TWI427919B - Encoding system and encoding method thereof - Google Patents

Description

Decoding device and decoding method thereof

The present invention relates to a decoding apparatus and a decoding method thereof.

The encoder is divided into an incremental encoder and an absolute encoder. The signal output by the incremental encoder is a TTL digital pulse signal, and the signal output by the absolute encoder is a Sin wave signal or a Cos wave signal. When the absolute encoder is coupled to a motor, the distance of rotation of the motor for a certain period of time is determined by the difference in position between the sine waves output by the encoder at two times. In this case, the sine wave at two moments needs to be decoded. It is conventional to determine the distance of the motor rotation by converting the sine wave into a pulse wave. Since the pulse wave only reflects the information at the apex of the sine wave, the position information at any time between the two vertices in the period of time is obtained. When the sine wave is converted into a pulse wave, it is lost, causing inaccuracy in determining the distance at which the motor rotates.

In view of the above, it is necessary to provide a decoding apparatus and a decoding method thereof that can accurately determine the position difference between any two points on a sine wave.

A sine wave decoding device, configured to calculate a distance between a first to-be-measured point and a second to-be-measured point of a two-sine wave with a phase difference of 90 degrees outputted by an encoder, the sine wave decoding device including a conversion And a processor coupled between the encoder and the processor to obtain the amplitude of the two-string wave at each point, and transmitting the same to the processor, the processor comprising: a data processing a unit storing a sign of a magnitude of the two-string wave, a sign of a difference between absolute values of amplitudes of the two-sine wave, and a correspondence between the three symbols and the complex interval, and storing corresponding to each interval a tangent function; an interval determining unit, configured to determine, according to the amplitude of the two sine waves of the first point to be measured and the amplitude of the two sine waves of the second point to be measured, the first point to be measured and the second point to be measured The interval in which the amplitude of the two-string wave is located, the data processing unit is configured to respectively select the corresponding tangent according to the interval in which the points formed by the amplitudes of the first and second points to be measured are located Function, and get the corresponding according to the selected tangent function And the θ value of the second point to be measured is further used to calculate the L value of the first and second points to be measured according to the formula L=N/2 π×θ, where N is the target resolution; and a position record is obtained. a unit for recording the number M of periods of the sine wave passing between the first and second points to be measured and using the formula S=L _Q +[M/4]×RL _P to obtain the two-string arbitrary The position difference S between two points, where L _Q and L _P are the L values of the second and first points to be measured, respectively, and R is the length of the sine wave of one period.

A decoding method for calculating a distance between a first to-be-measured point and a second to-be-measured point of a sine wave whose two phases are 90 degrees out of phase by an encoder, the decoding method comprising the following steps: Obtaining the amplitude of the two sine waves at each point and transmitting it to a processor, wherein the processor stores the sign of the amplitude of the two sine waves and the absolute value of the amplitude of the two sine waves a sign of the difference and its correspondence with the complex interval, and storing a tangent function corresponding to each interval; the processor is based on the amplitude of the two-string wave of the first point to be measured and the second string of the second point to be measured The amplitude of the wave determines an interval in which the point formed by the amplitude of the two sine waves of the first to-be-measured point and a second to-be-measured point is located; the processor obtains the first and second to-be-tested according to the obtained interval operation The θ value of the point is further used to calculate the L value of the first and second points to be measured according to the formula L=N/2 π×θ, where N is the target resolution; and the processor records the first and second The number of periods M of the sine wave passing between the points to be measured and the formula S=L _Q +[M/4]×RL _{P are} used to obtain the two The position difference S between any two points of the sine wave, wherein L _Q and L _P are the L values of the second and first points to be measured, respectively, and R is the length of the sine wave of one period.

The decoding method of the present invention applies the sine wave decoding device, and transmits the amplitude of each point of the two-string wave outputted by the encoder to the processor, and the amplitude corresponding to the two-string wave passes through the interval determining unit and the data in the processor. The processing unit and the position record obtaining unit are configured to obtain a position difference between the first and second points to be measured, and the position between any two points on the two-string wave can be accurately obtained compared with the conventional encoder. difference.

