JPS6123491B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for detecting a change in gear stage, that is, a shift point, of an automatic transmission used in a vehicle such as an automobile.

A fluid torque converter, a gear transmission mechanism,
It has a plurality of frictional engagement devices such as clutches and brakes, and the output of the engine is transmitted to the gear transmission mechanism via the hydraulic torque converter, and the frictional engagement devices are adjusted according to the engine load and vehicle speed. Automatic transmissions for vehicles that are configured to achieve one of a plurality of gears by selectively switching engagement have been well known, and many are in practical use. .

In the inspection and testing of automatic transmissions as mentioned above,
When the gear is actually changed during use,
That is, the output torque at the shift point and the oil pressure that drives the frictional engagement device may be detected, and when performing this inspection or test, it is necessary to find the shift point of the automatic transmission. Conventionally, output torque and oil pressure at the shift point of an automatic transmission have been detected by a person constantly monitoring changes in engine speed while constantly detecting the output torque and oil pressure using various sensors while the automatic transmission is operating. , predict the shift point based on the change in engine speed, manually operate the storage device based on the prediction, and record only the output torque and oil pressure detected by various sensors in the recording device near that shift point. It is done by doing. In inspections and tests according to the above-mentioned procedures, people are constantly involved in the inspections and tests to find the shift points of automatic transmissions, especially during long-term durability tests of 200 to 300 hours. Therefore, it is practically impossible to collect data on transmission characteristics when the output torque is similar to oil pressure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting a shift point that can detect the shift point of an automatic transmission without requiring human intervention, and an apparatus for implementing the method.

According to the present invention, this purpose is to collect the input shaft rotation speed data of the automatic transmission at a predetermined sampling rate, and to sequentially collect the input shaft rotation speed data at the sampling point and the input shaft rotation speed data at the previous sampling point. Find the difference from the shaft rotation speed data, determine whether the sign of this difference is constant over a predetermined time, and if the sign of the difference is constant over the predetermined time, then The automatic transmission is characterized in that the total value of the difference is calculated, the total value is compared with a set value, and when the total value is larger than the set value, it is determined that the gear stage of the automatic transmission has changed. A shift point detection method and an apparatus for implementing the method, comprising: means for collecting input shaft rotation speed data of an automatic transmission at a predetermined sampling rate; means for storing the input shaft rotation speed data;
Means for determining a difference between input shaft rotation speed data at a sampling point and input shaft rotation speed data at a sampling point immediately before this, and determining whether the sign of the difference is constant over a predetermined period of time. means and
means for calculating the sum of the differences in the predetermined time when the signs of the differences are the same over the predetermined time; means for comparing the total value with a set value; and means for comparing the total value with the set value; This is achieved by a shift point detection device for an automatic transmission characterized in that it has means for outputting a signal indicating that the gear stage of the automatic transmission has been changed when the shift point is greater than the above.

In an engine combined with an automatic transmission and given a constant load, the engine speed is
When the gear stage of an automatic transmission is changed, if it is an upshift, it will decrease continuously in a relatively large amount, whereas if it is a downshift, it will increase relatively greatly and continuously. Focusing on this, the shift point detection method and device according to the present invention detects the amount of change in engine speed over time and quantitatively determines the point at which the automatic transmission performs an upshift or downshift. This allows the shift point to be detected quantitatively and accurately, and the amount of change in engine speed over time as described above is automatically and continuously detected by the measuring device and the computing device. By this,
Shift point detection can be performed accurately even unattended or continuously for long periods of time without requiring workers to be constantly involved in inspections and tests.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram showing one embodiment of an automatic transmission bench performance testing device and a shift point detection device according to the present invention. In the figure, reference numeral 1 indicates a bench, and an assembly of an engine 4 and an automatic transmission 5 is fixed to the bench 1 by mounting devices 2 and 3. The output shaft 6 of the automatic transmission 5 is connected to the automatic operation control device 7, and the output shaft 6 of the automatic transmission 5 is connected to the automatic operation control device 7.
The automatic operation control device 7 automatically operates the vehicle according to a predetermined fixed pattern.

