Vehicle

Abstract

To provide a vehicle that avoids wrong recognition of a driver that engine behavior in an idle operation state is unstable.SOLUTION: A vehicle includes an engine, an auxiliary machine driven by the engine, a display device and a control device. The control device includes: an engine control section that controls the engine so that actual idling speed of the engine in an idle operation state becomes target idling speed that fluctuates in accordance with a load to the engine by the auxiliary machine; an acquisition section that acquires the actual idling speed; a change determination section that determines whether or not an accelerator opening is zero and the target idling speed is changing; a calculation section that calculates slow change idling speed obtained by performing moderating processing at a predetermined moderating degree relative to the actual idling speed when the change determination section makes an affirmative determination; and a display control section that causes the display device to display the slow change idling speed.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a vehicle. [Background technology]

[0002] It is known that the idle speed of an engine fluctuates in response to fluctuations in the load of an accessory on the engine (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-141369 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, if the idle speed indicated by the tachometer during idle operation fluctuates in a short period of time in response to fluctuations in the load on the auxiliary equipment, the driver may mistakenly believe that the behavior of the engine during idle operation is unstable.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vehicle that prevents the driver from mistakenly believing that the behavior of the engine is unstable during idling. [Means for solving the problem]

[0006] The above object can be achieved by a vehicle comprising an engine, an accessory driven by the engine, a display device, and a control device, wherein the control device comprises an engine control unit that controls the engine so that the actual idle speed of the engine in an idle operating state becomes a target idle speed that fluctuates according to the load on the engine by the accessory, an acquisition unit that acquires the actual idle speed, a change determination unit that determines whether the accelerator opening is zero and the target idle speed is changing, a calculation unit that, if the change determination unit makes a positive determination, calculates a gently changing idle speed that has been smoothed by a predetermined smoothing rate with respect to the actual idle speed, and a display control unit that displays the gently changing idle speed on the display device.

[0007] When the change determination unit makes a negative determination, the calculation unit may calculate the gentle-changing idle rotation speed with a smaller degree of smoothing than when the change determination unit makes a positive determination.

[0008] The engine may include a deviation determination unit that determines whether the actual idle rotation speed deviates from the target idle rotation speed, and when a negative determination is made by at least one of the change determination unit and the deviation determination unit, the calculation unit may calculate the gently changing idle rotation speed with a degree of smoothing that is smaller than when a positive determination is made by the change determination unit and the deviation determination unit.

[0009] The calculation unit calculates a gently changing running speed by smoothing the actual running speed of the engine while the vehicle is running with a predetermined smoothing factor, and the smoothing factor used to calculate the gently changing running speed may be smaller than the smoothing factor used to calculate the gently changing idle speed.

[0010] The calculation unit may calculate the gently changing idle speed by dividing the sum of the actual idle speeds of a predetermined number of consecutively detected data by the number of data, and may reduce the degree of smoothing by reducing the number of data. [Effects of the Invention]

[0011] According to the present invention, a vehicle can be provided that prevents the driver from mistakenly believing that the behavior of the engine is unstable during idling. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic configuration diagram of a vehicle according to an embodiment of the present invention; [Figure 2] 10 is a time chart illustrating an example of an actual idle rotation speed and a slowly changing idle rotation speed; [Figure 3] 10 is a flowchart illustrating a rotation speed display control. [Figure 4] 10 is a timing chart illustrating rotation speed display control. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Vehicle outline] FIG. 1 is a schematic diagram of a vehicle 1 according to this embodiment. In FIG. 1, the vehicle 1 includes an engine 10, a torque converter 20, an automatic transmission 22, a propeller shaft 26, axles 30, drive wheels 32, accessories 40, an ECU (Electronic Control Unit) 50, a sensor group 60, and a display device 70. The engine 10 is a driving force source for traveling. The torque converter 20 is a fluid-type power transmission connected to the engine 10. The automatic transmission 22 is connected to the torque converter 20. Power from the engine 10 is transmitted to the automatic transmission 22 via the torque converter 20. The propeller shaft 26 is connected to an output shaft 24 of the automatic transmission 22. The differential gear device 28 is connected to the propeller shaft 26. The drive wheels 32 are connected to the differential gear device 28 via the axles 30. The accessories 40 are driven by the engine 10. The accessories 40 are, for example, an air conditioner compressor.

[0014] The ECU 50 is an electronic control unit that includes a calculation processing circuit that performs various calculation processes related to the driving control of the vehicle 1, and a memory that stores control programs and data. The ECU 50 is an example of a control device, and functionally realizes an engine control unit, an acquisition unit, a change determination unit, a calculation unit, a display control unit, and a deviation determination unit, which will be described in detail later.

[0015] The ECU 50 is electrically connected to a group of sensors 60 and a display device 70. The group of sensors 60 includes a vehicle speed sensor, a crank angle sensor, and an accelerator position sensor. The vehicle speed sensor detects the vehicle speed of the vehicle 1. The crank angle sensor detects the rotation speed of the engine 10. The accelerator position sensor detects the accelerator position, which is the amount of operation of the accelerator pedal. The display device 70 is, for example, a liquid crystal display arranged on the dashboard. The ECU 50 causes the display device 70 to display a tachometer indicating the rotation speed of the engine 10.

[0016] When the engine 10 is idling, the ECU 50 controls the engine 10 so that the actual idle speed of the engine 10 becomes the target idle speed. Specifically, the ECU 50 controls the fuel injection amount and the air volume of the engine 10 so that the actual idle speed becomes the target idle speed. Here, the target idle speed is set higher as the load of the auxiliary device 40 on the engine 10 becomes greater. For example, if the auxiliary device 40 is an air conditioning compressor, the load of the auxiliary device 40 on the engine 10 becomes greater when the air conditioner in the vehicle cabin is on than when it is off. Therefore, the target idle speed is set higher so that the engine 10 does not stall due to the increased load of the auxiliary device 40. The above processing is an example of processing executed by the engine control unit.

[0017] [Calculating the slowly changing idle speed] The ECU 50 calculates the gently changing idle speed based on the actual idle speed of the engine 10 in an idle operating state detected by the crank angle sensor. The gently changing idle speed is an idle speed calculated by smoothing the actual idle speed at a predetermined smoothing rate. The gently changing idle speed changes more slowly than the actual idle speed. As will be described in detail later, the ECU 50 executes speed display control to display the gently changing idle speed on the tachometer of the display device 70.

[0018] Fig. 2 is a time chart illustrating the actual idle speed and the slowly changing idle speed. Fig. 2 illustrates a case where the actual idle speed detected by the crank angle sensor rises from a constant value and then becomes constant again. The example illustrates a case where the actual idle speed changes in sequence as R1, R2, ..., and then as slowly changing idle speed r1, r2, .... The slowly changing idle speed changes more slowly than the actual idle speed.

[0019] The gently changing idle speed is calculated as follows. For example, a total value Tn of the actual idle speeds R1, R2, R3, ... Rn of a predetermined number n of consecutively detected data is calculated. Next, the total value Tn is divided by the number n of data to calculate the gently changing idle speed. In other words, the gently changing idle speed is the average value of the actual idle speed. For example, the degree of smoothing is adjusted by increasing or decreasing the number n of data used to calculate the gently changing idle speed. The greater the number n of data, the greater the degree of smoothing. In other words, the greater the number n of data, the more gently changing the idle speed becomes relative to the actual idle speed. The smaller the number n of data, the lower the degree of smoothing. In other words, the smaller the number n of data, the closer the gently changing idle speed becomes to the actual idle speed. Note that the number n of data is an integer of 2 or greater.

[0020] The example in FIG. 2 shows the gentle change idle speed when the number of data points n=4. The gentle change idle speed r4 is calculated by dividing the sum T1 of the actual idle speeds R1, R2, R3, and R4 by 4. Next, the gentle change idle speed r5 is calculated by dividing the sum T2 of the actual idle speeds R2, R3, R4, and R5 by 4. In this way, the gentle change idle speed is also calculated at the timing when the actual idle speed is detected. In this way, the gentle change idle speed is calculated using a simple method.

[0021] [Rotation speed display control] 3 is a flowchart illustrating the rotation speed display control. First, the ECU 50 determines whether the vehicle 1 is stopped and the engine 10 is idling (step S1). If the answer is Yes in step S1, the ECU 50 determines whether the accelerator opening is zero and the target idle rotation speed is changing (step S2). If the amount of change in the target idle rotation speed per unit time is equal to or greater than a threshold, it is determined that the target idle rotation speed is changing. Step S2 is an example of processing executed by the change determination unit.

[0022] If the result of step S2 is Yes, ECU 50 acquires the actual idle speed and determines whether the actual idle speed deviates from the target idle speed (step S3). Specifically, if the difference between the actual idle speed and the target idle speed is equal to or greater than a threshold, it is determined that the actual idle speed deviates from the target idle speed. Step S3 is an example of processing executed by the deviation determination unit.

[0023] If the answer is Yes in step S3, the ECU 50 calculates the gently changing idle speed from the number of data nA (step S4). As a result, even if the load of the accessories 40 on the engine 10 fluctuates during idle operation, the gently changing idle speed indicated by the tachometer fluctuates gently. This prevents the driver from mistaking the behavior of the engine 10 during idle operation for unstable behavior. Step S4 is an example of processing executed by the acquisition unit and the calculation unit.

[0024] If either step S2 or S3 is No, the ECU 50 calculates the gently changing idle speed using the number of data nB (step S5). Here, the number of data nB is smaller than the number of data nA. That is, the smoothing factor in step S5 is smaller than the smoothing factor in step S4. Step S5 is an example of processing executed by the acquisition unit and the calculation unit. For example, if the accelerator pedal is depressed while the vehicle is stopped and idling, causing the actual idle speed to increase (No in step S2), the gently changing idle speed is calculated with a relatively small smoothing factor (step S5). This allows the driver to check the engine speed indicated on the tachometer and confirm the responsiveness of the engine 10. Also, if the target idle speed is constant or the actual idle speed has converged to the target idle speed (No in step S2), the gently changing idle speed is calculated with a relatively small smoothing factor (step S5). This is because the target idle speed and the actual idle speed are stable.

[0025] If the answer is No in step S1, the vehicle 1 is considered to be in a traveling state, and the ECU 50 calculates the gently changing traveling rotation speed using the number of data nC based on the actual rotation speed of the engine 10 (step S6). Here, the number of data nC is smaller than the number of data nB. That is, the smoothing factor in step S6 is smaller than the smoothing factors in steps S4 and S5. Therefore, the gently changing traveling rotation speed calculated in step S6 is closer to the actual rotation speed than the gently changing idle rotation speed calculated in steps S4 and S5. This allows the driver to properly grasp the change in the rotation speed of the engine 10 in response to changes in the accelerator opening while traveling.

[0026] The ECU 50 displays the gently changing idle rotation speed or the gently changing running rotation speed calculated as described above on the tachometer of the display device 70 (step S7). Step S7 is an example of a process executed by the display control unit.

[0027] Fig. 4 is a timing chart illustrating rotation speed display control. Fig. 4 shows the transitions of vehicle speed, the on / off state of an air conditioner compressor, which is an example of accessory 40, engine rotation speed, and the acceleration of the data number n described above. When the air conditioner compressor is turned on while the vehicle speed is 0 (Yes in step S1), the target idle rotation speed increases (Yes in step S2), the actual rotation speed follows the target idle rotation speed (Yes in step S3), and the data number n used to calculate the gentle-change idle rotation speed increases from data number nB to data number nA (step S4, time t1). After that, when the target idle rotation speed becomes constant (No in step S2), the data number n decreases from data number nA to data number nB (step S5, time t2).

[0028] When the air conditioner compressor is subsequently turned off, the target idle speed decreases (Yes in step S2), the actual idle speed deviates from the target idle speed (Yes in step S3), and the number of data points n increases from the number of data points nB to the number of data points nA (step S4, time t3). When the target idle speed then becomes constant (No in step S2), the number of data points n decreases from the number of data points nA to the number of data points nB (step S5, time t4).

[0029] When the vehicle 1 starts to travel (No in step S1), the number of data n decreases from the number of data nB to the number of data nC (step S6, time t5). Note that while the vehicle 1 is traveling, the engine 10 is controlled based on the target torque. Therefore, the target idle speed does not change even while the vehicle 1 is traveling.

[0030] The gently changing idle rotation speed may be calculated, for example, by multiplying the actual idle rotation speed by a constant coefficient K that is less than 1. In this case, the closer the coefficient K is to 1, the less the degree of smoothing.

[0031] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0032] 1 vehicle 10 Engine 40 Auxiliary Machinery 50 ECU (control device, engine control unit, acquisition unit, change determination unit, calculation unit, display control unit, deviation determination unit) 70 Display device

Claims

1. The engine and an accessory driven by the engine; a display device; a control device; The control device an engine control unit that controls the engine so that an actual idle speed of the engine in an idle operating state becomes a target idle speed that varies depending on a load on the engine caused by the auxiliary device; an acquisition unit that acquires the actual idle rotation speed; a change determination unit that determines whether the accelerator opening is zero and the target idle rotation speed is changing; a calculation unit that calculates a gently changing idle speed by smoothing the actual idle speed at a predetermined smoothing rate when the change determination unit makes a positive determination; a display control unit that causes the display device to display the slowly changing idle rotation speed.

2. 2. The vehicle of claim 1, wherein when the change determination unit makes a negative determination, the calculation unit calculates the gentle-change idle speed with a smaller degree of smoothing than when the change determination unit makes a positive determination.

3. a deviation determination unit that determines whether the actual idle rotation speed deviates from the target idle rotation speed, 3. The vehicle of claim 2, wherein when at least one of the change determination unit and the deviation determination unit makes a negative determination, the calculation unit calculates the gently changing idle rotation speed with a degree of smoothing that is smaller than when the change determination unit and the deviation determination unit make a positive determination.

4. the calculation unit calculates a gently changing running rotation speed obtained by smoothing an actual running rotation speed of the engine while the vehicle is running at a predetermined smoothing rate; 4. The vehicle according to claim 3, wherein the smoothing factor used to calculate the gently changing running speed is smaller than the smoothing factor used to calculate the gently changing idling speed.

5. 5. The vehicle according to claim 1, wherein the calculation unit calculates the gently changing idle speed by dividing a sum of the actual idle speeds of a predetermined number of consecutively detected data by the number of data, and reduces the smoothing factor by reducing the number of data.

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