JP5035171B2 - Brake control device - Google Patents

Description

  The present invention relates to a brake control device that controls braking force applied to wheels provided in a vehicle.

For example, Patent Document 1 describes a vehicle braking control device that reduces noise from a pump during a brake operation when the vehicle is stopped. In this device, the differential value of the target braking force is compared with a threshold value of a predetermined differential value calculated based on the vehicle state, and if the differential value of the target braking force exceeds the threshold value, the driving force of the pump or Limit the differential value of the target braking force.
JP 2005-289290 A

  However, the noise generated by the brake operation is not limited to the pump operation sound. For example, the operating sound of the control valve can also make the driver uncomfortable. Although the driver's discomfort can be reduced by reducing the control valve operating noise, it is preferable to minimize the influence of the operating noise reduction on the braking performance.

  Accordingly, an object of the present invention is to provide a brake control device that can reduce the control valve operating noise while suppressing the influence on the brake response.

  A brake control device according to an aspect of the present invention is provided in a detection system including at least one sensor provided in association with a vehicle, and a hydraulic circuit for controlling a braking force applied to the vehicle. The electromagnetic control valve is connected to the detection system so as to be able to receive the output from the detection system, and is supplied with a control current in accordance with a first current profile that is guaranteed to open and close the electromagnetic control valve with the required control response. A control unit that opens and closes the control valve. The control unit determines whether or not a decrease in the control responsiveness of the electromagnetic control valve is allowed based on the output from the detection system. A control current is applied to the electromagnetic control valve according to a second current profile that is adjusted to reduce the operating noise of the electromagnetic control valve over the current profile.

  According to this aspect, the operation sound of the electromagnetic control valve is reduced by switching the current profile to be used. By using the current profile for reducing the operating noise only when the decrease in the control response is allowed, it is possible to achieve both the brake response and the reduction of the operating noise.

  In the second current profile, the initial current applied at the start of energization of the electromagnetic control valve is adjusted to be smaller than the first current profile, and reaches a specified starting current that is guaranteed to change the open / close state of the electromagnetic control valve. The time required for the adjustment may be adjusted to be longer than the first current profile.

  In this way, it is possible to obtain a current profile for reducing operating noise in which the opening / closing speed of the control valve is made slower than the normal current profile.

  The initial current of the second current profile may be adjusted to a magnitude that ensures that the open / close state of the electromagnetic control valve is not changed.

  In this way, when the control current is increased from the initial current to the specified starting current, a current profile for reducing the operating noise can be obtained in which the control valve is opened and closed more slowly than the normal current profile. it can.

  The detection system may include at least one sensor that detects the operation of the driver. The control unit may acquire the driver's sensitivity to the operating sound of the electromagnetic control valve based on the detection result of the detection system, and may adjust the first current profile according to the acquired sensitivity. For example, the control unit may adjust the initial current of the first current profile.

  The detection system may include at least one sensor that detects an environmental sound of the vehicle. The control unit may acquire the environmental sound of the vehicle based on the detection result of the detection system, and may adjust the first current profile according to the acquired environmental sound. For example, the control unit may adjust the initial current of the first current profile.

  You may further provide the accumulator which stores the high pressure hydraulic fluid supplied to a hydraulic circuit, and the pump which pressurizes the hydraulic fluid of this accumulator according to the control command from a control part. The detection system may include at least one sensor that detects the operation of the driver. The control unit may determine whether or not the driver's sensitivity to the operation sound of the electromagnetic control valve is worse than the reference based on the detection result of the detection system, and may operate the pump when it is determined that the sensitivity is poor. .

  You may further provide the accumulator which stores the high pressure hydraulic fluid supplied to a hydraulic circuit, and the pump which pressurizes the hydraulic fluid of this accumulator according to the control command from a control part. The detection system may include at least one sensor that detects an environmental sound of the vehicle. The control unit may determine whether the environmental sound of the vehicle is in a state exceeding the reference based on the detection result of the detection system, and may operate the pump when it is determined that the vehicle exceeds the reference.

  Another aspect of the present invention is a brake control device. This device includes a detection system including at least one sensor provided in association with a vehicle, a wheel cylinder that applies a braking force to a wheel according to the hydraulic fluid pressure, and power that accumulates hydraulic fluid by supplying power. A hydraulic pressure source, a master cylinder that pressurizes the stored hydraulic fluid in response to a brake operation input, and a regulator that regulates the hydraulic fluid according to the hydraulic pressure of the master cylinder using a power hydraulic pressure source as a high-pressure source. Including a manual hydraulic pressure source, a regulator cut valve provided in the hydraulic fluid flow path from the regulator to the wheel cylinder, and shutting off the hydraulic fluid flow path according to a braking request, and the regulator cut valve closed based on the output from the detection system A control unit for adjusting the valve speed.

