CN109581044B - Voltage detection device applied to rotary transformer and working method - Google Patents
Voltage detection device applied to rotary transformer and working method Download PDFInfo
- Publication number
- CN109581044B CN109581044B CN201910085932.3A CN201910085932A CN109581044B CN 109581044 B CN109581044 B CN 109581044B CN 201910085932 A CN201910085932 A CN 201910085932A CN 109581044 B CN109581044 B CN 109581044B
- Authority
- CN
- China
- Prior art keywords
- signal
- voltage
- single chip
- chip microcomputer
- path
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/25—Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
- G01R19/2506—Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values ; Details concerning sampling, digitizing or waveform capturing
- G01R19/2509—Details concerning sampling, digitizing or waveform capturing
Abstract
The invention relates to a voltage detection device applied to a rotary transformer and a working method thereof.A standard sinusoidal signal enters a singlechip through a second absolute value conversion circuit, a preposed multiplexer, a sample-hold circuit, a plurality of AD conversion circuits and a postposition multiplexer in sequence, the preposed multiplexer and the postposition multiplexer are opened in sequence until 1/4 periods of the sinusoidal signal are collected, a polynomial of a least square method is used for fitting a functional relation between the collected digital signal and an actual value of a voltage value, and an obtained fitting curve is used as a reference curve; the signal to be measured enters the single chip microcomputer after being subjected to AD conversion, after nonlinear correction is carried out according to a reference curve, internal filtering is carried out, and then a voltage measured value worth accurate judgment of polarity is added. The circuit is stable and simple, small in size, low in cost, high in precision, high in speed, strong in anti-interference capability, outstanding in high reliability and high safety, has transportability, realizes real-time error calibration, and is very suitable for signal acquisition of the rotary transformer.
Description
Technical Field
The invention relates to a voltage acquisition device, in particular to a voltage detection device applied to a rotary transformer and a working method.
Background
The rotary transformer is a precise angle and rotating speed measuring device and is suitable for all rotation measuring occasions. Particularly in severe environments where conventional photoelectric encoders cannot normally operate at high temperature, severe cold, humidity, high speed, high vibration and the like. The rotary transformer can completely replace the photoelectric encoder. Therefore, the rotary transformer has been widely used in angle and rotation speed measurement systems in the fields of servo control systems, robot systems, machine tools, automobiles, electric power, metallurgy, textile, printing, aerospace, ships, weapons, electronics, metallurgy, mines, oil fields, water conservancy, chemical engineering, light industry, buildings, and the like.
The rotary transformer decoding circuit with high performance, stability and reliability is the key for measuring the angle and the rotating speed by using the rotary transformer. The AD conversion device is a core component of the resolver decoding circuit. In the ultra-high rotating speed measurement occasions such as an electric spindle and an electric automobile, the decoding circuit of the rotary transformer is required to have ultra-high decoding rate on the premise of ensuring the decoding precision. This requires that the AD conversion device in the resolver have both ultra-high sampling accuracy and sampling rate. In addition, due to the severe working environment of the rotary transformer, external factors such as temperature, humidity and vibration can cause unpredictable changes of circuit parameters in the AD conversion device, and the stable precision of AD conversion is influenced.
At present, limited by the development level of ADC chips, a single ADC is difficult to simultaneously realize high-speed and high-precision sampling, and the parallel sampling of a plurality of ADCs is an effective method for improving the sampling rate of a system. The multi-chip ADC parallel sampling is mainly divided into two structures of a frequency domain and a time domain. The frequency domain structure method is that a frequency domain division filter is used for carrying out frequency domain division on an input broadband signal into a plurality of paths of narrow-band signals so as to reduce the sampling rate of a single-chip ADC, and then the original input broadband signal is reconstructed by the sampled narrow-band signals. The band-split filter generally employs analog low-pass, band-pass and high-pass filters, and the transition band of the band-split filter has a great influence on the system performance. The time domain structure method is mainly that a plurality of ADCs adopt parallel time alternative sampling to finish sampling of input signals, and the method is called time alternative ADC sampling. However, the inconsistency of each channel can introduce three main channel mismatch errors, namely a time error caused by the inconsistency of the channel delay; gain errors caused by inconsistent gains of all channels; and thirdly, offset errors caused by the inconsistency of the reference levels of the ADC of the channels. Channel mismatch errors also have a large impact on the performance of the system.
