From 9fe69d4f3313451319d585164c28515db1c0bc8d Mon Sep 17 00:00:00 2001
From: Jaeyoung Lim <jaeyounglim@berkeley.edu>
Date: Fri, 9 Jan 2026 06:37:34 -0800
Subject: [PATCH] Make flap slew rate configurable (#26240)

* Make flap slew rate configurable

* Dynamically update params
---
 .../ActuatorEffectivenessControlSurfaces.cpp             | 5 ++++-
 .../ActuatorEffectivenessControlSurfaces.hpp             | 4 +++-
 src/modules/control_allocator/module.yaml                | 9 +++++++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.cpp b/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.cpp
index f6e216b855..093185e240 100644
--- a/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.cpp
+++ b/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.cpp
@@ -59,7 +59,7 @@ ActuatorEffectivenessControlSurfaces::ActuatorEffectivenessControlSurfaces(Modul
 		_param_handles[i].scale_spoiler = param_find(buffer);
 	}
 
-	_flaps_setpoint_with_slewrate.setSlewRate(kFlapSlewRate);
+	_flaps_setpoint_with_slewrate.setSlewRate(_param_ca_flap_slew.get());
 	_spoilers_setpoint_with_slewrate.setSlewRate(kSpoilersSlewRate);
 
 	_count_handle = param_find("CA_SV_CS_COUNT");
@@ -75,6 +75,9 @@ void ActuatorEffectivenessControlSurfaces::updateParams()
 		return;
 	}
 
+	// Update flap slewrates
+	_flaps_setpoint_with_slewrate.setSlewRate(_param_ca_flap_slew.get());
+
 	// Helper to check if a PWM center parameter is enabled, and clamp it to valid range
 	auto check_pwm_center = [](const char *prefix, int channel) -> bool {
 		char param_name[20];
diff --git a/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.hpp b/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.hpp
index 5e64e5a738..8a77a08080 100644
--- a/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.hpp
+++ b/src/modules/control_allocator/VehicleActuatorEffectiveness/ActuatorEffectivenessControlSurfaces.hpp
@@ -38,7 +38,6 @@
 #include <px4_platform_common/module_params.h>
 #include <lib/slew_rate/SlewRate.hpp>
 
-static constexpr float kFlapSlewRate = 0.5f; // slew rate for normalized flaps setpoint [1/s]
 static constexpr float kSpoilersSlewRate = 0.5f; // slew rate for normalized spoilers setpoint [1/s]
 
 class ActuatorEffectivenessControlSurfaces : public ModuleParams, public ActuatorEffectiveness
@@ -111,4 +110,7 @@ private:
 
 	SlewRate<float> _flaps_setpoint_with_slewrate;
 	SlewRate<float> _spoilers_setpoint_with_slewrate;
+	DEFINE_PARAMETERS(
+		(ParamFloat<px4::params::CA_SV_FLAP_SLEW>) _param_ca_flap_slew
+	)
 };
diff --git a/src/modules/control_allocator/module.yaml b/src/modules/control_allocator/module.yaml
index dd36a2d070..23405466a6 100644
--- a/src/modules/control_allocator/module.yaml
+++ b/src/modules/control_allocator/module.yaml
@@ -336,6 +336,15 @@ parameters:
             instance_start: 0
             default: 0
 
+        CA_SV_FLAP_SLEW:
+            description:
+                short: Control Surface slew rate for normalized flaps setpoint
+            type: float
+            decimal: 1
+            min: 0.0
+            max: 5.0
+            default: 0.5
+
         CA_SV_CS${i}_SPOIL:
             description:
                 short: Control Surface ${i} configuration as spoiler