FlightSims
FlightSims.jl is a general-purpose numerical simulator supporting nested environments and convenient macro-based data logging.
Road map
- ROS2 compatibility (not urgent)
NEWS
- See NEWS.md.
APIs
Main APIs can be found in FSimBase.jl.
In FlightSims.jl, the default differential equation (DE) solver is Tsit5()
for ordinary DE (ODE).
Features
If you want more functionality, please feel free to report an issue!
Nested Environments and Zoo
- Environments usually stand for dynamical systems but also include other utilities, for example, controllers.
- One can generate user-defined nested environments using provided APIs. Also, some predefined environments are provided for reusability. Take a look at FSimZoo.jl.
Utilities
- Some utilities are also provided for dynamical system simulation.
- Examples include
- Simulation rendering
- See FSimPlots.jl. Note that FSimPlots.jl is not exported in the default setting to reduce precompilation time.
- Simulation rendering
Examples
Basic: minimal examples
- For minimal examples of FlightSims.jl, see FSimBase.jl.
Optimal control and reinforcement learning
- For an example of infinite-horizon continuous-time linear quadratic regulator (LQR),
see the following example code (
test/environments/basics/lqr.jl
).
using FlightSims
const FS = FlightSims
using DifferentialEquations
using LinearAlgebra
using Plots
using Test
using Transducers
function test()
# linear system
A = [0 1;
0 0] # 2 x 2
B = [0 1]' # 2 x 1
n, m = 2, 1
env = LinearSystem(A, B) # exported from FlightSims
x0 = State(env)([1.0, 2.0])
p0 = zero.(x0) # auxiliary parameter
# optimal control
Q = Matrix(I, n, n)
R = Matrix(I, m, m)
lqr = LQR(A, B, Q, R) # exported from FlightSims
u_lqr = Command(lqr) # (x, p, t) -> -K*x; minimise J = ∫ (x' Q x + u' R u) from 0 to ∞
# simulation
tf = 10.0
Δt = 0.01
affect!(integrator) = integrator.p = copy(integrator.u) # auxiliary callback funciton
cb = PeriodicCallback(affect!, Δt; initial_affect=true) # auxiliary callback
@Loggable function dynamics!(dx, x, p, t)
@onlylog p # activate this line only when logging data
u = u_lqr(x)
@log x, u
@nested_log Dynamics!(env)(dx, x, p, t; u=u) # exported `state` and `input` from `Dynamics!(env)`
end
prob, df = sim(
x0, # initial condition
dynamics!, # dynamics with input of LQR
p0;
tf=tf, # final time
callback=cb,
savestep=Δt,
)
ts = df.time
xs = df.sol |> Map(datum -> datum.x) |> collect
us = df.sol |> Map(datum -> datum.u) |> collect
ps = df.sol |> Map(datum -> datum.p) |> collect
states = df.sol |> Map(datum -> datum.state) |> collect
inputs = df.sol |> Map(datum -> datum.input) |> collect
@test xs == states
@test us == inputs
p_x = plot(ts, hcat(states...)';
title="state variable", label=["x1" "x2"], color=[:black :black], lw=1.5,
) # Plots
plot!(p_x, ts, hcat(ps...)';
ls=:dash, label="param", color=[:red :orange], lw=1.5
)
savefig("figures/x_lqr.png")
plot(ts, hcat(inputs...)'; title="control input", label="u") # Plots
savefig("figures/u_lqr.png")
df
end
julia> test()
1001×2 DataFrame
Row │ time sol
│ Float64 NamedTup…
──────┼────────────────────────────────────────────
1 │ 0.0 (p = [1.01978, 1.95564], state =…
2 │ 0.01 (p = [1.01978, 1.95564], state =…
3 │ 0.02 (p = [1.03911, 1.91186], state =…
4 │ 0.03 (p = [1.05802, 1.86863], state =…
5 │ 0.04 (p = [1.07649, 1.82596], state =…
⋮ │ ⋮ ⋮
998 │ 9.97 (p = [-0.00093419, 0.00103198], …
999 │ 9.98 (p = [-0.000923913, 0.00102347],…
1000 │ 9.99 (p = [-0.00091372, 0.001015], st…
1001 │ 10.0 (p = [-0.00091372, 0.001015], st…
992 rows omitted
- (Deprecated; will be detached)
For an example of continuous-time value-iteration adaptive dynamic programming (CT-VI-ADP), take a look attest/continuous_time_vi_adp.jl
. - (Deprecated; will be detached)
For an example of continuous-time integral reinforcement learning for linear system (CT-IRL), take a look attest/continuous_time_linear_irl.jl
.
Multicopter position control
- For an example of backstepping position tracking controller for quadcopters,
see
test/environments/integrated_environments/backstepping_position_controller_static_allocator_multicopter_env.jl
.
Missile guidance with interactive visualisation
- See
test/pluto_guidance.jl
(thanks to @nhcho91).
Multicopter rendering
- For more details, see FSimPlots.jl.
Related packages
FSim family
- FSimBase.jl is the lightweight base package for numerical simulation supporting nested dynamical systems and macro-based data logger. For more functionality, see FlightSims.jl.
- FSimZoo.jl contains predefined environments and controllers for FlightSims.jl.
- FSimPlots.jl is the plotting package for predefined environments exported from FlightSims.jl
Packages using FlightSims.jl
- FaultTolerantControl.jl: fault tolerant control (FTC) with various models and algorithms of faults, fault detection and isolation (FDI), and reconfiguration (R) control.
- FlightGNC.jl (@nhcho91): FlightGNC.jl is a Julia package containing GNC algorithms for autonomous systems.
Useful packages
- It is highly based on DifferentialEquations.jl but mainly focusing on ODE (ordinary differential equations).
- The construction of nested environments are based on ComponentArrays.jl.
- The structure of the resulting data from simulation result is based on DataFrames.jl.
- Logging tool is based on SimulationLogger.jl.
Trouble shootings
sim
produces an empty Dataframe
- Please check whether you put
@Loggable
in front of the dynamics function in a proper way, e.g.,
function Dynamics!(env::MyEnv)
@Loggable function dynamics!(dx, x, p, t; u)
# return @Loggable dynamics!(dx, x, p, t; u) # This would not work
# blahblah...
end
end