JP2001122186A - Control method for vehicle with motor assist function and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wasteful consumption of energy during acceleration of a motor or inertial traveling, and to calculate a vehicle speed from a rotation speed of the motor without a sensor for detecting an actual vehicle speed. SOLUTION: This control method for a vehicle with a motor assist function provided with a human power drive system and an electric drive system in parallel generates an electric power drive force TM depending on human power drive force TP on the basis of a prescribed assist rate characteristic changing a ratio of the electric power drive force TM to the human power drive force TP according to the vehicle speed VSP. A motive power source of the electric drive system comprises the electric motor. When the human power drive force TP is below a lower limit value TPL, an assist rotation current iID is supplied to maintain a rotation speed v of the motor corresponding to the vehicle speed VSP at the time. When a prescribed assist stop condition set on the basis of the human drive force TP and the rotation speed v of the motor is satisfied, the assist rotation current iID is shut off.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control method and apparatus applied to a vehicle with an electric assist function for controlling an electric driving force with respect to a human driving force based on an auxiliary ratio characteristic stored in advance.

[0002]

2. Description of the Related Art An output ratio of an electric motor to a pedaling force in a bicycle with an electric assist function that detects a pedaling force (manual driving force) and controls the driving force (electric power driving force) of the electric motor according to the magnitude of the pedaling force. There is known a control method for gradually controlling an assist ratio (assist ratio) in a high vehicle speed range with respect to an increase in vehicle speed to control the drive of the electric motor (an assist ratio gradual decrease processing method in a high vehicle speed range) (Patent No. 1). 2623419).

In this system, during high-speed running, an assist ratio is gradually reduced with an increase in vehicle speed in order to prevent application of unnecessary motor driving force and prevent the vehicle speed from becoming excessively high as a bicycle. Is to give. That is, the assist ratio is constant when the vehicle speed is lower than the set vehicle speed, and the assist ratio characteristic (assist ratio characteristic) for decreasing the assist ratio when the vehicle speed is equal to or higher than the set vehicle speed is stored in advance, and the motor driving force is calculated every arithmetic processing cycle of the microcomputer. While controlling the motor driving force. In addition, by gradually reducing the assist ratio in the high vehicle speed range, there is also an effect of preventing unnecessary consumption of the battery.

The structure of the drive system of this bicycle with an electric assist function is such that two systems, a human drive system and a motor drive system, are provided in parallel, and a one-way clutch is interposed in the motor drive system. The motor is prevented from turning when no power is supplied or when the vehicle speed due to manual driving is higher than the rotation speed of the motor. When transmitting the driving force of the motor drive system, the clutch is connected to transmit the driving force.

[0005] The driving force (pedal force) of the human-powered driving system changes with a cycle of a half rotation of the crankshaft because it is input from a crank pedal. This is because the pedaling force becomes almost zero when the crank pedal comes to the top dead center or the bottom dead center. The motor is controlled so that its rotational speed becomes substantially zero each time the pedaling force becomes substantially zero, that is, the motor driving force becomes zero. The driving force periodically fluctuates between a desired driving force corresponding to the pedaling force obtained when the driver steps on the vehicle.

At this time, there is a state in which the one-way clutch is disengaged from a state where the speed of the motor is substantially zero until the rotation speed reaches a rotation speed corresponding to the vehicle speed. When the one-way clutch is disengaged, the driving force of the motor does not contribute to traveling, so that the driving force of the motor is delayed from the pedaling force by the time required for acceleration of the motor. Due to this delay, the energy required for accelerating the motor is wasted. In addition, this delay causes the clutch to be engaged when the motor actually starts to rotate, so that the shock is transmitted to the vehicle body, resulting in a poor ride quality.

To solve this problem, Japanese Patent No. 2634 is used.
In No. 121, the vehicle speed is not zero and the human driving force (pedal force)
When is substantially zero, a method of controlling the drive of the motor at a rotational speed necessary to generate the vehicle speed at that time is adopted. According to this method, the motor is driven so that the rotation speed of the motor substantially matches the vehicle speed at which the one-way clutch starts to be connected. Therefore, it is possible to reduce the shock that occurs when the motor starts rotating and the clutch is connected. It is possible to prevent the energy required for accelerating the motor from being wasted.

