CN203813709U - Controlling device for stepping motor of photoelectric direct-reading spectrometer - Google Patents

Abstract

The utility model belongs to the motor control technology, and especially relates to a controlling device for a stepping motor of a photoelectric direct-reading spectrometer. The stepping motor controlled by the device does not generate out-of-step phenomena, noise generated during the operation of the motor is reduced, the into-seam scanning precision is improved, and on-line rapid calculation can be achieved, and the controlling device can be used flexibly. The controlling device for the stepping motor of the photoelectric direct-reading spectrometer comprises the stepping motor, and the stepping motor is connected with a stepping motor driving chip. The controlling device is characterized in that the stepping motor driving chip is connected with a DSP processor through an optical coupling isolation logic conversion circuit, and the optical coupling isolation logic conversion circuit achieves the conversion and isolation of electrical levels.

Description

A kind of photo-electric direct reading spectrometer stepping motor control apparatus

Technical field

The utility model patent belongs to electric machines control technology, particularly a kind of photo-electric direct reading spectrometer stepping motor control apparatus.

Background technology

Photo-electric direct reading spectrometer is a kind of detecting instrument that obtains each constituent content of sample by the atom spectrum intensity after detecting sample and being excited, be widely used in metallurgy, machinery and other industrial department, carry out rapid analysis before smelting furnace and the product inspection of central laboratory.

Stepping motor is the executive component of extensive use in automatic control system and numerical control system, in occasions such as Digit Control Machine Tool, printer, draught machine, robot control, quartz clocks, has application.But stepping motor is owing to being subject to the restriction of this body structure, and it is very little that step angle can not be done, thereby when low frequency is controlled, easily produces vibration and step-out phenomenon easily occurs at high frequency time, and noise of motor is fairly obvious.

Photo-electric direct reading spectrometer enters to stitch scanning means and adopts stepping motor to drive, and the circuit that traditional stepping motor adopts analog circuit and separate type element to form is controlled, and because its control circuit is complicated, and has null offset phenomenon, and stability is not strong.Therefore, progressively by senior digital control approach, replaced, these senior digital control schemes mainly adopt Single-chip Controlling, compare with complicated analog circuit, and single-chip microcomputer has the advantages such as circuit design is simple, computing is fast, modification of program is convenient, control precision is high, inferred-zero drift.But, owing to entering to stitch scanning motion various informative, single-chip microcomputer cannot complete the design of rate curve in complex control algorithm requirement, particularly motion control.

Summary of the invention

In order to address the above problem, the utility model provides a kind of photo-electric direct reading spectrometer stepping motor control apparatus, and the stepping motor of its control step-out phenomenon can not occur, reduce the noise of motor operation, improve into seam scanning accuracy, and can realize online rapid calculation, applying flexible.

Its technical scheme is such: it comprises stepping motor, described stepping motor connects stepping motor and drives chip, it is characterized in that, described stepping motor drives chip to connect dsp processor by light-coupled isolation logic conversion circuit, and described light-coupled isolation logic conversion circuit is realized conversion and the isolation of level.

It is further characterized in that, described dsp processor is TMS320F2806 processor, described TMS320F2806 processor peripheral module comprises EPWM pulse-width modulation, ECAP capturing unit and SCI serial communication interface, pulse, direction and the enable signal that described stepping motor drives chip transmitted in described EPWM pulse-width modulation, described ECAP capturing unit is realized the signal capture of limit sensors, and described SCI serial communication interface is realized the serial communication of described TMS320F2806 processor and host computer;

Described SCI serial communication interface connects MAX3232 transceiver, external four the small size charge pump capacitor C 36 of described MAX3232 transceiver, C37, C38, C39, the T1OUT of described MAX3232 transceiver, R1OUT port connect computer breadboard and carry the transmitting and receiving tube pin of DB9 female, and the T1N of described MAX3232 transceiver, R1OUT port connect respectively SCITXDA, the SCIRXDA port of described TMS320F2806 processor;

Described TMS320F2806 processor connects clock circuit, power circuit and EEPROM power down storage protection circuit;

