New energy commercial vehicle resolver signal detection circuit

Abstract

The utility model relates to a new energy commercial vehicle resolver signal detection circuit comprising a filter circuit comprising a first filter unit and a second filter unit, and the output end of the second filter unit outputs the positive differential output and the negative differential output of a resolver signal to a decoding chip; the differential circuit comprises a buffer amplification unit and a third filtering unit, the input end of the buffer amplification unit is connected with the second output end of the first filtering unit, the output end of the buffer amplification unit is connected with the input end of the third filtering unit, and the output end of the third filtering unit outputs a decoding signal; and the micro-control unit is connected with the output end of the third filtering unit, and the micro-control unit is used for judging the fault type of the rotary transformer in combination with the information of the decoding chip. According to the utility model, through combination of multi-stage filtering, differential signal processing and the micro-control unit, the stability of a rotary transformer signal can be effectively improved, and faults can be accurately diagnosed.

Description

Technical Field

[0001] This utility model relates to the field of detection circuit technology, and in particular to a resolver signal detection circuit for new energy commercial vehicles. Background Technology

[0002] With the continuous development and application of new energy vehicle technology, electric commercial vehicles have become increasingly prominent in terms of energy conservation, environmental protection, and emission reduction. In the motor control system of electric commercial vehicles, resolver sensors can provide high-precision absolute position data, have strong anti-interference capabilities and good vibration adaptability, and are therefore widely used in electric vehicles.

[0003] However, in practical vehicle applications, the transmission quality of resolver signals is easily affected by many external factors in the in-vehicle environment of new energy commercial vehicles, such as electromagnetic interference (EMI) and mechanical vibration. Electric commercial vehicles typically use relatively long signal cables (approximately 3-4 meters), and these cables may pass through multiple adapter terminals. This makes the resolver signals susceptible to electromagnetic noise interference during transmission, and may even lead to signal loss or increased errors due to loose terminals or poor contact.

[0004] Most existing technical solutions employ fault detection functions embedded within the resolver sensor. The resolver chip typically integrates fault information internally and outputs it via an SPI interface or fixed I / O port for fault diagnosis by an external control unit. The fault information output built into the resolver chip is usually a simple digital signal, providing only general fault states such as signal loss or exceeding operating range. Because the output information is relatively coarse, it often cannot accurately determine the specific cause of the fault, such as signal transmission failure, electromagnetic interference, or a fault in the resolver sensor itself. Such fault information is too vague for accurate fault diagnosis in practical applications and fails to meet the requirements of high-reliability systems. More importantly, existing resolver fault detection circuits rely heavily on a single signal output method, lacking multi-dimensional information feedback and failing to comprehensively assess the health status of the resolver system. Therefore, ensuring the stability of the resolver signal in complex environments and accurately diagnosing various faults during signal transmission has become a pressing technical problem. Utility Model Content

[0005] The purpose of this invention is to provide a resolver signal detection circuit for new energy commercial vehicles to solve the above-mentioned problems.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This application provides a resolver signal detection circuit for new energy commercial vehicles, including:

[0008] The filtering circuit includes a first filtering unit and a second filtering unit. The input terminal of the first filtering unit is connected to the output terminal of the resolver sensor, the first output terminal of the first filtering unit is connected to the input terminal of the second filtering unit, and the output terminal of the second filtering unit outputs the positive differential output and the negative differential output of the resolver signal to the decoding chip.

[0009] The differential circuit includes a buffer amplifier unit and a third filter unit. The input terminal of the buffer amplifier unit is connected to the second output terminal of the first filter unit, and the output terminal of the buffer amplifier unit is connected to the input terminal of the third filter unit. The output terminal of the third filter unit outputs a decoded signal.

[0010] A microcontroller unit is connected to the output of the third filter unit. The microcontroller unit is used to determine the type of resolver fault by combining the information from the decoding chip.

[0011] Furthermore, the filtering circuit also includes a protection unit, which includes a first diode, a second diode, and a first capacitor. The resolver sensor includes a first output terminal and a second output terminal. The first output terminal is connected to the first diode and the first capacitor, respectively. The first capacitor is connected to the second diode, and the second output terminal is connected to the second diode.

[0012] Furthermore, the first filter unit includes a second capacitor, a third capacitor, and a first inductor. The second capacitor is connected to the second diode and the first inductor, respectively, and the third capacitor is connected to the first capacitor and the first inductor, respectively.

[0013] Furthermore, the second filter unit includes a first resistor, a second resistor, a ninth capacitor, a fourth capacitor, and a fifth capacitor. The first resistor and the fourth capacitor are connected, the second resistor and the ninth capacitor are connected, and the ninth capacitor is connected to both the fourth capacitor and the fifth capacitor.

[0014] Furthermore, the buffer amplification unit includes a first operational amplifier and a second operational amplifier, and the input terminals of the first operational amplifier and the second operational amplifier are respectively connected to the second output terminal of the first filtering unit.

[0015] Furthermore, the third filtering unit includes a third resistor, a fourth resistor, a sixth capacitor, and a seventh capacitor. The input terminals of the third resistor and the fourth resistor are respectively connected to the first operational amplifier and the second operational amplifier, and the output terminals of the third resistor and the fourth resistor are respectively connected to the sixth capacitor and the seventh capacitor.

[0016] Furthermore, the differential circuit also includes a processing unit, which includes a third operational amplifier, an eighth resistor, and a ninth resistor. One end of the eighth resistor is connected to the inverting input of the third operational amplifier, and the other end is connected to the output of the third operational amplifier. One end of the ninth resistor is connected to the non-inverting input of the third operational amplifier, and the other end is connected to a reference voltage.

[0017] Furthermore, the second filter unit also includes a tenth resistor, one end of which is connected to the first resistor and the fifth capacitor, and the other end of which is connected to the ninth capacitor and the fifth capacitor.

[0018] Furthermore, the differential circuit also includes an eleventh resistor, the first end of which is connected to the third resistor and the output terminal of the third operational amplifier.

[0019] Furthermore, the differential circuit also includes a twelfth resistor and an eighth capacitor, with one end of the twelfth resistor connected to the second end of the eleventh resistor and the other end connected to the eighth capacitor.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This application's resolver signal detection circuit for new energy commercial vehicles effectively improves resolver signal stability and accurately diagnoses faults through a combination of multi-stage filtering, differential signal processing, and a microcontroller unit. Unlike existing technologies that rely on simple fault information output from built-in hardware resolver decoding chips, this circuit uses a microcontroller unit (MCU) in conjunction with information provided by the decoding chip to perform a more detailed analysis and judgment of the resolver signal. This allows for accurate identification of various fault types in resolver signal transmission, including signal loss, electromagnetic interference, or sensor malfunctions. Real-time processing by the MCU enables faster and more accurate fault diagnosis, avoiding the lag and errors in existing methods. It also provides multi-dimensional feedback, facilitating a comprehensive assessment of the resolver system's health. The design of the filtering and differential circuits effectively reduces the impact of external electromagnetic interference and mechanical vibration on the signal, ensuring the quality of resolver signal transmission and guaranteeing high-reliability operation of electric commercial vehicles in complex environments. Compared to existing resolver fault detection methods, this technical solution significantly improves system stability and fault diagnosis accuracy, meeting the requirements of high-reliability motor control systems and demonstrating greater adaptability and practicality. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0024] Figure 1 This is a schematic diagram of the filter circuit for the resolver signal detection circuit of the new energy commercial vehicle in this embodiment;

[0025] Figure 2 This is a schematic diagram of the differential circuit of the resolver signal detection circuit for new energy commercial vehicles in this embodiment;

[0026] Figure 3 This is a waveform diagram of the differential signal output by the resolver sensor in the resolver signal detection circuit of the new energy commercial vehicle in this embodiment;

[0027] Figure 4 This is a schematic diagram of the resolver sensor in the resolver signal detection circuit for new energy commercial vehicles in this embodiment.

