Wheel sensor signal optimization processing device

Abstract

The invention belongs to the technical field of vehicle electronic control, and particularly discloses a wheel sensor signal optimization processing device, which comprises a signal conditioning module, an analog-to-digital conversion module and a digital signal processing module, and is characterized in that the signal conditioning module is used for conditioning an input wheel sensor differential signal; the analog-to-digital conversion module is used for converting the conditioned differential signal of the wheel sensor into a digital signal; and the digital signal processing module is used for analyzing and optimizing the digital signal. According to the invention, high-precision acquisition and intelligent processing of wheel sensor signals under complex working conditions can be realized.

Description

Technical Field

[0001] This application belongs to the technical field of vehicle electronic control, and specifically relates to a device for optimizing and processing wheel sensor signals. Background Art

[0002] In traditional wheel sensor systems, signals are often affected by various factors such as electromagnetic interference, temperature drift, mechanical vibration, and installation deviation, resulting in distorted or unstable output signals, thereby affecting the accuracy and reliability of downstream control systems. For example, in high-speed driving or bumpy road conditions, analog filters with fixed parameters are difficult to balance both response speed and anti-interference ability simultaneously; and for the problem of sensor voltage drift caused by temperature changes, if only a linear compensation model is adopted, it often cannot adapt to the non-linear and dynamic actual working conditions. In addition, many traditional solutions rely on manual periodic calibration to deal with sensor installation errors, which is inefficient and poses safety hazards.

[0003] In summary, the existing technologies as a whole have limitations such as poor response adaptability, insufficient temperature drift compensation accuracy, weak anti-interference ability, and high maintenance costs. There is an urgent need for a comprehensive optimization solution with multi-modal filtering capabilities, a dynamic temperature compensation mechanism, and high-precision digital processing capabilities to improve the reliability and intelligent processing level of wheel sensor signals and meet the requirements of modern automotive electronic systems for high-performance signal processing. Summary of the Invention

[0004] Aiming at the deficiencies in the prior art, the purpose of this application is to provide a device for optimizing and processing wheel sensor signals, and this application aims to achieve high-precision acquisition and intelligent processing of wheel sensor signals under complex working conditions.

[0005] To achieve the above purpose, this application provides the following technical solutions: A device for optimizing and processing wheel sensor signals, the device includes: a signal conditioning module, an analog-to-digital conversion module, and a digital signal processing module. Among them, the signal conditioning module is used to condition the input differential wheel sensor signal; the analog-to-digital conversion module is used to convert the conditioned differential wheel sensor signal into a digital signal; the digital signal processing module is used to analyze and optimize the digital signal.

[0006] Optionally, the signal conditioning module includes: an input protection unit, a low-noise differential input unit, a temperature compensation unit, and a multi-modal filtering unit. Among them, the input protection unit is used to provide electrical protection for the input differential wheel sensor signal; the low-noise differential input unit is used to suppress the common-mode interference in the differential wheel sensor signal; the temperature compensation unit is used to dynamically adjust the amplitude of the differential wheel sensor signal; the multi-modal filtering unit is used to remove the interference noise in the differential wheel sensor signal.

[0007] Optionally, the input protection unit includes: a first self - restoring fuse, a second self - restoring fuse, a first TVS protection diode, a second TVS protection diode, a common - mode choke coil, a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor, where, The anode of the first TVS protection diode is connected to the positive differential signal of the wheel sensor through the first self - restoring fuse, and the cathode of the first TVS protection diode D1 is connected to the first ground terminal; the anode of the second TVS protection diode is connected to the negative differential signal of the wheel sensor through the second self - restoring fuse, and the cathode of the second TVS protection diode is connected to the second ground terminal; the first end of the common - mode choke coil is connected to the anode of the first TVS protection diode, and the second end of the common - mode choke coil is connected to the anode of the second TVS protection diode; the first end of the first inductor is connected to the first end of the common - mode choke coil, and the second end of the first inductor is connected to the first input terminal of the low - noise differential input unit; the first end of the second inductor is connected to the second end of the common - mode choke coil, and the second end of the second inductor is connected to the second input terminal of the low - noise differential input unit; the first capacitor is connected in parallel with the common - mode choke coil; the first end of the second capacitor is connected to the second end of the first inductor, and the second end of the second capacitor is connected to the third ground terminal; the first end of the third capacitor is connected to the second end of the second inductor, and the second end of the third capacitor is connected to the fourth ground terminal.

[0008] Optionally, the low - noise differential input unit includes: a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a third inductor, a fourth inductor, a first operational amplifier, and a first resistor, where the first end of the third inductor serves as the first input terminal of the low - noise differential input unit, the first end of the fourth capacitor is connected to the first end of the third inductor, and the second end of the fourth capacitor is connected to the fifth ground terminal; the first end of the fourth inductor serves as the second input terminal of the low - noise differential input unit, the first end of the fifth capacitor is connected to the first end of the fourth inductor, and the second end of the fifth capacitor is connected to the sixth ground terminal; the first end of the sixth capacitor is connected to the second end of the third inductor to form a first node, and the second end of the sixth capacitor is connected to the second end of the fourth inductor to form a second node; the non - inverting input terminal of the first operational amplifier is connected to the first node through the seventh capacitor, and the inverting input terminal of the first operational amplifier is connected to the second node through the eighth capacitor; the output terminal of the first operational amplifier is connected to its inverting input terminal through the first resistor, and the output terminal of the first operational amplifier is connected to the input terminal of the temperature compensation unit.

