Niryo_robot_poses_handlers

This package is in charge of dealing with transforms, workspace, grips and trajectories.

Poses handlers node

Description - Poses handlers

The ROS Node is made of several services to deal with transforms, workspace, grips and trajectories.

It belongs to the ROS namespace: /niryo_robot_poses_handlers/.

Workspaces

A workspace is defined by 4 markers that form a rectangle. With the help of the robot’s calibration tip, the marker positions are learned. The camera returns poses (x, y, yaw) relative to the workspace. We can then infer the absolute object pose in robot coordinates.

Grips

When we know the object pose in robot coordinates, we can’t directly send this pose to the robot because we specify the target pose of the tool_link and not of the actual TCP (tool center point). Therefore we introduced the notion of grip. Each end effector has its own grip that specifies where to place the robot with respect to the object.

Currently, the notion of grip is not part of the python/tcp/blockly interface because it would add an extra layer of complexity that is not really necessary for the moment.

Therefore we have a default grip for all tools that is selected automatically based on the current tool id. However, everything is ready if you want to define custom grips, e.g. for custom tools or for custom grip positions.

The vision pick loop

  1. The camera detects objects relative to markers and sends xrel, yrel, yawrel.
  2. The object is placed on the workspace, revealing the object pose in robot coordinates x, y, z, roll, pitch, yaw.
  3. The grip is applied on the absolute object pose and gives the pose the robot should move to.

Poses & trajectories

List of poses

Parameters - Poses handlers

Poses Handlers’ Parameters
Name Description
workspace_dir Path to the Workspace storage mother folder
grip_dir Path to the Grip storage mother folder
poses_dir Path to the Poses storage mother folder
dynamic_frame_dir Path to the dynamic frames storage mother folder

Services - Poses handlers

Poses Handlers’ Services
Name Message Type Description
manage_workspace ManageWorkspace Save/Delete a workspace
get_workspace_ratio GetWorkspaceRatio Get ratio of a workspace
get_workspace_list GetNameDescriptionList Get list of workspaces name & description
get_workspace_poses GetWorkspaceRobotPoses Get workspace’s robot poses
get_workspace_points GetWorkspacePoints Get workspace’s robot points
get_workspace_matrix_poses GetWorkspaceMatrixPoses Get workspace’s robot matrix poses
get_target_pose GetTargetPose Get saved programs name
manage_pose ManagePose Save/Delete a Pose
get_pose GetPose Get Pose
get_pose_list GetNameDescriptionList Get list of poses name & description
manage_dynamic_frame ManageDynamicFrame Save/Edit/Delete a dynamic frame
get_dynamic_frame_list GetNameDescriptionList Get list of dynamic frame
get_dynamic_frame GetDynamicFrame Get dynamic frame
get_transform_pose GetTransformPose Get transform between two frames

All these services are available as soon as the node is started.

Dependencies - Poses handlers

Services & messages files - Poses handlers

GetDynamicFrame (Service)

string name
---
int32 status
string message
niryo_robot_poses_handlers/DynamicFrame dynamic_frame

GetPose (Service)

string name
---
int32 status
string message
niryo_robot_poses_handlers/NiryoPose pose

GetTargetPose (Service)

string workspace
float32 height_offset
float32 x_rel
float32 y_rel
float32 yaw_rel
---
int32 status
string message
niryo_robot_msgs/RobotState target_pose

GetTransformPose (Service)

string source_frame
string local_frame

geometry_msgs/Point position
niryo_robot_msgs/RPY rpy
---
int32 status
string message
geometry_msgs/Point position
niryo_robot_msgs/RPY rpy

GetWorkspaceMatrixPoses (Service)

string name
---
int32 status
string message
geometry_msgs/Point[] matrix_position
geometry_msgs/Quaternion[] matrix_orientation

GetWorkspacePoints (Service)

string name
---
int32 status
string message
geometry_msgs/Point[] points

GetWorkspaceRatio (Service)

string workspace
---
int32 status
string message
float32 ratio  # width/height

GetWorkspaceRobotPoses (Service)

string name
---
int32 status
string message
niryo_robot_msgs/RobotState[] poses

ManageDynamicFrame (Service)

int32 SAVE = 1
int32 SAVE_WITH_POINTS = 2
int32 EDIT = 3
int32 DELETE = -1

int32 cmd

niryo_robot_poses_handlers/DynamicFrame dynamic_frame

---
int32 status
string message

ManagePose (Service)

int32 cmd
int32 SAVE = 1
int32 DELETE = -1

niryo_robot_poses_handlers/NiryoPose pose
---
int32 status
string message

ManageWorkspace (Service)

int32 SAVE = 1
int32 SAVE_WITH_POINTS = 2
int32 DELETE = -1

int32 cmd

niryo_robot_poses_handlers/Workspace workspace

---
int32 status
string message

NiryoPose (Message)

string name
string description

float64[] joints 
geometry_msgs/Point position
niryo_robot_msgs/RPY rpy
geometry_msgs/Quaternion orientation

Workspace (Message)

string name # maximum lenght of workspace's name is 30 characters
string description

geometry_msgs/Point[] points
niryo_robot_msgs/RobotState[] poses