Problem changing the system modes when there are rules

まだ誰も着手していません。

Hi all

I am trying to use system modes for a system composed of these nodes: `{nav2, manipulator, camera, guard}`. `guard` is a special node that detects if the system has been compromised. In this case, all the nodes should be in mode `COMPROMISED` and `camera` in the inactive state. The specification is:

```
# system modes safety benchmark
---

safety:
ros__parameters:
type: system
parts:
manipulator
nav2
camera
guard
modes:
__DEFAULT__:
manipulator: active.__DEFAULT__
nav2: active.__DEFAULT__
camera: active.__DEFAULT__
guard: active.__DEFAULT__
COMPROMISED:
manipulator: active.COMPROMISED
nav2: active.COMPROMISED
camera: inactive.COMPROMISED
guard: active.COMPROMISED
rules:
guard_detect_compomise_in_default:
if_target: active.__DEFAULT__
if_part: [guard, active.COMPROMISED]
new_target: active.COMPROMISED
guard_detect_default_in_compromise:
if_target: active.COMPROMISED
if_part: [guard, active.__DEFAULT__]
new_target: active.__DEFAULT__

manipulator:
ros__parameters:
type: node
modes:
__DEFAULT__:
ros__parameters:
max_torque: 0.5
COMPROMISED:
ros__parameters:
max_torque: 0.1

nav2:
ros__parameters:
type: node
modes:
__DEFAULT__:
ros__parameters:
forbidden_areas: false
COMPROMISED:
ros__parameters:
forbidden_areas: true

guard:
ros__parameters:
type: node
modes:
__DEFAULT__:
ros__parameters:
compromised_system: false
COMPROMISED:
ros__parameters:
compromised_system: true

camera:
ros__parameters:
type: node
modes:
__DEFAULT__:
ros__parameters:
use_sim_time: false
COMPROMISED:
ros__parameters:
use_sim_time: false
```

If I change the mode of `guard`, all the system reacts as I want. **BUT** if I want to command all the system to go from `COMPROMISED` to `__DEFAULT__` I can't do it because `guard` is `COMPROMISED`, and that doesn't let the system reconfigure to `__DEFAULT__`.

Is there any way to combine the bottom-up rules with the possibility of changing the system mode (an up-bottom reconfiguration)?

Thanks!!

まず、issue に記載されている system-mode のルールとトップダウン再構成の動作を確認します。guard ルールが引き続き適用される状態で、コマンドによってシステムを COMPROMISED から __DEFAULT__ に移行できるかを判断します。対応している動作またはその制限が文書化され、適切なテストでカバーされていれば完了です。

索引モデルが issue の本文から書いたものです。