The LiftDrag system computes lift and drag forces enabling simulation of aerodynamic robots. More...

#include <AdvancedLiftDrag.hh>

Public Member Functions
	AdvancedLiftDrag ()
	Constructor. More...

	~AdvancedLiftDrag () override=default
	Destructor. More...

void	Configure (const Entity &_entity, const std::shared_ptr< const sdf::Element > &_sdf, EntityComponentManager &_ecm, EventManager &_eventMgr) override
	Configure the system. More...

void	PreUpdate (const UpdateInfo &_info, EntityComponentManager &_ecm) final
	Documentation inherited. More...

Public Member Functions inherited from System
	System ()=default
	Constructor. More...

virtual	~System ()=default
	Destructor. More...

Additional Inherited Members
Public Types inherited from System
using	PriorityType = int32_t
	Signed integer type used for specifying priority of the execution order of PreUpdate and Update phases. More...

Static Public Attributes inherited from System
constexpr static PriorityType	kDefaultPriority = {0}
	Default priority value for execution order of the PreUpdate and Update phases. More...

constexpr static std::string_view	kPriorityElementName
	Name of the XML element from which the priority value will be parsed. More...

Detailed Description

The LiftDrag system computes lift and drag forces enabling simulation of aerodynamic robots.

A tool can be found at the link below that automatically generates the Advanced Lift Drag plugin for you. All that is needed is to provide some physical parameters of the model. The README contains all necessary setup and usage steps.

https://github.com/PX4/PX4-Autopilot/blob/main/Tools/simulation/ gz/tools/avl_automation/

Note: Wind calculations can be enabled by setting the wind parameter in the world file.

System Parameters

<link_name>: Name of the link affected by the group of lift/drag properties. This can be a scoped name to reference links in nested models.
See also
entitiesFromScopedName to learn more about scoped names.
<rho>: Density of the fluid this model is suspended in.
<area>: Surface area of the link.
<CL0>: Lift Coefficient at zero angle of attack
<Cem0>: Pitching moment coefficient at zero angle of attack
<CD0>: Drag Coefficient at zero angle of attack
<CLa>: dCL/da (slope of CL-alpha curve) Slope of the first portion of the alpha-lift coefficient curve.
<CYa>: dCy/da (sideforce slope wrt alpha)
<Cella>: dCl/da (roll moment slope wrt alpha)
<Cema>: dCm/da (pitching moment slope wrt alpha - before stall)
<Cena>: dCn/da (yaw moment slope wrt alpha)
<CLb>: dCL/dbeta (lift coefficient slope wrt beta)
<CYb>: dCY/dbeta (side force slope wrt beta)
<Cellb>: dCl/dbeta (roll moment slope wrt beta)
<Cemb>: dCm/dbeta (pitching moment slope wrt beta)
<Cenb>: dCn/dbeta (yaw moment slope wrt beta)
<alphaStall>: angle of attack when airfoil stalls
<CemaStall>: Slope of the Cm-alpha curve after stall
<cp>: 3-vector replacing the center of pressure in the original LiftDragPlugin.
<CDp>: dCD/dp (drag coefficient slope wrt roll rate)
<CYp>: dCY/dp (sideforce slope wrt roll rate)
<CLp>: dCL/dp (lift coefficient slope wrt roll rate)
<Cellp>: dCl/dp (roll moment slope wrt roll rate)
<Cenp>: dCn/dp (yaw moment slope wrt roll rate)
<CDq>: dCD/dq (drag coefficient slope wrt pitching rate)
<CYq>: dCY/dq (side force slope wrt pitching rate)
<CLq>: dCL/dq (lift coefficient slope wrt pitching rate)
<Cellq>: dCl/dq (roll moment slope wrt pitching rate)
<Cemq>: dCm/dq (pitching moment slope wrt pitching rate)
<Cenq>: dCn/dq (yaw moment slope wrt pitching rate)
<CDr>: dCD/dr (drag coefficient slope wrt yaw rate)
<CYr>: dCY/dr (side force slope wrt yaw rate)
<CLr>: dCL/dr (lift coefficient slope wrt yaw rate)
<Cellr>: dCl/dr (roll moment slope wrt yaw rate)
<Cemr>: dCm/dr (pitching moment slope wrt yaw rate)
<Cenr>: dCn/dr (yaw moment slope wrt yaw rate)
<num_ctrl_surfaces>: Number of control surfaces
<controlJoints>: Vector that points to the joints that connect to the control surface
<ctrl_surface_direction>: Vectors of control surface deflections
<CD_ctrl>: Vector of the effect of the deflection on the coefficient of drag
<CY_ctrl>: Vector of the effect of the deflection on the coefficient of side force
<CL_ctrl>: Vector of the effect of the deflection on the coefficient of lift
<Cell_ctrl>: Vector of the effect of the deflection on the coefficient of roll moment
<Cem_ctrl>: Vector of the effect of the deflection on the coefficient of pitching moment
<Cen_ctrl>: Vector of the effect of the deflection on the coefficient of yaw moment
<AR>: Aspect ratio
<mac>: The mean-aerodynamic chord
<eff>: Wing efficiency (This is the Oswald efficiency factor for a 3D wing)
<cda>: The ratio of the coefficient of drag and alpha slope before stall.
<forward>: 3-vector representing the forward direction of motion in the link frame.
<upward>: 3-vector representing the direction of lift or drag.
<alphaStall>: Angle of attack at stall point; peak angle of attack.
<alpha>: The angle of attack
<beta>: The sideslip angle
<M>: The sigmoid blending parameter
<CD_fp_k1>: The first of the flat plate drag model coefficients
<CD_fp_k2>: The second of the flat plate drag model coefficients
<sdfConfig>: Copy of the sdf configuration used for this plugin

Constructor & Destructor Documentation

◆ AdvancedLiftDrag()

AdvancedLiftDrag ( )

Constructor.

◆ ~AdvancedLiftDrag()

~AdvancedLiftDrag ( )

overridedefault

Destructor.

Member Function Documentation

◆ Configure()

void Configure	(	const Entity &	_entity,
		const std::shared_ptr< const sdf::Element > &	_sdf,
		EntityComponentManager &	_ecm,
		EventManager &	_eventMgr
	)

overridevirtual

Configure the system.

Parameters

[in]	_entity	The entity this plugin is attached to.
[in]	_sdf	The SDF Element associated with this system plugin.
[in]	_ecm	The EntityComponentManager of the given simulation instance.
[in]	_eventMgr	The EventManager of the given simulation instance.