I am working on a fixed-wing aircraft model in Gazebo (gz-sim) integrated with ArduPilot SITL.
The model is inspired by and written based on the ArduPilot Talon fixed-wing example, adapting its overall structure, control surfaces, and plugin configuration.
I am currently experiencing issues where the aircraft does not generate sufficient forward acceleration and lift to take off. I suspect the problem is related to thrust modeling and lift/drag axis definitions, rather than control logic.
Can you help me identify where I went wrong and pinpoint the weak points in my setup?
<sdf version='1.11'>
<model name='asuman_v5'>
<link name='base_link'>
<inertial>
<mass>0.85580198896604698</mass>
<inertia>
<ixx>0.018808880958553501</ixx>
<ixy>0.000246699369689883</ixy>
<ixz>-3.4286127298079098e-05</ixz>
<iyy>0.0337043411689434</iyy>
<iyz>-2.25399149359833e-06</iyz>
<izz>0.016202861027244699</izz>
</inertia>
</inertial>
<collision name='base_link_collision'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/base_link.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='base_link_visual'>
<pose>0 0 0 1.57 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/textures/asuman.glb</uri>
</mesh>
</geometry>
</visual>
<sensor name="imu_sensor" type="imu">
<pose degrees="true">0 0 0 0 0 0</pose>
<always_on>1</always_on>
<update_rate>1000.0</update_rate>
</sensor>
<sensor name="navsat_sensor" type="navsat">
<always_on>1</always_on>
<update_rate>1</update_rate>
</sensor>
</link>
<joint name='elevator_joint' type='revolute'>
<pose relative_to='base_link'>-0.96499999999999997 -0.19 -0.075662999999999994 1.5708 0 0</pose>
<parent>base_link</parent>
<child>elevator_link</child>
<axis>
<xyz>0 0 1</xyz>
<limit>
<lower>-0.523599</lower>
<upper>0.523599</upper>
</limit>
<dynamics>
<damping>0.01</damping>
</dynamics>
</axis>
</joint>
<link name='elevator_link'>
<pose relative_to='elevator_joint'>0 0 0 0 0 0</pose>
<inertial>
<pose>-0.015115594439109901 9.6447061488882894e-05 -0.19022832430567199 0 0 0</pose>
<mass>0.057479741967468301</mass>
<inertia>
<ixx>0.00068187380185478596</ixx>
<ixy>1.3189780365394301e-08</ixy>
<ixz>-1.80556406084995e-08</ixz>
<iyy>0.00068591592053453005</iyy>
<iyz>8.4662385848795703e-08</iyz>
<izz>4.3947138398731999e-06</izz>
</inertia>
</inertial>
<collision name='elevator_link_collision'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/elevator_link.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='elevator_link_visual'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/elevator_link.STL</uri>
</mesh>
</geometry>
<material>
<diffuse>0.990196109 1 1 1</diffuse>
<ambient>0.990196109 1 1 1</ambient>
</material>
</visual>
</link>
<joint name='left_aileron_joint' type='revolute'>
<pose relative_to='base_link'>-0.12109 0.32743 -0.0092040000000000004 1.5651999999999999 0.094591999999999996 3.0767000000000002</pose>
<parent>base_link</parent>
<child>left_aileron_link</child>
<axis>
<xyz>7.1118999999999995e-05 -0.0013094000000000001 -1</xyz>
<limit>
<lower>-0.523599</lower>
<upper>0.523599</upper>
</limit>
<dynamics>
<damping>0.01</damping>
</dynamics>
</axis>
</joint>
<link name='left_aileron_link'>
<pose relative_to='left_aileron_joint'>0 0 0 0 0 0</pose>
<inertial>
<pose>0.0140974048167672 -0.0013547828590017401 0.131487275157919 0 0 0</pose>
<mass>0.051127814127108803</mass>
<inertia>
