A reset detection system and method for an electric power steering system

Abstract

The application provides a reset detection system and method of an electric power steering system, the system comprising a first adjustment module and a second adjustment module, a first micro control unit comprising a first reset pin, and a second micro control unit comprising a second digital signal interface pin; the first micro control unit is used for sending a fault signal to a first power management chip; the first power management chip comprises a second reset pin, and the first power management chip sets the second reset pin to a low level according to the fault signal; the second reset pin is used for sending a low level signal to the first reset pin and the second digital signal interface pin respectively; and the second micro control unit is used for judging that the first micro control unit is reset according to the low level signal. The technical scheme of the application has a faster reset detection speed, directly transmits through a hardware pin, and uses a redundant reset detection method. The redundancy is formed in combination with communication abnormality detection between double power controllers.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric power steering, in particular to a reset detection system and method of an electric power steering system. BACKGROUND

[0002] In order to meet the Fail Operational requirement of automatic driving, more and more electric power steering systems adopt a dual-controller architecture. However, in actual use, the microcontroller unit may reset due to microcontroller software and hardware exceptions, overvoltage, undervoltage, temperature overrun, etc. of the power management chip. The controller on the reset side will not be able to provide assistance during the reset process, which may cause the driver's hand force to suddenly increase and fluctuate greatly during the reset process. Moreover, the communication between the dual controllers will be temporarily interrupted, making it impossible to know whether the opposite microcontroller has reset, so that timely response measures cannot be taken. In the current dual-controller architecture electric power steering system, there is no method to directly detect the reset of the opposite controller.

[0003] In the prior art, the common judgment method is that when the communication abnormality between the dual controllers exceeds a period of time, it is considered that the slave controller is abnormal, so as to permanently cut off the assistance of the slave controller in the current ignition cycle, while keeping or increasing the assistance request of the master controller.

[0004] However, the above method still has many problems, including 1. The communication abnormality detection time is too long, and it takes several frames of messages to confirm the communication abnormality. 2. The communication abnormality cannot accurately determine whether a reset has occurred. 3. When a reset occurs, the hand force and hand force fluctuation become large and cannot be controlled in time due to the inability to detect and take measures in time. SUMMARY

[0005] In order to overcome the problem that whether a reset of the electric power steering system occurs cannot be confirmed in time, and the corresponding adjustment cannot be made in time, the purpose of the present application is to provide a reset detection system and method of an electric power steering system, which can detect whether a reset occurs in a redundant electric power steering system in time.

[0006] Specifically, the reset detection system of the electric power steering system comprises a first adjustment module and a second adjustment module, the first adjustment module comprises a first microcontroller unit and a first power management chip, and the second adjustment module comprises a second microcontroller unit and a second power management chip.

[0007] The first microcontroller unit comprises a first reset pin, and the second microcontroller unit comprises a second digital signal interface pin.

[0008] The first microcontroller unit is configured to send a fault signal to the first power management chip.

[0009] The first power management chip includes a second reset pin, which is used to receive the fault signal and set the second reset pin to a low level according to the fault signal.

[0010] The second reset pin is connected to the first reset pin and the second digital signal interface pin respectively, and the second reset pin is used to send a low-level signal to the first reset pin and the second digital signal interface pin respectively.

[0011] The second digital signal interface pin is used to receive the low-level signal.

[0012] The second microcontroller unit is used to determine that the first microcontroller unit has been reset based on the low-level signal.

[0013] Preferably, the first microcontroller includes a first fault pin, and the first power management chip includes a second fault pin; the first fault pin is connected to the second fault pin, and the first fault pin is used to send the fault signal to the second fault pin.

[0014] Preferably, the second digital signal interface pin is used to receive the low-level signal, and the low-level signal lasts for a first time. The second microcontroller unit is used to determine that the first microcontroller unit has been reset based on the low-level signal.

[0015] Preferably, the first adjustment module includes a first power assist controller, and the second adjustment module includes a second power assist controller, wherein the first power assist controller and the second power assist controller are communicatively connected.

[0016] The first microcontroller and the second microcontroller are used to continuously detect the communication status between the first power assist controller and the second power assist controller;

[0017] When communication between the first assist controller and the second assist controller is lost, and the loss continues for a second time; and when the second digital signal interface pin continuously receives the low-level signal for a first time, the second microcontroller unit is used to determine that the first microcontroller unit has been reset.

[0018] Preferably, the second microcontroller is used to control the assist ratio of the second assist controller to increase to 100% when the first microcontroller is reset.

[0019] Another aspect of the present invention provides a reset detection method for an electric power steering system, comprising:

[0020] The first microcontroller unit sends a fault signal to the first power management chip; based on the fault signal, the reset pin of the first power management chip is set to a low level; a low-level signal is sent to the first microcontroller unit and the second microcontroller unit respectively, and the second microcontroller unit receives the low-level signal and determines that the first microcontroller unit has been reset.

[0021] Preferably, the first microcontroller sends the fault signal to the second fault pin of the first power management chip via the first fault pin;

[0022] Based on the fault signal, the first power management chip sets its second reset pin to a low level;

[0023] The second reset pin sends a low-level signal to the first reset pin of the first microcontroller and the second digital signal interface pin of the second microcontroller, respectively.

[0024] The second digital signal interface pin receives the low-level signal and determines that the first microcontroller unit has been reset based on the low-level signal.

[0025] Preferably, the second digital signal interface pin receives the low-level signal, and the low-level signal lasts for a first time, indicating that the first microcontroller unit has been reset.

[0026] Preferably, the first power assist controller and the second power assist controller are communicatively connected.

[0027] The first microcontroller and the second microcontroller continuously monitor the communication status between the first power assist controller and the second power assist controller, respectively.

[0028] When communication between the first power assist controller and the second power assist controller is lost, and the loss state lasts for a second time; and the second digital signal interface pin receives the low-level signal, and the low-level signal lasts for a first time;

[0029] It is determined that the first microcontroller unit has been reset.

[0030] Preferably, when the first microcontroller is reset, the second microcontroller controls the second assist controller to increase the assist ratio to 100%.

[0031] Compared with existing technologies, the above technical solution has the following advantages:

[0032] 1. By transmitting signals directly through hardware pins, the reset status can be detected more quickly.

[0033] 2. By combining the reset detection method that transmits signals via pins with the communication anomaly detection method between the two power assist controllers, a redundant reset detection method is formed, which can further ensure timely and accurate detection of reset situations. Simultaneously, based on the reset situation, the power assist is adjusted accordingly, rather than being directly shut down, ensuring the stability of the power assist and increasing the operability and availability of the system.

[0034] 3. When a reset occurs, it can reduce the amplitude and duration of increased driver hand force and hand force fluctuations caused by the shutdown of the unilateral controller, thereby improving the stability and safety of the driving process. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a reset detection system for an electric power steering system in the prior art.

[0036] Figure 2 This is a schematic diagram of a reset detection system for an electric power steering system conforming to an embodiment of the present invention;

[0037] Figure 3 A schematic diagram of a reset detection system for an electric power steering system conforming to another embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of a reset detection method for an electric power steering system conforming to an embodiment of the present invention.

[0039] Figure label:

[0040] 1-First fault pin, 2-Second fault pin, 3-Second reset pin, 4-First reset pin, 5-Second digital signal interface pin;

[0041] 6 - Third fault pin, 7 - Fourth fault pin, 8 - Fourth reset pin, 9 - Third reset pin, 10 - First digital signal interface pin. Detailed Implementation

[0042] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0043] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0044] Figure 1 This is a schematic diagram of a reset detection system for an electric power steering system in the prior art. Figure 1As can be seen, the first microcontroller unit and the first power management chip, the second microcontroller unit and the second power management chip are independent of each other. They cannot directly know whether the microcontroller on the other side has been reset, and cannot take timely response measures, which further affects the driving experience of the vehicle and poses a safety hazard.

[0045] like Figure 2 The diagram shown is a schematic of a reset detection system for an electric power steering system conforming to an embodiment of the present invention.

[0046] The reset detection system includes a first adjustment module and a second adjustment module.

[0047] The first adjustment module includes a first microcontroller unit and a first power management chip, and the second adjustment module includes a second microcontroller unit and a second power management chip;

[0048] The first microcontroller includes a first reset pin 4, and the second microcontroller includes a second digital signal interface pin 5;

[0049] The first microcontroller unit is used to send a fault signal to the first power management chip; the first power management chip includes a second reset pin 3, and the first power management chip is used to receive the fault signal and set the second reset pin 3 to a low level according to the fault signal;

[0050] The second reset pin 3 is connected to the first reset pin 4 and the second digital signal interface 5 pin respectively. The second reset pin 3 is used to send a low-level signal to the first reset pin 4 and the second digital signal interface 5 respectively.

[0051] The second digital signal interface pin 5 is used to receive the low-level signal.

[0052] The second microcontroller unit is used to determine that the first microcontroller unit has been reset based on the low-level signal.

[0053] In this embodiment, the first and second adjustment modules are functionally redundant for the dual-controller architecture electric power steering system, but they can operate independently. It is understood that the method and corresponding hardware structure for the second microcontroller unit to determine if the first microcontroller unit has been reset, as described in this invention, mirror each other; similarly, the first microcontroller unit can determine if the second microcontroller unit has been reset using the corresponding method and hardware structure.

[0054] In reality, microcontroller units (MCUs) may reset due to MCU hardware or software malfunctions, or overvoltage, undervoltage, or temperature exceeding limits in the power management chip. The reset signal for the power management chip is typically defined by the power management chip vendor. In this project, the power management chip reset signal is a digital signal; a low level indicates a reset has occurred.

[0055] When the first power management chip is reset, it not only sends a low-level signal indicating the reset to the first microcontroller unit, but also sends it to the second microcontroller unit via a digital signal interface pin, enabling the second microcontroller unit to receive the information that the first power management chip has been reset in a timely manner. It should be understood that since the first and second adjustment modules are arranged in parallel, if the second power management chip is reset, the adjustment method is the same as when the first power management chip is reset; therefore, this will not be elaborated upon here.

[0056] In another embodiment of the invention, such as Figure 3 As shown, the first microcontroller includes a first fault pin 1, and the first power management chip includes a second fault pin 2; the first fault pin 1 is connected to the second fault pin 2, and the first fault pin 1 is used to send the fault signal to the second fault pin 2.

[0057] According to the fault signal, the first power management chip is used to pull the level of the second reset pin 3 low;

[0058] The second reset pin 3 is used to send a low-level signal to the first reset pin 4 of the first microcontroller and the second digital signal interface pin 5 of the second microcontroller, respectively.

[0059] The second digital signal interface pin 5 is used to receive the low-level signal, and the second microcontroller is used to determine that the first microcontroller has been reset based on the low-level signal.

[0060] Similarly, when the second microcontroller receives a fault signal, it sends the fault signal to the fourth fault pin 7 of the second power management chip via the third fault pin 6. Based on the fault signal, the second power management chip pulls the level of the fourth reset pin 8 of the second power management chip low. The fourth reset pin 8 sends a low-level signal to the third reset pin 9 of the second microcontroller and the first digital signal interface pin 10 of the first microcontroller.

[0061] The digital signal interface pins (5, 10) can be used to continuously receive the voltage level of the power management chip on the other side. Since the reset pin of the power management chip on the other side transmits a low-level signal to the digital signal interface pin, the voltage level of the reset pin of the power management chip on the other side can be determined simply by reading the voltage level at the digital signal interface pin, thereby monitoring whether the microcontroller unit on the other side has been reset.

[0062] In this embodiment, signals are directly transmitted using hardware pins, which can speed up the reset detection process. In other embodiments, the digital signal interface pins (5, 10) can also be analog signal interfaces.

[0063] Preferably, in another embodiment of the present invention, to ensure signal stability, after the second digital signal interface pin receives the low-level signal and the low-level signal persists for a first time, the second microcontroller unit is used to determine that the first microcontroller unit has been reset based on the low-level signal. Typically, the first time can be three times the motor control cycle, usually around 150 microseconds to 600 microseconds. However, the fastest detection time is much longer than this cycle; for example, if the detection cycle is increased to 100MHz, then three cycles would only amount to 0.3 microseconds, which would significantly increase the CPU load on the system.

[0064] To improve the accuracy of reset detection, in other embodiments, a redundant design can be implemented to determine whether a reset has occurred by detecting the communication status between the two assist controllers. Specifically, the first adjustment module includes a first assist controller, and the second adjustment module includes a second assist controller. The first microcontroller unit and the second microcontroller unit are used to continuously detect the communication status between the first assist controller and the second assist controller.

[0065] When communication between the first assist controller and the second assist controller is lost, and the loss continues for a second time; and when the second digital signal interface pin continuously receives the low-level signal for a first time, the second microcontroller determines that the first microcontroller has been reset.

[0066] With redundant detection settings, it is possible to accurately and quickly determine whether a reset has occurred. Compared to existing technologies that shut down assistance upon the occurrence of a communication anomaly, this provides the assistance system with more operational possibilities.

[0067] Correspondingly, if a reset is detected in the opposite microcontroller, in order to ensure smooth power assistance, in one embodiment of the present invention, if the second microcontroller determines that the first microcontroller has reset, it controls the power assistance ratio of the second power assist controller to increase to 100%, but should be below 50% of the motor's capacity. It is known in the art that, under normal circumstances, each of the two power assist controllers provides 50% assistance. However, because the first microcontroller has reset, the second microcontroller on the other side correspondingly increases the power assistance ratio of the second power assist controller, which can reduce the amplitude and duration of increased driver hand force and hand force fluctuations caused by the power assistance being turned off on one side.

[0068] Understandably, since the digital signal interface pins (5, 10) can be used to continuously receive the voltage level of the power management chip on the other side, when it is detected that the microcontroller unit on the other side has completed its reset and can provide power normally, the reset microcontroller unit gradually increases the power ratio to 50%, while the microcontroller unit on the other side gradually decreases the power ratio to 50%, and the sum of the power ratios on both sides is less than 100%. Thus, a complete detection reset, power adjustment, and recovery operation can be completed.

[0069] The reset detection system of the electric power steering system in the embodiments of the present invention can quickly determine whether a reset has occurred, and forms redundant detection judgment by detecting the communication status between the two controllers, making the judgment result more accurate. Based on the detection results, the power assist ratio is further adjusted, rather than simply turning off the system power assist, which effectively improves the availability of the electric power steering system and provides a guarantee for the user's safe driving.

[0070] In another embodiment of the present invention, a reset detection method for an electric power steering system is also provided, such as... Figure 4 As shown, it includes:

[0071] The first microcontroller unit sends a fault signal to the first power management chip;

[0072] Based on the fault signal, the reset pin of the first power management chip is set to a low level;

[0073] The low-level signal is sent to the first microcontroller and the second microcontroller respectively;

[0074] The second microcontroller receives the low-level signal and determines that the first microcontroller has been reset.

[0075] That is, the level information of the reset pin is simultaneously fed back to the microcontroller unit on this side and also to the microcontroller unit on the opposite side, so that the microcontroller units on both sides can ensure the synchronization of the reset information.

[0076] In addition, in another embodiment of the electronic power steering system reset detection method conforming to the present invention, the specific steps include:

[0077] The first microcontroller unit sends the fault signal to the second fault pin of the first power management chip through the first fault pin;

[0078] Based on the fault signal, the first power management chip pulls the level of the second reset pin of the first power management chip low;

[0079] The low-level signal of the second reset pin is sent to the first reset pin of the first microcontroller and the second digital signal interface pin of the second microcontroller, respectively.

[0080] The second digital signal interface pin receives the low-level signal and determines that the first microcontroller unit has been reset based on the low-level signal.

[0081] In this embodiment, the signal is directly transmitted through hardware pins, which can speed up the reset detection process.

[0082] The technical features of the reset detection method for the electric power steering system in this invention are the same as those of the reset detection system for the electric power steering system. Therefore, they will not be elaborated upon here.

[0083] As described above, the technical solution of this invention offers faster reset detection speed, directly transmitted via hardware pins; it also employs a redundant reset detection method. Combined with communication anomaly detection between the dual power steering controllers, this redundancy allows for accurate identification of whether a reset has occurred, facilitating individual responses to resets without needing to shut down the power steering solely based on communication anomalies, thus increasing system availability. When a reset occurs, it reduces the amplitude and duration of increased driver hand force and hand force fluctuations caused by the shutdown of a single controller.

[0084] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A reset detection system for an electric power steering system, characterized in that, Includes a first adjustment module and a second adjustment module. The first adjustment module includes a first microcontroller unit and a first power management chip, and the second adjustment module includes a second microcontroller unit and a second power management chip; The first microcontroller includes a first reset pin, and the second microcontroller includes a second digital signal interface pin; The first microcontroller unit is used to send a fault signal to the first power management chip; the first power management chip includes a second reset pin, and the first power management chip is used to receive the fault signal and set the second reset pin to a low level according to the fault signal; The second reset pin is connected to the first reset pin and the second digital signal interface pin respectively, and the second reset pin is used to send a low-level signal to the first reset pin and the second digital signal interface pin respectively; The second digital signal interface pin is used to receive the low-level signal, and the second microcontroller is used to determine that the first microcontroller has been reset based on the low-level signal; If the second microcontroller determines that the first microcontroller has been reset, it controls the second assist controller to increase the assist ratio to 100%, but it should be below 50% of the motor's capacity. When the digital signal interface pin continuously receives the level status of the power management chip on the other side, and detects that the microcontroller on the other side has completed its reset and can provide assistance normally, the microcontroller that has completed its reset gradually increases the assistance ratio to 50%, while the microcontroller on the other side gradually decreases the assistance ratio to 50%, and the sum of the assistance ratios on both sides is less than 100%. When the second microcontroller receives a fault signal, it sends the fault signal to the fourth fault pin of the second power management chip through the third fault pin. According to the fault signal, the second power management chip pulls the level of the fourth reset pin of the second power management chip low. The fourth reset pin sends a low-level signal to the third reset pin of the second microcontroller and the first digital signal interface pin of the first microcontroller.

2. The reset detection system for an electric power steering system as described in claim 1, characterized in that, The first microcontroller includes a first fault pin, and the first power management chip includes a second fault pin. The first fault pin is connected to the second fault pin, and the first fault pin is used to send the fault signal to the second fault pin.

3. The reset detection system for an electric power steering system as described in claim 2, characterized in that, The second digital signal interface pin is used to receive the low-level signal, and the low-level signal lasts for a first time. The second microcontroller unit is used to determine that the first microcontroller unit has been reset based on the low-level signal.

4. The reset detection system for an electric power steering system as described in claim 3, characterized in that, The first adjustment module includes a first power assist controller, and the second adjustment module includes a second power assist controller. The first power assist controller and the second power assist controller are communicatively connected. The first microcontroller and the second microcontroller are used to continuously detect the communication status between the first power assist controller and the second power assist controller; When communication between the first power assist controller and the second power assist controller is lost, and the loss continues for a second time; Furthermore, when the second digital signal interface pin continuously receives the low-level signal within the first time period, the second microcontroller unit is used to determine that the first microcontroller unit has been reset.

5. A method for detecting the reset of an electric power steering system, using the reset detection system for an electric power steering system as described in any one of claims 1-4, characterized in that, The first microcontroller unit sends a fault signal to the first power management chip; Based on the fault signal, the reset pin of the first power management chip is set to a low level; The low-level signal is sent to the first microcontroller and the second microcontroller respectively. The second microcontroller receives the low-level signal and determines that the first microcontroller has been reset.

6. The reset detection method for an electric power steering system as described in claim 5, characterized in that, The first microcontroller unit sends the fault signal to the second fault pin of the first power management chip through the first fault pin; Based on the fault signal, the first power management chip sets its second reset pin to a low level; The second reset pin sends a low-level signal to the first reset pin of the first microcontroller and the second digital signal interface pin of the second microcontroller, respectively. The second digital signal interface pin receives the low-level signal and determines that the first microcontroller unit has been reset based on the low-level signal.

7. The reset detection method for an electric power steering system as described in claim 6, characterized in that, The second digital signal interface pin receives the low-level signal, and the low-level signal lasts for a first time, indicating that the first microcontroller unit has been reset.

8. The reset detection method for an electric power steering system as described in claim 7, characterized in that, The first power assist controller and the second power assist controller are connected for communication. The first microcontroller and the second microcontroller continuously monitor the communication status between the first power assist controller and the second power assist controller, respectively. When communication between the first power assist controller and the second power assist controller is lost, and the loss state lasts for a second time; and the second digital signal interface pin receives the low-level signal, and the low-level signal lasts for a first time; It is determined that the first microcontroller unit has been reset.

9. The reset detection method for an electric power steering system as described in claim 8, characterized in that, When the first microcontroller is reset, the second microcontroller controls the second assist controller to increase the assist ratio to 100%.

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