  A master cut valve provided in the hydraulic fluid flow path from the master cylinder to the wheel cylinder may be further provided to block the hydraulic fluid flow path in response to a braking request. The control unit may adjust the valve closing speed of the regulator cut valve so that the regulator cut valve is closed more slowly than the master cut valve.

  Yet another embodiment of the present invention is a control device. This device includes a detection system including at least one sensor provided in association with a vehicle, an electromagnetic control valve that opens and closes a hydraulic fluid passage provided in the vehicle, and an operation noise of the electromagnetic control valve. In accordance with the current profile adjusted to reduce the operating noise of the electromagnetic control valve rather than the specified current profile when it is determined that the operating noise should be reduced. A control unit that applies a control current to the electromagnetic control valve.

  According to the present invention, the operation sound of the control valve can be reduced.

  In one embodiment of the present invention, an electromagnetic control valve opening / closing control method for changing an opening / closing state by gradually changing a control current is provided. The starting current of the electromagnetic control valve varies somewhat depending on, for example, the use environment and individual differences even if the control valve has the same specification. Therefore, it is generally assumed that the starting current is included in a certain range. The opening / closing operation sound of the control valve can be reduced by gently changing the current in the starting current range.

  In one embodiment, the control unit performs “current smoothing control” when the electromagnetic control valve is opened and closed. In the current smoothing control, a predetermined target starting current that is guaranteed to change the open / close state of the electromagnetic control valve is not given together with the start of energization, but it takes a certain time to reach the target starting current. Hereinafter, this time may be referred to as “annealing time”. In addition, an initial current that is less than the target starting current is applied when energization is started. Hereinafter, this initial current may be referred to as “annealing current”. The control current profile applied to the control valve has at least an annealing current and an annealing time as adjustable parameters.

  In the current smoothing control, a control current is supplied to the electromagnetic control valve in accordance with a startup current profile that gives a smoothing current at the start of energization and increases the target startup current until the annealing time elapses. By setting the annealing time relatively large, the current increase gradient to the target starting current can be reduced. As a result, the control valve operating noise can be reduced. In addition, applying an annealing current as the energization starts contributes to reducing the current increase gradient to the target starting current.

  The target startup current is set to, for example, the upper limit value of the startup current range described above or a value larger than that. Therefore, the target starting current is a value larger than the actual starting current, and when the target starting current is given (more precisely, while the current is increasing to the target starting current), the electromagnetic control valve is opened and closed. Further, the annealing current is set to a lower limit value of the starting current range or a value smaller than that, for example. In this case, it can be said that the annealing current has a magnitude that ensures that the open / close state of the electromagnetic control valve is not changed. The starting current range may be given as a specification of the electromagnetic control valve, or may be obtained experimentally or empirically. For example, the annealing time may be set longer than the required opening and closing time in the normal control of the electromagnetic control valve.

  For example, the current profile of the current smoothing control may be configured to increase the current linearly from giving the smoothing current to reaching the target starting current, or to increase the current non-linearly. May be. Further, the current profile may be set such that when the control current is smaller than the starting current range, the current is increased relatively fast, and the current is increased relatively slowly in the starting current range. If the starting current range is exceeded, the current may be increased relatively quickly. Alternatively, the current profile may be set so that the current is increased at a relatively low speed until the annealing time elapses, and the target starting current is given when the annealing time elapses.

  In one embodiment, the control unit detects the vehicle environment and determines whether or not to perform control valve operation sound reduction control based on the detection result. When it is determined that the operation sound reduction control should be executed, the control unit applies a control current to the control valve according to the current profile for reducing the operation sound. On the other hand, when it is determined that the operation noise reduction control should not be executed, a control current is applied to the control valve according to a normal current profile. For this purpose, a detection system for detecting the vehicle environment is provided along with the vehicle. The vehicle environment includes, for example, a vehicle driving situation, a vehicle environmental sound, a driver situation, and the like.

  The control valve may be an electromagnetic control valve provided in a brake hydraulic pressure circuit for controlling a braking force applied to the vehicle. The normal current profile is set, for example, so as to ensure that the control valve is opened and closed with the required control response. As a result, a desired brake response is usually realized.