[0028] Q1, First diode; Q2, Second diode; C1, First capacitor; C126, Second capacitor; C148, Third capacitor; L4, First inductor; R135, First resistor; R136, Second resistor; C2, Ninth capacitor; C3, Fourth capacitor; C206, Fifth capacitor; U14, First operational amplifier; U22, Second operational amplifier; R251, Third resistor; R252, Fourth resistor; C120, Sixth capacitor; C121, Seventh capacitor; U15, Third operational amplifier; R326, Eighth resistor; R234, Ninth resistor; R45, Tenth resistor; R258, Eleventh resistor; R253, Twelfth resistor; C185, Eighth capacitor; R254, Thirteenth resistor; R289, Fourteenth resistor. Detailed Implementation

[0029] To make the utility model's objectives, features, and advantages more apparent and understandable, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0031] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figures 1 to 4 The resolver signal detection circuit for new energy commercial vehicles disclosed in this embodiment includes:

[0033] The filtering circuit includes a first filtering unit and a second filtering unit. The input terminal of the first filtering unit is connected to the output terminal of the resolver sensor, the first output terminal of the first filtering unit is connected to the input terminal of the second filtering unit, and the output terminal of the second filtering unit outputs the positive differential output and the negative differential output of the resolver signal to the decoding chip.

[0034] The differential circuit includes a buffer amplifier unit and a third filter unit. The input terminal of the buffer amplifier unit is connected to the second output terminal of the first filter unit, and the output terminal of the buffer amplifier unit is connected to the input terminal of the third filter unit. The output terminal of the third filter unit outputs a decoded signal.

[0035] A microcontroller unit is connected to the output of the third filter unit. The microcontroller unit is used to determine the type of resolver fault by combining the information from the decoding chip.

[0036] In this embodiment, the output signals COS-P and COS-N of the resolver sensor are two differential signals, representing the positive and negative responses of the sensor to changes in the angle of the rotation axis, respectively. These two signals undergo preliminary processing through a filtering circuit. The filtering circuit includes a first filtering unit and a second filtering unit. The input terminal of the first filtering unit is connected to the output terminal of the resolver sensor, and its purpose is to remove high-frequency noise and common-mode interference. The first filtering unit guides the input signal to the ground plane through a low-impedance loop to reduce the impact of noise, while providing higher impedance to prevent interference signals from affecting the operation of subsequent circuits. After preliminary filtering, the signal is sent to the second filtering unit for further purification, and outputs the positive and negative differential resolver signals. These signals are connected to the decoding chip to determine the position of the motor. The first output of the first filter circuit flows into the COS+ and COS- network nodes via the second filter unit. COS+ and COS- are the COS input terminals of the resolver hardware decoding chip, which can determine the motor position based on the COS / SIN signal output by the resolver sensor. At the second output of the first filter circuit, part of the signal is further processed by a differential circuit, which includes a buffer amplification unit and a third filter unit. The buffer amplification unit prevents signal distortion during transmission and enhances the signal's driving force to ensure smooth transmission to subsequent circuits. The third filter unit removes any residual noise and unnecessary interference, ensuring the signal transmitted to the microcontroller unit (MCU) is sufficiently clean and accurate. These processed signals are ultimately output as a voltage (Ecos) and sampled by the MCU's ADC sampling pin for further analysis and judgment. Based on the feedback information from the decoding chip and the signal from the differential circuit, the MCU determines whether the resolver signal is abnormal and identifies the resolver fault type. By analyzing the time and frequency domain characteristics of the resolver signal, the MCU can detect whether the motor has positional deviations or other faults that may affect performance. By determining the type of resolver fault in real time, the system can take timely measures, such as adjusting the motor's operating status or issuing an alarm, thereby ensuring the safe and reliable operation of new energy vehicles.

[0037] The specific principle of this embodiment is that the COS-P and COS-N signals of the resolver sensor represent the positive and negative signals of the rotational position, respectively. Figure 4The output signals of S2 and S4 are often affected by high-frequency noise and common-mode interference. The first filtering unit guides these interference signals to the ground plane by providing low-impedance loops and high-impedance methods, thereby filtering out unwanted high-frequency noise while ensuring the integrity of the effective signal. After filtering, the signal is divided into two branches for processing. The first branch enters the differential circuit, where the operational amplifier (OPA) amplifies the COS-P and COS-N signals and changes their impedance to ensure that the signal can adapt to subsequent filtering and processing. After the differential circuit outputs the operational amplifier, the signal is amplified by the buffer amplification unit and finally sent to the third filtering unit. This unit further eliminates noise and unnecessary interference components in the signal, ultimately obtaining a clear signal output Ecos for sampling by the microcontroller unit. After passing through the second filtering unit, the second branch flows to the COS+ and COS- network nodes. These two nodes are connected to the input of the resolver hardware decoding chip. Based on the COS / SIN signals output by the resolver sensor, the decoding chip calculates the current position of the motor by analyzing the amplitude and phase information of these signals. This position information is sent by the decoding chip to the microcontroller unit for the system to perform more precise control and fault diagnosis.

[0038] In summary, the entire circuit's workflow involves tiered filtering, differential amplification, and decoding to ensure accurate acquisition and transmission of the resolver sensor's signal, avoiding the influence of noise and interference. The microcontroller unit analyzes the motor's state based on the sampled decoded signal, promptly detecting resolver faults and adjusting system behavior according to the analysis results, thereby improving the reliability and safety of new energy commercial vehicles.

[0039] It is worth noting that resolvers and differential signal resolvers are used to accurately measure rotation angles. The output signals of resolvers are typically sine and cosine signals (i.e., SIN and COS signals, such as...). Figure 3(This is a waveform diagram of the COS signal). In this embodiment, the COS signal represents the motor's rotational position, while the SIN signal provides another dimension of information about the motor's rotational angle. The amplitudes of these signals are usually fixed, while their phases vary. By analyzing the phase difference between these signals, the decoding chip can calculate the precise position of the motor. The COS+ and COS- signals are positive and negative differential versions of the COS signal, representing the positive and negative changes in the COS signal, respectively. One of the main advantages of using differential signals to transmit data is the ability to suppress common-mode noise (i.e., noise that occurs simultaneously on both signal lines), thereby improving the signal's anti-interference capability and transmission reliability. In this embodiment, the COS+ and COS- signals are input to the decoding chip and transmitted differentially to the chip's COS input terminal. The chip determines the motor's position based on the amplitude and phase information of these two signals. The main function of the hardware decoding chip is to extract rotational angle information from the COS+ and COS- signals. The decoding chip is typically implemented based on analog signal processing or digital signal processing technology, estimating the motor's rotational position by calculating the phase difference between the COS and SIN signals. Specifically, after receiving the COS+ and COS- signals, the decoding chip first performs differential processing on them. The phase difference between the COS+ and COS- signals typically reflects the change in rotational position. When the rotation sensor rotates, the phase changes of the COS+ and COS- signals represent the change in the position of the motor shaft. The COS and SIN signals are sinusoidal signals arranged with a 90-degree phase difference, meaning they differ by exactly one quadrant (90 degrees) within the same period. By analyzing the phase relationship between the COS and SIN signals, the decoding chip can calculate the rotation angle of the motor. Since the COS and SIN signals are periodic, the decoding chip can also accurately determine the absolute angular position of the motor through continuous sampling and signal processing. The hardware decoding chip uses internal algorithms (such as phase decoding or interpolation) to convert the amplitude and phase information of the COS and SIN signals into rotational position data of the motor. These calculations typically employ digital signal processing techniques, such as amplitude detection and phase decoding, to ultimately obtain the motor's position angle. The decoding chip ultimately outputs the motor's angle information. This data can be used for further processing by the control system, such as adjusting the motor drive and controlling its speed. By continuously reading and updating the motor's position, the control system can precisely control the motor's movement, preventing deviations or damage.

