Papers › Constrained Variational Policy Optimization for Safe Reinforcement Learning

Constrained Variational Policy Optimization for Safe Reinforcement Learning

28 Jan 2022arXiv:2201.11927archive 2025-07-28

Zuxin Liu, Zhepeng Cen, Vladislav Isenbaev, Wei Liu, Zhiwei Steven Wu, Bo Li, Ding Zhao

Safe reinforcement learning (RL) aims to learn policies that satisfy certain constraints before deploying them to safety-critical applications. Previous primal-dual style approaches suffer from instability issues and lack optimality guarantees. This paper overcomes the issues from the perspective of probabilistic inference. We introduce a novel Expectation-Maximization approach to naturally incorporate constraints during the policy learning: 1) a provable optimal non-parametric variational distribution could be computed in closed form after a convex optimization (E-step); 2) the policy parameter is improved within the trust region based on the optimal variational distribution (M-step). The proposed algorithm decomposes the safe RL problem into a convex optimization phase and a supervised learning phase, which yields a more stable training performance. A wide range of experiments on continuous robotic tasks shows that the proposed method achieves significantly better constraint satisfaction performance and better sample efficiency than baselines. The code is available at https://github.com/liuzuxin/cvpo-safe-rl.

PaperPDFCodeCode Syntology ran

In Syntology Open this paper in Syntology's Atlas, the map of the papers in Syntology's graph and their citations.

For agents, Syntology's MCP tool lists every function and class Syntology harvested from this paper and whether it ran (how to connect): get_harvested_code_for_paper(arxiv_id="2201.11927")

Code

Syntology Ran 5 of 11 code samples harvested from 2 repositories linked to this paper; 6 have no recorded run. Of those that ran: 3 ran · our draft was wrong; 2 ran with no contract checked.

By repository: official repository: 6 samples from 1 repository, 3 ran; community (archive-listed): 5 samples from 1 repository, 2 ran. The run record, sample by sample. “Ran” means executed on a synthesized input, not that the code is correct or reproduces the paper.

liuzuxin/cvpo-safe-rl officialmentioned in papermentioned on GitHubpytorch report
zifanwu/cal mentioned on GitHubpytorchMIT report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

11 samples harvested; 5 ran; 0 honoured the contract we drafted; 6 have no recorded run. Read from Syntology's graph 2026-09-24; that is when this build read the record, not when the samples ran.

3ran · our draft was wrong
2ran
6unverified

Licence: 6 of the 11 samples are pointer only, meaning Syntology does not serve that copy's text. This page shows no code text for any sample; each one links to its file in the repository.

Harvested from 2 repositories linked to this paper, official or community; each sample names its own and says which. “Ran” means the sample executed on a synthesized input. It does not mean the output is correct, and nothing here reproduces the paper's results. “Honoured” and “violated” refer to a contract Syntology drafted from the code itself; “our draft was wrong” and “fixture could not drive it” are failures of Syntology's instrument, not of the code.

Each sample ends with its code_sha256, Syntology's identity for that exact code. An agent fetches the stored sample with Syntology's MCP tool get_code(code_sha256="…") (how to connect); click an identity to copy that call.

Repository labels, per sample. official repository: The archive marks this repository official for the paper. named in the paper: The archive records that the paper mentions this repository; it is not marked official. community (archive-listed): In the archive's code links for this paper, not marked official and not recorded as mentioned in the paper. found in paper text by Syntology: Syntology found this repository in the paper's own text; whether it is the authors' implementation is not asserted. community: Not in the archive's code links for this paper; a community repository Syntology harvested. Samples from a repository marked official are listed first. Licence labels name the repository's licence as recorded at harvest. “Pointer only” means Syntology does not serve that copy's text, for one of four reasons: no licence file was found; the licence was not identified; the licence is recorded as permissive but that copy's record is not marked cleared; or the licence is outside the permissive list Syntology serves text under (MIT, Apache-2.0, BSD and similar). Some licences outside that list permit redistribution, such as WTFPL, and GPL-3.0 under its conditions; they are simply not on the list. Hover a licence label for the reason. File links open the file on GitHub at the default branch, which may have changed since the harvest.

bt liuzuxin/cvpo-safe-rl/safe_rl/policy/cvpo.py official repository ran · our draft was wrong fingerprinted GPL-3.0 (copyleft) · pointer only · 7a753817cb0801b7 · report
btr liuzuxin/cvpo-safe-rl/safe_rl/policy/cvpo.py official repository ran · our draft was wrong fingerprinted GPL-3.0 (copyleft) · pointer only · 548253ae95d04e97 · report
safe_inverse liuzuxin/cvpo-safe-rl/safe_rl/policy/cvpo.py official repository ran · our draft was wrong fingerprinted GPL-3.0 (copyleft) · pointer only · dff135af934deab2 · report
gen_data_dir_name liuzuxin/cvpo-safe-rl/script/experiment.py official repository unverified GPL-3.0 (copyleft) · pointer only · 0160612bd4e4291b · report
gen_exp_name liuzuxin/cvpo-safe-rl/script/experiment.py official repository unverified GPL-3.0 (copyleft) · pointer only · ab8d61d136e13ca0 · report
trial_name_creator liuzuxin/cvpo-safe-rl/script/experiment.py official repository unverified GPL-3.0 (copyleft) · pointer only · d134ec4327fe1db7 · report
GaussianPolicy zifanwu/cal/agent/cal.py community (archive-listed) ran · metamorphic tier: deterministic fingerprinted MIT (permissive) · a2295f0701fc2bfc · report
QcEnsemble zifanwu/cal/agent/cal.py community (archive-listed) ran · metamorphic tier: deterministic MIT (permissive) · 3af5f12862afaf0b · report
Agent zifanwu/cal/agent/cal.py community (archive-listed) unverified MIT (permissive) · e5ff05aed073a821 · report
CALAgent zifanwu/cal/agent/cal.py community (archive-listed) unverified MIT (permissive) · af538492c9636821 · report
init_weights zifanwu/cal/agent/cal.py community (archive-listed) unverified MIT (permissive) · c596497eefe6dd51 · report

Tasks

Reinforcement LearningReinforcement Learning (RL)Safe Reinforcement Learningreinforcement-learning

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections