JP3428289B2 - Electric vehicle braking control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention controls a regenerative braking device using an electric motor mounted on an electric vehicle, and also uses the regenerative braking device together during braking to regenerate braking force and mechanical braking device by the regenerative braking device. The present invention relates to a braking control device for an electric vehicle that is capable of obtaining a required braking force with the mechanical braking force of

[0002]

2. Description of the Related Art In recent years, electric vehicles have been attracting attention from the viewpoint of preventing air pollution and reducing noise from vehicles. In such electric vehicles, so-called regenerative braking can be easily performed. This regenerative braking can be performed by restricting the power supply to the traveling electric motor (motor) and switching this motor to a power generation state. During regenerative braking, a load is applied to the drive wheels to brake this. The rotation generated in the drive wheels can be converted into electric energy and recovered.

Such regenerative braking is controlled so as to occur when the accelerator pedal is released, and if the brake pedal is not depressed when the accelerator pedal is released, engine braking in the case of an automobile with an internal combustion engine. The control is performed so that a weaker regenerative braking (this regeneration is called weak regeneration) is generated, and when the brake pedal is depressed, generally, a regenerative braking force corresponding to the degree of depression of the brake pedal is generated. Is controlled.

FIG. 20 shows a schematic structure of a conventional regenerative braking combined braking system for an electric vehicle, and FIG. 21 is a graph showing a braking force characteristic of a conventional regenerative braking combined braking system for an electric vehicle.

As shown in FIG. 20, 011 is a brake pedal, 012 is a negative pressure type booster (vacuum booster mechanism) which constitutes a mechanical brake device (hereinafter referred to as a mechanical brake), and the negative pressure type booster 012 is a brake. It operates according to the depression of pedal 011. A vacuum tank 013 for supplying a negative pressure is connected to the negative pressure booster 012, and a pump motor 014 for reducing the pressure inside the vacuum tank 013 is attached to the vacuum tank 013. In the mechanical brake, the brake operating force (pedaling force) output from the negative pressure type booster 012 is converted into a brake hydraulic pressure by a master cylinder (not shown), and this brake hydraulic pressure is applied to a wheel side brake actuating member (for example, not shown). , The brake caliper) to actuate the brake actuating member and apply mechanical braking force to the wheels.

Reference numeral 015 is a motor controller for controlling the traveling motor 002 and the pump motor 014. During regenerative braking, the motor controller 015 controls the motor 0
A load (braking force) is applied to the drive wheels by issuing a regeneration command to 02 to switch the motor 002 to a power generation state, the rotational energy of the drive wheels is recovered as electrical energy, and the battery (not shown) is charged. When the brake pedal 011 is depressed, the motor controller 015
Brake stroke sensor 01 that detects the degree of depression
Set the regeneration command value based on the detection information from 6 and perform regeneration control.

[0007]

By the way, in the conventional mechanical brake, the mechanical braking force (mechanical braking force) is uniquely determined according to the depression state of the brake pedal 011. This mechanical braking force does not increase linearly with the depression amount (brake stroke) of the brake pedal 011 but the mechanical braking force increases as the braking stroke increases. The mechanical braking force added with the above-mentioned braking force by regenerative braking (regenerative braking force) will be exerted as the braking force of the vehicle. However, the total braking force exerted on this vehicle (the mechanical braking force). (Force + regenerative braking force), as shown in FIG.
I want to set to increase linearly with the depression of the brake pedal 011 or to increase in a state close to linear. Otherwise, the brake feeling will deteriorate.

As described above, the mechanical braking force is uniquely determined in correspondence with the brake stroke, so that the regenerative braking force is also determined when the increase characteristic of the total braking force is determined. On the other hand, the braking force (maximum regenerative braking force) that can be generated as the regenerative brake depends on the motor rotation speed, and can be generated regardless of the brake stroke. Therefore, it is possible to cover most of the total braking force with the regenerative braking force in a region where the total braking force is small and the required braking stroke is small.

However, in the conventional braking system for combined use with regenerative braking of an electric vehicle, the mechanical braking force is exerted from the region where most of the total braking force can be covered by the regenerative braking force as described above. Brake energy that can be recovered as electric energy by force is released as heat energy due to the operation of the mechanical brake, the energy recovery rate is limited, and the brake energy is efficiently converted into electrical energy as shown in FIG. It is not collected.

Japanese Patent Application Laid-Open No. 1-126103 discloses a braking device for an electric vehicle.
Japanese Patent No. 603 discloses a brake control device for an electric vehicle and a control method thereof, but in these techniques, adjustment of mechanical braking force is applied to a brake actuating member on a wheel side in order to enhance energy recovery rate by regenerative braking force. This is done by adjusting the supplied brake fluid pressure itself. However, it is difficult to maintain a good brake feeling in such adjustment of the brake fluid pressure itself, and a high level adjustment technique is required.

Further, Japanese Laid-Open Patent Publication No. 5-161213 discloses a braking device for an electric vehicle.
The energy recovery rate due to the regenerative braking force cannot be increased in a region where the brake stroke is small. Further, JP-A-1-198201 discloses a braking control device for an electric vehicle, but this technique is equivalent to the above-mentioned conventional technique, and the energy recovery rate by the regenerative braking force cannot be specially increased. .

From this point of view, the applicant of the present invention has specially proposed a regenerative braking combined-use brake device for an electric vehicle, which is capable of recovering the brake energy more efficiently as electric energy while improving the brake feeling. The application has already been filed as Japanese Patent Application No. 7-256661.

The regenerative braking combined braking device for an electric vehicle disclosed in Japanese Patent Application No. 7-256661 includes a regenerative braking device, a master cylinder with a booster mechanism, and a brake actuating member for applying mechanical braking force to wheels. A mechanical braking device having the same, a regenerative braking means for generating a regenerative braking force based on the motor speed, a required braking force required by the driver based on the operation of the brake pedal, and the calculated required braking force. A mechanical braking force calculation means for calculating the mechanical braking force of the mechanical braking device based on the maximum regenerative braking force calculated by the maximum regenerative braking force calculation means, and the mechanical braking force calculated by the mechanical braking force calculation means. It is designed to control the booster mechanism.

However, in this regenerative braking combined braking system for an electric vehicle, the regenerative braking force generated is changed according to the stroke amount of the brake pedal. At this time, the maximum value of the regenerative braking force is It is set according to the motor speed. That is, even if the brake pedal is strongly depressed, the regenerative braking force does not exceed the maximum value according to the motor rotation speed. Therefore, when the amount of depression of the brake pedal is changed during braking of the vehicle to generate it according to the stroke amount of the brake pedal,
The regenerative braking force changes in the range of 0 to the maximum value according to the motor rotation speed.

