JPH0125943B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a control device for an automobile transmission,
In particular, the present invention relates to a control device that uses a computer to automatically select and control the gear ratio of a transmission in accordance with the traveling speed of an automobile.

[Background of the invention]

Conventionally, so-called automatic transmissions that automatically select gear ratios according to the vehicle's driving speed, accelerator operation, etc. have mainly used planetary gears as their transmission gears. When selecting and switching the transmission gear ratio, there is no particular need for control such as synchronization at the rotational engagement portion.

However, in recent years, automatic transmissions have been put into practical use that use spur gear type transmissions, which were previously mainly operated by manual operation, to automatically shift gears by operating an actuator. Ta.

In this type of automatic transmission, synchronization at the rotational engagement part is essential for smooth gear shift operation when selecting gear ratios, so the transmission is controlled by program control using a microcomputer. A structure constructed as follows is generally used. Incidentally, as a transmission using a microcomputer (hereinafter referred to as a computer), for example, the one disclosed in Japanese Patent Application Laid-Open No. 136624/1983 is known.

However, in conventional computer-controlled transmission control devices, all controls are performed by a single program, resulting in significant control delays and insufficient driving characteristics.

[Object of the Invention] An object of the present invention is to provide a transmission control that eliminates the drawbacks of the prior art described above, has good responsiveness to gear ratio selective switching control, has little control delay, and can provide excellent driving characteristics. We are here to provide you with the equipment.

[Summary of the invention]

In order to achieve this object, the present invention provides a transmission control device using a computer, in which a control program is divided into a plurality of programs according to the control contents, and each program is operated at a different cycle. It is characterized by

[Embodiments of the invention]

Below, regarding the transmission control device according to the present invention,
A detailed explanation will be given with reference to the illustrated embodiment.

FIG. 1 shows an embodiment of the present invention, in which 1 is a transmission;
2 and 3 are rotation detectors, 4 is a control device, 5 is an actuator, 10 is an input shaft, 11 is an output shaft (axle),
12 is the countershaft, 13 is the clutch gear,
14 is a transmission gear, 15 is a back gear, and 16 is an idle gear.

The rotation detector 2 detects the rotation of the back gear 15. Since the back gear 15 is connected to each transmission gear 14 via the idle gear 16 and the counter shaft 12, the signal 2a output from the rotation detector 2 detects the rotation of the back gear 15. The rotation speed of the back gear 15 and the rotation speed of the transmission gear 14 at each stage can be known.

Further, the rotation detector 3 detects the rotation of the output shaft 11, and therefore, the rotation speed of the output shaft 11 can be known from the signal 3a.
Since the signal 3a is coupled to the propeller shaft of the automobile, the scanning speed of the automobile, that is, the vehicle speed can be known from the signal 3a.

Two rotation signals 2a from rotation detectors 2 and 3,
3a is input to the transmission control device 5, and the rotational speed of the back gear 15 and axle 11 and the transmission gear 14 of each stage are input.
The rotation speed of the back gear 15 is calculated from the rotation speed of the back gear 15. When the rotational speed of the next gear and the axle are synchronized, a control signal 5a is output to the actuator 5, and the clutch gear 13 is moved and connected to the transmission gear 14.

FIG. 2 shows the internal configuration of the transmission control device 5, in which 20 is a period measuring section, 21 is a central processing unit of a computer, 22 is a ROM, and 23 is an output device, which outputs a back gear rotation signal 2a and an axle rotation signal. When the signal 3a is input to the period measuring section 20, the periods of both are measured and the data is input to the central processing unit (CPU) 21. In CPU21, ROM
(Read Only Memory) 22, and the rotational speed of the back gear 15 and axle 11 is calculated based on the data obtained above. Further, the rotation speed of the transmission gear 14 can be calculated from the number of gears of the idle gear 16, the counter shaft 12, and the transmission gear 14. If the rotation speed of the transmission gear 14 and the rotation speed of the axle 11 are compared and it is determined that they are synchronized,
Data for moving the actuator 5 is output from the CPU 21 to the output device 23, and a control signal 5a is output to the actuator 5.

This control program is stored in the ROM 22, and includes calculations of the plurality of rotation speeds, actuator control, etc., and also controls such as self-diagnosis using lamp displays, etc. As the scale of the program increases, Some means must be taken to ensure that each control is performed accurately and without delay.

Therefore, in this embodiment, various rotation speed calculations, actuator control, lamp display, etc. are each made into one independent program, and by starting each program at different cycles, it is possible to perform multiple controls at the same time. It's like this.

FIG. 3 shows the program stored in the ROM 22 divided into several parts and their mutual relationships. Note that one program divided according to purposes in this way is called a task. In this embodiment, the tasks are divided into three: a shift task 31 for controlling actuators, a calculation task 32 for calculating the rotational speed of various gear shafts, and a display task 33 for displaying various malfunctions.

Next, the three tasks divided in this way are managed by a task startup program called a task scheduler 30. For example, the shift task 31 is started every 10ms, the calculation task 32 is started every 20ms, and the display task 33 is started every 40ms. Each of them is activated at a different cycle. This task scheduler 30 is composed of interrupts, and in particular activates a task at regular intervals using a timer interrupt 35 that occurs at regular intervals.

In addition to the interrupts 34, there are a countershaft interrupt 36 and an axle shaft interrupt 37 for notifying the completion of cycle measurement by the cycle measuring section 20, and each of these interrupts takes in the measured cycle. Timer interrupt 35
occurs every 10 ms, for example, and activates the task scheduler 30 to start a task. When the series of programs in the task is completed, the task scheduler 30 is returned to check whether there is a request to start another task. If there is an activation request, the requested task is activated, and if there is no request, an interrupt 34 is waited for, and only when a timer interrupt 35 occurs, the task is activated.

