CN104697563A - Grating encoder calibration system and grating encoder calibration method - Google Patents

Abstract

The invention relates to a grating encoder calibration system and a grating encoder calibration method. The system comprises a grating encoder used for outputting high and low level of three channels of three-phase position signals and one channel of speed signals, a microcontroller used for calculating the number of speed pulses output by the grating encoder through one-circle rotation and the number of speed pulses contained in the high and low level of the three-phase position signals and sending the data to a principal computer, and the principal computer used for receiving the data and judging whether the grating encoder is normal or not according to the data.

Description

Grating encoder check system and method

Technical field

The present invention relates to a kind of grating encoder check system and method.

Background technology

Switched reluctance machines is as a kind of novel high-performance variable ratio drive system, and the feedback of the low and high level of speed and position signalling is an important step.Grating encoder a kind ofly integrates light, mechanical, electrical digital detecting device, and being mainly used in the detection of motor speed and position, is the important component part of switched Reluctance Motor Control System.

Grating encoder has the photoelectric code disk of axle to form by a center, and photoelectric code disk is again be made up of outer code channel and interior code channel.Wherein outer code channel and interior code channel all have light and dark grid stroke and angularly distribute, and outer code channel respectively has 1024 Mingguang City's grid lines and half-light grid line, is mainly used in the velocity measuring of switched reluctance machines; Interior code channel is 8 Mingguang City's grid code channels and 8 half-light grid code channels that angularly distribute, carrys out the low and high level of detector switch magnetic resistance motor rotor relative to the position signalling of stator with interior code channel.By the grid stroke of the irradiation penetrating light code disc of light-emitting component, light activated element exports and forms square-wave pulse to detect low and high level and the rate signal of position signalling.

Therefore once there is the damage of glass raster, that pulse will be caused to export is inaccurate for the fault such as to puncture of light activated element, thus causes electric machine control system malfunctioning.

Summary of the invention

In view of this, fundamental purpose of the present invention is to provide a kind of grating encoder check system,

Comprise:

Grating encoder, for according to the low and high level of output 3 road three-phase position signal and 1 road rate signal;

Microcontroller, revolves for counting grating encoder the velocity pulse number turning around and export, and the velocity pulse number that the low and high level of described three-phase position signal comprises, and above-mentioned data are sent to host computer;

According to described data, host computer, for receiving described data, and judges that whether described grating encoder is normal.

Wherein,

Described host computer calculates phase difference angle θ, the P-pulse between the low and high level of three-phase position signal according to described data

The angle [alpha] that high level is corresponding, and the angle beta that P-pulse low level is corresponding.

Wherein,

$\mathrm{\θ}=\frac{R*360}{T}$

$\mathrm{\α}=\frac{H*360}{T}$

$\mathrm{\β}=\frac{L*360}{T}$

Wherein,

Described host computer judges the difference between the angle that the low and high level of three-phase position signal is corresponding and ideal value

Whether at error model

In enclosing;

Judge difference between three-phase phase declinate degree θ and ideal value whether in error range;

Judge the difference of velocity pulse number whether and between ideal value whether in error range;

If do not meet one of above-mentioned condition, then described grating encoder does not meet the demands.

The present invention further provides a kind of method verifying grating encoder, comprising:

Meter grating encoder revolves the velocity pulse number turning around and export;

The velocity pulse number that the low and high level counting described three-phase position signal comprises;

Phase difference angle θ, P-pulse between the low and high level calculating three-phase position signal according to described data

The angle [alpha] that high level is corresponding, and the angle beta that P-pulse low level is corresponding;

Judge difference between θ, α, β and ideal value whether in error range.

Wherein,

$\mathrm{\θ}=\frac{R*360}{T}$

$\mathrm{\α}=\frac{H*360}{T}$

$\mathrm{\β}=\frac{L*360}{T}.$

Grating encoder check system provided by the present invention and method accurately can detect whether grating encoder meets the demands.

Accompanying drawing explanation

Fig. 1 is grating encoder check system structural drawing according to an embodiment of the invention;

Fig. 2 is the 4 tunnel oscillograms that grating encoder produces;

The singlechip main program process flow diagram that Fig. 3 is the check system according to Fig. 1;

The host computer process flow diagram that Fig. 4 is the check system according to Fig. 1;

Embodiment

Below in conjunction with accompanying drawing and embodiments of the invention, technical scheme of the present invention is described in further detail.

Figure 1 shows that system construction drawing according to an embodiment of the invention.

Wherein, grating encoder 10 is connected to microprocessor 11, and the data from grating encoder received are transferred to host computer 13 by communication interface 12 by microprocessor 11;

Wherein, microprocessor 11 can be applicable to any one microprocessor of the present invention for well known in the art, such as, and single-chip microcomputer, DSP etc.Wherein, host computer 13 can be have data-handling capacity PC;

Wherein, communication interface 12 can be serial communication interface, parallel communication interface, USB etc.

