JP2571790Y2 - Vehicle driving force control device - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention is to prevent idling of drive wheels generated on a snowy road or a frozen road having a low coefficient of friction, for example, while the vehicle is running. The present invention relates to a vehicle driving force control device. (Prior Art) In general, when a vehicle is running on a slippery road surface having a low coefficient of friction as described above, tires naturally tend to slip easily. At the time when the driving force increases, it becomes very easy to idle. Similarly, not only on snowy roads or frozen roads, but also on unpaved roads and the like, drive wheels are easy to idle, but even on ordinary paved roads, a large amount of driving force is instantaneously applied to the drive wheels. When it is engaged, the drive wheels easily spin. (Problems to be Solved by the Invention) Therefore, in the case of wheel idling, the driver confirms the idling operation by a sudden increase in the engine speed or high noise of the engine sound, and according to the degree, the accelerator pedal. By reducing the opening of the engine, the engine output is reduced so that the driving wheels do not run idle. However,
Since the accelerator operation is performed in accordance with the idling of the drive wheels as described above, especially the accelerator operation must be performed, which not only greatly burdens the driver, but also provides sufficient steering stability. There is a disadvantage that it cannot be obtained. It is an object of the present invention to prevent the driver from idling even when traveling on a very slippery road such as a snowy road or a frozen road without having to frequently perform an accelerator operation. It is an object of the present invention to provide a vehicle driving force control device. [Structure of the Invention] (Means and Action for Solving the Problems) A wheel speed sensor for detecting the wheel speed of the driving wheel and the non-driving wheel, and a driving wheel and a non-driving wheel detected by the wheel speed sensor Driving wheel idling state amount calculating means for calculating the idling state amount of the driving wheel based on the vehicle speed and calculating the rate of change of the idling state amount, and idling state amount of the driving wheel calculated by the driving wheel idling state amount calculating means An engine control correction amount determining means for determining a correction amount for a reference engine control amount in accordance with the engine control amount, and changing the correction amount to a relatively large value only when the rate of change of the idling state amount of the drive wheel is positive; In response to the engine control correction amount determined by the correction amount determining means, the deactivated cylinder determining means for setting the number of cylinders for which fuel injection is to be deactivated, and the number of cylinders determined by the deactivated cylinder number determining means. A vehicular driving force control apparatus characterized by comprising a fuel injection control means for pausing the fuel injection. (Embodiment) Hereinafter, a vehicle driving force control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing a configuration of a vehicle driving force control device. First
In the figure, reference numeral 11 denotes a traction controller which will be described later in detail with reference to FIG. The traction controller 11 detects wheel speed signals VFR (front right wheel speed), VFL (front left wheel speed), VFL output from wheel speed sensors 11a to 11d for detecting the rotation speed of each wheel of the vehicle.
RR (rear right wheel speed), VRL (rear left wheel speed)
, And outputs a traction controller T / C signal for eliminating wheel slip. The value of the T / C signal increases as the slip ratio of the wheel increases. The T / C signal is transmitted to the fuel injection controller 1
The traction control is sent to 2 and the traction control according to the T / C signal, that is, driving force control is performed. When fuel is injected into a multi-cylinder engine, driving force control is performed by thinning out the cylinders that inject fuel. In other words, this controller
For example, in the case of a four-cylinder engine 12, control is performed to inject fuel into the injectors INJ1 to INJ4 for each cylinder. Next, referring to FIG.
Will be described in detail. In the traction controller 11, the rear wheel speed Vbi is calculated from the wheel speed signals VRR and VRL. Then, based on the rear wheel speed Vbi,
The vehicle moving average speed Vbi is calculated (step R1). Then, the vehicle moving average speed Vbi is multiplied by a constant “1.156” (step R2), and the constant “2” is added to calculate the current target wheel speed Vri (step R3). R2
"1.156" and "2" as R3 are numerical values for generating the target wheel speed Vri from the vehicle body speed Vbi, and take into account the slip ratio and the slip amount. At low speed
R3 is dominant and control is performed with a target of a slip amount of 2 km / h. At high speeds, R2 is dominant and, for example, at a speed of 100 km / h, a slip amount of about 18% is targeted. Both the values of R2 and R3 are determined according to the tuning results in actual vehicle tests. Next, the average drive wheel speed Vwi is calculated based on the front right drive wheel speed data Vwi output from the front right wheel speed sensor 11a (step R4). Then, the target wheel speed Vri is subtracted from the average drive wheel speed Vwi, and the idling state amount ΔVi of the right drive wheel is calculated (step R5). here,
If the idling state amount ΔVi is “positive” (step R6) and the change rate Δαi (step R7) of the idling state amount ΔVi is “positive” (step R8), the theory of the AND circuit AND1 is established. , Flip-flop FF is set. Accordingly, the gate G1 is opened, and the constant “20” (step R9) and the retard amount Rtd with respect to the idling state amount ΔVi obtained in step R10 are added (step R13). That is, in FIG. 2, the change rate Δαi of the idling state amount ΔVi is calculated in step R7, and an H level signal is output when the change rate Δαi is positive (0 <Δαi) in step R8. When the AND circuit AND1 is turned on, the flip-flop
FF is set, and a fixed value “20” is output as the retard amount (torque reduction amount) from step R9. Further, since the gate G1 is turned on at the same time, the retard amount (torque reduction amount) according to the idling state amount ΔVi set in step R10.
Is added to the fixed value “20”. That is, when the rate of change Δαi is always positive (0 <Δαi), at least the fixed value “20” is immediately set to the target value as the torque reduction amount. Increasing trend (change rate Δ
When αi is positive), the torque is appropriately reduced. In addition, "1.156" of "R2" in FIG. 2 is used to set a target wheel speed such that the slip ratio of the driving wheel falls within a range of 18% when driving at a high speed of, for example, 100 km / h. The "2" of "R3" is for setting a target wheel speed such that the slip amount is within about 2 km / h during low-speed running. Since "1.156" is multiplied by the wheel speed, "1.156" becomes dominant as the speed increases. On the other hand, at low speeds, the speed is low, so the value of “2” becomes more dominant than when multiplied by “1.156”. On the other hand, at low speeds, the speed is small, so when multiplied by "1.156",
The value of “2” becomes dominant. Also, "3" of "R11" is related to the condition of "R8",
If the rate of change Δαi is not positive in “R8” and the spatial state quantity (slip amount) is, for example, “3” km / h or less, the target wheel speed is set by the integral control of “R12”. Is what it is. In steps R6, R9, and R10, when the limit of the torque reduction amount is set to 40, "20 (half the limit)" of the slip R9 and "0 to 20 in accordance with the slip amount" in step R10 at the start of the control for the first large slip. Until ”to obtain the torque reduction amount. When the slip is about to decrease in steps R7, R8, and R11, the torque is reduced in step R12 instead of steps R9 and R10 to slowly settle the slip with respect to the target. Where the steps
The numerical values of R6, R8, R11 are numerical values for determining control switching, the numerical values of steps R9, R10, R12 are numerical values for determining the amount of torque reduction, and each value is a value based on an actual vehicle test . By the way, when the change rate Δαi of the idling state amount ΔVi is “negative” and the idling state amount ΔVi is “3” or less (step R11), the logic of the AND circuit AND2 is established, and the flip-flop FF is turned off. Reset. For this reason,
Gate G1 is closed and gate G2 is opened. Therefore, the result calculated in step R12 is set as the retard amount Rtd.