In Figure 4, approximately 10
The contents of the shift task 31 activated every ms are shown in a flowchart.

First, check the current shift potential and determine whether it is the optimal position. If the optimum position is determined, the current position is maintained and the shift task 31 is ended. Then, when the shift task 31 is activated again 10 ms later, the above processing is performed again.

If it is determined that the current position is not optimal, the optimal position is selected and gear shifting is started. Prior to the start of gear shifting, it is determined whether the current position is neutral, and if it is not neutral, it is temporarily set to neutral, and if it is neutral, gear shifting is started. The shift task consists of the above-mentioned processing, and shifts the gear to the optimum position.

The shift is started after confirming that the rotations of the shift gear 14 and the axle 11 are synchronized. Therefore,
From the rotation speed of the back gear 15, each transmission gear 14
It is also necessary to determine the rotation speed of the axle 11 from the output signal of the axle rotation detector 4. However, if this calculation is performed in the shift register 31, the task processing time becomes long and optimal control is not possible. Therefore, calculation of the number of rotations is made into one program, and a calculation task 32 with a cycle of 20 ms is made. FIG. 5 shows a flowchart of the contents of the calculation task 32. In the calculation task 32, the number of rotations of the back gear 15 is first calculated, and then the number of rotations of the axle 11 is calculated. The rotational speeds of the back gear 15 and the axle 11 are calculated using the following equations since the periods of each rotational signal are measured.

Na=1/Ga・Ta...(1) Nb=1/Gb・Tb...(2) Na; Back gear rotation speed Ga; Back gear gear teeth number Ta; Back gear rotation signal period Nb; Axle rotation speed Gb; Axle Number of pulses per rotation Tb: Axle rotation signal period Also, since each transmission gear 14 is connected to the back gear 15 via the idle gear 16 and the counter shaft 12, the rotation speed of each transmission gear is equal to the rotation speed of the back gear 15. Once this is known, it can be obtained from the following formula.

N _GEAR = K・Na ...(3) N _GEAR ; Speed ratio to the rotational speed K; Na of the speed change gear Calculate this for each speed change gear,
Retain memory. The condition for starting gear shifting is that the rotational speeds of the axle and transmission gear are synchronized, (2)
It is determined whether or not they are synchronized by looking at the difference between Nb and N _GEAR obtained from the equation and equation (3). However, since the above calculation is performed every 20ms, Nb and
Since it is almost impossible to detect when N _GEAR completely matches, it is necessary to determine a shiftable speed difference that will start shifting when the difference between the two becomes less than a certain value. Therefore, this shiftable rotational speed difference is calculated as ±several percent of the rotational speed of the axle. The above calculation is performed by the calculation task 32. A shift task 31 performs gear changes based on the various rotational speeds calculated in this task.

By the way, in this embodiment, in addition to the above two tasks, there is a display task 33 that displays various malfunctions when they occur. The contents of this display task 33 are shown in FIG.

First, it is detected whether or not there is a transmission failure, which is a serious failure, and if there is a failure, a transmission failure is displayed. As a means of detecting this failure,
If the completion of the shift cannot be confirmed even after a predetermined period of time has elapsed after the start of the shift, a problem may occur.

Next, a routine is entered in which the presence or absence of a failure in various detectors such as a rotation detector is checked, and if a failure occurs, it is displayed. As a means of confirming the failure, there is a case where the rotational speeds of the axle 11 and the speed change gear 14 do not match after confirming the completion of the shift. In addition, methods for displaying the timesheet failure indication and the detector failure indication include a visual indication using a lamp or a light emitting diode, and an audible indication using a buzzer. After completing the above series of failure displays, the display moves to the current shift position. The current position is confirmed and the corresponding lamp or light emitting diode is turned on to display the information.

As described above, according to this embodiment, the program of the transmission control device 5 is divided into tasks depending on the purpose, and each task is activated at a different cycle. Since this is fixed, other tasks can be activated and other controls can be performed while waiting for a certain amount of time or until a certain condition is met. Therefore, it is possible to perform multiple controls simultaneously and quickly.

〔Effect of the invention〕

As explained above, according to the present invention, since the program is independent for each controlled object, controlled objects that require responsiveness are operated in short cycles, and controlled objects that do not require a relatively long cycle are operated. As a result, it is possible to sufficiently improve the necessary responsiveness without increasing the load on the computer, and it is possible to easily obtain an automatic transmission with excellent running characteristics while eliminating the drawbacks of the conventional technology. .

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a transmission control device according to the present invention, FIG. 2 is a block diagram showing an embodiment of the control device, and FIG. 3 is an example of program division in an embodiment of the present invention. 4 is a flowchart showing an example of a shift task, FIG. 5 is a flowchart showing an example of a calculation task,
FIG. 6 is a flowchart showing an example of a display task. 1...Transmission, 2, 3...Revolution detector, 4...
Transmission control device, 5... actuator, 10...
...Input shaft, 11...Output shaft, 1...Counter shaft, 13...Clutch gear, 14...Transmission gear, 15...Back gear, 16...Idle gear, 20...Period measurement section, 21...Central processing Device (CPU), 22...ROM, 23...Output device, 3
0...Task scheduler, 31...Shift task, 32...Calculation task, 33...Display task.

Claims (1)

[Scope of Claims] 1. A detection means for detecting the rotational state of the transmission; a microcopyter for calculating a control value for selecting a gear ratio of the transmission based on the rotational state; and an actuator that shifts the gear ratio based on the control signal. a first calculation means that determines whether to shift from the above, and a second calculation means that compares and calculates the rotational speed of the transmission and the speed of the axle in a second period that is longer than the first period, and determines whether a shift is possible. A transmission control device comprising: