Signal processing circuit of rotary transformer type encoder
By designing a signal processing circuit for a resolver encoder, including protection processing, filtering, and ratio selection modules, the problem of adaptation difficulties in ratio switching of the resolver encoder was solved, realizing automatic ratio switching and high-precision motor control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHENZHEN WEICHUANG SOFTWARE CO LTD
- Filing Date
- 2025-11-18
- Publication Date
- 2026-04-21
AI Technical Summary
Existing resolver encoders require manual switching when adapting to different turns ratios, which is prone to errors and difficult to modify. Furthermore, the decoding chip has a wide range of voltage amplitude requirements, making adaptation difficult.
A signal processing circuit for a resolver encoder was designed, including a protection processing module, a filtering module, and a ratio selection module. The circuit can automatically switch the ratio to adapt to different ratios. The protection processing module protects the signal, the filtering module filters out interference signals, and the ratio selection module switches the ratio according to the control signal of the target device.
Automatic ratio switching of the resolver encoder signal processing circuit is realized, which improves the accuracy and flexibility of motor control, simplifies the ratio switching process, and adapts to different ratios with flexibility and compatibility.
Smart Images
Figure CN121907175A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of resolver encoder technology, and in particular to signal processing circuits for resolver encoders. Background Technology
[0002] Resolver encoders operate on the principle of transformers, consisting of a stator and a rotor. The stator windings act as the primary side of the transformer, receiving the excitation voltage, while the rotor windings act as the secondary side, obtaining the induced voltage through electromagnetic coupling. The induced voltage reflects the angular displacement of the motor, allowing the measurement of the motor's speed and position.
[0003] Because resolver encoders operate on the same principle as transformers, they share the same primary and secondary turns ratios. Different turns ratios result in different feedback voltage amplitudes, requiring the decoding chip to adapt to a wide voltage range. Currently, in related applications, encoder adapter circuits are mostly designed as optional accessories to accommodate different turns ratios, with one accessory for each ratio, resulting in a variety of accessories. Alternatively, mechanical switches can be used to switch between different turns ratios. All of these methods of turns ratio adaptation are manual and prone to errors, and once adapted, modifying the turns ratio is also quite difficult. Summary of the Invention
[0004] The signal processing circuit of the resolver encoder provided in this application can automatically switch the turns ratio to adapt to different turns ratios.
[0005] In a first aspect, this application provides a signal processing circuit for a resolver encoder. The signal processing circuit includes: a protection processing module connected to the signal output terminal of the resolver encoder, used to receive a target feedback signal output by the resolver encoder and output a first feedback signal according to the target feedback signal; a filtering module connected to the protection processing module, used to filter the first feedback signal and output a second feedback signal; and a ratio selection module connected to the filtering module, used to switch the corresponding ratio according to the control signal provided by the target device, convert the amplitude of the second feedback signal to obtain a third feedback signal, and output the third feedback signal to the decoding chip.
[0006] The further technical solution is that the target feedback signal includes a target sine feedback signal and a target cosine feedback signal; the protection processing module includes: a first protection processing unit, connected to the signal output terminal of the resolver encoder, used to receive the target sine feedback signal output by the resolver encoder, and output a first sine feedback signal according to the target sine feedback signal; a second protection processing unit, connected to the signal output terminal of the resolver encoder, used to receive the target cosine feedback signal output by the resolver encoder, and output a first cosine feedback signal according to the target cosine feedback signal.
[0007] A further technical solution is that the filtering module includes: a first filtering unit, which is connected to a first protection processing unit, for filtering the first sine feedback signal and outputting a second sine feedback signal; and a second filtering unit, which is connected to a second protection processing unit, for filtering the first cosine feedback signal and outputting a second cosine feedback signal.
[0008] A further technical solution is as follows: the target sinusoidal feedback signal includes a first target sinusoidal feedback signal and a second target sinusoidal feedback signal; the first sinusoidal feedback signal includes a first sub-sinusoidal feedback signal and a second sub-sinusoidal feedback signal; the first protection processing unit includes: a first reverse cutoff device, the first end of which is connected to the signal output terminal of the resolver encoder and a first filter unit, for receiving the first target sinusoidal feedback signal and outputting a first sub-sinusoidal feedback signal to the first filter unit according to the first target sinusoidal feedback signal; a second reverse cutoff device, the first end of which is connected to the second end of the first reverse cutoff device, the second end of which is connected to the signal output terminal of the resolver encoder and the first filter unit, for receiving the second target sinusoidal feedback signal and outputting a second sub-sinusoidal feedback signal to the first filter unit according to the second target sinusoidal feedback signal; and a third reverse cutoff device, the first end of which is connected to the second end of the first reverse cutoff device, and the second end of the third reverse cutoff device is grounded;
[0009] A further technical solution is that the first filtering unit includes: a first common-mode device, the first input terminal of which is connected to the first terminal of a first reverse cutoff device, and the second input terminal of which is connected to the first terminal of a second reverse cutoff device; a first bias device unit, the first terminal of which is connected to the first output terminal of the first common-mode device, the second terminal of which is connected to the second output terminal of the first common-mode device, and the third terminal of which is used to receive a bias signal; and a first filtering device unit, the first terminal of which is connected to the first terminal of the first bias device unit, and the second terminal of which is connected to the second terminal of the first bias device unit.
