JPH11147495A - Automatic transmission control unit and electric assisted cycle utilizing it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic transmission control unit and electric assisted cycle utilizing it, which allows optimum automatic transmission control without any shifting operation by a driver. SOLUTION: An assist unit 5 comprises a vehicle speed sensor, a pedal effort detector, and 21 CPU. The CPU automatically calculates a gear stage of a transmission 13 based on a vehicle speed and a pedal effort peak value, and outputs shifting instruction by the gear stage to a gear shifter (mechanism) and an actuator. A mean value of multiple pedal effort peak values is used as a pedal effort peak value, which enables a stable transmission control. Further, because gear stages that match the vehicle speed and pedal effort have been prepared in advance as a table, the CPU can easily find an optimum gear stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission control device, and more particularly to an electric assist bicycle.
The present invention relates to an automatic shift control device capable of automatically performing a shift control without a manual operation by a driver, and an electric assist bicycle using the same.

[0002]

2. Description of the Related Art In a motor-assisted bicycle equipped with a conventional transmission, a lever of a handle portion and a transmission mechanism of the transmission are connected by a wire, and the transmission mechanism is manually operated by manual operation of the lever. There is something like that.

Further, an invention relating to an electric continuously variable transmission for a bicycle in which the gear ratio of a continuously variable transmission attached to a bicycle is automatically controlled by a motor is disclosed in, for example, JP-A-6-127458. It has been made as it is.

According to the present invention, a display is provided at a position which is easily seen by a bicycle driver and is easy to operate by hand, for example, at the center of a handlebar. The (DOWN) soft switch is displayed. If any one of the soft switches is pressed by the driver during traveling, the speed change motor rotates in the pressed direction, and the speed ratio increases or decreases.

[0005]

As described above, according to the above-described conventional apparatus, the gearshift operation is performed when the driver does not operate the lever of the steering wheel or the up / down switch for gearshift command. However, there is a problem that the operation is not performed, which is inconvenient. Further, when the driver is unfamiliar with the shifting operation, there is a problem that it is not possible to issue a shifting command suitable for the running state of the bicycle, and it is difficult to make full use of the electric continuously variable transmission. For example, it is inconvenient to use unnecessary power because a suitable transmission gear is not selected during traveling, and it is necessary to shift the gears in advance so that the gear can be lightly extracted in consideration of the next gear when stopping. There was a problem that it was.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned problems of the prior art and to provide an automatic transmission control device and an automatic transmission control device capable of automatically performing an optimal transmission control without any driver performing a transmission operation. An object of the present invention is to provide an electric assisted bicycle.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an automatic transmission control device for increasing or decreasing the transmission ratio of a transmission. The first characteristic lies in that there are provided means for automatically determining the gear position thus determined, and means for automatically switching the gear position of the transmission to the gear position determined by the above means. A second feature of the present invention resides in that the automatic shift control device according to the first feature is applied to an electric assist bicycle including at least a pedaling force detector and a vehicle speed sensor.

According to the first feature, the gear is automatically switched to a gear corresponding to these according to the peak value of the pedaling force and the vehicle speed, so that there is no need to manually issue a control command as in the prior art, and the shift is changed. Ease of control is eliminated. According to the second feature, since the conventional electric assisted bicycle already includes the pedaling force detector, the vehicle speed sensor, and the battery, the present invention can be realized at low cost without adding an expensive device.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration diagram of a main part of an electric assist bicycle to which the automatic transmission control device of the present invention is applied, and FIG. 2 shows a main part of a component of an assist unit 5 of FIG. It should be noted that the present invention is not limited to the electric assist bicycle, but can be applied to other devices having a shift control device.

FIG. 1 is a schematic view of a main part of an electric assisted bicycle viewed from above. Reference numerals 1a and 1b denote pedals, reference numerals 2a and 2b denote cranks for transmitting human power applied to pedals 1a and 1b, and reference numeral 3 denotes a crank. The drive sprocket is driven to rotate by human power transmitted through the crank and assisted in turning by an electric motor 4. Reference numeral 5 denotes an assist unit, which is a transmission mechanism for transmitting the driving force of the electric motor 4 to the drive sprocket 3, a vehicle speed sensor 6, a pedaling force detector 7, and a CPU 8 shown in FIG.
And so on.

Reference numeral 10 denotes a rear wheel, 11 denotes a chain that transmits the rotational driving force of the drive sprocket 3 to a driven sprocket 12 of the rear wheel, 13 denotes a transmission that changes gear ratios, and 14 denotes the transmission 13 Speed shifter (mechanism)
And an actuator. The actuator includes a servomotor, a solenoid, and the like, and controls the operation of the shift shifter.

The vehicle speed sensor 6 is connected to the pedals 1a, 1
The vehicle speed is detected on the basis of the rotation speed of the gearshift b and the gear position selected by the shift shifter 14, and the pedaling force detector 7 detects the pedals 1a, 1
The driving force b is detected by, for example, a strain gauge. As the vehicle speed sensor 6 and the pedaling force detector 7, those conventionally known can be used.

