JPH03107668A - Running characteristic control device for vehicle - Google Patents

Abstract

PURPOSE:To improve stability and operability in driving by forcedly releasing active mode when a request for shift to slow running mode is judged from accelerator operating characteristic during active mode running. CONSTITUTION:When a change of running condition into the state to be shifted from active mode to slow mode is judged by a judging means 2, mode switching is conducted by a running mode selecting means 3. However, when it is judged that the accelerator operation by a driver requests the shift to slow mode before mode switching, on the basis of accelerating change 5 of accelerator opening 4, a mode releasing means 6 immediately releases the active mode, and the mode is shifted to, for example, a normal mode having intermediate characteristic. Thus, the problem of unconformity in running mode transiently generated at the time of running condition change is solved, the running mode is controlled to a running mode more applicable to the request of the driver, and stability and operability in driving can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device that automatically changes the driving characteristics of a vehicle according to the operating characteristics of a driver and the driving environment.

(Prior Art) As a means of changing the driving characteristics (modes) of a vehicle, for example, several types of shift patterns of an automatic transmission are set, and a different shift pattern is selected according to driving conditions, etc. Some automatic transmissions shift gears according to optimal shift patterns for city driving, high-speed driving, climbing, etc.

In this case, to specify the driving conditions for selecting the shift pattern, for example, according to Japanese Patent Laid-Open No. 63-28741, the acceleration is calculated from the differential value of the vehicle speed, this absolute value is integrated, and the calculated value is used to determine the driving condition when driving in the city. In addition, in Japanese Patent Application Laid-Open No. 180153/1983,
It is determined that the vehicle is in uphill travel when the vehicle speed decreases and the gear is switched from a high gear to a low gear even though the engine torque is maintained above a certain value.

When it is determined that the driving conditions have shifted to a specific state different from the previous shift pattern, the shift pattern is immediately changed and the driving mode is switched to the optimum driving mode.

Note that switching the driving mode is not limited to changing the shift pattern of the automatic transmission, but also changes the relationship between the throttle opening and the accelerator opening, and the characteristics of the engine output such as the accelerator opening and the air-fuel ratio concentration and ignition timing. This can also be achieved by changing the value depending on driving conditions, etc.

Therefore, for example, when changing from a wide road to a narrow road or from smooth driving to driving in traffic jams, the driving mode changes from a driving mode with excellent acceleration that is sensitive to accelerator operation.
By automatically switching to a driving mode that accelerates slowly in response to accelerator operation, it eliminates the need for delicate accelerator operations when starting, stopping, or repeating small accelerations and decelerations when driving in traffic jams, improving drivability. This will be a significant improvement.

(Problem to be Solved by the Invention) In such a case, a certain amount of judgment and calculation time is required from when the driving conditions change to when the driving mode is actually switched. etc., for a while, unlike the slow mode desired by the driver.
You may be forced to drive in the previously sensitive mode. In a sensitive mode where the output increases or decreases rapidly in response to accelerator operation, it is difficult to smoothly respond to repeated starts, stops, accelerations and decelerations when driving in traffic jams, which may require jerky accelerator operations and worsen ride comfort. do.

In this way, the actual driving conditions and the selected driving mode tend to become mismatched during the process of transient changes in the driving conditions, causing a loss in drivability even if it does not last for a long time.

Therefore, the present invention aims to solve this problem by immediately canceling the driving mode that is sensitive to accelerator operation in response to the driver's request when the vehicle transitions from a smooth driving state to a congested road. purpose.

(Means for Solving the Problems) Therefore, as shown in FIG. 1, the present invention provides a driving mode setting means 1 having at least an active mode with good acceleration and a slow mode with gentle acceleration, and means 2 for determining driving conditions; means 3 for selecting a driving mode based on the determined driving conditions; means 4 for detecting changes in accelerator opening; and means 5 for calculating an acceleration change value in accelerator opening. and means 6 for forcibly canceling the active mode by determining that the slow mode is required when the acceleration change value of the accelerator opening is larger than a predetermined value during active mode driving.

(Function) When it is determined that the driving condition has changed to a state where the transition from the active mode to the slow mode is necessary, the mode is switched by the driving mode selection means. When it is determined that a transition is requested based on the acceleration change in the accelerator opening, the active mode is immediately canceled and the system shifts to, for example, the normal mode, which has characteristics intermediate between the active mode and the slow mode. do.

Therefore, immediately after transitioning from a smooth driving condition to a traffic jam, the system immediately switches from active mode to normal mode, temporarily avoiding the oversensitive output response caused by active mode and preventing deterioration of driving stability.

During this time, when the output of the driving mode selection means is switched, the normal mode is shifted to a slow mode that matches the driving conditions, and stable driving becomes possible.

(Example) Embodiments of the present invention will be described below based on the drawings.

In FIG. 2, 10 is an engine and 11 is an automatic transmission. A drive device 13 that controls the gear shift according to the operating state etc. is provided, and each of these drive devices 1
The operation of 2.13 is controlled by a control circuit 14 composed of a microcomputer or the like.

Various signals are inputted to the control circuit 14 to detect the driving state of the vehicle, driving conditions, driving operations of the driver, etc. 15 is an accelerator sensor that detects the accelerator opening degree, and 16 is an accelerator sensor that detects the vehicle speed. 17 is a rotational speed sensor for detecting the engine rotational speed.

The control circuit 14 selects the optimum ignition timing control characteristic (mode) corresponding to the driving condition at that time from among several different control characteristics depending on the driving condition of the vehicle, and also selects the optimum ignition timing control characteristic (mode) corresponding to the driving condition of the vehicle. (In this case, the interlocking relationship between the accelerator pedal and the throttle valve is not a fixed direct proportional characteristic, but can be set to a freely proportional characteristic according to the selection, and the opening degree of the throttle valve is, for example, (drive controlled by motor)
Then, in the same way, the most suitable one suited to the driving conditions is selected from several set automatic transmission shift characteristics (shift patterns).

4 to 6 show at least three driving modes set in the control circuit 14, namely, an active mode with good acceleration, a slow mode with slow acceleration, and a driving mode with characteristics intermediate between these modes. Indicates normal mode.

In the active mode shown in Figure 4, the throttle opens wide in the low opening range of the accelerator, is held back in the middle range, and opens even further in the high opening range, resulting in an increase in output in response to accelerator operation. In addition, it is possible to provide leeway for overtaking driving, etc. Furthermore, regarding the shift characteristics of the automatic transmission, the hysteresis of upshifts and downshifts is reduced to achieve responsive acceleration and deceleration.

In the slow mode shown in Fig. 5, the throttle opening is delayed relative to the accelerator opening, thereby suppressing the oversensitive response of the output to the accelerator operation.
To reduce the shock caused by unpleasant longitudinal acceleration when repeatedly stopping. As for the shift characteristics, when starting from a low throttle opening, etc., the vehicle starts from second gear to prevent a sudden start.

The normal mode in Figure 6 is a standard mode with characteristics intermediate between those in Figures 4 and 5, and is set to appropriate output characteristics and shift characteristics without being too sensitive or sluggish in response to accelerator operation. Ru.

In this way, the driving mode that provides the optimal characteristics is selected depending on the vehicle's driving conditions. Specifically, this determination is made based on, for example, the average vehicle speed of the vehicle, the relationship between rotational speed and vehicle speed, or the accelerator opening. This is done by taking into account the relationship between speed and vehicle speed, and determines which driving condition you are in, such as highway driving, pitched driving, traffic jam driving, narrow road driving, normal road driving, etc., and then activates the active mode based on the judgment result. , slow mode, or normal mode is selected.

By the way, in this case, as mentioned above, a certain amount of judgment and calculation time is required from when the driving conditions change until the driving mode is actually switched. For a while after shifting to traffic jams, such as when the driver shifts to slow driving, the driver may be forced to use the previous active mode, which is more sensitive to accelerator operation, unlike the slower mode that the driver desires. In active mode, where the output increases and decreases rapidly in response to accelerator operation, it is difficult to deal with repeated starting, stopping, acceleration and deceleration when driving in traffic jams, and it may require jerky accelerator operation, which may affect ride quality. It also gets worse.

Therefore, in the present invention, when the driver requests the slow mode while driving in such an active mode, this is judged from the operating characteristics of the accelerator pedal, and the driving mode (slow mode) is selected based on the change in driving conditions. By forcibly canceling active mode immediately, shifting to normal mode, and then waiting for it to automatically shift to slow mode, you can avoid situations where driving conditions are changing transiently. We are trying to solve the problem of inconsistency in driving mode selection as much as possible.

By the way, the determination as to whether the slow mode is requested during active mode driving is made based on the acceleration change value (secondary difference value) of the accelerator opening change.

In the function y=f(x) just given, the value of y for the equally spaced values of X, xn=xo-+-n)H, is
If yn=f(xn), Δyn-y(n+ 1)-
Let yn be the first difference value, and Δ2 y n−Δy(n++
)-Δyn is the second-order difference value, and when is the time for the accelerator opening θ 0<1≦t0
If the first-order difference value in is Δθi, then the second-order difference value Δ2
θi is determined as Δ(θn+,)−Δθn. Therefore, this second-order difference value captures the acceleration-like change in the accelerator opening degree, and the second-order difference value becomes a large numerical value when the accelerator is depressed and then released by a large amount.

Figure 7 shows how the accelerator opening changes when the vehicle's driving characteristics differ from the driver's predictions, and it shows that the slightest accelerator operation (opening) resulted in a faster-than-expected acceleration. When the time comes, release the accelerator by a large amount. This diagram shows a pattern that occurs when driving smoothly to driving in traffic jams or to narrow roads. Normally, once a person experiences something like this, their learning ability kicks in, and from the second time onwards, the pattern will change. You will step on the accelerator a little more smoothly.

Therefore, the second-order difference value is compared with a predetermined value, and if it is larger than the predetermined value, it can be determined that at least the active mode is canceled, or in other words, switching from the active mode to the slow mode l\ is requested. So, if you judge this situation when driving in active mode,
The system immediately cancels the active mode and shifts to the normal mode, and waits for the normal mode to switch to the slow mode according to the determination result of the driving conditions.

FIG. 3 shows a flowchart of this series of control operations executed by the control circuit 14.

First, the current driving mode is checked to determine whether it is in the active mode (step 50). When not in active mode, this control is stopped.

On the other hand, when in the active mode, a second difference value of the accelerator opening is calculated and compared with a predetermined value set in advance (steps 51 and 52).

Note that this predetermined value is set to a value that corresponds to the accelerator operation when the driver depresses the accelerator and then suddenly releases it, to the extent that this does not occur in the normal active mode state.

When the second-order difference value is smaller than this predetermined value, it is determined that there is no particular problem in terms of driving performance, and the routine is returned to the initial state. However, when it is larger than the predetermined value, the mode is not active mode but gentler acceleration and deceleration. It is determined that the characteristics are requested, the active mode is canceled, and the mode shifts to the normal mode (step 53).

Compared to active mode, normal mode has a gentler sense of acceleration and deceleration, and drivability immediately after transitioning from high-speed driving to congested roads is considerably improved.

In this way, if there is a request from the driver, the active mode is canceled with priority over switching the driving mode due to a change in driving conditions, so that the transiently selected driving mode and the mode requested by the driver are When they do not match, it is possible to compensate for the inconsistency in automatic selection and improve the adaptability of the driving mode.

Note that after shifting to the normal mode, the mode shifts to the slow mode based on the determination of the driving conditions, but the normal mode will be maintained until then.

However, since the driver has requested the slow mode, the active mode may not necessarily be shifted to the normal mode, but may be directly shifted to the slow mode.

(Effects of the Invention) As described above, according to the present invention, when it is determined that the driver desires to shift to the slow driving mode from the accelerator operation characteristics while driving in the active mode, the driver waits for the determination of the driving conditions. It goes without saying that the active mode can be forcibly canceled, which solves the problem of transient driving mode irregularities such as when driving conditions change, making the system more adaptable to the driver's demands. It is possible to control the vehicle to a driving mode with a high level of performance, and is expected to improve driving stability and operability.

[Brief explanation of drawings]

Fig. 1 is a claim correspondence diagram showing the configuration of the present invention, Fig. 2 is a block diagram showing an embodiment of the invention, Fig. 3 is a flowchart showing control operation, and Figs. 4 (A) (B) to 6 Diagram (A
)(B) is an explanatory diagram showing the correspondence between accelerator opening and throttle opening in active mode, slow mode, and normal mode, as well as the shift characteristics of the automatic transmission, and Fig. 7 shows the changing state of accelerator opening. It is an explanatory diagram. 10...engine, 11...automatic transmission, 14...
- Control circuit, 15... accelerator sensor, 16... vehicle speed sensor, 17... rotation speed sensor. Figure 4 Figure (A) Figure (B) Shifting characteristics Figure 5 (A) Technology characteristics) 1 Figure (B) Figure 6 (A) Engineering: /Special characteristics diagram ( B) EJjL Machinery 1 Machinery 1 Figure 7

Claims (1)

[Claims] driving mode setting means having at least an active mode with good acceleration and a slow mode with gentle acceleration; means for determining driving conditions of the vehicle; and means for selecting a driving mode based on the determined driving conditions; means for detecting a change in accelerator opening; means for calculating an accelerating change in accelerator opening; and means for requesting a slow mode when the accelerating change in accelerator opening is larger than a predetermined value during active mode driving. A driving characteristic control device for a vehicle, comprising means for forcibly canceling an active mode upon determining that the vehicle is in an active mode.