1. Body structure
The industrial robot body is composed of rotating base, big arm, small arm and other parts, which is the most direct mechanical structure outside the robot. The robot body structural parts include cast iron, cast steel, cast aluminum, structural steel and other materials.
2. Reducer
The reducer is used to carry the load of each joint of the robot. The high speed and low torque output by the motor form a low speed and high torque after passing through the reducer, thus improving the output torque of each axis of the robot, so that the robot can bear a large load. Robots have high requirements for reducers, such as small size, small mass, large reduction ratio, high accuracy and shock resistance.
At present, there are two kinds of reducers widely used in multi-joint robots: one is RV reducer, the other is harmonic reducer. RV reducers are generally placed at heavy load positions such as boom and shoulder due to their higher rigidity and rotation accuracy; The harmonic reducer is placed on the forearm and wrist.
3. Drive control system
The drive control system is mainly used to control the robot to move according to the set motion parameters. It mainly includes servo driver, servo motor and controller.
(1) The servo motor is mainly used to drive the joints of the robot. It is required to have the maximum power mass ratio and torque inertia ratio, high starting torque, low inertia and a wide and smooth speed range;
(2) The servo driver is a device that drives the servo motor to move. According to the instructions of the controller, the servo driver gives the corresponding current to the servo motor, so as to ensure that the servo motor moves according to the required motion speed, acceleration, running position and other conditions, so as to ensure that the motion of the mechanical arm meets the set requirements.
(3) The controller can manually set its internal parameters to realize the position control, speed control, torque control and other functions of the robot.
4. "Axis" function of six-axis serial robot
Traditional six-axis industrial robots generally have 6 degrees of freedom, and the common ones include rotation (S-axis), lower arm (L-axis), upper arm (U-axis), wrist rotation (R-axis), wrist swing (B-axis) and wrist rotation (T-axis). Six joints are synthesized to achieve 6-DOF movement at the end.
One axis: the first axis is the part connecting the base, bearing the weight of the whole robot and the left and right rotation of the base;
Second axis: control the forward and backward swing of the robot boom;
Three-axis: control the forward and backward swing of robot jib;
Four axes: control the rotation of robot jib;
Five-axis: control and fine-tune the rotation of the wrist of the manipulator, usually when the product is grabbed, the product can be overturned;
Six axes: used for the rotation function of the end fixture part, which can more accurately locate the product.
TIps
According to different application scenarios, the wrist part also has different structural design methods. B (bend) represents bending structure, and R (reverse) represents rotating structure.