JP6689496B2 - Vehicle control device - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a vehicle control device, and more particularly, to a cooperative control for cooperatively controlling a hydraulic braking force generation means and a regenerative braking force generation means so that a braking force of a vehicle does not exceed a braking operation characteristic of an anti-skid control means. The present invention relates to a vehicle control device including a control means.

2. Description of the Related Art Conventionally, there has been known a hybrid vehicle that travels by using a motor generator (hereinafter abbreviated as a motor) that generates a driving force by the electric power of a battery and an engine together.
In this hybrid vehicle, the motor is operated as a generator during non-power running (such as during deceleration), and the rotational (kinetic) energy of the wheels is converted into electric energy to be stored in a battery to regenerate energy. We are aiming for efficient use.

Since the regenerative braking force generating means that performs regeneration uses the magnetic field generated by the field current in the motor to generate electric power, the regenerative braking force that acts on the drive wheels can be adjusted by controlling the induced voltage. It is possible (for example, Patent Document 1).
Therefore, there has been proposed a technique for cooperatively controlling the total braking force applied to the vehicle, that is, the hydraulic braking force by the so-called hydraulic pressure braking force generating means and the regenerative braking force by the regenerative braking force generating means.

  The vehicle control device of Patent Document 2 can apply a hydraulic braking force generation means that can apply a hydraulic braking force by a brake hydraulic pressure to wheels driven by a motor, and can apply a regenerative braking force by a rotational load of the motor to the wheels. At least one of the regenerative braking force generation means, the first condition that the temperature of the power source (battery) is equal to or higher than the first threshold value, and the second condition that the electric power held by the power source is equal to or higher than the second threshold value depend on the regenerative braking force. A predicting unit that predicts whether or not the condition is established during deceleration, and when the predicting unit predicts that one of the conditions is satisfied, the hydraulic braking force is added in addition to the regenerative braking force or in place of the regenerative braking force. It is given to the wheels.

By the way, an anti-skid control device (hereinafter, abbreviated as ABS) for preventing brake lock on each wheel of a vehicle is known.
ABS generally sets a wheel slip ratio (for example, 20%) that allows the wheel to exert a high braking force (for example, maximum braking force) as a target slip ratio in advance, and the ABS has a predetermined wheel slip ratio during vehicle braking. When the operation start threshold value is exceeded, the brake fluid pressure in the wheel cylinder of the wheel is switched to a reduced pressure state, and the wheel slip ratio of the traveling vehicle is configured to converge to a target slip ratio corresponding to a predetermined target state.
As a result, it is possible to avoid the continuous wheel lock state even during sudden braking, so that it is possible to improve the steering performance.

JP, 2016-142118, A JP, 2017-028914, A

When an occupant operates the brake pedal, the occupant's request is based on a predetermined operation characteristic (control map) that correlates the amount of operation of the brake pedal and the deceleration of the vehicle (total braking force applied to the vehicle). The braking force is set, the braking force generating means is controlled by the target operation amount corresponding to the required braking force, and the behavior of the vehicle is controlled.
Therefore, the shorter the time required for the braking force applied to the vehicle to reach the required braking force after the occupant operates the brake pedal, the shorter the braking distance of the vehicle and the higher the braking performance.
However, when the ABS is mounted on the vehicle for the purpose of improving the steering performance, the braking performance of the vehicle cannot be improved more than expected.

That is, at the time of vehicle braking, when the wheel slip ratio temporarily exceeds the ABS operation start threshold value due to some external factor, the ABS switches the brake fluid pressure to the reduced pressure state to converge the wheel slip ratio to the target slip ratio. Although safety in terms of braking performance is ensured, the tendency for the brake fluid pressure to rise is delayed and the braking distance increases.
Moreover, in the case of using the hydraulic braking force generating means for controlling the flow rate of the brake fluid, which is a viscous fluid, by the electromagnetic valve, safety is ensured from the viewpoint of operation response as compared with electric control, but There is concern that the braking distance will increase further.

Therefore, the hydraulic braking force tends to increase (speed of increase) so that the hydraulic braking force generated in the vehicle does not exceed the braking force characteristic (hereinafter referred to as the braking operation characteristic) set so as to correspond to the ABS operation start threshold value. Is set to be significantly lower than the braking operation characteristic of the ABS, it is possible to avoid the ABS operation which is undesired for the occupant.
As a result, although the undesired operation of the ABS can be avoided, the time required for the hydraulic braking force to reach the required braking force is further lengthened, and there is still a concern that the braking distance will increase while ensuring safety. It

Further, since the regenerative braking force generation means can perform control with high responsiveness, it is conceivable to use the hydraulic braking force and the regenerative braking force together as in the vehicle control device of Patent Document 2.
However, since the regenerative braking force generating means limits the operating period and the operating time due to the characteristics peculiar to the battery that accumulates the generated electric power, it is difficult to guarantee a stable braking force, and the hydraulic braking force is applied during vehicle braking. It is difficult to always use and the regenerative braking force together.
That is, it is desired to establish an effective technique for improving braking performance in a vehicle equipped with ABS.

  An object of the present invention is to provide a vehicle control device and the like that can achieve both steering performance and braking performance regardless of the electric power held by the power supply.

The vehicle control device according to claim 1, wherein a power source, a hydraulic system braking force generating unit capable of applying a hydraulic braking force to the wheels by a brake hydraulic pressure, and a regeneration by a rotational load of an electric motor connected to the wheels. Regenerative braking force generation means capable of applying a braking force, anti-skid control means for controlling the wheel slip ratio to converge to a predetermined target state by the braking force applied to the wheels during vehicle braking, and a brake pedal by an occupant The braking operation is a braking force corresponding to a predetermined target state of the anti-skid control means until the braking force acting on the vehicle reaches the required braking force while the braking force required by the occupant is set based on the depression operation In the vehicle control means, which is provided with the hydraulic pressure braking force generation means and the coordinated control means for cooperatively controlling the regenerative braking force generation means so as not to exceed the characteristics, Have detectable held power detecting means holdings power, the cooperative control means may have held power detected is set short regenerative operation period higher by the held power detection unit, the regenerative operation start of braking During the period, after performing the individual braking by the regenerative braking force that prohibits the application of the hydraulic braking force, the individual braking by the hydraulic braking force that prohibits the application of the regenerative braking force is performed.

