ours | |---|---|---|---| |Reward | 11.9 | 14.4 | 24.8 | | High-Speed Testing | IQL | BC | Ours | |---|---|---|---| |Reward | 10.4 | 10.7 | 20.9 | [1] Margolis, Gabriel B., and Pulkit Agrawal. "Walk these ways: Tuning robot control for generalization with multiplicity of behavior." Conference on Robot Learning. PMLR, 2023. We hope our responses address your concerns, and we are open to further discussion. Thank you once again for your valuable feedback. Warm Regards, Paper 8467 Authors

Reviewer 8Q7F2024-08-13

Thanks for the detailed response. I maintain my positive rating.

Authorsrebuttal2024-08-13

Thank Reviewer 8Q7F for your inspiring reply!

Dear Reviewer 8Q7F, Thank you for your reply and understanding. We will update our paper accordingly based on your and other reviewers' comments. We sincerely appreciate your positive comments and the discussions during rebuttal, which are of great help of improving our paper and also contribute to the community. Best wishes! Paper 8467 Authors

Reviewer Pxd27/10 · confidence 4/52024-07-13

Summary

This paper proposes the Make-An-Agent architecture, which synthesizes a policy neural network from an input trajectory. Make-An-Agent utilizes a parameter and behavior embedding. The behavior embedding is trained with the mutual information between the trajectory and the successful part of the trajectory. The behavior embedding is then used in a diffusion model to generate the policy parameters. This methodology is validated in MetaWorld, Robosuite, and quadrupedal locomotion environments. In MetaWorld and RoboSuite, Make-An-Agent outperforms baselines RL and IL baselines. Further experiments analyze how the trajectories and policies produced by Make-An-Agent differ from those directly trained through RL.

Strengths

1. The paper represents a novel take on learning multi-task policies by directly generating the parameters of a policy network from a demonstration. This is different from prior Meta-RL approaches that adapt existing networks. 1. The paper has extensive empirical comparisons to a variety of baselines from RL and IL. The proposed method outperforms baselines in MetaWorld and Robosuite by a large margin. 1. Make-An-Agent is capable of generating policies that are more diverse (Figure 8) and more robust (Figure 6) than baselines. 1. The behavior embedding is an important aspect of the Make-An-Agent architecture as demonstrated by Figure 7. 1. The paper analyzes the impact of important settings on the system's performance with the demonstration length, policy size and number of policy parameter sets used for training. 1. Implementation details are thoroughly described throughout the paper and in supplementary sections B and C.

Weaknesses

1. Table 1 only reports the best and top 5 generated policies. However, all policies had to be evaluated in the environment to decide what these top policies are. This is an unrealistic assumption that weakens the significance of the result. The paper must analyze in more detail the distribution of performance between generated policies and compare the full statistics of all generated policies to baselines for a fair comparison. 1. A weakness of directly generating policy parameters is the challenge of scaling up to larger policy networks. For example, policies operating from egocentric visual inputs in 3D spaces typically have tens of millions of parameters. The core idea of directly generating policy parameters is likely incapable of scaling to this setting of 1000x more policy parameters.

Questions

1. What fraction of generated policies outperform the baselines in Table 1? And what is the average policy performance between all generated policies, not just the top 5? See my point (1) under weaknesses above. 1. Given that the results in Figure 11b already show performance suffering with increased policy size, how can Make-An-Actor scale to more complex tasks that require higher parameter count policies?

Rating

7

Confidence

4

Soundness

4

Presentation

4

Contribution

4

Limitations

Yes, limitations are discussed in Section 6.

Reviewer Pxd22024-08-11

Thank you for the response. While I still appreciate the novelty of the approach, like other reviewers, I am also concerned about the evaluation criteria for selecting the best policies. The GPU hours comparison in the rebuttal is not a representative comparison because for Make-An-Agent, this also includes evaluation costs, which could be prohibitively expensive depending on the environment, as in the real world or a slower simulator. Figure 13 in the rebuttal is also unclear. Which environment are these results for? Why compare episode length in the tasks? A clearer comparison would be to generate a histogram of success rates, not trajectory lengths, for the Make-An-Agent generated policies across all condition trajectories.

Authorsrebuttal2024-08-11

Thank Reviewer Pxd2 for your supportive feedback!