[0008]

However, such a method is effective when the pedaling force is continuously generated.
For example, even when the vehicle speed is not zero but the vehicle is running by inertia without a pedal input, there is a problem that the battery is wasted because the voltage is always applied to the motor.

In order to realize such a method, it is necessary to detect the actual vehicle speed when the motor driving force is almost zero. For example, a rotation speed sensor for detecting the rotation speed of a crank or a wheel is required. In an electric vehicle such as a bicycle with an electric assist function for which cost reduction is required as described above, when the motor is rotating by using a rotor position detection sensor used to control the motor. By calculating and calculating the vehicle speed from the rotation speed of the rotor, it is possible to eliminate the vehicle speed sensor and reduce the cost.

However, in such a system, the vehicle speed cannot be obtained when the motor is stopped, and the actual vehicle speed cannot be detected when the clutch is released. Therefore, there is a problem that a current corresponding to the vehicle speed cannot be supplied to the motor after the pedaling force used in the above patent is lost.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the one-way clutch is disengaged from the state in which the motor speed reaches a rotation speed corresponding to the vehicle speed from a state in which the motor speed is substantially zero, so that the motor is driven. Since the driving force does not contribute to traveling, the motor driving force is delayed with respect to the pedaling force by the time required for the motor acceleration to prevent the energy required for the motor acceleration from being wasted, and the vehicle speed is not zero. However, when the vehicle is running by inertia without pedal input, the battery is not wasted and there is no sensor to detect the actual vehicle speed, and the vehicle speed is calculated from the motor rotation speed. A first object is to provide a control method for a vehicle with an electric assist function, which does not cause any inconvenience even in a vehicle with an electric assist function. It is a second object of the present invention to provide a control device for a vehicle with an electric assist function which is directly used for carrying out this method.

[0012]

According to the present invention, a first object is to provide a human-powered driving system and an electric driving system in parallel to provide a human-powered driving force ( _TP ).
Based on a predetermined auxiliary rate characteristic that changes the ratio of the power driving force (T _M ) to the vehicle speed (V _SP ) with respect to the human driving force (T _M ).
_In a control method for a vehicle with an electric assist function that generates an electric driving force (T _M ) according to _P ), a power source of the electric driving system is constituted by an electric motor, and the human driving force (T _P ) has a lower limit. In the state below the value (T _PL ), a rotating current (i _ID ) for maintaining the motor rotation speed (v) corresponding to the vehicle speed (V _SP ) at that time is supplied, and the manual driving force (T _P ) and the motor rotation speed are supplied. This is achieved by a control method for a vehicle with an electric assist function, wherein the following current (i _ID ) is cut off when a predetermined assist stop condition set based on (v) is satisfied.

Here, the motor is a direct current non-commutator motor (brushless DC motor), and a motor rotation speed (v) and a vehicle speed (V _SP ) are determined by using a signal indicating a rotation position of the rotor detected by a rotation position detector of the motor. ). In this case, the vehicle speed (V _SP ) can be obtained by multiplying the motor rotation speed (v) by the reduction ratio of the electric drive system.

The assist stop condition may be, for example, that a state in which the human-powered driving force (pedal force T _P ) is equal to or less than its lower limit (T _PL ) has continued for a predetermined time. That is, if this state ( _TP ≦ _TPL ) continues for a predetermined time or more, the assist is stopped to cut off the accompanying current (i _ID ), thereby preventing wasteful consumption of energy.

During this state (T _P ≦ T _PL ), the condition that the motor rotation speed (v) falls below the lower limit value (v _L ) is set as an assist stop condition, and the entrainment current (i _ID ) is cut off. You may make it. That is, the motor rotation speed (v)
Is decelerated to the lower limit value (v _L ) and cuts off the accompanying current (i _ID ) without waiting for a certain time. For this reason, wasteful consumption of energy can be more reliably prevented.

The condition for restarting the assist from the state where the entrainment current (i _ID ) is cut off under the assist stop condition is that v> v _L and T _P ≧ _{TP LR} (assist lower limit value). Can be. When the assist is restarted (at the time of re-acceleration assist), the assist rate (η _A ) is initially set to be smaller than the assist rate (η) obtained from the assist rate characteristic, and is gradually increased with time, and after a certain time, the assist rate characteristic is increased. Should be changed so as to match the auxiliary rate (η) obtained from By doing so, the shock at the time of restarting the assist can be reduced, and the riding comfort can be further improved.

A second object is to provide a man-powered drive system and an electric drive system in parallel, and to change the ratio of the power drive force (T _M ) to the human drive force (T _P ) together with the vehicle speed (V _SP ). a control apparatus for an electric assist function equipped vehicle to generate human power on the basis of the auxiliary rate characteristic (T _P) power driving force corresponding to the (T _M), and an electric motor as a power source of the electric drive system,
Human power (T _P) and the and the following rotation current setting unit for determining the rotational speed of the motor (v) and turns with based on the current (i _ID), human power (T _P) and the rotational speed of the motor (v ) and assist stop condition determining unit for determining the assist stop condition based on, wherein the Families around current setting unit brought Mawari current when the assist stop condition determining unit has determined that the assist stop condition is satisfied (i _ID) This is achieved by a control device for a vehicle with an electric assist function, wherein

The electric motor is a vector-controlled DC irregular.
It can be a sprue motor (brushless DC motor)
You. In this case, the vehicle speed (V_SP)When
Human driving force (pedal force T_PTarget torque of motor corresponding to)
(T_M= T_P× η) and the target torque calculation unit
Target torque (T_MMotor current command value corresponding to)
(I₀ ^*) Is calculated by vector control.
And i₀ ^*And i_IDAnd the sum (i₀ ^*+ I_ID= I^*)
And a calculator. This sum i^*
Control the motor current based on For example, PWM (Pusl
e Width Modulation) control.

In this case, a speed current (i _SP ) may be added to the current command value i ^* . That is, a speed current calculation unit for _obtaining a motor current (speed current i _SP ) required to generate a motor rotation speed (v) corresponding to the vehicle speed (V _SP ), and this speed current (i _SP ) is used as a current command value i ^It is sufficient to add an adder that sets the final current command value i ^* in addition to ^* . In this way, smoother motor speed control is possible.

[0020]

FIG. 1 is a diagram showing a power transmission system when the present invention is applied to an electric assisted bicycle, FIG. 2 is a diagram illustrating a motor control device, FIG. 3 is a diagram illustrating a configuration of an inverter, and FIG.
FIG. 5 is a block diagram illustrating the configuration of the control device, FIG. 5 is a conceptual diagram of the operation, FIG. 6 is an operation flow diagram of the main flow, and FIG. 7 is an operation flow diagram at the time of assist stop and assist restart according to the present invention.

In FIG. 1, the pedaling force of the driver is transmitted to a resultant shaft 3 via a crankshaft 1 driven by a pedal (not shown) and a one-way clutch 2. The output of the three-phase DC non-commutator motor 4 is transmitted to the resultant shaft 3 via the speed reducer 5 and the one-way clutch 6. The rotation of the resultant shaft 3 is transmitted to a rear wheel 8 as a driving wheel via a freewheel clutch 7.

The manual drive system is a transmission system from the crankshaft 1 to the rear wheel 8, and the electric drive system is a transmission system from the motor 4 to the rear wheel 8. The driving force of human-driven system that is pedaling force T _P
Is detected by the pedaling force sensor 9 from between the one-way clutch 2 and the resultant shaft 3.

Reference numeral 10 denotes a control device for the motor 4. The control device 10 and the depression force T _P depression force sensor 9 detects, controls the output torque T _M That the motor current of the motor 4 based on the vehicle speed V _SP of the vehicle speed sensor 11 detects. Reference numeral 12 denotes a DC power supply such as a battery. Here, the vehicle speed sensor 11
It can be formed by a sensor (not shown) for detecting the rotation speed of the rear wheel 8, the front wheel (not shown), the rotating portion of the drive system, and the like. The vehicle speed sensor 11 may be configured by a circuit that detects a rotation speed based on a back electromotive voltage induced in an armature coil of the motor 4 or calculated using a rotation speed v and a reduction ratio detected by an estimation unit 17 described later. It can also be constituted by what is required by:

As shown in FIGS. 2 and 4, the control unit 10 includes an inverter unit 13, a gate driving unit 14, and an arithmetic processing unit 15.
And The inverter unit 13 is configured by a known three-phase bridge circuit as shown in FIG. That is, MOS-F
Each set in which two switching elements Q _{1 to} Q ₆ such as ET and bipolar transistor are connected in series is connected in parallel to the power supply 12, while each set of switching elements Q ₁ and Q ₂ , Q ₃
And Q ₄ , and between Q ₅ and Q ₆ are connected to the armature coils of each phase of the motor 4. The gate driver 14 sends a gate signal to selectively turn on and off the switching element Q ₁ to Q ₆ to the gates of the switching elements Q ₁ to Q _6.

