Vehicle parameter definitions — multi-robot support via subclassing.
Classes:
| Name | Description |
|---|---|
VehicleParams |
Generic multi-rotor vehicle physics. |
TrackVehicleParams |
LAV2: ducted-fan quadrotor + tracked ground locomotion. |
TiltWheelVehicleParams |
ATMO: An Aerially Transforming Morphobot for Dynamic Ground Aerial Transition. |
dataclass
VehicleParams(*, rho: float = 1.184, g: float = 9.81, sim_dt: float = 0.01, step_dt: float = 0.01, randomization: dict[str, dict[str, tuple[float, float]]] = dict(), mass: float = 2.1, inertia: list = (lambda: [[0.015, 0.0, 0.0], [0.0, 0.0348, 0.0], [0.0, 0.0, 0.042503]])(), x: float = 0.0952, y: float = 0.114423, h: float = -0.0125, alpha: float = math.radians(8.0), diameter: float = 0.476, Cdx: float = 0.5, r_p: float = 0.0775, Ct: float = 0.666, Cq: float = 0.0716, theta0: float = math.radians(14.6), thetaTip: float = math.radians(6.8), theta1: float = math.nan, lock: float = 0.6051, cT: float = math.nan, cM: float = math.nan, spin_dir: tuple[float, float, float, float] = (1.0, 1.0, -1.0, -1.0), tau_f: float = 0.01, tau_m: float = 0.05, max_rpm: float = 10000.0, init_rpm: float = math.nan, rotor_rpm_rate_limit: float = 50000.0, tau_up: float = math.nan, tau_down: float = math.nan, mpc_xy_vel_max: float = 12.0, mpc_z_vel_max_up: float = 3.0, mpc_z_vel_max_dn: float = 1.5, mpc_acc_hor_max: float = 5.0, mpc_acc_up_max: float = 4.0, mpc_acc_down_max: float = 3.0, mpc_man_tilt_max: float = math.radians(35.0), mc_rollrate_max: float = math.radians(220.0), mc_pitchrate_max: float = math.radians(220.0), mc_yawrate_max: float = math.radians(200.0))
Generic multi-rotor vehicle physics.
The base class carries LAV2-compatible defaults for the shared multi-rotor
parameters so that VehicleParams() continues to produce a working
LAV2-flavoured flight configuration (without track / airframe specifics).
Concrete subclasses add robot-specific locomotion and geometry:
TrackVehicleParams— LAV2: tracked ground locomotion + ducted airframeTiltWheelVehicleParams— ATMO: tilting arms + two side motors whose belt transmissions synchronize four wheel shells
Methods:
| Name | Description |
|---|---|
__post_init__ |
Calculate derived parameters and resolve default sentinels. |
Attributes:
| Name | Type | Description |
|---|---|---|
rho |
float
|
Air density (kg/m³). |
g |
float
|
Gravitational acceleration (m/s²). |
sim_dt |
float
|
Simulation time step (s). |
step_dt |
float
|
Control time step (s). |
randomization |
dict[str, dict[str, tuple[float, float]]]
|
Per-component parameter-randomisation scale ranges. |
mass |
float
|
Total vehicle mass (kg — LAV2 default; override for other robots). |
inertia |
list
|
Inertia matrix (kg*m^2). |
x |
float
|
Arm length in x — rotor moment-arm for roll (m). |
y |
float
|
Arm length in y — rotor moment-arm for pitch (m). |
h |
float
|
CG height below rotor plane (m, negative = below). |
alpha |
float
|
Duct / rotor cant angle about y-axis (rad — 0 for flat rotors like ATMO). |
diameter |
float
|
Overall vehicle diameter (m). |
Cdx |
float
|
Body drag coefficient. |
r_p |
float
|
Propeller radius (m). |
Ct |
float
|
Thrust coefficient (blade-element). |
Cq |
float
|
Torque coefficient (blade-element). |
theta0 |
float
|
Blade root pitch angle (rad). |
thetaTip |
float
|
Blade tip pitch angle (rad). |
theta1 |
float
|
Blade twist (rad), defaults to theta0 - thetaTip. |
lock |
float
|
Lock number. |
cT |
float
|
Thrust coefficient T = cT·rpm² (N / rpm²); defaults from Ct. |
cM |
float
|
Reaction-torque coefficient M = cM·rpm² (N·m / rpm²); defaults from Cq. |
spin_dir |
tuple[float, float, float, float]
|
Rotor spin direction signs; + means clockwise, - means counter-clockwise. |
tau_f |
float
|
Motor filter time constant (s). |
tau_m |
float
|
Legacy motor time constant (s). |
max_rpm |
float
|
Maximum rotor speed (rpm — LAV2 default). |
init_rpm |
float
|
Initial rotor speed — defaults to 0.2·max_rpm. |
rotor_rpm_rate_limit |
float
|
Rotor-speed rate-of-change limit (rpm/s). |
tau_up |
float
|
Motor spin-up time constant (s), defaults to tau_m. |
tau_down |
float
|
Motor spin-down time constant (s), defaults to tau_m. |
mpc_xy_vel_max |
float
|
Maximum horizontal velocity setpoint magnitude in m/s (0 - 20). |
mpc_z_vel_max_up |
float
|
Maximum upward velocity setpoint in m/s (0.5 - 8). |
mpc_z_vel_max_dn |
float
|
Maximum downward velocity setpoint magnitude in m/s (0.5 - 4). |
mpc_acc_hor_max |
float
|
Maximum horizontal acceleration setpoint magnitude in m/s^2 (2 - 15). |
mpc_acc_up_max |
float
|
Maximum upward acceleration setpoint in m/s^2 (2 - 15). |
mpc_acc_down_max |
float
|
Maximum downward acceleration setpoint magnitude in m/s^2 (2 - 15). |
mpc_man_tilt_max |
float
|
Maximum manual tilt angle in radians (deg: 0 - 90). |
mc_rollrate_max |
float
|
Maximum roll-rate setpoint in rad/s (deg/s: 0 - 1800). |
mc_pitchrate_max |
float
|
Maximum pitch-rate setpoint in rad/s (deg/s: 0 - 1800). |
mc_yawrate_max |
float
|
Maximum yaw-rate setpoint in rad/s (deg/s: 0 - 1800). |
class-attribute
instance-attribute
rho: float = 1.184
Air density (kg/m³).
