JPH07315281A - Vehicle provided with electric motor - Google Patents

Abstract

PURPOSE:To precisely control a motor to a target value even when electric characteristics of parts such as motor characteristic are dispersed by computing a target value for motor output on the basis of pedaling force, computing an actual value for motor output, and controlling motor output so that both of the target value and the actual value are set to minimums. CONSTITUTION:A CPU 108 is provided with a target value computing means 114 and a travel regulating means 116. The target value computing means 114 decides an auxiliary rate to a vehicle speed S by using characteristics stored in a memory 110, and then, a target value for driving force to be outputted by a motor 44 is found. In the CPU 108, output of a motor output detecting means, in other words, an actual value FMR of motor output is read when the target value is decided, and a difference between them is computed by the travel computing means 116, and then, a signal is outputted to a motor electric power controlling unit 112 for setting the difference to O. This signal represents a duty of driving current of the motor 44, and in the motor electric power controlling unit 112, motor electric current is intermittently controlled on the basis of the signal, so that the actual value is matched with the target value.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a driving system by human power and a driving system by electric motor in parallel, and the driving force by the electric motor is approximately proportional to the magnitude of driving force by human power (hereinafter referred to as pedaling force). The present invention relates to a vehicle with an electric motor that is controlled.

[0002]

2. Description of the Related Art A bicycle is known in which a pedaling force is detected and the driving force of an electric motor is controlled in accordance with the magnitude of the driving force (Japanese Utility Model Laid-Open No. 56-76590, JP-A-2-74491).
issue). That is, the driving force of the electric motor is increased in proportion to the magnitude of human power to reduce the load of human power.

Since the driving force (pedal force) of human power is input from the crank pedal, it changes with a cycle of half rotation of the crankshaft. This is because the pedaling force becomes almost zero when the crank pedal reaches the top dead center or the bottom dead center.

FIG. 9 shows the change of the driving force by the human power, that is, the pedal effort F _L with respect to time t. It changes the cycle of the pedaling force F _L corresponds to a half rotation of the crank pedals.
Those previously proposed to detect the pedaling force F _L which periodically changes as the mode - but is intended to increase or decrease the driving force F _M of the data, the relationship between the pedal force F _L and the motor driving force F _M Kazuyoshi Was set to That is, the ratio F _M / F _L of the two is calculated as the auxiliary ratio η
Was defined as and the auxiliary rate η was set.

[0005]

[Problems of the prior art] Heretofore, the open loop control has been performed in which only the human power (pedaling force) is detected by a sensor and the motor output is controlled. However, since the components that make up the system have variations in performance, control of the motor output and hence the combined force of the human power and the motor output becomes inaccurate. For example, when using a permanent magnet type motor, there are variations in the characteristics of the permanent magnets and changes in the magnetic characteristics, there are variations in the characteristics of the pedaling force sensor, and there are also changes and variations in the internal resistance of the battery. It is possible to control the quality of individual parts with a small variation, but in this case, the productivity of the parts deteriorates.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to control a motor output with high accuracy even if there are variations in electrical characteristics of system components such as a motor and a battery. It is intended to provide a motorized vehicle.

[0007]

According to the present invention, an object of the present invention is to provide a human power drive system and an electric drive system in parallel, and control the output of an electric motor of the electric drive system approximately in proportion to the magnitude of the driving force by the human power. In a vehicle with an electric motor, the human power detection means for detecting the human power driving force, the motor output detection means for detecting the actual value of the electric motor output, and the target value of the electric motor output that periodically changes in synchronization with the human power And a travel control means for controlling the motor output in synchronism with the human power so as to minimize the difference between the target value and the actual value of the electric motor. Achieved by vehicles with electric motors.

[0008]

1 is a side view of an embodiment of the present invention, FIG. 2 is a power system diagram thereof, FIG. 3 is an exploded view of the power system, FIG. 4 is a side view showing a pedaling force detecting portion, and FIG. FIG. 6 is a block diagram showing the function of the controller, FIG. 7 is a characteristic diagram of the auxiliary ratio η, FIG. 8 is a motor output characteristic diagram, and FIG. 9 is a diagram showing periodic fluctuations of the driving force F. Is.

