Intelligent processing system and method for magnetoelectric tachometric transducer

Abstract

The invention discloses an intelligent processing system and method for a magnetoelectric tachometric transducer, and relates to the technical field of engine control, the system comprises an electronic control unit, a signal acquisition circuit, an amplification circuit and a signal calculation circuit; the signal acquisition circuit is used for acquiring a voltage signal output by the magnetoelectric rotating speed sensor; the amplifying circuit is used for amplifying the voltage signal to obtain an amplified signal; the signal calculation circuit is used for calculating the rotating speed of the engine at the second moment according to the amplified signal; the amplifying circuit is used for amplifying the voltage and comprises a numerical control variable resistor; the resistance value of the numerical control variable resistor is controlled by the electronic control unit, the amplification factor is adjusted by adjusting the resistance value, when the rotating speed is low and the signal is weak, the signal amplification factor is large to ensure that the signal can be normally detected, and when the rotating speed is high and the signal is strong, the signal amplification factor is small to reduce the interference signal.

Description

Technical Field

[0001] The present application relates to the field of engine control technology, and in particular to an intelligent processing system and method for a magnetoelectric speed sensor. Background Art

[0002] The crankshaft and camshaft speed signals are the time base for the comprehensive control of the engine. When the speed signal is abnormal, the fuel supply, injection, ignition and other links of the engine cannot operate normally. As a sensor with strong anti-interference ability, the magnetoelectric speed sensor is widely used in the comprehensive control system of the engine, but the performance of its signal processing circuit has a great influence on the quality of the processed time base signal. Therefore, the processing circuit of the magnetoelectric speed sensor is particularly important in the hardware of the engine control system.

[0003] The processing circuit of the existing magnetoelectric speed sensor usually only adopts the "limiting + amplification" processing method. When the speed is high and low, the signal strength output by the magnetoelectric speed sensor is very different. In order to meet the normal recognition of weak signals at low speeds, the processing circuit usually adjusts the amplification factor very large. The problem caused by this is that when the high-speed signal becomes stronger, the interference will also become stronger, and the existing processing circuit cannot filter out this part of the interference. Summary of the invention

[0004] The purpose of the present application is to provide an intelligent processing system and method for a magnetoelectric speed sensor, which can simultaneously perform normal identification of high speed and low speed, and can perform fault diagnosis on the magnetoelectric speed sensor.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a magnetoelectric speed sensor intelligent processing system, the magnetoelectric speed sensor intelligent processing system comprising an electronic control unit, a signal acquisition circuit, an amplification circuit and a signal calculation circuit;

[0007] The signal acquisition circuit is used to acquire the voltage signal output by the magnetoelectric speed sensor;

[0008] The amplifier circuit is used to amplify the voltage signal to obtain an amplified signal;

[0009] The amplifying circuit comprises: a digitally controlled variable resistor;

[0010] The electronic control unit is used to adjust the resistance value of the digitally controlled variable resistor according to the engine speed detected at the first moment; when the engine speed detected by the electronic control unit at the first moment is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be smaller, and the amplification factor of the amplifier circuit is increased; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be larger, and the amplification factor of the amplifier circuit is reduced;

[0011] The signal calculation circuit is used to calculate the engine speed at a second moment according to the amplified signal.

[0012] Optionally, the magnetoelectric speed sensor intelligent processing system further comprises: a static detection circuit; the static detection circuit is connected to the electronic control unit;

[0013] The static detection circuit specifically includes: a MOS tube and a gate resistor;

[0014] The drain of the MOS tube is connected to the power supply; the gate of the MOS tube is connected to the electronic control unit through the gate resistor; the source of the MOS tube is used to be connected to an interface at one end of the magnetoelectric speed sensor;

[0015] The electronic control unit is used to control the opening and closing of the MOS tube.

[0016] Optionally, the signal acquisition circuit includes: a diode clamp circuit;

[0017] The diode clamping circuit is used to obtain and limit the voltage signal output by the magnetoelectric rotation speed sensor to a fixed range.

[0018] Optionally, the diode clamp circuit specifically includes: a first resistor R1, a second resistor R2, a first capacitor C1, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4;

[0019] Among them, one end interface of the magnetoelectric speed sensor is connected to one end of the first resistor; the other end of the first resistor is connected to the first common end; the first common end is also connected to one end of the first capacitor, the positive end of the first diode, and the negative end of the second diode; the negative end of the first diode is grounded; the positive end of the second diode is grounded;

[0020] One end interface of the magnetoelectric speed sensor is connected to one end of the second resistor; the other end of the second resistor is connected to the second common end; the second common end is also connected to the other end of the first capacitor, the positive end of the fourth diode, and the negative end of the third diode; the negative end of the fourth diode is grounded; and the positive end of the third diode is grounded.

[0021] Optionally, the signal calculation circuit includes: a differential circuit and a hysteresis comparator;

[0022] The differential circuit is used to differentiate the amplified signal to obtain a differential signal;

[0023] The hysteresis comparator is used to convert the differential signal into a square wave voltage signal and send the square wave voltage signal to the electronic control unit; the electronic control unit is used to calculate the engine speed at the second moment according to the square wave voltage signal.

[0024] Optionally, the amplifying circuit specifically includes: a first operational amplifier U1, a second operational amplifier U2, a third resistor R3, a fifth resistor R5 and a fourth digitally controlled resistor R4;

[0025] After the diode clamping circuit limits the voltage signal output by the magnetoelectric speed sensor to a fixed range, the clamped positive output terminal signal is connected to the positive input terminal of the first operational amplifier, and the clamped negative output terminal signal is connected to the positive input terminal of the second operational amplifier; the negative input terminal of the first operational amplifier is connected to the negative input terminal of the second operational amplifier through the digitally controlled resistor, the output terminal of the first operational amplifier is connected to the negative input terminal of the first operational amplifier through the third resistor, and the output terminal of the second operational amplifier is connected to the negative input terminal of the second operational amplifier through the fifth resistor.

[0026] Optionally, the differential circuit specifically includes: a third operational amplifier U3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9;

[0027] The positive phase signal amplified by the amplifier circuit is connected to the positive phase input terminal of the third operational amplifier through the sixth resistor; the negative phase signal amplified by the amplifier circuit is connected to the negative phase input terminal of the third operational amplifier through the eighth resistor; the positive phase input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier through the seventh resistor; the negative phase input terminal of the third operational amplifier is grounded through the ninth resistor;

[0028] The output terminal of the third operational amplifier outputs a differential signal.

[0029] Optionally, the hysteresis comparator specifically includes: a fourth operational amplifier U4, an eleventh resistor R11, a twelfth resistor R12, a tenth digitally controlled resistor R10 and a fifth diode D5;

[0030] The fourth operational amplifier, the eleventh resistor and the tenth resistor constitute a hysteresis comparison circuit; the positive phase input terminal of the fourth operational amplifier is grounded through the tenth resistor, and the output terminal of the fourth operational amplifier is connected to the positive phase input terminal of the fourth operational amplifier through the eleventh resistor; the differential signal is connected to the negative phase input terminal of the fourth operational amplifier, and the output terminal of the fourth operational amplifier outputs the signal after hysteresis comparison; the signal after hysteresis comparison is cut off by the fifth diode to remove the negative half wave, and the fifth diode is connected in series with the twelfth resistor and then grounded;

[0031] The resistance value of the tenth digitally controlled resistor is controlled by an electronic control unit; when the amplification factor of the amplifier circuit is increased, the resistance value of the tenth digitally controlled resistor is synchronously increased; when the amplification factor of the amplifier circuit is reduced, the resistance value of the tenth digitally controlled resistor is synchronously decreased.

[0032] In a second aspect, the present application provides a magnetoelectric speed sensor intelligent processing method, the magnetoelectric speed sensor intelligent processing method comprising:

[0033] The diode clamp circuit obtains the voltage signal output by the magnetoelectric speed sensor;

[0034] The diode clamping circuit limits the voltage signal output by the magnetoelectric speed sensor to a fixed range to obtain a clamping voltage;

[0035] The amplifying circuit amplifies the clamping voltage to obtain an amplified signal; the amplifying circuit includes: a digitally controlled variable resistor; the resistance value of the digitally controlled variable resistor is controlled by an electronic control unit; when the engine speed detected by the electronic control unit at the first moment is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be smaller, thereby increasing the amplification factor of the amplifying circuit; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be larger, thereby reducing the amplification factor of the amplifying circuit;

[0036] The differential circuit differentiates the amplified signal to obtain a differential signal;

[0037] The hysteresis comparator converts the differential signal into a square wave voltage signal, and sends the square wave voltage signal to the electronic control unit;

[0038] The electronic control unit calculates the engine speed at the second moment according to the square wave voltage signal.

[0039] Optionally, the diode clamp circuit acquires the voltage signal output by the magnetoelectric speed sensor, specifically comprising:

[0040] When the engine is in a static state, the electronic control unit obtains the voltage of the other end interface of the magnetoelectric speed sensor; if the voltage is a normal voltage, the magnetoelectric speed sensor is normal;

[0041] When the magnetoelectric rotation speed sensor is normal, the diode clamping circuit acquires the voltage signal output by the magnetoelectric rotation speed sensor.

[0042] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0043] The present application provides a magnetoelectric speed sensor intelligent processing system and method, the system includes an electronic control unit, a signal acquisition circuit, an amplifier circuit and a signal calculation circuit; the signal acquisition circuit is used to acquire the voltage signal output by the magnetoelectric speed sensor; the amplifier circuit is used to amplify the voltage signal to obtain an amplified signal; the amplifier circuit includes: a digitally controlled variable resistor; the electronic control unit is used to adjust the resistance value of the digitally controlled variable resistor according to the engine speed detected at the first moment; when the engine speed detected by the electronic control unit at the first moment is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to a small value, and the amplification factor of the amplifier circuit is increased; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to a large value, and the amplification factor of the amplifier circuit is reduced; the signal calculation circuit is used to calculate the engine speed at the second moment according to the amplified signal. The present application can simultaneously perform normal identification of high speed and low speed, and can perform fault diagnosis on the magnetoelectric speed sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of the connection relationship between a magnetoelectric speed sensor intelligent processing system and an external period provided in one embodiment of the present application;

[0046] Figure 2 A circuit diagram of a magnetoelectric speed sensor intelligent processing system provided in one embodiment of the present application;

[0047] Figure 3A signal transmission schematic diagram of a magnetoelectric speed sensor intelligent processing system provided in one embodiment of the present application;

[0048] Figure 4 A schematic flow chart of the use steps of a magnetoelectric speed sensor intelligent processing system provided in one embodiment of the present application;

[0049] Figure 5 A schematic diagram of a static detection circuit provided in an embodiment of the present application;

[0050] Figure 6 A schematic diagram of a diode clamping circuit provided in an embodiment of the present application;

[0051] Figure 7 A schematic diagram of an amplifier circuit provided in an embodiment of the present application;

[0052] Figure 8 A schematic diagram of a differential circuit provided in an embodiment of the present application;

[0053] Fig. 9 A schematic diagram of a hysteresis comparator provided in accordance with an embodiment of the present application.

[0054] Reference numerals:

[0055] Engine-1, magnetoelectric speed sensor-2, intelligent processing circuit-3, ECU-4, static detection circuit-5, diode clamping circuit-6, amplifier circuit-7, differential circuit-8, hysteresis comparator-9. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] The processing circuit of the existing magnetoelectric speed sensor usually only adopts the "limiting + amplification" processing method. When the speed is high and low, the signal strength output by the magnetoelectric speed sensor is very different. In order to meet the normal recognition of weak signals at low speeds, the processing circuit usually adjusts the amplification factor very large. The problem caused by this is that when the high-speed signal becomes stronger, the interference will also become stronger, and the existing processing circuit cannot filter out this part of the interference.

[0058] Another problem is that the magnetoelectric speed sensor only outputs a signal when there is a speed. The traditional method is to detect the processed signal. When the engine has not started (the speed is 0), the magnetoelectric speed sensor has no signal output, and the existing processing circuit cannot diagnose faults of the magnetoelectric speed sensor.

[0059] The purpose of this application is to provide a magnetoelectric speed sensor intelligent processing system and method, which can simultaneously identify high and low speeds, and can perform fault diagnosis on the magnetoelectric speed sensor, improve the signal quality of the magnetoelectric speed sensor, generate a reliable speed time base signal, and ensure the safe and stable operation of the engine.

[0060] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0061] In an exemplary embodiment, Figure 1 As shown, a magnetoelectric speed sensor intelligent processing system is provided, and the magnetoelectric speed sensor intelligent processing system includes an electronic control unit, a signal acquisition circuit, an amplification circuit 7 and a signal calculation circuit.

[0062] The signal acquisition circuit is used to acquire the voltage signal output by the magnetoelectric rotation speed sensor.

[0063] The amplifier circuit 7 is used to amplify the voltage signal to obtain an amplified signal.

[0064] The amplifying circuit 7 includes: a digitally controlled variable resistor.

[0065] The electronic control unit is used to adjust the resistance value of the digitally controlled variable resistor according to the engine speed detected at the first moment; when the engine speed detected by the electronic control unit at the first moment is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is reduced to increase the amplification factor of the amplifier circuit; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is increased to reduce the amplification factor of the amplifier circuit.

[0066] The signal calculation circuit is used to calculate the engine speed at a second moment according to the amplified signal.

[0067] The magnetoelectric speed sensor intelligent processing system further comprises: a static detection circuit 5; the static detection circuit 5 is connected to the electronic control unit.

[0068] The static detection circuit 5 specifically includes: a MOS tube and a gate resistor.

[0069] Among them, the drain of the MOS tube is connected to the power supply; the gate of the MOS tube is connected to the electronic control unit through the gate resistor; the source of the MOS tube is used to connect to one end interface of the magnetoelectric speed sensor.

[0070] The electronic control unit is used to control the opening and closing of the MOS tube.

[0071] The signal acquisition circuit includes: a diode clamp circuit 6. The diode clamp circuit 6 is used to acquire and limit the voltage signal output by the magnetoelectric rotation speed sensor to a fixed range.

[0072] The signal calculation circuit includes: a differential circuit 8 and a hysteresis comparator 9;

[0073] The differential circuit 8 is used to differentiate the amplified signal to obtain a differential signal;

[0074] The hysteresis comparator 9 is used to convert the differential signal into a square wave voltage signal, and send the square wave voltage signal to the electronic control unit; the electronic control unit is used to calculate the engine speed at the second moment according to the square wave voltage signal;

[0075] In this embodiment, the intelligent processing system of the magnetoelectric rotation speed sensor is also referred to as an intelligent processing circuit 3.

[0076] The magnetoelectric speed sensor 2 in this embodiment measures the speed of the engine 1 based on electromagnetic induction. When the gears of the engine 1 rotate, the magnetic lines of force of the magnetoelectric speed sensor 2 are cut, thereby generating a periodic sinusoidal voltage in the sensor coil, and the voltage is proportional to the speed of the gears of the engine 1.

[0077] Intelligent processing circuit 3 Figure 2 As shown. The intelligent processing circuit 3 processes the engine 1 speed voltage signal collected by the magnetoelectric speed sensor 2 to obtain a voltage square wave signal V1, and outputs the voltage square wave signal to the ECU 4 (Electronic Control Unit). At the same time, the intelligent processing circuit 3 receives the control signal from the ECU 4 to control the MOS opening and closing and the size of the digital control resistor in the circuit.

[0078] Figure 2 The circuit in Figure 1The intelligent processing circuit 3 in the circuit includes 5 parts of "static detection circuit 5, clamping circuit, amplifier circuit 7, differential circuit 8, and hysteresis comparator 9". When the speed is 0, the magnetoelectric speed sensor 2 has no signal output. At this time, the magnetoelectric speed sensor 2 is equivalent to a resistor with a fixed resistance value. The ECU4 controls the MOS tube Q1 to turn on to detect the short circuit and open circuit of the magnetoelectric speed sensor 2; when the speed is not 0, the magnetoelectric speed sensor 2 has a signal output, and the ECU4 controls Q1 to turn off. The signal output by the speed sensor first passes through the clamping circuit, and the voltage is limited to a fixed value, and then passes through the amplifier circuit 7, the positive and negative voltage signals are amplified, and the common mode interference is filtered out; then the signal passes through the differential circuit 8 to further amplify the voltage, and at this time, it is ensured that the processed signal is amplified to the power supply voltage of the operational amplifier; finally, it passes through the hysteresis comparator 9 circuit. The hysteresis comparator circuit has the characteristics of anti-interference, which further increases the anti-interference ability of the circuit.

