JPS61119432A - Speed change control device for automatic transmission - Google Patents

Abstract

PURPOSE:To relieve shock due to speed changing and to obtain good transmission characteristic, by compensating the quantity of output torque change of an engine due to deviation between detected value and the standard value of parameter, when the actual value of output torque change of the engine deviates from the optimum value when the speed is changing. CONSTITUTION:When a vehicle is running, judgment is done whether speed change should be carried out or not from the present gear change step, vehicle speed V, throttle opening angle theta, etc., in a computer 36 for ECT, and when YES is obtained as a result, time standard value To of inertia phase is calculated based on the above data V and theta, and the kind of speed change which is going to be done hereafter, and a command of speed change is output. Then, change of engine r.p.m. is observed, and when it is judged that the r.p.m. Ne changes continuously and the inertia phase is started, a command of decreasing the engine r.p.m. Ne is given, and change of r.p.m. Ne is observed again. And after the inertia phase is finished, a deviation between inertia phase time T and the standard value To is obtained, and the decreasing quantity of the engine output torque is compensated according to the deviation.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a shift control device for an automatic transmission for a vehicle.

Conventional technology The method of reducing the output torque of an engine during gear shifting in order to alleviate the gear shifting impact is disclosed in Japanese Patent Application No. 56-1163, for example.
No. 28, Japanese Patent Application No. 1983-400, and Japanese Patent Application No. 1987-1
It has already been disclosed in No. 39145. In that case, if the amount of decrease in the output torque of the engine is too small, the time required for shifting increases, the thermal load on the frictional engagement device of the automatic transmission increases, and the durability of the frictional engagement device deteriorates. Furthermore, if the amount of decrease in the output torque of the engine is excessive, there may be problems such as the shift being completed in a short time, resulting in a large shift impact, or the engine stalling. Therefore, the amount of reduction in engine output torque during gear shifting needs to be set to an optimal value, but the optimal value is determined by the variations that inevitably occur between parts of the engine, automatic transmission, and control device, and the variations that occur as a set of parts. It is difficult to uniformly determine the speed change due to variations over time and depending on usage conditions, and with conventional devices, it has been difficult to consistently provide good speed change characteristics for each vehicle.

Problems to be Solved by the Invention An object of the present invention is to eliminate the effects of various variations and to optimally reduce the output torque of the engine during gear shifting. III
An object of the present invention is to provide a shift control device for an automatic transmission that can always obtain good shift characteristics for each vehicle.

Means for Solving the Problems In order to achieve this object, according to the present invention, a shift control device for an automatic transmission that changes the engine output torque during a shift has the following steps: A detection means for detecting the value, a reference value setting means for setting a reference value, a changing means for changing the output torque of the engine, and a changing means during gear shifting based on the deviation between the detected value of the parameter and the reference value. A change amount correcting means for correcting a change amount of engine output torque.

Effects of the Invention If the actual amount of change in the output torque of the engine during gear shifting deviates from the optimum value, the detected values of the parameters also deviate from the reference values. Therefore, by correcting the amount of change in the output torque of the engine based on the deviation between the detected value of the parameter and the reference value, it is possible to shift the amount of change in the output torque to the optimum value. Since the control of the present invention is performed for each individual vehicle, it is possible to maintain good shift characteristics with less shift impact, regardless of various variations.

The means of change are the advance amount of the engine's ignition timing, the intake air flow rate,
Fuel supply amount, opening/closing timing of intake and exhaust valves, or boost pressure,
Alternatively, it may be a means to change the combination of these.

Preferably, the parameters include engine rotational speed, rotational speed of rotating members in the automatic transmission, output shaft torque of the automatic transmission,
This is the time of the inertia phase or the longitudinal acceleration of the vehicle.

Preferably, the reference value is a function of intake throttle opening, vehicle speed, type of gear change, engine cooling water temperature, engine intake air temperature, or hydraulic oil temperature of the automatic transmission.

Example The present invention will be explained with reference to the embodiments shown in the drawings.