Generally, in the high motor rotation speed range,
The maximum regenerative braking force according to the motor speed is not a relatively large value, and in a region where the motor speed is low, in order to prevent a sudden regenerative braking force from being applied during braking and deterioration of the brake feeling. Is controlled so that the maximum regenerative braking force becomes small, and by changing the stroke amount of the brake pedal in this region, even if the regenerative braking force fluctuates between 0 and the maximum value, fluctuations per unit time The amount will not be large. However, the maximum value of the regenerative braking force becomes a relatively large value in the medium range between the low and high motor speed regions, so by changing the stroke amount of the brake pedal in this range, the regenerative braking force is changed. If the braking force is changed from 0 to the maximum value, the amount of change per unit time becomes large.

When the amount of fluctuation per unit time becomes large in this way, vibration occurs in the motor, and this vibration becomes a source of abnormal noise, causing a rattle of the vehicle body (a phenomenon such as knocking). There is a risk that Further, when the amount of fluctuation of the regenerative braking force becomes large, the braking force acting on the vehicle body changes abruptly, and as shown in FIG. 22, a knocking phenomenon occurs, which is not preferable as a brake feeling as a brake device.

The present invention is intended to solve the above-mentioned problems, and makes it possible to recover brake energy more efficiently as electric energy while improving the brake feeling regardless of the rotation speed of the motor. An object is to provide a braking control device for an automobile.

[0018]

SUMMARY OF THE INVENTION To achieve the above object, an electric vehicle braking control device of the present invention comprises a brake pedal.
Brake pedal operation detection means for detecting the operation of the dull,
Based on the detection result of the brake pedal operation detecting means,
Required braking force calculator to calculate the required braking force required by the transferor
A step, a battery mounted on the vehicle, an electric motor electrically connected to the battery and having an output shaft connected to a drive wheel of the vehicle, and a regenerative braking force calculation unit based on the number of revolutions of the electric motor. The braking force calculation means and the required braking force calculation means
Therefore, a regenerative command value calculating means for calculating a regenerative command value to the electric motor based on the required braking force calculated and the regenerative braking force calculated by the regenerative braking force calculating means, and the regenerative command value calculating means And a regeneration command value limiting means for outputting, as a regeneration command value, a value obtained by adding or subtracting the variation limit amount to the regeneration command value when the variation amount of the regeneration command value per unit time exceeds a preset variation limit amount. ,
And a regenerative braking force control means for controlling the regenerative braking force of the electric motor based on the regenerative command value calculated by the regenerative command value calculating means or the regenerative command value limited by the regenerative command value limiting means. It is a feature.

Therefore, by supplying electric power from the battery to the electric motor to drive the driving wheels to rotate, the vehicle can travel, and when the vehicle is running, the required braking force calculation means is
The required braking force required by the driver is calculated from the operation of the rake pedal.
The regenerative braking force calculating means calculates the maximum value of the regenerative braking force based on the rotation speed of the electric motor, and the regenerative command value calculating means calculates the regenerative command value to the electric motor based on the required braking force and the regenerative braking force. And the regeneration command value limiting means determines whether or not the variation amount of the regeneration command value per unit time exceeds a preset variation limit amount. That is, if the fluctuation amount of the regeneration command value does not exceed the fluctuation limit amount, this regeneration command value is output, but if the fluctuation amount of the regeneration command value exceeds the fluctuation limit amount, the fluctuation limit amount is added to the regeneration command value. , Or subtracted value is output as the regeneration command value. The regenerative braking force control means controls the regenerative braking force of the electric motor based on the regenerative command value calculated by the regenerative command value calculating means or the regenerative command value limited by the regenerative command value limiting means.

As described above, when the variation amount of the regeneration command value exceeds the variation limit amount, the braking force acting on the vehicle body changes abruptly. Therefore, the variation limit amount is added to or subtracted from the regeneration command value to limit. The fluctuation amount of the regenerative command value is suppressed by outputting the regenerated command value. Therefore, the regenerative braking force of the electric motor is controlled based on the regenerative command value equal to or less than the fluctuation limit amount or the restricted regenerative command value, and the fluctuation of the regenerative braking force per unit time regardless of the motor rotation speed. The amount does not increase, the occurrence of vibration of the electric motor is suppressed, a good regenerative braking force acts on the vehicle body, and a preferable brake feeling is obtained.

Further, the braking control device for an electric vehicle of the present invention is an electric vehicle having a regenerative braking device for generating a regenerative braking force in an electric motor driven by a battery mounted on the vehicle and a mechanical braking device for directly acting on wheels. In a vehicle brake control device, a brake cylinder pedal force is input through a booster mechanism to convert the pedal force into hydraulic pressure and output the master cylinder, and a liquid cylinder mounted on the wheel and output from the master cylinder. A brake operating member that receives a pressure to apply a braking force to the wheel, a brake pedal operation detecting unit that detects an operation of the brake pedal, and a request control required by the driver based on the detection result of the brake pedal operation detecting unit. A required braking force calculation means for calculating power, a regenerative braking force calculation means for calculating a maximum regenerative braking force from the rotation speed of the electric motor, and Regenerative command value calculation means for calculating a regenerative command value for the electric motor based on the required braking force calculated by the required braking force calculation means and the maximum regenerative braking force calculated by the regenerative braking force calculation means, and the regenerative command. When the fluctuation amount per unit time of the regenerative command value calculated by the value calculating means exceeds a preset fluctuation limit amount, the regenerative command value obtained by adding or subtracting the fluctuation limit amount is output as the regenerative command value. Regenerative command value limiting means, and regenerative braking force control for controlling the regenerative braking force of the electric motor based on the regenerative command value calculated by the regenerative command value calculating means or the regenerative command value limited by the regenerative command value limiting means. Means, the required braking force calculated by the required braking force calculation means, and the regenerative braking force of the electric motor controlled by the regenerative braking force control means. A mechanical braking force calculating means for calculating a mechanical braking force, and a mechanical braking force controlling means for controlling the boosting mechanism based on the mechanical braking force calculated by the mechanical braking force calculating means. It is a thing.

Therefore, by supplying electric power from the battery to the electric motor to rotate the drive wheels, the vehicle can run, and when the driver operates the brake, the required braking force calculation means is the brake pedal actuation detection means. The required braking force required by the driver is calculated based on the detection result of, the regenerative braking force calculation means calculates the maximum regenerative braking force from the rotation speed of the electric motor, and the regenerative command value calculation means calculates the required braking force and the maximum regenerative braking force. A regeneration command value to the electric motor is calculated based on the braking force, and the regeneration command value limiting means determines whether or not the variation amount of the regeneration command value per unit time exceeds a preset variation limit amount. That is, if the fluctuation amount of the regeneration command value does not exceed the fluctuation limit amount, this regeneration command value is output, but if the fluctuation amount of the regeneration command value exceeds the fluctuation limit amount, the fluctuation limit amount is added to the regeneration command value. , Or a subtracted value is output as a regenerative command value, and the regenerative braking force control means regenerates the electric motor based on the regenerative command value calculated by the regenerative command value calculating means or the regenerative command value limited by the regenerative command value limiting means. Control braking force.

On the other hand, the mechanical braking force calculation means calculates the mechanical braking force based on the required braking force and the regenerative braking force of the electric motor, and the mechanical braking force control means controls the boosting mechanism based on the mechanical braking force. The pedaling force of the brake pedal depressed by the driver is input through this boosting mechanism, and the braking force is applied to the wheels by the master cylinder and the brake operating member.

