JPH08175468A - Auxiliary power controller for auxiliary power type vehicle - Google Patents

Abstract

PURPOSE: To provide an auxiliary power controller for an auxiliary power type vehicle which can control auxiliary power for human force to a predetermined ratio with hgih precision. CONSTITUTION: Torsion bars (torque transmission shafts) 28, 36 are provided between an input shaft 23 and a resultant force shaft 24 and between a motor shaft 41 and the resultant force shaft 24, respectively. Potentiometers (detection means) 43, 64, 45 which detect phase angles of the input shaft 23, motor shaft 41, and resultant force shaft 26, respectively, are provided so that supply voltage (or current) to an electric motor 39 is controlled by comparing a difference in phase angles between the input shaft 23 and the resultant force shaft 24 with a difference in phase angles between the motor shaft 41 and the resultant force shaft 24. Human force is detected due to a difference in phase angles between the input shaft 23 and the resultant force shaft 24, and auxiliary power is detected due to a difference in phase angles between the motor shaft 41 and the resultant force shaft 24, and feedback control is performed so that auxiliary power becomes a predetermined ratio (assist ratio) for human force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary power control device for an auxiliary power type vehicle in which a drive system driven by human power and a drive system driven by an electric motor are arranged in parallel.

[0002]

2. Description of the Related Art As an auxiliary power vehicle, for example, a bicycle with an electric motor has been proposed and put into practical use. This bicycle with an electric motor is provided with a drive system based on an electric motor in addition to a drive system based on human power, and reduces physical load on the rider by detecting human power and applying auxiliary power corresponding to the magnitude to the wheels. It is a thing.

By the way, the magnitude of the auxiliary power is controlled so as to have a predetermined ratio (hereinafter referred to as an assist ratio) to human power (however, it is equal to or less than human power), but this control method detects detected human power. It was so-called open control based on (torque) and vehicle speed.

[0004]

However, in the conventional auxiliary power control method, the accuracy of the torque sensor or the like for detecting the human power is poor, and since the open control system is adopted, the assist ratio varies. However, there is a problem that the cost of assembling and adjusting parts is high.

The present invention has been made in view of the above problems, and an object of the present invention is to control auxiliary power of an auxiliary power type vehicle capable of controlling the auxiliary power with a predetermined ratio to human power with high accuracy. To provide a device.

[0006]

In order to achieve the above object, the invention according to claim 1 is characterized in that a drive system by human power and a drive system by an electric motor are provided in parallel, and the human power and motor shaft input to an input shaft are In an auxiliary power vehicle that transmits output auxiliary power to wheels via a resultant shaft, a torque transmission shaft that converts torque into a deflection angle is respectively provided between the input shaft and the resultant shaft and between the motor shaft and the resultant shaft. In addition to the above, a detecting means for detecting at least a phase angle between the input shaft and the motor shaft is provided, and the electric motor is controlled by the phase angle detected by the detecting means.

According to a second aspect of the invention, in the first aspect of the invention, in addition to the detecting means, a detecting means for detecting a phase angle of the resultant shaft is provided, and a phase angle difference between the input shaft and the resultant shaft is provided. And controlling the electric motor by comparing the phase angle difference between the motor shaft and the resultant shaft.

According to a third aspect of the invention, in the first or second aspect of the invention, the torque transmission shaft is a torsion bar or a helical coil spring.

A fourth aspect of the invention is characterized in that, in the first or second aspect of the invention, the detecting means is constituted by a potentiometer or a rotary encoder.

[0010]

According to the invention of claim 1, if the supply voltage (or current) to the electric motor is controlled so that the phase angle between the input shaft and the motor shaft is synchronized, the auxiliary power becomes equal to human power (that is, The feedback control can be performed so that the assist ratio becomes 1), and the balance between human power and auxiliary power can be maintained with high accuracy. In this case, it is not necessary to obtain the absolute values of the human power input to the input shaft and the auxiliary power output from the motor shaft.

According to the second aspect of the invention, the magnitude of human power is detected by the phase angle difference between the input shaft and the resultant shaft, and the magnitude of the auxiliary power is determined by the phase angle difference between the motor shaft and the resultant shaft. Since it is detected, the magnitude of the auxiliary power can be feedback-controlled with high accuracy at a predetermined ratio (assist ratio) to human power.