[0010] The further technical solution is as follows: the target cosine feedback signal includes a first target cosine feedback signal and a second target cosine feedback signal; the first cosine feedback signal includes a first sub-cosine feedback signal and a second sub-cosine feedback signal; the second protection processing unit includes: a fourth reverse cutoff device, the first end of which is connected to the signal output terminal of the resolver encoder and the second filtering unit, for receiving the first target cosine feedback signal and outputting a first sub-cosine feedback signal to the second filtering unit according to the first target cosine feedback signal; a fifth reverse cutoff device, the first end of which is connected to the second end of the fourth reverse cutoff device, the second end of which is connected to the signal output terminal of the resolver encoder and the filtering module, for receiving the second target cosine feedback signal and outputting a second sub-cosine feedback signal to the second filtering unit according to the second target cosine feedback signal; and a sixth reverse cutoff device, the first end of which is connected to the second end of the fourth reverse cutoff device, and the second end of the sixth reverse cutoff device is grounded.
[0011] A further technical solution is that the second filtering unit includes: a second common-mode device, the first input terminal of which is connected to the first terminal of the fourth reverse cutoff device, and the second input terminal of which is connected to the first terminal of the fifth reverse cutoff device; a second bias device unit, the first terminal of which is connected to the first output terminal of the second common-mode device, the second terminal of which is connected to the second output terminal of the second common-mode device, and the third terminal of which is used to receive a bias signal; and a second filtering device unit, the first terminal of which is connected to the first terminal of the second bias device unit, and the second terminal of which is connected to the second terminal of the second bias device unit.
[0012] A further technical solution is that the turns ratio selection module includes: a first resistive unit, the first end of which is connected to the first end of a first filtering device unit, and the second end of which serves as the first output terminal of the turns ratio selection module; a second resistive unit, the first end of which is connected to the second end of the first filtering device unit, and the second end of which serves as the second output terminal of the turns ratio selection module; a third resistive unit, the first end of which is connected to the second end of the second resistive unit; a fourth resistive unit, the first end of which is connected to the second end of the second resistive unit; and a third filtering device unit, a third filtering device unit. The first terminal of the device unit is connected to the second terminal of the first resistive unit, and the second terminal of the third filter device unit is connected to the second terminal of the second resistive unit; the selection unit has its first input terminal connected to the second terminal of the third resistive unit, its second input terminal connected to the second terminal of the fourth resistive unit, and its first output terminal connected to the second terminal of the first resistive unit. The selection unit is used to control the first input terminal and the first output terminal of the selection unit to connect when the control signal is high, switch the corresponding transformation ratio, and change the amplitude of the feedback signal output by the first output terminal, the second output terminal, the third output terminal, and the fourth output terminal of the transformation ratio selection module.
[0013] A further technical solution is that the turns ratio selection module includes: a fifth resistive unit, the first end of which is connected to the first end of the second filter element unit, and the second end of which serves as the third output terminal of the turns ratio selection module; a sixth resistive unit, the first end of which is connected to the second end of the second filter element unit, and the second end of which serves as the fourth output terminal of the turns ratio selection module; a seventh resistive unit, the first end of which is connected to the second end of the sixth resistive unit; an eighth resistive unit, the first end of which is connected to the second end of the sixth resistive unit; and a fourth filter element unit, the fourth filter element unit. The first terminal of the device unit is connected to the second terminal of the fifth resistive unit, and the second terminal of the fourth filter device unit is connected to the second terminal of the sixth resistive unit. The selection unit has its third input terminal connected to the second terminal of the seventh resistive unit, its fourth input terminal connected to the second terminal of the eighth resistive unit, and its second output terminal connected to the second terminal of the fifth resistive unit. The selection unit is used to control the fourth input terminal and the second output terminal of the selection unit to connect when the control signal is low, thereby switching the corresponding transformation ratio and converting the amplitude of the feedback signal output by the first, second, third, and fourth output terminals of the transformation ratio selection module.
[0014] A further technical solution is that the first resistive unit includes a first resistor; the second resistive unit includes a second resistor; the third resistive unit includes a third resistor; and the fourth resistive unit includes a fourth resistor.
[0015] The beneficial effects of this application are as follows: Unlike existing technologies, the signal processing circuit of the resolver encoder provided in this application includes a protection module to protect downstream circuits when electrostatic discharge or strong interference signals from other devices couple onto the feedback signal line. A filtering module is installed after the protection module to transmit unwanted signals to ground when they are subjected to high-frequency or common-mode interference from other devices during transmission. A turns ratio selection module is installed after the filtering module to switch the corresponding turns ratio based on the control signal provided by the target device, converting the amplitude of the second feedback signal to obtain a third feedback signal, and outputting the third feedback signal to the decoding chip. This automatic turns ratio switching adapts to different turns ratios and meets the high-precision motor control requirements of the target device. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:
[0017] Figure 1 This is a schematic diagram of the signal processing circuit of a resolver encoder provided in this application.
[0018] Figure 2 This is a schematic diagram of another embodiment of the signal processing circuit of the resolver encoder provided in this application;
[0019] Figure 3 This is a schematic diagram of another embodiment of the signal processing circuit of the resolver encoder provided in this application;
[0020] Figure 4 This is a schematic diagram of the structure of an embodiment of the resolver encoder provided in this application;
[0021] Figure 5 This is a schematic diagram of the structure of an embodiment of the target device provided in this application;
[0022] Figure 6 This is a schematic diagram of the structure of an embodiment of the decoding chip provided in this application. Detailed Implementation
[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It is understood that the specific embodiments described herein are only for explaining this application and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings, not all structures. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0025] See Figure 1 , Figure 1 This is a schematic diagram of an embodiment of the signal processing circuit of the resolver encoder provided in this application. The signal processing circuit 100 includes: a protection processing module 10, a filtering module 20, and a ratio selection module 30.