[0040] It is worth noting that, Figure 4R1 (RED) and R3 (BLK) are the two input terminals of the primary side of the resolver sensor, typically connected to a drive signal source. The primary side is the input portion of the resolver sensor and is usually excited by a voltage signal. In a resolver sensor, the primary side is stationary, and electrical signals are transmitted through these terminals. S1 (WHT), S3 (BLU), S2 (YEL), and S4 (GRN): These are the output terminals of the secondary side of the resolver sensor. The secondary winding of the resolver sensor generates corresponding output signals based on the primary side signal and the rotational position. S1 (WHT) and S3 (BLU): These ports are used to output secondary side signals, which are typically sinusoidal signals representing changes in rotation angle. S2 (YEL) and S4 (GRN): These are also secondary side signal output terminals, usually paired with S1 and S3. They typically have a phase difference and are used to provide detailed information about the rotational position.

[0041] In summary, the COS+ and COS- signals are input to the COS input terminal of the hardware decoding chip. The decoding chip determines the motor's rotational position by decoding the amplitude and phase relationship of these differential signals. This process relies on the phase difference between the COS and SIN signals, which represents changes in the motor's position. Through precise decoding algorithms, the decoding chip can provide accurate motor position data, thus providing the necessary information for the motor control system to ensure accurate motor control and fault detection.

[0042] In one embodiment, the filtering circuit further includes a protection unit, which includes a first diode Q1, a second diode Q2, and a first capacitor C1. The resolver sensor includes a first output terminal and a second output terminal. The first output terminal is connected to the first diode Q1 and the first capacitor C1, respectively. The first capacitor C1 is connected to the second diode Q2, and the second output terminal is connected to the second diode Q2.

[0043] In this embodiment, the filtering circuit includes a protection unit designed to prevent electrostatic discharge (ESD) damage to components in the circuit, particularly protecting the resolver sensor from ESD. The resolver sensor has two output terminals, a first output terminal and a second output terminal, used to output signals related to changes in the sensor angle. In this design, the first output terminal is connected to a first capacitor C1 via a first diode Q1, and the first capacitor C1 is then connected to a second diode Q2. The second output terminal is also connected to the second diode Q2. This connection method allows the protection unit to effectively handle ESD. Specifically, the first diode Q1 and the second diode Q2 can guide excessively high voltages during ESD, using their unidirectional conductivity to direct the electrostatic current to a safe path, thereby protecting sensitive components from overvoltage damage. The first capacitor C1 is used to filter and suppress high-frequency noise. When the ESD voltage rises instantaneously, the capacitor absorbs some charge, slowing down the voltage change and preventing the circuit from being subjected to excessive voltage surges. Through the series configuration of the first capacitor C1 and the second diode Q2, the capacitor provides synergistic effects for the diodes during ESD, ensuring that the voltage is effectively suppressed and guided to a safe region.

[0044] In one embodiment, the first filter unit includes a second capacitor C126, a third capacitor C148, and a first inductor L4. The second capacitor C126 is connected to the second diode Q2 and the first inductor L4, respectively, and the third capacitor C148 is connected to the first capacitor C1 and the first inductor L4, respectively.

[0045] In this embodiment, the first filtering unit includes a second capacitor C126, a third capacitor C148, and a first inductor L4. Specifically, one end of the second capacitor C126 is connected to the second diode Q2, and the other end is connected to the first inductor L4; one end of the third capacitor C148 is connected to the first capacitor C1, and the other end is also connected to the first inductor L4, enhancing the filtering effect and effectively suppressing high-frequency noise and common-mode interference. The second capacitor C126 and the third capacitor C148 provide a low-impedance loop for high-frequency common-mode signals, while the first inductor L4 provides a high impedance for common-mode signals, guiding interference signals to the ground plane, thus forming a highly efficient filtering network.

[0046] In one embodiment, the second filter unit includes a first resistor R135, a second resistor R136, a ninth capacitor C2, a fourth capacitor C3, and a fifth capacitor C206. The first resistor R135 is connected to the fourth capacitor C3, the second resistor R136 is connected to the ninth capacitor C2, and the ninth capacitor C2 is connected to both the fourth capacitor C3 and the fifth capacitor C206.

