JPH0510539B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to a shift operation timing determining device that determines the timing of an operation for changing the gear position of a transmission, that is, a shift operation. It is something.

[Prior art and its problems]

Conventionally, this type of gear shift position change instructing device judges the content of the instruction based on a balanced state between engine speed or vehicle speed and engine load, but it takes a considerable amount of time to reach this balanced state. Since this is necessary, this has the disadvantage that the timing of the change instruction is delayed and is not useful for improving fuel efficiency.

[Purpose of the invention]

The present invention was made under these circumstances, and an object of the present invention is to speed up the timing of issuing a shift operation instruction and improve the fuel-efficient driving instruction function.

[Key points of the invention]

The key point is to find the vehicle speed or engine rotation speed and the change in the vehicle speed or engine rotation speed per unit time, that is, the amount corresponding to acceleration, and then determine the appropriate amount from the relationship between either vehicle speed or engine rotation speed and acceleration. Zone that can be determined to be running based on acceleration (appropriate acceleration zone; ZONE1)
(Excessive acceleration zone; ZONE2)
The present invention is characterized in that the relationship is determined based on a previously stored determination map, and the timing of the shift operation is determined.

[Embodiments of the invention]

FIG. 1 is a schematic diagram showing a simple embodiment of the present invention in which only the shift-up timing is instructed, and FIG. 2 is a graph (map) showing the relationship between the appropriate acceleration zone and the excessive acceleration zone.

As is clear from FIG. 1, the instruction device for instructing the timing of the shift-up operation includes a control unit 1 having a central processing unit (CPU) 11 such as a microcomputer, a timer 12, etc.
A display unit 2 receives instructions from the unit 1 and displays the instructions. A vehicle speed signal (CV) and a signal GT indicating that the gear position (shift position) is the highest are input to the control unit 1, and the CPU 11 performs the following processing based on these signals. .

The CPU 11 receives a signal issued from the timer 12 at predetermined time intervals as an interrupt signal, and takes in the vehicle speed signal CV. As a result, the vehicle speed signal CV is sequentially sampled and captured at predetermined time intervals. Now, the vehicle speed data at times T and T + ΔT are respectively
If CV _T , CV _T+ 〓 _T , then from these data,
The acceleration component α of the vehicle can be determined as shown in the following equation (1).

α＝CV _T+ 〓 _T −CV _T ／(T＋ΔT)−T＝ΔVC／ΔT……
(1) Note that ΔCV=CV _T+ 〓 _T −CV _T. Furthermore, an acceleration sensor, a differentiator, or the like may be used to detect such acceleration.

On the other hand, regarding the relationship between vehicle speed CV and acceleration α,
Is it in the excessive acceleration zone (ZONE2)?
It has been confirmed that when measuring whether the acceleration is in the appropriate acceleration zone (ZONE1), it is expressed as shown in Figure 2. Therefore, by storing a map as shown in Fig. 2 in advance in a predetermined memory (not shown) in the control unit 1, the excessive acceleration zone (ZONE2) can be determined based on the relationship between the vehicle speed CV and acceleration α at a predetermined time. It is possible to determine whether the acceleration is within the appropriate acceleration zone (ZONE1).

In the flowchart of FIG. 3, ○A is the part that calculates the acceleration α (=ΔCV/ΔT), and ○B is the part that determines whether or not it is in ZONE 1 (appropriate acceleration zone). As a result, if it is ZONE 1, it is determined that the vehicle is running at an appropriate acceleration or less and the process is terminated.If it is not ZONE 1, it is determined whether the current gear position is at the highest gear position based on a signal given from the outside. If it is the highest gear, it is not possible to shift any further, so the process ends, and only if it is not the highest gear, it cannot be determined that fuel-saving driving is being done, so a shift up instruction is output to reduce fuel consumption. Try to keep it in check (see ○d).

In the above description, the shift-up instruction is determined based on the acceleration obtained from the vehicle speed and the highest gear position, but the shift-down timing can also be determined as follows.

FIG. 4 is a schematic diagram showing another embodiment of the present invention;
Figure 5 is a map for determining engine torque from the relationship between engine speed and engine load.
The figure shows a map for determining the gear stage to be used based on vehicle speed and engine rotational speed, Figure 7 is a map for determining shift up and down, and Figure 8 is a flowchart for explaining the operation of the second embodiment. It's a chat.

As is clear from FIG. 4, in this embodiment, in addition to the vehicle speed signal, an engine speed signal and an engine load signal are input to the control unit 1, and when this is applied as an indicating device, the control unit 1 receives an instruction. The output is not only for upshifting, but also for downshifting. As the engine load signal, a control rack position signal is used in the case of a diesel engine, and an intake air amount signal is used in the case of a gasoline engine.

The operation will be explained below with reference to FIG.

The control unit first determines the engine torque T from the engine rotational speed signal and engine load signal input thereto, using a map as shown in FIG. 5 (see ◯). ○ In B, determine whether this torque T is larger than a predetermined value T _L ,
If it is less than that, it is determined that engine braking is in progress and the process is terminated. If T>T _L , the currently used gear position is determined from the relationship between the vehicle speed and engine speed shown in FIG. 6 (see ◯C). In addition,
The shaded areas in Figure 6 indicate the 1st, 2nd, and final gear positions. Therefore, if none of these gear positions apply, it is determined that the clutch is in a disengaged state. Therefore, no further processing is performed. When the vehicle is in a predetermined gear position, it is determined whether or not it is in ZONE 1 (appropriate acceleration zone) based on the relationship between vehicle speed and acceleration in the same way as in the case of FIG. 1 (see ○D). If the result is YES, it is assumed that the state is close to normal running, and it is determined whether the state should shift up or down based on the relationship between engine speed and engine torque as shown in FIG. reference). In Fig. 7, "UP" and "DOWN" respectively indicate that when driving at a steady state, if the engine speed and torque are within this range, better fuel efficiency can be obtained by shifting up or down. represents, and also,
“OK” indicates that if the vehicle is within this range, the driving condition is appropriate in terms of fuel efficiency even without a shift operation. Therefore, if the relationship between the current engine speed and its torque is in the "DOWN" region, perform "downshift processing" as shown in ○F, and if the relationship is in the "OK" region, as in ○F. After performing "OK processing", proceed to "NEXT processing". On the other hand, when it is in the "UP" region, it is determined whether the current gear position is the highest gear (see circle), and only when it is not the highest gear, "shift up processing" is performed.
After (see ○), move to "NEXT processing",
If it is the highest stage, perform "OK processing". In addition,
In this case, whether or not the gear position is the highest gear position can be determined with reference to the map shown in FIG.
In addition, in ○D above, when it is determined that the engine is in the excessive acceleration region, the engine speed N is set to the predetermined value N ₁
(Refer to Figure 7) Determine whether or not it is above (see ○), and only when N is ₁ or more, perform the above ○ determination, and if N is less than ₁ , perform "OK processing" . Note that when the engine speed is N ₁ , no matter how much you shift up, the so-called "car lock" will occur.
An appropriate value is selected so that the phenomenon does not occur. In addition, if necessary, N ₁ can be changed depending on the gear stage in use.
may be set.

In Fig. 8, the content of the shift operation (UP, DOWN, OK) in ZONE 1 is determined based on the engine rotation speed N and engine torque T shown in Fig. 7, but the equal fuel consumption map as shown in Fig. 9 is It can be used to make a determination as follows.

Now, the gear ratio μ is defined as μ = engine speed / axle speed ...(2), and if the engine speed in the currently used gear is N _o and the engine torque is T _o , then the equivalent horsepower is The engine speed N _Ai of the other gears on the line (see the dotted line in Figure 9; horsepower is approximately proportional to the product of engine speed N and torque T),
The engine torque T _Ai is calculated as follows: N _Ai = Gear ratio μ _i of other gear i / Gear ratio μ _o ×N _o of the gear currently in use (3) T _Ai = Gear ratio μ of the currently used gear _o /gear ratio μ _i ×T _o of other gear stage i (4). Therefore, the fuel efficiency F(N _o , T _o ) for the gear currently in use and the fuel efficiency F(NAi , N _Ai ,
T _Ai ) on the equal fuel consumption curve Y in Figure 9 and compare it, and if the fuel efficiency rate for the gear in use is the minimum, it is "OK", and if the fuel efficiency rate is smaller by shifting up, then ``Shift-up processing'' is performed, and if shifting down results in a lower fuel efficiency, then ``shift-down processing'' is performed. In addition, the 9th
Curve Z in the figure is a full load curve.

FIG. 10 is a flowchart showing a modification of FIG. 8, which corresponds to the above description. As is clear from the same figure, the steps of ○ho in Fig. 8 are ○nu, ○ru,
The only difference is that the calculations as shown in equations (3) and (4) above are performed after decomposition into ○O and ○W, and the discrimination processing as described above is performed.The other points are completely the same, so the details will be omitted. Components that perform the same processing and judgment as in FIG. 8 are designated with the same reference numerals.

Next, a method of determining acceleration for determining appropriate upshift and downshift timing in any driving condition will be described.

In Fig. 2, the change in vehicle speed was used as an amount equivalent to acceleration as the criterion, but in Fig. 11, the increase ΔN/ΔT in engine rotation speed N at each scheduled time ΔT was used as an amount equivalent to acceleration, and each A map is shown for determining the driving state based on the engine rotation speed N and ΔN/ΔT for each gear stage. The solid line is the acceleration determination level for full load, and the dotted line is the acceleration determination level for part load (non-full load).
The fully loaded state is the Z part in Figures 5 and 9,
As shown in FIG. 5, it can be determined from the engine speed N and the engine load signal. Furthermore, part load is a state that is not a full load state, and this can also be determined in the same way.

If the increase ΔN/ΔT of N with respect to the engine speed N at a certain time is smaller than the determination level indicated by the dotted line,
It can be determined that the state is in the appropriate acceleration state (ZX1), and according to FIG. The process moves on to the steps below ○ in Figure 10. In addition, if ΔN/ΔT is larger than the determination level indicated by the dotted line and is in a part-load state (ZX2), it can be determined that there is excessive acceleration, and the process moves to the steps below in Figures 8 and 10, where it is determined that the state is fully loaded, and the solid line indicates If it is below the judgment level, it is judged that it is impossible to shift up, and the “OK
If the determination level is higher than the determination level indicated by the solid line (ZX3), the process moves to the process indicated by ○ in FIGS. 8 and 10. 11th
The determination level indicated by the solid line in the figure corresponds to the acceleration level at which sufficient driving force is guaranteed even if the gear is shifted up in a fully loaded state. This shift-up possible acceleration level L is defined as the slope θ _i (%) that allows climbing with full driving force at the gear used when climbing at a constant volume, and the driving force of 80 to 90% of the full driving force at the same vehicle speed when shifting up. It is expressed as the product of the difference between the pitching slope θ _i+1 (%) and the gravitational acceleration g, and is determined as L≒g×θ _i −θ _i+1 /100...(5) be done. Therefore, at a gear stage where the slope that can be climbed with full driving force at constant volume is θ _i (%), θ _{i +1}
(%) If you pitch at full load on a smaller slope, you will exceed the judgment level shown by the solid line in Figure 11,
It is determined that shift-up is possible, and θ _i+1 (%)
If you climb a larger gradient with full load, it will be determined that it is impossible to shift up. In addition, under the same condition, if the slope is greater than θ _i+1 (%), a small weight such as an empty cargo, for example, a weight M/3 of the weight M at a constant volume,
If the vehicle is fully loaded at stage 3, the driving force F generated by the engine will be the same as (will not decrease) or greater than that at constant volume, so F=Mα...(6) (α is the vehicle (acceleration), an acceleration more than three times that of constant volume occurs, which is greater than the acceleration level determined by equation (5), and it may be determined that a shift-up is possible. In this way, by determining whether upshifting is possible based on acceleration, accurate determination is possible regardless of the gradient of the slope or the loaded weight.
By combining the judgment with the regular running shown in the figure,
Under any driving condition, it is possible to accurately determine whether to shift up or down for fuel-efficient driving.

FIG. 12 is a flowchart showing a modification of FIG. 10. Since it is almost the same as FIG. 10 except that the acceleration determination at full load is added, the details will be omitted. In addition, the same processing as in FIGS. 8 and 10,
Components that make decisions are indicated by the same reference numerals.

Next, an example of a procedure for determining shift change timing will be shown. Even if it is determined that it is possible to shift up and down using the procedures shown in Figures 8, 10, and 12, and that an improvement in fuel efficiency is expected, noise may be added to the input signal, or the randomness of the road condition may cause Considering the impact, it is not possible to decide when it is time to change the shift based on a single determination result. Furthermore, the timing when it is determined that the shift is up and should actually be shifted up is different from the timing when it is determined that the shift is to be down and that the shift should actually be made. If it is determined to be a shift up, it will shift up early; if it is determined to be a downshift, it will shift up early.
It is more effective to increase fuel efficiency by using the current number of stages as long as possible. Therefore, the shift change timing is determined as shown in FIG. 8th, 10th, 1st
If the shift-up process has been performed continuously for more than t _u (approximately 1 to 2) seconds before the NEXT process in Figure 2, it is determined that it is time to shift up, and the shift-down process is performed for t _d (approximately 4 to 2 seconds). 5) If this is done continuously for more than a second, it is determined that it is time to downshift. "OK
In "Processing", T _uc (shift up timer) and T _DO (shift down timer) are used to compare with t _u and t _d seconds.
timer) to 0 seconds.

The various maps shown in FIGS. 2, 5 to 7, 9 and 11 are all stored in a predetermined memory within the control unit.

〔Effect of the invention〕

As described above, according to the present invention, a transitional state and a quasi-steady state are determined by calculating at least the acceleration, and the determination and processing are performed separately based on the determination results. Therefore, not only can judgment results be obtained quickly, but
Since this is in accordance with natural logic, the driver does not feel uncomfortable with the determination result, and therefore has the advantage that fuel-efficient driving can be carried out smoothly. Furthermore, by making a determination based on acceleration, it is possible to determine the appropriate shift operation timing in any case, regardless of whether the vehicle is on a hill or traveling on a flat surface, and regardless of the loaded weight.

Although this invention has been described above as a device for determining shift change timing, if the content of the determination is displayed to the driver using the display device indicated by reference numeral 2 in FIGS. It can be applied as a change indicating device. Moreover, by giving the above-mentioned instructions to a transmission that can automatically change gears, a fuel-saving automatic transmission can be realized. in this case,
As shown in FIG. 14, a shift position sensor 101,
Since the clutch sensor 102 is used, the sixth
Judgment as shown in the figure becomes unnecessary. In addition, shift changes during general driving are automatically performed via the shift position control actuator 103, clutch plate control actuator 104, and engine speed control actuator 105 at the shift up/down timing determined in FIGS. This enables fuel-saving gear shifting.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing an embodiment of this invention, Figure 2 is a schematic diagram showing an embodiment of this invention.
The figure is an acceleration determination map showing the relationship between the appropriate acceleration zone and the excessive acceleration zone, FIG. 3 is a flowchart for explaining the operation of FIG. 1, and FIG. 4 is a schematic diagram showing another embodiment of the present invention. , Fig. 5 is a map for determining engine torque from engine speed and engine load, Fig. 6 is a map for determining the gear position to be used from vehicle speed and engine speed, and Fig. 7 is a map for determining the gear position to be used from vehicle speed and engine speed. 8 is a flowchart for explaining the operation of FIG. 4, FIG. 9 is a map for determining fuel efficiency from engine speed and engine torque, and FIG. A flowchart showing a modification of the diagram, FIG. 11 is a map for determining the driving state from the relationship between the engine speed and its change,
FIG. 12 is a flowchart for explaining the operation of determining shift up or down from the engine speed and its change, and FIG. 13 is a flowchart for explaining the operation for determining shift change timing.
FIG. 14 is a schematic diagram showing a fuel-saving automatic transmission. Code explanation, 1... Control unit, 2...
...Display unit, 11...Central processing unit (CPU), 12...Timer.

Claims (1)

[Claims] 1. Acceleration detection means for detecting at least the acceleration of the vehicle, and storage means for dividing and storing a predetermined region represented by either vehicle speed or engine rotation speed and acceleration into an appropriate acceleration region and a non-suitable acceleration region. and a determining means for determining in which region the current driving condition is by referring to the stored contents, and determining the timing for changing the shift position of the transmission based on the determination result. A shift operation timing determining device.