A method and device for improving the accuracy of power shaft position signal

Abstract

The present invention relates to the field of industrial control, and in particular to a method and device for improving the accuracy of a power shaft position signal. The method mainly includes: detecting the effective edge according to the specified effective edge form of the power shaft position pulse signal, and calibrating the edge timestamp of the effective edge using a free time base clock; calculating the current cycle prediction value according to the effective edge timestamps of at least two cycles; calculating the micro-pulse generation parameters of the current cycle through the current cycle prediction value, the power shaft gear characteristic value, the standard tooth pulse frequency multiplication coefficient, and the frequency multiplication coefficient correction value; using the pulse generation parameters as the pulse generator input, and performing a superposition operation with the free time base clock, the carry output bit of the adder during the superposition operation corresponds to the micro-pulse of the power shaft position signal. The present invention can meet the needs of the ECU unit for obtaining the engine position and power control, and avoid the error caused by the missing teeth.

Description

Technical Field

[0001] The invention relates to the field of industrial control, and in particular to a method and a device for improving the accuracy of a power shaft position signal. Background Art

[0002] In the power control system of traditional fuel vehicles, the position status of the power shafts such as the crankshaft and camshaft corresponds to the state of the engine. In the actual control scenario, the position signal of the power shaft is obtained by the corresponding position sensor. The crankshaft signal is the crankshaft position sensor signal, and the camshaft signal is the camshaft position sensor signal. The two signals reflect the position information of the engine cylinder piston. In order to determine the engine's injection and ignition information, the Electronic Control Unit (ECU) in the power control system needs to process the crankshaft signal and camshaft signal to obtain the corresponding engine position information, and then generate injection and ignition pulses.

[0003] At present, the power shaft signal is usually obtained using a phase sensor, which detects the angular position signal of the power shaft and converts it into a pulse signal. However, the existing method of directly obtaining the power shaft position signal through a phase sensor has low accuracy and cannot judge the missing tooth condition of the power shaft.

[0004] In view of this, how to overcome the defects of the prior art and solve the problem of low accuracy in acquiring the power shaft position signal is a problem to be solved in the technical field. Summary of the invention

[0005] In view of the above defects or improvement requirements of the prior art, the present invention solves the problem of low accuracy in acquiring the power shaft position signal.

[0006] The embodiment of the present invention adopts the following technical solution:

[0007] In the first aspect, the present invention provides a method for improving the accuracy of a power shaft position signal, specifically: detecting an effective edge according to a specified effective edge form of a power shaft position pulse signal, and calibrating an edge timestamp of the effective edge using a free time base clock, wherein the effective edge corresponds to a concave and convex change position of a power shaft gear; calculating a current cycle prediction value based on effective edge timestamps of at least two cycles; calculating a micropulse generation parameter of the current cycle by using the current cycle prediction value, a power shaft gear characteristic value, a standard tooth pulse multiplication coefficient, and a multiplication coefficient correction value, wherein the micropulse generation parameter represents the number of micropulses within a unit clock cycle of the free time base clock; using the pulse generation parameter as a pulse generator input, and performing a superposition operation with the free time base clock, wherein the carry output bit of the adder during the superposition operation corresponds to the micropulse of the power shaft position signal.

[0008] Preferably, the calculation of the current cycle prediction value specifically includes: calculating the previous valid edge cycle measurement value through the valid edge timestamp of the current cycle and its previous valid edge timestamp; calculating the prediction error based on the previous valid edge measurement value and the prediction value of the previous cycle, and calculating the average error of at least two cycles, and then calculating the current cycle prediction value based on the average error.

[0009] On the other hand, the present invention provides a device for improving the accuracy of the power shaft position signal, specifically: including a signal sampling unit, a calculation unit and a pulse generation unit, specifically: the signal sampling unit is used to complete the edge timestamp calibration of the effective edge of the power shaft in the first aspect; the calculation unit is used to obtain the power shaft position pulse signal and the effective edge timestamp, and perform a predictive calculation of the current cycle prediction value according to the method provided in the first aspect to obtain micro-pulse generation parameters; the pulse generation unit completes the generation of micro-pulses of the power shaft position signal according to the method provided in the first aspect.

[0010] Preferably, the signal sampling unit includes: a free time base counter, a valid edge detection subunit, a sampling control subunit and a timestamp sampling register, specifically: the free time base counter is used to count according to the free time base clock to ensure the uniform accuracy of the micro-pulse duration period of the power shaft position signal; the valid edge detection subunit is used to detect the valid edge of the power shaft position pulse signal according to the specified valid edge form, and after the valid edge is detected, the valid edge identification flag signal is sent to the sampling control subunit; the sampling control subunit is used to send a sampling instruction to the timestamp sampling register after receiving the edge identification flag signal; after receiving the sampling instruction, the timestamp sampling register captures and saves the current free time base, and uses the current free time base as the edge timestamp of the effective edge of the power shaft.

[0011] Preferably, the calculation unit includes an algorithm state machine, a multiplier unit and a divider unit. Specifically: the calculation unit predicts the current cycle according to the valid edge timestamps of at least two cycles through a hardware algorithm state machine; after the cycle prediction is completed, the algorithm state machine jumps to the pulse parameter calculation state, and the pulse parameter is the number of micropulses contained in the unit time of the free time base clock.

[0012] Preferably, the prediction of the current cycle is achieved based on the valid edge timestamps of at least two cycles, specifically including: obtaining the current valid edge timestamp and at least two previous valid edge timestamps, taking the difference between two adjacent valid edge timestamps as an actual cycle, averaging the theoretical cycle and at least two actual cycles in the form of a geometric progression, and using the averaged cycle as the prediction of the current cycle.

[0013] Preferably, the computing unit also includes a multiplier and divider control bus, specifically: the multiplier and divider control bus includes an operation cycle, input enable and feedback output enable, and the data transmitted in the multiplier and divider control bus are the multiplier and multiplicand, the divisor and dividend.

[0014] Preferably, the pulse generating unit includes a full adder subunit and an intermediate result register. Specifically, the full adder subunit performs a superposition operation on the pulse generating parameters when each clock of the free time base counter is counted according to the control of the free time base counter clock, and the output of the full adder subunit is the micro-pulse of the power shaft position signal.

[0015] Preferably, the pulse generation parameter is superimposed once, specifically comprising: superimposing the pulse generation parameter according to the clock of the free time base counter to generate a carry, and using the pulse output by the adder carry as the micro pulse obtained by dividing the free time base clock according to the pulse generation parameter.

[0016] Preferably, the pulse generating unit also includes a pulse compensation unit. Specifically, the pulse compensation unit utilizes a high-speed clock to quickly generate micro-pulses equal to the number of pulses of missing teeth in the tooth missing cycle, so that the micro-pulses match the number of teeth of the power shaft to avoid continuous errors in the power shaft position caused by acceleration of the power shaft.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present invention are: by multiplying the frequency of the sensor signal of the power shaft to provide a micro-pulse signal with higher precision, and realizing missing tooth compensation, the demand for high-precision control of the engine is met.

[0018] On the other hand, the beneficial effect of the embodiment of the present invention is that the signal is predicted and analyzed, phase synchronized and processed with high precision by hardware methods, thereby meeting the needs of the ECU unit for obtaining the engine position and power control. In the preferred embodiment, the missing teeth are also compensated by the pulse compensation unit to avoid the error caused by the missing teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 A flow chart of a method for improving the accuracy of a power shaft position signal provided by an embodiment of the present invention;

[0021] Figure 2A schematic diagram of a crankshaft signal processing process within a specified period in an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the structure of a device for improving the accuracy of a power shaft position signal provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of another device structure for improving the accuracy of a power shaft position signal provided by an embodiment of the present invention;

[0024] Figure 5 A schematic diagram of another device structure for improving the accuracy of a power shaft position signal provided by an embodiment of the present invention;

[0025] Figure 6 A schematic diagram of the structure of another device for improving the accuracy of a power shaft position signal provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0027] The present invention is an architecture of a specific functional system, so the specific embodiments mainly illustrate the functional logical relationship between the various structural modules, and do not limit the specific software and hardware implementation methods.