[0009] Optionally, the temperature compensation unit includes: an analog multiplier, a second resistor, a third resistor, a fourth resistor, a ninth capacitor, a tenth capacitor, a second operational amplifier, a voltage-controlled oscillator, a digital-to-analog converter, an adder, and a microcontroller. Among them, the first end of the second resistor is connected to a constant current source, the second end of the second resistor is connected to the non-inverting input terminal of the second operational amplifier and is simultaneously connected to the control pin of the voltage-controlled oscillator; the inverting input terminal of the second operational amplifier is connected to a seventh ground terminal, and the output terminal of the second operational amplifier is connected to the first input terminal of the analog multiplier through the tenth capacitor; the second input terminal of the analog multiplier is connected to a reference voltage, and the output terminal of the analog multiplier is connected to the first ADC input channel of the MCU; the output pin of the voltage-controlled oscillator is connected to an eighth ground terminal through the series-connected fourth resistor and the ninth capacitor; the SPI interface of the digital-to-analog converter is connected to the data input pin of the MCU, and the output pin of the digital-to-analog converter is connected to the inverting input terminal of the adder; the non-inverting input terminal of the adder serves as the input terminal of the temperature compensation unit, and the output terminal of the adder is simultaneously connected to the input terminal of the analog-to-digital converter and the input terminal of the multi-modal filtering unit; the third resistor is connected across the output terminal and the inverting input terminal of the adder.

[0010] Optionally, the multi-modal filtering unit includes: a third operational amplifier, a programmable filter, a fifth resistor, a sixth resistor, a seventh resistor, and an eleventh capacitor. Among them, the non-inverting input terminal of the third operational amplifier serves as the input terminal of the multi-modal filtering unit, the inverting input terminal of the third operational amplifier is connected to its output terminal through the seventh resistor, and the output terminal of the third operational amplifier is connected to the input pin of the programmable filter; the clock pin of the programmable filter is connected to the PWM output terminal of the MCU, the first output pin of the programmable filter is connected to the input terminal of the analog-to-digital conversion module through the fifth resistor, and at the same time, the second output pin of the programmable filter is connected to a ninth ground terminal through the sixth resistor, and the eleventh capacitor is connected in parallel across the two ends of the sixth resistor.

[0011] Optionally, the analog-to-digital conversion module includes: an eighth resistor, a ninth resistor, a tenth resistor, a twelfth capacitor, a thirteenth capacitor, a fourth operational amplifier, an ADC chip, a low-temperature-drift voltage reference source, and a digital isolator. Among them, the first end of the eighth resistor serves as the input end of the analog-to-digital conversion module, and the second end of the eighth resistor is connected to the non-inverting input end of the fourth operational amplifier; the first end of the ninth resistor is connected to the second end of the second inductor, and the second end of the ninth resistor is connected to the inverting input end of the fourth operational amplifier; the inverting input end of the fourth operational amplifier is connected to its output end through the tenth resistor; the twelfth capacitor is connected in parallel across the two ends of the eighth resistor; the thirteenth capacitor is connected in parallel across the two ends of the ninth resistor; the output end of the fourth operational amplifier is connected to the first positive input pin of the ADC chip; the power input pin of the low-temperature-drift voltage reference source is connected to the +5V power supply, the ground pin of the low-temperature-drift voltage reference source VREF is connected to the tenth ground terminal, and the output pin of the low-temperature-drift voltage reference source is connected to the positive reference voltage pin of the ADC chip; the first side of the digital isolator is connected to the SPI interface of the ADC chip, and the second side of the digital isolator ISO is connected to the digital signal processing module.

[0012] Optionally, the digital signal processing module uses a dual-core ARM processor.

[0013] Compared with the prior art, the beneficial effects brought by this application are as follows: By constructing a multi-level collaborative structure composed of a signal conditioning module, an analog-to-digital conversion module, and a digital signal processing module, this application can achieve high-precision acquisition and intelligent processing of wheel sensor signals under complex working conditions. Among them, by using a multi-level differential amplification and multi-modal filtering structure, this application can significantly improve the anti-electromagnetic interference and noise suppression capabilities; by adopting a temperature dynamic compensation mechanism, it can effectively eliminate the signal drift caused by environmental temperature changes, and finally can output stable, accurate, and strongly anti-interference wheel signals, providing high-reliability input support for the vehicle control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a schematic structural diagram of a wheel sensor signal optimization processing device provided by an embodiment of this application; <![CDATA[ ]] Figure 2 is a schematic circuit diagram of an input protection unit provided by another embodiment of this application; Figure 3 is a schematic circuit diagram of a low-noise differential input unit provided by another embodiment of this application; Figure 4 is a schematic circuit diagram of a temperature compensation unit provided by another embodiment of this application; Figure 5It is a schematic circuit diagram of a multi-modal filtering unit provided by another embodiment of the present application; Figure 6 It is a schematic circuit diagram of an analog-to-digital conversion module provided by another embodiment of the present application; Detailed implementation manners The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. Although specific embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present application can be more thoroughly understood and the scope of the present application can be fully conveyed to those skilled in the art.