class-attribute
instance-attribute
g: float = 9.81
Gravitational acceleration (m/s²).
class-attribute
instance-attribute
sim_dt: float = 0.01
Simulation time step (s).
class-attribute
instance-attribute
step_dt: float = 0.01
Control time step (s).
class-attribute
instance-attribute
randomization: dict[str, dict[str, tuple[float, float]]] = field(default_factory=dict)
Per-component parameter-randomisation scale ranges.
class-attribute
instance-attribute
mass: float = 2.1
Total vehicle mass (kg — LAV2 default; override for other robots).
class-attribute
instance-attribute
inertia: list = field(default_factory=lambda: [[0.015, 0.0, 0.0], [0.0, 0.0348, 0.0], [0.0, 0.0, 0.042503]])
Inertia matrix (kg*m^2).
class-attribute
instance-attribute
x: float = 0.0952
Arm length in x — rotor moment-arm for roll (m).
class-attribute
instance-attribute
y: float = 0.114423
Arm length in y — rotor moment-arm for pitch (m).
class-attribute
instance-attribute
h: float = -0.0125
CG height below rotor plane (m, negative = below).
class-attribute
instance-attribute
alpha: float = math.radians(8.0)
Duct / rotor cant angle about y-axis (rad — 0 for flat rotors like ATMO).
class-attribute
instance-attribute
diameter: float = 0.476
Overall vehicle diameter (m).
class-attribute
instance-attribute
Cdx: float = 0.5
Body drag coefficient.
class-attribute
instance-attribute
r_p: float = 0.0775
Propeller radius (m).
class-attribute
instance-attribute
Ct: float = 0.666
Thrust coefficient (blade-element).
class-attribute
instance-attribute
Cq: float = 0.0716
Torque coefficient (blade-element).
class-attribute
instance-attribute
theta0: float = math.radians(14.6)
Blade root pitch angle (rad).
class-attribute
instance-attribute
thetaTip: float = math.radians(6.8)
Blade tip pitch angle (rad).
class-attribute
instance-attribute
theta1: float = math.nan
Blade twist (rad), defaults to theta0 - thetaTip.
class-attribute
instance-attribute
lock: float = 0.6051
Lock number.
class-attribute
instance-attribute
cT: float = math.nan
Thrust coefficient T = cT·rpm² (N / rpm²); defaults from Ct.
class-attribute
instance-attribute
cM: float = math.nan
Reaction-torque coefficient M = cM·rpm² (N·m / rpm²); defaults from Cq.
class-attribute
instance-attribute
spin_dir: tuple[float, float, float, float] = (1.0, 1.0, -1.0, -1.0)
Rotor spin direction signs; + means clockwise, - means counter-clockwise.
LAV2 defaults to rotors 0/1 clockwise and 2/3 counter-clockwise, so the
signs are (+,+,-,-).
class-attribute
instance-attribute
tau_f: float = 0.01
Motor filter time constant (s).
class-attribute
instance-attribute
tau_m: float = 0.05
Legacy motor time constant (s).
class-attribute
instance-attribute
max_rpm: float = 10000.0
Maximum rotor speed (rpm — LAV2 default).
class-attribute
instance-attribute
init_rpm: float = math.nan
Initial rotor speed — defaults to 0.2·max_rpm.
class-attribute
instance-attribute
rotor_rpm_rate_limit: float = 50000.0
Rotor-speed rate-of-change limit (rpm/s).
class-attribute
instance-attribute
tau_up: float = math.nan
Motor spin-up time constant (s), defaults to tau_m.
class-attribute
instance-attribute
tau_down: float = math.nan
Motor spin-down time constant (s), defaults to tau_m.
class-attribute
instance-attribute
mpc_xy_vel_max: float = 12.0
Maximum horizontal velocity setpoint magnitude in m/s (0 - 20).
class-attribute
instance-attribute
mpc_z_vel_max_up: float = 3.0
Maximum upward velocity setpoint in m/s (0.5 - 8).
class-attribute
instance-attribute
mpc_z_vel_max_dn: float = 1.5
Maximum downward velocity setpoint magnitude in m/s (0.5 - 4).
class-attribute
instance-attribute
mpc_acc_hor_max: float = 5.0
Maximum horizontal acceleration setpoint magnitude in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_acc_up_max: float = 4.0
Maximum upward acceleration setpoint in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_acc_down_max: float = 3.0
Maximum downward acceleration setpoint magnitude in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_man_tilt_max: float = math.radians(35.0)
Maximum manual tilt angle in radians (deg: 0 - 90).
class-attribute
instance-attribute
mc_rollrate_max: float = math.radians(220.0)
Maximum roll-rate setpoint in rad/s (deg/s: 0 - 1800).
class-attribute
instance-attribute
mc_pitchrate_max: float = math.radians(220.0)
Maximum pitch-rate setpoint in rad/s (deg/s: 0 - 1800).
class-attribute
instance-attribute
mc_yawrate_max: float = math.radians(200.0)
Maximum yaw-rate setpoint in rad/s (deg/s: 0 - 1800).
__post_init__()
Calculate derived parameters and resolve default sentinels.
dataclass
TrackVehicleParams(*, rho: float = 1.184, g: float = 9.81, sim_dt: float = 0.01, step_dt: float = 0.01, randomization: dict[str, dict[str, tuple[float, float]]] = dict(), mass: float = 2.1, inertia: list = (lambda: [[0.015, 0.0, 0.0], [0.0, 0.0348, 0.0], [0.0, 0.0, 0.042503]])(), x: float = 0.0952, y: float = 0.114423, h: float = -0.0125, alpha: float = math.radians(8.0), diameter: float = 0.476, Cdx: float = 0.5, r_p: float = 0.0775, Ct: float = 0.666, Cq: float = 0.0716, theta0: float = math.radians(14.6), thetaTip: float = math.radians(6.8), theta1: float = math.nan, lock: float = 0.6051, cT: float = math.nan, cM: float = math.nan, spin_dir: tuple[float, float, float, float] = (1.0, 1.0, -1.0, -1.0), tau_f: float = 0.01, tau_m: float = 0.05, max_rpm: float = 10000.0, init_rpm: float = math.nan, rotor_rpm_rate_limit: float = 50000.0, tau_up: float = math.nan, tau_down: float = math.nan, mpc_xy_vel_max: float = 12.0, mpc_z_vel_max_up: float = 3.0, mpc_z_vel_max_dn: float = 1.5, mpc_acc_hor_max: float = 5.0, mpc_acc_up_max: float = 4.0, mpc_acc_down_max: float = 3.0, mpc_man_tilt_max: float = math.radians(35.0), mc_rollrate_max: float = math.radians(220.0), mc_pitchrate_max: float = math.radians(220.0), mc_yawrate_max: float = math.radians(200.0), r_w: float = 0.0285, B: float = 0.2, track_speed_limit: float = 40.0 * math.pi, ground_speed_limit: float = 2.5, ground_yaw_rate_limit: float = 7.0, ground_position_threshold: float = 0.5, track_effort_limit: float = 9.39, track_velocity_gain: float = 6.17)
Bases: VehicleParams
LAV2: ducted-fan quadrotor + tracked ground locomotion.
Inherits all multi-rotor and airframe-geometry defaults from
VehicleParams and adds LAV2-specific track parameters.
Methods:
| Name | Description |
|---|---|
__post_init__ |
Calculate derived parameters and resolve default sentinels. |
Attributes:
| Name | Type | Description |
|---|---|---|
r_w |
float
|
Sprocket radius (m). |
B |
float
|
Effective differential allocation width fitted to yaw-rate response (m). |
track_speed_limit |
float
|
Output-shaft speed limit for the speed-controlled track drive (rad/s). |
ground_speed_limit |
float
|
PX4-aligned maximum commanded chassis speed (m/s). |
ground_yaw_rate_limit |
float
|
PX4 manual/Acro maximum commanded yaw rate (rad/s). |
ground_position_threshold |
float
|
Position error below which the ground controller commands zero speed (m). |
track_effort_limit |
float
|
Peak drive-shaft torque for each physical track actuator (N·m). |
track_velocity_gain |
float
|
Initial MuJoCo velocity-servo gain for each track drive (N·m·s/rad). |
rho |
float
|
Air density (kg/m³). |
g |
float
|
Gravitational acceleration (m/s²). |
sim_dt |
float
|
Simulation time step (s). |
step_dt |
float
|
Control time step (s). |
randomization |
dict[str, dict[str, tuple[float, float]]]
|
Per-component parameter-randomisation scale ranges. |
mass |
float
|
Total vehicle mass (kg — LAV2 default; override for other robots). |
inertia |
list
|
Inertia matrix (kg*m^2). |
x |
float
|
Arm length in x — rotor moment-arm for roll (m). |
y |
float
|
Arm length in y — rotor moment-arm for pitch (m). |
h |
float
|
CG height below rotor plane (m, negative = below). |
alpha |
float
|
Duct / rotor cant angle about y-axis (rad — 0 for flat rotors like ATMO). |
diameter |
float
|
Overall vehicle diameter (m). |
Cdx |
float
|
Body drag coefficient. |
r_p |
float
|
Propeller radius (m). |
Ct |
float
|
Thrust coefficient (blade-element). |
Cq |
float
|
Torque coefficient (blade-element). |
theta0 |
float
|
Blade root pitch angle (rad). |
thetaTip |
float
|
Blade tip pitch angle (rad). |
theta1 |
float
|
Blade twist (rad), defaults to theta0 - thetaTip. |
lock |
float
|
Lock number. |
cT |
float
|
Thrust coefficient T = cT·rpm² (N / rpm²); defaults from Ct. |
cM |
float
|
Reaction-torque coefficient M = cM·rpm² (N·m / rpm²); defaults from Cq. |
spin_dir |
tuple[float, float, float, float]
|
Rotor spin direction signs; + means clockwise, - means counter-clockwise. |
tau_f |
float
|
Motor filter time constant (s). |
tau_m |
float
|
Legacy motor time constant (s). |
max_rpm |
float
|
Maximum rotor speed (rpm — LAV2 default). |
init_rpm |
float
|
Initial rotor speed — defaults to 0.2·max_rpm. |
rotor_rpm_rate_limit |
float
|
Rotor-speed rate-of-change limit (rpm/s). |
tau_up |
float
|
Motor spin-up time constant (s), defaults to tau_m. |
tau_down |
float
|
Motor spin-down time constant (s), defaults to tau_m. |
mpc_xy_vel_max |
float
|
Maximum horizontal velocity setpoint magnitude in m/s (0 - 20). |
mpc_z_vel_max_up |
float
|
Maximum upward velocity setpoint in m/s (0.5 - 8). |
mpc_z_vel_max_dn |
float
|
Maximum downward velocity setpoint magnitude in m/s (0.5 - 4). |
mpc_acc_hor_max |
float
|
Maximum horizontal acceleration setpoint magnitude in m/s^2 (2 - 15). |
mpc_acc_up_max |
float
|
Maximum upward acceleration setpoint in m/s^2 (2 - 15). |
mpc_acc_down_max |
float
|
Maximum downward acceleration setpoint magnitude in m/s^2 (2 - 15). |
mpc_man_tilt_max |
float
|
Maximum manual tilt angle in radians (deg: 0 - 90). |
mc_rollrate_max |
float
|
Maximum roll-rate setpoint in rad/s (deg/s: 0 - 1800). |
mc_pitchrate_max |
float
|
Maximum pitch-rate setpoint in rad/s (deg/s: 0 - 1800). |
mc_yawrate_max |
float
|
Maximum yaw-rate setpoint in rad/s (deg/s: 0 - 1800). |
class-attribute
instance-attribute
r_w: float = 0.0285
Sprocket radius (m).
class-attribute
instance-attribute
B: float = 0.2
Effective differential allocation width fitted to yaw-rate response (m).
class-attribute
instance-attribute
track_speed_limit: float = 40.0 * math.pi
Output-shaft speed limit for the speed-controlled track drive (rad/s).
class-attribute
instance-attribute
ground_speed_limit: float = 2.5
PX4-aligned maximum commanded chassis speed (m/s).
class-attribute
instance-attribute
ground_yaw_rate_limit: float = 7.0
PX4 manual/Acro maximum commanded yaw rate (rad/s).
class-attribute
instance-attribute
ground_position_threshold: float = 0.5
Position error below which the ground controller commands zero speed (m).
class-attribute
instance-attribute
track_effort_limit: float = 9.39
Peak drive-shaft torque for each physical track actuator (N·m).
class-attribute
instance-attribute
track_velocity_gain: float = 6.17
Initial MuJoCo velocity-servo gain for each track drive (N·m·s/rad).
class-attribute
instance-attribute
rho: float = 1.184
Air density (kg/m³).
class-attribute
instance-attribute
g: float = 9.81
Gravitational acceleration (m/s²).
class-attribute
instance-attribute
sim_dt: float = 0.01
Simulation time step (s).
class-attribute
instance-attribute
step_dt: float = 0.01
Control time step (s).
class-attribute
instance-attribute
randomization: dict[str, dict[str, tuple[float, float]]] = field(default_factory=dict)
Per-component parameter-randomisation scale ranges.