Disclosure of Invention
The invention provides a voltage detection device applied to a rotary transformer and a working method thereof aiming at the problem of contradiction between acquisition efficiency and acquisition precision in the AD conversion process, and realizes high-speed, high-precision and bipolar analog signal acquisition, conversion and processing.
The technical scheme of the invention is as follows: a voltage detection device applied to a rotary transformer comprises a zero-crossing voltage comparator, two paths of absolute value conversion circuits, a front-mounted multiplexer, a rear-mounted multiplexer, a sample-hold circuit, a plurality of AD conversion circuits and a single chip microcomputer; the signal to be detected is sent to a zero-crossing voltage comparator and a first absolute value conversion circuit, the polarity of the signal to be detected is judged through the zero-crossing voltage comparator, the judgment result is sent to a single chip microcomputer, and the signal to be detected is converted into a positive voltage signal through the first absolute value conversion circuit and then is input to each pre-multi-channel selector; the standard sinusoidal signal provided by the clock by the single chip microcomputer is converted into a positive voltage signal by the second absolute value conversion circuit and then is input into each path of preposed multi-path selector, the preposed multi-path selector is connected with a corresponding AD conversion circuit after passing through each path of sampling and holding circuit, the output of each path of AD conversion circuit is sent into the single chip microcomputer by the postposition multi-path selector, and the single chip microcomputer outputs multi-path selection signals to the preposition and postposition multi-path selectors.
The working method of the voltage detection device applied to the rotary transformer comprises the steps that firstly, a standard sinusoidal signal sequentially passes through a second absolute value conversion circuit, a front-mounted multi-path selector, a sampling and holding circuit, a plurality of AD conversion circuits and a rear-mounted multi-path selector to enter a single chip microcomputer, the front-mounted multi-path selector and the rear-mounted multi-path selector are sequentially opened until 1/4 periods of the sinusoidal signal are collected, a polynomial of a least square method is used for fitting a functional relation between a collected digital signal and an actual voltage value, and an obtained fitting curve is used as a reference curve for the single chip microcomputer to process AD conversion data of a signal to be detected; then, a signal to be detected is selected to enter the single chip microcomputer through the first absolute value conversion circuit, the pre-multi-channel selector, the sampling and holding circuit, the plurality of AD conversion circuits and the post-multi-channel selector in sequence, a digital quantity signal converted by the signal to be detected is subjected to nonlinear correction according to a reference curve in the single chip microcomputer, internal filtering is carried out, and a voltage actual measurement value worth accurately judging polarity is added.
The invention has the beneficial effects that: the voltage detection device and the working method thereof applied to the rotary transformer have the advantages of stable and simple circuit, small volume, low cost, high precision, high speed, strong anti-interference capability, outstanding high reliability and high safety, portability, realization of real-time error calibration, complete accordance with various requirements of the rotary transformer on real-time property, precision, speed, working environment and the like of an AD conversion device, and are very suitable for a decoding circuit of the rotary transformer.
Drawings
FIG. 1 is a block diagram of a voltage detection device for a resolver according to the present invention;
FIG. 2 is a schematic diagram of sinusoidal signal relationships according to the present invention;
FIG. 3 shows ADCX and V under non-ideal conditions of the present inventionActual valueScatter between and a functional relationship graph after fitting;
fig. 4 is a flowchart illustrating the operation of the voltage detecting apparatus applied to the resolver according to the present invention.
Detailed Description
As shown in fig. 1, the voltage detection device applied to the resolver is a structural block diagram, and mainly comprises a zero-crossing voltage comparator, two absolute value conversion circuits, a front multiplexer, a rear multiplexer, a sample-and-hold circuit, an AD conversion circuit and a single chip microcomputer.