[0026] The protection processing module 10 is connected to the signal output terminal of the resolver encoder, and is used to receive the target feedback signal output by the resolver encoder and output the first feedback signal according to the target feedback signal.
[0027] In some embodiments, the main function of the protection processing module 10 is to protect the subsequent circuit when there is static electricity or strong interference signals from other devices coupled to the encoder feedback signal line.
[0028] In some embodiments, the protection processing module 10 can set up corresponding protection processing units according to the actual number of target feedback signals. For example, if the target feedback signals include sine feedback signals and cosine feedback signals, then corresponding protection processing units can be set up for the sine feedback signals and cosine feedback signals respectively.
[0029] The filtering module 20 is connected to the protection processing module 10 and is used to filter the first feedback signal and output the second feedback signal.
[0030] In some embodiments, the main function of the filtering module 20 is to transmit unwanted signals to the ground when the signal is interfered with by high-frequency interference or common-mode signal interference from other devices during transmission, thereby improving detection accuracy.
[0031] The transformer ratio selection module 30 is connected to the filter module 20 and is used to switch the corresponding transformer ratio according to the control signal provided by the target device, convert the amplitude of the second feedback signal to obtain the third feedback signal, and output the third feedback signal to the decoding chip 40. The main function of the transformer ratio selection module 30 is to switch the transformer ratio through a controllable analog switch, thereby converting the amplitude of the output signal. In this way, the transformer ratio selection module 30 can limit the amplitude of the third feedback signal input to the decoding chip 40 to the amplitude range required by the decoding chip 40, so as to facilitate the processing of the decoding chip 40.
[0032] In some embodiments, the control signal may originate from the internal main control chip of the target device or from other external controllers. In some embodiments, the target device may be a frequency converter. In some embodiments, the target device may be a servo controller, etc.
[0033] In this embodiment, a protection processing module 10 is provided in the signal processing circuit 100 to protect the subsequent circuits when electrostatic discharge or strong interference signals from other devices couple onto the feedback signal line. A filtering module 20 is provided after the protection processing module 10. When the signal is subjected to high-frequency interference or common-mode signal interference from other devices during transmission, the filtering module 20 can transmit these unwanted signals to ground. A transformer ratio selection module 30 is provided after the filtering module 20. The transformer ratio selection module 30 switches the corresponding transformer ratio according to the control signal provided by the target device, converts the amplitude of the second feedback signal to obtain a third feedback signal, and outputs the third feedback signal to the decoding chip 40. This automatic transformer ratio switching adapts to different transformer ratios and meets the high-precision requirements of the target device for motor control.
[0034] See Figure 2 , Figure 2 This is a schematic diagram of another embodiment of the signal processing circuit 100 for the resolver encoder provided in this application. The signal processing circuit 100 includes: a protection processing module 10, a filtering module 20, and a ratio selection module 30.
[0035] In some embodiments, the target feedback signal includes a target sine feedback signal and a target cosine feedback signal. The protection processing module 10 includes a first protection processing unit 11 and a second protection processing unit 12.
[0036] The first protection processing unit 11 is connected to the signal output terminal of the resolver encoder, and is used to receive the target sinusoidal feedback signal output by the resolver encoder, and output the first sinusoidal feedback signal according to the target sinusoidal feedback signal.
[0037] The second protection processing unit 12 is connected to the signal output terminal of the resolver encoder, and is used to receive the target cosine feedback signal output by the resolver encoder, and output the first cosine feedback signal according to the target cosine feedback signal.
[0038] In some embodiments, the filtering module 20 includes a first filtering unit 21 and a second filtering unit 22.
[0039] The first filtering unit 21 is connected to the first protection processing unit 11 and is used to filter the first sine feedback signal and output the second sine feedback signal; the second filtering unit 22 is connected to the second protection processing unit 12 and is used to filter the first cosine feedback signal and output the second cosine feedback signal.
[0040] The transformer ratio selection module 30 is connected to the first filter unit 21 and the second filter unit 22. It is used to switch the corresponding transformer ratio according to the control signal, convert the amplitude of the second sine feedback signal to obtain the third sine feedback signal, and output the third sine feedback signal to the decoding chip 40. The transformer ratio selection module 30 is also used to switch the corresponding transformer ratio according to the control signal provided by the target device, convert the amplitude of the second cosine feedback signal to obtain the third cosine feedback signal, and output the third cosine feedback signal to the decoding chip 40.
[0041] In this embodiment, a protection processing module 10 is provided in the signal processing circuit 100 to protect the subsequent circuits when electrostatic discharge or strong interference signals from other devices couple onto the feedback signal line. A filtering module 20 is provided after the protection processing module 10. When the signal is subjected to high-frequency interference or common-mode signal interference from other devices during transmission, the filtering module 20 can transmit these unwanted signals to ground. A transformer ratio selection module 30 is provided after the filtering module 20. The transformer ratio selection module 30 switches the corresponding transformer ratio according to the control signal provided by the target device, converts the amplitude of the second feedback signal, and outputs the third feedback signal to the decoding chip 40. This automatic transformer ratio switching adapts to different transformer ratios and meets the high-precision requirements of the target device for motor control.
