JP2014000903A - Brake grear, control method, and program - Google Patents

Abstract

[PROBLEMS] To reduce the capacity of a pump while adapting to various operations.
A brake booster that increases a force applied to a brake pedal by a negative pressure that is lower than an atmospheric pressure, a pump that generates a negative pressure, and a control unit that controls driving of the pump are provided. The control means determines whether or not the frequency of the operation applied to the brake pedal is higher than a predetermined first threshold, and determines that the frequency of the operation applied to the brake pedal is higher than the first threshold. If the negative pressure is higher than a predetermined second threshold, the pump is driven at a high speed and the pump is driven at a high speed when the negative pressure is determined to be higher than the second threshold. If so, it is determined whether or not the negative pressure is higher than a predetermined third threshold value. If it is determined that the negative pressure is higher than the third threshold value, the pump is driven at a low speed.
[Selection] Figure 2

Description

  The present invention relates to a brake device, a control method, and a program.

  In small cars, brake boosters using negative pressure are used. In general, the intake air pressure of an internal combustion engine is used to generate the negative pressure.

  In an automobile using a direct-injection type gasoline engine or diesel engine as an internal combustion engine or a so-called electric vehicle, a vacuum pump is used to generate a negative pressure because the difference between the intake air pressure and the atmospheric pressure is small or no intake air pressure is generated. .

  In order to generate a sufficient negative pressure even in various ways of driving by the driver, it is necessary to increase the capacity of the vacuum pump sufficiently.

  Conventionally, it can be driven by a master brake cylinder, in particular a tandem master brake cylinder (THZ), a vacuum brake force amplifier (booster) and at least one further pressure source for assisting the braking force, preferably a control unit. A method for controlling pressure generation in an electronically controllable brake installation for an automobile, advantageously with a hydraulic pump capable of applying that pressure to a vehicle wheel brake Detecting an approach to a point below a predetermined ratio with the operating force (operation limit point) of the brake force amplifier (booster), detecting a pressure gradient (THZ pressure gradient) of the master brake cylinder, and the booster It is detected that the operating limit point has been approached, and the detected THZ pressure gradient has exceeded the pressure gradient limit value. If, by driving the additional pressure source for the brake force assistance, while others are adapted to generate additional braking pressure (for example, see Patent Document 1).

Special Table 2007-516897

  However, on the basis of a general operation method, the capacity of the vacuum pump is large and waste is generated.

  Accordingly, an object of the present invention is to solve the above-described problems, that is, to provide a brake device, a control method, and a program that can reduce the capacity of the pump while accommodating various operations.

  In order to solve the above problems, one aspect of the brake device of the present invention includes a brake booster that increases a force applied to a brake pedal by a negative pressure that is lower than atmospheric pressure, and a pump that generates a negative pressure. Control means for controlling the driving of the pump, and the control means determines whether the frequency of the operation applied to the brake pedal is higher than a predetermined first threshold value, and is applied to the brake pedal. When it is determined that the frequency of the operation is greater than the first threshold, it is determined whether the negative pressure is higher than a predetermined second threshold, and the negative pressure is determined to be higher than the second threshold. If the pump is driven at a high speed and the pump is driven at a high speed, it is determined whether the negative pressure is higher than a predetermined third threshold and the negative pressure is determined to be higher than the third threshold. Drive the pump at low speed if And features.

  Further, according to one aspect of the brake device of the present invention, in addition to the above-described configuration, the control unit determines whether or not the speed at which the negative pressure increases is faster than a predetermined fourth threshold value. When it is determined that the speed at which the speed becomes higher than the fourth threshold value, it is determined whether or not the frequency of the operation applied to the brake pedal is higher than the first threshold value.

  Further, according to one aspect of the brake device of the present invention, in addition to the above-described configuration, when the control unit is activated, the pump is driven at a high speed.