As described above, in the regenerative braking device, when the fluctuation amount of the regenerative command value exceeds the fluctuation limit amount, the braking force acting on the vehicle body suddenly changes, so that the regenerative command value fluctuates. The fluctuation amount of the regeneration command value is suppressed by outputting the regeneration command value obtained by adding or subtracting the limiting amount. Therefore, the regenerative braking force of the electric motor is controlled based on the regenerative command value equal to or less than the fluctuation limit amount or the restricted regenerative command value, and the fluctuation of the regenerative braking force per unit time regardless of the motor rotation speed. The amount does not grow,
Generation of vibration of the electric motor is suppressed, a good regenerative braking force acts on the vehicle body, and a favorable brake feeling is obtained. On the other hand, in the mechanical brake device, the regenerative braking force is sufficiently exerted, the recovery rate of the brake energy to the electric energy is increased, and the energy can be effectively used.

In the braking control device for an electric vehicle according to the present invention, the fluctuation limit amount is set to be different depending on the rotation speed of the electric motor.

That is, in a region where the motor rotation speed is low or a region where the motor rotation speed is high, the maximum value of the regenerative braking force corresponding to the motor rotation speed is a relatively small value, and therefore, even if the regeneration command value changes a little, Since the fluctuation amount of the motor torque per hit does not become large, the fluctuation limit amount is set high, while the maximum value of the regenerative braking force is relatively large in the middle region between the low and high motor speeds. Is a value, so
When the regeneration command value changes significantly, the amount of change in motor torque per unit time increases, so the change limit amount is set low. Therefore, the regenerative braking force according to the motor rotation speed acts on the vehicle body, and a good brake feeling is obtained.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a control block showing a schematic configuration of a regenerative braking combined type braking device as a braking control device for an electric vehicle according to an embodiment of the present invention, and FIG. 2 is a regenerative braking combined type of the electric vehicle according to the present embodiment. Sections showing a booster mechanism of the brake device, FIGS. 3 to 6 are schematics showing electromagnetic valve control of the booster mechanism in the brake device, FIG. 7 is a control block in the brake device, and FIG. 8 is a brake force calculation process in the brake device. Control block, FIG. 9 is a main flowchart showing braking force control in the braking device, and FIG.
0 is a flowchart showing the emergency avoidance control in the braking device, FIG. 11 is a flowchart showing the determination of the duty value of the solenoid valve in the braking device, FIG. 12 is a flowchart showing the limiting control of the regeneration command value in the braking device, and FIG. 13 is the motor rotation. 14 is a graph showing a limit command value according to the number, FIG. 14 is a graph showing changes in the regenerative fluctuation amount controlled by the limit command value, FIG. 15 is a table relating to duty values of electromagnetic valves in the brake device, and FIG. FIG. 17 is a graph showing setting characteristics relating to valve duty values, FIG. 17 is a flow chart showing drive control of a solenoid valve in the brake device, FIG. 18 is a table explaining drive control contents of the solenoid valve in the brake device, and FIG. 19 is a brake of the brake device. A graph showing force characteristics is shown.

The braking control device for an electric vehicle according to the present embodiment uses a regenerative braking device together during braking, and a required braking force is obtained by the regenerative braking force by the regenerative braking device and the mechanical braking force by the mechanical braking device. It was made possible. As shown in FIG. 1, 11 is a vehicle brake pedal, 12 is a negative pressure booster (master cylinder with a vacuum booster mechanism) that constitutes a mechanical brake device (mechanical brake), and this negative pressure booster 12 is a brake pedal. It operates according to the depression of 11. A vacuum tank 13 for supplying a negative pressure to the negative pressure booster 12.
Is connected, and the vacuum tank 13 is provided with a pump motor 14 for reducing the pressure inside the vacuum tank 13.

In this mechanical brake, the brake operating force (pedal force) output from the negative pressure type booster 12 is converted into brake fluid pressure by the master cylinder 12A, and this brake fluid pressure is passed through the brake fluid pipes 22A and 22B to the wheel side. Of the brake operating members 23L, 23R, 24L, 24R to supply the brake operating members 23L, 23R, 24L, 24R.
4R is activated to apply mechanical braking force to the wheels. Also, the brake fluid pipes 22A, 2 on the rear wheel side
Proportioning valve (PCV) for each 2B
25 is interposed to reduce the mechanical braking force of the rear wheels as compared with the front wheels to stabilize the vehicle posture during braking by preventing the rear wheels from locking.

By the way, in the negative pressure type booster 12,
A negative pressure control cylinder 18 in which a negative pressure control piston 18B is slidably incorporated inside the operating rod 18A.
C is mounted movably in the axial direction, and the negative pressure control piston 18B is fixed to the operating rod 18A. The negative pressure booster 12 has a first solenoid valve 1
9, the second solenoid valve 20, and the third solenoid valve 21 are connected, and the boosting ratio of the negative pressure booster (boost booster) 12 can be controlled by these three solenoid valves 19, 20, 21.

Reference numeral 26 is a regenerative control unit for controlling regenerative braking. The regenerative control unit 26 is provided as one functional element in a motor controller 15 (see FIG. 7) described later, and a regenerative command is given to the traveling motor 2. The driving motor 2 is switched to a power generation state to apply a load, that is, a braking force, to the drive wheels, and the rotation of the drive wheels is recovered as electric energy to charge the battery 3. The above-mentioned brake pedal 11 is provided with a brake pedal force sensor (or a brake stroke sensor) 17 for detecting the degree of pedaling. In the regenerative control unit 26, when the brake pedal 11 is stepped on, the brake pedal force sensor 17 outputs a signal. A map set in advance based on the detection information (see FIG. 19)
The braking force characteristic line A) is used to set a regeneration command value, and the regeneration control is performed while feeding back the regeneration state of the motor 2 detected by the current sensor 29. In the regenerative state of the motor 2, the torque component current and the excitation component current output from the motor controller 15 to the motor 2 may be indirectly detected, or the regenerative current of the motor 2 may be detected. You may make it detect directly.

Further, 27 is a boosting command section and a negative pressure control section. The boosting command section and negative pressure control section 27 provide pedaling force information from the brake pedaling force sensor 17 and regeneration command information from the regeneration control section 26. Based on the regenerative current state of the traveling motor 2 from the current sensor 29 and the brake fluid pressure information from the fluid pressure sensor 30, the states of the solenoid valves 19, 20, 21 described above are controlled.

Now, the negative pressure type booster 12 described above will be described. As shown in FIG. 2, in the negative pressure booster 12, the booster piston 52 and the diaphragm 53 are provided in the booster shell 51 that operates the master cylinder 12A, so that the inside is a front shell chamber (negative pressure chamber) 54 and a rear portion. It is partitioned into a shell room (control room) 55. A valve cylinder 56 is fixed to the center of the booster piston 52, and the valve cylinder 56 is slidably supported at the center of the booster shell 51. Booster shell 51
The negative pressure introducing pipe 57 is connected to the front shell chamber 54 of the vacuum tank 1 described above.
Connected to 3.