10‧‧‧ converter

20‧‧‧Offset adjuster

30‧‧‧Amplitude adjuster

40‧‧‧ processor

41‧‧‧Interval decision unit

42‧‧‧Data Processing Unit

43‧‧‧Synthesis unit

44‧‧‧Location Recording Unit

45‧‧‧Result output unit

50‧‧‧ monitor

60‧‧‧Encoder

620‧‧‧First sine wave

621‧‧‧Second sine wave

622‧‧‧A phase digital pulse signal

623‧‧‧B phase digital pulse signal

624‧‧‧Synthesis pulse signal

444‧‧‧Sawtooth wave

70‧‧‧Transition circuit

1 is a schematic block diagram of a preferred embodiment of a decoding device of the present invention.

2 is a functional block diagram of a processor of a preferred embodiment of the decoding device of the present invention.

3 is a schematic diagram of interval division in a preferred embodiment of the decoding apparatus of the present invention.

4 is a waveform diagram before the offset adjustment is performed in the preferred embodiment of the decoding apparatus of the present invention.

Figure 5 is a waveform diagram after decoding in a preferred embodiment of the decoding apparatus of the present invention.

6A and 6B are flowcharts showing a preferred embodiment of a decoding method of the decoding apparatus of the present invention.

Referring to FIG. 1 to FIG. 5 together, a preferred embodiment of the sine wave decoding device of the present invention includes a converter 10, an offset adjuster 20, an amplitude adjuster 30, a processor 40, a monitor 50, and a The encoder 60 and a conversion circuit 70.

The converter 10 is connected between the encoder 60 and the offset adjuster 20 to obtain the amplitude of a first sine wave 620 and a second sine wave 621 output by the encoder 60 at each point, and It is transmitted to the offset adjuster 20, wherein the phase difference between the first and second sine waves 620 and 621 is 90 degrees.

The offset adjuster 20 is configured to adjust the geometric center lines of the first sine wave 620 and the second sine wave 621 to the same horizontal line, and construct a first and second sine waves 620 and 621 according to the amplitude of each of the first and second sine waves 620 and 621. As shown in the coordinate axis of FIG. 3, the abscissa of the coordinate axis is the amplitude of the second sine wave 621, and the ordinate is the amplitude of the first sine wave 620. Among them, the function of constructing the coordinate axis is to divide the four sections A, B, C and D, which will be described below. The geometric center line of the sine wave is the transverse center line of the sine wave, and the dotted line in FIG. 4 is the geometric center line of the first sine wave 620, and the X axis is the geometric center line of the second sine wave 621. The geometric centerlines of the first sine wave 620 and the second sine wave 621 are not on the same horizontal line, that is, the offset adjuster 20 is required to adjust it.

The amplitude adjuster 30 is coupled between the offset adjuster 20 and the processor 40. The amplitude adjuster 30 is configured to adjust the amplitudes of the first sine wave 620 and the second sine wave 621 adjusted by the offset adjuster 20 to 1 unit to facilitate subsequent processing of the first sine wave by the processor 40. The 620 and the second sine wave 621 are subjected to analysis processing. The monitor 50 The processor 40 is coupled to display the results of the processor 40 output. Wherein, the unit represents a specified length. If the unit indicates 5 mm, 1 unit indicates 5 mm, and 2 units indicates 10 mm.

The conversion circuit 70 is connected between the encoder 60 and the processor 40 to convert the first sine wave 620 and the second sine wave 621 output by the encoder 60 into an A-phase digital pulse signal 622 and a B-phase digital pulse signal. 623 and transmit it to the processor 40.

The processor 40 includes a section determining unit 41, a data processing unit 42, a synthesizing unit 43, a position recording obtaining unit 44, and a result output unit 45.

The interval determining unit 41 is configured to determine the amplitude Sin β 1 of the first sine wave 620 received by the processor 40 at a certain time point, the amplitude Sin β 2 of the second sine wave 621, and the amplitude of the two sine waves. The difference between the absolute values of the values | Sin β 1 |-| Sin β 2|, and determining the first sine wave 620 and the second sine wave 621 at this time according to the contents stored in the data processing unit 42 as in Table 1. The interval in which the amplitude is composed is the interval in which the A interval, the B interval, the C interval, and the D interval are as shown in FIG. 3 .

The data processing unit 42 also stores a complex formula, wherein each formula corresponds to an interval in Table 1, as shown in Table 2.

The data processing unit 42 is further configured to calculate values of the corresponding angles α and θ based on the section known by the section determining unit 41 and the formula stored therein. Moreover, the data processing unit 42 will calculate L: L = N / 2 π × θ (5) according to the formula (5).

Wherein, N is the target resolution, that is, 360 degrees is divided into N equal parts to indicate the accuracy of the decoding apparatus of the present invention. In this embodiment, N=2000.