[0042] Furthermore, the signal processing circuit 100 can process the target sine feedback signal and the target cosine feedback signal, and then output the third sine feedback signal and the third cosine feedback signal to the decoding chip 40.
[0043] See Figure 3 , Figure 3 This is a schematic diagram of another embodiment of the signal processing circuit of the resolver encoder provided in this application. The signal processing circuit 100 includes: a protection processing module 10, a filtering module 20, and a ratio selection module 30.
[0044] In some embodiments, the target sinusoidal feedback signal includes a first target sinusoidal feedback signal and a second target sinusoidal feedback signal; the first sinusoidal feedback signal includes a first sub-sinusoidal feedback signal and a second sub-sinusoidal feedback signal.
[0045] In some embodiments, the first protection processing unit 11 includes: a first reverse cut-off device 111, a second reverse cut-off device 112, and a third reverse cut-off device 113.
[0046] The first terminal of the first reverse cutoff device 111 is connected to the signal output terminal of the resolver encoder and the first filter unit 21, and is used to receive the first target sinusoidal feedback signal and output the first sub-sinusoidal feedback signal to the first filter unit 21 according to the first target sinusoidal feedback signal.
[0047] In some embodiments, the first target sinusoidal feedback signal can be sin+. The first reverse cutoff device 111 can be composed of two diodes connected in series. For example, the cathode of the first diode is connected to the signal output terminal of the resolver encoder and the first filter unit 21, the anode of the second diode is connected to the anode of the first diode, and the cathode of the second diode serves as the second terminal of the first reverse cutoff device 111.
[0048] The first end of the second reverse cut-off device 112 is connected to the second end of the first reverse cut-off device 111. The second end of the second reverse cut-off device 112 is connected to the signal output end of the resolver encoder and the first filter unit 21. It is used to receive the second target sinusoidal feedback signal and output the second sub-sinusoidal feedback signal to the first filter unit 21 according to the second target sinusoidal feedback signal.
[0049] In some embodiments, the second target sinusoidal feedback signal can be sin-. The second reverse cutoff device 112 can be composed of two diodes connected in series. For example, the cathode of the first diode is connected to the second terminal of the first reverse cutoff device 111, and the anode of the second diode is connected to the anode of the first diode. The cathode of the second diode serves as the second terminal of the second reverse cutoff device 112.
[0050] The first terminal of the third reverse cutoff device 113 is connected to the second terminal of the first reverse cutoff device 111, and the second terminal of the third reverse cutoff device 113 is grounded.
[0051] In some embodiments, the third reverse cutoff device 113 may be composed of two diodes connected in series. For example, the cathode of the first diode is connected to the second terminal of the first reverse cutoff device 111, and the anode of the second diode is connected to the anode of the first diode. The cathode of the second diode serves as the second terminal of the third reverse cutoff device 113.
[0052] In some embodiments, the target cosine feedback signal includes a first target cosine feedback signal and a second target cosine feedback signal; the first cosine feedback signal includes a first sub-cosine feedback signal and a second sub-cosine feedback signal.
[0053] The second protection processing unit 12 includes: a fourth reverse cut-off device 121, a fifth reverse cut-off device 122 and a sixth reverse cut-off device 123.
[0054] The first end of the fourth reverse cut-off device 121 is connected to the signal output terminal of the resolver encoder and the second filter unit 22, and is used to receive the first target cosine feedback signal and output the first sub-cosine feedback signal to the second filter unit 22 according to the first target cosine feedback signal.
[0055] In some embodiments, the first target cosine feedback signal can be cos+. The fourth reverse cutoff device 121 can be composed of two diodes connected in series. For example, the cathode of the first diode is connected to the signal output terminal of the resolver encoder and the second filter unit 22, the anode of the second diode is connected to the anode of the first diode, and the cathode of the second diode serves as the second terminal of the fourth reverse cutoff device 121.
[0056] The first end of the fifth reverse cut-off device 122 is connected to the second end of the fourth reverse cut-off device 121. The second end of the fifth reverse cut-off device 122 is connected to the signal output end of the resolver encoder and the filter module 20. It is used to receive the second target cosine feedback signal and output the second sub-cosine feedback signal to the second filter unit 22 according to the second target cosine feedback signal.
[0057] In some embodiments, the second target cosine feedback signal can be cos-. The fifth reverse cutoff device 122 can be composed of two diodes connected in series. For example, the cathode of the first diode is connected to the second terminal of the fourth reverse cutoff device 121, the anode of the second diode is connected to the anode of the first diode, and the cathode of the second diode serves as the second terminal of the fifth reverse cutoff device 122.
[0058] The first terminal of the sixth reverse cut-off device 123 is connected to the second terminal of the fourth reverse cut-off device 121, and the second terminal of the sixth reverse cut-off device 123 is grounded.
[0059] In some embodiments, the sixth reverse cutoff device 123 can be composed of two diodes connected in series. For example, the cathode of the first diode is connected to the second terminal of the fourth reverse cutoff device 121, and the anode of the second diode is connected to the anode of the first diode. The cathode of the second diode serves as the second terminal of the sixth reverse cutoff device 123.
[0060] In some embodiments, the first filtering unit 21 includes: a first common-mode device L1, a first bias device unit 211, and a first filtering device unit 212.
[0061] The first input terminal of the first common-mode device L1 is connected to the first terminal of the first reverse cutoff device 111, and the second input terminal of the first common-mode device L1 is connected to the first terminal of the second reverse cutoff device 112.
