Five Parameters To Help You Choose Industrial Robots

Due to the different structures, uses, and requirements of industrial robots, their performance also varies. Generally speaking, industrial robot manufacturers will attach a description of the main technical parameters to their products. Of course, there is a lot of information in the data, including the number of control axes, load-bearing capacity, working range, motion speed, position accuracy, installation method, protection level, environmental requirements, power supply requirements, robot external dimensions and weight, and other parameters related to use, installation, and transportation.
However, to evaluate the performance of a robot, it mainly depends on these five parameters:
1. The working range of the robot
The working range of industrial robots refers to the spatial area that can be reached by the robot arm or hand mounting point, usually with the center of the robot arm end mounting plate as the reference point, excluding the size and shape of end effectors (such as fixtures, welding guns, etc.). This range determines the maximum area that robots can cover during task execution and is one of the important indicators for measuring robot performance.
The working range of industrial robots is influenced by various factors, including the length of the robotic arm, the number of joints, the range of joint angles, and degrees of freedom. For example, robots with longer arms can cover a wider space, while the number of joints and angle range directly affect their flexibility and range of motion. In addition, the control system, load capacity, and safety restrictions of the working environment of robots can also affect their working range. In practical use, it is necessary to consider the possible collisions that may occur after installing the end effector.
2. The carrying capacity of robots
Carrying capacity refers to the maximum mass that a robot can withstand at any position within its working range, and this indicator is one of the important parameters for measuring robot performance. According to different application scenarios and requirements, the carrying capacity of industrial robots varies greatly, usually measured in units of load mass (kg).
The carrying capacity not only depends on the quality of the load, but is also closely related to the robot's operating speed, acceleration, and the quality of the end effector. For example, during high-speed operation, for safety reasons, the maximum weight of objects that the robot can grasp at high speeds is usually used as the indicator of carrying capacity. In addition, the length, structural strength, and power of the driving system (such as motors and reducers) of the robot arm also affect its load-bearing capacity.
Generally speaking, the load-bearing capacity provided in the product technical parameters refers to the weight of objects that can be grasped by the robot during high-speed motion, assuming that the center of gravity of the load is located at the wrist reference point without considering the end effector. Therefore, when designing application solutions, it is also necessary to consider the weight of the end effector. Processing robots such as welding and cutting do not need to grasp objects, and the carrying capacity of the robot refers to the mass of end effectors that the robot can install. The cutting robot needs to bear the cutting force, and its carrying capacity usually refers to the maximum cutting feed force that can be borne during cutting.
3. Degrees of Freedom
The degree of freedom (DOF) of industrial robots refers to the number of joints in the robot mechanism that can move independently, and is an important indicator for measuring the flexibility and functionality of robots. The degrees of freedom are usually represented by the number of linear movements, swings, or rotations of an axis, with each joint corresponding to one degree of freedom. Each degree of freedom typically corresponds to an independent axis, so the degrees of freedom are equal to the number of joints in the robot.
In the field of industrial robots, the design of degrees of freedom depends on specific applications, generally ranging from 3 to 6 degrees of freedom, but there are also special applications that require more or less degrees of freedom. For example, common six axis robots are widely used in fields such as automotive manufacturing and electronic assembly due to their flexibility, while four axis SCARA robots focus on precise operations within a plane.
4. Movement speed
The motion speed of industrial robots refers to the speed at which the robot moves while performing tasks, usually measured in degrees per second (DPS) or linear velocity (mm/s). Generally speaking, the motion speed of a robot is mainly determined by the joint speed, which is the rotational speed of each joint of the robot, usually measured in degrees per second (°/s). The speed of motion determines the work efficiency of a robot and is an important parameter reflecting the performance level of the robot.
Of course, the faster the movement speed, the better. This still depends on the application scenario. For example, when a welding robot is performing welding work on a car body, if the welding speed is too fast, it may lead to a decrease in the quality of the weld seam, resulting in problems such as incomplete welding and uneven weld seam; If the speed is too slow, it will reduce production efficiency and increase production costs. Of course, the speed of movement can be adjusted.
5. Positioning accuracy
The positioning accuracy of industrial robots is one of the important indicators to measure their performance, usually divided into two aspects: repetitive positioning accuracy and absolute positioning accuracy.
Repetitive positioning accuracy refers to the precision at which the end effector of an industrial robot can reach the target position when performing the same task multiple times. This indicator reflects the consistency of robots under the same conditions. For example, high-speed and high-precision industrial robots used in electronic manufacturing have a repeatability accuracy of ± 0.02mm.
Absolute positioning accuracy refers to the deviation between the actual position reached by the robot's end effector and the theoretical target position. This indicator is usually lower than the accuracy of repeated positioning, as absolute positioning accuracy is affected by mechanical errors, control algorithm errors, and system resolution. In most cases, the repeat positioning accuracy is higher than the absolute positioning accuracy, because the repeat positioning accuracy mainly depends on the accuracy of the robot joint reducer and transmission device, while the absolute positioning accuracy is influenced by more initial conditions and environmental variables.
Above are the five important parameters for evaluating the performance of industrial robots, which are usually written in the product manual of industrial robots. Mastering these basic knowledge will give you a general understanding of the performance of industrial robots.