KR20020018755A - Method for controlling shift of vehicle - Google Patents

Abstract

PURPOSE: A speed change control method of a vehicle is provided to prevent shock from difference of air amount by compensating the difference of the air amount gradually in changing speed frequently, and to improve operation and idling performance by preventing the stop of the engine. CONSTITUTION: A stop of a vehicle at N-range or traveling slowly at D-range is detected(20), and changing from the N-range to the D-range, or from the D-range to the N-range is detected(21). The difference of air amount at the D-range and at the N-range is calculated according to temperature of coolant in changing speed(22). Time for increasing the air amount is decided according to temperature of coolant(23). The air amount is increased gradually according to the decided time(24). The difference of air amount at N and D ranges is calculated with detecting stopping or traveling slowly and speed change, and the air amount is compensated with increasing gradually. Shock and stop of the engine are prevented, and idling performance is improved.

Description

Vehicle shift control method {METHOD FOR CONTROLLING SHIFT OF VEHICLE}

The present invention relates to a shift control method of a vehicle, and more particularly, a shock due to an imbalance of an idle air amount and a negative pressure of an intake air amount due to a change in the throttle opening degree caused by frequent shifting N and D stage operations when driving in an automatic shift vehicle. And it relates to a shift control method of the vehicle to prevent the engine stop.

In general, in the city with heavy traffic congestion on the road, drivers frequently shift from D to N and from N to D.

At this time, the brake is applied after the N-speed shift, and when the D-shift is intermittently, the accelerator is stepped on, and when the vehicle is shifted to the N-speed while driving, and the gear is shifted back to the D-speed before the vehicle stops completely, In addition, a shift shock may be generated, and an engine amount may be stopped when using a rapidly decreasing air amount when shifting from the shift stage D to N and an intake manifold negative pressure during braking.

Therefore, in the related art, the air volume reduction and the difference generated during the shift of the N and D stages are compensated only by the time delay and the tailing time to prevent the shock, but the air volume difference temporarily increases after the time delay. By doing so, it is impossible to prevent shock.

Therefore, an object of the present invention is to improve the driving performance and idle performance by gradually compensating for the difference in air volume generated during frequent shifting to the N and D stages according to the slow motion of the vehicle to prevent shock caused by the air volume difference.

In order to achieve the above object, the present invention includes the steps of determining whether the vehicle is in the middle of the vehicle running in the stop or D stage while driving the vehicle; Determining whether a shift occurs from the N stage to the D stage and the D stage to the N stage; Calculating a difference between air amounts of the N stage and the D stage according to the cooling water temperature when the shift occurs in the step; Determining a time for increasing the amount of air according to the cooling water temperature in the step; It is characterized by consisting of a step of gradually increasing the amount of air to be increased by the time determined in the step.

Therefore, the present invention is to determine the difference in the amount of air generated according to the cooling water temperature, time when the continuous shift is made to the N- and D-stage during stop and slow running while driving, gradually correcting the determined air amount by the difference in air volume This prevents shock and engine shutdown, which improves operability and idling performance.

1 is a shift control block diagram of a vehicle used in the present invention.

2 is a flowchart illustrating a shift control method of a vehicle of the present invention.

Figure 3a is a diagram of the air volume difference according to the cooling water temperature during the shift control of the present invention vehicle.

Figure 3b is a decision time diagram according to the cooling water temperature in the shift control of the present invention vehicle.

Figure 3c is an increase in air volume diagram according to the determination time in the shift control of the vehicle of the present invention.

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention.

1 is a shift control block diagram of a vehicle used in the present invention, the vehicle speed sensor 10 for detecting a vehicle speed while driving; An inhibitor switch 11 for detecting a position of a selection lever of a shift pattern during the driving; A water temperature sensor 12 which detects the coolant temperature while the vehicle is running; Control signal for gradually increasing the amount of air by the time to increase the amount of air, the amount of air according to the water temperature by a predetermined program the signal detected from the vehicle speed sensor 10, the inhibitor switch 11, the water temperature sensor 12 Control means 13 for outputting; The actuator 14 is configured to drive the air amount gradually by the signal output from the control means 13.

FIG. 2 is a flowchart illustrating a method for controlling a shift of a vehicle according to the present invention, comprising: determining whether a vehicle is stopped at a N stage (1.25 Kph or less) or a vehicle is traveling slowly (20 Kph or less) at a D stage while driving a vehicle; Determining (21) whether the vehicle traveling in the step 20 is shifted from the N stage to the D stage and from the D stage to the N stage; Calculating a difference between the air amounts ΔQ of the N stage and the D stage according to the cooling water temperature if the shift occurs in the step 21; Determining (23) a time (Δt) for increasing the amount of air according to the cooling water temperature in the step (22-); Step 24 is performed to incrementally increase the air amount ΔQ to be increased at the time Δt determined in the step 23 by ramp driving.

According to the present invention made as described above, when the vehicle travels in a city center with heavy traffic while driving, the driver frequently shifts the shift stage from the N stage to the D stage and the D stage to the N stage.

At this time, in the control means 13, the vehicle speed is 20 Kph or less in the state where the shift stage is shifted from the N stage to the D stage through the vehicle speed sensor 11 or the vehicle speed is shifted from the D stage to the N stage. It is determined whether this is 1.25 Kph or less (step 20).

If it is not the above condition, it goes to the start state, and if the condition is satisfied, is the shift stage shifted from the N stage to the D stage through the inhibit switch 11 or is the shift from the D stage to the N stage? (Step 21).

Subsequently, the control unit 13 detects the water temperature sensor 12 of the current cooling water temperature (WT) of the vehicle, and calculates an air difference (ΔQ) between the N stages and the D stages according to the detected cooling water temperature (WT). That is, as shown in FIG. 3, the difference in air amount ΔQ according to the sensed cooling water temperature WT is, for example, when the cooling water temperature WT is 34 ° C., the difference in air amount ΔQ = │Qn -Qd│ = │5.94-8.52│ = 2.58, and when the cooling water temperature (WT) is 20 ℃, the air volume difference (ΔQ) is 2.7, and when the cooling water temperature (WT) is 77 ℃, the air volume difference (ΔQ) is 1.2 (Step 22).

As such, when the air amount difference ΔQ according to the cooling water temperature WT is calculated, the control unit 13 determines the time Δt to increase the air amount according to the current cooling water temperature WT, that is, the time ( Δt) = f (WT), and as the cooling water temperature (WT) increases, the value of the air amount difference (ΔQ) decreases, so that the form of the function f (x) = 1 / x appears as shown in FIG. In addition, the air amount increase time Δt according to the cooling water temperature WT is determined.

When the air amount increase time Δt is determined as described above, the control means 13 increases the calculated difference in air amount difference ΔQ for the determined air amount increase time Δt during control f (x) = (ΔQ). / Δt × x) to gradually increase to the actuator 14 as shown in FIG. 3 to compensate for the amount of air.

As described above, the present invention determines whether the vehicle is slowing in the N stage while the vehicle is running or stops in the D stage, and determines whether the shift occurs from the N stage to the D stage and the D stage to the N stage. After calculating the difference between the air volume of the N stage and the D stage according to the cooling water temperature, by determining the time to increase the air volume in accordance with the cooling water temperature, and by gradually increasing the amount of air to be increased by this determined time to correct the air volume, Since the shock and the engine stop due to the difference in the amount of air in accordance with the N, D-speed shift will be prevented to provide the effect of improving the operability and idling performance.

Claims (1)

Determining whether the vehicle is slowing in the N stage while the vehicle is running or in the D stage; Determining whether a shift occurs from the N stage to the D stage and the D stage to the N stage; Calculating a difference in air volume between the N stage and the D stage according to the cooling water temperature when the shift occurs in the step; Determining a time for increasing the amount of air according to the cooling water temperature in the step; And gradually increasing the amount of air to be increased by the time determined in the step.