JPH06153315A - Brake system for motor vehicle - Google Patents

Abstract

PURPOSE:To achieve brake feeling similar to that of a vehicle employing an internal-combustion engine as a drive source while enhancing energy recovery efficiency in a motor vehicle having driving wheels subjected to regenerative brake. CONSTITUTION:First regenerative brake power corresponding to normal hydraulic brake power is determined based on the operating amount of a brake pedal 8 while second regenerative brake power corresponding to engine brake is determined based on the operating amount of an accelerator pedal 28 and r.p.m. of a motor 2 so that the motor 2 exhibits sum of first and second regenerative brake powers. When the accelerator pedal and the brake pedal 8 are operated concurrently, regenerative brake is disabled and switching is made to hydraulic brake.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a drive wheel which is connected to a motor which uses a battery as an energy source and driven, and which is capable of hydraulic braking and regenerative braking by operating a brake operator and an accelerator operator. Electric vehicles.

[0002]

2. Description of the Related Art Conventionally, as an electric vehicle having drive wheels capable of regenerative braking, for example, Japanese Patent Publication No. 56-6204.
Alternatively, those described in JP-B-49-28933 are known.

[0003]

By the way, in a vehicle using an internal combustion engine as a drive source, so-called engine braking acts by returning the accelerator pedal in addition to the hydraulic braking force associated with the operation of the brake pedal. On the other hand, in an electric vehicle that uses a motor as a drive source, it is possible to exert the regenerative braking force by making the motor function as a generator, but if the regenerative braking force is exerted by operating the brake pedal, the internal combustion engine It feels uncomfortable because the braking force equivalent to the engine brake of the vehicle that is the drive source is not obtained, and when the regenerative braking force is exerted by operating the accelerator pedal, most of the kinetic energy of the vehicle is discarded by hydraulic braking. It is uneconomical because of the need.

The present invention has been made in view of the above circumstances, and it is possible to obtain a braking feeling close to that of a vehicle which uses an internal combustion engine as a drive source and which is excellent in energy recovery efficiency. The purpose is to provide.

[0005]

In order to achieve the above object, a braking device for an electric vehicle according to the present invention is connected to and driven by a motor having a battery as an energy source, and
An electric vehicle having drive wheels capable of hydraulic braking and regenerative braking by operating a brake operator and an accelerator operator, and means for determining a first regenerative braking force based on an operating state of the brake operator, Means for determining the second regenerative braking force based on the operating state of the accelerator operator and the rotation speed of the motor, and driving by outputting the total regenerative braking force obtained by adding the first and second regenerative braking forces The first feature is that the vehicle includes means for regeneratively braking the wheel.

In addition to the above-mentioned first feature, the present invention also provides:
A second feature is that a means for prohibiting regenerative braking is provided when the motor is driven by the operation of the accelerator operator.

In addition to the above-mentioned first feature, the present invention also provides:
A third feature is that the brake operation amount detection sensor for detecting the operation amount of the brake operation element includes means for correcting the output when the brake operation element is not operated to zero.

[0008]

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

1 to 50 show an embodiment of the present invention. FIG. 1 is an overall configuration diagram of an electric vehicle equipped with the braking device, FIG. 2 is a block diagram of a control system, and FIGS. FIG. 5 is a schematic explanatory view of the braking mode, FIG. 5 is a diagram showing the structure and characteristics of the differential pressure valve, and FIGS.
0 is a diagram showing the structure and characteristics of a differential pressure valve according to another embodiment.

As shown in FIG. 1, this electric vehicle has a pair of front wheels Wf as driven wheels and a pair of rear wheels W as driving wheels.
The rear wheel Wr is connected to an electric motor 2 that uses a battery 1 as an energy source through a four-stage transmission 3 and a differential gear 4. A PDU (power drive unit) 5 is interposed between the battery 1 and the motor 2 to control the driving of the motor 2 by the battery 1 and to charge the battery 1 with the electric power generated by the motor 2 in association with regenerative braking. Control. PD
The U5 and the transmission 3 are connected to a motor / mission control ECU (electronic control unit) 6, and the motor / mission control ECU 6 is connected to a brake ECU (electronic control unit) 7.

The master cylinder 9 operated by the brake pedal 8 is connected to an accumulator 11 that accumulates pressure by a hydraulic pump 10 via a modulator 12 and a brake cylinder 13f for each front wheel Wf and a brake cylinder 13r for each rear wheel Wr. Connected to. Modulator 12
Has a two-channel ABS (anti-lock brake system) control valve 14f for the front wheels and a one-channel ABS control valve 14r for the rear wheels, and when front wheel Wf and rear wheel Wr tend to lock, The brake hydraulic pressure transmitted to the brake cylinders 13f and 13r is reduced.

A brake cylinder 13f for the front wheel Wf is provided in an oil passage connecting the master cylinder 9 and the modulator 12.
Differential pressure valve 16f for controlling the brake hydraulic pressure transmitted to
And a differential pressure valve 16r for controlling the brake hydraulic pressure transmitted to the brake cylinder 13r of the rear wheel Wr.

The differential pressure valve 16f for the front wheels is a spring 1
A valve body 18f biased in the valve opening direction by 7f and a linear solenoid 1 for adjusting the set load of the spring 17f.
9f, the differential pressure valve 16r for the rear wheels has the same structure as that for the front wheels. The differential pressure valve 16f,
The one-way valves 15f, 1 that restrict the hydraulic pressure transmission from the master cylinder 9 to the modulator 12 and allow the hydraulic pressure transmission from the modulator 12 to the master cylinder 9 are provided at 16r.
5r are provided in parallel.

As can be seen by referring also to FIG.
The brake ECU 7 includes a battery provided in the battery 1.
Battery current sensor 20₁, Battery voltage sensor 20₂Oh
And the battery temperature sensor 21 and the rotation speed of the motor 2 are detected.
Outgoing motor rotation speed sensor 22, front wheel Wf and rear wheel
Wheel speed sensor 23 provided in Wr_FL, 23_FR, 2
Three _RL, 23_RRAnd a brake provided on the brake pedal 8.
Rake pedal force sensor 24₁And brake operation switch
Touch 24₂And the access provided on the accelerator pedal 28
Provided in the accumulator 12 and the opening degree sensor 25.
Accumulator pressure sensor 26 and differential pressure valve 16
provided between f and 16r and the modulator 12, respectively.
When a pair of hydraulic sensors 27f and 27r are connected,
Together, the oils controlled based on their output signals
The pressure pump 10, the differential pressure valves 16f and 16r, and
The ABS control valves 14f and 14r are connected.

The PDU 5 for controlling the battery 1 and the motor 2 and the transmission 3 are connected to a motor / mission control ECU 6 which operates by receiving a regenerative braking command and a mission shift command from the brake ECU 7. .

Next, an outline of each braking mode will be described with reference to FIGS. 3 and 4.

Front wheels W in a vehicle equipped with this braking device
There are three types of braking modes for f and the rear wheel Wr: [mode 3], [mode 2], and [mode 1], and any one of them is selected by the initial determination to perform braking in a predetermined mode. , The mode is changed during braking according to the change in the driving state. [ Mode 3 ] This mode is selected in the normal operating state. That is, it is selected when each system is functioning normally, and is not braking suddenly, is not steering, and is not operating the antilock braking system.
In [Mode 3], the front wheel Wf is hydraulically braked and the rear wheel Wr is
When the brake pedal 8 is depressed, only the rear wheel Wr is regeneratively braked and the front wheel Wf is not hydraulically braked. When the braking force of the rear wheel Wr exceeds the revolving point P which is the regenerative limit determined by various conditions of the battery 1 and the motor 2, the rear wheel Wr is braked by the combined use of regeneration and hydraulic pressure, and the front wheel Wf Hydraulic braking is started. When the braking force reaches the break point Q, the braking force of the rear wheel Wr is weakened by the action of the well-known proportional pressure reducing valve provided inside the modulator 12, and eventually the polygonal line O.
A braking force distribution characteristic shown by PQR is given. The braking force distribution characteristic OPQR is biased above the ideal distribution characteristic shown by the broken line, that is, the braking force distribution of the rear wheels Wr is biased to exceed the ideal distribution characteristic, whereby regenerative braking of the rear wheels Wr is possible. Is used to charge the battery 1 to extend the travelable distance per charge. [ Mode 2 ] This mode is selected when the steering operation is performed or the antilock brake system is activated when the systems are functioning normally and the hard braking is not being performed. This [mode 2] is also the above-mentioned [mode 3]
Similarly, in this mode, the front wheels Wf are hydraulically braked and the rear wheels Wr are hydraulically and regeneratively braked. However, when the brake pedal 8 is stepped on, the hydraulic braking of the front wheels Wf is performed concurrently with the regenerative braking of the rear wheels Wr. If the braking force of the rear wheels Wr exceeds the regenerative limit in the meantime, the rear wheels Wr regenerate and hydraulically operate. Is braked by the combination of. When the braking force reaches the turning point Q, the braking force of the rear wheel Wr is weakened by the proportional pressure reducing valve, and as a result, the polygonal line OQ showing the braking force distribution characteristic of the [mode 2].
The R is given more weight to the braking force of the front wheel Wf than to the ideal distribution characteristic shown by the broken line. As described above, by selecting [Mode 2] during the steering or the operation of the anti-lock brake system and simultaneously braking the front wheels Wf and the rear wheels Wr from the time of the initial braking, it is possible to avoid the deterioration of the steering stability. it can. [ Mode 1 ] In this mode, even if each system is not functioning normally, or even if each system is functioning normally,
Selected during hard braking or when the antilock braking system is operating under certain conditions. In this [mode 1], regenerative braking of the rear wheels Wr is not performed, and the front wheels Wf and the rear wheels Wr
Both r are braked by hydraulic pressure. In this way the rear wheel Wr
By performing only hydraulic braking without performing regenerative braking of
The responsiveness of the braking force can be enhanced as compared with the regenerative braking in which the response is slightly delayed while the rotation of the rear wheel Wr is transmitted to the motor 2 via the differential 4 and the transmission 3. Thus, the braking force distribution characteristic indicated by the polygonal line OQR has a greater weight on the braking force of the front wheel Wf than the ideal distribution characteristic indicated by the broken line as in the above [Mode 2].
As described above, by selecting the [Mode 1] during the sudden braking, the braking responsiveness can be improved.