An operating rod 18A connected to the brake pedal 11 and a control valve 58 controlled by the operating rod 18A are provided at one end of the valve cylinder 56, and a valve is provided at the center of the valve cylinder 56. The piston 59 is slidably fitted. The front end of the operating rod 18A is swingably coupled to the rear end of the valve piston 59. Further, the return spring 6 is provided between the operating rod 18A and the control valve 58.
0 is installed. On the other hand, an output pestle 61 is attached to the front end of the valve cylinder 56, and the tip of the output pestle 61 is connected to a piston (not shown) of the master cylinder 12A. A valve cylinder return spring 62 for applying a backward force to the booster piston 52 is interposed between the valve cylinder 56 and the booster shell 51, and is disposed between the front shell chamber 54 and the rear shell chamber 55. When there is no pressure difference between the booster piston 52 and the booster piston 52, the booster piston 52 is always located at the backward limit.

Therefore, when the brake pedal 11 is depressed and the operating rod 18A advances, the valve piston 59 advances, which opens the control valve 58 and opens the opening 63 of the valve cylinder 56 and the rear shell chamber 55. And communicate with each other, and the atmosphere will flow in. Then, when the operating rod 18A is advanced, the pushing force of the valve piston 59 is directly transmitted to the output punch 61.

By the way, as described above, the inside of the negative pressure control cylinder 18C which is movable to the operating rod 18A is divided into the air chamber 71 and the atmospheric pressure chamber 72 by the negative pressure control piston 18B. Then, the cylinder control port 73 of the air chamber 71 is connected to the vacuum tank 13 through the first electromagnetic valve 19 so that a negative pressure can be supplied to the air chamber 71. When the negative pressure is introduced into the air chamber 71, The negative pressure control cylinder 18C moves forward (booster side, left side in the figure).

A flexible partition 74 capable of closing the opening 63 leading to the rear shell chamber (control chamber) 55 of the negative pressure type booster 12 is attached to the outside of the atmospheric pressure chamber 72, and negative pressure control is performed. When the cylinder 18C moves forward, the partition 74 closes this opening 63, and the negative pressure control cylinder 1
When 8C retracts, this opening 63 is opened. Furthermore,
An air hole 75 is formed in the operating rod 18A, one end of this air hole 75 communicates with the rear shell chamber 55, and a booster boost control port 76 is connected to the other end, which is opened by the partition 74. When the part 63 is closed,
The boosting state of the negative pressure type booster 12 is controlled according to the air pressure supplied from the booster boosting control port 76 into the rear shell chamber 55 through the air hole 75. Of course, when the opening 63 is opened, the inside of the rear shell chamber 55 is in the atmospheric pressure state and the normal negative pressure type booster 1 is used.
A boost state of 2 is exhibited. Then, the booster boost control port 76 can supply the negative pressure from the vacuum tank 13 through the second solenoid valve 20, and the third solenoid valve 21.
Atmospheric pressure can be supplied through. Here, the second solenoid valve 2
The negative pressure booster 12 is adjusted by adjusting the air pressure in the rear shell chamber 55 through duty control of 0 and the third solenoid valve 21.
It is designed to change the boost status of.

The control modes of the three solenoid valves 19, 20, and 21 described above are set by the boost command section and the negative pressure control section 27. As shown in FIG. 18, this control mode includes a pressure increasing mode, a pressure reducing mode, a holding mode, a stop mode, and a prohibit mode. The prohibit mode is selected, for example, when the brake is not operated or when the brake is suddenly applied. In this prohibit mode, as shown in FIG. 3, all the solenoid valves 19, 20, 21 are turned off and closed. Therefore, in the negative pressure booster 12, the front shell chamber (negative pressure chamber) 54 is set to a negative pressure by the vacuum tank, and the rear shell chamber (control chamber) 55 is evacuated by moving the operating rod 18A by depressing the brake pedal 11. The opening 63 is set to the atmospheric pressure.

The pressure reducing mode and the stop mode are selected, for example, when the brake pedal 11 is stepped back. In the pressure reducing mode and the stop mode, as shown in FIG. 4, the first solenoid valve 19 and the second solenoid valve 20 are connected to each other. The third solenoid valve 2 is turned on.
1 is turned off. Therefore, in the negative pressure booster 12, the front shell chamber 54 is made a negative pressure by the vacuum tank, and the opening 63 is closed by the partition 74 by the movement of the negative pressure control cylinder 18C, and the rear portion is made a negative pressure. The shell chamber 55 is decompressed.

Further, the holding mode is selected, for example, during the regenerative braking operation. In this holding mode, as shown in FIG. 5, only the first solenoid valve 19 is turned on and the second solenoid valve 20 and the third solenoid valve 20 are turned on.
The solenoid valve 21 is turned off. Therefore, in the negative pressure booster 12, the front shell chamber 54 is made a negative pressure by the vacuum tank, and the opening 63 is closed by the partition 74 by the movement of the negative pressure control cylinder 18C. The pressure in the shell chamber 55 is the operating rod 18 due to the depression of the brake pedal 11.
The adjusting pressure can be held according to the moving amount of A.

Further, the pressure increasing mode is selected, for example, when the brake pedal 11 is further depressed. In this pressure increasing mode, as shown in FIG. 6, the first solenoid valve 19 is turned on and the second solenoid valve 20 is turned off. The third solenoid valve 21 is turned on. Therefore, in the negative pressure type booster 12, the front shell chamber 54 is made to have a negative pressure by the vacuum tank, and the negative pressure control cylinder 18C moves to open the opening 6 by the partition 74.
3 is closed, the opening 63 and the shell chamber 55 are closed.
The pressure of is increased to approach atmospheric pressure.

Here, the control block in the brake system of this embodiment will be described. As shown in FIG.
The brake controller 28 includes a brake pedal force sensor 1
A pedaling force sensor input unit 31 to which a pedaling force detection signal of the brake pedal 11 from 7 and a hydraulic pressure sensor input unit 32 to which a brake hydraulic pressure detection signal from the hydraulic pressure sensor 30 is input are provided. Further, a motor rotation speed input unit 33 that detects the motor rotation speed from a pulse signal from the motor controller 15 that controls the traveling motor 2, and a brake switch input unit 34 that detects ON / OFF of the brake switch from the voltage from the motor controller 15. And are provided. A filter 35 for stabilizing the pedaling force sensor signal is connected to the output side of the pedaling force sensor input unit 31, and the pedaling force signal processed by the filter 35 is an abnormality detecting unit 36, an emergency avoidance braking detecting unit 37, a computer. On the other hand, the brake pedal force signal before being processed by the filter 35 is sent to the computer 39 through the abnormality detecting unit 38 together with the rotation speed signal from the motor rotation speed input unit 33.

