Surface Finish: Tool Paths and Robot Motion =========================================== ``SurfaceFinishService`` (``client.surface_finish``) builds a tool path on an object and turns it into robot motion, for sanding, polishing, painting, dispensing and similar tasks. It works in **stages**. Data from every stage is kept and can be read, and **redoing a stage clears the results of later stages**. .. note:: ``SurfaceFinishService`` requires the ``surface_finish`` license (:doc:`/activate_licenses`). .. code-block:: text Stage 1 Stage 2 Stage 3 Export GenerateNominalPath ──▶ RefinePath ──────────▶ CreateRobotMotion ──────▶ GenerateRCATrajectoryFile nominal_cartesian refined_cartesian basic_solution / advanced_solution The result is a ``surface_finish.Path`` config (type ``CONFIG_TYPE_SURFACE_PATH``) parented to the object. Read it with ``SurfaceFinishService.Get`` or ``ConfigService.Get``. Stage 1: nominal path --------------------- ``GenerateNominalPath(GenerateNominalPathRequest)`` takes a ``header`` (the path name, with ``parent`` set to the **object** the path lies on) and one path generator. It returns ``path_names``: one request can create several paths, for example a raster split into separate passes. .. list-table:: Path generators :header-rows: 1 :widths: 26 16 58 * - Request field - Source - Description * - ``manual_path`` - any - ``ManualPath``: you provide ``CartesianWaypoint`` s, relative to the parent. * - ``mesh_sketch_path`` - mesh - ``MeshSketchPath``: a polyline through ``points`` on the mesh surface (parent frame), resampled at ``fixed_spacing`` or ``variable_spacing``. * - ``mesh_raster_path`` - mesh - ``MeshRasterPath``: a raster (zig-zag) pattern covering the mesh or a ``polygon_border`` region. * - ``edge_path`` - CAD - ``EdgePath``: follows CAD edges; adjacent ``faces`` define the tool Z axis. * - ``surface_scan_path`` - CAD - ``FaceRasterPath``: a raster pattern on CAD faces. * - ``surface_sketch_path`` - CAD - ``FaceSketchPath``: a path through sketch ``points`` on CAD faces. Mesh sketch path ~~~~~~~~~~~~~~~~ .. literalinclude:: /../../examples/python/mesh_toolpath_sketch_example.py :language: python :start-at: path_req = GenerateNominalPathRequest( :end-before: except grpc.RpcError :dedent: 12 Mesh raster path ~~~~~~~~~~~~~~~~ .. literalinclude:: /../../examples/python/mesh_toolpath_raster_example.py :language: python :start-at: path_req = GenerateNominalPathRequest( :end-before: except grpc.RpcError :dedent: 12 Key ``MeshRasterPath`` parameters (all lengths in m, angles in rad): ``raster_line_spacing`` Distance between raster lines. ``fixed_spacing`` Distance between waypoints along a line. ``blending_radius`` Corner blending radius. ``border_offset`` Inward offset from the region border. ``raster_path_joining_distance_threshold`` Lines closer than this are joined into one continuous path. ``principal_rotation_angle`` *or* ``specified_direction`` Raster direction: an angle about the mesh's principal direction, or a world-frame vector projected onto the mesh. ``minimum_toolpath_length`` Shorter paths after splitting are dropped. ``align_with_initial_direction`` / ``align_with_previous`` / ``align_with_direction`` How each waypoint's X axis is oriented. CAD-based generators ~~~~~~~~~~~~~~~~~~~~ ``EdgePath``, ``FaceRasterPath`` and ``FaceSketchPath`` follow the CAD edges or faces listed in ``edges`` or ``faces``. Each entry is the OCCT entry string (``TDF_Label``) of a ``TopoDS_Edge`` or ``TopoDS_Face`` in the STEP file. In C++, ``flexiv::pdk::surface_finish::ToOcctEntryString(shape, shape_tool)`` (````) computes it. The helper exists only in builds with ``FLEXIV_PDK_ENABLE_OCCT_INTEGRATION=ON``, and the binary release ships