[0062] The first end of the first bias device unit 211 is connected to the first output terminal of the first common-mode device L1, the second end of the first bias device unit 211 is connected to the second output terminal of the first common-mode device L1, and the third end of the first bias device unit 211 is used to receive the bias signal.
[0063] In some embodiments, the first biasing device unit 211 may be composed of multiple resistors connected in series, such as two resistors, three resistors, etc. Figure 3 Taking two resistors as an example: the first terminal of resistor R3 is connected to the first output terminal of the first common-mode device L1, and the first terminal of resistor R5 is connected to the second terminal of resistor R3. The second terminal of resistor R5 is connected to the second output terminal of the first common-mode device L1. The second terminal of resistor R3 serves as the third terminal of the first bias device unit 211, receiving the bias signal REFOUT. Because the encoder's feedback signal has a negative value, but the decoding chip 40 cannot recognize negative signals, the bias signal REFOUT is used to increase the signal bias during signal processing, raising the feedback signal to a positive value. The resistance values of resistors R3 and R5 can be 10KΩ.
[0064] The first end of the first filter device unit 212 is connected to the first end of the first bias device unit 211, and the second end of the first filter device unit 212 is connected to the second end of the first bias device unit 211.
[0065] In some embodiments, the first filtering device unit 212 may be composed of multiple capacitors, such as two capacitors, three capacitors, etc. Figure 3 Taking three capacitors as an example: the first terminal of capacitor C1 is connected to the first terminal of the first bias device unit 211, and the second terminal of capacitor C1 is connected to the second terminal of the first bias device unit 211. The first terminal of capacitor C2 is connected to the first terminal of the first bias device unit 211, the first terminal of capacitor C3 is connected to the second terminal of capacitor C2, and the second terminal of capacitor C3 is connected to the second terminal of the first bias device unit 211. The second terminal of capacitor C2 is grounded.
[0066] The second filtering unit 22 includes: a second common-mode device L2, a second bias device unit 221, and a second filtering device unit 222.
[0067] The first input terminal of the second common-mode device L2 is connected to the first terminal of the fourth reverse cutoff device 121, and the second input terminal of the second common-mode device L2 is connected to the first terminal of the fifth reverse cutoff device 122.
[0068] The first end of the second bias device unit 221 is connected to the first output terminal of the second common-mode device L2, the second end of the second bias device unit 221 is connected to the second output terminal of the second common-mode device L2, and the third end of the second bias device unit 221 is used to receive the bias signal.
[0069] In some embodiments, the second bias device unit 221 may be composed of multiple resistors connected in series, such as two resistors, three resistors, etc. Figure 3 Taking two resistors as an example: the first terminal of resistor R13 is connected to the first output terminal of the second common-mode device L2, and the first terminal of resistor R14 is connected to the second terminal of resistor R13. The second terminal of resistor R14 is connected to the second output terminal of the second common-mode device L2. The second terminal of resistor R13 serves as the third terminal of the second bias device unit 221, receiving the bias signal REFOUT. Because the encoder's feedback signal has a negative value, but the decoding chip 40 cannot recognize negative signals, the bias signal REFOUT is used to increase the signal bias during signal processing, raising the feedback signal to a positive value. The resistance values of resistors R13 and R14 can be 10KΩ.
[0070] The first end of the second filter device unit 222 is connected to the first end of the second bias device unit 221, and the second end of the second filter device unit 222 is connected to the second end of the second bias device unit 221.
[0071] In some embodiments, the second filter element unit 222 may be composed of multiple capacitors, such as two capacitors, three capacitors, etc. Figure 3 Taking three capacitors as an example: the first terminal of capacitor C10 is connected to the first terminal of the second bias device unit 221, and the second terminal of capacitor C10 is connected to the second terminal of the second bias device unit 221. The first terminal of capacitor C13 is connected to the first terminal of the second bias device unit 221, the first terminal of capacitor C15 is connected to the second terminal of capacitor C13, and the second terminal of capacitor C15 is connected to the second terminal of the second bias device unit 221. The second terminal of capacitor C13 is grounded.
[0072] The transformer ratio selection module 30 includes: a first resistive unit 31, a second resistive unit 32, a third resistive unit 33, a fourth resistive unit 34, a third filtering device unit 35, a fifth resistive unit 36, a sixth resistive unit 37, a seventh resistive unit 38, an eighth resistive unit 39, a fourth filtering device unit 310, and a selection unit 311. The first resistive unit 31, the second resistive unit 32, the third resistive unit 33, the fourth resistive unit 34, and the third filtering device unit 35 correspond to the aforementioned first filtering unit 21. The fifth resistive unit 36, the sixth resistive unit 37, the seventh resistive unit 38, the eighth resistive unit 39, and the fourth filtering device unit 310 correspond to the aforementioned second filtering unit 22.
[0073] The first end of the first resistive unit 31 is connected to the first end of the first filter device unit 212, and the second end of the first resistive unit 31 serves as the first output end of the ratio selection module 30.
[0074] The first end of the second resistive unit 32 is connected to the second end of the first filter unit 212, and the second end of the second resistive unit 32 serves as the second output end of the ratio selection module 30.
[0075] The first end of the third resistive unit 33 is connected to the second end of the second resistive unit 32.
[0076] The first end of the fourth resistive unit 34 is connected to the second end of the second resistive unit 32.
[0077] The first end of the third filter element unit 35 is connected to the second end of the first resistive unit 31, and the second end of the third filter element unit 35 is connected to the second end of the second resistive unit 32.
