Industrial Robot Control System: The Intelligent Core of Robot Maintenance

The industrial robot control system, often referred to as the brain of the robot, is a key factor determining its functions and applications. It sends command signals to the drive system and actuators according to preset programs and implements control. Next, this article will delve into the robot control system.

The control system of an industrial robot The "control" objective is to make the controlled object operate in the expected manner. The basic prerequisite for achieving this objective is familiarity with the characteristics of the controlled object. Specifically, the essence of control is the precise management of the output torque of the drive.

Basic Working Principle of Robot Maintenance The working principle of a robot is based on a teach-and-playback mechanism. The robot teach pendant, also known as lead-through teaching, involves manually guiding the robot to complete the action sequence step by step according to actual requirements. During this process, the industrial robot automatically records the posture, position, process parameters, and motion parameters of each action, and automatically generates a program for continuous execution. After teaching is completed, simply issuing a start command allows the robot to automatically complete the entire sequence according to the taught content.

Robot Control Classification Based on whether a feedback mechanism is present, robot control can be divided into two categories: open-loop control and closed-loop control. The prerequisite for precise open-loop control is: accurately mastering the model of the controlled object, and that this model remains unchanged during the control process.

According to the different desired control variables, robot control can be divided into three types: force control, position control, and hybrid control. Position control is further subdivided into single-joint position control (including position feedback, position-velocity feedback, position-velocity-acceleration feedback) and multi-joint position control. Multi-joint position control can be further divided into resolved motion control and centralized control. Force control includes direct force control, impedance control, and force-position hybrid control.

Intelligent control methods for robot maintenance encompass various forms such as fuzzy control, adaptive control, optimal control, neural network control, fuzzy neural network control, and expert control.

Control System Hardware Configuration and Structure From electrical hardware to software architecture, the control system for robot maintenance involves numerous complex components. Given that the robot control process requires handling a large number of coordinate transformations and interpolation calculations, while also accommodating low-level real-time control requirements, most robot control systems on the current market adopt a hierarchical microcomputer control system structure, typically a two-level computer servo control system.

The specific operational process is as follows: After receiving the job instructions input by the operator, the main control computer first parses the instructions to determine the hand motion parameters. Subsequently, kinematics, dynamics, and interpolation calculations are performed, ultimately yielding the coordinated motion parameters for each robot joint. These parameters are transmitted via communication lines to the servo control level, serving as setpoint signals for each joint's servo control system. The robot driver on the joint converts this signal into an analog signal, which then drives each joint to produce coordinated motion.

Sensors feed back the motion output signals of each joint to the servo control level computer, forming a local closed-loop control, thereby achieving precise control of the robot's spatial motion for maintenance.

PLC-based Motion Control Regarding PLC-based motion control, there are primarily two methods: The first method utilizes the PLC output port to issue pulse commands to drive the motor, while achieving closed-loop position control of the robot servo motor with the help of general-purpose I/O or counting components. The second method involves achieving closed-loop position control of the motor through an externally expanded position control module of the PLC. This method primarily relies on high-speed pulse output for control, falls under the category of position control, and is typically focused on point-to-point position control.

Documentation archive number: 24214. Content organized from the old site database.