The signal from the hydraulic pressure sensor input section 32 is also sent to the abnormality detecting section 36 together with the pedaling force signal, and is also sent to the computer 39. Further, signals from the motor rotation speed input unit 33 and the brake switch input unit 34 are also sent to the computer 39. The abnormality detecting unit 36 compares the brake pedal force with the brake hydraulic pressure to detect an abnormality of the negative pressure type booster 12, and the abnormality detecting unit 38 compares the brake pedal force before the filtering process and the rotation speed of the traveling motor 2 with each other. By comparison, an abnormality of the regenerative brake is detected. Further, the emergency avoidance braking detection unit 37 is configured to detect whether or not the emergency avoidance braking should be performed based on the fluctuation of the brake pedal force.

Then, the computer 39 sets a regeneration command value for the traveling motor 2 based on each input signal and outputs this signal. This regeneration command signal is converted from a digital signal to an analog signal through a digital / analog converter (D / A) 41 and sent to the motor controller 15. Further, in this computer 39, based on each input signal, the above-mentioned three solenoid valves 1
A control signal is output to 9, 20, and 21 via the gate driver 40.

The braking force calculation processing by the motor controller 15 and the brake controller 28 will now be described. As shown in FIG. 8, the motor controller 15 has a regenerative braking force calculation means 101, a regeneration command value calculation means 102, a regeneration command value limiting means 103, and a regenerative braking force control means 104. On the other hand, the brake controller 28 has a required braking force calculation means 201 and a mechanical braking force calculation means 202. In other words, the braking force operated by the driver is divided into the regenerative braking force and the mechanical braking force to operate.

Brake pedal force is input from the brake pedal force sensor 17 to the required braking force calculation means 201 of the brake controller 28, and the required required braking force is calculated based on this brake pedal force, and the regeneration command value calculation means 102 and the machine. It is output to the braking force calculation means 202. The regenerative braking force calculation means 101 of the motor controller 15 uses the motor 2
The maximum regenerative braking force is calculated from the number of revolutions, and the regenerative command value calculating means 102 calculates the regenerative command value for the motor 2 based on the maximum regenerative braking force and the required braking force. The regeneration command value limiting means 103 adds or subtracts the variation limit amount to the regeneration command value when the variation amount of the regeneration command value per unit time exceeds a preset variation limit amount. Is output as a regeneration command value. Therefore, the regenerative braking force control means 104 regenerates the regenerative braking force (regeneration) of the motor 2 based on the regenerative command value calculated by the regenerative command value calculating means 102 or the regenerative command value limited by the regenerative command value limiting means 103. Current control). At this time, the detection result of the rotation speed of the motor 2 is fed back to the controllers 15 and 28.

On the other hand, the mechanical braking force calculation means 202 of the brake controller 28 has a required braking force calculation means 201.
The mechanical braking force is calculated based on the required braking force calculated by the above and the regenerative braking force (regenerative current control) controlled by the regenerative braking force control means 104 of the motor controller 15, and the duty control is performed according to this mechanical braking force. A signal is sent to each solenoid valve 19, 20, 21 as the mechanical braking force control means 203, and the negative pressure booster 12 is supplied.
Is adjusted, and the brake fluid pressure to the brake actuating members 23L, 23R, 24L, 24R is adjusted in accordance with the adjustment of the boosting force. At this time, the brake fluid pressure is fed back to the mechanical braking force.

Since the boosting state of the negative pressure type booster 12 can be controlled while the duty of each solenoid valve 19, 20, 21 is controlled in this manner, the mechanical braking force can be freely reduced. Of course, this mechanical braking force increases in accordance with the pedal effort, but by reducing the degree of increase, the mechanical brake can be reduced. Therefore,
For example, even if the regenerative braking force is set as shown by the braking force characteristic line A in FIG. 19 and the value B obtained by subtracting the regenerative braking force from the total braking force is set as the mechanical braking force, the mechanical braking force B is also set. It can be generated reliably.

Here, the operation control of the regenerative braking combined type brake device of the electric vehicle of this embodiment will be described with reference to a flowchart. Since this brake device has the above-described configuration, the brake device shown in FIG.
While setting the regenerative braking force as shown by the characteristic line A as shown in FIG.
Based on the flowchart of FIG. 12, each solenoid valve 19, 2
Adjust while driving 0, 21.

That is, as shown in FIG. 9, step A10
At this time, initialization is performed, and at the time of this initialization, the solenoid valves 19, 20, 21 are checked. If normal (OK), the process proceeds to step A20, and if abnormal (FAULT), the control is stopped. At step A20, the value T of the time axis counter The count is initialized, that is, set to 0. Then, in step A30,
It is determined whether or not the required period (here, 5 msec) has passed, and in step A40, the switch (SW) related to the electromagnetic valve drive command, that is, the brake switch is read. The reading of the brake switch can be changed to the reading of the detection value of the brake pedal force sensor 17.

Then, in step A50, it is determined whether or not the brake switch is on (ON), that is, whether or not the brake operation is performed. If the switch is on (ON), the process proceeds to step A60. If it is not on, the count value E after the step A250 is entered and the brake is started The count is initialized, that is, set to 0.
At step A60, the time axis counter value T coun
It is determined whether t is an initial value, that is, 0, and the counter value T
If the count is 0, the process proceeds to step A70 and the counter value T Set count to 10. Then, in step A80, the number of acquired output data K = 0 is set,
At step A90, for example, A / D is performed every 50 msec.
Read the value (output value of each sensor). Then, in step A100, the number K of captured output data is added, and in step A110, it is determined whether or not the number K of captured output data has reached a preset number N of captured data. That is, in step A110, if the number K of captured output data is less than the number N captured, the above-described processing of steps A90 to A110 is repeated, and if the number K captured of output data reaches the number captured N, Step A1
At 20, as a filtering process by a filter (first-order filter), each sensor output XX ₁ ,
X ₂ , X ₃ ... X _n are added and divided by the number N of taken in to obtain the average value as the output value X used for control.

At step A130, the abnormality detector 36,
It is determined from the detection information from 38 whether there is a system abnormality. If there is a system abnormality, the process proceeds to step A190,
SR = 5, that is, the prohibit mode can be selected.
On the other hand, if there is no system abnormality in step A130,
The process proceeds to step A140, and it is determined whether or not the state is an emergency avoidance state. Then, in this step A140, if the state is not an emergency avoidance state, the process proceeds to step A150 to determine the duty value (DUTY value), and step A16
Move to 0 and count value T The count value is updated, and in step A170, the counter value E required for the time elapsed after the brake pedal 11 is first depressed. The count is updated, and in step A180, each solenoid valve 19, 20, 21
Drive.

On the other hand, if it is determined in step A140 that the condition should be avoided, the process proceeds to step A200 and the counter value E It is determined whether the count is greater than 20. In this step A200, the counter value E coun
If t is greater than 20, then in step A210, SR
1, that is, the pressure increasing mode is selectable, and the counter value E If the count is 20 or less, in step A220, SR5, that is, the prohibit mode is selected. Next, in step A230, as in step A40 described above, the switch (S
W), that is, the brake switch is read, and this brake switch is turned off (OF) in step A240.
When it becomes F), the process returns to step A20.

