Vehicle control system

Abstract

The objective is to provide a vehicle control system that accumulates data capable of accurately determining whether an engine failure is due to past over-revving. [Solution] The vehicle control device is a vehicle control device equipped with an engine, and includes a storage unit that stores occurrence data representing the occurrence of over-rotation of the engine for a predetermined number of times the over-rotation has occurred, and a recording unit that, when the over-rotation is detected, records in the storage unit, in association with the occurrence data, at least one of first data relating to the change in the engine speed after the over-rotation has been reached and second data that allows the vehicle to infer whether or not it is performing a first run equivalent to circuit driving.

Description

Technical Field

[0001] The present invention relates to a control device for a vehicle.

Background Art

[0002] When the engine speed becomes equal to or higher than a predetermined threshold value, there is a possibility of an over-rev, which is an over-rotation of the engine, and engine damage is assumed. Since it is necessary to avoid engine damage, when the engine speed becomes equal to or higher than the threshold value, it is known to store data associated with the data for 10 seconds before and after the time when the engine speed becomes equal to or higher than the threshold value. Specifically, data such as date and time, vehicle speed information, gear position information, and total mileage information is stored. Such data is used for failure diagnosis (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a circuit mode for improving the running performance of a vehicle in a circuit, control for releasing a limiter that restricts the occurrence of an over-rev may be performed. By this control, the vehicle can perform circuit running at an engine speed higher than the threshold maximum rotation speed before the limiter release in the circuit. By improving the running performance of the vehicle, the driver of the vehicle can enjoy motor sports. The circuit mode is selected based on an intentional operation by the driver.

[0005] However, selecting circuit mode increases the likelihood of over-revving. This places a high load on the engine, potentially leading to engine failure such as engine damage. Engine failure doesn't necessarily occur during track driving; it could also occur months later while driving on public roads. In such cases, relying on the aforementioned data memory makes it difficult to accurately determine whether the engine failure was caused by past over-revving.

[0006] Therefore, the present invention aims to provide a vehicle control device that stores data capable of accurately determining whether or not an engine failure is caused by past over-revving. [Means for solving the problem]

[0007] The vehicle control device according to the present invention is a vehicle control device equipped with an engine, comprising: a storage unit that stores occurrence data representing the occurrence of over-rotation of the engine for a predetermined number of occurrences of the over-rotation; and a recording unit that, when over-rotation is detected, records in the storage unit, in association with the occurrence data, at least one of first data relating to the change in the engine speed after reaching the over-rotation and second data that allows the vehicle to infer whether or not it is performing a first run equivalent to circuit driving.

[0008] In the above configuration, when over-rotation is detected, at least one of a third data set relating to the absolute value of the vehicle's acceleration after reaching the over-rotation and a fourth data set relating to the accelerator pedal opening amount corresponding to the amount of depression of the accelerator pedal provided on the vehicle may be recorded in the storage unit in association with the generated data.

[0009] In the above configuration, the recording unit may record in the storage unit, in association with the generated data, at least one of the following: first data relating to the change in the engine speed after reaching the over-speed; second data that allows estimation of whether or not the vehicle is performing a first run equivalent to circuit driving; third data relating to the absolute value of the vehicle's acceleration after reaching the over-speed; and fourth data relating to the accelerator opening degree corresponding to the amount of depression of the accelerator pedal provided on the vehicle, which is capable of generating a histogram that distinguishes between the first run and a second run different from the first run. [Effects of the Invention]

[0010] According to the present invention, it is possible to accumulate data that allows for accurate determination of whether or not an engine failure is caused by past over-revving. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing the general configuration of the vehicle. [Figure 2] This is a flowchart illustrating an example of engine ECU operation. [Figure 3] (a) is an example of engine speed trend data. (b) is an example of driving history data. [Figure 4] (a) is an example of the acceleration waveform for lateral acceleration. (b) is an example of the time average and frequency distribution of the absolute values ​​of lateral acceleration. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

[0013] As shown in Figure 1, the vehicle 100 includes an engine 10, a manual transmission 25, and a clutch 21 connecting the engine 10 and the manual transmission 25. A throttle valve 12 is provided in the intake passage 11 of the engine 10.

[0014] The engine 10 is, for example, a gasoline engine and is controlled by an engine ECU (Electronic Control Unit) 70. The engine ECU 70 is an electronic control unit that includes an arithmetic processing circuit that performs various calculations related to the driving control of the vehicle 100, a memory that stores control programs and data, and input / output ports. The engine ECU 70 is an example of a control device for the vehicle 100 and functionally implements the storage unit 71 and recording unit 72, which will be described in more detail later.

[0015] The arithmetic processing circuit includes a microprocessor such as a CPU (Central Processing Unit). Memory includes RAM (Random Access Memory), ROM (Read Only Memory), and non-volatile memory. Non-volatile memory includes EEPROM (Electrically Erasable Programmable ROM), etc. The storage unit 71 can be implemented using non-volatile memory.

[0016] For example, the engine ECU 70 controls the motor 13 that drives the throttle valve 12, thereby changing the opening degree of the throttle valve 12. As the opening degree of the throttle valve 12 increases, the amount of intake air to the engine 10 increases, so the engine ECU 70 increases the fuel consumption in accordance with this increase in intake air. By adjusting the opening degree of the throttle valve 12 and the fuel injection amount in this way, the engine ECU 70 controls the engine speed, which represents the number of rotations per unit time of the output shaft 14 of the engine 10.

[0017] The manual transmission 25 has multiple gears, and the gear ratio is changed by selecting one of the multiple gears achieved by the combination of these gears. The gear of the manual transmission 25 is selected by the driver of the vehicle 100 operating the shift lever 50.

[0018] The clutch 21 includes a flywheel 22 fixed to the output shaft 14 of the engine 10 and a clutch disc 23 fixed to the input shaft 24 of the manual transmission 25. The clutch disc 23 is driven in the extending direction of the input shaft 24 (the left - right direction in FIG. 1) to switch the transmission state of the driving force between the engine 10 and the manual transmission 25. For example, when the driver depresses the clutch pedal 60, the clutch disc 23 is separated from the flywheel 22. At this time, the clutch 21 is disengaged, and no driving force is transmitted between the engine 10 and the manual transmission 25.

[0019] On the other hand, when the depression of the clutch pedal 60 is released, the clutch disc 23 moves leftward in FIG. 1 under the biasing force of a biasing member (not shown) and is pressed against the flywheel 22. At this time, the clutch 21 is engaged, and the driving force is transmitted between the engine 10 and the manual transmission 25. That is, the output shaft 14 of the engine 10 is connected to the input the input shaft 24 of the manual transmission 25 via the clutch 21.

[0020] Thus, the clutch 21 is disengaged by the driver's operation of depressing the clutch pedal 60, while it is engaged when the operation of depressing the clutch pedal 60 is released.

[0021] Also, in the manual transmission 25, when the operating position of the shift lever 50 is in neutral, the rotation of the input shaft 24 is not transmitted to the output shaft of the manual transmission 26. On the other hand, when the operating position of the shift lever 50 is in a forward - driving position such as first gear, second gear, third gear, or in a reverse - driving position such as reverse, the rotation of the input shaft 24 is transmitted to the output shaft 26.

[0022] The output shaft 26 of the manual transmission 25 is connected to the differential 28 via the propeller shaft 27. The driving force of the engine 10 transmitted through the manual transmission 25 is transmitted to the differential 28 via the propeller shaft 27. The driving force transmitted to the differential 28 is distributed to the left and right drive shafts 29L and 29R, and then transmitted to the left and right drive wheels 30L and 30R connected to the drive shafts 29L and 29R.

