Platform Design of Multi-axis Motion Controller and Research of Single Axis Servo Motor Control Algorithm Based on DSP+CPLD
|Course||Mechanical and Electronic Engineering|
|Keywords||Multi-axis controller DSP programmable logic technology PCI bus Motor control|
With the development of the motion control system, motion controller, as the core role of the motion control system, has an increasingly effect on the modern industry. Its capability has a direct impact on the controlled object’s work performance and work efficiency. The issue is established on the existing laboratory platform - 6 DOF welding robot, and its aim is to design an open, multi-axis motion controller to achieve welding robot’s real-time trajectory planning and coordination of the action of the six joints in the welding process. Apart from this, the controller should have properties such as good openness and scalability.In the full research of motion controllers’ development at home and abroad, it is ultimately determined to adopt the PC+controller control program as the overall design of the controller. The controller’s main part choose DSP+CPLD as the major control unit, with the powerful data-processing capabilities of DSP to control the motor, programmable logic of CPLD to conduct associated logical control, its cost-effective general-purpose I/O to expand the I/O of DSP, PCI bus to communicate with PC so as to meet the requirements of stability and speed of data transfer.The application of the programmable logic technology in the process of hardware design and the extension of CPLD chip as a system master have completed a number of logic controls and I/O port expansions. As the focus of this program, this component was classified according to the functions during the designing. In addition, the hardware debugging after the success of the schematic design is one of the main tasks of this thesis. The hardware debugging steps, the debug content and the common problems in the process of debugging are all discussed in the paper.As for the control algorithm of servo motor, this paper introduces the control mode of servo motor briefly, and adopts the speed control mode in this program in the end, giving the basis to calculate and adjust the various parameters in this mode. As for the motor control strategy, taking simple PID as the starting point, this paper steps down gradually, drawing characteristic curve of the drive with the help of analysis of experimental results, finding the dead zone of servo motor control, zero correction and some other problems, and putting forward a solution to these problems. As for the stability of motor control, this program tries to adjust PID parameters on line through fuzzy control of the motor combined with advanced control algorithms. Eventually it will work out fuzzy PID control algorithms with dead-zone and high-speed feedforward. In the process of tracking the complex trail of servo motors this program proposes cubic polynomial interpolation operations and improvements to its application, and ultimately achieves the movement accuracy and speed of the controller.As for the software, to complete the motion controller’s function and to implement algorithms of single motor and multi-motors on the DSP, this thesis has offered a flow chart of program design of the overall algorithm, and a detailed explanation about the key design concepts.