JPH02256961A - Automatic speed change control device of vehicle - Google Patents

Abstract

PURPOSE:To obtain the speed change characteristic synthetically containing a running condition change by estimating running resistance being based on each change tendency of a physical quantity, related to combustion of an engine, and acceleration of a vehicle and, in accordance with this estimated running resistance, changing a speed change pattern. CONSTITUTION:A speed change ratio determining means (f), in accordance with a running condition of a vehicle detected in a running condition detecting means (a), operates in accordance with a predetermined speed change pattern an operating means (g) performing a speed change. A running resistance arithmetic means (d), being based on each change tendency of a physical quantity (for instance, intake amount, fuel amount, etc.) related to combustion of an engine detected in a physical quantity detecting means (b) and acceleration of the vehicle detected in an acceleration detecting means (c), calculates an estimated value corresponding to a value of running resistance, when it is large exceeding a reference value, the speed change pattern is changed so as to correspond to the large running resistance by a pattern change means (e). Thus, the speed change characteristic, synthetically containing a change of the running condition such as a loading amount or the like, can be obtained.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to an automatic transmission control device for a vehicle.

(Prior art) Shift control of automatic transmissions used in vehicles, etc. refers to a shift pattern (so-called shift diagram) in accordance with the vehicle speed and throttle opening while the vehicle is running, and determines the gear ratio according to the driving condition. Generally, the gear ratio of an automatic transmission is changed by using the automatic transmission, but the above-mentioned shift pattern is predetermined assuming typical driving conditions. Therefore, if the driving condition is as expected, On the other hand, it is possible to obtain satisfactory shifting characteristics, but when driving under unexpected conditions, such as when driving at a relatively high speed on a pitched road, when driving with a large number of passengers (carrying load), or when driving immediately after starting. There was a problem in which the determined gear ratio was not appropriate during cold engine operation.

As a countermeasure against such problems, a conventional method has been proposed in Japanese Patent Application Laid-Open No. 180153/1983 in which if the engine load is constant and the vehicle speed decreases, it is determined that the vehicle is running on a hill, and the shift pattern is changed to one suitable for driving on a hill. JP-A-62-1650 which detects the occurrence of a busy shift phenomenon (which tends to occur mainly when driving on a hill) based on the number of shifts and the number of gear changes, and changes the shift pattern based on whether the vehicle is running on a hill.
52, and Japanese Patent Application Laid-Open No. 63-16716, in which the change in load is determined by counting the number of people getting on and off, and the shift pattern is changed according to the amount of load.
The one described in Publication No. 1 is known.

(Problem to be Solved by the Invention) However, each of the above-mentioned conventional devices has a configuration that individually detects a specific driving condition, such as driving on an uphill road or driving with a heavy load, and changes the shift pattern. Therefore, it could not necessarily be said that it corresponded appropriately to actual driving conditions.

In other words, the optimum or ideal transmission characteristics of a vehicle are those that optimize the gear ratio between the engine and the drive wheels according to the amount of running resistance acting on the vehicle at that time, and achieve just the right amount of driving force. It can be said to give. To this end, an important point is how to recognize the magnitude of running resistance.

Incidentally, in the case of a manual transmission, the magnitude of the running resistance is determined by the driver. He is said to be able to select a suitable gear ratio and has high driving skills.

The ideal of an automatic transmission is to be able to make shift decisions that are equal to or better than those of the above-mentioned skilled driver.

However, as shown in the above-mentioned known examples, even up to the present, the level at which appropriate judgments can be made in all driving conditions has not yet been reached.

(Objective of the Invention) Therefore, the present invention provides the following points: ■ The magnitude of the driving force required by a running vehicle is the running resistance at that time (i.e., an external force that attempts to decelerate the vehicle, such as the slope of the road surface, the tire It was estimated by focusing on the fact that the amount of rolling resistance (rolling resistance, air resistance, live load, etc.) is affected by the amount of rolling resistance (rolling resistance, air resistance, live load, etc.), and that the amount of running resistance can be estimated from changes in engine output and changes in vehicle acceleration. By changing the shift pattern according to the magnitude of running resistance, the objective is to obtain shift characteristics that comprehensively take into account changes in running conditions such as changes in the slope of the road surface and changes in the amount of cargo.

(Means for Solving the Problems) In order to achieve the above object, the automatic transmission control device for a vehicle according to the present invention has driving state detection means a for detecting the driving state of the vehicle, as shown in FIG. and physical quantity detection means for detecting physical quantities involved in engine combustion; acceleration detection means C for detecting acceleration of the vehicle; and acceleration detection means C for detecting the acceleration of the vehicle; a running resistance calculation means d for calculating an estimated value corresponding to the magnitude, and when the estimated value exceeds a predetermined reference value,
A pattern changing means e that changes the speed change pattern so as to obtain a speed change characteristic suitable for a case where running resistance is large; a speed ratio determining means f that refers to the speed change pattern according to the running condition of the vehicle and determines the speed ratio; and operating means g for operating the automatic transmission so as to obtain the selected transmission gear ratio.

(Function) In the present invention, based on the tendency of increase/decrease in physical quantities involved in engine combustion (for example, intake air amount or fuel supply amount, etc., which are correlated with engine output torque) and vehicle acceleration, An estimated value corresponding to the magnitude of running resistance is calculated.

When the estimated value exceeds the reference value, the shift pattern is changed to correspond to the large running resistance.

Therefore, since the magnitude of running resistance corresponds to changes in overall running conditions, such as the slope of the road surface, the weight of the load, or wind pressure, it is necessary to optimally change the shift pattern according to all running conditions. I can do it.

(Example) Hereinafter, the present invention will be explained based on the drawings.

2 to 6 are diagrams showing an embodiment of an automatic transmission control device for a vehicle according to the present invention.

First, the configuration will be explained. In Fig. 2, 1 is a sensor group, and sensor group 1 includes a throttle opening sensor 2 that detects the throttle opening TVO, a vehicle speed sensor 3 that detects the vehicle speed, and a gasoline type F (regular gasoline or high-octane gasoline). Type detection sensor 4 that detects
, an engine water temperature sensor 5 that detects the engine water temperature TF;
ATF oil temperature sensor 6 that detects oil temperature T0 of the automatic transmission;
It has a vehicle body load sensor 7 that detects the load W on the vehicle body. The throttle opening sensor 2 and the vehicle speed sensor 3 function as a driving state detecting means, and the throttle opening sensor 2 also functions as a physical quantity detecting means. In addition, the physical quantity detection means may be one that detects the amount of fuel supplied (or may be the amount of injection), boost pressure, or the like. In short, any device that detects physical quantities related to engine combustion may be used.

Reference numeral 10 denotes an automatic transmission control unit (hereinafter referred to as ATCU) as a gear ratio determining means, and the ATCUIO is internally provided with a mapped gear shift pattern.

This shift pattern is referred to by the throttle opening TVO and the vehicle speed ■, and the current gear ratio is determined by this reference operation and the shift signal SEL is output. Reference numeral 11 denotes a valve controller (operating means) of the automatic transmission, and the pulp controller 11 combines valves according to SEL and operates the gear ratio of the automatic transmission.

Here, the above-mentioned shift pattern is a shift diagram corresponding to, for example, a 4-speed forward automatic transmission with an overdrive (OD) of 1st to 4th speeds, and at a predetermined high speed or higher, the highest gear (OD)
) is now selected. However, when the OD prohibition signal OD is input, OD is not selected.

On the other hand, 20 is a sub-control device as an acceleration detection means, a running resistance calculation means, and a pattern change means.The sub-control device 20 calculates the vehicle acceleration i according to various signals from the sensor group 1, and and TVO(T
An estimated value λ of running resistance is calculated based on the moving average value of VO), and if this λ exceeds a predetermined reference value,
It operates to output OD and □. In this sub-control device 20, there are two function tables used when calculating λ, that is, f (x) shown in FIG. 4(a).
There are a function table and a g(!, function table) shown in FIG. 4(b).The details of these tables will be described later.

Next, the effect will be explained.

FIG. 3 is a flowchart showing part of the processing executed inside the sub-control device 20. As shown in FIG. In this flowchart, first, the vehicle speed V detected by the vehicle speed sensor 3 and the throttle opening TVO detected by the throttle opening sensor 2 are read (steer knob P+, Pg), and the moving average value TVO of TVO is calculated according to the following formula (■). is calculated (step P3).

・・・・・・■ The above formula ■ is used to smooth out some of the variations and fluctuations in accelerator depression while driving using a filter, and increase the reliability of the data.The time constant of the above formula ■ is 2.
It is preferable to set the time to about 0 seconds.

Next, although the processing steps are omitted, the first-order difference value ΔV (t) of ■ at a predetermined time Δt is determined, and this is used as the acceleration of the vehicle. Note that the above ΔV is used for actual calculation processing.
If (t) is used as is, there will be large variations;
Since this interferes with the calculation process, it is smoothed and removed (step P).

However, when smoothing, some filters like the above formula (■) are not used. α. As shown in Figure 5, the distribution of , has a sharp peak, and the height of this peak provides useful information.If the above formula (■) is used, this peak information is lost. Therefore, in this embodiment, nonlinear filters with different charging and discharging time constants are used. In other words, in Fig. 6, peak information is captured by rapid charging, and then connected to the next peak by slow discharging. With this method, it is possible to eliminate erroneous information without losing sight of instantaneous changes in vehicle acceleration (peak information).

