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 TO RELATED APPLICATIONS) This application claims priority from a Chinese patent application bearing application number 202410123586.4 and entitled "Torque signal processing method, EPS sensor and storage medium" filed with the State Intellectual Property Office of the People's Republic of China on January 29, 2024, the entire contents of which are incorporated herein by reference.

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

[0003] A torque sensor in an electronic power steering (EPS) serves as a sensor element for the EPS, converting the torque of the steering shaft of the vehicle's steering wheel into a voltage signal. The EPS determines the amount of assist to be provided to the steering shaft based on this electrical signal, so the accuracy of the voltage signal detected by the torque sensor affects the accuracy of the assist provided by the electric power steering system.

[0004] Generally, the voltage signal detected by the torque sensor is converted into a pulse width modulation (PWM) signal, and the PWM signal is used to control the assist of the electric power steering system. Specifically, the initial voltage corresponding to the torque sensor is subtracted from the voltage signal detected by the torque sensor, and 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 zero.

[0005] However, in practical applications, external electromagnetic interference or structural problems can cause the torque sensor's initial voltage to be inaccurate, leading to a large error in the PWM signal, which in turn affects the assist accuracy of the electric power steering system.

[0006] It should be noted that the information disclosed in the Background of the Invention section is merely intended to enhance understanding of the general background of the invention, and should not be construed as an admission or in any way implying that the organization of said information is prior art known to those skilled in the art. Summary of the Invention [Problem 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 in the PWM signal in the prior art. [Means for solving the problem]

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

[0009] In one possible embodiment, determining a duty ratio of a first PWM signal based on a first torque signal collected by the first torque sensor includes determining a duty ratio of the first PWM signal based on a first voltage collected by the first torque sensor, an average initial voltage, and a conversion coefficient; determining a duty ratio of a second PWM signal based on a second torque signal collected by the second torque sensor includes determining a duty ratio 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, and the first initial voltage and the second initial voltage are 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 so that a first theoretical torque value detected by the first torque sensor and a second theoretical torque value detected by the second torque sensor have the same magnitude and opposite directions.

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

[0012] In one possible embodiment, determining the duty ratio of the first PWM signal based on the first voltage collected by the first torque sensor, the average initial voltage, and a conversion coefficient is performed by the formula T1′=X+K(V A -(V A0 +V B0) / 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 a first voltage collected by the first torque sensor, and V A0 is the first initial voltage, and V B0 is the second initial voltage, Determining a duty ratio of a second PWM signal based on the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient is performed by the formula T2′=XK((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 a second voltage collected by the second torque sensor, and V A0 is the first initial voltage, and V B0 is the second initial voltage.

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

[0014] In one possible embodiment, the torque signal processing method further comprises: Identifying a first standard duty ratio based on the formula T1″=Y+(T1′−T2′) / 2, wherein T1″ is the first standard duty ratio; determining a 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, Y is 50%.

[0016] In one possible embodiment, before determining 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: Sampling a first voltage analog signal output by a first torque sensor to obtain a first voltage collected by the first torque sensor; Sampling a second voltage analog signal output by a second torque sensor to obtain a second voltage collected by the second torque sensor.

[0017] In one possible embodiment, the torque signal processing method further comprises: 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 torque is zero.

[0018] In a second aspect, embodiments of the present application provide an EPS sensor, the EPS sensor comprising: a first torque sensor; a second torque sensor; and a controller configured to perform the torque signal processing method of any one of the first aspects.

[0019] In a third aspect, an embodiment of the present application provides a computer-readable storage medium having a program stored therein, the program, when executed, controlling a device in 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 a fourth aspect, the present invention provides a vehicle including the EPS sensor according to the second aspect. [Effects of the Invention]

[0021] In this technical solution, when the torque is 0, 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 a conversion coefficient. According to the technical solution of the embodiment of the present application, when the average initial voltage is used as the initial voltage and the torque detected by one torque sensor deviates significantly from the theoretical value and the torque detected by the other torque sensor deviates slightly from the theoretical value, the deviations between the torque sensors can be equalized, compared with the theoretical value, and then averaged for distribution adjustment, thereby effectively improving the accuracy of the duty ratios of the PWM signals actually output by the sensors.

[0022] In order to more clearly explain the technical solutions in the embodiments of the present application, the following briefly introduces drawings required for use in the embodiments. Obviously, the drawings described below are only some of the embodiments of the present application, and those skilled in the art can obtain other drawings from these drawings without any creative efforts. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram of an application scene of EPS according to related technology. [Figure 2] 1 is a schematic structural diagram of an EPS sensor according to an embodiment of the present invention. [Figure 3] 1 is a schematic flowchart of a torque signal processing method according to an embodiment of the present invention. [Figure 4] 10 is a schematic flowchart of another torque signal processing method according to an embodiment of the present invention. [Figure 5] 1 is a schematic structural diagram of an EPS sensor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] In order to better understand the technical solution of the present application, the following detailed description of the embodiments of the present application will be given with reference to the accompanying drawings.

[0025] It is clear that the described embodiments are only a part of the embodiments of the present application, and do not represent all of the embodiments. Based on the embodiments of the present application, a person skilled in the art can obtain other embodiments without any creative effort, and all of these embodiments shall fall within the scope of protection of the present application.

[0026] The terms used in the examples are for the purpose of describing particular examples only and are not intended to limit the present application. As used in the examples and the appended claims, the singular forms "a," "an," "the," "said," and "the" are intended to include the plural forms unless the context clearly dictates otherwise.

[0027] The term "and / or" used in this specification is merely a relational relationship that describes related objects, and indicates that three relationships may exist. For example, A and / or B can indicate three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this text generally indicates that the related objects before and after it are in an "or" relationship.

[0028] An electric power steering system (EPS) is a power steering system that provides assist torque directly by relying on a motor. During actual vehicle use, the EPS receives the steering wheel torque and steering wheel angle applied by the driver from various sensors, calculates the 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 EPS aims to help the driver overcome the steering resistance torque and achieve vehicle steering.

[0029] For ease of understanding, the following detailed description will be given with reference to the drawings and specific examples.

[0030] Fig. 1 is a schematic diagram of an application scene of an EPS according to related art. As shown in Fig. 1, the application scene includes a steering wheel 101, an electronic power steering system 102, a steering shaft 103, a rack-and-pinion steering 104, and tires 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 FIG. 1, a steering wheel 101 controls the steering of tires 105 via a steering shaft 103 and a rack and pinion steering 104, an EPS sensor 1022 collects torque on the steering shaft 103, an ECU 1021 outputs a power assist motor control command corresponding to the torque signal received based on the torque signal, and a power assist motor 1023 assists a gear reduction mechanism 1024 to apply an assist torque to the steering shaft 103, thereby assisting the rotation of the steering shaft 103.

[0032] In actual application, when a driver turns 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 collected by the EPS sensor 1022 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, which further assists the rotation of the steering shaft 103, and finally drives the gear rack steering 104 to control the steering of the tires 105.

[0033] 1 is merely an exemplary description of an application scenario in an embodiment of the present application, and does not limit the scope of protection of the present application. It should be understood that the EPS sensor 1022 is merely an exemplary 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 the present application is not specifically limited to the type of sensor.

[0034] Fig. 2 is a schematic structural diagram of an EPS sensor according to an embodiment of the present invention. As shown in Fig. 2, in this embodiment, the EPS sensor includes a first torque sensor 201, a second torque sensor 202, and a controller 203, which are mounted on a circuit board 204. The first torque sensor 201 and the second torque sensor 202 are symmetrically mounted 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 but 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, and 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] That is, 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 is A increases according to a preset gradient, and the second voltage V collected by the second torque sensor 202 B decreases according to the same gradient, i.e., V A -2.5=2.5-V Band 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 decreases according to a preset gradient, and the second voltage V collected by the second torque sensor 202 B increases according to the same slope, i.e., 2.5-V A =V B -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 | is satisfied. After the EPS sensor converts the voltage into the duty ratio of the PWM signal, the duty ratio T1 of the first PWM signal and the duty ratio 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, the present application uses a microcontroller unit (MCU) chip with relatively low specifications. 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 example shows the voltage values ​​collected by the two torque sensors and the duty ratios of the corresponding PWM signals under ideal conditions. However, in actual applications, due to hardware or structural issues with the electromagnetic torque sensor itself, it is susceptible to electromagnetic interference, resulting in large discrepancies between the voltage values ​​collected by the two torque sensors and their theoretical values. Note that these theoretical values ​​are obtained by test calibration of the torque sensors. The theoretical values ​​obtained vary depending on factors such as torque sensor model, manufacturer, and manufacturing precision. The theoretical values ​​mentioned here are calibration results that conform to international requirements established in accordance with appropriate regulations based on these different results, and do not belong to the prior art. When torque is 0, the first initial voltage detected by the first torque sensor is V. A0 and the second initial voltage detected by the second torque sensor is V B0Due to hardware or structural problems of the electromagnetic torque sensor itself, V A0 and V B0 is usually not the theoretical value of 2.5V, and V A0 and V B0 The offset amount for 2.5V is also different, that is, |V A -V A0 |≠|V B0 -V B In the related art, when the voltage value is directly converted into the PWM duty ratio, |T1-50%|≠|50%-T2|.

[0038] To solve this problem, the present embodiment provides a torque signal processing method, in which an average initial voltage is used as the initial voltage, and when the torque detected by one torque sensor has a large deviation from the theoretical value and the torque detected by the other torque sensor has a small deviation from the theoretical value, 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 ratio of the PWM signal actually output, as will be described in detail below.

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

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

[0041] Before converting the voltage analog signals, the controller must first sample the voltage signals. Specifically, the controller 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 signals collected by the torque sensors are voltage analog signals, and the controller is a microcontroller unit (MCU) chip with an AD conversion port. The AD conversion port is an analog quantity identification port that can identify voltage values ​​within a certain voltage range and convert them into corresponding digital quantity formats for use by the controller. The AD conversion port of the controller samples the voltage analog signal output by the first torque sensor to obtain the first voltage, and the AD conversion port of the controller samples the voltage analog signal output by the second torque sensor to obtain the second voltage.

[0042] When the torque is zero, the voltage collected by the first torque sensor is a first initial voltage, and the voltage collected by the second torque sensor is a second initial voltage. When converting a voltage into a PWM signal, directly subtracting the first initial voltage from the first voltage and multiplying the result by a conversion coefficient may result in a large error between the duty ratio of the resulting PWM signal and its theoretical value. To avoid this problem, in this embodiment, the first initial voltage and the second initial voltage are averaged to obtain an average initial voltage. The difference between the first voltage collected by the first torque sensor and the average initial voltage is calculated to obtain a first relative voltage. The duty ratio of the first PWM signal is determined based on the first relative voltage and the conversion coefficient. The conversion coefficient is used to convert a voltage analog signal into a PWM signal.

[0043] In this embodiment, the duty ratio of the first PWM signal is calculated by the formula T1′=X+K(V A -(V A0 +V B0) / 2), where T1' is the duty cycle of the first PWM signal, X is the preset duty cycle parameter, K is a conversion coefficient, and V A is the first voltage collected by the first torque sensor, and V A0 is the first initial voltage, V B0 is the second initial voltage, where X may be 50%. Note that in the present application, since the first torque sensor and the second torque sensor are arranged symmetrically with respect to the steering shaft in physical space, 50% is set as the preset duty ratio parameter. Naturally, those skilled in the art can replace the preset duty ratio 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 present embodiment is not limited thereto.

[0044] In practical applications, the type of signal output from the torque sensor is usually a voltage analog signal. However, the voltage analog signal has poor interference resistance. Therefore, in this embodiment, after the first torque sensor and the second torque sensor output the voltage analog signals, the controller converts the voltage of the voltage analog signals into a duty ratio of a PWM signal to improve the interference resistance of the output signals.

[0045] In step S302, the duty ratio 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.

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

[0047] In the present embodiment, the formula T2′=XK((V A0 +V B0 ) / 2-V B) determines the duty ratio of the second PWM signal, where T2' is the duty ratio of the second PWM 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, and V A0 is the first initial voltage, V B0 is the second initial voltage, where X may be 50%. Of course, those skilled in the art can replace the preset duty ratio parameter X with any value, such as 30%, 60%, or 70%, according to actual needs, and the present embodiment is not limited thereto.

[0048] As will be appreciated, in order to reduce the amount of calculation in the controller, the controller may process the first voltage collected by the first torque sensor using the equation T1′=X+K(V A -(V A0 +V B0 ) / 2), i.e., if the torque is positive (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 ) / 2) to calculate T1', where the first relative voltage is positive and the torque is negative (i.e., the steering shaft is rotating counterclockwise), if the first voltage is less than 2.5V, the controller still uses this formula to calculate T1', where the first relative voltage is negative. Similarly, when processing the second voltage collected by the second torque sensor, the controller uses the formula: T2'=XK((V A0 +V B0 ) / 2-V B ), i.e., when the torque is positive (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 B) to calculate T2', 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, when the second relative voltage is a positive number.

[0049] In summary, 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 when the torque is 0, 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 a conversion coefficient. According to the technical solution of the present embodiment, when the average initial voltage is used as the initial voltage and the torque detected by one torque sensor deviates significantly from its theoretical value and the torque detected by the other torque sensor deviates slightly from its theoretical value, the offset amounts of the torque detected by the two torque sensors from their theoretical values ​​can be averaged to reduce the error in the duty ratio of the PWM signal actually output.

[0050] The controller is located in the EPS sensor, and the PWM signal output by the controller is the signal output by the EPS sensor. When the EPS sensor outputs the PWM signal to the EPS controller, problems such as signal distortion and signal interference may occur, which may result in a discrepancy between the signal received by the EPS controller and the signal output from the EPS sensor. To verify whether the signal received by the EPS controller and the signal output from the EPS sensor match, the present embodiment provides another torque signal processing method, which will be described in detail below.

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

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

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

[0054] As can be seen, in order to reduce the calculation amount of the controller, the controller uses the formula T1''=Y+(T1'-T2') / 2 when calculating the first standard duty ratio, 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 ratio is calculated using the formula T1''=Y+(T1'-T2') / 2. Similarly, when the torque is negative (i.e., the steering shaft rotates counterclockwise), the first voltage is smaller than 2.5V and the second voltage is larger than 2.5V, and the obtained T1' is smaller than T2', so the first standard duty ratio T1'' is still calculated using the formula T1''=Y+(T1'-T2') / 2, and the first standard duty ratio T1'' is smaller than Y. Similarly, when calculating the second standard duty ratio, the controller 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 obtained T1' at this time is greater than T2', and the controller uses the formula T2''=Y-(T1'-T2') / 2 to calculate the second standard duty ratio T2'', and the second standard duty ratio is less than Y at this time. 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 obtained T1' at this time is less than T2', and the controller still uses the formula T2''=Y-(T1'-T2') / 2 to calculate the second standard duty ratio T2'', and the second standard duty ratio is greater than Y at this time.

[0055] In step S401, the first standard duty ratio T1'' and the second standard duty ratio T2'' must 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 ratio T1'' and the second standard duty ratio T2'' satisfy |T1''-50%|=|50%-T2''|. If they do, it indicates that there are no problems such as signal distortion or signal interference during signal transmission, that is, the first standard duty ratio T1'' and the second standard duty ratio T2'' are reliable. If they do not, it indicates that there are problems such as signal distortion or signal interference during signal transmission, that is, the first standard duty ratio T1'' and the second standard duty ratio T2'' are unreliable. In this case, the EPS controller marks T1'' and T2'' and outputs error information. By cross-verifying the two PWM signals, the safety of the signal transmission process is verified.

[0056] By cross-validating the two PWM signals, the EPS controller receives a reliable signal, which reduces the deviation when the EPS controller applies power assist force to the steering shaft based on this signal. This means that the user will feel a smoother feel when turning the steering wheel, improving the user experience.

[0057] In practical applications, the torque sensor may fail. If a short circuit or open circuit occurs in the 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 is 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 a voltage range close to the minimum measurement range of the measurement range in which the torque sensor collects voltages, and the second voltage range is a voltage range close to the maximum measurement range of the measurement range in which the torque sensor collects voltages. In this embodiment, the measurement range in which the torque sensor collects voltages is 0 to 5 V, the first voltage range is 0 to 0.5 V, and the second voltage range is 4.5 to 5 V. If the voltage collected by the torque sensor is within the range of 0 to 0.5 V or 4.5 to 5 V, the duty ratio of the PWM signal corresponding to the voltage analog signal is 0 to 12.5% ​​or 87.5 to 100%. That is, if the duty ratio of the output PWM signal is 0-12.5% ​​or 87.5-100%, it can be determined that the torque sensor is faulty. Of course, those skilled in the art can set the fault voltage and the corresponding duty ratio to other values ​​according to actual needs, and the embodiments of the present application are not specifically limited thereto.

[0058] Because there is a one-to-one mapping relationship between the duty ratio of the PWM signal and torque, the duty ratio of the PWM signal can reflect the magnitude of the current torque. In one possible embodiment, the mapping relationship between the duty ratio of the PWM signal and torque can be represented by a table. As shown in Table 1, when the duty ratio of the first PWM signal is 87.5% and the duty ratio of the second PWM signal is 12.5%, the torque is 12 N·m; when the duty ratio of the first PWM signal is 50% and the duty ratio of the second PWM signal is 50%, the torque is 0 N·m; and when the duty ratio of the first PWM signal is 12.5% ​​and the duty ratio of the second PWM signal is 87.5%, the torque is -12 N·m. In theory, the sum of the duty ratio of the first PWM signal and the duty ratio of the second PWM signal is 100%, and the duty ratios of the two PWM signals can be verified for accuracy with each other. For example, as shown in Table 1, if the sum of the duty ratio of the first PWM signal 87.5% and the duty ratio of the second PWM signal 12.5% ​​is 100%, the first PWM signal and the second PWM signal are accurate, and if the sum of the duty ratio of the first PWM signal and the duty ratio of the second PWM signal is not equal to 100%, one or both of the first PWM signal and the second PWM signal 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 4.5 V, and the second voltage collected by the second torque sensor 202 is 0.5 V. After the first voltage is converted into a first PWM signal, the duty ratio of the first PWM signal is 87.5%, and after the second voltage is converted into a second PWM signal, the duty ratio 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 0.5 V, and the second voltage collected by the second torque sensor 202 is 4.5 V. After the first voltage is converted into a first PWM signal, the duty ratio of the first PWM signal is 12.5%, and after the second voltage is converted into a second PWM signal, the duty ratio of the second PWM signal is 87.5%.

[0061] The magnitude of the torque detected by the first torque sensor and the second torque sensor can be identified based on the correspondence relationship between the duty ratio of the PWM signal and the torque, and the duty ratio of the first PWM signal and the duty ratio of the second PWM signal.

[0062] Corresponding to the above embodiment, the present application further provides an EPS sensor.

[0063] 5 is a schematic structural diagram of an EPS sensor according to an embodiment of the present invention. As shown in FIG. 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 the first torque and outputs a first voltage analog signal.

[0065] The second torque sensor 502 acquires a 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 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, and determines the duty ratio of the second PWM signal based on the second voltage, the average initial voltage, and the conversion coefficient collected by the second torque sensor.

[0067] In one possible embodiment, as shown in FIG. 5, the controller 503 is an 8-bit MCU chip, and two AD conversion interfaces of the MCU chip perform voltage sampling on the voltage analog signals output from the two torque sensors respectively, and convert the voltage V into a first voltage V A and the second voltage V B The MCU chip receives the first voltage V A and the second voltage V B to obtain corresponding first and second PWM signals, and output the first and second duty cycles T1" and T2" to the two output terminals of the MCU chip. Of course, those skilled in the art can configure the controller as other devices according to actual needs, and the embodiments of the present application are not specifically limited thereto.

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

[0069] In the present embodiment, "at least one" refers to one or more, and "plurality" refers to two or more. "And / or" describes a relationship between related objects. For example, A and / or B indicates that three relationships can exist: A exists alone, A and B exist simultaneously, and B exists alone. However, A and B may be singular or plural. The character " / " generally indicates that the related objects before and after it are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, and c can refer to 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 algorithm step described in the embodiments disclosed herein can be realized by electronic hardware, computer software, and a combination of electronic hardware. Whether these functions are implemented by hardware or software depends on the specific application and design constraints of the technical solution. Professionals may implement the described functions using different methods for each specific application, and such implementations should be considered within the scope of this application.

[0071] For convenience and conciseness of explanation, those skilled in the art can refer to the corresponding processes in the above method examples for the specific operating processes of the above-described systems, devices and means, and the description thereof will be omitted here.

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

[0073] In this specification, the same or similar parts between the embodiments are referred to each other. In particular, the device embodiment and the terminal embodiment are basically similar to the method embodiment, so the explanation will be relatively simple, and for the relevant parts, please refer to the explanation of the method embodiment.

Claims

1. 1. A torque signal processing method, comprising: determining a duty ratio of a first PWM signal based on a first torque signal collected by a first torque sensor; determining a duty ratio of the second PWM signal based on a second torque signal collected by the second torque sensor; a duty ratio of the first PWM signal is used to represent a first torque detected by the first torque sensor, and a duty ratio of the second PWM signal is used to represent a second torque detected by the second torque sensor.

2. determining a duty ratio of a first PWM signal based on a first torque signal collected by the first torque sensor includes determining a duty ratio of the first PWM signal based on a first voltage collected by the first torque sensor, an average initial voltage, and a conversion coefficient; determining a duty ratio of a second PWM signal based on a second torque signal collected by the second torque sensor includes determining a duty ratio of a second PWM signal based on a second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient; 2. The torque signal processing method according to claim 1, wherein the average initial voltage is an 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 voltage values ​​collected by the first torque sensor and the second torque sensor, respectively, when torque is zero.

3. 2. The torque signal processing method according to claim 1, wherein the first torque sensor and the second torque sensor are arranged symmetrically so that a first theoretical torque value detected by the first torque sensor and a second theoretical torque value detected by the second torque sensor have the same magnitude but opposite directions.

4. determining a duty ratio 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 a difference between the first voltage collected by the first torque sensor and the average initial voltage to obtain a first relative voltage; and determining a duty ratio of a first PWM signal based on the first relative voltage and the conversion coefficient; 3. The torque signal processing method according to claim 2, wherein determining the duty ratio of the second PWM signal based on the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient includes: calculating a 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 ratio of the second PWM signal based on the second relative voltage and the conversion coefficient.

5. Determining a duty ratio of a first PWM signal based on a first voltage collected by the first torque sensor, an average initial voltage, and a conversion coefficient is performed using the formula T １ '=X+K(V Ａ -(V Ａ０ +V Ｂ０ determining a duty ratio of the first PWM signal based on T １ where X′ is the duty ratio of the first PWM signal, X is a preset duty ratio parameter, K is the conversion coefficient, and V Ａ is a first voltage collected by the first torque sensor, and V Ａ０ is the first initial voltage, and V Ｂ０ is the second initial voltage, Determining a duty ratio of a second PWM signal based on a second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient is performed using the formula T ２ '=X-K((V Ａ０ +V Ｂ０ ) / 2-V Ｂ determining a duty ratio of the second PWM signal based on T ２ ' is the duty ratio of the second PWM signal, X is the duty ratio parameter, K is the conversion coefficient, and V Ｂ is a second voltage collected by the second torque sensor, and V Ａ０ is the first initial voltage, and V Ｂ０ 5. The method of claim 4, wherein: is the second initial voltage.

6. 6. The method of claim 5, wherein X is 50%.

7. The torque signal processing method further comprises: Formula T １ '' = Y + (T １ '-T ２ A first standard duty ratio is determined based on T １ '' is the first standard duty ratio, and Y is a preset standard duty ratio parameter; Formula T ２ '' = Y - (T １ '-T ２ A second standard duty ratio is determined based on T ２ 2. The method of claim 1, further comprising: wherein "" is the second standard duty ratio; and Y is the standard duty ratio parameter.

8. 8. The method of claim 7, wherein Y is 50%.

9. before determining 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, sampling a first voltage analog signal output by a first torque sensor to obtain a first voltage collected by the first torque sensor; and sampling a second voltage analog signal output by a second torque sensor to obtain a second voltage collected by the second torque sensor.

10. 2. The method of 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 torque is zero.

11. An EPS sensor, a first torque sensor; a second torque sensor; and a controller configured to perform the torque signal processing method according to any one of claims 1 to 10.

12. A computer-readable storage medium on which a program is stored, A computer-readable storage medium, characterized in that, when executed, the program controls a device in which the computer-readable storage medium is located to execute the torque signal processing method described in any one of claims 1 to 10.

13. A vehicle comprising the EPS sensor of claim 11.

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