[0015] It should be noted that in the description of the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that technicians may use different terms to refer to the same component. The specification and claims of this application do not use the difference in terms as a way to distinguish components, but use the difference in the functions of components as the criterion for distinction. As mentioned throughout the specification and claims, the term "comprising" or "including" is an open-ended term, so it should be interpreted as "including but not limited to". The subsequent description of the specification is a preferred implementation manner for implementing the present application, but the description is for the purpose of the general principles of the specification and is not used to limit the scope of the present application. The protection scope of the present application shall be determined by the scope defined by the appended claims.

[0016] For the convenience of understanding the embodiments of the present application, the following will further explain with specific embodiments as examples in conjunction with the accompanying drawings, and each accompanying drawing does not constitute a limitation to the embodiments of the present application.

[0017] In an exemplary embodiment, Figure 1 It is a schematic structural diagram of a wheel sensor signal optimization processing device provided by an embodiment of the present application, as Figure 1 shown. The device includes: a signal conditioning module, an analog-to-digital conversion module, and a digital signal processing module. Among them, the signal conditioning module is used to condition the differential signal of the wheel sensor; the analog-to-digital conversion module is used to convert the conditioned differential signal of the wheel sensor into a digital signal; the digital signal processing module is used to analyze and optimize the digital signal.

[0018] In another exemplary embodiment, the signal conditioning module includes: an input protection unit, a low-noise differential input unit, a temperature compensation unit, and a multi-modal filtering unit. Among them, the input protection unit is used to provide electrical protection for the input wheel sensor differential signal; the low-noise differential input unit is used to suppress the common-mode interference in the input wheel sensor differential signal; the temperature compensation unit is used to dynamically adjust the amplitude of the input wheel sensor differential signal; and the multi-modal filtering unit is used to remove the interference noise in the input wheel sensor differential signal.

[0019] In another exemplary embodiment, as Figure 2 shown, the input protection unit includes a first self-resetting fuse F1, a second self-resetting fuse F2, a first TVS protection diode D1, a second TVS protection diode D2, a common-mode choke coil CMCC, a first inductor L1, a second inductor L2, a first capacitor C1, a second capacitor C2, and a third capacitor C3. Among them, the anode of the first TVS protection diode D1 is connected to the positive differential signal (+) of the wheel sensor through the first self-resetting fuse F1, and the cathode of the first TVS protection diode D1 is connected to the first ground terminal G1; the anode of the second TVS protection diode D2 is connected to the negative differential signal (-) of the wheel sensor through the second self-resetting fuse F2, and the cathode of the second TVS protection diode D2 is connected to the second ground terminal G2; the first end of the common-mode choke coil CMCC is connected to the anode of the first TVS protection diode D1, and the second end of the common-mode choke coil CMCC is connected to the anode of the second TVS protection diode D2; the first end of the first inductor L1 is connected to the first end of the common-mode choke coil, and the second end of the first inductor L1 is connected to the first input terminal IN1 of the low-noise differential input unit; the first end of the second inductor L2 is connected to the second end of the common-mode choke coil, and the second end of the second inductor L2 is connected to the second input terminal IN2 of the low-noise differential input unit; the first capacitor C1 is connected in parallel with the common-mode choke coil CMCC; the first end of the second capacitor C2 is connected to the second end of the first inductor L1, and the second end of the second capacitor C2 is connected to the third ground terminal G3; the first end of the third capacitor C3 is connected to the second end of the second inductor L2, and the second end of the third capacitor C3 is connected to the fourth ground terminal G4.

[0020] In this embodiment, the input protection unit first connects the first self-resetting fuse F1 and the second self-resetting fuse F2 in series on the positive and negative differential signal paths of the wheel sensor. When the input current increases abnormally (such as short circuit or surge), the fuse will automatically cut off the circuit to prevent component damage, and has a self-resetting function, and can automatically resume conduction after the abnormality is eliminated, improving the maintainability and reliability of the system.

[0021] Next, the signal enters the first TVS protection diode D1 and the second TVS protection diode D2. These two transient suppression diodes are respectively connected in parallel on the signal line and connected to the ground terminals (G1, G2). When the signal voltage exceeds the normal operating range due to external interference or surge, the first TVS protection diode D1 and the second TVS protection diode D2 will conduct in a very short time, clamp the overvoltage within a safe range, and quickly introduce the excess charge into the ground wire, thereby effectively preventing the high voltage from breaking down the subsequent amplifier circuit.

[0022] Subsequently, the signal passes through the common-mode choke coil CMCC. This device is symmetrically composed of two inductors, which are respectively connected in series on the positive and negative signal lines, and use the magnetic core coupling effect to generate high impedance to the common-mode signal and present low impedance to the differential-mode signal, thereby effectively blocking common-mode interference signals such as power supply noise and ground return interference. At the same time, the first capacitor C1 is connected in parallel across CMCC to further absorb the common-mode high-frequency noise component as a high-frequency channel, reducing the possibility of its coupling to the subsequent circuit.

[0023] Furthermore, the first inductor L1 and the second inductor L2 are respectively connected in series with the positive and negative signal lines. Their function is to increase the ability to suppress high-frequency noise on the differential-mode path. By increasing the impedance to high-frequency signals, these two inductors can effectively weaken differential-mode interference such as motor interference and pulse spurious signals.