FIG. 3 shows the characteristics of the pedaling force when the bicycle is spilled. Since a person rides on a bicycle by repeatedly applying a force, releasing a force, applying a force, and releasing a force to the pedals 1a and 1b, the pedaling force of the pedals 1a and 1b that are rotationally driven by human power is illustrated. The size is periodically repeated as shown. If the pedaling force is minimum at a certain time t1, the peak (maximum) P1 will be reached at the next time t2, and will be minimum again at the next time t3.
Then, it becomes the peak P2. The driver usually pedals at his own pace, so the pedaling force fluctuates smoothly at a cycle according to the driver's pace, but sometimes the pedal is suddenly applied and abnormal pedaling is performed. . At this time, the treading force changes like the time t9 to t11 in FIG. 3, and the change value of the treading force (Δ treading force) becomes much larger than in the case of the normal sawing.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG. This flowchart is
It mainly shows the operation of the CPU of FIG.

When the bicycle is spilled, step S1 is operated, and the CPU 8 detects the treading force from the treading force detector 7. In step S2, it is determined whether or not the pedaling force is smaller than a preset value m. This value m is a very small value as the pedaling force, and can be set to, for example, 5 kg weight. When this determination is negative, that is, when the pedaling force is greater than m, the process proceeds to step S3, and the difference between the pedaling force detected this time and the previous pedaling force, that is, the change value Δ pedaling force of the pedaling force is calculated. Next, in step S4, it is determined whether or not the Δ pedaling force is positive.

When the determination is affirmative (for example, at times t1 to t2, t3 to t4 in FIG. 3), the process proceeds to step S5, and it is determined whether the first flag is "1". Assuming that the first flag is 0, the process proceeds to step S6 to determine whether the Δ pedaling force is greater than a preset value n. Here, a determination is made as to whether the driver is riding a bicycle at a normal pace or has an abnormal manner of riding. When the determination is negative, the process proceeds to step S7, and the detected value of the pedaling force is held. However,
When the determination is affirmative, the process proceeds to step S8, where a second flag is set (flag 2 ← 1). And step S
Proceeding to 7, the detected value of the pedal effort is held.

The above processing (steps S1 to S8) is shown in FIG.
Is repeatedly performed when the pedaling force is increasing, and the detected value of the pedaling force in step S7 is updated each time the pedaling force is repeated. That is, as shown in FIG. 5 showing a part of FIG. 3 in an enlarged manner, the detected value of the pedaling force is updated at each control loop timing.

While the above processing is being repeated, for example, after the time t2 in FIG. 3, the Δ pedaling force turns negative, and the determination in step S4 becomes negative. At this time, step S
The peak hold value at 7 is P1.

When the determination in step S4 is negative and the process proceeds to step S9, it is determined whether or not the first flag is "1". If this determination is negative, step S
Proceeding to 10, a first flag is set (flag 1 ←
1). Next, in step S11, it is determined whether or not the second flag is set. If the determination is negative, the process proceeds to step S12, where the pedal effort peak hold value P1 is set.
Is stored in a certain register X, for example. On the other hand, when the determination in step S11 is affirmative, the process proceeds to step S13, where the second flag is lowered (flag 2 ← 0).
Proceed to 14. That is, when the second flag is set, the pedal effort peak hold value is an abnormal value, and is discarded without being stored in the register X.

In step S14, it is determined whether the pedaling force peak hold value stored in the register X has reached a predetermined number. For example, it is determined whether three pedaling force peak hold values have been collected. If this determination is negative, the process returns to step S1, and the above-described processing is repeated.

If the determination in step S14 is affirmative, that is, if it is determined that three pedal effort peak hold values (P1, P2, P3) are gathered, the process proceeds to step S15. An average value (moving average value) of three pedal effort peak hold values is obtained. It is apparent that the moving average value changes when a new pedaling force peak hold value P4 is obtained, as determined from P2, P3, and P4.

Next, in step S16, the CPU 8 takes in the vehicle speed from the vehicle speed sensor 6. Then, step S1
The program proceeds to 7, where a gear position is determined from the moving average of the pedal effort peak hold value and the vehicle speed, and the gear position is output in step S18. For the gear position in step S17, a table (or shift map) that preliminarily associates the moving average value of the pedal effort peak hold value, the vehicle speed, and the gear position with, for example,
8 or RO accessible by CPU 8
M, etc., and the gear may be determined from the table. The table relating the moving average value, the vehicle speed, and the gear position of the pedaling force peak hold value should be prepared in accordance with the physical strength of the driver, the condition of the traveling road surface, and the like so that the driver can select the table. It may be.

The gear speeds are, for example, three speeds of first speed, second speed, and third speed.
As for the speed, the travel distance of one rotation of the crank is long, and in the second gear, the travel distance of one rotation of the crank is set between the first and third speeds.