[0078] In some embodiments, the third filtering device unit 35 may be composed of multiple capacitors, such as two capacitors, three capacitors, etc. Figure 3 Taking two capacitors as an example: the first terminal of capacitor C4 is connected to the second terminal of the first resistive unit 31, the first terminal of capacitor C9 is connected to the second terminal of capacitor C4, and the second terminal of capacitor C9 is connected to the second terminal of the second resistive unit 32. The second terminal of capacitor C4 is grounded.
[0079] The first end of the fifth resistive unit 36 is connected to the first end of the second filter device unit 222, and the second end of the fifth resistive unit 36 serves as the third output end of the ratio selection module 30.
[0080] The first end of the sixth resistive unit 37 is connected to the second end of the second filter unit 222, and the second end of the sixth resistive unit 37 serves as the fourth output end of the ratio selection module 30.
[0081] The first end of the seventh resistive unit 38 is connected to the second end of the sixth resistive unit 37.
[0082] The first end of the eighth resistive unit 39 is connected to the second end of the sixth resistive unit 37.
[0083] The first end of the fourth filter element unit 310 is connected to the second end of the fifth resistive unit 36, and the second end of the fourth filter element unit 310 is connected to the second end of the sixth resistive unit 37.
[0084] In some embodiments, the fourth filter unit 310 may be composed of multiple capacitors, such as two capacitors, three capacitors, etc. Figure 3 Taking two capacitors as an example: the first terminal of capacitor C20 is connected to the second terminal of the fifth resistive unit 36, the first terminal of capacitor C22 is connected to the second terminal of capacitor C20, and the second terminal of capacitor C22 is connected to the second terminal of the sixth resistive unit 37. The second terminal of capacitor C20 is grounded.
[0085] The first input terminal S1A of the selection unit 311 is connected to the second terminal of the third resistive unit 33. The third input terminal S2A of the selection unit 311 is connected to the second terminal of the seventh resistive unit 38. The second input terminal S1B of the selection unit 311 is connected to the second terminal of the fourth resistive unit 34. The fourth input terminal S2B of the selection unit 311 is connected to the second terminal of the eighth resistive unit 39. The first output terminal D1 of the selection unit 311 is connected to the second terminal of the first resistive unit 31. The second output terminal D2 of the selection unit 311 is connected to the second terminal of the fifth resistive unit 36.
[0086] When the control signal is high, the selection unit 311 connects its first input terminal S1A and first output terminal D1, and connects its third input terminal S1B and second output terminal D2, switching the corresponding turns ratio and converting the amplitude of the feedback signals output from the first, second, third, and fourth output terminals of the turns ratio selection module 30. The conversion unit 311 outputs the feedback signal SINH from its first output terminal, SINL from its second output terminal, COSH from its third output terminal, and COSL from its fourth output terminal.
[0087] When the control signal is low, the selection unit 311 controls the second input terminal S2A and the first output terminal D1 of the selection unit 311 to be connected, and controls the fourth input terminal S2B and the second output terminal D2 of the selection unit 311 to be connected, thereby switching the corresponding transformation ratio and changing the amplitude of the feedback signal output by the first output terminal, the second output terminal, the third output terminal and the fourth output terminal of the transformation ratio selection module 30.
[0088] When the control signal is high, the signal amplitude of the feedback signal between the first output terminal and the second output terminal of the ratio selection module 30 satisfies the following voltage division relationship: A / (B+C+A); where A represents the resistance value of the third resistive unit 33, B represents the resistance value of the first resistive unit 31, and C represents the resistance value of the second resistive unit 32.
[0089] When the control signal is high, the signal amplitude of the feedback signal between the third and fourth output terminals of the ratio selection module 30 satisfies the following voltage division relationship: D / (E+F+D); where D represents the resistance value of the seventh resistive unit 38, E represents the resistance value of the fifth resistive unit 36, and F represents the resistance value of the sixth resistive unit 37.
[0090] When the control signal is low, the signal amplitude of the feedback signal between the first output terminal and the second output terminal of the ratio selection module 30 satisfies the following voltage division relationship: G / (B+C+G); where G represents the resistance value of the fourth resistive unit 34.
[0091] When the control signal is low, the signal amplitude of the feedback signal between the third and fourth output terminals of the ratio selection module 30 satisfies the following voltage division relationship: H / (E+F+H); where H represents the resistance value of the eighth resistive unit 39.
[0092] The first output terminal of the ratio selection module 30 can output a feedback signal SINH, the second output terminal of the ratio selection module 30 can output a feedback signal SINL, the third output terminal of the ratio selection module 30 can output a feedback signal COSH, and the fourth output terminal of the ratio selection module 30 can output a feedback signal COSL.
[0093] In some embodiments, the first resistive unit 31 includes a first resistor R1; the second resistive unit 32 includes a second resistor R2; the third resistive unit 33 includes a third resistor R6; the fourth resistive unit 34 includes a fourth resistor R9; the fifth resistive unit 36 includes a fifth resistor R10; the sixth resistive unit 37 includes a sixth resistor R12; the seventh resistive unit 38 includes a seventh resistor R15; and the eighth resistive unit 39 includes an eighth resistor R18.
[0094] The resistance values of the first resistor R1, the second resistor R2, the third resistor R6, the fourth resistor R9, the fifth resistor R10, the sixth resistor R12, the seventh resistor R15, and the eighth resistor R18 are all 4.99KΩ.
