JPH02229955A - Automatic speed change gear control device - Google Patents

Abstract

PURPOSE:To perform proper shift down by a method wherein a descending engine brake state at the same step is detected, and from an overrun decision car speed set at each step to a value higher than that of a shift down schedule and an actual car speed, shift down to a minimum step at which on overrun occurs is effected. CONSTITUTION:On the assumption of a descending period, a shift down car speed being high only in an idle state is set, so that overrun is prevented from occurring, and a car speed during completion of gear shifting is prevented from a decrease on a flat rod and on an ascending road. When an output state of an accel pedal stepping-on amount sensor 9a is continued for a specified time, it is detected as a descending engine brake state. In this case, if the step is the same, a speed change gear 4 is controlled so that shift down to a step at which no overrun of an engine occurs when shift down from a current step is effected as an overrun decision car speed during idle shift down operation set at each step is compared with an actual car speed detected by a car speed sensor 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic transmission aIIla device, and more particularly to a device for controlling the speed change of an electronically controlled ifl automatic transmission based on a shift schedule based on vehicle speed and accelerator pedal depression amount. It is something. [Prior Art] As is well known from Japanese Unexamined Patent Application Publication No. 11769/1983 by the present applicant, gear shifting in a conventional electronic II type automatic transmission is performed by pressing down on the accelerator pedal. This is done according to a preset shift map memory schedule depending on the amount.

Therefore, the optimal gear to shift to is determined only by the vehicle and the amount of accelerator pedal depression.

[Problem to be solved by the invention]

However, when the engine brake was activated by releasing the accelerator pedal, the following problems occurred. (1) If the shift schedule is set to a low value for vehicles to shift down appropriately on Hirakawa roads and uphill roads, the vehicle speed will change during gear shifting on downhill roads. Engine overruns when finished.

(2) If the setting is set high to ensure an appropriate downshift on a downhill road, the engine speed will drop during the shift on a flat or uphill road, resulting in a drop in engine speed at the end of the shift. It is too late and the engine's output cannot be fully utilized. In this way, there was a problem that it was not possible to achieve both. SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an automatic transmission control device that can downshift at appropriate timing both when descending and when ascending a hill. [Means for Solving the Problems] In order to achieve the object described above, an automatic transmission control device according to the present invention includes an accelerator pedal depression amount sensor, a gear position position sensor, and a system that detects the same gear based on the output states of both sensors. Detects the downhill engine braking condition of the gear and shifts the gearbox to the lowest gear that will not overrun. and control means for downshifting.

〔Example〕

FIG. 1 shows an embodiment of an automatic transmission control system according to the present invention, in which 1 is an engine, and 2 is a clutch body, which is composed of a well-known friction clutch. 3 is a clutch actuator that controls the engagement amount of the clutch body 2, 3a
4 is a clutch position sensor, 4 is a transmission, 5 is a transmission actuator for changing gears of the transmission 114, 5a is a gear position sensor, and 6 is an output shaft (drive shaft). 7 is the gear selection range of the shift 514 (see Figure 4)
7a is a select lever position sensor that outputs a signal indicating the position of the selected select lever 7. 8 is a select lever position sensor that outputs a vehicle speed signal detected from the rotation speed of the drive shaft 6. Vehicle speed sensor, 9
is an accelerator pedal, and 9a is an accelerator pedal position sensor. Furthermore, the IO is controlled at appropriate timing by controlling the clutch actuator 3 and the transmission actuator 5 based on signals from the clutch position sensor 3a, gear position sensor 5a, select lever 4QW sensor 7a, and accelerator pedal position l sensor 9a. This is a control device that acts as a control means for performing downshift operations, and is composed of a microcomputer. Next, the operation of the embodiment shown in FIG. 1 will be explained based on the flowchart shown in FIG. 2 and the shift map shown in FIG. 3. The program shown in the flowchart of FIG. 2 is executed at a fixed time period V4 (for example, several tens of seconds per cycle! l1), and when this program is started, the control HIVi
W10 reads the clutch position, current gear position, select lever position, and accelerator depression amount from the clutch position sensor 3a, gear position sensor 5a, select lever position sensor 7a, and accelerator pedal position sensor 9a, respectively (second Step Sl in the figure).

Next, the select lever position read in step SL is checked (step S2 in the same step), and if it is in a fixed range (including neutral), a timer counter (
(described later) is reset to 0 (step S3). Further, from the fixed range indicated by the select lever position sensor 7a, the gear stage including fail-safe (including neutral) for that range is determined (step S4).

The gear for the range determined by this fixed range processing is stored in memory A (step S5), and the contents of memory 8 are stored in the optimum gear memory (step S6), and the optimum gear and current gear are stored in memory A (step S5). Compare with Dan (
Step S7), if they are the same, there is no need for gear shifting, so only normal clutch control according to the vehicle condition is performed (Step S7); if the optimum gear and the current gear are not the same, the gear is shifted. Control is performed (step S8) and the process ends. Next, if the select lever position is in automatic shift range D5 (see Figure 4) in step S2, the optimum gear position corresponding to that range is determined by the shift map (see Figure 3).
(step 310), and stores the found suitable gear stage in memory B (step Sll). Next, the optimal gear stage up to the previous time, that is, the suitable gear stage determined at the start of the flowchart, is stored in memory B (step Sll). The stage is neutral [NJ
Check whether it was (same step Sl2)
, if neutral is "N", the timer counter is reset to O (step 314), and the contents of memory B are stored in memory A (step S15). Steps S6 to S9 perform the aforementioned processing and end. In step 312, if the optimum gear up to the previous time was not neutral [NJ], in order to determine whether engine braking is being performed, first check whether the accelerator pedal 9 is depressed (step S
l3) If the accelerator pedal 9 is depressed and the process is in a non-idle state, the processing from step 314 onwards is performed and the process ends. If the accelerator pedal 9 is in the idle state in step S13, the contents of memory B are compared with the previous optimal gear (step 316), and if memory B is lower than the previous optimal gear, the shift has already been made. Since it is now down, perform the processing from step 314 described above. When the gear B is higher than the previous optimal gear, the shift will be up, so store the previous optimal gear stored in the optimal gear memory in memory B (step 317) and hold L. Then proceed to step SI8. If the memory B is the same as the previous optimal gear in step S16, there is no need to shift "Mal", so the clutch position is checked (step SI8), and if the clutch position is disengaged, the process from step 514 described above is performed. However, if the clutch is engaged, the [gear setting value indicating the lowest gear from which no further downshifts will be performed]
(same step Sl9). Here, if memory B≦gear setting value, there is no need to downshift any further, so step S
Processing after 14 is performed, but if memory B>gear setting value, the timer counter value for measuring the time when engine braking (see Figure 3) is performed in the same gear does not overflow. It is compared with the MAX value (step S20), and if there is no overflow, it is incremented by l (step 521). If the timer counter value is greater than or equal to the MAX value in step 520, there is no need to increment by adding l, so the process proceeds to step 322, and the timer counter value is set to [shift when engine braking is performed continuously in the same gear]. and a timer setting value that specifies the time to perform downtime (step S22). Here, it can be defined as "time until it is determined that a downshift is required - timer setting value x flowchart period". In step 322, if the timer counter value <timer setting value, the process from step 315 described above is performed without performing a downshift, but if the timer counter value≧timer setting value, a memo is stored in memory A. A value of 1 (gear level lowered by one level) is stored (step S23). Then, the overrun vehicle speed of the gear stage stored in memory A is determined from the memory map shown in Fig. 3 (step S
24), compare it with the actual vehicle speed (same step S25), and as a result, if the vehicle speed>overrun vehicles, memory B
and the previous optimal gear stage (step 526 of the same step 7).
As a result, if memory B≠optimum gear stage up to the previous time, the timer counter value is reset to O (step 32).
7) The process from step Sl5 described above is performed, but if the gear position in memory B is the most recent optimum gear, the process from step 315 described above is performed without resetting the timer counter value. That is, when 1 is subtracted from memory B in step 323 and the result is, for example, 2 gears, and an overrun is determined in step 325 at these 2 gears, the 3rd gear gear in memory B before subtracting 1 is stored in the memory. A (step s15) and set this as the optimum gear (step 36)
By doing so, the downshift process is performed (step s8).
．． In step 325, if vehicles≦overrun vehicles, the gear in memory B is compared with the gear setting value in order to check whether downshifting to a lower speed is possible (step 32B); As a result, if memory B≦gear setting value, the gear in memory B cannot be downshifted to a lower gear, so step S26 described above
I will proceed with the subsequent processing, but step. Memory B at step S2B>
If the gear position is set, 1 is subtracted from the gear position in memory B, the process returns to step 323, and the process in F is repeated to search for a gear position that allows downshifting. On the other hand, memory B is used to downshift to find the lowest gear that can be downshifted, and the optimum gear memory is used to store the optimum gear from the previous process.
Memory A is used to link the gear in memory B with the optimum gear memory. Also, the timer setting value may be set for each gear. [Effects of the Invention] As described above, according to the present invention, the downhill engine brake condition is detected and only the idle condition is set high for each gear. Since the transmission is configured to downshift from 1 to the lowest gear that does not overrun, the downshift operation can be performed as early as possible without overrunning when descending a slope, and engine braking can be applied. Since the overrun judgment cars are set high for each gear, you can downshift without any problems even when climbing hills. Therefore, drivers can easily obtain rare decelerations and drive safely.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an automatic transmission control device according to the present invention, FIG. 2 is a flowchart of a control program executed by the control means of the present invention, and FIG. 3 is an automatic transmission operation according to the present invention. FIG. 4 is a diagram showing the position of the select lever.

Claims (1)

[Claims] The accelerator pedal depression amount sensor, gear position sensor, and the output state of both sensors detect the downhill engine braking condition in the same gear, and the overrun is set higher than the downshift schedule only in the idle state for each gear. An automatic transmission control device comprising a control means for downshifting a transmission from a determined vehicle speed and an actual vehicle speed determined by a vehicle speed sensor to the lowest gear that does not overrun.