Next, an estimated value λ of the running resistance is calculated based on the thus obtained TVO, that is, the physical quantity involved in engine combustion, and W, that is, the acceleration of the vehicle (step ps). The calculation of λ is performed as follows. That is, the function table f (X) shown in FIG. 4(a) is referred to on TVO, and the function table g (g
) is referenced by i, and both r (111, g, *) looked up from these two tables are compared and the smaller value is determined as λ. f (X) shown is, for example, a linear function straight line connecting two points (a) and (b), where TVO in (a) corresponds to the throttle opening normally used on a flat road, and TVO in (b) corresponds to the throttle opening normally used on a flat road. TVO corresponds to the throttle opening normally used on steep slopes.

is, for example, a linear function straight line connecting two points (c) and (d), and d in (c) corresponds to the acceleration on an uphill slope road,
i in (d) corresponds to the acceleration on a flat road. In addition, f fx), g (1
11 is merely an example and is not limited thereto.

Here, the concept of calculating λ will be explained. now,
Assume that running resistance is zero (which is impossible in reality). In this case, as long as even a small amount of engine output torque is generated and that engine output torque is transmitted to the wheels, the vehicle will accelerate. This is because the driving force that exceeds the running resistance (zero) is applied.On the other hand, when the running resistance is a certain value (for example, let the value be A), and the driving force A' which is equivalent to A, the vehicle will The vehicle continues to run at a constant speed without accelerating or decelerating.At this time, consider a case where the running resistance increases by ΔA.In this case, if the driving force remains A', the vehicle will decelerate; The acceleration acting on the vehicle should become smaller. To explain this more specifically, in Figure 4 (a) and (b), i) the throttle is opened (TVO is large), and as a result, the acceleration () is If it is large, the running resistance (λ) is small.

il) If the acceleration decreases when the throttle opening is constant, the running resistance increases.

iii) If the acceleration remains the same, does not increase much, or decreases even though the throttle is opened, the running resistance is large.

From these representative facts, we have reached the conclusion that there is a correlation between the engine's output torque, which determines the driving force, and the acceleration of the vehicle to which that driving force is applied, which corresponds to the magnitude of the running resistance. can do.

Therefore, the physical quantity that manipulates the engine's output torque (
Function table f (x) with TVO) as a parameter
and the function table g(2) whose parameter is the acceleration (α) of the vehicle, and by referring to these two tables, the magnitude of the running resistance (more precisely, the estimated value λ) can be calculated. It is possible to know. Furthermore, since it is only necessary to refer to the table and compare, the processing steps can be simplified and the process can be highly implemented.

In addition, since the two function tables are simple linear functions, they can be configured with a simple electric circuit network. In this way, λ can be obtained in real time, and the system can be made inexpensive. You can also do that.

The above-determined λ is used as follows.

That is, it is determined whether λ exceeds a predetermined reference value LHi (step P, ), and when the command is YES, oD, □ for prohibiting OD is output (step P7). On the other hand, when the NO instruction is given in step P6, that is, when λ does not exceed the predetermined reference value LLow.
It is determined whether the value is lower than (Loi>LLol, I) (step P,), and when the command is YES, the output of 0DINH is stopped (inhibition is canceled) (step P,). The above two reference values □1 and L0- are used to determine the reference points for changing the shift pattern (OD prohibition here) and returning (OD prohibition cancellation), and are used to determine the vehicle's power characteristics and automatic transmission. It may be set appropriately by taking into consideration the transmission diagram, etc.

In this way, in this embodiment, throttle opening information (TVO) is used as a physical quantity related to engine combustion, and this
According to VO and acceleration information (α), refer to two correlation tables f (X) g (21), and use the smaller one of the tables f ( When λ exceeds Llli and is large, the shift pattern is changed (OD is prohibited), and when λ is smaller than LLO-, the shift pattern is restored (OD prohibition is canceled).

Therefore, the shift pattern can be changed and restored depending on the magnitude of running resistance, and the shift pattern can be changed in response to changes in all driving environments, including road slope, tire rolling resistance, number of passengers (load amount), wind pressure, etc. Patterns can be changed.

In this embodiment, the moving average value TVO of the throttle opening TVO is used as a physical quantity related to combustion in the engine, but the present invention is not limited to this.
TV○/N e divided by e may be used.

In addition, when determining λ based on two function tables, f is look-amplified from the tables. ) ,,
The smaller of g fz) is set as λ, and this “
It is not limited to comparison conditions such as “small”. For example,
When the graphs in Fig. 4(a) and Fig. 4(b) are each flipped upside down, the “larger” one of f (X) and g (z) looked up from the table is λ
This is because it will be determined as follows.

Also, according to various parameters, the function table f<x+
, g+. may be changed, or the reference value L)li may be changed. In other words, if the gasoline is high octane and the engine power is large, the value of point (c) of g(2) may be increased or the reference value LMi may be decreased, and the load on the vehicle is large. If g (z)
The value of the point (c) may be decreased or L Hi may be increased. Furthermore, as the cumulative distance of the vehicle increases, the engine output generally tends to decrease, so if the cumulative distance increases, the value at point (c) of g (z) may be decreased. Furthermore, as the engine water temperature increases, the engine output tends to decrease, so the value of point (c) of g(2) may be decreased or L84 may be increased.Alternatively, depending on the vehicle speed, f IX), g(
z) may be changed. This is because as the vehicle speed increases and the engine speed increases, the generated torque tends to decrease, so when driving at high speed, λ may increase involuntarily even on a flat road. , if 4
When speed prohibition (OD prohibition) is activated, the engine speed becomes extremely high (this is because there is a problem that the engine speed increases as the vehicle speed increases).

An unwanted increase in λ can be avoided by increasing the value of point (b). Of course, the calculation of λ may be stopped at a predetermined high vehicle speed (for example, 120 km/h) or higher. Furthermore, various methods can be considered, such as changing f (x), g n, and Lh+ according to the number of times OD is inhibited, and changing f (Kl, g < zl, LHi, according to the remaining amount of fuel).

In the above embodiment, there is no particular mention of when the calculation of λ should be performed. For example, in the case of an automatic transmission with four forward gears, there is a method (Method I) that calculates λ at all gears, regardless of the current gear, and a method that calculates λ at all gears, regardless of the current gear, and a method that calculates λ at a specific gear (preferably one before the highest gear). A possible method (method ①) is to calculate λ only at the gear position (ie, 3rd gear). Method 1 has the advantage of improving busy shift avoidance performance as λ increases quickly when driving on a hill while driving in 4th gear. There are disadvantages in terms of heart, such as the need for memory, etc., and inconveniences such as OD being prohibited for a while if you move to a flat road after being prohibited from ○D. On the other hand, although method ↑ can simplify the hardware, it has been pointed out that it has some drawbacks such as slightly inferior performance in avoiding busy shifts. In reality, method 1 (2) should be selected depending on the characteristics of the vehicle (such as whether it is a highly sporty car or a car that prioritizes ride comfort). However, when considering tuning, method ■ is preferable.

In the above embodiment, the pattern is changed between the shift pattern that allows OD (4th speed) and the shift pattern that prohibits ○D, but in addition to prohibiting OD, 1st speed and The shift diagram between 2nd speed and 2nd speed and 3rd speed may be changed.

Further, in the embodiment, the highest stage is set to 4th speed, but the present invention is not limited to this.

(Effects) According to the present invention, it is possible to change the shift pattern according to the running resistance, and to obtain a shift characteristic that comprehensively takes into account changes in running conditions such as changes in the gradient of the running road surface and changes in the amount of cargo. I can do it.

[Brief explanation of drawings]

FIG. 1 is a conceptual configuration diagram of the present invention, and FIGS. 2 to 6 are diagrams showing an embodiment of an automatic transmission control device for a vehicle according to the present invention.
Figure 2 is its configuration diagram, Figure 3 is a flowchart showing its processing, Figures 4 (a) and (b) are diagrams each showing its function table f(., g+z), and Figure 5 is its acceleration distribution. FIG. 6 is a graph showing nonlinear filtering of the acceleration. 2...Throttle opening sensor (driving state detection means, physical quantity detection means), 3...Vehicle speed sensor (driving state detection means), 10
...ATCU (speed ratio determining means), 11...
...Valve controller (operating means), 20...
...Sub control device (acceleration detection means, running resistance calculation means, pattern change means).

Claims (1)

[Scope of Claims] a) Running state detection means for detecting the running state of the vehicle; b) Physical quantity detection means for detecting a physical quantity involved in engine combustion; c) Acceleration detection means for detecting the acceleration of the vehicle. ,d)
a running resistance calculation means for calculating an estimated value corresponding to the magnitude of running resistance acting on the own vehicle based on the relationship between the physical quantity and the acceleration; and e) when the estimated value exceeds a predetermined reference value. , a pattern changing means for changing the speed change pattern so as to obtain a speed change characteristic suitable for cases where running resistance is large; f) referring to the speed change pattern according to the running condition of the vehicle;
An automatic transmission control device for a vehicle, comprising: a transmission ratio determining means for determining a transmission ratio; and g) an operation means for operating an automatic transmission to achieve the determined transmission ratio.