In short, during sudden braking during braking in the above [Mode 3] or [Mode 2], the mode is changed to [Mode 1]. On the other hand, if the steering operation is performed during braking in [Mode 3], or if the anti-lock brake system is activated due to the detection of a wheel lock tendency due to a low friction coefficient road (low μ road), 3] was changed to [Mode 2],
When a stronger wheel locking tendency due to a low friction coefficient road is detected during braking in [mode 2], the mode is changed to [mode 1]. As described above, by selecting [Mode 2] or [Mode 1] depending on the steering condition and the road surface friction coefficient, it is possible to avoid a decrease in steering stability. The change from [Mode 3] to [Mode 2] or [Mode 1] is a line of equal braking force, that is, a line in which the sum of the braking force of the front wheels Wf and the braking force of the rear wheels Wr is kept constant. Along the
This prevents a sudden change in the total braking force of the front and rear wheels Wf, Wr.

FIG. 5A shows a differential pressure valve 1 on the front wheel Wf side.
6f shows a specific structure, and the differential pressure valve 16r on the rear wheel Wf side also has the same structure. As is clear from the figure, the differential pressure valve 16f includes a valve body 18f biased in a valve opening direction by a spring 17f and a linear solenoid 1 for adjusting a set load of the spring 17f.
9 f, and a one-way valve 15 f that restricts hydraulic pressure transmission from the master cylinder 9 to the modulator 12.

According to the differential pressure valve 16f, the input oil pressure P _IN and the output oil pressure P _OUT match with each other when the linear solenoid 19f is demagnetized, but the linear solenoid 19f is excited to apply the biasing force f _S to the valve body 18f. In the urged state, FIG.
Input / output characteristics having hysteresis as shown by O, A, B, and C are obtained in (B). That is, the output oil pressure P _OUT is zero while the input oil pressure P _IN increases from the O point to the A point,
When the valve body 18f opens at point A, the output oil pressure P _OUT increases in accordance with the increase of the input oil pressure P _IN in the relationship of P _OUT = P _IN −fs / a (1). Here, a is the cross-sectional area of the input port. Then, the valve body 18f is also to reduce the input hydraulic pressure P _IN point B is the output hydraulic pressure P _OUT is maintained in a closed state does not decrease immediately, the output hydraulic pressure P _OUT point C that coincides with the input hydraulic pressure P _IN Is held constant until. When the one-way valve 15f is opened at point C, the output hydraulic pressure P _OUT and the input hydraulic pressure P _IN match,
The output oil pressure P _OUT decreases to the point O while maintaining the relationship of P _OUT = P _IN (2). At this time, the hysteresis H between the pressure increase and the pressure decrease is determined by H = fs / a (3), and its value becomes relatively large.

Therefore, in the case where the ratio of the hydraulic braking force to the regenerative braking force changes in the process of increasing or decreasing the pedaling force of the brake pedal 8, the sum of the two braking forces does not change suddenly. It is necessary to control the height as shown in FIG. That is, in the region from the point O to the point A where the output hydraulic pressure P _OUT (that is, the hydraulic braking force) does not increase even if the input hydraulic pressure P _IN (that is, the pedaling force) increases, the regenerative braking force increases as the pedaling force increases, In the region of points A to B where the output hydraulic pressure P _OUT increases, the increase of the regenerative braking force is suppressed, and in the region of points B to C where the output hydraulic pressure P _OUT does not decrease even if the input hydraulic pressure P _IN decreases. It is necessary to suppress the reduction of the regenerative braking force in the region from the point C to the point O where the regenerative braking force is reduced as the pedaling force is reduced and the output hydraulic pressure P _OUT is reduced. The above operation will be described later in detail with reference to flowcharts and graphs.

Next, the operation of the braking device having the above configuration will be described with reference to the flowchart of the main routine shown in FIG.

First, in step S100, various programs and data are stored in the storage devices of the brake ECU 7 and the motor / mission control ECU 6, and the braking device is initially set in an operable state.

In step S200, the battery current is
Sensor 20₁, Battery voltage sensor 20₂, Battery temperature
Degree sensor 21, motor rotation speed sensor 22, wheel speed sensor
23 _FL, 23_FR, 23_RL, 23_RR，、 Brake pedal depression
Force sensor 24₁, Accelerator position sensor 25, accumulator
Data pressure sensor 26 and hydraulic pressure sensors 27f and 27r
The force signal is read into the brake ECU 7 (see Fig. 2).
See). Then, the vehicle is calculated by the vehicle speed calculation routine (see FIG. 7).
The calculation of the speed V is performed, and the steering angle calculation routine (Fig.
8 to FIG. 9), the steering angle θ is calculated.

In step S300, the regenerative braking force equivalent to the engine brake of a vehicle having an internal combustion engine as a drive source is calculated by an engine brake (hereinafter abbreviated as "emble") equivalent regenerative braking force calculation routine (see FIGS. 10 to 11). Calculation is performed.

In step S400, the limit value of the regenerative braking force that can be exerted at each moment is calculated by the regeneration limit calculation routine (see FIGS. 12 to 16) based on the state of the battery 1 and the state of the motor 2. .

In step S500, the presence / absence of brake operation is first determined based on the output of the brake operation switch 24 ₂ provided on the brake pedal 8. Therefore, if braking is in progress, the [mode 3], [mode 2], [mode 1] is determined by the mode determination routine (see FIGS. 17 to 21) based on the state of the braking operation or the steering operation or the friction coefficient of the road surface. ] Is selected, and the mode change from [mode 3] to [mode 2] or [mode 1] is determined. Subsequently, the differential pressure valve operation amount determination routine (see FIGS. 22 to 28) determines the differential pressure valve operation amount that determines the hydraulic braking force of the front wheels Wf and the rear wheels Wr, and the regenerative braking force command value determination routine. (Fig. 2
9 to 35), the magnitude of the regenerative braking force of the rear wheel Wr is obtained.

On the other hand, when it is determined that the braking is not being performed based on the output of the brake operation switch 24 ₂ , the zero point correction of the brake pedal tread force sensor 24 ₁ is performed by the brake pedal tread force sensor 0 correction routine (see FIG. 36). Is done. After the differential pressure valve output value and the regeneration command value are both set to zero, each variable clearing routine (see FIG.
7), each variable is set to zero.

In step S600, the shift command routine (see FIGS. 38 to 42) calculates a shift position at which the regenerative braking force can be maximized, and the transmission 3 is automatically operated toward the shift position. It

In step S700, the fail determination routine (see FIGS. 43 to 47) determines the failure of each system. If it is determined that some failure has occurred, [Mode 1] is unconditionally selected, and the front wheels Wf and the rear wheels Wr are hydraulically braked as in a normal hydraulic braking system.

In step S800, hydraulic braking of the front wheels Wf and the rear wheels Wr is executed by the differential pressure valve output routine.

In step S900, regenerative braking of the rear wheels Wr is executed by the regeneration command output routine (see FIG. 48).

In step S1000, antilock control is performed to prevent excessive slip of the front wheels Wf or the rear wheels Wr. That is, the wheel speed sensors 23 _FL , 23 _FR , 2
When it is detected from the output signals of 3 _RL and 23 _{RR that} the wheels are about to enter the locked state, the ABS control valves 14f and 14r of FIG. 1 are controlled. As a result, the modulator 12 interposed between the master cylinder 9 and the brake cylinders 13f and 13r is activated, and the brake hydraulic pressure transmitted to the brake cylinders 13f and 13r of the wheels that tend to lock is reduced to lock the wheels. To be prevented.

Next, the specific contents of the vehicle speed calculation routine in step S200 of the flow chart of FIG. 6 will be described based on the flow chart of FIG.

First, in step S201, the wheel speed V _WFL of the left front wheel Wf and the wheel speed V _WFR of the right front wheel Wf detected by the wheel speed sensors 23 _FL and 23 _FR of the left and right front wheels Wf which are driven wheels are compared, Wheel speed V of left front wheel Wf
If _WFL is greater than the wheel speed V _{WF R} of the right front wheel Wf, that is, when in the right turning, the left and right wheel speed difference ΔV with computed by V _WFL -V _WFR at step S202, turning inner wheel The speed V _WFR is adopted as the vehicle speed V. on the other hand,
The wheel speed V _WFL of the left front wheel Wf is the wheel speed V _{WFR of the} right front wheel Wf
If the following is true, that is, if the vehicle is turning left, step S
At 203, the left and right wheel speed difference ΔV is calculated by V _WFR −V _WFL , and the wheel speed V _WFL of the turning inner wheel is adopted as the vehicle speed V.

Next, the specific contents of the steering angle calculation routine in step S200 of the flow chart of FIG. 6 will be described based on the flow chart of FIG. 8 and the schematic diagram of FIG.

First, in step S211, the steering angle estimated value θ _Cn is calculated based on the following equation.

Θ _Cn = (L / T) * (1 + KV ² ) * (ΔV / V) (4) where L is the vehicle wheel base, T is the vehicle tread, and K is the stability factor.

