Fixes termination term effort limit check logic (#3163)

# Description

Fix the logic in `joint_effort_out_of_limit()`; this function aims to
detect effort limit violations by comparing the desired (computed)
effort against the applied effort, noting that the simulator clips
applied torque to the limit assign on creation.

Originally, the logic was written such that if the applied and computed
torques are equal, then a violation has occurred. However, this is wrong
as shown by the below example:

```python
from isaaclab.managers import SceneEntityCfg
from isaaclab.envs.mdp.terminations import joint_effort_out_of_limit

env = ...  # any ManagerBasedRLEnv with an Articulation named "robot"
cfg = SceneEntityCfg(name="robot", joint_ids=[0])  # single joint for clarity
art = env.scene["robot"]

# Case A: no clipping (should be False but returns True now)
art.data.computed_torque[:] = 0.0
art.data.applied_torque[:] = 0.0
assert joint_effort_out_of_limit(env, cfg).item() is False  # CURRENT: True (bug)

# Case B: clipping (should be True but returns False now)
art.data.computed_torque[:] = 100.0
art.data.applied_torque[:] = 50.0  # pretend actuator clipped to ±50
assert joint_effort_out_of_limit(env, cfg).item() is True   # CURRENT: False (bug)

```

The solution is hence simply to flip the limit detection logic.

Fixes #3155


## Type of change

- Bug fix (non-breaking change which fixes an issue)

## Checklist

- [x] I have run the [`pre-commit` checks](https://pre-commit.com/) with
`./isaaclab.sh --format`
- [x] I have made corresponding changes to the documentation (N/A)
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] I have updated the changelog and the corresponding version in the
extension's `config/extension.toml` file (N/A)
- [x] I have added my name to the `CONTRIBUTORS.md` or my name already
exists there

CONTRIBUTORS.md

@@ -90,6 +90,7 @@ Guidelines for modifications:
 * Lukas Fröhlich
 * Manuel Schweiger
 * Masoud Moghani
+* Maurice Rahme
 * Michael Gussert
 * Michael Noseworthy
 * Miguel Alonso Jr

source/isaaclab/config/extension.toml

 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "0.45.1"
+version = "0.45.3"
 
 
 # Description

source/isaaclab/docs/CHANGELOG.rst

 Changelog
 ---------
 
+0.45.3 (2025-08-20)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed :meth:`isaaclab.envs.mdp.terminations.joint_effort_out_of_limit` so that it correctly reports whether a joint
+  effort limit has been violated. Previously, the implementation marked a violation when the applied and computed
+  torques were equal; in fact, equality should indicate no violation, and vice versa.
+
 0.45.2 (2025-08-18)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab/isaaclab/envs/mdp/terminations.py

@@ -134,12 +134,12 @@ def joint_effort_out_of_limit(
 
     In the actuators, the applied torque are the efforts applied on the joints. These are computed by clipping
     the computed torques to the joint limits. Hence, we check if the computed torques are equal to the applied
-    torques.
+    torques. If they are not, it means that clipping has occurred.
     """
     # extract the used quantities (to enable type-hinting)
     asset: Articulation = env.scene[asset_cfg.name]
     # check if any joint effort is out of limit
-    out_of_limits = torch.isclose(
+    out_of_limits = ~torch.isclose(
         asset.data.computed_torque[:, asset_cfg.joint_ids], asset.data.applied_torque[:, asset_cfg.joint_ids]
     )
     return torch.any(out_of_limits, dim=1)

source/isaaclab/test/assets/test_articulation.py

@@ -29,6 +29,8 @@ import isaaclab.utils.math as math_utils
 import isaaclab.utils.string as string_utils
 from isaaclab.actuators import ActuatorBase, IdealPDActuatorCfg, ImplicitActuatorCfg
 from isaaclab.assets import Articulation, ArticulationCfg
+from isaaclab.envs.mdp.terminations import joint_effort_out_of_limit
+from isaaclab.managers import SceneEntityCfg
 from isaaclab.sim import build_simulation_context
 from isaaclab.utils.assets import ISAAC_NUCLEUS_DIR
 
@@ -728,6 +730,39 @@ def test_joint_pos_limits(sim, num_articulations, device, add_ground_plane):
     assert torch.all(within_bounds)
 
 
+@pytest.mark.parametrize("num_articulations", [1, 2])
+@pytest.mark.parametrize("device", ["cuda:0", "cpu"])
+@pytest.mark.parametrize("add_ground_plane", [True])
+def test_joint_effort_limits(sim, num_articulations, device, add_ground_plane):
+    """Validate joint effort limits via joint_effort_out_of_limit()."""
+    # Create articulation
+    articulation_cfg = generate_articulation_cfg(articulation_type="panda")
+    articulation, _ = generate_articulation(articulation_cfg, num_articulations, device)
+
+    # Minimal env wrapper exposing scene["robot"]
+    class _Env:
+        def __init__(self, art):
+            self.scene = {"robot": art}
+
+    env = _Env(articulation)
+    robot_all = SceneEntityCfg(name="robot")
+
+    sim.reset()
+    assert articulation.is_initialized
+
+    # Case A: no clipping → should NOT terminate
+    articulation._data.computed_torque.zero_()
+    articulation._data.applied_torque.zero_()
+    out = joint_effort_out_of_limit(env, robot_all)  # [N]
+    assert torch.all(~out)
+
+    # Case B: simulate clipping → should terminate
+    articulation._data.computed_torque.fill_(100.0)  # pretend controller commanded 100
+    articulation._data.applied_torque.fill_(50.0)  # pretend actuator clipped to 50
+    out = joint_effort_out_of_limit(env, robot_all)  # [N]
+    assert torch.all(out)
+
+
 @pytest.mark.parametrize("num_articulations", [1, 2])
 @pytest.mark.parametrize("device", ["cuda:0", "cpu"])
 def test_external_force_buffer(sim, num_articulations, device):