Research On Industrial Robot Controller With Drivers Integrated And Its Software Development

Industrial robots are playing an increasing role in the modern industrial automation process, while the domestic robot systems lag far behind those of foreign brands in functionality, stability and reliability, which is detrimental to the development of the domestic robot industry. As the core component of a robot control system, robot controller directly affects the performance of the robot control system, such as openness, position accuracy, trajectory accuracy and so on. But it’s also a technical problem. For sake of the industrialized development of domestic industrial robot, it’s quite urgent to resolve this problem and develop the robot controller with independent intellectual property rights.Under the project background of the research on the robot control system with drivers integrated and aiming to implement the PC control system, this article focuses on the following issues: the robot calibration, trajectory planning and software design.First, kinematics is the basis of the robot control system, and the kinematic model can greatly influence the system accuracy. This article finishes the kinematic modeling of a six-DOF industrial robot by MDH method, and solves the kinematic forward and inverse equations with nominal parameters. Considering the geometric errors resulting from robot manufacturing and assembly process, the calibration algorithm of industrial robot is researched. The current researches on robot calibration are briefly summarized, and then the robot calibration algorithm based on position vector errors is proposed. Simulations and experiments are conducted to verify the effectiveness of this method.Second, the robot trajectory planning algorithms are explored. Given that the typical S curve trajectory planning method with seven segments is not sufficient for practical applications, this article proposes a S curve planning method based on critical displacements under reasonable assumptions. This method can analyze the concrete form of S curve according to the constraints on displacement, velocity, acceleration and jerk, and thus finish the motion planning. Considering the JOG function of the control system, the real time trajectory planning methods in joint, world and tool coordinate system is introduced. As to the continuous trajectory in task space, this article focuses on the smooth transition between the adjacent unit trajectories with gesture planning taken into consideration. A transition method based on the 5th degree Bezier curve is proposed, and simulations are implemented to validate the method.Finally, based on the aforementioned research results, the PC control software for the project is developed on Windows with RTX extended. A hierarchical software design solution is proposed to satisfy the demands of the control system. In order to realize the data interaction between PC software and the sublayer controller, the standard Ethernet bus and UDP protocol are adopted, and simulations are made to test the real-time and reliability performance.