[0095] That is, when the control signal CTR is high, the first input terminal S1A and the first output terminal D1 of the selection unit 311 are connected. At this time, the signal amplitude between the feedback signals SINH and SINL satisfies the voltage division relationship of R6 / (R1+R2+R6). Similarly, when the second input terminal S1B and the second output terminal D2 of the selection unit 311 are connected, the signal amplitude between the feedback signals COSH and COSL satisfies the voltage division relationship of R15 / (R10+R12+R15).
[0096] When the control signal CTR is low, the third input terminal S1B and the first output terminal D1 of the selection unit 311 are connected. At this time, the signal amplitude between the feedback signals SINH and SINL satisfies the voltage division relationship of R9 / (R1+R2+R9). Similarly, the fourth input terminal S2B and the second output terminal D2 of the selection unit 311 are connected, and the signal amplitude between the feedback signals COSH and COSL satisfies the voltage division relationship of R18 / (R10+R12+R18).
[0097] The signal amplitude conversion can be achieved through the above three circuit processing steps. When the selected decoding chip 40 is AD2S1205, the signal amplitude requirement of the decoding chip 40 is between 3 and 4V. The feedback signals SINH, SINL, COSH, and COSL are sent to the decoding chip 40 through the above processing circuit. Combined with the control of the main control chip inside the target device, the design of an automatically controllable rotary encoder interface circuit can be realized. The processing method is simple, the use is flexible, and the compatibility is good.
[0098] Understandable. Figure 3 The design uses two transformer ratios as examples, and the main control chip of the target device can control... Figure 3 The selection unit 311 switches between different turns ratios. Due to the characteristics of the analog electronic switch of the selection unit 311, the switching will not affect the signal quality of the output signal of the resolver encoder 200, meeting the high precision requirements of the target equipment for motor control, and the turns ratio switching is more flexible and simple.
[0099] See Figure 4 , Figure 4 This is a schematic diagram of an embodiment of the resolver encoder provided in this application. The resolver encoder 200 includes a signal processing circuit 100. The signal processing circuit 100 is as described in any of the above embodiments.
[0100] See Figure 5 , Figure 5 This is a schematic diagram of an embodiment of the target device provided in this application. The target device 300 includes a resolver encoder 200. The resolver encoder 200 is as described in any of the above embodiments.
[0101] See Figure 6 , Figure 6 This is a schematic diagram of an embodiment of the decoding chip provided in this application. The decoding chip has corresponding pins that are connected to the signal processing circuit 100.
[0102] In summary, the resolver encoder 200, its signal processing circuit 100, and the target device 300 provided in this application include a protection processing module 10 in the signal processing circuit 100 to protect downstream circuits when electrostatic discharge or strong interference signals from other devices couple onto the feedback signal line. A filtering module 20 is provided after the protection processing module 10 to transmit unwanted signals to ground when the signal is subjected to high-frequency interference or common-mode interference from other devices during transmission. A turns ratio selection module 30 is provided after the filtering module 20 to switch the corresponding turns ratio according to the control signal, convert the amplitude of the second feedback signal, and output the third feedback signal to the decoding chip 40. This automatic turns ratio switching adapts to different turns ratios and meets the high-precision motor control requirements of the target device 300.
[0103] Furthermore, the resolver encoder 200, its signal processing circuit 100, and the target device 300 provided in this application can simplify the way the turns ratio of the resolver encoder 200 is adapted, and improve the ease of use of the target device 300, so that switching between different turns ratios of the encoder can be achieved simply by selecting parameters.
[0104] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.
[0105] If the integrated units in the other embodiments described above are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processing circuit component (processor) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.
[0106] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.
Claims
1. A signal processing circuit for a resolver encoder, characterized in that, include: The protection processing module is connected to the signal output terminal of the resolver encoder and is used to receive the target feedback signal output by the resolver encoder and output a first feedback signal according to the target feedback signal. A filtering module, connected to the protection processing module, is used to filter the first feedback signal and output a second feedback signal; The transformer ratio selection module, connected to the filtering module, is used to switch the corresponding transformer ratio according to the control signal provided by the target device, convert the amplitude of the second feedback signal to obtain the third feedback signal, and output the third feedback signal to the decoding chip.
2. The signal processing circuit according to claim 1, characterized in that, The target feedback signal includes: a target sine feedback signal and a target cosine feedback signal; the protection processing module includes: The first protection processing unit is connected to the signal output terminal of the resolver encoder and is used to receive the target sinusoidal feedback signal output by the resolver encoder and output a first sinusoidal feedback signal according to the target sinusoidal feedback signal. The second protection processing unit is connected to the signal output terminal of the resolver encoder and is used to receive the target cosine feedback signal output by the resolver encoder and output a first cosine feedback signal according to the target cosine feedback signal.
3. The signal processing circuit according to claim 2, characterized in that, The filtering module includes: A first filtering unit, connected to the first protection processing unit, is used to filter the first sinusoidal feedback signal and output a second sinusoidal feedback signal. The second filtering unit, connected to the second protection processing unit, is used to filter the first cosine feedback signal and output the second cosine feedback signal.
