Position and Pose

Load Waypoint Pose from Resource Library

pose = lebai:load_pose(name, dir)

• Parameters
  • name Name
  • dir Workspace name. Optional, default root directory
• Returns
  • pose Pose relative to base

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "load_pose", "params": [{"name": "", "dir": ""}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {"kind": ""}, "id": 1 }

Save Waypoint Pose to Resource Library

lebai:save_pose(name, pose, dir)

• Parameters
  • name Name
  • pose Pose relative to base
  • dir Workspace name. Optional, default root directory

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "save_pose", "params": [{"name": "", "dir": "", "data": {}}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {}, "id": 1 }

Load Feature Coordinate System from Resource Library

frame = lebai:load_frame(name, dir)

• Parameters
  • name Name
  • dir Workspace name. Optional, default root directory
• Returns
  • frame Offset relative to base

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "load_frame", "params": [{"name": "", "dir": ""}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {"position": {}, "rotation": {}}, "id": 1 }

Forward Kinematics

cart = lebai:kinematics_forward(pose)

Convert joint angles to Cartesian position and pose through robot forward kinematics.

• Parameters
  • pose Pose
• Returns
  • cart Cartesian space pose

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "get_forward_kin", "params": [{"kind": ""}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {"position": {}, "rotation": {}}, "id": 1 }

Inverse Kinematics

joints = lebai:kinematics_inverse(pose, joints)

Convert Cartesian position and pose to joint angles through robot inverse kinematics. The calculation result depends on current TCP settings and current joint position.

• Parameters
  • pose Pose
  • joints Joint space reference position. Optional, default is current feedback joint position. When multiple solutions exist, the solution closest to joints will be chosen.
• Returns
  • joints Joint space pose

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "get_inverse_kin", "params": [{"kind": ""}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {"joint": [0]}, "id": 1 }

Pose Feature Coordinate System Transformation

c = lebai:pose_trans(a, b)

Using a as user coordinate system $\{A\}$, b is pose description relative to coordinate system $\{A\}$. Finally returns pose description relative to robot world coordinate system

• Parameters
  • a Pose $A$
  • b Pose $B$
• Returns
  • c Pose $C = AB$

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "get_pose_trans", "params": [{"from": {"kind": ""}, "from_to": {"kind": ""}}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {"position": {}, "rotation": {}}, "id": 1 }

Inverse of Pose

c = lebai:pose_inverse(a)

Used to find pose description of inverse of homogeneous matrix $A$ corresponding to pose a. Can be used to solve pose equations.

Inverse of homogeneous matrix equals its transpose $A^{-1}=A^T$.

• Parameters
  • a Pose $A$
• Returns
  • c Inverse of $A$: $A^{-1}$

JSON-RPC

// Request:
{ "jsonrpc": "2.0", "method": "get_pose_inverse", "params": [{"kind": ""}], "id": 1 }
// Response:
{ "jsonrpc": "2.0", "result": {"position": {}, "rotation": {}}, "id": 1 }

Add Pose 3.1.13

pose = lebai:pose_add(base, delta, frame)

Pose after moving delta in frame direction from base position

• Parameters
  • base. Starting pose
  • delta. Pose offset
  • frame. Direction of pose offset, only valid for pose part. Optional, default base direction
• Returns
  • pose. Pose after movement

Example Program

base = {x=-0.4, y=0, z=0.1, rz=-1.57, ry=0, rx=1.57}
frame = {x=0, y=0, z=0, rz=0, ry=-0.78, rx=0} -- Rotate 45° around y-axis to make z-axis point diagonally up
delta = {x=0, y=0, z=0.1, rz=0, ry=0, rx=0} -- Move 0.1m along z-axis
pose = lebai:pose_add(base, delta, frame)
lebai:movej(base, 0.4, 0.1)
lebai:movel(pose, 0.4, 0.1)