In M2rH, input shaft lO and output shaft I2 of automatic transmission
A fluid torque converter 14, an overdrive device 16, and an underdrive device 18 are coaxially provided between the two. The lock-up clutch L/C is provided in parallel with the fluid torque converter 14, and under predetermined operating conditions, the engine power is transferred to the overdrive device 16 via the lock-up clutch L/C without passing through the fluid torque converter 14. communicated. The overdrive device 16 has one planetary gearing 20 and the underdrive device 18 has two planetary gearings 22,24. The connection between the rotating elements of the planetary gear units 20, 22, 24 and the fixing of the rotating elements are performed by clutches CO to C2, brakes BO to B3, and one-way clutches FO to F2.

FIG. 3 shows the relationship between the gear stage and the engagement state of each frictional engagement device. ○ and × indicate an engaged state and a disengaged state, respectively, △ indicates a retained state only when the engine is driven, D is a drive range, 2 is a second range,
L means low range, R means reverse range, and Olo means overdrive.

Returning to FIG. 2, the hydraulic control circuit 30 includes a plurality of solenoid valves 32.
These electromagnetic valves 32a to 32c control engagement and release of frictional engagement devices (including lock-up clutches L/C) other than one-way clutches. The ECT (electronic MIl converter) computer 36 is
The gear position and shift timing are determined from the vehicle speed v1, intake throttle opening θ, etc., and the solenoid valve 32 is controlled based on the values.

The engine computer 38 calculates the fuel injection amount, ignition timing, etc. from the engine rotational speed Ne, the intake air flow rate Q, etc., and controls the engine 40.

Figure 4 shows the electric/hydraulic control circuit section of the hydraulic control surface wi30,
ECT computer 36 and engine computer 38
A detailed block diagram is shown. Engine computer 3
8 is A which receives an analog signal from an intake air temperature sensor, etc.
/D (Analog/Digital) converter 3811 Input interface circuit 382 that receives pulse signals from a throttle sensor, etc., CPU 362, Output interface circuit 3 that sends out pulse signals such as ignition signals
84, and memory 385, which are connected to a bus 386.
are connected to each other by.

The ECT computer 36 includes an input interface circuit 361 that receives pulse signals from a throttle sensor, etc.
, CPU 362, solenoid valves 32a to 32c, output interface circuit 363 that sends an off signal,
and a memory 364, which are connected to each other by a bus 365. The solenoid valve 32a engages and releases the lock-up clutch L/C at 11! The solenoid valve 32b controls the L/C control pulp 301 to
The shift pulp 302 and the 1-2 shift valve 303 are controlled, and the solenoid valve 32C'' controls the 2-3 shift pulp 304.

Output interface circuit 3 of ECT computer 36
63 to the input interface circuit 382 of the engine computer 38, engine output torque change commands and return commands are sent.

Figures 5 and 6 show the case where the engine output torque is positive (
2 is a flowchart for controlling the speed change during an upshift in a power-on state.

First, the value of the flag IPRASH that displays the gear shift stage is determined (Step 44). If IPHASE = O, proceed to the next step 46; [If PHASE = 1, proceed to Step 52; if IPHASE = 2, proceed to Step 44). Proceed to 58.

Next, the current gear, vehicle speed V1, intake throttle opening θ,
It is determined whether or not a shift should be performed based on the shift pattern select switch and various shift prohibition signals (step 46), and only if the determination is positive, the process proceeds to the following.

Next, based on the vehicle speed v1, intake throttle opening θ, and the type of shift to be performed, a base rate value TO of the inertia phase time is calculated (step 48), and a shift command is generated (step 50). The base rate value To is the time of the inertia phase when the amount of decrease in the output torque of the m-factor is optimal (that is, when good shifting characteristics with reduced shifting impact can be obtained), and is the time of the inertia phase when the amount of decrease in the output torque of the The control signal for the solenoid valve 32 is switched.