The arithmetic processing unit 15 is configured as shown in FIG. 4 and includes a microcomputer (MicroProcessor Unit, MP).
U) and various memories. In this embodiment, the magnitude and phase of the armature currents i _U , i _V , i _W supplied to the armature (stator) are determined based on the rotation angle θ and the rotation speed v of the rotor of the motor 4. ^{Is obtained} by calculation. That is, vector control is performed.

The rotation angle θ and the speed v of the rotor are
One of hall IC16 as the rotational position detector provided respectively for the phases (16U, 16V, 16W) is output position signal _{P (P U, P V,} P W) based on the calculating unit 17
Estimate by That is, the Hall IC 16 has an electrical angle of 60 °.
Each position signal P is turned on / off every time the rotor rotates 60 °.

The calculating section 17 detects from the change in the position signal P that the rotor has turned by an electrical angle of 60 °, and calculates the rotation speed v from the time interval in which the position signal P is kept constant without changing.
Is detected. Further, using this rotation speed v, a rotation angle θ within a time interval in which the position signal P does not change is calculated. As a result, the rotation angle θ during rotation of the rotor can be obtained with high resolution. Also, this calculating unit 17
The speed of the vehicle (vehicle speed V _SP ) is determined using the reduction ratio of the electric drive system and the diameter of the drive wheels.

The estimated values of the rotation angle θ, the rotation speed v, and the vehicle speed V _SP obtained by the calculation unit 17 are input to a torque current calculation unit 18. The current calculator 18 is a target torque calculator 19
The magnitude and phase of the current command value i ₀ ^* are calculated based on the torque target value T _M obtained in the above, the rotation angle θ, and the rotation speed v (see FIG. 5).

The target torque calculator 19 determines a target motor torque T _M based on the vehicle speed V _SP and the pedaling force T _P.
For example, as shown in FIG. 4, the set vehicle speed (for example, 15 km /
h) Assistance ratio (assist ratio) η for vehicle speed V _SP less than
(= T _M / T _P ) is set to 1.0, and the set vehicle speed (for example, 1
In a high-speed range of 5 km / h or more, the target value of the motor torque T _M is obtained as T _M = _TP · η according to the assist ratio characteristic in which the assist ratio η decreases linearly with the increase of the vehicle speed V _SP . Note that this auxiliary rate η is equal to another set vehicle speed (for example, 24 km / h).
And becomes 0.

In this motor 4, the torque T _M corresponds to the actual armature current i _R (i _U , i _V , i _W ). Current calculator 1
Numeral 8 finds the magnitude and phase of the armature current i _R required to generate the target torque value T _M by vector calculation, and outputs it as a current command value i ₀ ^* .

The current command value i ₀ ^* is actually U,
It is output separately for each phase of V and W. That is, the current calculation unit 18 uses the sine wave pattern data stored in the memory 20 to specify the current command values i ₀ ^* (i ₀ ^* _U , i ₀ ^* _V , i) in which the phases are shifted from each other by 120 ° in electrical angle. ₀ ^* _W ) is output. The current command value i ₀ ^* of each phase is a sine wave whose amplitude changes according to the magnitude of the target torque value T _M , and its amplitude and phase are calculated based on the rotation angle θ, the rotation speed v, the inertia of the rotating part, and the like. It was done.

In FIG. 4, reference numeral 21 denotes a speed current calculation unit. The speed current calculation unit 21 generates a motor current i _SP necessary for setting a motor rotation speed (v) corresponding to the vehicle speed V _SP when the human driving force (T _P ) is larger than the lower limit value (T _PL ).
Is calculated (see FIG. 5). When the manual driving force (T _P ) is larger than the lower limit (T _PL ), the motor 4 is rotating. Therefore, if the signal of the vehicle speed (V _SP ) is a certain level or more, this condition T _P > T _PL is satisfied. it is conceivable that.

