Sampling circuit and encoder system
By combining the sample-and-hold module and the analog-to-digital converter module, the sampling accuracy of the encoder signal is improved, the limitations of sensor materials and structural processing technology are solved, and the measurement accuracy and reliability of the encoder are enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-17
- Publication Date
- 2026-03-27
AI Technical Summary
Existing technologies struggle to effectively improve encoder signal sampling accuracy. Sensor materials and manufacturing processes limit the improvement of analog signal quality, high-precision analog-to-digital converters increase costs, and structural processing technology restricts the improvement of installation accuracy.
A combination of a sample-and-hold module and an analog-to-digital converter module is used. The sample-and-hold module holds the analog signal voltage value, while the analog-to-digital converter module performs multiple samples to improve the signal sampling accuracy.
By sampling multiple times, the signal sampling accuracy of the encoder is improved, the measurement error is reduced, and the angle signal sampling accuracy and reliability of the encoder are significantly improved.
Smart Images
Figure CN224054248U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of encoder, and in particular to a sampling circuit and an encoder system. BACKGROUND
[0002] In the field of encoder technology, improving signal sampling precision is a continuous research and development focus. High-precision angle position sensors have important applications in industrial automation, robotics, aerospace, and precision manufacturing.
[0003] In the prior art, the signal sampling precision of the encoder is usually improved by improving the quality of the sensor analog signal, but it is limited by the sensor material and process level; improving the resolution of the analog-to-digital converter, but a high-precision analog-to-digital converter will increase the cost; improving the installation accuracy between the sensor and the measured object, but it is limited by the existing structure processing technology and is not easy to implement. Practical new type content
[0004] The embodiments of the present application provide a sampling circuit and an encoder system to output a high-resolution sampling voltage and improve the signal sampling precision of the encoder.
[0005] In a first aspect, the embodiments of the present application provide a sampling circuit, comprising a sample-and-hold module and an analog-to-digital conversion module.
[0006] The input end of the sample-and-hold module is connected with a sensor, and the output end of the sample-and-hold module is connected with the analog-to-digital conversion module.
[0007] The sensor is configured to output an analog signal to the sample-and-hold module, the sample-and-hold module is configured to output a voltage value of the analog signal at a current time to the analog-to-digital conversion module when receiving a trigger signal, and the analog-to-digital conversion module is configured to sample the voltage value at the current time, and the analog signal is configured to represent a rotation position of a rotating shaft.
[0008] In one of the embodiments, the sample-and-hold module comprises a first sample-and-hold unit and a second sample-and-hold unit.
[0009] The first end of the first sample-and-hold unit is the input end of the sample-and-hold module, the second end of the first sample-and-hold unit is the output end of the sample-and-hold module, the first end of the first sample-and-hold unit is connected with the sensor, and the second end of the first sample-and-hold unit is connected with the analog-to-digital conversion module.
[0010] The first end of the second sample-and-hold unit is the input end of the sample-and-hold module, the second end of the second sample-and-hold unit is the output end of the sample-and-hold module, the first end of the second sample-and-hold unit is connected with the sensor, and the second end of the second sample-and-hold unit is connected with the analog-to-digital conversion module.
[0011] The sensor outputs a first analog signal to a first sample-and-hold unit, and the first sample unit outputs a first voltage to an analog-to-digital conversion module after receiving a trigger signal, the first voltage being a voltage value of the first analog signal at a current time;
[0012] The sensor outputs a second analog signal to a second sample-and-hold unit, and the second sample unit outputs a second voltage to the analog-to-digital conversion module after receiving the trigger signal, the second voltage being a voltage value of the second analog signal at the current time.
[0013] In one of the embodiments, the analog-to-digital conversion module comprises a first analog-to-digital conversion unit and a second analog-to-digital conversion unit;
[0014] The first analog-to-digital conversion unit is connected to a second end of the first sample-and-hold unit, and the first analog-to-digital conversion unit samples the first voltage to generate first data;
[0015] The second analog-to-digital conversion unit is connected to a second end of the second sample-and-hold unit, and the second analog-to-digital conversion unit samples the second voltage to generate second data.
[0016] In one of the embodiments, the sampling circuit further comprises a calculation angle module connected to the analog-to-digital conversion module, and the calculation angle module is configured to process the voltage values output by the analog-to-digital conversion module to generate an angle signal.
[0017] In one of the embodiments, the calculation angle module comprises a tangent operation unit configured to perform an inverse tangent function operation on the first data and the second data to generate the angle signal.
[0018] In one of the embodiments, the calculation angle module further comprises a summation unit and a precision unit;
[0019] The input end of the summation unit is connected to the first analog-to-digital conversion unit and the second analog-to-digital conversion unit, the output end of the summation unit is connected to the input end of the precision unit, and the output end of the precision unit is connected to the tangent operation unit.
[0020] In one of the embodiments, the first analog-to-digital conversion unit and the second analog-to-digital conversion unit respectively sample the output results of the first sample-and-hold unit and the second sample-and-hold unit multiple times to improve the sampling precision.
[0021] In one of the embodiments, the first analog-to-digital conversion unit samples the first voltage continuously 4 M times to obtain the first data DU1[i], where i=1, 2,..., 4 M ;
[0022] The second analog-to-digital conversion unit samples the second voltage continuously 4 M times to obtain the second data DU2[i], where i=1, 2,..., 4M ;
[0023] The summation unit is configured to sum the first data and the second data, respectively;
[0024] The precision unit is configured to perform a higher resolution calculation on the summed first data and the summed second data, respectively.
[0025] In one of the embodiments, the sampling circuit comprises a communication interface, and the calculation angle module transmits the angle signal through the communication interface.
[0026] In one of the embodiments, the first sample-and-hold unit comprises a switch and a holding capacitor.
[0027] The first end of the switch is connected with the sensor, and the second end of the switch is connected with the first end of the holding capacitor and the analog-digital conversion module.
[0028] The second end of the holding capacitor is grounded.
[0029] In a second aspect, the embodiments of the present application provide an encoder system, comprising a sensor and the sampling circuit as any of the above, wherein the sensor is connected with the sampling circuit.
[0030] The sampling circuit and the encoder system provided by the embodiments of the present application, the sampling circuit comprises a sample-and-hold module and an analog-digital conversion module; the input end of the sample-and-hold module is connected with the sensor, and the output end of the sample-and-hold module is connected with the analog-digital conversion module; the sensor is configured to output an analog signal to the sample-and-hold module, and the sample-and-hold module is configured to output a voltage value of the analog signal at the current time to the analog-digital conversion module when receiving a trigger signal; the analog-digital conversion module samples the voltage value at the current time; and the analog signal is used to represent the rotation position of the rotating shaft. The embodiments of the present application keep the voltage value of the analog signal at the sampling time through the sample-and-hold module, so that the analog-digital conversion module samples the kept voltage value multiple times, thereby obtaining a digital voltage value with higher resolution and precision than the resolution and precision of the analog-digital conversion module, and improving the signal sampling precision of the encoder. BRIEF DESCRIPTION OF DRAWINGS
[0031] The accompanying drawings, which are incorporated herein and form part of the specification, illustrate embodiments consistent with the present application and, together with the description, further serve to explain the principles of the application.
[0032] Figure 1 A structure schematic diagram of the sampling circuit provided by an embodiment of the present application;
[0033] Figure 2 A structure schematic diagram of the sampling circuit provided by an embodiment of the present application;
[0034] Figure 3 A schematic diagram of the analog signal provided by an embodiment of the present application;
[0035] Figure 4 Analog signal diagram provided for another embodiment of the present application;
[0036] Figure 5 Structure diagram of the first sample and hold unit provided for an embodiment of the present application.
[0037] Reference signs:
[0038] 100, sensor; 200, sampling circuit; 210, sample and hold module; 211, first sample and hold unit; 212, second sample and hold unit; 220, analog-to-digital conversion module; 221, first analog-to-digital conversion unit; 222, second analog-to-digital conversion unit; 230, angle calculation module.
[0039] The specific embodiments of the present application have been shown in the above drawings, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION
[0040] The exemplary embodiments will be described in detail herein with reference to the accompanying drawings. In the following description, the same numbers refer to the same or similar elements throughout the drawings, unless otherwise indicated. The implementations described in the following exemplary embodiments are not meant to represent all implementations consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with some aspects of the present application as detailed in the appended claims.
