Development Of Precision Subdivision Module In The Embedded System For The Non-circular Section Part Spinning

Spinning technology, also called metal spinning forming technology, is a new kind of special forming technology in the modern metal pressure process, integrated forging, pressing, stretching, bending, ring rolling pressure and rolling process characteristics of the less advanced process without cutting processing. Due to the advanced embedded numerical control system, the automation level and machining precision of spinning equipment are higher and higher, by which some complex non-circle section hollow parts can also be achieved.This paper is financially supported by the National Natural Scientific Fund Project Research on spinning forming method and deformation mechanism of the hollow part with non-circular section. A spinning method of straight-line fitting arc based on contour discrete tracking point and its embedded system control scheme are demonstrated. The hardware and software of precision subdivision module in the embedded system are also emphatically researched in this paper.The main research contents as follows:Firstly, the paper compares and analyzes the research situation of numerical control spinning device at home and abroad of which the automaton level and processing precision still need to improve. And then the research situation of embedded numerical control system and application of precision subdivision module in the embedded system are mainly discussed.Secondly, due to the spinning method of straight-line fitting arc based on contour discrete tracking point, the function relation between contour subdivision precision and maximum fitting error is deduced. Then machining control scheme of non-circular section part is analyzed, trajectory of roller is launched according to geometric characteristics, and the method of three-axis linkage control which is driven by servo motor with ball screw is chosen to complete the spinning process of non-circular section part.Thirdly, the controllable digital frequency conversion circuit is developed based on FPGA kernel, the optimization algorithms about coefficient of frequency division and frequency multiplication is mainly analyzed and researched, which is used to calculate for the example of triangle arc section part. Then hardware design of frequency multiplication module and frequency division module of controllable digital frequency conversion circuit are emphatically demonstrated, and circuit waveforms are test and analyzed through Quartusâ…¡device testing platform.Fourthly, the design scheme of FIFO cache memory integrated by FPGA and SRAM is given, FIFO structure is programmed based on FPGA kernel, and the function of each module in the FIFO structure is detailed analyzed and discussed. Then the cause of FIFO metastability effect is demonstrated and the solution method based on Gray-encoder is also given, circuit waveforms are test and analyzed through Quartusâ…¡device testing platform.Fifthly, in order to correct and compensate feedback signal error of bottom encoder, PISO precision correction circuit is developed in the FPGA kernel. The cause of feedback signal error and principle of compensating circuit are explained. Then the hardware design of PISO module is mainly analyzed, through Quartusâ…¡device testing platform and laser curving experiment, the function of PISO module is validated.