<ixx>0.00028429632953432199</ixx>
<ixy>5.9183592389288598e-07</ixy>
<ixz>3.3929204084462002e-07</ixz>
<iyy>0.00028859845594671597</iyy>
<iyz>-4.94536947306201e-07</iyz>
<izz>4.89981386187481e-06</izz>
</inertia>
</inertial>
<collision name='left_aileron_link_collision'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/left_aileron_link.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='left_aileron_link_visual'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/left_aileron_link.STL</uri>
</mesh>
</geometry>
<material>
<diffuse>0.990196109 1 1 1</diffuse>
<ambient>0.990196109 1 1 1</ambient>
</material>
</visual>
</link>
<joint name='propeller_joint' type='revolute'>
<pose relative_to='base_link'>0.33079710274728602 0 -0.074999992249100006 -1.5999677469079703 0 -3.14159265358979</pose>
<parent>base_link</parent>
<child>propeller_link</child>
<axis>
<xyz>1 0 0</xyz>
<limit>
<lower>-inf</lower>
<upper>inf</upper>
</limit>
<dynamics>
<spring_reference>0</spring_reference>
<spring_stiffness>0</spring_stiffness>
</dynamics>
</axis>
</joint>
<link name='propeller_link'>
<pose relative_to='propeller_joint'>0 0 0 0 0 0</pose>
<inertial>
<pose>-0.0053630881541813502 1.4099030254399699e-07 3.78928112507518e-07 0 0 0</pose>
<mass>0.0010143569356122701</mass>
<inertia>
<ixx>4.5218235483174499e-07</ixx>
<ixy>2.0485187050766101e-13</ixy>
<ixz>-2.4531939173851098e-13</ixz>
<iyy>4.4864425722368299e-07</iyy>
<iyz>1.41223672722648e-08</iyz>
<izz>5.95286300084247e-09</izz>
</inertia>
</inertial>
<!--
<collision name='propeller_link_collision'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/propeller_link.STL</uri>
</mesh>
</geometry>
</collision>
-->
<visual name='propeller_link_visual'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/propeller_link.STL</uri>
</mesh>
</geometry>
<material>
<diffuse>0.127450988 0.127450988 0.127450988 1</diffuse>
<ambient>0.127450988 0.127450988 0.127450988 1</ambient>
</material>
</visual>
</link>
<joint name='right_aileron_joint' type='revolute'>
<pose relative_to='base_link'>-0.11967 -0.33074999999999999 -0.0090760000000000007 1.5708 -4.2351647362715017e-22 -3.1415853071795872</pose>
<parent>base_link</parent>
<child>right_aileron_link</child>
<axis>
<xyz>0.068007999999999999 -0.0072281999999999997 0.99765999999999999</xyz>
<limit>
<lower>-0.523599</lower>
<upper>0.523599</upper>
</limit>
<dynamics>
<damping>0.01</damping>
</dynamics>
</axis>
</joint>
<link name='right_aileron_link'>
<pose relative_to='right_aileron_joint'>0 0 0 0 0 0</pose>
<inertial>
<pose>0.0040974048167672 -0.0013547828590017401 -0.131487275157919 0 0.08 0</pose>
<mass>0.051127814127108803</mass>
<inertia>
<ixx>0.00028429632953432199</ixx>
<ixy>5.9183592389288598e-07</ixy>
<ixz>3.3929204084462002e-07</ixz>
<iyy>0.00028859845594671597</iyy>
<iyz>-4.94536947306201e-07</iyz>
<izz>4.89981386187481e-06</izz>
</inertia>
</inertial>
<collision name='right_aileron_link_collision'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/right_aileron_link.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='right_aileron_link_visual'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/right_aileron_link.STL</uri>
</mesh>
</geometry>
<material>
<diffuse>0.990196109 1 1 1</diffuse>
<ambient>0.990196109 1 1 1</ambient>
</material>
</visual>
</link>
<joint name='rudder_joint' type='revolute'>
