---
license: apache-2.0
tags:
  - reinforcement-learning
  - robotics
  - quadruped
  - locomotion
  - isaac-lab
  - ppo
  - rsl-rl
library_name: rsl-rl
pipeline_tag: reinforcement-learning
---

# Go2+Z1 Walking Policy V2 (rotation-capable + heading-tracking)

PPO walking policy for **Unitree Go2 + Z1** composite robot, **upgraded over V1** to support large in-place rotations and heading commands — needed for autonomous navigation through warehouse aisles.

## What's new vs V1

| | V1 | V2 |
|---|---|---|
| Yaw command range `ω_z` | [-0.5, 0.5] rad/s | **[-2.0, 2.0] rad/s** (covers 180° pivot) |
| Heading command | none | 30 % of envs receive `heading` command (`heading_command=True`, `rel_heading_envs=0.3`) |
| `track_ang_vel_z_exp` reward weight | 0.75 | 1.2 |
| Iterations | 1500 | 3000 |
| Task ID | `Isaac-Velocity-Flat-Go2Z1-v0` | `Isaac-Velocity-Flat-Go2Z1-V2-v0` |

V1 oscillated whenever the commanded yaw error exceeded ~90°. V2 fixes that by giving the policy direct experience with large angular commands during training.

## Files

- `model_*.pt` — actor-critic checkpoint (rsl-rl `OnPolicyRunner` format)

## Usage

Identical to V1 (same architecture). See V1 README for code:
<https://huggingface.co/m3/go2z1-walking-rsl-rl-v1>

For end-to-end inference inside Isaac Sim, the goal-directed nav script that drives this policy is:

```python
# Pseudocode — see go2_z1_warehouse/stage4_joint_eval/walk_warehouse_navigate.py
yaw_err = (target_yaw - cur_yaw + π) % 2π - π
v_fwd   = clip(0.8 * cos(yaw_err), 0.2, 0.8)
w_z     = clip(1.5 * yaw_err, -2.0, 2.0)   # V2 supports the full range
cmd_term.vel_command_b[:] = (v_fwd, 0, w_z)
action = actor(obs)
```

## Training data

On-policy RL — no offline dataset. The full task definition lives in:

- Repo: <https://github.com/aws300/go2_z1_warehouse>
- V2 task config: `go2_z1_warehouse/stage1_walking/flat_v2_env_cfg.py`
- Auto-pipeline launcher: `go2_z1_warehouse/v2_pipeline/auto_chain.sh`

## Predecessor

- V1 (no rotation): [m3/go2z1-walking-rsl-rl-v1](https://huggingface.co/m3/go2z1-walking-rsl-rl-v1)

## Citation

```bibtex
@misc{go2z1-walking-v2,
  title  = {Go2+Z1 Walking Policy V2 (rotation-capable + heading-tracking)},
  author = {m3},
  year   = {2026},
  url    = {https://huggingface.co/m3/go2z1-walking-rsl-rl-v2}
}
```