  In this case, the control unit may determine whether or not a decrease in control responsiveness of the electromagnetic control valve is allowed based on an output from the detection system. The control unit performs the operation sound reduction control when it is determined that the decrease in the control responsiveness is permitted, and performs the normal opening / closing control when it is determined that the decrease in the control responsiveness is not permitted. Good. By executing the operation sound reduction control only when the decrease in control responsiveness is allowed, it is possible to achieve both the brake responsiveness and the reduction of driver discomfort.

  An example of a current profile used in one embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating an example of a prescribed current profile that realizes a required control response in a control valve. FIG. 2 is a diagram illustrating an example of a current profile for reducing the operation sound of the control valve.

  FIG. 1 shows profiles P1 and P2 as an example of a prescribed current profile. Profile P1 is indicated by a solid line, and profile P2 is indicated by a broken line. This defined current profile is used for normal control of the control valve. In each of the two profiles P1 and P2, energization is started as the brake is turned on, and the target starting current Az is reached before the predetermined time T1 elapses after the brake is turned on. After the time T1, the supply of the target starting current Az is continued. The time T1 is a required time allowed for the opening / closing operation in the normal control, and is set based on the control response required for the control valve.

  The profile P1 and the profile P2 have different current fluctuations from the start of energization to the switching operation completion time T1. In the profile P1, the target activation current Az is given at the time of braking on, whereas in the profile P2, the control current is increased linearly from the braking on to time T1 to the target activation current Az.

  The current At shown in FIG. 1 is the actual starting current value of the control valve. When the control current supplied to the control valve exceeds the actual starting current At, the open / close state of the control valve is changed. That is, when the control current exceeds the actual starting current At, for example, a normally open control valve is closed, and a normally closed control valve is opened. As described above, the actual starting current At has variations caused by various factors such as individual differences in control valves, changes with time, and usage environments.

  In the profile P1, the control current exceeds the actual starting current At substantially simultaneously with braking on, and an opening / closing operation noise is generated. In the profile P2, an opening / closing operation sound is generated when the control current exceeds the actual starting current At. In any case, since the control current reaches the target starting current Az by the time T1 set to satisfy the required responsiveness, the current increase gradient is relatively large. For this reason, the operation sound of the control valve tends to be loud.

  On the other hand, FIG. 2 shows a profile Q1 as an example of a current profile for reducing operating noise. The profile Q1 is set so that the smoothing current Aa is energized when the braking is turned on, and the control current is increased to the target starting current Az over the smoothing time T2 from the braking on. After the time T2, the supply of the target starting current Az is continued. The annealing time T2 is set longer than the opening / closing operation completion time T1 in the normal control current profile. For this reason, the current gradient in the actual starting current At can be reduced to reduce the opening / closing operation noise.

  Further, the annealing current Aa is set smaller than the actual starting current At. As a result, the current gradient in the actual starting current At can be further reduced while avoiding the generation of a large operating noise at the start of energization as in the profile P1 described above. Therefore, the opening / closing operation sound of the control valve can be further reduced.

  The annealing current Aa takes into account, for example, variations in the control current given by the control unit (for example, the brake ECU), variations in the characteristics of the control valve, environmental temperature changes, etc., based on the average value of the actual starting current At measured in advance. Is set. The target starting current Az can be set similarly. As a result, the smoothing current Aa is set to a magnitude that guarantees that the open / close state of the control valve is not changed, and the target starting current Az is set to a magnitude that guarantees that the open / close state of the control valve is changed. it can. Since the actual starting current At varies stochastically, a situation may occur in which the actual starting current At is exceptionally smaller than the set annealing current Aa or exceptionally larger than the target starting current Az. It should be noted that the annealing current Aa and the target starting current Az may be set to allow such an exceptional situation.

  In one embodiment of the present invention, when it is determined that the control responsiveness of the control valve should be prioritized, the control unit selects, for example, the normal current profile shown in FIG. If it is determined that it should be, for example, the current profile shown in FIG. 2 is selected. The control unit provides a control current to the control valve according to the selected current profile. Therefore, it is possible to achieve both responsiveness of the control valve and reduction of operating noise.

  FIG. 3 is a system diagram showing the brake control device 20 according to one embodiment of the present invention. A brake control device 20 shown in the figure constitutes an electronically controlled brake system (ECB) for a vehicle, and controls braking force applied to four wheels provided on the vehicle. The brake control device 20 according to the present embodiment is mounted on, for example, a hybrid vehicle that includes an electric motor and an internal combustion engine as a travel drive source. In such a hybrid vehicle, each of regenerative braking that brakes the vehicle by regenerating kinetic energy of the vehicle into electric energy and hydraulic braking by the brake control device 20 can be used for braking the vehicle. The vehicle in the present embodiment can execute brake regenerative cooperative control that generates a desired braking force by using both the regenerative braking and the hydraulic braking together.

  As shown in FIG. 3, the brake control device 20 includes disc brake units 21FR, 21FL, 21RR and 21RL provided for each wheel, a master cylinder unit 27, a power hydraulic pressure source 30, and a brake actuator. 40.

  Disc brake units 21FR, 21FL, 21RR, and 21RL apply braking force to the right front wheel, the left front wheel, the right rear wheel, and the left rear wheel of the vehicle, respectively. The master cylinder unit 27 as the manual hydraulic pressure source in the present embodiment sends the brake fluid pressurized according to the operation amount by the driver of the brake pedal 24 as the brake operation member to the disc brake units 21FR to 21RL. To do. The power hydraulic pressure source 30 can send the brake fluid as the working fluid pressurized by the power supply to the disc brake units 21FR to 21RL independently from the operation of the brake pedal 24 by the driver. is there. The brake actuator 40 appropriately adjusts the hydraulic pressure of the brake fluid supplied from the power hydraulic pressure source 30 or the master cylinder unit 27 and sends it to the disc brake units 21FR to 21RL. Thereby, the braking force with respect to each wheel by hydraulic braking is adjusted.

  Each of the disc brake units 21FR to 21RL, the master cylinder unit 27, the power hydraulic pressure source 30, and the brake actuator 40 will be described in more detail below. Each of the disc brake units 21FR to 21RL includes a brake disc 22 and wheel cylinders 23FR to 23RL incorporated in the brake caliper, respectively. The wheel cylinders 23FR to 23RL are connected to the brake actuator 40 via different fluid passages. Hereinafter, the wheel cylinders 23FR to 23RL are collectively referred to as “wheel cylinders 23” as appropriate.

  In the disc brake units 21FR to 21RL, when brake fluid is supplied to the wheel cylinder 23 from the brake actuator 40, a brake pad as a friction member is pressed against the brake disc 22 that rotates with the wheel. Thereby, a braking force is applied to each wheel. In this embodiment, the disc brake units 21FR to 21RL are used, but other braking force applying mechanisms including a wheel cylinder 23 such as a drum brake may be used.

  In this embodiment, the master cylinder unit 27 is a master cylinder with a hydraulic booster, and includes a hydraulic booster 31, a master cylinder 32, a regulator 33, and a reservoir. The hydraulic booster 31 is connected to the brake pedal 24, amplifies the pedal effort applied to the brake pedal 24, and transmits it to the master cylinder 32. When the brake fluid is supplied from the power hydraulic pressure source 30 to the hydraulic pressure booster 31 via the regulator 33, the pedal effort is amplified. The master cylinder 32 generates a master cylinder pressure having a predetermined boost ratio with respect to the pedal effort.

  A reservoir 34 for storing brake fluid is disposed above the master cylinder 32 and the regulator 33. The master cylinder 32 communicates with the reservoir 34 when the depression of the brake pedal 24 is released. On the other hand, the regulator 33 is in communication with both the reservoir 34 and the accumulator 35 of the power hydraulic pressure source 30, and the reservoir 34 is used as a low pressure source, the accumulator 35 is used as a high pressure source, and the hydraulic pressure is approximately equal to the master cylinder pressure. Is generated. Hereinafter, the hydraulic pressure in the regulator 33 is appropriately referred to as “regulator pressure”. The master cylinder pressure and the regulator pressure do not need to be exactly the same pressure. For example, the master cylinder unit 27 can be designed so that the regulator pressure is slightly higher.

  The power hydraulic pressure source 30 includes an accumulator 35 and a brake pump 36. The accumulator 35 converts and stores the pressure energy of the brake fluid boosted by the brake pump 36 into the pressure energy of an enclosed gas such as nitrogen, for example, about 14 to 22 MPa. The brake pump 36 has a motor 36 a as a drive source, and its suction port is connected to the reservoir 34, while its discharge port is connected to the accumulator 35. The accumulator 35 is also connected to a relief valve 35 a provided in the master cylinder unit 27. When the pressure of the brake fluid in the accumulator 35 increases abnormally to about 25 MPa, for example, the relief valve 35 a is opened, and the high-pressure brake fluid is returned to the reservoir 34.

  As described above, the brake control device 20 includes the master cylinder 32, the regulator 33, and the accumulator 35 as a supply source of brake fluid to the wheel cylinder 23. A master pipe 37 is connected to the master cylinder 32, a regulator pipe 38 is connected to the regulator 33, and an accumulator pipe 39 is connected to the accumulator 35. These master pipe 37, regulator pipe 38 and accumulator pipe 39 are each connected to a brake actuator 40.

  The brake actuator 40 includes an actuator block in which a plurality of flow paths are formed, and a plurality of electromagnetic control valves. The flow paths formed in the actuator block include individual flow paths 41, 42, 43 and 44 and a main flow path 45. The individual flow paths 41 to 44 are respectively branched from the main flow path 45 and connected to the wheel cylinders 23FR, 23FL, 23RR, 23RL of the corresponding disc brake units 21FR, 21FL, 21RR, 21RL. Thereby, each wheel cylinder 23 can communicate with the main flow path 45.

  In addition, ABS holding valves 51, 52, 53 and 54 are provided in the middle of the individual flow paths 41, 42, 43 and 44. Each of the ABS holding valves 51 to 54 has a solenoid and a spring that are ON / OFF controlled, and both are normally open electromagnetic control valves that are opened when the solenoid is in a non-energized state. Each of the ABS holding valves 51 to 54 in the opened state can distribute the brake fluid in both directions. That is, the brake fluid can flow from the main flow path 45 to the wheel cylinder 23, and conversely, the brake fluid can also flow from the wheel cylinder 23 to the main flow path 45. When the solenoid is energized and the ABS holding valves 51 to 54 are closed, the flow of brake fluid in the individual flow paths 41 to 44 is blocked.

  Further, the wheel cylinder 23 is connected to the reservoir channel 55 via pressure reducing channels 46, 47, 48 and 49 connected to the individual channels 41 to 44, respectively. ABS decompression valves 56, 57, 58 and 59 are provided in the middle of the decompression channels 46, 47, 48 and 49. Each of the ABS pressure reducing valves 56 to 59 has a solenoid and a spring that are ON / OFF controlled, and is a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. When the ABS pressure reducing valves 56 to 59 are closed, the flow of brake fluid in the pressure reducing flow paths 46 to 49 is blocked. When the solenoid is energized and the ABS pressure reducing valves 56 to 59 are opened, the brake fluid is allowed to flow through the pressure reducing flow paths 46 to 49, and the brake fluid flows from the wheel cylinder 23 to the pressure reducing flow paths 46 to 49 and It returns to the reservoir 34 via the reservoir channel 55. The reservoir channel 55 is connected to the reservoir 34 of the master cylinder unit 27 via a reservoir pipe 77.

  The main channel 45 has a separation valve 60 in the middle. By this separation valve 60, the main channel 45 is divided into a first channel 45 a connected to the individual channels 41 and 42 and a second channel 45 b connected to the individual channels 43 and 44. The first flow path 45a is connected to the front wheel wheel cylinders 23FR and 23FL via the individual flow paths 41 and 42, and the second flow path 45b is connected to the rear wheel wheel cylinder via the individual flow paths 43 and 44. Connected to 23RR and 23RL.

  The separation valve 60 has a solenoid and a spring that are ON / OFF controlled, and is a normally closed electromagnetic control valve that is closed when the solenoid is in a non-energized state. When the separation valve 60 is in the closed state, the flow of brake fluid in the main flow path 45 is blocked. When the solenoid is energized and the separation valve 60 is opened, the brake fluid can be circulated bidirectionally between the first flow path 45a and the second flow path 45b.

  In the brake actuator 40, a master channel 61 and a regulator channel 62 communicating with the main channel 45 are formed. More specifically, the master channel 61 is connected to the first channel 45 a of the main channel 45, and the regulator channel 62 is connected to the second channel 45 b of the main channel 45. The master channel 61 is connected to a master pipe 37 that communicates with the master cylinder 32. The regulator channel 62 is connected to a regulator pipe 38 that communicates with the regulator 33.

  The master channel 61 has a master cut valve 64 in the middle. The master cut valve 64 is provided on the brake fluid supply path from the master cylinder 32 to each wheel cylinder 23. The master cut valve 64 has a solenoid and a spring that are ON / OFF-controlled, and the valve closing state is guaranteed by the electromagnetic force generated by the solenoid when supplied with a prescribed control current, so that the solenoid is in a non-energized state. It is a normally open electromagnetic control valve that is opened in some cases. The master cut valve 64 in the opened state can cause the brake fluid to flow in both directions between the master cylinder 32 and the first flow path 45 a of the main flow path 45. When a prescribed control current is applied to the solenoid and the master cut valve 64 is closed, the flow of brake fluid in the master flow path 61 is interrupted.