As the retard amount Rtd, for example, a voltage of 4.5 V is output as a T / C (traction / control) signal in FIG. 3 as a retard amount Rtd of 40 degrees. And
This T / C signal is subjected to A / D conversion and becomes IVR data. Then, processing for stopping fuel injection is performed based on the flowchart of FIG. Next, the fuel injection controller 12 to which the T / C signal is input will be described in detail with reference to FIG. Third
In the figure, a T / C signal is converted into an 8-bit digital signal by an A / D converter 21 and output to a fuel injection CPU (central processing unit) 22 which controls fuel injection to each cylinder. . Further, the CPU 12 outputs an H level signal from the rotation sensor (not shown) every time the crankshaft makes one rotation.
The C signal is inputted, and the SGT signal which becomes H level every time the crankshaft rotates 90 degrees is inputted. By the way, INJ1 to INJ4 are injectors (fuel injectors) provided in a one-to-one correspondence with the cylinders # 1 to # 4. The injectors INJ1 to INJ4 are connected to the collectors of the driving transistors Q1 to Q4. Then, the transistors Q1 to Q4 are controlled by outputs of D-type flip-flops FF1 to FF4. The D terminals of the flip-flops FF1 to FF4 are grounded, and the clock C terminal is
The signal from the terminal P21 of the CPU 22 is input, and the preset terminal P is connected to the PA4 of the PIA (peripheral interface adapter) 23.
A control signal from the terminal PA7 is input. In addition, CPU21
Stores data of FIGS. 7 to 11 described later.
RAM 24 is connected. Here, DCUT in FIG. 8 indicates fuel cut cylinder data. In the fuel cut cylinder data DCUT, as shown in FIG. 8, fuel cut information of each cylinder is set in upper and lower 4 bits. The upper one and the lower one are the same. In FIG. 13, since the right shift and the left shift are performed in the flow for determining the fuel cut cylinder in accordance with the torque limit instruction, the same value is set for both the upper and lower parts. Only the higher rank is referred later. DCUTF in FIG. 9 indicates fuel cut data.
The upper bits of the fuel cut data DCUTF are counters for post-fuel cut processing (referred to as DCUTF counters in FIG. 13 described later). This counter counts 7 from the time when the fuel cut instruction disappears (IVR = 0) and the fuel cut cylinder disappears (DCUT = 0) (steps S65 to S67 in FIG. 13 described later). Here, the lower two bits store the cylinder IFCYL at the start of fuel cut. If seven or more cycles have elapsed since the end of the previous fuel cut, the fuel cut start cylinder IFCYL is set. Otherwise, use the cylinder at the time of the previous start. This is because, as shown in FIG. 6, the fuel cut is controlled every eight cycles. For example, when the fuel is cut once at the output level 1 and the fuel is injected seven times, the fuel cut is performed during the seven times. Even if the output level 1 is instructed once, and the first cylinder is cut after the instruction is issued, 8
It is cut twice during the cycle, resulting in a large torque reduction. In FIG. 13, this is prevented by using a DCUTF counter and an IFCUT. Further, the vibration is reduced by performing the smooth control in this manner. FCYL in FIG. 10 indicates injection information. This injection information
The upper 4 bits of the FCYL are information on the injector that is currently on, and the lower 2 bits are the cylinder that is the current injection timing.
No Yes. The expression FCYL in the flowchart of FIG. 12 indicates only the upper 4 bits, and the expression of FCYL in the flowchart of FIG.
The expression FCYL shows only these lower two bits.
That is, IFCYL and FFC of steps S63 and S44 described later are used.
The calculation of CYL is a 2-bit operation. Therefore, (FCYL-IFCYL) takes only values of 0 to 3 (e
x.1-3 = 2, c = ab if a ≧ b, c = if a <b
a + 4-b). DTRIG in FIG. 11 indicates injection mode storage data. This injection mode storage data DTRIG includes information such as four-cylinder simultaneous injection (this mode is used when the injection amount is large during acceleration or the like and it is not possible to make a sequential injection in time) or whether injection is currently being performed. It is a memory that stores. The meaning of each bit is as described in FIG. Here, in the simultaneous injection mode, since the same amount of fuel is injected into each cylinder, this memory is referred to so that it can be distinguished from normal sequential processing. Next, the sequence of ignition, injection, and the like for each of the cylinders # 1 to # 4 of the four-cylinder engine will be described with reference to FIG. In this example, after the SGC signal goes high,
In the cylinder ignition process, the # 4 cylinder injection process is started. Then, the injection process changes from # 4 cylinder → # 2 cylinder → # 1 cylinder → # 3 cylinder. Further, the ignition process shifts from # 1 cylinder → # 3 cylinder → # 4 cylinder → # 2 cylinder. In this manner, fuel is injected into the cylinders in order for each cylinder, and then ignited. Next, the operation of the embodiment of the present invention configured as described above will be described. When the accelerator pedal is suddenly depressed, the wheel spins, and the idling state amount ΔVi is calculated by subtracting the target wheel speed Vri from the average driving wheel speed Vwi in step R5 in FIG. Therefore,
If the accelerator is suddenly depressed at the time of starting or the like, the wheels idle in accordance with the amount of the depression, so the idling state amount Δ
Vi increases. Then, according to the idling state amount ΔVi, T /
The C signal is determined and sent to the fuel injection controller 12. Then, the T / C signal is supplied to the A / D converter 21 shown in FIG.
Is converted to an 8-bit signal and stored as IVR data. The IVR data structure is shown in FIG. Next, the fuel injection control will be described with reference to FIG. 12 and FIG. FIG. 12 is a flowchart showing a general process for controlling fuel injection, and FIG. 13 is a process for determining a cylinder for stopping fuel injection according to the above-mentioned IVR data. First, general fuel injection control will be described with reference to FIG. The process of the flowchart of FIG. 12 is performed every time the SGT signal of FIG. 5 becomes H level.
First, various calculations are performed as initial settings (step
S11). Then, it is determined whether the seventh bit of the DTRIG data shown in FIG.
S12). If the determination in step S12 is "YES", it is determined whether all of the 0th to 3rd bits of the DTRIG data are 0 (step S13). This step S13
If it is determined to be "YES", the output pulse width DTI
NJ is set to 1/4 (step S14). That is, in the case of simultaneous injection, the output pulse width for the injectors # 1 to # 4
DTINJ is one quarter. If “NO” is determined in step S12, the processes in steps S13 and S14 are skipped. Then, “F0 (16
Next, the H level is set to the sixth bit of the DTRIG data, and the simultaneous injection mode is set (step S16).
The response delay DTD × 15 of the injectors # 1 to # 4 is added to the output pulse width DTINJ (step S17). Then, TRMSB is set in the accumulator A (step S18).
Here, TRMSB is a memory for temporarily storing information for injecting all four cylinders at the time of simultaneous injection. The upper 4 bits of this TRMSB correspond to each of the cylinders # 2, # 4, # 3, and # 1. In FIG. 12, when the No. 1 cylinder is not detected and the injection is not yet finished, the injection information is set to all the cylinders (step S15). Then, the temporarily stored value is transferred to the accumulator A. Further, if not in the simultaneous injection mode, the injection cylinder is reset (step S2
0). Then, it is determined whether the sixth bit of the DTRIG data is at the H level, that is, whether the mode is the simultaneous injection mode (step S19). If “NO” is determined in the process of step S19, the cylinders # 1 to
4 is set (step S2).
0). If it is determined “YES” in step S19, the process of step S20 is skipped. Then, the accumulator A in which the FCYL data as shown in FIG. 10 and the cylinder す る to be injected are set.
Is ORed and set to FCYL data (step
S21). Then, the logical product of the data (PA4 to PA7) for the port P4 of the PIA23 in FIG. 3 and the inverted signal of the accumulator A is obtained (step S22). Where port P
The data for 4 is negative logic. Next, the value of the upper 4 bytes of the free running counter FRC is set in the DOFF data (step S23). Here, DOFF is set in step S22.