[0023] The engine ECU 70 is connected to a GPS (Global Positioning System) 59, an engine speed sensor 63, an input shaft speed sensor 65, a vehicle speed sensor 66, an accelerator pedal position sensor 68, and an acceleration sensor 69. The GPS 59 is indirectly connected to the engine ECU 70 via a navigation device (not shown). The GPS 59 determines the current position of the vehicle 100. The current position is determined by latitude and longitude. The engine speed sensor 63 detects the rotational speed of the output shaft 14 of the engine 10 per unit time. That is, the engine speed sensor 63 detects the rotational speed of the output shaft 14. The input shaft speed sensor 65 detects the input shaft speed, which is the rotational speed of the input shaft 24 of the manual transmission 25 per unit time. That is, the input shaft speed sensor 65 detects the rotational speed of the input shaft 24.

[0024] The vehicle speed sensor 66 detects the rotational speed per unit time of the propeller shaft 27, which is connected to the output shaft 26 of the manual transmission 25. In other words, the vehicle speed sensor 66 detects the rotational speed of the propeller shaft 27. Based on the rotational speed or rotational speed detected by the vehicle speed sensor 66, the engine ECU 70 calculates the wheel rotational speed, which is the rotational speed of the drive wheels 30L and 30R, and the vehicle speed. The accelerator pedal position sensor 68 detects the amount of depression of the accelerator pedal 40. The amount of depression of the accelerator pedal 40 is linked to the opening of the throttle valve 12, and is therefore sometimes called the accelerator opening. For this reason, it can be said that the amount of depression of the accelerator pedal 40 corresponds to the accelerator opening. The acceleration sensor 69 detects the lateral acceleration and longitudinal acceleration of the vehicle 100.

[0025] The engine ECU 70 controls the vehicle 100 based on the output signals from the engine speed sensor 63, the input shaft speed sensor 65, and the vehicle speed sensor 66, as well as the amount of depression of the accelerator pedal 40 and the clutch pedal 60. For example, the engine ECU 70 drives the motor 13 based on the output signal from the accelerator pedal position sensor 68 (i.e., the accelerator opening) and adjusts the opening of the throttle valve 12 as described above. This allows the engine ECU 70 to control the engine speed.

[0026] Furthermore, the engine ECU 70 is connected to a mode selector switch 67 for switching the driving mode of the vehicle 100. The engine ECU 70 selects one of several driving modes in response to the driver's operation on the mode selector switch 67. The driving modes include an eco mode that reduces fuel consumption and a circuit mode that improves the driving performance of the vehicle 100 on a race track.

[0027] Specifically, when Eco Mode is selected, the engine ECU 70 makes the response of the throttle valve 12 to accelerator input more moderate compared to the normal state where no driving mode is selected. Also, when Circuit Mode is selected, the engine ECU 70 removes the limiter that restricts the occurrence of over-revving. This allows the vehicle 100 to drive on a circuit at an engine speed higher than the threshold maximum RPM before the limiter was removed. If the driver's consent has been obtained in advance, the engine ECU 70 may determine whether the vehicle has driven on a circuit in the past based on the area of ​​the circuit identified by map information and the position determined by GPS 59. If the vehicle 100's position was previously within the area of ​​the circuit, the engine ECU 70 can determine that the vehicle has driven on a circuit in the past.

[0028] In this embodiment, the driving is not limited to circuit driving; any driving similar to circuit driving is acceptable as long as the engine 10 is under a high load. In other words, in this embodiment, any driving equivalent to circuit driving is acceptable. Circuit driving and driving equivalent to circuit driving are examples of the first type of driving. Also, over-revving, which represents excessive rotation of the engine 10, is sometimes called overrunning. In particular, over-revving is often called overrunning when the engine 10 is a diesel engine.

[0029] The memory unit 71 of the engine ECU 70 stores OR (Over Revolution) events, which represent the occurrence of over-revving in the engine 10, up to a predetermined number of times. An OR event is an example of occurrence data. For example, the memory unit 71 stores three or more events. When driving a vehicle 100 equipped with a manual transmission 25, there is a high possibility of over-revving occurring due to incorrect operation of the shift lever 50 (for example, an operating error). However, if over-revving occurs only once or twice, the possibility of engine 10 failure is low. For this reason, the memory unit 71 stores at least the most recent three events.

[0030] The recording unit 72 of the engine ECU 70 detects engine over-revving when the engine speed exceeds a threshold maximum speed. When over-revving is detected, the recording unit 72 records engine speed transition data in the storage unit 71 in association with the OR event. The engine speed transition data is an example of first data and is data relating to the engine speed transition of engine 10 after it has reached over-revving. By accumulating engine speed data in the storage unit 71, the degree of damage to engine 10 caused by past over-revving can be identified or estimated (hereinafter simply referred to as identified).

[0031] Furthermore, if the recording unit 72 detects an over-rev, it records the driving history data in the storage unit 71, associating it with the OR event. The driving history data is an example of the second data, and is data that allows for the inference of whether or not driving equivalent to circuit driving has occurred. For example, the driving history data includes the average vehicle speed, maximum vehicle speed, and maximum engine speed during the over-rev event up to the time the OR event is recorded. The average vehicle speed is calculated using a known method.

[0032] The driving history data may include the highest engine speed since the OR event was recorded. The driving history data may also include the time percentage and frequency of high-speed driving at a throttle opening higher than the threshold opening, up to the time the OR event was recorded. Instead of selecting a circuit mode, it becomes possible to infer whether or not driving equivalent to circuit driving has occurred based on average speed, maximum speed, maximum engine speed, etc. If it is inferred that driving equivalent to circuit driving has occurred, it is identified that there was a past instance of driving that caused significant damage to engine 10.

[0033] The recording unit 72 may choose not to record both the engine speed data and the driving history data in the storage unit 71, but to record only one of them. In other words, the recording unit 72 may record at least one of the engine speed data and the driving history data in the storage unit 71 in association with an OR event. Recording both the engine speed data and the driving history data improves the accuracy of determining the possibility of engine 10 failure. Recording either the engine speed data or the driving history data frees up space in the storage unit 71.

[0034] The processes performed by the engine ECU 70 will be explained with reference to Figures 2 and 3(a) and (b).

[0035] First, as shown in Figure 2, the engine ECU 70 determines whether or not over-revving has occurred (step S1). Specifically, the engine ECU 70 determines whether or not the engine speed has exceeded the threshold maximum rotational speed. The threshold maximum rotational speed, also known as the rev limit, represents the limit of the acceptable rotational speed. The threshold maximum rotational speed is set in advance through experiments, design, simulations, etc. If over-revving has not occurred (step S1: NO), the engine ECU 70 terminates processing.

[0036] On the other hand, if over-revving occurs (Step S1: YES), the engine ECU 70 records an OR event (Step S2). In other words, if over-revving occurs, the engine ECU 70 detects the over-revving and records an OR event. As a result, OR events accumulate in the engine ECU 70.

[0037] When an OR event is recorded, the engine ECU 70 records engine speed transition data (step S3). For example, as shown in Figure 3(a), the engine ECU 70 records engine speed transition data in association with one OR event. The engine speed transition data includes multiple engine speed ranges after over-revving occurs and the cumulative time of the engine speed detected within those ranges.

[0038] The minimum range Ne1-Ne2, the maximum range Ne3-Ne4, and the intermediate range Ne2-Ne3, which fall between the minimum and maximum ranges, are all set appropriately according to the design and other factors. In this embodiment, engine speed Ne1 is the minimum speed and engine speed Ne4 is the maximum speed. The range widths of the engine speed ranges may be the same or different. Setting either the same or different range widths may improve the accuracy of determining the degree of damage to the engine 10. In this way, since cumulative time is associated with each engine speed range, it becomes possible to determine the degree of damage to the engine 10 after an over-rev has occurred.

[0039] After recording the engine speed trend data, the engine ECU 70 records the driving history data (step S4) and terminates the process. For example, as shown in Figure 3(b), the engine ECU 70 records the driving history data in association with one OR event. The driving history data includes data about the driving state of vehicle 100 up to the time the OR event was recorded. Specifically, the driving history data includes average vehicle speed, maximum vehicle speed, and maximum engine speed as data. The driving history data may also include data other than these, if it is possible to infer that there was driving equivalent to circuit driving. This may improve the accuracy of the inference.

[0040] Thus, each time an over-rev occurs, the engine ECU 70 records engine speed progression data and driving history data in association with the OR event. Note that after recording three OR events, if the engine ECU 70 records a fourth OR event, it erases the oldest first OR event and the engine speed progression data and driving history data associated with it. The engine ECU 70 then records the fourth OR event and subsequent events after erasing the first OR event and its associated engine speed progression data and driving history data.

[0041] As a result, the engine ECU 70 stores the most recent three OR events. Consequently, the oldest OR event is overwritten by the newest OR event. The number of OR events stored in the engine ECU 70 can be determined as appropriate depending on the design. The engine ECU 70 may also skip either step S3 or S4, depending on the design. In this case, the engine ECU 70 stores either engine speed progression data or driving history data.

[0042] Thus, according to this embodiment, the engine ECU 70 stores OR events up to the number of times over-revving has occurred. Furthermore, when the engine ECU 70 detects over-revving, it records at least one of the engine speed change data and driving history data for a specific period in association with the OR event. The specific period is, for example, the period from the detection of over-revving to the detection of the fuel cut trigger on the trip in which over-revving occurred. The fuel cut trigger represents an event that stops or suppresses fuel injection to prevent over-revving. As a result, data is accumulated that allows for accurate determination of whether or not a failure of the engine 10 is due to past over-revving.

[0043] The engine ECU 70 may also record data other than engine speed progression data and driving history data as target data and associate it with OR events. For example, the engine ECU 70 may record at least one of the following as target data and associate it with OR events: absolute value data of lateral acceleration, absolute value data of longitudinal acceleration, and accelerator opening data. The absolute value data of lateral acceleration and the absolute value data of longitudinal acceleration are examples of third data. Accelerator opening data is an example of fourth data. Depending on the memory capacity, the engine ECU 70 may also record at least one of the following as target data and associate it with OR events: engine speed progression data, driving history data, and target data.

[0044] For example, as shown in Figure 4(a), the acceleration sensor 69 can detect the lateral acceleration, which varies alternately from left to right, according to the driving state of the vehicle 100. In this case, the recording unit 72 of the engine ECU 70 calculates the average value per unit time for the absolute value of the lateral acceleration. The unit time is set in advance to several tens of seconds or several minutes.

[0045] As a result, as shown in Figure 4(b), the recording unit 72 can obtain time-averaged values ​​Z1 and Z2 that clearly distinguish between general driving, which represents driving on public roads, and circuit driving. General driving is an example of the second driving. When the recording unit 72 obtains the time-averaged values ​​Z1 and Z2, it counts the frequency of the absolute values ​​of the left and right accelerations for each unit interval, which is divided into multiple intervals, and generates a histogram of the frequency distribution.

[0046] Since the histograms of the frequency distribution of general driving and the histograms of the frequency distribution of circuit driving are separated as features, the recording unit 72 can determine whether or not there is a history of circuit driving by looking at the histograms. In this way, if the recording unit 72 records the absolute value data of lateral acceleration in association with OR events in the storage unit 71, it can determine whether or not there is a history of circuit driving by looking at the histograms. The absolute value of longitudinal acceleration, accelerator opening, engine speed, and driving history are basically the same as the absolute value of lateral acceleration, so a detailed explanation will be omitted.

[0047] It should be noted that the recording unit 72 may not be able to acquire sufficient target data to generate a histogram. In this case, the recording unit 72 may determine whether or not circuit driving has occurred by comparing the maximum value Max_g of the time-averaged Z1 or the maximum value Max_h of the time-averaged Z2 with criterion CL. Criterion CL is a reference value that distinguishes the difference between general driving and circuit driving, and is set in advance based on design, experiments, etc.

[0048] For example, if the recording unit 72 finds a maximum value Max_h of the time-averaged Z2 that is greater than criterion CL, it can determine that there is a history of circuit driving. Conversely, if the recording unit 72 finds a maximum value Max_g of the time-averaged Z1 that is smaller than criterion CL, it can determine that there is no history of circuit driving. Instead of such maximum values ​​Max_g of time-averaged Z1 or Max_h of time-averaged Z2, the recording unit 72 may use the trip average Tm_g of time-averaged Z1 or the trip average Tm_h of time-averaged Z2. Similarly, the recording unit 72 can determine whether or not there is a history of circuit driving by using the trip averages Tm_g and Tm_h. The recording unit 72 may also record such maximum values ​​Max_g and Max_h, and trip averages Tm_g and Tm_h, in the storage unit 71 in association with OR events.

[0049] In addition, if the recording unit 72 detects the occurrence of a deceleration acceleration greater than the threshold acceleration based on the longitudinal acceleration, it may record position data, including the position of the vehicle 100 at the time the deceleration acceleration occurred, in the storage unit 71 in association with the OR event. When the recording unit 72 detects the occurrence of deceleration acceleration in subsequent instances, it can determine whether or not there is a history of circuit driving based on whether or not the position at that time is close to the previous position. For example, if the recording unit 72 has already stored the position of the vehicle 100 within the area of ​​the circuit, it can determine whether or not there is a history of circuit driving based on whether or not that position is close to the position at subsequent instances.

[0050] Furthermore, the recording unit 72 may change the location recording method according to the storage capacity of the memory unit 71. For example, if the storage capacity of the memory unit 71 is small and the locations are close to each other, the recording unit 72 may update a single frequency counter and record the location data in association with OR events. On the other hand, if the storage capacity of the memory unit 71 is large and the locations are not close to each other, the recording unit 72 may update a frequency counter for each location and record the location data in association with OR events.

[0051] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims.

[0052] For example, a hybrid vehicle (HV) equipped with a motor generator may be used as the vehicle 100 described above. In this case, an HV-ECU may be used as the control device for vehicle 100 instead of the engine ECU 70. [Explanation of Symbols]

[0053] 10 Engines 25 Manual transmission 50 Shift lever 70 Engine ECU 71 Storage section 72 Records Section

Claims

1. A control device for a vehicle equipped with an engine, A storage unit that stores occurrence data representing the occurrence of over-rotation of the engine for a predetermined number of times the over-rotation has occurred, When over-rotation is detected, the recording unit records at least one of the following in association with the generated data: first data relating to the change in the engine speed after reaching the over-rotation, and second data that allows for the estimation of whether or not the vehicle is performing a first run equivalent to circuit driving. A control device for a vehicle equipped with the following features.

2. When the recording unit detects over-rotation, it records at least one of the following in association with the generated data: a third data relating to the absolute value of the vehicle's acceleration after reaching the over-rotation, and a fourth data relating to the accelerator pedal opening amount corresponding to the amount the accelerator pedal is pressed down on the vehicle. The vehicle control device according to feature 1.

3. The recording unit records in the storage unit, in association with the generated data, at least one of the following: first data relating to the change in engine speed after reaching the over-speed; second data that allows estimation of whether the vehicle is performing a first run equivalent to circuit driving; third data relating to the absolute value of the vehicle's acceleration after reaching the over-speed; and fourth data relating to the accelerator opening degree corresponding to the amount of depression of the accelerator pedal provided on the vehicle, which allows generation of a histogram that distinguishes between the first run and a second run different from the first run. A vehicle control device according to claim 1 or 2.

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