In FIG. 1, reference numeral 10 denotes a vehicle body frame, which includes a head pipe 12, a down tube 14 extending obliquely downward and rearward from the head pipe 12, and a seat tube 16 standing upward from a rear portion of the down tube 14.
And an auxiliary seat tube 1 that stands upright in parallel behind it
8, a cross pipe 15 fixed to a rear end of the down tube 14, a pair of left and right chain stays 20 and 20 (see FIG. 3) extending rearward from the cross pipe 15, an upper end of the seat tube 14 and an auxiliary seat tube. 18
Seat stay 2 that connects the rear end of the chain stay 20
2 and.

A front fork 24 and a steering handlebar 26 are held on the head pipe 12 so as to be rotatable left and right. A front wheel 28 is attached to the lower end of the front fork 24. A saddle seat 30 is provided on the upper end of the seat tube 16.
Is installed. A rear wheel 32 is attached to the rear ends of the chain stays 20, 20. The hub 34 of the rear wheel 32 incorporates an internal transmission.

A power unit 40 serves as a power source of the bicycle equipped with the electric motor. This power unit 40 is
It has a case 42 and a permanent magnet type DC electric motor 44 fixed to this case so as to project obliquely upward and upward. The case 42 is attached to the lower rear portion of the down tube 14, and in this state, the motor 44 is parallel to the down tube 14.

Next, the power unit 40 will be described. Figure 1,
In FIG. 3, the crank shaft 46 is inserted through the case 42,
Crank arms 48, 48 are fixed to both ends thereof. The crank arm 48 has crank pedals 50, 50.
Is installed.

The rotation of the motor 44 is, as shown in FIGS. 3 and 5, a planetary roller type speed reducer 52, a one-way clutch 54,
Via the small bevel gear 56 and the large bevel gear 58, the crankshaft 46
It is transmitted to the cylindrical resultant shaft 60 that is rotatably held by. A chain sprocket 62 is fixed to the resultant shaft 60, and the rotation of the sprocket 62 is transmitted to a sprocket 66 provided on the hub 34 by a chain 64. The rotation of the sprocket 66 is transmitted to the hub 34 via the one-way clutch 68.

Rotation from the rear wheel 32 toward the motor 44 is interrupted by a one-way clutch 68 installed in the hub 34.
The planetary roller type speed reducer 52 is a known one,
A planetary roller is sandwiched between a sun roller provided on the motor shaft 44a and a ring roller held by the motor output detection lever 70, and the revolution of the planetary roller is transmitted to the small bevel gear 56 via the one-way clutch 54. .

The motor output detection lever 70 for holding the ring roller constitutes a part of motor output detection means 72 (see FIG. 5) for detecting the driving force of the motor 44 by the reaction force applied to the ring roller. . This lever 70
A spring (not shown) has a habit of returning the ring roller in a direction opposite to the reaction force direction, and the amount of rotation of the lever 70 is detected by a potentiometer 74 which is a motor output sensor.

On the other hand, the rotation input manually from the pedal 50 is transmitted to the resultant shaft 60 via the crankshaft 46, the one-way clutch 76, and the planetary gear type speed increaser 78. Therefore, the rotation input from the crankshaft 46 is generated by the resultant shaft 6.
From 0 to the rear wheel 32 via the chain 64. The rotation of the crankshaft 46 is not transmitted to the motor 44 by the action of the clutch 54 while the motor 44 is stopped. In addition, the clutch 76 is activated when the crankshaft 46 is stopped or in reverse rotation.
Therefore, the rotation of the motor 44 is not transmitted to the crankshaft 46. Here, the chain 64 is located on the right side of the plane A in the vehicle longitudinal direction including the motor shaft 44a (see FIG. 5).

As shown in FIGS. 3 and 5, the planetary gear type speed increaser 78 includes a ring gear 80 fixed to the resultant shaft 60, a sun gear 84 fixed to the pedal effort detection lever 82, and a planet interposed therebetween. And a gear 86. Crankshaft 46
Revolves the planetary gear 86 via the one-way clutch 76.

The pedal effort detecting lever 82 constitutes a part of the pedal effort detecting means 88 for detecting the driving force when the pedal 50 is manually driven by the reaction force applied to the sun gear 84. The pedaling force detecting means 88 is located on the left side of the plane A.

That is, the lever 8 of the pedal effort detecting means 88
2 has one protrusion 88a as shown in FIGS.
The protrusion 88a comes into contact with the stopper 90 and restricts rotation in the clockwise direction in FIG. 4, in other words, rotation in the direction opposite to the direction in which the pedal force of the pedal 50 is applied. Another second lever 92 abuts on the projection 88a, and the second lever 92 rotates clockwise by the counterclockwise rotation of the lever 82.

This second lever 92 is provided with a return habit by a return spring 94, whereby the lever 82 is moved to the position shown in FIG.
The habit of returning to the clockwise direction is given by. And this second
The rotation amount of the lever 92 is transmitted to a potentiometer 96 as a pedaling force sensor. As a result, the lever 82 rotates counterclockwise in FIG. 4 in proportion to the pedaling force of the pedal 50, and the second
Since the lever 92 rotates in the clockwise direction, this pedaling force is obtained from the rotation amount of the potentiometer 96.

In FIG. 3, reference numeral 98 denotes a vehicle speed sensor as vehicle speed detecting means, which is provided near the outer peripheral surface of the ring gear 80 of the planetary gear type speed increaser 78 which rotates integrally with the resultant shaft 60. The sensor 98 is composed of, for example, a magnetic detection element having a magnet on the back surface, and is opposed to a yoke formed in a gear shape on the outer peripheral surface of the ring gear 80. A reed switch, an electromagnetic pickup coil, a magnetic resistance element, a Hall element, or the like can be used as the magnetic detection element. As the sensor 98, various known types such as capacitance type and optical type can be used.

In FIG. 1, 100 is a rechargeable battery such as a lead battery, and two batteries 100 are housed in a battery case 102. This battery case 102 is a seat tube 1
6 and the auxiliary seat tube 18 are mounted.
Reference numeral 104 is a controller and 106 is a main switch.
It is housed in front of.

The vehicle speed S the controller 1 detected by the pedaling force F _L and the vehicle speed detecting means 98 detected by the pedal force detection means 88
04, this controller 104 is the pedaling force F
Motor output is controlled by controlling the motor current based on _L and vehicle speed S
Generate _M.

The controller 104, as shown in FIG.
CPU 108, memory 110, and motor power controller 1
12 and other devices. The memory 110 stores the auxiliary ratio η (see FIG. 7) that changes with the vehicle speed S and the like. This assist rate η is the motor driving force F _{M with} respect to the pedaling force F _L.
Is defined by the ratio (F _M / F _L ), and is set to the characteristic shown in FIG. 7, for example. The characteristic of this solid line is that the vehicle speed S is S _F
It becomes a constant value η ₀ (= 1) in the following low / medium speed range, and S _F <
In the high speed region of S <S _E , it gradually decreases linearly or in a curve, and becomes 0 in the super high speed region of S _E <S.

The CPU 108 has a target value calculating means 114.
And a traveling control means 116. Target value calculation means 1
First, the memory 14 calculates the auxiliary ratio η with respect to the vehicle speed S.
It is determined using the characteristics stored in 0. At this time, the target value F _M of the driving force that the motor 44 should output is [F _M = η ·
F _L ].

[0026] Figure 9 are those vehicle speed S indicates the change of the total drive force F = F _L + F _M at the time of the following S _F, as is apparent from this figure, the driving force is an auxiliary force by the motor 44 F _M is obtained by F _M = η · F _L , and the total driving force F also changes in accordance with the periodic change of the pedal effort F _L.

When the target value F _M is determined in the CPU 108, the output of the motor output detecting means 72, that is, the actual value F _MR of the motor output is read and the two are compared. That is, the traveling control means 116 determines the difference between the two, ΔF _M = (F _M −F _{M R} ).
Is calculated, and a signal is sent to the motor power control unit 112 so that this difference ΔF _M becomes zero. This signal indicates the duty of the drive current of the motor 44, and the motor power control unit 112 intermittently controls the motor current based on this signal to match the actual value F _MR with the target value F _M. As a result, the actual value F _{MR of the} motor output is accurately controlled so as to reach the target value F _M.

Since the pedal effort F _L changes periodically here,
Also it becomes 0 the motor drive current to the time pedal force F _L is 0, the motor speed is also reduced to less than the speed corresponding to the cruising vehicle speed S. Thus then again the motor current when the pedaling force F ^L is increased increased from 0, the motor output F _M via a one-way clutch 54 when the motor rotational speed acceleration to reach a rotational speed corresponding to the vehicle speed S at that time It will be transmitted to the resultant shaft 60. That is, there is a time delay between the acceleration of the motor 44 and the engagement of the one-way clutch 54.

FIG. 9a shows this time delay. N here
₀ indicates the motor rotation speed N corresponding to the vehicle speed at this time.
To eliminate this delay a in this embodiment, pedal force F _L is 0
The motor continues to rotate at a rotation speed N ₀ corresponding to the cruise vehicle speed at this time even when the speed becomes close. The principle is as follows.

[0031] In the DC motor, the motor applied voltage (V _M), the motor current (I), the following equation is established between the rotational speed (N). V _M = I · R + k · N where R is an amateur equivalent resistance, k is a proportional constant,
k · N represents the armature back electromotive force.

The motor torque (T _M ) is generally proportional to the motor current (I) although it depends on the type such as series winding or shunt winding. Therefore, with C as a constant, the following equation is obtained. T _M = C · I Therefore, with (R / C) = j, the following equation is obtained. V _M = j · T _M + k · N (1) In the equation (1), the first term (j · T _M ) on the right side is a term relating to torque, and the second term (k · N) is a rotational speed. It is a section regarding.

[0033] when the pedal force F _L is 0 in the conventional apparatus to attempt to zero the motor rotational speed N and the driving force F _M of the motor to zero. That is, in equation (1), T _M
= 0 and N = 0. Therefore, the motor applied voltage V _M is controlled to be zero.

[0034] On the other hand in this embodiment, the depression force F _L is 0
Even when, the motor rotation speed N is maintained at the rotation speed N ₀ corresponding to the vehicle speed. That is, the motor torque T _M = 0 and the rotation speed N = N ₀ are set at the time of no load. Therefore, from the equation (1), V _M = j · 0 + k · N ₀ = k · N ₀

[0035] By maintaining the motor voltage V _M to the V _MO is when this voltage V _M and no-load motor voltage V _M0, motor voltage V _M is below V _MO, even when the pedal force F _L is smaller The motor rotation speed N is maintained at N ₀ . Thus since the motor may be generating a driving force F _M from N ₀ when the pedal force F _L becomes V _M ≧ V _M0 increases, there is no time delay required for acceleration of the motor, the energy consumed during the acceleration -(E _a ) is also unnecessary.

During the period of the no-load motor voltage V _M0 for maintaining the motor at the rotation speed N ₀ , the current I becomes extremely small, so that the energy consumption −E ₀ is significantly smaller than the energy −E _a required for acceleration. That is, since E ₀ << E _a , the efficiency is improved.

Next, the operation at this time will be described with reference to FIG. The characteristic of the equation (1) is a straight line with a downward slope of − (k / j) as shown by the solid line in FIG. Pedal force F _L, which is now
When the motor voltage V _M for outputting the torque T _M of the motor determined by the equation (1) is obtained using the motor rotation speed N ₀ at that time, the operating point at that time is the point indicated by A in FIG.

Here, consider a case where the pedal effort F _L decreases.
Since it is considered that the vehicle speed S does not change due to inertia, the controller 104 keeps the motor rotation speed N ₀ and outputs V
Only _M is reduced. That is, the operating point A at this time descends on the straight line AB having the speed N ₀ . And it becomes V _M = V _M0 = kN ₀ becomes the pedaling force F _L is approximately 0, the controller 104 keeps the motor voltage V _M to V _M0. Therefore, the operating point of the motor is kept at point B.

[0039] When the depressing force F _L is V _M> V _M0 increases again, to move the operating point from point B toward the point A. At this time, since the motor is already rotating at the speed N ₀ , there is no time delay until the one-way clutch 54 is engaged due to the acceleration of the motor, and the delay a described in FIG. 9 is almost eliminated.

In the above embodiment, since the vehicle speed detecting means 98 is provided so as to face the ring gear 80, when the pedal is stopped, the detected vehicle speed becomes 0 and the power supply to the motor becomes 0. For this reason, power consumption is reduced and power is saved when traveling on a long downhill or when the pedal is stopped for inertial traveling. However, in the present invention, this may be provided in the front wheel 28 shown in FIG.

Note that the present invention uses F _M , V _M , and T used for calculation.
_M , N, N _{0, data} and the like may be increased or decreased or changed within a range where the effect of the present invention can be obtained, and the present invention includes this case. For example, the no-load motor voltage V _M0 may be slightly higher or lower than kN ₀ obtained by the equation (1).

In the above embodiment, the sprocket 62 is fixed to the resultant shaft 60 and the rear wheel 32 is driven by the transmission system including the chain drive mechanism. However, the present invention uses the transmission system including the shaft drive mechanism to drive the rear wheel. May be driven.

Further, a plurality of types of characteristics of the auxiliary rate η may be stored in the memory 110 so that any one of the characteristics can be selected by the selection switch. The characteristic may be moved in parallel with respect to the vehicle speed S by this switch, and may be changed to any characteristic discontinuously or continuously.

Further, in this embodiment, the motor output is obtained by measuring the reaction force to the ring roller of the planetary roller type speed reducer 52. However, as shown by the dotted line in FIG. It may be measured directly before the force is transmitted. In this case, for example, it is possible to measure by holding the motor main body rotatably around the shaft and detecting the reaction force to the motor and the balance point of the return spring.

FIG. 10 is a power system diagram of another embodiment.
In this embodiment, a resultant force detecting means 120 is provided instead of the motor output detecting means 72. The resultant force detecting means 120 detects the resultant force F (= F _L + F _MR ) applied to the resultant shaft 60. For example, a tensioner that is pressed against the tension side of the chain 64 is provided, and the resultant force F is calculated from the displacement amount of the tensioner. It can be detected. In this case, the controller 104A determines the actual motor output value F _MR.
Actual value calculation means 122 for calculating F _MR = F−F _L
Equipped with.

[0046]

As described above, the invention of claim 1 calculates the target value of the motor output based on the pedaling force (F _L ) while detecting the actual value F _MR of the motor output, and the difference ΔF =
Since the F _M -F _MR controls the motor output so as to minimize, it can be accurately controlled even motor output to a target value F _M if there are variations in the electrical characteristics of components such as motor characteristics .

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention.

[Fig. 2] Power system diagram

[Fig. 3] Development view of the power system

FIG. 4 is a side view showing a pedaling force detection unit.

FIG. 5 is a sectional view taken along line VV.

FIG. 6 is a block diagram showing a configuration of a controller.

[Fig. 7] Characteristic diagram of the assistance rate

FIG. 8 Motor output characteristic diagram

FIG. 9 is a diagram showing periodic fluctuations in pedaling force and motor output.

FIG. 10 is a power system diagram of another embodiment.

[Explanation of symbols]

 32 rear wheel 44 electric motor 46 crankshaft 72 actual value detecting means 88 pedaling force detecting means 98 vehicle speed detecting means 104, 104A controller 114 target value calculating means 120 resultant force detecting means 122 actual value calculating means

Front page continuation (72) Inventor Fumio Ito 2500 Shinkai, Iwata, Shizuoka Prefecture Yamaha Motor Co., Ltd.

Claims (1)

[Claims] 1. A vehicle with an electric motor in which a human-powered drive system and an electric drive system are provided in parallel, and the output of an electric motor of the electric drive system is controlled substantially in proportion to the magnitude of the driving force by the human power. Human power detection means for detecting force, motor output detection means for detecting an actual value of the electric motor output, target value calculation means for calculating a target value of the electric motor output that periodically changes in synchronization with the human power, A vehicle with an electric motor, comprising: travel control means for controlling the motor output in synchronization with the human power so as to minimize the difference between the target value and the actual value of the electric motor.