Thus, according to the present invention, the auxiliary power (or an amount proportional thereto) is detected and feedback-controlled so that the auxiliary power has a predetermined ratio with respect to the human power (or an amount proportional thereto). Therefore, the above-mentioned effects can be obtained.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of an electric motor vehicle equipped with an auxiliary power control device according to the present invention, FIG. 2 is a plan sectional view of a power unit of the same electric motor bicycle, and FIG. 3 is a functional block diagram of the auxiliary power control device. 4 is a flowchart showing the auxiliary power control procedure.

First, a schematic structure of the bicycle 1 with an electric motor will be described with reference to FIG.

In FIG. 1, reference numeral 2 denotes a head pipe located in front of the vehicle body, and a handle stem 3 is rotatably inserted in the head pipe 2. A handle 4 is attached to the upper end of the handle stem 3, and a front fork 5 is attached to the lower end of the handle stem 3, and a front wheel 6 is rotatably attached to the lower end of the front fork 5. It is supported.

A main frame 7 extends obliquely downward from the head pipe 2 rearward, and a boss 9 for supporting a crank shaft 8 is attached to a rear end portion of the main frame 7. A seat pipe 10 is provided upright from the boss 9 so as to incline upward and obliquely upward.
A seat 11 is supported on the upper end of the seat pipe 10.

Cranks 12 are attached to the left and right ends of the crankshaft 8, and pedals 13 are pivotally supported at the ends of the cranks 12. A large-diameter sprocket 15 is attached to the inside of the crank 12 on one side (left side) of the crankshaft 8.

Further, at a connecting portion between a pair of left and right chain stays 16 extending rearward of the vehicle body and a pair of left and right seat stays 17 extending obliquely downward and rearward from an intermediate portion of the seat pipe 10. A rear wheel 18 is rotatably supported, and a small-diameter sprocket 19 is provided on the rear wheel 18 side. In addition, the seat pipe 10 and the rear wheel 18
A removable battery 20 is mounted in the space between and.

By the way, in the electric motor-assisted bicycle 1, a power unit 21 is disposed behind the crankshaft 8. Here, details of the configuration of the power unit 21 will be described with reference to FIG.

In the housing 22 of the power unit 21, a hollow input shaft 23 and a resultant shaft 24, which are divided into two parts on the left and right sides and are coaxially arranged in the lateral direction, are bearings 25, 26, 27.
It is rotatably supported by. These input shafts 2
3 and the resultant force shaft 24 are relatively rotatable, and one end of the resultant shaft 24 is relatively rotatably fitted to the outer periphery of the end portion of the input shaft 23 as shown in the figure. A torsion bar 28 is inserted inside the input shaft 23 and the resultant shaft 24. One end of the torsion bar 28 is connected to the outer end of the input shaft 23, and the other end of the torsion bar 28 is connected. Is the resultant shaft 24
Is attached to the outer edge of the.

Thus, the housing 22 of the input shaft 23
A small-diameter sprocket 30 is provided on the outer periphery of the outer end portion extending outward through a one-way clutch 29, and an endless chain 31 is wound around the sprocket 30 and the sprocket 15.

A large-diameter gear 33 is provided on the outer periphery of the intermediate portion of the resultant shaft 24 via a one-way clutch 32, and the outer periphery of the outer end portion of the resultant shaft 24 extending outside the housing 22 is provided. The sprocket 34 is bound. An endless chain 35 is attached to the sprocket 34 and the sprocket 19 (see FIG. 1) provided on the rear wheel 18 side.
Is wrapped around.

Further, a torsion bar 36 is rotatably supported in the housing 22 by a bearing 14, and a large diameter gear 37 is connected to one end (left end) of the torsion bar 36 and the other end thereof is connected. A small-diameter gear 38 is attached to the (right end), and the gear 38 meshes with the gear 33.

On the other hand, behind the torsion bar 36, an electric motor 39 is installed laterally attached to the housing 22, and the bearing 4 of the electric motor 39 is arranged.
A gear 42 having a small diameter is attached to one end of a motor shaft 41 rotatably supported by 0. The gear 42 meshes with the gear 37.

Thus, in this embodiment, three potentiometers 43, 44 and 45 are arranged in the housing 22, and the potentiometer 43 is the input shaft 23.
The gear 46 connected to the input shaft of the gear 46 is engaged with a gear 47 formed on the outer periphery of the input shaft 23. The potentiometer 44 detects the phase angle of the motor shaft 41, and a gear 48 connected to the input shaft of the potentiometer 44 meshes with a gear 49 formed on the outer circumference of the torsion bar 36. Further, the potentiometer 45 detects the phase angle and the rotation speed of the resultant shaft 24, and the gear 50 connected to the input shaft thereof meshes with the gear 51 formed on the outer periphery of the resultant shaft 24. .

Incidentally, the potentiometers 43, 44, 4
5 is electrically connected to the controller 60 shown in FIG. 3, and the auxiliary power control device according to the present invention includes the torsion bars 28, 36 and potentiometers 43, 44, 45.
And a controller 60.

Next, the operation of the auxiliary power control system according to the present invention will be described below with reference to FIGS. 3 and 4.

When the rider alternately depresses the left and right pedals 13 to drive the crankshaft 8 to rotate, this rotation passes through the sprocket 15, the chain 31, the sprocket 30, and the one-way clutch 29, and the input shaft 23 and the torsion bar 2 are rotated.
Therefore, as shown in FIG. 3, the human power (torque) input to the crankshaft 8 is transmitted to the resultant shaft 24 via the torsion bar 28.

On the other hand, the rotation of the motor shaft 41 of the electric motor 39 is caused by the gears 42, 37, the torsion bar 36, the gear 38,
The auxiliary power output from the motor shaft 41 is transmitted to the resultant shaft 24 via the torsion bar 36, as shown in FIG. 3, through the 33 and the one-way clutch 32.

Thus, the resultant shaft 24 is rotationally driven by both human power and auxiliary power, and its rotation is sprocket 3
4, the chain 35 and the sprocket 19 and then the rear wheel 18
Therefore, the rear wheel 18 is rotationally driven by both human power and auxiliary power, and the bicycle 1 with the electric motor is driven.

As described above, since the human power and the auxiliary power are transmitted to the resultant shaft 24 through the torsion bars 28 and 36, the torsion bars 28 and 36 have the magnitudes of the human power and the auxiliary power, respectively. Twisting by a proportional amount, this twist appears as a phase angle C of the resultant force shaft 24, and this phase angle C is detected by a potentiometer 45 which is input by the rotation of the resultant force shaft 24 via gears 51 and 50. At the same time, the rotation of the input shaft 23 is input to the potentiometer 43 via the gears 47 and 46, and the rotation of the motor shaft 41 is input to the potentiometer 44 via the gears 49 and 48. Therefore, the phase angle A of the input shaft 23 and the motor Phase angle B of shaft 41
Are detected by the potentiometers 43 and 44 (STEP 1 in FIG. 4), and the detection results are input to the controller 60.

Then, the controller 60 causes the phase angle difference (C
-A) and (CB) are calculated to obtain the human power input to the input shaft 23 and the auxiliary power output from the motor shaft 41 (STEP 2 in FIG. 4).

Further, in this embodiment, the rotation speed of the resultant shaft 24 is detected by the potentiometer 45 (see FIG. 4).
3), this detection result is also input to the controller 60, and the controller 60 sets a predetermined assist ratio (ratio of auxiliary power to human power) R corresponding to the rotation speed of the resultant shaft 24 (that is, vehicle speed) (see FIG. 4). STEP 4), then,
The actual assist ratio R _M is calculated by the following formula (see FIG. 4).
STEP 5).

[0035]

## EQU1 ## R _M = (C−B) / (C−A) When the actual assist ratio R _M is obtained by the above equation, this actual assist ratio R _M is compared with the set value R (see FIG. 4).
If both are equal (R _M = R) in STEP6), the motor control gain is held as it is by the controller 60, and the magnitude of the auxiliary power generated by the electric motor 39 is maintained at the current value.

When the actual assist ratio R _M is smaller than the set value R (R _M <R), the motor control gain is increased by the controller 60 (STEP in FIG. 4).
7) The auxiliary power is increased until the supply voltage (or current) from the battery 20 to the electric motor 39 increases and R _M = R.