Since this vehicle control device is provided with the anti-skid control means for controlling the wheel slip ratio to converge to a predetermined target state by the braking force applied to the wheels during vehicle braking, it is possible to prevent the brake lock of the wheels. It is possible to secure steering performance.
A braking force corresponding to a predetermined target state of the anti-skid control means is set until the braking force acting on the vehicle reaches the required braking force while the braking force required by the passenger is set based on the operation of the brake pedal by the passenger. Since the braking force acting on the vehicle reaches the required braking force, the braking force acting on the vehicle is provided with the cooperative control means for cooperatively controlling the hydraulic pressure braking force generating means and the regenerative braking force generating means so as not to exceed the braking operation characteristic. During the period, the braking force of the vehicle can be increased without operating the braking force reduction process by the anti-skid control means.
The cooperative control means has an owned power detecting means capable of detecting the owned power of the power source, and the cooperative control means sets the regeneration operation period to be shorter as the owned power detected by the owned power detecting means is higher , and from the start of braking, During the regenerative operation period, after the individual braking by the regenerative braking force that prohibits the application of the hydraulic braking force is performed, the individual braking by the hydraulic braking force that prohibits the application of the regenerative braking force is performed. It is possible to increase the frequency of application of the regenerative braking force that promotes the load movement of the vehicle body weight, regardless of the electric power possessed. Moreover, the full charge of the power source can be delayed, and even when the power source is close to full charge, the braking by the regenerative braking force that promotes the load movement of the vehicle body weight can be effectively executed.

According to a second aspect of the present invention, in the first aspect of the present invention, the cooperative control means makes the rate of increase of the regenerative braking force substantially equal to the rate of increase of the braking operation characteristic during the regenerative operation period from the start of braking. It is characterized by being set to.
With this configuration, the maximum regenerative energy can be recovered even if the regenerative operation period is short.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, the cooperative control means sets the regeneration operation period to be short when the internal resistance of the power supply is high.
With this configuration, even in a situation where it is difficult to secure the regenerative braking force, it is possible to switch from the regenerative braking force to the hydraulic braking force at an early stage to secure the braking performance.

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the cooperative control unit sets the increase rate of the hydraulic braking force to be smaller than the increase rate of the braking operation characteristic. It is characterized by that.
With this configuration, when the vehicle is braked, it is possible to avoid the operation of the anti-skid control means that is unwilling to the passenger.

  According to the vehicle control device of the present invention, it is possible to achieve both steering performance and braking performance in a vehicle equipped with the anti-skid control means, regardless of the power held by the power supply.

FIG. 1 is an overall schematic configuration diagram of a vehicle control device according to a first embodiment. It is a brake hydraulic pressure circuit diagram of a braking mechanism. FIG. 3 is a functional block diagram of a first ECU and a second ECU. It is explanatory drawing of a 1st cooperation mode. It is explanatory drawing of a 2nd cooperation mode. It is explanatory drawing of a 3rd cooperation mode. It is a flow chart which shows an ABS control processing procedure. It is a flow chart which shows a cooperation control processing procedure. It is a flow chart which shows a friction braking mode processing procedure. It is a flow chart which shows the 1st cooperation mode processing procedure. It is a flow chart which shows the 2nd cooperation mode processing procedure. It is a flow chart which shows the 3rd cooperation mode processing procedure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The following description exemplifies a case where the present invention is applied to a control device for a hybrid vehicle, and does not limit the present invention, its application, or its application.

Hereinafter, Embodiment 1 of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a vehicle V according to this embodiment includes a braking mechanism B capable of controlling a hydraulic braking force related to the stopping performance of the vehicle V, a driving force related to the traveling performance of the vehicle V, and a stopping performance of the vehicle V. A power train mechanism P capable of controlling the regenerative braking force according to the above, a brake pedal 1 which is an input device operable by an occupant, and front and rear wheels 2a to 2d which are output devices are provided. The vehicle V is controlled by an anti-skid control mechanism (hereinafter referred to as ABS) so that the wheel slip ratio s converges to a predetermined target state during braking, and the friction braking mode and the independent braking by the hydraulic braking force are performed. The first to third cooperative modes, which are cooperative braking by the hydraulic braking force and the regenerative braking force, can be selectively executed.

First, the braking mechanism B will be described.
2. FIG. 2 is a brake fluid pressure circuit diagram of the braking mechanism B.
As shown in FIGS. 1 and 2, the braking mechanism B includes a stroke simulator 3 (reaction force generating mechanism) that applies a reaction force to the brake pedal 1 according to a pedal stroke (hereinafter, abbreviated as stroke) St. An electric brake booster (hereinafter abbreviated as an electric booster) 4 capable of generating a brake hydraulic pressure corresponding to a hydraulic braking force, and a master capable of directly generating a brake hydraulic pressure corresponding to a stroke St of a brake pedal 1 by an occupant. A cylinder 5 and wheel cylinders 6a to 6d capable of braking the rotation of the four front, rear, left, and right wheels 2a to 2d of the vehicle V by a brake fluid pressure generated by the master cylinder 5 or the electric booster 4, respectively, by applying frictional force. A main component is a first ECU (Electronic Control Unit) 10 capable of controlling the electric booster 4.

Next, the stroke simulator 3 will be described.
The stroke simulator 3 absorbs and consumes the brake fluid pressure sent from the master cylinder by simulating the amount of oil consumption, and when the occupant depresses or depresses the brake pedal 1, the stroke simulator 3 passes through the brake pedal 1. An operation reaction force having a preset characteristic can be applied to an occupant (leg of the occupant).
The stroke simulator 3 is formed by, for example, a cylinder, a piston slidable in the cylinder, and a biasing means for biasing the piston (all are not shown), and is basically used for operating the brake pedal 1. The operation reaction force (pedal force) applied to the occupant is adjusted based on the accompanying brake fluid pressure.

