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Connor
2021-08-25 10:10:22 -06:00
parent 966f954528
commit e25d6ff9f4
5 changed files with 95 additions and 35 deletions
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5
julia/plotting.jl
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@@ -18,7 +18,8 @@ function plot_orbits(paths::Vector{Array{Float64,2}};
primary::String="Earth",
plot_theme::Symbol=:juno,
labels::Vector{String}=Vector{String}(),
title::String="Spacecraft Position")
title::String="Spacecraft Position",
colors::Vector{String}=Vector{String}())
N = 32
θ = collect(range(0,length=N,stop=2π))
@@ -33,7 +34,7 @@ function plot_orbits(paths::Vector{Array{Float64,2}};
for i = 1:length(paths)
path = [ x for x in paths[i] ]
label = labels != [] ? labels[i] : "orbit"
color = random_color()
color = colors != [] ? colors[i] : random_color()
push!(t1, scatter3d(;x=(path[:,1]),y=(path[:,2]),z=(path[:,3]),
mode="lines", name=label, line_color=color, line_width=3))
end

14
julia/propagator.jl
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@@ -26,13 +26,13 @@ function prop_one(ΔV::Vector{T},
mag, α, β = ΔV
if mag > 1 || mag < 0
throw(ErrorException("ΔV input is too high: $mag"))
elseif α > π || α < -π
throw(ErrorException("α angle is incorrect: $α"))
elseif β > π/2 || β < -π/2
throw(ErrorException("β angle is incorrect: $β"))
end
# if mag > 1 || mag < 0
# throw(ErrorException("ΔV input is too high: $mag"))
# elseif α > π || α < -π
# throw(ErrorException("α angle is incorrect: $α"))
# elseif β > π/2 || β < -π/2
# throw(ErrorException("β angle is incorrect: $β"))
# end
thrust_rθh = mag * [cos(β)*sin(α), cos(β)*cos(α), sin(β)]
a,e,i,Ω,ω,ν = xyz_to_oe(state, μ)

80
julia/single_shoot.jl
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@@ -1,13 +1,8 @@
using NLsolve
using NLsolve, NLopt
function treat_inputs(x::AbstractVector, n::Int)
inputs = reshape(copy(x),(3,n))'
for i in 1:n
inputs[i,1] = 0.5*tanh(inputs[i,1]) + 0.5
inputs[i,2] = π*tanh(inputs[i,2])
inputs[i,3] = π*tanh(inputs[i,3])/2
end
return inputs
function treat_inputs(x::AbstractVector)
n::Int = length(x)/3
reshape(x,(3,n))'
end
function single_shoot(start::Vector{Float64},
@@ -21,13 +16,72 @@ function single_shoot(start::Vector{Float64},
tol=1e-2)
function f!(F,x)
F[1:6] .= prop(treat_inputs(x,n), start, craft, μ, tf-t0)[1][end,:] - final
F[1:6] .= prop(treat_inputs(x), start, craft, μ, tf-t0)[1][end,:] - final
F[7:3n] .= 0.
# if typeof(F[1]) == Float64 println(F[1:6]) end
# if typeof(F[1]) == Float64 println(treat_inputs(x,n)[1:8,1]) end
end
return nlsolve(f!, x0, ftol=tol, autodiff=:forward, iterations=10_000)
end
function single_shoot2(start::Vector,
final::Vector,
craft::Sc,
μ::AbstractFloat,
t0::AbstractFloat,
tf::AbstractFloat,
x0::Vector,
tol=1e-8)
n::Int = length(x0)/3
m0 = craft.mass
f(x::Vector) = m0 - prop(treat_inputs(x), start, craft, μ, tf-t0)[2][end]
f_constraint(x::Vector) = norm(prop(treat_inputs(x), start, craft, μ, tf-t0)[1][end,:] - final)
function nlfunc(x::Vector, grad::Vector)
try
if length(grad) != 0
ForwardDiff.gradient!(grad, f, x)
end
f(x)
catch e
println("Error was $e")
throw(e)
end
end
function nlconstraint(x::Vector, grad::Vector)
if length(grad) != 0
ForwardDiff.gradient!(grad, f_constraint, x)
end
f_constraint(x)
end
opt = Opt(:LD_MMA, 3n)
lower_bounds = Vector{Float64}()
upper_bounds = Vector{Float64}()
for i in 1:3n
if i%3 == 1
push!(lower_bounds, 0.)
push!(upper_bounds, 1.)
elseif i%3 == 2
push!(lower_bounds, -π)
push!(upper_bounds, π)
elseif i%3 == 0
push!(lower_bounds, -π/2)
push!(upper_bounds, π/2)
end
end
opt.lower_bounds = lower_bounds
opt.upper_bounds = upper_bounds
opt.xtol_rel = 1e-4
opt.min_objective = nlfunc
inequality_constraint!(opt, nlconstraint, 1e-8)
(minf, minx, ret) = optimize(opt, x0)
numevals = opt.numevals
return minf, minx, ret, numevals
end

6
julia/test/propagator.jl
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@@ -27,9 +27,9 @@
@test craft.mass == start_mass - craft.mass_flow_rate*stepsize
# Test that a bad ΔV throws an error
craft = Sc("test")
start_mass = craft.mass
@test_throws ErrorException prop_one([1.5, 0., 0.], start, craft, μs["Earth"], stepsize)
# craft = Sc("test")
# start_mass = craft.mass
# @test_throws ErrorException prop_one([1.5, 0., 0.], start, craft, μs["Earth"], stepsize)
# Test that a full propagation doesn't take too long

25
julia/test/single_shoot.jl
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@@ -6,26 +6,31 @@
e = rand(0.01:0.01:0.5)
i = rand(0.01:0.01:π/6)
T = 2π*√(a^3/μs["Earth"])
prop_time = 2T
n = 50
# A simple orbit raising
start = oe_to_xyz([ a, e, i, 0., 0., 0. ], μs["Earth"])
ΔVs = repeat([0.6, 0., 0.]', outer=(n,1))
final = prop(ΔVs, start, sc, μs["Earth"], T)[1][end,:]
final = prop(ΔVs, start, sc, μs["Earth"], prop_time)[1][end,:]
new_T = 2π*√(xyz_to_oe(final, μs["Earth"])[1]^3/μs["Earth"])
# This should be close enough to 0.6
x0 = repeat([atanh((0.4-0.5)/0.5), 0., 0.], n)
result = single_shoot(start, final, sc, μs["Earth"], 0.0, T, n, x0)
x0 = repeat([0.59, 0., 0.], n)
result = single_shoot2(start, final, sc, μs["Earth"], 0.0, prop_time, x0)
# Test and plot
@test converged(result)
@test result[3] == :XTOL_REACHED
path1 = prop(zeros((100,3)), start, sc, μs["Earth"], T)[1]
path2, mass = prop(treat_inputs(result.zero, n), start, sc, μs["Earth"], T)
path3 = prop(zeros((100,3)), path2[end,:], sc, μs["Earth"], T)[1]
savefig(plot_orbits([path1, path2, path3]), "single_shoot_test.html")
if converged(result)
@test norm(path2[end,:] - final) < 2e-2
sc = Sc("test")
path2, mass = prop(treat_inputs(result[2]), start, sc, μs["Earth"], prop_time)
path3 = prop(zeros((100,3)), path2[end,:], sc, μs["Earth"], new_T)[1]
path4 = prop(zeros((100,3)), final, sc, μs["Earth"], new_T)[1]
savefig(plot_orbits([path1, path2, path3, path4],
labels=["inital", "transit", "after transit", "final"],
colors=["#FFFFFF","#FF4444","#44FF44","#4444FF"]),
"single_shoot_test.html")
if result[3] == :XTOL_REACHED
@test norm(path2[end,:] - final) < 1e-6
end
end