JP2900747B2 - Automatic transmission control device for vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission control device for a vehicle, which is controlled by a vehicle speed information and accelerator operation information.

[0002]

2. Description of the Related Art Conventionally, as an electronically controlled automatic transmission of a vehicle equipped with a multi-stage automatic transmission, there is generally known an electronically controlled automatic transmission in which a gear position is selected according to a vehicle speed and a throttle opening. I have.

[0003] First, selection of an optimal shift gear position during traveling largely depends on the torque generated by the engine and the vehicle speed. Here, the vehicle speed can be easily measured, but the generated torque of the engine cannot be easily measured. Therefore, the accelerator opening (throttle opening) having a large correlation with the torque is measured. In the A / T control unit, a shift line is drawn on two variable planes, ie, a vehicle speed and an accelerator opening, and a shift map indicating an optimal shift gear position is set in advance.

[0004] A vehicle speed detection value from a vehicle speed sensor and
By comparing the accelerator opening detection value from the accelerator opening sensor with the shift map, the shift is performed when the plotted operating point crosses the shift line.

[0005] In some vehicles, not only the position of the operating point on the shift map but also a time delay process such as not re-shifting for a certain period of time after shifting is introduced. Does not change that the gear position is selected according to the vehicle speed and the accelerator opening.

[0006]

However, in the above-mentioned conventional electronically controlled automatic transmission, the gear position is basically selected by the vehicle speed and the accelerator opening. The driver may be dissatisfied when driving.

(1) A driver accustomed to driving a vehicle equipped with an automatic transmission accelerates from a stop at an intersection in a general urban area and attempts to cruise at a constant speed, and intentionally releases the accelerator pedal at a desired speed. Shift the automatic transmission to the overdrive position.

However, when the driver wants to cruise, he wants to upshift without returning the accelerator to a specific amount.

(2) The driver depresses the accelerator when overtaking a highway or on a mountainous road (uphill) because of a lack of power and wishing to downshift. However, I do not readily shift, so I step further. The gear is finally shifted by this stepping on again.

In this case, it is desired to downshift with the first depression of the accelerator.

(3) The shift control is performed by giving a shift command when a shift is determined based on the measured current vehicle speed and accelerator opening. However, even if a shift command is given, there is a delay in the operation of a hydraulic valve or the like of the shift mechanism due to inertia or the like, and there is no instantaneous shift. That is,
Actually, a mechanical shift is performed with a time delay to the shift command. For this reason, the delay in the mechanical shift may give the driver an uncomfortable shift.

Regarding the above problem, the same applies to a shift control using a known accelerator opening differential value.

The accelerator opening differential value is a change in the accelerator opening detection value in a predetermined time, and is calculated using the present data and one accelerator opening past data. For accelerator work that is not performed, the accelerator opening degree differential value information is not always accurate accelerator operation prediction information, and gives a feeling of strangeness to the driver during a sudden change operation of the accelerator where the prediction accuracy decreases. .

The accelerator opening differential value is a linear prediction that connects two accelerator opening data with a straight line. When the driver stops suddenly depressing the accelerator or returning the accelerator, the accelerator opening differential is calculated. The overshoot and undershoot of the accelerator operation amount considered by the value information is small, and the downshift or upshift is performed without the downshift or upshift with the actual accelerator operation amount. The shift control is performed only when the shift is performed, and the shift control that responds to the driver's shift expectation is not always achieved.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. A first object of the present invention is to provide an automatic transmission control apparatus for a vehicle in which a shift is controlled by vehicle speed information and accelerator operation information. It is an object of the present invention to achieve a shift control that responds to a driver's expectation of a shift without giving the driver a sense of incompatibility with the shift based on operation prediction.

A second object of the present invention, in addition to the first object, is to prohibit an error in accelerator operation amount data observation and improper shift control from being performed when the driver operates the accelerator without meaning. .

[0017]

According to a first aspect of the present invention, there is provided an automatic transmission control apparatus for a vehicle, comprising:
A means for predicting an accelerator operation amount future value using a non-linear equation based on one or more accelerator operation amount data, and performing shift control based on a gear ratio determined based on the vehicle speed detection value and the accelerator operation amount future value.

That is, as shown in the claim correspondence diagram of FIG. 1, a speed change means c provided between the engine a and the drive wheels b to obtain a multi-stage or stepless speed ratio, and a speed ratio by the speed change means c Actuator d for changing the vehicle speed by an external control command, and vehicle speed detecting means e for detecting the vehicle speed
An accelerator operation amount detecting means f for detecting an accelerator operation amount; a data storage means g for storing and setting an accelerator operation amount detection value at predetermined time intervals; and a nonlinear equation based on three or more accelerator operation amount data. Accelerator operation amount future value prediction means h for predicting an accelerator operation amount future value, speed ratio determination means i for determining a gear ratio based on a vehicle speed detection value and an accelerator operation amount future value, and a determined speed ratio is obtained. And a shift control means j for outputting a control command to the shift actuator d.

According to a second aspect of the present invention, there is provided an automatic transmission control apparatus for a vehicle, wherein an accelerator operation amount future value deviates from an upper limit value or a lower limit value based on a moving average and a moving standard deviation. This is a means for defining the future value of the manipulated variable as the upper limit or the lower limit.

That is, as shown in the claim correspondence diagram of FIG. 1, in the automatic transmission control device for a vehicle according to claim 1, a moving average calculating means k for calculating a moving average of the accelerator operation amount from a plurality of accelerator operation amount data. A moving standard deviation calculating means m for calculating a moving standard deviation of the accelerator operation amount based on a plurality of accelerator operation amount data; and a future accelerator operation amount value from the accelerator operation amount future value predicting means h, a moving average and a moving standard value. Accelerator operation amount future value defining means n for defining the accelerator operation amount future value to the upper limit value or the lower limit value when the deviation is outside the upper limit value or the lower limit value due to the deviation.
And characterized in that:

[0021]

The operation of the first aspect of the present invention will be described.

At the time of traveling with an accelerator operation, the accelerator operation amount detection value from the accelerator operation amount detection means f is stored and set at predetermined time intervals in the data storage means g. A future accelerator operation amount is predicted using a nonlinear equation based on three or more accelerator operation amount data. Then, the gear ratio determination means i determines the gear ratio based on the vehicle speed detection value from the vehicle speed detection means e and the accelerator operation amount future value from the accelerator operation amount future value prediction means h. A control command for obtaining the determined speed ratio is output to the speed change actuator d, and the speed ratio of the speed change means c provided between the engine a and the drive wheels b is optimally controlled.

Here, the prediction of the accelerator operation amount future value will be specifically described. For example, when a quadratic equation is used as a nonlinear equation, three values of the current data and the two past data are used.
A quadratic equation passing through three points is determined by one accelerator operation amount data. An accelerator operation amount that is a predetermined time ahead of the present time, that is, a future accelerator operation amount can be predicted by a quadratic equation using the time and the accelerator operation amount as axes.

Therefore, accelerator operation prediction is accurately performed by using three or more accelerator operation amount data, and the shift control is performed based on the future accelerator operation amount future value based on the prediction. The shift time delay is compensated, and the driver does not feel uncomfortable shifting.

Further, when the driver suddenly stops stepping on the accelerator or stops returning the accelerator by using the non-linear equation, the actual accelerator operation amount becomes larger when the driver steps on the pedal and becomes smaller when the driver returns the pedal. However, the overshoot and the undershoot increase the possibility of downshifting or upshifting without downshifting or upshifting with the actual accelerator operation amount, and achieve shift control in response to the driver's shift expectation. .

The operation of the second aspect of the present invention will be described.

When determining the future value of the accelerator operation amount, the moving average calculating means k calculates a moving average of the accelerator operation amount based on the plurality of accelerator operation amount data, and the moving standard deviation calculating means m calculates the plurality of accelerator operation amount data. , The moving standard deviation of the accelerator operation amount is calculated, and in the accelerator operation amount future value defining means n, the accelerator operation amount future value from the accelerator operation amount future value predicting means h becomes the upper limit or the lower limit based on the moving average and the moving standard deviation. If the value deviates from the value, the accelerator operation amount future value is defined as the upper limit or the lower limit.

Therefore, in the event of an accelerator operation amount data observing error due to a failure of the accelerator operation amount detecting means f or an accelerator operation that is meaningless to the driver, such as an accelerator flapping, the accelerator operation amount future value becomes the upper limit value or the lower limit value. It is prohibited to perform improper speed change control as specified and not specified.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

First, the configuration will be described.

FIG. 2 is an automatic transmission control system to which the automatic transmission control device for a vehicle according to the embodiment of the present invention is applied.

In FIG. 2, 1 is an engine, 2 is an automatic transmission, 3 is a vehicle speed sensor (corresponding to vehicle speed detecting means e), 4 is an accelerator opening sensor (corresponding to accelerator operation amount detecting means f), and 5 is A / A It is a T control unit.

The automatic transmission 2
Are a torque converter 2a having a built-in torque converter, a speed change mechanism 2b (corresponding to speed change means c) for obtaining the fourth forward speed by means of planetary gears, a first shift solenoid 2c and a second shift solenoid 2d (speed change actuator). d), and an output shaft 2d connected to drive wheels (not shown).

The A / T control unit 5 includes an input circuit for processing input signals from the vehicle speed sensor 3 and the accelerator opening sensor 4, and a RAM (corresponding to data storage means g) for storing a shift map and accelerator opening data. ) And RO
M and a CPU for performing various arithmetic processes related to shift control
And both shift solenoids 2c,
And an output driver for outputting a drive current to the 2d.

Next, the operation will be described.

[Shift Control Processing] FIG. 3 is a flowchart showing the flow of the shift control processing performed by the A / T control unit 5, and each step will be described below.

In step 30, the vehicle speed V and the accelerator opening future value THV + 1 are read.

Here, the future accelerator opening value THV + 1 is the latest value obtained by the accelerator opening future value prediction processing shown in FIG.

In step 31, the vehicle speed V and the accelerator opening future value THV + 1 are compared with the shift map.

As shown in FIG. 4, the shift map itself is a vehicle speed-accelerator opening map used in normal shift control. In this map, the accelerator opening is replaced by the accelerator opening on the vertical axis. The future value of the opening is used.

In step 32, the gear position is determined based on the position on the shift map of the operating point determined by the vehicle speed V and the accelerator opening future value THV + 1 (corresponding to the gear ratio determining means i).

In step 33, a control command for obtaining the gear position determined in step 32 is output to both shift solenoids 2c and 2d (corresponding to shift control means j).

[Accelerator opening future value prediction processing] FIG.
Each step will be described below with a flowchart showing the flow of the accelerator opening future value prediction processing operation performed by the / T control unit 5.

In step 50, the accelerator opening THV0 at time (t ₀ ) stored in the RAM of the A / T control unit 5 and the accelerator opening THV-1 at time (t ₀ -Δt) are calculated. The accelerator opening THV-2 at time (t ₀ -2Δt) is read.

In step 51, the quadratic equation passing through the above three points, y = ax ² + bx + c, is substituted for the data of the three points, and the coefficients a, b, and c are calculated by three simultaneous equations. Here, the _{THV0 = y 0 t 0 = x} 0 THV-1 = y 1 t 0 -Δt = x 1 THV-2 = y 2 t 0 -2Δt = x 2.

In step 52, a future accelerator opening THV + 1 is calculated by the following quadratic equation using a, b, and c obtained in step 51.

THV + 1 = a (t ₀ + Δt) ² + b (t ₀ + Δt) + c The above steps 50 to 52 correspond to the accelerator operation amount future value prediction means h.

In step 53, the accelerator opening moving average x _At is calculated by the following equation using the accelerator opening moving average x _At-1 obtained last time and the accelerator opening future value THV + 1 in step 52. In addition, the accelerator opening is calculated using the previously obtained accelerator opening movement standard deviation σ _t-1 and the present standard deviation (the absolute value of the difference between the accelerator opening moving average x _At and the accelerator opening future value THV + 1). The moving standard deviation σ _t is calculated by the following equation (corresponding to the moving average calculating means k and the moving standard deviation calculating means m).

X _At = (9 · x _At−1 + THVO) / 10 σ _t = (9 · σ _t−1 + | x _At −THVO |) / 10 _At step 54, the accelerator opening degree future value THV + 1 is calculated. (X _At
−σ _t ) is determined.

In step 55, YES in step 54
When it is determined that the accelerator opening future value THV + 1 is equal to THV + 1
= Is defined the lower limit of x _At -σ _t.

In step 56, the accelerator opening degree future value T
It is determined whether HV + 1 exceeds (x _At + σ _t ).

In step 57, YES in step 56
When it is determined that the accelerator opening future value THV + 1 is equal to THV + 1
= Is defined to the upper limit value of x _At + σ _t.

The above steps 54 to 57 correspond to the accelerator operation amount future value defining means n.

[Prediction of Accelerator Opening Future Value] The most characteristic feature of the present invention is the accelerator operation prediction method.

Generally, the driver's accelerator operation changes depending on input information to the driver and the driver's own intention. Therefore, it is impossible to accurately predict the driver's accelerator operation. However, from the past accelerator operation patterns of the driver, the near future (within 1 second)
It is not impossible to predict the accelerator operation tendency.

