Torque signal processing method, eps sensor and storage medium

Abstract

The embodiment of the application provides a torque signal processing method, an EPS sensor and a storage medium, and the method comprises the following steps: determining the 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; determining the duty cycle of a second PWM signal according to a second voltage collected by a second torque sensor, the average initial voltage and the conversion coefficient. The average initial voltage is calculated 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, and the duty cycle of the first PWM signal and the duty cycle of the second PWM signal are determined according to 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. The initial voltage adopts the average initial voltage, so that the offset of the torque detected by the two torque sensors relative to the theoretical value is averaged, and thus the error of the duty cycle of the actually output PWM signal is small.

Description

Technical Field

[0001] This application relates to the field of signal processing technology, specifically to a torque signal processing method, an EPS sensor, and a storage medium. Background Technology

[0002] In an electric power steering (EPS) system, the torque sensor serves as the sensing element, converting the torque of the vehicle's steering wheel shaft into a voltage signal. The EPS determines the amount of assistance provided to the steering shaft based on this electrical signal. Therefore, the accuracy of the voltage signal detected by the torque sensor is closely related to the accuracy of the electric power steering system's assistance.

[0003] 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 electric power steering system. Specifically, the initial voltage corresponding to the torque sensor can be subtracted from the voltage signal detected by the torque sensor, and the PWM signal can be obtained 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 0.

[0004] However, in practical applications, due to external electromagnetic interference or 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 accuracy of the electric power steering system.

[0005] It should be noted that the information disclosed in the background section of this application is intended only to enhance the understanding of the general background of this application, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] In view of this, this application provides a torque signal processing method, an EPS sensor, and a storage medium to help solve the problem of large errors in PWM signals in the prior art.

[0007] In a first aspect, embodiments of this application provide a torque signal processing method, including:

[0008] Based on the first torque signal collected by the first torque sensor, the duty cycle of the first PWM signal is determined, and the duty cycle of the first PWM signal is used to characterize the first torque detected by the first torque sensor.

[0009] Based on the second torque signal acquired by the second torque sensor, the duty cycle of the second PWM signal is determined. The duty cycle of the second PWM signal is used to characterize the second torque detected by the second torque sensor.

[0010] In one possible implementation,

[0011] The step of determining the duty cycle of the first PWM signal based on the first torque signal acquired by the first torque sensor includes: determining the duty cycle of the first PWM signal based on the first voltage and average initial voltage acquired by the first torque sensor and the conversion coefficient.

[0012] The step of determining the duty cycle of the second PWM signal based on the second torque signal acquired by the second torque sensor includes: determining the duty cycle of the second PWM signal based on the second voltage acquired by the second torque sensor, the average initial voltage, and the conversion coefficient.

[0013] The average initial voltage is the average of the first initial voltage collected by the first torque sensor and the 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 when the torque is 0, respectively.

[0014] In one possible implementation, the first torque sensor and the second torque sensor are symmetrically arranged such that the theoretical value of the first torque detected by the first torque sensor is equal in magnitude and opposite in direction to the theoretical value of the second torque detected by the second torque sensor.

[0015] In one possible implementation,

[0016] The step of determining the duty cycle of the first PWM signal based on the first voltage and average initial voltage collected by the first torque sensor 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.

[0017] The step of determining the duty cycle of the second PWM signal based on the second voltage acquired by the second torque sensor, the average initial voltage, and the conversion coefficient includes: calculating the difference between the second voltage acquired 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.

[0018] In one possible implementation,

[0019] The step of determining the duty cycle of the first PWM signal based on the first voltage and 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, where T1′ is the duty cycle of the first pulse width modulation signal, X is the preset duty cycle parameter, K is the conversion coefficient, and V A The first voltage, V, is acquired by the first torque sensor. A0 V is the first initial voltage. B0 This is the second initial voltage;

[0020] The step of 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: according to the formula: T2′=XK((V A0 +V B0 ) / 2-V B The duty cycle of the second pulse width modulation signal is determined, where T2′ is the duty cycle of the second pulse width modulation signal, X is the duty cycle parameter, K is the conversion coefficient, and V... B The second voltage, V, is acquired by the second torque sensor. A0 V is the first initial voltage. B0 This is the second initial voltage.

[0021] In one possible implementation, X is 50%.