[0047] In this embodiment, the second filtering unit includes a first resistor R135, a second resistor R136, a ninth capacitor C2, a fourth capacitor C3, and a fifth capacitor C206. The first resistor R135 is connected to the fourth capacitor C3, the second resistor R136 is connected to the ninth capacitor C2, and the ninth capacitor C2 is in turn connected to both the fourth capacitor C3 and the fifth capacitor C206. This circuit design uses a combination of resistors and capacitors to eliminate noise in the signal through different impedance matching and filtering functions. The connection of the first resistor R135 and the fourth capacitor C3 forms a low-pass filter, which can effectively block high-frequency noise. The combination of the second resistor R136 and the ninth capacitor C2 is used to filter out noise in certain specific frequency ranges before flowing into the COS+ and COS- network nodes. The second filtering unit is composed of an RC low-pass filter unit. The differential mode cutoff frequency of the RC filter is 1 / 2πRC (R is the first resistor R135 + the second resistor R136, C is 1 / 2 * the ninth capacitor C2 + the fifth capacitor C206), and the common mode cutoff frequency is 1 / 2πRC (R is the second resistor R136, C is the ninth capacitor C2). COS+ and COS- are the COS input terminals of the resolver hardware decoding chip. The hardware decoding chip can determine the position of the motor based on the COS / SIN signal output by the resolver sensor. The resistance values ​​of the first resistor R135 and the second resistor R136 are equal, and the capacitance values ​​of the ninth capacitor C2 and the fourth capacitor C3 are equal.

[0048] In one embodiment, the buffer amplification unit includes a first operational amplifier U14 and a second operational amplifier U22, the input terminals of the first operational amplifier U14 and the second operational amplifier U22 being connected to the second output terminal of the first filtering unit, respectively.

[0049] In this embodiment, the buffer amplification unit includes a first operational amplifier U14 and a second operational amplifier U22, with their input terminals connected to the second output terminal of the first filtering unit. The main function of the buffer amplification unit is to amplify the signal and ensure that the signal is not affected by loading effects. By using two-stage operational amplifiers, signal strength can be increased while avoiding signal distortion or nonlinearity problems in noise reduction processing. In addition, the buffer amplification unit also provides electrical isolation, preventing downstream circuits from being directly affected by input signal fluctuations and ensuring stable and efficient signal transmission.

[0050] In one embodiment, the third filtering unit includes a third resistor R251, a fourth resistor R252, a sixth capacitor C120, and a seventh capacitor C121. The input terminals of the third resistor R251 and the fourth resistor R252 are respectively connected to the first operational amplifier U14 and the second operational amplifier U22, and the output terminals of the third resistor R251 and the fourth resistor R252 are respectively connected to the sixth capacitor C120 and the seventh capacitor C121.

[0051] This embodiment includes a third resistor R251, a fourth resistor R252, a sixth capacitor C120, and a seventh capacitor C121. The inputs of the third resistor R251 and the fourth resistor R252 are connected to the first operational amplifier U14 and the second operational amplifier U22, respectively, and their outputs are connected to the sixth capacitor C120 and the seventh capacitor C121, respectively. This design, through the combination of resistors and capacitors, further filters the signal to ensure that the signal quality meets the requirements of the decoding chip. The third and fourth resistors R252 adjust the current path of the signal, while controlling the amplitude and frequency range of the signal. The sixth capacitor C120 and the seventh capacitor C121 serve to denoise and shape the waveform, further purifying the signal and eliminating possible interference from the preceding operational amplifier. In this way, the third filtering unit ensures that the buffered and amplified signal can be transmitted more accurately to subsequent circuits, achieving the requirements of accurate decoding.

[0052] In one embodiment, the differential circuit further includes a processing unit, which includes a third operational amplifier U15, an eighth resistor R326, and a ninth resistor R234. One end of the eighth resistor R326 is connected to the inverting input of the third operational amplifier U15, and the other end is connected to the output of the third operational amplifier U15. One end of the ninth resistor R234 is connected to the non-inverting input of the third operational amplifier U15, and the other end is connected to a reference voltage.

