Method and system for model validation of motor vehicle carbon footprint

Abstract

The present application relates to a motor vehicle carbon load model verification method and system, comprising the following steps: cutting into pure electric mode on the premise that the hybrid vehicle meets the verification condition; in the pure electric mode, the motor is controlled to drag the engine to a set speed N, and after dragging for a set period of time and reaching a steady state, the differential pressure sensor output value P1 of the particle trap and the exhaust flow value M1 are obtained; the current flow resistance R1 of the particle trap is obtained according to M1 and P1, the calibrated carbon load model theoretical value F1 is obtained by looking up a table, and is compared with the actual value F2 of the current carbon load model; if the difference between F1 and F2 is less than a set value, the verification times C1 is increased by 1; if it is not less than the set value, F1 is assigned to F2, the verification times C1 is increased by 1, and the number of abnormal verification results C2 is increased by 1; when C2 / C1 exceeds a set value, an error signal is triggered and recorded, and the verification is completed.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, specifically to a method and system for verifying the carbon load model of motor vehicles. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] When a motor vehicle is powered by a diesel engine, the exhaust gas passes through a diesel particulate filter (DPF) to collect particulate matter, thereby reducing the environmental harm caused by exhaust emissions. The DPF has a carbon load parameter, which indicates the number of particles captured. When the carbon load reaches a certain value, it needs to be regenerated to ensure stable performance.

[0004] The carbon load of a diesel particulate filter (DPF) cannot be directly detected. Instead, it is obtained through complex calculations by a computational model mounted on the vehicle's computer. If there are problems such as original exhaust soot deviation (referring to deviations in the original emission characteristics of diesel engines related to soluble organic matter), combustion deterioration, or intake leakage, the carbon load calculated by the model will be inaccurate, making it impossible to determine the actual carbon load of the particulate filter and thus affecting its reliable operation. Summary of the Invention

[0005] To address the technical problems mentioned above, this invention provides a method and system for verifying the carbon load model of motor vehicles. Utilizing the characteristic of hybrid vehicles that can operate purely on electric power, and ensuring the vehicle's normal operation and the accuracy of all sensors, the system uses an electric motor to drive the engine, obtaining the DPF flow resistance at a set speed and exhaust gas flow rate. Based on this flow resistance, a calibrated theoretical carbon load value is obtained, which is then compared with the actual carbon load value displayed by the onboard computer to achieve verification.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of the present invention provides a method for verifying the carbon load model of motor vehicles, comprising the following steps:

[0008] Under the premise that the hybrid vehicle meets the verification conditions, switch to pure electric mode;

[0009] In pure electric mode, the control motor drives the engine to a set speed N, and after driving for a set period of time and reaching a stable state, the output value P1 of the differential pressure sensor of the particulate filter and the exhaust gas flow value M1 are obtained.

[0010] Based on M1 and P1, the current flow resistance R1 of the particulate trap is obtained. The theoretical value F1 of the calibrated carbon loading model is obtained by looking up the table and compared with the actual value F2 of the current carbon loading model.

[0011] If the difference between F1 and F2 is less than the set value, then the actual value of the current carbon loading model F2 is normal, and the number of verifications C1 is incremented by 1.

[0012] If the difference between F1 and F2 is not less than the set value, then the actual value of the current carbon loading model, F2, is abnormal. F1 is assigned to F2, the number of verifications, C1, is incremented by 1, and the number of verification results that are abnormal, C2, is incremented by 1. When C2 / C1 exceeds the set value, an error signal is triggered and recorded, and the verification is completed.

[0013] After the verification is completed, the timer for the verification interval is reset, and the timer starts counting down again for the next verification.

[0014] The verification conditions that hybrid vehicles must meet are as follows:

[0015] The particulate filter and the connected differential pressure sensor are functioning correctly.

[0016] The differential pressure sensor of the particulate filter does not exhibit zero-point drift when the engine is stationary.

[0017] The actual carbon loading F2 exceeds the set value;

[0018] The battery pack's SOC is greater than the set value;

[0019] The engine is not started;

[0020] The engine meets the conditions for reverse towing start;

[0021] The set interval T1 for periodic verification has been reached.

[0022] In pure electric mode, the motor drives the engine to the set speed N. During this time, the engine runs by being driven by the motor and no fuel is injected.

[0023] A steady state includes a stable rotational speed and a stable exhaust gas flow rate;

[0024] A stable rotational speed is defined as a change in rotational speed that is less than a set value.

[0025] A stable exhaust gas flow rate is defined as an exhaust gas flow rate variation that is less than a set value.

[0026] If the change in rotational speed or exhaust gas flow rate is not less than the set value within the set time period, then this test will be terminated.

[0027] A second aspect of the present invention provides a system for implementing the above-described verification method, comprising:

[0028] A differential pressure sensor is connected to the particulate filter of the hybrid vehicle to be tested;

[0029] An exhaust gas flow sensor is connected to the particulate filter outlet of the hybrid vehicle to be calibrated.

[0030] A tachometer is connected to the engine of the hybrid vehicle to be calibrated;

[0031] The processor is configured to: obtain the flow resistance of the particulate filter based on the exhaust gas flow rate obtained by the exhaust gas flow sensor and the pressure difference obtained by the pressure difference sensor, output the theoretical value F1 of the calibrated carbon loading model, and compare it with the actual value F2 of the carbon loading model to obtain the difference between F1 and F2.

[0032] The processor is also configured to: if the difference between F1 and F2 is less than a set value, then the verification count C1 is incremented by 1; if it is not less than the set value, then F1 is assigned to F2, the verification count C1 is incremented by 1, and the number of verification results that are abnormal is incremented by 1; when C2 / C1 exceeds the set value, an error signal is triggered and recorded, and the verification is completed.

[0033] Compared with existing technologies, one or more of the above technical solutions have the following beneficial effects:

[0034] 1. Taking advantage of the fact that hybrid vehicles can operate on pure electric power, under the premise of ensuring that the vehicle can operate normally and that all sensors are accurate, the motor drives the engine to obtain the flow resistance of the particulate filter at a set speed and exhaust flow rate. Based on this flow resistance, the calibrated theoretical value of carbon load is obtained and compared with the current actual carbon load value to achieve verification.

[0035] 2. At the start of the verification, the system determines that the vehicle and the particulate filter are functioning normally by setting the conditions.

[0036] 3. The accurate parameter is the value measured by the differential pressure sensor on the particulate filter at the steady state point when no oil is injected. This value reflects the differential pressure of the particulate filter at this time. By periodically calibrating the carbon loading model using this accurate parameter, the carbon loading output by the model can be guaranteed to be accurate.

[0037] 4. By calculating the proportion of verification anomalies to the number of verifications, we can infer issues such as the reliability and consistency of the particle trap. Attached Figure Description

[0038] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0039] Figure 1 This is a schematic diagram of the verification process for the carbon load model of motor vehicles provided in one or more embodiments of the present invention. Detailed Implementation

[0040] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0041] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the scope of exemplary embodiments of the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms “comprising” and / or “including” are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0043] DPF: Particle trap.

[0044] SOC: The current remaining charge of the battery.

[0045] Carbon loading model: A complex calculation process used to calculate the carbon content within the DPF. The results obtained from the carbon loading model are usually displayed on the vehicle's computer.

[0046] Hybrid electric vehicles are vehicles whose drive system consists of two or more individual drive systems that can operate simultaneously. The vehicle's driving power is provided by the individual drive systems individually or jointly, depending on the actual driving conditions.

[0047] The following embodiments use a diesel engine + electric motor (motor) as an example to provide a method and system for verifying the carbon load model of motor vehicles. Taking advantage of the fact that hybrid vehicles can operate purely on electric power, under the premise of ensuring that the vehicle can operate normally and that all sensors are accurate, the electric motor drives the engine to obtain the DPF flow resistance at a set speed and exhaust gas flow rate. Based on this flow resistance, the calibrated theoretical value of carbon load is obtained and compared with the actual carbon load value displayed by the on-board computer to achieve verification.

[0048] Example 1:

[0049] like Figure 1 As shown, the method for verifying the carbon load model of motor vehicles includes the following steps:

[0050] Set the following limitations:

[0051] 1. No DPF differential pressure sensor or DPF-related faults; ensure that the calibration occurs when there are no DPF faults. If there are faults, do not calibrate.

[0052] 2. The DPF differential pressure sensor does not exhibit zero-point drift when the engine is static (the detection result is accurate). Before each carbon load model calibration, the status of the DPF differential pressure sensor should be confirmed. For hybrid vehicles, in pure electric mode (i.e., when the engine T15 is powered on but not started), no exhaust gas passes through the DPF, and the measured value of the differential pressure sensor can be approximated as 0. If the measured value is not zero, it is considered that there is a zero-point measurement deviation. If the deviation is too large, the sensor is considered inaccurate, and the sensor inaccuracy fault needs to be addressed before calibration.

[0053] 3. The actual carbon loading F2 exceeds the set value.

[0054] 4. SOC is greater than the set value; the verification process occurs when the vehicle is running in pure electric mode and does not require engine participation, so a higher SOC is required.

[0055] 5. Engine not started; ensure that the engine is switched from a non-started state to a motor-driven state during subsequent verification processes.

[0056] 6. The engine meets the conditions for reverse towing and starting; the engine water temperature and other conditions meet the requirements to be able to be towed to the set speed, ensuring normal operation in pure electric mode and that the motor can reliably drive the engine.

[0057] 7. The set interval T1 for periodic verification has been reached.

[0058] Once the hybrid vehicle meets all the above conditions, in pure electric mode, the control motor drives the engine to a set speed N (driven by the motor only, without fuel injection). After a driving time T2, the engine speed and exhaust gas flow rate reach a stable state, and the exhaust gas flow rate M1 and the differential pressure sensor P1 are obtained. If the engine speed and exhaust gas flow rate are not stable for a long time, the test is terminated.

[0059] In this embodiment, a stable rotational speed refers to a rotational speed whose change is less than a set value.

[0060] In this embodiment, a stable exhaust gas flow rate refers to an exhaust gas flow rate change that is less than a set value.

[0061] The flow resistance R1 of the DPF at the current moment is calculated using the exhaust gas flow rate M1 and the pressure difference P1. Based on this flow resistance R1, the theoretical value F1 of the carbon loading model under this flow resistance is obtained by referring to the table.

[0062] Obtain the actual value F2 of the carbon loading model at the current moment, and compare F2 with F1;

[0063] If the difference between F1 and F2 is less than the set value, then the actual value F2 of the current carbon loading model is normal, and the number of verifications of the carbon loading model C1 is incremented by 1.

[0064] If the difference between F1 and F2 is not less than the set value, then the actual value F2 of the current carbon loading model is abnormal. The theoretical carbon loading F1 obtained from the table lookup is then assigned to the actual value F2 of the carbon loading model, and the verification ends.

[0065] When a value needs to be assigned, the number of times the carbon loading model is verified (C1) is incremented by 1, and the number of times the carbon loading model verification result is abnormal (C2) is also incremented by 1.

[0066] When the number of tests C1 is not less than the set value, calculate the number of abnormal carbon loading model verification results C2, which is the proportion of the number of carbon loading model verification results C1, i.e., C2 / C1. If this proportion exceeds the set value, an error signal is triggered and recorded.

[0067] After the verification is completed, the timer for the verification interval is reset, and the timer starts counting down again for the next verification.

[0068] The above method first ensures that the vehicle can operate normally by setting certain conditions.

[0069] Secondly, considering that the carbon load output by the model may be inaccurate due to various reasons and cannot reflect the actual carbon deposit situation of the DPF, the value measured by the differential pressure sensor at the steady state point without oil injection is considered relatively accurate and can reflect the differential pressure of the DPF at this time. By periodically calibrating the carbon load model with this accurate parameter, it can be ensured that the carbon load output by the model is accurate.

[0070] Furthermore, by calculating the proportion of verification anomalies to the number of verifications, we can infer issues such as the reliability and consistency of DPF components.

[0071] The above method utilizes the characteristic that hybrid vehicles can operate on pure electric power. Under the premise of ensuring that the vehicle can operate normally and that all sensors are accurate, the electric motor drives the engine to obtain the DPF flow resistance at a set speed and exhaust gas flow rate. Based on this flow resistance, the calibrated theoretical value of carbon load is obtained and compared with the actual carbon load value displayed by the on-board computer to achieve verification.

[0072] Example 2:

[0073] This embodiment provides a system for implementing the above method, including:

[0074] A differential pressure sensor is connected to the particulate filter of the hybrid vehicle to be tested;

[0075] An exhaust gas flow sensor is connected to the particulate filter outlet of the hybrid vehicle to be calibrated.

[0076] A tachometer is connected to the engine of the hybrid vehicle to be calibrated;

[0077] The processor is configured to: obtain the flow resistance of the particulate filter based on the exhaust gas flow rate obtained by the exhaust gas flow sensor and the pressure difference obtained by the pressure difference sensor, output the theoretical value F1 of the calibrated carbon loading model, and compare it with the actual value F2 of the carbon loading model to obtain the difference between F1 and F2.

[0078] The processor is also configured to: if the difference between F1 and F2 is less than a set value, then the verification count C1 is incremented by 1; if it is not less than the set value, then F1 is assigned to F2, the verification count C1 is incremented by 1, and the number of verification results that are abnormal is incremented by 1; when C2 / C1 exceeds the set value, an error signal is triggered and recorded, and the verification is completed.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for verifying the carbon load model of motor vehicles, characterized in that, include: Under the premise that the hybrid vehicle meets the verification conditions, switch to pure electric mode; In pure electric mode, the control motor drives the engine to a set speed N, and after driving for a set period of time and reaching a stable state, the output value P1 of the differential pressure sensor of the particulate filter and the exhaust gas flow value M1 are obtained. Based on M1 and P1, the current flow resistance R1 of the particulate trap is obtained. The theoretical value F1 of the calibrated carbon loading model is obtained by looking up the table and compared with the actual value F2 of the current carbon loading model. If the difference between F1 and F2 is less than the set value, the verification count C1 is incremented by 1; if it is not less than the set value, F1 is assigned to F2, the verification count C1 is incremented by 1, and the number of verification results that are abnormal is incremented by 1; when C2 / C1 exceeds the set value, an error signal is triggered and recorded, and the verification is completed. The verification conditions for hybrid vehicles are as follows: The particulate filter and the connected differential pressure sensor are functioning correctly. The differential pressure sensor of the particulate filter does not exhibit zero-point drift when the engine is stationary. The actual value of F2 in the current carbon loading model exceeds the set value; The battery pack's SOC is greater than the set value; The engine is not started; The engine meets the conditions for reverse towing start; The set interval T1 for periodic verification has been reached.

2. The method for verifying the carbon load model of motor vehicles as described in claim 1, characterized in that, Zero-point drift refers to the following: Before each calibration, the status of the particulate filter differential pressure sensor is obtained. When the hybrid vehicle is powered on in pure electric mode but not started, if the measured value of the particulate filter differential pressure sensor is not 0, there is a zero-point measurement deviation.

3. The method for verifying the carbon load model of motor vehicles as described in claim 1, characterized in that, In pure electric mode, the motor drives the engine to the set speed N. During this time, the engine runs by being driven by the motor and no fuel is injected.

4. The method for verifying the carbon load model of motor vehicles as described in claim 1, characterized in that, A steady state includes a stable rotational speed and a stable exhaust gas flow rate; A stable rotational speed is defined as: the change in rotational speed is less than the set value; A stable exhaust gas flow rate is defined as: the change in exhaust gas flow rate is less than the set value.

5. The method for verifying the carbon load model of motor vehicles as described in claim 4, characterized in that, If the change in rotational speed or exhaust gas flow rate is not less than the set value within the set time period, then this test will be terminated.

6. The method for verifying the carbon load model of motor vehicles as described in claim 1, characterized in that, If the difference between F1 and F2 is less than the set value, then the actual value F2 of the current carbon loading model is normal, and the number of verifications C1 is incremented by 1.

7. The method for verifying the carbon load model of motor vehicles as described in claim 1, characterized in that, If the difference between F1 and F2 is not less than the set value, then the actual value F2 of the current carbon loading model is abnormal, and F1 is assigned to F2.

8. The method for verifying the carbon load model of motor vehicles as described in claim 1, characterized in that, After the verification is completed, the timer for the verification interval is reset, and the timer starts counting down again for the next verification.

9. A vehicle carbon load model verification system, used to implement the vehicle carbon load model verification method as described in any one of claims 1-8, characterized in that, The system includes: A differential pressure sensor is connected to the particulate filter of the hybrid vehicle to be tested; An exhaust gas flow sensor is connected to the particulate filter outlet of the hybrid vehicle to be calibrated. A tachometer is connected to the engine of the hybrid vehicle to be calibrated; The processor is configured to: obtain the flow resistance of the particulate filter based on the exhaust gas flow rate obtained by the exhaust gas flow sensor and the pressure difference obtained by the pressure difference sensor, output the theoretical value F1 of the calibrated carbon loading model, and compare it with the actual value F2 of the current carbon loading model to obtain the difference between F1 and F2. The processor is also configured to: if the difference between F1 and F2 is less than a set value, then the verification count C1 is incremented by 1; if it is not less than the set value, then F1 is assigned to F2, the verification count C1 is incremented by 1, and the number of verification results that are abnormal is incremented by 1; when C2 / C1 exceeds the set value, an error signal is triggered and recorded, and the verification is completed.

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