[0024] To cooperate with the inductor to form an effective filtering structure, the second capacitor C2 and the third capacitor C3 are respectively connected to the ends of the first inductor L1 and the second inductor L2 and grounded, thus forming a typical LC low-pass filter. This structure can bypass the high-frequency interference in the signal, thereby effectively suppressing the differential-mode noise, especially having a significant effect in dealing with transient voltage or electromagnetic interference (EMI).

[0025] In summary, through the multi-level and multi-path design, the input protection unit can not only achieve systematic protection of the input signal against overvoltage, surge, common-mode interference, and differential-mode noise, but also effectively ensure the signal-to-noise ratio and dynamic response of the subsequent low-noise differential input circuit, laying a solid foundation for the stable and accurate operation of the entire wheel sensor signal optimization processing system.

[0026] In another exemplary embodiment, as Figure 3As shown, the low-noise differential input unit includes a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a third inductor L3, a fourth inductor L4, a first operational amplifier U1, and a first resistor R1. Among them, the first end of the third inductor L3 serves as the first input terminal of the low-noise differential input unit. The first end of the fourth capacitor C4 is connected to the first end of the third inductor L3, and the second end of the fourth capacitor C4 is connected to a fifth ground terminal G5. The first end of the fourth inductor L4 serves as the second input terminal of the low-noise differential input unit. The first end of the fifth capacitor C5 is connected to the first end of the fourth inductor L4, and the second end of the fifth capacitor C5 is connected to a sixth ground terminal G6. The first end of the sixth capacitor C6 is connected to the second end of the third inductor L3 to form a first node N1, and the second end of the sixth capacitor C6 is connected to the second end of the fourth inductor L4 to form a second node N2. The non-inverting input terminal of the first operational amplifier U1 is connected to the first node N1 through the seventh capacitor C7, and the inverting input terminal of the first operational amplifier U1 is connected to the second node N2 through the eighth capacitor C8. The output terminal of the first operational amplifier U1 is connected to its inverting input terminal through the first resistor R1, and the output terminal of the first operational amplifier U1 is connected to the input terminal of the temperature compensation unit.

[0027] In this embodiment, the low-noise differential input unit is designed to receive the weak differential signal output by the wheel sensor with high fidelity and suppress the common-mode interference to the greatest extent, ensuring excellent signal-to-noise ratio and electrical stability in the subsequent signal processing stage. This unit first connects the third inductor L3 and the fourth inductor L4 in series in the positive and negative channels of the differential signal respectively. The introduction of the inductor can effectively filter out the high-frequency interference components, especially the high-frequency common-mode noise from radio frequency sources such as motors and wireless interference. At the same time, the fourth capacitor C4 and the fifth capacitor C5 are connected to the input terminals of the third inductor L3 and the fourth inductor L4 respectively and grounded, thus forming a high-frequency bypass network to the ground, which helps to further weaken the high-frequency noise components on the signal line and further improve the anti-interference ability of the system.

[0028] In addition, the output terminals of the third inductor L3 and the fourth inductor L4 are respectively connected to both ends of the sixth capacitor C6 to form two key nodes N1 and N2. C6 plays a role of AC coupling, enabling the differential signal to be effectively extracted by the subsequent operational amplifier.

[0029] Further, the non-inverting input terminal of the first operational amplifier U1 is connected to node N1 through the seventh capacitor C7, and the inverting input terminal is connected to node N2 through the eighth capacitor C8, so that the seventh capacitor C7 and the eighth capacitor C8 can not only complete the coupling function, but also have further high-frequency noise filtering ability. Since the first operational amplifier U1 uses a zero-drift high-precision amplifier, it can significantly reduce low-frequency noise, temperature drift, and DC offset error, thus ensuring high linearity and accuracy of the differential signal during the entire amplification process. The output terminal of the first operational amplifier U1 forms a negative feedback loop with its inverting terminal through the first resistor R1, which can construct a stable gain structure, thereby enabling linear amplification of the input signal. At the same time, the output signal of the first operational amplifier U1 is fed into the temperature compensation unit to provide an accurate differential voltage source for the amplitude correction and compensation processing in the next stage.

[0030] In summary, the low-noise differential input unit can achieve high-fidelity extraction and amplification of the weak differential signal of the wheel sensor through the structure of "inductor pre-filtering + capacitor ground absorption + precision operational amplifier differential amplification", while suppressing common-mode interference and high-frequency noise, thereby providing a stable, accurate, and low-noise input signal for the subsequent temperature compensation and digital processing modules.

[0031] In another exemplary embodiment, as Figure 4As shown, the temperature compensation unit includes an analog multiplier MUL (such as Analog Devices AD633), a second resistor R2, a third resistor R3, a fourth resistor R4, a ninth capacitor C9, a tenth capacitor C10, a second operational amplifier U2, a voltage-controlled oscillator VCO (such as Mini-Circuits ZX95-850), a digital-to-analog converter DAC (such as Analog Devices AD5662), an adder U3, and a microcontroller MCU (such as STM32H745ZI). Among them, the first end of the second resistor R2 is connected to a constant current source CCS, and the second end of the second resistor R2 is connected to the non-inverting input terminal of the second operational amplifier U2 and is also connected to the control pin VCTRL of the voltage-controlled oscillator VCO; the inverting input terminal of the second operational amplifier U2 is connected to a seventh ground terminal G7, and the output terminal of the second operational amplifier U2 is connected to the first input terminal (X input) of the analog multiplier MUL through the tenth capacitor C10; the second input terminal (Y input) of the analog multiplier MUL is connected to a reference voltage Vref; the output terminal of the analog multiplier MUL is connected to the first ADC input channel ADC1 of the MCU; the output pin OUT of the voltage-controlled oscillator VCO is connected to an eighth ground terminal G8 through the fourth resistor R4 and the ninth capacitor C9 connected in series; the SPI interface of the digital-to-analog converter DAC is connected to the data input pin MISO of the MCU, and the output pin VOUT of the digital-to-analog converter is connected to the inverting input terminal of the adder U3; the non-inverting input terminal of the adder U3 serves as the input terminal of the temperature compensation unit, and the output terminal of the adder U3 is connected to the input terminal of the digital-to-analog converter DAC and the input terminal of the multi-modal filtering unit at the same time; the third resistor R3 is connected across the output terminal and the inverting input terminal of the adder U3.

[0032] In this embodiment, the temperature compensation unit can dynamically adjust the amplitude of the differential signal of the wheel sensor according to the ambient temperature change, so as to suppress the influence of temperature drift on the accuracy of the differential signal, thereby realizing high-stability signal conditioning. Specifically, the constant current source CCS generates a voltage signal proportional to the temperature at different temperatures through the second resistor R2. On the one hand, this voltage signal is sent to the control pin VCTRL of the voltage-controlled oscillator VCO, so that the output frequency of the voltage-controlled oscillator VCO changes with the temperature. On the other hand, this voltage signal is also used as the input of the second operational amplifier U2. The output of the second operational amplifier U2 is coupled to the first input terminal of the analog multiplier MUL through the tenth capacitor C10 and multiplied by the reference voltage Vref input at the second terminal to obtain an analog voltage signal containing temperature information, which is input to the first ADC channel ADC1 of the microcontroller MCU for real-time sampling. The MCU controls the output of the digital-to-analog converter DAC in combination with the temperature estimation result. The correction voltage output by the digital-to-analog converter DAC is introduced into the compensation path through the VOUT pin connected to the inverting terminal of the adder U3 and superimposed and adjusted with the original signal in the adder U3. The non-inverting input terminal of the adder U3 serves as the input terminal of the temperature compensation unit to receive the uncompensated original signal, and the output terminal provides the compensated stable signal, which is respectively sent to the analog-to-digital converter and the multi-modal filtering unit for subsequent processing. The third resistor R3 between the output terminal and the inverting terminal of the adder U3 provides negative feedback to ensure linear stability of the compensation gain. In addition, the output of the voltage-controlled oscillator VCO is grounded through the RC network formed by the fourth resistor R4 and the ninth capacitor C9, which can suppress high-frequency interference and further improve the system stability.

[0033] In summary, the temperature compensation unit can realize adaptive dynamic correction of temperature drift in the analog signal path, and has the advantages of fast response, high precision and compact structure, so as to effectively improve the reliability and accuracy of the sensor signal in a complex temperature environment.

[0034] In another exemplary embodiment, as Figure 5As shown, the multimodal filtering unit includes a third operational amplifier U4, a programmable filter PF (such as an LTC1068 programmable filter), a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eleventh capacitor C11. Among them, the non-inverting input terminal of the third operational amplifier U4 serves as the input terminal of the multimodal filtering unit. The inverting input terminal of the third operational amplifier U4 is connected to its output terminal through the seventh resistor R7. The output terminal of the third operational amplifier U4 is connected to the input pin IN of the programmable filter PF. The clock pin CLK of the programmable filter PF is connected to the PWM output terminal of the MCU. The first output pin OUT1 of the programmable filter PF is connected to the input terminal of the analog-to-digital conversion module through the fifth resistor R5. At the same time, the second output pin OUT2 of the programmable filter PF is connected to the ninth ground terminal G9 through the sixth resistor R6, and the eleventh capacitor C11 is connected in parallel across the two ends of the sixth resistor R6.

[0035] In this embodiment, the multimodal filtering unit is designed to dynamically adjust the filtering parameters according to different vehicle operating conditions (such as low-speed driving, high-speed driving, or bumpy roads) to effectively suppress various types of noise in the wheel sensor signal, thereby improving the signal purity and system adaptability. Specifically, the input signal first enters the non-inverting input terminal of the third operational amplifier U4. The third operational amplifier U4 adopts a non-inverting proportional amplification structure, and its inverting input terminal is connected to its own output terminal through the seventh resistor R7 to form a negative feedback path, thus ensuring the stability and linear gain regulation during the signal amplification process. The output signal of the third operational amplifier U4 is connected to the input pin IN of the programmable filter PF. The PF can dynamically adjust the filtering characteristics according to the external clock signal. This clock signal is provided by the PWM pin of the MCU. By controlling the duty cycle and frequency, the PF can be configured as a low-pass, band-pass, or high-pass filter in different modes, changing the cut-off frequency and filter order to cope with noise interference in different frequency ranges. The first output OUT1 of the PF is connected to the analog-to-digital conversion module through the fifth resistor R5 to provide the filtered output of the main signal path. The second output OUT2 is grounded through the sixth resistor R6, and the eleventh capacitor C11 is connected in parallel with the sixth resistor R6 to form an RC absorption network for absorbing and bypassing the residual high-frequency signals output by the filter, thereby further reducing the possibility of electromagnetic interference coupling.

[0036] In summary, the multimodal filtering unit combines the flexibility of the programmable filter and the pre-stage gain conditioning ability of the operational amplifier, which can not only improve the signal bandwidth adaptation ability but also automatically switch the filtering mode through the MCU under different working conditions to achieve a highly adaptive and highly robust signal purification effect, thereby being beneficial to improving the anti-interference ability and detection accuracy of the entire system in complex road conditions and dynamic temperature environments.

[0037] In another exemplary embodiment, as Figure 6 shown, the analog-to-digital conversion module includes: an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a twelfth capacitor C12, a thirteenth capacitor C13, a fourth operational amplifier U5, an ADC chip (a 24-bit Σ-Δ ADC can be used, such as TI ADS124S08), a low-temperature drift voltage reference source VREF (for example, Maxim MAX6126A25 is used), and a digital isolator ISO (for example, Broadcom ACPL-064L is used). Among them, the first end of the eighth resistor R8 serves as the input end of the analog-to-digital conversion module, and the second end of the eighth resistor R8 is connected to the non-inverting input end of the fourth operational amplifier U5; the first end of the ninth resistor R9 is connected to the second end (common-mode reference end) of the second inductor L2, and the second end of the ninth resistor R9 is connected to the inverting input end of the fourth operational amplifier U5; the inverting input end of the fourth operational amplifier U5 is connected to its output end through the tenth resistor R10; the twelfth capacitor C12 is connected in parallel across the two ends of the eighth resistor R8; the thirteenth capacitor C13 is connected in parallel across the two ends of the ninth resistor R9; the output end of the fourth operational amplifier U5 is connected to the first positive input pin AINP1 of the ADC chip; the power input pin VIN of the low-temperature drift voltage reference source VREF is connected to the +5V power supply, the ground pin GND of the low-temperature drift voltage reference source VREF is connected to the tenth ground terminal G10, and the output pin VOUT of the low-temperature drift voltage reference source VREF is connected to the positive reference voltage pin REF+ of the ADC chip; the first side of the digital isolator ISO is connected to the SPI interface of the ADC chip, and the second side of the digital isolator ISO is connected to the digital signal processing module.

[0038] In this embodiment, the analog-to-digital conversion module is responsible for converting the analog signal of the wheel sensor after multi-stage conditioning and filtering into a digital signal with high precision and transmitting it to the digital signal processing module for further analysis and control. Specifically, the analog signal from the multi-modal filtering unit first enters the eighth resistor R8, and is applied to the non-inverting input terminal of the fourth operational amplifier U5 through this resistor to provide an input voltage reference. At the same time, the ninth resistor R9 is connected to the common-mode reference terminal of the second inductor L2 to provide a ground reference level, and its output is connected to the inverting input terminal of the fourth operational amplifier U5. To construct a stable differential amplification path, a tenth resistor R10 is connected between the inverting input terminal and the output terminal of the fourth operational amplifier U5 to achieve negative feedback to stabilize the gain and output voltage. The twelfth capacitor C12 and the thirteenth capacitor C13 are respectively connected in parallel across the eighth resistor R8 and the ninth resistor R9 to form a filtering network for the differential channel, which is used to filter out the high-frequency noise that may remain in the previous stage and improve the signal stability. The output of the fourth operational amplifier U5, as the conditioned precise differential signal, is connected to the first positive input pin AINP1 of the high-precision ADC chip through its output pin for analog-to-digital conversion. In addition, to ensure the sampling accuracy of the ADC, this module is equipped with a low-temperature-drift voltage reference source VREF to provide a constant and stable reference voltage REF+ for the ADC, which can greatly reduce the influence of temperature fluctuations on the conversion accuracy. Further, to ensure the integrity of the digital-to-analog conversion data transmission in a high-noise environment, this module uses a digital isolator ISO to electrically isolate the SPI interface of the ADC from the subsequent digital signal processing module. In this way, not only can the ground loop and interference conduction be avoided, but also the electromagnetic compatibility and safety of the device can be improved.

[0039] In summary, through multiple designs such as high-precision differential amplification, anti-interference filtering, low-drift reference voltage, and data isolation transmission, the analog-to-digital conversion module ensures the high precision, high stability, and high anti-interference ability of the wheel sensor analog signal during the sampling conversion process, providing a reliable guarantee for the subsequent digital analysis and control of the system.

[0040] In another exemplary embodiment, the analog-to-digital conversion module further includes a protection circuit, and the protection circuit includes a third TVS protection diode D3 and a fourth TVS protection diode D4. Among them, the cathode of the third TVS protection diode D3 is connected to the second positive input pin AINP2 of the ADC chip, and the anode of the third TVS protection diode D3 is connected to the first analog ground pin AGND1 of the ADC chip; the cathode of the fourth TVS protection diode D4 is connected to the negative input pin AINN of the ADC chip, and the anode of the fourth TVS protection diode D4 is connected to the second analog pin AGND₂ of the ADC chip.