[0053] In this embodiment, the differential circuit includes a processing unit, which consists of a third operational amplifier U15, an eighth resistor R326, and a ninth resistor R234. One end of the eighth resistor R326 is connected to the inverting input of the third operational amplifier U15, and the other end is connected to the output of the third operational amplifier U15. One end of the ninth resistor R234 is connected to the non-inverting input of the third operational amplifier U15, and the other end is connected to a reference voltage. The main function of the processing unit is to further process the differential signal, optimize the signal output by adjusting the voltage difference at the input terminals, and ensure that the signal meets the input requirements of the decoding chip. The third operational amplifier U15 achieves differential amplification of the signal through its inverting and non-inverting input terminals, while the eighth and ninth resistors R234 adjust the gain and voltage reference.

[0054] In one embodiment, the second filter unit further includes a tenth resistor R45, one end of which is connected to the first resistor R135 and the fifth capacitor C206, and the other end of which is connected to the ninth capacitor C2 and the fifth capacitor C206; the differential circuit further includes an eleventh resistor R258, one end of which is connected to the third resistor R251 and the output terminal of the third operational amplifier U15; the differential circuit further includes a twelfth resistor R253 and an eighth capacitor C185, one end of which is connected to the second end of the eleventh resistor R258, and the other end of which is connected to the eighth capacitor C185.

[0055] In this embodiment, the second filtering unit further optimizes the filtering effect through the tenth resistor R45. An eleventh resistor R258 is added to the differential circuit, with its first end connected to the third resistor R251 and the output of the third operational amplifier U15, enhancing signal stability and accuracy. The differential circuit includes a twelfth resistor R253 and an eighth capacitor C185. One end of the twelfth resistor R253 is connected to the second end of the eleventh resistor R258, and the other end is connected to the eighth capacitor C185. This design further improves the phase and amplitude characteristics of the signal, ensuring high quality and high reliability during signal transmission.

[0056] In one embodiment, the second filter unit further includes a thirteenth resistor R254 and a fourteenth resistor R289, which are respectively connected to the first inductor L4 for voltage division connection of the differential circuit.

[0057] In a specific scenario implementation, when COS-P and COS-N are outputting normally, the peak value of Vcos is 3.16V. At this time, the expression for the ADC pin voltage is: Ecos = (2.5V ± Vcos) * , which makes = 1 / 2 and = 2 / 3. According to this formula, the maximum value of Ecos is (2.5V + 1.58V) * 2 / 3 = 2.72V; the minimum value of Ecos is (2.5V - 1.58V) * 2 / 3 = 0.613V.

[0058] When incentives ( Figure 4 When resistors R1 and R3 of the resolver sensor are disconnected, there is no induced voltage at COS-P and COS-N, which is equivalent to a wire connected in parallel with the tenth resistor R45, and the impedance Z=0. In this case, Vcos=0, and there is no voltage division with the thirteenth resistor R254 and the fourteenth resistor R289. Therefore, the expression for the ADC pin voltage is: the Ecos value is (2.5V+0V)*2 / 3=1.66V;

[0059] When one of the COS-P and COS-N lines is open, the voltage Vcos is determined by a voltage divider circuit consisting of the tenth resistor R45, the thirteenth resistor R254, and the fourteenth resistor R289. In this case, the Vcos voltage can be expressed as: Vcos = 3.3V * tenth resistor R45 / (tenth resistor R45 + thirteenth resistor R254 + fourteenth resistor R289), where tenth resistor R45 / (tenth resistor R45 + thirteenth resistor R254 + fourteenth resistor R289) > 0.76. The expression for the ADC pin voltage is: the value of Ecos is (2.5V - 3.3 * 0.8V) * 2 / 3 = 0V. The ADC voltage value is used to determine whether the excitation signal and COS signal are open. When Ecos equals 1.65V, the short excitation is considered open; Ecos is within the range of 0.613~2.72V without fault; when Ecos equals 0V, the COS is considered open.