A gear 9 having a predetermined number of teeth is attached to the crankshaft 8 of the engine 4.
An electromagnetic pickup device 10 is installed near the. The electromagnetic pickup device 10 is sensitive to the rotation of the gear 9 and generates a signal with a frequency corresponding to the rotation speed. The signal generated by the electromagnetic pickup device 10 is transmitted to a frequency-voltage converter 1.
1 is input. Frequency-voltage converter 11 generates a voltage signal according to frequency.

The shift point detection device 12 is constructed as shown in FIG. The shift point detection device 12 includes an analog-to-digital converter 14 for converting a voltage signal corresponding to the engine speed as an input signal, that is, an analog signal, into a digital signal, and for sampling the digital signal, that is, engine speed data. digital switch 15a for manually selecting and setting the rate of change in engine speed; and digital switch 1 for manually selecting and setting the time required to obtain the rate of change in engine speed.
5b and a condition setting device 15 including a digital switch 15c that manually selects and sets the measured value of the change in engine speed; a timer clock circuit 16 that generates the sampling rate set by the digital switch 15a; a storage device 17 that stores a program for performing the output and engine rotation speed data taken in at a predetermined sampling rate; a central processing unit 18 that performs signal processing according to the program stored in the storage device 17; Output signal generation circuit 19 that generates a trigger pulse signal when the shift point is reached
and a common bus 20 that connects these to each other. The output signal generated by the output signal generation circuit 19 is applied to the output terminal 21.

Next, the shift point detection method according to the present invention will be explained with reference to the flowchart shown in FIG.

A voltage signal indicating the engine speed signal inputted to the input terminal 13 is input to the analog-digital converter 1.
4, and is converted into a digital signal at a predetermined sampling rate t based on the clock signal generated by the timer clock circuit 16, for example, from 1 msec to 100 msec.
The data is collected by the central processing unit 18 every msec and sequentially written to the storage device 17. The central processing unit 18 sequentially processes the engine rotational speed data at the sampling time Tn and the previous sampling time.
Calculate the difference △Nn between Tn _-1 and the engine rotation speed data. Further, the central processing unit 18 sequentially calculates the difference △.
It is determined whether the sign of Nn is the same over a predetermined time (an integral multiple of the sampling rate), which corresponds to 3t in this embodiment. That is, it is determined whether the engine speed continues to increase over a predetermined period of time or whether it decreases over a predetermined period of time. When the sign of the difference ΔNn is constant over the predetermined period, the central processing unit 18 calculates the difference ΔNn during the predetermined period.
Find the sum of Nn. Next, the central processing unit 18
compares the total value Nr with the set value Nt,
When Nr≧Nt, the central processing unit 18 determines that the gear stage of the automatic transmission 5 has changed, and outputs an output signal generation command signal to the output signal generation device 19. The output signal generation circuit 19 receives the signal and outputs a trigger pulse signal to the output terminal 21. When the central processing unit 18 outputs the output signal generation command signal once, it stops taking in new engine rotation speed data for a predetermined time, for example, a time corresponding to 7t, and does not perform any calculations, and then the predetermined time elapses. Later, new engine speed data is taken in again, and the calculations as described above are restarted.

FIG. 4 is a graph simulating changes in engine speed near one upshift speed change point. In this graph, T ₁ , T ₂ . . . indicate each sampling time point. As shown in this graph, when the engine speed changes, the sign of the engine speed difference △Nn changes when the sampling time shifts from T ₄ → T ₅ to T ₅ → T ₆ ,
The sign of the difference ΔNn remains the same over the sampling time T ₅ →T ₈ , ie, for a period corresponding to 3t. Therefore, the central processing unit 18 calculates the total value (amount of change in engine speed) Nr. The amount of change Nr in engine speed between T ₅ → T ₈ is △N ₅ +△
N ₆ +△N ₇ . If the absolute value of this amount of change Nr is smaller than the set value Nt, then the central processing unit 18
determines whether the sign of the difference ΔNn in engine speed is the same over the sampling time T ₆ →T ₉ . The sign of the difference △Nn is the sampling time T ₆ →
Since it is the same for T ₉ as well, the central processing unit 18 calculates the amount of change Nr in the engine rotation speed between the sampling times T ₆ and T ₉ . The amount of change Nr between T ₆ → T ₉ is △N ₆ +△N ₇ +△N ₈
If the absolute value of this change amount Nr is larger than the set value Nt, the central processing unit 18 outputs an output signal generation signal to the output signal generation circuit 19 at sampling time _T9 . When the central processing unit 18 generates one output signal generation command signal, it stops collecting engine rotational speed data and all calculations for a predetermined period of time. Therefore, the sampling point
During the period from T ₁₀ to T ₁₆ , engine rotational speed data at each sampling point is not collected. At sampling time _T17 , the central processing unit 18 resumes collecting engine rotation speed data and resumes calculation.

In addition, the sampling rate, the time to determine whether the signs of the difference in engine speed are the same, the set value Nt, the time to stop collecting engine speed data, etc., depend on the automatic transmission to be tested and its It may be arbitrarily determined depending on the characteristics of the engine to be connected.

By collecting engine speed data at each sampling rate of a relatively short time and determining whether the sign of the difference in engine speed between each sampling time is the same over a predetermined period of time, Erroneous detection of the shift point due to instantaneous fluctuations in the engine speed at one sampling time point is avoided, and the shift point is detected without a large delay with respect to the actual shift point.

The output signal of the output terminal 21 is input to a computer (not shown in the figure) that collects data of the automatic transmission, and when this computer receives a trigger pulse signal from the output terminal 21, it calculates, for example, the immediately preceding data based on that point in time. 0.5 seconds, 1.5 seconds immediately after, total 2
Outputs various data such as output torque and oil pressure per second to a graphic display, etc. Furthermore, just before
The data for 0.5 seconds is extracted from the immediately preceding data, for example, 3 seconds, which is constantly saved by the computer. As a result, changes in the output torque and oil pressure near the shifting points of the automatic transmission are depicted as time-series waveforms on the graphic display.

In the above-mentioned embodiment, the detection of the shift point during an upshift was described, but it goes without saying that the detection of the shift point during a downshift can be similarly detected using the method and apparatus described above. It is.

Although the present invention has been described in detail with respect to specific embodiments above, it will be appreciated by those skilled in the art that the present invention is not limited thereto and that various embodiments can be made within the scope of the present invention. It should be obvious.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of an automatic transmission bench test device and a shift point detection device according to the present invention, and FIG. 2 is a block line diagram showing an embodiment of the shift point detection device according to the present invention. Figure 3 is a flowchart showing the operation of the shift point detection device;
The figure is a graph simulating changes in engine speed near a shift point of an automatic transmission. 1... Bench, 2, 3... Mounting device, 4... Engine, 5... Automatic transmission, 6... Output shaft, 7...
...Automatic operation control device, 8...Crankshaft, 9...
Gear, 10... Electromagnetic pickup, 11... Frequency-voltage converter, 12... Gear shift point detection device, 13
... Input terminal, 14 ... Analog-digital converter, 15 ... Condition setting device, 16 ... Timer clock circuit, 17 ... Storage device, 18 ... Central processing unit, 19 ... Output signal generation circuit, 20 …
...Common bus, 21...Output terminal.

Claims (1)

[Scope of Claims] 1. Input shaft rotation speed data of an automatic transmission is collected at a predetermined sampling rate, and the input shaft rotation speed data at the sampling time and the input shaft rotation speed at the previous sampling time are sequentially collected. find the difference between the difference and the data, determine whether the sign of this difference is constant over a predetermined time, and if the sign of the difference is constant over the predetermined time, the difference in the predetermined time , the total value is compared with a set value, and when the total value is larger than the set value, it is determined that the gear stage of the automatic transmission has changed. How to get out. 2 means for collecting input shaft rotation speed data of an automatic transmission at a predetermined sampling rate; means for storing the input shaft rotation speed data; means for determining whether the sign of the difference is constant over the predetermined time period, and means for determining whether the sign of the difference is constant over the predetermined time period. means for calculating the sum of said differences over a predetermined time when they are the same; means for comparing said sum with a set value; and when said sum is greater than said set value, a gear stage of the automatic transmission is switched. 1. A shift point detection device for an automatic transmission, comprising means for outputting a signal indicating that the shift point has shifted.