Top 10 robotic arm manufacturing companies (Part 1)
In the application of industrial robots, Arm robot (also known as robotic arm) has a great influence on the accuracy and speed of work. In this article, we will briefly explain the use of the robotic arm as well as introduce methods and criteria for choosing good products. In addition, the article mentions enterprise rankings and top 10 companies in the field of Arm robotics.
In the application of industrial robots, Arm robot (also known as robotic arm) has a great influence on the accuracy and speed of work. In this article, we will briefly explain the use of the robotic arm as well as introduce methods and criteria for choosing good products. In addition, the article mentions enterprise rankings and top 10 companies in the field of Arm robotics.
1. What is Arm Robot?
In today’s modern industrial robots, arm-type vertical articulating robots are leading the way. Arm robot is a type of mechanical arm like a human hand, which is pre-programmed, continuously operated and controlled by a program.
The term robotic arm can refer to the entire machine device, or in some cases to just a large, complex part of the robot. Connecting parts are connected by couplings, called “shafts”, which allow transmission of force and circular motion.
A universal robot arm that can be moved with 6 axes, integrated 2 links and 3 joints.
2.Operation principle
- Actuator
The actuator is an important element that makes up the joints of the robot, helping the arm to move up and down, rotate.
In power transmission, electricity is the most common form, while hydraulics and pneumatics are also commonly used. Hydraulics used in some parts have the characteristics that they are easy to generate large forces and are subject to strong external influences.
- Geared motor
The geared motor is a device to increase the power of the motor. If you combine gears with different number of teeth and reduce 1/10 of the rotation, the power of the motor will increase 10 times. This device is similar to a bicycle sprocket. In bicycles, the size of the wheel’s gears has always been different. Normally, bicycles use to change the gears of the rear wheel. If we make this gear the largest gear, with the smallest number of revolutions, the pedal will be lighter, the speed will slow down, even if you climb uphill, it will be easier. In short, the output power can be increased.
- Encoder
The encoder is a device that checks the position (angle) of the motor shaft. Owning an encoder allows the robot to know which direction the robot is in and where it is moving. Conventional optical encoders are equipped with a rotating disc at the motor spindle. The disc has slots for light to pass through in a system, the Light Emitting Diode and the light receiving unit (Photo Diode) confirm the light intensity (contrast) on either side.
Whenever the motor rotates, light passes through or is blocked, so looking at this signal, we can know the angle and speed of rotation. Besides, the servo motor also participates in controlling the position and speed of rotation accurately.
- Transmission system
The transmission system is an important element that helps to transmit the power received from the actuator or geared motor. Thanks to the transmission system, one can change the direction and magnitude of the force. We take the bicycle as an example as mentioned earlier, the chain connecting the crank to the rear wheel corresponds to the transmission. Bicycles run using a transmission, which transmits rotation from the pedals to the rear wheel.
From there, the mechanism of the robot is similar. The robot’s motors are mostly located near the joints, but they can also be located far away by using transmission systems such as belts and gears.
3.Criteria for selection of robotic arm
- Degrees of freedom (range of movement)
The robot arm has an axis number that corresponds to a human joint. The greater the number of axes, the higher the degrees of freedom (wider range of movement), the more complex the operation, corresponding to 3D spatial work. For that reason, in manufacturing plants, vertically articulated robots are becoming mainstream.
When choosing a robotic arm, a robot with a low degree of freedom and a small number of axes will make assembly simple, it is important to have a system configuration that can take advantage of each feature, such as a robot Vertical joints with high degrees of freedom perform work in hard to reach depths.
- Carrying weight (load)
The maximum weight that Arm robot can lift. All companies design the load, so the buyer must consult and choose the load of the workpiece to be shipped. The conveyed volume is closely related to the way the axes and links of the robot arm are connected. For example, a longitudinal articulated robot and a parallel robot have a motor structure that is connected to the head, so we need a large motor closer to the original axis. For that reason, the carrying volume is usually smaller than the size and weight of the entire robot body.
It is worth noting that the balance load of the robot must be considered and the robot arm selected according to the object to be moved.
- Transmission method
The robot arm transmission method is often mentioned as hydraulic, pneumatic, electrodynamic, manual. Depending on each mode of transmission, it is decisive for the speed, intensity, and accuracy of the operating machine.
The most common mode of transmission is electromotive force. Electrodynamic transmission has the advantages of easy operation, high speed, and compactness in installation.
Hydraulic transmission is easy to output a large amount of force, sometimes strongly impacted from the outside, so it is often used as a robot carrying heavy objects. Pneumatic actuators, compared to electric drives, are less accurate in terms of positioning accuracy, but they are capable of flexibly controlling force through air compression. In addition, gas pressure transmission also has the advantage of easily generating large forces, although not as much as hydraulics.
Refer to the object’s load, speed, accuracy of operation. At the same time, the size of the actuator is also a factor worth considering.
- Speed
In terms of the speed of manipulating the robot arm, which one is fast does not waste time. It is important to choose the right equipment for the production line speed. This means that if the robot’s speed is faster than necessary, the waiting time at the end-to-end process increases, creating wasteful inventory that takes time to deduct the increase in processing volume.
In addition, it is essential to establish human safety countermeasures with collaborative robots and unguarded robots.
- Accuracy
In production using industrial robots, the same operations are repeated over and over, so accuracy is required.
Normally, the accuracy and the number of joints are inversely proportional to each other even though the number of joints is large, the accuracy can be improved by enhancing the quality of the servo motor as well as the durability of the material.