[0060] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A new energy commercial vehicle resolver signal detection circuit, characterized in that, The application relates to a rotary encoder, which comprises the following parts: a filter circuit, which comprises a first filter unit and a second filter unit, the input end of the first filter unit is connected with the output end of a rotary sensor, the first output end of the first filter unit is connected with the input end of the second filter unit, and the output end of the second filter unit outputs positive and negative differential outputs of a rotary signal to a decoding chip; a differential circuit, which comprises a buffer amplification unit and a third filter unit, the input end of the buffer amplification unit is connected with the second output end of the first filter unit, the output end of the buffer amplification unit is connected with the input end of the third filter unit, and the output end of the third filter unit outputs a decoding signal; a micro control unit, which is connected with the output end of the third filter unit, and is used for judging a rotary fault type in combination with information of the decoding chip.

2. The new energy commercial vehicle resolver signal detection circuit according to claim 1, characterized in that, The filter circuit further comprises a protection unit, the protection unit comprises a first diode (Q1), a second diode (Q2) and a first capacitor (C1), the rotary sensor comprises a first output end and a second output end, the first output end is connected with the first diode (Q1) and the first capacitor (C1) respectively, the first capacitor (C1) is connected with the second diode (Q2), and the second output end is connected with the second diode (Q2).

3. The new energy commercial vehicle resolver signal detection circuit according to claim 2, characterized in that, The first filter unit comprises a second capacitor (C126), a third capacitor (C148) and a first inductor (L4), the second capacitor (C126) is connected with the second diode (Q2) and the first inductor (L4) respectively, and the third capacitor (C148) is connected with the first capacitor (C1) and the first inductor (L4) respectively.

4. The new energy commercial vehicle resolver signal detection circuit according to claim 1, characterized in that, The second filter unit comprises a first resistor (R135), a second resistor (R136), a ninth capacitor (C2), a fourth capacitor (C3) and a fifth capacitor (C206), the first resistor (R135) is connected with the fourth capacitor (C3), the second resistor (R136) is connected with the ninth capacitor (C2), and the ninth capacitor (C2) is connected with the fourth capacitor (C3) and the fifth capacitor (C206) respectively.

5. The new energy commercial vehicle resolver signal detection circuit according to claim 1, characterized in that, The buffer amplification unit comprises a first operational amplifier (U14) and a second operational amplifier (U22), the input ends of the first operational amplifier (U14) and the second operational amplifier (U22) are connected with the second output end of the first filter unit respectively.

6. The new energy commercial vehicle resolver signal detection circuit according to claim 5, characterized in that, The third filter unit comprises a third resistor (R251), a fourth resistor (R252), a sixth capacitor (C120) and a seventh capacitor (C121), the input ends of the third resistor (R251) and the fourth resistor (R252) are connected with the first operational amplifier (U14) and the second operational amplifier (U22) respectively, and the output ends of the third resistor (R251) and the fourth resistor (R252) are connected with the sixth capacitor (C120) and the seventh capacitor (C121) respectively.

7. The new energy commercial vehicle resolver signal detection circuit according to claim 6, characterized in that, The differential circuit further comprises a processing unit, the processing unit comprising a third operational amplifier (U15), an eighth resistor (R326) and a ninth resistor (R234), one end of the eighth resistor (R326) being connected to the inverting input terminal of the third operational amplifier (U15), the other end being connected to the output terminal of the third operational amplifier (U15); one end of the ninth resistor (R234) being connected to the non-inverting input terminal of the third operational amplifier (U15), the other end being connected to a reference voltage.

8. The new energy commercial vehicle resolver signal detection circuit according to claim 4, characterized in that, The second filtering unit further comprises a tenth resistor (R45), one end of the tenth resistor (R45) being connected to the first resistor (R135) and the fifth capacitor (C206), the other end being connected to the ninth capacitor (C2) and the fifth capacitor (C206).

9. The new energy commercial vehicle resolver signal detection circuit according to claim 7, characterized in that, The differential circuit further comprises an eleventh resistor (R258), a first end of the eleventh resistor (R258) being connected to the third resistor (R251) and the output terminal of the third operational amplifier (U15).

10. The new energy commercial vehicle resolver signal detection circuit according to claim 9, characterized in that, The differential circuit further comprises a twelfth resistor (R253) and an eighth capacitor (C185), one end of the twelfth resistor (R253) being connected to a second end of the eleventh resistor (R258), the other end being connected to the eighth capacitor (C185).

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