How to choose industrial robots? Nine Points for Attention in the Selection of Industrial Robots
For senior mechanical and electrical engineers in the automation industry, selecting the right robot may be a simple task. But for those designers or factories who are ready to purchase or import robots for the first time, they may be confused. So, how to choose a suitable industrial robot? The following nine considerations for the selection of industrial robots are discussed:
1. Application occasions
First of all, the most important source is to evaluate the imported robot, what kind of application it is used in and what kind of manufacturing process.
If the application process needs to be completed by the machine cooperatively next to the manual, the cooperative robot should be a good option for the semi-automatic line with common man-machine mixture, especially the situation where the work station needs to be changed frequently or the line needs to be shifted, as well as the situation where the new torque sensor is used.
If you are looking for a compact material handling robot, you may want to choose a horizontal joint robot.
If you are looking for a situation where small objects can be quickly picked up and put down, the parallel robot is most suitable for this demand.
2. Payload
Payload is the maximum load that a robot can carry in its workspace. From 3Kg to 1300Kg, for example. If you want the robot to finish moving the target workpiece from one station to another, you need to pay attention to adding the weight of the workpiece and the weight of the robot gripper to its workload. In addition, special attention should be paid to the load curve of the robot. The actual load capacity will be different at different distances in the space range.
3. Degrees of freedom (number of axes)
The number of axes configured by the robot is directly related to its degree of freedom. For a simple and straightforward situation, such as taking from one belt line to another, a simple 4-axis robot is enough.
However, if the application scene is in a narrow workspace and the robot arm needs a lot of twisting and rotation, a 6-axis or 7-axis robot will be the best choice.
The number of axes generally depends on the application. It should be noted that on the premise of cost permitting, the flexibility of selecting more shafts is not a problem. In this way, it is convenient to reuse the transformation robot to another application process, which can adapt to more work tasks, rather than finding that the number of axes is insufficient.
4. Maximum motion range
When evaluating the target application, you should know the maximum distance that the robot needs to reach. Choosing a robot is not just based on its payload - it also needs to consider the exact distance it reaches. Each company will give a map of the action range of the corresponding robot, from which it can be judged whether the robot is suitable for a specific application. The horizontal range of motion of the robot. Pay attention to the non working area near and behind the robot.
5. Repeated positioning accuracy
Similarly, this factor also depends on your application situation. Repetition accuracy can be described as the ability of a robot to complete routine tasks and reach the same position every time.
It is 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 robot with super precision and repeatability. 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 each link of assembly engineering, such as the positioning accuracy of incoming materials, and the repetitive positioning accuracy of the work piece itself in the fixture.
6. Speed
This parameter is closely related to each user. In fact, it depends on the Cycle Time that needs to be completed in the job. The specification table lists the maximum speed of this type 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 will also mark the maximum acceleration of the robot.
7. Body weight
The weight of robot body is an important factor in the design of robot unit. If the industrial robot must be installed on a customized machine, or even on the guide rail, you may need to know its weight to design the corresponding support.
8. Brake 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 others are not equipped with brakes on all axes. To ensure accurate and repeatable positions in the work area, a sufficient number of brakes are required. In another special case, when an unexpected power failure occurs, the axle of the load bearing robot without brakes will not lock, which may cause an accident risk.
9. Degree of protection
According to the use environment of the robot, select a standard that reaches a certain level of protection (IP code). Some manufacturers provide the same robot with different IP protection grades for different occasions. If the robot works in food related products, medicines, medical appliances, or flammable and explosive environments, the IP rating will be different.