[0041] In this embodiment, the protection circuit is mainly used to establish a fast-response overvoltage protection mechanism at the input end of the ADC chip to prevent damage to the high-precision analog-to-digital conversion module caused by external transient interference, voltage spikes or abnormal connections. The third TVS protection diode D3 and the fourth TVS protection diode D4 are respectively connected to the differential input channels of the ADC chip. When the voltage at the input end of the ADC chip exceeds the safe operating range due to external interference, momentary misconnection or other abnormal conditions, the third TVS protection diode D3 and the fourth TVS protection diode D4 will break down and conduct within a nanosecond response time, quickly discharging the overvoltage current to the ground terminal (AGND), thereby limiting the input voltage not to exceed its breakdown voltage and protecting the high-precision sampling circuit inside the ADC chip from the risks of breakdown, electric shock or permanent damage.

[0042] In summary, without disturbing the normal signal passage, the protection circuit can provide an efficient and passive input protection mechanism for the analog-to-digital conversion module, significantly improving the reliability, robustness and service life of the analog-to-digital conversion module in complex electromagnetic environments and abnormal operating conditions.

[0043] In another exemplary embodiment, the digital signal processing module uses a dual-core ARM processor (Cortex-M7 + Cortex-M4).

[0044] In this embodiment, after the differential analog signal is converted into a high-resolution digital signal through signal conditioning, multi-modal filtering, and an analog-to-digital conversion module, it is input into the digital signal processing module. Among them, the main core Cortex-M7 has high-frequency floating-point operation capabilities. First, it performs noise suppression in the preprocessing stage on the incoming original digital signal, including one-dimensional sliding average filtering (SMA) to weaken periodic interference, a median filter to remove spike pulse interference, and exponential weighted moving average (EWMA) to enhance signal smoothness. On this basis, the digital signal processing module also embeds an adaptive filtering algorithm (such as LMS or NLMS), which dynamically adjusts the filtering coefficients according to environmental changes to adapt to the signal characteristic differences of the vehicle under different working conditions (such as high speed, bumpy, braking). Subsequently, the processor performs a fast Fourier transform (FFT) analysis on the signal to extract frequency-domain features to assist in discriminating abnormal tire rotation states or mechanical resonance features; at the same time, discrete wavelet transform (DWT) is also introduced for multi-scale decomposition to accurately extract potential transient fault features in the signal. For the slow variable offset caused by temperature drift, a dynamic correction mechanism based on Kalman filtering or polynomial fitting is used to compensate for the trend term. The secondary core Cortex-M4 is responsible for the real-time operation of the state machine logic and the bus protocol stack, such as data packing, handshaking, and feedback control of CAN and LIN. At the same time, it periodically reads the status data of external temperature sensors or in-vehicle ECUs to implement an adaptive compensation control strategy.

[0045] In summary, the two processors transfer characteristic variables and abnormal event flags through a shared memory area, supplemented by hardware interrupts to complete time synchronization and resource coordination, ensuring a smooth and low-latency processing flow. Finally, the signal processing module outputs key indicators such as wheel speed, acceleration, short-time spectrum features, temperature calibration values, rotation direction, and abnormal event flag bits for the vehicle system to call for ABS braking, ESP stability control, TPMS systems, and in-vehicle state prediction models.

[0046] The above is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural or equivalent process transformation made using the specification and drawings of the present application, or directly or indirectly applied in other related technical fields, is similarly included in the patent protection scope of the present application.

Claims

1. An optimized processing device for wheel sensor signals, characterized in that The device includes: a signal conditioning module, an analog-to-digital conversion module, and a digital signal processing module, where the signal conditioning module is used to condition the input differential signal of the wheel sensor; the analog-to-digital conversion module is used to convert the conditioned differential signal of the wheel sensor into a digital signal; the digital signal processing module is used to analyze and optimize the digital signal.

2. The wheel sensor signal optimization processing device according to claim 1, characterized in that The signal conditioning module includes: an input protection unit, a low-noise differential input unit, a temperature compensation unit, and a multi-modal filtering unit, where the input protection unit is used to provide electrical protection for the input differential signal of the wheel sensor; the low-noise differential input unit is used to suppress the common-mode interference in the differential signal of the wheel sensor; the temperature compensation unit is used to dynamically adjust the amplitude of the differential signal of the wheel sensor; the multi-modal filtering unit is used to remove the interference noise in the differential signal of the wheel sensor.

3. The wheel sensor signal optimization processing device according to claim 2, characterized in that The input protection unit includes: a first self-recovery fuse, a second self-recovery fuse, a first TVS protection diode, a second TVS protection diode, a common-mode choke coil, a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor, where the anode of the first TVS protection diode is connected to the positive differential signal of the wheel sensor through the first self-recovery fuse, and the cathode of the first TVS protection diode D1 is connected to a first ground terminal; the anode of the second TVS protection diode is connected to the negative differential signal of the wheel sensor through the second self-recovery fuse, and the cathode of the second TVS protection diode is connected to a second ground terminal; the first end of the common-mode choke coil is connected to the anode of the first TVS protection diode, and the second end of the common-mode choke coil is connected to the anode of the second TVS protection diode; the first end of the first inductor is connected to the first end of the common-mode choke coil, and the second end of the first inductor is connected to the first input terminal of the low-noise differential input unit; the first end of the second inductor is connected to the second end of the common-mode choke coil, and the second end of the second inductor is connected to the second input terminal of the low-noise differential input unit; the first capacitor is connected in parallel with the common-mode choke coil; the first end of the second capacitor is connected to the second end of the first inductor, and the second end of the second capacitor is connected to a third ground terminal; the first end of the third capacitor is connected to the second end of the second inductor, and the second end of the third capacitor is connected to a fourth ground terminal.