The pulse signal that grating encoder 10 produces in rotary course comprises 3 groups of A phase position signals (1), B phase position signal (2), C phase position signal (3) and one group of speed pulse signal (4), as shown in Figure 2, and sending microprocessor 11 to, the present invention is described for single-chip microcomputer.Those skilled in the art can know, because the frequency of velocity pulse is very high, therefore the crystal oscillator frequency of single-chip microcomputer should far above velocity pulse frequency.

Then, enter singlechip main program, as shown in Figure 3.

First, in step 100, single-chip microcomputer initialization;

Then, in step 101, enable single-chip microcomputer ECT module, three-phase position signal and rate signal rising edge trigger respectively, and enter interruption subroutine, i.e. step 102;

Be understandable that, because the frequency of rate signal is higher, in order to avoid dropout, rate signal can be set to high priority;

Then, in step 102, the counter counts grating encoder in single-chip microcomputer revolves each the comprised velocity pulse number of the high and low level of low and high level of the three-phase position signal turned around; Meter grating encoder revolves the velocity pulse number turned around;

Then enter step 103, single-chip microcomputer by the above-mentioned data that collect stored in register;

Then in step 104, send data to host computer 13 by serial ports, and enter host computer 13 workflow.

Be illustrated in figure 4 the workflow of host computer 13, the present invention is for 12/8 pole switching reluctance motor.

First, host computer 13 calculates corresponding angle respectively by the velocity pulse number that the high and low level of the low and high level of three-phase position signal is corresponding;

The umber of pulse differed by the low and high level of three-phase position signal calculates the phase differential of three-phase position signal;

Because 8 plain code roads and 8 private mark roads angularly distribute, so each code channel should account for 22.5 degree, 15 degree of angles should be differed between plain code road and private mark road, therefore just can judge in grating disc, whether code channel etching meets the requirements by detection angles, and whether photodiode exists diffraction.

Particularly, grating encoder rotates a circle, if the velocity pulse number that the phase differential of three position signallings is corresponding is R, the velocity pulse number that the high level of each P-pulse is corresponding is H, the low level corresponding speed pulse number of each P-pulse is L, velocity pulse number is T, phase difference angle θ between the low and high level that then can obtain three-phase position signal according to following formula (1)-(3), the angle [alpha] that P-pulse high level is corresponding, and the angle beta that P-pulse low level is corresponding:

$\mathrm{\θ}=\frac{R*360}{T}$ Formula (1)

$\mathrm{\α}=\frac{H*360}{T}$ Formula (2)

$\mathrm{\β}=\frac{L*360}{T}$ Formula (3)

Host computer judges whether all in error range (such as, 0.5 degree) difference between the angle that the low and high level of three-phase position signal is corresponding and ideal value (22.5 degree);

Judge whether the difference between three-phase phase difference and ideal value (15 degree) (such as, is less than 0.5 degree) in error range;

Because the outer code channel occulting light grid line number of grating encoder is respectively 1024, the light and shade code channel of interior code channel is respectively 8, so each salient pole of rotor and velocity pulse number theory corresponding to groove should be 64.

Judge that whether difference between velocity pulse number and ideal value (64) is error range (such as, 10).

The above, be only preferred embodiment of the present invention, and be not used to limit protection scope of the present invention.

Claims (6)

1. a grating encoder check system, comprising:

Grating encoder, for according to the low and high level of output 3 road three-phase position signal and 1 road rate signal;

Microcontroller, revolves for counting grating encoder the velocity pulse number turning around and export, and the velocity pulse number that described three-phase position signal comprises, and above-mentioned data are sent to host computer;

According to described data, host computer, for receiving described data, and judges that whether described grating encoder is normal.

2. check system according to claim 1, is characterized in that:

Described host computer calculates phase difference angle θ between the low and high level of three-phase position signal, angle [alpha] that P-pulse high level is corresponding according to described data, and the angle beta that P-pulse low level is corresponding.

3. check system according to claim 2, is characterized in that:

。

4. check system according to claim 3, is characterized in that:

Described host computer judges difference between the angle that the low and high level of three-phase position signal is corresponding and ideal value whether in error range;

Judge difference between three-phase phase declinate degree θ and ideal value whether in error range;

Judge the difference of velocity pulse number whether and between ideal value whether in error range;

If do not meet one of above-mentioned condition, then described grating encoder does not meet the demands.

5. verify a method for grating encoder, comprising:

Meter grating encoder revolves the velocity pulse number turning around and export;

The velocity pulse number that the low and high level counting described three-phase position signal comprises;

Phase difference angle θ between the low and high level calculating three-phase position signal according to described data, the angle [alpha] that P-pulse high level is corresponding, and the angle beta that P-pulse low level is corresponding;

Judge difference between θ, α, β and ideal value whether in error range.

6. method of calibration according to claim 5, is characterized in that: