DE69609562T2 - Drive arrangement for a hybrid vehicle and control method for suppressing vibrations - Google Patents

Description

BACKGROUND OF THE INVENTION Field of the invention

The present invention relates generally to a drive device and a method for controlling the same. More particularly, the invention relates to a drive device for outputting or using a force or power generated by a high-efficiency motor and a method for controlling such a drive device.

Description of the state of the art

In known drive devices for transmitting a power generated by an engine to an output shaft, torque converters using a fluid are generally used to convert the power of the engine into a torque transmitted to the output shaft. In conventional fluid-based torque converters, an input shaft and an output shaft are not completely locked or connected to each other and, accordingly, there is an energy loss corresponding to a slip that occurs between the input shaft and the output shaft. The energy loss, which is consumed as heat, is expressed as the product of the speed difference between the input shaft and the output shaft and the torque transmitted at that time.

In vehicles with such a power transmission device attached, a large energy loss occurs in a transient or temporary state such as a start-up time. The energy efficiency is not 100% even in a stationary driving state. Compared with manual transmissions, the torque converters result in lower fuel consumption.

Drive devices for transmitting power by mechanical-electrical-mechanical conversion have been proposed to eliminate such a disadvantage (for example, in JAPANESE PATENT APPLICATION GAZETTE No. 51-22132 "ARRANGEMENT OF ROTARY POWER-DRIVEN MACHINES"). This proposed system connects a power generated by a motor to a power transmission device comprising an electromagnetic clutch and a rotary armature, and realizes a reduction ratio (torque conversion ratio) of 1+P2/P1, where P1 represents a number of poles of the rotary armature and P2 represents a number of poles of the electromagnetic clutch. Unlike the conventional fluid-based torque converters, this arrangement has substantially no energy loss due to slippage. It is therefore possible to keep the energy loss in the power transmission device relatively small by improving the efficiency of the electromagnetic clutch and the rotary armature.

However, the proposed drive device for transmitting power by mechanical-electrical-mechanical conversion has a fixed torque conversion ratio and is therefore not applicable to systems requiring a wide variation in the torque conversion ratio, such as vehicles. It is difficult to realize a desired torque conversion ratio according to the driving conditions of the vehicle and the engine. As discussed above, a liquid Drive devices using liquid cannot be exempt from energy loss due to slippage occurring between the input shaft and the output shaft.

In engines that rotate the output shaft by a vibration force, such as internal combustion engines that generate mechanical energy through an intake, compression, combustion and exhaust cycle, the vibration force can be transmitted to the output shaft. When a drive device having such an engine for transmitting a vibration force is mounted in a vehicle, the vibration force transmitted to the output shaft undesirably vibrates the vehicle itself or other equipment arranged in the vehicle.

Some devices have been proposed to suppress the vibration of transmitted torque in the engine which rotates the output shaft by its vibration force. An example of such a device is provided with an engine which uses a flywheel attached to a crankshaft or output shaft of the engine as its rotor, as disclosed in JAPANESE PATENT LAYING-OPEN GAZETTE No. 61-155635. This system allows a torque having a reverse phase to that of the vibration torque transmitted to the crankshaft to be applied from the engine to the crankshaft via the flywheel, thereby reducing the vibration of the torque. In this system, however, the flywheel directly attached to the crankshaft of the engine, which is the source of torque vibration, is used to reduce the torque vibration. This results in a fairly small damping of the vibration component (i.e. a fairly small smoothing effect) and requires a large torque to compensate for the vibration component.

The vibration force influences the behavior of the object to be controlled, regulated or monitored in the method of controlling the motor or controlling the power transmission device. Protocol control determines the behavior based on the force oscillation and implements the undesired control based on the determined behavior.

The closest prior art document AU-A-58401/73 (see the preambles of claims 1, 7, 20 and 21) relates to a dual mode vehicle capable of running on conventional roads or on electric roads and comprising a heat engine, a motor and a generator. A vibration component cannot be dampened in such a vehicle.

Document EP-A-0 604 979 relates to a vibration damping control system for self-propelled vehicles which is effective to minimize a wide range of vehicle vibration generated by engine revolution. A controller operates a motor generator to provide torque vibration in an opposite phase to the vehicle vibration based on a phase difference between engine revolution and a frequency of the vehicle vibration. However, vibration components cannot be reduced in an arrangement comprising a clutch motor.

SUMMARY OF THE INVENTION

An object of the present invention is therefore to output a force generated by a motor to an output shaft with a high degree of efficiency or, alternatively, to use the force with a high degree of efficiency to output a torque in the direction of rotation of the output shaft of the motor.

Another object of the present invention is to eliminate a vibration component of the power output from the engine which rotates the output shaft by its vibration force.

The object is achieved by devices according to claims 1 and 7 and by methods according to claims 20 and 21.

More particularly, the above and other related objects of the present invention are at least partially realized by a first drive device for transmitting a power to an output shaft. The first drive device comprises: a motor having an output shaft, the motor rotating the output shaft by a vibration force thereof; target state determining means for setting a target state of the output shaft of the motor; motor control means for controlling an operation of the motor to make the output shaft of the motor reach the target state set by the target state determining means; output shaft state measuring means for measuring a state of the output shaft of the motor; a clutch motor comprising a first rotor connected to the output shaft of the motor and a second rotor connected to the output shaft, the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to each other, a force being transmitted between the output shaft of the motor and the output shaft via the electromagnetic connection of the first and second rotors; and a clutch motor control device for controlling a degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor and for changing or regulating or controlling the rotation of the second rotor relative to the first rotor to allow the state of the output shaft of the motor measured by the output shaft state measuring device to be within a predetermined range as an insensitivity range or a neutral zone or a dead zone which includes the target state set by the target state determination device.

The first drive device of the invention can reduce the vibration component of a force generated by the motor and output the force to the output shaft without or with reduced vibration. When the condition of the output shaft of the motor is in the predetermined range including the target state, the clutch motor control means is not activated to let the condition of the output shaft of the motor reach the target state. This implies that the predetermined state is a dead zone. Even if the vibration component of the force generated by the motor changes the condition of the output shaft of the motor, as long as the change is in the predetermined range including the target state, the clutch motor control means does not vary the degree of electromagnetic coupling of the first rotor with the second rotor in the clutch motor. The vibration component of the force is therefore not output to the output shaft. If the predetermined range is smaller than the range of a varied state or a changed condition of the output shaft of the motor due to the vibration of the force, the force is output to the output shaft with a reduced vibration.

According to an aspect of the first drive device, the predetermined range is a predetermined first range, and the clutch motor control means comprises means for controlling the clutch motor to allow the state of the output shaft of the motor to be in the predetermined first range while the state of the output shaft of the motor, which cher measured by the output shaft state measuring device lies in a predetermined second range which includes the predetermined first range.

According to another aspect of the first drive device, the condition of the output shaft of the engine is varied by the vibration force of the engine in the predetermined second range when the engine control means controls the operation of the engine to allow the condition of the output shaft to reach the target state set by the target state determining means.

According to yet another aspect of the first drive device, the state of the output shaft of the motor is a change in the rotational speed of the output shaft.

According to another aspect of the first drive device, the state of the output shaft of the motor is an initial state of a torque on the output shaft of the motor.

According to another aspect of the first drive device, the state of the output shaft of the motor is a difference between a rotation speed of the output shaft of the motor and a rotation speed of the output shaft.

According to one aspect of the present invention, a second drive device for transmitting a power to an output shaft comprises: a motor having an output shaft, the motor rotating the output shaft by a vibration force thereof; a target state determining means for setting a target state of the output shaft of the motor; a motor control means for controlling an operation of the motor to make the output shaft of the motor reach the target state set by the target state determining means; an output shaft state measuring means for measuring a state of the output shaft le of the engine; a clutch motor comprising a first rotor connected to the output shaft of the engine and a second rotor connected to the output shaft, the second rotor being coaxial and relatively rotatable with the first rotor, the first and second rotors being electromagnetically connected to each other, wherein a force is transmitted between the output shaft of the engine and the output shaft via the electromagnetic connection of the first and second rotors; a clutch motor control device for controlling a degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor and for changing or regulating the rotation of the second rotor relative to the first rotor to allow the state of the output shaft of the engine measured by the output shaft state measuring device to reach the target state set by the target state determining device; an auxiliary motor connected to the output shaft; and an auxiliary motor control device for controlling the auxiliary motor to cancel a vibration component of the power transmitted to the output shaft by the clutch motor.

According to an aspect of the second drive device, the auxiliary motor control means further comprises: vibration component measuring means for measuring the vibration component of the force transmitted to the output shaft, and vibration component reducing means for controlling the auxiliary motor to cancel the vibration component measured by the vibration component measuring means. In this arrangement, the vibration component measuring means may comprise means for measuring the vibration component of the force based on the degree of electromagnetic connection of the first rotor and the second rotor controlled by the clutch motor control means, or the vibration component measuring means may comprise means for measuring the vibration ation component of the force based on the state of the output shaft of the engine measured by the output shaft state measuring means. The vibration component reducing means may comprise means for controlling the auxiliary motor to allow the auxiliary motor to output a specific force to the output shaft, the specific force having the same magnitude as that of the vibration component of the force transmitted to the output shaft but having a phase difference of half the cycle of the vibration component.

According to an aspect of the second drive device, the auxiliary motor control means further comprises: vibration component measuring means for measuring the vibration component of the force transmitted to the output shaft; frequency calculating means for calculating a frequency of the vibration component of the force measured by the vibration component measuring means; sine wave applying means for subsequently controlling an amplitude and a phase of a sine wave having a frequency calculated by the frequency calculating means and turning on the auxiliary motor to apply the sine wave having the controlled amplitude and phase to the output shaft; and auxiliary power setting means for extracting an optimal sinusoidal power having an optimal amplitude and an optimal phase which reduces the vibration component of the force measured by the vibration component measuring means from the sinusoidal power subsequently applied by the sinusoidal power applying means and for setting an auxiliary force applied by the auxiliary motor to the output shaft. In this arrangement, the vibration component measuring means may comprise means for measuring the vibration component of the force based on a rotational state of the output shaft.

According to another aspect of the second drive device, the auxiliary motor control device further comprises: vibration component measuring means for measuring the vibration component of the power transmitted to the output shaft; frequency calculating means for calculating a frequency of the vibration component of the power transmitted to the output shaft based on the state of the output shaft of the motor measured by the output shaft state measuring means; sine power applying means for frequency calculating means for calculating a frequency of the vibration component of the power measured by the vibration component measuring means; a sinusoidal power applying means for subsequently controlling an amplitude and a phase of a sinusoidal power having a frequency calculated by the frequency calculating means and for turning on the auxiliary motor to apply the sinusoidal power having the controlled amplitude and phase to the output shaft; and an auxiliary power adjusting means for taking out an optimum sinusoidal power having an optimal amplitude and an optimum phase which reduces the vibration component of the force measured by the vibration component measuring means from the sinusoidal power subsequently applied by the sinusoidal power applying means and for adjusting an auxiliary force applied by the auxiliary motor to the output shaft.

According to still another aspect of the second drive device, the state of the output shaft of the motor is a rotation state of the output shaft.

According to another aspect of the second drive device, the state of the output shaft of the motor is an initial state of a torque on the output shaft of the motor.

According to another aspect of the second drive device, the state of the output shaft of the motor is a difference between a rotation speed of the output shaft of the motor and a rotation speed of the second rotor of the clutch motor.

According to another aspect of the present invention, a third drive device for transmitting a power to an output shaft comprises: a motor having an output shaft, the motor rotating the output shaft by a vibration force thereof; a target state determining means for setting a target state of the output shaft of the motor; a motor control means for controlling an operation of the motor to make the output shaft of the motor reach the target state set by the target state determining means; output shaft state measuring means for measuring a state of the output shaft of the motor; a complex motor comprising a first rotor connected to the output shaft of the motor, a second rotor connected to the output shaft, coaxial and relatively rotatable to the first rotor, and a stator for rotating the second rotor, the first rotor and the second rotor constituting a first motor, the second rotor and the stator constituting a second motor; a first motor control means for controlling a degree of electromagnetic connection of the first rotor and the second rotor in the first motor of the complex motor and for changing or regulating or controlling the rotation of the second rotor relative to the first rotor to allow the state of the output shaft of the motor measured by the output shaft state measuring means to be in a predetermined range as a dead zone which includes the target state set by the target state determining means; and a second motor control means for controlling the second motor in the complex motor.

The third drive device of the invention can output the power to the output shaft without or with at least reduced vibration. This arrangement in which the first motor is integrally connected to the second motor can reduce the weight and size of the entire drive device.

According to still another aspect of the present invention, a fourth drive device for transmitting power to an output shaft comprises: a motor having an output shaft, the motor rotating the output shaft by a vibration force thereof; target state determining means for setting a target state of the output shaft of the motor; motor control means for controlling an operation of the motor to make the output shaft of the motor reach the target state set by the target state determining means; output shaft state measuring means for measuring a state of the output shaft of the motor; a complex motor comprising a first rotor connected to the output shaft of the motor, a second rotor connected to the output shaft, coaxial and relatively rotatable to the first rotor, and a stator for rotating the second rotor, the first rotor and the second rotor constituting a first motor, the second rotor and the stator constituting a second motor; a first motor control device for controlling a degree of electromagnetic connection of the first rotor and the second rotor in the first motor of the complex motor and for regulating the rotation of the second rotor relative to the first rotor to allow the state of the output shaft of the motor measured by the output shaft state measuring device to reach the target state set by the target state determining device; and a second motor control device for controlling the second motor of the complex motor to control a vibration component of the To cancel or eliminate the force transmitted to the output shaft by the first motor of the complex engine.

The fourth drive device of the invention can transmit the power to the output shaft without or with at least reduced damping. This arrangement, in which the first motor is integrally connected to the second motor, can reduce the weight and size of the entire drive device.

According to another aspect of the present invention, a fifth drive device for transmitting a power to the output shaft may comprise: a motor having an output shaft, the motor rotating the output shaft by a vibration force thereof; a target state determining means for setting a target state of the output shaft of the motor; a motor control means for controlling an operation of the motor to make the output shaft of the motor reach the target state set by the target state determining means; an output shaft state measuring means for measuring a state of the output shaft of the motor; a complex motor comprising a first rotor connected to the output shaft of the motor, a second rotor connected to the output shaft, coaxial and relatively rotatable to the first rotor, and a stator for rotating the second rotor, the first rotor and the second rotor constituting a first motor, the second rotor and the stator constituting a second motor; a first motor control means for controlling a degree of electromagnetic connection of the first rotor and the second rotor in the first motor of the complex motor and for changing or regulating or controlling the rotation of the second rotor relative to the first rotor to enable the state of the output shaft of the motor measured by the output shaft state measuring means to be in a predetermined range as a deadband range or a neutral zone or a dead zone which includes the target state set by the target state determining means; and a second motor control means for controlling the second motor in the complex motor.

The fifth drive device of the invention can transmit the power to the output shaft without or with at least reduced vibration. This arrangement in which the first motor is integrally connected to the second motor can reduce the weight and size of the entire drive device.

The present invention is directed to a first method for controlling a drive device for transmitting a power to an output shaft. The first method comprises the steps of: (a) providing a motor having an output shaft, the motor rotating the output shaft by a vibration force therefrom, and a clutch motor comprising a first rotor connected to the output shaft of the motor and a second rotor connected to the output shaft, the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to each other, a power being transmitted between the output shaft of the motor and the output shaft via the electromagnetic connection of the first and second rotors; (b) setting a target state of the output shaft of the motor; (c) controlling an operation of the motor to make the output shaft of the motor reach the target state; (d) measuring a state of the output shaft of the motor; and (e) changing a degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor to allow the state of the output shaft of the motor to be in a predetermined range as a dead zone which includes the target state.

The present invention is further directed to a second method of controlling a drive device for transmitting a power to an output shaft. The second method comprises the steps of: (a) providing a motor having an output shaft, the motor rotating the output shaft by a vibration force thereof, a clutch motor comprising a first rotor connected to the output shaft of the motor and a second rotor connected to the output shaft, the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to each other, a power being transmitted between the output shaft of the motor and the output shaft via the electromagnetic connection of the first and second rotors, and an auxiliary motor connected to the output shaft; (b) setting a target state of the output shaft of the motor; (c) controlling an operation of the motor to allow the output shaft of the motor to reach the target state; (d) measuring a state of the output shaft of the motor; and (e) controlling a degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor to allow the state of the output shaft of the motor to reach the target state; and (f) controlling the auxiliary motor to cancel a vibration component of the power transmitted to the output shaft by the clutch motor.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic view showing an arrangement of a drive device 20 as a first embodiment embodiment according to the present invention,

Fig. 2 is a cross-sectional view showing detailed arrangements of a clutch motor 30 and an auxiliary motor 40 included in the drive device 20 of Fig. 1,

Fig. 3 is a schematic view showing a general structure of a vehicle with the drive device 20 of Fig. 1 incorporated therein,

Fig. 4 is a graphical representation showing the basic operation of the drive device 20,

Fig. 5 is a flowchart showing a torque control routine executed by the controller 80;

6 and 7 are flowcharts showing details of the control process of the clutch motor 30 executed in step S108 in the flowchart of Fig. 5;

Fig. 8 shows an oscillation of the torque Te and the speed Ne of the motor 50;

Fig. 9 is a graphical representation showing the process of feedback control;

10 and 11 are flowcharts showing details of the control process of the assist motor 40 executed in step S110 in the flowchart of FIG. 5;

Fig. 12 is a flowchart showing a part of the control method of the clutch motor 30 performed by the controller 80 in a drive device 20B a second embodiment according to the present invention;

Fig. 13 is a flowchart showing a part of the control process of the assist motor 40 executed by the controller 80 in the drive device 20B of the second embodiment;

Fig. 14 shows the rotation speed Ne of the motor 50, the torque Tc of the clutch motor 30, the torque Ta of the auxiliary motor 40 and the torque Td transmitted to the output shaft 22 when the motor 50 is in a stationary driving state at the set driving points of the target motor torque Te* and the target motor rotation speed Ne* in the second embodiment;

Fig. 15 is a flowchart showing a part of the control process of the assist motor 40 executed by the controller 80 in a drive device 20C of a third embodiment according to the invention;

Fig. 16 is a flowchart showing a sinusoidal power torque determination routine executed by the controller 80 of the drive device 20C of the third embodiment;

Fig. 17 schematically illustrates a drive device 20D as a modification of the drive devices of the first to third embodiments;

Fig. 18 schematically shows another drive device 20E as a modification of the first embodiment;

Fig. 19 schematically shows a drive device 20F as another modification of the first embodiment;

and

Fig. 20 schematically shows a drive device 20G as still another modification of the first embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Fig. 1 is a schematic view showing the arrangement of a drive device 20 as a first embodiment according to the present invention; Fig. 2 is a cross-sectional view showing the detailed arrangements of a clutch motor 30 and an auxiliary motor 40 included in the drive device 20 of Fig. 1; and Fig. 3 is a schematic view showing a general structure of a vehicle having the drive device 20 of Fig. 1 included therein. The general arrangement of the vehicle will be described first for better understanding.

Referring to Fig. 3, the vehicle is provided with an engine 50 driven by gasoline as a power source. The air taken in from an air supply system via a throttle valve 66 is mixed with fuel, i.e., gasoline in this embodiment, injected from a fuel injection valve 51. The air/fuel mixture is supplied to a combustion chamber 52 to be explosively ignited and burned. A linear motion of the piston 54, which is pushed down by the explosion of the air/fuel mixture, is converted into a rotary motion of a crankshaft 56. The throttle valve 66 is driven to open and close a moving member 68. A spark plug 62 converts a high voltage which is applied by an ignition device 58 via a distributor 60 to a spark plug which explosively ignites and burns the air/fuel mixture.

The operation of the engine 50 is controlled by an electronic control unit (hereinafter referred to as EFIECU) 70. The EFIECU 70 receives information from various sensors that detect the operating conditions of the engine 50. These sensors include a throttle valve position sensor 67 for detecting the position of the throttle valve 66, a total vacuum sensor 72 for measuring a load applied to the engine 50, a water temperature sensor 74 for measuring the temperature of cooling water in the engine 50, and a speed sensor 76 and an angle sensor 78 mounted on the distributor 60 for measuring the rotational speed and the rotational angle of the crankshaft 56. A start switch 79 for detecting a start state ST of an ignition key (not shown) is also connected to the EFIECU 70. Other sensors and switches connected to the EFIECU 70 are omitted from the drawings.

The crankshaft 56 of the engine 50 is connected to an output shaft 22 via a clutch motor 30 and an auxiliary motor 40 (described in detail later). The output shaft 22 further connects a differential gear 24 which optionally transmits the torque output from the output shaft 22 of the drive device 20 to the left and right drive wheels 26 and 28. The clutch motor 30 and the auxiliary motor 40 are driven and controlled by a controller 80. The controller 80 includes an internal control CPU and receives inputs from a shift lever position sensor 84 attached to a shift lever 82 and an acceleration position sensor 65 attached to an accelerator pedal 64, as described in detail later. The controller 80 sends and receives a variety of data and information to and from the EFIECU 70 by means of communication. Details of the control process including a communication protocol will be described later.

With reference to Fig. 1, the drive device 20 essentially comprises the engine 50, the clutch motor 30 with an outer rotor 32 and an inner rotor 34, the auxiliary motor 40 with a rotor 42 and the control device 80 for driving and controlling the clutch motor 30 and the auxiliary motor 40. The outer rotor 32 of the clutch motor 30 is mechanically connected to the crankshaft 56 of the engine 50, while its inner rotor 34 is mechanically connected to the rotor 42 of the auxiliary motor 40.

As shown in Fig. 1, the clutch motor is designed as a synchronous motor having permanent magnets 35 fixed to an inner surface of the outer rotor 32 and three-phase coils 36 wound on slots formed in the inner rotor 34. Power is supplied to the three-phase coils 36 via a rotary transformer 38. A thin laminated sheet of non-directional electromagnetic steel is used to form projections and slots for the three-phase coils 36 in the inner rotor 34. A resolver 39 for measuring a rotation angle θe of the crankshaft 56 is fixed to the crankshaft 56. The resolver 39 can also serve as the angle sensor 78 mounted on the distributor 60.

The auxiliary motor 40 is also designed as a synchronous motor having three-phase coils 44 wound on a stator 43 fixed to a housing 45 to generate a rotating magnetic field. The stator 43 is also made of a thin laminated sheet of non-directional electromagnetic steel. A plurality of permanent magnets 46 are attached to an outer surface of the rotor 42. In the auxiliary motor 40, an interaction between a magnetic field formed by the permanent magnets 46 and a rotating magnetic field formed by the three-phase coils 44 results in rotation of the rotor. tors 42. The rotor 42 is mechanically connected to the output shaft 22 which functions as a torque output shaft of the drive device 20. A resolver 48 for measuring a rotation angle θd of the output shaft 22 is attached to the output shaft 22, which is further supported by a bearing 49 held in the housing 45.

The inner rotor 34 of the clutch motor 30 is mechanically connected to the rotor 42 of the auxiliary motor 40 and further to the output shaft 22. When the rotation and axial torque of the crankshaft 56 of the engine 50 are transmitted to the inner rotor 34 of the clutch motor 30 via the outer rotor 32, the rotation and torque are added to or subtracted from the transmitted rotation and torque by the auxiliary motor 40.

While the auxiliary motor 40 is designed as a conventional three-phase permanent magnet type synchronous motor, the clutch motor 30 comprises two rotating elements or rotors, i.e., the outer rotor 32 with the permanent magnets 35 and the inner rotor 34 with the three-phase coils 36. The detailed structure of the clutch motor 30 will be described with reference to the cross-sectional view of Fig. 2. The outer rotor 32 of the clutch motor 30 is fixed to a peripheral end of a wheel 57 rotating around the crankshaft 56 by means of a thrust bolt 59a and a screw 59b. A central portion of the wheel 57 protrudes to form a shaft-shaped member to which the inner rotor 34 is rotatably fixed by means of bearings 37A and 37B. One end of the output shaft 22 is fixed to the inner rotor 34.

A plurality of permanent magnets 35, four in this embodiment, are fixed to the inner surface of the outer rotor 32, as mentioned above. The permanent magnets 35 are magnetized toward the axial center of the clutch motor 30 and have magnetic poles of alternately opposite directions. The three-phase coils 36 of the inner rotor 34, which face the permanent magnets 35 with a small gap, are wound on a total of 24 slots (not shown) formed in the inner rotor 34. Supply of electricity to the respective coils generates magnetic fluxes that pass through the protrusions (not shown) separating the slots from each other. Supply of a three-phase alternating current to the respective coils rotates this magnetic field. The three-phase coils 36 are connected to receive electric power supplied from the rotary transformer 38. The rotary transformer 38 includes primary windings 38a fixed to the housing 45 and secondary windings 38b fixed to the output shaft 22 coupled to the inner rotor 34. Electromagnetic induction allows electric current to be transferred from the primary windings 38a to the secondary windings 38b or vice versa. The rotary transformer 38 has windings for three phases, ie, the U, V and W phases, to enable the transfer of three-phase electric currents.

Mutual influence of a magnetic field formed by an adjacent pair of permanent magnets 35 and a rotating magnetic field formed by the three-phase coils 36 of the inner rotor 34 results in a variety of behaviors of the outer rotor 32 and the inner rotor 34. The frequency of the three-phase alternating current supplied to the three-phase coils 36 is generally equal to a difference between the rotational speed (revolutions per second) of the outer rotor 32 directly connected to the crankshaft 56 and the rotational speed of the inner rotor 34. This results in a slip between the rotations of the outer rotor 32 and the inner rotor 34. Details of the control operations of the clutch motor 30 and the auxiliary motor 40 will be described later using the flow charts.

As mentioned above, the clutch motor 30 and the auxiliary motor 40 are driven and controlled by the controller 80. Now returning to Fig. 1, the controller 80 includes a first drive circuit 91 for driving the clutch motor 30, a second drive circuit 92 for driving the auxiliary motor 40, a control CPU 90 for controlling the first and second drive circuits 91 and 92, and a battery 94 including a number of secondary cells. The control CPU 90 is a one-chip microprocessor including a RAM 90a used as a working memory, a ROM 90b in which various control programs are stored, an input/output port (not shown), and a serial communication port (not shown) through which data is sent to and received from the EFIECU 70. The control CPU 90 receives a variety of data through the input/output interface. The input data includes a rotation angle θe of the crankshaft 56 of the engine 50 from the function sensor 39, a rotation angle θd of the output shaft 22 from the function sensor 48, an accelerator pedal position AP (pressure amount of the accelerator pedal 64) from the accelerator pedal position sensor 65, a shift lever position SP from the shift lever position sensor 84, currents Iuc and Ivc of the clutch motor from two ammeters or ampere-hour meters 95 and 96 in the first drive circuit 91, currents Iua and Iva of the auxiliary motor from two ammeters or ampere-hour meters 97 and 98 in the second drive circuit 92, and a remaining capacity BRM of the battery 94 from a remaining capacity meter 99. The remaining capacity meter 99 can measure the remaining capacity BRM of the battery 94 by any known method, for example, by measuring the specific gravity of a electrolytic solution in the battery 94 or the total weight of the battery 94, by calculating the currents and charging and discharging times or by causing an instantaneous short circuit between terminals of the battery and measuring the internal resistance resistance to the electric current.

The control CPU 90 outputs a first control signal SW1 for driving six transistors Tr1 to Tr6 which function as circuit elements of the first drive circuit 91, and a second control signal SW2 for driving six transistors Tr11 to Tr16 which function as circuit elements for the second drive circuit 92. The six transistors Tr1 to Tr6 in the first drive circuit 91 form a transistor inverter and are arranged in pairs to function as a source and a sink with respect to a pair of power lines P1 and P2. The three-phase coils (U, V, W) 36 of the clutch motor 30 are connected to the corresponding contacts of the paired transistors via the rotary transformer 38. The power lines P1 and P2 are connected to plus and minus terminals of the battery 94, respectively. The first control signal SW1 output from the control CPU 90 sequentially controls the turn-on time of the paired transistors Tr1 to Tr6. The electric current flowing through each coil 36 undergoes PWM (Pulse Width Modulation) to generate a quasi-sinusoidal oscillation, which allows the three-phase coils 36 to form a rotating magnetic field.

The six transistors Tr11 to Tr16 in the second drive circuit 92 also form a transistor inverter and are arranged in the same manner as the transistors Tr1 to Tr6 in the first drive circuit 91. The three-phase coils (U, V, W) 44 of the auxiliary motor 40 are connected to the corresponding contacts of the paired transistors. The second control signal SW2 output from the control CPU 90 sequentially controls the on-time of the paired transistors Tr11 to Tr16. The electric current flowing through each coil 44 undergoes PWM to generate a quasi-sinusoidal oscillation, which allows the three-phase coils 44 to form a rotating magnetic field.

The drive device 20 thus configured operates according to the operating principles described below, in particular the principle of torque conversion. For example, it is assumed that the motor 50 driven by the EFIECU 70 rotates at a speed Ne equal to a predetermined value N1. While the transistors Tr1 to Tr6 in the first drive circuit 91 are in an OFF position, the controller 80 does not supply current to the three-phase coils 36 of the clutch motor 30 via the rotary transformer 38. No supply of electric current causes the outer rotor 32 of the clutch motor 30 to be electromagnetically separated from the inner rotor 34. This causes the crankshaft 56 of the engine 50 to spin. Under the condition that all transistors Tr1 to Tr6 are in the OFF position, no regeneration of energy occurs from the three-phase coils 36 and the engine 50 is kept in an idle state.

When the control CPU 90 of the controller 80 outputs the first control signal SW1 to turn on and off the transistors Tr1 to Tr6 in the first drive circuit 91, a constant electric current based on the difference between the rotational speed Ne of the crankshaft 56 of the engine 50 and a rotational speed Nd of the output shaft 22 (i.e., a difference Nc(=Ne-Nd) between the rotational speed of the outer rotor 32 and that of the inner rotor 34 in the clutch motor 30) is passed through the three-phase coils 36 of the clutch motor 30. Accordingly, a certain slip exists between the outer rotor 32 and the inner rotor 34 which are connected to each other in the clutch motor 30. At this time, the inner rotor 34 rotates at the rotation speed Nd which is smaller than the rotation speed Ne of the crankshaft 56 of the engine 50. In this state, the clutch motor 30 operates as a generator and performs the regenerative operation to regenerate an electric power via the first drive circuit 91. In order to allow the auxiliary motor 40 to generate an energy identical to the electric energy which In order to consume the power regenerated by the clutch motor 30, the control CPU 90 controls on and off the transistors Tr11 to Tr16 in the second drive circuit 92. The on/off control of the transistors Tr11 to Tr16 allows an electric current to flow through the three-phase coils 44 of the assist motor 40, and thus the assist motor 40 performs the current operation to generate a torque.

Referring to Fig. 4, while the crankshaft 56 of the engine 50 is driven at a speed N1 and a torque T1, an energy in a range G1 is regenerated as an electric current by the clutch motor 30. The regenerated current is supplied to the auxiliary motor 40 and converted into an energy in a range G2 which enables the output shaft 22 to rotate at a speed N2 and a torque T2. The torque conversion is carried out in the manner discussed above, and the energy is thus generated as a torque to the output shaft 22 in accordance with the slip in the clutch motor 30 or the speed difference Nc (=Ne-Nd).

In another example, it is assumed that the motor 50 is driven at a speed Ne=N2 and a torque Te=T2, and the output shaft 22 is rotated at the speed N1 which is greater than the speed N2. In this state, the inner rotor 34 of the clutch motor 30 rotates relative to the outer rotor 32 in the rotation direction of the output shaft 22 at a speed defined by the absolute value of the speed difference Nc (=Ne-Nd). When operating as a normal motor, the clutch motor 30 consumes electric power to apply the energy of rotation to the output shaft 22. When the control CPU 90 of the controller 80 controls the second drive circuit 92 to allow the auxiliary motor 40 to regenerate electric power, a slip between the rotor 42 and the stator 43 of the auxiliary motor 40 causes the regenerative current to flow through the three phase coils 44. To allow the clutch motor 30 to consume the energy regenerated by the auxiliary motor 40, the control CPU 90 controls the first drive circuit 91 and the second drive circuit 92. This allows the clutch motor 30 to be driven without using an electric current stored in the battery 94.

Returning to Fig. 4, when the crankshaft 56 of the engine 50 is driven at the speed N2 and the torque T2, the energy in the sum of the areas G2 and G3 is regenerated as an electric current by the auxiliary motor 40 and supplied to the clutch motor 30. Supply of regenerated current enables the output shaft 22 to rotate at the speed N1 and the torque T1.

Unlike the torque conversion and speed conversion discussed above, the drive device 20 of the embodiment can charge the battery 94 with a surplus of electric energy or discharge the battery 94 to supplement the electric energy. This is implemented by controlling the mechanical energy output from the motor 50 (i.e., the product of the torque Te and the speed Ne), the electric energy regenerated or consumed by the clutch motor 30, and the electric energy regenerated or consumed by the auxiliary motor 40. The output energy from the motor 50 can therefore be transmitted as power to the output shaft 22 with a higher efficiency.

The torque conversion discussed above is carried out according to a torque control method shown in the flow chart of Fig. 5. When the program starts the torque control routine, the control CPU 90 of the controller 80 first receives data of the rotational speed NTd of the output shaft 22 in step S100. The rotational speed Nd of the output shaft 22 can be obtained from the function generator 48. In subsequent step S101, control CPU 90 reads accelerator pedal position AP from accelerator pedal position sensor 65. The driver depresses accelerator pedal 64 when ineffectiveness of torque output is sensed. The accelerator pedal position AP value accordingly corresponds to the desired output torque (i.e., the desired torque of output shaft 22) desired by the driver. The program then proceeds to step S102, in which control CPU 90 calculates a target output torque (of output shaft 22) Td* corresponding to accelerator pedal position input AP. Target output torque Td* is thus referred to as the torque output control value. Torque output control values Td* have been previously set for the respective accelerator pedal positions AP. In response to an accelerator pedal position input AP, the torque output control value Td* corresponding to the accelerator pedal position input AP is taken from the preset torque output control values Td*.

In step S103, an amount of energy Pd to be applied to the output shaft 22 is calculated according to the expression Pd=Td*xNd, that is, the extracted torque output control value Td* (of the output shaft 22) is multiplied by the speed input Nd of the output shaft 22. The program then proceeds to step S104, in which the control CPU 90 sets a target motor torque Te* and a target motor speed Ne* of the motor 50 based on the energy output Pd thus obtained. It is assumed here that all the energy Pd to be output from the output shaft 22 is supplied from the motor 50. Since the mechanical energy supplied by the motor 50 is equal to the product of the torque Te and the speed Ne of the motor 50, the relationship between the energy output Pd and the target motor torque Te* and the target motor speed Ne* can be expressed as Pd=Te*xNe*. However, numerous combinations of the target motor torque Te* and the target motor speed Ne* are possible. which satisfy the above relationship. In this embodiment, an optimal combination of the target motor torque Te* and the target motor speed Ne* is selected in order to realize operation of the motor 50 with the highest possible efficiency.

In subsequent step S106, the control CPU 90 determines a torque control value Tc* of the clutch motor 30 based on the target motor torque Te* set in step S104. In order to keep the rotation speed Ne of the motor 50 at a substantially constant level, it is desirable to set the torque of the clutch motor 30 equal to the torque of the motor 50. The process in step S106 accordingly sets the torque control value Tc* of the clutch motor 30 equal to the target motor torque Te*.

After setting the torque control value Tc* of the clutch motor in step S106, the program proceeds to steps S108, S110, and S111 to control the clutch motor 30, the auxiliary motor 40, and the motor 50, respectively. Advantageously, the control operations of the clutch motor 30, the auxiliary motor 40, and the motor 50 are shown as separate steps. In the current method, however, these control operations are comprehensively executed. For example, the control CPU 90 simultaneously controls the clutch motor 30 and the auxiliary motor 40 by an interrupt process while passing an instruction to the EFIECU 70 through communication to simultaneously control the motor 50.

6 and 7 are flowcharts showing details of the control process of the clutch motor 30 which is executed in step S108 in the flowchart of Fig. 5. When the program starts with the clutch motor routine, the control CPU 90 of the controller 80 first determines in step S120 whether the target motor torque Te* or the target motor speed Ne* of the motor 50 has been changed from the corresponding data of the previous cycle. The Target engine torque Te* and target engine speed Ne* are varied with a change in accelerator pedal position AP (that is, a change in a depression amount of accelerator pedal 64 by the driver) or with a change in a driving point of engine 50 by another reason. When the driving point of engine 50 has been changed, the program determines in step S120 that target engine torque Te* or target engine speed Ne* of engine 50 has been changed from the previous data and proceeds to step S134 in the flowchart of Fig. 7.

The control CPU 90 first reads the rotation angle θd of the output shaft 22 from the function encoder 48 in step S134 and the rotation angle θe of the crankshaft 56 of the engine 50 from the function encoder 39 in step S136. The control CPU 90 then calculates a relative angle θc of the output shaft 22 and the crankshaft 56 by the equation θc=θe-θd in step S138.

The program proceeds to step S140, in which the control CPU 90 receives inputs of the clutch motor currents Iuc and Ivc flowing through the U-phase and V-phase of the three-phase coils 36 in the clutch motor 30, respectively, from the ammeters 95 and 96. Although the currents naturally flow through all three phases U, V and W, measurement is only required for the currents passing through the two phases since the sum of the currents is zero. In subsequent step S142, the control CPU 90 performs a transformation of coordinates (a three-phase to a two-phase transformation) using the values of the currents flowing through the three phases obtained in step S140. The transformation of coordinates maps the values of currents flowing through the three phases to the values of currents passing through d and q axes of the permanent magnet type synchronous motor and is carried out according to equation (1) given below:

The transformation of coordinates is performed because the currents flowing through the d- and q-axes are essential for the torque control in the permanent magnet type synchronous motor.

Alternatively, the torque control may be carried out directly with the currents flowing through the three phases. After transforming into the currents of the two axes, the control CPU 90 calculates deviations of the currents Idc and Iqc actually flowing through the d and q axes from the current control values Idc* and Iqc* of the respective axes calculated from the torque control value Tc* of the clutch motor 30, and determines voltage control values Vdc and Vqc for the d and q axes in step S144. According to a concrete method, the control CPU 90 carries out operations following the equations (2) and (3) below:

ΔIdc = Idc* - Idc

ΔIqc = Iqc* - Iqc.......... (2)

Vdc = Kp1 · ΔIdc + ΣKi1 · ΔIdc

Vqc = Kp2 · ΔIqc + XKi2 · ΔIqc......... (3)

where Kp1, Kp2, Ki1 and Ki2 represent coefficients which are adjusted to suit the characteristics of the motor used. The voltage control value Vdc (Vqc) includes a part in proportion to the deviation ΔI from the current control value I* (first term on the right side of equation (3)) and a summation of historical data of the Deviations ΔI for "i" times (second expression on the right side).

The control CPU 90 then reverse transforms the coordinates of the voltage control values thus obtained (a two-phase to a three-phase transformation) in step S146. This corresponds to an inversion of the transformation performed in step S142. The reverse transformation determines voltages Vuc, Vvc and Vwc actually applied to the three-phase coils 36 as given below:

The actual voltage control is accompanied by an on-off operation of the transistors Tr1 to Tr6 in the first drive circuit 91. In step S148, the on-and-off time of the transistors Tr1 to Tr6 in the first drive circuit 91 is PWM (Pulse Width Modulation) controlled to obtain the voltage control values Vuc, Vvc and Vwc determined by the above equation (4).

On the other hand, when the clutch motor control is performed at a fixed driving point of the motor 50, the program determines in step S120 in the flowchart of Fig. 6 that neither the target motor torque Te* nor the target motor speed Ne* of the motor 50 has been changed from the previous data and proceeds to step S122 to obtain data of the speed Ne of the motor 50. The speed Ne of the motor 50 may be calculated from the rotation angle θe of the crankshaft 56 read by the resolver 39 or directly measured by the speed sensor 76 mounted on the distributor 60. In the latter case, the Control CPU 90 data of the speed Ne of the engine 50 by communicating with the EFIECU 70 which is connected to the speed sensor 76.

The control CPU 90 calculates a deviation ΔNe by subtracting the input speed Ne from the target motor speed Ne* in step S124. The absolute deviation value ΔNe is compared with a first threshold Nref1 in step S126 and then with a second threshold Nref2 in step S128. The first threshold Nref1 is used to define a range in which the motor 50 is assumed to be in a stationary driving state at the specified driving point. When the speed Ne is in this range, i.e., in the range (target motor speed Ne* - first threshold Nref1) to (target motor speed Ne* + first threshold Nref1), feedback control is performed to ensure stable driving of the motor 50. The rotation speed Ne of the motor 50 is controlled with the feedback data of the transmitted torque Tc of the clutch motor 30 (i.e., the torque Te* of the motor 50), as will be described in detail later. The range in which the motor 50 can be assumed to be in a stationary driving state at the specified driving point is determined depending on the type, characteristics and driving point of the motor 50. The first threshold value Nref1 is therefore individually set by taking such characteristics of the motor 50 into account.

The second threshold value Nref2 is used to define a neutral zone or dead zone from the target motor speed Ne* in the feedback control. The neutral zone or dead zone is set to compensate for the vibration components of the speed Ne (unevenness or wide variation in one rotation) due to vibration outputs of the motor 50 (output sions in the intake, compression, combustion and exhaust cycles) when the engine 40 is driven at the target engine torque Te* and the target engine speed Ne*. Fig. 8 shows pulsation of the torque Te and the speed Ne of the engine 50. In this embodiment, the second threshold value Nref2 is set to be slightly larger than the amplitude of the wave of the pulsation speed Ne, as clearly seen in Fig. 8. The pulsation components of the speed Ne vary depending on the type, characteristics and driving point of the engine 50. The second threshold value Nref2 is therefore individually set by taking such characteristics of the engine 50 into consideration.

If the absolute deviation value ΔNe is larger than the first threshold value Nref1 in step S126, the program determines that the motor 50 has not yet reached a steady-state driving state and proceeds to step S134 in the flowchart of Fig. 7. If the absolute deviation value ΔNe is not larger than the first threshold value Nref1 in step S126, but is larger than the second threshold value Nref2 in step S128, the control CPU 90 sets a new torque control value Tc* of the clutch motor 30 in step S130. The new torque control value Tc* is determined by subtracting the product of a control gain Kn and the deviation ΔNe from the existing data of a torque control value Tc* set in the previous cycle of the clutch motor control:

Tc* = Previous Tc* - Kn · ΔNe (5)

In the case that the output energy Pd of the motor 50 is constant, the torque Te of the motor 50 is equal to the torque Tc of the clutch motor 30. The output energy Pd is equal to the product of the speed Ne and the torque Te of the motor 50. The speed Ne of the motor 50 is therefore inversely proportional to the torque Tc of the clutch motor 30. This is the reason why the new torque control value Tc* is calculated according to the equation (5) given above in step S130. The feedback control of the rotation speed Ne of the motor 50 can achieve stable driving of the motor 50.

If the absolute deviation value ΔNe is not larger than the second threshold value Nref2 in step S128, the existing data of a torque control value Tc* is on the other hand set as a new torque control value Tc* in step S132. After processing either step S130 or step S132, the program proceeds to step S134 in the flowchart of Fig. 7.

Fig. 9 is a graph showing the concrete process of steps S126 to S132. When the target engine torque Te* and the target engine speed Ne* of the engine 50 are set, the torque Tc of the clutch motor 30 is set equal to the target engine torque Te*. The engine 50 is simultaneously controlled to obtain the target engine torque Te* and the target engine speed Ne* by the engine control process (control of the throttle valve position, fuel injection, and spark ignition by the EFIECU 70, as described later) performed in step S111 in the torque control routine of Fig. 5. When the motor 50 enters the region of a stationary driving state, that is, when the rotation speed Ne enters the range of (target motor speed Ne* - first threshold Nref1) to (target motor speed Ne* + first threshold Nref1), the rotation speed Ne of the motor 50 is controlled on the curve of a constant output energy Pd (Pd = TcxNe) with the feedback data of a transmitted torque Tc of the clutch motor 30 (that is, the torque Te of the motor 50). When the rotation speed Ne of the motor 50 enters the insensitivity region or the neutral zone or the dead zone which is defined by the range of (target motor speed Ne* - second threshold Nref2) to (target motor speed Ne* + second threshold Nref2), that is, when the speed Ne enters the box-shaped region in the graph of Fig. 9, no feedback control is performed, but the speed Ne is maintained in this state. When no feedback control is performed based on the vibration components of the speed Ne (unevenness or wide variation in one rotation), no vibration outputs are transmitted to the output shaft 22.

The torque control value Tc* is positive when a positive torque is applied to the output shaft 22 in the rotation direction of the crankshaft 56. For example, it is assumed that a positive value is set to the torque control value Tc*. When the rotational speed Ne of the motor 50 is greater than the rotational speed Nd of the output shaft 22 in this assumption, that is, when the rotational speed difference Nc (=Ne-Nd) is positive, the clutch motor 30 is controlled to perform the regenerative operation and generate a regenerative current corresponding to the rotational speed difference Nc. On the other hand, when the rotational speed Ne of the motor 50 is smaller than the rotational speed Nd of the output shaft 22, that is, when the rotational speed difference Nc (=Ne-Nd) is negative, the clutch motor 30 is controlled to perform the current operation and rotate relative to the crankshaft 56 in the rotational direction of the output shaft 22 at a speed defined by the absolute value of the rotational speed difference Nc. For the positive torque control value Tc*, the regenerative operation and the current operation of the clutch motor 30 perform the identical switching control. According to a concrete method, the transistors Tr1 to Tr6 of the first drive circuit 91 are controlled to allow a positive torque to be applied to the output shaft 22 by the combination of the magnetic field generated by the permanent magnets 35 applied to the outer rotor 32 with the rotating magnetic field generated by the currents flowing through the three-phase coils 36 on the inner rotor 34 in the clutch motor 30. The identical switching control is carried out for the regenerative operation and the current operation of the clutch motor 30 as long as the sign of the torque control value Tc* is not changed. The clutch motor control routine of Figs. 6 and 7 is therefore applicable to the regenerative operation and the current operation. Under the condition of braking of the output shaft 22 or reverse movement of the vehicle, the torque control value Tc* has a negative sign. The clutch motor control routine of Figs. 6 and 7 is therefore applicable to the control operation under such conditions when the relative angle θc is varied in the reverse direction in step S138.

10 and 11 are flowcharts showing details of the control process of the auxiliary motor 40 executed in step S110 in the flowchart of Fig. 5. Referring to the flowchart of Fig. 10, when the program enters the auxiliary motor control routine, the control CPU 90 of the controller 80 first receives data of the rotational speed Nd of the output shaft 22 in step S150. The rotational speed Nd of the output shaft 22 is calculated from the rotational angle θd of the output shaft 22 read from the function generator 48. The control CPU 90 then receives data of the rotational speed Ne of the motor 50 in step S152.

A speed difference Nc between the speed input Nd of the output shaft 22 and the speed input Ne of the motor 50 is calculated according to the equation Nc=Ne-Nd in step S154. In the following step S156, the electric current (energy) Pc regenerated or consumed by the clutch motor 30 is calculated according to the given equation (6):

Pc = Ksc · Nc · Tc (6)

where Ksc represents the efficiency of a regenerative operation or a current operation in the clutch motor 30. The Product NcxTc defines the current corresponding to the area G1 in the graphical representation of Fig. 4, where Nc and Tc denote the speed difference and the actual torque generated by the clutch motor 30, respectively.

In step S158, a torque control value Ta* of the assist motor 40 is determined by the given equation (7):

Ta* = Ksa · Pc/Nd (7)

where Ksa represents the efficiency of the regenerative operation or the current operation in the auxiliary motor 40. The thus obtained torque control value Ta* of the auxiliary motor 40 is compared with a maximum torque Tamax which potentially loads the auxiliary motor 40 in step S160. If the torque control value Ta* exceeds the maximum torque Tamax, the program jumps to step S162 in which the torque control value Ta* is limited to the maximum torque Tamax.

After the torque control value Ta* is set equal to the maximum torque Tamax in step S162 or after the torque control value Ta* is determined not to exceed the maximum torque Tamax in step S160, the program proceeds to step S164 in the flowchart of Fig. 11. The control CPU 90 reads the rotation angle θd of the output shaft 22 from the function generator 48 in step S164 and receives data of the auxiliary motor currents Iua and Iva flowing through the U-phase and the V-phase of the three-phase coils 44 in the auxiliary motor 40, respectively, from the ammeters 97 and 98 in step S166. The control CPU 90 then performs a transformation of coordinates for the currents of the three phases in step S168, calculates voltage control values Vda and Vqa in step S170, and performs an inverse transformation of coordinates for the voltage control values in step S172. In the following step S174, the control CPU 90 determines the on and off time of the Transistors Tr11 to Tr16 in the second drive circuit 92 for PWM (Pulse Width Modulation) control. The processing performed in steps S168 to S174 is similar to that performed in steps S142 to S148 of the clutch motor control routine shown in the flowchart of Figs. 6 and 7.

The auxiliary motor 40 is subject to the current operation for the positive torque control value Ta* and to the regenerative operation for the negative torque control value Ta*. Like the current operation and the regenerative operation of the clutch motor 30, the auxiliary motor control routine of Figs. 10 and 11 is applicable to the current operation and the regenerative operation of the auxiliary motor 40. This is also true when the output shaft 22 rotates in the opposite direction of the crankshaft 56, i.e., when the vehicle is moving backward. The torque control value Ta* of the auxiliary motor 40 is positive when a positive torque is transmitted to the output shaft 22 in the rotational direction of the crankshaft 56.

The control of the engine 50 (step S111 in Fig. 5) is performed in the following manner. In order to obtain stationary drive with the target engine torque Te* and the target engine speed Ne* (set in step S104 in Fig. 5), the control CPU 90 controls the torque Te and the speed Ne of the engine 50 to approximate the target engine torque Te* and the target engine speed Ne*, respectively. According to a concrete method, the control CPU 90 sends an instruction to the EFIECU 70 through communication to control the amount of fuel injection or the throttle valve position. Such control eventually makes the torque Te and the speed Ne of the engine 50 approximate the target engine torque Te* and the target engine speed Ne*.

This procedure allows the output (TexNe) of the motor 50 to perform a free torque conversion and to if to be transmitted to the output shaft 22.

In the arrangement of the first embodiments, when the rotation speed Ne of the motor 50 is in the range of (target motor speed Ne* - first threshold Nref1) to (target motor speed Ne* + first threshold Nref1), the rotation speed Ne is controlled with the feedback data of the torque Tc of the clutch motor 30. The motor 50 is then constantly driven at the drive point of the target motor torque Te* and the target motor speed Ne*. When the rotation speed Ne of the motor 50 is in the range of (target motor speed Ne* - second threshold Nref2) to (target motor speed Ne* + second threshold Nref2), no feedback control of the rotation speed Ne based on the torque Tc of the clutch motor 30 is performed. The unevenness in rotation of the crankshaft 56 (vibration torque) due to vibration outputs of the engine 50 is accordingly not transmitted to the output shaft 22. This effectively prevents the vehicle from being vibrated by the vibration outputs of the engine 50, ensuring improved drivability.

In the first embodiment, the rotation speed Ne of the motor 50 is feedback-controlled by the torque Tc of the clutch motor 30 when the rotation speed Ne is in the range (Ne* - Nref1) to (Ne* + Nref1). However, an alternative arrangement may determine only the non-feedback control zone (the range (Ne* - Nref2) to (Ne* + Nref2)) without setting the first threshold value Nref1.

A second embodiment of the present invention is realized by a drive device 20B having the hardware identical to that of the drive device 20 of the first embodiment. A description of the concrete hardware arrangement and the essential operating principles of the drive device 20B of the second embodiment is accordingly omitted. The symbols used in the description of the first embodiment have the same meaning in the second embodiment unless otherwise specified.

The drive device 20B of the second embodiment also performs the torque control routine of Fig. 5 which is performed by the controller 80 of the drive device 20 of the first embodiment. However, in the second embodiment, the process of step S108 in the flowchart of Fig. 5 is followed by the clutch motor control routine of Figs. 12 and 7 instead of the clutch motor control routine of Figs. 6 and 7 in the first embodiment. The process of step S110 in the flowchart of Fig. 5 is followed by the auxiliary motor control routine of Figs. 13 and 11 instead of the auxiliary motor control routine of Figs. 10 and 11 in the first embodiment. The following mainly describes the different points of the clutch motor control and the auxiliary motor control performed by the drive device 20B of the second embodiment from the control of the first embodiment.

When the program starts with the clutch motor control routine of Fig. 12, the control CPU 90 of the controller 80 executes the process of steps S220 to S226, which are identical to steps S120 to S126 in the clutch motor control routine of the first embodiment shown in Fig. 6. The control CPU 90 first determines in step S220 whether the target motor torque Te* or the target motor speed Ne* of the motor 50 has been changed from the corresponding data of the previous cycle. If neither the target motor torque Te* nor the target motor speed Ne* has been changed, the program proceeds to step S222 to receive data of a speed Ne of the motor 50. The control CPU 90 then calculates a deviation ΔNe by subtracting the input speed Ne from the target motor speed Ne* in step S224. The absolute deviation value ΔNe is compared with a threshold value Nref1 in step S226.

When the absolute deviation value ΔNe is not larger than the threshold value Nref1 in step S226, that is, when the rotation speed Ne of the motor 50 is in the range of (target motor rotation speed Ne* - threshold value Nref1) to (target motor rotation speed Ne* + threshold value Nref1), the program determines that the motor 50 is in the range of a steady-state drive state. The control CPU 90 then sets a new torque control value Tc* of the clutch motor 30 in step S230 by subtracting the product of the control gain Kn and the deviation ΔNe from the existing data of the torque control value Tc* set in the previous cycle of the clutch motor control. The program subsequently executes steps S134 to S148 in the flow chart of Fig. 7 as previously described.

While the dead zone in which the rotation speed Ne is in the range of (target engine rotation speed Ne* - second threshold Nref2) to (target engine rotation speed Ne* + second threshold Nref2) is set in the clutch motor controller of the first embodiment, such a dead zone is not set in the clutch motor controller of the second embodiment. The feedback control is accordingly implemented with the vibration components of the rotation speed Ne due to the vibration outputs of the motor 50. This causes the vibration torque to be transmitted to the output shaft 22. In the second embodiment, the vibration torque transmitted to the output shaft 22 is reduced by the auxiliary motor control discussed below.

When the program starts with the auxiliary motor control routine of Fig. 13, the control CPU 90 of the controller 80 executes the Processes of steps S250 to S258, which are identical to steps S150 to S158 in the auxiliary motor control routine of the first embodiment shown in Fig. 10. The control CPU 90 receives data of the rotational speed Nd of the output shaft 22 in step S250 and data of the rotational speed Ne of the motor 50 in step S252, and calculates the rotational speed difference Nc in step S254. The control CPU 90 then calculates the electric current Pc regenerated by the clutch motor 30 in step S256 and the torque control value Ta* of the auxiliary motor 40 in step S258.

In subsequent step S259, a new torque control value Ta* of the assist motor 40 is calculated according to the equation (8) given below, i.e., by subtracting the difference between the torque control value Tc* of the clutch motor 30 and the target motor torque Te* from the torque control value Ta* calculated in step S258:

New Ta* = Ta* - (Tc*-Te*) (8)

wherein the torque control value Tc* is determined by the process of steps S220 to S230 in the flowchart of Fig. 12 and used for the process of steps S134 to S148 in the flowchart of Fig. 7. The torque control value Tc* in the equation (8) may be the new torque control value Tc* set in step S230 in the flowchart of Fig. 12 or, on the other hand, the torque control value Tc* set in step S108 in the flowchart of Fig. 5.

After setting the new torque control value Ta* in step S159, the control CPU 90 compares the new torque control value Ta* thus obtained with the maximum torque Tamax that the auxiliary motor 40 can potentially generate in step S260. If the torque control value Ta* exceeds the maximum torque Tamax, the program proceeds to step S263, in which the torque control value Ta* is limited to the maximum torque Tamax. The program then proceeds to steps S164 to S174 in the flow chart of Fig. 11 described previously.

In the drive device 20B of the second embodiment, the clutch motor control is carried out in synchronism with the auxiliary motor control. According to a concrete method, the operation of the voltages Vuc, Vvc and Vwc applied to the three-phase coils 36 in the clutch motor control is carried out simultaneously with that of the voltages Vua, Vva and Vwa applied to the three-phase coils 44 in the auxiliary motor control. The PWM control of the on and off of the transistors Tr1 to Tr6 in the clutch motor control (step S148 in the flowchart of Fig. 7) is carried out in synchronism with that of the transistors Tr11 to Tr16 in the auxiliary motor control (step S174 in the flowchart of Fig. 11).

The second embodiment is characterized by the clutch motor control synchronous with the auxiliary motor control and the operation of the voltages applied to the three-phase coils 44 based on the torque control value Ta* calculated according to the equation (8) in step S259 in the auxiliary motor control. These characteristics allow the auxiliary motor 40 to eliminate the vibration torque transmitted to the output shaft 22 via the clutch motor 30.

Fig. 14 shows the rotation speed Ne of the motor 50, the torque Tc of the clutch motor 30, the torque Ta of the auxiliary motor 40 and the torque Td output to the output shaft 22 when the motor 50 is in a stationary driving state at a predetermined driving point of the target motor torque Te* and the target motor rotation speed Ne*. The rotation speed Ne of the motor 50 is varied in a periodic manner around the target motor rotation speed Ne*. In order to make the rotation speed Ne of the motor 50 approach the target motor rotation speed Ne*, the transmitted torque Tc of the clutch motor 30 is oscillated by the target motor torque Te*. In the steady-state driving state, a calculation of step S258 gives a constant torque control value Ta* of the auxiliary motor 40. However, the final torque control value Ta* of the auxiliary motor 40, which is determined in step S259 by subtracting the difference between the torque control value Tc* and the target motor torque Te* from the constant torque control value Ta*, is oscillated at the same amplitude as the transmitted torque Tc of the clutch motor 30. Since the clutch motor control is performed synchronously with the auxiliary motor control, the oscillation torque control value Ta* of the auxiliary motor 40 has a phase difference π from the oscillation torque Tc of the clutch motor 30. The output shaft 22 receives the torque Tc of the clutch motor 30 and the torque Ta of the auxiliary motor 40. The vibration torque Tc of the clutch motor 30 and the vibration torque Ta of the auxiliary motor 40 have the phase difference π canceled out from each other, so that a non-vibration torque is applied to the output shaft 22.

In the drive device 20B of the second embodiment, even if the feedback control of the rotation speed Ne of the motor 50 based on the torque Tc of the clutch motor 30 causes the vibration force of the motor 50 to be transmitted to the output shaft 22, the torque Ta of the assist motor 40 is controlled to compensate for the torque Tc of the clutch motor 30 transmitted with vibration. A non-vibration torque is output to the output shaft 22 as necessary. This arrangement effectively prevents the vehicle from being vibrated by the vibration outputs of the motor 50, ensuring improved drivability.

The arrangement of the second embodiment subtracts the vibration torque Tc of the clutch motor 30 from the torque control value Ta* of the auxiliary motor 40 to calculate the vibration According to a modified arrangement, waveforms of the vibration torque transmitted to the output shaft 22 through the clutch motor 30 are measured at various driving points of the motor 50 and stored in advance. The waveform of the vibration torque is inverted corresponding to a certain driving point of the motor 50 and added to the torque control value Ta* of the auxiliary motor 40 to cancel the vibration torque transmitted to the output shaft 22 through the clutch motor 30. With this arrangement, it is not necessary to perform the clutch motor control in synchronism with the auxiliary motor control. The inverted waveform of the vibration torque should be added to the torque control value Ta* of the auxiliary motor 40 at a specific timing measured on the rotation angle θe of the crankshaft 56 of the engine 50 by the function generator 39.

A third embodiment of the present invention is realized by a drive device 20C having the hardware identical to that of the drive device 20 of the first embodiment. A description of the concrete hardware arrangement and the essential operating principles of the drive device 20C of the third embodiment is accordingly omitted. The symbols used in the description of the first embodiment have the same meaning in the third embodiment unless otherwise specified.

The drive device 20C of the third embodiment also executes the torque control routine of Fig. 5 which is executed by the controller 80 of the drive device 20 of the first embodiment. However, in the third embodiment, similarly to the second embodiment, the process of step S108 in the flowchart of Fig. 5 is followed by the clutch motor control routine of Figs. 12 and 7. 6 and 7 in the first embodiment. The process of step S110 in the flowchart of Fig. 5 follows the auxiliary motor control routine of Figs. 10 and 15 instead of the auxiliary motor control routine of Figs. 10 and 11 in the first embodiment. The clutch motor control has already been described in the second embodiment and will therefore not be explained here. The following mainly describes the different points of the clutch motor control and the auxiliary motor control performed by the drive device 20C of the third embodiment from the control of the first embodiment.

When the program starts with the auxiliary motor control routine, the control CPU 90 of the controller 80 first executes the process of steps S150 to S162 in the auxiliary motor control routine of the first embodiment shown in Fig. 10, which has already been described in the first embodiment and will therefore not be explained here.

The control CPU 90 then reads the rotation angle Ad of the output shaft 22 from the function generator 48 in step S360 in the flow chart of Fig. 15. In the following step S362, it is determined whether a necessary sine wave torque has already been determined. The necessary sine wave torque is for reducing the vibration torque transmitted to the output shaft 22 and is determined according to a sine wave torque determination routine of Fig. 16.

The sinusoidal power torque determination routine is executed to determine a required sinusoidal power torque that can reduce the vibration torque transmitted to the output shaft 22 when the feedback control is initiated in the clutch motor control routine of Fig. 12 to control the rotational speed Ne of the motor 50 applied to the Feedback data of the torque Tc of the clutch motor 30, that is, when the absolute deviation value ΔNe becomes equal to or smaller than the threshold value Nref1 in step S226.

When the program starts with the sinusoidal output torque determination routine of Fig. 16, the control CPU 90 of the controller 80 first reads the data of a rotational speed Ne of the motor 50 in step S380. The frequency of the vibration torque transmitted to the output shaft 22 is calculated from the inputted rotational speed Ne of the motor 50 in step S382. The vibration torque transmitted to the output shaft 22 is based on the vibration outputs of the motor 50. If the number of vibrations per revolution of the motor 50 is known, the frequency of the vibration torque can be determined by measuring the rotational speed Ne of the motor 50. The number of vibrations per revolution of the engine 50 can be determined according to the type and number of cylinders of the engine 50 and the connection of the piston of each cylinder to the crankshaft 56.

Sinusoidal power torques having a predetermined amplitude but different phases are successively applied to the output shaft 22 at the specific frequency calculated from the rotation speed Ne of the motor 50. The control CPU 90 simultaneously measures the rotation speed Nd of the output shaft 22 to detect a change in rotation of the output shaft 22. The control CPU 90 extracts the optimum phase which can minimize the amplitude of the variation in rotation and determines the optimum phase as a predetermined phase of a necessary sinusoidal power torque in step S384. The predetermined amplitude is determined, for example, as the average of the vibration torque transmitted to the output shaft 22 based on the historical experimental data. However, the predetermined amplitude may be any arbitrary value. as long as it can cause the variation in rotation of the output shaft 22. The variation in rotation of the output shaft 22 is determined by measuring the rotation speed Ne of the output shaft 22 in a plurality of times at predetermined intervals. The amplitude of the variation in rotation depends on the amplitude of vibration. The sinusoidal power torque can be added to the output shaft 22 by any desired method. For example, a new torque control value Ta* of the auxiliary motor 30 is determined by adding a value of sinusoidal power torque corresponding to the rotation angle Ad of the output shaft 22 to the torque control value Ta*, and the process of steps S166 to S174 in the flowchart of Fig. 11 in the first embodiment is carried out with the new torque control value Ta*. Although the difference in phase between each pair of sinusoidal power torques applied to the output shaft 22 in step S384 is π/64 in the third embodiment, the sinusoidal power torques may have any phase change.

While sinusoidal power torques having the specified phase but different amplitudes are added to the output shaft 22 one after another, a variation in one rotation of the output shaft 22 is determined. The control CPU 90 extracts the optimum amplitude which minimizes the amplitude of the variation in one rotation and determines the optimum amplitude as a specified amplitude of the required sinusoidal power torque in step S386. The program then exits the sinusoidal power torque determination routine and returns to the auxiliary motor control routine of Fig. 15. Although the amplitude of sinusoidal power torques added to the output shaft 22 is varied from the predetermined amplitude by the amount of 1/50 at a time in step S386, the amplitude can be changed to any desired amount at a time. In this way, the control CPU 90 determines the frequency, phase and amplitude of the required sinusoidal power torque which is applied to the Output shaft 22 can reduce the vibration torque transmitted.

The sinusoidal power torque determination routine of Fig. 16 is executed to determine a required sinusoidal power torque when the rotation speed Ne of the engine 50 is determined to reach a steady state. If the rotation speed Ne of the engine 50 has not yet reached a steady state or, on the other hand, if the sinusoidal power torque determination routine of Fig. 16 has not yet been completed to determine a required sinusoidal power torque, it is determined in step S362 in the flowchart of Fig. 15 that a desired sinusoidal power torque has not yet been determined. In this case, the program proceeds to steps S366 to S374, which are the same as steps S166 to S174 of the first embodiment shown in Fig. 11 and therefore will not be described here.

If it is determined in step S362 that a necessary sinusoidal power torque has already been determined, the program proceeds to step S364 to determine an additional torque Tas. The additional torque Tas represents the value of a sinusoidal power torque corresponding to the rotation angle θd of the output shaft 22 input in step S360 (more specifically, the value of an equation of a sinusoidal power torque at a time corresponding to the rotation angle θd of the output shaft 22). A new torque control value Ta* of the auxiliary motor 40 is determined in step S356 by adding the additional torque Tas to the torque control value Ta*. The process of steps S366 to S374 is then carried out with the new torque control value Ta*.

In the drive device 20C of the third embodiment, the vibration torque transmitted to the output shaft 22 can be reduced by using a sinusoidal power torque ment having a specific frequency based on the rotation speed Ne of the motor 50, the optimum phase and the optimum amplitude. This arrangement effectively prevents the vehicle from being vibrated by vibration outputs of the motor 50, ensuring improved drivability. The phase and amplitude of the additional sinusoidal power torque are determined at any time when the rotation speed Ne of the motor reaches a steady state. The varying vibration can therefore be prevented even if the vibration torque transmitted to the output shaft 22 is varied with the lapse of time.

In the drive device 20C of the third embodiment, the vibration torque transmitted to the output shaft 22 is reduced by the sinusoidal power torque having the optimally set frequency, phase and amplitude. A modified arrangement may determine a further variation in rotation of the output shaft 22 based on the data of a rotation speed Nd of the output shaft 22 after addition of the sinusoidal power torque, determine a second sinusoidal power torque capable of reducing the further variation in rotation, and add the second sinusoidal power torque to the output shaft 22. In this arrangement, the second sinusoidal power torque is determined in response to the vibration torque generated after application of the sinusoidal power torque to the output shaft 22. The frequency of the second sinusoidal power torque may be adjusted based on the variation in rotation of the output shaft 22, with the phase and the amplitude of the second sinusoidal power torque being determined in the same manner as above. Third, fourth and further sinusoidal power torques may be applied to the output shaft 22 according to requirements.

The first to third embodiments described above control the motor 50 to make the rotation speed Ne of the motor 50 the target speed In another preferred arrangement, the motor 50 may be controlled to produce the torque Te*. In the latter case, the torque Te of the motor 50 may be read from stress-strain curve data measured with a strain gauge attached to the crankshaft 56 or derived from the torque Tc of the clutch motor 30 and the speed Ne of the motor 50.

In the first to third embodiments described above, the rotational speed Ne of the motor 50 is controlled with the feedback data of a torque Tc of the clutch motor 30. Another modified arrangement may feedback control the difference between the rotational speed Ne of the motor 50 and the rotational speed Ne of the output shaft 22 with the data of a torque Tc of the clutch motor 30 to make the difference between Ne and Nd coincide with the difference between the target motor rotational speed Ne* and the rotational speed Nd.

In the first to third embodiments, the clutch motor 30 and the auxiliary motor 40 are separately mounted at different positions of the output shaft 22. However, similar to a modified drive device 20D shown in Fig. 17, the clutch motor and the auxiliary motor may be integrally connected to each other. A clutch motor 30D of the drive device 20D includes an inner rotor 34D connecting the crankshaft 56 and an outer rotor 32D connected to the output shaft 22. Three-phase coils 36D are mounted on the inner rotor 34D, and permanent magnets 35D are arranged on the outer rotor 32D such that the outer surface and the inner surface thereof have different magnetic poles. An auxiliary motor 40D includes the outer rotor 32D of the clutch motor 30D and a stator 43 with three-phase coils 44 attached thereto. In this structure, the outer rotor 32D of the clutch motor 30D also acts as a rotor of the auxiliary motor 40D. Since the three-phase coils 36D are attached to the inner rotor 34D which connects the crankshaft 56, a rotating converter or transformer 38D for supplying electric current to the three-phase coils 36D of the clutch motor 30D is attached to the crankshaft 56.

In the drive device 20D, the voltage applied to the three-phase coils 36D on the inner rotor 34D is controlled with respect to the inner surface magnetic pole of the permanent magnets 35D arranged on the outer rotor 32D. This allows the clutch motor 30D to operate in the same manner as the clutch motor 30D of the drive device 20 shown in Fig. 1. The voltage applied to the three-phase coils 44 on the stator 43 is controlled with respect to the outer surface magnetic pole of the permanent magnets 35D arranged on the outer rotor 32D. This allows the auxiliary motor 40D to operate in the same manner as the auxiliary motor 40 of the drive device 20. The torque control routine of Fig. 5, the clutch motor control routines of Figs. 6, 7 and 12 and the auxiliary motor control routines of Figs. 10, 11, 13 and 15 are also applicable to the drive device 20D shown in Fig. 17, which accordingly perform the same operations and exert the same effects as the drive device 20 shown in Fig. 1.

As discussed above, the outer rotor 32D operates simultaneously as one of the rotors in the clutch motor 30D and as the rotor of the auxiliary motor 40D, effectively reducing the size and weight of the entire drive device 20D.

The control methods of the first embodiment are also applicable to another modified drive device 20E shown in Fig. 18, wherein the auxiliary motor 40 is arranged between the motor 50 and the clutch motor 3U, or to yet another modified drive device 20F shown in Fig. 19, wherein the motor 50 is arranged between the clutch motor 30 and the auxiliary motor 40. The following describes the essential operations of the drive device 20E shown in Fig. 18 and the drive device 20F shown in Fig. 19.

For example, it is assumed that the engine 50 is driven at a drive point of a torque Te and a rotational speed Ne. When a torque Ta is added to the crankshaft 56 by the auxiliary motor 40 connected to the crankshaft 56, the sum of the torques (Te + Ta) therefore acts on the crankshaft 56. When the clutch motor 30 is controlled to generate the torque Tc equal to the sum of the torques (Te + Ta), the torque Tc (= Te + Ta) is transmitted to the output shaft 22.

When the rotational speed Ne of the motor 50 is greater than the rotational speed Nd of the output shaft 22, the clutch motor 30 regenerates an electric current based on the rotational speed difference Nc between the rotational speed Ne of the motor 50 and the rotational speed Nd of the output shaft 22. The regenerated current is supplied to the auxiliary motor 40 via the power lines P1 and P2 and the second drive circuit 92 to activate the auxiliary motor 40. Provided that the torque Ta of the auxiliary motor 40 is substantially equal to the electric current regenerated by the clutch motor 30, free torque conversion is permitted for the power output from the motor 50 in a range that satisfies the relationship of equation (9) given below. Since the relationship of equation (9) represents the ideal state with an efficiency of 100%, (TcxNd) is a little smaller than (TexNe) in the actual state:

Te · Ne = Tc · Nd (9)

Referring to Fig. 4, under the condition that the crankshaft 56 rotates at the torque T1 and at the speed N1, the energy corresponding to the sum of the areas G1 + G3 is regenerated by the clutch motor 30 and supplied to the Auxiliary motor 40 converts the energy received in the sum of the areas G1 + G3 into the energy corresponding to the sum of the areas G2 + G3 and transfers the converted energy to the crankshaft 56.

When the rotational speed Ne of the motor 50 is smaller than the rotational speed Nd of the output shaft 22, the clutch motor 30 operates as a normal motor. In the clutch motor 30, the inner rotor 34 rotates relative to the outer rotor 32 in the rotational direction of the output shaft 22 at a rotational speed defined by the absolute value of the rotational speed difference Nc(=Ne-Nd). Provided that the torque Ta of the auxiliary motor 40 is set to a negative value that allows the auxiliary motor 40 to regenerate electric power substantially equal to the electric power consumed by the clutch motor 30, free torque conversion is also permitted for the power output from the motor 50 within the range that satisfies the relationship of the equation (9) given above.

Referring to Fig. 4, under the condition that the crankshaft 56 rotates at the torque T2 and at the speed N2, the energy corresponding to the area G2 is regenerated by the assist motor 40 and consumed by the clutch motor 30 like the energy corresponding to the area G1.

The clutch motors 30 of the drive device 20E and the drive device 20F operate in the same manner as the clutch motor 30 of the drive device 20 of the first embodiment. The control methods of the first embodiment are therefore applicable to these drive devices 20E and 20F.

In the drive device 20E of Fig. 18, the clutch motor 30 and the auxiliary motor 40 are separately mounted at different locations of the crankshaft 56. Similarly to still another drive device 20G shown in Fig. 20, the clutch motor and the auxiliary motor may be integrally connected to each other. A clutch motor 30G of the drive device 20G includes an outer rotor 32G connecting the crankshaft 56 and an inner rotor 34 connected to the output shaft 22. Three-phase coils 36 are attached to the inner rotor 34, and permanent magnets 35G are arranged on the outer rotor 32G such that the outer surface and the inner surface thereof have different magnetic poles. An auxiliary motor 40G includes the outer rotor 32G of the clutch motor 30G and a stator 43 having three-phase coils 44 attached thereto. In this structure, the outer rotor 32G of the clutch motor 30G functions as a rotor of the auxiliary motor 40G.

In the drive device 20G, the voltage applied to the three-phase coils 36 on the inner rotor 34 is controlled with respect to the inner surface magnetic pole of the permanent magnets 35G attached to the outer rotor 32G. This allows the clutch motor 30G to operate in the same manner as the clutch motor 30 of the drive device 20E shown in Fig. 18. The voltage applied to the three-phase coils 44 on the stator 43 is controlled with respect to the outer surface magnetic pole of the permanent magnets 35G attached to the outer rotor 32G. This allows the auxiliary motor 40G to operate in the same manner as the auxiliary motor 40 of the drive device 20E. The control methods of the first embodiment are also applicable to the drive device 20G shown in Fig. 20, which accordingly performs the same operations and exerts the same effects as those of the drive device 20E shown in Fig. 18.

Similar to the drive device 20D shown in Fig. 17, the clutch motor and the auxiliary motor are integrally connected to each other, effectively reducing the size and weight of the entire drive device 20G.

In the above embodiments, the gasoline engine, which Gasoline is used as energy than the engine 50 uses. However, the principle of the invention is to be applicable to other engines which output a vibratory force.

Permanent magnet (PM) type synchronous motors are used for the clutch motor 30 and the auxiliary motor 40 in the above-described drive devices. Other motors such as variable reluctance (VR) type synchronous motors, vernier thrusters, DC motors, induction motors, superconducting motors, and stepping motors can be used for the regenerative operation and the current operation.

The rotary transformer 38 used as a means for transmitting electric power to the clutch motor 30 may be replaced by a slip ring brush contact, slip ring mercury contact, semiconductor magnetic energy coupling, or the like.

In the above driving devices, transistor inverters are used for the first and second driving circuits 91 and 92. Other examples applicable to the driving circuits 91 and 92 include IGBT (insulated gate bipolar mode transistor) inverters, thyristor inverters, voltage PWM (pulse width modulation) inverters, square wave inverters (voltage inverters and current inverters), and resonance inverters.

The battery 94 may comprise Pb cells, NiMH cells, Li cells or the like cells. A capacitor may be used instead of the battery 94.

Although the drive device in the above embodiments is mounted on or in a vehicle, it can be mounted on or in other transportation devices, such as ships and aircraft, as well as on a variety of industrial machines or equipment.

Claims (21)

1. Drive device for transmitting a force to an output shaft (22), the drive device comprising: A motor (50) having an output shaft (56), the motor rotating the output shaft (56) by a vibration force thereof, a clutch motor (30; 30D, G) comprising a first rotor connected to the output shaft (56) of the motor and a second rotor connected to the output shaft (22), the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to one another, a force being transmitted between the output shaft (56) of the motor and the output shaft (22) via the electromagnetic connection of the first and second rotors, marked by a target state determination device for setting (S104) a target state (Te*; Ne*-Nd) of the output shaft (56) of the motor, a motor control device for controlling (S111) an operation of the motor (50) to let the output shaft (56) of the motor reach the target state (Te*; Ne*-Nd) set by the target state determining device, an output shaft state measuring device for measuring (S122) a state (ΔNe; Te; Ne-Nd) of the output shaft of the motor, and a clutch motor control device (S108) for controlling the Rotating the second rotor relative to the first rotor and changing the degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor (30) when the state (ΔNe; Te; Ne-Nd) of the output shaft (56) is outside a predetermined range (Nref2) which includes the target state (Te*; Ne*-Nd) to cause the state (ΔNe; Te; Ne-Nd) of the output shaft (56) of the motor to reach the target state. 2. Drive device according to claim 1, wherein the predetermined range is a predetermined first range (Nref2), and wherein the clutch motor control means comprises means for controlling the clutch motor (30; 30D, 30G) to allow the state (ΔNe) of the output shaft (56) of the motor to be in the predetermined first range (Nref2) while the state (Ne) of the output shaft (56) of the motor (50) measured by the output shaft state measuring means is in a predetermined second range (Nref1) comprising the predetermined first range (Nref2). 3. A drive device according to claim 2, wherein the state of the output shaft of the engine is varied by the vibration force of the engine in the predetermined second range (Nref1) when the engine control means controls the operation of the engine to allow the state of the output shaft to reach the target state set by the target state determining means. 4. Drive device according to one of the preceding claims, in which the state of the output shaft of the motor is a change (ΔNe) in the speed of the output shaft (56). 5. Drive device according to one of claims 1 to 3, wherein the state of the output shaft of the motor is off initial state of a torque (Te) on the output shaft (56) of the motor. 6. Drive device according to one of claims 1 to 3, in which the state of the output shaft of the motor is a difference between the speed (Ne) of the output shaft of the motor and a speed (Nd) of the output shaft. 7. Drive device for transmitting a force to an output shaft (22), the drive device comprising: A motor (50) having an output shaft (56), the motor rotating the output shaft (56) by a vibration force thereof, a clutch motor (30; 30D, G) comprising a first rotor connected to the output shaft (56) of the motor and a second rotor connected to the output shaft (22), the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to one another, a force being transmitted between the output shaft (56) of the motor and the output shaft (22) via the electromagnetic connection of the first and second rotors, marked by a target state determining device for setting (S104) a target state (Ne*; Te*; Ne*-Nd) of the output shaft (56) of the engine, a motor control device for controlling (S111) an operation of the motor (50) to make the output shaft (56) of the motor reach the target state (Ne*; Te*; Ne*-Nd) set by the target state determining device, an output shaft state measuring device for measuring (S222) a state (Ne; Te; Ne-Nd) of the output shaft of the motor, and a clutch motor control device for controlling (S108) a degree of electromagnetic connection of the first Rotor and the second rotor in the clutch motor and for controlling the rotation of the second rotor relative to the first rotor to cause the state (Ne; Te; Ne-Nd) of the output shaft (56) of the motor to reach the target state (Ne*; Te*; Ne*-Nd), an auxiliary motor (40; 40D, G) which is connected to the output shaft (22), and an auxiliary motor control device for controlling (S110) the auxiliary motor (40; 40D, G) to cancel a vibration component (Tc*-Te*; Tas) of the power transmitted to the output shaft (22) by the clutch motor (30) (S259; S365). 8. Drive device according to claim 7, wherein the auxiliary motor control device further comprises: a vibration component measuring device for measuring the vibration component (Tc*-Te*) of the force transmitted to the output shaft (22), and a vibration component reducing device for controlling the auxiliary motor (40; 40D, G) to cancel the vibration component (Tc*-Te*) measured by the vibration component measuring device. 9. A drive device according to claim 8, wherein the vibration component measuring means comprises means for measuring the vibration component of the force based on the degree of electromagnetic connection (Tc*) of the first rotor and the second rotor, which is controlled by the clutch motor control means. 10. A drive device according to claim 8, wherein the vibration component measuring means comprises means for measuring the vibration component of the force based on the state (Ne) of the output shaft of the engine measured by the output shaft state measuring means (S222). 11. A drive device according to claim 8 or 9, wherein the vibration component reducing means comprises means for controlling the auxiliary motor (40; 40D, G) to allow the auxiliary motor to output a specific force (Tc*-Te*) to the output shaft (22) (S259), wherein the specific force (Tc*-Te*) has the same magnitude as that of the vibration component of the force transmitted to the output shaft (22) but has a phase difference of half the cycle of the vibration component. 12. Drive device according to claim 7, wherein the auxiliary motor control device further comprises: a vibration component measuring device for measuring the vibration component of the force which is transmitted to the output shaft (22), a frequency calculation device for calculating a frequency of the vibration component of the force measured by the vibration component measuring device, a sinusoidal power application device for subsequently controlling an amplitude and a phase of a sinusoidal power with a frequency calculated by the frequency calculation device and for switching on the auxiliary motor (40; 40D, G) to apply the sinusoidal power with the controlled amplitude and phase to the output shaft (22) and an additional power setting device for tapping an optimal sinusoidal power with an optimal amplitude and an optimal phase, which reduces the vibration component of the force measured by the vibration component measuring device from the sinusoidal power subsequently applied by the sinusoidal power application device, and for setting (S364) an additional force (Tas) applied by the auxiliary motor (40; 40D, G) to the output shaft (22). 13. A drive device according to claim 12, wherein the vibration component measuring means comprises means for measuring the vibration component of the force based on a rotational state (θd) of the output shaft (22). 14. Drive device according to claim 7, wherein the auxiliary motor control device further comprises: a vibration component measuring device for measuring (S364) the vibration component of the force which is transmitted to the output shaft (22), a frequency calculation device for calculating a frequency of the vibration component of the power transmitted to the output shaft (22) based on the state of the output shaft of the engine measured by the output shaft state measuring device, a sinusoidal power application device for a frequency calculation device for calculating a frequency of the vibration component of the force which is measured by the vibration component measuring device, a sinusoidal power application device for subsequently controlling an amplitude and a phase of a sinusoidal power with a frequency calculated by the frequency calculation device and for switching on the auxiliary motor (40; 40D, G) to apply the sinusoidal power with the controlled amplitude and phase to the output shaft (22), and an additional power setting device for tapping an optimal sinusoidal power with an optimal amplitude and an optimal phase, which reduces the vibration component of the force measured by the vibration component measuring device from the sinusoidal power subsequently applied by the sinusoidal power application device, and for setting (S364) an additional force (Tas) applied by the auxiliary motor (40; 40D, G) to the output shaft (22). 15. Drive device according to one of claims 7 to 14, in which the state of the output shaft of the motor is a rotation state (Ne) of the output shaft. 16. Drive device according to one of claims 7 to 14, in which the state of the output shaft of the motor is an initial state of a torque (Te) on the output shaft of the motor. 17. Drive device according to one of claims 7 to 14, in which the state of the output shaft of the motor is a difference between a rotation speed (Ne) of the output shaft of the motor and a rotation speed (Nd) of the second rotor of the clutch motor. 18. Drive device according to one of claims 1 to 6 for transmitting a force to an output shaft (22), the drive device further comprising: a complex motor (20D, 20G) comprising a clutch motor (30D; 30G) and a stator for rotating the second rotor, wherein the stator and the second rotor or the first rotor form a second motor (40D; 40G), and a second motor control device for controlling the second motor (40) in the complex motor (30D; 30G). 19. Drive device for transmitting a force to the output shaft (22) according to one of claims 7 to 17, wherein the drive device comprises: a complex motor (20D) comprising a clutch motor (30D) and a stator for rotating the second rotor, wherein the second rotor and the stator form the auxiliary motor (40D). 20. A method for controlling a drive device for transmitting a force to an output shaft, the method comprising the steps of: (a) providing a motor (50) having an output shaft (56), the motor rotating the output shaft (56) by a vibration force thereof, and a clutch motor (30; 30D, G) comprising a first rotor connected to the output shaft (56) of the motor and a second rotor connected to the output shaft (22), the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to one another, a force being transmitted between the output shaft (56) of the motor and the output shaft (22) via the electromagnetic connection of the first and second rotors, characterized by the steps: (b) Setting (S104) a target state of the output shaft (56) of the motor, (c) controlling (S111) an operation of the motor to allow the output shaft (56) of the motor to reach the target state, (d) measuring a state (ΔNe; Te; Ne-Nd) of the output shaft (56) of the engine, and (e) changing the degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor (30) when the state (ΔNe; Te; Ne-Nd) of the output shaft (56) is outside a predetermined range (Nref2) which includes the target state (Te*; Ne*-Nd) to make the state (ΔNe; Te; Ne-Nd) of the output shaft (56) of the motor reach the target state. 21. Method for controlling a drive device for transmitting a force to an output shaft (22), the method comprising the steps: (a) providing a motor (50) having an output shaft (56), the motor rotating the output shaft (56) by a vibration force thereof, a clutch motor (30; 30D, G) having a first rotor connected to the output shaft (56) of the motor and a second rotor connected to the output shaft (22), the second rotor being coaxial and relatively rotatable to the first rotor, the first and second rotors being electromagnetically connected to each other, a force being transmitted between the output shaft (56) of the motor and the output shaft (22) via the electromagnetic connection of the first and second rotors, and an auxiliary motor (40; 40D, G) which is connected to the output shaft (22), characterized by the steps: (b) Setting (S104) a target state of the output shaft (56) of the motor, (c) controlling an operation of the motor to cause the output shaft (56) of the motor to reach the target state, (d) measuring a state (ΔNe; Te; Ne-Nd) of the output shaft (56) of the engine, and (e) controlling a degree of electromagnetic connection of the first rotor and the second rotor in the clutch motor (30) to make the state (Ne; Te; Ne-Nd) of the output shaft (56) of the motor reach the target state (Ne*; Te*; Ne*-Nd), and (f) controlling an auxiliary motor (40; 40D, G) to cancel a vibration component of the power transmitted to the output shaft (22) by the clutch motor (30; 30D, G).