Reference numeral 22 denotes a follow-up current setting unit, and based on the motor rotation speed (v) and the manual driving force (T _P ), the human driving force (T _P ) becomes equal to or lower than its lower limit value (T _PL ). Sometimes (T _P ≦ T _PL ), the current required to drive the motor at the rotation speed (v) at this time, that is, the follow-up current (i _ID )
Is calculated.

The follow-up current (i _ID ) is added to the current command value (i ₀ ^* ) by the adder 23. This added value (i ₀ ^* +
The speed current (i _SP ) is further added to i _ID ) in the adder 24, and the final current command value i ^* (= i ₀ ^* +
i _ID + i _SP ). As can be seen from FIG. 5, the current command value i ₀ ^* is a component corresponding to the treading force (T _P ), the speed current (i _{S P} ) is a component corresponding to the vehicle speed (V _SP ), i _ID ) is such that the pedaling force (T _P ) is zero (strictly speaking, the lower limit T
_This is a component for setting the rotation speed (v) (that is, the no-load rotation speed) at the time of ( _PL or less).

In FIG. 4, reference numeral 25 denotes an assist stop condition determining unit.
You. The assist stop condition determining unit 25 is provided with a manual driving force.
(Treading force T_P) And motor rotation speed (v)
It is determined whether or not the
Current i_IDCut off. Also, the speed current i
_SPAlso shuts off and stops assisting. On the other hand, the following current i
_IDPedaling force (T_P) Is the lower limit of assist restart
Value (T_PLR) (T_{PL R}> T_PL)
Is the pedaling force (T_P) Was increased and driving was resumed.
Assistance is resumed.

When this assist is restarted (re-acceleration assist is started), for example, a method disclosed in Japanese Patent Application Laid-Open No. 9-267791 can be used. That auxiliary rate target torque calculating section 19 (η _A) was smaller than the auxiliary rate of normal as determined from the auxiliary rate characteristic (eta), the auxiliary constant over time (eta _A) a predetermined time after increased gradually to Control is performed so as to match the regular auxiliary rate (η). In this way, the shock when the one-way clutch is engaged is reduced when the assist is resumed during running and the one-way clutch is engaged, so that the riding comfort can be improved.

The final current command value i to which the speed current (i _SP ) and the accompanying current (i _ID ) are added by the adders 23 and 24
^* Is input to the subtracter 25, wherein the difference between the actual current value i _R of the armature (i ^* -i _R) is determined separately for each phase. This current value i _R is obtained by detecting the current (i _U , i _V ) of the UV phase winding of the armature with a Hall CT (Current Transformer, current transformer) ( _C T _U , _C T _V ) or the like, and detecting the W-phase current. Can be obtained by calculation. The difference (i ^* -i _R) becomes armature current error signals are input to the command current control unit 26. The current control unit 26 sets the gate of the inverter 13 to PW
A gate drive signal driven by the M method is generated and sent to the gate drive unit 14. As a result, the motor 4 is subjected to PWM control to generate a target torque value T _M , and the bicycle can run by the motor output T _M and the pedaling force T _P.

Next, the operation will be described with reference to FIGS. First, the main flow operation will be described with reference to FIG. The output of each sensor is input to the arithmetic processing unit 15 (FIGS. 2 and 3) (step S100 in FIG. 6). That is, the position signal P of the rotational position detector 16, the output signal of the pedal force (T _P) (not shown) torque sensor to detect a (T _P), the battery 12 (FIG. 2,
The battery voltage detection signal and the like in 3) are digitized and input via the input interface.

The arithmetic processing unit 15 monitors the state of charge of the battery based on the battery voltage detection signal, and displays the remaining amount of the battery capacity on the remaining amount display means such as an LED (step S102). The arithmetic processing unit 15 determines various operation states based on the input information, determines an operation mode corresponding to each state, and performs the processing (step S104). This processing mode includes a stop mode, a transmission mode, an auxiliary mode, a restart mode, and the like. The arithmetic processing unit 15
When the occurrence of an abnormality is detected from the output signal of each sensor, predetermined processing such as battery protection (for example, overdischarge prevention) is performed (step S106). Then, the above operation is repeated.

The operation of assist stop and assist restart is performed according to FIG. First, the pedaling force (T _P ) is compared with its lower limit (T _PL ) (step S150), and T _P ≦ T _PL
In the case of (1), the rotation control is performed (step S152). That is. The entrainment current setting unit 22 supplies the entrainment current (i _ID ) to the motor 4 from the rotation speed (v) at that time. When a predetermined time (for example, 0.8 seconds) elapses in this state (step S154), it is determined whether the motor rotation speed (v) is equal to or lower than a lower limit value (v _L , for example, 150 rpm) (step S156). If it is equal to or less than the lower limit (v ≦ v _L ), it is considered that the vehicle stops, and the assist is immediately stopped (step S158).

If v> v _L , it is considered that the vehicle is still running without stopping (step S156), so that the entrainment current (i _ID ) is kept flowing (step S160). The pedaling force (T _P) is the lower limit value (T _PL) The following (T _P ≦ T _PL, step S162), and the rotational speed (v) is the lower limit value if (v _L) or less (v ≦ v _L, step S164) The assist is stopped because the vehicle is considered to stop (step S15).
8). If the rotation speed (v) is higher than the lower limit (v _L ) (step S164). Since it is considered that the vehicle is still coasting, this state is continued for a certain time (for example, 4.2 seconds) (step 166), and then the assist is stopped (step S).
158).

The pedal force (T _P) is the lower limit value (T _PL) than in large (T _P> T _PL, step S162), and assist resumed lower limit value (T _PLR, where T _PLR> T _PL) than small (T _P <T
_{In the case of PLR} , step S168), it is considered that the pedaling force (T _P ) is not large enough to re-accelerate, and the assist is stopped after a certain time (eg, 4.2 seconds) has elapsed (step S168).
166, S158). If pedaling force (T _P) is larger than the resumption limit value (T _PLR) (step S168), it believed to pedaling force (T _P) began to increase during coasting starts reacceleration assist (step S170).

In the re-acceleration assist, as described above, the auxiliary rate (η _A ) is initially set smaller than the normal auxiliary rate (η), and is gradually increased with time to increase the normal auxiliary rate (η). This is controlled so as to match with. In step S150, the pedaling force (T _P ) is reduced to the lower limit value (T _P ).
_PL ), the regular assist is continued (step S).
172).

[0044]

According to the present invention, as described above, the human driving force (T
_{When P} ) is equal to or less than the lower limit value (T _PL ), the follow-up current (i _ID ) is supplied, so that the time required for accelerating the motor rotation speed at the time of re-acceleration becomes shorter, and the energy required for accelerating the motor can be reduced. it can. Further, when the predetermined assist stop condition set based on the manual driving force (T _P ) and the motor rotation speed (v) is satisfied, the accompanying current (i _ID ) is cut off. Can be prevented.

In this case, since the assist stop condition is set without using the vehicle speed (V _SP ), the motor rotation speed (v) can be set without separately providing a sensor for detecting the actual vehicle speed.
The present invention can be applied to a vehicle that calculates the vehicle speed (V _SP ) from the vehicle speed without increasing the number of parts. According to a seventh aspect of the present invention, there is provided an apparatus directly used for performing the method of the first aspect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a power transmission system applied to an electric assist bicycle according to the present invention.

FIG. 2 is an explanatory diagram of a motor control device.

FIG. 3 shows an inverter.

FIG. 4 is a diagram showing a configuration of a control device.

FIG. 5 is a conceptual diagram of the operation.

FIG. 6 is an operation flowchart of a main flow.

FIG. 7 is an operation flowchart of assist stop / restart processing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Crankshaft 4 Three-phase DC non-commutator motor 8 Rear wheel (drive wheel) 10 Control device 13 Inverter unit 14 Gate drive unit 15 Operation processing unit 18 Torque current operation unit 19 Target torque operation unit 21 Vehicle speed current operation unit 22 current setting portions 23, 24 adder 25 assist stop condition determining unit _{i R (i U, i V} , i W) armature current _{P (P U, P V,} P W) position signal θ rotation angle V _SP speed T _P human power (tread force) T _PL human power lower limit T _PLR human power assist restarting the lower limit v motor rotation speed v _L motor lower limit T _M driving power of the rotational speed (motor driving force)

Claims (8)

[Claims] 1. A man-powered driving system and an electric-powered driving system are provided in parallel, and a predetermined auxiliary ratio characteristic for changing the ratio of the electric power driving force (T _M ) to the human driving force (T _P ) together with the vehicle speed (V _SP ). in human power (T _P) control method of an electric auxiliary function with the vehicle for generating a driving power (T _M) in accordance with the basis, and constitutes a power source of the electric drive system with an electric motor, the human power When (T _P ) is equal to or less than the lower limit value (T _PL ), a rotating current (i _ID ) that maintains the rotation speed (v) of the motor corresponding to the vehicle speed (V _SP ) at that time is supplied, and the manual driving force ( A method for controlling a vehicle with an electric assist function, wherein the following current (i _ID ) is cut off when a predetermined assist stop condition set based on _TP ) and a motor rotation speed (v) is satisfied. 2. The electric assist system according to claim 1, wherein the electric motor is a DC non-commutator motor, and the motor rotation speed (v) and the vehicle speed (V _SP ) are obtained based on an output signal of a motor rotation position detector. Control method for vehicles with functions. 3. The control of the vehicle with an electric assist function according to claim 1, wherein the assist stop condition is such that a state in which the human-powered driving force (T _P ) is equal to or lower than the lower limit value (T _{P L} ) has continued for a predetermined time. Method. 4. The motor rotation speed (v) while the human-powered driving force (T _P ) keeps the state below its lower limit (T _PL ).
4. The control method for a vehicle with an electric assist function according to claim 3, wherein an assist stop condition is set when the vehicle speed is equal to or less than the lower limit value (v _L ). 5. A follow-up current (i) under an assist stop condition.
_When the rotation speed (v) of the motor exceeds the lower limit (v _L ) while supplying the _ID ) and the manual driving force (T _P ) increases beyond the lower limit (T _PLR ) of the assist, The control method for a vehicle with an electric assist function according to any one of claims 1 to 4, wherein the assist by the electric power driving force ( _TM ) is restarted. 6. A predetermined auxiliary ratio characteristic for providing a human drive system and an electric drive system in parallel and changing a ratio of a power drive force (T _M ) to a human drive force (T _P ) together with a vehicle speed (V _SP ). A control device for a vehicle with an electric assist function that generates an electric driving force (T _M ) according to a human driving force (T _P ) based on an electric motor serving as a power source of an electric driving system and a human driving force (T _P) ) And a rotational current (i _ID ) based on the rotational speed (v) of the motor, and an assist stop based on the manual driving force (T _P ) and the rotational speed (v) of the motor. An assist stop condition determining unit that determines a condition. The assisting current setting unit interrupts the accompanying current (i _ID ) when the assist stop condition determining unit determines that the assist stop condition is satisfied. Vehicle with electric assist function Control device. 7. The motor according to claim 6, wherein the electric motor is a vector-controlled DC non-commutator motor, and the motor rotation speed (v) and the vehicle speed (V _SP ) are based on an output signal of a rotation position detector of the motor. while sought Te, the vehicle speed based on the auxiliary rate characteristic (V _SP) and human power and the target torque computing section for obtaining the target torque (T _M) of the motor corresponding to (T _P), the target torque (T _M) And a torque current calculator for obtaining a motor current command value (i ₀ ^* ) corresponding to the following by vector control, and a sum of the current command value (i ₀ ^* ) and the follow-up current (i _ID ) as a final current command value (i _ID ). a control device for a vehicle with an electric assist function, comprising: an adder i ^* ). 8. The human-powered driving force (T _P ) according to claim 7,
Is larger than the lower limit value (T _PL ), a speed current calculator for _obtaining a speed current (i _SP ) required to generate a motor rotation speed (v) corresponding to the vehicle speed (V _SP ), and a current command value ( A control device for a vehicle with an electric assist function, comprising: an adder that obtains a sum of (i ₀ ^* ), a follow-up current (i _ID ), and the speed current (i _SP ) to obtain a final current command value (i ^* ).