How To Set The Coordinate System Of Industrial Robots?

1. Earth (world) coordinate system
Imagine, what would you do if you lost your way on Earth? You may look for a reference point, such as the North Star, to determine your position. Similarly, industrial robots also have a 'North Star', which is the geodetic coordinate system. This coordinate system is a Cartesian coordinate system with the earth as a reference, and all other coordinate systems are directly or indirectly related to it. In multi robot linkage or robot systems with external axis movement, this coordinate system is particularly important.
There exists a relative orientation between any two coordinate systems, which is called attitude.
Common methods for describing posture include Euler angles, coordinate transformation matrices, quaternions, and rotation vectors. Among them, the Euler angle decomposes the attitude description into three continuous rotational processes, with each rotation revolving around an axis orthogonal to the axis revolving around the forward and backward rotations. The three consecutive rotational processes in Euler's angle are as follows: the first rotation angle is the yaw angle ψ (yaw), also known as heading or azimuth, with its rotation axis being the z-axis; The angle of the second rotation is the pitch angle θ, also known as elevation, with its rotation axis being the x-axis; The angle of the third rotation is the roll angle ϕ (roll), also known as the bank angle, and its rotation axis is the y-axis.
2. Base coordinate system
The base coordinate system is the "home" of the robot, consisting of the robot base point and coordinate orientation. This coordinate system serves as the foundation for other coordinate systems of the robot, ensuring the predictability of the movement of the fixedly installed robot. When you stand in front of the robot and manipulate the teaching pendant in the base coordinate system, you will find that by manipulating the teaching pendant up and down, the robot will move along the X-axis; Manipulate the teaching pendant left and right, and the robot will move along the Y-axis; Twist the joystick and the robot will move along the Z-axis. The direction of this coordinate system is consistent with the Cartesian coordinate system in mathematics.
3. Tool coordinate system
The tool coordinate system is the "hand" of the robot, which is used to determine the position and orientation of the tool. This coordinate system consists of the tool center point (TCP) and coordinate orientation, which must be set in advance. When there is no definition, the robot will use the default tool coordinate system. This coordinate system is crucial for ensuring that the tool accurately reaches the predetermined position.
4. Workpiece coordinate system
The workpiece coordinate system is the "eye" of the robot, which is used to determine the position and orientation of the workpiece. This coordinate system consists of the workpiece origin and coordinate orientation, and is usually determined using the three-point method: the X-axis is determined by two known points, the Y-axis is determined by a third point, and the Z-axis direction is determined using the right-hand rule. This coordinate system is the most suitable for programming robots, as it helps the robot "see" the position of the workpiece.
5. Joint coordinate system
The joint coordinate system is the "joint" of a robot, which is set in the joints of the robot and represents the absolute angle of each axis relative to its origin position. This coordinate system is crucial for the motion control of robots, as it ensures that each joint of the robot can accurately move to a predetermined position.
6. User coordinate system
The user coordinate system is the "brain" of the robot, which allows users to customize the Cartesian coordinate system for each workspace. This coordinate system is used for teaching and executing position registers, executing position compensation instructions, etc. When there is no definition, robots will use the geodetic coordinate system. This coordinate system provides users with flexibility, allowing them to customize the robot's workspace according to their own needs.
Have you gained a clearer understanding of the coordinate system of industrial robots through this article? Remember, the coordinate system is the compass for precise robot operation. By understanding and correctly setting these coordinate systems, you can easily operate robots and maximize their efficiency in your factory. Braun Robotics, as a leader in the industry, has always been committed to providing the most accurate and reliable robot solutions. Choosing us means choosing professionalism and efficiency.