class-attribute
instance-attribute
mass: float = 2.1
Total vehicle mass (kg — LAV2 default; override for other robots).
class-attribute
instance-attribute
inertia: list = field(default_factory=lambda: [[0.015, 0.0, 0.0], [0.0, 0.0348, 0.0], [0.0, 0.0, 0.042503]])
Inertia matrix (kg*m^2).
class-attribute
instance-attribute
x: float = 0.0952
Arm length in x — rotor moment-arm for roll (m).
class-attribute
instance-attribute
y: float = 0.114423
Arm length in y — rotor moment-arm for pitch (m).
class-attribute
instance-attribute
h: float = -0.0125
CG height below rotor plane (m, negative = below).
class-attribute
instance-attribute
alpha: float = math.radians(8.0)
Duct / rotor cant angle about y-axis (rad — 0 for flat rotors like ATMO).
class-attribute
instance-attribute
diameter: float = 0.476
Overall vehicle diameter (m).
class-attribute
instance-attribute
Cdx: float = 0.5
Body drag coefficient.
class-attribute
instance-attribute
r_p: float = 0.0775
Propeller radius (m).
class-attribute
instance-attribute
Ct: float = 0.666
Thrust coefficient (blade-element).
class-attribute
instance-attribute
Cq: float = 0.0716
Torque coefficient (blade-element).
class-attribute
instance-attribute
theta0: float = math.radians(14.6)
Blade root pitch angle (rad).
class-attribute
instance-attribute
thetaTip: float = math.radians(6.8)
Blade tip pitch angle (rad).
class-attribute
instance-attribute
theta1: float = math.nan
Blade twist (rad), defaults to theta0 - thetaTip.
class-attribute
instance-attribute
lock: float = 0.6051
Lock number.
class-attribute
instance-attribute
cT: float = math.nan
Thrust coefficient T = cT·rpm² (N / rpm²); defaults from Ct.
class-attribute
instance-attribute
cM: float = math.nan
Reaction-torque coefficient M = cM·rpm² (N·m / rpm²); defaults from Cq.
class-attribute
instance-attribute
spin_dir: tuple[float, float, float, float] = (1.0, 1.0, -1.0, -1.0)
Rotor spin direction signs; + means clockwise, - means counter-clockwise.
LAV2 defaults to rotors 0/1 clockwise and 2/3 counter-clockwise, so the
signs are (+,+,-,-).
class-attribute
instance-attribute
tau_f: float = 0.01
Motor filter time constant (s).
class-attribute
instance-attribute
tau_m: float = 0.05
Legacy motor time constant (s).
class-attribute
instance-attribute
max_rpm: float = 10000.0
Maximum rotor speed (rpm — LAV2 default).
class-attribute
instance-attribute
init_rpm: float = math.nan
Initial rotor speed — defaults to 0.2·max_rpm.
class-attribute
instance-attribute
rotor_rpm_rate_limit: float = 50000.0
Rotor-speed rate-of-change limit (rpm/s).
class-attribute
instance-attribute
tau_up: float = math.nan
Motor spin-up time constant (s), defaults to tau_m.
class-attribute
instance-attribute
tau_down: float = math.nan
Motor spin-down time constant (s), defaults to tau_m.
class-attribute
instance-attribute
mpc_xy_vel_max: float = 12.0
Maximum horizontal velocity setpoint magnitude in m/s (0 - 20).
class-attribute
instance-attribute
mpc_z_vel_max_up: float = 3.0
Maximum upward velocity setpoint in m/s (0.5 - 8).
class-attribute
instance-attribute
mpc_z_vel_max_dn: float = 1.5
Maximum downward velocity setpoint magnitude in m/s (0.5 - 4).
class-attribute
instance-attribute
mpc_acc_hor_max: float = 5.0
Maximum horizontal acceleration setpoint magnitude in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_acc_up_max: float = 4.0
Maximum upward acceleration setpoint in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_acc_down_max: float = 3.0
Maximum downward acceleration setpoint magnitude in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_man_tilt_max: float = math.radians(35.0)
Maximum manual tilt angle in radians (deg: 0 - 90).
class-attribute
instance-attribute
mc_rollrate_max: float = math.radians(220.0)
Maximum roll-rate setpoint in rad/s (deg/s: 0 - 1800).
class-attribute
instance-attribute
mc_pitchrate_max: float = math.radians(220.0)
Maximum pitch-rate setpoint in rad/s (deg/s: 0 - 1800).
class-attribute
instance-attribute
mc_yawrate_max: float = math.radians(200.0)
Maximum yaw-rate setpoint in rad/s (deg/s: 0 - 1800).
