---
active: true
derived: false
header: 'Apply Controller'
level: 1.2
normative: true
reviewed: null
links:
  - SWE-001
  - SWE-002
  - SWE-003
  - SWE-004
  - SWE-005
asil: D
---

# SWA-002: Apply Controller

## Verantwortung

Zentraler Controller fuer Apply, Hold und Release der Parkbremse.
ASIL-D-Kern der EPB-Software. Implementiert in `src/apply_controller.c`.

## Statische Sicht

```plantuml
@startuml
[Apply Controller] --> [Actuator Driver L] : apply/release
[Apply Controller] --> [Actuator Driver R] : apply/release
[Switch Debouncer] --> [Apply Controller] : sw_apply, sw_release
[Safety Manager] --> [Apply Controller] : auto_apply, hill_hold_request
[Apply Controller] --> [Display Manager] : status
[Apply Controller] <-- [Watchdog] : alive_check
@enduml
```

## Schnittstellen (Provided)

```c
Status apply_ctrl_init(void);
void   apply_ctrl_step_50ms(const ApplyInputs* in);
EpbStatus apply_ctrl_get_status(void);
```

## Dynamisches Verhalten

```plantuml
@startuml
[*] --> Released
Released --> Applying : apply_request & v_low
Applying --> Applied : current_target_reached
Applied --> Releasing : release_request & preconditions_ok
Applied --> Applied : 50ms hold check (re-clamp if needed)
Releasing --> Released : release_complete
Applying --> Error : timeout > 1500ms
Releasing --> Error : timeout > 1200ms
Error --> Released : reset & no fault
@enduml
```

## Ressourcen

- Stack: <= 384 B
- Worst-Case Timing: 350 us / Aufruf

## Designentscheidungen

| Entscheidung | Begruendung |
|--------------|-------------|
| Statische Allokation, kein Heap | Determinismus, MISRA C 21.3 |
| State Machine | Einfacher zu verifizieren, deterministisch |
| 50ms Step-Funktion | Synchron zur Inclinometer-Abtastung |

## Mapping auf Anforderungen

| Anforderung | Wie abgedeckt |
|-------------|---------------|
| SWE-001 | Hold-Zustand mit periodischer Klemmkraft-Pruefung |
| SWE-002 | Watchdog-Pet im step_50ms |
| SWE-003 | sw_apply Input wird sofort ausgewertet |
| SWE-004 | Current-Target-Detektion via Actuator-Driver-Feedback |