JP3094556B2 - Fuel injection amount control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to traction control in an internal combustion engine, particularly a vehicle such as an automobile equipped with a diesel engine. More specifically, the present invention relates to controlling the fuel injection amount of an engine according to the slip of a driving wheel. The present invention relates to an apparatus for performing the above.

[0002]

2. Description of the Related Art In a motor vehicle, the driving wheels may slip or spin or meander when starting or suddenly accelerating due to road surface conditions, tire wear conditions, and the like. For stable running, when excessive slip occurs on the drive wheels, the engine torque is reduced by reducing the fuel supply to the engine promptly,
It is preferable to operate the brakes of the driving wheels to suppress the slip. Based on such a concept, a technique for controlling the fuel supply amount in accordance with the speed difference between the drive wheel and the driven wheel to change the engine torque, and also controlling the brake, is disclosed in, for example, As described in JP-A-288331, JP-A-1-174546, JP-A-3-37246, etc., various proposals have been made conventionally.

[0003]

In the case of a diesel engine, the fuel injection amount changes according to the accelerator opening operated by the accelerator pedal, and the torque generated by the engine also changes according to them. When the accelerator pedal demanding the above-described injection amount is depressed, the injection amount reaches a plateau, so that a so-called “dead zone” where the injection amount does not change in response to the operation of the accelerator pedal is generated. Therefore,
In such a region, even if the injection amount reduction control should be performed in response to the increase in the slip of the drive wheels,
As a result of the controller not executing the instruction for the reduction correction, there is a problem that a rapid decrease in the injection amount (torque) cannot be obtained and the responsiveness of the traction control deteriorates.

[0004] Specifically, for example, in an engine having a characteristic as shown in FIG.
The required injection amount when the engine speed is _Ne1 is higher (larger) than the line of the maximum injection amount (Full-Q). Even if it occurs, unless the controller forcibly sets the accelerator opening signal of the injection amount governor pattern to 20% or less.
Since the fuel injection amount to the engine does not decrease and the engine torque does not decrease, it is not possible to immediately cope with the slip of the drive wheels. As a result, it is clear that the drivability, responsiveness, running stability, and the like of the automobile deteriorate.

In the prior art, attempts have been made to suppress the torque generated by the engine by manipulating the maximum injection amount of fuel to the engine itself. Since it is relatively small and the controllability of the rotation speed is poor, there is also a problem that the fluctuation of the rotation speed is large. It is an object of the present invention to address these problems of the prior art.

[0006]

According to the present invention, in order to address the above-mentioned problems, the control method is changed for each operation area mainly for a diesel engine using an electronically controlled fuel injection pump. As a result of considering the optimal control method for each area, the rotational speed of
When changing the generated torque by controlling the fuel injection amount for based have been engine slip ratio calculated from the difference between the rotational speed of the degrees and the drive wheels, or the current operating state of the engine is in a partial load region Or in the full load area,
When in the partial load range, set according to the slip ratio.
Using the pseudo signal of one of the engine speed or the accelerator opening corrected by the corrected amount and the measured value of the other ,
The corrected injection amount is calculated according to the banana pattern , and
When in the full load range , the maximum injection amount and slip ratio
Maximum injection amount after correction using the correction amount determined by response
By calculating the, there is provided a fuel injection amount control apparatus characterized by being configured so as to form a correction operation of the fuel injection amount of the engine.

[0007]

According to the present invention, when the control device determines that the operating state of the engine is not in the partial load range, that is, not in the full load range, the engine speed determined in accordance with the slip ratio of the drive wheels. or pseudo correction signal for one of the accelerator opening is read out as correction amounts are calculated thereby corrected engine speed or accelerator opening Rutotomoni, it
And the governor pattern control of the fuel injection amount corresponding to the other measured value of the engine speed or the accelerator opening is performed, and the generated torque of the engine is adjusted to an appropriate value. As a result,
Compared to correcting the calculated fuel injection amount itself
To correct the fuel injection amount when the slip rate increases
The control of the fuel injection amount in a state where there is no slip
Because it can be close to the turn, such
Even in such a case, good operation controllability can be maintained. When the control device determines that the operating state of the engine is in the full load range, a correction signal for the maximum injection amount determined in accordance with the slip ratio of the drive wheels is read out, whereby the maximum injection amount is determined. As a result, the injection amount at that time is suppressed to an appropriate value, and the generated torque of the engine is reduced, so that in any case, the slip of the drive wheels is quickly converged.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the relation of each means constituting the fuel injection amount control device of the present invention. In the figure, a slip ratio calculating means 1 calculates a slip ratio S from a drive wheel speed N _DR and a driven wheel speed N _DN, and calculates a slip ratio S = (drive wheel speed N _DR −driven wheel speed N _DN ) /
The slip ratio signal S is output to the brake driving means 5 and the correction amount calculating means 2 by calculating as the driven wheel speed _NDN . The correction amount calculation means 2 calculates and outputs the pseudo rotation number correction amount ΔN to the rotation number correction amount calculation means 3 and the maximum injection amount correction amount K to the control amount calculation means 4 based on the slip ratio S.