Described EEPROM power down storage protection circuit comprises AT24C256 storage chip, and the SCL of described AT24C256 storage chip, SDA port connect respectively GPIO33 port and the GPIO32 port of general purpose I/O port of TMS320F2806 processor;

Described stepping motor is two-phase four line stepping motors, and described stepping motor drives the TB6560 that chip is Toshiba to drive chip, and described TB6560 drives chip to comprise that interface is set in segmentation, interface and automatic half stream interface are set in current attenuation;

Described TB6560 drives current detecting end NFA, the NFB port of chip three single-pole double-throw switch (SPDT)s that are connected in parallel, described TB6560 drives DCY1, DCY2, M1, M2, the TQ2 port of chip to connect toggle switch SWDIP-6, and described TB6560 drives the TQ2 port of chip to connect the inverse output terminal 1 that monostable can repeated trigger chip 74HC123 port, CLK port connect the negative edging trigger input 1 that monostable can repeated trigger chip 74HC123 port, output OUT_AP, the OUT_AM of described TB6560, OUT_BP, OUT_BM port connect 4 sockets of six pin socket CON6, two other socket of described six pin socket CON6 connects protective circuit, described protective circuit is composed in series with fuse FUSE2 after by piezo-resistance RZ1, diode D10, capacitor C 55, polar capacitor C4 parallel connection, and described TB6560 drives the MO of chip, PROTECT port to connect indicator light D4, D5;

Described light-coupled isolation logic conversion circuit comprises High-Speed Coupled Device TLP2531 and optical coupling isolator PC817, described High-Speed Coupled Device TLP2531 connects clock signal terminal and the pulse signal end that described TB6560 drives chip, described optical coupling isolator PC817 connects the Enable Pin that described TB6560 drives chip, the PUL+ of described light-coupled isolation logic conversion circuit and DIR+ port are connected respectively EPWM1B and the EPWM1A port of described TMS320F2806 processor, the ENA+ port of described light-coupled isolation logic conversion circuit is unsettled, PUL-, DIR-and ENA-ground connection.

Adopt after structure of the present utility model, stepping motor drives chip to connect dsp processor by light-coupled isolation logic conversion circuit, light-coupled isolation logic conversion circuit is realized conversion and the isolation of level, adopts dsp processor to drive chip to control to stepping motor, can realize the control of complicated algorithm, reduce the noise of motor operation, improve into seam scanning accuracy, when the rate curve of calculated step motor, dsp processor can be in line computation, do not take ROM space, apply more flexible.

Accompanying drawing explanation

Fig. 1 is photo-electric direct reading spectrometer electric machine control system figure;

Fig. 2 is the trapezoidal acceleration and deceleration curves schematic diagram of step motor control;

Fig. 3 is for add/deceleration is to rate curve impact effect figure;

Fig. 4 is TMS320F2806 processor chips mount structure figure;

Fig. 5 is TB6560 stepper motor driving circuit structure chart;

Fig. 6 is MAX3232 transceiver circuit structure chart;

Fig. 7 is EEPROM power down storage protection circuit structure diagram;

Fig. 8 is testing current schematic diagram on command signal and NFA resistance;

Fig. 9 is winding serial connection noninductive resistance test biphase current schematic diagram.

Embodiment

As shown in Figure 1, a kind of photo-electric direct reading spectrometer stepping motor control apparatus, it comprises stepping motor 1, stepping motor 1 connects stepping motor and drives chip 2, stepping motor drives chip 2 to connect dsp processor 4 by light-coupled isolation logic conversion circuit 3, and light-coupled isolation logic conversion circuit 3 is realized conversion and the isolation of level.

See Fig. 1, shown in Fig. 4, dsp processor 4 is TMS320F2806 processor 5, TMS320F2806 processor 5 is the fixed DSPs based on TMS320C2xx kernel, that integrated level is higher, the motion control family device that performance is stronger, kernel and I/O voltage are respectively 1.8V and 3.3V, by+5V input, through the conversion of ASM1117 chip, provided, analog power and digital power, with inductance, isolate in analog and digitally, power pin goes lotus root to select 0.1uF polarity free capacitor, outside 20M can reach 100MHz without source clock frequency after inner frequency multiplication of phase locked loop, in sheet, the FLASH of 32k provides user to store instruction and data, TMS320F2806 processor 5 peripheral modules comprise EPWM pulse-width modulation 6, ECAP capturing unit 7 and SCI serial communication interface 8, EPWM pulse-width modulation 6 transmission stepping motors drive the pulse of chip 2, direction and enable signal, ECAP capturing unit 7 is realized the signal capture of limit sensors, SCI serial communication interface 8 is realized the serial communication of TMS320F2806 processor 5 and host computer, TMS320F2806 processor 5 connects clock circuit 9, power circuit 10 and EEPROM power down storage protection circuit 11.

As shown in Figure 6, SCI serial communication interface 8 connects MAX3232 transceiver, external four the small size charge pump capacitor C 36 of MAX3232 transceiver, C37, C38, C39, the T1OUT of MAX3232 transceiver, R1OUT port connect computer breadboard and carry the transmitting and receiving tube pin of DB9 female, and the T1N of MAX3232 transceiver, R1OUT port connect respectively SCITXDA, the SCIRXDA port of TMS320F2806 processor.

As shown in Figure 7; photo-electric direct reading spectrometer is the necessary gated sweep process in real time of user in the course of the work; the current movement position record of motor when particularly power down or accident occur; so designed EEPROM power down storage protection circuit 11; EEPROM power down storage protection circuit 11 comprises AT24C256 storage chip; the SCL of AT24C256 storage chip, SDA port connect respectively GPIO33 port and the GPIO32 port of general purpose I/O port of TMS320F2806 processor 5, i.e. the 5th pin and the 100th pin.

As shown in Figure 5, stepping motor 1 is two-phase four line stepping motors, and stepping motor drives the TB6560 that chip 2 is Toshiba to drive chip, and the inner integrated bridge MOSFET that enjoys a double blessing drives; The highest withstand voltage 40V, single-phase output maximum current 3.5A (peak value).Based on Double power driving principle, adopt the sinusoidal wave current waveform driving as segmentation, improved to a great extent stepping motor and driven low-frequency noise bigger than normal, lost at a high speed the shortcoming of step, TB6560 drives chip to comprise that interface is set in segmentation, interface and automatic half stream interface are set in current attenuation, TB6560 drives current detecting end NFA, the NFB port of chip three single-pole double-throw switch (SPDT)s that are connected in parallel, TB6560 drives DCY1, DCY2, M1, M2, the TQ2 port of chip to connect toggle switch SWDIP-6, by toggle switch, can set flexibly segmentation, current attenuation and the function of semi-fluid automatically, TB6560 drives the TQ2 port of chip to connect the inverse output terminal 1 that monostable can repeated trigger chip 74HC123 port, CLK port connect the negative edging trigger input 1 that monostable can repeated trigger chip 74HC123 port, output OUT_AP, the OUT_AM of TB6560, OUT_BP, OUT_BM port connect 4 sockets of six pin socket CON6, two-phase four line stepping motors connect this 4 sockets, two other socket of six pin socket CON6 connects protective circuit, protective circuit is composed in series with fuse FUSE2 after by piezo-resistance RZ1, diode D10, capacitor C 55, polar capacitor C4 parallel connection, and TB6560 drives the MO of chip, PROTECT port to connect indicator light D4, D5, TB6560 drives chip synchronizing, half step to be provided, within 1/8,1/16 fine minute, to have arranged, and NFA, the external noninductive resistance of NFAB pin are controlled output current, I=1/NF _rresistance size is respectively 1.2 ohm, 330 milliohms, 500 milliohms, M0, Protect pin are used as operating state and protection indication, and Reset is reseting pin, Low level effective, OSC capacitor C that pin connects 3 sizes determine chopping frequency size, recommend the corresponding chopping frequency 40KHZ of 100 ~ 1000PF to 400KHZ, it is 0,25% that the external toggle switch of DCY1/DCY2 arranges decay mode, 50%, 100%, the drive system using step " semi-fluid automatically " function is set: select monostable to detect CLK signal by repeated trigger chip 74HC123, when motor is normally worked, TQ2 is low level, electric current maintains NFA, NFB pin set point 100%, during no pulse input, TQ2 is high level, TQ1 and TQ2 different conditions determine current working current size, external voltage is for being no more than 40V, recommendation+24V, input adds fuse FUSE2 and piezo-resistance RZ1 protection and filtering, size of current, evanescent mode and automatically semi-fluid setting can realize by toggle switch SWDIP-6, in Table 1, shown in table 2

Light-coupled isolation logic conversion circuit 3 comprises High-Speed Coupled Device TLP2531 and optical coupling isolator PC817, High-Speed Coupled Device TLP2531 is a High-Speed Coupled Device for two passages, by photodiode, the open-collector triode of the linear amplifier of high-gain and Schottky clamper forms, there is temperature-compensating, electric current and voltage compensation, the high functions such as input and output isolation, be used for isolating CLK and CW signal, optical coupling isolator PC817 is common optical coupler isolator, be used for isolating ENABLE signal, vibration while working for stepping reducing motor is large, the shortcomings such as noise is large, can adopt the segmentation setting of electric current, evanescent mode arrange to improve High-Speed Coupled Device, TLP2531 connects clock signal terminal and the pulse signal end that TB6560 drives chip, optical coupling isolator PC817 connects the Enable Pin that TB6560 drives chip, the PUL+ of light-coupled isolation logic conversion circuit and DIR+ port are connected respectively EPWM1B and the EPWM1A port of TMS320F2806 processor, the ENA+ port of light-coupled isolation logic conversion circuit is unsettled, PUL-, DIR-and ENA-ground connection.

See Fig. 2, Figure 3 shows that the steady rapid movement of realizing motor, impact while reducing start and stop, prevent from losing step, suitable speed Curve Design is very important, and common stepper motor speed curve has step curve, exponential curve and sigmoid curve, step curve is in Step Motor speed process, acceleration keeps a steady state value constant, and speed rises or declines with linear rule, the time interval of step-by-step impulse determine stepper motor speed, for using stepping motor according to linear pattern acceleration and deceleration operation, must determine step-by-step impulse time interval c according to speed ramp curve ₀t _p, c ₁t _p, c ₂t _p... _., c here _nby the definite count value of processor on-chip timer, t _pbe the cycle of timer, unit is second, the different command pulse time interval corresponding rotor angular speed w0, w1, w2 ...If rate curve parameter, determines as acceleration, deceleration, step number, normal operating rate, can use conventional methods in advance with form interval data memory time.But this method applicability is bad, and need very large memory headroom, consider the clock frequency of TMS320F2806 processor 100MHz and powerful digital signal processing function, adopted rate curve real-time computing technique here.

If the time interval , f _pbe the count frequency of timer, c is counting number.Rotor angular speed can be expressed as , for step angle, acceleration constant, velocity function , position function

（1）

N walks the corresponding time .The time interval between such two pulses , and , abbreviation

（2）

Each step of formula (2) all needs to carry out sqrt computing, and CPU burden is heavier.According to Taylor series, to formula (2) abbreviation, solve c _niterative computation expression formula, see formula (3), derivation result:

（n=1,2,3…） （3）

(3) formula has been described adjacent two time interval c in linear pattern acceleration and deceleration curves medium velocity uphill process _nthe rule of progressively successively decreasing.Supplement moderating process c _nexpression formula

（n<m） （4）

During computational speed curve, there are two kinds of situations: the first is constant-speed operation after accelerating to setting speed, then decelerate to 0 by setting deceleration; The second situation occurs when motion step number is very little.Be that motor does not enter the decelerating phase to given speed.

Photo-electric direct reading spectrometer host computer Electric Machine Control software adopts VC++ programming.VC++ does not carry serial communication control, utilizes ActiveX control MSComm can conveniently realize with DSP serial communication.TMS320F2806 processor receives the parameters such as starting position, end position, motor step distance of motor operation by serial ports, complete assigned operation.Software systems comprise: communication protocol rule, rate control module, serial ports transceiver module and motor drive module.Whole software translating completes at CCS2.2 platform.

To text message codings such as motor start position information, end position information, motor step distance and flushing, pre-burning, firing times, word length is individual character 16 bits respectively; Communication port arranges COM1-COM4 according to current main flow desktop computer with notebook computer, COM1/2 correspondence desktop computer COM1/2 wherein, and COM3/4 is mapped as the RS232/USB mouth of notebook computer.Communication port adopts dibit coding.Washing time, prespark period and firing time submit to TMS320F2806 processor that the system startup stand-by period is set with serial communication form; in motor operation course, break down while stopping; system is write current location information to EEPROM power down protection memory circuit; can read motor current location information when guaranteeing that system is reworked; system arranges relative initial point and absolute initial point, and initial point can be specified by starting position relatively.

Step Motor speed control system mainly comprises two functional modules: main program, ePWM cycle interruption program.After system powers in main program, initialization phase-locked loop, house dog, enable peripheral hardware clock; Forbid global interrupt.And acceleration accel and dccel, motor that calculating ePWM timer, lifting speed are set move step number step, set operating rate speed, the parameters such as step angle.Calculate starting impulse time delay counting c0 and minimal time delay cmin, .And relatively by static umber of pulse max_lim and the acceleration accel that accelerates to setting speed, umber of pulse accel_lim corresponding to speed maximum that dccel is definite.If max_lim>accel_lim, just illustrate that not accelerating to setting speed motor has entered deceleration regime; Otherwise whole lifting speed is controlled as complete ladder type rate curve; Corresponding critical pulse number decal_val while being slowed down by max_lim and lifting speed acceleration calculation; In conjunction with formula (3) (4), complete the time-delay calculation of accelerating and decelerating part; As inceptive impulse time delay counting c0<c _min, motor does not need to accelerate directly to demarcate normal speed running status, otherwise proceeds to acceleration mode; Wait for ePWM unit cycle interruption, carry out the time interval cn that interrupt service routine calculates adjacent pulse.Trapezoidal acceleration and deceleration curves real time algorithm correlation computations is described below:

// calculate motor while accelerating to setting speed to move step number;

// calculate motor while accelerating to maximal rate to move step number;

// can accelerate to setting speed, calculate deceleration step number;

// motor does not arrive setting speed, calculates deceleration step number;

When TMS320F2806 processor receives acceleration-deceleration by serial ports,, step angle, after step number step information, starts to calculate,, numerical value, and in conjunction with formula (3), adjacent two command pulse time intervals of (4) computational speed curve.In ePWM module responds, have no progeny and just can complete the trapezoidal acceleration and deceleration control of stepping motor at service routine renewal ePWM period register TPRD.

By structure of the present utility model, 42BYG250A stepping motor is tested, observe current waveform and noise.The parameter of electric machine: step angle 1.8, operating voltage 9 ~ 30V, 1.3 ohm of winding resistances, winding inductance 2.1mH, holding torque 0.23N.m.S-350-24 type Switching Power Supply provides driver test job voltage 24V, adopts Tektronix TDS1012B dual channel oscilloscope to do current waveform test and the composition measurement of photoelectric direct streamer spectrometer system metal sample.Fig. 8 is voltage waveform on command signal and NFA resistance, and 16 segmentations arrange, command pulse frequency 2.5KHz.50% mixes decay current controls.As seen from the figure, electric current increases to peak value by 0 by sinusoidal waveform, corresponding command pulse number 16, noninductive sampling resistor powers on and is pressed with " negative pressure " feature and is symmetry shape simultaneously, this is to drive chip internal H full-bridge circuit up and down pipe to be closed simultaneously when afterflow, electric current by " " result of flow through motor winding feedback power, waveform for the sinusoidal segmentation control of clear view motor winding current, at 0.5 ohm of noninductive resistance of A/B phase winding output serial connection, with oscilloscope, observe, as shown in Figure 9, current waveform is smooth, electric machine rotation is steady, sinusoidal feature is obvious.Test result shows: system operates steadily, and current waveform is good, and noise is low, and positioning precision is high.

Claims (8)

1. a photo-electric direct reading spectrometer stepping motor control apparatus, it comprises stepping motor, described stepping motor connects stepping motor and drives chip, it is characterized in that, described stepping motor drives chip to connect dsp processor by light-coupled isolation logic conversion circuit, and described light-coupled isolation logic conversion circuit is realized conversion and the isolation of level.

2. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 1, it is characterized in that, described dsp processor is TMS320F2806 processor, described TMS320F2806 processor peripheral module comprises EPWM pulse-width modulation, ECAP capturing unit and SCI serial communication interface, pulse, direction and the enable signal that described stepping motor drives chip transmitted in described EPWM pulse-width modulation, described ECAP capturing unit is realized the signal capture of limit sensors, and described SCI serial communication interface is realized the serial communication of described TMS320F2806 processor and host computer.

3. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 2, it is characterized in that, described SCI serial communication interface connects MAX3232 transceiver, external four the small size charge pump capacitor C 36 of described MAX3232 transceiver, C37, C38, C39, the T1OUT of described MAX3232 transceiver, R1OUT port connect computer breadboard and carry the transmitting and receiving tube pin of DB9 female, and the T1N of described MAX3232 transceiver, R1OUT port connect respectively SCITXDA, the SCIRXDA port of described TMS320F2806 processor.

4. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 2, is characterized in that, described TMS320F2806 processor connects clock circuit, power circuit and EEPROM power down storage protection circuit.

5. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 4; it is characterized in that; described EEPROM power down storage protection circuit comprises AT24C256 storage chip, and the SCL of described AT24C256 storage chip, SDA port connect respectively GPIO33 port and the GPIO32 port of general purpose I/O port of TMS320F2806 processor.

6. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 2, it is characterized in that, described stepping motor is two-phase four line stepping motors, described stepping motor drives the TB6560 that chip is Toshiba to drive chip, and described TB6560 drives chip to comprise that interface is set in segmentation, interface and automatic half stream interface are set in current attenuation.

7. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 6, it is characterized in that, described TB6560 drives current detecting end NFA, the NFB port of chip three single-pole double-throw switch (SPDT)s that are connected in parallel, described TB6560 drives DCY1, DCY2, M1, M2, the TQ2 port of chip to connect toggle switch SWDIP-6, and described TB6560 drives the TQ2 port of chip to connect the inverse output terminal 1 that monostable can repeated trigger chip 74HC123 port, CLK port connect the negative edging trigger input 1 that monostable can repeated trigger chip 74HC123 port; output OUT_AP, the OUT_AM of described TB6560, OUT_BP, OUT_BM port connect 4 sockets of six pin socket CON6; two other socket of described six pin socket CON6 connects protective circuit; described protective circuit is composed in series with fuse FUSE2 after by piezo-resistance RZ1, diode D10, capacitor C 55, polar capacitor C4 parallel connection, and described TB6560 drives the MO of chip, PROTECT port to connect indicator light D4, D5.

8. a kind of photo-electric direct reading spectrometer stepping motor control apparatus according to claim 6, it is characterized in that, described light-coupled isolation logic conversion circuit comprises High-Speed Coupled Device TLP2531 and optical coupling isolator PC817, described High-Speed Coupled Device TLP2531 connects clock signal terminal and the pulse signal end that described TB6560 drives chip, described optical coupling isolator PC817 connects the Enable Pin that described TB6560 drives chip, the PUL+ of described light-coupled isolation logic conversion circuit and DIR+ port are connected respectively EPWM1B and the EPWM1A port of described TMS320F2806 processor, the ENA+ port of described light-coupled isolation logic conversion circuit is unsettled, PUL-, DIR-and ENA-ground connection.