[0022] In one possible implementation, the method further includes:

[0023] The first standard duty cycle is determined according to the formula: T1″=Y+(T1′-T2′) / 2, where T1″ is the first standard duty cycle;

[0024] The second standard duty cycle is determined according to the formula: T2″=Y-(T1′-T2′) / 2, where T2″ is the second standard duty cycle.

[0025] In one possible implementation, Y is 50%.

[0026] In one possible implementation, before determining the duty cycle of the first PWM signal based on the first voltage and average initial voltage acquired by the first torque sensor and the conversion coefficient, the method further includes:

[0027] The first voltage analog signal output by the first torque sensor is sampled to obtain the first voltage collected by the first torque sensor; the second voltage analog signal output by the second torque sensor is sampled to obtain the second voltage collected by the second torque sensor.

[0028] In one possible implementation, the method further includes:

[0029] The average initial voltage is determined 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.

[0030] Secondly, embodiments of this application provide an EPS sensor, comprising:

[0031] First torque sensor;

[0032] Second torque sensor;

[0033] A controller configured to perform the method described in any of the first aspects.

[0034] Thirdly, embodiments of this application provide a computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform the method described in any one of the first aspects.

[0035] Fourthly, embodiments of this application provide a vehicle including the EPS sensor described in the second aspect.

[0036] In this scheme, 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 then determined based on the first voltage collected by the first torque sensor, the second voltage collected by the second torque sensor, the average initial voltage, and the conversion coefficient. Using the scheme provided in this application embodiment, the average initial voltage is adopted. When the torque detected by one torque sensor deviates significantly from the theoretical value, while the torque detected by another torque sensor deviates less significantly from the theoretical value, the deviations generated between the torque sensors can be balanced. After comparison with the theoretical value, the deviations are averaged and adjusted, effectively improving the duty cycle accuracy of the PWM signal actually output by the sensors. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 A schematic diagram illustrating an application scenario of EPS for related technologies;

[0039] Figure 2 This is a schematic diagram of the structure of an EPS sensor provided in an embodiment of this application;

[0040] Figure 3 A schematic flowchart illustrating a torque signal processing method provided in an embodiment of this application;

[0041] Figure 4 A schematic flowchart illustrating another torque signal processing method provided in an embodiment of this application;

[0042] Figure 5 This is a schematic diagram of the structure of an EPS sensor provided in an embodiment of this application. Detailed Implementation

[0043] To better understand the technical solution of this application, the embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0044] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0045] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0046] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0047] Electric Power Steering (EPS) is a power steering system that directly relies on an electric motor to provide auxiliary torque. During actual vehicle use, EPS receives data from various sensors on the steering wheel torque and angle applied by the driver, calculates the assist torque, and converts it into a current command for the assist motor. This command then controls the assist motor to generate the corresponding assist torque. This assist torque is amplified by a gear reduction mechanism and applied to the steering gear. Ultimately, this assists the driver in overcoming steering resistance torque, thus enabling the vehicle to be steered.

[0048] For ease of understanding, a detailed description is provided below with reference to the accompanying drawings and specific embodiments.

[0049] See Figure 1 This is a schematic diagram illustrating an application scenario of EPS (Expanded Power Supply) for related technologies. For example... Figure 1 As shown, in this application scenario, 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 are illustrated. Specifically, the electronic power steering system 102 includes an electronic control unit (ECU) 1021, an EPS sensor 1022, a power steering motor 1023, and a gear reduction mechanism 1024.

[0050] like Figure 1 As shown, the steering wheel 101 controls the steering of the tires 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 assist motor control command corresponding to the received torque signal according to the received torque signal; the power assist motor 1023 applies auxiliary torque to the steering shaft 103 through the power assist gear reduction mechanism 1024 to assist the steering shaft 103 in rotating.

[0051] In practical applications, 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 collected torque signal of the steering shaft 103 rotation to the ECU 1021. The ECU 1021 controls the power steering motor 1023 to drive the gear reduction mechanism 1024 to rotate based on the received torque signal, thereby assisting the steering shaft 103 to rotate, and finally driving the rack and pinion steering gear 104 to control the steering of the tires 105.

[0052] It should be pointed out that, Figure 1This is merely an illustrative description of an application scenario involved in the embodiments of this application, and should not be construed as a limitation on the scope of protection of this application. Furthermore, it is understood that the EPS sensor 1022 is only an exemplary description, and could also be an angle sensor or a torque angle sensor (the torque angle sensor is an integration of a torque sensor and an angle sensor). This application does not specifically limit the type of sensor.

[0053] See Figure 2 This is a schematic diagram of the structure of an EPS sensor provided in an embodiment of this application. Figure 2 As shown in the embodiment of this application, the EPS sensor includes a first torque sensor 201, a second torque sensor 202, and a controller 203 disposed on the circuit board 203. The first torque sensor 201 and the second torque sensor 202 are symmetrically disposed on both sides of the steering shaft 103, so that the first torque detected by the first torque sensor 201 and the second torque detected by the second torque sensor 202 are equal in magnitude and opposite in direction.

[0054] 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.

[0055] In other words, after the first torque sensor and the second torque sensor 202 convert the torque into a voltage signal, when the steering shaft 103 rotates clockwise (i.e., the torque is positive), the first voltage V collected by the first torque sensor 201... A The second voltage V collected by the second torque sensor 202 increases according to a preset gradient. B Following the same gradient decrease, that is, V A -2.5 = 2.5 - V B When the steering shaft 103 rotates counterclockwise (i.e., the torque is negative), the first voltage V collected by the first torque sensor 201... A The second voltage V collected by the second torque sensor 202 decreases according to a preset gradient. B Following the same gradient increase, that is, 2.5-V A =V B -2.5. That is to say, the first voltage V A Second voltage V B Satisfy | V A -2.5|=|2.5-V BAfter the EPS sensor converts the voltage into the duty cycle of the PWM signal, the duty cycle T1 of the first PWM signal and the duty cycle T2 of the second PWM signal should satisfy |T1-50%|=|50%-T2|. 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, in this embodiment, 2.5V is selected as the relative value within the effective range of the torque sensor (0.5V~4.5V) to ensure sampling accuracy.

[0056] The above embodiment represents the ideal state, showing the voltage values ​​and corresponding PWM signal duty cycles collected by the two torque sensors. However, in practical applications, due to inherent hardware or structural issues with electromagnetic torque sensors, they are susceptible to electromagnetic interference, leading to significant errors in the voltage values ​​collected by the two torque sensors compared to the theoretical values. It should be noted that these theoretical values ​​are obtained through experimental calibration of the torque sensors. Due to differences in the model, manufacturer, and manufacturing precision of the torque sensors, the obtained theoretical values ​​will vary. The theoretical values ​​mentioned in this paper are calibration results that conform to international requirements, determined according to appropriate rules from these different results, and do not belong to existing technology. 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 aforementioned hardware or structural issues of the electromagnetic torque sensor, 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 related technologies, if the voltage value is directly converted into the PWM duty cycle, then |T1-50%|≠|50%-T2|.

[0057] To address this issue, this application provides a torque signal processing method. The initial voltage is an averaged initial voltage. When the torque detected by one torque sensor deviates significantly from the theoretical value, while the torque detected by another torque sensor deviates less significantly, the offsets of the torques detected by the two torque sensors relative to the theoretical value can be averaged, thereby reducing the error in the duty cycle of the actual output PWM signal. This will be described in detail below.

[0058] See Figure 3This is a schematic flowchart illustrating a torque signal processing method provided in an embodiment of this application. This method can be applied to... Figure 1 The application scenarios shown are as follows: Figure 3 The process mainly includes the following steps.

[0059] Step S301: 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.

[0060] Before converting the analog voltage signal, the controller needs to sample the voltage signal. Specifically, it samples the first analog voltage signal output by the first torque sensor to obtain the first voltage acquired by the first torque sensor; the controller then samples the second analog voltage signal output by the second torque sensor to obtain the second voltage acquired by the second torque sensor. In one possible implementation, the voltage signal acquired by the torque sensor is an analog voltage signal, and the controller is a microcontroller unit (MCU) chip equipped with an AD conversion port. The AD conversion port is an analog signal recognition port that can identify voltage values ​​within a certain voltage range and convert them into corresponding digital quantities for the controller's use. The controller samples the analog voltage signal output by the first torque sensor through its AD conversion port to obtain the first voltage; the controller's AD conversion port also samples the analog voltage signal output by the second torque sensor to obtain the second voltage.

[0061] When the torque is 0, the voltage collected by the first torque sensor is the first initial voltage, and the voltage collected by the second torque sensor is the second initial voltage. When converting the voltage to a PWM signal, directly subtracting the first initial voltage from the first voltage and multiplying by the conversion coefficient may result in a large error between the duty cycle of the obtained PWM signal and the theoretical value. To avoid this problem, in this embodiment, the average initial voltage is obtained by averaging the first and second initial voltages. 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; the duty cycle of the first PWM signal is determined based on the first relative voltage and the conversion coefficient. The conversion coefficient is the conversion factor for converting the voltage analog signal to the PWM signal.

[0062] In this embodiment of the application, the formula T1′=X+K(V) is used. 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 The first voltage, V, is collected by the first torque sensor. A0 The first initial voltage, VB0 The second initial voltage is defined as X, which can be 50%. It should be noted that, since the first torque sensor and the second torque sensor are physically symmetrical about the steering axis in this application, 50% is set as a 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, X can be set to 30%, 60%, or 70% according to the relative deviation angle of its asymmetrical design. This application does not limit this.

[0063] In practical 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 capability, in this embodiment, 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 the duty cycle of the PWM signal to improve the anti-interference capability of the output signal.

[0064] Step S302: 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.

[0065] Specifically, the difference between the second voltage acquired by the second torque sensor and the average initial voltage is calculated to obtain the second relative voltage; based on the second relative voltage and the conversion coefficient, the duty cycle of the second PWM signal is determined.

[0066] In this embodiment of the application, the formula T2′=XK((V A0 +V B0 ) / 2-V B The duty cycle of the second PWM signal is determined, 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 The second voltage, V, is collected by the second torque sensor. A0 The first initial voltage, V B0 The second initial voltage is defined as X, which can be 50%. Of course, those skilled in the art can replace the preset duty cycle parameter X with any value as needed, such as 30%, 60%, or 70%, and this application does not limit this.

[0067] Understandably, in order to reduce the computational load on the controller, the controller uses the formula: T1′=X+K(V) when processing the first voltage collected by the first torque sensor. A -(V A0 +V B0 ) / 2), that is, when the torque is positive (i.e., the steering shaft rotates clockwise), the first voltage is greater than 2.5V, using the formula T1′=X+K(V A -(V A0 +VB0 ) / 2) Calculate T1′, at which point the first relative voltage is positive; when the torque is negative (i.e., the steering shaft rotates counterclockwise), the first voltage is less than 2.5V, and the same formula is used to calculate T1′, at which point the first relative voltage is negative. Similarly, the controller uses the formula: T2′=XK((V A0 +V B0 ) / 2-V B In other words, when the torque is positive (i.e., the steering shaft rotates clockwise), the second voltage is less than 2.5V, using the formula T2′=XK((V A0 +V B0 ) / 2-V B 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.

[0068] In summary, 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 average initial voltage is calculated. Then, 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, the duty cycle of the first PWM signal and the duty cycle of the second PWM signal are determined. Using the scheme provided in this application embodiment, the initial voltage is 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 significantly from the theoretical value, the offsets of the torques detected by the two torque sensors relative to the theoretical value can be averaged, thereby reducing the error in the duty cycle of the actual output PWM signal.

[0069] The aforementioned controller is located within the EPS sensor. The PWM signal output by the controller is the same as the signal output by the EPS sensor. During the process of the EPS sensor outputting the PWM signal to the EPS controller, signal distortion or interference may occur, causing the signal received by the EPS controller to be inconsistent with the signal output by the EPS sensor. To verify whether the signal received by the EPS controller is consistent with the signal output by the EPS sensor, this application provides another torque signal processing method, which is described in detail below.

[0070] See Figure 4 This is a flowchart illustrating another torque signal processing method provided in an embodiment of this application. Figure 4 As shown, the method is in Figure 3 The illustrated embodiment also includes the following steps.

[0071] 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.

[0072] 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 this embodiment, 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, such as 30%, 60%, or 70%, and this embodiment does not limit this.

