Problem

struct Problem{Q<:QuadratureRule, T<:AbstractFloat}

Trajectory Optimization Problem. Contains the full definition of a trajectory optimization problem, including:

• dynamics model (Model)
• objective (Objective)
• constraints (ConstraintSet)
• initial and final states
• Primal variables (state and control trajectories)
• Discretization information: knot points (N), time step (dt), and total time (tf)

Constructors:

Problem(model, obj, constraints, x0, xf, Z, N, tf) # defaults to RK3 integration
Problem{Q}(model, obj, constraints, x0, xf, Z, N, tf) where Q<:QuadratureRule
Problem(model, obj, xf, tf; x0, constraints, N, X0, U0, dt, integration)
Problem{Q}(prob::Problem)  # change integration

where Z is a trajectory (Vector of KnotPoints)

Arguments

• model: Dynamics model. Can be either Discrete or Continuous
• obj: Objective
• X0: Initial state trajectory. If omitted it will be initialized with NaNs, to be later overwritten by the solver.
• U0: Initial control trajectory. If omitted it will be initialized with zeros.
• x0: Initial state. Defaults to zeros.
• xf: Final state. Defaults to zeros.
• dt: Time step
• tf: Final time. Set to zero to specify a time penalized problem.
• N: Number of knot points. Defaults to 51, unless specified by dt and tf.
• integration: One of the defined integration types to discretize the continuous dynamics model.

Both X0 and U0 can be either a Matrix or a Vector{Vector}, but must be the same. At least 2 of dt, tf, and N need to be specified (or just 1 of dt and tf).

change_integration(prob::Problem, Q<:QuadratureRule)

Change dynamics integration for the problem

initial_controls!(::Union{Problem,AbstractSolver}, U0::Vector{<:AbstractVector})
initial_controls!(::Union{Problem,AbstractSolver}, U0::AbstractMatrx)

Copy the control trajectory

initial_states!(::Union{Problem,AbstractSolver}, X0::Vector{<:AbstractVector})
initial_states!(::Union{Problem,AbstractSolver}, X0::AbstractMatrix)

Copy the state trajectory

size(prob::Problem) -> Tuple

Get number of states, controls, and knot points

Copy the problem

integration(::Problem)
integration(::DynamicsConstraint)

Get the integration rule

states(::Problem)
states(::AbstractSolver)
states(::Traj)

Get the state trajectory

controls(::Problem)
controls(::AbstractSolver)
controls(::Traj)

Get the control trajectory