its header only when the library contains it. The object must have a ``Visual`` whose ``mesh.filename`` is the STEP file. If an object has several visual files, set ``cad_filename`` (or ``mesh_filename``) to choose one. Waypoint spacing for CAD paths (and for ``MeshSketchPath``) is either ``fixed_spacing`` (m) or ``variable_spacing``, a ``VariableSpacing`` (``min_spacing``, ``max_spacing``, ``position_tolerance``, ``orientation_tolerance``). ``FaceRasterPath`` can be bounded by an ``EdgeBorder`` (keep a distance from given edges) or a ``PolygonBorder``. Stage 2: refinement ------------------- Optional. ``RefinePath(RefinePathRequest(path_name, refinement))`` modifies the nominal waypoints. Stage 3 uses ``refined_cartesian`` if it is present, otherwise ``nominal_cartesian``. ``PathRefinement`` operations are applied in this order: 1. ``reversed_order``: reverse the waypoint order; 2. ``align_with_previous``: rotate each waypoint about its local Z to align with the previous one; 3. ``rotation_offset``: rotate each waypoint in its own frame; 4. ``position_offset``: translate each waypoint in its own frame. .. warning:: Set ``rotation_offset`` to the identity (``w=1``) if you do not want a rotation. An unset quaternion is all zeros. Stage 3: robot motion --------------------- ``CreateRobotMotion(CreateRobotMotionRequest(path_name, solver_preferences))`` computes joint trajectories. .. list-table:: ``SolverPreferences`` :header-rows: 1 :widths: 30 70 * - Field - Description * - ``system_name`` - **Required.** The system that executes the path. * - ``tcp_ecp_name`` - **Required.** The TCP (tool) or ECP (external control point) that follows the path, e.g. ``"system_1.arm.flange"``. * - ``solver_type`` - ``SOLVER_TYPE_BASIC`` (result in ``basic_solution``) or ``SOLVER_TYPE_ADVANCED`` (result in ``advanced_solution``). * - ``null_space`` - Desired elbow swivel angle and external axis positions. * - ``external_robot_axis``, ``external_workpiece_axis`` - How external axes may move (none, preset, preferred, not used). * - ``tool_symmetry`` - Ignore rotation about the tool axis (for example, polishing wheels). * - ``joint_position_seed`` - Start configuration. If empty, the current robot state is used. * - ``tcp_to_attach_object``, ``object_grasp_pose`` - ECP only: the robot holds the part and moves it past a fixed tool. .. literalinclude:: /../../examples/python/linear_path_trajectory_generation_example.py :language: python :start-after: # 5. Run Basic solve to compute the robot joint positions for the generated path :end-before: # 6. Get the generated path config :dedent: 8 Process parameters and export ----------------------------- Each ``CartesianWaypoint`` carries ``velocity``, ``acceleration`` and a ``wrench`` (force/torque to apply in contact). Edit them on the path and save it back with ``ConfigService.Save(SaveConfigRequest(surface_path=...))``. Then ``GenerateRCATrajectoryFile`` writes a robot trajectory (``.traj``) file on the server, at ``/linear_path//.traj``, where ```` is the active workcell's folder in the server's workcell directory (``flexiv_pdk_data/workcell/`` for the containerized server, see :doc:`install_server`). .. literalinclude:: /../../examples/python/linear_path_trajectory_generation_example.py :language: python :start-after: # 6. Get the generated path config and set the Cartesian :end-before: if __name__ == "__main__": :dedent: 8 Complete example ---------------- The example prints ``grpc.RpcError`` instead of raising it and does not check every ``status.code``. Production code should check both; see :doc:`error_handling`. .. literalinclude:: /../../examples/python/linear_path_trajectory_generation_example.py :language: python