  Further, one aspect of the control method of the present invention is a control of a brake device having a brake booster that increases a force applied to the brake pedal by a negative pressure that is lower than the atmospheric pressure, and a pump that generates the negative pressure. A step of determining whether the frequency of an operation applied to the brake pedal is greater than a predetermined first threshold; and the frequency of the operation applied to the brake pedal is greater than a first threshold. A step of determining whether or not the negative pressure is higher than a predetermined second threshold, and a step of driving the pump at a high speed if the negative pressure is determined to be higher than the second threshold. And determining whether the negative pressure is higher than a predetermined third threshold when the pump is driven at a high speed; and determining that the negative pressure is higher than the third threshold, Drive at low speed It is intended to include the steps of.

  Furthermore, one aspect of the program of the present invention is provided in a brake device having a brake booster that increases a force applied to a brake pedal by a negative pressure that is lower than atmospheric pressure, and a pump that generates the negative pressure. Determining whether the frequency of the operation applied to the brake pedal is greater than a predetermined first threshold; and the frequency of the operation applied to the brake pedal is greater than the first threshold. A step of determining whether or not the negative pressure is higher than a predetermined second threshold when determined, and a step of driving the pump at a high speed when it is determined that the negative pressure is higher than the second threshold; When the pump is being driven at a high speed, the step of determining whether or not the negative pressure is higher than a predetermined third threshold value, and if it is determined that the negative pressure is higher than the third threshold value, The are intended to perform a process including the step of driving at a low speed.

  According to one aspect of the present invention, it is possible to provide a brake device, a control method, and a program that can reduce the capacity of a pump while accommodating various operations.

It is a block diagram which shows the function structure of a brake device. 7 is a flowchart illustrating pump drive processing 41. It is a figure which shows the example of a threshold value.

  Hereinafter, a brake device according to an embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a block diagram illustrating a functional configuration of the brake device. The brake device 11 is provided in a vehicle such as a gasoline vehicle, a hybrid vehicle, or an electric vehicle, and generates a braking force.

  The brake device 11 includes a brake pedal 21, a brake booster 22, an electric vacuum pump 23, a master cylinder 24, a brake 25, an ECU (Engine Control Unit) 26, a hydraulic pressure sensor 27, a negative pressure sensor 28, and a brake switch 29. Is done. The brake pedal 21 is provided in the driver's seat and is stepped on by the driver when generating braking force. That is, a pedaling force is applied to the brake pedal 21 by a pedal operation 20 that is depressed by the driver. When a pedal operation 20 is applied to the brake pedal 21, the force generated thereby is transmitted to the brake booster 22 by a rod, a ring, or the like.

  The brake booster 22 is a so-called booster, and increases the force applied to the brake pedal 21. More specifically, the brake booster 22 increases the force applied to the brake pedal 21 by the negative pressure generated by the electric vacuum pump 23. Negative pressure is a pressure lower than atmospheric pressure.

  More specifically, the brake booster 22 is a vacuum brake booster. Inside the housing of the brake booster 22 are formed two chambers partitioned by a movable rubber diaphragm. In a state where the brake pedal 21 is not operated, the diaphragm is held substantially at the center of the housing. In a state where the diaphragm is held substantially at the center, a vacuum valve for releasing pressure from one chamber is opened, and an air valve for introducing air pressure into one chamber is closed. The pressure is released from the other chamber. Thereby, the pressure of the two chambers partitioned by the diaphragm is set to an equal negative pressure.

  When the brake pedal 21 is operated, the vacuum valve is closed and the air valve is opened by the force from the brake pedal 21. From the opened air valve, atmospheric pressure is introduced into one of the chambers. Since the pressure inside one chamber is higher than the pressure in the other chamber, a force (a force in the same direction as the force from the brake pedal 21) is generated to move the diaphragm to the low pressure chamber side. The brake booster 22 increases the force applied to the brake pedal 21 by the force that the diaphragm moves.

  Hereinafter, the chamber is also referred to as a tank.

  The force increased by the brake booster 22 is transmitted to the master cylinder 24.

  The electric vacuum pump 23 is a piston type, rotary type, diaphragm type or other type of pump, and generates a negative pressure that is lower than the atmospheric pressure. In other words, the electric vacuum pump 23 supplies negative pressure to the brake booster 22 by drawing air from the brake booster 22 (chamber thereof).

  The master cylinder 24 changes the force transmitted from the brake booster 22 to the pressure of the brake fluid in the pipe. The pressure generated in the master cylinder 24 is transmitted to the brake 25 through the brake fluid in the pipe. The brake 25 is a disc brake, a drum brake, or the like, and generates a braking force by sandwiching the disc with a pad or pressing a shoe against the inner periphery of the drum by the pressure transmitted by the brake fluid.

  The ECU 26 includes a dedicated IC, a general-purpose embedded microcomputer, and the like, and controls the engine and the brake device 11 by executing a control program. That is, the ECU 26 receives a signal from the hydraulic pressure sensor 27 that detects the pressure generated in the master cylinder 24, a signal from the negative pressure sensor 28 that detects the pressure in the chamber of the brake booster 22, and the pedal operation 20. A signal from the brake switch 29 that is turned on or off, vehicle speed information 31 indicating the vehicle speed, GPS (Global Positioning System) information 32 indicating the vehicle position, ITS (Intelligent Transport Systems) information 33, and navigation information 34 Based on the above, various processes such as a pump drive process 41 for controlling the electric vacuum pump 23 are executed.

  Next, the pump drive process 41 is demonstrated with reference to the flowchart of FIG. In step S11, when the vehicle power is turned on (turned on), the pump drive process 41 sets the mode of the brake device 11 to the vehicle activation mode. In step S12, the pump drive process 41 determines whether or not the mode of the brake device 11 is the vehicle activation mode.

  In step S12, when the mode of the brake device 11 is not the vehicle activation mode, that is, the constant speed operation mode or the variable speed operation mode, the procedure proceeds to step S13. In step S13, the pump drive processing 41 refers to the signal from the brake switch 29 or the signal from the hydraulic pressure sensor 27 that detects the pressure generated by the master cylinder 24, and determines the number of pedal operations 20 per unit time. It is calculated | required and it is determined whether the operation frequency of the brake pedal 21 is below A times / minute which is a predetermined threshold value. If it is determined in step S13 that the operation frequency of the brake pedal 21 is A times / minute or less, the procedure proceeds to step S14, and the pump drive process 41 sets the mode of the brake device 11 to the constant speed operation mode. Then, it is determined whether or not the negative pressure in the tank is equal to or higher than a predetermined threshold value −MkPa, and the determination process is repeated until the negative pressure in the tank becomes equal to or higher than −MkPa.

  FIG. 3 is a diagram illustrating an example of threshold values. As shown in FIG. 3, −MkPa, which is the threshold for the normal / low-consumption startup level, is set to −50 kPa, for example.

  If it is determined in step S14 that the negative pressure in the tank indicated by the signal from the negative pressure sensor 28 for detecting the pressure in the chamber of the brake booster 22 is equal to or higher than -MkPa, the procedure proceeds to step S15, and the pump The drive process 41 drives the pump motor of the electric vacuum pump 23 at a low speed.

  In step S <b> 16, the pump drive process 41 determines whether or not the negative pressure in the tank is equal to or lower than a predetermined threshold value −QkPa. As shown in FIG. 3, -QkPa, which is a threshold value of the pump stop level, is set to -70 kPa, for example. In addition, -QkPa which is a threshold value of a pump stop level is good also as -80 kPa, for example.

  If it is determined in step S16 that the negative pressure in the tank is not lower than -QkPa, the procedure returns to step S15, and the pump motor of the electric vacuum pump 23 is driven at a low speed.

  If it is determined in step S16 that the negative pressure in the tank is -QkPa or less, the procedure proceeds to step S17, and the pump drive processing 41 stops driving the pump motor of the electric vacuum pump 23, and the procedure is step. Returning to S13, the determination process is repeated.

  If it is determined in step S13 that the operation frequency of the brake pedal 21 is not less than or equal to A times / minute, the operation frequency of the brake pedal 21 is high. Therefore, the procedure proceeds to step S21, and the pump drive processing 41 is performed by the brake device 11. Is set to the variable speed operation mode, and it is determined whether or not the consumption speed of the negative pressure in the tank is equal to or lower than GkPa / second which is a predetermined threshold value. If it is determined in step S21 that the negative pressure consumption rate in the tank is equal to or lower than GkPa / sec, that is, the speed at which the negative pressure increases is not faster than a predetermined threshold, the procedure goes to step S22. move on. In step S22, the pump drive process 41 determines whether or not the negative pressure in the tank is equal to or higher than a predetermined threshold value −MkPa.

  If it is determined in step S22 that the negative pressure in the tank is equal to or higher than a predetermined threshold value −MkPa, that is, the negative pressure in the tank is equal to or higher than the normal / low-consumption start level, the procedure In S23, the pump drive process 41 drives the pump motor of the electric vacuum pump 23 at high speed.

  In step S24, the pump drive process 41 determines whether or not the negative pressure in the tank is equal to or higher than a predetermined threshold value −PkPa. As shown in FIG. 3, the speed switching level threshold value −PkPa is set, for example, higher than the pump stop level threshold value −QkPa and lower than the normal / low consumption start level threshold value −MkPa. .

  If it is determined in step S24 that the negative pressure in the tank is equal to or higher than -PkPa, the procedure proceeds to step S25, and the pump drive process 41 drives the pump motor of the electric vacuum pump 23 at a low speed.

  In step S26, the pump drive process 41 determines whether or not the negative pressure in the tank is equal to or lower than a predetermined threshold value −QkPa.

  If it is determined in step S26 that the negative pressure in the tank is -QkPa or less, the procedure proceeds to step S27, and the pump drive process 41 stops driving the pump motor of the electric vacuum pump 23. Returning to S13, the determination process is repeated.

  If it is determined in step S26 that the negative pressure in the tank is not lower than -QkPa, the procedure returns to step S25, and the pump motor of the electric vacuum pump 23 is driven at a low speed.

  If it is determined in step S24 that the negative pressure in the tank is not greater than -PkPa, the procedure returns to step S23, and the pump drive process 41 drives the pump motor of the electric vacuum pump 23 at high speed.

  On the other hand, if it is determined in step S22 that the negative pressure in the tank is not equal to or higher than a predetermined threshold value −MkPa, that is, the negative pressure in the tank is not equal to or higher than the normal / low-consumption start level, the procedure proceeds to step S22. Returning to S21, the pump drive process 41 repeats the procedure for determining whether or not the consumption rate of the negative pressure in the tank is equal to or less than a predetermined threshold value of GkPa / sec.

  If it is determined in step S21 that the negative pressure consumption rate in the tank is not less than or equal to GkPa / sec, that is, the speed at which the negative pressure increases is faster than a predetermined threshold, the procedure proceeds to step S28. In step S28, the pump drive process 41 determines whether or not the negative pressure in the tank is equal to or higher than a predetermined threshold value −NkPa, and the determination process is performed until the negative pressure in the tank becomes equal to or higher than −NkPa. Is repeated. As shown in FIG. 3, −NkPa, which is the threshold for the startup level at the start / high consumption, is higher than −PkPa, which is the threshold for the speed switching level, for example, and −MkPa, which is the threshold for the startup level during normal / low consumption. Set low.

  If it is determined in step S28 that the negative pressure in the tank has reached -NkPa or more, the procedure proceeds to step S23, and the pump drive process 41 drives the pump motor of the electric vacuum pump 23 at a high speed. Proceed to S24.

  If it is determined in step S12 that the mode of the brake device 11 is the vehicle activation mode, the procedure proceeds to step S31. In step S31, the pump drive process 41 drives the pump motor of the electric vacuum pump 23 at a high speed. In step S32, the pump drive process 41 determines whether or not the negative pressure in the tank is equal to or higher than a predetermined threshold value −NkPa. If it is determined in step S32 that the negative pressure in the tank is not greater than -NkPa, the procedure returns to step S31, and the pump drive process 41 drives the pump motor of the electric vacuum pump 23 at high speed.

  If it is determined in step S32 that the negative pressure in the tank is equal to or higher than -N kPa, the procedure proceeds to step S25, and the pump drive processing 41 drives the pump motor of the electric vacuum pump 23 at a low speed. Proceed to S26.

  In step S11, when the vehicle power is turned on (turned on), the procedures in steps S41 and S42 are performed in parallel with the procedures in steps S12 to S32. That is, in step S41, the pump drive processing 41 performs vehicle speed information 31, GPS (Global Positioning System) information 32 indicating the position of the vehicle, ITS (Intelligent Transport Systems) information 33, and vehicle data acquired as navigation information 34 ( Based on vehicle speed, GPS information, ITS information, navigation data), it is discriminated whether it is city driving or highway driving. In step S42, the pump drive process 41 updates (learns) the level values of the high-speed consumption activation level (activation level during activation / high consumption) and the low-speed consumption activation level (normal / low consumption activation level).

  For example, the pump drive process 41 sets the mode of the brake device 11 to the constant speed operation mode when it is determined that the vehicle is traveling in the city in step S41, and the mode of the brake device 11 when it is determined that the vehicle is traveling on the highway. Is set to variable speed operating mode. Alternatively, for example, in step S41, the pump drive process 41 sets the mode of the brake device 11 to the variable speed operation mode when it is determined that the vehicle is traveling in an urban area, and when it is determined that the vehicle is traveling on a highway, the brake device 11 This mode may be set to a constant speed operation mode.

  Thus, depending on the frequency of the pedal operation 20, the mode of the brake device 11 changes to either the constant speed operation mode or the variable speed operation mode, and the control pattern for driving the pump motor of the electric vacuum pump 23 changes.

  The normal / low-consumption start level or the start / high-consumption start level, which is a threshold used for determination when the pump motor of the electric vacuum pump 23 is driven at high speed, drives the pump motor of the electric vacuum pump 23 at low speed. This is different from the value of the speed switching level, which is a threshold value used for determination.

  The mode of the brake device 11 includes a start mode, a constant speed operation mode, and a variable speed operation mode.

  As described above, the brake device 11 includes the brake booster 23 that increases the force applied to the brake pedal by the negative pressure that is lower than the atmospheric pressure, the electric vacuum pump 23 that generates the negative pressure, and the electric vacuum pump. ECU26 which controls the drive of 23 is provided. The ECU 26 that executes the pump drive process 41 determines whether or not the frequency of the pedal operation 20 applied to the brake pedal 21 is higher than a predetermined first threshold value (for example, A times / minute) (for example, Step S13) When it is determined that the frequency of the pedal operation 20 applied to the brake pedal 21 is higher than the first threshold value, the negative pressure is higher than a predetermined second threshold value (for example, -NkPa). If it is determined that the negative pressure is higher than the second threshold value, the electric vacuum pump 23 is driven at a high speed (for example, the procedure of step S23). When the pump 23 is driven at a high speed, it is determined whether or not the negative pressure is higher than a predetermined third threshold (for example, -PkPa) (for example, the procedure of step S24), and the negative pressure is the third level. The threshold of If it is judged to be high, driving the electric vacuum pump 23 at a low speed (e.g., procedure of step S25). Therefore, even if the capacity of the electric vacuum pump 23 is reduced as compared with the conventional one (for example, the capacity is reduced by about 20%), the brake operation is repeated in a short time, so-called pumping brake is performed, Even if a strong braking operation is repeated, the negative pressure can be maintained and a desired negative pressure can be generated more quickly. Therefore, the braking force with respect to the pedaling force applied to the brake pedal 21 does not decrease, and the brake operation feeling is uncomfortable. Don't give. That is, the capacity of the pump can be further reduced while accommodating various operations.

  Further, the ECU 26 that executes the pump drive process 41 determines whether or not the speed at which the negative pressure increases is faster than a predetermined fourth threshold (for example, GkPa / second) (for example, the procedure of step S21). ), When it is determined that the speed at which the negative pressure increases is faster than the fourth threshold value, it is determined whether the frequency of the operation applied to the brake pedal is higher than the first threshold value. In this case, even if the capacity of the electric vacuum pump 23 is reduced, a desired negative pressure can be generated more quickly when necessary, the braking force applied to the pedal force applied to the brake pedal 21 does not decrease, and the brake operation feeling is uncomfortable. Don't give.

  Furthermore, the ECU 26 that executes the pump drive process 41 drives the electric vacuum pump 23 at a high speed when activated (for example, the procedure of step S31). Even if the capacity of the electric vacuum pump 23 is reduced, a desired negative pressure can be generated more quickly after the start-up. Therefore, even if the brake is applied immediately after the start-up, the braking force can be generated and the brake operation feeling can be generated. Does not give a sense of incongruity.

  As described above, the capacity of the pump can be further reduced while accommodating various operations.

  The series of processes described above can be executed by hardware or can be executed by software. When a series of processing is executed by software, a program constituting the software executes various functions by installing a computer incorporated in dedicated hardware or various programs. For example, the program is installed in a general-purpose microcomputer from a program recording medium.

  The program executed by the computer may be a program that is processed in time series in the order described in this specification, or in parallel or at a necessary timing such as when a call is made. It may be a program for processing.

  The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 11 ... Brake device, 21 ... Brake pedal, 22 ... Brake booster, 23 ... Electric vacuum pump (pump), 24 ... Master cylinder, 25 ... Brake, 26 ... ECU (control means), 27 ... Hydraulic pressure sensor, 28 ... Negative Pressure sensor, 29 ... Brake switch, 31 ... Vehicle speed information, 32 ... GPS information, 33 ... ITS information, 34 ... Navigation information, 41 ... Pump drive processing

Claims (5)

A brake booster that increases the force applied to the brake pedal by negative pressure, which is lower than atmospheric pressure,
A pump for generating the negative pressure;
Control means for controlling the drive of the pump,
The control means includes
Determining whether the frequency of the operation applied to the brake pedal is greater than a predetermined first threshold;
If it is determined that the frequency of operations applied to the brake pedal is greater than the first threshold, it is determined whether the negative pressure is higher than a predetermined second threshold;
When it is determined that the negative pressure is higher than the second threshold, the pump is driven at a high speed,
When the pump is driven at high speed, it is determined whether the negative pressure is higher than a predetermined third threshold;
When it is determined that the negative pressure is higher than the third threshold, the pump is driven at a low speed. The brake device according to claim 1, wherein
The control means includes
Determining whether or not the speed at which the negative pressure increases is faster than a predetermined fourth threshold;
When it is determined that the speed at which the negative pressure increases is faster than the fourth threshold value, it is determined whether or not the frequency of the operation applied to the brake pedal is higher than the first threshold value. Brake device to play. The brake device according to claim 1, wherein
The control means includes
A brake device characterized by driving the pump at high speed when starting. In a control method of a brake device having a brake booster that increases a force applied to a brake pedal by a negative pressure that is lower than an atmospheric pressure, and a pump that generates the negative pressure,
Determining whether the frequency of operations applied to the brake pedal is greater than a predetermined first threshold;
When it is determined that the frequency of operations applied to the brake pedal is greater than the first threshold, the step of determining whether the negative pressure is higher than a predetermined second threshold;
If it is determined that the negative pressure is higher than the second threshold, driving the pump at a high speed;
When the pump is driven at high speed, determining whether the negative pressure is higher than a predetermined third threshold;
And a step of driving the pump at a low speed when it is determined that the negative pressure is higher than the third threshold value. A computer provided in a brake device having a brake booster that increases the force applied to the brake pedal by a negative pressure that is lower than the atmospheric pressure, and a pump that generates the negative pressure.
Determining whether the frequency of operations applied to the brake pedal is greater than a predetermined first threshold;
When it is determined that the frequency of operations applied to the brake pedal is greater than the first threshold, the step of determining whether the negative pressure is higher than a predetermined second threshold;
If it is determined that the negative pressure is higher than the second threshold, driving the pump at a high speed;
When the pump is driven at high speed, determining whether the negative pressure is higher than a predetermined third threshold;
When the negative pressure is determined to be higher than the third threshold value, a program for performing a process including a step of driving the pump at a low speed.

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