[0041] First, the terms involved in the present application are explained:
[0042] Encoder: A device or algorithm used to convert information from one form to another. Encoders can be divided into different forms according to their use, among which the sine and cosine incremental encoder is used to represent the rotary position by outputting sine and cosine signals, and is usually used in high-precision position measurement and control systems.
[0043] Over-sampling principle: A signal processing technique used to improve the performance of analog-to-digital conversion (ADC) or digital-to-analog conversion (DAC) systems. The basic principle is to sample the signal at a sampling rate higher than the Nyquist rate (twice the signal bandwidth). The main purpose of over-sampling is to improve the resolution of the signal, reduce quantization noise and simplify filter design by increasing the sampling rate.
[0044] In a sine-cosine encoder, a sensor generates two analog signals when rotating: a sine signal and a cosine signal. These signals are usually generated by optical or magnetic principles. By sampling and converting these two signals into digital signals, the precise angle of the rotating shaft can be calculated.
[0045] In the prior art, the signal sampling accuracy of an encoder is usually improved by improving the quality of the sensor analog signal, but this is limited by the sensor material and process level; improving the resolution of the analog-to-digital converter, but a high-precision analog-to-digital converter increases the cost; improving the installation accuracy between the sensor and the measured object, but this is limited by the existing structure processing technology and is not easy to implement.
[0046] The sampling circuit provided by the present application includes a sample-and-hold module and an analog-to-digital conversion module; the input end of the sample-and-hold module is connected with a sensor, and the output end of the sample-and-hold module is connected with the analog-to-digital conversion module; the sensor is used to output an analog signal to the sample-and-hold module, the sample-and-hold module is used to output the voltage value of the current time of the analog signal to the analog-to-digital conversion module when receiving a trigger signal, the analog-to-digital conversion module samples the voltage value of the current time, and the analog signal is used to represent the rotation position of a rotating shaft. The present application keeps the voltage value of the analog signal at the sampling time through the sample-and-hold module, so that the analog-to-digital conversion module samples the kept voltage value multiple times, thereby obtaining a digital voltage value with higher resolution and accuracy than the analog-to-digital conversion module, and improving the signal sampling accuracy of the encoder.
[0047] The technical solutions of the present application and how the technical solutions of the present application solve the above technical problems will be described in detail below with specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of the present application will be described below with reference to the drawings.
[0048] The present application provides a sampling circuit, as shown in Figure 1 The present application provides a sampling circuit, as shown in Figure 1 The structure schematic diagram of the sampling circuit provided by an embodiment of the present application, the sampling circuit 200 includes a sample-and-hold module 210 and an analog-to-digital conversion module 220; the input end of the sample-and-hold module 210 is connected with a sensor 100, and the output end of the sample-and-hold module 210 is connected with the analog-to-digital conversion module 220; the sensor 100 is used to output an analog signal to the sample-and-hold module 210, the sample-and-hold module 210 is used to output the voltage value of the current time of the analog signal to the analog-to-digital conversion module 220 when receiving a trigger signal, the analog-to-digital conversion module 220 samples the voltage value of the current time, and the analog signal is used to represent the rotation position of a rotating shaft.
[0049] The encoder comprises a rotating shaft, which is usually directly connected with the mechanical part to be detected, such as a motor shaft, a rotating platform or other rotating mechanical devices, and is used to detect the rotating motion of the rotating mechanical devices. The motion of the rotating shaft is detected by the sensor 100, which outputs an analog signal according to the motion of the rotating shaft, and the analog signal is used to represent the motion of the rotating shaft and the motion of the rotating mechanical devices to be detected. The sample-and-hold module 210 holds the voltage value of the analog signal at the moment when the trigger signal is received, so that the analog-to-digital conversion module 220 can collect the voltage value of the analog signal at the current moment. Since the sample-and-hold module 210 can hold the voltage value of the analog signal, the analog-to-digital conversion module 220 can perform synchronous sampling on the analog signal.
[0050] In one embodiment, the analog-to-digital conversion module samples the output of the sample-and-hold module multiple times to improve the sampling accuracy.
