Research And Implementation Of Several Key Techniques Of Embedded Motion Controller

The motion controller, as the key component of Computerized Numerical Control(CNC) system, is the research focus of CNC technology. This dissertation aims at developing a controller to meet the requirements of openness, performance stability, functional integration and high reliability.The motion control algorithm and key technologies of embedded motion controller were studied in this dissertation.The main researches of this dissertation are as follows:Firstly, the hardware structure of embedded motion controller based on ARM, DSP and FPGA was introduced. ARM, as the main control unit, is responsibe for the G code analysis, state switch and interacting with the HMI; DSP is responsible for interpolation, velocity planning and look-ahead algorithm; FPGA is the bridge for ARM and DSP communication, besides, it is responsible for pulse output and I/O management. Linux operation system runs on the ARM. Therefore, when accessing the peripherals, the virtual address instead of physical address shoule be used. DSP hardware configuration was studied, and the booting from NOR Flash was realized; FPGA pulse homogenization scheme was put forward.Secondly, interpolation and velocity planning algorithm for motion control were studied in detail, multi-axis linear interpolation and circular interpolation algorithm were realized; the interpolation algorithm of eclipse and spartial arc based on geometry transform was studied. The trapezoidal and S-shaped velocity planning algorithms, which are commonly used in the motion control system, were discussed and optimized. Based on piecewise Hermite interpolation and three-times spline fitting, the PVT/Complete/Percent/Continuous description of PVT(Position-Velocity-Time) algorithm were discussed in detail. Through software simulation, the correctness and validity of the algorithm was verified.Thirdly, the continuous path control was studied in detail, and the continuous path processing framework was put forward. The transition model of line to line, line to arc, arc to line, arc to arc, of the inflection point was established, the velocity constraint conditions was analysed. Because the inflection point velocity constraint model consists of recursive inequalities, it is difficult to be achieved in practice. By introducing the proportional coefficient and correction of acceleration, an feasible algorithm of dynamic look-ahead was put forward.Finally, the function and performance of motion controller was tested by the experiments on the motion control system of automatic dispensing equipment which was established based on the controller. Continuous processing of multi-segment line and spline curve was achieved. The results indicate that the motion controller developed has powerful function and high performance.