As shown in FIG. 2, the electric booster 4 is connected to the reservoir tank 7 and includes an electric motor, a hydraulic pump, an accumulator (not shown), and the like.
The electric booster 4 is connected to the wheel cylinders 6a and 6b capable of braking the front wheels 2a and 2b, which are drive wheels, via an open / close solenoid valve 8b, and is a driven wheel via an open / close solenoid valve 8c. The wheels 2c and 2d are communicated with wheel cylinders 6c and 6d capable of braking. The solenoid valves 8b and 8c are opened when energized.
As shown in FIG. 2, return flow paths connected to the reservoir tank 7 are connected to the upstream flow paths of the wheel cylinders 6a to 6d, respectively. Solenoid valves 9a to 9d which are opened by energization are arranged in these return flow paths, respectively.

Next, the master cylinder 5 will be described.
The master cylinder 5 includes a first pressure generating chamber 5a and a second pressure generating chamber 5b.
The first and second pressure generating chambers 5a and 5b are respectively connected to the reservoir tank 7 and have compression springs inside. The first and second pressure generating chambers 5a and 5b are configured to be capable of pumping substantially the same brake fluid pressure according to the depression operation of the brake pedal 1.
The first pressure generating chamber 5a communicates with the wheel cylinders 6a, 6b via an openable / closable electromagnetic valve 8a, and the second pressure generating chamber 5b communicates with the wheel cylinders 6c, 6d via an openable / closable electromagnetic valve 8d. Has been done. The solenoid valves 8a and 8d are closed when energized, and are deenergized and opened when the electric booster 4 is abnormal.

With the above configuration, when the electric booster 4 is abnormal, the solenoid valves 8a and 8d are opened and the solenoid valves 8b and 8c are closed, so that the brake hydraulic pressure is directly applied to the wheel cylinders 6a to 6d from the master cylinder 5. Is supplied. When the electric booster 4 is normal, the solenoid valves 8a and 8d are closed and the solenoid valves 8b and 8c are opened, and brake hydraulic pressure is supplied from the electric booster 4 to the wheel cylinders 6a to 6d. When the electric booster 4 is normal, the solenoid valves 8b and 8c are closed and the solenoid valves 9a to 9d are opened, so that the brake fluid pressure is discharged from the wheel cylinders 6a to 6d, and the brake pressure is forcibly suppressed. Power can be reduced.
The solenoid valves 8b and 8c correspond to the ABS inlet valve, and the solenoid valves 9a to 9d correspond to the ABS outlet valve.

Next, the first ECU 10 will be described.
The first ECU 10 includes a CPU (Central Processing Unit), a ROM, a RAM, an in-side interface, an out-side interface, and the like, and inputs a detection signal from a stroke sensor 21 that detects a stroke St of the brake pedal 1. There is. The ROM stores various programs, data and maps for controlling the pedaling force and the braking force, and the RAM has a processing area used when the CPU performs a series of processes.
As shown in FIG. 3, the first ECU 10 includes an operation reaction force setting unit 11, a required braking force setting unit 12, a hydraulic pressure control unit 13, and the like.

The operation reaction force setting unit 11 holds a pedaling force characteristic map (not shown) defined by the pedaling force with which the occupant operates the brake pedal 1 and the stroke St of the brake pedal 1.
Since the strength of the occupant's sense is proportional to the logarithm of the strength of the stimulus (Weber-Fechner's law), the pedaling force characteristic map is defined by a logarithmic function.
The operation reaction force setting unit 11 sets a pedal force corresponding to the target operation reaction force based on the stroke St detected by the stroke sensor 21 and the pedal force characteristic map, and outputs an operation command signal corresponding thereto as a control brake fluid pressure. It outputs to the stroke simulator 3 via.

The required braking force setting unit 12 holds a braking characteristic map (not shown) defined by the pedaling force with which the occupant operates the brake pedal 1 and the deceleration (braking force) required by the occupant.
The stroke St reflects the deceleration request of the occupant with the operation amount of the occupant as a parameter.
Therefore, the required braking force setting unit 12 sets the required braking force Fa requested by the occupant for the vehicle V using the pedaling force set through the detected stroke St of the brake pedal 1 and the braking characteristic map. is doing.

The hydraulic pressure control unit 13 creates an operation command signal corresponding to the hydraulic braking force Ff based on the hydraulic braking force Ff in each braking mode input from the second ECU 40 described later, and outputs it to the electric booster 4. Specifically, when the friction braking mode and the first to third cooperative modes are executed, the operation command signals for the solenoid valves 8b and 8c are created based on the operation command signals input from the second ECU 40, and the wheel cylinders 6a to 6d are operated. The brake fluid pressure is controlled.
Further, the hydraulic control unit 13 outputs the operation command signals for the solenoid valves 8b and 8c and the solenoid valves 9a to 9d based on the wheel slip rate s in order to converge the wheel slip rate s to a predetermined target state during the ABS operation. It is created and is output to each solenoid valve 8b, 8c, 9a-9d.

Next, the power train mechanism P will be described.
As shown in FIG. 1, the power train mechanism P includes a motor generator (hereinafter abbreviated as a motor) 31 as a regenerative braking force (regenerative torque) generation source and a power generation source, and a power transmission mechanism such as a pulley for the motor 31. A multi-cylinder reciprocating engine 32 as a power source, which is connected via a gear, and an automatic transmission (hereinafter abbreviated as AT) as a fluid transmission mechanism capable of transmitting driving force to the front wheels 2a, 2b via a differential mechanism. 33, and a second ECU 40 and the like capable of controlling the motor 31, the engine 32 and the like.

