Homemade computerized embroidery machine.
Registration code (password) are everywhere: 234560 (333)
The principle of operation of the computer embroidery machine. The idea behind this decision is this: Take a cheap b / a IBM PC computer type P-1 and any sewing machine, via the parallel port (LPT IBM PC connector for connecting a printer), a control device 8 keys are connected transistor two stepper motor (hereinafter SM) controlling the movement of the device embroidery machine hoop on the coordinates X and Y, (hereinafter SPC, also known as - the coordinate system). The computer re-creases all the problems and provides a speed of more than 1000 embroidery stitches per minute in the presence of sufficient capacity drives that exceeds the rate of any existing municipal computer embroidery machines. Attachment to a computer compact and cheap. The engine also has a sewing machine to control the thyristor switch, in its simplest form is reversible (with separate excitation winding) DC motor. The engine receives the voltage polarity pulse duration adjustable in the commission of trafficking in the machine shaft. As soon as the shaft of the sewing machine to finish the next turn when the SM will finish moving the hoop, the PC will calculate the current position, will give a new team to manage the main drive. This can be either simple stress relief (to be a natural deceleration), or a forced slowing down to a complete stop - the voltage at the motor field winding is fed to the opposite polarity or pulse voltage of 2 types. If the stitch length is less than 2 mm (the needle in the up state is about half of the turnover of the machine shaft), and SM time to move the hoop - reached a top speed of embroidery! Then again, PC displays a new command to the rotation shaft of the machine, the supply voltage is supplied to the motor drive, etc., until all the embroidery piece of embroidery of the current color. The dynamics of the actuators is taken into account in the SM software. If the computer controls the step motor, first set for a starting speed, then with each step it increases to realistic as possible, followed by rotation with a constant velocity. And when the step motor drive must be stopped, there is inhibition (rapid decrease in the rate of SM to a minimum and stop). In principle, the algorithm is quite simple, there is a circuit diagram of the acceleration and deceleration, the interval of each step of the motor is calculated as a function of total displacement, which stands at the time of dispersal, the movement with maximum speed and braking, the drive to take the weight of the body. The essence of software management: In the IBM PC is a chip timer, you have access to DOS and Windows 98 (Windows XP on more complex rules, and this requires a more powerful computer, so work in embroidery mode it is not provided). In the three timer counters, two of which you can actually use, and with them, you can specify the duration of each step for the two SM. That is, program, with the calculated data for each of these cases, taking into account the real dynamic characteristics of the drives, calculates each step, sets the pulse width (for both SM) for each subsequent step of acceleration, deceleration, and movement! There is no any problem with their controllers, and communication with a PC! I was all that was tested in 1988 on a computer of its own making "Murman". Further, through the parallel port on the management of keys issued to SM. Keys are managed directly from the port 378h, the movement created by the shift register bits in the port to the left or the right (but this is done in software in a PC - simply the conclusion of a new byte) to increase the torque step motor, first pulse is applied to the next coil, and then removed from the previous one. The number of shifts is strictly proportional to (in the particular case equal to) the length of the stitches of the fi-la Design - umbilical cord embroidery machine format. The computer at the moment is completely at the disposal of embroidery machine. In the old days the PC was worth> $ 1000, to apply the IBM PC would have been wasted, now the PC for this purpose can be purchased for $ 50, quite a Pentium-150 Mhz, HDD 2-3 Gb, RAM 16 Mb. Monitor 14'' 600x800. When the needle punctures the fabric, moving "inside" the machine, and the thread goes around the canoe, the processor is more than enough time to complete all preliminary calculations for the SM parameters, and the main drive (GP) for the next stitch, the calculation of the ancillary data for the row status bar, display screen to change the design and service Operating System. The basic relationship between force and acceleration during acceleration SM: F (V) - Fc = M * A; A = (F (V) - Fc)) / M = F (V) / M - Fc / M; (1) F (V) - power of dispersal, c taking into account the changes in torque step motor when the rotational speed; Fc - the power of resistance (friction), under braking with a minus sign! Asp - average acceleration. This acceleration is obtained experimentally and confirmed by testing. Ap - average acceleration acceleration, At - the average speed of inhibition; Ap = Asp * (1-Ks) = At Asp * (1-Ks), (2) The basic relationship between speed and the way (and the dimension of the symbol path for visibility is the number of steps N). For the mean values for individual steps or fairly consider the motion under acceleration or braking uniformly accelerated: V = A * T; T = V / A; (3) Np = VM * TR / 2, Nm = VM * T / 2 (4) Nd = VM * td - no acceleration (5) N = (A * T ^ 2) / 2; T = SQR ((2 * N) / A) (6) T1 = SQR ((2 * N) / A1); T2 = SQR ((2 * N) / A2); Tn = SQR ((2 * N) / An) dTn = Tn-Tn-1 - the duration of the next step; Vn = 1 / dTn In
To begin overclocking: Given: VM, Asr, Kc, N. We have approximated the dependence of the values of A (V) or A (N) or a table in the range from 0 to V = VM (or from N = 0 Nm), it thus can be significantly non-linear, it is possible to consider that the first step acceleration can have a static friction, and you can use the fact that the first few steps the motor can be at the same mo-ments of SM, ie, slightly dependent on the speed, etc. - Pre-test TR = VM / Asr * (1-Kc), Np = VM * TR / 2 should be Np <= N / 2 - Conduct rendering steps (filled columns 3 and 4 of the table) until 1/dTn