[0079] The static detection circuit 5 performs fault detection on the magnetoelectric speed sensor 2 when the engine 1 is in a static state, and determines whether the magnetoelectric speed sensor 2 works normally.

[0080] The static detection circuit 5 includes a MOS tube and two end interfaces of the magnetoelectric speed sensor 2 ; the MOS tube is connected to one end interface of the magnetoelectric speed sensor 2 .

[0081] The MOS tube is used to obtain the output of the electronic control unit; when the engine 1 is in a static state, if a normal voltage can be detected at the other end interface of the magnetoelectric speed sensor 2, then the magnetoelectric speed sensor 2 is normal.

[0082] The diode clamping circuit 6 clamps the input voltage of the magnetoelectric speed sensor 2 to the diode drop voltage V2 (generally, the clamping voltage of a single diode is ±0.6V to ±0.7V).

[0083] The diode clamping circuit 6 is used to limit the voltage signal output by the magnetoelectric rotation speed sensor 2 to a fixed range to obtain a clamping voltage.

[0084] The amplifier circuit 7 amplifies the clamped voltage to obtain an amplified voltage V3. The amplification factor of the amplifier circuit 7 is controlled by a digitally controlled variable resistor.

[0085] The amplifier circuit 7 is used to amplify the clamp voltage to obtain an amplified signal.

[0086] The amplifier circuit 7 includes: a digitally controlled variable resistor; the resistance value of the digitally controlled variable resistor is controlled by an electronic control unit; when the speed of the engine 1 at the first moment detected by the electronic control unit is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to a smaller value, thereby increasing the amplification factor of the amplifier circuit 7; when the speed of the engine 1 detected by the electronic control unit is higher than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to a larger value, thereby reducing the amplification factor of the amplifier circuit 7.

[0087] The differential circuit 8 converts the positive and negative voltages of the amplified voltage V3 into a single-channel voltage V4 for output.

[0088] The differential circuit 8 is used to differentiate the amplified signal to obtain a differential signal.

[0089] The hysteresis comparator 9 converts the differential single-channel voltage V4 into a square wave voltage V5 (V5 is the positive and negative power supply voltage of the selected operational amplifier, generally ±5V) and outputs it.

[0090] The hysteresis comparator 9 is used to convert the differential signal into a square wave voltage signal and send the square wave voltage signal to the electronic control unit; the electronic control unit calculates the speed of the engine 1 at the second moment according to the square wave voltage signal.

[0091] The ECU 4 receives the speed voltage signal V5 processed by the intelligent processing circuit 3 and calculates the speed of the engine 1 .

[0092] The ECU 4 can control the MOS tube of the static detection circuit 5 , the amplifier circuit 7 and the digitally controlled variable resistor of the hysteresis comparator 9 in the intelligent processing circuit 3 .

[0093] The method of ECU4 controlling the MOS tube: ECU4 outputs a high-level signal to the G pole of the MOS tube, and the MOS tube is turned on; ECU4 outputs a low-level signal to the G pole of the MOS tube, and the MOS tube is turned off.

[0094] The method of ECU4 controlling digitally controlled variable resistors: There are many kinds of digitally controlled variable resistors. Taking the digitally controlled resistor MAX5400 chip as an example, ECU4 is connected to MAX5400 through the SPI bus. ECU4 writes different values ​​to MAX5400 through the SPI bus, and the resistance of MAX5400 changes accordingly.

[0095] Specifically, the diode clamp circuit includes: a first resistor R1, a second resistor R2, a first capacitor C1, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4.

[0096] Among them, one end interface of the magnetoelectric speed sensor is connected to one end of the first resistor; the other end of the first resistor is connected to the first common end; the first common end is also connected to one end of the first capacitor, the positive end of the first diode, and the negative end of the second diode; the negative end of the first diode is grounded; and the positive end of the second diode is grounded.

[0097] One end interface of the magnetoelectric speed sensor is connected to one end of the second resistor; the other end of the second resistor is connected to the second common end; the second common end is also connected to the other end of the first capacitor, the positive end of the fourth diode, and the negative end of the third diode; the negative end of the fourth diode is grounded; and the positive end of the third diode is grounded.

[0098] The amplifying circuit specifically includes: a first operational amplifier U1, a second operational amplifier U2, a third resistor R3, a fifth resistor R5 and a fourth digitally controlled resistor R4.

[0099] After the diode clamping circuit limits the voltage signal output by the magnetoelectric speed sensor to a fixed range, the clamped positive output terminal signal is connected to the positive input terminal of the first operational amplifier, and the clamped negative output terminal signal is connected to the positive input terminal of the second operational amplifier; the negative input terminal of the first operational amplifier is connected to the negative input terminal of the second operational amplifier through the digitally controlled resistor, the output terminal of the first operational amplifier is connected to the negative input terminal of the first operational amplifier through the third resistor, and the output terminal of the second operational amplifier is connected to the negative input terminal of the second operational amplifier through the fifth resistor.

[0100] The differential circuit specifically includes: a third operational amplifier U3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9.

[0101] Among them, the positive phase signal amplified by the amplifier circuit is connected to the positive phase input terminal of the third operational amplifier through the sixth resistor; the negative phase signal amplified by the amplifier circuit is connected to the negative phase input terminal of the third operational amplifier through the eighth resistor; the positive phase input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier through the seventh resistor; and the negative phase input terminal of the third operational amplifier is grounded through the ninth resistor.

[0102] The output terminal of the third operational amplifier outputs a differential signal.

[0103] The hysteresis comparator specifically includes: a fourth operational amplifier U4, an eleventh resistor R11, a twelfth resistor R12, a tenth digitally controlled resistor R10 and a fifth diode D5.

[0104] The fourth operational amplifier, the eleventh resistor and the tenth resistor constitute a hysteresis comparison circuit; the positive phase input terminal of the fourth operational amplifier is grounded through the tenth resistor, and the output terminal of the fourth operational amplifier is connected to the positive phase input terminal of the fourth operational amplifier through the eleventh resistor; the differential signal is connected to the negative phase input terminal of the fourth operational amplifier, and the output terminal of the fourth operational amplifier outputs the signal after hysteresis comparison; the signal after hysteresis comparison is cut off from the negative half wave by the fifth diode, and the fifth diode is connected in series with the twelfth resistor and then grounded.

[0105] The resistance value of the tenth digitally controlled resistor is controlled by an electronic control unit; when the amplification factor of the amplifier circuit is increased, the resistance value of the tenth digitally controlled resistor is synchronously increased; when the amplification factor of the amplifier circuit is reduced, the resistance value of the tenth digitally controlled resistor is synchronously decreased.

[0106] As an optional implementation, the connection mode of each circuit in this embodiment can also be described as follows:

[0107] The static detection circuit 5 specifically includes: a MOS tube, a gate resistor and two-terminal interfaces of the magnetoelectric speed sensor 2 .

[0108] The drain of the MOS tube is connected to a power supply; the gate of the MOS tube is connected to an electronic control unit via the gate resistor; and the source of the MOS tube is connected to an interface at one end of the magnetoelectric speed sensor 2 .

[0109] The diode clamp circuit 6 specifically includes: a first resistor R1, a second resistor R2, a first capacitor C1, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4.

[0110] The two end interfaces of the magnetoelectric speed sensor 2 are respectively connected in series with one pole of the first resistor and the second resistor; the other poles of the first resistor and the second resistor are connected in parallel with the first capacitor;

[0111] The other electrode of the first resistor is grounded through the anode of the first diode and the cathode of the second diode; the other electrode of the second resistor is grounded through the anode of the fourth diode and the cathode of the third diode.

[0112] The amplifier circuit 7 specifically includes: a first operational amplifier U1, a second operational amplifier U2, a third resistor R3, a fifth resistor R5 and a fourth digitally controlled resistor R4.

[0113] After the diode clamping circuit 6 limits the voltage signal output by the magnetoelectric speed sensor 2 to a fixed range, the clamped positive output terminal signal is connected to the positive input terminal of the first operational amplifier, and the clamped negative output terminal signal is connected to the positive input terminal of the second operational amplifier; the negative input terminal of the first operational amplifier is connected to the negative input terminal of the second operational amplifier through the digitally controlled resistor, the output terminal of the first operational amplifier is connected to the negative input terminal of the first operational amplifier through the third resistor, and the output terminal of the second operational amplifier is connected to the negative input terminal of the second operational amplifier through the fifth resistor.

[0114] The differential circuit 8 specifically includes: a third operational amplifier U3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9.

[0115] The positive phase signal amplified by the amplifier circuit 7 is connected in series with the sixth resistor and then connected to the positive phase input terminal of the third operational amplifier; the negative phase signal amplified by the amplifier circuit 7 is connected in series with the eighth resistor and then connected to the negative phase input terminal of the third operational amplifier; the positive phase input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier through the seventh resistor; the negative phase input terminal of the third operational amplifier is grounded through the ninth resistor. The output terminal of the third operational amplifier outputs the differential signal.

[0116] The hysteresis comparator 9 specifically includes: a fourth operational amplifier U4, an eleventh resistor R11, a twelfth resistor R12, a tenth digitally controlled resistor R10 and a fifth diode D5.

[0117] The fourth operational amplifier, the eleventh resistor and the tenth resistor constitute a hysteresis comparison circuit; the positive phase input terminal of the fourth operational amplifier is grounded through the tenth resistor, and the output terminal of the fourth operational amplifier is connected to the positive phase input terminal of the fourth operational amplifier through the eleventh resistor; the differential signal is connected to the negative phase input terminal of the fourth operational amplifier, and the output terminal of the fourth operational amplifier outputs the signal after hysteresis comparison; the signal after hysteresis comparison is cut off from the negative half wave by the fifth diode, and the fifth diode is connected in series with the twelfth resistor and then grounded.

[0118] In addition, the resistance value of the tenth digitally controlled resistor is controlled by an electronic control unit; when the amplification factor of the amplifier circuit 7 is increased, the resistance value of the tenth digitally controlled resistor is synchronously increased; when the amplification factor of the amplifier circuit 7 is reduced, the resistance value of the tenth digitally controlled resistor is synchronously decreased.

[0119] This embodiment can perform static detection on the magnetoelectric speed sensor 2 to determine whether the magnetoelectric speed sensor 2 is good or bad, and can also adjust the amplification factor of the processing circuit and the threshold voltage of the processing circuit output signal through a digitally controlled variable resistor.

[0120] The processing circuit of the existing magnetoelectric speed sensor 2 usually only adopts the "limiting + amplification" processing method. When the speed is high and low, the signal strength output by the magnetoelectric speed sensor 2 is very different. In order to meet the normal recognition of weak signals at low speeds, the processing circuit usually adjusts the amplification factor very large. The problem caused by this is that when the high-speed signal becomes stronger, the interference will also become stronger, and the existing processing circuit cannot filter out this part of the interference.

[0121] Another problem is that the magnetoelectric speed sensor 2 only outputs a signal when there is a speed. The traditional method is to detect the processed signal. When the engine 1 has not started (the speed is 0), the magnetoelectric speed sensor 2 has no signal output, and the existing processing circuit cannot diagnose the sensor fault.

[0122] This embodiment proposes two methods to address the above two shortcomings:

[0123] (1) The amplification factor is adjustable: when the speed is low and the signal is weak, the signal amplification factor is large to ensure that the signal can be detected normally. When the speed is high and the signal is strong, the signal amplification factor is small to reduce the interference signal.

[0124] (2) A static detection circuit 5 is designed. When there is no rotation speed, although the magnetoelectric rotation speed sensor 2 has no signal output, the static detection circuit 5 can still detect whether there is a short circuit or open circuit inside the magnetoelectric rotation speed sensor 2.

[0125] In an exemplary embodiment, Figure 3 As shown, a magnetoelectric speed sensor intelligent processing system is provided, and the magnetoelectric speed sensor intelligent processing system includes a static detection circuit, a diode clamping circuit, an amplifier circuit, a differential circuit and a hysteresis comparator connected in sequence. In this embodiment, the magnetoelectric speed sensor intelligent processing system is also referred to as an intelligent processing circuit.

[0126] The specific circuit structure of each part of the system is as follows:

[0127] The static detection circuit includes MOS tube Q1, gate resistor R13, Q1's D-stage is connected to the 5.0V power supply, and the gate is connected to the ECU through the gate resistor R13. It is used to detect whether the magnetoelectric sensor is short-circuited or open-circuited after the ECU is powered on and before the engine is started. It is not used at the same time as the "diode clamp circuit, amplifier circuit, differential circuit and hysteresis comparator".

[0128] The diode clamping circuit includes resistors R1 and R2, capacitor C1, diodes D1, D2, D3, and D4. The positive output terminal and negative output terminal of the magnetoelectric speed sensor are connected in series with one pole of resistors R1 and R2 respectively, and then the other poles of R1 and R2 are connected in parallel with C1. R1 and R2 play the role of limiting the current size, and C1 plays the role of preliminary filtering. The other pole of R1 is grounded through the positive pole of D1 and the negative pole of D2 to clamp the positive output terminal signal after current limiting (positive signal after clamping); the other pole of R2 is grounded through the positive pole of D4 and the negative pole of D3 to clamp the negative output terminal after current limiting (negative signal after clamping). The diode plays the role of clamping, limiting the voltage at the right end of R1 and R2 to the positive phase voltage drop of the diode. The positive signal and negative signal after clamping are connected to the amplifier circuit.

[0129] The amplifier circuit includes operational amplifiers U1 and U2, resistors R3 and R5, and digitally controlled resistor R4. The clamped positive phase output terminal signal is connected to the positive phase input terminal of U1, and the clamped negative phase output terminal signal is connected to the positive phase input terminal of U2. The negative phase input terminal of U1 is connected to the negative phase input terminal of U2 through the digitally controlled resistor R4, the output terminal of U1 is connected to the negative phase input terminal of U1 through the resistor R3, and the output terminal of U2 is connected to the negative phase input terminal of U2 through the resistor R5. The output terminal of U1 outputs the amplified and clamped positive phase output terminal signal (amplified positive signal), and the output terminal of U2 outputs the amplified and clamped negative phase output terminal signal (amplified negative signal).

[0130] The differential circuit includes an operational amplifier U3, resistors R6, R7, R8, and R9. The amplified positive-phase signal is connected in series with R6 and then connected to the positive-phase input terminal of U3. The amplified negative-phase signal is connected in series with R8 and then connected to the negative-phase input terminal of U3. The positive-phase input terminal of U3 is connected to the output terminal through R7, and the negative-phase input terminal of U3 is grounded through R9. The output terminal of U3 outputs the differential signal.

[0131] The differential signal is connected to the hysteresis comparator, which includes an operational amplifier U4, resistors R11 and R12, a digitally controlled resistor R10 and a diode D5. U4, R11 and R10 constitute a hysteresis comparison circuit, the positive phase input of U4 is grounded through R10, and the output of U4 is connected to the positive phase input of U4 through R11. The differential signal is connected to the negative phase input of U4, and the output of U4 outputs the signal after hysteresis comparison. The signal after hysteresis comparison is cut off by D5 and grounded after being connected in series with R12.

[0132] The signal after D5 with the negative half wave removed is the processed speed signal, which is connected to the ECU for detection and identification.

[0133] When the magnetoelectric speed sensor intelligent processing system is used, Figure 4 As shown, the following steps may be specifically included:

[0134] S201: When the ECU is powered on and the engine is in a static state, a static detection is performed on the magnetoelectric speed sensor.

[0135] Specifically: Static detection circuit such as Figure 5 As shown. After the ECU is powered on, in the static state of the engine, the ECU outputs a high level, and the MOS tube is turned on. If the magnetoelectric speed sensor is not damaged, the voltage value after the magnetoelectric speed sensor and R2 voltage division can be detected at point A; on the contrary, if the magnetoelectric speed sensor is short-circuited, the power supply voltage of 5.0V is detected at point A, and if the magnetoelectric speed sensor is disconnected, 0V is detected at point A. In short, when the magnetoelectric speed sensor is disconnected or short-circuited, the voltage detected at point A is different from the voltage detected at normal speed, thereby realizing static detection. When the engine is running, the ECU outputs a low level and turns off the MOS tube.

[0136] S202: Receive a voltage signal V1 from a magnetoelectric rotation speed sensor.

[0137] Specifically: after the engine starts running, the gear disc cuts the magnetic field of the magnetoelectric speed sensor to generate a sinusoidal voltage signal V1, which has two paths, positive and negative.

[0138] S203: Clamp the voltage signal V1 of the magnetoelectric speed sensor to obtain a diode clamping voltage V2.

[0139] Specifically: The diode clamp circuit is as follows: Figure 6 When the input voltage V1 of the magnetoelectric speed sensor changes, the voltage is always clamped at the diode drop voltage V2 (±0.6V~±0.7V) after passing through the resistor.

[0140] S204: Amplify the diode clamping voltage V2 to obtain an amplified voltage V3.

[0141] Specifically: Amplifier circuit Figure 7 As shown. The amplification factor of this amplifier circuit is R4 is a digitally controlled variable resistor that supports ECU online programming to control the resistance value. By adjusting the resistance value of R4 by ECU, the output voltage V3 of the amplifier circuit can be changed.

[0142] S205: Differentiate the amplified voltage V3 to obtain a single-path differential voltage V4.

[0143] Specifically: Differential circuit such as Figure 8 The positive and negative voltages are differentiated to obtain a single voltage V4, V4 = 2V3.

[0144] S206: The differential voltage V4 is converted into a square wave voltage signal V5 (±5V) through a hysteresis comparator. Fig. 9 If the absolute value of the input voltage V4 is greater than the threshold voltage The hysteresis comparator outputs a square wave voltage V5 that jumps between ±5V. R10 is a digitally controlled variable resistor, and the resistance value of R10 can be adjusted by the ECU to change the hysteresis comparator threshold voltage V ref size.

[0145] S207: Send the square wave voltage signal V5 to the ECU to calculate the engine speed.

[0146] This embodiment has the following advantages over the prior art:

[0147] 1. Use digitally controlled resistors to make the amplification factor of the amplifier circuit and the threshold comparison voltage of the hysteresis comparator variable. When the speed is low, the signal generated by the magnetoelectric speed sensor is weak, and the amplification factor can be increased and the threshold comparison voltage can be reduced, so that the signal can be recognized normally, and the upper limit of the signal recognition of the magnetoelectric speed sensor is broadened; when the speed is high, the signal generated by the magnetoelectric speed sensor is strong, and the amplification factor can be reduced and the threshold comparison voltage can be increased to filter out the strong interference signal, thereby improving the reliability of the signal processing.

[0148] 2. Add a static detection circuit. When the engine control system is just powered on and the engine is not running, the quality of the sensor can be determined based on the static voltage. This solves the problem that the previous technology can only determine the quality of the speed sensor after the engine is running.

[0149] In addition, the digitally controlled resistor in this embodiment may also use other solutions. This embodiment only describes the case of directly using an existing digitally controlled resistor chip.

[0150] In an exemplary embodiment, a magnetoelectric speed sensor intelligent processing method is provided, comprising:

[0151] With the engine at rest:

[0152] The voltage of the other end interface of the magnetoelectric speed sensor is obtained; if the voltage is a normal voltage, the magnetoelectric speed sensor is normal.

[0153] With the engine at rest:

[0154] A voltage signal output by the magnetoelectric rotation speed sensor is obtained.

[0155] A diode clamping circuit is used to limit the voltage signal output by the magnetoelectric rotation speed sensor to a fixed range to obtain a clamping voltage.

[0156] The clamping voltage is amplified by an amplifier circuit to obtain an amplified signal; the amplifier circuit includes: a digitally controlled variable resistor; the resistance value of the digitally controlled variable resistor is controlled by an electronic control unit; when the engine speed at the first moment detected by the electronic control unit is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be smaller, and the amplification factor of the amplifier circuit is increased; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be larger, and the amplification factor of the amplifier circuit is reduced.

[0157] The amplified signal is differentiated by using a differential circuit to obtain a differential signal.

[0158] The differential signal is converted into a square wave voltage signal by using a hysteresis comparator, and the square wave voltage signal is sent to an electronic control unit.

[0159] The electronic control unit is used to calculate the engine speed at the second moment according to the square wave voltage signal.

[0160] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0161] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0162] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. An intelligent processing system for a magnetoelectric speed sensor, characterized in that: The magnetoelectric speed sensor intelligent processing system includes an electronic control unit, a signal acquisition circuit, an amplification circuit and a signal calculation circuit; The signal acquisition circuit is used to acquire the voltage signal output by the magnetoelectric speed sensor; The amplifier circuit is used to amplify the voltage signal to obtain an amplified signal; The amplifying circuit comprises: a digitally controlled variable resistor; The electronic control unit is used to adjust the resistance value of the digitally controlled variable resistor according to the engine speed detected at the first moment; when the engine speed detected by the electronic control unit at the first moment is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be smaller, and the amplification factor of the amplifier circuit is increased; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be larger, and the amplification factor of the amplifier circuit is reduced; The signal calculation circuit is used to calculate the engine speed at a second moment according to the amplified signal.

2. The intelligent processing system for magnetoelectric speed sensor according to claim 1 is characterized in that: The magnetoelectric speed sensor intelligent processing system further comprises: a static detection circuit; the static detection circuit is connected to the electronic control unit; The static detection circuit specifically includes: a MOS tube and a gate resistor; The drain of the MOS tube is connected to the power supply; the gate of the MOS tube is connected to the electronic control unit through the gate resistor; the source of the MOS tube is used to be connected to an interface at one end of the magnetoelectric speed sensor; The electronic control unit is used to control the opening and closing of the MOS tube.

3. The intelligent processing system for magnetoelectric speed sensor according to claim 1 is characterized in that: The signal acquisition circuit includes: a diode clamp circuit; The diode clamping circuit is used to obtain and limit the voltage signal output by the magnetoelectric rotation speed sensor to a fixed range.

4. The intelligent processing system for magnetoelectric speed sensor according to claim 3 is characterized in that: The diode clamp circuit specifically includes: a first resistor R1, a second resistor R2, a first capacitor C1, a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; Among them, one end interface of the magnetoelectric speed sensor is connected to one end of the first resistor; the other end of the first resistor is connected to the first common end; the first common end is also connected to one end of the first capacitor, the positive end of the first diode, and the negative end of the second diode; the negative end of the first diode is grounded; the positive end of the second diode is grounded; One end interface of the magnetoelectric speed sensor is connected to one end of the second resistor; the other end of the second resistor is connected to the second common end; the second common end is also connected to the other end of the first capacitor, the positive end of the fourth diode, and the negative end of the third diode; the negative end of the fourth diode is grounded; and the positive end of the third diode is grounded.

5. The intelligent processing system for magnetoelectric speed sensor according to claim 1 is characterized in that: The signal calculation circuit includes: a differential circuit and a hysteresis comparator; The differential circuit is used to differentiate the amplified signal to obtain a differential signal; The hysteresis comparator is used to convert the differential signal into a square wave voltage signal and send the square wave voltage signal to the electronic control unit; the electronic control unit is used to calculate the engine speed at the second moment according to the square wave voltage signal.

6. The intelligent processing system for magnetoelectric speed sensor according to claim 5 is characterized in that: The amplifying circuit specifically includes: a first operational amplifier U1, a second operational amplifier U2, a third resistor R3, a fifth resistor R5 and a fourth digitally controlled resistor R4; After the diode clamping circuit limits the voltage signal output by the magnetoelectric speed sensor to a fixed range, the clamped positive output terminal signal is connected to the positive input terminal of the first operational amplifier, and the clamped negative output terminal signal is connected to the positive input terminal of the second operational amplifier; the negative input terminal of the first operational amplifier is connected to the negative input terminal of the second operational amplifier through the digitally controlled resistor, the output terminal of the first operational amplifier is connected to the negative input terminal of the first operational amplifier through the third resistor, and the output terminal of the second operational amplifier is connected to the negative input terminal of the second operational amplifier through the fifth resistor.

7. The intelligent processing system for magnetoelectric speed sensor according to claim 6 is characterized in that: The differential circuit specifically includes: a third operational amplifier U3, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8 and a ninth resistor R9; The positive phase signal amplified by the amplifier circuit is connected to the positive phase input terminal of the third operational amplifier through the sixth resistor; the negative phase signal amplified by the amplifier circuit is connected to the negative phase input terminal of the third operational amplifier through the eighth resistor; the positive phase input terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier through the seventh resistor; the negative phase input terminal of the third operational amplifier is grounded through the ninth resistor; The output terminal of the third operational amplifier outputs a differential signal.

8. The intelligent processing system for magnetoelectric speed sensor according to claim 7 is characterized in that: The hysteresis comparator specifically includes: a fourth operational amplifier U4, an eleventh resistor R11, a twelfth resistor R12, a tenth digitally controlled resistor R10 and a fifth diode D5; The fourth operational amplifier, the eleventh resistor and the tenth resistor constitute a hysteresis comparison circuit; the positive phase input terminal of the fourth operational amplifier is grounded through the tenth resistor, and the output terminal of the fourth operational amplifier is connected to the positive phase input terminal of the fourth operational amplifier through the eleventh resistor; the differential signal is connected to the negative phase input terminal of the fourth operational amplifier, and the output terminal of the fourth operational amplifier outputs the signal after hysteresis comparison; the signal after hysteresis comparison is cut off by the fifth diode to remove the negative half wave, and the fifth diode is connected in series with the twelfth resistor and then grounded; The resistance value of the tenth digitally controlled resistor is controlled by an electronic control unit; when the amplification factor of the amplifier circuit is increased, the resistance value of the tenth digitally controlled resistor is synchronously increased; when the amplification factor of the amplifier circuit is reduced, the resistance value of the tenth digitally controlled resistor is synchronously decreased.

9. A method for intelligent processing of a magnetoelectric speed sensor, characterized in that: The intelligent processing method of the magnetoelectric speed sensor comprises: The diode clamp circuit obtains the voltage signal output by the magnetoelectric speed sensor; The diode clamping circuit limits the voltage signal output by the magnetoelectric speed sensor to a fixed range to obtain a clamping voltage; The amplifying circuit amplifies the clamping voltage to obtain an amplified signal; the amplifying circuit includes: a digitally controlled variable resistor; the resistance value of the digitally controlled variable resistor is controlled by an electronic control unit; when the engine speed detected by the electronic control unit at the first moment is lower than a preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be smaller, thereby increasing the amplification factor of the amplifying circuit; when the engine speed detected by the electronic control unit is higher than the preset threshold, the resistance value of the digitally controlled variable resistor is adjusted to be larger, thereby reducing the amplification factor of the amplifying circuit; The differential circuit differentiates the amplified signal to obtain a differential signal; The hysteresis comparator converts the differential signal into a square wave voltage signal, and sends the square wave voltage signal to the electronic control unit; The electronic control unit calculates the engine speed at the second moment according to the square wave voltage signal.

10. The intelligent processing method of the magnetoelectric speed sensor according to claim 9, characterized in that: The diode clamp circuit obtains the voltage signal output by the magnetoelectric speed sensor, specifically comprising: When the engine is in a static state, the electronic control unit obtains the voltage of the other end interface of the magnetoelectric speed sensor; if the voltage is a normal voltage, the magnetoelectric speed sensor is normal; When the magnetoelectric rotation speed sensor is normal, the diode clamping circuit acquires the voltage signal output by the magnetoelectric rotation speed sensor.

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