Next, step 52 changes the engine rotation distance Ne to look like vL.
), detecting the start of the inertia phase. Engine rotation distance Ne
If it begins to rise (downshift) or fall (upshift) continuously, it can be determined that the inertia phase has started. It is determined whether or not the inertia phase has started (step 54), and if the determination is apricot, the flag I
1 is assigned to PHASE (step 55) to perform a reset. When the start of the inertia phase is detected (the determination in step 54 is positive), a command is issued to reduce the output torque of the engine (step 56), and changes in the engine rotational speed Ne are again monitored. A decrease in engine output torque is due to a decrease in the advance of the ignition timing, a decrease in the amount of fuel injected from the fuel injection valve,
This is done by reducing the intake air flow rate, etc., or by a combination of these. When the inertia phase ends, the engine rotational speed Ne becomes almost constant.

Specifically, the start and end of the inertia phase can be detected as follows. In other words, in a power-on upshift, the inertia phase starts when the condition of Net<Ne1-1 is 0, assuming that the opening/closing rotation speed detected at regular intervals is Net (i indicates the i-th sample value). It can be defined as a case of consecutive times. Furthermore, the end of the inertia phase can be defined as when the engine rotation speed Ne reaches this value by adding a predetermined value Nl to the product of the output shaft rotation speed No of the automatic transmission and the gear ratio of the high speed gear. can. The reason for summing the predetermined value Nl is to take slippage due to the fluid torque converter into consideration. Similarly, for downshifts, the start and end of the inertia phase can be detected.

Step 60: Determine whether the inertia phase has ended.
), if the determination is negative, 2 is assigned to the flag ■PRASH (step 61) and reset is performed, and if the determination is positive, the output torque of the engine is returned to the original value before the reduction ( Step 62).

Next, calculate the time T of the inertia phase (step 64),
Standard g1. The deviation of T with respect to To is determined (step 66). The inertia phase time can be calculated from the difference between the inertia phase start time and end time. If the deviation is large, that is, if the amount of reduction in the output torque of the engine is inappropriate, it is determined whether a warning operation such as turning on a lamp is necessary (step 68), and if necessary, it is executed (step 68). Step 70). It is determined whether the old reference value (sampling number) for the number of times the deviation of T with respect to To is checked should be changed (step 72). If the amount of correction for the amount of decrease in the output torque of the engine is too large, a large deviation of T from TO occurs. A large deviation of T toward the smaller side occurs, and correction is made to reduce the amount of decrease in the output torque again, but a hunting phenomenon occurs in which a large deviation of T from To to the larger side occurs again. Therefore, the amount of correction is set to a relatively small value, but if the amount of deviation is excessive, the number of sampling times must be changed (step 74), that is, the number of times the counters (error counter and sampling counter) overflow can be reduced. Thus, the amount of decrease in output torque can be corrected more quickly.

It is determined whether an overflow has occurred in the counters (error counter and sampling counter) (Step 76); if not, it is determined whether T has deviated from TO to a larger or smaller value. Step 78), and register this determination result in the corresponding position of the error counter (Step 80). Figure 71. t
Shows the contents of the sampling counter and error counter. In Figure 6, T and T have already been changed six times.
The relationship between O and O has been inspected, and in the error counter, O indicates that the deviation of T with respect to To was less than a predetermined value, and -1 indicates that T has deviated greatly to the smaller side with respect to To. respectively mean that T has deviated greatly from To to the larger side. Next, the sampling number M is increased by 1 (step 82), and M is compared with the reference number M1 (step 84). If M>old, the deviation occurrence ratio α is calculated (step 86). In Figure 6, old =
6, α=(-376)X 100 ==-50
%.

The absolute value 1α1-zl of the deviation occurrence ratio calculated last time is compared with the absolute value 1α11 of the deviation occurrence ratio calculated this time, and the step 86Llα11 is compared with the allowable case αl (step 90). ] If α11<1α1-11, - that is, the absolute value of the deviation occurrence ratio α has decreased compared to the previous time, and - and 1α11 exceeds the allowable value, then the output torque of the engine during gear shifting will decrease. Modify the amount (step 92).

When αi is negative, that is, T is smaller than To, the amount of decrease is decreased, and when αl is positive, that is, T
When is larger than To, the amount of decrease is increased. 1α1
If 1 ≧ 1 α 1 - work 1, that is, if the absolute value of the occurrence ratio ko is increasing, how does the deviation occurrence ratio α change from the deviation occurrence ratio αi−p p times before to the current deviation occurrence ratio α1? In order to find out whether α1 p+...
- Compare αi-1°α1 (step 94). From this comparison, it is determined whether α is diverging or not. Step 96
), if α has diverged, a warning is given by lighting a lamp, etc. (step 98), and if it has not diverged, the amount of correction for the amount of decrease in engine output torque is increased (step 1).
00). This indicates that although the direction of correction is correct, since the amount of correction is small, it is determined that it is taking a long time to bring the deviation within a predetermined value.

FIG. 8 shows αl-3 to αi 11+αi-1, α1. A regression line is obtained from α11 to αi, and if this regression line does not move toward 0, it is determined that α is diverging. From αl-3~αi, for example, αi as shown in the figure.
Two straight lines are obtained for the two values of It is determined that the amount of decrease is small, and the amount of correction is increased in step 100. When the sign of αi is reversed and its absolute value is greater than or equal to the predetermined value as in the case of P2, it is determined that the amount of correction is too large, and in step 100, the absolute value of the amount of correction is decreased and the amount of correction is Reverse the sign.

After correcting the amount of reduction in engine output torque, the error counter and sampling counter as well as the flag IPHASE
(steps 102 and 104).

In the embodiments shown in FIGS. 5 and 6, the inertia phase time T and its standard [To are selected as parameters that are correlated with the shift impact during gear shifting, but instead of T and To, the engine rotation speed, It is also possible to select parameters such as the output shaft torque of the automatic transmission or vehicle longitudinal acceleration and their reference values. When the engine rotation distance Ne is taken as a parameter, for example, the value of Ne after a predetermined time from the inertia phase start time is compared with its reference [NeO. Alternatively, the first derivative Ne with respect to time of Ne after a predetermined time is compared with its base m[eO. Furthermore, the method of producing the inertia phase is not limited to the method of monitoring the engine rotational speed, but other gentle methods such as the method of monitoring the rotational speed of the rotating members of the automatic transmission are also possible.

Furthermore, steps 72 and 74 in FIG. 6 can be omitted.

FIG. 9 and FIG. 1filO are routine flowcharts for controlling Ha during downshifting with power on. Only the parts different from the flowcharts in FIGS. 5 and 6 will be explained.

In step 48b, a reference value ΔGO related to the longitudinal acceleration G of the vehicle is calculated. FIG. 10 shows changes in acceleration G during downshifting in the power-on state. In the inertia phase, G is maintained at a very small value. Therefore, by monitoring the change in G, when G is maintained at a small value, it can be determined that the inertia phase has started, and when G changes significantly again to a large value, the inertia phase starts. It can be determined that the process has ended. The amount of G overshoot that occurs immediately after the end of the inertia phase is defined as ΔG, and ΔG.

is set as a reference value of ΔG. If the amount of decrease in the output torque of the engine is smaller than the optimum value, ΔG will be larger than ΔGO.

In steps 52b and 58b, the start and end of the inertia phase are detected by monitoring changes in acceleration G.

Further, the timer is started to operate after the start of the inertia phase (step 110), and after the elapsed time t since the start of the inertia phase measured by the timer reaches a predetermined value to (the determination in step +12 is t≧to ), the engine output torque is commanded to decrease (step 56), and the output torque is controlled so that the decrease coincides with the overshoot period of G in FIG.

In step 64b, ΔG is calculated, and in step 66b, the deviation of ΔG from ΔGo is determined.

1α at step 90! If 1≧αl, it is determined whether or not it is permissible to modify the amount of decrease in the output torque (step 116), and if so, the modification is performed in step 92. Further, if it is determined in step 96 that α is diverging, it is determined whether or not it is permissible to change the amount of correction of the amount of decrease in output torque, and if it is OK, step 100 is performed.
Change the correction amount in . The permission to change the amount of correction mentioned here means, for example, if we take the ignition timing of an engine as an example, the possible range of ignition timing is determined based on the engine's requirements.
It is determined whether or not the modification of the present invention deviates from the predetermined range. If the output torque deviates from the specified range, instead of changing the output torque correction amount,
It is determined that the timing for reducing the output torque is not appropriate, and to is changed, that is, the timing for instructing a reduction in the output torque of the engine (step 120), and ΔG is reduced.

G also in the embodiments of FIGS. 9 and 1O.

Instead of GO, other parameters such as the output shaft torque of the automatic transmission during inertia phase time T1 and their reference values can be selected. Also, steps 72 and 74 can be omitted.

FIG. 1 is a functional block diagram of the present invention.

The inertia phase time detection means 126 detects the inertia phase time T during gear shifting, the output shaft torque detection means 128 of the automatic transmission detects the output shaft torque Te of the automatic transmission, and the engine rotation speed detection means 130 detects the engine rotation. Detect the speed Ne,
The vehicle longitudinal direction acceleration detection means 132 detects the vehicle longitudinal direction acceleration G (the front direction is assumed to be positive). T, Tr, N
One of e+G is selected as a parameter having a functional relationship with the magnitude of the shift impact, and is sent to the deviation calculation means 134. The deviation calculating means 134 calculates the deviation between the reference value sent from the reference value setting means 136 and the actual value of the parameter, and the change amount correcting means 138 uses the output torque changing means 140 based on this deviation. The amount of change in engine 4° output torque that is changed during gear shifting is corrected.

In the embodiment, the amount of decrease in the engine output torque during gear shifting is controlled, but for example, when downshifting at high vehicle speeds, it may be necessary to increase the engine output torque in order to alleviate the gear shifting impact. It will be obvious to those skilled in the art that the equation can also be applied to control the amount of increase in engine output torque.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of the present invention, FIG. 2 is a schematic diagram of the entire control system, FIG. 3 is a diagram showing the operating state of each friction engagement device at each gear stage, and FIG. 5 and 6 are flowcharts of the shift control routine during upshifting in the power-on state, and FIG. Figures 9 and 10 are diagrams illustrating changes in the occurrence ratio;
The figure is a diagram showing changes in vehicle longitudinal acceleration during downshifting in a power-on state. 40... Engine, 126... Inertia phase time detection means, 128... Output shaft torque detection means of automatic transmission,
130... Engine rotational speed detection means, 132... Vehicle longitudinal direction acceleration detection means, 138... Change amount correction means, 140... Output torque change means. Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. In a shift control device for an automatic transmission that changes the output torque of an engine during a shift, a detection means for detecting the value of a parameter correlated with the magnitude of a shift impact, and a standard for setting a reference value. a value setting means, a changing means for changing the output torque of the engine, and a change amount for correcting the change amount of the engine output torque changed by the changing means during gear shifting based on the deviation between the detected value of the parameter and the reference value. A speed change control device for an automatic transmission, comprising: correcting means. 2. The changing means is a means for changing the advance amount of the ignition timing of the engine, the intake air flow rate, the fuel supply amount, the opening/closing timing of the intake and exhaust valves, the boost pressure, or a combination thereof, Shift control device 3 according to claim 1, wherein the parameter is an engine rotation speed, a rotation speed of a rotating member in the automatic transmission, an output shaft torque of the automatic transmission, an inertia phase time, or a longitudinal acceleration of the vehicle. A speed change control device according to claim 1 or 2, characterized in that: 4. Claims characterized in that the reference value is a function of intake throttle opening, vehicle speed, type of shift, engine cooling water temperature, engine intake air temperature, or automatic transmission hydraulic fluid temperature. The speed change control device according to any one of items 1 to 3.