[0051] Specifically, if the input signal is dynamically changing, it may cause inaccurate conversion results. By holding the signal through the sample-and-hold module, multiple sampling can be performed to make the final digital quantity more stable and accurate, thereby improving the measurement accuracy. Secondly, by sampling the same voltage value multiple times and taking the average or performing other processing, a result with higher resolution than the original resolution of the analog-to-digital conversion module can be obtained. This technique can effectively reduce measurement errors and improve the angular signal sampling accuracy of the encoder. The present application holds the voltage value of the analog signal at the sampling moment through the sample-and-hold module 210, so that the analog-to-digital conversion module 220 can sample the held voltage value multiple times, thereby obtaining a digital quantity voltage value with higher resolution and accuracy than the resolution and accuracy of the analog-to-digital conversion module 220, thereby improving the signal sampling accuracy of the encoder.
[0052] In one embodiment, as shown in Figure 2 , the analog-to-digital conversion module 220 samples the output of the sample-and-hold module 210 multiple times to improve the sampling accuracy. Figure 2The structure schematic diagram of the sampling circuit provided by an embodiment of the present application is shown in the figure. The sample-and-hold module 210 comprises: a first sample-and-hold unit 211 and a second sample-and-hold unit 212; the first end of the first sample-and-hold unit 211 is the input end of the sample-and-hold module 210, the second end of the first sample-and-hold unit 211 is the output end of the sample-and-hold module 210, the first end of the first sample-and-hold unit 211 is connected with the sensor 100, and the second end of the first sample-and-hold unit 211 is connected with the analog-to-digital conversion module 220; the first end of the second sample-and-hold unit 212 is the input end of the sample-and-hold module 210, the second end of the second sample-and-hold unit 212 is the output end of the sample-and-hold module 210, the first end of the second sample-and-hold unit 212 is connected with the sensor 100, and the second end of the second sample-and-hold unit 212 is connected with the analog-to-digital conversion module 220; the sensor 100 outputs a first analog signal to the first sample-and-hold unit 211, and the first sample-and-hold unit outputs a first voltage to the analog-to-digital conversion module 220 after receiving a trigger signal, the first voltage being the voltage value of the first analog signal at the current time; the sensor 100 outputs a second analog signal to the second sample-and-hold unit 212, and the second sample-and-hold unit outputs a second voltage to the analog-to-digital conversion module 220 after receiving a trigger signal, the second voltage being the voltage value of the second analog signal at the current time.
[0053] In one of the embodiments, the first analog-to-digital conversion unit and the second analog-to-digital conversion unit respectively sample the output results of the first sample-and-hold unit and the second sample-and-hold unit for multiple times to improve the sampling accuracy.
[0054] In one of the embodiments, as shown in the figure, Figure 2 the analog-to-digital conversion module 220 comprises: a first analog-to-digital conversion unit 221 and a second analog-to-digital conversion unit 222; the first analog-to-digital conversion unit 221 is connected with the second end of the first sample-and-hold unit 211, and the first analog-to-digital conversion unit 221 samples the first voltage to generate first data; the second analog-to-digital conversion unit 222 is connected with the second end of the second sample-and-hold unit 212, and the second analog-to-digital conversion unit 222 samples the second voltage to generate second data.
[0055] In one of the embodiments, the sampling circuit 200 further comprises a calculation angle module 230, the calculation angle module 230 is connected with the analog-to-digital conversion module 220, and the calculation angle module 230 is configured to process the voltage value output by the analog-to-digital conversion module 220 to generate an angle signal.
[0056] When the encoder is in a uniform rotation state, the sensor 100 outputs one or more sets of sine and cosine signals, wherein one set of sine and cosine signals comprises one sine signal and one cosine signal, as shown in the figure, Figure 3 Figure 3 The schematic diagram of the analog signal provided by an embodiment of the present application is shown in the figure, which correspondsFigure 2 The first analog signal and the second analog signal are sampled by the first sample-and-hold unit 211 and input to the first analog-to-digital converter unit 221 (ADC) for sampling and conversion into a digital value DU1, i.e., the first data; the second analog signal is sampled by the second sample-and-hold unit 212 and input to the second analog-to-digital converter unit 222 for sampling and conversion into a digital value DU2, i.e., the second data; the angle calculation module 230 generates an angle signal by processing the first data and the second data, i.e., calculates the arctangent of the first data and the second data to obtain the final angle ATAN (DU1 / DU2).
[0057] If the sampling of the first and second analog signals is not performed simultaneously, the sampling results will deviate from the actual values. For example... Figure 4 As shown, Figure 4 This is a schematic diagram of an analog signal provided in another embodiment of this application. Assuming the sampling time of the first analog signal is delayed by T0 compared to the second analog signal, the calculated angle is ATAN(DU1 / DU2). However, what is actually needed is the voltage value of the first and second analog signals at the same moment. Therefore, to avoid errors, the actual angle calculated by the angle calculation module 230 should be ATAN(DU1 / DU2). Therefore, to accurately calculate the angle, the first data DU1 and the second data DU2 collected by the first analog-to-digital converter 221 and the second analog-to-digital converter 222 must be values at the same time to ensure accurate angle calculation and avoid errors. Thus, by using the first sample-and-hold unit 211 and the second sample-and-hold unit 212 to hold down the voltage values of the first and second analog signals at the sampling time, it is convenient for the first analog-to-digital converter 221 and the second analog-to-digital converter 222 to perform multiple samplings, thereby ensuring that the first and second data are sampled values at the same time and ensuring synchronous sampling of the signals.
[0058] In one embodiment, the first sample-and-hold unit and the second sample-and-hold unit can be a series-type hold, a feedback hold, or a capacitor-corrected hold. The first sample-and-hold unit and the second sample-and-hold unit can also be other types of hold, which are not limited herein.
[0059] In one embodiment, such as Figure 5 As shown, Figure 5 This is a schematic diagram of the structure of a first sampling and holding unit 211 provided in an embodiment of this application. The first sampling and holding unit 211 includes a switch and a holding capacitor. The first end of the switch is connected to the sensor 100, and the second end of the switch is connected to the first end of the holding capacitor and the analog-to-digital conversion module 220. The second end of the holding capacitor is grounded. In this embodiment, the first sampling and holding unit is a series-type holding device. The first sampling and holding unit can also be other types of holding devices, which are not limited in this application.
[0060] Specifically, the second sample-and-hold unit 212 has the same circuit structure as the first sample-and-hold unit 211. During the sampling phase, the switch of the first sample-and-hold unit 211 is closed, and the capacitor is rapidly charged to track the input analog signal voltage. During this process, the capacitor voltage quickly rises to the same level as the first analog signal voltage. During the holding phase, the switch is open, and the capacitor voltage is fixed at the value at the sampling time. Due to the capacitor's charge-holding characteristic, this voltage value remains stable for a short period. The stable voltage signal is output from the first sample-and-hold unit 211 and supplied to the subsequent ADC (analog-to-digital converter module 220) for digitization processing. The first sample-and-hold unit 211 plays the role of "holding" the voltage value, ensuring that the signal received by the ADC is accurate and stable.
[0061] In one embodiment, the angle calculation module 230 includes a tangent calculation unit, which is used to perform an arctangent function operation on the first data and the second data to generate an angle signal.
[0062] In one embodiment, the angle calculation module 230 further includes a summation unit and a precision unit;
[0063] The input terminal of the summation unit is connected to the first analog-to-digital converter 221 and the second analog-to-digital converter 222, the output terminal of the summation unit is connected to the input terminal of the precision unit, and the output terminal of the precision unit is connected to the tangent operation unit.
[0064] In one embodiment, the first analog-to-digital converter 221 continuously converts the first voltage to 4 M The first data DU1[i] is obtained by sampling, where i=1,2,...,4 M The second analog-to-digital converter 222 continuously converts the second voltage to 4 M The second sampling yields the second data DU2[i], where i = 1, 2, ..., 4. M The summation unit is used to sum the first data and the second data respectively; the precision unit is used to perform resolution calculations on the summed first data and the second data respectively.
[0065] Specifically, after the system is powered on and initialized, the first sample-and-hold unit 211 and the second sample-and-hold unit 212 wait for a trigger signal. The trigger signal can be generated by an external trigger command or an internal timer. The trigger signal serves to activate the first sample-and-hold unit 211 and the second sample-and-hold unit 212 at the same time. The first analog-to-digital conversion unit and the second analog-to-digital conversion unit sample the first voltage and the second voltage multiple times, respectively, solving the problem that the input signal is dynamically changing and may cause inaccurate conversion results. After the signal is held by the sample-and-hold module, multiple sampling is performed, so that the final digital quantity is more stable and accurate, thereby improving the measurement accuracy.
[0066] At the moment of receiving the trigger signal, the first sample-and-hold unit 211 and the second sample-and-hold unit 212 are quickly charged, and the current analog signal voltage values are simultaneously held, that is, the first sample-and-hold unit 211 holds the voltage value AU1 of the first analog signal, and the second sample-and-hold unit 212 holds the voltage value AU2 of the second analog signal.
[0067] Optionally, there is a delay T1 after receiving the trigger signal. This time interval is to ensure that the sample-and-hold unit is fully charged and the voltage value is stably held. After the delay T1 ends, the system simultaneously starts the first analog-to-digital conversion unit 221 and the second analog-to-digital conversion unit 222. The first analog-to-digital conversion unit 221 samples the voltage AU1 of the first sample-and-hold unit 211 continuously 4 M times to obtain a series of digital quantities DU1[i], where i is 1 to 4 M ; similarly, the second analog-to-digital conversion unit 222 samples the voltage AU2 of the second sample-and-hold unit 212 continuously 4 M times to obtain a series of digital quantities DU2[i], where i is 1 to 4 M . The sample-and-hold module 210 and the analog-to-digital conversion module 220 together ensure high-precision signal sampling and angle calculation, thereby significantly improving the accuracy and reliability of the encoder.
[0068] The summation unit in the angle calculation module 230 sums DUI[i] to obtain SDU1 and sums DU2[i] to obtain SDU2. The precision unit calculates the digital quantity after increasing the M-bit resolution according to the oversampling principle. The final digital quantity of the first analog signal U M1 = SDUI / 2 M ; the final digital quantity of the second analog signal U M2 = SDU2 / 2 M . The tangent operation unit is used to perform an arctangent function operation on U M1 and U M2 to generate an angle signal, and the angle signal is ATAN(U M1 / UM2 The application keeps the analog signal voltage value at the sampling time through the sample and hold module 210, and the analog-digital conversion module 220 samples the kept voltage value multiple times, so that a digital voltage value with higher resolution and accuracy than the analog-digital conversion module 220 can be obtained.
[0069] In one of the embodiments, the sampling circuit includes a communication interface, and the angle calculation module 230 transmits the angle signal through the communication interface.
[0070] Specifically, the communication interface can be one or more of an asynchronous serial communication interface (UART), a synchronous serial communication interface (SPI), an inter-integrated circuit communication interface, a serial peripheral interface, a synchronous serial communication protocol for industrial automation (BISS-C), a bus EtherCAT, and CANOPEN. The application does not limit the type of the communication interface, which can be determined according to the actual situation. CANopen is a high-level protocol based on the CAN (Controller Area Network) bus. EtherCAT is a real-time Ethernet protocol designed for industrial automation. The angle calculation module 230 transmits the angle signal to other control systems or display devices through the communication interface.
[0071] The embodiment of the application provides an encoder system, including the sensor 100 and any of the above sampling circuits 200.
[0072] The division of the modules is only a logical function division, and in actual implementation, another division manner can be used, for example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed modules can be indirect coupling or communication connection through some interfaces, devices or modules, and can be electrical, mechanical or other forms.
[0073] The modules described as separate components can or can not be physically separated, and the components displayed as modules can or can not be physical modules, that is, can be located in one place or can be distributed on a plurality of network units. According to the actual needs, some or all of the modules can be selected to achieve the purpose of the embodiment.
[0074] In addition, the functional modules in each of the embodiments of the application can be integrated in one processing module, or each module can exist physically, or two or more modules can be integrated in one module.
[0075] It should be understood that many of the materials described herein are only given by way of example in describing the embodiments; it is, therefore, contemplated to be within the scope of the application that the materials can be substituted with other functionally equivalent materials. In general, the only meaningful limitations in terms of materials are dictated by the specific requirements of the application, and the materials must be compatible with the other materials used in the application. Further, it is intended that each of the embodiments and examples described herein can be implemented independently of one another and / or in various permutations, if appropriate. It is further intended that each of the examples described herein can stand on its own or can be combined with any of the other examples described herein.
Claims
1. A sampling circuit, characterized by, The sampling holding module and the analog-digital conversion module are included. An input end of the sampling holding module is connected with the sensor, and an output end of the sampling holding module is connected with the analog-digital conversion module. The sensor is configured to output an analog signal to the sampling holding module, and the sampling holding module is configured to output a voltage value of the analog signal at a current time to the analog-digital conversion module when a trigger signal is received. The sampling holding module includes a first sampling holding unit and a second sampling holding unit. A first end of the first sampling holding unit is an input end of the sampling holding module, a second end of the first sampling holding unit is an output end of the sampling holding module, the first end of the first sampling holding unit is connected with the sensor, and the second end of the first sampling holding unit is connected with the analog-digital conversion module. A first end of the second sampling holding unit is an input end of the sampling holding module, a second end of the second sampling holding unit is an output end of the sampling holding module, the first end of the second sampling holding unit is connected with the sensor, and the second end of the second sampling holding unit is connected with the analog-digital conversion module. The trigger signal is configured to activate the first sampling holding unit and the second sampling holding unit at the same time, and the first sampling holding unit and the second sampling holding unit are configured to synchronously hold a current analog signal voltage value after receiving the trigger signal. The sensor is configured to output a first analog signal to the first sampling holding unit, and the first sampling holding unit is configured to output a first voltage to the analog-digital conversion module after receiving the trigger signal, the first voltage being a voltage value of the first analog signal at a current time. The sensor is configured to output a second analog signal to the second sampling holding unit, and the second sampling holding unit is configured to output a second voltage to the analog-digital conversion module after receiving the trigger signal, the second voltage being a voltage value of the second analog signal at a current time. The analog-digital conversion module includes a first analog-digital conversion unit and a second analog-digital conversion unit. The first analog-digital conversion unit is connected with the second end of the first sampling holding unit, and the first analog-digital conversion unit is configured to sample the first voltage to generate first data. The second analog-digital conversion unit is connected with the second end of the second sampling holding unit, and the second analog-digital conversion unit is configured to sample the second voltage to generate second data.
2. The sampling circuit of claim 1, wherein, The sampling circuit further includes a calculation angle module, the calculation angle module is connected with the analog-digital conversion module, and the calculation angle module is configured to process voltage values output by the analog-digital conversion module to generate an angle signal.
3. The sampling circuit of claim 2, wherein, The calculation angle module includes a tangent operation unit, and the tangent operation unit is configured to perform an inverse tangent function operation on the first data and the second data to generate the angle signal.
4. The sampling circuit of claim 3, wherein, The calculation angle module further includes a summation unit and a precision unit. An input terminal of the summing unit is connected with the first and second analog-digital conversion units, an output terminal of the summing unit is connected with an input terminal of the precision unit, and an output terminal of the precision unit is connected with the tangent operation unit.
5. The sampling circuit of claim 4, wherein, The first and second analog-digital conversion units respectively sample the output results of the first and second sample-holding units multiple times to improve sampling precision.
6. The sampling circuit of claim 5, wherein, The first analog-digital conversion unit continuously samples the first voltage 4 M times to obtain first data DU1[i], where i = 1, 2,..., 4 M ; The second analog-digital conversion unit continuously samples the second voltage four times to obtain the second data DU2[i], where i = 1, 2,..., 4 M M ; The summing unit is configured to sum the first and second data respectively. The precision unit is configured to perform high-resolution calculation on the summed first and second data respectively.
7. The sampling circuit of claim 2, wherein, The sampling circuit further comprises a communication interface, and the angle calculation module transmits the angle signal through the communication interface.
8. An encoder system, characterized by The sampling circuit according to any one of claims 1-7 is connected with a sensor.