[0073] Understandably, to reduce the computational load on the controller, the controller uses the formula T1″=Y+(T1′-T2′) / 2 when calculating the first standard duty cycle. That is, when the torque is 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. In this case, T1′ is greater than T2′, and the first standard duty cycle T1″ is calculated using the formula T1″=Y+(T1′-T2′) / 2, meaning 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. In this case, T1′ is less than T2′, and the first standard duty cycle T1″ is still calculated using the formula T1″=Y+(T1′-T2′) / 2, meaning the first standard duty cycle is greater than Y. The standard duty cycle is less than Y. Similarly, the controller uses the formula T2″=Y-(T1′-T2′) / 2 to calculate the second standard duty cycle. That is, 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. In this case, T1′ is greater than T2′, and the formula T2″=Y-(T1′-T2′) / 2 is used to calculate the second standard duty cycle T2″. In this case, 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. In this case, T1′ is less than T2′, and the formula T2″=Y-(T1′-T2′) / 2 is still used to calculate the second standard duty cycle T2″. In this case, the second standard duty cycle is greater than Y.

[0074] Step S401 ensures that the first standard duty cycle T1″ and the second standard duty cycle T2″ satisfy |T1″-50%|=|50%-T2″|. After receiving the PWM signal from the EPS sensor, the EPS controller first verifies whether the first standard duty cycle T1″ and the second standard duty cycle T2″ satisfy |T1″-50%|=|50%-T2″|. If they satisfy this, it indicates that there is no signal distortion or interference during signal transmission, meaning the first standard duty cycle T1″ and the second standard duty cycle T2″ are reliable. If they do not satisfy this, it indicates that there is signal distortion or interference during signal transmission, meaning the first standard duty cycle T1″ and the second standard standard duty cycle T2″ are unreliable. In this case, the EPS controller will mark T1″ and T2″ and output an error message. Through the mutual verification of the two PWM signals, the safety of the signal transmission process is checked.

[0075] By verifying the two PWM signals, the EPS controller receives a reliable signal, which allows the EPS controller to provide steering assist with a smaller deviation when providing assistance to the steering shaft based on the signal. In other words, it makes the steering wheel feel smooth when the user turns it, thus improving the user experience.

[0076] In practical applications, torque sensors may malfunction. When a short circuit or open circuit fault occurs in the torque sensor, the voltage collected by the faulty torque sensor cannot be used as an input voltage. In one possible implementation, a torque sensor malfunction can be 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 closest to the minimum range of the torque sensor's collected voltage, and the second voltage range is the voltage range closest to the maximum range of the torque sensor's collected voltage. In this embodiment, the range of the torque sensor's collected voltage is 0–5V, the first voltage range is 0–0.5V, and the second voltage range is 4.5–5V. When the voltage collected by the torque sensor is within the 0–0.5V or 4.5–5V range, the duty cycle of the PWM signal corresponding to the voltage analog signal is 0–12.5% ​​or 87.5%–100%. That is, when the duty cycle of the output PWM signal is 0–12.5% ​​or 87.5%–100%, the torque sensor malfunction can be determined. Of course, those skilled in the art can set the fault voltage and the corresponding duty cycle to other values ​​according to actual needs, and the embodiments of this application do not impose specific limitations on this.

[0077] Because there is a one-to-one mapping between the duty cycle of the PWM signal and the torque, the duty cycle of the PWM signal can reflect the current torque magnitude. In one possible implementation, the mapping relationship between the duty cycle of the PWM signal and the torque can be represented by a table, as shown in Table 1. When the duty cycle of the first PWM signal is 87.5% and the duty cycle of the second PWM signal is 12.5%, the torque is 12 N·m; when the duty cycle of the first PWM signal is 50% and the duty cycle of the second PWM signal is 50%, the torque is 0 N·m; when the duty cycle of the first PWM signal is 12.5% ​​and the duty cycle of the second PWM signal is 87.5%, the torque is -12 N·m. Furthermore, theoretically, the sum of the duty cycles of the first and second PWM signals is 100%, and the duty cycles of the two PWM signals can be 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 cycles of the first PWM signal and 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.

[0078] Table 1:

[0079] 87.5％ 12.5％ 12 N·m 50％ 50％ 0N·m 12.5％ 87.5％ -12N·m

[0080] Specifically, when the torque of the steering shaft 103 is 12 N·m, the first voltage collected by the first torque sensor 201 is 4.5V, and the second voltage collected by the second torque sensor 202 is 0.5V. After converting the first voltage into a first PWM signal, the duty cycle of the first PWM signal is 87.5%, and after converting the second voltage 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 0.5V, and the second voltage collected by the second torque sensor 202 is 4.5V. After converting the first voltage into a first PWM signal, the duty cycle of the first PWM signal is 12.5%, and after converting the second voltage into a second PWM signal, the duty cycle of the second PWM signal is 87.5%.

[0081] By understanding the relationship between the duty cycle of the PWM signal and the torque, and by considering the duty cycles of the first PWM signal and the second PWM signal, the magnitude of the torque detected by the first torque sensor and the second torque sensor can be determined.

[0082] Corresponding to the above embodiments, this application also provides an EPS sensor.

[0083] See Figure 5This is a schematic diagram of the structure of an EPS sensor provided in an embodiment of this application. Figure 5 As shown, the EPS sensor includes: a first torque sensor 501, a second torque sensor 502, and a controller 503.

[0084] The first torque sensor 501 is used to acquire the first torque and output a first voltage analog signal.

[0085] The second torque sensor 502 is used to acquire the second torque and output a second voltage analog signal.

[0086] The controller 503 is used to sample 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.

[0087] In one possible implementation, such as Figure 5 As shown, the controller 503 is an 8-bit MCU chip. The two AD conversion interfaces of the MCU chip sample the voltage analog signals output by the two torque sensors to obtain the first voltage V. A Second voltage V B The MCU chip responds to the first voltage V. A Second voltage V B The signal is processed to obtain a first PWM signal and a second PWM signal, 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 configure the controller as other devices according to actual needs, and the embodiments of this application do not impose specific limitations on this.

[0088] In a specific implementation, this application embodiment also provides a computer storage medium, wherein the computer storage medium may store a program, and when the program is executed, it may include some or all of the steps of the simulation scene generation method provided in various embodiments of this application. The storage medium may be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0089] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, the simultaneous existence of A and B, or the existence of B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related 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 represent: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0090] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art 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.

[0091] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0092] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0093] The same or similar parts between the various embodiments in this specification can be referred to mutually. In particular, the device embodiments and terminal embodiments are basically similar to the method embodiments, so the description is relatively simple, and the relevant parts can be referred to the description in the method embodiments.

Claims

1. A torque signal processing method, characterized in that, include: Based on the first torque signal collected by the first torque sensor, the duty cycle of the first PWM signal is determined, and the duty cycle of the first PWM signal is used to characterize the first torque detected by the first torque sensor. Based on the second torque signal acquired by the second torque sensor, the duty cycle of the second PWM signal is determined, and the duty cycle of the second PWM signal is used to characterize the second torque detected by the second torque sensor. The step of determining the duty cycle of the first PWM signal based on the first torque signal acquired by the first torque sensor includes: determining the duty cycle of the first PWM signal based on the first voltage and average initial voltage acquired by the first torque sensor and the conversion coefficient. The step of determining the duty cycle of the second PWM signal based on the second torque signal acquired by the second torque sensor includes: determining the duty cycle of the second PWM signal based on 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 the first initial voltage collected by the first torque sensor and the 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 when the torque is 0, respectively.

2. The method according to claim 1, characterized in that, The first torque sensor and the second torque sensor are symmetrically arranged such that the theoretical value of the first torque detected by the first torque sensor is equal in magnitude and opposite in direction to the theoretical value of the second torque detected by the second torque sensor.

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

4. The method according to claim 3, characterized in that, The step of determining the duty cycle of the first PWM signal based on the first voltage and 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, and V A The first voltage, V, is acquired by the first torque sensor. A0 V is the first initial voltage. B0 This is the second initial voltage; The step of 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: using the formula: T2′=XK((V A0 +V B0 ) / 2-V B The duty cycle of the second PWM signal is determined, 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 The second voltage, V, is acquired by the second torque sensor. A0 V is the first initial voltage. B0 This is the second initial voltage.

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

6. The method according to claim 4, characterized in that, The method further includes: The first standard duty cycle is determined according to the formula: T1″=Y+(T1′-T2′) / 2, where T1″ is the first standard duty cycle and Y is the 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.

7. The method according to claim 6, characterized in that, The value of Y is 50%.

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

9. The method according to claim 1, characterized in that, The method further includes: The average initial voltage is determined 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.

10. An EPS sensor, characterized in that, include: First torque sensor; Second torque sensor; A controller configured to perform the method according to any one of claims 1 to 9.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device on which the computer-readable storage medium is located to perform the method according to any one of claims 1 to 9.

12. A vehicle, characterized in that, include: The EPS sensor according to claim 10.

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