The motor 31 is a three-phase AC synchronous motor that is connected to the wheels 2a and 2b, and has a switching mechanism (not shown) that has a switch function that can linearly switch the energization state of each winding. It is configured to control the induced voltage generated in the.
Therefore, when the vehicle V is decelerated, the reverse torque based on the induced voltage in the motor 31 is applied to the wheels 2a and 2b, and the electric power generated by the motor 31 is generated by the second battery 36 (for example, lithium ion) which is an auxiliary power source. Battery).

The second ECU 40 includes a CPU, a ROM, a RAM, an in-side interface, an out-side interface, and the like. The ROM stores various programs and data for controlling the regeneration amount, a map and the like, and the RAM has a processing area used when the CPU performs a series of processes.
The second ECU 40 is mainly in parallel with the electric booster 4, the first ECU 10, the DCDC converter 34 that converts the power supply voltage generated by the motor 31, and various loads (not shown) such as an air conditioner mounted on the vehicle V. It is electrically connected to the first battery 35 that is a power source.
The DCDC converter 34 is configured to be able to supply the converted power supply voltage to the first battery 35.

  The second ECU 40 also detects the SOC (State Of Charge) of the second battery 36, the SOC sensor 22, the temperature sensor 23 that can detect the temperature of the second battery 36, the vehicle speed of the vehicle V (vehicle body speed). ), A wheel speed sensor 25 capable of detecting the speeds of the wheels 2a to 2d, a rod displacement sensor 26 capable of detecting displacements of the suspension rod lengths of the wheels 2a to 2d, and a vehicle V Each detection signal is input from the gradient sensor 27 capable of detecting the gradient of the road surface on which the vehicle runs, and an operation command signal is output to the first ECU 10 and the motor 31.

  As shown in FIG. 3, the second ECU 40 controls the ABS control unit 41 (anti-skid control means) so that the wheel slip ratio s is converged to a predetermined target state by the braking force applied to the wheels 2a to 2d during vehicle braking. , A load movement detection unit 42 (load movement detection means) that detects a load movement of the vehicle body weight of the vehicle V, and a cooperation control unit 43 (cooperation control means) that cooperatively controls the hydraulic braking force Ff and the regenerative braking force Fr. The regeneration control unit 44 and the like are provided.

First, the ABS control unit 41 will be described.
The ABS control unit 41 closes the solenoid valves 8b, 8c and closes the solenoid valves 8b and 8c when the wheel slip ratio s is larger than the ABS operation start threshold value sa set based on the target state capable of ensuring the traveling stability of the vehicle V. It is configured to open 9a to 9d to start the ABS control.
Then, during the ABS control, when the wheel slip ratio s is larger than the target slip ratio sb (sb <sa), the solenoid valves 8b and 8c are closed and the solenoid valves 9a to 9d are opened to operate the wheel cylinders 6a to 6d. The lock of the wheels 2a to 2d is avoided by reducing the fluid pressure of the solenoid valves 9a to 9d and the solenoid valves 8b and 8c are opened and the solenoid valves 9a to 9d are closed when the wheel slip ratio s is equal to or less than the target slip ratio sb. However, the braking force of the wheels 2a to 2d is increased by increasing the hydraulic pressure of the wheel cylinders 6a to 6d.

The ABS control unit 41 calculates the wheel slip ratio s of the front wheels 2a and 2b based on the detection signals of the vehicle speed sensor 24 and the wheel speed sensor 25. Specifically, a pseudo slip rate obtained by dividing the difference value between the wheel speed of the front wheels 2a and the vehicle body speed by the vehicle body speed and a pseudo slip rate obtained by dividing the difference value between the wheel speed of the front wheels 2b and the vehicle body speed by the vehicle body speed are calculated. The larger value of the pseudo slip ratios is set as the wheel slip ratio s representing the front wheels 2a and 2b. As the vehicle body speed, the wheel speed of the slower wheel of the rear driven wheels 2c and 2d is used as the vehicle body speed.
The ABS operation start threshold value sa and the target slip ratio sb are calculated based on the road surface μ. In the present embodiment, the road surface μ is estimated and calculated by collating the detected wheel speed and the acceleration of the vehicle V with the μ table, but a μ sensor may be provided and the output value from this μ sensor may be used. .

As shown in FIG. 3, the ABS control unit 41 has a braking operation characteristic setting unit 41a.
The braking operation characteristic setting unit 41a sets the braking operation characteristic A that defines the tendency of the braking force of the vehicle V corresponding to the ABS operation start threshold value sa.
As shown in FIGS. 4 to 6, the braking operation characteristic A is defined by the time t from the start of braking and the braking force acting on the vehicle V.
The braking operation characteristic A can be expressed by a linear function of the following equation when the road surface μ is constant.
A = K1 × t (1)
Note that K1 is an ABS operating coefficient.
Therefore, when the occupant depresses the brake pedal 1, even if the braking force of the vehicle V has not reached the required braking force Fa (arrival time tb), the vehicle V is temporarily reduced due to the decrease in the road surface μ. When the applied braking force exceeds the braking operation characteristic A, the depressurization process by ABS is executed and the brake fluid pressure in the wheel cylinders 6a to 6d is reduced.

Next, the load movement detection unit 42 will be described.
The load movement detection unit 42 detects displacement speeds and displacement accelerations of the suspension rods of the wheels 2a to 2d based on the displacements of the suspension rod lengths of the wheels 2a to 2d input from the rod displacement sensors 26, respectively.
The load movement of the vehicle body weight of the vehicle V is detected by the detected displacement speed and displacement acceleration of the suspension rods of the wheels 2a to 2d.

Next, the cooperation control unit 43 will be described.
When the vehicle is being braked, the cooperative control unit 43 selects a corresponding braking mode from the friction braking mode and each cooperative mode according to the state of charge SOC of the second battery 36 detected by the SOC sensor 22, and determines a predetermined cooperative mode. When is selected, the hydraulic braking force Ff by the braking mechanism B and the regenerative braking force Fr by the power train mechanism P are cooperatively controlled.
Specifically, when the SOC is 97% or more, the friction braking mode, when the SOC is 90% or more and less than 97%, the first cooperative mode, when the SOC is 30% or more and less than 90%, the second When the cooperation mode and SOC are less than 30%, the third cooperation mode is selected.

The cooperative control unit 43 sets an operating characteristic corresponding to the pressure increasing speed of the hydraulic braking force Ff by the braking mechanism B based on the braking operating characteristic A. The operating characteristic of the hydraulic braking force Ff is defined by the time t from the start of braking and the braking operating characteristic A.
The operating characteristic of the hydraulic braking force Ff can be expressed by a linear function of the following equation.
Ff = K2 × t (2)
K2 is a friction braking actuation coefficient.
The operation characteristic of the hydraulic braking force Ff is set to a value smaller than the braking operation characteristic A so that the ABS does not operate due to a temporary change in the braking force with respect to the vehicle V (change in the road surface μ).
In the present embodiment, the friction braking actuation coefficient K2 is set within the range defined by the following equation in consideration of the braking distance of the vehicle V.
1/2 × K1 ≦ K2 <2/3 × K1 (3)

  As shown in FIG. 3, the cooperative control unit 43 includes a first cooperative mode control unit 43a and a second cooperative mode control unit in which the ratio of the regenerative braking force Fr to the total braking force is larger than that of the first cooperative mode control unit 43a. The unit 43b and the third cooperative mode control unit 43c in which the ratio of the regenerative braking force Fr to the total braking force is larger than that of the second cooperative mode control unit 43b within the period in which the maximum load is transferred to the front wheels 2a and 2b are provided. .

First, the first cooperation mode control unit 43a will be described.
As shown in FIG. 4, the first cooperative mode control unit 43a executes the individual braking by the regenerative braking force Fr that prohibits the application of the hydraulic braking force Ff during the regenerative operation period from the start of braking to the time ta, and the time ta After that, the individual braking is performed by the hydraulic braking force Ff that prohibits the application of the regenerative braking force Fr. Specifically, up to time ta, the regenerative braking force Fr is controlled to increase by the operation characteristic of the equation (4) having the same coefficient as the braking operation characteristic A, and after the time ta, the hydraulic braking force Ff is changed to the operation characteristic of the equation (2). The increase is controlled by.
Fr = K1 × t (4)
As a result, even when the SOC of the second battery 36 is close to being fully charged, the frequency of applying the regenerative braking force Fr that accelerates the load movement of the vehicle body weight is increased.

The first cooperation mode control unit 43a calculates the time ta based on the SOC and the internal resistance of the second battery 36.
Since the time ta is set in proportion to the reciprocal of the SOC of the second battery 36, the higher the SOC, the shorter the regenerative operation period.
Further, since the time ta is set in proportion to the reciprocal of the internal resistance of the second battery 36, the regeneration is performed as the temperature of the second battery 36 is lower, except for the period of normal temperature (−20 ° C. to 20 ° C.). The operation period is shortened, and the higher the temperature of the second battery 36 is, the shorter the regenerative operation period is.
In the first cooperative mode control unit 43a, the sum of the hydraulic braking force Ff and the regenerative braking force Fr (basically, the regenerative operation period is a minute period, so the hydraulic braking force Ff) reaches the required braking force Fa. At the time point (time tb), the increase control of the braking force is ended, and the required braking force Fa is maintained until the occupant depresses the brake pedal 1.

Next, the second cooperation mode control unit 43b will be described.
As shown in FIG. 5, the second cooperation mode control unit 43b controls the hydraulic braking force Ff to be smaller than the braking operation characteristic A, and the regenerative braking force Fr is the difference between the braking operation characteristic A and the hydraulic braking force Ff. The braking force is controlled to be less than or equal to it.
The second cooperative mode control unit 43b prohibits application of the regenerative braking force Fr after a lapse of a predetermined period after the sum of the hydraulic braking force Ff and the regenerative braking force Fr reaches the required braking force Fa.

Specifically, the hydraulic braking force Ff is controlled to increase by the operating characteristic of the equation (2) until the time tb at which the operating characteristic of the hydraulic braking force Ff corresponds to the required braking force Fa, and after time tb, the occupant brake pedal. The required braking force Fa is maintained until the pedal 1 is depressed.
Further, regarding the regenerative braking force Fr, the braking operation characteristic A is controlled to increase by the operation characteristic of the equation (5) until the time tc corresponding to the required braking force Fa, and the operation characteristic of the equation (6) is obtained from the time tc to the time tb. The decrease is controlled by.
Fr = (K1-K2) × t (5)
Fr = Fa−K2 × t (6)

As a result, the braking force equivalent to the difference between the braking operation characteristic A and the hydraulic braking force Ff can be compensated for by using the regenerative braking force Fr having high responsiveness, and the braking force acting on the vehicle V can be quickly added to the required braking force Fa. Has reached. Moreover, after the braking force acting on the vehicle V reaches the required braking force Fa, until the hydraulic braking force Ff reaches the required braking force Fa, the braking force acting on the vehicle V is accurately adjusted using the regenerative braking force Fr. The required braking force Fa is converged.
After the hydraulic braking force Ff reaches the required braking force Fa, application of the regenerative braking force Fr is prohibited.

Next, the third cooperation mode control unit 43c will be described.
As shown in FIG. 6, the third cooperative mode control unit 43c controls the regenerative braking force Fr to be larger than the hydraulic braking force Ff during the set period from the start of braking.
The third cooperative mode control unit 43c sets a set period from the start of braking to the maximum load movement of the vehicle body weight with respect to the front wheels 2a and 2b based on the detection result of the load movement detection unit 42.

Specifically, the time td at which the maximum weight of the vehicle body weight moves with respect to the front wheels 2a and 2b is detected based on the displacement speed and the displacement acceleration of the suspension rods of the wheels 2a to 2d input from the load movement detection unit 42, and the time from the start of braking is detected. Set the set period up to td.
Moreover, when the road surface ahead of the traveling direction of the vehicle V has a large forward downward slope directed downward, the time td is changed to an earlier time so that the set period becomes shorter according to the road surface slope detected by the slope sensor 27. There is.
As a result, the switching timing based on the load movement can be optimized according to the road surface gradient on which the vehicle V travels.

Then, the third cooperative mode control unit 43c prohibits application of the hydraulic braking force Ff from the start of braking to the time td, and the regenerative braking force Fr has the same operating characteristic of the equation (4) having the same coefficient as the braking operating characteristic A. After the time td, application of the regenerative braking force Fr is prohibited and the hydraulic braking force Ff is increased controlled by the operation characteristic of the equation (2).
Thus, by increasing the usage ratio of the regenerative braking force Fr immediately after braking, the maximum load transfer to the front wheels 2a, 2b capable of exhibiting a high braking force is accelerated, so that the braking force acting on the vehicle V is reduced. The required braking force Fa is reached early.

  The regenerative control unit 44 creates an operation command signal corresponding to the regenerative braking force Fr input from the cooperative control unit 43, and outputs it to the switching mechanism of the motor 31. Specifically, when executing the first to third cooperative modes, an operation command signal for the switching mechanism of the motor 31 is created based on the regenerative braking force Fr input from the cooperative control unit 43, and the induced voltage generated in the motor 31 is calculated. Have control.

Next, the ABS control processing procedure will be described based on the flowchart of FIG. 7.
Note that Si (i = 1, 2 ...) Shows steps for each process.

As shown in FIG. 7, first, various information is read (S1), and the process proceeds to S2.
In S2, it is determined whether or not the brake pedal 1 is depressed by the occupant.
As a result of the determination in S2, when the brake pedal 1 is stepped on by the occupant, the wheel slip ratio s of the front wheels 2a and 2b is calculated based on the detection signals of the vehicle speed sensor 24 and the wheel speed sensor 25 (S3), and S4 is executed. Transition.
In S4, the road surface μ is calculated based on the wheel speed and the acceleration of the vehicle V, and the process proceeds to S5.
In S5, the ABS operation start threshold value sa and the target slip ratio sb are calculated based on the road surface μ, and the process proceeds to S6.

In S6, it is determined whether the flag F is 0 or not.
As a result of the determination in S6, if the flag F is 0, that is, if so-called ABS control is not yet executed, the process proceeds to S7.
In S7, it is determined whether the wheel slip ratio s is equal to or greater than the ABS operation start threshold value sa.
As a result of the determination in S7, when the wheel slip ratio s is equal to or more than the ABS operation start threshold value sa, 1 is substituted into the flag F (S8), and the process proceeds to S9.
In S9, the solenoid valves 8b and 8c are closed and the solenoid valves 9a to 9d are opened to perform the pressure reducing process, and then the process returns.
As a result of the determination in S6, if the flag F is 1, that is, so-called ABS control has already been executed, the process proceeds to S10.

In S10, it is determined whether the wheel slip ratio s is equal to or higher than the target slip ratio sb.
As a result of the determination in S10, if the wheel slip ratio s is equal to or higher than the target slip ratio sb, the process proceeds to S9, and if the wheel slip ratio s is less than the target slip ratio sb, the process proceeds to S12.
In S12, the solenoid valves 8b and 8c are opened and the solenoid valves 9a to 9d are closed to execute the pressure increasing process, and then the process returns.
As a result of the determination in S2, if the occupant does not depress the brake pedal 1, 0 is assigned to the flag F (S11), and the process proceeds to S12.

Next, the cooperative control processing procedure will be described based on the flowchart of FIG.
The cooperative control process is repeatedly executed at a predetermined cycle and is executed in parallel with the ABS control process shown in FIG. 7.

As shown in FIG. 8, first, various information is read (S21), and the process proceeds to S22.
In S22, it is determined whether or not the brake pedal 1 is depressed by the occupant.
As a result of the determination in S22, when the brake pedal 1 is depressed by the occupant, the process proceeds to S23.
In S23, it is determined whether or not the flag f is 0 and so-called cooperative mode processing is not executed.
When the flag f is 0 as a result of the determination in S23, the required braking force Fa required by the occupant is calculated (S24), and the process proceeds to S25.
In S25, the ABS actuation braking characteristic A and the ABS actuation coefficient K1 are calculated based on the ABS actuation start threshold sa, and the friction braking coefficient K2 is calculated based on the braking performance of the vehicle V (S26), and then the process proceeds to S27.

In S27, it is determined whether the SOC of the second battery 36 is 97% or more.
As a result of the determination in S27, when the SOC of the second battery 36 is 97% or more, there is a high possibility that the second battery 36 will be overcharged due to the execution of the regenerative braking, so the process proceeds to S28.
In S28, the friction braking mode process is executed and the process returns.
When the SOC of the second battery 36 is less than 97% as a result of the determination in S27, the process proceeds to S29, and it is determined whether the SOC of the second battery 36 is 90% or more.
As a result of the determination in S29, when the SOC of the second battery 36 is 90% or more, there is a high possibility that the second battery 36 will be overcharged due to the execution of regenerative braking, so the process proceeds to S30.
In S30, the first cooperative mode process is executed, 1 is assigned to the flag f (S31), and then the process returns.

As a result of the determination in S29, if the SOC of the second battery 36 is less than 90%, the process proceeds to S32, and it is determined whether the SOC of the second battery 36 is 30% or more.
As a result of the determination in S32, when the SOC of the second battery 36 is 30% or more, there is a low possibility that the second battery 36 will be overcharged due to the execution of regenerative braking, so the process proceeds to S33.
In S33, the second cooperative mode process is executed, and the process proceeds to S31.
As a result of the determination in S32, when the SOC of the second battery 36 is less than 30%, it is extremely unlikely that the second battery 36 is overcharged due to the execution of regenerative braking, so the process proceeds to S34.
In S34, the third cooperative mode process is executed, and the process proceeds to S31.

Next, the friction braking mode process of S28 will be described.
As shown in the flowchart of FIG. 9, in the friction braking mode process, first, in S41, the hydraulic braking force Ff is set based on the equation (2) and the elapsed time t from the start of braking, and the regenerative braking force Fr is set to 0. After setting, the process proceeds to S42.
In S42, an operation command signal for the set hydraulic braking force Ff and regenerative braking force Fr is output, and the process proceeds to S43.
In S43, it is determined whether the hydraulic braking force Ff is greater than or equal to the required braking force Fa.
As a result of the determination in S43, if the hydraulic braking force Ff is greater than or equal to the required braking force Fa, the process ends, and if the hydraulic braking force Ff is less than the required braking force Fa, the process returns to S41.

Next, the first cooperative mode process of S30 will be described.
As shown in the flowchart of FIG. 10, in the first cooperative mode process, first in S51,
The time ta corresponding to the regenerative operation period is calculated based on the SOC and the internal resistance of the second battery 36, and the process proceeds to S52.

In S52, it is determined whether the elapsed time t from the start of braking is the time ta or less.
As a result of the determination in S52, when the elapsed time t from the start of braking is equal to or less than the time ta, the hydraulic braking force Ff is set to 0 and the regenerative braking force Fr is set based on the equation (4) and the elapsed time t from the start of braking. (S53), the process proceeds to S54.
In S54, an operation command signal for the set hydraulic braking force Ff and regenerative braking force Fr is output, and the process proceeds to S55.

In S55, it is determined whether the sum of the hydraulic braking force Ff and the regenerative braking force Fr has reached the required braking force Fa.
As a result of the determination in S55, when the sum of the hydraulic braking force Ff and the regenerative braking force Fr reaches the required braking force Fa, the process ends.
As a result of the determination in S55, if the sum of the hydraulic braking force Ff and the regenerative braking force Fr has not reached the required braking force Fa, the process returns to S52.
As a result of the determination in S52, when the elapsed time t from the start of braking exceeds the time ta, the hydraulic braking force Ff is set based on the equation (2) and the elapsed time t from the start of braking, and the regenerative braking force Fr is set to 0. After setting (S56), the process proceeds to S42.

Next, the second cooperative mode processing of S33 will be described.
As shown in the flowchart of FIG. 11, in the second cooperative mode process, first, in S61, it is determined whether the sum of the hydraulic braking force Ff and the regenerative braking force Fr is less than the required braking force Fa.
If the result of the determination in S61 is that the sum of the hydraulic braking force Ff and the regenerative braking force Fr is less than the required braking force Fa, the hydraulic braking force Ff is set based on the equation (2) and the elapsed time t from the start of braking, and the regenerative braking force is set. The power Fr is set based on the equation (5) and the elapsed time t from the start of braking (S62), and the process proceeds to S63.

In S63, an operation command signal for the set hydraulic braking force Ff and regenerative braking force Fr is output, and the process returns to S61.
If the result of the determination in S61 is that the sum of the hydraulic braking force Ff and the regenerative braking force Fr is greater than or equal to the required braking force Fa, it is determined whether the hydraulic braking force Ff set by the operating characteristic of the equation (2) is greater than or equal to the required braking force Fa. A determination is made (S64).

If the result of the determination in S64 is that the hydraulic braking force Ff is greater than or equal to the required braking force Fa, the hydraulic braking force Ff is set to the required braking force Fa, the regenerative braking force Fr is set to 0 (S65), and the process proceeds to S66.
In S66, an operation command signal for the set hydraulic braking force Ff and regenerative braking force Fr is output, and the process ends.
As a result of the determination in S64, when the hydraulic braking force Ff is less than the required braking force Fa, the hydraulic braking force Ff is set based on the formula (2) and the elapsed time t from the start of braking, and the regenerative braking force Fr is calculated by the formula (6). And based on the elapsed time t from the start of braking (S67), the process proceeds to S63.

Next, the third cooperative mode process of S34 will be described.
As shown in the flowchart of FIG. 12, in the third cooperative mode processing, first, in S71, it is determined whether or not it is before the switching timing based on the load movement of the vehicle V.
The switching timing for switching from regenerative braking to hydraulic braking is determined by the time td when the maximum weight of the vehicle body is moved with respect to the front wheels 2a and 2b. At this time, the time td is adjusted to be shorter according to the magnitude of the forward downward slope.
As a result of the determination in S71, before the switching timing based on the load movement of the vehicle V, the hydraulic braking force Ff is set to 0 and the regenerative braking force Fr is set based on the equation (4) and the elapsed time t from the start of braking. (S72), the process proceeds to S73.

In S73, an operation command signal for the set hydraulic braking force Ff and regenerative braking force Fr is output, and the process returns to S71.
As a result of the determination in S71, after the switching timing based on the load movement of the vehicle V, it is determined whether the hydraulic braking force Ff set by the operation characteristic of the equation (2) is equal to or greater than the required braking force Fa (S74).

If the result of the determination in S74 is that the hydraulic braking force Ff is greater than or equal to the required braking force Fa, the hydraulic braking force Ff is set to the required braking force Fa, the regenerative braking force Fr is set to 0 (S75), and the process proceeds to S76.
In S76, an operation command signal for the set hydraulic braking force Ff and regenerative braking force Fr is output, and the process ends.
If the result of the determination in S74 is that the hydraulic braking force Ff is less than the required braking force Fa, the hydraulic braking force Ff is set based on equation (2) and the elapsed time t from the start of braking, and the regenerative braking force Fr is set to 0. (S77), the process proceeds to S73.

Next, the operation and effect of the vehicle control device will be described.
The control device according to the first embodiment includes the ABS control unit 41 that controls the wheel slip ratio s to converge to the ABS operation start threshold value sa by the braking force applied to the wheels 2a to 2d during vehicle braking. The brake lock of 2a to 2d can be prevented, and the steering performance can be secured.
The ABS operation start threshold sa of the ABS control unit 41 is set until the braking force Fa required by the occupant is set based on the operation of the brake pedal 1 by the occupant and the braking force acting on the vehicle V reaches the required braking force Fa. Since the cooperative control unit 43 that cooperatively controls the braking mechanism B and the power train mechanism P is provided so as not to exceed the braking operation characteristic A that is the corresponding braking force, the braking force acting on the vehicle V reaches the required braking force Fa. Until then, the braking force of the vehicle V can be increased without operating the braking force reduction process by the ABS control unit 41.
The cooperation control unit 43 has the SOC sensor 22 capable of detecting the SOC of the second battery 36, and the cooperation control unit 43 distributes the hydraulic braking force Ff and the regenerative braking force Fr based on the SOC detected by the SOC sensor 22, so-called execution. Since the type of the cooperative mode to be changed is changed, it is possible to increase the frequency of application of the regenerative braking force Fr that promotes the load movement of the vehicle body weight, regardless of the SOC of the second battery 36.

  The cooperative control unit 43 sets the regenerative operation period (time ta) based on the SOC detected by the SOC sensor 22 and prohibits application of the hydraulic braking force Ff from the start of braking to the regenerative operation period (time ta). After the independent braking by the regenerative braking force Fr is performed, the individual braking is performed by the hydraulic braking force Ff that prohibits the application of the regenerative braking force Fr, so that the full charge of the second battery 36 can be delayed, and Even when the second battery 36 is close to being fully charged, it is possible to effectively execute the braking by the regenerative braking force Fr that promotes the load movement of the vehicle body weight.

  Since the cooperative control unit 43 sets the increase rate of the regenerative braking force Fr to be substantially equal to the increase rate of the braking operation characteristic A during the regeneration operation period (time ta) from the start of braking, even if the regeneration operation period is short. , Can recover the maximum regenerative energy.

  The cooperative control unit 43 sets the regenerative operation period (time ta) to be short when the internal resistance of the second battery 36 is high. Therefore, even if it is difficult to secure the regenerative braking force Fr, the regenerative braking period Fr is regenerated early. The braking performance can be secured by switching from the braking force Fr to the hydraulic braking force Ff.

  Since the cooperative control unit 43 sets the increase rate of the hydraulic braking force Ff to be smaller than the increase rate of the braking operation characteristic A, it is possible to avoid an unintended ABS operation for the occupant during vehicle braking.

Next, a modified example in which the above embodiment is partially modified will be described.
1] In the above embodiment, an example in which the wheels are applied to a hybrid vehicle in which the wheels can be driven by an engine has been described, but the invention may be applied to an electric vehicle that does not include an engine.
Further, although the example applied to the front-wheel drive vehicle has been described, it may be applied to the rear-wheel drive vehicle or the four-wheel drive vehicle.

2) In the above-described embodiment, an example is described in which the operating characteristics (pressure rising tendency) of the hydraulic braking force are set commonly in the first to third cooperative modes, but the operating characteristics may be different for each cooperative mode.
For example, in the first cooperative mode, when the hydraulic braking force at time ta is started from the braking operation characteristic, the operating characteristic is set to be gentler than the operating characteristic of the hydraulic braking force in the second cooperative mode, and at the time ta. When the hydraulic braking force is started from zero, the operating characteristic is set to be sharper than the operating characteristic of the hydraulic braking force in the second cooperative mode.

3] In the above-described embodiment, an example in which the regenerative braking force is controlled so as to match the braking operation characteristic during the regenerative operation period has been described. However, in order to ensure control stability, the regenerative braking force is controlled by the braking operation characteristic. It is also possible to control the braking force by a certain amount.

4] Others can be implemented by those skilled in the art in a form in which various modifications are added to the above-described embodiment or a combination of the embodiments without departing from the spirit of the present invention. Such modifications are also included.

1 Brake Pedal 2a-2d Wheel 22 SOC Sensor 31 Motor 36 Second Battery 41 ABS Control Section 43 Cooperative Control Section B Braking Mechanism P Powertrain Mechanism V Vehicle

Claims (4)

A power source, a hydraulic braking force generating means capable of applying a hydraulic braking force to the wheels by a brake hydraulic pressure, and a regenerative braking force capable of applying a regenerative braking force to the wheels by a rotational load of an electric motor connected to the power source. Generating means, anti-skid control means for controlling the wheel slip ratio to converge to a predetermined target state by the braking force applied to the wheels during vehicle braking, and the braking force required by the occupant based on the operation of the brake pedal by the occupant. And the hydraulic pressure system so that the braking force acting on the vehicle does not exceed the braking operation characteristic that is the braking force corresponding to the predetermined target state of the anti-skid control means until the braking force acting on the vehicle reaches the required braking force. In a vehicle control means comprising a braking force generation means and a cooperative control means for cooperatively controlling the regenerative braking force generation means,
And a possessed power detecting means capable of detecting the possessed power of the power source,
The cooperative control means sets the regenerative operation period to be shorter as the retained power detected by the retained power detection means is higher, and the regenerative operation prohibiting the application of the hydraulic braking force during the regenerative operation period from the start of braking. A vehicle control device, characterized in that, after performing independent braking by a braking force, independent braking by the hydraulic braking force that prohibits application of the regenerative braking force is performed.   The said cooperative control means set the increase rate of the said regenerative braking force so that it may become substantially equal to the increase rate of the said braking operation characteristic during the regeneration operation period from the said braking start. Vehicle control device.   The vehicle control device according to claim 1 or 2, wherein the cooperative control unit sets the regenerative operation period to be short when the internal resistance of the power source is high.   The vehicle control according to any one of claims 1 to 3, wherein the cooperative control unit sets an increase rate of the hydraulic braking force to be smaller than an increase rate of the braking operation characteristic. apparatus.