The signal to be detected is sent to the zero-crossing voltage comparator and the absolute value conversion circuit, the polarity of the signal to be detected is judged through the zero-crossing voltage comparator, the judgment result is sent to the single chip microcomputer, and the signal to be detected is converted into a positive voltage signal through the absolute value conversion circuit and then is input to each pre-multi-channel selector for signal selection. The standard sinusoidal signal provided by the clock by the single chip is converted into positive voltage signal by the absolute value conversion circuit and then input to each path of preposed multi-path selector for signal selection, the preposed multi-path selector is connected with the corresponding AD conversion circuit after passing through each path of sampling and holding circuit, the signal is sent to the single chip by the postposition multi-path selector, and the single chip outputs multi-path selection signal to the preposition and postposition multi-path selectors.
When the analog signal is subjected to AD conversion, a certain conversion time is needed, the analog signal is basically unchanged in the conversion time, so that the conversion precision can be ensured, the sampling and holding circuit is a circuit for realizing the function, and the signal only needs to be kept for one sampling period.
The AD converter is a main part and is responsible for AD conversion. The system adopts a design scheme of connecting five AD in parallel, works in turn, and equivalently improves the conversion efficiency by about five times.
The single chip microcomputer is the core of the whole circuit and is used for judging polarity, processing digital quantity, selecting channels and providing working clocks for five branches.
The specific working process of the system is as follows (taking 400 sampling periods of the single chip microcomputer as an example).
In order to achieve good correction, the period of the standard sinusoidal signal is 400 times the switching period of each branch. Thus, different sampling values can enter the sampling channel (namely the singlechip can sample for 100 times in the period of the sine signal 1/4).
The signal to be measured is divided into two paths and respectively sent to a zero-crossing voltage comparator and an absolute value conversion circuit, the zero-crossing voltage comparator is used for polarity judgment, VOHIf the input voltage is positive, the voltage signal is output as +5V, and if the input voltage is negative, the voltage signal is output as 0V, and the signal is transmitted from a common IO pin of the singlechip, so that the purpose of judging the polarity of the signal to be detected is achieved. The output voltage of the absolute value conversion circuit is the absolute value of the input voltage, and the other does not change.
Fig. 2 is a schematic diagram of the signal relationship of the present invention, and a sinusoidal signal a is obtained by an absolute value conversion circuit b, then is selected by a multiplexer to be passed through to obtain c, and is obtained by sampling and holding to obtain d.
The input signal is divided into five paths, and the five paths work in turn. Before this, it is necessary to select the input signal, and it is the pre-multiplexer that is used to select the input signal. Specific signal selection is referred to table 1 below (where 0 represents that the pre-multiplexer of the branch selects the standard sinusoidal signal, and 1 represents that the pre-multiplexer of the branch selects the signal to be measured). Since environmental changes and device aging are slow processes, only half of the small period has a sinusoidal input for the entire large period.
And (e) outputting the converted one-path signal by the rear-mounted multi-path selector from top to bottom, wherein the conversion is performed once and the switching is performed once, and the table 1 is an input signal selection table.
TABLE 1
The signal then passes through a sample-and-hold block as shown at d in figure 2. And then the corresponding digital value can be obtained through the AD converter as shown by f in fig. 2.
After the digital quantity is transmitted into the single chip microcomputer, a voltage value is reversely deduced according to the digital quantity (a 12-bit AD conversion chip is adopted in the system). The general AD conversion is linear, which means that the voltage and the converted digital quantity are proportional. Therefore, the voltage value can be directly reversely deduced through the proportionality coefficient in the single chip microcomputer. However, in actual work, the acquired signal to be measured is generally nonlinear, and we only know the converted digital quantity and cannot reversely deduce the voltage value, at this time, in order to ensure accuracy, the relation curve of the digital quantity and the voltage value needs to be known, and the voltage value can be reversely deduced, here, the sine wave signal is used as a standard signal to fit the curve relation between the digital quantity and the voltage value, and the voltage value can be obtained by obtaining the curve corresponding to the digital signal of the signal to be measured after the curve relation is subjected to AD conversion, so that accuracy is ensured.