Therefore, it is considered that the accelerator operation is predicted by modeling the accelerator operation amount. Generally, the modeling of the manipulated variable is identified by a statistical method, for example, by an autoregressive equation or a multiple regression equation. However, in such a method, since processing is performed by the least square method, there is a problem that a large amount of RAM capacity is required for storing data for processing, and time is required for arithmetic processing.

On the other hand, in steps 50 to 52 of the flow chart of FIG. 5, the accelerator opening data THV0, THV-1, and THV-2 at three points having the same time interval are used as shown in FIG.
As shown by the dotted line characteristic, a quadratic equation y = a passing through three points
x ² + bx + c is identified, and the y coordinate of (t ₀ + Δt) existing on this quadratic equation is set as the accelerator opening future value THV + 1 after Δt, so that the data storage capacity is reduced.
Acceleration degree future value THV + 1 can be obtained with high accuracy by shortening the calculation processing time.

However, while the prediction was simplified in this way, the fact that the statistical processing was not performed was a disaster, and the three contact points of accelerator opening data THV0, THV-1, and THV-2 showed sensor contact points. Accelerator opening future value THV due to data observation error due to failure or unintentional operation of driver (eg, meaningless fluttering of accelerator)
+1 may change discontinuously. If the processing is performed statistically, such a momentary error is buried as one error.

Therefore, in order to prohibit extremely inappropriate shifting from being performed mainly due to an error prediction caused by an observation error of the sensor, a range is set by limiting the future accelerator opening value THV + 1. For the prediction that deviates from the above, a method is used in which the upper limit or lower limit of the range is substituted for the future accelerator opening THV + 1 without using the future accelerator opening THV + 1 based on the prediction.

More specifically, the method is performed in steps 53 to 57 in FIG. 5, and the accelerator opening future value THV + 1 is set as follows by this processing.

1) When x _At −σ _t ≦ THV + 1 ≦ x _At + σ _t THV + 1 = a (t ₀ + Δt) ² + b (t ₀ + Δt) + c 2) THV + 1 <x _At −σ _{t THV + 1 = x at -σ t} ( lower limit) 3) THV + 1> THV + 1 = x at + σ t ( upper limit when x _at + σ _t) is [shift control action] set as described above when the The shift control is performed using the accelerator opening future value THV + 1 as the accelerator operation information, and its characteristic action will be described.

First, accelerator opening data THV0 at three points
, THV-1 and THV-2 are used to accurately obtain the future accelerator opening THV + 1, and the shift control is performed based on this prediction based on the future accelerator opening THV + 1 earlier than the actual accelerator opening THV + 1. Thereby, the time delay of the mechanical shift is compensated, and the driver does not feel unnatural shift.

Second, by using a quadratic equation which is a non-linear equation, when the driver suddenly stops stepping on the accelerator or stops returning the accelerator, when the driver depresses the accelerator pedal more than the actual accelerator operation amount, Time gets smaller. However, due to the overshoot and the undershoot, the possibility of downshifting or upshifting is increased without downshifting or upshifting with the actual accelerator operation amount, and shift control responding to the driver's shift expectation is achieved. .

That is, as shown in FIG. 7, when the driver suddenly stops stepping on the accelerator or stops returning the accelerator, the future accelerator pedal opening value is larger than the actual accelerator pedal opening value when the driver steps back. Time is getting smaller. This is because it is unavoidable that the driver's sudden operation of the accelerator cannot be predicted.

On the other hand, the overshoot and the undershoot solve the problem well.

That is, the inconvenience in the conventional shift control device based on the vehicle speed and the accelerator opening is exactly generated in the overshoot portion and the undershoot portion as a result of the analysis of the experimental data. Specifically, it is assumed that the driver suddenly steps on the accelerator in anticipation of a downshift and stops halfway. At this time, the predicted accelerator opening value overshoots the actual accelerator opening value, and even if the actual accelerator opening value does not shift down on the shift map, the accelerator opening future value is larger by the overshoot in this accelerator opening future value. By setting the value, the downshift is executed without performing the accelerator depression operation again. The same applies to the case of an upshift, and the future value of the accelerator opening becomes smaller by the amount of the undershoot, so that the upshift is executed without performing a sufficient accelerator return operation.

Next, the effects will be described.

(1) In an automatic transmission control device for a vehicle in which the speed is controlled by the vehicle speed information and the accelerator operation information, the accelerator is operated by using a quadratic equation based on three accelerator opening data THV0, THV-1, and THV-2. A device that predicts the future opening value THV + 1 and performs shift control based on the gear position determined based on the vehicle speed V and the accelerator opening future value THV + 1. Gear shift control that responds to the driver's gear shift expectation can be achieved without giving a shift.

(2) The accelerator operation amount future value THV + 1 is obtained by calculating the accelerator opening moving average x _At and the accelerator opening moving standard deviation σ.
_The upper limit (x _At + σ _t ) or lower limit (x _At −
σ _t ), the device for specifying the accelerator operation amount future value THV + 1 to the upper limit (x _At + σ _t ) or the lower limit (x _At -σ _t ) is used. It is possible to prohibit inappropriate shifting control from being performed when the driver does not operate the accelerator.

Although the embodiment has been described with reference to the drawings, the specific configuration is not limited to the embodiment, and even if there are changes and additions without departing from the scope of the invention, the invention is included in the invention. It is.

For example, in the embodiment, an example in which the present invention is applied to a multi-stage automatic transmission has been described. However, the present invention can also be applied to a continuously variable transmission (CVT) in which the gear ratio is changed steplessly. In this case, similarly to the multi-stage automatic transmission, the shift map is used as it is, and a future accelerator opening is used instead of the accelerator opening as shift input information.

[0072]

According to the first aspect of the present invention, there is provided an automatic transmission control apparatus for a vehicle in which a shift is controlled based on vehicle speed information and accelerator operation information, using a nonlinear equation based on three or more accelerator operation amount data. Means for predicting the future accelerator operation amount, and performing gear shift control based on the gear ratio determined based on the vehicle speed detection value and the accelerator operation amount future value. Thus, an effect is obtained that the shift control in response to the driver's shift expectation can be achieved.

According to the second aspect of the present invention, when the future accelerator operation amount deviates from an upper limit value or a lower limit value based on the moving average and the moving standard deviation, the accelerator operation amount future value is changed to the upper limit value or the lower limit value. Is provided, in addition to the above effects, an effect is obtained that it is possible to prohibit an error in the observation of accelerator operation amount data and the execution of inappropriate shift control during accelerator operation that has no meaning to the driver.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims showing an automatic transmission control device for a vehicle according to the present invention.

FIG. 2 is a shift control system diagram to which the vehicle automatic shift control device according to the embodiment is applied;

FIG. 3 is a flowchart illustrating a flow of a shift control processing operation performed by an A / T control unit of the embodiment device.

FIG. 4 is a shift map diagram stored and set in an A / T control unit of the embodiment device.

FIG. 5 is a flowchart showing a flow of an accelerator opening degree future value prediction processing operation performed by an A / T control unit of the embodiment device.

FIG. 6 is a graph showing a method of predicting a future accelerator opening in the apparatus according to the embodiment.

FIG. 7 is a simulation result diagram showing a relationship between an actual accelerator opening value and a future accelerator opening value.

[Explanation of symbols]

 a engine b driving wheel c speed change means d speed change actuator e vehicle speed detection means f accelerator operation amount detection means g data storage means h accelerator operation amount future value prediction means i gear ratio determination means j shift control means k moving average calculation means m movement standard Deviation calculating means n Accelerator operation amount future value defining means

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48 B60K 41/00-41 / 28 F02D 41/00-45/00

Claims (2)

(57) [Claims] 1. A speed change means provided between an engine and drive wheels to obtain a multi-stage or stepless speed change ratio, a speed change actuator for changing a speed ratio by the speed change device by an external control command, and a vehicle speed Vehicle speed detecting means for detecting, accelerator operation amount detecting means for detecting an accelerator operation amount, data storage means for storing and setting an accelerator operation amount detection value at predetermined time intervals, and a nonlinear equation based on three or more accelerator operation amount data Accelerator operation amount future value predicting means for predicting an accelerator operation amount future value by using the following; speed ratio determining means for determining a speed ratio based on a vehicle speed detection value and an accelerator operation amount future value; And a shift control means for outputting a control command to be obtained to the shift actuator. 2. The automatic transmission control device for a vehicle according to claim 1, wherein a moving average calculating means for calculating a moving average of the accelerator operation amount based on the plurality of accelerator operation amount data, and an accelerator operation amount based on the plurality of accelerator operation amount data. Moving standard deviation calculating means for calculating the moving standard deviation of the accelerator operation amount future value from the accelerator operation amount future value predicting means deviates from an upper limit or a lower limit value by a moving average and a moving standard deviation; An automatic shift control device for a vehicle, comprising: an accelerator operation amount future value defining unit that defines the future amount value as an upper limit value or a lower limit value.