Torque signal processing method, EPS sensor, and storage medium

Abstract

A torque signal processing method, EPS sensor, and storage medium according to an embodiment of the present invention include determining the duty ratio of a first PWM signal based on a first voltage, an average initial voltage, and a conversion coefficient collected by a first torque sensor, and determining the duty ratio of a second PWM signal based on a second voltage, an average initial voltage, and a conversion coefficient collected by a second torque sensor. When the torque is zero, an average initial voltage is calculated based on the first initial voltage collected by the first torque sensor and the second initial voltage collected by the second torque sensor, and the duty ratios of the first PWM signal and the second PWM signal are determined based on the first voltage collected by the first torque sensor, the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient. Using the average initial voltage as the initial voltage averages the offsets of the torques detected by the two torque sensors relative to the theoretical value, thereby reducing the error in the duty ratio of the PWM signal actually output.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims priority to the Chinese patent application filed with the China National Intellectual Property Administration on January 29, 2024, with application number 202410123586.4 and application title "Torque signal processing method, EPS sensor and storage medium," and all contents of said Chinese patent application are incorporated into this application by reference.

[0002] The present invention relates to the field of signal processing technology, and more particularly to a torque signal processing method, an EPS sensor, and a storage medium. [Background technology]

[0003] In an electric power steering (EPS) system, the torque sensor acts as an EPS sensor element to convert the torque of the steering shaft of the vehicle's steering wheel into a voltage signal. The EPS uses this electrical signal to determine the magnitude of the assist provided to the steering shaft; therefore, the accuracy of the voltage signal detected by the torque sensor is directly related to the accuracy of the assist provided by the electric power steering system.

[0004] Generally, it is necessary to convert the voltage signal detected by the torque sensor into a pulse width modulation (PWM) signal, and then use the PWM signal to control the assist of the electric power steering system. Specifically, the initial voltage corresponding to the torque sensor can be subtracted from the voltage signal detected by the torque sensor, and then the PWM signal can be obtained based on the conversion relationship between the voltage and the PWM signal. Here, the initial voltage is the voltage detected by the torque sensor when the torque is 0.

[0005] However, in actual applications, due to external electromagnetic interference or its own structural problems, the initial voltage of the torque sensor becomes inaccurate, the error of the PWM signal increases, and further affects the assist accuracy of the electric power steering system.

[0006] It should be noted that the information disclosed in the background art part of the present invention is only for deepening the understanding of the general background art of the present invention, and it should not be construed as an approval or any form of implication that the composition of the information is the prior art known to those skilled in the art.

Summary of the Invention

Problems to be Solved by the Invention

[0007] In view of this, the present invention provides a torque signal processing method, an EPS sensor and a storage medium to solve the problem of large error of the PWM signal in the prior art.

Means for Solving the Problems

[0008] In a first aspect, an embodiment of the present application provides a torque signal processing method, and the torque signal processing method includes: specifying the duty ratio of the first PWM signal based on the first torque signal collected by the first torque sensor; specifying the duty ratio of the second PWM signal based on the second torque signal collected by the second torque sensor, where the duty ratio of the first PWM signal is used to represent the first torque detected by the first torque sensor, and the duty ratio of the second PWM signal is used to represent the second torque detected by the second torque sensor.

[0009] In a possible embodiment, specifying the duty ratio of the first PWM signal based on the first torque signal collected by the first torque sensor includes specifying the duty ratio of the first PWM signal based on the first voltage, the average initial voltage and the conversion coefficient collected by the first torque sensor. Determining the duty cycle of a second PWM signal based on a second torque signal collected by the second torque sensor includes determining the duty cycle of a second PWM signal based on a second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient. The average initial voltage is the average value of the first initial voltage collected by the first torque sensor and the second initial voltage collected by the second torque sensor, where the first initial voltage and the second initial voltage are the voltage values ​​collected by the first torque sensor and the second torque sensor, respectively, when the torque is 0.

[0010] In one possible embodiment, the first torque sensor and the second torque sensor are arranged symmetrically such that the first theoretical torque value detected by the first torque sensor and the second theoretical torque value detected by the second torque sensor have the same magnitude and opposite directions.

[0011] In one possible embodiment, determining the duty cycle of a first PWM signal based on a first voltage collected by the first torque sensor, an average initial voltage, and a conversion coefficient includes: calculating the difference between the first voltage collected by the first torque sensor and the average initial voltage to obtain a first relative voltage; and determining the duty cycle of a first pulse width modulated signal based on the first relative voltage and a conversion coefficient. Determining the duty cycle of a second PWM signal based on a second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient includes: calculating the difference between the second voltage collected by the second torque sensor and the average initial voltage to obtain a second relative voltage; and determining the duty cycle of a second pulse width modulated signal based on the second relative voltage and the conversion coefficient.

[0012] In one possible embodiment, the duty cycle of the first PWM signal can be determined based on the first voltage collected by the first torque sensor, the average initial voltage, and the conversion coefficient, using the formula T1'=X+K(V A -(V A0 +V B0including identifying the duty ratio of the first pulse width modulation signal based on (T1') / 2, where T1' is the duty ratio of the first pulse width modulation signal, X is a preset duty ratio parameter, K is the conversion coefficient, and V A is the first voltage collected by the first torque sensor, and V A0 is the first initial voltage, and V B0 is the second initial voltage, Based on the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient, identifying the duty ratio of the second PWM signal includes identifying the duty ratio of the second pulse width modulation signal based on the formula T2' = X - K((V A0 + V B0 ) / 2 - V B ), where T2' is the duty ratio of the second pulse width modulation signal, X is the duty ratio parameter, K is the conversion coefficient, and V B is the second voltage collected by the second torque sensor, V A0 is the first initial voltage, and V B0 is the second initial voltage.

[0013] In one possible embodiment, the X is 50%.

[0014] In one possible embodiment, the torque signal processing method further includes identifying the first standard duty ratio based on the formula T1'' = Y + (T1' - T2') / 2, where T1'' is the first standard duty ratio, and identifying the second standard duty ratio based on the formula T2'' = Y - (T1' - T2') / 2, where T2'' is the second standard duty ratio.

[0015] In one possible embodiment, the Y is 50%.

[0016] In one possible embodiment, before identifying the duty ratio of the first PWM signal based on the first voltage collected by the first torque sensor, the average initial voltage, and the conversion coefficient, the torque signal processing method further includes The first voltage analog signal output by the first torque sensor is sampled to obtain the first voltage collected by the first torque sensor, This includes sampling the second voltage analog signal output by the second torque sensor to obtain the second voltage collected by the second torque sensor.

[0017] In one possible embodiment, the torque signal processing method further includes: This includes determining the average initial voltage based on a first initial voltage collected by the first torque sensor and a second initial voltage collected by the second torque sensor when the torque is 0.

[0018] In the second phase, the present embodiment provides an EPS sensor, which is, First torque sensor and, The second torque sensor, A controller configured to perform the torque signal processing method described in any one of the first paragraphs, is included.

[0019] In the third aspect, the embodiment of the present invention provides a computer-readable storage medium in which a program is stored, and when executed, the program controls the device on which the computer-readable storage medium is located to perform the torque signal processing method described in any one of the first aspects.

[0020] In the fourth phase, the embodiment of the present application provides a vehicle including the EPS sensor described in the second phase. [Effects of the Invention]

[0021] In this proposed technology, when the torque is 0, the average initial voltage is calculated based on the first initial voltage collected by the first torque sensor and the second initial voltage collected by the second torque sensor. The duty cycle of the first PWM signal and the duty cycle of the second PWM signal are then determined based on the first voltage collected by the first torque sensor, the second voltage collected by the second torque sensor, the average initial voltage, and a conversion coefficient. According to the proposed technology in this embodiment, if the average initial voltage is used as the initial voltage, and the deviation of the torque detected by one torque sensor from the theoretical value is large, and the deviation of the torque detected by the other torque sensor from the theoretical value is small, the amount of deviation occurring between the torque sensors can be equalized, compared with the theoretical value, and then averaged and adjusted for distribution. This effectively improves the accuracy of the duty cycle of the PWM signal actually output by the sensor.

[0022] To more clearly explain the technical concept in the embodiments of this application, the drawings necessary for use in the embodiments are briefly introduced below. Clearly, the drawings described below represent only a portion of the embodiments of this application, and those skilled in the art can obtain other drawings from these without any creative effort. [Brief explanation of the drawing]

[0023] [Figure 1] This is a schematic diagram illustrating application scenarios for EPS using related technologies. [Figure 2] This is a schematic diagram of the EPS sensor according to the present embodiment. [Figure 3] This is a schematic flowchart of the torque signal processing method according to the embodiment of the present invention. [Figure 4] This is a schematic flowchart of another torque signal processing method according to the present embodiment. [Figure 5] This is a schematic diagram of the EPS sensor according to the present embodiment. [Modes for carrying out the invention]

[0024] To better understand the technical proposal of this application, embodiments of this application will be described in detail below with reference to the attached drawings.

[0025] It is clear that the embodiments described are only a selection of the embodiments of this application, and not all of them. A person skilled in the art will know that all other embodiments obtained without creative effort based on the embodiments of this application fall within the scope of protection of this application.

[0026] The terms used in the embodiments of this application are for the purpose of describing specific embodiments and are not intended to limit the application. The singular forms “one,” “one kind,” “the said,” and “the said” used in the embodiments and the appended claims are intended to include the plural form unless the context clearly indicates otherwise.

[0027] As used herein, the terms "and / or" merely describe a relationship between related objects, and there may be three possible relationships. For example, A and / or B can indicate three situations: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in the text generally indicates that the preceding and following related objects are in an "or" relationship.

[0028] An electric power steering system (EPS) is a power steering system that provides assist torque by directly relying on a motor. In actual vehicle use, the EPS receives steering wheel torque and steering wheel angle applied by the driver to the steering wheel, collected by various sensors, calculates assist torque, converts it into a current command for the power assist motor, and controls the power assist motor to generate the corresponding assist torque. This assist torque is amplified by a gear reduction mechanism and then acts on the steering. Ultimately, the aim is to help the driver overcome steering resistance torque and achieve vehicle steering.

[0029] To facilitate understanding, the following will be explained in detail with reference to drawings and specific examples.

[0030] Figure 1 is a schematic diagram of an application scenario of EPS using related technologies. As shown in Figure 1, the application scenario includes a steering wheel 101, an electronic power steering system 102, a steering shaft 103, a rack and pinion steering system 104, and a tire 105. Here, the electronic power steering system 102 specifically includes an electronic control unit (ECU) 1021, an EPS sensor 1022, a power assist motor 1023, and a gear reduction mechanism 1024.

[0031] As shown in Figure 1, the steering wheel 101 controls the steering of the tires 105 via the steering shaft 103 and rack and pinion steering 104, the EPS sensor 1022 collects torque in the steering shaft 103, the ECU 1021 outputs a power assist motor control command corresponding to the torque signal based on the received torque signal, and the power assist motor 1023 assists the rotation of the steering shaft 103 by assisting the gear reduction mechanism 1024 and applying assist torque to the steering shaft 103.

[0032] In actual application, when the driver rotates the steering wheel 101, the steering wheel 101 rotates the steering shaft 103, and at this time, the EPS sensor 1022 transmits the torque signal of the rotation of the steering shaft 103 that it has collected to the ECU 1021. Based on the received torque signal, the ECU 1021 controls the power assist motor 1023 to rotate the gear reduction mechanism 1024, further assisting the rotation of the steering shaft 103, and finally drives the gear rack steering 104 to control the steering of the tires 105.

[0033] Figure 1 is merely an illustrative description of an application scenario in the embodiment of this application and does not limit the scope of protection of this application. Also, as should be understood, the EPS sensor 1022 is merely an illustrative description and may be an angle sensor or a torque angle sensor (a torque angle sensor is integrated with a torque sensor and an angle sensor), and this application is not specifically limited to the type of sensor.

[0034] Figure 2 is a schematic diagram of the EPS sensor according to an embodiment of the present invention. As shown in Figure 2, in this embodiment, the EPS sensor includes a first torque sensor 201, a second torque sensor 202, and a controller 203 provided on a circuit board 204. The first torque sensor 201 and the second torque sensor 202 are provided symmetrically on both sides of the steering shaft 103, so that the first torque detected by the first torque sensor 201 and the second torque detected by the second torque sensor 202 are equal in magnitude and opposite in direction.

[0035] When the steering shaft 103 rotates clockwise (i.e., the torque is positive), the first torque detected by the first torque sensor 201 gradually increases, and the second torque detected by the second torque sensor 202 gradually decreases. When the steering shaft 103 rotates counterclockwise (i.e., the torque is negative), the first torque detected by the first torque sensor 201 gradually decreases, and the second torque detected by the second torque sensor 202 gradually increases.

[0036] In other words, after the first torque sensor 201 and the second torque sensor 202 convert the torque into a voltage signal, when the steering shaft 103 rotates clockwise (i.e., the torque is positive), the first voltage V collected by the first torque sensor 201 A The second voltage V increases according to a preset gradient and is collected by the second torque sensor 202. B It decreases according to the same gradient, i.e., V A -2.5 = 2.5 - V BTherefore, when the steering shaft 103 rotates counterclockwise (i.e., the torque is negative), the first voltage V collected by the first torque sensor 201 is A The second voltage V decreases according to a preset gradient and is collected by the second torque sensor 202. B It increases according to the same gradient, i.e., 2.5-V A =V B It is -2.5. That is, the first voltage V A and the second voltage V B That is, |V A -2.5|=|2.5-V B The following conditions must be met: After the EPS sensor converts the voltage into the duty cycle of the PWM signal, the duty cycle T1 of the first PWM signal and the duty cycle T2 of the second PWM signal should satisfy |T1-50%|=|50%-T2|. Note that the first torque sensor 201 and the second torque sensor 202 are installed symmetrically, and in order to save costs, this invention employs a relatively low-spec microcontroller unit (MCU) chip. Therefore, in this embodiment, 2.5V is selected as a relative value within the effective measurement range of the torque sensor, which is 0.5V to 4.5V, to ensure sampling accuracy.

[0037] The above embodiment shows the voltage values ​​and corresponding PWM signal duty cycles collected by two torque sensors under ideal conditions. However, in actual applications, due to hardware or structural issues with the electromagnetic torque sensors themselves, they are susceptible to electromagnetic interference, resulting in large errors between the voltage values ​​collected by the two torque sensors and their theoretical values. It should be noted that these theoretical values ​​were obtained through test calibration of the torque sensors, and since factors such as the torque sensor model number, manufacturer, and manufacturing precision differ, the obtained theoretical values ​​also differ. The theoretical values ​​mentioned here are calibration results that conform to international requirements, defined according to appropriate rules based on these different results, and do not belong to prior art. In the case of 0 torque, the first initial voltage detected by the first torque sensor is V A0 The second initial voltage detected by the second torque sensor is V B0Therefore, due to hardware or structural problems with the electromagnetic torque sensor itself, V A0 and V B0 Normally, the theoretical value is not 2.5V, and V A0 and V B0 The offset amount relative to 2.5V is also different, namely, |V A -V A0 |≠|V B0 -V B Therefore, in related technologies, if the voltage value is directly converted to the PWM duty cycle, then |T1-50%|≠|50%-T2|.

[0038] To solve this problem, the present embodiment provides a torque signal processing method in which the average initial voltage is adopted, and when the deviation of the torque detected by one torque sensor from the theoretical value is large and the deviation of the torque detected by the other torque sensor from the theoretical value is small, the offset amounts of the torque detected by the two torque sensors from the theoretical value are averaged to reduce the error in the duty cycle of the PWM signal actually output. This will be explained in detail below.

[0039] Figure 3 is a flowchart of the torque signal processing method according to an embodiment of the present invention. As shown in Figure 3, the method mainly includes the following steps.

[0040] In step S301, the duty cycle of the first PWM signal is determined based on the first voltage, average initial voltage, and conversion coefficient collected by the first torque sensor.

[0041] The controller needs to sample the voltage signal before converting the voltage analog signal. Specifically, it samples the first voltage analog signal output by the first torque sensor to obtain the first voltage collected by the first torque sensor, and samples the second voltage analog signal output by the second torque sensor to obtain the second voltage collected by the second torque sensor. In one possible embodiment, the voltage signal collected by the torque sensor is a voltage analog signal, and the controller is a microcontroller unit (MCU) chip equipped with an AD conversion port. The AD conversion port is an analog quantity identification port that identifies voltage values ​​within a certain voltage range, converts them into a corresponding digital quantity format, and allows the controller to use them. The controller's AD conversion port samples the voltage analog signal output from the first torque sensor to obtain the first voltage, and the controller's AD conversion port samples the voltage analog signal output from the second torque sensor to obtain the second voltage.

[0042] When the torque is 0, the voltage collected by the first torque sensor is the first initial voltage, and the voltage collected by the second torque sensor is the second initial voltage. When converting the voltage to a PWM signal, directly subtracting the first initial voltage from the first voltage and multiplying by a conversion coefficient may result in a large error between the duty cycle of the resulting PWM signal and the theoretical value. To avoid this problem, in this embodiment, the average initial voltage can be obtained by averaging the first initial voltage and the second initial voltage. The difference between the first voltage collected by the first torque sensor and the average initial voltage is calculated to obtain the first relative voltage, and the duty cycle of the first PWM signal is determined based on the first relative voltage and the conversion coefficient. Here, the conversion coefficient is a conversion coefficient that converts a voltage analog signal to a PWM signal.

[0043] In this embodiment, the duty cycle of the first PWM signal is given by the formula T1' = X + K(V A -(V A0 +V B0It is calculated according to ) / 2), where T1' is the duty cycle of the first PWM signal, X is a preset duty cycle parameter, K is a conversion coefficient, and V A V is the first voltage collected by the first torque sensor, A0 V is the first initial voltage. B0 is the second initial voltage. Here, X may be 50%. In this application, since the first torque sensor and the second torque sensor are provided symmetrically with respect to the steering shaft in physical space, 50% is set as the preset duty cycle parameter. Naturally, a person skilled in the art can replace the preset duty cycle parameter X with any value based on the actual design distribution. For example, X may be set to 30%, 60%, or 70% based on the relative deviation angle of the asymmetric design, and the embodiments of this application are not limited thereto.

[0044] In actual applications, the type of signal output from a torque sensor is usually a voltage analog signal. However, because voltage analog signals have low interference resistance, in this embodiment, after the first and second torque sensors output voltage analog signals, the controller converts the voltage in the voltage analog signal into a duty cycle of a PWM signal to improve the interference resistance of the output signal.

[0045] In step S302, the duty cycle of the second PWM signal is determined based on the second voltage, average initial voltage, and conversion coefficient collected by the second torque sensor.

[0046] Specifically, the difference between the second voltage collected by the second torque sensor and the average initial voltage is calculated to obtain the second relative voltage, and the duty cycle of the second PWM signal is determined based on the second relative voltage and the conversion coefficient.

[0047] In the embodiment of this application, the formula T2' = XK((V A0 +V B0 ) / 2-V BThe duty cycle of the second PWM signal is determined by ), where T2' is the duty cycle of the second PWM signal, X is the duty cycle parameter, K is the conversion coefficient, and V B This is the second voltage collected by the second torque sensor, V A0 V is the first initial voltage. B0 is the second initial voltage, where X may be 50%. Naturally, those skilled in the art can replace the preset duty cycle parameter X with any value, such as 30%, 60%, or 70%, depending on their actual needs, and the embodiments of this application are not limited thereto.

[0048] To understand that reducing the computational load on the controller, the controller processes the first voltage collected by the first torque sensor using the formula T1' = X + K(V A -(V A0 +V B0 Using ) / 2), that is, when the torque is a positive number (i.e., the steering shaft rotates clockwise), the first voltage is greater than 2.5V, and the formula T1'=X+K(V A -(V A0 +V B0 T1' is calculated using () / 2), and when the first relative voltage is a positive number and the torque is a negative number (i.e., the steering shaft rotates counterclockwise), the first voltage is less than 2.5V, and T1' is still calculated using this formula, and when the first relative voltage is a negative number, the controller processes the second voltage collected by the second torque sensor using the formula: T2'=XK((V A0 +V B0 ) / 2-V B Using the formula T2' = XK((V), that is, when the torque is a positive number (i.e., the steering shaft rotates clockwise), the second voltage is less than 2.5V, and the formula T2' = XK((V A0 +V B0 ) / 2-V BT2' is calculated using the formula, and when the second relative voltage is a negative number and the torque is a negative number (i.e., the steering shaft rotates counterclockwise), the second voltage is greater than 2.5V, and T2' is still calculated using this formula, and when the second relative voltage is a positive number.

[0049] In summary, when the torque is 0, the average initial voltage is calculated based on the first initial voltage collected by the first torque sensor and the second initial voltage collected by the second torque sensor. The duty cycle of the first PWM signal and the duty cycle of the second PWM signal are then determined based on the first voltage collected by the first torque sensor, the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient. According to the technical proposal of this embodiment, if the average initial voltage is used as the initial voltage, and the deviation of the torque detected by one torque sensor from the theoretical value is large, and the deviation of the torque detected by the other torque sensor from the theoretical value is small, the offset amounts of the torque detected by the two torque sensors from the theoretical value can be averaged to reduce the error in the duty cycle of the PWM signal actually output.

[0050] The controller described above is located at the EPS sensor, and the PWM signal output by the controller is the same as the signal output by the EPS sensor. In the process of the EPS sensor outputting the PWM signal to the EPS controller, problems such as signal distortion and signal interference may occur, which may cause the signal received by the EPS controller and the signal output from the EPS sensor to not match. To verify whether the signal received by the EPS controller and the signal output from the EPS sensor match, this embodiment of the present invention provides an alternative torque signal processing method, which will be described in detail below.

[0051] Figure 4 is a schematic flowchart of another torque signal processing method according to an embodiment of the present invention. As shown in Figure 4, the method further includes the following steps, based on the embodiment shown in Figure 3.

[0052] In step S401, the first standard duty cycle is determined based on the formula T1''=Y+(T1'-T2') / 2, and the second standard duty cycle is determined based on the formula T2''=Y-(T1'-T2') / 2.

[0053] Specifically, the first standard duty cycle T1'' is determined by substituting the duty cycle T1' of the first PWM signal and the duty cycle T2' of the second PWM signal into the formula T1''=Y+(T1'-T2') / 2, and the second standard duty cycle T2'' is determined by substituting the duty cycle T1' of the first PWM signal and the duty cycle T2' of the second PWM signal into the formula T2''=Y-(T1'-T2') / 2. In the embodiment of this application, Y is 50%. Of course, those skilled in the art can replace the preset standard duty cycle parameter Y with any value, for example, 30%, 60%, or 70%, according to their actual needs, and the embodiment of this application is not limited thereto.

[0054] To make it clear that in order to reduce the computational load on the controller, the controller uses the formula T1''=Y+(T1'-T2') / 2 when calculating the first standard duty cycle, that is, when the torque is a positive number (i.e., the steering shaft rotates clockwise), the first voltage is greater than 2.5V and the second voltage is less than 2.5V, and the resulting T1' is greater than T2', and the first standard duty cycle is calculated using the formula T1''=Y+(T1'-T2') / 2. The duty cycle T1'' is calculated, and at this time the first standard duty cycle is greater than Y. Similarly, when the torque is a negative number (i.e., the steering shaft rotates counterclockwise), the first voltage is less than 2.5V and the second voltage is greater than 2.5V, and the resulting T1' is less than T2'. The first standard duty cycle T1'' is still calculated using the formula T1''=Y+(T1'-T2') / 2, and at this time the first standard duty cycle is less than Y. Similarly, when the controller calculates the second standard duty cycle, it uses the formula T2''=Y-(T1'-T2') / 2, that is, when the torque is a positive number (i.e., the steering shaft rotates clockwise), the first voltage is greater than 2.5V and the second voltage is less than 2.5V, and the resulting T1' is greater than T2', so the second standard duty cycle T2'' is calculated using the formula T2''=Y-(T1'-T2') / 2, and in this case the second standard duty cycle is less than Y. Similarly, when the torque is a negative number (i.e., the steering shaft rotates counterclockwise), the first voltage is less than 2.5V and the second voltage is greater than 2.5V, and the resulting T1' is less than T2', and the second standard duty cycle T2'' is still calculated using the formula T2''=Y-(T1'-T2') / 2, and in this case the second standard duty cycle is greater than Y.

[0055] Step S401 ensures that the first standard duty cycle T1'' and the second standard duty cycle T2'' always satisfy |T1''-50%|=|50%-T2''|. After receiving the PWM signal output from the EPS sensor, the EPS controller first verifies whether the first standard duty cycle T1'' and the second standard duty cycle T2'' satisfy |T1''-50%|=|50%-T2''|. If it does, it indicates that there are no problems such as signal distortion or signal interference during signal transmission, meaning that the first standard duty cycle T1'' and the second standard duty cycle T2'' are reliable. If it does not, it indicates that there are problems such as signal distortion or signal interference during signal transmission, meaning that the first standard duty cycle T1'' and the second standard duty cycle T2'' are unreliable. In this case, the EPS controller marks T1'' and T2'' and outputs error information. The safety of the signal transmission process is verified by cross-verification of the two PWM signals.

[0056] By cross-validating the two PWM signals, the EPS controller receives a reliable signal, reducing the deviation when the EPS controller provides power assist force to the steering shaft based on this signal. This results in a smoother feel when the user turns the steering wheel, improving the user experience.

[0057] In actual applications, torque sensors may fail. If a short circuit or open circuit occurs in a torque sensor, the voltage collected by the failed torque sensor cannot be used as the input voltage. In one possible embodiment, if the voltage collected by the torque sensor falls within a first voltage range or a second voltage range, the torque sensor can be identified as having failed. Here, the first voltage range is the voltage range closest to the minimum measurement range among the measurement ranges in which the torque sensor collects voltage, and the second voltage range is the voltage range closest to the maximum measurement range among the measurement ranges in which the torque sensor collects voltage. In this embodiment, the measurement range in which the torque sensor collects voltage is 0 to 5V, the first voltage range is 0 to 0.5V, and the second voltage range is 4.5 to 5V. When the voltage collected by the torque sensor falls within the range of 0V to 0.5V or 4.5V to 5V, the duty cycle of the PWM signal corresponding to the voltage analog signal is 0 to 12.5% ​​or 87.5% to 100%. In other words, if the duty cycle of the output PWM signal is 0-12.5% ​​or 87.5%-100%, it can be determined that the torque sensor is faulty. Naturally, those skilled in the art can set the fault voltage and corresponding duty cycle to other values ​​according to their actual needs, and the embodiments of this application are not specifically limited thereto.

[0058] Because there is a one-to-one mapping relationship between the duty cycle of a PWM signal and torque, the duty cycle of a PWM signal can reflect the magnitude of the current torque. In one possible embodiment, the mapping relationship between the duty cycle of a PWM signal and torque can be represented by a table, as shown in Table 1. When the duty cycle of the first PWM signal is 87.5% and the duty cycle of the second PWM signal is 12.5%, the torque is 12 N·m. When the duty cycle of the first PWM signal is 50% and the duty cycle of the second PWM signal is 50%, the torque is 0 N·m. When the duty cycle of the first PWM signal is 12.5% ​​and the duty cycle of the second PWM signal is 87.5%, the torque is -12 N·m. Furthermore, theoretically, the sum of the duty cycles of the first and second PWM signals is 100%, and the duty cycles of the two PWM signals can be verified for accuracy relative to each other. For example, as shown in Table 1, if the sum of the duty cycles of the first PWM signal (87.5%) and the second PWM signal (12.5%) is 100%, then the first and second PWM signals are accurate. If the sum of the duty cycles of the first and second PWM signals is not equal to 100%, then one or two of the signals from the first and second PWM signals are inaccurate.

[0059] [Table 1]

[0060] Specifically, when the torque of the steering shaft 103 is 12 N·m, the first voltage collected by the first torque sensor 201 is 4.5V, and the second voltage collected by the second torque sensor 202 is 0.5V. After converting the first voltage to a first PWM signal, the duty cycle of the first PWM signal is 87.5%, and after converting the second voltage to a second PWM signal, the duty cycle of the second PWM signal is 12.5%. Similarly, when the torque of the steering shaft 103 is -12 N·m, the first voltage collected by the first torque sensor 201 is 0.5V, and the second voltage collected by the second torque sensor 202 is 4.5V. After converting the first voltage to a first PWM signal, the duty cycle of the first PWM signal is 12.5%, and after converting the second voltage to a second PWM signal, the duty cycle of the second PWM signal is 87.5%.

[0061] The relationship between the duty cycle of the PWM signal and the torque, and the duty cycles of the first PWM signal and the second PWM signal, allow us to determine the magnitude of the torque detected by the first torque sensor and the second torque sensor.

[0062] In accordance with the above embodiments, the present application further provides an EPS sensor.

[0063] Figure 5 is a schematic diagram of the EPS sensor according to an embodiment of the present invention. As shown in Figure 5, the EPS sensor includes a first torque sensor 501, a second torque sensor 502, and a controller 503.

[0064] The first torque sensor 501 collects a first torque and outputs a first voltage analog signal.

[0065] The second torque sensor 502 collects the second torque and outputs a second voltage analog signal.

[0066] The controller 503 performs voltage sampling on the first voltage analog signal and the second voltage analog signal, determines the duty cycle of the first PWM signal based on the first voltage, average initial voltage, and conversion coefficient collected by the first torque sensor, and determines the duty cycle of the second PWM signal based on the second voltage, average initial voltage, and conversion coefficient collected by the second torque sensor.

[0067] In one possible embodiment, as shown in Figure 5, the controller 503 is an 8-bit MCU chip, and the two AD conversion interfaces of the MCU chip perform voltage sampling on the voltage analog signals output from the two torque sensors, respectively, and the first voltage V A and second voltage V B The MCU chip obtains the first voltage V A and second voltage V B The system processes the data to obtain the corresponding first and second PWM signals, which are then output to the two output terminals of the MCU chip, with a first duty cycle T1'' and a second duty cycle T2'', respectively. Naturally, those skilled in the art can configure the controller as other devices according to their actual needs, and the embodiments of this application are not specifically limited thereto.

[0068] In a specific implementation, the embodiment of the present invention further provides a computer storage medium, which may store a program, and when the program is executed, it may include some or all of the steps in each embodiment of the simulation scene generation method according to the embodiment of the present invention. The aforementioned storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), or the like.

[0069] In the embodiments of this application, "at least one" means one or more, and "multiple" means two or more. "and / or" describes the relationship between related objects; for example, A and / or B indicates that there can be three relationships: A existing alone, A and B existing together, and B existing alone. However, A and B may be singular or plural. The letter " / " generally indicates that the preceding and succeeding related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these terms, including any combination of single or plural terms. For example, at least one of a, b, and c may be a, b, c, ab, ac, bc, or abc, where a, b, and c may be singular or plural.

[0070] Those skilled in the art will recognize that each means and algorithmic step described in the embodiments disclosed herein can be implemented by electronic hardware, computer software, or a combination of electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the proposed technology. While experts in the art may implement the described functions using different methods for each specific application, such implementations should be considered within the scope of the present invention.

[0071] Those skilled in the art will find, for the convenience and brevity of explanation, that the specific operating processes of the systems, apparatus, and means described above can be found by referring to the corresponding processes in the embodiments of the above method, and will therefore be omitted here.

[0072] In some embodiments provided by this Application, any function may be implemented in the form of a software function unit and stored on a computer-readable storage medium if sold or used as an independent product. Based on this understanding, any part of the present invention that is essential to or contributes to the prior art, or any part of the present invention, may be embodied in the form of a computer software product, which is stored on a storage medium and contains several instructions for causing a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in each embodiment of this Application. The aforementioned storage mediums include various media capable of storing program code, such as USB flash drives, removable hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0073] Identical or similar parts between each embodiment in this specification are to be referenced to one another. In particular, the embodiments of the apparatus and the embodiments of the terminals are essentially the same as those of the embodiments of the method, and therefore their description is relatively simple; for relevant parts, refer to the description of the embodiments of the method.

Claims

1. A torque signal processing method, Based on the first torque signal collected by the first torque sensor, the duty cycle of the first PWM signal is determined, This includes determining the duty cycle of the second PWM signal based on the second torque signal collected by the second torque sensor, The duty cycle of the first PWM signal is used to represent the first torque detected by the first torque sensor, and the duty cycle of the second PWM signal is used to represent the second torque detected by the second torque sensor. Determining the duty cycle of a first PWM signal based on a first torque signal collected by the first torque sensor includes determining the duty cycle of a first PWM signal based on a first voltage, an average initial voltage, and a conversion coefficient collected by the first torque sensor. Determining the duty cycle of the second PWM signal based on the second torque signal collected by the second torque sensor includes determining the duty cycle of the second PWM signal based on the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient. A torque signal processing method characterized in that the average initial voltage is the average value of a first initial voltage collected by the first torque sensor and a second initial voltage collected by the second torque sensor, and the first initial voltage and the second initial voltage are the voltage values ​​collected by the first torque sensor and the second torque sensor, respectively, when the torque is 0.

2. The torque signal processing method according to claim 1, characterized in that the first torque sensor and the second torque sensor are provided symmetrically such that the first theoretical torque value detected by the first torque sensor and the second theoretical torque value detected by the second torque sensor have the same magnitude and opposite directions.

3. Determining the duty cycle of the first PWM signal based on the first voltage collected by the first torque sensor, the average initial voltage, and the conversion coefficient includes: calculating the difference between the first voltage collected by the first torque sensor and the average initial voltage to obtain a first relative voltage; and determining the duty cycle of the first PWM signal based on the first relative voltage and the conversion coefficient. The duty cycle of the second PWM signal is determined based on the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient, by the second torque sensor. The torque signal processing method according to claim 1, characterized by comprising: calculating the difference between the collected second voltage and the average initial voltage to obtain a second relative voltage; and determining the duty cycle of the second PWM signal based on the second relative voltage and the conversion coefficient.

4. The duty cycle of the first PWM signal can be determined based on the first voltage, average initial voltage, and conversion coefficient collected by the first torque sensor, as shown by equation T １ ' = X + K(V) Ａ - (V Ａ０ +V Ｂ０ This includes determining the duty cycle of the first PWM signal based on (2) and T １ ' is the duty cycle of the first PWM signal, X is a preset duty cycle parameter, K is the conversion coefficient, V Ａ V is the first voltage collected by the first torque sensor, Ａ０ V is the first initial voltage, Ｂ０ This is the second initial voltage, Based on the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient, specifying the duty ratio of the second PWM signal involves the formula T ２ ’ = X - K((V Ａ０ + V Ｂ０ ) / 2 - V Ｂ ), and includes specifying the duty ratio of the second PWM signal. T ２ ’ is the duty ratio of the second PWM signal, X is the duty ratio parameter, K is the conversion coefficient, V Ｂ is the second voltage collected by the second torque sensor, V Ａ０ is the first initial voltage, V Ｂ０ is the second initial voltage. The torque signal processing method according to claim 3 is characterized by this.

5. The torque signal processing method according to claim 4, characterized in that X is 50%.

6. The torque signal processing method further includes: Formula T １ '' = Y + (T １ '-T ２ Based on ') / 2, the first standard duty cycle is identified, T １ '' is the first standard duty cycle, and Y is a preset standard duty cycle parameter, Formula T ２ '' = Y - (T １ '-T ２ Based on ') / 2, identify the second standard duty cycle, T ２ The torque signal processing method according to claim 1, characterized in that '' is the second standard duty cycle and Y is the standard duty cycle parameter.

7. The torque signal processing method according to claim 6, characterized in that Y is 50%.

8. Before determining the duty cycle of the first PWM signal based on the first voltage, average initial voltage, and conversion coefficient collected by the first torque sensor, further, The first voltage analog signal output by the first torque sensor is sampled to obtain the first voltage collected by the first torque sensor, The torque signal processing method according to claim 1, characterized in that it includes sampling a second voltage analog signal output by a second torque sensor to obtain a second voltage collected by the second torque sensor.

9. The torque signal processing method according to claim 1, further comprising determining an average initial voltage based on a first initial voltage collected by the first torque sensor and a second initial voltage collected by the second torque sensor when the torque is zero.

10. It is an EPS sensor, First torque sensor and The second torque sensor and An EPS sensor comprising a controller configured to perform the torque signal processing method described in any one of claims 1 to 9.

11. A computer-readable storage medium in which a program is stored, The computer-readable storage medium is characterized in that, when the program is executed, it controls the device on which the computer-readable storage medium is located to execute the torque signal processing method described in any one of claims 1 to 9.

12. A vehicle characterized by including the EPS sensor described in claim 10.

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