Small guide for rapid formation of manipulator (11): standard nomenclature of coordinate system

Directory ：

Quick completion guide of mechanical arm （ zero ）： Main contents and analysis methods of the guide

Quick completion guide of mechanical arm （ One ）： The development of manipulator

Quick completion guide of mechanical arm （ Two ）： Application of mechanical arm

Quick completion guide of mechanical arm （ 3、 ... and ）： Mechanical structure of mechanical arm

Quick completion guide of mechanical arm （ Four ）： Reducer of key components of mechanical arm

Quick completion guide of mechanical arm （ 5、 ... and ）： End actuators

Quick completion guide of mechanical arm （ 6、 ... and ）： Stepper motor driver

Quick completion guide of mechanical arm （ 7、 ... and ）： Description method of robot arm posture

Quick completion guide of mechanical arm （ 8、 ... and ）： Kinematic modeling （ standard DH Law ）

Quick completion guide of mechanical arm （ Nine ）： Forward kinematics analysis

Quick completion guide of mechanical arm （ Ten ）： Reachable workspace

Quick completion guide of mechanical arm （ 11、 ... and ）： Standard naming of coordinate system

Quick completion guide of mechanical arm （ Twelve ）： Inverse kinematics analysis

******************** Here is the main body ********************

         In order to describe the pose relationship between the manipulator and the operating object , We need to give special names to the manipulator and workspace and determine special “ standard ” Coordinate system . The five coordinate systems shown in the following figure are the coordinate systems that need to be named in this chapter . The naming of these five coordinate systems and their subsequent application in the programming and control system of the manipulator provide a kind of universality with the characteristics of simple and easy to understand . The motion of all manipulators will be described according to these coordinate systems .

1. Base coordinate system {B}

         Base coordinate system {B} Located on the base of the operating arm . It just gives the coordinate system {0} Another name for . Because it is fixedly connected to the static part of the manipulator , So it is sometimes called connecting rod 0.

2. Table coordinate system {S}

         Table coordinate system {S} The location of is related to the task . As shown in the figure below , It is located on a corner of the manipulator workbench . For users of the manipulator system , Table coordinate system {S} It is a general coordinate system , All the movements of the manipulator are performed relative to it . Sometimes called task coordinate system 、 World coordinate system or universal coordinate system . The workbench coordinate system is usually determined according to the base coordinate system , namely BT.

3. Target coordinate system {G}

        Target coordinate system {G} It is the description of the tool position when the manipulator moves the tool . Especially at the end of the manipulator movement , The tool coordinate system should coincide with the target coordinate system . Target coordinate system {G} It is usually determined according to the workbench coordinate system . In the diagram above , The target coordinate system is located at the shaft hole where the pin shaft is to be inserted . Generally speaking , The motion of all manipulators can be described according to these coordinate systems , They provide a standard for describing the operation of the manipulator .

4. Working coordinate system {T}

         Tool coordinate system {T} Attached to the end of the tool held by the mechanical arm . When there is no clamping tool in the hand of the manipulator , Tool coordinate system {T} The origin of is between the fingers of the manipulator . The tool coordinate system is usually determined according to the wrist coordinate system . In the diagram above , The origin of the tool coordinate system is defined at the end of the gripper pin shaft of the manipulator .

5. Wrist coordinate system {W}

         Wrist coordinate system {W} The end link attached to the mechanical arm . The coordinate system fixed on the connecting rod at the end of the manipulator can also be called the coordinate system {N}. In most cases , Wrist coordinate system {W} The origin of is located on the wrist of the manipulator , It moves with the end link of the manipulator . It is defined relative to the base coordinate system , namely