Here, the determination as to whether or not the state is an emergency avoidance state in step A140 described above will be described in detail. As shown in FIG. 10, in step B10, first, the A / D value K of the current output value of the brake pedal force sensor 17 and the A / D value K _n-1 of the output value of the brake pedal force sensor 17 one sample period before. Difference ΔK (however, ΔK = K−K
_n-1 ) is the output value increase amount of the brake pedal force sensor 17, and this increase amount ΔK is calculated. Next, step B20.
Then, it is determined whether or not the increase amount ΔK is a predetermined value (here, 2.0) or more. If the increase amount ΔK is the predetermined value or more,
The process proceeds to step B40 and avoidance braking is performed. If it is determined in step B20 that this increase amount ΔK is not equal to or greater than the predetermined value, the process proceeds to step B30, where the current output value K of the brake pedal force sensor 17 itself is a predetermined value (here,
4.0) or more is determined. And step B3
If the output value K is equal to or more than a predetermined value at 0, avoidance braking is performed. That is, when the brake pedal 11 is rapidly depressed or when the amount of depression of the brake pedal 11 itself is sufficiently large, it is determined to perform avoidance braking.

Further, according to the above step A150,
The determination of the duty value (DUTY value) will be described in detail.
As shown in FIG. 11, first, in step C10,
The maximum regenerative braking force FRmax is calculated from the motor speed and the regenerative braking force map (see characteristic A in FIG. 19),
Next, in step C20, the brake pedal force sensor 1
The target braking force FT is calculated from the output value of 7 and the pedaling force-brake force map. Then, in step C30, it is determined whether or not the maximum regenerative braking force FRmax is larger than the target braking force FT. In this step C30,
If the maximum regenerative braking force FRmax is larger than the target braking force FT, the process proceeds to step C160, where SR =
4, that is, the stop mode is selectable. Then, in step C170, the regeneration command value is calculated to a value corresponding to the target braking force FT, and in step C170,
Clip control of the calculated regenerative command value is performed to set and output the regenerative command value.

If the maximum regenerative braking force FRmax is not larger than the target braking force FT in step C30, the process proceeds to step C40 and the regeneration command value is set according to the maximum regenerative braking force FRmax. Then, in step C50, the target brake hydraulic pressure PT is calculated and calculated, and in step C60, the difference M (= PT- between the target brake hydraulic pressure PT and the actual hydraulic pressure (detected brake hydraulic pressure) PR.
PR) is calculated, and in step C70, it is determined whether or not the magnitude (absolute value) of the difference M is larger than a first predetermined value (for example, 1.0). If the magnitude of the difference M is larger than the first predetermined value in step C70, this is
This is the case where the brake fluid pressure is suddenly requested, and in step C150, SR = 5, that is, the prohibit mode can be selected.

If the magnitude of the difference M is equal to or smaller than the first predetermined value in step C70, the magnitude (absolute value) of the difference M is smaller than the first predetermined value in step C80. , 0.1). If the magnitude of the difference M is smaller than the second predetermined value in step C80, it can be said that the brake fluid pressure is in the target region. Therefore, in step C140, SR = 3, that is, select the holding mode,
Holds brake fluid pressure.

If the magnitude of the difference M is not smaller than the second predetermined value in step C80, the magnitude of the difference M is between the second predetermined value and the first predetermined value. In some cases, pressure increase control or pressurization control is performed. That is, in step C90, it is determined whether the difference M is less than a predetermined value (for example, -0.1). Here, the difference M is a predetermined value (-0.
If it is less than 1), it is determined that the actual hydraulic pressure is excessive, and in step C120, SR = 2, that is, the pressure reducing mode is selected to reduce the pressure. Then, in step C130, the difference M
1 or a table as shown in FIG. 15 depending on the value of
Based on the map shown in FIG. c
Calculate the out.

On the other hand, in step C90, if the difference M is not less than the predetermined value (-0.1), it is determined that the actual hydraulic pressure is insufficient,
In step C100, SR = 1, that is, the pressure increasing mode is selected to increase the pressure. Then, in step C110, according to the value of the difference M, the duty value V is calculated based on the table as shown in FIG. 15 or the map as shown in FIG. Calculate the count.

The duty value V The count is set to increase stepwise as the magnitude of the difference M increases, as shown in the table shown in FIG. 16 and the map shown in FIG. V The count may be set in a step shape finer than this, or in a step shape rougher than this.

Further, according to the above step C180,
The clip control of the regeneration command value will be described in detail. As shown in FIG. 12, first, in step D10, it is determined whether the motor rotation speed NE of the traveling motor 2 is equal to or higher than a first predetermined value NE1 (for example, 2500 rpm). Then, in this step C10, the motor rotation speed NE becomes the first
If the value is equal to or more than the predetermined value NE1, the traveling motor 2 is rotating in the high speed range, and the process proceeds to step D20, where the clip (C
LIP value to V1 (clip voltage, for example 0.06
V). If the motor rotational speed NE is smaller than the first predetermined value NE1 in step C10, step C10 is executed.
In step D100, it is determined whether the motor speed NE of the traveling motor 2 is equal to or higher than a second predetermined value NE2 (for example, 1000 rpm). Then, in step C100, if the motor rotation speed NE is equal to or greater than the second predetermined value NE2, the traveling motor 2 is rotating in the medium speed range, and the process proceeds to step D110, where the regeneration command is issued. The clip (CLIP) value as the upper limit value of the variation amount of the value is V2 (clip voltage, for example, 0.
04V). On the other hand, in step C100, if the motor rotation speed NE is smaller than the second predetermined value NE2, the traveling motor 2 is rotating in the low speed range, and the process proceeds to step D120, where the fluctuation of the regeneration command value is made. The clip (CLIP) value as the upper limit value of the amount is set to V3 (clip voltage, for example, 0.06V).

When the clip (CLIP) value as the upper limit value of the variation amount of the regeneration command value is set in this way, the variation amount A of the actual regeneration command value is calculated in step D30,
In step D40, the fluctuation amount A of this actual regeneration command value
Is negative, that is, whether the motor rotation speed is increasing is determined. Then, in step D40, if the variation amount A of the regeneration command value is not negative, it is assumed that the motor rotation speed has decreased, and in step D50, the variation amount A of the regeneration command value and the set clip (CLIP) value. Compare. Then, the variation A of the regeneration command value is clipped (CLI
If it is greater than or equal to the P) value, the value obtained by subtracting the clip (CLIP) value from the previous command value is output as the regeneration command value in step D60.

If the variation amount A of the actual regeneration command value is negative in step D40, it is assumed that the motor rotation speed is increasing, and the variation amount B of the actual regeneration command value is determined in step D70. The calculated amount is compared with the amount of fluctuation B of the regeneration command value and the set clip (CLIP) value in step D80. If the variation B of the regeneration command value is equal to or larger than the clip (CLIP) value, the value obtained by adding the clip (CLIP) value to the previous command value is output as the regeneration command value in step D90. Then, in step D80,
If the variation amount B of the regeneration command value is smaller than the clip (CLIP) value, the regeneration command value calculated in step C170 (see FIG. 11) is output. In step D50, if the variation amount A of the regeneration command value is smaller than the clip (CLIP) value, the process proceeds to step D70 and the same processing as described above is performed.

As described above, in the clip control of the regenerative command value, the amount of fluctuation A, B of the regenerative command value per unit time is set as the upper limit value of the amount of fluctuation of the regenerative command value set for each motor rotation speed (CLIP). ) When the value is V1, V2 or V3 or more, the regenerative command value calculated this time is not adopted,
Clip values V1, V2, V3 are added to the regenerative command value calculated last time.
The regenerative command value is limited by adding or subtracting.

That is, the maximum value of the regenerative braking force generated by the traveling motor 2 is set in accordance with the motor rotation speed, and as shown in FIG. Since the maximum value of the braking force is not a relatively large value, the fluctuation amount per unit time in this area does not become large. However, since the maximum value of the regenerative braking force becomes a relatively large value in the middle range of the motor rotation speed, the fluctuation amount per unit time in this range becomes large. Then, the braking force acting on the vehicle body suddenly changes, causing a knocking phenomenon, which is not preferable for the brake feeling. Therefore, in the present embodiment, the upper limit value of the variation amount is set in each of the low, medium, and high regions of the motor rotation speed.

Therefore, when the calculated regenerative command value exceeds the upper limit value, the regenerative command value is limited and output. Therefore, as shown in FIG. 14, the amount of regenerative fluctuation per unit time does not increase, the knocking phenomenon is suppressed, and smooth deceleration is achieved.

By the way, when the duty value is set in the above-described processing, each solenoid valve 1 is set based on this duty value.
Drives 9, 20, and 21 are performed. That is, as shown in FIG. 17, when SR = 1 in step E10, that is, when the pressure increasing mode is selectable, the duty value V is increased in step E20. It is determined whether the count is positive, and the duty value V If the count is positive, the pressure increasing mode is set in step E30, and in step E40,
V is the count value of the duty value count to V c
Reduce to round-1. In step E20, the duty value V If count is not positive, step E
At 50, the hold mode is set.

Further, step E10 and step E60
If it is determined that SR = 2, that is, the pressure reduction mode can be selected, the duty value V c
It is determined whether or not outt is positive, and the duty value V c
If the count is positive, the depressurization mode is set in step E80, and the count value of the duty value is set to V in step E90. count to V Reduce to count-1.
In step E70, the duty value V coun
If t is not positive, the holding mode is set in step E100.

Further, step E10 and step E6
If the determination is 0, step E110, and SR = 3, that is, the holding mode can be selected, the holding mode is set in step E120. Also, steps E10 and 6
If SR = 4, that is, if the stop mode can be selected in the determination of 0, 110, or 130, the stop mode is set in step E140. Then, step E10,
If SR = 5, that is, if the prohibit mode can be selected in the determinations of 60, 110, and 130, the prohibit mode is set in step E140.

In this way, each solenoid valve 19, 20, 21
As shown in FIG. 19, it is possible to increase the ratio of the regenerative braking force to the total braking force and recover the braking energy more efficiently as electric energy by appropriately controlling the above. Note that FIG. 19 shows an example of the energy recovery rate curve. Compared to the conventional example (FIG. 21), the energy recovery rate is greatly improved, especially in the region where the brake pedal force is small, and as a whole, it is efficiently recovered as electrical energy. become able to.

As a result, it becomes possible to greatly extend the traveling distance per charge (external charging) of the electric vehicle, that is, the cruising distance. As a result of the simulation based on the amount of current (Ah), for example, a result expected to improve the traveling distance by about 16% could be obtained. In addition, in a test using an actual vehicle, it was possible to obtain a result expected to improve the traveling distance by, for example, about 10%. Also, instead of directly controlling the brake fluid pressure itself,
Since the brake fluid pressure itself is controlled through the negative pressure type booster 12, it is possible to perform a brake control while exhibiting a good brake feeling.

In the above embodiment, the braking control device for an electric vehicle according to the present invention has been described as a combined regenerative braking type braking device, but it may be a regenerative braking device for an electric vehicle.

[0074]

As described above in detail with reference to the embodiments, according to the braking control apparatus for an electric vehicle of the present invention, the operation of the brake pedal is performed in the electric vehicle in which the battery and the driving electric motor are mounted on the vehicle. Driver's request based on
The required braking force calculation means for calculating the required braking force, the regenerative braking force calculation means for calculating the regenerative braking force based on the rotation speed of the electric motor, and the regeneration command value to the electric motor based on the required braking force and the regenerative braking force. Regenerative command value calculating means, and when the fluctuation amount of the calculated regenerative command value per unit time exceeds a preset fluctuation limit amount, the regenerative command value is added to or subtracted from the fluctuation limit amount. Since the regenerative command value limiting means for outputting the value and the regenerative braking force control means for controlling the regenerative braking force of the electric motor based on the regenerative command value are provided, the fluctuation amount of the regenerative command value exceeds the fluctuation limit amount. If this occurs, the braking force that acts on the vehicle body will change suddenly.Therefore, the amount of change in the regenerative command value will be suppressed, and the regenerative braking force of the motor will be controlled so that it does not change suddenly. Is suppressed, Good regenerative braking force acts on the body, regardless of the number of revolutions of the motor, it is possible to improve the braking feeling.

Further, according to the braking control device for an electric vehicle of the present invention, the regenerative braking device for generating the regenerative braking force in the electric motor driven by the battery mounted on the vehicle and the mechanical braking device for directly acting on the wheels are provided. When installed, the pedal force of the brake pedal is input through the booster mechanism to convert the pedal force to hydraulic pressure and output it, and to the wheel that is mounted on the wheel and receives the hydraulic pressure output from the master cylinder to brake the wheel. A brake actuating member for applying force, and a brake pedal actuation detecting means for detecting actuation of the brake pedal,
A required braking force calculation means for calculating the required braking force required by the driver based on the detection result of the brake pedal operation detection means, a regenerative braking force calculation means for calculating the maximum regenerative braking force from the rotation speed of the electric motor, and a required control Regenerative command value calculating means for calculating a regenerative command value to the electric motor based on the power and the maximum regenerative braking force, and regenerative when the fluctuation amount of this regenerative command value per unit time exceeds a preset fluctuation limit amount. Regenerative command value limiting means for outputting a command value plus or minus a variation limiting amount as a regenerative command value, regenerative braking force control means for controlling the regenerative braking force of the electric motor based on the regenerative command value, required braking force and electric motor Since the mechanical braking force calculation means for calculating the mechanical braking force based on the regenerative braking force of and the mechanical braking force control means for controlling the boosting mechanism based on the mechanical braking force are provided, By increasing the recovery rate of the electrical energy of the brake energy enough to exhibit the raw braking force,
While energy can be used effectively, the amount of fluctuation of the regenerative braking force per unit time does not become large regardless of the number of motor revolutions of the vehicle, and the generation of vibration of the electric motor is suppressed to ensure good regeneration of the vehicle body. Brake feeling can be improved by applying the braking force.