Dear Reviewer Pxd2, Thank you for your prompt reply and constructive suggestions. * In our GPU hours comparison, we have included the evaluation and inference costs. For very slower simulators, we strongly agree that filtering policies by selecting condition trajectories that are close to optimal may reduce evaluation time costs. Even if more interaction time is required, the evaluation cost in most environments is still significantly lower than the cost of fine-tuning. * In our real-robot experiments, as discussed in our paper, we utilize the IsaacGym simulator to collect policies and trajectories and also evaluate the generated policies before deploying them on the real robot, which ensures that we conduct evaluations at a relatively low cost. Our experiments aim to demonstrate that policies generated and evaluated in simulation can still achieve excellent results in real-world scenarios. * Figure 13 presents results from the door unlock (seen) and coffee button (unseen) environments, both of which exhibit medium performance across all seen/unseen tasks. * We chose to use trajectory length as it more accurately reflects the performance of the condition trajectories compared to the success condition. For example, two trajectories might both achieve success, but their lengths could differ, with shorter trajectories indicating closer to optimal and more efficient performance. Using trajectory length to evaluate policies also makes it easier to compare with condition trajectories. * We fully acknowledge your suggestion, and we provide a table showing the generated policies' success rates across all condition trajectories for all seen/unseen tasks. We can see that on seen tasks, our method can generate more than 55% of policies that perform better than the best baselines. On unseen tasks, on average at least 35% of the policies perform better than the best baselines. This fully demonstrates the superiority of our method. * Additionally, if we select trajectories with success signals for policy generation, in seen tasks, more than 82% of the policies outperform the baselines, and in unseen tasks, more than 50% do so. For environments where evaluation is challenging, using success trajectories can also more efficiently yield optimal policies. We will include these results as histograms in the final version of our paper. | Average success rate (seen) | Generated policies across all trajectories | | ------ | ----- | | 0% | 21.2% | | 0-60% | 5.2% | | 60-80% | 17.7% | | 80-100% | 26.5% | | 100% | 29.4% | | Average success rate (unseen) | Generated policies across all trajectories | | ------ | ----- | | 0% | 27.8% | | 0-60% | 12.0% | | 60-80% | 28.2% | | 80-100% | 19.6% | | 100% | 12.4% | | Average success rate (seen) | Generated policies across success trajectories | | ------ | ----- | | 0% | 3.2% | | 0-60% | 6.9% | | 60-80% | 11.2% | | 80-100% | 8.4% | | 100% | 70.3% | | Average success rate (unseen) | Generated policies across success trajectories | | ------ | ----- | | 0% | 10.7% | | 0-60% | 17.8% | | 60-80% | 21.4% | | 80-100% | 18.9% | | 100% | 31.2% | **In summary**, we agree that the evaluation cost could become a weakness of our method when generating multiple policies. However, it is undeniable that the broader exploration of parameter spaces offers more effective solutions for policy generalization compared to prior works. We also believe that using these multiple policies for a mixture of experts could be a promising direction. Thank you for acknowledging the novelty of our work and for providing such insightful feedback. We welcome any further discussions and greatly value the opportunity to continue improving our research. Best Regards, Paper 8467 Authors

Reviewer 957J6/10 · confidence 4/52024-07-13

Summary

In this work, the authors present Make-An-Agent, which is a method to generate policy parameters given a few intended trajectories from a task. The proposed method is straightforward, which makes it better that it seems to work in the experiments in the work. The method first generates a large dataset of policies as well as their rollout traces, all parametrized in the same way, using standard RL algorithms. Then, the authors learn an autoencoder on top of the policy parameters. Finally, the method learns a trajectory conditional generator using diffusion for creating policy latents. Putting them together, on a new environments the authors generate some trajectories (here, by running SAC for 0.5M steps), and then generate a new policy using the trajectory latent which gets translated to a policy latent by the diffusion model. The experiments are done on a real robot locomotion task as well as two manipulation task suites in simulation. In all of these cases, the best generated policies perform well in the experiments compared with meta-learning approaches.

Strengths

+ The approach is novel, and the algorithm and the released code are both quite simple. + The experiments have a wide breadth, and showing the applicability in multiple different domains show the potential of this method. + While the dataset is large (1000+ policies per task) it is not excessively large to be prohibitive.

Weaknesses

- The reported metric (best generated policy performance, avg top 5 generated policy performance) both seem _fudged_. It seems like the authors are generating a large number of policies, and then picking the best generated policy out of them to get their numbers. This seems dishonest, as for a large number N of generated policies, every method will get a very high score. - While the authors report the "qualification rate" i.e the % of policies getting 100% success rate in test, I am not sure how this works. As they report the "best policy score", and since qualification rate is > 0 for all tasks, why is figure 5 (ours) not all 100%? What am I missing? - The drop between top-1 and top-5 is concerning, since I cannot tell whether the authors got lucky finding a perfect policy from the long tail. - The authors don't mention the overall compute overhead and how it compares with the baselines, which I believe is a strong consideration for such a method.

Questions

- Please detail the compute budget for each of the baselines as well as your method. - If possible, please release the dataset as well as the pretrained networks with your code.

Rating

6

Confidence

4

Soundness

3

Presentation

4

Contribution

3

Limitations

- Generating larger networks will be more difficult, so I wish the authors took advantage of any special properties of network weights while training. - The comparison metric is fuzzy and can seem unfair.

Area Chair kGqK2024-08-13

Required Action: Please Respond to the Author Rebuttal

Dear Reviewer 957J, As the Area Chair for NeurIPS 2024, I am writing to kindly request your attention to the authors' rebuttal for the paper you reviewed. The authors have provided additional information and clarifications in response to the concerns raised in your initial review. Your insights and expertise are invaluable to our decision-making process, and we would greatly appreciate your assessment of whether the authors' rebuttal adequately addresses your questions or concerns. Please review the rebuttal and provide feedback. Your continued engagement ensures a fair and thorough review process. Thank you for your time and dedication to NeurIPS 2024. Best regards, Area Chair, NeurIPS 2024

Authorsrebuttal2024-08-13

Thank Reviewer 957J for your replay and suggestions!

Dear Reviewer 957J, Thank you for your constructive suggestions and understanding. We would like to provide further clarification on the concerns you raised: > In the real world, the majority of time and energy is spent on evaluating the robot in a real environment, which is a lot more expensive than simple GPU hours. We completely agree with this point. To ensure a relatively low cost on evaluations, in our real-robot experiments, we utilize the IsaacGym simulator to collect policies and trajectories and evaluate the generated policies before deploying them on the real robot. Our experiments aim to demonstrate that policies generated and evaluated in simulation can still achieve excellent results in real-world scenarios. For tasks where it is not feasible to evaluate in simulations, we try to discuss alternative methods inspired by other reviewers for utilizing multiple policies in decision-making, such as majority voting and using the mixture of experts, to improve the robustness and stability of real-robot decisions. We believe these are very promising directions and hope our work will inspire the community to explore more. > Release of full code and pretrained model library As we have promised, we will release all datasets, pretrained models, and training code in our final version. We greatly appreciate your support. > Disambiguating between GPU hours needed for training (done offline) and rollouts/evaluation needed for model selection (done online). Based on your suggestion, we will provide a detailed report on the computational costs associated with each part of our method. Additionally, we will include a separate discussion of the evaluation costs and alternative approaches in the limitations section. Thank you again for your positive comments and valuable suggestions regarding real-world evaluation, which have greatly helped us further discuss the weaknesses and improve the quality of our paper. We appreciate the time and effort you’ve put into reviewing and the rebuttal process. We will supplement our paper based on all of these discussions. Best wishes, Paper 8467 Authors

Reviewer U6yw6/10 · confidence 3/52024-07-15

Summary

This paper presents Make-An-Agent, a conditional diffusion model that generates policy parameters based on demonstration of target behaviors. The authors propose an autoencoder to encode policy network parameters into compact latent representations. The behavior embeddings are learned using contrastive learning between long-term trajectories and their success or future states. Then, a conditional diffusion model is used to generate policy latent code conditioned on the learned behavior embedding, which can then be decoded to policy parameters via the pretrained decoder. Extensive results in simulated environment including MetaWorld and Robosuite demonstrate the effectiveness of the proposed method. Also, there is real-world deployment on quadrupedal locomotion.

Strengths

- The paper is well-written and easy to follow - The experimental analysis is pretty thorough.

Weaknesses

- Despite the experiments are overall complete, there are many more interesting aspects to look at, which may further strengthen the paper. Please check questions for more details. - The real-world experiment has very limited results presented.

Questions

- Is there any way to roughly predict the performance of the generateed parameters without actually evaluating them? For example, assuming the learned data distribution nicely reflects the given behavior, the generation distribution in the policy parameter space should somewhat follow the mode that gives good performance; perhaps something similar to the "Parameter distinction" experiments but among the generation from the proposed model only can be interesting. - Is any of the statistics of the generated policy parameters useful? For example, does the mean still a valid policy parameter? Is the variance of the generated parameters correlated with how "out-of-distribution" the behavior is? - It would be interesting to briefly look at the geometry in the behavior embedding space. For example, how does small perturbation in the behavior embedding affect the performance of the generated policy parameters. Or even more interesting, is it possible to compose behaviors by messing around the conditioning of the diffusion model, which then gives a compositional policy? - Could the authors report the performance distribution for all generations (as opposed to the best or top 5)? This can probably provide some insight into the generation behavior and what distribution (w.r.t. the data distribution in generative modeling not performance distribution) is actually learned by the model. Also, it would be interesting to see the performance distribution in seen and unseen tasks. - For ablation of policy network, could the authors discuss how architectural difference (beyond hidden size; e.g., constructing policy as very small recurrent network or transformer) can potentially affect the results? - In real-world evaluation, could the authors provide more details about the behaviors and policies in trainnig dataset and testing? - Given the proposed method being a generator of the policy (which can easily produce many models at a time), it would be also interesting to check the mixture of expert setup. For example, will using something simple like majority voting in generated policies improves robustness in "Adaptability to environmental randomness on seen tasks"? - Could the authors report some failure cases? Or is there any failure mode like certain type behaviors/demonstrations always lead to bad-performing generated policies?

Rating

6

Confidence

3

Soundness

3

Presentation

3

Contribution

3

Limitations

Limitations are discussed in the paper.

Area Chair kGqK2024-08-13

Required Action: Please Respond to the Author Rebuttal

Dear Reviewer U6yw, As the Area Chair for NeurIPS 2024, I am writing to kindly request your attention to the authors' rebuttal for the paper you reviewed. The authors have provided additional information and clarifications in response to the concerns raised in your initial review. Your insights and expertise are invaluable to our decision-making process, and we would greatly appreciate your assessment of whether the authors' rebuttal adequately addresses your questions or concerns. Please review the rebuttal and provide feedback. Your continued engagement ensures a fair and thorough review process. Thank you for your time and dedication to NeurIPS 2024. Best regards, Area Chair, NeurIPS 2024

Reviewer U6yw2024-08-13

Thanks for the rebuttal

Thanks for the rebuttals. The mixture-of-experts result is really nice. It would be nice to include this result with the computational overhead of doing so (which I assume is pretty marginal) in the final version. For Fig.13 (re "the statistics of the generated policy parameters"), I was previously referring to experimenting in the parameter space but this result also looks nice. Lastly, for architecture, I don't think the use of other architectures like RNN or transformer (on non-reactive or partially-observable tasks) is trivially extendable; but I am not 100% positive. Overall, the new results look nice. I will keep my rating.

Authorsrebuttal2024-08-13

Thank you for your inspiring reply!

Dear Reviewer U6yw, Thank you for your thoughtful feedback and understanding! We further discuss the points you raised. > mixture-of-experts computational overhead When using the mixture-of-experts approach for decision making, while it involves using multiple policies to output actions, the inference cost for these policies is very low. As a result, the computational cost is less than 1/10 of the baseline fine-tuning cost. We will include detailed statistics on this in the final version of our paper. > the statistics of the generated policy parameters in parameter space Given the high dimensionality of the parameter space, we primarily compare the trajectories obtained from deployed policies. Directly averaging the generated parameters does not yield ideal results, mainly because the parameter distribution in the latent parameter space and the parameter space are not smooth. > the use of other architectures like RNN or transformer If we use RNN as the policy backbone, and the parameter count of the RNN is not larger by an order of magnitude, it is feasible to use our model to generate RNNs. Our method directly flattens the network parameters into a vector before encoding and generating, without imposing special requirements on the network structure during the generation process. We sincerely appreciate your positive comments and insightful discussions. The constructive suggestions for practical applications are crucial for improving the quality of our paper, and we will ensure that all discussions and new results are included in the final version. Best wishes! Paper 8467 Authors

Reviewer 8Q7F2024-08-10

Thanks for the response. * collecting data from **fix locations** and **highly sub-optimal** would hugely hurt the baselines' performance. I understand the work has achieved better results with such settings. I'm curious about which factor results in the weak performance of baselines. * In some settings, it's expensive and unsafe to evaluate the policy (like real-world) while it's simpler to collect expert demonstrations with teleoperation systems. * About real-world experiments, the paper seems only to provide some visualizations. What about the success rate and other baselines.

Reviewer 957J2024-08-13

Thank you for the response and the discussion. After reading this rebuttal, the only point of contention that remains for me is how efficiency is reported. In the real world (which is where I study robotics) the majority of time and energy is spent on evaluating the robot in a real environment, which is a lot more expensive than simple GPU hours. Since the number of runs required is not disambiguated from GPU hours needed to train/generate/fine-tune, I am keeping my current score. I still recommend acceptance of the paper, which would be a strong accept with: 1. Release of full code and pretrained model library, and 2. Disambiguating between GPU hours needed for training (done offline) and rollouts/evaluation needed for model selection (done online.)

Program Chairsdecision2024-09-25

Decision

Accept (poster)

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