Ideal digital value ADCX and actual voltage value VActual valueThe relationship is linear, as shown in the following formula.
Note: maximum output value of 12 bits AD is 2124096 and 5 is the maximum input voltage value of AD (unit: volt).
While ADCX and V are changed in environment or the device is agedActual valueIf the relationship is non-linear, then it needs single chip to calculate ADCX and VActual valueThe functional relationship of (a).
When the input is a standard sine wave, ADCX and V can be knownActual valueThe clock of the standard sine signal is provided by the singlechip, so the voltage V input into the AD convertersinKnown as Vsin| sin (it) | (where i is the number of sampling points in a sine cycle and t is a small cycle) and the converted theoretical voltage value VtsinAlso known as Vtsin＝Vsin/5X 4096, voltage value V after conversionActual valueAfter entering the singlechip, the V will replace the original VtsinForming scatter points (shown as e in fig. 2). Until 1/4 cycles of the sinusoidal signal are acquired, a polynomial fit of least squares is used to re-determine ADCX and VActual valueThe functional relationship between the two functions is used as a reference curve of AD conversion data of the signal to be detected processed by the singlechip later, such as a continuous curve in figure 4. Then every time a cycle of the sinusoidal signal passes, a new V is usedActual valueReplace the original VActual valueSo as to form a new curve, and so on. And adding the polarity judgment corresponding to the time into the test voltage value to obtain an accurate acquisition value.
In the subsequent 3/4 periods of the sinusoidal signal, the signal to be measured is input, and the single chip microcomputer can calculate the corresponding voltage value according to the new fitting curve and the obtained AD value. The scatter points are fitted to a continuous curve as shown in fig. 3, with the abscissa being the corresponding digital quantity and the ordinate being the corresponding voltage value.
The filtering mode adopted by the system is a sliding (recursive) average filtering algorithm. The method has a very good inhibition effect on periodic interference and is high in smoothness. The method comprises the following specific steps:
(1) continuously taking N sampling values is regarded as a queue, and the length of the queue is fixed to N;
(2) each time a new data is sampled and put into the tail of the queue, and the data at the head of the original queue is thrown away (first-in first-out principle);
(3) and carrying out arithmetic mean operation on the N data in the queue to obtain a new filtering result.
As shown in fig. 4, the signal to be measured is AD-converted to obtain a digital value, and after nonlinear correction is performed on the corresponding relationship curve between the digital value and the voltage value fitted according to the sinusoidal signal, the accurate voltage value can be output by internal filtering and adding the polarity judgment value.