<pose relative_to='base_link'>-0.96499999999999997 0 0 1.5708 -4.2351647362715017e-22 -3.1415853071795872</pose>
<parent>base_link</parent>
<child>rudder_link</child>
<axis>
<xyz>0 -1 0</xyz>
<limit>
<lower>-0.523599</lower>
<upper>0.523599</upper>
</limit>
<dynamics>
<damping>0.01</damping>
</dynamics>
</axis>
</joint>
<link name='rudder_link'>
<pose relative_to='rudder_joint'>0 0 0 0 0 0</pose>
<inertial>
<pose>0.014534539892347299 0.0127734305027923 -0.00016522210447695299 0 0 0</pose>
<mass>0.0220843580567032</mass>
<inertia>
<ixx>4.0468391512494997e-05</ixx>
<ixy>-8.6232350321230395e-07</ixy>
<ixz>-5.2884964335724902e-09</ixz>
<iyy>1.6896631121444e-06</iyy>
<iyz>-2.1874374361294601e-07</iyz>
<izz>4.1987304369692302e-05</izz>
</inertia>
</inertial>
<collision name='rudder_link_collision'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/rudder_link.STL</uri>
</mesh>
</geometry>
</collision>
<visual name='rudder_link_visual'>
<pose>0 0 0 0 0 0</pose>
<geometry>
<mesh>
<scale>1 1 1</scale>
<uri>model://asuman_v5/meshes/rudder_link.STL</uri>
</mesh>
</geometry>
<material>
<diffuse>0.990196109 1 1 1</diffuse>
<ambient>0.990196109 1 1 1</ambient>
</material>
</visual>
</link>
<plugin filename="gz-sim-joint-state-publisher-system"
name="gz::sim::systems::JointStatePublisher">
</plugin>
<plugin
filename="gz-sim-joint-position-controller-system"
name="gz::sim::systems::JointPositionController">
<joint_name>left_aileron_joint</joint_name>
<initial_position>0.0</initial_position>
<topic>/left_aileron_joint/cmd_pos</topic>
<p_gain>10</p_gain>
<i_gain>0.0</i_gain>
<d_gain>0.0</d_gain>
<i_max>1</i_max>
<i_min>-1</i_min>
<cmd_max>5</cmd_max>
<cmd_min>-5</cmd_min>
</plugin>
<plugin
filename="gz-sim-joint-position-controller-system"
name="gz::sim::systems::JointPositionController">
<joint_name>right_aileron_joint</joint_name>
<initial_position>0.0</initial_position>
<topic>/right_aileron_joint/cmd_pos</topic>
<p_gain>10</p_gain>
<i_gain>0.0</i_gain>
<d_gain>0.0</d_gain>
<i_max>1</i_max>
<i_min>-1</i_min>
<cmd_max>5</cmd_max>
<cmd_min>-5</cmd_min>
</plugin>
<plugin
filename="gz-sim-joint-position-controller-system"
name="gz::sim::systems::JointPositionController">
<joint_name>elevator_joint</joint_name>
<initial_position>0.0</initial_position>
<topic>/elevator_joint/cmd_pos</topic>
<p_gain>10</p_gain>
<i_gain>0.0</i_gain>
<d_gain>0.0</d_gain>
<i_max>1</i_max>
<i_min>-1</i_min>
<cmd_max>5</cmd_max>
<cmd_min>-5</cmd_min>
</plugin>
<plugin
filename="gz-sim-joint-position-controller-system"
name="gz::sim::systems::JointPositionController">
<joint_name>rudder_joint</joint_name>
<initial_position>0.0</initial_position>
<topic>/rudder_joint/cmd_pos</topic>
<p_gain>10</p_gain>
<i_gain>0.0</i_gain>
<d_gain>0.0</d_gain>
<i_max>1</i_max>
<i_min>-1</i_min>
<cmd_max>5</cmd_max>
<cmd_min>-5</cmd_min>
</plugin>
<!-- motor_joint cw -->
<plugin filename="gz-sim-lift-drag-system"
name="gz::sim::systems::LiftDrag">
<a0>0.3</a0>
<alpha_stall>1.4</alpha_stall>
<cla>4.25</cla>
<cda>0.10</cda>
<cma>0.00</cma>
<cla_stall>-0.025</cla_stall>
<cda_stall>0.0</cda_stall>
<cma_stall>0.0</cma_stall>
<area>0.05</area>
<air_density>1.2041</air_density>
<cp>0.084 0 0</cp>
<forward>0 1 0</forward>
<upward>-1 0 0</upward>
<link_name>propeller_link</link_name>
</plugin>
<plugin filename="gz-sim-lift-drag-system"
name="gz::sim::systems::LiftDrag">
<a0>0.3</a0>
