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Three-axis robotic arm
The blogger bought this robotic arm on Taobao. This robotic arm should be 6-axis, but in fact only 3 axes are the core, which is the axis required to establish the coordinate system. The other top three axes are all Some additional mechanical claws control the axis, which is not the axis of the core robotic arm. Therefore, only 3 axes can complete the motion of the robotic arm in the three-dimensional coordinate system, as shown in the figure.
The control principle and motion equation solution of three-axis manipulator
Because directly on the three-axis three-dimensional coordinate system will be a bit more complicated, it will be much simpler to look at the vertical coordinate system first and add an axis.
Vertical coordinate system
In the vertical coordinate system, the robot arm actually only uses axis 1 and axis 2 , which can ensure that the robot arm reaches the point in the vertical plane, so we first establish the hammer coordinate system, list the motion formula, and solve it.
Create a coordinate system
The point reached by the top of the robotic arm is the point （x2,y2）we want, θ1and the sum θ2is the rotation angle of the robotic arm 轴2and the 轴1corresponding servo respectively . （x1,y1）2 coordinate axis corresponding to the point, （△x2,△y2）as in （x1,y1）the current coordinate origin.
Write the equation of motion
Write the motion equation according to the coordinate series:
Solve θ1andθ2
It takes 2 minutes to list the equation and 2 hours to solve the equation. The final hand calculated expression is shown in the figure:
The θ1sum is θ2the angle of the steering gear we need.
Three-axis space
Just add it directly Z轴to reach any point in the space~ Z轴no solution is required, and the movement in the vertical plane of the robotic arm is not affected, just control the steering gear to reach the corresponding angle of movement.
MCU control
Friends who use PYB can refer to my blog to realize the movement of the robotic arm~
Micropython-control of three-axis robotic arm based on single chip microcomputer
If you feel good, please leave a thumbs up for the blogger who is struggling to solve the equation~