Hall sensor fault diagnosis method, device and steering control system

Abstract

To solve the technical problems of the existing Hall sensor fault diagnosis method being relatively complex and poor reliability, the present application provides a Hall sensor fault diagnosis method, which obtains the rotor rotation frequency of a three-phase motor by creatively converting three-phase sampling current signals of the three-phase motor, and obtains the average frequency of a Hall sensor by converting three-phase Hall signals of the Hall sensor, and then obtains a first frequency difference value by subtracting the average frequency of the Hall sensor from the rotor rotation frequency of the three-phase motor, and compares the first frequency difference value with a first preset threshold to determine whether the Hall sensor has a fault. This method checks whether the Hall sensor has a fault by the difference in frequency, and the scheme is simple and easy to implement. Moreover, it can respond to various possible faults of the Hall sensor, and has high reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of Hall sensor fault diagnosis, and in particular to a Hall sensor fault diagnosis method, device and steering control system. BACKGROUND

[0002] In the field of automobiles, the application of electric power steering systems (EPS) is gradually becoming the mainstream of automobile steering system technology, especially in the field of new energy and electric drive passenger cars. EPS can provide steering assistance to the driver according to the steering torque, steering angle, vehicle speed, road conditions and other factors, making steering more relaxed and gentle, and also enabling the vehicle to have good straight-line holding ability and the ability to suppress the reaction force of bumpy roads, ensuring road feel under various driving conditions.

[0003] The EPS is generally installed on a traditional mechanical steering system, which generally includes a steering wheel, a steering column, an intermediate shaft 5, a steering gear, a pinion, a tie rod, a knuckle arm, and a steering wheel. The EPS generally includes a processor, a steering motor, a pre-drive circuit, an inverter bridge, and various sensors. Among them, the general steering motor is a three-phase motor, which generally has a Hall sensor, a current sampling circuit and other sensing devices. The Hall sensor is one of the key sensors of the EPS, which is commonly installed on the three-phase motor for measuring the rotor speed of the three-phase motor. If the Hall signal of the Hall sensor is abnormal, it will cause the motor winding to be abnormally turned on, resulting in a large current, and even burning out the motor. Therefore, it is very important to judge and protect the fault of the Hall sensor.

[0004] The prior art has mentioned a scheme of detecting the actual rotor speed of the Hall sensor under the condition of a fixed target speed of the motor input, and when the target speed and the actual speed are inconsistent, the speed consistency is achieved by compensating the motor angle. However, this method cannot determine whether the motor is abnormal or the Hall sensor is abnormal, and is not helpful for the discovery of Hall sensor faults. The prior art also mentions a fault judgment method of combining the three-phase state of the Hall signal and predicting the next time sequence state from the current state, and if they are inconsistent, it is considered that the Hall signal is abnormal. However, this method is relatively complex and has poor reliability, for example, when the Hall signal is disturbed in a certain way, the three signals change in the same direction at the same time, and the next time sequence prediction state is also met. At this time, the abnormality cannot be determined by this state. SUMMARY

[0005] Therefore, in order to solve the technical problem of the prior art that the Hall sensor fault diagnosis method is relatively complex and has poor reliability, a Hall sensor fault diagnosis method, device and steering control system are provided.

[0006] The application provides a fault diagnosis method of a Hall sensor for detecting the position of a three-phase motor.

[0007] Obtaining a three-phase sampling current signal of the three-phase motor, obtaining an induced electromotive force of the three-phase motor based on the three-phase sampling current signal, and obtaining a rotor rotation frequency of the three-phase motor according to the induced electromotive force;

[0008] Obtaining a three-phase Hall signal of the Hall sensor, and obtaining an average frequency of the Hall sensor based on the three-phase Hall signal;

[0009] Obtaining a first frequency difference value according to the rotor rotation frequency and the average frequency of the Hall sensor, comparing the first frequency difference value with a first preset threshold value, and determining that the Hall sensor has a fault when the first frequency difference value is greater than or equal to the first preset threshold value.

[0010] Further, the "obtaining a three-phase sampling current signal of the three-phase motor, obtaining an induced electromotive force of the three-phase motor based on the three-phase sampling current signal, and obtaining a rotor rotation frequency of the three-phase motor according to the induced electromotive force" specifically includes the following steps:

[0011] Obtaining a three-phase sampling current signal of the three-phase motor from a current sampling circuit;

[0012] Converting the three-phase sampling current signal into an alpha-axis current and a beta-axis current through a Clark transformation;

[0013] Obtaining an alpha-axis voltage and a beta-axis voltage according to the alpha-axis current and the beta-axis current, and obtaining an alpha-axis induced electromotive force and a beta-axis induced electromotive force through a state observer according to the alpha-axis voltage, the beta-axis voltage and a bus voltage;

[0014] Obtaining a rotor rotation speed through a digital phase-locked loop based on the alpha-axis induced electromotive force and the beta-axis induced electromotive force;

[0015] Converting the rotor rotation speed to obtain the rotor rotation frequency.

[0016] Further, the "obtaining a three-phase Hall signal of the Hall sensor, and obtaining an average frequency of the Hall sensor based on the three-phase Hall signal" specifically includes the following steps:

[0017] Obtaining a three-phase Hall signal of the Hall sensor, the three-phase Hall signal being a square wave signal, and obtaining a frequency of the three-phase Hall signal through period sampling of the three-phase Hall signal;

[0018] Obtaining the average frequency of the Hall sensor by averaging the frequency of the three-phase Hall signal.

[0019] Further comprising the following steps:

[0020] Obtaining a magnetic encoding frequency of a magnetic encoding signal of a motor position magnetic encoder;

[0021] According to the magnetic encoding frequency and the average frequency, a second frequency difference value is obtained; the second frequency difference value is compared with a second preset threshold value, and when the second frequency difference value is greater than or equal to the second preset threshold value, it is judged that the Hall sensor has a fault. By obtaining the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder, the above-mentioned first frequency difference value and a first preset threshold value fault checking method can be further checked, and the accuracy and reliability of the checking are ensured through double checking.

[0022] The second aspect of the present application provides a fault diagnosis device of a Hall sensor, the Hall sensor being used for detecting the position of a three-phase motor; the fault diagnosis device comprises:

[0023] A three-phase motor rotor frequency calculation module is used for obtaining three-phase sampling current signals of the three-phase motor, obtaining induced electromotive forces of the three-phase motor based on the three-phase sampling current signals, and obtaining a rotor rotation frequency of the three-phase motor according to the induced electromotive forces;

[0024] A Hall sensor signal frequency calculation module is used for obtaining three-phase Hall signals of the Hall sensor, and obtaining an average frequency of the Hall sensor based on the three-phase Hall signals;

[0025] A Hall sensor fault diagnosis module is used for obtaining a first frequency difference value according to the rotor rotation frequency and the average frequency of the Hall sensor; the first frequency difference value is compared with a first preset threshold value, and when the first frequency difference value is greater than or equal to the first preset threshold value, it is judged that the Hall sensor has a fault.

[0026] Further, the three-phase electronic rotor frequency calculation module comprises:

[0027] A three-phase motor sampling current signal acquisition unit is used for acquiring three-phase sampling current signals of the three-phase motor from a current sampling circuit;

[0028] An α-axis current and β-axis current conversion unit is used for converting the three-phase sampling current signals into α-axis current and β-axis current through Clark conversion;

[0029] An α-axis and β-axis induced electromotive force output unit is used for obtaining α-axis voltage and β-axis voltage according to the α-axis current and the β-axis current; and obtaining α-axis induced electromotive force and β-axis induced electromotive force through a state observer according to the α-axis voltage, the β-axis voltage and bus voltage;

[0030] a rotor speed calculation unit configured to obtain a rotor speed from the alpha-axis induced electromotive force and the beta-axis induced electromotive force via a digital phase-locked loop;

[0031] a rotor frequency calculation unit configured to obtain the rotor rotation frequency based on the rotor speed.

[0032] Further, the Hall sensor signal frequency calculation module comprises:

[0033] a Hall sensor signal acquisition unit configured to acquire three-phase Hall signals of the Hall sensor, the three-phase Hall signals being square wave signals, and obtain frequencies of the three-phase Hall signals by periodically sampling the three-phase Hall signals;

[0034] a Hall sensor average frequency acquisition unit configured to obtain an average frequency of the Hall sensor by averaging the frequencies of the three-phase Hall signals.

[0035] Further, the method further comprises a magnetic encoding frequency calculation module configured to obtain a magnetic encoding frequency of a magnetic encoding signal of a motor position magnetic encoder.

[0036] The Hall sensor abnormal fault diagnosis module is further configured to obtain a second frequency difference value according to the magnetic encoding frequency and the average frequency, compare the second frequency difference value with a second preset threshold value, and determine that the Hall sensor has a fault when the second frequency difference value is greater than or equal to the second preset threshold value. By obtaining the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder, the method of checking the fault of the first frequency difference value and the first preset threshold value can be further checked, and the accuracy and reliability of the checking can be ensured through double checking.

[0037] The third aspect of the present application provides a steering control system comprising a processor and computer readable instructions executable on the processor, wherein the computer readable instructions are configured to implement the above-mentioned fault diagnosis method when executed by the processor.

[0038] The fourth aspect of the present application provides one or more readable storage media, wherein the readable storage media store computer readable instructions, and the computer readable instructions are configured to implement the above-mentioned fault diagnosis method when executed by the processor.

[0039] The application provides a fault diagnosis method and device of a Hall sensor and a steering control system, which obtains a rotor rotation frequency of a three-phase motor through conversion of three-phase sampling current signals of the three-phase motor, and obtains an average frequency of the Hall sensor through conversion of three-phase Hall signals of the Hall sensor, compares a first frequency difference obtained by subtracting the average frequency of the Hall sensor from the rotor rotation frequency of the three-phase motor with a first preset threshold, and judges whether the Hall sensor is faulty. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0041] Figure 1 is a flow chart of the fault diagnosis method of the Hall sensor in the embodiment of the specific embodiment of the present application;

[0042] Figure 2 is a further refined flow chart of step SA in the embodiment of the specific embodiment of the present application;

[0043] Figure 3 is a further refined flow chart of step SB in the embodiment of the specific embodiment of the present application;

[0044] Figure 4 is a flow chart of the fault diagnosis method of the Hall sensor in the embodiment of the specific embodiment of the present application;

[0045] Figure 5 is a frame diagram of the fault diagnosis device of the Hall sensor in the embodiment of the specific embodiment of the present application;

[0046] Figure 6 is Figure 5 is a frame diagram of the three-phase motor rotor frequency calculation module in the embodiment;

[0047] Figure 7 is Figure 5 is a frame diagram of the Hall sensor signal frequency calculation module in the embodiment;

[0048] Figure 8 is a frame diagram of the further preferred fault diagnosis device of the Hall sensor in the embodiment of the specific embodiment of the present application;

[0049] Figure 9This is a schematic diagram of an electric power steering system provided in one embodiment of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] This embodiment provides a fault diagnosis method for Hall sensors, which can be applied in the field of Hall sensors detecting the position of three-phase motors to diagnose faults in Hall sensors. For example, it can be applied to the electric power steering system mentioned in the background art to diagnose faults in Hall sensors used to detect the position of the three-phase motor in an electric power steering system in a car. However, its application is not limited to electric power steering systems.

[0052] In one embodiment, such as Figure 1 As shown, a fault diagnosis method for a Hall sensor is provided, and the method is applied... Figure 9 Taking the electric power steering system in the example, the following steps are included:

[0053] SA, Three-phase motor rotor frequency calculation steps: Obtain the three-phase sampling current signal of the three-phase motor, obtain the induced electromotive force of the three-phase motor based on the three-phase sampling current signal, and obtain the rotor rotation frequency of the three-phase motor based on the induced electromotive force.

[0054] SB, Hall sensor signal frequency calculation steps: Obtain the three-phase Hall signal of the Hall sensor, and obtain the average frequency of the Hall sensor based on the three-phase Hall signal;

[0055] SC, Hall sensor fault diagnosis steps: A first frequency difference is obtained based on the rotor rotation frequency and the average frequency of the Hall sensor; the first frequency difference is compared with a first preset threshold. When the first frequency difference is greater than or equal to the first preset threshold, the Hall sensor is determined to be faulty. When a fault is determined, a fault position signal representing the fault is generated. This fault position signal allows for timely disconnection of the three-phase motor power supply.

[0056] Specifically, in this example, such as Figure 2 As shown, step SA specifically includes the following steps:

[0057] Please combine Figure 9For understanding, step SA1, three-phase motor sampling current signal obtaining step: obtaining three-phase sampling current signals Ia / Ib / Ic of the three-phase motor from a current sampling circuit; the three-phase motor generally outputs a driving signal through a pre-driving circuit, the driving signal is input to an inverter bridge to generate three-phase alternating current output to the three-phase motor; the current sampling circuit is arranged at the inverter bridge to sample the three-phase alternating current of the three-phase motor. Of course, it can also be arranged at the three-phase motor.

[0058] Step SA2, α-axis current and β-axis current transforming step: vector control is generally a control process as follows: through a position instruction, a vector decomposition of a current instruction is realized to realize that the three-phase motor is changed into two-phase current for control. Specifically, through a position instruction, a speed instruction is generated, through the speed instruction, a torque instruction is generated, through the torque instruction, a current instruction is generated, through the current instruction, a voltage instruction is generated, and finally through the voltage instruction, a control voltage for driving the three-phase motor to act is output. In this example, through the current instruction, the three-phase sampling current signal is transformed into an α-axis current I α and a β-axis current I β through Clark transformation; the α-axis and the β-axis are known to the public, and the motor is now commonly used for vector control to make the motor achieve maximum torque. By controlling the voltage and phase of the motor, the magnetic flux and the current phase are adjusted to achieve maximum torque, which is actually realized by coordinate transformation to convert the three-phase fixed coordinate system UVW into the 2-phase rotating coordinate system 2-phase fixed coordinate.

[0059] Step SA3, α-axis and β-axis induced electromotive force outputting step: in this example, according to the α-axis current I α and the β-axis current I β , the α-axis voltage u α and the β-axis voltage u β are obtained through the voltage instruction; the α-axis induced electromotive force e α and the β-axis induced electromotive force are obtained through a state observer according to the α-axis voltage u α , the β-axis voltage u β and a bus voltage; the state observer is known to the public, which is a kind of dynamic system that obtains the estimated value of the state variable according to the measured value of the external variable (input variable and output variable) of the system, also known as state reconstructor. The α-axis induced electromotive force e α and the β-axis induced electromotive force e β obtained through the state observer are known to those skilled in the art, and the application only applies them here as an intermediate link, and will not be described again. The bus voltage is obtained as known to the public, which is generally obtained by sampling and calculating through the above-mentioned current sampling circuit.

[0060] Step SA4, rotor speed calculating step: the α-axis induced electromotive force e αand the β-axis induced electromotive force e β The rotor speed is obtained through a digital phase-locked loop; the α-axis induced electromotive force e α and the β-axis induced electromotive force e β After that, the position angle of the rotor can be expressed by the following formula:

[0061]

[0062] where Θ r is the position angle, ω r is the angular velocity, and the above position angle is obtained through a digital phase-locked loop, and ω r is adjusted to keep its input as 0, i.e., the rotor speed ω r .

[0063] Step SA5, rotor rotation frequency calculation step: based on the rotor speed, the rotor rotation frequency is converted.

[0064] The relationship between the motor rotor speed and the frequency is expressed by the following formula:

[0065] In the formula, n is the motor speed, f is the power frequency, and p is the pole pair number of the motor rotating magnetic field. In this example, p=3 or 4.

[0066] In this example, as shown in FIG. 2, step SB specifically includes the following steps: Figure 3

[0067] Step SB1, Hall sensor signal acquisition step: acquiring the three-phase Hall signals HALL_A / HALL_B / HALL_C of the Hall sensor, the three-phase Hall signals being square wave signals, and obtaining the frequencies of the three-phase Hall signals by periodically sampling the three-phase Hall signals HALL_A / HALL_B / HALL_C; generally, the three-phase Hall signals HALL_A / HALL_B / HALL_C are periodically sampled by a timer arranged in the processor, for example, the sampling frequency is set to be greater than the frequency of the Hall signals, and the rising edge sampling is set, so that the three-phase Hall signals HALL_A / HALL_B / HALL_C can be sampled, and three frequencies of the three-phase Hall signals are obtained.

[0068] Step SB2, Hall sensor average frequency acquisition step: averaging the frequencies of the three-phase Hall signals HALL_A / HALL_B / HALL_C to obtain the average frequency of the Hall sensor. Since the frequencies of the three-phase Hall signals HALL_A / HALL_B / HALL_C obtained by sampling include three frequencies, the three frequencies obtained in this example are averaged to obtain the average frequency.

[0069] ​In step SC, the rotor rotation frequency is subtracted from the average frequency of the Hall sensor, and the absolute value thereof is taken as a first frequency difference value; the first preset threshold value is obtained according to the experience of the technician or through experimental testing, and the setting of the first preset threshold value needs to consider the manufacturing deviation.

[0070] As a preferred mode, as shown in Figure 4 Further comprising the following steps:

[0071] Step SD, magnetic encoding frequency calculation step: obtaining the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder; the motor position magnetic encoder is a sensor known to the public, which can also be arranged on the motor for collecting the motor position. The magnetic encoding signal is extracted from the collected magnetic encoding signal, which is known to the public and will not be described here.

[0072] In step SC, further comprising the following steps: obtaining a second frequency difference value according to the magnetic encoding frequency and the average frequency; comparing the second frequency difference value with a second preset threshold value, and when the second frequency difference value is greater than or equal to the second preset threshold value, determining that the Hall sensor has a fault. By obtaining the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder, the above-mentioned first frequency difference value and a first preset threshold value for fault checking can be further checked, and the accuracy and reliability of the checking can be ensured through double checking. Similarly, the magnetic encoding frequency is subtracted from the average frequency of the Hall sensor, and the absolute value thereof is taken as the second frequency difference value.

[0073] It should be understood that the steps SA, SB and SC in the above embodiments do not mean the order of execution, and the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0074] In an embodiment, a fault diagnosis device for a Hall sensor is provided, which corresponds to the fault diagnosis method in the above-mentioned embodiments. As shown in Figure 5 The Hall sensor is used to detect the position of a three-phase motor; the fault diagnosis device comprises:

[0075] A three-phase motor rotor frequency calculation module is configured to obtain three-phase sampling current signals of the three-phase motor, obtain induced electromotive force of the three-phase motor based on the three-phase sampling current signals, and obtain a rotor rotation frequency of the three-phase motor according to the induced electromotive force;

[0076] A Hall sensor signal frequency calculation module is configured to obtain three-phase Hall signals of the Hall sensor, and obtain an average frequency of the Hall sensor based on the three-phase Hall signals;

[0077] The Hall sensor fault diagnosis module is configured to obtain a first frequency difference value according to the rotor rotation frequency and the average frequency of the Hall sensor; compare the first frequency difference value with a first preset threshold value; when the first frequency difference value is greater than or equal to the first preset threshold value, determine that the Hall sensor has a fault. When it is determined that there is a fault, a fault position signal indicating the occurrence of the fault is generated, and the power supply of the three-phase motor can be cut off in time through the fault position signal.

[0078] Specifically, as shown in Figure 6 The three-phase electronic rotor frequency calculation module includes:

[0079] The three-phase motor sampling current signal acquisition unit is configured to acquire three-phase sampling current signals of the three-phase motor from a current sampling circuit.

[0080] The α-axis current and β-axis current conversion unit is configured to convert the three-phase sampling current signals into α-axis current and β-axis current through Clark conversion.

[0081] The α-axis and β-axis induced electromotive force output unit is configured to obtain α-axis voltage and β-axis voltage according to the α-axis current and the β-axis current; and obtain α-axis induced electromotive force and β-axis induced electromotive force through a state observer according to the α-axis voltage, the β-axis voltage, and bus voltage.

[0082] The rotor speed calculation unit is configured to obtain rotor speed through a digital phase-locked loop based on the α-axis induced electromotive force and the β-axis induced electromotive force.

[0083] The rotor frequency calculation unit is configured to obtain the rotor rotation frequency based on the rotor speed.

[0084] As shown in Figure 7 The Hall sensor signal frequency calculation module includes:

[0085] The Hall sensor signal acquisition unit is configured to acquire three-phase Hall signals of the Hall sensor, the three-phase Hall signals being square wave signals, and obtain the frequency of the three-phase Hall signals through periodic sampling of the three-phase Hall signals.

[0086] The Hall sensor average frequency acquisition unit is configured to obtain the average frequency of the Hall sensor by averaging the frequency of the three-phase Hall signals.

[0087] As a further preferred mode, as shown in Figure 8 The magnetic encoding frequency calculation module is configured to obtain the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder.

[0088] The Hall sensor abnormal fault diagnosis module is further configured to obtain a second frequency difference value according to the magnetic encoding frequency and the average frequency; compare the second frequency difference value with a second preset threshold value; and determine that the Hall sensor has a fault when the second frequency difference value is greater than or equal to the second preset threshold value. By obtaining the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder, the above-mentioned first frequency difference value and a first preset threshold value can be further checked for faults, thereby ensuring the accuracy and reliability of the check through double checking.

[0089] The specific limitations of the fault diagnosis device can refer to the limitations of the fault diagnosis method described above, and will not be described here. Each module in the above fault diagnosis device can be realized by software, hardware and their combination in whole or in part. The above modules can be embedded in or independent of the processor in hardware form, or stored in the memory of the computer device in software form, so that the processor calls and executes the operations corresponding to each of the above modules.

[0090] In one embodiment, as shown in Figure 9 An electric power steering control system is provided. The electric power steering control system includes a processor, a pre-drive circuit, an inverter bridge, a current sampling circuit and a Hall sensor; usually also includes a power management circuit, etc., which provides power for the processor, etc., wherein the processor is used to receive the sampling results of the current sampling circuit and the Hall sensor, and process and analyze them, and output a control signal to the pre-drive circuit, the pre-drive circuit receives the control signal, processes it and outputs a drive signal, and the inverter bridge converts the drive signal into three-phase alternating current to provide power for the three-phase motor 400. The three-phase motor here is used as a steering assist motor, which can be generally installed on the steering column or the steering gear. The reduction mechanism provides an assist torque to the driver. The steering control system generally includes a memory (not shown in the figure), which includes a readable storage medium, an internal memory. In this example, the memory is directly integrated into the processor, that is, the processor contains a FLASH device on the chip. The computer readable instructions are executed by the processor to implement the fault diagnosis method mentioned in the above embodiments. The readable storage medium provided in this embodiment includes non-volatile readable storage medium and volatile readable storage medium. The structure of the electric power steering control system is known to the public. In this example, the structure is not improved, and only the fault diagnosis method and device of the Hall sensor inside are improved, so it will not be described here.

[0091] In one embodiment, one or more computer readable storage media having computer readable instructions stored thereon are provided. The readable storage medium provided in this embodiment includes non-volatile readable storage medium and volatile readable storage medium. The computer readable instructions stored on the readable storage medium are executed by one or more processors to implement the above-mentioned fault diagnosis method.

[0092] The Hall sensor fault diagnosis method, device and steering control system provided by the present application obtain the rotor rotation frequency of the three-phase motor by creatively converting the three-phase sampling current signals of the three-phase motor, and obtain the average frequency of the Hall sensor by converting the three-phase Hall signals of the Hall sensor. The first frequency difference is obtained by subtracting the average frequency of the Hall sensor from the rotor rotation frequency of the three-phase motor, and compared with a first preset threshold to determine whether the Hall sensor has a fault. This method checks whether the Hall sensor has a fault by the difference in frequency, which is simple and easy to implement. It can also react to various faults that may occur in the Hall sensor, and has high reliability. At the same time, as a further preferred way, the magnetic encoding frequency of the magnetic encoding signal of the motor position magnetic encoder can be further obtained to further check the fault of the first frequency difference and the first preset threshold, thereby ensuring the accuracy and reliability of the check through double checking.

[0093] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional units and modules is exemplified, and in actual application, the above functions can be completed by different functional units and modules according to needs, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above.

[0094] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method of failure diagnosis of a Hall sensor for detecting a position of a three-phase motor, characterized by, The fault diagnosis method comprises the following steps: Obtaining three-phase sampling current signals of the three-phase motor, obtaining induced electromotive forces of the three-phase motor based on the three-phase sampling current signals, and obtaining a rotor rotation frequency of the three-phase motor according to the induced electromotive forces; Obtaining three-phase Hall signals of the Hall sensor, and obtaining an average frequency of the Hall sensor based on the three-phase Hall signals; Obtaining a first frequency difference value according to the rotor rotation frequency and the average frequency of the Hall sensor; Comparing the first frequency difference value with a first preset threshold value, obtaining a magnetic encoding frequency of a magnetic encoding signal of a motor position magnetic encoder when the first frequency difference value is greater than or equal to the first preset threshold value, further verifying the first frequency difference value and the first preset threshold value, ensuring the accuracy and reliability of the verification through double verification, obtaining a second frequency difference value according to the magnetic encoding frequency and the average frequency, and comparing the second frequency difference value with a second preset threshold value, and determining that the Hall sensor has a fault when the second frequency difference value is greater than or equal to the second preset threshold value.

2. The Hall sensor fault diagnosis method according to claim 1, characterized by, The "obtaining three-phase sampling current signals of the three-phase motor, obtaining induced electromotive forces of the three-phase motor based on the three-phase sampling current signals, and obtaining a rotor rotation frequency of the three-phase motor according to the induced electromotive forces" specifically comprises the following steps: Obtaining three-phase sampling current signals of the three-phase motor from a current sampling circuit; Converting the three-phase sampling current signals into α-axis current and β-axis current through Clark transformation; Obtaining α-axis voltage and β-axis voltage according to the α-axis current and the β-axis current, and obtaining α-axis induced electromotive force and β-axis induced electromotive force through a state observer according to the α-axis voltage, the β-axis voltage and bus voltage; Obtaining rotor speed through a digital phase-locked loop based on the α-axis induced electromotive force and the β-axis induced electromotive force; Converting the rotor speed to obtain the rotor rotation frequency.

3. The Hall sensor fault diagnosis method according to claim 1, characterized by, The "obtaining three-phase Hall signals of the Hall sensor, and obtaining an average frequency of the Hall sensor based on the three-phase Hall signals" specifically comprises the following steps: Obtaining three-phase Hall signals of the Hall sensor, the three-phase Hall signals being square wave signals, obtaining the frequency of the three-phase Hall signals through period sampling of the three-phase Hall signals, and obtaining the average frequency of the Hall sensor by averaging the frequency of the three-phase Hall signals. The fault diagnosis device comprises:

4. A failure diagnosis device of a Hall sensor for detecting a position of a three-phase motor, characterized by, A three-phase motor rotor frequency calculation module for obtaining three-phase sampling current signals of the three-phase motor, obtaining induced electromotive forces of the three-phase motor based on the three-phase sampling current signals, and obtaining a rotor rotation frequency of the three-phase motor according to the induced electromotive forces; A Hall sensor signal frequency calculation module for obtaining three-phase Hall signals of the Hall sensor, and obtaining an average frequency of the Hall sensor based on the three-phase Hall signals. ​ The Hall sensor fault diagnosis module is configured to obtain a first frequency difference value according to the rotor rotation frequency and an average frequency of the Hall sensor; compare the first frequency difference value with a first preset threshold value; when the first frequency difference value is greater than or equal to the first preset threshold value, obtain a magnetic encoding frequency of a magnetic encoding signal of a motor position magnetic encoder; further verify the first frequency difference value and a first preset threshold value fault checking method to ensure the accuracy and reliability of the verification through double verification; obtain a second frequency difference value according to the magnetic encoding frequency and the average frequency; compare the second frequency difference value with a second preset threshold value; when the second frequency difference value is greater than or equal to the second preset threshold value, determine that the Hall sensor has a fault.

5. The apparatus for diagnosing a failure of a Hall sensor according to claim 4, characterized by, The three-phase electronic rotor frequency calculation module comprises: A three-phase motor sampling current signal acquisition unit is configured to acquire three-phase sampling current signals of a three-phase motor from a current sampling circuit. An α-axis current and β-axis current conversion unit is configured to convert the three-phase sampling current signals into α-axis current and β-axis current through Clark conversion. An α-axis and β-axis induced electromotive force output unit is configured to obtain α-axis voltage and β-axis voltage according to the α-axis current and the β-axis current; and obtain α-axis induced electromotive force and β-axis induced electromotive force through a state observer according to the α-axis voltage, the β-axis voltage and bus voltage. A rotor speed calculation unit is configured to obtain rotor speed through a digital phase-locked loop based on the α-axis induced electromotive force and the β-axis induced electromotive force. A rotor frequency calculation unit is configured to obtain the rotor rotation frequency through conversion based on the rotor speed.

6. The apparatus for diagnosing a failure of a Hall sensor according to claim 4, characterized by, The Hall sensor signal frequency calculation module comprises: A Hall sensor signal acquisition unit is configured to acquire three-phase Hall signals of the Hall sensor, the three-phase Hall signals being square wave signals; and obtain the frequency of the three-phase Hall signals through periodic sampling of the three-phase Hall signals. A Hall sensor average frequency acquisition unit is configured to obtain the average frequency of the Hall sensor by averaging the frequency of the three-phase Hall signals.

7. A steering control system comprising a processor and computer readable instructions operable on the processor, wherein, The computer readable instructions enable the processor to implement the fault diagnosis method of any one of claims 1-3.

8. A readable storage medium, on which computer readable instructions are stored, characterized in that, The computer readable instructions enable the processor to implement the fault diagnosis method of any one of claims 1-3.

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