The time when the port was output in is stored. The value of the free running counter is copied to the FRC. No.
In the right column of Fig. 12, the next time to turn off the injector is set (set in the output compare register, and an interrupt is issued when the value of this register matches the FRC. To turn off the injector) and turn on the injector. Also, DT
INJ calculates the injector on time (corresponding to the injection amount) and adds this to the current time (FRC) to determine the off time. Then, the output pulse width TINJ (n) for the n-th cylinder # is calculated (step S24). Hereinafter, it is determined whether the sixth bit of the DTRIG data is at the L level (step S25). That is, it is determined whether the injection is simultaneous injection. If “NO” is determined in step S25, that is, if it is determined that simultaneous injection is performed, TINJ1
= TINJ2 = TINJ3 = TINJ4 (step S26), and the injection times in the injectors # 1 to # 4 are made the same. Next, it is determined whether the P21 terminal of the CPU 21 is at the H level (step S27). When the P21 terminal is at the H level, that is, when the injection is not completed, a ΦCR process described later is performed. On the other hand, if it is determined that the P21 terminal is not at the H level, if the current injection ends earlier than the end time set in ΦCR1 (step S29), P4 is set again (step S30), and ΦCR Processing is performed. This ΦC
Processing for stopping fuel injection is performed by the R processing. Next, FIG. 13 illustrates a process of determining a cylinder for stopping fuel injection according to the above-mentioned IVR data. In this flowchart, a description will be given of a process of stopping fuel injection in accordance with the above IVR data. First, it is determined whether the IVR data is “0” (step S41). If it is determined in step S41 that the IVR data is not "0", it is determined whether the DCUTF counter is "7" (step S42). In this step S42, the DCUTF counter is "7"
If not, the DCUTF counter is set to "0" (step S43). Next, the DCUT is shifted to the right by IFCYL, and (FCYL-IFCFL) is set in the accumulator A. Thereafter, the IVR data is shifted right by 5 bits (step S44), and the upper 3 bits of the IVR data are compared in a step described later, as shown in FIG. First, when the accumulator A = 0 and the IVR data is “0”, the logical product of DCUT and “BB (hexadecimal)” is obtained and stored in the DCUT (step S47). Also, I
When VR data is "1", DCUT and "44 (hexadecimal)"
Is exclusive-ORed and stored in the DCUT (step S49). Furthermore, when the IVR data is “2” or more, DC
The logical sum of UT and “44 (hexadecimal)” is calculated and stored in the DCUT (step S50). On the other hand, if “NO” is determined in step S45, the process proceeds to step S51, and it is determined whether the accumulator A = 2. If the accumulator A = 2 and the IVR data is smaller than 3 (step S52), the logical product of DCUT and "EE (hexadecimal)" is calculated and the result is stored in the DCUT. (Step S53). If the IVR data is "3" (step S5
4) The logical sum of DCUT and "11 (hexadecimal)" is calculated (step S55). On the other hand, if the IVR data is “4” or more,
The exclusive OR of DCUT and "11 (hexadecimal)" is calculated (step S56). On the other hand, if it is determined “NO” in step S51, it is determined whether the accumulator A is “1”. If the accumulator A is “1”, the IVR data is “4” or less. The logical product of DCUT and “77 (hexadecimal)” is calculated (step S59), and if the IVR data is “5” or more, the exclusive OR of DCUT and “88 (hexadecimal)” is calculated. (Step S60). On the other hand, if it is determined that “NO” is determined in step S57, the logical product of DCUT and “DD (hexadecimal)” is obtained (step S61). As described above, the DCUT flag is set according to the value of the IVR data. And DCUT
Shifted IFCYL left. By the way, if “YES” is determined in the above step S63, IFCYL = FCYL is set (step S63). Further, if “YES” is determined in step S41, it is determined whether DCUT = 0 (step S64).
If “YES” is determined in this step S64, the DCUT
The F counter is incremented by "1" (step S65). And
It is determined whether the DCUTF counter is equal to 8 (step S6).
6) If “YES” is determined, the process returns to step S12 in FIG. 12 after “7” is set in the DCUTF counter. Thereafter, the steps in FIG. 12 are executed, and the injection of fuel to the cylinders indicated by “-” in FIG. 6 is stopped in accordance with levels 0 to 5 for the upper three bits of the IVR data. Therefore, when the idling state amount ΔVi becomes large, “0” →
The level is sequentially shifted as “5”, and the driving force of the engine is weakened. That is, it is controlled in a direction to reduce the idling of the wheel. [Effects of the Invention] As described in detail above, according to the present invention, even when traveling on a very slippery road surface such as a snowy road or a frozen road, the driver does not need to frequently operate the accelerator, and the drive wheels are not required. Can be prevented, and the rate of change of the slip rate is also used to determine the number of cylinders for shutting off the fuel supply. Is increasing?
Alternatively, it is possible to provide a vehicular driving force control device capable of changing the number of fuel cut-off cylinders depending on whether the number is decreasing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a driving force control device for a vehicle according to an embodiment of the present invention, FIG. 2 is a block diagram showing a traction controller according to an embodiment of the present invention, FIG. FIG. 3 is a block diagram showing a fuel injection controller, and FIG.
FIG. 5 shows the level of the IVR data, FIG. 5 shows the timing of fuel injection, FIG. 6 shows the fuel cut pattern, FIG. 7 shows the IVR format, and FIG. 8 shows the DCU.
FIG. 9 is a diagram showing the format of DCUTF, FIG. 10 is a diagram showing the format of FCYL, FIG.
FIG. 11 is a diagram showing a DTRIG format, FIG. 12 is a flowchart showing a fuel injection operation, and FIG. 13 is a flowchart showing a fuel cut operation. 11 traction controller, 12 fuel injection control controller, 21 A / D converter, 22 CPU (central processing unit), 23 PIA (peripheral interface adapter), FF1 ~
FF4: D-type flip-flop, Q1 to Q4: transistor, I
NJ1 to INJ4 ... injectors.

Continuation of front page    (72) Inventor Tsuyoshi Funakoshi               1 Nakashinkiri, Okazaki-shi, Hashime-cho               In the passenger car technology center (72) Inventor Susumu Nishikawa               1 Nakashinkiri, Okazaki-shi, Hashime-cho               In the passenger car technology center (72) Inventor Shuji Ikeda               1 Nakashinkiri, Okazaki-shi, Hashime-cho               In the passenger car technology center                (56) References JP-A-58-8436 (JP, A)                 JP-A-60-151160 (JP, A)                 JP-A-60-128057 (JP, A)                 JP-A-60-194730 (JP, A)                 Tokiko 55-46494 (JP, B2)

Claims (1)

(57) [Rules for requesting registration of utility model] A wheel speed sensor for detecting the wheel speeds of the driving wheels and the non-driving wheels; and calculating the idling state amounts of the driving wheels based on the vehicle speeds of the driving wheels and the non-driving wheels detected by the wheel speed sensors, and calculating the idling state amounts of the driving wheels. A driving wheel idling state amount calculating means for calculating a change rate of the driving wheel, and a correction amount for a reference engine control amount in accordance with the idling state amount of the driving wheel calculated by the driving wheel idling state amount calculating means. An engine control correction amount determining means for changing the correction amount to a relatively large value only when the rate of change of the wheel idling state amount is positive; and, in accordance with the engine control correction amount determined by the engine control correction amount determination means, The fuel cell system further comprises: deactivated cylinder determining means for setting the number of cylinders for which injection is to be deactivated; and fuel injection control means for deactivating fuel injection for the number of cylinders determined by the deactivated cylinder number determining means. A driving force control device for a vehicle.