  A stroke simulator 69 is connected to the master channel 61 via a simulator cut valve 68 on the upstream side of the master cut valve 64. That is, the simulator cut valve 68 is provided in a flow path connecting the master cylinder 32 and the stroke simulator 69. The simulator cut valve 68 has a solenoid and a spring that are ON / OFF controlled, and the valve opening state is guaranteed by the electromagnetic force generated by the solenoid upon receipt of a specified control current, and the solenoid is in a non-energized state. It is a normally closed electromagnetic control valve that is closed in some cases. When the simulator cut valve 68 is closed, the flow of brake fluid between the master flow path 61 and the stroke simulator 69 is blocked. When the solenoid is energized and the simulator cut valve 68 is opened, the brake fluid can be circulated bidirectionally between the master cylinder 32 and the stroke simulator 69.

  The stroke simulator 69 includes a plurality of pistons and springs, and creates a reaction force corresponding to the depression force of the brake pedal 24 by the driver when the simulator cut valve 68 is opened. As the stroke simulator 69, in order to improve the feeling of brake operation by the driver, it is preferable to employ one having a multistage spring characteristic.

  The regulator flow path 62 has a regulator cut valve 65 in the middle. The regulator cut valve 65 is provided on the brake fluid supply path from the regulator 33 to each wheel cylinder 23. The regulator cut valve 65 also has a solenoid and a spring that are ON / OFF controlled, and the valve closing state is guaranteed by the electromagnetic force generated by the solenoid upon receipt of a specified control current, and the solenoid is in a non-energized state. It is a normally open electromagnetic control valve that is opened in some cases. The regulator cut valve 65 that has been opened can cause the brake fluid to flow in both directions between the regulator 33 and the second flow path 45 b of the main flow path 45. When the solenoid is energized and the regulator cut valve 65 is closed, the flow of brake fluid in the regulator flow path 62 is blocked.

  In addition to the master channel 61 and the regulator channel 62, an accumulator channel 63 is also formed in the brake actuator 40. One end of the accumulator channel 63 is connected to the second channel 45 b of the main channel 45, and the other end is connected to an accumulator pipe 39 that communicates with the accumulator 35.

  The accumulator flow path 63 has a pressure-increasing linear control valve 66 in the middle. Further, the accumulator channel 63 and the second channel 45 b of the main channel 45 are connected to the reservoir channel 55 via the pressure-reducing linear control valve 67. The pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 each have a linear solenoid and a spring, and both are normally closed electromagnetic control valves that are closed when the solenoid is in a non-energized state. In the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67, the opening degree of the valve is adjusted in proportion to the current supplied to each solenoid.

  The pressure-increasing linear control valve 66 is provided as a common pressure-increasing control valve for each of the wheel cylinders 23 provided corresponding to each wheel. Similarly, the pressure-reducing linear control valve 67 is provided as a pressure-reducing control valve common to the wheel cylinders 23. That is, in this embodiment, the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 are a pair of common control valves that control the supply and discharge of the working fluid sent from the power hydraulic pressure source 30 to each wheel cylinder 23. It is provided as. If the pressure-increasing linear control valve 66 and the like are made common to each wheel cylinder 23 in this way, it is preferable from the viewpoint of cost as compared with the case where a linear control valve is provided for each wheel cylinder 23.

  Here, the differential pressure between the inlet and outlet of the pressure-increasing linear control valve 66 corresponds to the differential pressure between the pressure of the brake fluid in the accumulator 35 and the pressure of the brake fluid in the main flow path 45, and the inlet / outlet of the pressure-reducing linear control valve 67. The pressure difference therebetween corresponds to the pressure difference between the brake fluid pressure in the main flow path 45 and the brake fluid pressure in the reservoir 34. Further, the electromagnetic driving force according to the power supplied to the linear solenoid of the pressure increasing linear control valve 66 and the pressure reducing linear control valve 67 is F1, the spring biasing force is F2, and the pressure increasing linear control valve 66 and the pressure reducing linear control valve are Assuming that the differential pressure acting force according to the differential pressure between the inlet / outlet of 67 is F3, the relationship of F1 + F3 = F2 is established. Therefore, the differential pressure between the inlet and outlet of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67 is controlled by continuously controlling the power supplied to the linear solenoids of the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67. can do.

  In the brake control device 20, the power hydraulic pressure source 30 and the brake actuator 40 are controlled by a brake ECU 70 as a control unit in the present embodiment. The brake ECU 70 is configured as a microprocessor including a CPU, and includes a ROM that stores various programs, a RAM that temporarily stores data, an input / output port, a communication port, and the like in addition to the CPU. The brake ECU 70 can communicate with a host hybrid ECU (not shown) and the like, and based on control signals from the hybrid ECU and signals from various sensors, the brake pump 36 of the power hydraulic pressure source 30 and the brake The electromagnetic control valves 51 to 54, 56 to 59, 60, and 64 to 68 constituting the actuator 40 are controlled.

