What is SCARA Robot?
SCARA robots, also known as Selective Compliance Assembly Robot Arm or joint robotic arm, which are one of the most common forms of industrial robots in today's industrial field. SCARA robots are suitable for mechanical automation in many industrial fields, such as automatic assembly, painting, handling, welding and so on.
1. The movement of the SCARA robot arm.
The robot's robotic arm is made of several rigid rods and rotating or moving joint, which is an open ring joint one end fixed on the base, the other end is freely mounted end actuator (such as a welding gun). When operating the robot, end effector at the front of the robot arm must be in a position and attitude appropriate to the processed workplace, as well as these positions and postures are synthesized by the movement of several arm joint.
Therefore, in SCARA robot motion control, we must know the relationship between the variable space of each joint of the robot arm and the position and posture of the end effector, which is the robot kinematic model. Once the geometry of a robot arm is determined, its kinematic model can be determined, which is the basis of the robot's motion control.
2. Robot track planning.
The motion path of the end of the robot manipulator is the space curve of the motion trajectory from the position and posture of the starting point to the position and posture of the posture. The task of trajectory planning is to use a function to "interpolate" or "approach" a given path and produce a series of "control set points" to control the robot movement. At present, the commonly used track planning methods include spatial joint interpolation and Cartesian spatial planning.
3. The control of the SCARA robot.
When a robot dynamic motion equation has been given, its control purpose is to maintain the robot's dynamic response according to predetermined performance requirements. However, because of the inertial force, coupling reaction force and gravity load of the robot, it is quite complicated and difficult to control it with high precision, high speed and high dynamic quality. At present, the control method used in industrial robots is to treat each joint of the robot as a separate servo mechanism, just put a nonlinear, inter-joint-coupled variable load system, reduced to a linear non-coupled separate system.
Advantages of SCARA robots
- Compact structure, large operating range and small installation footprint.
- Has a high accessibility. Joint coordinate robots can move their hands into a closed space like a car body for work, and right-angle coordinate robots cannot do such work.
- No rails are required because there is no moving joint. Rotating joint are easy to seal, because of bearing parts are a large number of production of standard parts, resulting in friction and inertia is small, good reliability.
- The required SCARA drive torque is small and the energy consumption is small.
- Replace a lot of complex work that is not suitable for manpower and harmful to health.