The above equation will be further described with reference to FIG. Considering a state in which the vehicle is making a steady turn with a turning radius R, the wheel speeds of the turning inner wheel and the turning outer wheel are V and V + ΔV, respectively. Since the wheel speeds V and V + ΔV are respectively proportional to the distance from the center of turning, V: V + ΔV
V = R: R + T is established, and therefore the turning radius R is represented by R = T * (V / ΔV) (5).

On the other hand, as is well known, there is a relation of θ = (L / R) * (1 + KV ² ) ... (6) between the turning radius R and the actual steering angle θ. By substituting the equation (5) into the equation (6), the above equation (4) is obtained.

Then, in step S212, the above (4)
Result of calculating expression three times for each loop θ _Cn, Θ_Cn-1, Θ_Cn-2
The steering angle estimated value θ_CIs obtained
It Estimated steering angle θ calculated in this way_CIs it
After that, the steering angle θ_CUsed as.

Next, the specific contents of the engine braking equivalent regenerative braking force calculation routine in step S300 of the flow chart of FIG. 6 will be described based on the flow chart of FIG. 10 and the graph of FIG.

First, in step S301, the motor torque T _M is obtained based on the motor rotation speed N _M and the accelerator opening TH. FIG. 11 shows the motor torque T _M
Shows a map for obtaining the motor rotation speed N _M
When the accelerator opening TH is determined, the corresponding motor torque T _M is given by the function f _M ( _NN , TH). When the motor torque T _M is above the origin of the vertical axis, it becomes a drive torque, and when it is below the origin, it becomes a regenerative torque.

In the subsequent step S302, whether the motor torque T _M obtained in the step S301 is positive or negative is judged, and when the motor torque T _M is negative and regenerative braking is performed, regenerative braking corresponding to the engine brake is executed in step S303. power T _RGE is set as the -T _M. On the other hand, when the motor torque T _M is non-negative and normal driving is performed in step S302, the engine braking equivalent regenerative braking force T _RGE is set to zero in step S304, and the regeneration corresponding to the axle torque is performed in step S305. Braking force limit T
_RGLM is set to zero.

As described above, when the motor torque T _M becomes non-negative by depressing the accelerator pedal 28, the regenerative braking force limit T _RGLM corresponding to the axle torque is set to zero. When the pedal 8 and the pedal 8 are simultaneously operated, it is possible to generate the driving force of the motor 2 by operating the accelerator pedal 28 and simultaneously generate the hydraulic braking force instead of the regenerative braking force by operating the brake pedal 28. . As a result, not only a feeling similar to that of a vehicle having an internal combustion engine as a drive source can be obtained, but also a hydraulic braking force can be generated at the time of starting on a slope to prevent the vehicle from retreating.

Next, the specific contents of the regeneration limit calculation routine in step S400 of the flow chart of FIG. 6 will be described with reference to the flow chart of FIG. 12 and FIGS.
A description will be given based on the graph of 6.

First, in step S401, it is determined whether or not the regenerative limit flag LMTFL is set to "1", and if NO, the regenerative braking force limit T _MRGLM of the motor 2 is set in FIG. 13 in step S402.
2 and the motor 2 output by the motor speed sensor 22
Is calculated from the rotation speed N _{M of} Regenerative braking force limit T
_MRGLM is given by the function f _LM (N _M ),
The change in the regenerative braking force limit T _MRGLM due to the output signal N _M of the motor rotation speed sensor 22 linearly increases as the rotation speed N _M of the motor 2 increases, then becomes substantially constant, and then sharply decreases.

Then, in step S403, the temperature limit coefficient K _T of the battery 1 is determined by the map of FIG. 14 and the battery temperature TEMP output by the battery temperature sensor 21.
Required from. That is, since the capacity of the battery 1 increases as the temperature rises, as shown in FIG. 14, the temperature limit coefficient K _T is set to linearly increase from 1 as the battery temperature TEMP exceeds the reference value TEMP _0. . Then, in step S404, the regenerative braking force limit T _MRGLM is corrected by multiplying the regenerative braking force limit T _{MRGL M} obtained in step S402 by the temperature limit coefficient K _T obtained in step S403.

If the battery determination timer BTM reset at each predetermined battery voltage determination cycle is counting in steps S405 and 406, step S40
In step 7, the regenerative braking force limit T _MRGLM is subtracted from the regenerative braking force T _RGE corresponding to the _engine to calculate the net regenerative braking force limit T _MRGLM , and in step S408, the gear ratio R _TM of the transmission 3 is multiplied to obtain the final value. The regenerative braking force limit T _RGLM corresponding to the specific axle torque is determined.

If the battery determination timer BTM has timed up in step S405, the battery determination timer BTM is reset in step S409 each time, and the regenerative braking force limit by the voltage of the battery 1 in the following steps S410 to S417. _Correct T _MRGLM .

That is, in step S410, the battery
Voltage sensor 20₂Battery voltage V detected in_BATTWhere
Fixed battery voltage limit V_BTLMIf less than
At step S411, the regeneration limit flag LMTFL is set to "0".
Set to. In step S410,
Battery voltage sensor 20₂Battery voltage V detected in
_BATTIs the predetermined battery voltage limit V_BTLMAbove
And in step S412 the regeneration limit flag LMT
If FL is not set to 1, ie battery
Battery voltage for the first time after the constant timer BTM times out
V_BATTIs the battery voltage limit V_BTLMIf the above
To the current regenerative braking force T in step S413._MRGRLTo
Regenerative braking force limit T_MRGLMSet to
At step S414, the regeneration limit flag LMTFL is set to "1".
Set to.

In the next loop, step S412
Is YES, the battery voltage limit V _BTLM is subtracted from the battery voltage V _BATT detected by the battery voltage sensor 20 ₂ in step S415 to obtain the battery overvoltage ΔV, and in the following step S416, based on the map of FIG. The limit reduction coefficient K _LMDN is determined as a function of the battery overvoltage ΔV. Then, in step S417, by multiplying the limit reduction coefficient K _LMDn correcting the regenerative braking force limit T _{MRGL M} to the regenerative braking force limit T _MRGLM.

Therefore, as shown in FIG. 16, the battery voltage V is _lower than the preset battery voltage limit V _{BTLM.
When BATT} rises, the regenerative braking force limit T _MRGLM is successively decreased to decrease the regenerative braking force T _MRGRL ,
This can prevent problems such as deterioration of the battery 1 and damage to the elements of the PDU 5 due to an excessive rise in the battery voltage V _BATT . Moreover, the regenerative braking force T
_{Since MRGRL} decreases stepwise for each battery voltage determination cycle determined by the battery determination timer BTM, the regenerative braking force T _{MRGRL does not} suddenly change. In addition, after reducing the regenerative braking force limit T _MRGLM , the battery voltage V
_Since the response speed until _BATT decreases is much slower than the cycle of the control loop, the judgment of each loop may cause the regenerative braking force limit T _{MR GLM} to decrease more than necessary. The battery voltage V _BATT is determined by making a determination at each battery voltage determination period that is longer than
Can be controlled appropriately.

Next, the specific contents of the mode determination routine in step S500 of the flow chart of FIG. 6 will be described based on the flow charts of FIGS. 17, 18, 19, 21 and the graph of FIG.

First, in step S501 of the flowchart in FIG. 17, a fail flag FAILFL, which will be described later, is set.
Is not set to "1", step S5
In order to correct the zero point of the brake pedal pedal force sensor 24 ₁ provided on the brake pedal 8, the differential pressure valve 16f is subtracted by subtracting an average deviation P ₂₀ (see FIG. 36) described later from the output value P ₂ thereof. , 16r corrected input oil pressure P _IN
Ask for. That is, this brake pedal depression force sensor 24 ₁
In the zero point correction, if the output of the brake pedal depression force sensor 24 ₁ is excessive, the regenerative braking force determined based on that output exceeds the specified value, and conversely the output of the brake pedal depression force sensor 24 ₁ becomes In order to prevent the regenerative braking force from falling below a specified value if it is too small, the output of the brake pedal depression force sensor 24 ₁ is correctly matched to zero in the state where the brake pedal 8 is not operated, and the brake pedal 8 It is performed in order to match the magnitude of the operation amount with the magnitude of the regenerative braking force.

Succeedingly, in a step S503, it is determined whether or not the braking currently being performed is a hard braking.

FIG. 18 shows a sudden braking judgment routine. First, when the pedal effort F _B detected by the brake pedal pedal force sensor 24 ₁ in step S'1 is equal to or more than a predetermined threshold value, it is unconditional. It is determined that there is a sudden braking, and the sudden braking flag is "1" in step S'2.
Is set to.

On the other hand, when the pedaling force F _B is less than the predetermined threshold value in step S′1 and the sudden braking determination timer PTM is at the initial value t ₀ at the start of counting in step S′3, step S ′ is executed. At '4, the pedal effort F _B at that time is set as the initial pedal effort F _B1 . When the sudden braking determination timer PTM is not counted down to zero in the subsequent step S'5, the counting is performed in step S'6 and the sudden braking flag is set to "0" in step S'7.
Is set to.

In step S'5, the sudden braking judgment time is determined.
When the PTM is counted down to zero, that is, predetermined
Time t₀Is passed, step S'8
Force F _BIs t₀Rear pedal force F_B2And then suddenly in step S'9
Brake judgment timer PTM is t₀Is reset to. So
Then, in the subsequent step S′10, t₀Rear pedal force F_B2And early
Pedaling force F_B1Is the difference in pedaling force change threshold ΔF_BCompared to
The difference is the pedal effort change threshold ΔF_BIf it exceeds
At step S'2, the sudden braking flag is set to "1",
If it is not over, sudden braking flag is set in step S'7.
Is set to "0".

As described above, when the pedaling force F _B exceeds the first threshold value and when the increase amount of the pedaling force F _B within the predetermined time exceeds the second threshold value, it is determined that the braking is sudden. To be judged.

Subsequently, in step S505 of the flowchart of FIG. 17, it is determined whether or not the steering is currently being performed.

FIG. 19 shows a steering condition determination routine. First, in step S'11, a steering determination steering angle threshold value θ _CS is calculated from the vehicle speed V based on the map shown in FIG. In '12, the steering angle calculation routine (Fig. 8
Steering angle θ _C and the steering determination threshold value θ
_If the steering angle θ _C is greater than the steering determination steering angle threshold value θ _CS , it is determined that the steering is in progress and the step S ′ is performed.
In step 13, the steering flag STRFL is set to "1". On the contrary, if the steering angle θ _C is equal to or less than the steering determination steering angle threshold value θ _CS , it is determined that steering is not in progress, and the steering flag STRFL is set in step S544. Set to "0".

[0063] As apparent from FIG. 20, small at turning determination steering angle threshold theta _CS is the vehicle speed V greater, to become large when a small vehicle speed V, in high speed small steering angle theta _C
Even if it is, it is determined that the steering is being performed, and conversely, it cannot be determined that the steering is being performed unless the steering angle θ _C is large during low speed traveling.

FIG. 21 shows another embodiment of the steering condition determining routine. In step S'21, the lateral acceleration α of the vehicle body is the difference ΔV between the left and right wheel speeds, the vehicle body speed V, and the tread T. From, it is calculated by α = ΔV * V / T. Then, the comparing lateral acceleration alpha and the turning determination lateral acceleration threshold alpha _S in step S'22, when the lateral acceleration alpha is long exceeds the turning determination lateral acceleration threshold alpha _S, turning in And the steering flag ST in step S'23.
If RFL is set to "1" and conversely the lateral acceleration α is equal to or less than the steering determination lateral acceleration threshold value α _S , it is determined that steering is not in progress, and the steering flag STRF is determined in step S'24.
Set L to "0".

Then, in step S506 of the flow chart of FIG. 17, it is determined that the steering is not in progress, and step S50
The mode 2 flag M2FL described later in 7 is not set to "1", the anti-lock brake system of the front wheels Wf is not operating in step S508, and step S508
When the anti-lock brake system for the rear wheels Wr is not operating at 509, that is, when the fail, the sudden braking, the steering, and the anti-lock braking system are not in operation. , Step S51
[Mode 3] is selected by 0 and the mode 3 flag M3FL is selected.
Is set to "1".

If it is determined in step S506 that the steering is being performed, steps S511 and S511 are performed.
At 512, the mode 2 timer M2TM starts counting, and at step S513, [mode 2] is selected and the mode 2 flag M2FL is set to "1". Furthermore, if the anti-lock brake system for the front wheels Wf is operating in step S508, or if the anti-lock brake system for the rear wheels Wr is operating in step S509, then step S51 is similarly performed.
The mode 2 flag M2FL is set to "1" in 1 to step S513.

If the fail flag FAILFL is set to "1" in step S501, or if it is determined in step S504 that the vehicle is being suddenly braked, "mode 1" is selected in step S514. Then, the mode 1 flag M1FL is set to "1". Further, in step S507, the mode 2 flag M
2FL is set to "1", and step S5
If the mode 2 timer M2TM is up in 15 and the anti-lock brake system for the front wheels Wf or the rear wheels Wr is operating in step S516,
The process proceeds to step S514 and the mode 1 flag M1F
L is set to "1". That is, when the anti-lock brake system is in operation after the predetermined time defined by the mode 2 timer M2TM after the [mode 2] is selected, the [mode 2] is selected to reduce the braking force. Despite this, it is determined that the wheels still tend to lock, and the mode shifts to [Mode 1].

Thus, when the [mode 3] is selected and the steering is performed or the antilock brake system is activated, the mode shifts to the [mode 2], or after shifting to the [mode 2], a predetermined value is set. If the anti-lock brake system is still operating after the lapse of time, the mode is further shifted to [Mode 1]. Then, when a failure occurs and when a sudden braking is applied, [mode 3]
From any state of [Mode 2] and [Mode 2], the mode is unconditionally changed to [Mode 1].

Next, the specific contents of the differential pressure valve operation amount determination routine in step S500 of the flow chart of FIG. 6 will be described based on the flow charts of FIGS. 22 to 24 and the graphs of FIGS. 25 to 28.

First, the steps of the flowchart of FIG.
In S521, the mode 1 flag M1FL is set to "1".
Not set and mode 2 in step S522
If the flag M2FL is not set to "1", immediately
If [Mode 3] is selected, step S
At 523, the front side differential pressure valve operation amount ΔP _OF
And rear differential pressure valve operation amount ΔP_ORBut each car
Regenerative braking force limit T equivalent to shaft torque_RGLMAnd the front
Hydraulic pressure / torque conversion constant K_FAnd rear oil pressure / torque conversion
Number K_RBased on ΔP_OF= T_RGLM / (K_F+ K_R)… (7) ΔP_OR= T_RGLM / (K_F+ K_R) (8) (see FIG. 24A).

Explaining the above equation further, as shown in FIGS.
_OF is the input hydraulic pressure P _IN (see step S502 of the mode determination routine in FIG. 17) and is the front hydraulic pressure / torque conversion constant K.
The hydraulic braking force T _OR on the rear side is obtained by multiplying _F by the input hydraulic pressure P _IN, and the rear hydraulic pressure / torque conversion constant K
_It is calculated by multiplying _R. However, in actuality, in the braking force distribution of [mode 3] shown in FIG.
From point O to point P, only the regenerative braking force of the rear wheel Wr acts, and after point P when the regenerative braking force limit T _RGLM corresponding to the axle torque is reached, the regenerative braking force is maintained at a constant value, and the rear wheel Wr
And the hydraulic braking force of the front wheels Wf start to increase from zero. Therefore, when the regenerative braking force of the rear wheel Wr reaches the P point that is the regenerative braking force limit T _RGLM and hydraulic braking of the rear wheel Wr and the front wheel Wf is started, if the hydraulic braking force starts to increase from zero, The connection between the regenerative braking and the hydraulic braking at the point P is smoothly performed.

For this purpose, the regenerative braking force limit T _RGLM
And the differential pressure valve operation amount ΔP _OF on the front side and the differential pressure valve operation amount ΔP _OR on the rear side have the relationship shown in FIG. 26 (A) corresponding to the expressions (7) and (8). . That is, if the relationships of the expressions (7) and (8) are satisfied, K _F * T _RGLM / (K _F +) before the input oil pressure P _IN reaches the differential pressure valve operation amount ΔP _OF on the front side.
The hydraulic braking force of only K _R ) is suppressed by the differential pressure valve 16f, and similarly, K _R * T _RGLM / (K _F +) until the input hydraulic pressure P _IN reaches the differential pressure valve operation amount ΔP _OR on the rear side.
As a result of suppressing the hydraulic braking force corresponding to K _R ) by the differential pressure valve 16r, the hydraulic braking force equivalent to the regenerative braking force limit T _RGLM corresponding to the axle torque is suppressed in total. As a result, the front wheel Wf and the rear wheel Wr are not reached until the point P.
The hydraulic braking force of 1 acts to smoothly connect the regenerative braking and the hydraulic braking.

On the other hand, in the braking force distribution of [mode 2] shown in FIG. 3, the regenerative braking force of the rear wheel Wr and the front wheel Wf from the point O.
After the hydraulic braking force of the rear wheel Wr reaches the regenerative braking force limit _TRGLM of the rear wheel Wr, the regenerative braking force is maintained at a constant value and the hydraulic braking force of the rear wheel Wr newly acts. Begin to. Therefore, when the regenerative braking force of the rear wheel Wr reaches the regenerative braking force limit _TRGLM corresponding to the axle torque, the rear wheel Wr
If the hydraulic braking force of is started to increase from zero, the regenerative braking and the hydraulic braking are smoothly connected.

For this purpose, the regenerative braking force limit T _RGLM
The differential pressure valve operation amount ΔP _OR on the rear side and ΔP _OR = T _RGLM / K _R (9), that is, the relationship shown in FIG. In other words, if the relation of the expression (9) is satisfied,
Until the input hydraulic pressure P _IN reaches the differential pressure valve operation amount ΔP _OR on the rear side, the regenerative braking force limit T _RGLM equivalent to the axle torque
The hydraulic braking force equal to is suppressed by the differential pressure valve 16r, whereby the hydraulic braking force of the rear wheel Wr acts for the first time at the regenerative braking force limit T _RGLM as shown in FIG. And hydraulic braking is smoothly connected.

[0075] Subsequently, the differential pressure valve operation amount [Delta] P _OF step S526 the front side of the flow chart of FIG. 23 is determined whether it is zero, if [Delta] P _OF is not zero, [Delta] P _OF at that time in step S527 Is set as the hold value during delay ΔP _OFD, and the front delay timer DLYTM _F is reset in step S528.
If ΔP _OF is zero in step S526, until the front delay timer DLYTM _F expires in subsequent steps S529 and S530.
In step S531, the hold value ΔP _OFD during delay is set to the differential pressure valve operation amount ΔP _OF, and in step S532.
The initial value of ΔP _OFD0 used in. Then, when the front delay timer DLYTM _F times out in step S529, a temporary delay filtering process is performed in step S532 to obtain a filter value ΔP _{OFD of} ΔP _OF.
Is calculated by ΔP _OFD = K _ODF * ΔP _OFD0 + (1−K _ODF ) ΔP _OF (10), and the filter value ΔP is calculated in the following step S573.
_{OFD is set} to the holding value ΔP _OFD0 at the delay one loop before and the differential pressure valve operation amount ΔP _OF . Where K _ODF
Is the first-order lag coefficient.

The flowchart of FIG. 24 shows a temporary delay filtering process for the differential pressure valve operation amount ΔP _OR on the rear side, and since the content thereof is substantially the same as that of the flowchart of FIG. Omit it.
The difference between FIG. 24 and FIG. 23 is that “F
The only difference is that "r" and " _F " are changed to "Rr" and " _R " representing the rear side and "'" is added to the step number.
Since the differential pressure valve operation amount determination routine is executed only while the brake pedal 8 is being operated (see FIG. 6), useless power consumption can be prevented.

As is apparent from FIG. 28, even if the hydraulic braking force rises too early when switching from regenerative braking to hydraulic braking, the hydraulic braking force is delayed by the delay time. Since the rising speed of the hydraulic braking force is delayed by the temporary delay control, it is possible to smoothly switch from the regenerative braking to the hydraulic braking while keeping the total sum of the regenerative braking force and the hydraulic braking force substantially constant.

Next, the specific contents of the routine for determining the regenerative braking force command value in step S500 of the above-described flowchart of FIG. 6 will be described based on the flowcharts of FIGS. 29 to 32 and the graphs of FIGS. 33 to 34.

First, the outline of the method for determining the regenerative braking force command value will be described with reference to the graph of FIG.

As described above, when the differential pressure valve 16f (16r) having the structure shown in FIG. 5 is used, the output of the differential pressure valve 16f (16r) is increased in the process of increasing the pedal effort of the brake pedal 8 and in the process of decreasing it. The hydraulic pressure P _OUT has a hysteresis as shown in FIG. That is, even if the input oil pressure P _IN increases from the point O in proportion to the increase in the pedaling force, the input oil pressure P _IN
IN reaches the differential pressure valve operation amount ΔP ₀ and the differential pressure valve 16f
In the region until (16r) opens, the output hydraulic pressure P _OUT
Does not occur and the differential pressure Δ between the input hydraulic pressure P _IN and the output hydraulic pressure P _OUT
P becomes equal to the value of the input oil pressure P _IN .

Differential pressure valve 16f (16r) at point A
When the valve is opened, the output hydraulic pressure P _OUT is generated, and the output hydraulic pressure P _OUT
In the region up to the point B where _OUT reaches the maximum output hydraulic pressure P _OUTmax , the differential pressure ΔP between the input hydraulic pressure P _IN and the output hydraulic pressure P _OUT becomes the constant differential valve operation amount ΔP ₀ . Even if the pedal effort is loosened at the point B, the output hydraulic pressure P _OUT does not decrease, and the output hydraulic pressure maximum value P _OUTmax is maintained until the point C at which the input hydraulic pressure P _IN and the output hydraulic pressure P _OUT match. In that region, the differential pressure ΔP is It becomes P _IN -P _{OUT max} . Then, after reaching point C, the output hydraulic pressure P _OUT begins to decrease toward point O, and the differential pressure ΔP becomes zero in that region. When the brake pedal 8 is depressed at point D in the process of releasing the pedal effort and the pedal effort is increased again, the output hydraulic pressure P _{OUT is changed} by the characteristic of the differential pressure valve 16f (16r).
Does not increase, and the output hydraulic pressure minimum value P from point D to point E
_It is held at _OUTmin , and the differential pressure ΔP is P _IN −P in that region.
_OUTmin .

In short, the differential pressure ΔP is obtained by P _IN −P _OUTmax in the regions ,, the differential pressure ΔP becomes zero in the region, and the differential pressure ΔP is obtained by P _IN −P _OUTmin in the regions. The value of the maximum output hydraulic pressure P _OUTmax is calculated from the input hydraulic pressure P _{IN for} each loop by the differential pressure valve operation amount Δ.
The output hydraulic pressure P _OUT may be obtained by subtracting P _0, and the maximum value of the output hydraulic pressure P _OUT may be set as the maximum output hydraulic pressure P _OUTmax . It is possible to determine that the input hydraulic pressure P _IN has _fallen below the maximum output hydraulic pressure P _OUTmax , and in this region, the input hydraulic pressure P _IN and the output hydraulic pressure P _IN can be determined.
_{Since OUT} is the same, the minimum value of the output hydraulic pressure P _OUT may be set as the minimum output hydraulic pressure P _OUTmin . Also it has entered the area, it is possible to determine by the input hydraulic pressure P _IN exceeds the output hydraulic pressure minimum value P _OUTMIN, it Mochikaeru the output hydraulic pressure minimum value P _OUTMIN in this region as the output hydraulic pressure maximum value P _OUTmax Makes it possible to think in the same way as the area.

The above is the differential pressure valve 1 on the front side.
6f will be described in more detail with reference to the flowchart of FIG. In the flowchart of FIG. 29, the output hydraulic pressure maximum value P _OFmax the front side and rear side output hydraulic pressure maximum value P _OUTmax in FIG 34, with expressed by P _ORmax, the output hydraulic pressure minimum value P _OUTMIN the front side and the rear side It is represented by the minimum output oil pressure values P _ORmin and P _ORmin .

Step S53 of the flowchart in FIG. 29.
If the pressure reduction flag PDNFL _F is "0" at 1, that is, if it is in a region other than the region of FIG. 34, step S
At 532, the output hydraulic pressure P of the front side differential pressure valve 16f
_OUTF is calculated by subtracting the differential pressure valve operation amount ΔP _OF of the differential pressure valve 16f from the input hydraulic pressure P _IN . Then, in step S533, the output hydraulic pressure P _OUTF is the maximum output hydraulic pressure P.
_{When OUTmax} is exceeded, the output hydraulic pressure maximum value P _OUTmax is replaced with the output hydraulic pressure P _OUTF in step S534 each time.

If the input oil pressure P _IN falls below the maximum output oil pressure P _OUTmax in step S535, the output oil pressure P _OUTF
Is determined to have entered the pressure reducing area, and step S53 is performed.
As well as set the decompression flag pNDFL _F to "1" at 6, after replacing the output hydraulic pressure minimum value P _OUTMIN in output hydraulic pressure maximum value P _OUTmax in step S537, step S53
At 8, the differential pressure ΔP _F is set to zero so that the characteristic of the region is obtained. On the other hand, in step S535, the input oil pressure P
_{If IN} is _{equal to} or _larger than the output hydraulic pressure maximum value P _OUTmax , that is, if it is in any area other than the area, in step S539, the differential pressure ΔP _{F is set} to the input oil pressure P _IN.
It is calculated by subtracting the output hydraulic pressure maximum value P _OUTmax from.

In step S531, the pressure reduction flag PDN
When FL _F is set to “1”, that is, when it is in the region of the region, first, in step S540, the input hydraulic pressure P _{IN is set} to the output hydraulic pressure P _OUTF, and then in step S541, the output hydraulic pressure P _OUTF is the output hydraulic pressure. _{Below the} minimum value P _OUTmin ,
In each case, the output hydraulic pressure minimum value P _OUTmin is replaced with the output hydraulic pressure P _OUTF in step S542. And step S5
If the input oil pressure P _IN exceeds the output oil pressure minimum value P _OUTmin in 43, it is determined that the pressure has entered the region, and the pressure reduction flag PDNFL _F is set to “0” in step S544, and the output oil pressure maximum value P _OUTmax is output in step S545. The minimum hydraulic pressure value P _OUTmin is replaced, and in step S539 the differential pressure Δ
P _F is calculated by subtracting the maximum output hydraulic pressure P _OUTmax from the input hydraulic pressure P _IN . On the other hand, when the input oil pressure P _IN becomes equal to or smaller than the output oil pressure minimum value P _{OU Tmin} in step S543, it is determined that the input oil pressure P _IN has not entered the region, and the differential pressure ΔP _F is set to zero in step S538.

The flow chart of FIG. 30 is a flow chart for obtaining the differential pressure ΔP _R for the differential pressure valve 16r on the rear side, and since the contents thereof are substantially the same as the flow chart of FIG. 29, duplicated description will be omitted. . The difference between FIG. 30 and FIG. 29 is that the subscript “ _F ” indicating the front side is used.
Is changed to the subscript " _R " that indicates the rear side, and the only difference is that the step number is marked with "'".

As described above, the front side differential pressure ΔP _F
And the differential pressure ΔP _R on the rear side are determined, the regenerative braking output value T _RG is calculated using the front hydraulic pressure / torque conversion constant K _F and the rear hydraulic pressure / torque conversion constant K _R in step S546 of FIG. , T _RG = K _F ΔP _F + K _R ΔP _R (11)

By the way, in the flow charts of FIGS. 29 and 30, the output oil pressure P of the differential pressure valves 16f and 16r is shown.
_The hydraulic pressure sensors 27f and 27r for detecting _OUTF and P _OUTR
However, by directly detecting the output hydraulic pressures P _OUTF and P _OUTR using the hydraulic pressure sensors 27f and 27r, the control can be simplified.

FIG. 35 shows a regenerative braking force command value determination routine when the hydraulic pressure sensors 27f and 27r are used. That is, the front-side output hydraulic pressure P _OUTF and the rear-side output hydraulic pressure P _OUTR are directly detected by the hydraulic pressure sensors 27f and 27r, so that the input hydraulic pressure P at step S571.
By subtracting the detected output hydraulic pressures P _OUTF and P _OUTR from _IN, the differential pressure ΔP _F between the front side and the rear side is calculated.
ΔP _R is calculated. Then, in step S572, the regenerative braking output value T _RG is calculated by the above equation (11).

Then, from the flowchart of FIG.
The process moves to the flowchart of 1. Here, the temporary delay control of the regenerative braking force when [Mode 2] is selected is shown.

First, step S in the flowchart of FIG.
If the mode 2 flag M2FL is not set to "1" in 547, the regenerative braking output value T _RG at that time is set as the hold value during delay T _RGD in step S548, and the mode 2 delay timer M2DLYTM is reset in step S549. Further, in step S550, the mode 2 delay flag M2DLYFL is set to "1". The mode 2 flag M2FL is set to "1" in step S547, the mode 2 delay flag M2DLYFL is set to "1" in step S551, and the mode 2 delay timer M2DL is set in step S552.
YTM is determined to be in delay unless a time-up regeneration, while continuing to count the mode 2 delay timer M2DLYTM in step S553, the delay time of the holding value T _RGD as a regenerative braking output value T _RG in step S554 The braking force is held constant, and the delay hold value T _RGD is set to the filter value T _RGD0 one loop before.

Mode 2 delay in step S552
When the timer M2DLYTM times out, step
In S555, the temporary delay filtering process is performed to regenerate.
Braking output value T_RGFilter value T_RGDThe T_RGD= K_DT_RGD0+ (1-K_D) T_RG It is calculated by (12). Where K_DIs a temporary delay coefficient.
In the following step S556, the filter value T_RGDRegenerative braking output
Force value T_RGUntil the following, the first-order delay control continues
Then, in step S557, the filter value T_RGD1 loop
Previous filter value T _RGD0And the filter value
T_RGDRegenerative braking output value T_RGAnd Then, the
Filter value T at step S556_RGDIs the regenerative braking output value T_RG
When the following is reached, the temporary delay control ends, and step S558 is performed.
Mode 2 delay flag M2DLYFL is set to "0".
Is set.

The following flowchart of FIG. 32 shows the primary delay control of the regenerative braking force when [Mode 1] is selected.

This flowchart is based on the mode 2 flag M2FL and the mode 2 in the above-mentioned flowchart of FIG.
The delay flag M2DLYFL and the mode 2 delay timer M2DLYTM are respectively the mode 1 flag M1.
The FL, the mode 1 delay flag M1DLYFL, and the mode 1 delay timer M1DLYTM have substantially the same control content only by being changed, and the step corresponding to step S547 to step S558 in FIG. S547 'to step S
Duplicated description will be omitted by adding 548 '.

However, when [Mode 1] is entered during delay or filtering in [Mode 2], the delay and filtering processing in [Mode 2] is stopped and switched to the delay and filtering processing in [Mode 1]. Therefore, in step S547 ', the mode 1
When the flag M1FL is set to "1", the mode 2 flag M is set in steps S559 and S560.
2FL is set to "1" and the mode 2 delay flag M2DLYFL is set to "1", the mode 2 delay flag M2DLYFL is set to "0" in step S561. There is.

As is apparent from FIG. 33, even if there is a delay in the rise of the hydraulic braking force when switching from the regenerative braking to the hydraulic braking, the reduction start of the regenerative braking force is delayed by the delay time and Since the reduction speed of the regenerative braking force is delayed by the temporary delay control, it is possible to smoothly switch from the regenerative braking to the hydraulic braking while keeping the total sum of the regenerative braking force and the hydraulic braking force substantially constant.

The hydraulic braking force delay control (see FIG. 28) and the regenerative braking force delay control (see FIG. 33)
Is appropriately selected according to the characteristics of the braking device, and delay control of hydraulic braking force and regenerative braking force can be used together.

Next, the specific contents of the brake pedal depression force sensor 0 correction routine that is executed when braking is not being performed in step S500 of the above-described flowchart of FIG. 6 will be described based on the flowchart of FIG.

First, in step S581, the added value S
The output value P ₂ detected by the brake pedal depression force sensor 24 ₁ this time is added to AM to calculate a new addition value SAM, and N is incremented in step S583 until N reaches a predetermined number N ₀ in step S582. The addition of the output value P ₂ is repeated. When N reaches the predetermined number N ₀ in step S582, the average deviation P ₂₀ is calculated by dividing the added value SAM at that time by the predetermined number N ₀ in step S584, and then N is set to 1 in step S585.
And SAM to zero.

Therefore, when the brake pedal 8 is not operated,
Brake pedal pedal force sensor 24 ₁Mean deviation of output values of
Difference P₂₀Is requested, the explanation is given in step S502 of FIG.
As is clear, the brake pedal depression force sensor 24₁Output
Value P₂From the average deviation P₂₀The difference by subtracting
Input oil pressure P of the pressure valves 16f and 16r_INIs required.

Next, the specific contents of each variable clearing routine in step S500 of the above-mentioned flowchart of FIG. 6 will be described based on the flowchart of FIG.

Here, the mode 1 flag M1FL,
Mode 2 flag M2FL, mode 3 flag M3FL, M
2 timer M2TM, front decompression flag PDNFL _F ,
Rear pressure reduction flag PDNFL _R , front output hydraulic pressure maximum value P _OFmax , rear output hydraulic pressure maximum value P _ORmax , front output hydraulic pressure minimum value P _OFmin , rear output hydraulic pressure minimum value P _ORmin , front delay holding value ΔP _OFD , rear delay holding value The differential pressure ΔP _ORD and the hold value T _RGD during delay are set to zero.

Next, step S in the flowchart of FIG.
The specific contents of the shift command routine in 600 will be described with reference to the flowcharts of FIGS. 38 to 40 and FIGS. 41 and 42.
The graph will be described below.

If the shift is in progress in step S601 of the flowcharts of FIGS. 38 to 40, the shift flag SHFL is set to "1" in step S602, and then in step S603, the converted regenerative braking force T corresponding to the axle torque is set. _RG is set to zero and step S
At 604, both the front side differential pressure valve operation amount ΔP _0F and the rear side differential pressure valve operation amount ΔP _0R are made zero. As a result, the front wheel Wf and the rear wheel Wr are braked by the normal hydraulic pressure without performing regenerative braking during the shift.

If the shift flag SHFL is set to "1" in step S605 even though the shift is not in progress in step S601, it is determined that the shift is completed, and in the subsequent step S606, the front wheels Wf and the rear wheels Wr. The hydraulic braking of is released and step S6
At 07, the shift flag SHFL is set to "0".

If the steering flag STRFL is set to "1" during steering in step S608, a shift command to be described later is not issued.

In the following steps S609 to S613, the estimated regenerative power E _(n) at the current shift position n is calculated. That is, in step S609, the converted regenerative braking force T _RG is divided by the gear ratio R _(n) to calculate the motor torque T _{MT (n) at the} nth speed. And step S
At 612, the motor torque T is calculated based on the graph of FIG.
_The motor efficiency η _(n) is obtained from _{MT (n)} and the rotation speed N _{M of the} motor 2, and the motor efficiency η is calculated in the following step S613.
By multiplying _(n) by the motor torque T _{MT (n)} and the rotation speed N _M of the motor 2, the estimated regenerative power E _{(n) at the} shift position n is calculated.

Next, in steps S614 to S622, the estimated regenerative electric power E _(n-1) when downshifting from the current shift position is calculated. That is, step S61
If the current shift position n is the 1st speed in step 4, the downshift is substantially impossible, and thus step S615 is performed.
The estimated regenerative electric power E _(n-1) in the case of downshifting is set to zero. On the other hand, when the current shift position n is any one of the 2nd speed to the 4th speed in step S614, the estimated regenerative electric power E ₍ in the case of downshifting to the n-1th speed in steps S616 to S622 as described above _{). n-1)} is calculated. At that time, in step S617, the motor torque T
_{When MT (n-1)} exceeds the regenerative braking force limit value T _LM ,
In step S618, the regenerative braking force limit value T _LM is set to the motor torque T _{MT (n-1 )} . In the case of downshifting, in step S619, the rotational speed N _{M (n-1)} of the motor 2 at the time of downshifting is the gear ratio R _(n) , R _(n-1) and the rotational speed N _{M (} n _{M at the} nth speed _{). n)} , and as a result, if the number of revolutions N _{M (n-1)} is overrev in step S620, the estimated regenerative power E is calculated in step S615.
_(n-1) is set to zero.

Next, in steps S623 to S630, the estimated regenerative electric power E _{(n + 1)} when shifting up from the current shift position is calculated. That is, step S62
When the current shift position n is the fourth speed in step 3, it is practically impossible to shift up, so step S624.
The estimated regenerative electric power E _{(n + 1)} in the case of upshifting is set to zero. In subsequent steps S625 to S630,
Estimated regenerative electric power E when shifting up like the above
_{(n + 1)} is calculated. At that time, when the motor torque T _{MT (n + 1)} exceeds the regenerative braking force limit value T _LM in step S626, the regenerative braking force limit value T _LM motor torque T _MT at step S627 _{(n + 1)} It should be noted that in the case of the shift up, no overrev is generated, so the determination of the overrev performed in the case of the shift down is not performed.

Thus, in steps S631 to S633, the current estimated regenerative power E _(n) , the estimated regenerative power E _(n-1) in the case of downshifting, and the estimated regenerative power E _{(n + 1} in the case of upshifting _{). )} Are compared, and if E _(n-1) is maximum, a downshift command is issued in step S634, and conversely, if E _{(n + 1)} is maximum, step S6 is performed.
At 35, a shift-up command is issued.

The above shift operation will be described with reference to the time chart of FIG. For example, it is assumed that the pedaling force of the brake pedal 8 is operated so as to gradually increase at times T ₁ , T ₃ , and T ₈ , and a regenerative braking command is issued at time T ₂ .
At this time, when it is determined to shift down the shift position from, for example, the third speed to the second speed in order to maximize the regenerative energy, the clutch is released at time T ₄ .

When the clutch is released, the rear wheel Wr and the motor 2 are disconnected and the regenerative braking force becomes impossible. Therefore, at time T ₄
Regenerative braking command of the motor 2 to T ₇ is canceled from. Then, while regenerative braking is not performed, that is, from time T ₄ to T
_During the period up to ₇ , a hydraulic brake command is issued and hydraulic braking replaces regenerative braking. And Thus, at time T ₅ in the disengagement period of the clutch from time T ₄ to T _6, a shift command is issued downshifting from the third speed to the second speed is executed.

As described above, the total braking force is
T₂~ T_FourThen, due to regenerative braking, time T_Four~ T₇Then oil
Time T due to pressure braking₇~ T₉With regenerative braking,
Tick T ₉After that, it is secured by using both regenerative braking and hydraulic braking.
It

Next, the specific contents of the fail judgment routine in step S700 of FIG. 6 will be described based on the flowcharts of FIGS. 43 to 45 and the graphs of FIGS. 46 and 47.

Step S70 of the flowchart shown in FIG.
If the failure flag FAILFL (see step S501 in FIG. 17) is not set to "1" in step 1, no failure occurs in the regenerative braking system in the following steps S702 to S708. The brake pedal depression force sensor 24 ₁ fails, the accelerator opening sensor 25 fails, the wheel speed sensor 23 _FL ,
23 _FR , 23 _RL , 23 _RR fail, ABS control valves 14f, 14r fail, differential pressure valves 16f, 16r
And the failure of the hydraulic pump 10 are sequentially determined.

Next, the subroutine of step S702 (judgment of regenerative fail) of FIG. 43 will be described with reference to the flowchart of FIG.

First, in step S'31, the actual regenerated electric power E _RG generated by the motor 2 is set to the battery voltage sensor 20 ₂
The output signal V _B of the battery current sensor 20 ₁ is multiplied by the output signal I _B of the battery current sensor 20 ₁ . Subsequent step S ′
32 and S'33, step S613 in FIG.
Whether or not the actual regenerative power E _RG exists between two values obtained by adding and subtracting the predetermined value α to the estimated regenerative power E _(n) calculated in step 1, that is, between E _(n) + α and E _(n) −α. Is judged. That is, when the actual regenerative power E _RG and the estimated regenerative power E _(n) are in the shaded area in FIG. 46, it is determined that the regenerative braking system is abnormal.

In the case where the above-mentioned abnormality judgment is made first, and in step S'34, the temporary fail flag FAILFL '.
Is not set to "1", step S'3
At 5, the temporary fail flag FAILFL 'is set to "1". Then, when it is judged again in the next loop that the regenerative braking system is abnormal, that is, when the temporary fail flag FAILFL 'is set to "1" in step S'34, finally fail in step S'36. The flag FAILFL is set to "1". When it is determined in steps S'32 and S'33 that the regenerative braking system is normal, in steps S'37 and S'38 the temporary fail flag FAILFL 'and the fail flag FA.
ILFL is set to "0", and step S'35
If the temporary fail flag FAILFL is set to "1" at step S38, the fail flag FAI is set at step S'38.
LFL is set to "0".

[0120] Compared estimated regenerative electric power E as described above and _(n) the actual regenerative power E _RG, when the actual regenerative power E _RG is determined that there is an abnormality an excessive or too small beyond the predetermined value If the temporary fail flag FAILFL 'is set and the above abnormality is continuously detected in the next loop, the fail flag F is detected.
By setting AILFL, it is possible to reliably determine the failure of the regenerative braking system without being affected by radio interference or the like.

Next, the subroutine of step S703 (brake pedal depression force sensor fail determination) of FIG. 43 will be described with reference to the flowchart of FIG.

First, in steps S'41 and S'42, it is determined whether or not the output signal of the brake pedal depression force sensor 24 ₁ is between 0.4V and 4.6V. As shown in the graph of FIG. 47, the output V _FB of the brake pedal depression force sensor 24 ₁ changes from 0.5 V to 4. V as the depression force F _B increases.
It is set so as to increase linearly up to 5V and thereafter to be maintained at a constant value of 4.5V. Since the error of the brake pedal tread force sensor 24 ₁ is within an allowable range of ± 0.1 V, if the brake pedal tread force sensor 24 ₁ is normal, the output V _FB has a minimum value of 0.4 V and a maximum value of 4 V. Should be between .6V. However, in steps S'41 and S'42, the output V _FB changes from 0.4 V to 4.6.
If it is not within the range of V, the brake pedal depression force sensor 2
It is judged that 4 ₁ is abnormal.

In the case where the above-mentioned abnormality judgment is made first, and in step S'43, the temporary fail flag FAILFL '.
Is not set to "1", step S'4
At 4, the temporary fail flag FAILFL 'is set to "1". When it is determined again in the next loop that the brake pedal depression force sensor 24 ₁ is abnormal, that is, when the temporary fail flag FAILFL 'is set to "1" in step S'43, the final step S'45 is executed. The fail flag FAILFL is set to "1".

Further, even though the brake pedal switch is not turned on in step S'46, that is, the brake pedal 8 is not operated, the output of the brake pedal depression force sensor 24 ₁ is output in step S'47. V
_{If FB} exceeds 0.6 V, it is determined that the brake pedal depression force sensor 24 ₁ is abnormal, and the routine goes to the step S'43.

Then, steps S'41, S'42,
Brake pedal depression force sensor 24 ₁ at S'46 and S'47
Is determined to be normal, step S'4
8, the temporary fail flag FAILFL 'and the fail flag FAILFL are set to "0" at S49, the brake pedal switch is turned on at step S'46, and the temporary fail flag FAILF at step S'44.
If L'is set to "1", step S'4
At 9, the fail flag FAILFL is set to "0".

Operate the brake pedal 8 as described above.
If the brake pedal pedal force sensor 24₁Output V_FB
Indicates an impossible value (0.4 V or less and 4.6 V or more)
The brake pedal and when the brake pedal is not operated.
Rake pedal force sensor 24 ₁Output V_FBCannot be
When the value (0.6V or more) is displayed, it is judged that there is an abnormality.
Therefore, the brake pedal depression force sensor 24₁Output error
Not only the brake pedal depression force sensor 24₁Sticking
It is possible to reliably detect a trouble caused by. Only
Also using the temporary fail flag FAILFL '
Is detected continuously, make a final abnormality judgment
Brakes without being affected by radio interference, etc.
Pedal force sensor 24₁The fail of
You can

Then, in step S800 of FIG. 6, the differential pressure valve operation amounts ΔF _OF and ΔF _OR determined in steps S523 to S525 of FIG. 22 are output and the subroutine of step S900 of FIG.
In step S901 of the regenerative command output routine of 8, the final regenerative torque command value T _RGT is calculated as the sum of the regenerative output command value T _RG and the engine braking equivalent regenerative braking force T _RGE. The regenerative torque command value _TRGT is output. As a result, [Mode 3],
In each of [Mode 2] and [Mode 1], the regenerative braking force and the hydraulic braking force are exerted at a predetermined ratio shown in FIG.

FIG. 49 shows a second embodiment of the differential pressure valve 16f (16r).

As shown in FIG. 49 (A), the differential pressure valve 16f of this embodiment is constituted by a spool 29f on which a valve seat on which a valve element 18f is seated is movable, and this spool 29f is constituted by a spring 30f. It is biased toward the valve body 18f. When the spool 29f moves to the right, the output port communicates with the reservoir 32 of the master cylinder 9 via the oil passage 31f.

It is clear that FIG. 49 (B) is also referred to.
To excite the linear solenoid 19f and
Urging force to fs₁Is activated, the input port
Input hydraulic pressure P to be applied_INOutput until the point increases from O point to A point
Output hydraulic pressure P to port_OUTDoes not occur, the valve body at point A
When 18f separates from the spool 29f, the output hydraulic pressure P
_OUTIs P_OUT= P_IN-Fs₁/ B ... (13). Where b is the spool 29f
It is an inner diameter cross-sectional area.

Subsequently, when the pedal effort is relaxed at point B to reduce the input oil pressure P _IN , the valve oil 18f is closed, so that the output oil pressure P _OUT is held constant, and eventually the input oil pressure P _IN reaches the point C. When reduced, for communicating the output port to the reservoir 32 spool 29f is moved to the right, the output pressure P _OUT
Decreases to the point D while maintaining the relationship of P _OUT = P _IN − (fs ₁ −fs ₂ ) / a (14). Here, fs ₂ is an urging force by which the spring 30f presses the spool 29f leftward, and a is an outer diameter cross-sectional area of the spool 29f. Then, after the output hydraulic pressure P _OUT becomes zero at the point D, the output hydraulic pressure P _OUT is held at zero until the input hydraulic pressure P _IN decreases from the point D to the point O.

Thus, in this embodiment, the magnitude of the hysteresis H is H = {(1 / b) + (1 / a)} * fs ₁ + (fs ₂ / a) (15) As is clear from 5 (B) and 49 (B),
The hysteresis H of the second embodiment can be made smaller than that of the first embodiment so that it can be substantially ignored. Therefore, the magnitude of the regenerative braking force is shown in FIG.
By just performing the control as in (C), that is, by performing the same control when the depression force of the brake pedal 8 increases and decreases,
The brake pedal 8 is the sum of the regenerative braking force and the hydraulic braking force.
It is possible to make it proportional to the pedaling force of, so that the regenerative braking force command value determination routine can be greatly simplified.

FIG. 50 shows a third embodiment of the differential pressure valve 16f (16r).

As shown in FIG. 50A, in the differential pressure valve 16f of this embodiment, the spool 29f, which is biased to the right by the linear solenoid 19f and to the left by the spring 30f, slides left and right. The oil passage 34f connected to the input port and the oil passage 35f connected to the output port are communicated with each other via a groove 33f provided at the center of the spool 29f. When the spool 29f moves to the right, the output port becomes the oil passage 35.
It communicates with the reservoir 32 of the master cylinder 9 via f, the groove 33f and the oil passage 31f.

As is apparent from FIG. 50B as well, the linear solenoid 19f is excited and the valve body 18f is excited.
When the urging force fs1 is applied to the output port, the output hydraulic pressure P _OUT does not occur at the output port until the input hydraulic pressure P _IN applied to the input port increases from the O point to the A point, and the spool 29f moves left at the A point. Then, the input port and the output port communicate with each other via the groove 29f, and the output hydraulic pressure P _OUT increases with the relationship of P _OUT = P _IN − (fs ₁ −fs ₂ ) / a (16). Here, a is the cross-sectional area of the spool 29f.

Then, when the pedal effort is relaxed at point B to decrease the input oil pressure P _IN , the spool 29f is moved to the right so that the output port and the input port are cut off and the output oil pressure P _IN is decreased.
_OUT is held constant, and when the input hydraulic pressure P _IN eventually decreases to point C, the output port communicates with the reservoir 32 via the groove 29f, so that the output hydraulic pressure P _OUT is P _OUT = P _IN − (fs ₁ -fs ₂ ') / a ... keeping the relationship (17) reduces to point D. Here, fs ₂ ′ is the urging force of the spring 30f after the spool 29f has moved. Then, after the output hydraulic pressure P _OUT becomes zero at the point D, the output hydraulic pressure P _OUT is kept at zero until the input hydraulic pressure P _IN decreases from the point D to the point O.

Therefore, in this embodiment, the magnitude of the hysteresis H is H = kδ / a (18) Where k is the spring constant of the spring 30f, δ
Is the amount of movement of the spool 29f. According to the third embodiment, as is clear from FIG. 50 (B), the hysteresis H is further smaller than that of the second embodiment.
Therefore, in this case as well, the magnitude of the regenerative braking force is shown in FIG.
It is possible to avoid the occurrence of an error in the total sum of the regenerative braking force and the hydraulic braking force by simply performing the control as described above, and thus the regenerative braking force command value determination routine can be greatly simplified.

Although the embodiments of the present invention have been described above in detail, the present invention is not limited to the above embodiments, and various design changes can be made.

For example, in the embodiment, the vehicle in which the front wheel Wf is the driven wheel and the rear wheel Wr is the driving wheel has been illustrated, but the present invention is applied to the vehicle in which the front wheel Wf is the driving wheel and the rear wheel Wr is the driven wheel. However, it is applicable.

[0140]

As described above, according to the first feature of the present invention, the first regenerative braking force is determined based on the operating state of the brake operating element, and the operating state of the accelerator operating element and the rotation of the motor. The second regenerative braking force is determined based on the number, and the total regenerative braking force obtained by adding the first and second regenerative braking forces is output to regeneratively brake the drive wheels. The braking force equivalent to the hydraulic braking force in the vehicle and the braking force equivalent to the engine braking can be simultaneously exerted by the regenerative braking to obtain a comfortable braking feeling and to enhance the energy recovery efficiency by the regenerative braking. Becomes

Further, according to the second feature of the present invention, regenerative braking is prohibited when the motor is driven by the operation of the accelerator operator, so that when the accelerator operator and the brake operator are simultaneously operated. It is possible to obtain a feeling similar to that of a vehicle using an internal combustion engine as a drive source, by sufficiently generating the driving force of the motor by the accelerator operator and sufficiently exerting the hydraulic braking force by the brake operator.

According to the third aspect of the present invention, the brake operation amount detection sensor includes means for correcting the output when the brake operator is not operated to zero, whereby the brake is operated when the brake operator is not operated. The output of the operation amount detection sensor can be correctly matched to zero, and thereby the magnitude of the regenerative braking force determined based on the output of the brake operation amount detection sensor can be prevented from becoming excessive or excessive.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an electric vehicle including a braking device according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control system

FIG. 3 is a schematic explanatory diagram of a braking mode.

FIG. 4 is a graph showing braking force distribution in each mode.

FIG. 5 is a diagram showing the structure and characteristics of a differential pressure valve.

FIG. 6 is a flowchart of a main routine.

FIG. 7 is a flowchart of a vehicle speed calculation routine.

FIG. 8 is a flowchart of a steering angle calculation routine.

FIG. 9 is a schematic diagram showing a vehicle in a steady turn.

FIG. 10 is a flowchart of a regenerative braking force calculation routine equivalent to an engine braking.

FIG. 11 is a graph showing a relationship between motor torque and motor rotation speed and accelerator opening.

FIG. 12 is a flowchart of a regeneration limit calculation routine.

FIG. 13 is a graph showing the relationship between the motor speed and the regenerative braking force limit value.

FIG. 14 is a graph showing the relationship between the battery temperature and the battery temperature coefficient.

FIG. 15 is a graph showing the relationship between the limit reduction coefficient and the battery overvoltage.

FIG. 16 is a graph showing changes in battery voltage and regenerative braking force due to battery voltage control.

FIG. 17 is a flowchart of a mode determination routine.

FIG. 18 is a flowchart of a sudden braking determination routine.

FIG. 19 is a flowchart of a steering condition determination routine.

FIG. 20 is a graph showing a relationship between a vehicle speed and a turning determination steering angle threshold value.

FIG. 21 is a flowchart of another embodiment of the steering condition determination routine.

FIG. 22 is a first partial diagram of a flowchart of a differential pressure valve operation amount determination routine.

FIG. 23 is a second partial diagram of a flowchart of a differential pressure valve operation amount determination routine.

FIG. 24 is a third partial diagram of a flowchart of a differential pressure valve operation amount determination routine.

FIG. 25 is a graph showing the relationship between the braking force and the input hydraulic pressure.

FIG. 26 is a graph showing the relationship between the input hydraulic pressure and the total braking force.

FIG. 27 is a graph showing the relationship between the differential pressure valve operation amount and the regenerative braking force limit value.

FIG. 28 is a graph showing an operation when the hydraulic braking force is delay-controlled.

FIG. 29 is a first partial diagram of a flowchart of a regenerative braking force command value determination routine.

FIG. 30 is a second partial diagram of a flowchart of a regenerative braking force command value determination routine.

FIG. 31 is a third partial diagram of a flowchart of a regenerative braking force command value determination routine.

FIG. 32 is a fourth partial diagram of the flowchart of the regenerative braking force command value determination routine.

FIG. 33 is a graph showing an operation when the regenerative braking force is controlled by delay.

FIG. 34 is a graph showing the relationship between the input oil pressure and the output oil pressure.

FIG. 35 is a flowchart of another embodiment of a regenerative braking force command value determination routine.

FIG. 36 is a flowchart of a brake pedal sensor 0 correction routine.

FIG. 37 is a flowchart of a variable clearing routine

FIG. 38 is a first flowchart of a shift command routine.
Map

FIG. 39 is a second flowchart of the shift command routine.
Map

FIG. 40 is a third flowchart of the shift command routine.
Map

FIG. 41 is a graph showing the relationship between motor efficiency and motor rotation speed and motor torque.

FIG. 42 is a time chart when a shift change is performed during braking.

FIG. 43 is a flowchart of a fail determination routine.

FIG. 44 is a flowchart of a regenerative fail determination routine.

FIG. 45 is a flowchart of a brake pedal pedal force sensor fail detection routine.

FIG. 46 is a graph used for regenerative fail judgment.

FIG. 47 is a graph used for detecting a brake pedal depression force sensor failure.

FIG. 48 is a flowchart of a regeneration command output routine.

FIG. 49 is a view showing the structure and characteristics of the second embodiment of the differential pressure valve.

FIG. 50 is a view showing the structure and characteristics of a third embodiment of the differential pressure valve.

[Explanation of symbols]

1 Battery 2 Motor 8 Brake pedal (brake operator) 24 Brake pedal pedal force sensor (brake operation amount detection sensor) 28 Accelerator pedal (accelerator operator) T _RG Regenerative output command value (first regenerative braking force) T _RGE Emble equivalent Regenerative braking force (second regenerative braking force) T _RGT Regenerative torque command value (total regenerative braking force) Wr Rear wheel (driving wheel)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Ikuo Nonaga Inventor Ikuo Nonaga 1-4-1 Chuo, Wako-shi, Saitama Inside the Honda R & D Co., Ltd. No. 1 Stock Company Honda Technical Research Institute

Claims (3)

[Claims] 1. A battery (1) is connected to and driven by a motor (2) whose energy source is an energy source, and hydraulic braking and regenerative braking are possible by operating a brake operator (8) and an accelerator operator (28). An electric vehicle having various driving wheels (Wr), a means for determining a first regenerative braking force (T _RG ) based on an operation state of a brake operator (8), and an accelerator operator (2).
8) means for determining the second regenerative braking force (T _RGE ) based on the operating state of the motor (2) and the number of revolutions of the motor (2), and the first and second regenerative braking forces (T _RG , T _RGE ). _Is output to output the total regenerative braking force ( _TRGT )
r) for regenerative braking.
Braking device for electric vehicles. 2. The electric vehicle according to claim 1, further comprising means for prohibiting regenerative braking when the motor (2) is brought into a driving state by operating the accelerator operator (28). Braking system. 3. A brake operation amount detection sensor (24) for detecting an operation amount of the brake operation element (8) is provided with a means for correcting the output when the brake operation element (8) is not operated to zero. The braking device for an electric vehicle according to claim 1, wherein: