Torque signal processing method, EPS sensor and storage medium

Abstract

Provided in the embodiments of the present application are a torque signal processing method, an EPS sensor and a storage medium. The method comprises: on the basis of a first voltage collected by a first torque sensor, an average initial voltage and a conversion coefficient, determining the duty ratio of a first PWM signal; and, on the basis of a second voltage collected by a second torque sensor, the average initial voltage and the conversion coefficient, determining the duty ratio of a second PWM signal. The average initial voltage is calculated on the basis of a first initial voltage collected by the first torque sensor when torque is 0 and a second initial voltage collected by the second torque sensor when the torque is 0. The duty ratio of the first PWM signal and the duty ratio of the second PWM signal are determined on the basis of 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 an average initial voltage as an initial voltage can average the offset of torque measured by two torque sensors with respect to a theoretical value, such that errors of the duty ratios of actually output PWM signals are small.

Description

Torque signal processing method, EPS sensor and storage medium

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on January 29, 2024, with application number 202410123586.4 and application name “Torque signal processing method, EPS sensor and storage medium”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of signal processing technology, and in particular to a torque signal processing method, an EPS sensor, and a storage medium. Background Art

[0003] The torque sensor in the Electric Power Steering (EPS) system serves as the EPS's sensing element, converting the torque of the vehicle's steering wheel's steering shaft into a voltage signal. The EPS uses this electrical signal to determine the amount of power assist provided to the steering shaft. Therefore, the accuracy of the voltage signal detected by the torque sensor is closely related to the accuracy of the power assist provided by the electric power steering system.

[0004] Typically, the voltage signal detected by the torque sensor needs to be converted into a pulse width modulation (PWM) signal, which is then used to control the power steering system's steering. Specifically, the PWM signal is obtained by subtracting the initial voltage corresponding to the torque sensor from the voltage signal detected by the torque sensor. The PWM signal is then converted based on the conversion relationship between voltage and PWM signals. The initial voltage is the voltage detected by the torque sensor when the torque is zero.

[0005] However, in actual applications, due to external electromagnetic interference or its own structural problems, the initial voltage of the torque sensor is inaccurate, resulting in a large error in the PWM signal, which in turn affects the power steering accuracy of the electric power steering system.

[0006] It should be pointed out that the information disclosed in the background technology section of this application is only intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the Invention

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

[0008] In a first aspect, an embodiment of the present application provides a torque signal processing method, comprising:

[0009] determining a duty cycle of a first PWM signal according to a first torque signal acquired by a first torque sensor, wherein the duty cycle of the first PWM signal is used to represent a first torque detected by the first torque sensor;

[0010] The duty cycle of the second PWM signal is determined according to the second torque signal collected by the second torque sensor, where the duty cycle of the second PWM signal is used to represent the second torque detected by the second torque sensor.

[0011] In one possible implementation,

[0012] Determining the duty cycle of the first PWM signal according to the first torque signal acquired by the first torque sensor includes: determining the duty cycle of the first PWM signal according to the first voltage acquired by the first torque sensor, the average initial voltage, and the conversion coefficient;

[0013] Determining the duty cycle of the second PWM signal according to the second torque signal acquired by the second torque sensor includes: determining the duty cycle of the second PWM signal according to the second voltage acquired by the second torque sensor, the average initial voltage, and the conversion coefficient;

[0014] The average initial voltage is the average of a first initial voltage collected by the first torque sensor and a second initial voltage collected by the second torque sensor. 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.

[0015] In a possible implementation, the first torque sensor and the second torque sensor are symmetrically arranged, 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 are equal in magnitude and opposite in direction.

[0016] In one possible implementation,

[0017] 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 pulse width modulation signal based on the first relative voltage and the conversion coefficient;

[0018] 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 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 the second pulse width modulation signal based on the second relative voltage and the conversion coefficient.

[0019] In one possible implementation,

[0020] The method of determining the duty cycle of the first PWM signal according to the first voltage and the average initial voltage collected by the first torque sensor and the conversion coefficient includes: according to the formula: T1′=X+K(V A -(V A0 +V B0 ) / 2), determine the duty cycle of the first pulse width modulation signal, wherein T1′ is the duty cycle of the first pulse width modulation signal, X is the preset duty cycle parameter, K is the conversion coefficient, V A is the first voltage collected by the first torque sensor, V A0 is the first initial voltage, V B0 is the second initial voltage;

[0021] The step of determining the duty cycle of the second PWM signal according to the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient comprises: determining the duty cycle of the second PWM signal according to the formula: T2′=XK((V A0 +V B0 ) / 2-V B ), determine the duty cycle of the second pulse width modulation signal, wherein T2′ is the duty cycle of the second pulse width modulation signal, X is the duty cycle 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.

[0022] In a possible implementation, X is 50%.

[0023] In a possible implementation, the method further includes:

[0024] According to the formula: T1″=Y+(T1′-T2′) / 2, determine the first standard duty cycle, where T1″ is the first standard duty cycle;

[0025] According to the formula: T2″=Y-(T1′-T2′) / 2, the second standard duty cycle is determined, and T2″ is the second standard duty cycle.

[0026] In a possible implementation, Y is 50%.

[0027] In one possible implementation, before determining the duty cycle of the first PWM signal according to the first voltage and the average initial voltage collected by the first torque sensor and the conversion coefficient, the method further includes:

[0028] Sampling a first voltage analog signal output by a first torque sensor to obtain a first voltage collected by the first torque sensor;

[0029] The second voltage analog signal output by the second torque sensor is sampled to obtain a second voltage collected by the second torque sensor.

[0030] In a possible implementation, the method further includes:

[0031] An average initial voltage is determined according to 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.

[0032] In a second aspect, an embodiment of the present application provides an EPS sensor, comprising:

[0033] a first torque sensor;

[0034] a second torque sensor;

[0035] A controller, wherein the controller is configured to execute the method according to any one of the first aspects.

[0036] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored program, wherein when the program is running, the device where the computer-readable storage medium is located is controlled to execute any one of the methods described in the first aspect.

[0037] In a fourth aspect, an embodiment of the present application provides a vehicle, comprising: the EPS sensor described in the second aspect.

[0038] In this solution, an average initial voltage is calculated based on the first initial voltage detected by the first torque sensor and the second initial voltage detected by the second torque sensor when the torque is 0. The duty cycle of the first PWM signal and the duty cycle of the second PWM signal are determined based on the first voltage detected by the first torque sensor, the second voltage detected by the second torque sensor, the average initial voltage, and the conversion coefficient. By adopting the solution provided in the embodiment of this application, the initial voltage uses the average initial voltage. When the torque detected by one torque sensor deviates significantly from the theoretical value, while the torque detected by the other torque sensor deviates less from the theoretical value, the deviation between the torque sensors can be balanced and then averaged and distributed after comparison with the theoretical value, effectively improving the duty cycle accuracy of the PWM signal actually output by the sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0040] FIG1 is a schematic diagram of an application scenario of EPS provided by related art;

[0041] FIG2 is a schematic structural diagram of an EPS sensor provided in an embodiment of the present application;

[0042] FIG3 is a flow chart of a torque signal processing method provided in an embodiment of the present application;

[0043] FIG4 is a flow chart of another torque signal processing method provided in an embodiment of the present application;

[0044] FIG5 is a schematic structural diagram of an EPS sensor provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0046] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0047] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0048] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0049] Electric Power Steering (EPS) is a power steering system that directly relies on an electric motor to provide assist torque. During vehicle use, the EPS receives the steering wheel torque and steering wheel angle applied by the driver, as measured by various sensors. It calculates the assist torque and converts it into a current command for the power-assisted motor, which then controls the motor to generate the corresponding assist torque. This torque is amplified by a gear reduction mechanism and applied to the steering gear. Ultimately, it helps the driver overcome steering resistance and achieve vehicle steering.

[0050] For ease of understanding, a detailed description is given below with reference to the accompanying drawings and specific embodiments.

[0051] Figure 1 illustrates an EPS application scenario. This scenario depicts a steering wheel 101, an electronic power steering system 102, a steering shaft 103, a rack-and-pinion steering gear 104, and a tire 105. The electronic power steering system 102 specifically includes an electronic control unit (ECU) 1021, an EPS sensor 1022, a power-assisted motor 1023, and a gear reduction mechanism 1024.