[0009] Rotation speed correction amount calculation means 3 calculates the corrected engine speed N _e 'from the actual engine speed N _e and the pseudo rotational speed correction amount .DELTA.N, outputs to the control amount calculation means 4. Maximum after the control amount calculation means 4, which determines the maximum injection quantity Full-Q based on the actual engine speed N _e and the accelerator opening Accp, etc., were corrected by it <br/> maximum injection quantity correction amount K Injection amount Fu
'calculates the engine speed N _e of the corrected' ll-Q to calculate the injection quantity q from the accelerator opening Accp and the like.
These two operations values Ru is outputted as the injection quantity command value q _FIN to alternatively fuel injection pump. That is, the engine is at full load
When in the operating state, the corrected maximum injection amount Full-Q '
While the injection amount command value q _FIN is output, the engine
After the correction when the operation state is other than the load, that is, in the partial load operation state
Is output as an injection amount command value q _FIN . This
Selection means for performing the selection operation of is not specifically shown.
Is the current operating state of the engine in the full load operating range?
The operation state determining means (not shown) for determining whether or not
It operates in accordance with the
All the selection means are provided in a part of an electronic control device described later.
be able to. Further, the brake driving means 5 controls the hydraulic pressure acting on the brake for the driving wheel based on the slip ratio S.

FIG. 2 is a schematic diagram showing the overall configuration of the fuel injection amount control device according to the present invention, including related equipment. In FIG. (Example: front wheel) Reference numeral 10 denotes a diesel engine mounted on a vehicle. 11 is an accelerator pedal, 12 is an accelerator pedal 11
An accelerator opening sensor for detecting an opening degree of a main intake throttle valve that is opened and closed by operation of a driven wheel speed sensor 13 for detecting a driven wheel speed N _DN ; a driving wheel speed sensor 14 for detecting a driving wheel speed N _DR ; Reference numeral 15 denotes an electronically controlled distribution type fuel injection pump as an actuator; 16, a brake for the driving wheel 8; 17, an electromagnetic valve for releasing the hydraulic pressure supplied to the driving wheel brake 16 to a reservoir to reduce the pressure; A solenoid valve for supplying hydraulic pressure to the brake 16 to increase the pressure;
Is an electronic control unit (ECU) which incorporates the respective units shown in FIG. 1 and centrally controls equipment related to the present invention; Accumulators are shown.

The operation procedure of the control device according to the present invention will be described with reference to a flowchart shown in FIG. 3 and FIG. 4 connected thereto. This control program is executed by an electronic control unit (ECU) 19, for example, on the diesel engine 1
It is repeatedly executed at short intervals corresponding to one rotation of the crankshaft of zero. When the control program starts, in step 100, the drive wheel speed N _DR , the driven wheel speed N _DN , the actual engine speed N _e , the accelerator opening are determined from the output signals of various sensors in order to detect the state of the engine and the vehicle. Ac
Captures operating parameters such as cp and transmission shift position. In step 101, the engine speed range is determined, and in step 102, the shift position of the transmission is determined, and it is determined whether or not the slip ratio needs to be detected.
In step 24, the slip ratio S is set to 0 so that the slip ratio control is not performed. If it is determined that the slip ratio is necessary, the process proceeds to step 103 and the slip ratio calculation process is executed.

In step 103, the driven wheel speed N _DN and the driving wheel speed N _DR are fetched.
According to the value taken in the previous step, the wheel rotational speed difference dN
The, dN ← calculated as N _DR -N _DN, which is then converted into the slip ratio S as S ← dN / N _DN at step 105, to generalize. Subsequently, in step 106, it is determined whether or not the slip control is necessary based on whether or not the slip ratio S is larger than a predetermined value (for example, 20%). Rate S
Is set to 0, but when it is determined that the slip ratio S is equal to or more than the predetermined value, the traction control is performed in step 107 and thereafter.

In step 107, it is determined whether or not the slip ratio S is larger than a predetermined value (for example, 40%) for performing the brake control.
The two solenoid valves 17 for adjusting the hydraulic pressure of the brake
And 18 are closed to hold the brake oil pressure at a constant value, and when the slip ratio S is equal to or greater than a predetermined value, the brake oil pressure is further finely controlled as described below.

In step 109, it is determined whether or not the brake oil pressure needs to be increased more than the present time, based on whether or not the brake oil pressure has become equal to or more than the hold pressure with the slip ratio S of 40% or more in the past, and this condition is not satisfied. If
In step 110, the solenoid valve 17 is closed and the solenoid valve 18 is closed.
Open the brake oil pressure further. If this condition is satisfied, the electromagnetic valve 18 is closed in step 111,
The brake oil pressure is prevented from increasing any more, and the routine proceeds to step 112, where it is further determined whether or not the slip ratio S at that time is within a predetermined range (for example, 60% ≦ S ≦ 80%). If it is within the predetermined range, step 113
Then, the solenoid valve 17 is opened to lower the brake hydraulic pressure. If the brake hydraulic pressure is not within the predetermined range, the previous state is maintained.

Step 114 and subsequent steps correspond to the control of the torque generated by the engine, which is a feature of the present invention.
4 and thereafter, the process proceeds to step 114, in which the pseudo rotation speed correction amount ΔN corresponding to the slip ratio S at that time is read from a map having contents as shown in FIG. The actual engine speed _{Ne is} corrected, and the corrected engine speed _Ne 'is determined. Further, the routine proceeds to step 116, where the corrected engine speed N _e 'and the accelerator opening Accp , which is the actually measured value, are calculated from the figure.
The injection amount q is calculated by a normal governor pattern as illustrated in FIG.

In step 117, the actual engine speed N
_{In addition} to calculating the maximum injection amount Full-Q according to _e , the correction amount K of the maximum injection amount corresponding to the slip ratio S at that time is determined in step 118 by using a map such as that shown in FIG. In step 119, the maximum injection amount Full-Q is multiplied by the maximum injection amount correction amount K to calculate the corrected maximum injection amount Full-Q '. In step 120, the operating state of the engine determined by the control device 19
Depends on whether or not is in the full load range.
Step 1 with the corrected maximum injection amount Full-Q 'calculated in 9
One of the injection amounts q calculated in step 16 is selected. All negative
If it is determined that it is in the load region, the process proceeds to step 121, and the corrected maximum injection amount Full-Q ′ is set as the injection amount command value q _FIN , but is not in the full load region, in other words, in the partial load region.
If it is determined that there is, the process proceeds to step 122, where the injection amount q obtained in step 116 is set in the output port, and the control ends. Thereafter, the steps from 100 to 123 are repeatedly executed at predetermined intervals.

FIG. 7 is a time chart illustrating the operating state of the embodiment. (A) is a diagram showing the relationship between the detected values of the driving wheel speed sensor 14 and the driven wheel speed sensor 13 for detecting the rotation speed of the driving wheel 8 and the driven wheel 9, and the slip ratio;
(B) is a diagram showing a state of the brake hydraulic pressure corresponding to the slip ratio shown in FIG. (A). When the slip ratio becomes 40% or more, the electromagnetic valve 18 is opened to release the brake 1 of the drive wheel 8.
Then, when the brake oil pressure reaches the hold pressure, the solenoid valve 18 is closed, and the oil pressure is suppressed from rising any more to maintain the hold pressure. This results in a slip rate of 60
%, The solenoid valve 17 is opened intermittently (duty ratio control), and the brake oil pressure of the drive wheels 8 is gradually reduced so that the slip ratio becomes 20% or less.

FIG. 7 (c) shows an example of the value of the pseudo rotation speed correction amount ΔN which changes according to the change of the slip ratio. (D) is a diagram illustrating a change in the injection amount,
A solid line indicates a change in the injection amount by the conventional fuel injection amount control device, and a broken line indicates a change in the injection amount according to the present invention. In the case of the conventional technology, the trapezoidal part has the maximum injection amount Full
Since the reduction control by the -Q control and the subsequent control by the governor control are performed, the response of the injection amount reduction is slow, and the slip rate cannot be reduced in a short time.However, in the fuel injection amount control device of the present invention, In response to the increase in the slip ratio, the injection amount is decreased immediately, and the abnormal state is terminated early.

[0019] In the embodiments described above, but using the correction value of the engine speed N _e as a pseudo signal, the present invention is not limited to this example, the use of correction values of the accelerator opening degree signal Accp similar Effects can be obtained.

[0020]

As is apparent from the above description, the present invention controls the fuel injection amount when the slip ratio of the drive wheels increases, by controlling the pseudo signal and the maximum injection amount for the engine speed or the accelerator opening. by performing together, that is, use a slip control, the partial load range, performs a governor pattern control in the pseudo signal one of the engine speed or the accelerator opening degree, the correction of the maximum injection quantity at full load region Traction control,
Since smooth control can be performed in consideration of the slip in the entire operation region, the time until the convergence of the slip can be reduced. In particular, according to the control of the partial load region in the present invention,
If so, one of the engine speed or accelerator opening
Use the pseudo signal determined according to the slip ratio,
For the other, use the measured values as they are and
Determine the fuel injection amount by applying it to the pattern
To correct the fuel injection amount when the slip rate increases
The control is performed by, for example, the finally calculated fuel injection amount itself.
Of the original control pattern, that is,
Calculation pattern of fuel injection amount without lip
Can be close. Therefore, slip occurs
The operation controllability is improved even during the operation. Further, according to the control device of the present invention, torque controllability is improved, and smooth running and acceleration feeling as well as high running stability can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the relationship between each means constituting a fuel injection amount control device according to the present invention.

FIG. 2 is a schematic diagram showing an overall configuration including a fuel injection amount control device of the present invention and its related devices.

FIG. 3 is a part of a flowchart showing a control procedure in the embodiment of the fuel injection amount control device of the present invention.

FIG. 4 is another part of the flowchart connected to FIG. 3;

FIG. 5 is a characteristic diagram for giving a pseudo rotation speed correction amount in the embodiment of the fuel injection amount control device of the present invention.

FIG. 6 is a characteristic diagram for giving a maximum injection amount correction amount in the embodiment of the fuel injection amount control device of the present invention.

FIG. 7 is a time chart showing an operation state of the fuel injection amount control device according to the embodiment of the present invention.

FIG. 8 is a characteristic diagram showing a control example in a conventional fuel injection amount control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Slip ratio calculation means 2 ... Correction amount calculation means 3 ... Rotation speed correction amount calculation means 4 ... Control amount calculation means 5 ... Brake drive means 8 ... Drive wheels 9 ... Driving wheels 10 ... Diesel engine 11 ... Accelerator pedal 12 ... Accelerator Opening sensor 13 ... Driven wheel speed sensor 14 ... Drive wheel speed sensor 15 ... Fuel injection pump 16 ... Brake for drive wheel 17, 18 ... Solenoid valve 19 ... Electronic control unit (ECU) 20 ... Hydraulic pump for brake 21 ... Accumulator for brake N _DR … Drive wheel speed N _DN … Following wheel speed dN… Difference in wheel speed S… Slip ratio ΔN… Pseudo rotation speed correction amount K… Maximum injection amount correction amount N _e … Real engine rotation speed _Ne ′… Corrected engine speed Accp: accelerator opening Full-Q: maximum injection amount Full-Q ': maximum injection amount after correction q: injection amount q _FIN : injection amount command value

Continuation of the front page (56) References JP-A-62-288331 (JP, A) JP-A-63-207726 (JP, A) JP-A-63-183251 (JP, A) JP-A-63-143343 (JP) JP-A-64-12961 (JP, A) JP-A-3-210042 (JP, A) JP-A-3-141839 (JP, A) JP-A-3-42544 (JP, A) 60-166736 (JP, A) JP-A-61-89955 (JP, A) JP-A-61-123848 (JP, U) JP-A-60-45131 (JP, U) JP-A-3-37246 (JP, A) U) Japanese Utility Model Hei 1-174546 (JP, U) Special Table 58-500177 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 29/00-45/00

Claims (1)

(57) [Claims] 1. A rotational speed of the rotational speed and the driving wheel of the driven wheels
When controlling the fuel injection amount to change the generated torque relative to engine based on the slip ratio calculated from the difference,
It is determined whether the current operating state of the engine is in the partial load range or in the full load range. When the engine is in the partial load range, the engine is supplemented with a correction amount determined in accordance with the slip ratio.
One pseudo signal of the corrected engine speed or accelerator opening
And the other measured value, and supplemented according to the governor pattern.
Calculating an injection amount after positive, also when in the full load range, the correction determined corresponding to the maximum injection quantity and the slip ratio
To calculate the maximum injection amount after correction using the amount
A fuel injection amount control device configured to correct the fuel injection amount of the engine .