Borrowed value descriptor for a TOPP3 problem solved from C. More...

#include <formulation.h>

Data Fields
struct CoppRobot *	robot
	Mutable robot handle that owns station-indexed constraint storage.
size_t	idx_s_start
	Start station index.
struct CoppSliceF64	a_linearization
	Reference profile a[k] used to linearize third-order constraints.
double	a_start
	Boundary value a(idx_s_start) = dot{s}^2.
double	a_final
	Boundary value a(idx_s_final) = dot{s}^2.
double	b_start
	Boundary value b(idx_s_start) = ddot{s}.
double	b_final
	Boundary value b(idx_s_final) = ddot{s}.
size_t	num_stationary_max_start
	User-input stationary upper bound at the start.
size_t	num_stationary_max_end
	User-input stationary upper bound at the end.
double	a_linearization_floor
	Denominator floor used when linearizing third-order constraints.
struct CoppSliceF64	b_linearization
	Optional path acceleration b[k] paired with a_linearization.

Detailed Description

Borrowed value descriptor for a TOPP3 problem solved from C.

This is not an owning handle. robot, a_linearization, and b_linearization are borrowed only during the solver call. Building the internal TOPP3 problem mutates the robot's internal linearized third-order constraint cache.

Example

The example below builds a TOPP3 descriptor using a seed a profile for third-order constraint linearization.

struct Topp3Problem problem = {
    robot,
    0,
    (struct CoppSliceF64){a_seed.data, a_seed.len},
    0.0,
    0.0,
    0.0,
    0.0,
    1,
    1,
    1e-10,
};

b_linearization is the last field, so a positional initializer that omits it, such as the one above, leaves it empty and selects direct linearization. The example below refines around a previously solved third-order profile with adaptive linearization.

struct Topp3Problem refined = problem;
refined.a_linearization = (struct CoppSliceF64){profile.a.data, profile.a.len};
refined.b_linearization = (struct CoppSliceF64){profile.b.data, profile.b.len};

Definition at line 289 of file formulation.h.

Field Documentation

◆ robot

struct CoppRobot* Topp3Problem::robot

Mutable robot handle that owns station-indexed constraint storage.

Definition at line 293 of file formulation.h.

◆ idx_s_start

size_t Topp3Problem::idx_s_start

Start station index.

The final index is derived from a_linearization.len - 1.

Definition at line 298 of file formulation.h.

◆ a_linearization

struct CoppSliceF64 Topp3Problem::a_linearization

Reference profile a[k] used to linearize third-order constraints.

Definition at line 302 of file formulation.h.

◆ a_start

double Topp3Problem::a_start

Boundary value a(idx_s_start) = dot{s}^2.

Definition at line 306 of file formulation.h.

◆ a_final

double Topp3Problem::a_final

Boundary value a(idx_s_final) = dot{s}^2.

Definition at line 310 of file formulation.h.

◆ b_start

double Topp3Problem::b_start

Boundary value b(idx_s_start) = ddot{s}.

Definition at line 314 of file formulation.h.

◆ b_final

double Topp3Problem::b_final

Boundary value b(idx_s_final) = ddot{s}.

Definition at line 318 of file formulation.h.

◆ num_stationary_max_start

size_t Topp3Problem::num_stationary_max_start

User-input stationary upper bound at the start.

Definition at line 322 of file formulation.h.

◆ num_stationary_max_end

size_t Topp3Problem::num_stationary_max_end

User-input stationary upper bound at the end.

Definition at line 326 of file formulation.h.

◆ a_linearization_floor

double Topp3Problem::a_linearization_floor

Denominator floor used when linearizing third-order constraints.

Definition at line 330 of file formulation.h.

◆ b_linearization

struct CoppSliceF64 Topp3Problem::b_linearization

Optional path acceleration b[k] paired with a_linearization.

Leave empty (data = NULL, len = 0, as zero-initialization does) to linearize every third-order row of station k at a_linearization[k]. When non-empty, each row is instead anchored where that row is nearly active at the feasible state (a_linearization, b_linearization), so a slack row is anchored high and a tight one stays near the state. It must then have the same length as a_linearization, otherwise the solver returns COPP_STATUS_SOLVER_INVALID_INPUT when it builds the problem, and the two must be the a and b of one previously solved third-order profile; the b of a TOPP2 profile is discretized differently and must not be used.

Prefer this adaptive mode when a spans a wide range over the window, and especially when a can approach zero (about 1e-10): anchoring both rows of one axis at the same small a_linearization[k] cancels b and c and leaves a[k] <= 3 * a_linearization[k]. On profiles that stay well away from zero the two modes agree closely, and leaving this field empty is cheaper.

Definition at line 352 of file formulation.h.

The documentation for this struct was generated from the following file:

bindings/c/include/copp/formulation.h

COPP C ABI 0.2.3 C interface for COPP trajectory optimization

Data Fields