__post_init__()
Calculate derived parameters and resolve default sentinels.
dataclass
TiltWheelVehicleParams(*, rho: float = 1.184, g: float = 9.81, sim_dt: float = 0.01, step_dt: float = 0.01, randomization: dict[str, dict[str, tuple[float, float]]] = dict(), mass: float = 2.1, inertia: list = (lambda: [[0.015, 0.0, 0.0], [0.0, 0.0348, 0.0], [0.0, 0.0, 0.042503]])(), x: float = 0.0952, y: float = 0.114423, h: float = -0.0125, alpha: float = math.radians(8.0), diameter: float = 0.476, Cdx: float = 0.5, r_p: float = 0.0775, Ct: float = 0.666, Cq: float = 0.0716, theta0: float = math.radians(14.6), thetaTip: float = math.radians(6.8), theta1: float = math.nan, lock: float = 0.6051, cT: float = math.nan, cM: float = math.nan, spin_dir: tuple[float, float, float, float] = (-1.0, -1.0, 1.0, 1.0), tau_f: float = 0.01, tau_m: float = 0.05, max_rpm: float = 10000.0, init_rpm: float = math.nan, rotor_rpm_rate_limit: float = 50000.0, tau_up: float = math.nan, tau_down: float = math.nan, mpc_xy_vel_max: float = 12.0, mpc_z_vel_max_up: float = 3.0, mpc_z_vel_max_dn: float = 1.5, mpc_acc_hor_max: float = 5.0, mpc_acc_up_max: float = 4.0, mpc_acc_down_max: float = 3.0, mpc_man_tilt_max: float = math.radians(35.0), mc_rollrate_max: float = math.radians(220.0), mc_pitchrate_max: float = math.radians(220.0), mc_yawrate_max: float = math.radians(200.0), arm_hinge_axes: tuple[tuple[float, float, float], ...] = ((-1.0, 0.0, 0.0), (1.0, 0.0, 0.0)), arm_tilt_speed: float = math.pi / 2 / 4.0, wheel_radius: float = 0.125, wheel_half_base: float = 0.135, drive_speed_limit: float = 10.0, drive_no_load_speed: float = 170.0 * 2.0 * math.pi / 60.0, drive_effort_limit: float = 1.84, ground_speed_limit: float = 1.25, ground_yaw_rate_limit: float = 1.25 / 0.135, ground_position_threshold: float = 0.1, drive_velocity_gain: float = 1.8, drive_velocity_limit_sim: float = 25.0, drive_armature: float = 0.002)
Bases: VehicleParams
ATMO: An Aerially Transforming Morphobot for Dynamic Ground Aerial Transition.
Quadrotor + tilting arms + two side motors driving four belt-coupled wheel shells (formerly Caltech M4 / Mandralis).
Rotor coefficients cT / cM are set directly (e.g. from SDF motor
constants) rather than derived from blade-element Ct / Cq.
Methods:
| Name | Description |
|---|---|
__post_init__ |
Calculate derived parameters and resolve default sentinels. |
Attributes:
| Name | Type | Description |
|---|---|---|
spin_dir |
tuple[float, float, float, float]
|
ATMO follows PX4 direction convention: rotors 0/1 CCW, 2/3 CW. |
arm_hinge_axes |
tuple[tuple[float, float, float], ...]
|
Arm hinge rotation axes (unit vectors). |
arm_tilt_speed |
float
|
Maximum commanded arm-tilt speed (rad/s). |
wheel_radius |
float
|
Wheel radius (m). |
wheel_half_base |
float
|
Half the lateral wheel spacing (m). |
drive_speed_limit |
float
|
Maximum side-drive target from the public ATMO controller (rad/s). |
drive_no_load_speed |
float
|
ServoCity 170 RPM motor output-shaft speed at no load and 12 V (rad/s). |
drive_effort_limit |
float
|
Per-side peak torque after applying 0.85 belt efficiency (N·m). |
ground_speed_limit |
float
|
Maximum chassis speed from wheel radius times drive-speed limit (m/s). |
ground_yaw_rate_limit |
float
|
Maximum point-turn yaw rate from the public ATMO geometry (rad/s). |
ground_position_threshold |
float
|
Position error below which the ground controller commands zero speed (m). |
drive_velocity_gain |
float
|
Initial per-side closed-loop velocity-servo gain (Nms/rad). |
drive_velocity_limit_sim |
float
|
PhysX leader-joint safety speed, kept above motor no-load speed (rad/s). |
drive_armature |
float
|
Modeled motor and transmission inertia reflected at each leader joint (kg*m²). |
rho |
float
|
Air density (kg/m³). |
g |
float
|
Gravitational acceleration (m/s²). |
sim_dt |
float
|
Simulation time step (s). |
step_dt |
float
|
Control time step (s). |
randomization |
dict[str, dict[str, tuple[float, float]]]
|
Per-component parameter-randomisation scale ranges. |
mass |
float
|
Total vehicle mass (kg — LAV2 default; override for other robots). |
inertia |
list
|
