Carrier coordinate system inertial coordinate system world coordinate system

World coordinate system

The world coordinate system is a special coordinate system , It establishes the reference system needed to describe other coordinate systems . in other words , The world coordinate system can be used to describe the position of all other coordinate systems or objects . So many people define the world coordinate system as “ The maximum coordinate system we are concerned with ”, Through this coordinate system, we can describe and depict all the entities we want to depict .

World coordinate system is also called global coordinate system or universal coordinate system .

Object coordinate system

An object coordinate system is associated with a particular object , Each object has its own specific coordinate system . The coordinate systems of different objects are independent of each other , Can be the same , Can be different , There's no connection . meanwhile , The object coordinate system is bound to the object , Binding means that an object moves or rotates , The object coordinate system has the same translation or rotation , Motion synchronization between object coordinate system and object , Bind to each other .

For example, the object coordinate system ： Each of us has our own coordinate system , When we decided to move on , The absolute direction of each person's actual progress is different , It could be North , Or south , Or other directions . Here, front, back, left and right are the concepts in the object coordinate system . When you tell Zhang San to go ahead , It means that Mr. Zhang San moves along the front of his object coordinate system . As for whether Zhang San is going east or North , This is the description of Zhang San's motion in the world coordinate system .

Object coordinate system is also called model coordinate system .

Inertial coordinate system

Inertial coordinate system is produced to simplify the transformation from world coordinate system to object coordinate system . The origin of the inertial coordinate system coincides with the origin of the object coordinate system , The axis of the inertial coordinate system is parallel to the axis of the world coordinate system . After introducing the inertial coordinate system , To convert the object coordinate system to the inertial coordinate system, you only need to rotate , The conversion from inertial coordinate system to world coordinate system only needs translation .

contact

The following figure shows the relationship between the three coordinate systems . In the object coordinate system of the robot ,y The shaft points from the foot to the head x The axis points to its left . Rotate around the origin of the object coordinate system . Knowing that the axis of the object coordinate system is parallel to the world coordinate system, we get the inertial coordinate system . Last , Translating the origin of the inertial coordinate system to the origin of the world coordinate system completes the conversion from the inertial coordinate system to the world coordinate system .