The data processing unit 42 processes the amplitudes of the first sine wave 620 and the second sine wave 621 received by the processor 40 at all points in time to obtain a value of the complex angle θ to obtain a value of the complex L, and according to the L The value draws a sawtooth wave 444. The sawtooth wave 444 is used to illustrate that the amplitudes of the first sine wave 620 and the second sine wave 621 are continuously changed rather than discretely changed, thereby converting the sine wave into a pulse wave to determine between two time points. The position difference is more precise. In other embodiments, the sawtooth wave 444 may not be generated, that is, the actual drawing action is not required, and only the L value of the two time points to be measured may be calculated according to the formula (5).

The synthesizing unit 43 is configured to combine the A-phase digital pulse signal 622 and the B-phase digital pulse signal 623 transmitted by the conversion circuit 70 into a combined pulse signal 624.

The position record obtaining unit 44 is configured to record the complete number M of the synthesized pulse signals 624 passing between the first time point P to be measured and the second time point Q to be measured, and is also used to calculate the first and the first The L values of the time points P and Q to be measured are respectively recorded as L _P and L _Q , and the position difference between the first and second time points P and Q to be measured is calculated according to formula (6): S=L _Q +[M/4]×RL _P (6)

Wherein, S represents the position difference between the first and second time points P and Q to be tested, [M/4] represents an integer for the value of M/4, and R represents the length of the sine wave of one cycle, and R =N/2 π×2 π=N. Since the sine wave of one cycle can be converted into four synthesized pulse signals, the number of cycles of the sine wave experienced between the first and second time points P and Q to be tested is M/4, that is, the first and the first The number of complete cycles of the sine wave between the time points P and Q to be measured is [M/4]. In other embodiments, the first and second time points to be tested may also be two points to be tested.

As shown in FIG. 6A and FIG. 6B, the step of obtaining the position difference between the first and second time points P and Q to be tested by using the decoding device of the present invention includes:

Step S1: The amplitude of the first sine wave 620 and the second sine wave 621 output by the encoder 60 at each point is obtained through the converter 10 and transmitted to the offset adjuster 20.

Step S2: The first sine wave 620 and the second sine wave 621 are correspondingly converted into the A-phase digital pulse signal 622 and the B-phase digital pulse signal 623 through the conversion circuit 70, and transmitted to the processor 40.

Step S3: The offset adjuster 20 determines the first sine wave 620 and the second sine wave 621. Whether the geometric centerlines are on the same horizontal line.

Step S4: If the geometric center lines of the first and second sine waves 620 and 621 are not on the same horizontal line, the offset adjuster 20 adjusts the geometric center lines of the first sine wave 620 and the second sine wave 621. Up to the same horizontal line, and constructing a coordinate axis as shown in FIG. 3 according to the amplitudes of the first and second sine waves 620 and 621 at each point, and adjusting the first sine wave 620 and the second sine wave 621. The amplitude at each point is transmitted to the amplitude adjuster 30.

Step S5: If the geometric center lines of the first and second sine waves 620 and 621 are on the same horizontal line, the offset adjuster 20 constructs a first and second sine waves 620 and 621 according to the amplitude of each of the first and second sine waves 620 and 621. The coordinate axis shown in FIG. 3 transmits the amplitude of the first sine wave 620 and the second sine wave 621 at each point to the amplitude adjuster 30.

Step S6: The amplitude adjuster 30 determines whether the amplitudes of the first sine wave 620 and the second sine wave 621 are 1 unit.

Step S7: If the amplitudes of the first sine wave 620 and the second sine wave 621 are not one unit, the amplitudes of the first sine wave 620 and the second sine wave 621 are adjusted to one by the amplitude adjuster 30. The unit transmits the signal received by the amplitude adjuster 30 to the processor 40.

Step S8: If the amplitudes of the first sine wave 620 and the second sine wave 621 are one unit, the signal received by the amplitude adjuster 30 is transmitted to the processor 40.

Step S9: The section determining unit 41 determines the section in which the point formed by the amplitudes of the first sine wave 620 and the second sine wave 621 is located at each time point according to the content in Table 1.

Step S10: The data processing unit 42 calculates the values of the angles α and θ corresponding to the first sine wave 620 and the second sine wave 621 at each time point according to the interval obtained by the section determining unit 41 and the content in Table 2. And obtaining the value of the complex number L according to the formula (5) to draw the sawtooth wave 444; and calculating the L values L _P and L _{Q of} the first time point P to be tested and the second time point Q to be measured.

Step S11: The synthesizing unit 43 combines the A-phase digital pulse signal 622 and the B-phase digital pulse signal 623 transmitted by the conversion circuit 70 into a combined pulse signal 624.

Step S12: The position record obtaining unit 44 records the complete number M of the synthesized pulse signals 624 passing between the first time point P to be measured and the second time point Q to be measured.

Step S13: The position record obtaining unit 44 obtains the position difference S between the first and second time points P and Q to be tested according to the formula (6). According to the characteristics of the encoder 60 and the position difference S, the advancement length of a screw connected to the motor between the first and second time points P and Q to be tested can be calculated. For example, according to the specification of the encoder 60, when the resolution N is 2000, the encoder 60 displays the digit "1000", that is, the motor rotates once, and drives the screw to advance the distance between the two teeth, that is, At 0.5 mm, the first and second time points P and Q to be measured can be calculated, and the advancement length of the screw is

Step S14: The result output unit 45 of the processor 40 transmits the position difference S obtained by the position record obtaining unit 44 and the advance length of the screw obtained by the position difference S to the monitor 50 for the tester. Know the measurement results.

The operation of the aforementioned decoding apparatus will be described below by way of example. Referring to FIG. 5 together, in the embodiment, the amplitude of the first sine wave 620 corresponding to the first time point P to be measured is 0, and the amplitude of the second sine wave 621 is 1. The section determining unit 41 can know from the contents in Table 1 that the point formed by the amplitudes of the first sine wave 620 and the second sine wave 621 is located in the C section. The data processing unit 42 calculates θ=0 according to the content in Table 2, and further can know the L value L _P =N/2 π×θ=0 of the first time point P to be tested according to the formula (5).

The amplitude of the first sine wave 620 corresponding to the second time point Q to be measured is -1, and the amplitude of the second sine wave 621 is 0. According to the content in Table 1, it can be known that the ratio of the points formed by the first sine wave 620 and the second sine wave 621 is in the B interval, and θ=3 π/2 is calculated according to the content in Table 2, and then according to Equation (5) can know that the L value L _Q = N/2 π × θ = 2000/2 π × 3 π/2 = 1500 of the second time point Q to be measured. At this time, the position record obtaining unit 44 records that the complete number M of the synthesized pulse signals 624 passing between the first time point P to be measured and the second time point Q to be measured is 3, and therefore, according to the formula (6) The position difference S=1500+[3/4]×2000-0=1500 between the first time point P to be tested and the second time point Q to be measured can be obtained. If it is specified that when the resolution N is 2000, the encoder 60 displays the digit "1000", that is, the motor rotates one revolution, and drives the screw to advance 0.5 mm, then the first and second time to be tested can be calculated. Between points P and Q, the advancement length of the screw is

In the foregoing step S10, the data processing unit 42 calculates the values of the angles α and θ corresponding to the first sine wave 620 and the second sine wave 621 at each time point, and obtains the sawtooth wave 444 according to the purpose of characterizing this. The amplitudes of the first sine wave 620 and the second sine wave 621 are continuously changed rather than discretely changed, thereby being more accurate than converting the sine wave into a pulse wave to determine the position difference between the two time points. In other embodiments, in step S10, "the data processing unit 42 obtains the value of the complex number L according to the formula (5) to draw the sawtooth wave 444" can be deleted, that is, the action that actually has to be drawn is not required, and only according to the formula (5) The L values L _P and L _Q of the first time point P to be measured and the second time point Q to be measured may be calculated. In addition, in the embodiment, the offset adjuster 20 and the amplitude adjuster 30 function to process the first sine wave 620 and the second sine wave 621 more conveniently and accurately, the offset adjuster 20 and the amplitude. The regulator 30 can also be omitted. In addition, in the embodiment, the function of the synthesized pulse signal 624 is mainly to more conveniently identify how many cycles have elapsed between the first time point P to be tested and the time point Q to be measured, so in other embodiments, The conversion circuit 70 and the synthesis unit 43 in the processor 40 can be omitted to reduce the cost. The position record obtaining unit 44 calculates the time interval between the two sine waves and the time interval between the two time points to be measured. The number of complete cycles elapsed between the first time point P to be tested and the time point Q to be tested is obtained.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