Conversely, when the actual assist ratio R _M is larger than the set value R (R _M > R), the motor control gain is reduced by the controller 60 (STEP 8 in FIG. 4), and the battery The auxiliary power is reduced until the supply voltage (or current) from 20 to the electric motor 39 decreases and R _M = R.

As described above, according to the present embodiment, the magnitude of the human power is determined by the phase angle difference (CA) between the input shaft 23 and the resultant force shaft 24, and the phase angle difference between the motor shaft 41 and the resultant force shaft 24. (C-
Since the amount of the auxiliary power is accurately detected by B), the amount of the auxiliary power can be feedback-controlled with high accuracy at a predetermined ratio (assist ratio) to the human power.

Further, according to this embodiment, variations in the output characteristics of the electric motor 39 due to temperature, secular change, battery 2
Voltage fluctuations of 0, resistance fluctuations of wires and connectors (not shown), etc. can be corrected, and highly accurate control is always possible.

By the way, if the supply voltage (or current) to the electric motor 39 is controlled so that the phase angle A of the input shaft 23 and the phase angle B of the motor shaft 41 are synchronized, the auxiliary power becomes equal to human power. Feedback control (that is, assist ratio = 1) is possible, and the balance between human power and auxiliary power can be maintained with high accuracy. In this case, since it is not necessary to obtain the absolute values of the human power input to the input shaft 23 and the auxiliary power output from the motor shaft 41,
The potentiometer 45 becomes unnecessary.

In the above embodiments, the torsion bar is used as the torque transmission shaft for converting the torque into the torsion angle, but a helical coil spring or the like can be used as the torque transmission shaft. The above is the input shaft,
Although the example using the potentiometer as the detecting means for measuring the phase angle of the motor shaft or the like has been described, a rotary encoder or the like can be used as the detecting means.

[0042]

As is apparent from the above description, according to the present invention, the auxiliary power (equal to the amount proportional to the auxiliary power) is detected, and this is set to the predetermined value with respect to the human power (or the amount proportional to the human power). Since feedback control is performed so that the ratio becomes
The effect that the auxiliary power can be controlled with a predetermined ratio to human power with high precision is obtained.

[Brief description of drawings]

FIG. 1 is a side view of an automobile with an electric motor including an auxiliary power control device according to the present invention.

FIG. 2 is a plan sectional view of a power unit of an automobile with an electric motor including an auxiliary power control device according to the present invention.

FIG. 3 is a functional block diagram of an auxiliary power control device according to the present invention.

FIG. 4 is a flowchart showing an auxiliary power control procedure.

[Explanation of symbols]

 1 Bicycle with electric motor (auxiliary power vehicle) 23 Input shaft 24 Combined shaft 28,36 Torsion bar (torque transmission shaft) 39 Electric motor 41 Motor shaft 44-45 Potentiometer (detection means)

Claims (4)

[Claims] 1. An auxiliary power vehicle in which a driving system driven by human power and a driving system driven by an electric motor are arranged in parallel, and the human power input to the input shaft and the auxiliary power output from the motor shaft are transmitted to the wheels via the resultant shaft. And a torque transmission shaft for converting torque into a deflection angle between the input shaft and the resultant shaft, and between the motor shaft and the resultant shaft.
An auxiliary power control device for an auxiliary power vehicle, characterized in that at least detection means for detecting a phase angle between the input shaft and the motor shaft is provided, and the electric motor is controlled by the phase angle detected by the detection means. . 2. A detection means for detecting a phase angle of the resultant shaft is provided in addition to the detection means, and a phase angle difference between the input shaft and the resultant shaft and a phase angle difference between the motor shaft and the resultant shaft are compared. The auxiliary power control device for an auxiliary power vehicle according to claim 1, wherein the electric motor is controlled by performing the operation. 3. The auxiliary power control device for an auxiliary power type vehicle according to claim 1, wherein the torque transmission shaft is a torsion bar or a helical coil spring. 4. The auxiliary power control device for an auxiliary power vehicle according to claim 1, wherein the detection means is composed of a potentiometer or a rotary encoder.