[0052] As shown in Figure 1, the steering wheel 101 controls the steering of the tire 105 through the steering shaft 103 and the rack and pinion steering gear 104; the EPS sensor 1022 is used to collect the torque on the steering shaft 103; the ECU 1021 outputs the power-assisted motor control instruction corresponding to the torque signal based on the received torque signal; the power-assisted motor 1023 applies the auxiliary torque to the steering shaft 103 through the power-assisted gear reduction mechanism 1024, thereby assisting the steering shaft 103 to rotate.

[0053] In actual use, when the driver turns the steering wheel 101, the steering wheel 101 drives the steering shaft 103 to rotate. At this time, the EPS sensor 1022 transmits the torque signal collected by the steering shaft 103 to the ECU 1021. Based on the received torque signal, the ECU 1021 controls the power-assisting motor 1023 to drive the gear reduction mechanism 1024 to rotate, thereby assisting the rotation of the steering shaft 103 and ultimately driving the rack and pinion steering gear 104 to control the steering of the tires 105.

[0054] It should be noted that Figure 1 is merely an illustrative example of an application scenario involved in the embodiments of this application and should not be construed as limiting the scope of protection of this application. Furthermore, it should be understood that EPS sensor 1022 is merely an illustrative example and may also be an angle sensor or a torque angle sensor (a torque angle sensor is an integrated combination of a torque sensor and an angle sensor). This application does not specifically limit the sensor type.

[0055] See Figure 2, which is a schematic diagram of the structure of an EPS sensor provided in an embodiment of the present application. As shown in Figure 2, in this embodiment of the present application, the EPS sensor includes a first torque sensor 201, a second torque sensor 202, and a controller 203, which are arranged on a circuit board 203. The first torque sensor 201 and the second torque sensor 202 are symmetrically arranged on either side 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.

[0056] 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.

[0057] 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 (ie, the torque is positive), the first voltage V collected by the first torque sensor 201 is A According to the preset gradient increase, the second voltage V collected by the second torque sensor 202 B Following the same decreasing gradient, that is, V A -2.5=2.5-V B When the steering shaft 103 rotates counterclockwise (ie, the torque is negative), the first voltage V collected by the first torque sensor 201 A According to the preset gradient decrease, the second voltage V collected by the second torque sensor 202 BFollow the same gradient increase, that is, 2.5-V A =V B -2.5. That is, the first voltage V A and the second voltage V B Satisfaction|V A -2.5|=|2.5-V B |. After the EPS sensor converts the voltage into a PWM signal duty cycle, 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|. It should be noted that since the first torque sensor 201 and the second torque sensor 202 are symmetrically arranged, and to save costs, this application uses a lower-specification microcontroller unit (MCU) chip. Therefore, this embodiment of the application selects 2.5V as the relative value within the effective range of the torque sensor of 0.5V to 4.5V to ensure sampling accuracy.

[0058] The above embodiment shows the voltage values ​​collected by the two torque sensors and the duty cycle of the corresponding PWM signals under ideal conditions. However, in actual applications, due to hardware or structural problems of the electromagnetic torque sensor itself, it is susceptible to electromagnetic interference, resulting in a large error in the voltage values ​​collected by the two torque sensors relative to the theoretical value. It should be pointed out that the theoretical value is obtained through experimental calibration of the torque sensor. Due to differences in factors such as the model, manufacturer and manufacturing accuracy of the torque sensor, the theoretical value obtained is also different. The theoretical value mentioned in this article is a calibration result that meets international requirements determined from these different results according to appropriate rules and does not belong to the prior art. At 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 B0 , due to the hardware or structural problems of the electromagnetic torque sensor itself, V A0 and V B0 It is often not the theoretical value of 2.5V, and V A0 and V B0 The offset relative to 2.5V is also different, that is, |V A -V A0 |≠|V B0 -V B In the related art, the voltage value is directly converted into the PWM duty cycle, so |T1-50%|≠|50%-T2|.

[0059] To address this issue, an embodiment of the present application provides a torque signal processing method that uses an average initial voltage as the initial voltage. When the torque detected by one torque sensor deviates significantly from the theoretical value, while the torque detected by the other torque sensor deviates less from the theoretical value, the offsets of the torques detected by the two torque sensors relative to the theoretical value can be averaged, thereby minimizing the error in the duty cycle of the actual output PWM signal. This method is described in detail below.

[0060] Referring to Figure 3, which is a flow chart of a torque signal processing method provided in an embodiment of the present application, the method can be applied to the application scenario shown in Figure 1. As shown in Figure 3, the method mainly includes the following steps.

[0061] Step S301: determining a duty cycle of a first PWM signal according to a first voltage collected by a first torque sensor, an average initial voltage, and a conversion coefficient.

[0062] Before the controller converts the voltage analog signal, it must first sample the voltage signal. 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; the controller then 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 implementation, 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 can identify voltage values ​​within a certain voltage range and convert them into corresponding digital quantities for use by the controller. The controller's AD conversion port samples the voltage analog signal output by the first torque sensor to obtain the first voltage; the controller's AD conversion port samples the voltage analog signal output by the second torque sensor to obtain the second voltage.

[0063] 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 into a PWM signal, if the first voltage is directly subtracted from the first initial voltage and multiplied by the conversion coefficient, the duty cycle of the obtained PWM signal may be larger than the theoretical value. To avoid this problem, in an embodiment of the present application, the average of the first initial voltage and the second initial voltage is taken to obtain the average 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; based on the first relative voltage and the conversion coefficient, the duty cycle of the first PWM signal is determined. Among them, the conversion coefficient is the conversion coefficient of the voltage analog signal to the PWM signal.

[0064] In the embodiment of the present application, the formula T1′=X+K(V A -(V A0 +V B0 ) / 2) Calculate the duty cycle of the first PWM signal, where T1′ is the duty cycle of the first PWM signal, X is the preset duty cycle parameter, K is the conversion coefficient, and V A is the first voltage collected by the first torque sensor, V A0 is the first initial voltage, V B0 is the second initial voltage. Wherein, X can be 50%. It should be noted that since the first torque sensor and the second torque sensor are symmetrically arranged about the steering axis in physical space in this application, 50% is set as the preset duty cycle parameter. Of course, those skilled in the art can replace the preset duty cycle parameter X with any value according to the actual design distribution. For example, according to the relative deviation angle of its asymmetric design, X is set to 30%, 60% or 70%. The embodiments of this application do not limit this.

[0065] In actual applications, the signal type output by the torque sensor is usually a voltage analog signal. However, since the voltage analog signal has poor anti-interference ability, in an embodiment of the present application, after the first torque sensor and the second torque sensor 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 anti-interference ability of the output signal.

[0066] Step S302: determining a duty cycle of a second PWM signal according to the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient.

[0067] 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 cycle of the second PWM signal is determined according to the second relative voltage and the conversion coefficient.

[0068] In the embodiment of the present application, the formula T2′=XK((V A0 +V B0 ) / 2-V B ), determine the duty cycle of the second PWM signal, 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 is the second voltage collected by the second torque sensor, V A0 is the first initial voltage, V B0 is the second initial voltage. Wherein, X can be 50%. Of course, those skilled in the art can replace the preset duty cycle parameter X with any value according to actual needs, for example, 30%, 60% or 70%, and the embodiment of the present application does not limit this.

[0069] It can be understood that in order to reduce the amount of calculation of the controller, the controller uses the formula: T1′=X+K(V A -(V A0 +V B0 ) / 2), that is, when the torque is positive (ie 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', at this time the first relative voltage is a positive number; when the torque is negative (i.e. the steering shaft rotates counterclockwise), the first voltage is less than 2.5V, and T1' is still calculated using this formula, at this time the first relative voltage is a negative number. 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 ), that is, when the torque is positive (ie 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 ) is used to calculate T2′, at which point the second relative voltage is negative; when the torque is negative (i.e., the steering shaft rotates counterclockwise), the second voltage is greater than 2.5V, and the same formula is still used to calculate T2′, at which point the second relative voltage is positive.

[0070] 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. The duty cycle of the first PWM signal and the duty cycle of 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 solution provided in the embodiment of the present application, the average initial voltage is used as the initial voltage. When the torque detected by one torque sensor deviates significantly from the theoretical value, while the torque detected by the other torque sensor deviates less from the theoretical value, the offsets of the torques detected by the two torque sensors relative to the theoretical value can be averaged, thereby minimizing the error in the duty cycle of the actual output PWM signal.

[0071] The controller is located in the EPS sensor. The PWM signal output by the controller is also the signal output by the EPS sensor. The EPS sensor's transmission of the PWM signal to the EPS controller may result in signal distortion or interference, causing the signal received by the EPS controller to be inconsistent with the signal output by the EPS sensor. To verify the consistency of the signal received by the EPS controller with the signal output by the EPS sensor, an alternative torque signal processing method is provided in embodiments of the present application, which is described in detail below.

[0072] Referring to Figure 4 , which is a flow chart of another torque signal processing method provided in an embodiment of the present application, as shown in Figure 4 , the method further includes the following steps based on the embodiment shown in Figure 3 .

[0073] Step S401: Determine the first standard duty cycle according to the formula: T1″=Y+(T1′-T2′) / 2; determine the second standard duty cycle according to the formula: T2″=Y-(T1′-T2′) / 2.

[0074] Specifically, the duty cycle T1′ of the first PWM signal and the duty cycle T2′ of the second PWM signal are substituted into the formula T1″=Y+(T1′-T2′) / 2 to determine the first standard duty cycle T1″; the duty cycle T1′ of the first PWM signal and the duty cycle T2′ of the second PWM signal are substituted into the formula T2″=Y-(T1′-T2′) / 2 to determine the second standard duty cycle T2″. In the embodiment of the present application, Y is 50%. Of course, those skilled in the art can replace the preset standard duty cycle parameter Y with any value according to actual needs, for example, 30%, 60% or 70%, and the embodiment of the present application is not limited to this.

[0075] It can be understood that in order to reduce the amount of calculation of the controller, the controller uses the formula T1″=Y+(T1′-T2′) / 2 when calculating the first standard duty cycle. That is to say, when the torque is positive (i.e. the steering shaft rotates clockwise), the first voltage is greater than 2.5V, and the second voltage is less than 2.5V. At this time, the obtained T1′ is greater than T2′, and the formula T1″=Y+(T1′-T2′) / 2 is used to calculate the first standard duty cycle T1″. At this time, the first standard duty cycle is greater than Y; similarly, when the torque is negative (i.e. the steering shaft rotates counterclockwise), the first voltage is less than 2.5V, and the second voltage is greater than 2.5V. At this time, the obtained T1′ is less than T2′. The formula T1″=Y+(T1′-T2′) / 2 is still used to calculate the first standard duty cycle T1″. At this time, the first standard duty cycle is greater than Y. The quasi-duty cycle is less than Y. Similarly, the controller uses the formula T2″=Y-(T1′-T2′) / 2 when calculating the second standard duty cycle. That is to say, when the torque is positive (i.e. the steering shaft rotates clockwise), the first voltage is greater than 2.5V, and the second voltage is less than 2.5V. At this time, the obtained T1′ is greater than T2′, and the formula T2″=Y-(T1′-T2′) / 2 is used to calculate the second standard duty cycle T2″. At this time, the second standard duty cycle is less than Y; similarly, when the torque is negative (i.e. the steering shaft rotates counterclockwise), the first voltage is less than 2.5V, and the second voltage is greater than 2.5V. At this time, the obtained T1′ is less than T2′, and the formula T2″=Y-(T1′-T2′) / 2 is still used to calculate the second standard duty cycle T2″. At this time, the second standard duty cycle is greater than Y.

[0076] Through step S401, the first standard duty cycle T1″ and the second standard duty cycle T2″ must satisfy |T1″-50%|=|50%-T2″|. After the EPS controller receives the PWM signal output by the EPS sensor, it will first verify whether the first standard duty cycle T1″ and the second standard duty cycle T2″ satisfy |T1″-50%|=|50%-T2″|. If satisfied, it means that there are no problems such as signal distortion or signal interference during the signal transmission process, that is, the first standard duty cycle T1″ and the second standard duty cycle T2″ are reliable; if not satisfied, it means that there are problems such as signal distortion or signal interference during the signal transmission process, that is, the first standard duty cycle T1″ and the second standard duty cycle T2″ are unreliable, then the EPS controller will mark T1″ and T2″ and output an error message. Through the mutual verification of the two PWM signals, the security of the signal transmission process is verified.

[0077] By mutual verification of the two PWM signals, the EPS controller receives a reliable signal, so that the EPS controller has a smaller deviation when providing power assistance to the steering shaft according to the signal. In other words, the user feels smooth when turning the steering wheel, improving the user experience.

[0078] In practical applications, a torque sensor may malfunction. When a short circuit or open circuit occurs in the torque sensor, the voltage collected by the faulty torque sensor cannot be used as input voltage. In one possible implementation, a torque sensor fault is determined when the voltage collected by the torque sensor falls within a first voltage range or a second voltage range. The first voltage range is the voltage range close to the minimum range of the torque sensor's collected voltage, and the second voltage range is the voltage range close to the maximum range of the torque sensor's collected voltage. In this embodiment of the present application, the torque sensor collects voltage within a range of 0 to 5V, with the first voltage range being 0 to 0.5V and the second voltage range being 4.5 to 5V. When the voltage collected by the torque sensor is within the range of 0 to 0.5V or 4.5 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, a torque sensor fault is determined when the duty cycle of the output PWM signal is 0 to 12.5% ​​or 87.5% to 100%. Of course, those skilled in the art may set the fault voltage and the corresponding duty cycle to other values ​​according to actual needs, and the embodiments of the present application do not impose specific limitations on this.

[0079] Because there's a one-to-one mapping between the duty cycle of a PWM signal and torque, the duty cycle of a PWM signal can reflect the current torque. In one possible implementation, the mapping 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; and 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%, allowing the duty cycles of the two PWM signals to be used to verify each other's accuracy. For example, as shown in Table 1, if the sum of the duty cycle of the first PWM signal (87.5%) and the duty cycle of the second PWM signal (12.5%) is 100%, then the first PWM signal and the second PWM signal are accurate. If the sum of the duty cycle of the first PWM signal and the duty cycle of the second PWM signal is not equal to 100%, then one or both of the first PWM signal and the second PWM signal are inaccurate.

[0080] Table 1:

[0081] 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 cycle of the first PWM signal is 87.5%, and after the second voltage is converted into 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 0.5 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 cycle of the first PWM signal is 12.5%, and after the second voltage is converted into a second PWM signal, the duty cycle of the second PWM signal is 87.5%.

[0082] The magnitude of the torque detected by the first torque sensor and the second torque sensor can be determined by the corresponding relationship between the duty cycle of the PWM signal and the torque and the duty cycle of the first PWM signal and the duty cycle of the second PWM signal.

[0083] Corresponding to the above embodiments, the present application also provides an EPS sensor.

[0084] 5 , which is a schematic diagram of the structure of an EPS sensor provided in an embodiment of the present application, as shown in FIG5 , the EPS sensor includes: a first torque sensor 501 , a second torque sensor 502 , and a controller 503 .

[0085] The first torque sensor 501 is used to collect a first torque and output a first voltage analog signal.

[0086] The second torque sensor 502 is used to collect a second torque and output a second voltage analog signal.

[0087] The controller 503 is used to perform voltage sampling on the first voltage analog signal and the second voltage analog signal, and determine 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 determine 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.

[0088] In a possible implementation, as shown in FIG5 , the controller 503 is an 8-bit MCU chip. The two AD conversion interfaces of the MCU chip respectively sample the voltage analog signals output by the two torque sensors to obtain the first voltage V A and the second voltage V B MCU chip to the first voltage V A and the second voltage V BProcessing is performed to obtain corresponding first PWM signals and second PWM signals, and the first duty cycle T1″ and the second duty cycle T2″ are output at the two output terminals of the MCU chip respectively. Of course, those skilled in the art can set the controller to other devices according to actual needs, and the embodiments of the present application do not impose specific restrictions on this.

[0089] In a specific implementation, the present invention further provides a computer storage medium, wherein the computer storage medium may store a program that, when executed, may include some or all of the steps of each embodiment of the simulation scenario generation method provided in the present invention. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

[0090] In the embodiments of the present application, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects 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 plural items. For example, at least one of a, b and c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0091] Those skilled in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented using a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0092] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0093] In the several embodiments provided in this application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application is essentially or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of this application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program code.

[0094] In this specification, reference can be made to the same or similar parts between the various embodiments. In particular, for the device embodiment and the terminal embodiment, since they are basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the description in the method embodiment.

Claims

1. A torque signal processing method, characterized in that: include: determining a duty cycle of a first PWM signal according to a first torque signal acquired by a first torque sensor, wherein the duty cycle of the first PWM signal is used to represent a first torque detected by the first torque sensor; The duty cycle of the second PWM signal is determined according to the second torque signal collected by the second torque sensor, where the duty cycle of the second PWM signal is used to represent the second torque detected by the second torque sensor.

2. The method according to claim 1, characterized in that Determining the duty cycle of the first PWM signal according to the first torque signal acquired by the first torque sensor includes: determining the duty cycle of the first PWM signal according to the first voltage acquired by the first torque sensor, the average initial voltage, and the conversion coefficient; Determining the duty cycle of the second PWM signal according to the second torque signal acquired by the second torque sensor includes: determining the duty cycle of the second PWM signal according to the second voltage acquired by the second torque sensor, the average initial voltage, and the conversion coefficient; The average initial voltage is the average of a first initial voltage collected by the first torque sensor and a second initial voltage collected by the second torque sensor. 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.

3. The method according to claim 1, characterized in that The first torque sensor and the second torque sensor are symmetrically arranged, 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 are equal in magnitude and opposite in direction.

4. The method according to claim 2, characterized in that 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. 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 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 the second PWM signal based on the second relative voltage and the conversion coefficient.

5. The method according to claim 4, characterized in that The method of determining the duty cycle of the first PWM signal according to the first voltage and the average initial voltage collected by the first torque sensor and the conversion coefficient includes: according to the formula: T1′=X+K(V A -(V A0 +V B0 ) / 2), determine the duty cycle of the first PWM signal, where T1′ is the duty cycle of the first PWM signal, X is the preset duty cycle parameter, K is the conversion coefficient, V A is the first voltage collected by the first torque sensor, V A0 is the first initial voltage, V B0 is the second initial voltage; The step of determining the duty cycle of the second PWM signal according to the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient comprises: determining the duty cycle of the second PWM signal according to the formula: T2′=XK((V A0 +V B0 ) / 2-V B ), determine the duty cycle of the second PWM signal, 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 is the second voltage collected by the second torque sensor, V A0 is the first initial voltage, V B0 is the second initial voltage.

6. The method according to claim 5, characterized in that The X is 50%.

7. The method according to claim 1, characterized in that The method further comprises: Determine a first standard duty cycle according to the formula: T1″=Y+(T1′-T2′) / 2, where T1″ is the first standard duty cycle and Y is a preset standard duty cycle parameter; The second standard duty cycle is determined according to the formula: T2″=Y-(T1′-T2′) / 2, where T2″ is the second standard duty cycle and Y is the standard duty cycle parameter.

8. The method according to claim 7, characterized in that The Y is 50%.

9. The method according to claim 2, characterized in that Before determining the duty cycle of the first PWM signal according to the first voltage and the average initial voltage collected by the first torque sensor and the conversion coefficient, the 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; The second voltage analog signal output by the second torque sensor is sampled to obtain a second voltage collected by the second torque sensor.

10. The method according to claim 1, characterized in that The method further comprises: An average initial voltage is determined according to 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.

11. An EPS sensor, characterized in that: include: a first torque sensor; a second torque sensor; A controller configured to execute the method according to any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 10.

13. A vehicle, characterized in that: include: The EPS sensor according to claim 11.

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