Claims (2)
1. A working method of a voltage detection device applied to a rotary transformer comprises a zero-crossing voltage comparator, two paths of absolute value conversion circuits, a front multipath selector, a rear multipath selector, a sample hold circuit, a plurality of AD conversion circuits and a single chip microcomputer; the signal to be detected is sent to a zero-crossing voltage comparator and a first absolute value conversion circuit, the polarity of the signal to be detected is judged through the zero-crossing voltage comparator, the judgment result is sent to a single chip microcomputer, and the signal to be detected is converted into a positive voltage signal through the first absolute value conversion circuit and then is input to each pre-multi-channel selector; the standard sine signal provided by the clock by the single chip microcomputer is converted into a positive voltage signal by the second absolute value conversion circuit and then is input into each path of prepositive multi-path selector, the prepositive multi-path selector is connected with the corresponding AD conversion circuit after passing through each path of sampling and holding circuit, each path of AD conversion circuit outputs the signal and then is sent into the single chip microcomputer by the postpositive multi-path selector, the single chip microcomputer outputs the multi-path selection signal to the prepositive and postpositive multi-path selectors, the method is characterized in that the standard sine signal firstly passes through the second absolute value conversion circuit, the prepositive multi-path selector, the sampling and holding circuit, a plurality of AD conversion circuits and the postpositive multi-path selector in sequence and enters the single chip microcomputer, the prepositive and postpositive multi-path selectors are opened in sequence until 1/4 periods of the sine signal are collected, the sine signal is used as the standard signal, the fitting implementation method comprises the following steps: the clock of the standard sine signal is provided by the singlechip and is input into the voltage V of the AD convertersinKnown as VsinWhere i is the number of the sampling point in a sine cycle, t is a small cycle, and the converted theoretical voltage value Vtsin＝VsinMaximum output value of 2 for 12-bit AD of 5X 4096124096, 5 is the maximum input voltage value of AD, and when the converted voltage value enters the single chip microcomputer, it will replace the original VtsinForming scatter points, 1/4 periods of sinusoidal signal are collected, and least squares polynomial is used to fit the collected digital signal to the voltageThe functional relation between the actual values of the values is used as a reference curve for the singlechip to process AD conversion data of the signal to be detected;
and then in the subsequent 3/4 periods of the sinusoidal signal, selecting a signal to be detected to enter a single chip microcomputer after sequentially passing through a first absolute value conversion circuit, a preposed multiplexer, a sample-and-hold circuit, a plurality of AD conversion circuits and a postpositional multiplexer, wherein a digital quantity signal converted by the signal to be detected is subjected to nonlinear correction according to a reference curve in the single chip microcomputer, is subjected to internal filtering, and is added with a voltage measured value which is worth accurately judging the polarity.
2. The operating method of the voltage detection apparatus applied to the resolver according to claim 1, wherein the internal filtering employs a moving average filtering algorithm to suppress the periodic interference, specifically as follows:
1) continuously taking N sampling values is regarded as a queue, and the length of the queue is fixed to N;
2) each time a new data is sampled and put into the tail of the queue, and the data at the head of the original queue is thrown away;
3) and carrying out arithmetic mean operation on the N data in the queue to obtain a new filtering result.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910085932.3A CN109581044B (en) | 2019-01-29 | 2019-01-29 | Voltage detection device applied to rotary transformer and working method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910085932.3A CN109581044B (en) | 2019-01-29 | 2019-01-29 | Voltage detection device applied to rotary transformer and working method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109581044A CN109581044A (en) | 2019-04-05 |
| CN109581044B true CN109581044B (en) | 2020-11-24 |
Family
ID=65918322
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910085932.3A Active CN109581044B (en) | 2019-01-29 | 2019-01-29 | Voltage detection device applied to rotary transformer and working method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109581044B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114062824B (en) * | 2021-11-19 | 2023-12-26 | 河北新大长远电力科技股份有限公司 | Power quality monitoring method and device based on distribution room |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1229923A (en) * | 1998-02-20 | 1999-09-29 | 弗兰克公司 | Voltage indicator using serial comparison voltage measurement |
