Industrial robots can accurately perform high-precision tasks such as welding and assembly, and their core lies in the unique control system architecture and programming methods. Modern industrial robots commonly adopt closed-loop control systems, which convert human instructions into precise robotic arm movements through the collaborative work of controllers, servo drives, and sensors.
1. The evolution path of programming methods
① Teaching Programming
As the most traditional way, the operator guides the movement trajectory of the robotic arm through a handheld teaching pendant. This method is suitable for simple repetitive tasks, such as in the automotive spot welding scene, where the operator guides the welding gun through each welding point in sequence, and the system records the coordinates to achieve a repeat positioning accuracy of ± 0.1mm. However, for complex surface machining tasks, instructional programming requires significant debugging time.
② Offline programming
The emergence of technology has broken through the limitations of physical space. Engineers build a virtual working environment in 3D simulation software and automatically generate the optimal motion path after importing CAD models. A certain aircraft parts company used interactive manufacturing application software to plan the skin riveting path, reducing the programming time from 3 days to 2 hours, while controlling the trajectory error within 0.05mm. This method can also detect the collision risk between the robotic arm and the fixture in advance.
③ Self-programming
Representing the future direction, robots equipped with vision systems can perceive environmental changes in real time. For example, AGV handling robots use laser SLAM technology to establish environmental maps, autonomously plan paths in dynamic warehousing scenarios, and can recalculate avoidance routes within 200ms when encountering sudden obstacles. The welding robot can automatically adjust the welding gun angle and travel speed through the melt pool vision monitoring system.
2. The accuracy guarantee mechanism of the control system
At the hardware level, the dual encoder feedback system plays a crucial role. The 17-bit absolute encoder at the servo motor end and the 21-bit multi-turn encoder at the joint end form a double check, which can effectively eliminate errors caused by the transmission clearance of the gearbox.
Temperature compensation technology is equally important. After continuous operation for 4 hours, the RV reducer will generate a temperature rise of about 15 ℃, resulting in a gear clearance change of 0.008mm. The advanced control system corrects the thermal deformation error in real time through a temperature sensor embedded in the reducer, ensuring the accuracy and stability of 8-hour continuous operation.
The breakthrough in force control technology has endowed robots with "touch". The six-axis force sensor can detect forces and torques in three directions (XYZ), and with an impedance control algorithm, the polishing robot can maintain a constant contact force of 10N ± 0.5N. This technology has been successfully applied to the polishing of aircraft engine blades, controlling the surface roughness within Ra0.4 μm.
3. The changes brought about by cutting-edge technology
The low latency feature of 5G technology makes remote precision operation possible. A maintenance robot at a nuclear power plant achieved precise control from 1000 kilometers away through a 5G network, with an end-to-end latency of only 8ms.
With the penetration of AI technology, robots are beginning to possess autonomous decision-making capabilities. The advancement of emerging technologies is driving the continuous evolution of industrial robots towards smarter and more precise directions.