Struct SoModelBackend 

pub struct SoModelBackend { /* private fields */ }

RobotModelBackend backed by the robot’s own libfcimodels shared object.

Obtain one from crate::model::model_library::load_from_robot (online) or from SoModelBackend::open / SoModelBackend::from_bytes (offline, e.g. from a captured library).

Implementations

impl SoModelBackend

pub unsafe fn open(path: &Path) -> FrankaResult<SoModelBackend>

Loads a libfcimodels shared object from an existing file.

The file is not removed when the backend is dropped; use SoModelBackend::from_bytes for a downloaded library.

Port of franka::LibraryLoader plus franka::ModelLibrary’s symbol binding (src/library_loader.cpp, src/model_library.cpp, 0.9.2).

Safety

This dlopens path, which runs the shared object’s DT_INIT constructors and then calls function pointers resolved out of it — i.e. it executes the file’s code in this process, with no sandbox and no validation of its contents.

The caller asserts that path is a trusted libfcimodels build for the current platform: it came from a source the caller is willing to run arbitrary native code from (a Franka control unit over the FCI command socket, or a library captured from one and stored somewhere only trusted principals can write), the file cannot be swapped between this call and the load, and its thirty exported entry points have the signatures libfcimodels.h of libfranka 0.9.2 declares. Loading anything else is undefined behaviour.

Errors

FrankaError::Model when the file cannot be dlopened (wrong architecture, missing dependency, not a shared object) or when any of the thirty expected symbols is absent — libfranka reports the same two conditions as ModelException("libfranka: Cannot load model library: ...") and ModelException("libfranka: Symbol cannot be found: ...").

pub unsafe fn from_bytes(bytes: &[u8]) -> FrankaResult<SoModelBackend>

Writes bytes to a fresh, 0600, uniquely named file under std::env::temp_dir, loads it, and removes the file when the returned backend is dropped.

This is what libfranka does with the LoadModelLibrary response (LibraryDownloader::LibraryDownloader, which names the file with Poco::TemporaryFile::tempName() and unlinks it in its destructor).

Safety

bytes are written to disk and dlopened, so this executes them in this process; see SoModelBackend::open for what that means. The caller asserts that bytes are a trusted libfcimodels build for the current platform — in the online path, that trust is the FCI peer itself, which already commands the arm.

Errors

FrankaError::Model when the file cannot be created or written (libfranka: "libfranka: Cannot save model library."), or for the reasons listed on SoModelBackend::open.

Trait Implementations

impl Debug for SoModelBackend

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl RobotModelBackend for SoModelBackend

fn coriolis( &self, q: &[f64; 7], dq: &[f64; 7], i_total: &[f64; 9], m_total: f64, f_x_ctotal: &[f64; 3], _gravity_earth: &[f64; 3], ) -> [f64; 7]

c_NE(q, dq, I_total, m_total, F_x_Ctotal).

gravity_earth is ignored: the FCI v5 model library’s Coriolis entry point takes no gravity vector and franka::Model::coriolis (0.9.2) has no such parameter either. See the module documentation.

fn gravity( &self, q: &[f64; 7], gravity_earth: &[f64; 3], m_total: f64, f_x_ctotal: &[f64; 3], ) -> [f64; 7]

g_NE(q, gravity_earth, m_total, F_x_Ctotal).

fn mass( &self, q: &[f64; 7], i_total: &[f64; 9], m_total: f64, f_x_ctotal: &[f64; 3], ) -> [f64; 49]

M_NE(q, I_total, m_total, F_x_Ctotal).

fn pose(&self, q: &[f64; 7], joint_index: usize) -> [f64; 16]

Pose of a joint frame in the base frame. Port of RobotModelBase::pose.

fn pose_flange(&self, q: &[f64; 7]) -> [f64; 16]

Pose of the flange frame. Port of RobotModelBase::poseFlange.

fn pose_ee(&self, q: &[f64; 7], f_t_ee: &[f64; 16]) -> [f64; 16]

Pose of the end-effector frame. Port of RobotModelBase::poseEe.

fn pose_stiffness( &self, q: &[f64; 7], f_t_ee: &[f64; 16], ee_t_k: &[f64; 16], ) -> [f64; 16]

Pose of the stiffness frame. Port of RobotModelBase::poseStiffness.

fn body_jacobian(&self, q: &[f64; 7], joint_index: usize) -> [f64; 42]

Body (LOCAL) Jacobian of a joint frame. Port of RobotModelBase::bodyJacobian.

fn body_jacobian_flange(&self, q: &[f64; 7]) -> [f64; 42]

Body Jacobian of the flange frame. Port of RobotModelBase::bodyJacobianFlange.

fn body_jacobian_ee(&self, q: &[f64; 7], f_t_ee: &[f64; 16]) -> [f64; 42]

Body Jacobian of the end-effector frame. Port of RobotModelBase::bodyJacobianEe.

fn body_jacobian_stiffness( &self, q: &[f64; 7], f_t_ee: &[f64; 16], ee_t_k: &[f64; 16], ) -> [f64; 42]

Body Jacobian of the stiffness frame. Port of RobotModelBase::bodyJacobianStiffness.

fn zero_jacobian(&self, q: &[f64; 7], joint_index: usize) -> [f64; 42]

Zero (LOCAL_WORLD_ALIGNED) Jacobian of a joint frame. Port of RobotModelBase::zeroJacobian.

fn zero_jacobian_flange(&self, q: &[f64; 7]) -> [f64; 42]

Zero Jacobian of the flange frame. Port of RobotModelBase::zeroJacobianFlange.

fn zero_jacobian_ee(&self, q: &[f64; 7], f_t_ee: &[f64; 16]) -> [f64; 42]

Zero Jacobian of the end-effector frame. Port of RobotModelBase::zeroJacobianEe.

fn zero_jacobian_stiffness( &self, q: &[f64; 7], f_t_ee: &[f64; 16], ee_t_k: &[f64; 16], ) -> [f64; 42]

Zero Jacobian of the stiffness frame. Port of RobotModelBase::zeroJacobianStiffness.