Further, according to the braking control apparatus for an electric vehicle of the present invention, the preset fluctuation limit amount is set to be different depending on the rotation speed of the electric motor, so that in a region where the motor rotation speed is low or a region where the motor rotation speed is high. Since the maximum value of the regenerative braking force according to the motor speed is relatively small and the fluctuation amount per unit time does not become large, the fluctuation limit amount is set high, while the low and high motor speed regions are set. In the middle range, the maximum value of regenerative braking force is relatively large and the amount of fluctuation per unit time is large. Since the regenerative braking force acts, a good brake feeling can be obtained.

[Brief description of drawings]

FIG. 1 is a control block diagram showing a schematic configuration of a regenerative braking combined-type brake device as a braking control device for an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a booster mechanism of a regenerative braking combined-type brake device for an electric vehicle according to the present embodiment.

FIG. 3 is a schematic diagram showing solenoid valve control of a booster mechanism in a brake device.

FIG. 4 is a schematic diagram showing solenoid valve control of a booster mechanism in a brake device.

FIG. 5 is a schematic diagram showing solenoid valve control of a booster mechanism in a brake device.

FIG. 6 is a schematic diagram showing solenoid valve control of a booster mechanism in a brake device.

FIG. 7 is a control block diagram in the brake device.

FIG. 8 is a control block diagram of a braking force calculation process in the braking device.

FIG. 9 is a main flowchart showing a braking force control in the braking device.

FIG. 10 is a flowchart showing emergency avoidance control in the braking device.

FIG. 11 is a flowchart showing determination of a duty value of a solenoid valve in the brake device.

FIG. 12 is a flowchart showing the control of limiting the regeneration command value in the brake device.

FIG. 13 is a graph showing a limit command value according to a motor rotation speed.

FIG. 14 is a graph showing a change in regenerative fluctuation amount controlled by a limit command value.

FIG. 15 is a table relating to duty values of solenoid valves in a brake device.

FIG. 16 is a graph showing a setting characteristic relating to a duty value of a solenoid valve in a brake device.

FIG. 17 is a flowchart showing drive control of a solenoid valve in the brake device.

FIG. 18 is a table illustrating the drive control contents of the solenoid valve in the brake device.

FIG. 19 is a graph showing a braking force characteristic of the braking device of the present embodiment.

FIG. 20 is a schematic configuration diagram of a conventional regenerative braking combined-type braking device for an electric vehicle.

FIG. 21 is a graph showing a braking force characteristic of a conventional regenerative braking combined braking device for an electric vehicle.

FIG. 22 is a graph showing changes in the conventional regeneration fluctuation amount.

[Explanation of symbols]

2 motor (generator) 3 battery 11 brake pedal 12 negative pressure type booster (master cylinder with vacuum booster mechanism) 12A master cylinder 13 vacuum tank 15 motor controller 18A operating rod 18B negative pressure control piston 18C negative pressure control cylinders 19, 20, 21 Solenoid Valves 23L, 23R, 24L, 24R Brake Actuating Member 26 Regenerative Control Section 27 Booster Command Section and Negative Pressure Control Section 28 Brake Controller 29 Current Sensor 30 Hydraulic Pressure Sensor 31 Treading Force Sensor Input Section 32 Hydraulic Pressure Sensor Input Section 33 Motor Rotation speed input unit 34 Brake switch input unit 39 Computer 54 Front shell chamber (negative pressure chamber) 55 Rear shell chamber (control chamber) 58 Control valve 63 Opening 71 Air chamber 72 Atmospheric pressure chamber 73 Cylinder control port 74 Partition 75 Air Hole 76 Star boost control port 101 regenerative braking force calculating means 102 Regenerative command value calculating unit 103 Regenerative command value limiting unit 104 regenerative braking force control unit 201 requested braking force calculating means 202 mechanical braking force calculating means 203 mechanical braking force control means

Claims (3)

(57) [Claims] 1. A brake for detecting the operation of a brake pedal.
A pedal operation detecting means and a brake pedal operation detecting hand
The required braking force required by the driver is calculated based on the gear detection results.
Required braking force calculation means for calculating, a battery mounted on the vehicle, an electric motor electrically connected to the battery and having an output shaft connected to drive wheels of the vehicle, and regeneration based on the rotation speed of the electric motor. Regenerative braking force calculating means for calculating the braking force,
Required braking force calculated by the required braking force calculation means
And a regenerative command value calculating means for calculating a regenerative command value for the electric motor based on the regenerative braking force calculated by the regenerative braking force calculating means, and a unit time of the regenerative command value calculated by the regenerative command value calculating means. When the variation amount per hit exceeds a preset variation limit amount, regenerative command value limiting means for outputting a regenerative command value obtained by adding or subtracting the variation limit amount to the regenerative command value, and the regenerative command value calculating means. Of the electric vehicle comprising: regenerative braking force control means for controlling the regenerative braking force of the electric motor based on the regeneration command value calculated by the above or the regeneration command value limited by the regeneration command value limiting means. Braking control device. 2. A braking control device for an electric vehicle, comprising: a regenerative braking device for generating a regenerative braking force in an electric motor driven by a battery mounted on a vehicle; and a mechanical braking device that directly acts on wheels, wherein a pedaling force of a brake pedal is applied. Is input through a booster mechanism to convert the pedaling force into a hydraulic pressure and outputs the hydraulic pressure, and a master cylinder that is mounted on the wheel and receives the hydraulic pressure output from the master cylinder to apply a braking force to the wheel. A brake operation member, and a brake pedal operation detecting means for detecting an operation of the brake pedal,
A required braking force calculation means for calculating a required braking force required by the driver based on the detection result of the brake pedal operation detection means, and a regenerative braking force calculation means for calculating a maximum regenerative braking force from the rotation speed of the electric motor, Regenerative command value calculating means for calculating a regenerative command value for the electric motor based on the required braking force calculated by the required braking force calculating means and the maximum regenerative braking force calculated by the regenerative braking force calculating means; When the fluctuation amount of the regenerative command value calculated by the command value calculating means per unit time exceeds the preset fluctuation limit amount, the regenerative command value is added or subtracted as the regenerative command value. Based on the regeneration command value limiting means, and the regeneration command value calculated by the regeneration command value calculating means or the regeneration command value limited by the regeneration command value limiting means. Based on the regenerative braking force control means for controlling the regenerative braking force of the electric motor, the required braking force calculated by the required braking force calculation means, and the regenerative braking force of the electric motor controlled by the regenerative braking force control means Mechanical braking force calculation means for calculating the mechanical braking force,
A braking control device for an electric vehicle, comprising: a mechanical braking force control unit that controls the boosting mechanism based on the mechanical braking force calculated by the mechanical braking force calculation unit. 3. The braking control device for an electric vehicle according to claim 1, wherein the fluctuation limit amount differs depending on the rotation speed of the electric motor.