Motor hall signal high fault-tolerant acquisition device and method

Abstract

The application provides a motor Hall signal high fault-tolerant acquisition device and method, and belongs to the technical field of motor control. The device comprises: a Hall acquisition circuit, used for acquiring original three-phase Hall signals; an auxiliary acquisition circuit, used for monitoring motor operating parameters and generating three-phase auxiliary position signals; a core algorithm circuit, used for, when it is determined that the original Hall signals have failed, reconstructing compensation Hall position signals based on the three-phase auxiliary position signals and a preset motor physical model, and combining the normal Hall signals to generate final three-phase Hall position signals; and a Hall signal output circuit, used for conditioning and outputting the final signals. The application solves the problems of the existing Hall signal fault-tolerant scheme, such as limited fault-tolerant capability, increased system complexity and poor universality. By solidifying fault diagnosis and signal reconstruction in independent hardware, correct position signals can be continuously output even when all Hall sensors fail, thereby greatly improving the reliability of the motor system, simplifying the main control software design, and having good universality.

Description

High-Fault-Tolerant Acquisition Device and Method for Motor Hall Signals Technical Field

[0001] This application relates to the field of motor control technology, and in particular to a fault-tolerant circuit and method for processing motor position sensor signals. Background Technology

[0002] Brushless DC motors are widely used in aerospace, precision drives, and other fields with extremely high reliability requirements due to their high efficiency and reliability. These motors typically rely on Hall effect sensors to detect rotor position, thereby achieving precise electronic commutation control. However, in harsh applications such as missile flight, strong vibrations and extreme temperature changes can significantly increase the failure rate of Hall sensors and their signal acquisition circuits. If any phase Hall signal is lost, remains fixed at a high or low level, or other errors occur, the motor's main controller will be unable to obtain the correct rotor position, leading to commutation failure, motor shutdown, and potentially catastrophic consequences.

[0003] To address the aforementioned issues, several solutions have been proposed in the prior art. One common approach is a dual-redundancy design, which involves configuring two independent sets of Hall sensors and acquisition circuits. When the primary circuit fails, the system switches to the backup circuit. While this approach improves reliability to some extent, it significantly increases the system's size, weight, cost, and wiring complexity, and cannot handle the extreme case of simultaneous failure of both phases. Another approach integrates a software fault-tolerant algorithm into the motor's main controller. When an abnormal Hall signal is detected in one phase, the state of the faulty phase is estimated using signals from other normal phases or the motor model. This approach not only greatly increases the complexity and verification difficulty of the main control software, easily introducing new logical errors, but also requires a high level of expertise from developers and lacks versatility. More importantly, these software algorithms typically only handle single-phase faults and are ineffective in situations where two or even three phases of Hall signals fail.

[0004] Furthermore, some solutions switch to a sensorless control mode based on zero-crossing detection of the motor's back EMF when the Hall signal fails. However, these solutions typically integrate fault diagnosis and mode switching logic within the main controller, and their final output is a commutation signal directly used to drive the power devices, rather than a standard rotor position signal. This design fails to completely decouple fault tolerance from the main control function, resulting in the entire system not being "transparent" to the main controller. System integration and software maintenance remain highly complex, and versatility is poor. Therefore, existing technologies for solving the reliability problem of motor Hall sensor signals generally suffer from limited fault tolerance, increased system hardware and software complexity, high cost, and poor versatility. Summary of the Invention

[0005] The purpose of this application is to provide a high-fault-tolerant acquisition circuit and method for motor Hall signals, aiming to solve the technical problems of limited fault tolerance, increased system hardware and software complexity, and poor versatility in existing Hall signal fault-tolerant schemes. This application, by setting up an independent hardware unit, can still provide a stable and accurate standard Hall position signal to the motor main controller even when the Hall sensor experiences any single-phase, multi-phase, or even complete phase failure, thereby simplifying the main control software design and possessing good versatility.

[0006] To achieve the above objectives, this application provides a high-fault-tolerant acquisition device for motor Hall signals, comprising: a Hall acquisition circuit for acquiring raw three-phase Hall signals from motor Hall sensors; an auxiliary acquisition circuit for monitoring at least one operating parameter of the motor and generating a three-phase auxiliary position signal related to the motor rotor position based on the operating parameter; a core algorithm circuit, the signal input terminals of which are respectively connected to the output terminals of the Hall acquisition circuit and the auxiliary acquisition circuit; the core algorithm circuit is configured to: when it is determined that at least one phase of the three-phase Hall signals has a fault, reconstruct a compensation Hall position signal corresponding to the fault based on the three-phase auxiliary position signal and a preset motor physical model, and combine it with the normal Hall signal to generate and output the final three-phase Hall position signal; and a Hall signal output circuit connected to the signal output terminal of the core algorithm circuit for conditioning the final three-phase Hall position signal and outputting it to the motor main control unit.

[0007] Optionally, the auxiliary acquisition circuit includes: a resistor divider network for dividing the three-phase phase voltages of the motor; a circuit for generating a virtual neutral point potential based on the divided three-phase phase voltages; and a voltage comparator array for comparing the divided phase voltages with the virtual neutral point potential to generate the three-phase auxiliary position signal.

[0008] Optionally, the preset motor physical model is such that the zero-crossing point of the motor phase voltage leads the corresponding Hall signal transition time by 30° electrical angle.

[0009] Optionally, the core algorithm circuit determines whether a fault has occurred by monitoring whether the three-phase Hall signal remains at a high or low level for a preset duration.

[0010] Optionally, the core algorithm circuit is a programmable logic device.

[0011] Optionally, the auxiliary acquisition circuit is configured to generate the three-phase auxiliary position signal by detecting the zero-crossing event of the motor's back electromotive force.

[0012] Optionally, at least one of the Hall acquisition circuit and the Hall signal output circuit uses an optocoupler to achieve electrical isolation of the signal.

[0013] Optionally, the Hall signal output circuit further includes a filtering circuit for filtering the final three-phase Hall position signal.

[0014] To achieve the above objectives, this application also provides a high-fault-tolerant acquisition method for motor Hall signals, comprising the following steps:

[0015] Obtain the raw three-phase Hall signals from the motor Hall sensor;

[0016] Monitor at least one operating parameter of the motor, and generate a three-phase auxiliary position signal related to the motor rotor position based on the operating parameter;

[0017] When it is determined that at least one phase of the three-phase Hall signal has a fault, the compensation Hall position signal corresponding to the fault is reconstructed based on the three-phase auxiliary position signal and the preset motor physical model, and combined with the normal Hall signal to generate the final three-phase Hall position signal.

[0018] The final three-phase Hall position signal is conditioned and then output to the motor main control unit.

[0019] Optionally, the preset motor physical model is a motor phase voltage zero-crossing moment that leads the corresponding Hall signal transition moment by 30° electrical angle; the step of reconstructing the compensated Hall position signal corresponding to the fault includes: calculating the current motor speed based on the normal Hall signal or the three-phase auxiliary position signal; using the transition edge of the three-phase auxiliary position signal as a reference, calculating the delay time corresponding to the 30° electrical angle based on the current motor speed, and generating the compensated Hall position signal based on the delay time.

[0020] Compared with existing technologies, this application has the following advantages: 1. Extremely high reliability and fault tolerance. By introducing an independent auxiliary signal source based on other motor operating parameters and setting up a core algorithm circuit, this application can continuously output the correct Hall position waveform even in extreme cases where any one, two, or even all three phases of the Hall sensor fail, ensuring uninterrupted motor operation and greatly improving the reliability of the entire motor drive system. 2. Simplified main control software and reduced system complexity. This application embeds complex fault diagnosis and signal reconstruction logic into a dedicated hardware circuit, making it completely transparent to the motor main controller. The main controller does not need to write any fault-tolerant code; it only needs to process standard Hall signals, which greatly reduces the development difficulty, testing workload, and error risk of the main control software. 3. Strong versatility and easy integration. As an independent hardware unit, the output interface of this application is fully compatible with standard Hall sensors. It can be used as a "plug-and-play" enhanced alternative, seamlessly integrated into existing motor control systems without any modification to the original main controller hardware or software, exhibiting excellent versatility and portability. Attached Figure Description

[0021] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same components or steps.

[0022] Figure 1 is a schematic diagram of the system structure of a high-fault-tolerant acquisition device for motor Hall signals provided in an embodiment of this application;

[0023] Figure 2 is a flowchart of a high-fault-tolerant acquisition method for motor Hall signals provided in an embodiment of this application;

[0024] Figure 3 is a specific circuit diagram of the Hall acquisition module circuit in an embodiment of this application;

[0025] Figure 4 is a specific circuit diagram of the auxiliary acquisition module circuit in an embodiment of this application;

[0026] Figure 5 is a specific circuit diagram of the core algorithm circuit in an embodiment of this application;

[0027] Figure 6 is a schematic diagram of a specific Hall signal output circuit in an embodiment of this application.

[0028] Figure 7 is a flowchart of a high-fault-tolerant acquisition method for motor Hall signals provided in an embodiment of this application; Detailed Implementation

[0029] 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 embodiments of the present invention, and not all embodiments. 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.

[0030] This embodiment provides a highly fault-tolerant acquisition device and method for motor Hall signals. Please refer to Figure 1, which is a schematic diagram of the system structure of a highly fault-tolerant acquisition device for motor Hall signals according to an embodiment of this application. Specifically, this device can be seamlessly integrated as an independent hardware unit between the motor Hall sensor and the motor main control unit. Its core function is that when the original Hall signal fails, it can reconstruct the signal using other operating parameters of the motor, thereby providing the main control unit with a consistently correct and standard Hall position signal.

[0031] As shown in Figure 1, the device mainly includes four cooperating units: Hall acquisition circuit 100, auxiliary acquisition circuit 200, core algorithm circuit 300, and Hall signal output circuit 400.

[0032] The signal input terminal of the Hall acquisition circuit 100 is connected to the output terminal of the motor Hall sensor to receive the raw three-phase Hall signal from the sensor. It is understandable that in practical applications, due to significant differences in the electrical environments between the motor side and the control side, such as different ground potentials or strong common-mode interference, this unit typically also performs electrical isolation and level conversion functions.

[0033] The input terminal of the auxiliary acquisition circuit 200 is connected to a specific node of the motor to monitor at least one operating parameter of the motor. In this embodiment, the operating parameter may specifically be the three-phase voltages U, V, and W of the motor. The core task of this unit is to generate a set of parallel three-phase auxiliary position signals, independent of the Hall sensors, based on these operating parameters that have a definite physical correlation with the rotor position. It can be understood that this auxiliary signal constitutes the key basis for subsequent signal reconstruction.

[0034] As the core of the entire device, the signal input terminals of the core algorithm circuit 300 are connected to the output terminals of the Hall acquisition circuit 100 and the auxiliary acquisition circuit 200, respectively. This unit is configured to execute the following logic: real-time monitoring of the health status of the three-phase Hall signals provided by unit 100; and, upon determining that at least one phase of the three-phase Hall signals has a fault, activating a fault-tolerant mechanism, and dynamically reconstructing a compensation Hall position signal corresponding to the fault based on the three-phase auxiliary position signals provided by unit 200 and a preset motor physical model; finally, combining the reconstructed compensation signal with the still-normal Hall signals (if any) to generate and output a complete set of three-phase Hall position signals. It should be noted that when all Hall signals are normal, this unit directly transmits the input Hall signals. The preset motor physical model is defined as the motor phase voltage zero-crossing point leading the corresponding Hall signal transition time by 30° electrical angle.

[0035] The input of the Hall signal output circuit 400 is connected to the output of the core algorithm circuit 300, and its output is connected to an external motor control unit. This unit is used to perform final signal conditioning on the final three-phase Hall position signal from the unit 300, such as further electrical isolation, filtering, and shaping, thereby ensuring that a stable, clean Hall signal that conforms to standard interface specifications is output to the motor control unit.

[0036] Through the coordinated operation of the above-mentioned units, this device achieves transparent fault-tolerant processing of Hall signal faults. No matter what kind of fault occurs in the Hall sensor, the motor main control unit can always receive the correct rotor position information, thereby ensuring the high reliability of the motor drive system.

[0037] The specific circuit implementation and working process of each unit in this embodiment will be described in more detail below with reference to Figures 3 to 6.

[0038] Please refer to Figure 3, which is a schematic diagram of a specific Hall acquisition circuit 100. In one embodiment of this application, the unit consists of three identical circuits, each responsible for processing one phase Hall signal. The original three-phase Hall signals HALLA0, HALLB0, and HALLC0 from the motor Hall sensor are typically high-voltage signals, such as 15V. Taking phase A as an example, the original Hall signal HALLA0 is input to the input terminal of optocoupler U2. Optocoupler U2 achieves electrical isolation between the input and output sides through optical signals, effectively blocking the transmission of ground loops and common-mode noise. At the output terminal of optocoupler U2, i.e., the phototransistor side, the isolated signal is converted into a low-voltage logic level acceptable to the subsequent core algorithm circuit 300, such as 3.3V, through external circuits such as pull-up resistors. After processing, the three isolated Hall signals are labeled HALLA1, HALLB1, and HALLC1, respectively. By employing optocouplers U2, U3, and U4, this unit achieves secure acquisition, electrical isolation, and level adaptation of the original Hall signal.

[0039] It should be noted that at least one of the Hall acquisition circuit and the Hall signal output circuit uses an optocoupler to achieve electrical isolation of the signal.

[0040] The auxiliary acquisition circuit includes: a resistor divider network for dividing the three-phase phase voltage of the motor; a circuit for generating a virtual neutral point potential based on the divided three-phase phase voltage; and a voltage comparator array for comparing the divided phase voltage with the virtual neutral point potential to generate the three-phase auxiliary position signal.

[0041] Please refer to Figure 4, which is a schematic diagram of a specific circuit of the auxiliary acquisition circuit 200. This unit is used to extract rotor position information from the three-phase phase voltages U, V, and W of the motor. Specifically, the three-phase phase voltages U, V, and W are first processed by a resistor divider network to proportionally scale the high-voltage phase voltages to a safe range, for example, from hundreds of volts to several volts. The three phase voltage signals after voltage division are then converged to a single point through a star-connected network composed of resistors R7, R8, and R9, thereby generating a virtual neutral point potential. It can be understood that this virtual neutral point potential is ideally equal to the average value of the instantaneous values ​​of the three-phase voltages. The circuit further employs a voltage comparator array, such as the three comparators U1B, U1C, and U1D in the LM139 chip with four integrated comparators. Taking phase A as an example, the positive input terminal of voltage comparator U1B receives the divided phase U voltage, and its negative input terminal is connected to the aforementioned virtual neutral point potential. When the U-phase voltage is higher than the virtual neutral point potential, comparator U1B outputs a high level; otherwise, it outputs a low level. Thus, the output of comparator U1B generates a square wave digital signal HA, whose transition edge precisely corresponds to the zero-crossing moment of the U-phase voltage. Similarly, comparators U1C and U1D process the V-phase and W-phase voltages respectively, generating corresponding zero-crossing signals HB and HC. These three square wave signals HA, HB, and HC together constitute the three-phase auxiliary position signal, which is strictly related to the rotor position, and are transmitted to the core algorithm circuit 300.

[0042] Please refer to Figure 5, which is a schematic diagram of a specific circuit of the core algorithm circuit 300. In this embodiment, the core device of this unit is a programmable logic device, specifically a high-performance microcontroller U8, such as the STMicroelectronics STM32G431 series chip. This microcontroller U8 integrates powerful computing capabilities, abundant timer resources, and input / output pins. As shown in the figure, multiple input pins of the microcontroller U8 are connected to three isolated Hall signals HALLA1, HALLB1, and HALLC1 from the Hall acquisition circuit 100, and three auxiliary position signals HA, HB, and HC from the auxiliary acquisition circuit 200. The output pins of the microcontroller U8 are used to generate the processed three-phase Hall signals HALLA2, HALLB2, and HALLC2. The microcontroller U8 internally runs a pre-programmed firmware algorithm, which is crucial for realizing the core functions of this application. Its detailed logic will be described below in conjunction with the method flow.

[0043] Please refer to Figure 6, which is a schematic diagram of a specific Hall signal output circuit 400. This unit is used to convert the digital signals HALLA2, HALLB2, and HALLC2 generated by the microcontroller U8 into final standard Hall signals that can directly drive the motor main control unit. Similar to the input, the output also requires electrical isolation. Taking phase A as an example, the processed Hall signal HALLA2 drives the input of optocoupler U15. At the output of optocoupler U15, the signal is restored to the operating level required by the motor main control unit (e.g., 15V). In addition, to improve signal quality and suppress high-frequency noise or jitter that may be introduced during digital processing, a filter circuit, such as a low-pass RC filter circuit composed of resistors and capacitors, can be set on the output circuit. This filter circuit can smooth the edges of the signal, ensuring that the waveforms of the final output Hall signals HALLAout, HALLBout, and HALLCout are clean and stable. The core algorithm circuit determines whether a fault has occurred by monitoring whether the three-phase Hall signals are constantly at a high or low level within a preset time.

[0044] Next, referring to the method flowchart shown in Figure 2, we will explain in detail the high-fault-tolerant acquisition method executed inside the core algorithm circuit 300 (i.e., microcontroller U8) in this embodiment.

[0045] Referring to Figure 2, the method begins at step S10. After the device is powered on, the microcontroller U8 performs initialization operations, including setting its internal peripherals and variables.

[0046] Subsequently, in step S20, the microcontroller U8 periodically acquires the level status of the three isolated Hall signals HALLA1, HALLB1, and HALLC1 output by the Hall acquisition circuit 100, as well as the level status of the three auxiliary position signals HA, HB, and HC output by the auxiliary acquisition circuit 200, through its input pins.

[0047] Next, in the crucial step S30, Hall signal fault diagnosis is performed. The microcontroller U8 internally sets up a status monitor for each phase of the Hall signal. This monitor uses a timer to determine whether the signal remains consistently high or low within a preset duration. The preset duration is a key parameter, typically set to several times the normal Hall signal transition period at the current motor speed. For example, if the Hall signal period is 10 milliseconds at the current motor speed, the preset duration can be set to 30 milliseconds. If the level of a certain phase Hall signal (such as HALLA1) remains unchanged within 30 milliseconds, the microcontroller U8 determines that the Hall signal of that phase has a "sticky" fault. This fault mode is the most common manifestation when the Hall sensor or its circuitry is damaged. Through this mechanism, faults in any one, two, or even three phases of the Hall signal can be accurately diagnosed.

[0048] If the judgment result of step S30 is negative, that is, all three-phase Hall signals have normal level transitions within a preset time period, it indicates that the Hall sensor system is working normally. Accordingly, the process proceeds to step S40, in which the microcontroller U8 directly transmits the three Hall signals HALLA1, HALLB1, and HALLC1 without modification to its output pin, so that the output signals HALLA2, HALLB2, and HALLC2 are completely consistent with the input signals.

[0049] Conversely, if the judgment result of step S30 is yes, that is, at least one Hall signal failure is detected, the system initiates the fault-tolerant reconfiguration process, first executing step S50 to calculate the motor speed. It is understood that the method of speed calculation depends on the fault condition. As an optional implementation, it can be divided into the following two cases: First, if at least one Hall signal is normal (for example, only phase A is faulty, while phases B and C are normal), the microcontroller U8 uses the time interval between two consecutive rising edges of a normal Hall signal (such as HALLB1) to accurately calculate the current motor speed; Second, if all three Hall signals fail, the microcontroller U8 uses auxiliary position signals to calculate the speed, for example, by measuring the time interval between two consecutive rising edges of the auxiliary signal HA, which corresponds to one complete electrical cycle (360° electrical angle) of the motor rotation, thereby calculating the motor speed.

[0050] After obtaining the motor speed, the process proceeds to step S60 to reconstruct the fault Hall signal. The core of this step lies in utilizing a preset motor physical model. In this embodiment, for a typical brushless DC motor, this physical model can be specifically defined as follows: the zero-crossing moment of the motor phase voltage leads the Hall signal transition moment of its corresponding phase by 30° electrical angle. The microcontroller U8 performs compensation calculations based on this model. Specifically, firstly, based on the motor speed calculated in step S50, the time T_electrical required for the current complete electrical cycle (360° electrical angle) is determined; then, the delay time Δt corresponding to the 30° electrical angle is calculated, and its calculation formula is: Δt = (30 / 360) * T_electrical. Wherein, Δt is the time difference between the auxiliary signal transition edge and the expected Hall signal transition edge.

[0051] For a Hall signal phase deemed faulty (e.g., phase A), microcontroller U8 closely monitors its corresponding auxiliary position signal HA. When a transition (e.g., from low to high) is detected in HA, microcontroller U8 immediately starts an internal timer and sets it to a calculated delay time Δt. When the timer finishes, microcontroller U8 immediately toggles the level of its corresponding output pin HALLA2. In this way, even if the original HALLA0 signal is completely lost or remains fixed, the device can accurately generate a timing-correct compensated Hall position signal HALLA2 after a delay of Δt, based on the auxiliary signal HA. Meanwhile, for normal signal phases (e.g., phases B and C), microcontroller U8 still performs pass-through operation, i.e., HALLB2 = HALLB1, HALLC2 = HALLC1. Finally, microcontroller U8 combines the normal pass-through signal and the reconstructed compensated signal to form a complete three-phase Hall signal set: HALLA2, HALLB2, and HALLC2.

[0052] Regardless of whether the process proceeds through step S40 or step S60, it will eventually enter step S70. In this step, the generated three-phase Hall signals HALLA2, HALLB2, and HALLC2 are stably output to the Hall signal output circuit 400, and after being conditioned by this unit, they are provided to the motor main control unit.

[0053] Using the above method, the device in this embodiment can independently and automatically complete fault diagnosis and signal reconstruction of Hall signals without relying on the main control unit software intervention. Even in the extreme case where all three-phase Hall signals fail, it can ensure that the motor control system obtains reliable rotor position information, thereby ensuring the continuous and stable operation of the motor.

[0054] This embodiment is an optional implementation of Embodiment 1, and its purpose is to demonstrate that the core algorithm circuit 300 can be implemented by different types of programmable logic devices. The overall system architecture of this embodiment is completely consistent with that shown in Figure 1. The circuit structure and function of the Hall acquisition circuit 100, the auxiliary acquisition circuit 200, and the Hall signal output circuit 400 are the same as those described in Embodiment 1.

[0055] The main difference between this embodiment and embodiment 1 is that the core device of the core algorithm circuit 300 is no longer the microcontroller U8, but a field-programmable gate array or a complex programmable logic device.

[0056] During operation, all the algorithm logic implemented by the microcontroller firmware in Example 1, including the acquisition of input signals, fault diagnosis logic, calculation of motor speed, calculation of the delay time corresponding to 30° electrical angle, and the final signal pass-through and reconstruction logic, are all described in this example using hardware description languages ​​such as Verilog or VHDL. After synthesis, placement and routing, they are solidified into pure digital logic circuits inside the field-programmable gate array or complex programmable logic device chip.

[0057] Specifically, the field-programmable gate array (FPGA) can be internally designed with multiple parallel state machines and counter units. For example, an independent monitoring unit can be designed for each phase Hall signal. This unit contains a counter that continuously counts when the signal level remains constant. Once the count value exceeds a preset threshold (corresponding to a preset duration), a fault flag is triggered. Simultaneously, a speed calculation unit can be designed. This unit can monitor the edges of all six input signals in parallel and calculate the time interval between edges based on the currently valid signal source, thereby updating the motor speed in real time. Another key unit is the signal generation unit. Based on the state of the fault flag, it determines whether to directly transmit the input Hall signal or start a precise delay counter based on the edge of the auxiliary signal, the current speed, and a 30° phase difference model, and generate a compensated Hall signal output after the counting is complete.

[0058] The core advantage of using field-programmable gate arrays (FPGAs) or complex programmable logic devices (CPLDs) lies in their inherent parallel processing capabilities. Unlike the serial processing of microcontrollers based on instruction sequences, FPGAs can monitor and process all input signals simultaneously, resulting in extremely low latency from fault occurrence to signal reconstruction completion, and highly deterministic response time. This is of great significance for applications with extremely high real-time control requirements, such as high-speed motors or precision servo systems.

[0059] This embodiment demonstrates that the function of the core algorithm circuit 300 can be implemented by a variety of programmable logic devices. Whether it is a software-based microcontroller, a hardware-based field-programmable gate array, or a complex programmable logic device, all can implement the technical solution proposed in this application, thereby supporting higher-level functional limitations on this unit.

[0060] This embodiment is another optional implementation of Embodiment 1, and its purpose is to demonstrate that the auxiliary acquisition circuit 200 can be constructed based on different operating parameters of the motor. The overall system architecture of this embodiment can also refer to Figure 1, in which the structure and function of the Hall acquisition circuit 100, the core algorithm circuit 300, and the Hall signal output circuit 400 can remain unchanged.

[0061] The main difference between this embodiment and Embodiment 1 lies in the design principle and specific circuit of the auxiliary acquisition circuit 200. In this embodiment, the auxiliary acquisition circuit 200 no longer generates auxiliary signals by monitoring the relationship between phase voltage and virtual neutral point, but is configured to generate three-phase auxiliary position signals by detecting the zero-crossing event of the motor back electromotive force.

[0062] For many types of brushless DC motors, a back electromotive force (EMF) is induced in the windings as the motor rotates, and this back EMF is related to the rotor position and speed. The waveform of the back EMF and its zero-crossing points have a fixed and predictable physical relationship with the rotor's magnetic pole positions. Therefore, detecting the zero-crossing points of the back EMF can also serve as a reliable source of rotor position information, independent of Hall sensors.

[0063] In this embodiment, the auxiliary acquisition circuit 200 can be designed to include a resistor network for detecting the motor terminal voltage, and a comparator circuit for extracting the back electromotive force (EMF) signal and detecting its zero-crossing point. For example, the back EMF can be measured directly or indirectly on a non-conducting phase of the motor using a certain circuit topology, and compared with a reference level (e.g., half of the DC bus voltage) to obtain the zero-crossing signal of the back EMF.

[0064] Accordingly, the algorithm logic within the core algorithm circuit 300 also needs to be adaptively adjusted. The "preset motor physical model" upon which it is based will no longer be "the phase voltage zero-crossing point leading the Hall signal jump by 30° electrical angle," but rather "the phase relationship between the back electromotive force zero-crossing point and the corresponding Hall signal jump point." This phase relationship varies depending on the motor design and the detection method, and may be a fixed phase difference, such as 0°, 30°, or 60° electrical angle. During the device design phase, this phase difference value needs to be determined and preset based on the specific characteristics of the motor used.

[0065] During operation, when the core algorithm circuit 300 detects a Hall signal fault, its reconstruction logic uses the zero-crossing edge of the back EMF signal as a reference, and calculates and generates a compensated Hall signal based on the current speed and a newly preset phase difference (e.g., 0°). If the phase difference is 0°, the reconstruction process is simpler, and the zero-crossing back EMF signal can be directly output as the compensated Hall signal.

[0066] This embodiment demonstrates that the operating parameters monitored by the auxiliary acquisition circuit can be selected in multiple ways. Whether it is phase voltage or back electromotive force, as long as the parameter can reflect the rotor position, it can be used to generate an auxiliary position signal, thereby supporting broader protection for the unit and its monitored parameters.

[0067] This embodiment is another optional implementation of Embodiment 1, mainly demonstrating the diversity of signal isolation devices. The overall system architecture, core working principle, and implementation methods of the core algorithm circuit 300 and auxiliary acquisition circuit 200 in this embodiment can be consistent with Embodiment 1.

[0068] The main difference between this embodiment and Embodiment 1 lies in the electrical isolation devices used in the Hall acquisition circuit 100 and the Hall signal output circuit 400. In Embodiment 1, optocouplers were used to achieve electrical isolation of the signals. In this embodiment, however, these optocouplers are replaced by more advanced high-speed digital isolators.

[0069] High-speed digital isolators enable signal transmission across isolation barriers using capacitive coupling or magnetic coupling techniques such as miniature transformers. For example, Analog Devices' ADuM series or Texas Instruments' ISO77xx series digital isolator chips can be used. These chips typically integrate multiple independent isolation channels within a single package, significantly reducing the board footprint compared to using multiple discrete optocouplers.

[0070] In the Hall effect acquisition circuit 100, a multi-channel digital isolator can be used to replace the three optocouplers U2, U3, and U4. Similarly, in the Hall effect signal output circuit 400, another multi-channel digital isolator can be used to replace the three optocouplers U15, U16, and U17. When the signal crosses the isolation boundary, it is coupled and transmitted through a changing electric or magnetic field, rather than an optical signal.

[0071] Compared to traditional optocouplers, high-speed digital isolators offer several performance advantages. Firstly, they provide higher transmission rates, lower propagation delays, and better consistency, which is particularly important for high-speed motor control systems. Secondly, they exhibit higher common-mode transient immunity, more effectively suppressing high-voltage, high-speed common-mode noise interference generated during motor driver switching, thereby improving signal transmission reliability. Furthermore, their power consumption is typically lower.

[0072] The operation of this embodiment is exactly the same as that of Embodiment 1. The signal flow and processing logic remain unchanged; only the physical implementation of the signal when crossing the isolation boundary has changed. This embodiment demonstrates that the electrical isolation function in the device can be achieved through a variety of different technical means. Whether it is traditional optocoupler or modern digital isolation technology, both can meet the requirements of this application, thereby supporting a broader understanding of the "conditioning" function in the signal acquisition and output unit.

[0073] Referring to Figure 7, this application also provides a high-fault-tolerant acquisition method for motor Hall signals, applied in the aforementioned high-fault-tolerant acquisition device for motor Hall signals, comprising the following steps:

[0074] Step S701: Obtain the original three-phase Hall signal from the motor Hall sensor;

[0075] Specifically, after the device is powered on, the Hall acquisition circuit continuously acquires the original three-phase Hall signals (HALLA0, HALLB0, HALLC0) from the three Hall sensors of the motor. This unit first performs electrical isolation and level conversion on these signals to obtain isolated three-phase Hall signals (HALLA1, HALLB1, HALLC1) suitable for subsequent logic circuit processing, and then transmits them to the core algorithm circuit.

[0076] Step S702: Monitor at least one operating parameter of the motor, and generate a three-phase auxiliary position signal related to the motor rotor position based on the operating parameter;

[0077] Steps S702 and S701 are performed in parallel, with the auxiliary acquisition circuit monitoring the motor's operating parameters in real time. In a preferred embodiment, the operating parameters are the motor's three-phase phase voltages (U, V, W). This unit scales the three-phase phase voltages using a resistor divider network and constructs a virtual neutral point (N). Subsequently, a voltage comparator array (such as U1B, U1C, U1D) compares each phase voltage after voltage division with the virtual neutral point potential, generating three digital square wave signals (HA, HB, HC). The transition edges of these auxiliary position signals (HA, HB, HC) precisely correspond to the zero-crossing points of each phase voltage, thus providing a second rotor position information independent of the Hall sensor.

[0078] Step S703: When it is determined that at least one phase of the three-phase Hall signal has a fault, based on the three-phase auxiliary position signal and the preset motor physical model, a compensation Hall position signal corresponding to the fault is reconstructed, and combined with the normal Hall signal to generate the final three-phase Hall position signal.

[0079] This step is the core of achieving high fault tolerance, and its sub-steps are as follows:

[0080] Fault Diagnosis: The core algorithm circuit monitors the isolated Hall signals (HALLA1, HALLB1, HALLC1) acquired in step S701 in real time. It sets up a time-based fault judgment mechanism for each phase signal. Specifically, the core algorithm circuit maintains a timer or counter. If a Hall signal (e.g., HALLA1) remains high or low for a preset duration (e.g., a time window much longer than the normal Hall signal period at the current speed) without the expected transition, it determines that the Hall signal of that phase has a "sticky" fault. This mechanism can effectively detect single-phase, two-phase, or all three-phase failures.

[0081] Signal Reconstruction: Once a fault is diagnosed, the signal reconstruction logic is initiated immediately.

[0082] a. Calculating motor speed: The core algorithm circuit first needs to obtain the current motor speed. The speed calculation adaptively selects the signal source based on the fault condition.

[0083] If at least one phase of the Hall signal is normal, the electrical cycle (360° electrical angle) time is calculated using the time interval between the consecutive transition edges of the normal phase signal, and then the rotational speed is obtained.

[0084] If all three-phase Hall signals fail, the motor's rotational electrical cycle (i.e., T_electrical) and speed are calculated by using the time interval between the continuous transition edges of the three-phase auxiliary position signals (such as the HA signal) generated in step S702.

[0085] b. Applying a motor physical model and generating compensation signals: This method is based on a key, pre-defined motor physical model. In a preferred embodiment, this model is: the zero-crossing moment of the motor phase voltage leads the corresponding phase Hall signal transition moment by 30° electrical angle.

[0086] Based on this model, the core algorithm circuit (300) first calculates the precise delay time Δt corresponding to the 30° electrical angle. The calculation formula is: Δt = (30 / 360) * T_electrical.

[0087] Subsequently, for each Hall channel determined to be faulty (e.g., phase A), the core algorithm circuit monitors the transition edge (e.g., rising edge) of its corresponding auxiliary position signal (HA). Once a transition is detected, a delay timer is immediately started, with a delay value set to Δt.

[0088] When the timer expires, the core algorithm circuit controls the output signal (HALLA2) of that phase to undergo a level transition. Through this operation, even if the original HALLA1 signal has failed, a compensated Hall signal HALLA2 can be generated at the correct time.

[0089] c. Synthesizing the final signal: For Hall channels that have not experienced a fault, their signals (such as HALLB1, HALLC1) are directly transmitted (i.e., HALLB2 = HALLB1, HALLC2 = HALLC1). Finally, the reconstructed compensation signal is combined with the transmitted normal signal to form a complete and correct final three-phase Hall position signal (HALLA2, HALLB2, HALLC2).

[0090] Step S704: After conditioning the final three-phase Hall position signal, output it to the motor main control unit.

[0091] Specifically, the Hall signal output circuit receives the final three-phase Hall position signals (HALLA2, HALLB2, HALLC2) from the core algorithm circuit. This unit performs further electrical isolation, filtering, and waveform shaping on these signals to eliminate possible jitter and noise, ultimately outputting stable, clean Hall signals (HALLAout, HALLBout, HALLCout) that conform to the motor main control unit interface standard, ensuring that the main control unit can reliably acquire the signals.

[0092] This method, through the aforementioned process, embeds complex fault-tolerant logic into the hardware, enabling real-time and automatic repair of Hall sensor faults. Regardless of the number of faulty phases, it guarantees the correctness of the output signal and is completely transparent to the main control unit, greatly improving the robustness and reliability of the motor drive system while eliminating the need for complex fault-tolerant algorithm development in the main control software.

[0093] In a preferred embodiment, the preset motor physical model is specifically: the zero-crossing time of the motor phase voltage is 30° electrical angle ahead of the Hall signal transition time of the corresponding phase.

[0094] The technical principle is explained as follows: For a typical square-wave driven brushless DC motor (BLDC), its back electromotive force (EMF) waveform is ideally a trapezoidal wave. Theoretical analysis and experiments show that there is a fixed phase relationship between the zero-crossing point of the back EMF (i.e., the zero-crossing point of the phase voltage relative to the virtual neutral point) and the Hall signal transition point used for electronic commutation. Specifically, the zero-crossing point of the back EMF leads the corresponding Hall signal transition point by 30° electrical angle. This relationship is determined by the electromagnetic design of the motor itself (such as the magnetization method of the magnets and the winding distribution) and the commutation logic. Therefore, as long as the zero-crossing point of the phase voltage can be accurately detected, the correct Hall signal transition time can be predicted by adding a 30° electrical angle delay.

[0095] In this application, this physical relationship is preset and solidified in the algorithm or logic of the core algorithm circuit (300) as a reference for signal reconstruction. It should be noted that "30° electrical angle" is a preferred value for the most common motor design. The core idea of ​​this model is to use a predetermined and fixed electrical angle phase difference. Therefore, for some specific motor designs, this predetermined electrical angle may be 25°, 35°, etc., which does not deviate from the core idea of ​​this application, that is, to predict signals based on a determined phase difference model.

[0096] Based on the above model, the steps for reconstructing the compensated Hall position signal corresponding to the fault are further refined into the following sub-steps, which have a clear process and strong computational determinism:

[0097] a) Calculate the current motor speed: The speed is the basis for calculating the time delay. The core algorithm circuit (300) is configured to adaptively select available signal sources to calculate the motor's rotational electrical cycle T_electrical (i.e., the time required to rotate 360° electrical angle), the reciprocal of which is the electrical speed.

[0098] First priority (in case of partial fault): If at least one phase of the three-phase Hall signal is still working normally (e.g., only phase A is faulty), the core algorithm circuit uses the time interval between two consecutive in-direction transition edges (e.g., two consecutive rising edges) of the Hall signal of the normal phase (e.g., HALLB1) as T_electrical. This is because the normal Hall signal directly reflects the commutation cycle of the motor and is the most accurate.

[0099] Second priority (in case of complete failure): If all three-phase Hall signals fail, the three-phase auxiliary position signal (such as HA) from the auxiliary acquisition circuit is used instead. T_electrical can also be obtained by measuring the time interval between two consecutive unidirectional transition edges of the auxiliary signal HA. This is because the frequency of the auxiliary position signal is strictly consistent with the motor's electrical frequency.

[0100] b) Calculate the delay time Δt corresponding to a 30° electrical angle: After obtaining the electrical cycle T_electrical, the core algorithm circuit can calculate the actual time delay Δt corresponding to a 30° electrical angle through a simple proportional calculation. The calculation formula is as follows: Δt = (30 / 360) * T_electrical = T_electrical / 12. This calculation ensures that the delay time Δt can follow the changes in motor speed in real time, thus maintaining the accuracy of compensation at any speed.

[0101] c) Generate a compensated Hall position signal: This step is the specific execution of the reconstruction action.

[0102] Reference signal selection: The transition edge of the three-phase auxiliary position signal corresponding to the faulty Hall channel is used as the reference trigger point. For example, for the faulty A-phase Hall signal, the transition edge of the auxiliary signal HA is monitored.

[0103] Delay and transition: Once a transition (e.g., a rising edge from low to high) is detected in the reference signal (such as HA), the core algorithm circuit immediately starts a high-precision timer and sets the timing value to the calculated delay time Δt.

[0104] Signal Output: When the timer finishes counting down, it immediately controls the corresponding output pin (used to output the compensated Hall signal, such as HALLA2) to undergo a level transition (from high to low or from low to high). In this way, a compensated Hall position signal that is completely synchronized with the correct timing is generated.

[0105] Technical Effects: By employing the aforementioned method based on a physical model and real-time speed calculation, this application can dynamically and accurately reconstruct the rotor position information even when the Hall sensor experiences any degree of failure, ensuring the continuous and stable operation of the motor drive system under extreme fault conditions. This method transforms complex model calculations into deterministic, time-delayed hardware operations, resulting in rapid response and high reliability.

[0106] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-fault-tolerant acquisition device for motor Hall signals, characterized in that, include: Hall effect acquisition circuit, used to acquire raw three-phase Hall signals from motor Hall sensors; An auxiliary acquisition circuit is used to monitor at least one operating parameter of the motor and generate a three-phase auxiliary position signal related to the rotor position of the motor based on the operating parameter. The core algorithm circuit has its signal input terminals connected to the output terminals of the Hall acquisition circuit and the auxiliary acquisition circuit, respectively. The core algorithm circuit is configured to: when it is determined that at least one phase of the three-phase Hall signals has a fault, dynamically reconstruct a compensation Hall position signal corresponding to the fault based on the three-phase auxiliary position signals and a preset motor physical model, and combine this with the normal Hall signals to generate and output the final three-phase Hall position signal; the preset motor physical model is such that the zero-crossing point of the motor phase voltage leads the corresponding Hall signal transition time by 30° electrical angle. The steps for reconstructing the compensated Hall position signal corresponding to the fault include: calculating the current motor speed based on the normal Hall signal or the three-phase auxiliary position signal; using the transition edge of the three-phase auxiliary position signal as a reference, calculating the delay time corresponding to the 30° electrical angle based on the current motor speed, and generating the compensated Hall position signal based on the delay time; a Hall signal output circuit, connected to the signal output terminal of the core algorithm circuit, is used to condition the final three-phase Hall position signal and output it to the motor main control unit; the auxiliary acquisition circuit includes: a resistor voltage divider network for dividing the three-phase phase voltage of the motor; a circuit for generating a virtual neutral point potential based on the divided three-phase phase voltage; and a voltage comparator array for comparing the divided phase voltage with the virtual neutral point potential to generate the three-phase auxiliary position signal; the auxiliary acquisition circuit is configured to generate the three-phase auxiliary position signal by detecting the zero-crossing event of the motor back electromotive force.

2. The data acquisition device according to claim 1, characterized in that, The core algorithm circuit determines whether a fault has occurred by monitoring whether the three-phase Hall signal remains at a constant high or low level within a preset time period.

3. The data acquisition device according to claim 1, characterized in that, The core algorithm circuit is a programmable logic device.

4. The data acquisition device according to claim 1, characterized in that, At least one of the Hall acquisition circuit and the Hall signal output circuit uses an optocoupler to achieve electrical isolation of the signal.

5. The data acquisition device according to claim 1, characterized in that, The Hall signal output circuit also includes a filtering circuit for filtering the final three-phase Hall position signal.

6. A high-fault-tolerant acquisition method for motor Hall signals, characterized in that, The high-fault-tolerant acquisition device for motor Hall signals according to any one of claims 1 to 5 includes the following steps: acquiring raw three-phase Hall signals from motor Hall sensors; monitoring at least one operating parameter of the motor and generating a three-phase auxiliary position signal related to the motor rotor position based on the operating parameter; when it is determined that at least one phase of the three-phase Hall signals has a fault, reconstructing a compensation Hall position signal corresponding to the fault based on the three-phase auxiliary position signal and a preset motor physical model, and combining it with the normal Hall signal to generate the final three-phase Hall position signal; and outputting the final three-phase Hall position signal to the motor main control unit after conditioning.

Images