| CN202083398U (en) * | 2011-04-22 | 2011-12-21 | 长丰集团有限责任公司 | Signal conditioning circuit of rotating transformer |
| CN102506695A (en) * | 2011-10-09 | 2012-06-20 | 联合汽车电子有限公司 | Precision detection system for rotary transformer |
| CN102721362A (en) * | 2012-06-27 | 2012-10-10 | 同济大学 | Rotating transformer position measuring system and method |
| CN103001635A (en) * | 2012-12-10 | 2013-03-27 | 北京航天测控技术有限公司 | Testing method for conversion accuracy of digital signals and analog signals of rotary transformer module |
| CN103543431A (en) * | 2013-10-22 | 2014-01-29 | 江苏靖江互感器厂有限公司 | Method and system for measuring errors of electromagnetic type mutual inductor based on digital signal processing |
| CN107728097A (en) * | 2017-10-12 | 2018-02-23 | 湖南银河电气有限公司 | A kind of rotary transformer verifying attachment and its method for inspection |
| TWM563642U (en) * | 2018-02-09 | 2018-07-11 | 大陸商上海蔚蘭動力科技有限公司 | Testing system |
-
2019
- 2019-01-29 CN CN201910085932.3A patent/CN109581044B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1229923A (en) * | 1998-02-20 | 1999-09-29 | 弗兰克公司 | Voltage indicator using serial comparison voltage measurement |
| CN202083398U (en) * | 2011-04-22 | 2011-12-21 | 长丰集团有限责任公司 | Signal conditioning circuit of rotating transformer |
| CN102506695A (en) * | 2011-10-09 | 2012-06-20 | 联合汽车电子有限公司 | Precision detection system for rotary transformer |
| CN102721362A (en) * | 2012-06-27 | 2012-10-10 | 同济大学 | Rotating transformer position measuring system and method |
| CN103001635A (en) * | 2012-12-10 | 2013-03-27 | 北京航天测控技术有限公司 | Testing method for conversion accuracy of digital signals and analog signals of rotary transformer module |
| CN103543431A (en) * | 2013-10-22 | 2014-01-29 | 江苏靖江互感器厂有限公司 | Method and system for measuring errors of electromagnetic type mutual inductor based on digital signal processing |
| CN107728097A (en) * | 2017-10-12 | 2018-02-23 | 湖南银河电气有限公司 | A kind of rotary transformer verifying attachment and its method for inspection |
| TWM563642U (en) * | 2018-02-09 | 2018-07-11 | 大陸商上海蔚蘭動力科技有限公司 | Testing system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109581044A (en) | 2019-04-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104038226B (en) | The time-interleaved analog-digital converter of multichannel | |
| CN108155910B (en) | High-speed sine and cosine encoder decoding method based on FPGA | |
| CN102111158B (en) | Device for subdividing sine signal and cosine signal of position sensor and coding data, and implementation method thereof | |
| CN111721329B (en) | three-Hall magnetoelectric encoder and arc-tangent-free calculation angle calculation method | |
| CN107843227B (en) | Method for improving precision of encoder based on calibration technology | |
| CN109581044B (en) | Voltage detection device applied to rotary transformer and working method | |
| CN109612502B (en) | Method and system for testing transmission delay of internal signal of magnetic encoder chip | |
| CN110780110B (en) | Fundamental voltage zero crossing point automatic detection method and system and sampling device | |
| US5606515A (en) | Sensor conditioning circuitry for use with electrically excited transducers | |
| CA1192954A (en) | Device for measuring the phase angle between a sine wave signal and cyclic logic signal of the same frequency | |
| CN111999559B (en) | Digital linear phase comparison method based on double ADCs | |
| CN115001494A (en) | Interleaving sampling background self-adaptive self-calibration method | |
| Qian et al. | The fast time-interleaved ADC channel mismatch calibration method based on equivalent sampling and dynamic reference point | |
| CN207529214U (en) | A kind of rotation speed measuring module for DCS system | |
| KR100384173B1 (en) | Apparatus and method for high resolution processing of encoder signal for a motor control | |
| CN111130660B (en) | Phase noise measuring probe circuit | |
| CN110567363A (en) | angle detection device and detection method thereof | |
| Balestrieri et al. | Research trends and challenges on DAC testing | |
| CN117249846B (en) | Encoder pre-decoding processing method, system and storage medium | |
| Kiryanov et al. | Algorithms of interpolation of quadrature signals for high-resolution encoders of linear and angular displacements | |
| CN104444671A (en) | Elevator speed measurement method and system and elevator low-speed starting control method | |
| US11722343B1 (en) | Resolver integral demodulation using zero crossing points | |
| Balestrieri et al. | DAC testing: recent research directions | |
| CN214703760U (en) | Double-channel self-adaptive current sampling circuit of magnetic particle flaw detector | |
| CN108444393B (en) | double-A/D (analog/digital) cross-scale grating displacement measuring device and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |