A protection method for a high-gear starting clutch of an automobile

Abstract

The present invention discloses a protection method for a high-gear starting clutch of an automobile, including: S1: determining whether the current operating condition of the vehicle is a starting protection condition, and if so, setting a starting flag signal representing entry into the starting protection condition; S2: determining whether the current operating condition of the vehicle is a starting completion condition, and if so, resetting the starting flag signal representing starting completion; S3: confirming the current starting gear, and judging whether it is a high-gear start according to the current starting gear. If so, an alarm reminder is given to the driver according to the high-gear starting state. The present invention is based on a manual transmission vehicle (MT). By identifying the characteristics of the high-gear starting state of the vehicle, protection restrictions and instrument reminders are carried out when the vehicle has a high-gear starting condition, so as to better limit or improve problems such as clutch overheating and ablation caused by high-gear starting conditions with large impacts, high rotational speed differences, and large torques.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle intelligent control, and particularly to a protection method for a high-gear starting clutch of an automobile. Background Art

[0002] For some commercial vehicle models, such as manual transmission (MT) engineering dump trucks, due to reasons such as drivers' bad driving habits, poor road conditions, and users' pursuit of speed, in actual use situations and scenarios, there are many high-gear starting conditions with high torque, high speed, and difficult clutch engagement. For such high-gear starting conditions, if they occur frequently, the following hazards will be brought:

[0003] 1. Cause a huge impact on the transmission. If starting directly in a high gear, then in order to prevent the engine from stalling, the engine speed must be increased. When the speed is higher, the power and torque will be greater. When the high power is transmitted to the transmission system, it will cause a certain impact on the transmission, thereby reducing the service life of the transmission.

[0004] 2. Wear the clutch. When starting in a high gear, the clutch gear and the current vehicle speed cannot be matched, and the clutch must be controlled to remain in the semi-clutch state for a long time to ensure that the vehicle does not stall until it can enter the vehicle speed matching the current gear, and then the clutch can be fully released. During this period, the wear on the clutch is quite large, and it will also delay the starting time.

[0005] 3. Increase engine carbon deposition. When starting in a high gear, due to the small torsional force, the power and speed cannot be synchronized, so more gasoline will be consumed than starting in the first gear. And directly starting in a high gear will cause the gasoline not to burn fully. Over time, it will cause more carbon deposition in the engine, further increasing fuel consumption.

[0006] The existing methods for automatic transmission models (AMT or DCT) usually require adding transmission input / output shaft sensors, clutch travel sensors, transmission controllers (TCU), etc. in terms of hardware, and adding a clutch temperature model in terms of software to calculate and protect the clutch temperature under various operating conditions of the vehicle.

[0007] For manual transmission models (MT), generally there are no such multiple sensors, so the above solutions are not applicable to many current manual transmission models and application scenarios. Therefore, the common practice for manual transmission models is:

[0008] 1. By directly identifying whether the clutch is in an overload state and then implementing overload protection by restricting the engine speed. For example, patent "CN114526295A" discloses an overload protection method, device, vehicle, and storage medium for a clutch. The drawbacks of this solution are as follows: It still needs to add relevant sensors of the clutch to achieve the function. On the one hand, it increases the manufacturing cost. On the other hand, adding sensors for detection increases the complexity of the system, which in turn leads to an increase in system failure rate. Moreover, there is no warning prompt, which is not user-friendly, and drivers may make this mistake for a long time.

[0009] 2. By identifying the starting gear and determining whether the gear is safe. For example, "CN115130590A" discloses a method for identifying the starting gear based on vehicle data analysis. However, the drawback of this solution is that the scheme for judging the start does not take into account the unstable speed ratio at the beginning of starting, and the determination may be inaccurate.

[0010] In summary, therefore, it is necessary to develop a control strategy framework applicable to solving the problems and scenarios of manual transmission vehicle models.

[0011] The information disclosed in the above background art section is only intended to increase the overall understanding of the present invention and should not be regarded as an admission or any form of suggestion that this information constitutes prior art known to those of ordinary skill in the art. Summary of the Invention

[0012] The object of the present invention is to provide a protection method for the clutch in high-gear starting of an automobile. Based on a manual transmission vehicle model (MT), by identifying the characteristics of the high-gear starting state of the vehicle, protection restrictions and instrument reminders are carried out when the vehicle is in a high-gear starting working condition, so as to better limit or improve problems such as clutch overheating and ablation caused by high-gear starting working conditions with large impacts, high rotational speed differences, and large torques.

[0013] To achieve the above-mentioned invention object, the technical solution of the present invention is as follows:

[0014] A protection method for the clutch in high-gear starting of an automobile, comprising the following steps:

[0015] S1: Judge whether the current operating condition of the vehicle is entering the starting protection condition. If so, set the starting flag bit signal indicating the entry into the starting protection condition.

[0016] S2: Judge whether the current operating condition of the vehicle is the starting completion condition. If so, reset the starting flag bit signal indicating the starting completion.

[0017] S3: Confirm the current starting gear, and judge whether it is a high-gear starting according to the current starting gear. If so, give an alarm reminder to the driver according to the high-gear starting state.

[0018] Specifically, determining whether the current operating condition of the vehicle is a starting protection condition in step S1 includes:

[0019] Determining whether the neutral switch signal is in a non-set non-neutral state; determining whether the clutch switch signal is in a set depressed state; determining whether there is a change in vehicle speed signal; determining whether the throttle signal is in a depressed state; determining whether the engine idle signal is in a non-idle condition; if all are yes, it is determined as the starting protection condition.

[0020] Specifically, step S1 further includes: determining whether the engine torque / speed and throttle opening exceed a preset threshold, and if they exceed the preset threshold, restricting the engine speed and engine torque.

[0021] Specifically, determining whether the current operating condition of the vehicle is a starting completion condition in step S2 includes:

[0022] Determining whether the neutral switch signal is in a reset neutral state; or determining whether the clutch switch signal is in a reset released state; if one of them is yes, it is determined as the starting completion condition.

[0023] Specifically, confirming the current starting gear in step S3 includes:

[0024] Calculating the engine speed N1 / drive shaft speed N2, and then comparing it with the calibrated transmission actual gear - speed ratio range. If it falls within the corresponding speed ratio range, it is judged to the corresponding gear and lasts for ti time. If the gear does not change, take the judged gear; if the gear changes, take the changed gear.

[0025] Specifically, if it is determined according to the current starting gear in step S3 that it is a high - gear start, then an alarm reminder is given to the driver according to the high - gear start state, including:

[0026] In the current driving cycle state, count the number of times N1 when the starting gear ≥ gear threshold x. If this count value N1 > threshold a, an a - type alarm reminder is given to the instrument through the can message.

[0027] Specifically, if it is determined according to the current starting gear in step S3 that it is a high - gear start, then an alarm reminder is given to the driver according to the high - gear start state, including:

[0028] When the engine is in the running state, accumulate the number of times N2 when the starting gear ≥ gear threshold y. If this number N2 > threshold b within a certain running time Ti in the engine running state, an b - type alarm reminder is given to the instrument through the can message.

[0029] Advantages of the present invention:

[0030] 1. Compared with automatic transmission models, this solution is based on manual transmission models and can identify the starting conditions of large impact, high speed and difficult clutch engagement during driving;

[0031] 2. By limiting the engine speed / torque under such working conditions, problems such as clutch overheating and ablation can be better limited or improved;

[0032] 3. Under the premise that the transmission input shaft signal can be saved, the gear determination condition after the start flag is reset can be set to determine whether to start in a high gear;

[0033] 4. At the same time, different instrument reminder types and release strategies are used to distinguish between different frequencies of high-speed starting, but the existing technical solutions have not developed corresponding solutions to these problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a schematic diagram of the steps of a method for protecting a high-gear starting clutch of an automobile.

[0035] Figure 2 The present invention is a flow chart of a method for protecting a high-gear starting clutch of an automobile. DETAILED DESCRIPTION

[0036] In order to explain the technical content of the present invention in detail, the purpose and effect achieved are described below in combination with the embodiments and the accompanying drawings. In the description of the embodiments, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0037] According to a specific implementation method of this scheme, a protection method for a high-gear starting clutch of an automobile is provided. Figure 1 As shown, the execution subject of the following embodiments may be a controller installed on the vehicle. The controller takes the Electronic Control Unit, the electronic control unit ECU as an example. The ECU may be composed of a microcontroller MCU, a memory ROM, a RAM, an input / output interface I / O, an analog-to-digital converter A / D, and large-scale integrated circuits such as shaping and driving. The ECU determines the current operating condition of the vehicle based on the acquired vehicle operating status data and performs corresponding operation instructions.

[0038] The specific steps include:

[0039] S1: determining whether the current operating condition of the vehicle is a start protection condition, and if so, setting a start flag signal indicating that the vehicle has entered the start protection condition;

[0040] To determine the current operating condition of the vehicle, the ECU specifically obtains data on the vehicle's operating state to judge the current operating condition of the vehicle. In this application, it is mainly to determine whether the vehicle enters the starting protection condition.

[0041] The data on the vehicle's operating state refers to the parameters during the vehicle's driving, which can be engine speed, vehicle running speed, engine throttle state, clutch state, etc. The obtained data on the vehicle's operating state includes but is not limited to the above data, as long as it can confirm that the current operating condition is the starting condition. The starting protection condition refers to the working state in the starting condition where it is confirmed that the vehicle is not in the neutral gear state, the clutch is depressed, there is a vehicle speed change, the throttle is depressed, and it is not in the idle condition. If all the above conditions are met, it is determined that the vehicle enters the starting protection condition, and the starting flag bit = 1 is set; otherwise, the starting flag bit = 0, that is, it is not in the starting protection condition.

[0042] After entering the starting protection condition, the ECU sets the starting flag bit signal indicating the entry into the starting protection condition; the purpose is to make the corresponding flag bit set when the above-mentioned working state confirmation occurs, regardless of whether the corresponding interruption is enabled, and the target element to be operated is executed and maintained. The advantage of this is that by determining the actual position of the shift execution component based on the historical position of the shift execution component and the position change amount of the shift execution component relative to the historical position, there is no need to additionally add a position sensor when identifying the actual position of the shift execution component, reducing costs.

[0043] S2: Judge whether the current operating condition of the vehicle is the starting completed condition. If so, reset the starting flag bit signal indicating the starting completion.

[0044] Here, for AMT / DCT vehicles of the automatic transmission type with a transmission input shaft speed sensor, the ECU can directly calculate the slip speed of the torque converter lock-up clutch using the input shaft speed sensor signal and the engine speed signal to determine the gear. However, for MT vehicles of the manual transmission type without a transmission input shaft speed sensor in this embodiment, it is necessary to reset the starting flag bit for the state indicating starting completed and in-gear driving or the state indicating starting completed. Therefore, in this embodiment, there is no need to additionally add a position sensor when identifying the actual position of the shift execution component, reducing costs.

[0045] S3: Confirm the current starting gear, and judge whether it is a high-gear start according to the current starting gear. If so, give an alarm reminder to the driver according to the high-gear start state.

[0046] During the starting process, the gear ratio is constantly changing, making it impossible to accurately determine the gear position. In this embodiment, after the clutch is engaged and the engine has run for a period of time, the vehicle speed becomes relatively stable, and the ECU can identify the current gear position, improving the accuracy of gear position identification. The ECU judges and stores the starting gear position in the Rom-cache and Ram-non-volatile memory, and finally compares it with the calibrated threshold to determine whether the driver's behavior belongs to the high-gear starting behavior and reminds the driver. The advantage of this is that it can humanely correct the driver's behavior in real time and prevent the driver from making long-term driving mistakes due to system repair protection types. To remind the driver, voice and / or dashboard display methods can be used. Optionally, the reminder method can be the flashing of a warning light and an alarm on the in-vehicle display panel, or a warning statement popping up on the screen of the in-vehicle display panel, or a device with a broadcasting function on the vehicle broadcasting a driving improper reminder, etc. Any method that can achieve the purpose of reminding the driver belongs to the protection scope of this application.

[0047] Therefore, the solution of this embodiment is based on a manual transmission vehicle model, which can identify starting conditions with large impacts, high engine speeds, and difficult clutch engagement during driving. Without adding the input shaft signal of the transmission, by setting the conditions for judging the gear after the starting flag bit is reset, the judgment of whether it is a high-gear start is realized, with high accuracy. The whole process is realized by software, reducing the cost of sensors. At the same time, a reminder strategy is made to better limit or improve problems such as clutch overheating and ablation caused by high-gear starting conditions with large impacts, high speed differences, and large torques, reducing the damage to the clutch caused by improper driving behaviors and increasing the service life of the clutch, ultimately achieving the purpose of this embodiment.

[0048] As a preferred technical solution of this embodiment, in step S1, judging whether the current operating condition of the vehicle is a starting protection condition includes:

[0049] (1) The neutral switch is not set; - confirm that the vehicle is not in the neutral state; the ECU judges the neutral state by confirming the opening and closing of the neutral switch. In the triggered case, it is in the on state, that is, when the vehicle is in neutral, the contact switch is in the off state and the vehicle stops running, and when the vehicle is in gear, the contact switch is in the on state and the vehicle starts running.

[0050] (2) The clutch switch is set; - confirm that the clutch is depressed; within the time period when the engine speed changes from 0 to the idle speed, the state of the clutch is obtained through a sensor. The state of the clutch can be obtained by detecting the clutch pedal opening information or the clutch pedal force information, etc. If the ECU obtains the clutch pedal opening information or the clutch pedal force information according to the detection result of the sensor, it indicates that the driver has depressed the clutch pedal.

[0051] (3) Vehicle speed signal; - Confirm that there is a change in vehicle speed; The engine speed can be collected by a speed sensor installed on the engine at regular intervals. When the engine speed collected by the speed sensor is 0, it indicates that the vehicle is in a stationary state and the vehicle has not started.

[0052] (4) Throttle signal; - Confirm that the throttle is depressed; Obtain the state of the engine throttle. The state of the engine throttle can be obtained by detecting the throttle pedal opening information of the engine or by detecting the throttle pedal force information of the engine. Among them, the throttle pedal opening information of the engine can be measured by a sensor that can measure distance installed on the throttle pedal, and the throttle pedal force information of the engine can be measured by a pressure sensor installed on the throttle pedal. If the ECU obtains the throttle pedal opening information or the throttle pedal force information of the engine according to the detection result of the sensor, it indicates that the engine throttle is in the open state, the driver has operated the clutch, and the engine throttle pedal has been depressed; If the ECU does not obtain the throttle pedal opening information or the throttle pedal force information of the engine according to the detection result of the sensor, it indicates that the engine throttle state is in the closed state, the driver has not operated the engine throttle, and the engine throttle pedal has not been depressed.

[0053] (5) Engine idle speed or state; - Confirm that it is not in the idle operating condition; The engine speed collected by the speed sensor rises from 0 until the collected engine speed becomes the idle speed. Among them, the idle speed is known and is related to the engine model. The idle speed can be set in advance in the ECU, so the ECU can judge whether the engine is in the idle state according to the engine speed collected by the speed sensor.

[0054] If the above conditions are all satisfied simultaneously within a certain period of time, it is determined as the starting protection working condition, and the starting flag bit = 1 is set; Otherwise, the starting flag bit = 0. The above information can be obtained from the vehicle instrument through the CAN bus, but is not limited to this.

[0055] As a preferred technical solution of this embodiment, in step S2, to judge whether the current operating condition of the vehicle is the starting completion working condition, it includes whether the ECU judges the following conditions are satisfied:

[0056] Clutch released: Clth_st = 0, indicating starting completed and driving in gear;

[0057] Return to neutral: Gbx_stNPos = 1, indicating starting completed and need to shift gears for driving;

[0058] If any one of the above is satisfied, it is determined as the starting completion working condition.

[0059] As a preferred technical solution of this embodiment, the current starting gear is confirmed in step S3. This solution is that the ECU determines the starting gear when the starting flag position of the transmission input shaft speed sensor is reset as follows:

[0060] The gear judgment logic is to calculate: PT_rTraN2N, that is, engine speed N1 / drive shaft speed N2, and then compare it with the calibrated actual gear-speed ratio range of the transmission. If it falls in the corresponding speed ratio range, the corresponding gear is judged and lasts for ti time. The time can be calibrated. If the gear does not change, the judged gear is taken; if the gear changes, the gear after the change is taken. The minimum value of the judged gear here is generally 1.

[0061] As the preferred technical solution of this embodiment, this embodiment provides two different types of instrument reminders and release strategies, specifically:

[0062] (1) In this driving cycle, when the engine is running, the number of times the starting gear position is ≥ the markable gear position threshold x is counted. If the count value N1>threshold a, a Class A alarm reminder of the instrument is issued through the CAN message.

[0063] Accordingly, the clearing condition for the Class A alarm reminder is: until the end of the current driving cycle, the alarm is cleared after a new judgment and count is performed in the next driving cycle.

[0064] (2) When the engine is running, the number of times N2 when the starting gear position is ≥ the calibrable gear position threshold value y is recorded. This record is a cumulative record and is stored in RAM. The cumulative running time of the engine running state is recorded. If the number N2> threshold value b within a certain running time Ti, the instrument's Class B alarm reminder is issued through the CAN message, where the threshold value b and the certain running time Ti are both calibrable values. It is worth pointing out that the cumulative running time of the Class B alarm reminder is the cumulative time under the engine running state, which can be the cumulative time of multiple cycle driving, which is different from the single cycle driving time of the Class A alarm reminder.

[0065] Accordingly, the clearing condition of the Class B alarm reminder is: the UDS diagnostic protocol is cleared, then the alarm is cleared; or within a certain running time Ti after the instrument alarm, the number of starting gears ≥ the threshold N2 ≤ the threshold b, then the alarm is cleared.

[0066] In this embodiment, the gear thresholds x and y can also be different values, for example, gear threshold y < gear threshold x. By calibrating two different gear thresholds, reminder strategies for two different situations are covered, that is, Class A alarm reminder covers reminders in a single ultra-high gear starting state, and Class B alarm reminder covers reminders in multiple higher gear starting states.

[0067] As a preferred technical solution of this embodiment, step S1 further includes: simultaneously determining that if the throttle opening > threshold (markable), and the rotational speed or torque > threshold (markable), then the engine rotational speed or torque is limited.

[0068] The following is further described with reference to the Figure 2 flowchart according to the actual scenario:

[0069] For a manual transmission MT engineering dump truck, due to reasons such as the driver's bad driving habits, poor road conditions, and the user's pursuit of speed, in actual use situations and scenarios, there are many high-torque, high-rotational-speed, and high-gear start-up conditions where the clutch is difficult to engage.

[0070] At this time, the ECU collects the neutral gear signal, vehicle speed signal, clutch switch signal, throttle signal, and engine idle speed signal. The ECU will determine in real time based on these five signals whether the current vehicle enters the start protection working condition. When entering the start protection working condition, the ECU first sets the start flag bit signal indicating the entry into the start protection working condition. At the same time, it determines whether the engine torque / rotational speed and throttle opening exceed the preset threshold. If they exceed the preset threshold, the engine rotational speed and engine torque are limited to protect the clutch. At this time, the ECU collects the clutch signal and neutral gear signal again to determine whether the clutch is released or the neutral gear is returned. If either one is satisfied, it indicates the start completion working condition state, and then the start flag bit signal indicating the start completion is reset. At this time, when the engine rotational speed is relatively stable, the ECU calculates the ratio of the engine rotational speed N1 to the drive shaft rotational speed N2 and compares it with the calibrated transmission actual gear - speed ratio. If it falls within the corresponding speed ratio range, the gear entered is determined. Finally, it is determined whether it is a high-gear start by comparing the gear with the calibrated threshold, and the number of high-gear starts is recorded in real time. If the number of high-gear starts in this driving is greater than the threshold a, the instrument gives a warning for type a reminder; if the number of high-gear starts recorded within a period of time is greater than the threshold b, the instrument gives a warning for type b reminder.

[0071] Although the present invention has been described in detail with specific embodiments above, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A protection method for the high-gear starting clutch of an automobile, characterized in that: S1: Determine whether the current operating condition of the vehicle is entering the starting protection condition. If so, set the starting flag signal indicating the entry into the starting protection condition; S2: Determine whether the current operating condition of the vehicle is the starting completion condition. If so, reset the starting flag signal indicating the starting completion; S3: Confirm the current starting gear, including: Calculate the engine speed N1 / propeller shaft speed N2, and then compare it with the calibrated transmission actual gear-ratio range. If it falls within the corresponding ratio range, it is judged to be the corresponding gear and lasts for ti time. If the gear does not change, take the judged gear; if the gear changes, take the changed gear; Judge whether it is a high-gear start according to the current starting gear. If so, give an alarm reminder to the driver according to the high-gear starting state, including: In the current driving cycle state, count the number of times N1 when the starting gear ≥ gear threshold x. If this count value N1 > threshold a, give an alarm reminder of type a to the instrument through the can message; When the engine is running, accumulate the number of times N2 when the starting gear ≥ gear threshold y. If this number N2 > threshold b within a certain running time Ti during the engine running state, give an alarm reminder of type b to the instrument through the can message.

2. The protection method of a high-gear starting clutch for an automobile according to claim 1, characterized in that, In step S1, the judgment of whether the current operating condition of the vehicle is the starting protection condition includes: Judge whether the neutral switch signal is in the non-set non-neutral state; and judge whether the clutch switch signal is in the set depressed state; and judge whether there is a vehicle speed change in the vehicle speed signal; and judge whether the throttle signal is in the depressed state; and judge whether the engine idle signal is in the non-idle condition; if all are, it is determined to be the starting protection condition.

3. The protection method of a high-gear starting clutch for an automobile according to claim 1, characterized in that, Step S1 also includes: judging whether the engine torque / speed and throttle opening exceed the preset threshold. If they exceed the preset threshold, limit the engine speed and engine torque.

4. A protection method for a high-gear starting clutch of an automobile according to claim 1, characterized in that In step S2, the judgment of whether the current operating condition of the vehicle is the starting completion condition includes: Judge whether the neutral switch signal is in the reset neutral state; or judge whether the clutch switch signal is in the reset released state; if either one is, it is determined to be the starting completion condition.

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