A method and system for diagnosing an automobile alternator fuse

Abstract

The application discloses a kind of diagnosis method and system of vehicle-mounted generator fuse, and the fuse is connected between generator and battery, one end of the fuse connection generator is point A, and one end of the connection battery is point B, when vehicle is not started, the voltage of point A and point B is collected, whether the fuse is suspected abnormal according to the voltage of point A and point B is judged;If it is judged that the fuse is suspected abnormal, after the vehicle is started, the voltage of point A and point B is collected, whether the fuse is open circuit according to the voltage of point A and point B is judged using first method;If it is judged that the fuse is normal, after the vehicle is started, the voltage of point A and point B is collected, whether the fuse is open circuit according to the voltage of point A and point B is judged using second method.The application is staged to the characteristic judgment when vehicle is running, whether the fuse of generator is open circuit can be accurately judged, avoid all misjudgment and missing judgment situation.

Description

Technical Field

[0001] This invention belongs to the field of automotive technology, specifically relating to a diagnostic method and system for vehicle-mounted generator fuses. Background Technology

[0002] The existing vehicle insurance, such as the primary insurance outside the electrical distribution box, including the starter fuse and generator fuse, often cannot promptly detect abnormal fuse blowouts, posing a potential hazard to the normal use of the vehicle.

[0003] The fuses in the distribution box, some of which use diodes connected in parallel for fuse indication, such as... Figure 1 The industrial-grade technical solution shown consists of a fuse 1, a fuse indicator light 2, and a resistor 3 within the electrical equipment 4. When the fuse fails and the electrical equipment is activated, current flows from the L terminal through the fuse indicator light 2 and resistor 3 to the N terminal, illuminating the fuse indicator light 2 as an alarm indication. This solution does not illuminate the indicator light even if the fuse is open when the corresponding electrical equipment is not in operation; that is, the fuse's open circuit can only be determined when the equipment is operating.

[0004] For vehicle alternator fuses, since the alternator charges the vehicle's battery, the fuse is essentially connected between the alternator and the battery. When the corresponding load on the vehicle is not activated, such as when the vehicle is started and the ignition key is in the ON position, the fuse will activate if the next level of the fuse is a power distribution and management controller. Figure 1 The current from indicator light 2 and resistor 3 may not be able to flow to the negative terminal of the power supply when the load is not turned on, meaning that the indicator light solution is not suitable for all vehicle electronic and electrical architectures. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide a diagnostic method and system for vehicle-mounted generator fuses that is highly accurate and reliable.

[0006] The technical solution adopted in this invention is: a diagnostic method for a vehicle-mounted generator fuse, wherein the fuse is connected between the generator and the battery, with point A being the end of the fuse connected to the generator and point B being the end connected to the battery.

[0007] When the vehicle is not started, the voltage at points A and B is collected, and the fuse is suspected to be faulty based on the voltage at points A and B.

[0008] If the fuse is suspected to be faulty, the voltage at points A and B is collected after the vehicle is started. The first method is used to determine whether the fuse is open based on the voltage at points A and B.

[0009] If the fuse is determined to be normal, after the vehicle is started, the voltage at points A and B is collected, and the second method is used to determine whether the fuse is open based on the voltage at points A and B.

[0010] Furthermore, when the ignition lock is in the ACC or ON position and the engine speed is less than the rated speed value, the vehicle is determined not to be started; when the ignition lock is in the ON position and the engine speed is greater than or equal to the rated speed value, the vehicle is determined to be started.

[0011] Furthermore, the process of determining whether the fuse is suspected of being abnormal based on the voltage at points A and B is as follows: if the voltage at point A is less than the first calibration value, and the absolute value of the voltage difference between points A and B is greater than the second calibration value, then the fuse is suspected of being abnormal; otherwise, the fuse is considered normal.

[0012] Furthermore, the first method is to detect in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, as well as the absolute value of the voltage difference between point A and point B;

[0013] If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the absolute value of the voltage difference between point A and point B is greater than the third calibration value, then the fuse is determined to be open.

[0014] Furthermore, the second method is: to detect in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, the magnitude of the voltage at point B at the current moment and the voltage at point B at the previous moment, and the absolute value of the voltage difference between point A and point B;

[0015] If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the voltage at point B is less than the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B is greater than the fourth calibration value, then it is determined that the fuse may be open.

[0016] Furthermore, if, after determining that the fuse may be open, the voltage at point B continues to decrease, and the absolute value of the voltage difference between points A and B is greater than the fifth calibration value, then the fuse is determined to be open.

[0017] A diagnostic system for a vehicle-mounted generator fuse is disclosed. The fuse is connected between the generator and a battery, with point A connecting the fuse to the generator and point B connecting it to the battery. The system also includes a voltage acquisition module and a diagnostic module.

[0018] The voltage acquisition module is used to detect and acquire the voltage at points A and B in real time.

[0019] The diagnostic module is used to determine whether the fuse is suspected of being faulty based on the voltage at points A and B when the vehicle is not started; if the fuse is suspected of being faulty, then after the vehicle is started, the first method is used to determine whether the fuse is open circuit based on the voltage at points A and B; if the fuse is normal, then after the vehicle is started, the second method is used to determine whether the fuse is open circuit based on the voltage at points A and B.

[0020] Furthermore, the process of determining whether the fuse is suspected of being abnormal based on the voltage at points A and B is as follows: if the voltage at point A is less than the first calibration value, and the absolute value of the voltage difference between points A and B is greater than the second calibration value, then the fuse is suspected of being abnormal; otherwise, the fuse is considered normal.

[0021] Furthermore, the first method is to determine in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, as well as the absolute value of the voltage difference between point A and point B;

[0022] If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the absolute value of the voltage difference between point A and point B is greater than the third calibration value, then the fuse is determined to be open.

[0023] Furthermore, the second method is to determine in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, the magnitude of the voltage at point B at the current moment and the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B.

[0024] If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the voltage at point B is less than the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B is greater than the fourth calibration value, then it is determined that the fuse may be open.

[0025] If, after determining that the fuse may be open, the voltage at point B continues to decrease and the absolute value of the voltage difference between points A and B is greater than the fifth calibration value, then the fuse is determined to be open.

[0026] The beneficial effects of this invention are as follows:

[0027] This invention combines the vehicle's starting status with continuous sampling of the voltage at both ends of the fuse (points A and B). By utilizing the changing trends and rates of change of the voltage at each of the two sampling points, as well as the changing trend of the voltage difference between the two points, it determines whether the fuse is damaged and promptly notifies the driver and vehicle maintenance personnel, avoiding driving hazards caused by generator fuse failure. The diagnostic method is simple and highly applicable.

[0028] This invention performs feature judgment in stages during vehicle operation, which can accurately determine whether the generator fuse is open, avoiding all misjudgments and omissions.

[0029] This invention makes predictions before the vehicle starts, covering the entire operating conditions after the vehicle is powered on, thus improving the probability and speed of fault detection. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of an existing technology insurance connection.

[0031] Figure 2 This is a schematic diagram of the generator fuse voltage sampling point of the present invention.

[0032] Figure 3 This is a flowchart of the generator fuse diagnosis process before vehicle startup according to the present invention.

[0033] Figure 4 This is a flowchart of the generator fuse diagnosis process after vehicle startup according to the present invention. Detailed Implementation

[0034] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] like Figure 2 As shown, this invention establishes two voltage sampling points at both ends of the fuse between the generator and the battery, which are connected to the controller (ECU) by a line. The controller is used to monitor the voltage at both ends of the fuse and perform diagnostic judgments. At the same time, the controller reads information such as the vehicle ignition lock status and engine speed from the CAN bus.

[0036] The aforementioned controller can be a single controller, or it can be performed by the engine controller (EECU), vehicle controller (HCU or VCU), or instrumentation.

[0037] Ignition lock status and engine speed do not necessarily have to be obtained from the CAN bus as bus signals. The ECU can also directly connect to the ignition lock or speed sensor and obtain hard-wired signals directly from the ignition lock or speed sensor.

[0038] The diagnostic judgment logic based on the vehicle status and voltage change trend is shown in Table 1:

[0039] Table 1. Diagnostic logic for vehicle status and voltage changes.

[0040]

[0041]

[0042] Once the vehicle is started, the ECU determines that the vehicle is in the starting state based on the ignition lock position (ON position) and the engine speed (≥400rpm).

[0043] If the fuse between points A and B is not blown, the voltage difference between points A and B will be minimal, and both will be in a high voltage state (generally between 26V and 28.5V) when the generator is working normally.

[0044] If the vehicle's generator malfunctions, or the vehicle's load increases abnormally, the voltage at points A and B will be pulled down together, and the voltage difference between points A and B will be extremely small.

[0045] When abnormal electromagnetic interference occurs in the vehicle, the transient voltage at points A and B will fluctuate abnormally, and the transient voltage difference at points A and B will not rise steadily.

[0046] When the fuse blows, with the vehicle running and the engine running, the voltage at point A will first rise and then reach a relatively steady state, fluctuating only slightly with the engine speed; while the voltage at point B will first drop from 26V-28.5V to 24V-26V, providing a feasible way for us to determine if the fuse has been blown, but we must also distinguish the above-mentioned abnormal situations.

[0047] A conventional fuse connects to the high voltage of the power supply on one end and the load on the other. When the fuse breaks, the voltage difference changes significantly (e.g., from 24V to less than 1V), providing more accurate and convenient diagnosis for conventional fuses. However, for fuses between generators and batteries, since both ends of the fuse (points A and B) are the positive terminals of the power supply, the voltage fluctuation after the fuse breaks is within 2-4V or even less, making direct diagnosis difficult.

[0048] Therefore, this solution comprehensively considers the rate of voltage decrease, voltage difference, and continuous change characteristics to screen and eliminate other abnormal operating conditions, and accurately determine the circuit breaker failure.

[0049] Based on the above principles, this invention provides a diagnostic method for vehicle-mounted generator fuses, such as... Figure 3 , Figure 4 As shown,

[0050] When the vehicle is not started, the voltage at points A and B is collected, and the fuse is suspected to be faulty based on the voltage at points A and B.

[0051] If the fuse is suspected to be faulty when the vehicle is not started, the voltage at points A and B is collected after the vehicle is started. The first method is used to determine whether the fuse is open based on the voltage at points A and B.

[0052] If the fuse is deemed to be functioning correctly when the vehicle is not started, then after the vehicle is started, the voltage at points A and B is collected. Based on the voltage at points A and B, a second method is used to determine whether the fuse is open-circuited (i.e., monitoring whether the fuse is open-circuited during vehicle use).

[0053] In the above scheme, when the ignition lock is in the ACC or ON position and the engine speed is lower than the rated speed value, it is determined that the vehicle is powered on but not started; when the ignition lock is in the ON position and the engine speed is greater than or equal to the rated speed value, it is determined that the vehicle is started. The rated speed value can be set to 300rpm to 500rpm, preferably 400rpm.

[0054] In the above scheme, the process of determining whether the fuse is suspected of being abnormal based on the voltage at points A and B is as follows: if the voltage at point A is less than the first calibration value, and the absolute value of the voltage difference between points A and B is greater than the second calibration value, then the fuse is suspected of being abnormal; otherwise, the fuse is considered normal.

[0055] In the above scheme, the first method is: to detect in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, as well as the absolute value of the voltage difference between point A and point B; if at a certain moment, the voltage at point A at the current moment is greater than the voltage at point A at the previous moment, that is, the voltage at point A increases, and the absolute value of the voltage difference between point A and point B is greater than the third calibration value, then it is determined that the fuse is open.

[0056] In the above scheme, the second method is: to detect in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, the magnitude of the voltage at point B at the current moment and the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B.

[0057] If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the voltage at point B is less than the voltage at point B at the previous moment (i.e., the voltage at point A increases and the voltage at point B decreases), and the absolute value of the voltage difference between points A and B is greater than the fourth calibration value, then it is determined that the fuse may be open, and the next step of judgment is continued.

[0058] If, after determining that the fuse may be open, the voltage at point B continues to decrease, and the absolute value of the voltage difference between points A and B is greater than the fifth calibration value, then the fuse is determined to be open. The continuous decrease in voltage at point B means that the voltage decrease at point B reaches a set value within a set time period. This set time period is 5-20 minutes, preferably 10 minutes, and the set value is 0.5V-2V, preferably 1V. When the voltage decrease at point B reaches the set value within the set time period, and the absolute value of the voltage difference between points A and B is greater than the fifth calibration value, then the fuse is determined to be open.

[0059] The first to fifth calibration values ​​mentioned above can be the same, all different, or partially the same and partially different.

[0060] This invention also provides a diagnostic system for a vehicle-mounted generator fuse. The fuse is connected between the generator and the battery, with one end of the fuse connected to the generator designated as point A and the other end connected to the battery designated as point B. The system also includes a voltage acquisition module and a diagnostic module.

[0061] The voltage acquisition module is used to detect and acquire the voltage at points A and B in real time.

[0062] The diagnostic module is used to determine whether the fuse is faulty based on the voltage at points A and B when the vehicle is not started; if the fuse is faulty, the module uses a first method to determine whether the fuse is open circuit based on the voltage at points A and B after the vehicle is started; if the fuse is normal, the module uses a second method to determine whether the fuse is open circuit based on the voltage at points A and B after the vehicle is started.

[0063] Example 1

[0064] Before the vehicle is started, the ECU determines that the vehicle is in a stationary state after being powered on (i.e., not started) based on the ignition lock position (ACC or ON) and the engine speed (<400rpm).

[0065] The possible range of voltage variation at points A and B is not only affected by the aforementioned location between the two positive terminals of the power supply, but the voltage fluctuation trend and fluctuation situation also differ depending on whether the vehicle is running or not.

[0066] Before the vehicle starts, the voltages at points A and B are similar to those of the battery. After the fuse blows, point B becomes the battery voltage, while point A becomes the floating voltage. The voltage difference between points A and B may be above 15V (taking a 24V electrical system in a commercial vehicle as an example). When the voltage at point A is lower than the rated value, such as below 5V, this situation may be caused by an interruption in the sampling line at point A of the ECU, or it may be due to a blown fuse. Therefore, this situation can only be judged as a suspected abnormality of the alternator fuse.

[0067] After entering the "Diagnosis after vehicle startup" process, if the sampling line at point A is interrupted, the voltage at point A will remain unchanged; if the generator fuse is open, the voltage at point A will be similar to that of the generator and will rise rapidly (e.g., to above 26V). If the voltage difference between points A and B is greater than the third calibration value (e.g., 2V), it can be determined that the generator fuse is open and damaged.

[0068] Example 2

[0069] Once the ECU determines that the vehicle is in the starting state, it collects the voltage at point A and point B in real time and reads the diagnostic information before the vehicle started to check if it is normal.

[0070] If the insurance is diagnosed as normal before starting the vehicle, then:

[0071] When, at a certain moment, compared to the previous moment, the voltage at point B decreases and the voltage at point A increases, and the voltage difference between points A and B is greater than the fourth calibration value (e.g., 2V), the ECU proceeds to the next step of judgment.

[0072] If the above state is caused by electromagnetic interference, then the duration will not be too long.

[0073] When the voltage at point B continues to decrease (e.g., a decrease of 0.5V within 10 minutes), and the voltage difference between points A and B is still greater than the fifth calibration value (e.g., 2V), the ECU determines that the fuse has blown. The 10-minute calibration value is set to account for the fact that a generator fuse failure will not have a sudden impact on driving safety in the short term; therefore, this judgment time logic can be added to the diagnostic method.

[0074] If a suspected abnormality is diagnosed before the vehicle is started, then after the vehicle is started:

[0075] When the voltage at point A increases compared to the previous moment, and the voltage difference between points A and B is greater than the third calibration value (e.g., 2V), the ECU determines that the fuse is open.

[0076] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0077] To make the description of this disclosure more detailed and complete, illustrative descriptions of the embodiments and specific examples of the present invention have been provided above; however, this is not the only form of implementing or utilizing the specific examples of the present invention. The embodiments cover the features of multiple specific examples and the method steps and their order for constructing and operating these specific examples. However, other specific examples may also be used to achieve the same or equivalent functions and order of steps.

[0078] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0079] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Contents not described in detail in this specification belong to prior art known to those skilled in the art.

Claims

1. A diagnostic method for vehicle-mounted generator fuses, characterized in that: The fuse is connected between the generator and the battery, with point A connecting the fuse to the generator and point B connecting it to the battery. When the vehicle is not started, the voltage at points A and B is collected, and the fuse is suspected to be faulty based on the voltage at points A and B. If the fuse is suspected to be faulty, the voltage at points A and B is collected after the vehicle is started. The first method is used to determine whether the fuse is open based on the voltage at points A and B. If the fuse is determined to be normal, after the vehicle is started, the voltage at points A and B is collected, and the second method is used to determine whether the fuse is open based on the voltage at points A and B. The second method is to detect in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, the magnitude of the voltage at point B at the current moment and the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B. If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the voltage at point B is less than the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B is greater than the fourth calibration value, then it is determined that the fuse may be open. If, after determining that the fuse may be broken, the voltage at point B continues to decrease and the absolute value of the voltage difference between points A and B is greater than the fifth calibration value, then the fuse is determined to be broken. The continuous decrease in voltage at point B means that the amount of voltage decrease at point B within a set time reaches the set value.

2. The diagnostic method for vehicle-mounted generator fuses according to claim 1, characterized in that: When the ignition lock is in the ACC or ON position and the engine speed is lower than the rated speed, the vehicle is confirmed not to be started. When the ignition lock is in the ON position and the engine speed is greater than or equal to the rated speed value, the vehicle is started.

3. The diagnostic method for vehicle-mounted generator fuses according to claim 1, characterized in that, The process of determining whether a fuse is suspected of being abnormal based on the voltage at points A and B is as follows: if the voltage at point A is less than the first calibration value, and the absolute value of the voltage difference between points A and B is greater than the second calibration value, then the fuse is suspected of being abnormal; otherwise, the fuse is considered normal.

4. The diagnostic method for vehicle-mounted generator fuses according to claim 1, characterized in that, The first method is to detect in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, as well as the absolute value of the voltage difference between point A and point B; If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the absolute value of the voltage difference between point A and point B is greater than the third calibration value, then the fuse is determined to be open.

5. A diagnostic system for vehicle-mounted generator fuses, characterized in that: A fuse is connected between the generator and the battery, with one end of the fuse connected to the generator (point A) and the other end connected to the battery (point B). The system also includes a voltage acquisition module and a diagnostic module. The voltage acquisition module is used to detect and acquire the voltage at points A and B in real time. The diagnostic module is used to determine whether the fuse is suspected of being abnormal based on the voltage at points A and B when the vehicle is not started. If the fuse is suspected to be faulty, after the vehicle is started, the first method is used to determine whether the fuse is open based on the voltage at points A and B. If the fuse is determined to be normal, then after the vehicle is started, use the second method to determine whether the fuse is open based on the voltage at points A and B. The second method is to determine in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, the magnitude of the voltage at point B at the current moment and the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B. If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the voltage at point B is less than the voltage at point B at the previous moment, and the absolute value of the voltage difference between points A and B is greater than the fourth calibration value, then it is determined that the fuse may be open. If, after determining that the fuse may be broken, the voltage at point B continues to decrease and the absolute value of the voltage difference between points A and B is greater than the fifth calibration value, then the fuse is determined to be broken. The continuous decrease in voltage at point B means that the amount of voltage decrease at point B within a set time reaches the set value.

6. The diagnostic system for vehicle-mounted generator fuses according to claim 5, characterized in that, The process of determining whether a fuse is suspected of being abnormal based on the voltage at points A and B is as follows: if the voltage at point A is less than the first calibration value, and the absolute value of the voltage difference between points A and B is greater than the second calibration value, then the fuse is suspected of being abnormal; otherwise, the fuse is considered normal.

7. The diagnostic system for vehicle-mounted generator fuses according to claim 5, characterized in that, The first method is to determine in real time the magnitude of the voltage at point A at the current moment and the voltage at point A at the previous moment, as well as the absolute value of the voltage difference between point A and point B; If at a certain moment, the voltage at point A is greater than the voltage at point A at the previous moment, and the absolute value of the voltage difference between point A and point B is greater than the third calibration value, then the fuse is determined to be open.

Images