4. The wheel sensor signal optimization processing device according to claim 2, characterized in that The low-noise differential input unit includes: a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a third inductor, a fourth inductor, a first operational amplifier, and a first resistor, where the first end of the third inductor serves as the first input terminal of the low-noise differential input unit, the first end of the fourth capacitor is connected to the first end of the third inductor, and the second end of the fourth capacitor is connected to a fifth ground terminal; the first end of the fourth inductor serves as the second input terminal of the low-noise differential input unit, the first end of the fifth capacitor is connected to the first end of the fourth inductor, and the second end of the fifth capacitor is connected to a sixth ground terminal; The first end of the sixth capacitor is connected to the second end of the third inductor to form a first node, and the second end of the sixth capacitor is connected to the second end of the fourth inductor to form a second node; The non-inverting input terminal of the first operational amplifier is connected to the first node through the seventh capacitor, and the inverting input terminal of the first operational amplifier is connected to the second node through the eighth capacitor; The output terminal of the first operational amplifier is connected to its inverting input terminal through the first resistor, and the output terminal of the first operational amplifier is connected to the input terminal of the temperature compensation unit.

5. The wheel sensor signal optimization processing device according to claim 2, wherein, The temperature compensation unit includes: an analog multiplier, a second resistor, a third resistor, a fourth resistor, a ninth capacitor, a tenth capacitor, a second operational amplifier, a voltage-controlled oscillator, a digital-to-analog converter, an adder, and a microcontroller, where the first end of the second resistor is connected to a constant current source, and the second end of the second resistor is connected to the non-inverting input terminal of the second operational amplifier and is simultaneously connected to the control pin of the voltage-controlled oscillator; the inverting input terminal of the second operational amplifier is connected to a seventh ground terminal, and the output terminal of the second operational amplifier is connected to the first input terminal of the analog multiplier through the tenth capacitor; a reference voltage is applied to the second input terminal of the analog multiplier, and the output terminal of the analog multiplier is connected to the first ADC input channel of the MCU; the output pin of the voltage-controlled oscillator is connected to an eighth ground terminal through the fourth resistor and the ninth capacitor connected in series; the SPI interface of the digital-to-analog converter is connected to the data input pin of the MCU, and the output pin of the digital-to-analog converter is connected to the inverting input terminal of the adder; the non-inverting input terminal of the adder serves as the input terminal of the temperature compensation unit, and the output terminal of the adder is simultaneously connected to the input terminal of the analog-to-digital converter and the input terminal of the multi-modal filtering unit; the third resistor is connected across the output terminal and the inverting input terminal of the adder.

6. The wheel sensor signal optimization processing device according to claim 2, wherein, The multi-modal filtering unit includes: a third operational amplifier, a programmable filter, a fifth resistor, a sixth resistor, a seventh resistor, and an eleventh capacitor, where the non-inverting input terminal of the third operational amplifier serves as the input terminal of the multi-modal filtering unit, the inverting input terminal of the third operational amplifier is connected to its output terminal through the seventh resistor, and the output terminal of the third operational amplifier is connected to the input pin of the programmable filter; the clock pin of the programmable filter is connected to the PWM output terminal of the MCU, the first output pin of the programmable filter is connected to the input terminal of the analog-to-digital conversion module through the fifth resistor, and at the same time, the second output pin of the programmable filter is connected to a ninth ground terminal through the sixth resistor, and the eleventh capacitor is connected in parallel across the sixth resistor.

7. The wheel sensor signal optimization processing device according to claim 2, wherein, The analog-to-digital conversion module includes: an eighth resistor, a ninth resistor, a tenth resistor, a twelfth capacitor, a thirteenth capacitor, a fourth operational amplifier, an ADC chip, a low-temperature-drift voltage reference source, and a digital isolator, where the first end of the eighth resistor serves as the input terminal of the analog-to-digital conversion module, and the second end of the eighth resistor is connected to the non-inverting input terminal of the fourth operational amplifier; The first end of the ninth resistor is connected to the second end of the second inductor, and the second end of the ninth resistor is connected to the inverting input terminal of the fourth operational amplifier; The inverting input terminal of the fourth operational amplifier is connected to its output terminal through the tenth resistor; The twelfth capacitor is connected in parallel across the two ends of the eighth resistor; The thirteenth capacitor is connected in parallel across the two ends of the ninth resistor; The output terminal of the fourth operational amplifier is connected to the first positive input pin of the ADC chip; The power input pin of the low-temperature-drift voltage reference source is connected to the +5V power supply, the grounding pin of the low-temperature-drift voltage reference source VREF is connected to the tenth grounding terminal, and the output pin of the low-temperature-drift voltage reference source is connected to the positive reference voltage pin of the ADC chip; The first side of the digital isolator is connected to the SPI interface of the ADC chip, and the second side of the digital isolator ISO is connected to the digital signal processing module.

8. The wheel sensor signal optimization processing device according to claim 7, wherein, The digital signal processing module uses a dual-core ARM processor.

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