<alpha_stall>1.4</alpha_stall>
<cla>4.25</cla>
<cda>0.10</cda>
<cma>0.00</cma>
<cla_stall>-0.025</cla_stall>
<cda_stall>0.0</cda_stall>
<cma_stall>0.0</cma_stall>
<area>0.05</area>
<air_density>1.2041</air_density>
<cp>-0.084 0 0</cp>
<forward>0 -1 0</forward>
<upward>-1 0 0</upward>
<link_name>propeller_link</link_name>
</plugin>
<!-- left wing -->
<plugin filename="gz-sim-lift-drag-system"
name="gz::sim::systems::LiftDrag">
<a0>0.13</a0>
<cla>3.7</cla>
<cda>0.06417112299</cda>
<cma>0</cma>
<alpha_stall>0.3391428111</alpha_stall>
<cla_stall>-3.85</cla_stall>
<cda_stall>-0.9233984055</cda_stall>
<cma_stall>0</cma_stall>
<cp>0 0.27 0.029</cp>
<area>0.16</area>
<air_density>1.2041</air_density>
<forward>1 0 0</forward>
<upward>0 1 0</upward>
<link_name>base_link</link_name>
<control_joint_name>left_aileron_joint</control_joint_name>
<control_joint_rad_to_cl>-0.75</control_joint_rad_to_cl>
</plugin>
<!-- right wing -->
<plugin filename="gz-sim-lift-drag-system"
name="gz::sim::systems::LiftDrag">
<a0>0.13</a0>
<cla>3.7</cla>
<cda>0.06417112299</cda>
<cma>0</cma>
<alpha_stall>0.3391428111</alpha_stall>
<cla_stall>-3.85</cla_stall>
<cda_stall>-0.9233984055</cda_stall>
<cma_stall>0</cma_stall>
<cp>0 -0.27 0.029</cp>
<area>0.16</area>
<air_density>1.2041</air_density>
<forward>1 0 0</forward>
<upward>0 1 0</upward>
<link_name>base_link</link_name>
<control_joint_name>right_aileron_joint</control_joint_name>
<control_joint_rad_to_cl>-0.75</control_joint_rad_to_cl>
</plugin>
<plugin name="ArduPilotPlugin"
filename="ArduPilotPlugin">
<!-- Port settings. -->
<fdm_addr>127.0.0.1</fdm_addr>
<fdm_port_in>9002</fdm_port_in>
<connectionTimeoutMaxCount>5</connectionTimeoutMaxCount>
<lock_step>1</lock_step>
<have_32_channels>0</have_32_channels>
<!-- Frame transforms.-->
<modelXYZToAirplaneXForwardZDown>0 0 0 0 0 0</modelXYZToAirplaneXForwardZDown>
<gazeboXYZToNED>0 0 0 3.141593 0 1.57079632</gazeboXYZToNED>
<!-- Sensors. -->
<imuName>base_link::imu_sensor</imuName>
<control channel="0">
<jointName>right_aileron_joint</jointName>
<multiplier>-1.0471976</multiplier>
<offset>-0.5</offset>
<servo_min>1000</servo_min>
<servo_max>2000</servo_max>
<type>COMMAND</type>
<cmd_topic>/right_aileron_joint/cmd_pos</cmd_topic>
</control>
<control channel="1">
<jointName>elevator_joint</jointName>
<multiplier>1.0471976</multiplier>
<offset>-0.5</offset>
<servo_min>1000</servo_min>
<servo_max>2000</servo_max>
<type>COMMAND</type>
<cmd_topic>/elevator_joint/cmd_pos</cmd_topic>
</control>
<control channel="2">
<jointName>propeller_joint</jointName>
<multiplier>500</multiplier>
<offset>0</offset>
<servo_min>1000</servo_min>
<servo_max>2000</servo_max>
<type>VELOCITY</type>
<p_gain>0.20</p_gain>
<i_gain>0</i_gain>
<d_gain>0</d_gain>
<i_max>1</i_max>
<i_min>-1</i_min>
<cmd_max>100.0</cmd_max>
<cmd_min>0</cmd_min>
</control>
<control channel="3">
<jointName>left_aileron_joint</jointName>
<multiplier>1.0471976</multiplier>
<offset>-0.5</offset>
<servo_min>1000</servo_min>
<servo_max>2000</servo_max>
<type>COMMAND</type>
<cmd_topic>/left_aileron_joint/cmd_pos</cmd_topic>
</control>
<control channel="4">
<jointName>rudder_joint</jointName>
<multiplier>1.0471976</multiplier>
<offset>-0.5</offset>
<servo_min>1000</servo_min>
<servo_max>2000</servo_max>
<type>COMMAND</type>
<cmd_topic>/rudder_joint/cmd_pos</cmd_topic>
</control>
</plugin>
</model>
</sdf>