10‧‧‧ converter

20‧‧‧Offset adjuster

30‧‧‧Amplitude adjuster

40‧‧‧ processor

50‧‧‧ monitor

60‧‧‧Encoder

70‧‧‧Transition circuit

Claims (8)

a decoding device, configured to calculate a distance between a first to-be-measured point and a second to-be-measured point by a two-sine wave with a phase difference of 90 degrees output by an encoder, the sine wave decoding device comprising a converter and a processor coupled between the encoder and the processor to obtain the amplitude of the two-string wave at each point, and transmitting the same to the processor, the processor comprising: a data processing unit, And storing a sign of a magnitude of the amplitude of the two sine waves, a sign of a difference between absolute values of amplitudes of the two sine waves, and a correspondence between the three symbols and the complex interval, and storing a tangent function corresponding to each interval An interval determining unit, configured to determine the first to-be-measured point and the second to-be-measured point according to the amplitude of the two-chord wave of the first to-be-measured point and the amplitude of the two-chord wave of the second to-be-measured point The data processing unit is configured to select a corresponding tangent function according to the interval in which the points formed by the amplitudes of the two sine waves of the first and second points to be measured are located in the interval in which the points formed by the amplitudes of the waves are located, And obtaining the first and corresponding according to the selected tangent function The θ value of the two points to be measured is also used to calculate the L value of the first and second points to be measured according to the formula L=N/2 π×θ, where N is the target resolution; and a position record obtaining unit, For recording the number M of cycles of the sine wave passing between the first and second points to be measured and obtaining any two points of the two-string wave by the formula S=L _Q +[M/4]×RL _P The position difference S between, where L _Q and L _P are the L values of the second and first points to be measured, respectively, and R is the length of the sine wave of one period. The decoding device of claim 1, wherein an amplitude adjuster is further connected between the converter and the processor, and the amplitude adjuster is configured to adjust the amplitude of the two-string wave outputted by the converter to be consistent, and The adjusted two-string wave is transmitted to the processor. The decoding device of claim 1, wherein the converter and the processor are further An offset adjuster is coupled to adjust the geometric centerline of the two-string wave to the same horizontal line and transmit the adjusted two-string wave to the processor. The decoding device of claim 1, further comprising a conversion circuit connected between the encoder and the processor to convert the two-string wave into a two-digit pulse signal and Outputting to the processor; the processor further includes a synthesizing unit, the synthesizing unit is configured to combine the two-digit pulse signals into a composite pulse signal, and the position recording and obtaining unit is configured to record the first and second to-be-measured points The number of synthesized pulse signals passed between them determines the number M of cycles of the sine wave experienced. A decoding method for calculating a distance between a first to-be-measured point and a second to-be-measured point by a two-sine wave whose phase is 90 degrees out of phase by an encoder, the decoding method comprising the following steps: Obtaining the amplitude of the two sine waves at each point and transmitting it to a processor, wherein the processor stores the sign of the amplitude of the two sine waves and the absolute value of the amplitude of the two sine waves a sign of the difference and its correspondence with the complex interval, and storing a tangent function corresponding to each interval; the processor is based on the amplitude of the two-string wave of the first point to be measured and the second string of the second point to be measured The amplitude of the wave determines an interval in which the point formed by the amplitude of the two sine waves of the first to-be-measured point and a second to-be-measured point is located; the processor obtains the first and second to-be-tested according to the obtained interval operation The θ value of the point is further used to calculate the L value of the first and second points to be measured according to the formula L=N/2 π×θ, where N is the target resolution; and the processor records the first and second The number of periods M of the sine wave passing between the points to be measured and the formula S=L _Q +[M/4]×RL _{P are} used to obtain the two The position difference S between any two points of the sine wave, wherein L _Q and L _P are the L values of the second and first points to be measured, respectively, and R is the length of the sine wave of one period. The decoding method according to claim 5, wherein after the step "the converter obtains the amplitude of the two-string wave at each point": the amplitude of the two-string wave output by the converter through an amplitude adjuster Adjust to be consistent before transferring to the processor. The decoding method of claim 5, wherein after the step "the converter obtains the amplitude of the two-string wave at each point": adjusting the geometric center line of the two-string wave through an offset adjuster Transfer to the processor after the same level. The decoding method of claim 5, wherein the step "the processor records the number of periods M of the sine wave passing between the first and second points to be tested" is implemented by the following steps: The circuit converts the two-string pulse into a two-digit pulse signal, and transmits the two-digit pulse signal to the processor; the two-digit pulse signal is combined into a combined pulse signal by the processor; and the first pulse is recorded by the processor The number of synthesized pulse signals experienced between the first and second points to be measured, and the number M of periods of the sine wave passing between them is calculated accordingly.