After the optimum gear is output in step S18, the first flag is set in step S22 or S
Since 1 is maintained until it is returned to 0 in 24, step S
The determination at 9 is affirmative, so that steps S10 to S18 are passed, and the processing of steps S1, S2, S3, S4, S9, and S1 is repeated.

Next, a description will be given of the speed change control performed in accordance with the gear stage output obtained as described above. As described above, in step S2, it is determined whether or not the pedaling force ≦ m is satisfied. As described above, m is set to a small value (for example, 5 kg weight) where the treading force is close to 0. Therefore, in FIG.
The determination in step S2 is affirmative, and the process proceeds to step S20. In step S20, it is determined whether the first flag is "1". If this determination is affirmative, the routine proceeds to step S21, where gear shift control is performed according to the gear position output obtained in step S18. Then, the process proceeds to step S22, where the first flag is returned to 0.

If the determination in step S4 is affirmative and the first flag is determined to be 1 in step S5 (step S5 is affirmative), the process proceeds to step S23.
The gear shift control is performed according to the gear position output obtained in step S18. That is, in FIG.
When the pedaling force reaches a point B at which the pedaling force turns positive, the gear shift control in step S23 is performed. Next, in step S24, the first flag is set to 0, and the process proceeds to step S6.

As described above, according to the present embodiment, the moving average value of the pedal effort peak hold value is automatically determined even if the driver does not perform any shifting operation while the driver is riding a bicycle. Based on the vehicle speed, the optimum gear is automatically determined, and the shift control can be automatically performed.

Further, since the gear position is obtained from the moving average value of the pedal effort peak hold value and the vehicle speed, for example, if the gear position is obtained from one pedal force peak hold value and the vehicle speed, in some cases, the gear position is determined. It is assumed that the gear is switched every rotation and unstable gear shift control is performed. However, according to the present embodiment, stable gear shift control can be expected.

Further, when the bicycle is unusually sawed, the pedaling force peak hold value at this time is ignored. It becomes a control system.

Further, since this shift control is performed when the pedaling force is small, gear switching can be smoothly performed.

Further, since the known power assisted bicycle is already provided with the pedaling force detection mechanism and the vehicle speed detection mechanism, the present invention can be realized without adding a new hardware mechanism.
When the actuator provided in the transmission 13 is incorporated in the assist unit 5, the structure around the transmission can be simplified. In this way, only the speed change wire can be provided from the assist unit 5 to the transmission 13.

[0032]

According to the present invention, the gear is automatically switched to a gear corresponding to the peak value of the pedaling force and the vehicle speed, so that the gear shift control is inappropriate for those who are not accustomed to gear shift control. On the other hand, there is no need for a person who is accustomed to speed change control to manually issue a control command as in the related art, so that the effect of speed change control is reduced.

When the present invention is applied to a battery-assisted bicycle, the conventional battery-assisted bicycle already has a treading force detector, a vehicle speed sensor, and a battery, so that it can be manufactured at low cost without adding an expensive device. There are effects that can be realized. Also,
Even if you do not need to change gears when you stop again, you can select the optimal gear position, so there is no hassle of gear change, and it is automatically optimized when you start again Is selected, the driver can lightly pull out the gear and also has the effect of suppressing the consumption of the battery for the electric auxiliary motor.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a main part of an electric assist bicycle to which the present invention is applied.

FIG. 2 is a block diagram illustrating a configuration of a main part of the assist unit in FIG. 1;

FIG. 3 is a characteristic diagram of the pedaling force during running a bicycle.

FIG. 4 is a flowchart showing the operation of one embodiment of the present invention.

FIG. 5 is an enlarged view of a part of the waveform in FIG. 3;

[Explanation of symbols]

1a, 1b pedal, 2a, 2b crank, 3 drive sprocket, 4 electric motor, 5 assist unit, 6 vehicle speed sensor, 7 pedal force detector, 8 CPU
Reference numeral 10: rear wheel, 11: chain, 12: driven sprocket, 13: transmission, 14: transmission shifter (mechanism) and actuator.

Claims (5)

[Claims] 1. An automatic transmission control device for increasing or decreasing a transmission ratio of a transmission, comprising: means for automatically obtaining a gear stage adapted from a peak value of a pedaling force and a vehicle speed, and a gear of the transmission. Means for automatically switching the gear to the gear determined by said means. 2. The automatic transmission control device according to claim 1, further comprising a table capable of obtaining a gear position adapted to the peak value of the pedaling force and the vehicle speed from the vehicle speed. . 3. The automatic transmission control device according to claim 1, wherein a moving average value obtained by averaging a plurality of peak values of the pedaling force is used as the peak value of the pedaling force. . 4. The automatic transmission control device according to claim 1, wherein a peak value of the treading force is ignored when a change rate of the treading force is equal to or more than a predetermined value. Automatic transmission control device. 5. An electric assist bicycle, wherein the automatic transmission control device according to claim 1 is applied to an electric assist bicycle having at least a pedal force detector and a vehicle speed sensor.