Inertia matrix (kg*m^2). |
x |
float
|
Arm length in x — rotor moment-arm for roll (m). |
y |
float
|
Arm length in y — rotor moment-arm for pitch (m). |
h |
float
|
CG height below rotor plane (m, negative = below). |
alpha |
float
|
Duct / rotor cant angle about y-axis (rad — 0 for flat rotors like ATMO). |
diameter |
float
|
Overall vehicle diameter (m). |
Cdx |
float
|
Body drag coefficient. |
r_p |
float
|
Propeller radius (m). |
Ct |
float
|
Thrust coefficient (blade-element). |
Cq |
float
|
Torque coefficient (blade-element). |
theta0 |
float
|
Blade root pitch angle (rad). |
thetaTip |
float
|
Blade tip pitch angle (rad). |
theta1 |
float
|
Blade twist (rad), defaults to theta0 - thetaTip. |
lock |
float
|
Lock number. |
cT |
float
|
Thrust coefficient T = cT·rpm² (N / rpm²); defaults from Ct. |
cM |
float
|
Reaction-torque coefficient M = cM·rpm² (N·m / rpm²); defaults from Cq. |
tau_f |
float
|
Motor filter time constant (s). |
tau_m |
float
|
Legacy motor time constant (s). |
max_rpm |
float
|
Maximum rotor speed (rpm — LAV2 default). |
init_rpm |
float
|
Initial rotor speed — defaults to 0.2·max_rpm. |
rotor_rpm_rate_limit |
float
|
Rotor-speed rate-of-change limit (rpm/s). |
tau_up |
float
|
Motor spin-up time constant (s), defaults to tau_m. |
tau_down |
float
|
Motor spin-down time constant (s), defaults to tau_m. |
mpc_xy_vel_max |
float
|
Maximum horizontal velocity setpoint magnitude in m/s (0 - 20). |
mpc_z_vel_max_up |
float
|
Maximum upward velocity setpoint in m/s (0.5 - 8). |
mpc_z_vel_max_dn |
float
|
Maximum downward velocity setpoint magnitude in m/s (0.5 - 4). |
mpc_acc_hor_max |
float
|
Maximum horizontal acceleration setpoint magnitude in m/s^2 (2 - 15). |
mpc_acc_up_max |
float
|
Maximum upward acceleration setpoint in m/s^2 (2 - 15). |
mpc_acc_down_max |
float
|
Maximum downward acceleration setpoint magnitude in m/s^2 (2 - 15). |
mpc_man_tilt_max |
float
|
Maximum manual tilt angle in radians (deg: 0 - 90). |
mc_rollrate_max |
float
|
Maximum roll-rate setpoint in rad/s (deg/s: 0 - 1800). |
mc_pitchrate_max |
float
|
Maximum pitch-rate setpoint in rad/s (deg/s: 0 - 1800). |
mc_yawrate_max |
float
|
Maximum yaw-rate setpoint in rad/s (deg/s: 0 - 1800). |
class-attribute
instance-attribute
spin_dir: tuple[float, float, float, float] = (-1.0, -1.0, 1.0, 1.0)
ATMO follows PX4 direction convention: rotors 0/1 CCW, 2/3 CW.
class-attribute
instance-attribute
arm_hinge_axes: tuple[tuple[float, float, float], ...] = ((-1.0, 0.0, 0.0), (1.0, 0.0, 0.0))
Arm hinge rotation axes (unit vectors).
class-attribute
instance-attribute
arm_tilt_speed: float = math.pi / 2 / 4.0
Maximum commanded arm-tilt speed (rad/s).
class-attribute
instance-attribute
wheel_radius: float = 0.125
Wheel radius (m).
class-attribute
instance-attribute
wheel_half_base: float = 0.135
Half the lateral wheel spacing (m).
class-attribute
instance-attribute
drive_speed_limit: float = 10.0
Maximum side-drive target from the public ATMO controller (rad/s).
class-attribute
instance-attribute
drive_no_load_speed: float = 170.0 * 2.0 * math.pi / 60.0
ServoCity 170 RPM motor output-shaft speed at no load and 12 V (rad/s).
class-attribute
instance-attribute
drive_effort_limit: float = 1.84
Per-side peak torque after applying 0.85 belt efficiency (N·m).
class-attribute
instance-attribute
ground_speed_limit: float = 1.25
Maximum chassis speed from wheel radius times drive-speed limit (m/s).
class-attribute
instance-attribute
ground_yaw_rate_limit: float = 1.25 / 0.135
Maximum point-turn yaw rate from the public ATMO geometry (rad/s).
class-attribute
instance-attribute
ground_position_threshold: float = 0.1
Position error below which the ground controller commands zero speed (m).
class-attribute
instance-attribute
drive_velocity_gain: float = 1.8
Initial per-side closed-loop velocity-servo gain (Nms/rad).
class-attribute
instance-attribute
drive_velocity_limit_sim: float = 25.0
PhysX leader-joint safety speed, kept above motor no-load speed (rad/s).
class-attribute
instance-attribute
drive_armature: float = 0.002
Modeled motor and transmission inertia reflected at each leader joint (kg*m²).
class-attribute
instance-attribute
rho: float = 1.184
Air density (kg/m³).
class-attribute
instance-attribute
g: float = 9.81
Gravitational acceleration (m/s²).
class-attribute
instance-attribute
sim_dt: float = 0.01
Simulation time step (s).
class-attribute
instance-attribute
step_dt: float = 0.01
Control time step (s).
class-attribute
instance-attribute
randomization: dict[str, dict[str, tuple[float, float]]] = field(default_factory=dict)
Per-component parameter-randomisation scale ranges.
class-attribute
instance-attribute
mass: float = 2.1
Total vehicle mass (kg — LAV2 default; override for other robots).
class-attribute
instance-attribute
inertia: list = field(default_factory=lambda: [[0.015, 0.0, 0.0], [0.0, 0.0348, 0.0], [0.0, 0.0, 0.042503]])
Inertia matrix (kg*m^2).
class-attribute
instance-attribute
x: float = 0.0952
Arm length in x — rotor moment-arm for roll (m).
class-attribute
instance-attribute
y: float = 0.114423
Arm length in y — rotor moment-arm for pitch (m).
class-attribute
instance-attribute
h: float = -0.0125
CG height below rotor plane (m, negative = below).
class-attribute
instance-attribute
alpha: float = math.radians(8.0)
Duct / rotor cant angle about y-axis (rad — 0 for flat rotors like ATMO).
class-attribute
instance-attribute
diameter: float = 0.476
Overall vehicle diameter (m).
class-attribute
instance-attribute
Cdx: float = 0.5
Body drag coefficient.
class-attribute
instance-attribute
r_p: float = 0.0775
Propeller radius (m).
class-attribute
instance-attribute
Ct: float = 0.666
Thrust coefficient (blade-element).
class-attribute
instance-attribute
Cq: float = 0.0716
Torque coefficient (blade-element).
class-attribute
instance-attribute
theta0: float = math.radians(14.6)
Blade root pitch angle (rad).
class-attribute
instance-attribute
thetaTip: float = math.radians(6.8)
Blade tip pitch angle (rad).
class-attribute
instance-attribute
theta1: float = math.nan
Blade twist (rad), defaults to theta0 - thetaTip.
class-attribute
instance-attribute
lock: float = 0.6051
Lock number.
class-attribute
instance-attribute
cT: float = math.nan
Thrust coefficient T = cT·rpm² (N / rpm²); defaults from Ct.
class-attribute
instance-attribute
cM: float = math.nan
Reaction-torque coefficient M = cM·rpm² (N·m / rpm²); defaults from Cq.
class-attribute
instance-attribute
tau_f: float = 0.01
Motor filter time constant (s).
class-attribute
instance-attribute
tau_m: float = 0.05
Legacy motor time constant (s).
class-attribute
instance-attribute
max_rpm: float = 10000.0
Maximum rotor speed (rpm — LAV2 default).
class-attribute
instance-attribute
init_rpm: float = math.nan
Initial rotor speed — defaults to 0.2·max_rpm.
class-attribute
instance-attribute
rotor_rpm_rate_limit: float = 50000.0
Rotor-speed rate-of-change limit (rpm/s).
class-attribute
instance-attribute
tau_up: float = math.nan
Motor spin-up time constant (s), defaults to tau_m.
class-attribute
instance-attribute
tau_down: float = math.nan
Motor spin-down time constant (s), defaults to tau_m.
class-attribute
instance-attribute
mpc_xy_vel_max: float = 12.0
Maximum horizontal velocity setpoint magnitude in m/s (0 - 20).
class-attribute
instance-attribute
mpc_z_vel_max_up: float = 3.0
Maximum upward velocity setpoint in m/s (0.5 - 8).
class-attribute
instance-attribute
mpc_z_vel_max_dn: float = 1.5
Maximum downward velocity setpoint magnitude in m/s (0.5 - 4).
class-attribute
instance-attribute
mpc_acc_hor_max: float = 5.0
Maximum horizontal acceleration setpoint magnitude in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_acc_up_max: float = 4.0
Maximum upward acceleration setpoint in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_acc_down_max: float = 3.0
Maximum downward acceleration setpoint magnitude in m/s^2 (2 - 15).
class-attribute
instance-attribute
mpc_man_tilt_max: float = math.radians(35.0)
Maximum manual tilt angle in radians (deg: 0 - 90).
class-attribute
instance-attribute
mc_rollrate_max: float = math.radians(220.0)
Maximum roll-rate setpoint in rad/s (deg/s: 0 - 1800).
class-attribute
instance-attribute
mc_pitchrate_max: float = math.radians(220.0)
Maximum pitch-rate setpoint in rad/s (deg/s: 0 - 1800).
class-attribute
instance-attribute
mc_yawrate_max: float = math.radians(200.0)
Maximum yaw-rate setpoint in rad/s (deg/s: 0 - 1800).
__post_init__()
Calculate derived parameters and resolve default sentinels.