In the previous article, we introduced four of the nine parameters for selecting industrial robots, and here we will discuss the remaining five.
05 Repetitive accuracy
Similarly, this factor also depends on your application situation. Repetitive accuracy can be described as the ability of a robot to complete routine work tasks and reach the same position every time.
Generally between ± 0.05mm and ± 0.02mm, or even more precise. For example, if you need your robot to assemble an electronic circuit board, you may need a super precision repetitive precision robot. If the application process is relatively rough, such as packaging, palletizing, etc., industrial robots do not need to be so precise.
On the other hand, the selection requirements for robot accuracy in assembly engineering are also related to the transmission and calculation of dimensions and tolerances in various stages of assembly engineering, such as the positioning accuracy of incoming materials and the repeated positioning accuracy of the workpiece itself in the fixture. This indicator is represented in 2D as positive or negative ±. In fact, due to the fact that the motion repetition points of the robot are not linear but move in 3D space, the actual situation of this parameter can be any position within the spherical space within the tolerance radius.
Of course, the current combination of motion compensation with current machine vision technology will reduce the robot's requirements and dependence on incoming material accuracy, and improve the overall assembly accuracy.
06 Speed
This parameter is closely related to each user. In fact, it depends on the Cycle Time that needs to be completed in the assignment. The specification table lists the maximum speed of this model of robot, but we should know that considering the acceleration and deceleration from one point to another, the actual running speed will be between 0 and the maximum speed. This parameter is usually measured in degrees per second. Some robot manufacturers also label the maximum acceleration of the robot.
07 Body weight
The weight of the robot body is an important factor in designing the robot unit. If an industrial robot must be installed on a customized machine, or even on a guide rail, you may need to know its weight to design the corresponding support.
08 Braking and Moment of Inertia
Basically, each robot manufacturer provides information about their robot braking system. Some robots are equipped with brakes on all axes, while other robot models are not equipped with brakes on all axes. To ensure precise and repeatable positions in the workspace, it is necessary to have a sufficient number of brakes. Another special situation is that when an unexpected power outage occurs, the axle of the load-bearing robot without brakes will not lock, which poses a risk of accidents.
At the same time, some robot manufacturers also provide the rotational inertia of robots. In fact, for the safety of the design, this will be an additional guarantee. You may also notice the applicable torque on different shafts. For example, if your action requires a certain amount of torque to complete the work correctly, you need to check whether the maximum torque applicable on that axis is correct. If the selection is not correct, the robot may shut down due to overload.
09 Protection level
Select a standard that meets a certain level of protection (IP level) based on the usage environment of the robot. Some manufacturers offer a product range of identical robotic arms with different IP protection levels for different occasions. If the robot works in products related to food production, pharmaceuticals, medical devices, or flammable and explosive environments, the IP level will vary. Generally, standard: IP40, oil mist: IP67, cleanliness ISO level: 3.