[0028] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0029] Embodiment 1:

[0030] In the engine of a fuel vehicle, the power system crankshaft and camshaft are connected to the engine cylinder piston, and the engine status is determined by the position of the crankshaft and camshaft. The function of the crankshaft position sensor is to determine the position of the crankshaft, that is, the angle of rotation of the crankshaft and the engine speed, and to determine the basic ignition timing by cooperating with the camshaft position sensor. The camshaft position sensor is a sensing device, also called a synchronous signal sensor. It is a cylinder identification and positioning device that inputs the camshaft position signal to the ECU and is the main control signal for ignition control. The higher the position accuracy of the crankshaft and camshaft, the higher the control accuracy of the engine.

[0031] like Figure 1 As shown, the specific steps of the method for improving the accuracy of the power shaft position signal provided by the embodiment of the present invention are as follows.

[0032] Step 101: Detect the effective edge according to the specified effective edge form of the power shaft position pulse signal, and calibrate the edge timestamp of the effective edge using the free time base clock.

[0033] The power shaft in this embodiment includes the crankshaft and camshaft in the power system. The position signals obtained by the position sensors of the two shafts are angle pulse signals corresponding to the gear positions. The high level in the angle pulse signal indicates the protrusion of the gear, and the low level indicates the depression of the gear. In this embodiment, the original angle pulse signal obtained by the sensor is called a position pulse signal, and the jump edge between the high level and the low level in the pulse is called an effective edge. The effective edge corresponds to the change position of the depression and protrusion of the power shaft gear.

[0034] In order to obtain a high-precision power shaft position signal, it is first necessary to obtain the valid edge in the position pulse signal. According to the configured valid edge form, the valid edge is detected and the edge timestamp is marked using the free time base TimeBase0. The valid edge forms include the "concave → convex" form or the "convex → concave" form of the crankshaft / camshaft gear, which correspond to the jump edge from low level to high level and the jump edge from high level to low level, respectively. You can choose according to actual needs.

[0035] Step 102: Calculate the current cycle prediction value based on the valid edge timestamps of at least two cycles.

[0036] In order to avoid errors and compensate for missing teeth, it is also necessary to predict the pulse period. For uniform gears, the period of each pulse is consistent. Error compensation and missing tooth compensation can be performed through the period prediction value. Specifically: First, the effective edge timestamp of the current cycle calculated in step 101 and its previous effective edge timestamp are used to calculate the previous effective edge period measurement value T m_k-1 Then, based on the previous valid edge measurement value T m_k-1 and the predicted value T of the previous cycle k-1 Calculate the forecast error and calculate the average error for at least two periods Then calculate the current cycle forecast value T based on the average error k The calculation formula is as follows:

[0037]

[0038] Among them, T k is the current period forecast value, T m_k-1 is the measured value of the previous valid edge period, T m_k-2 is the measured value of the first two valid edge cycles, is the average error over multiple cycles.

[0039] Furthermore, the prediction error of each cycle is the difference between the predicted value and the actual measured value of the cycle, and the calculation formula is as follows:

[0040] ek -1 =T m_k-1 -T k-1 Among them, the previous valid edge cycle measurement value refers to the valid edge cycle measurement value before the current cycle prediction value, and the previous two valid edge cycle measurement values ​​refer to the valid edge cycle measurement values ​​before the previous valid edge cycle measurement value.

[0041] Step 103: Calculate the micro-pulse generation parameters of the current cycle through the current cycle prediction value, the power shaft gear characteristic value, the standard tooth pulse frequency multiplication coefficient and the frequency multiplication coefficient correction value.

[0042] In this embodiment, the position pulse signal is frequency-multiplied by the micropulse generation parameter to obtain a micropulse with higher precision. The micropulse generation parameter represents the number of micropulses within a clock cycle of the unit free time base clock; the standard tooth pulse frequency multiplication number represents the frequency multiplication number of the micropulse output relative to the position pulse signal input; the power shaft gear characteristic value represents the number of standard teeth contained in the current tooth, that is, the number of standard teeth contained in the normal tooth and the missing tooth, respectively, and is configured according to the physical structure of the gear of the crankshaft or camshaft.

[0043] Specifically: the current edge period prediction value T calculated in step 102 k , calculate the micro-pulse generation parameter A of the current cycle according to the crankshaft / camshaft gear characteristic value c, the standard tooth angle frequency multiplication coefficient n and the frequency multiplication coefficient correction value Δn configured according to the actual hardware attributes inc The calculation formula is as follows:

[0044]

[0045] Among them, A inc is the micro-pulse generation parameter of the current cycle, c is the gear characteristic value, n is the standard tooth angle multiplication coefficient, and Δn is the multiplication coefficient correction value.

[0046] Step 104: The pulse generation parameter is used as the pulse generator input to perform a superposition operation with the free time base clock. During the superposition operation, the carry output bit of the adder corresponds to the micro-pulse of the power shaft position signal.

[0047] In the method provided in this embodiment, a hardware adder is used to implement pulse superposition processing, thereby reducing the CPU load. inc As the input of the hardware pulse generator, under the free time base clock TimeBase0, the hardware adder is used to add A incPerform the superposition operation, and the carry position of the adder is the high-precision micro-pulse after frequency multiplication. The calculation formula is as follows:

[0048]

[0049] Among them, C out is the output of the adder, A tmp is the intermediate result of the adder without the carry bit, TB0_Clk is the clock signal of the free time base clock TimeBase0, A inc Generates parameters for the pulse.

[0050] In this formula, A inc is the expected number of micro pulses per cycle of the free time base clock TB0_Clk. The value of the free time base clock TB0_Clk corresponds to the standard tooth angle multiplication factor n, which can be configured through the register. After configuration, the adder can use the free time base clock TB0_Clk as a trigger signal to A inc To perform superposition, that is, in the current A tmp Based on "+A inc ". Whenever a carry bit is output in the superposition result, it means that a micro pulse is currently generated. For example, Figure 2 Middle A inc =0.5, which means that each TB0_Clk cycle contains 0.5 micro-pulse angle_pulse cycles, so an integer carry will be generated every two TB0_Clk clocks, that is, an integer carry will be generated every two "+Ainc" operations, and the superposition result is that an angle pulse angle_pluse is generated every two TB0_Clk cycles, thereby dividing the original position pulse signal Crank and obtaining a position signal with higher accuracy.

[0051] After steps 101 to 104 provided in this embodiment, the frequency doubling of the position pulse signal of the power shaft can be completed according to the free time base clock TimeBase0 and the micro-pulse generation parameters, and missing tooth compensation is achieved to obtain a higher precision position signal.

[0052] In a specific implementation scenario, the crankshaft signal processing process within a specified period is as follows: Figure 2 As shown in the figure, TB0_Clk is the pulse signal of the free time base TimeBase0, which is consistent with the period of the free time base TimeBase0; Crank is the original position pulse signal obtained by the position sensor, which is generally in the form of 60-2 teeth. The arrows mark the periods of normal gear and missing gear. Crank and TB0_Clk are asynchronous. The numbers in the figure represent the corresponding values ​​of each row of data.

[0053] According to step 101, when the effective edge of Crank is identified, that is, when the vertical line position of the pulse pattern in Crank is identified, the free time base Timebase0 is used to mark the edge timestamp to obtain the effective edge timestamp Crank_ts data.

[0054] After obtaining the effective edge timestamp Crank_ts data, according to step 102, the prediction error is calculated by the timestamp of the current cycle, the previous effective edge timestamp and the effective edge prediction value to predict the current tooth cycle T k .

[0055] Then according to step 103, through T k , the configured standard tooth pulse frequency multiplication number n and the current tooth characteristic parameter c, calculate the number of pulses contained in the unit free time base clock TB0_Clk, that is, the micro-pulse generation parameter A inc .

[0056] Then, according to step 104, an adder is used to perform superposition, and TB0_Clk is divided to obtain an angle pulse angle_pulse output, that is, a micro-pulse output of the power shaft position.

[0057] The signal properties of the camshaft are similar to those of the crankshaft, so the signal processing process is also similar to the crankshaft signal processing. The above process can be used to achieve high precision.

[0058] The method for improving the accuracy of the power shaft position signal provided in this embodiment uses a period prediction algorithm based on a free time base to predict the current gear period of the crankshaft / camshaft, and uses a frequency multiplication algorithm with superposition operation under the high-speed reference clock of the free time base clock to generate high-precision pulses representing the crankshaft / camshaft angle, and fills the pulses for the missing tooth period to compensate, so as to provide higher-precision power shaft position micro-pulses.

[0059] Embodiment 2:

[0060] In order to improve the operation efficiency and reduce the load of the CPU in the ECU, the method for improving the accuracy of the power shaft position signal provided in Example 1 can be implemented using the hardware device provided in this embodiment.

[0061] like Figure 3 As shown, the device includes a signal sampling unit, a calculation unit and a pulse generating unit, wherein the calculation unit is used for period prediction and calculation of pulse parameters.

[0062] The signal sampling unit completes the edge timestamp calibration of the effective edge of the power shaft in Example 1. The effective edge of the input crankshaft / camshaft position pulse signal Crank is calibrated, and the effective edge timestamp Crank_ts information of the crankshaft / camshaft after the timestamp calibration is output.

[0063] like Figure 4 As shown, the signal sampling unit includes: a free time base counter, a valid edge detection subunit, a sampling control subunit and a time stamp sampling register.

[0064] Figure 4 In the example, the free time base subunit is specifically a free time base counter TimeBase 0. The free time base counter counts according to the free time base clock to ensure the uniformity of the precision of the micro-pulse duration period of the power shaft position signal.

[0065] The signal sampling unit detects the valid edge through the valid edge type configured by the valid edge detection subunit. The valid edge detection subunit detects the valid edge of the power shaft position pulse signal according to the specified valid edge form. After the valid edge is detected, the valid edge identification flag signal valid_egde_detected is sent to the sampling control subunit.

[0066] After receiving the edge recognition signal valid_edge_detected, the sampling control subunit sends a sampling instruction mark_sign to the timestamp sampling register.

[0067] After receiving the sampling instruction mark_sign, the timestamp sampling register captures and saves the current free time base Timebase0, and uses the current free time base Timebase0 as the edge timestamp of the effective edge of the power axis.

[0068] The cycle prediction module completes the prediction calculation of the current tooth cycle based on the crankshaft / camshaft information after time stamp calibration input by the signal sampling unit, and considers the cumulative average error of multiple cycles.

[0069] In the case of inc The calculation unit obtains the power shaft position pulse signal Crank and the effective edge timestamp Crank_ts, and performs a prediction calculation of the current cycle prediction value according to the method provided in Example 1 to obtain the micropulse generation parameter A inc .

[0070] like Figure 5 As shown, the computing unit includes an algorithm state machine, a multiplier unit and a divider unit.

[0071] The calculation unit predicts the current cycle according to the valid edge timestamps of at least two cycles through the hardware algorithm state machine. Specifically, the calculation unit predicts the current cycle of the crankshaft / camshaft gear through the hardware algorithm state machine.

[0072] The prediction principle is that the default cycle increases or decreases uniformly in the form of a geometric progression, obtains the current valid edge timestamp and at least two previous valid edge timestamps, takes the difference between the two adjacent valid edge timestamps as an actual cycle, averages the theoretical cycle and at least two actual cycles in the form of a geometric progression, and uses the averaged cycle as the prediction of the current cycle. The specific formula is as follows:

[0073]

[0074] Among them, T k is the current cycle of the forecast; T k-1 is the previous cycle, that is, the difference between the current valid edge timestamp and the previous valid edge timestamp; T k-2 is the difference between the previous valid edge timestamp and the previous two valid edge timestamps in the previous two cycles. Further, in order to obtain a more accurate calculation result, more cycles can be used for averaging.

[0075] After the cycle prediction is completed, the algorithm state machine jumps to the pulse parameter calculation state. The pulse parameter is the number of micropulses contained in the unit time of the free time base clock. The specific calculation formula is as follows:

[0076]

[0077] Among them, A inc is the micro-pulse generation parameter of the current cycle, c is the gear characteristic value, n is the standard tooth angle multiplication factor, T k is the current period of the forecast.

[0078] Furthermore, to avoid the multiplier / divider being too large, the present embodiment adopts the multi-cycle decomposition principle to decompose the multiplication and division operations into small-bit-width multiplication and division operations. Therefore, the computing unit also includes a multiplier and divider control bus control bus, which includes an operation cycle, an input enable, and a feedback output enable. The data transmitted in the multiplier and divider control bus data bus are the multiplier and multiplicand, and the divisor and dividend.

[0079] Furthermore, a data storage subunit can be used to support the user in storing the crankshaft / camshaft gear characteristics used, such as the crankshaft / camshaft gear characteristic value c, the standard tooth angle multiplication coefficient n of the crankshaft / camshaft gear, and the multiplication coefficient correction value Δn, for use in the cycle prediction calculation process.

[0080] The pulse generation unit completes the generation of the power shaft position signal micropulse according to the method provided in Example 1. The pulse generation principle is: the time base clock is divided to obtain the micropulse, the frequency division process is realized by the superposition and carry method, and the micropulse duration period is calibrated by the time base clock to ensure uniform accuracy.

[0081] like Figure 6 As shown, the pulse generation unit includes a full adder subunit and an intermediate result register. The full adder subunit performs a superposition operation on the pulse generation parameters when each free time base technical clock TB0_Clk is counted according to the control of the free time base counting clock TB0_Clk. The output of the full adder subunit is the micro pulse of the power shaft position signal. The specific calculation formula is as follows:

[0082]

[0083] Among them, C out is the output of the adder, A tmp is the intermediate result of the adder without the carry bit, TB0_Clk is the clock signal of the free time base clock TimeBase0, A inc Generates parameters for the pulse.

[0084] Pulse generation parameters A inc The number of angle pulses contained in the unit TB0_Clk cycle, the pulse generation parameter A inc The clock TB0_Clk of the time base counter is superimposed to generate a carry, that is, the frequency of TB0_Clk is divided by 1 / A. inc The relatively slow angle pulse obtained, the output of the full adder subunit is the angle_pulse angle pulse, that is, the pulse output by the adder carry is used as the micro pulse obtained by dividing the time base counter according to the pulse generation parameter.

[0085] Furthermore, in order to avoid large cycle prediction errors due to acceleration, resulting in loss of angle pulses and crankshaft position detection errors, a pulse compensation unit is also used in this embodiment to compensate for the angle pulses generated by the current tooth.

[0086] The pulse compensation unit uses the high-speed clock High_Clk to quickly generate micro pulses equal to the missing tooth pulse number missing_pluse_number in the missing tooth cycle, so that the micro pulses match the number of power shaft teeth to avoid continuous errors in the power shaft position caused by the acceleration of the power shaft.

[0087] The device for improving the accuracy of the power shaft position signal provided in this embodiment has the following beneficial effects:

[0088] (1) Using hardware algorithms to predict and process periodic crankshaft / camshaft signals frees the CPU from periodic repetitive events, greatly reducing the CPU load.

[0089] (2) The low-precision crankshaft / camshaft sensor signal is frequency-multiplied to obtain a high-precision micro-pulse signal and a micro-pulse of the crankshaft / camshaft angle position, and a pulse compensation function is added to support the generation of more accurate engine control signals.

[0090] (3) The crankshaft / camshaft gear characteristics, crankshaft / camshaft signal effective edges, and crankshaft / camshaft signal multiplication coefficients can all be configured to suit a variety of scenarios.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for improving the accuracy of a power shaft position signal, characterized in that: Specifically include: Detecting effective edges according to the specified effective edge form of the power shaft position pulse signal, and calibrating edge timestamps of the effective edges using a free time base clock, wherein the effective edges correspond to concave and convex change positions of the power shaft gear; Calculate the current cycle prediction value based on the valid edge timestamps of at least two cycles; Calculate the micropulse generation parameter of the current cycle by using the current cycle prediction value, the power shaft gear characteristic value, the standard tooth pulse frequency multiplication coefficient and the frequency multiplication coefficient correction value, wherein the micropulse generation parameter represents the number of micropulses within a unit clock cycle of the free time base clock; The pulse generation parameter is used as the pulse generator input to perform a superposition operation with the free time base clock. During the superposition operation, the carry output bit of the adder corresponds to the micro-pulse of the power shaft position signal.

2. The method for improving the accuracy of the power shaft position signal according to claim 1, characterized in that: The calculating of the current cycle prediction value specifically includes: Calculate the previous valid edge period measurement value through the valid edge timestamp of the current period and its previous valid edge timestamp; The prediction error is calculated based on the previous valid edge measurement value and the prediction value of the previous cycle, and the average error of at least two cycles is calculated, and then the prediction value of the current cycle is calculated based on the average error.

3. A device for improving the accuracy of a power shaft position signal, characterized in that: It includes signal sampling unit, calculation unit and pulse generation unit, specifically: The signal sampling unit is used to complete the edge time stamp calibration of the effective edge of the power shaft in claim 1 or 2; The calculation unit is used to obtain the power shaft position pulse signal and the effective edge timestamp, and perform a prediction calculation of the current cycle prediction value according to the method provided in claim 1 or 2 to obtain the micropulse generation parameter; The pulse generating unit completes the generation of micro-pulses of the power shaft position signal according to the method provided in claim 1 or 2.

4. The device for improving the accuracy of the power shaft position signal according to claim 3, characterized in that: The signal sampling unit includes: a free time base counter, an effective edge detection subunit, a sampling control subunit and a timestamp sampling register, specifically: The free time base counter is used to count according to the free time base clock to ensure the uniformity of the precision of the micro-pulse duration period of the power shaft position signal; The effective edge detection subunit is used to detect the effective edge of the power shaft position pulse signal according to the specified effective edge form, and after detecting the effective edge, send the effective edge identification flag signal to the sampling control subunit; The sampling control subunit is used to send a sampling instruction to the timestamp sampling register after receiving the edge recognition flag signal; After receiving the sampling instruction, the timestamp sampling register captures and saves the current free time base, and uses the current free time base as the edge timestamp of the effective edge of the power axis.

5. The device for improving the accuracy of the power shaft position signal according to claim 3, characterized in that: The computing unit includes an algorithm state machine, a multiplier unit and a divider unit, specifically: The calculation unit predicts the current cycle according to the valid edge timestamps of at least two cycles through a hardware algorithm state machine; After the cycle prediction is completed, the algorithm state machine jumps to the pulse parameter calculation state, and the pulse parameter is the number of micropulses contained in the unit time of the free time base clock.

6. The device for improving the accuracy of the power shaft position signal according to claim 5, characterized in that: The prediction of the current cycle is realized according to the valid edge timestamps of at least two cycles, specifically including: Get the current valid edge timestamp and at least two previous valid edge timestamps, take the difference between two adjacent valid edge timestamps as an actual cycle, average the theoretical cycle and at least two actual cycles in the form of a geometric progression, and use the averaged cycle as the prediction of the current cycle.

7. The device for improving the accuracy of the power shaft position signal according to claim 5, characterized in that: The computing unit also includes a multiplier and divider control bus, specifically: The multiplier and divider control bus includes an operation cycle, an input enable and a feedback output enable, and the data transmitted in the multiplier and divider control bus are a multiplier and a multiplicand, a divisor and a dividend.

8. The device for improving the accuracy of the power shaft position signal according to claim 3, characterized in that: The pulse generation unit includes a full adder subunit and an intermediate result register, specifically: The full adder subunit performs a superposition operation on the pulse generation parameter when each free time base counter clock is counted according to the control of the free time base counter clock, and the output of the full adder subunit is the micro pulse of the power shaft position signal.

9. The device for improving the accuracy of the power shaft position signal according to claim 8, characterized in that: The performing a superposition operation on the pulse generation parameters specifically includes: The pulse generation parameter is superimposed on the clock of the free time base counter to generate a carry, and the pulse output by the adder carry is used as a micro pulse obtained by dividing the free time base clock according to the pulse generation parameter.

10. The device for improving the accuracy of a power shaft position signal according to claim 3, characterized in that: The pulse generating unit further includes a pulse compensating unit, specifically: The pulse compensation unit uses a high-speed clock to quickly generate micro pulses equal to the number of pulses of the missing teeth in the missing tooth cycle, so that the micro pulses match the number of teeth of the power shaft to avoid continuous errors in the power shaft position caused by acceleration of the power shaft.

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