JP3666394B2 - Vehicle driving force control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict energy consumption while improving acceleration performance in driving a part of a plurality of drive wheels by an internal combustion engine, and driving the remaining wheels by a motor. SOLUTION: Front wheels 1FL and 1FR are driven by an engine 2, rear wheels 1RL and 1RR are driven by a DC motor 4 through an electromagnetic clutch 11, and the DC motor 4 is driven by power generated by a power generator 7. The electromagnetic clutch 11 is in a non-fastened state when an accelerator pedal 14 is not operated, and it gets into a fastened state when the accelerator pedal is operated. Interlocked with motor output torque of the DC motor 4, clutch transmission torque is controlled in accordance with its increased quantity.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a driving force control apparatus for a vehicle in which a plurality of driving wheels of a vehicle are divided into two groups, one group is driven by an internal combustion engine (engine), and the other group is driven by an electric motor.
[0002]
[Prior art]
An example of a driving force control device for a vehicle in which one of the front and rear wheels is driven by an engine and the other is driven by an electric motor is disclosed in, for example, Japanese Patent Application Laid-Open No. 11-243608 (hereinafter simply referred to as a conventional example).
In this conventional example, the front wheels are driven by an engine, the rear wheels are driven by a motor, and a rear wheel drive command is issued when the speed difference between the front wheel speed VF and the rear wheel speed VR exceeds a predetermined value ΔVS. At this time, an equation for predicting the subsequent change of the axle speed VR is calculated based on the axle rotation speed VR and each acceleration dVR, and the motor rotation speed is calculated from the prediction equation and the motor speed rising characteristic. The time t required until Vm becomes equal to the speed corresponding to VR is calculated, the motor is idled for t, the motor is temporarily stopped after t has elapsed, the clutch is turned on, and then the motor is restarted. Thus, there is described an electric drive device for a vehicle in which the output torque is gradually increased.
[0003]
[Problems to be solved by the invention]
However, in the above conventional example, the motor is driven when the speed difference between the front wheel speed VF and the rear wheel speed VR becomes equal to or greater than the predetermined value ΔVS, so that the shock caused by the generation of torque is eliminated. Therefore, in a state where the motor rotation speed is matched with the driving wheel speed, the energization of the temporary motor is stopped, the energization of the motor is started after the clutch is turned on, and the motor torque is gradually increased. However, in a four-wheel drive vehicle or the like, it is important to speed up the torque response at the time of starting and shorten the wheel idling time. When the clutch control command and the motor torque command are simultaneously commanded as in the conventional example, If the motor torque command is not executed in consideration of the actual torque delay of the clutch, there is an unsolved problem that the clutch slips, causing power loss and shortening the clutch life.
[0004]
In order to solve this unsolved problem, it is conceivable that the motor torque is generated after the clutch is securely turned on. However, in this case, there is a new unsolved problem that the start acceleration performance becomes slow.
Therefore, the present invention has been made paying attention to the above-mentioned unsolved problems of the conventional example, preventing clutch slippage while maintaining good start acceleration while preventing clutch slippage, and further, driving force control system An object of the present invention is to provide a vehicle driving force control device that can suppress power consumption of the vehicle.
[0005]
[Means for Solving the Problems]
  In order to solve the above problems, a vehicle driving force control apparatus according to a first aspect drives a main driving wheel constituting a part of a plurality of driving wheels in a front-rear direction disposed in the vehicle by an internal combustion engine or a main motor. In the vehicle driving force control apparatus in which the remaining driven wheels are driven by the driven motor, the driven motor control means for controlling the driving of the driven motor is interposed between the driven motor and the driven wheels. Clutch means that can be turned on and off in accordance with a clutch transmission torque command to which the received transmission torque is input, slave motor drive necessity judgment means that judges whether or not the driven motor is driven by the slave motor, and whether or not the slave motor drive is necessary And a clutch control means for outputting a clutch transmission torque command for controlling the clutch means to a connected state when the result of the judgment by the judgment means is that the driven wheel is required to be driven.The clutch control means is configured to be interlocked with the follower motor output torque control command when the clutch means is connected, and to output a clutch transmission torque command according to the follower motor output torque control command to the clutch means.It is characterized by having.
[0006]
  According to a second aspect of the present invention, there is provided a vehicle driving force control apparatus that drives main driving wheels constituting a part of a plurality of driving wheels in the front-rear direction disposed in the vehicle by an internal combustion engine or a main motor, and the remaining subordinate driving wheels. In a vehicle driving force control apparatus in which driving wheels are driven by a slave motor, slave motor control means for driving and controlling the slave motor, and a transmission torque inserted between the slave motor and the slave drive wheel are input. The clutch means that can be switched according to the clutch transmission torque command, the slave motor drive necessity judgment means that judges whether or not the driven wheel is driven by the slave motor, and the determination result of the slave motor drive necessity judgment means Clutch control means for outputting a clutch transmission torque command for controlling the clutch means to be in a connected state when the driven wheel is required to drive, the slave motor control means,When clutch means is connectedIn addition to being interlocked with the clutch transmission torque command of the clutch control means, the slave motor output torque is controlled according to the clutch transmission torque command.
  Further, in the vehicle driving force control apparatus according to claim 3, in the invention according to claim 1 or 2, the slave motor drive necessity determination unit determines that the drive is necessary when the accelerator stepping operation is performed. It is configured as described above.
[0007]
  Furthermore, a vehicle driving force control apparatus according to a fourth aspect is the first aspect.Or 3In the present invention, the clutch control means is configured to control connection of the clutch means by electric power supplied from an energization control system of the slave motor control means.The
[0008]
  Claims5A vehicle driving force control apparatus according to claim 1 is provided.4In any one of the inventions, the slave motor control means includes clutch slip detection means for detecting clutch slip based on a rotational speed deviation between the input side and the output side of the clutch means during connection control of the clutch means, When clutch slip is detected by the clutch slip detection means, the output torque of the slave motor is corrected in a decreasing direction.
[0009]
  And claims6A vehicle driving force control apparatus according to claim5In the invention according to the present invention, the correction in the direction in which the slave motor output torque is reduced is continued until clutch slip detection means no longer detects clutch slip.
  Furthermore, the claims7A vehicle driving force control apparatus according to claim5In the invention according to the invention, the correction in the reduction direction of the slave motor output torque is performed by gradually reducing the slave motor output torque.
[0010]
  Still further, the claims8A vehicle driving force control apparatus according to claim5Thru7In the invention according to any one of the above, the clutch slip detection means includes slave motor rotation speed detection means for detecting the rotation speed of the slave motor, and slave drive wheel rotation speed detection means for detecting the rotation speed of the slave drive wheel. The clutch slip is detected from the rotational speed difference detected by the secondary motor rotational speed detecting means and the secondary driving wheel rotational speed detecting means.
[0011]
【The invention's effect】
    According to the first aspect of the present invention, the slave motor drive necessity judgment means judges whether or not the slave motor needs to be driven, and the clutch control means controls the clutch means to the connected state when the judgment result indicates that the drive is necessary. Therefore, the energy required for connecting the clutch means should not be wasted.TheThe energy efficiency of the vehicle can be improved, and particularly when the slave motor is driven without a battery using the generated power using the rotational force of the internal combustion engine, excessive power generation is suppressed and the load on the internal combustion engine is reduced. The effect of reducing the fuel consumption can be obtained.In addition, since the clutch transmission torque command value is controlled in accordance with the motor output torque control command in conjunction with the motor output torque control command for the slave motor, the vehicle acceleration performance is improved without causing a time lag of waiting for the clutch connection. In addition, it is possible to obtain an effect that wasteful energy consumption for connecting the clutch means can be suppressed.
[0012]
  Moreover, according to the invention which concerns on Claim 2,When clutch means is connectedSince the slave motor output torque command is controlled in accordance with the clutch transmission torque command, the slave motor output torque can be increased without waiting until the clutch means is completely connected. The effect that the acceleration performance of the vehicle can be improved without occurring is obtained.
  Furthermore, according to the third aspect of the invention, since it is determined that driving is required when the accelerator operation is being performed, energy required for connection of the clutch means is wasted when the slave motor driving force is not required when the vehicle is stopped. The effect that it can prevent doing is acquired.
[0013]
Furthermore, according to the fourth aspect of the invention, the power for controlling the connection of the clutch means by the clutch control means is supplied from the energization control system for the slave motor of the slave motor control means. Therefore, it is possible to obtain the effect that the clutch means can be controlled in connection with the output torque of the slave motor without providing a special control device.
[0015]
  Claims5According to the invention, the clutch slip detecting means detects the slip state of the clutch means, and the follower motor output torque is corrected in a decreasing direction so as to eliminate the slip of the clutch means. The effect that the clutch means can be extended in life by suppressing or eliminating the slip of the clutch means while continuing the operation is obtained.
[0016]
  And claims6According to the invention, the slave motor output torque is reduced until the slip generated by the clutch means is eliminated, so that it is possible to reliably prevent the clutch means from slipping and prolong the life of the clutch means. can get.
  Furthermore, the claims7According to the invention, since the slave motor output torque is gradually reduced to eliminate slipping of the clutch means, there is no sudden torque fluctuation when the slave motor output torque is reduced. The effect that the occurrence of shock can be surely prevented is obtained.
[0017]
  Still further, the claims8According to the invention according to the present invention, since the rotational speeds on the input side and the output side of the clutch means are detected on the basis of the output speed of the slave motor and the rotational speed of the driving wheel, it is possible to accurately detect the clutch slip. can get.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing a first embodiment when the present invention is applied to a four-wheel drive vehicle. Left and right front wheels 1FL and 1FR as main drive wheels are driven by an engine 2 which is an internal combustion engine. The left and right rear wheels 1RL and 1RR as drive wheels are driven by a DC motor 4 which is a sub-motor.
[0019]
The output torque Te of the engine 2 is transmitted to the left and right front wheels 1FL and 1FR via the transmission and the differential gear 5. A part of the output torque Te of the engine 2 is transmitted to the generator 7 through the endless belt 6.
The generator 7 rotates at a rotational speed Nh obtained by multiplying the rotational speed Ne of the engine 2 by the pulley ratio, and becomes a load on the engine 2 in accordance with the field current Ifg adjusted by the 4WD controller 8. A voltage corresponding to the power is generated. The electric power generated by the generator 7 is supplied to the DC motor 4 via the junction box 9. The output shaft of the DC motor 4 is connected to a speed reducer 10, an electromagnetic clutch 11 as a clutch means, and a differential gear 12, and the left and right output sides of the differential gear 12 are connected to left and right rear wheels 1RL and 1RR via drive shafts 13L and 13R, respectively. It is connected.
[0020]
An accelerator stroke sensor 15 for detecting the depression amount of the accelerator pedal 14 is provided, and the accelerator depression amount AS detected by the accelerator stroke sensor 15 is output to the 4WD controller 8. Each of the wheels 1FL to 1RR is provided with a wheel speed sensor 16FL to 16RR that detects the wheel speed, and the wheel speed Vw detected by the wheel speed sensors 16FL to 16RR._FL~ Vw_RRIs output to the 4WD controller 8. Further, a shift position sensor 17 for detecting the shift position of the transmission is provided, and the shift position detected by the shift position sensor 17 is input to the 4WD controller 8. Furthermore, a 4WD switch 18 is provided in the vicinity of the driver's seat to select whether or not to set the four-wheel drive state.
[0021]
Further, as shown in FIG. 2, the generator 7 has a delta-connected three-phase stator coil SC and a field coil FC, and a rectifier circuit 19 in which each connection point of the stator coil SC is constituted by a diode. The rectifier circuit 19 outputs a DC voltage V.
The field coil FC has one end connected to the output side of the 4WD relay 21 connected to the battery 20 having a predetermined voltage (for example, 12 volts) through the diode D1 in the reverse direction, and the other end connected to the voltage regulator (regulator). ) 22 is grounded. The 4WD relay 21 has one end of the relay coil connected to the output side of the ignition relay 24 connected to the battery 20 via the ignition switch 23, and the other end connected to the 4WD controller 8.
[0022]
Then, the generator 7 adjusts the field current Ifg for the field coil FC by the 4WD controller 8, thereby controlling the power generation load torque Th and the power generation voltage V for the engine 2. The voltage regulator 22 receives a generator control command (field current value) C1 subjected to pulse width modulation (PWM) from the 4WD controller 8, and sets the field current of the generator 7 to a value corresponding to the generator control command C1. Ifg is adjusted.
[0023]
A motor relay 25 and a current sensor 26 are connected in series in the junction box 9, and the motor relay 25 interrupts power supplied to the DC motor 4 according to a command from the 4WD controller 8. The current sensor 26 detects the armature current Ia supplied from the generator 7 to the DC motor 4 and outputs the detected armature current Ia to the 4WD controller 8. Further, the motor voltage Vm supplied to the DC motor 4 is detected by the 4WD controller 8.
[0024]
Further, in DC motor 4, field current Ifm is controlled by a pulse width modulated field control command as a motor output torque command from 4WD controller 8, and drive torque Tm is adjusted by adjusting the field current Ifm. The temperature of the DC motor 4 is detected by the thermistor 27, and the detected temperature value is input to the 4WD controller 8, and the rotation speed Nm of the output shaft of the DC motor 4 is detected by the motor rotation speed sensor 28. The number Nm is input to the 4WD controller 8.
[0025]
The electromagnetic clutch 11 has one end of the exciting coil 11 a connected to the output side of the 4WD relay 21 and the other end connected to the 4WD controller 8, and the switching transistor 29 as a switching element in the 4WD controller 8. Is grounded. The energizing current of the exciting coil 11a is controlled by the clutch control command CL that is pulse-width-modulated supplied to the base of the transistor 29, whereby the torque transmission force transmitted from the DC motor 4 to the drive wheels 1RL and 1RR is controlled. The
[0026]
As shown in FIG. 3, the 4WD controller 8 includes a 4WD relay control unit 8A, a motor relay control unit 8B, a DC motor 4, a generator 7, and a drive wheel torque control unit 8C that controls the electromagnetic clutch 11.
The 4WD relay control unit 8A is in an ON state in which the switch signal of the 4WD switch 18 selects four-wheel drive, and the shift position of the transmission detected by the shift position sensor 17 is any one of the drive range, the 2 range, and the 1 range. When a certain on condition is satisfied, the relay coil of the 4WD relay 21 is energized and the 4WD relay 21 is controlled to be in an on state. When the above on condition is not satisfied, the relay coil is deenergized and the 4WD relay 21 is turned off. Control to the state.
[0027]
Based on the armature current Ia to the DC motor 4 detected by the current sensor 26 and the motor temperature detected by the thermistor 27, the motor relay control unit 8B determines that the armature current Ia is less than the set value and the motor temperature is less than the set. In some cases, it is determined that the DC motor 4 is in a normal state, and the DC motor 4 is energized. However, when the armature current Im is in an overcurrent state and the motor temperature is in an overheated state, The power supply to is cut off by the motor relay 25.
[0028]
The drive wheel torque control unit 8C executes a drive wheel torque control process shown in FIG.
This drive wheel torque control process is executed as a timer interrupt process at predetermined time intervals (for example, 10 msec). First, the accelerator depression amount AS detected by the accelerator stroke sensor 15 is read in step S1, and then the process proceeds to step S2. Then, it is determined whether or not the accelerator pedal 14 is operated. This determination is made based on whether or not the accelerator depression amount AS is equal to or greater than a predetermined value ASs near zero. When AS <ASs, the accelerator depression amount AS is less than a minute value and the accelerator pedal 14 is operated. It judges that it is not, and moves to step S3.
[0029]
In this step S 3, the generator voltage target value Vt for the generator 7, the field control current Ifm ′ for the field coil of the DC motor 4, and the clutch target torque T for the electromagnetic clutch 11._CLIs set to “0”, and the process proceeds to step S11 to be described later.
On the other hand, when the determination result in step S2 is AS ≧ ASs, it is determined that the accelerator pedal 14 is depressed and the accelerator operation is being performed, and the process proceeds to step S4. Based on the accelerator depression amount AS. The motor output torque Tm is calculated with reference to the motor torque calculation map shown in FIG. Here, the motor torque calculation map takes the accelerator depression amount AS on the horizontal axis, the motor output torque Tm on the vertical axis, and the motor output torque Tm when the accelerator depression amount AS is between “0” and a predetermined value ASs. When the accelerator depression amount AS increases from the predetermined value ASs, the motor output torque Tm increases as the accelerator depression amount AS increases, and when the accelerator depression amount AS exceeds a relatively large set value ASb, The motor output torque Tm is the maximum value Tm despite the increase in the depression amount AS._MAXThe characteristic line L1 is set so as to be limited to.
[0030]
Next, the process proceeds to step S5, where the motor field current target value Ifmt is calculated with reference to the motor field current target value calculation map shown in FIG. 4 based on the motor rotation speed Nm. Here, in the motor field current target value calculation map, the horizontal axis indicates the motor rotation speed Nm, the vertical axis indicates the motor field current target value Ifmt, and the motor rotation speed Nm increases from “0”. Between the set value N1 of 1 and the motor field current target value Ifmt is the preset maximum current value I_MAXWhen the motor rotational speed Nm increases beyond the first selected value N1, the motor field current target value Ifmt decreases accordingly with a relatively large slope, and the motor rotational speed Nm is set to the first setting. Between the second set value N2 larger than the value N1 and the third set value N3 larger than the second set value N2, the motor field current target value Ifmt is the maximum current I._MAXAbout half the current value I_LWhen the motor rotation speed Nm increases beyond the third set value N3, the characteristic line L2 is set so that the motor field current target value Ifmt decreases accordingly with a relatively large slope. .
[0031]
Next, the process proceeds to step S6, where the motor induced voltage E is calculated with reference to the motor induced voltage calculation map shown in FIG. 4 based on the motor rotation speed Nm and the motor field current target value Ifmt. . Here, the motor induced voltage calculation map uses the motor field current target value Ifmt as a parameter, the horizontal axis represents the motor rotation speed Nm, the vertical axis represents the motor induced voltage E, and the motor rotation speed Nm increases. The motor induced voltage E is set so that the motor induced voltage E increases even when the motor induced voltage E increases nonlinearly and the motor field current target value Ifmt increases.
[0032]
Next, the process proceeds to step S7, and the armature current target value map preset based on the motor output torque Tm calculated in step S4 and the motor field current target value Ifmt calculated in step S5 is referred to. Thus, the armature current target value Iat for the DC motor 4 is calculated. Here, although the armature current target value map is not shown, when the motor output torque Tm is “0”, the armature current target value Iat becomes “0” regardless of the value of the motor field current target value Ifmt, As the motor output torque Tm increases from this state, the armature current target value Iat increases, and as the motor field current target value Ifmt increases, the armature current target value Iat decreases, and the motor output torque When the value becomes larger, the armature current target value Iat is set to “0” sequentially from the smaller motor field current target value Ifmt.
[0033]
Next, the process proceeds to step S8, the armature current Ia detected by the current sensor 25 is read, and then the process proceeds to step S9, where PID calculation is performed based on the armature current target value Iat and the armature current Ia. The armature control current Ia ′ is calculated, and the voltage target value Vt for the generator 7 is calculated by performing the following equation (1) based on the armature control current Ia ′ and the motor induced voltage E.
[0034]
Vt = Ia ′ × R + E (1)
Here, R is the resistance of the electric wire and the resistance of the coil of the DC motor 4.
Next, the process proceeds to step S10, and PID control calculation is performed based on the motor field current target value Ifmt calculated in step S5 and the current motor field current Ifm to calculate the motor field control current Ifm '.
[0035]
Next, the process proceeds to step S11, where the calculation of the following equation (2) is performed based on the motor output torque Tm, and the clutch transmission torque T to the electromagnetic clutch 11 is calculated._CLIs calculated.
T_CL= Tm × K_DEF× K_TM  + T_CL0  ………… (2)
Where K_DEFIs the reduction ratio in the differential gear 12, K_TM  Is the clutch torque margin, T_CL0Is the clutch initial torque.
[0036]
Next, the process proceeds to step S12 and the clutch transmission torque T_CLFor example, the clutch initial torque T_CL0Set value T corresponding to_S1Whether or not T is exceeded and T_CL> T_S1If YES, the routine proceeds to step S13, where the clutch current command value I_CLAs a relatively large current setting value I_SUIs set and then the process proceeds to step S17._CL≦ T_S1When it is, the routine proceeds to step S14, where the clutch transmission torque T_CLWhether or not is greater than “0” and T_CLIf> 0, the routine proceeds to step S15, where the clutch current command value I_CLCurrent setting value I_SUA relatively small set current I of about 1/5_SLIs set, and the process proceeds to step S17 to be described later._CLWhen = 0, the routine proceeds to step S16, where the clutch current command value I_CLAs “0” is set, the process proceeds to step S17.
[0037]
In step S17, the clutch current command value I set in any of steps S13, S15 and S16._CLIs subjected to pulse width modulation (PWM) to calculate a clutch current control output CL having a duty ratio corresponding to the set current value.
Next, the process proceeds to step S18, where the voltage target value Vt for the generator 7 is pulse width modulated to calculate the generator control output C1 having a duty ratio corresponding to the voltage target value Vt, and then the process proceeds to step S19. Then, the motor field control current Ifm ′ for the DC motor 4 is subjected to pulse width modulation to calculate a motor field control output MF having a duty ratio corresponding to the control current Ifm ′.
[0038]
Next, the process proceeds to step S20, the switching transistor 29 for controlling the electromagnetic clutch 11 with the clutch current control output CL, the generator control output C1 and the motor field control output MF having the duty ratio set in steps S17 to S19, and the generator 7 respectively. After being output to the voltage regulator 22 and the field coil of the DC motor 4, the timer interrupt process is terminated and the program returns to a predetermined main program.
[0039]
In the process of FIG. 4, the process of step S2 and the accelerator stroke sensor 15 correspond to the slave motor drive necessity determination means, and the processes of steps S11 to S17 correspond to the clutch control means.
Next, the operation of the first embodiment will be described with reference to the time chart shown in FIG.
[0040]
Now, with the automatic transmission select lever set to the parking (P) range and the accelerator pedal 14 released, the ignition switch 23 is turned on to stop the vehicle with the engine 2 started. Shall.
In this stop state, when the 4WD switch 18 is turned on at time t1 as shown in FIG. 5A, at this time t1, the select lever is in the parking range as shown in FIG. In the relay control unit 8B, the 4WD relay 21 is controlled to be in an OFF state, the input of the power system power supply to the 4WD controller 8 is stopped, the field coil FC of the generator 7 from the battery 20, and the motor relay of the junction box 10 25, the power supply to the clutch coil 11a of the electromagnetic clutch 11 is stopped.
[0041]
From this stop state, the select lever is moved from the parking range to the drive (D) range through the R range and the N range at time t2, and a predetermined time of about 0.05 seconds has elapsed since the drive range was selected at time t3. At time t4, the 4WD relay control unit 8B controls the 4WD relay 21 to the on state as shown in FIG. 5B.
[0042]
In this state, since the accelerator pedal 14 continues to be released as shown in FIG. 5G, even if the processing of FIG. 4 is executed, the process proceeds from step S2 to step S3 to Voltage target value Vt, motor field control current Ifm ′ for DC motor 4 and clutch transmission torque T_CLAre set to “0”, the generator control output C1, the motor field output MF, and the clutch control output CL are maintained in the OFF state as shown in FIGS. 5D, 5E, and 5F. .
[0043]
After that, when the accelerator pedal 14 is depressed at time t5 and the accelerator depression amount is output from the accelerator stroke sensor 15, it is determined in step S2 that the accelerator is being operated in step S2, and the process proceeds to step S4. Thus, the motor output torque Tm corresponding to the accelerator depression amount AS is calculated.
Next, in steps S5, S6, and S7, the motor field current target value Ifmt, the motor induced voltage E, and the field current target value Iat are calculated. In step S9, the voltage target value Vt for the generator 7 is calculated. In step S10, PID calculation processing is performed based on the motor field current target value Ifmt and the actual motor field current Ia detected by the current sensor 26 to calculate the motor field control current Ifm '. In step S11, the motor output torque is calculated. Based on the Tm, the calculation of the equation (1) is performed, and the clutch transmission torque T_CLIs calculated.
[0044]
At this time, since the motor output torque Tm is maintained at “0” until the accelerator depression amount AS of the accelerator pedal 14 reaches the set value ASs, the voltage target value Vt and the motor field control current Ifm ′ of the generator 7 are “ 0 "is maintained, but clutch transmission torque T_CLFor the clutch initial torque T according to the above equation (2)._CL0Increase by minutes. For this reason, the process proceeds to step S15 via steps S12 and S14, and the clutch control current I_CLIs a relatively small set current I_SLThis clutch control current I_CLIs subjected to pulse width modulation, and a clutch control output CL having a relatively small duty ratio is output to the switching transistor 29 as shown in FIG. 5 (e), whereby the battery 20, 4WD relay is applied to the clutch coil 11a of the electromagnetic clutch 11. By being supplied via 21, the electromagnetic clutch 11 is engaged with a relatively small engagement force.
[0045]
In this state, the voltage target value Vt of the generator 7 is “0”, but since the engine 2 is started and the rotor of the generator 7 is rotating, the permanent magnet provided from the generator 7 to the rotor is provided. The output voltage V corresponding to the minute is generated as shown in FIG. 5G, but the DC motor 4 maintains the rotation stopped state by maintaining the control current Ifm ′ at “0” via the motor.
[0046]
Thereafter, when the accelerator depression amount AS exceeds the set value ASs, the motor output torque Tm gradually increases as the accelerator depression amount AS increases, and the motor field current target value Ifmt becomes the maximum value I_MAXTherefore, the armature current target value Iat of the DC motor 4 is increased, the voltage target value Vt for the generator 7 is increased, and the motor field control current Ifm ′ is increased, whereby the output of the generator 7 is increased. As the voltage V increases, the armature current Ia of the DC motor 4 increases, and a large motor output torque is generated in the DC motor 4.
[0047]
On the other hand, clutch transmission torque T_CLIndicates that the clutch initial torque Tm increases as the motor output torque Tm increases._CL0When the value becomes larger, the process proceeds from step S12 to step S13, and the clutch control current I_CLAs the normal set current I_SUIs selected, and this is pulse-width modulated, so that a clutch control output CL having a large duty ratio is output to the switching transistor 29, whereby a large current is supplied to the clutch coil 11a of the electromagnetic clutch 11 and the clutch engagement force is increased. It becomes a normal value and a large clutch transmission torque, and the output torque of the DC motor 4 is transmitted to the rear wheels 1RL and 1RR via the speed reducer 10, the electromagnetic crunch 11 and the differential gear 12, and further via the drive shafts 13L and 13R. These rear wheels 1RL and 1RR are rotationally driven.
[0048]
Thereafter, when the motor rotation speed Nm exceeds the first set value N1, the motor field current target value Ifmt decreases accordingly, and when the motor rotation speed Nm exceeds the second set value N2, the set value I_LAnd the induced voltage E of the DC motor 4 is decreased to increase the current flowing through the DC motor 4 to obtain the required motor output torque Tm. As a result, even if the DC motor 4 rotates at a high speed, the required motor output torque Tm can be obtained because the increase in the motor induced voltage E is suppressed and the decrease in the motor output torque is suppressed. Further, the motor field current Ifm is controlled in two steps, in which the rotational speed Nm of the DC motor 4 is less than the predetermined rotational speed N1 and more than the predetermined rotational speed N2, thereby enabling control compared to continuous field current control. Necessary electronic circuits can be manufactured at low cost.
[0049]
Thereafter, when the accelerator pedal 14 is released, in the process of FIG. 4, the process proceeds from step S2 to step S3, and the voltage target value Vt of the generator 7, the motor field current target value Ifmt, and the clutch are the same as when the vehicle is stopped. Transmission torque T_CLIs set to “0”, the drive of the generator 7, the DC motor 4, and the electromagnetic clutch 11 is stopped.
[0050]
As described above, according to the first embodiment, when the accelerator pedal 14 is not depressed, the clutch control output CL of the electromagnetic clutch 11 is set to “0”. Consumption can be cut, and the motor output torque Tm is set based on the accelerator depression amount AS, and the armature current target value Iat is calculated based on the motor output torque Tm and the motor field current target value Ifmt, Based on the armature current target value Iat and the motor induced voltage E, the calculation of the equation (1) is performed to calculate the voltage target value Vt of the generator 7, and the motor output torque Tm and the clutch initial torque T are calculated._CL0And the clutch transmission torque T_CLAnd this clutch transmission torque T_CLSince the clutch control output CL is controlled in two stages so as to generate the above, a time lag waiting for clutch connection does not occur, and the vehicle acceleration performance can be improved.
[0051]
Next, a second embodiment of the present invention will be described with reference to FIG.
In the second embodiment, instead of supplying the clutch coil 11a of the electromagnetic clutch 11 from the battery 20 via the 4WD relay 21, the electric power supplied from the junction box 9 to the DC motor 4 is supplied to the electromagnetic clutch 11. It is what I did.
[0052]
That is, in 2nd Embodiment, as shown in FIG. 6, it mentioned above except that the end of the clutch coil 11a of the electromagnetic clutch 11 is connected to the connection line between the junction box 9 and the DC motor 4. In the first embodiment, the configuration is the same as in FIG. 2, and the same reference numerals are given to the corresponding parts to those in FIG.
[0053]
According to the second embodiment, when the accelerator pedal 14 is depressed and the process of FIG. 4 proceeds to step S4 from step S2, the armature current Ia increases as the motor output torque Tm increases. In response to this, the clutch current I supplied to the clutch coil 11a of the electromagnetic clutch 11_CLThe clutch current I_CLIs controlled by the clutch control output CL, so that the clutch current I is reliably linked to the increase of the motor output torque of the DC motor._CLThe vehicle acceleration performance can be improved without causing a time lag for waiting for clutch engagement.
[0054]
In the second embodiment, the case where the electric power input to the DC motor 4 is supplied to the electromagnetic clutch 11 has been described. However, the present invention is not limited to this, and the electric power supplied to the DC motor is not limited to this. It is also possible to detect and control the power supplied to the clutch coil 11a of the electromagnetic clutch 11 via the 4WD relay 21 based on the detected power.
[0055]
Next, a third embodiment of the present invention will be described with reference to FIGS.
In the third embodiment, slip of the electromagnetic clutch 11 is detected, and the motor output torque is controlled so as to eliminate the clutch slip.
That is, in the third embodiment, whether the processing of FIG. 4 in the first embodiment described above with the 4WD controller 8 is in the motor output torque reduction control state next to the processing of step S3 as shown in FIG. A step S21 for resetting the control flag F1 indicating NO to “0” indicating that the motor output torque reduction correction state is not added is added, and the motor torque calculation process shown in FIG. 8 is executed in step S4. The same processing as that in FIG. 4 is performed, and the same processing steps as those in FIG. 4 are given the same step numbers, and the detailed description thereof is omitted.
[0056]
In the motor torque calculation process, first, in step S31, the motor output torque Ta is calculated with reference to the motor output torque calculation map based on the accelerator depression amount AS in the same manner as step S4 in FIG. , The wheel speed detected by the wheel speed sensors 16RL to 16RR, that is, the output speed Nw of the clutch is read, and then the process proceeds to step S33 where the rotation of the DC motor 4 detected by the motor speed sensor 28 is read. The number Nm is read, converted by a predetermined reduction ratio, and the clutch input side rotational speed Nm ′ is calculated. Then, the process proceeds to step S34.
[0057]
In this step S34, the clutch slip amount ΔN (= Nm′−Nw) of the electromagnetic clutch 11 is calculated by subtracting the clutch output side rotational speed Nw from the clutch input side rotational speed Nm ′, and then the process proceeds to step S35. Thus, it is determined whether or not the control flag F1 indicating whether or not the motor output torque reduction control state is set to “1” indicating the motor output torque reduction correction state, and this is set to “1”. When the control flag F1 is reset to “0”, the routine jumps to step S43, which will be described later, and it is determined that the motor output torque reduction correction state is not in effect, and the routine proceeds to step S36 where the clutch slip amount ΔN is set to “ It is determined whether or not a threshold value α close to 0 ″ is exceeded. If ΔN ≦ α, it is determined that the electromagnetic clutch 11 is not slipping, and The process proceeds to step S37, the motor output torque Ta calculated in step S31 is set as the motor output torque Tm as it is, the process is terminated, and the process proceeds to step S5 in FIG. 7. If ΔN> α, the process proceeds to step S37. The process proceeds to S38.
[0058]
In this step S38, the control flag F1 is set to “1” representing the motor output torque decrease correction state, and then the process proceeds to step S39, where a value obtained by subtracting the predetermined value β from the motor output torque Ta calculated in the step S31 is obtained. After calculating as a new motor output torque Tb (i), the routine proceeds to step S40, where it is determined whether or not the clutch slip amount ΔN is “0”, and when ΔN> 0, the slip continues. Then, the process proceeds to step S41, and the motor output torque Tb (i) calculated in step S39 is set as the motor output torque Tm as it is, and then the process proceeds to step S5 in FIG. 7. When N = 0, the process proceeds to step S42. Then, after the previous motor output torque Tb (i-1) is set as the motor output torque Tm, the process proceeds to step S5 in FIG.
[0059]
In step S43, a value obtained by subtracting the predetermined value β from the previous motor output torque Tb (i-1) is calculated as a new motor output torque Tb (i), and then the process proceeds to step S40.
In the process of FIG. 8, the process of steps S31 to S34, the wheel speed sensors 16RL to 16RR, and the motor rotation speed sensor 28 correspond to the clutch slip detection means, and the process of step S21 of FIG. 7 and step S35 of FIG. -The process of step S32 constitutes a motor output voltage correction means.
[0060]
According to the third embodiment, when the vehicle is started by depressing the accelerator pedal 14, the electromagnetic clutch 11 is engaged as shown in FIG. 9, but the motor output torque Tm is determined by the determination result of step S36. When the clutch slip amount ΔN is less than or equal to the threshold value α, it is determined that there is no slip in the electromagnetic clutch 11 and the process proceeds to step S27, and the motor output torque Ta calculated in step S31 is set as the motor output torque Tm as it is. As in the first embodiment, the motor output torque Tm increases as the motor output torque Ta increases.
[0061]
However, when the clutch input side rotational speed Nm ′ becomes larger than the clutch output side rotational speed Nw at time t11 and the electromagnetic clutch 11 slips, the clutch slip amount ΔN calculated in step S34 is less than or equal to the threshold value α. In some cases, the motor output torque Ta is continuously set as the motor output torque Tm. However, when the clutch slip amount ΔN exceeds the threshold value α at time t12, the process proceeds from step S36 to step S38, and the control flag F1 is set. Then, the process proceeds to step S39, where a value obtained by subtracting the set value β from the motor output torque Ta calculated in step S31 is calculated as a new motor output torque Tb (i), and then in step S40. Since the clutch slip amount ΔN is larger than “0”, the process proceeds to step S41, and step S3. The motor output torque Tb (i) calculated in 9 is set as the motor output torque Tm.
[0062]
Therefore, the current motor output torque Tb (i) is reduced by the set value β with respect to the motor output torque Ta calculated in step S31, and accordingly, the motor field control output MF of the DC motor is also reduced. Therefore, the actual motor output torque of the DC motor 4 is reduced.
Next, when the processing of FIG. 8 is executed, since the control flag F1 is set to “1”, the process proceeds from step S35 to step S43, and the motor output torque Tb (i) is further set to the previous value Tb ( i-1) is decreased by the set value β, and even in this state, when the clutch slip amount ΔN has not decreased to “0”, the routine proceeds to step S41, where the motor output torque Tm (i) is set as the motor output torque Tm. As a result, the actual motor output torque of the DC motor 4 is further reduced.
[0063]
In this way, the motor output torque Tm is gradually decreased by the set value β gradually, thereby reducing the clutch slip amount ΔN of the electromagnetic clutch 11, and the clutch slip amount ΔN becomes “0”, that is, at the electromagnetic clutch 11 at time t 13. When no slip occurs, the process proceeds from step S40 to step S42, and the previous motor output torque Tb (i-1) is set as the motor output torque Tm, so that the motor output torque Tm becomes the previous value. This state is maintained until the accelerator pedal 14 is released and the process of FIG. 7 proceeds from step S2 to step S3 to step S21, so that the control flag F1 is reset to “0”.
[0064]
Therefore, when the electromagnetic clutch 11 deteriorates and slips, the motor output torque is gradually decreased and corrected to reduce the clutch slip amount ΔN. Therefore, the torque reduction in the DC motor 4 is accompanied by a rapid torque fluctuation. It is possible to smoothly perform the operation without causing vibration and shock.
In addition, since the reduction correction of the motor output torque is continued until the clutch slip amount ΔN becomes “0”, the reduction of the motor output torque can be suppressed by the reduction to the maximum torque that can be transmitted by the electromagnetic clutch 12. 4, the 4WD function for driving the rear wheels 1RL and 1RR can be maintained in a state as high as possible.
[0065]
In the first to third embodiments, the case where the electromagnetic clutch 11 is applied as the clutch means has been described. However, the present invention is not limited to this, and a fluid pressure clutch can also be applied. For this, it is only necessary to control the clutch engagement force by electrically controlling the pressure control valve that controls the fluid pressure supplied to the fluid pressure clutch, and any other clutch that can electrically control the clutch engagement force is applied. can do.
[0066]
Moreover, in the said 1st-3rd embodiment, although the case where the input shaft of the generator 7 was connected with the engine 2 via the belt 6 was demonstrated, it is not limited to this, The input shaft may be connected to the rotating portion from the output side of the transfer to the front wheels 1FL and 1FR. In this case, the load during idling of the engine 2 can be reduced.
[0067]
Further, in the first to third embodiments, the case where the generator 7 is provided and the DC motor 4 is driven using the rotational force of the engine 2 has been described. However, the present invention is not limited to this. The generator 7 may be omitted, and power may be supplied to the DC motor 4 from the battery 20 or another battery.
Furthermore, in the first to third embodiments, the motor output torque Tm is added to the torque margin K in the equation (2)._TMMultiplied by the clutch transmission torque T_CLHowever, the present invention is not limited to this, and the torque margin K is included in the motor output torque Tm._TMMay be added.
[0068]
Still further, in the first to third embodiments, the clutch control current I_CLHowever, the present invention is not limited to this, and it may be controlled in multiple stages of three or more stages or continuously without depending on the clutch transmission torque Tm. From the motor output torque Tm input to the clutch transmission torque T_CLIt may be controlled so that becomes larger.
[0069]
In the first to third embodiments, the clutch transmission torque T based on the motor output torque Tm._CLHowever, the present invention is not limited to this, and the clutch transmission torque T is calculated._CLIs first obtained, and this clutch transmission torque T_CLA smaller motor output torque Tm may be calculated based on the above.
[0070]
Furthermore, in the first to third embodiments, the case where the DC motor 4 is applied as the electric motor has been described. However, the present invention is not limited to this, and an AC motor capable of varying the motor output torque is applied. You can also.
In the first to third embodiments, the present invention is applied to a four-wheel drive vehicle. However, the present invention is not limited to this, and two or more drive wheels are provided in the front-rear direction. The present invention can be applied to a case where some main drive wheels are driven by an internal combustion engine or a main motor and the remaining sub drive wheels are driven by a sub motor.
[Brief description of the drawings]
FIG. 1 is a schematic device configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a block diagram of a control system in the first embodiment.
FIG. 3 is a functional block diagram showing a 4WD controller according to the first embodiment.
FIG. 4 is a flowchart illustrating an example of a driving wheel torque control processing procedure in the 4WD controller according to the first embodiment.
FIG. 5 is a time chart for explaining operations in the first embodiment;
FIG. 6 is a block diagram of a control system showing a second embodiment of the present invention.
FIG. 7 is a flowchart showing an example of a driving wheel torque control processing procedure in a 4WD controller according to a third embodiment of the present invention.
8 is a flowchart showing a specific example of the motor torque calculation process of FIG.
FIG. 9 is a time chart for explaining operations in the third embodiment.
[Explanation of symbols]
1FL, 1FR Front wheel
1RL, 1RR Rear wheel
2 Engine
4 DC motor
7 Generator
8 4WD controller
9 Junction box
10 Reducer
11 Electromagnetic clutch
15 Accelerator stroke sensor
16FL-16RR Wheel speed sensor
17 Shift position sensor
18 4WD switch
20 battery
21 4WD relay
22 Voltage regulator
26 Current sensor
28 Motor rotation speed sensor

Claims (8)

Driving force of a vehicle in which main driving wheels constituting a part of a plurality of driving wheels arranged in the longitudinal direction of the vehicle are driven by an internal combustion engine or a main motor and the remaining sub driving wheels are driven by a sub motor. In the control device, a slave motor control means for driving and controlling the slave motor, and a clutch means capable of being interrupted according to a clutch transmission torque command inputted with a transfer torque inserted between the slave motor and the slave drive wheel A slave motor drive necessity judgment means for judging whether or not the slave motor needs to be driven by the slave motor, and the clutch means when the judgment result of the slave motor drive necessity judgment means is a drive necessity for the slave drive wheel. and a clutch control means for outputting a clutch transmission torque command to control the connected state, the clutch control means may be linked to sub power motive output torque control command during connection of the clutch means Driving force control apparatus for a vehicle, characterized in that it is configured to output a clutch transmission torque command corresponding to the sub power motive output torque control command to the clutch means. Driving force of a vehicle in which main driving wheels constituting a part of a plurality of driving wheels arranged in the longitudinal direction of the vehicle are driven by an internal combustion engine or a main motor and the remaining sub driving wheels are driven by a sub motor. In the control device, a slave motor control means for driving and controlling the slave motor, and a clutch means capable of being interrupted according to a clutch transmission torque command inputted with a transfer torque inserted between the slave motor and the slave drive wheel A slave motor drive necessity judgment means for judging whether or not the slave motor needs to be driven by the slave motor, and the clutch means when the judgment result of the slave motor drive necessity judgment means is a drive necessity for the slave drive wheel. and a clutch control means for outputting a clutch transmission torque command to control the connected state, the sub power motive control means, the clutch transfer torque fingers of the clutch control unit when connecting the clutch means Together interlocked, the driving force control apparatus for a vehicle, characterized in that it is configured to control the sub power motive output torque in accordance with the clutch transfer torque command.   3. The vehicle driving force control device according to claim 1, wherein the sub-motor driving necessity determination unit is configured to determine that driving is required when an accelerator depression operation is performed. . Said clutch control means, driving of the vehicle according to claim 1 or 3, characterized in that it is configured to perform connection control of the clutch means by the power supplied from the power supply control system of the sub power motive control means Force control device. The slave motor control means includes clutch slip detection means for detecting clutch slip based on a difference in rotational speed between the input side and the output side of the clutch means during connection control of the clutch means, and the clutch slip detection means the upon detecting the driving force control apparatus for a vehicle according to any one of claims 1 to 4, characterized in that it is configured to correct the sub power motive output torque reduction direction. 6. The driving force control apparatus for a vehicle according to claim 5, wherein the correction of the slave motor output torque in the decreasing direction is continued until clutch slip detection means no longer detects clutch slip. 6. The vehicle driving force control apparatus according to claim 5, wherein the correction of the slave motor output torque in the decreasing direction is performed by gradually reducing the slave motor output torque. The clutch slip detection means includes slave motor rotation speed detection means for detecting the rotation speed of the slave motor and slave drive wheel rotation speed detection means for detecting the rotation speed of the slave drive wheel, and the slave motor rotation speed detection means. The vehicle driving force control device according to any one of claims 5 to 7 , wherein clutch slippage is detected from a rotational speed difference detected by the driven wheel rotational speed detecting means.

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