4. The signal processing circuit according to claim 3, characterized in that, The target sinusoidal feedback signal includes a first target sinusoidal feedback signal and a second target sinusoidal feedback signal; the first sinusoidal feedback signal includes a first sub-sinusoidal feedback signal and a second sub-sinusoidal feedback signal. The first protection processing unit includes: The first reverse cut-off device has its first end connected to the signal output terminal of the resolver encoder and the first filtering unit, and is used to receive the first target sinusoidal feedback signal and output the first sub-sinusoidal feedback signal to the first filtering unit according to the first target sinusoidal feedback signal. The second reverse cut-off device has a first end connected to the second end of the first reverse cut-off device, and the second end of the second reverse cut-off device is connected to the signal output terminal of the resolver encoder and the first filter unit. It is used to receive the second target sinusoidal feedback signal and output the second sub-sinusoidal feedback signal to the first filter unit according to the second target sinusoidal feedback signal. The third reverse cutoff device has a first end connected to the second end of the first reverse cutoff device, and the second end of the third reverse cutoff device is grounded.
5. The signal processing circuit according to claim 4, characterized in that, The first filtering unit includes: A first common-mode device, wherein the first input terminal of the first common-mode device is connected to the first terminal of the first reverse cutoff device, and the second input terminal of the first common-mode device is connected to the first terminal of the second reverse cutoff device; A first bias device unit, wherein a first end of the first bias device unit is connected to a first output terminal of the first common-mode device, a second end of the first bias device unit is connected to a second output terminal of the first common-mode device, and a third end of the first bias device unit is used to receive a bias signal. A first filter element unit, wherein a first end of the first filter element unit is connected to a first end of the first bias device unit, and a second end of the first filter element unit is connected to a second end of the first bias device unit.
6. The signal processing circuit according to claim 3, characterized in that, The target cosine feedback signal includes a first target cosine feedback signal and a second target cosine feedback signal; the first cosine feedback signal includes a first sub-cosine feedback signal and a second sub-cosine feedback signal. The second protection processing unit includes: The fourth reverse cut-off device has its first end connected to the signal output terminal of the resolver encoder and the second filtering unit, and is used to receive the first target cosine feedback signal and output the first sub-cosine feedback signal to the second filtering unit according to the first target cosine feedback signal. The fifth reverse cutoff device has its first end connected to the second end of the fourth reverse cutoff device, and its second end connected to the signal output terminal of the resolver encoder and the filtering module. It is used to receive the second target cosine feedback signal and output the second sub-cosine feedback signal to the second filtering unit according to the second target cosine feedback signal. A sixth reverse cutoff device, wherein the first end of the sixth reverse cutoff device is connected to the second end of the fourth reverse cutoff device, and the second end of the sixth reverse cutoff device is grounded.
7. The signal processing circuit according to claim 6, characterized in that, The second filtering unit includes: The second common-mode device has its first input terminal connected to the first terminal of the fourth reverse cutoff device, and its second input terminal connected to the first terminal of the fifth reverse cutoff device. The second bias device unit has a first terminal connected to the first output terminal of the second common-mode device, a second terminal connected to the second output terminal of the second common-mode device, and a third terminal used to receive a bias signal. The second filter element unit has a first end connected to the first end of the second bias device unit, and a second end connected to the second end of the second bias device unit.
8. The signal processing circuit according to claim 5, characterized in that, The transformer ratio selection module includes: The first resistive unit has its first end connected to the first end of the first filter unit, and its second end serves as the first output terminal of the ratio selection module. The second resistive unit has its first end connected to the second end of the first filter unit, and its second end serves as the second output terminal of the ratio selection module. The third resistive unit, wherein the first end of the third resistive unit is connected to the second end of the second resistive unit; A fourth resistive unit, wherein the first end of the fourth resistive unit is connected to the second end of the second resistive unit; A third filter element unit, wherein a first end of the third filter element unit is connected to a second end of the first resistive unit, and a second end of the third filter element unit is connected to a second end of the second resistive unit; The selection unit has a first input terminal connected to the second terminal of the third resistive unit, a second input terminal connected to the second terminal of the fourth resistive unit, and a first output terminal connected to the second terminal of the first resistive unit. The selection unit is used to control the first input terminal and the first output terminal of the selection unit to connect when the control signal is high, thereby switching the corresponding turns ratio and changing the amplitude of the feedback signal output by the first, second, third, and fourth output terminals of the turns ratio selection module.
9. The signal processing circuit according to claim 7, characterized in that, The transformer ratio selection module includes: The fifth resistive unit has its first end connected to the first end of the second filter unit, and its second end serves as the third output terminal of the turns ratio selection module. The sixth resistive unit has its first end connected to the second end of the second filter unit, and its second end serves as the fourth output terminal of the turns ratio selection module. The seventh resistive unit, wherein the first end of the seventh resistive unit is connected to the second end of the sixth resistive unit; The eighth resistive unit, wherein the first end of the eighth resistive unit is connected to the second end of the sixth resistive unit; A fourth filter element unit, wherein the first end of the fourth filter element unit is connected to the second end of the fifth resistive unit, and the second end of the fourth filter element unit is connected to the second end of the sixth resistive unit; The selection unit has its third input terminal connected to the second terminal of the seventh resistive unit, its fourth input terminal connected to the second terminal of the eighth resistive unit, and its second output terminal connected to the second terminal of the fifth resistive unit. The selection unit is used to control the fourth input terminal and the second output terminal of the selection unit to connect when the control signal is low, thereby switching the corresponding turns ratio and changing the amplitude of the feedback signal output by the first output terminal, second output terminal, third output terminal, and fourth output terminal of the turns ratio selection module.
10. The signal processing circuit according to claim 8, characterized in that, The first resistive unit includes a first resistor; the second resistive unit includes a second resistor; the third resistive unit includes a third resistor; and the fourth resistive unit includes a fourth resistor.