  Further, a regulator pressure sensor 71, an accumulator pressure sensor 72, and a control pressure sensor 73 are connected to the brake ECU 70. The regulator pressure sensor 71 detects the pressure of the brake fluid in the regulator flow path 62 on the upstream side of the regulator cut valve 65, that is, the regulator pressure, and gives a signal indicating the detected value to the brake ECU 70. The accumulator pressure sensor 72 detects the pressure of the brake fluid in the accumulator flow path 63, that is, the accumulator pressure on the upstream side of the pressure increasing linear control valve 66, and gives a signal indicating the detected value to the brake ECU 70. The control pressure sensor 73 detects the pressure of the brake fluid in the first flow path 45a of the main flow path 45, and gives a signal indicating the detected value to the brake ECU 70. The detection values of the pressure sensors 71 to 73 are sequentially given to the brake ECU 70 every predetermined time, and are stored and held in a predetermined storage area of the brake ECU 70.

  When the separation valve 60 is opened and the first flow path 45 a and the second flow path 45 b of the main flow path 45 communicate with each other, the output value of the control pressure sensor 73 is the low pressure of the pressure-increasing linear control valve 66. This indicates the hydraulic pressure on the high pressure side of the pressure-reducing linear control valve 67 and the output value can be used to control the pressure-increasing linear control valve 66 and the pressure-reducing linear control valve 67. When the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 are closed and the master cut valve 64 is opened, the output value of the control pressure sensor 73 indicates the master cylinder pressure. Further, the separation valve 60 is opened so that the first flow path 45a and the second flow path 45b of the main flow path 45 communicate with each other, and the ABS holding valves 51 to 54 are opened, while the ABS pressure reducing valves 56 are opened. When? 59 is closed, the output value of the control pressure sensor 73 indicates the working fluid pressure acting on each wheel cylinder 23, i.e., the wheel cylinder pressure.

  Further, the sensor connected to the brake ECU 70 includes a stroke sensor 25 provided on the brake pedal 24. The stroke sensor 25 detects a pedal stroke as an operation amount of the brake pedal 24 and gives a signal indicating the detected value to the brake ECU 70. The output value of the stroke sensor 25 is also sequentially given to the brake ECU 70 every predetermined time, and is stored and held in a predetermined storage area of the brake ECU 70. A brake operation state detection unit other than the stroke sensor 25 may be provided in addition to the stroke sensor 25 or in place of the stroke sensor 25 and connected to the brake ECU 70. Examples of the brake operation state detection means include a pedal depression force sensor 26 (see FIG. 4) that detects the operation force of the brake pedal 24, and a brake switch that detects that the brake pedal 24 is depressed.

  The brake control device 20 configured as described above can execute brake regeneration cooperative control. The brake control device 20 starts braking in response to a braking request. The braking request is generated when a braking force should be applied to the vehicle, for example, when the driver operates the brake pedal 24. In response to the braking request, the brake ECU 70 calculates a required braking force, and calculates a required hydraulic braking force that is a braking force to be generated by the brake control device 20 by subtracting the braking force due to regeneration from the required braking force. Here, the braking force by regeneration is supplied to the brake control device 20 from the hybrid ECU. Then, the brake ECU 70 calculates the target hydraulic pressure of each wheel cylinder 23FR to 23RL based on the calculated required hydraulic braking force. The brake ECU 70 determines the value of the control current supplied to the pressure-increasing linear control valve 66 and the pressure-decreasing linear control valve 67 so that the wheel cylinder pressure becomes the target hydraulic pressure.

  As a result, in the brake control device 20, the brake fluid is supplied from the power hydraulic pressure source 30 to the wheel cylinders 23 via the pressure-increasing linear control valve 66, and braking force is applied to the wheels. Further, brake fluid is discharged from each wheel cylinder 23 through the pressure-reducing linear control valve 67 as necessary, and the braking force applied to the wheel is adjusted. In the present embodiment, a wheel cylinder pressure control system is configured including the power hydraulic pressure source 30, the pressure-increasing linear control valve 66, the pressure-decreasing linear control valve 67, and the like. A so-called brake-by-wire braking force control is performed by the wheel cylinder pressure control system. The wheel cylinder pressure control system is provided in parallel to the brake fluid supply path from the master cylinder unit 27 to the wheel cylinder 23.

  When brake-by-wire braking force control is performed, the brake ECU 70 closes the regulator cut valve 65 so that the brake fluid delivered from the regulator 33 is not supplied to the wheel cylinder 23. Further, the brake ECU 70 closes the master cut valve 64 and opens the simulator cut valve 68. This is because the brake fluid sent from the master cylinder 32 in accordance with the operation of the brake pedal 24 by the driver is supplied not to the wheel cylinder 23 but to the stroke simulator 69. During the brake regeneration cooperative control, a differential pressure corresponding to the magnitude of the regenerative braking force acts between the upstream and downstream of the regulator cut valve 65 and the master cut valve 64.

  The brake control device 20 according to the present embodiment can naturally control the braking force by the wheel cylinder pressure control system even when the required braking force is provided only by the hydraulic braking force without using the regenerative braking force. . Regardless of whether or not the brake regeneration cooperative control is executed, the control mode for controlling the braking force by the wheel cylinder pressure control system will be appropriately referred to as a “linear control mode” below. Or it may be called control by brake-by-wire.

  FIG. 4 is a diagram schematically showing a configuration of a control system according to an embodiment of the present invention. This control system includes a brake ECU 70 as a control unit and a detection system including various sensors provided in the vehicle. The brake ECU 70 controls the brake pump 36 and the brake actuator 40 based on the detection result of the detection system.

  The detection system includes, for example, a sensor group for detecting the traveling state of the vehicle, a sensor group for detecting the operation of the driver, and a sensor group for detecting environmental sound. The sensor group for detecting the running state of the vehicle includes a vehicle speed sensor 81 and a shift sensor 84, for example. The sensor group for detecting the operation of the driver includes, for example, a brake pedal stroke sensor 25, a brake pedal depression force sensor 26, a steering sensor 86, and a microphone 87. The sensor group for detecting the environmental sound includes, for example, a blinker sensor 82, a window opening / closing switch 83, a raindrop sensor 85, and a speaker 88.

  The brake pedal stroke sensor 25 and the brake pedal depression force sensor 26 detect the stroke and the depression force of the brake pedal 24 by the driver, respectively. The vehicle speed sensor 81 detects the vehicle speed. The turn signal sensor 82 detects whether the direction indicator of the vehicle is lit, that is, whether it is lit. The window opening / closing switch 83 detects the opening / closing state of each window of the vehicle. The shift sensor 84 detects the position of the shift lever. The raindrop sensor 85 detects the amount of rainfall. The steering sensor 86 detects a steering angle and a steering angular velocity. Each sensor is connected so that a detection result can be transmitted to the brake ECU 70. Each sensor transmits a detection result to the brake ECU 70 periodically (for example, in a calculation cycle of the brake ECU 70).

  The microphone 87 and the speaker 88 are connected to the multimedia ECU 80. The multimedia ECU 80 is connected to the brake ECU 70 so that signals can be transmitted and received. The microphone 87 detects the utterance volume level of the driver. The multimedia ECU 80 transmits a signal indicating the utterance volume level of the driver to the brake ECU 70. The microphone 87 detects environmental sounds such as road noise during traveling. The multimedia ECU 80 transmits a signal indicating the environmental sound to the brake ECU 70. Further, the multimedia ECU 80 transmits a signal indicating the sound volume level output from the speaker 88 to the brake ECU 70. The speaker 88 is, for example, a speaker of an audio system provided in the vehicle.

  In the brake control device shown in FIG. 3, the regulator cut valve 65 can be one of the main operating noise sources. One reason is that the accumulator 35 is connected to the regulator 33 as a high pressure source. For this reason, the situation where the high pressure of the accumulator 35 acts also on the regulator cut valve 65 downstream of the regulator 33 may occur. Further, for example, in the case of adopting brake assist that utilizes hydraulic fluid supply from the regulator 33 during sudden braking, it is preferable to increase the flow rate of the regulator cut valve 65. As a result, the target activation current Az of the regulator cut valve 65 tends to increase, and when the normal valve closing current profile is used, there is a possibility that the operation noise when the regulator cut valve 65 is closed becomes large. Therefore, in this embodiment, a current profile for reducing operating noise is selected only for the regulator cut valve 65 according to the determination result.

  FIG. 5 is a flowchart for explaining a control process according to an embodiment of the present invention. In this process, the brake ECU 70 determines whether or not the brake responsiveness is allowed to be relaxed from the required specification, and selects either the first current profile or the second current profile according to the determination result. To do. The brake ECU 70 supplies a control current to the regulator cut valve 65 according to the selected current profile. For other control valves including the master cut valve 64, the brake ECU 70 supplies a control current according to an individual current profile adjusted for each control valve.

  For example, the brake ECU 70 may adjust the valve closing speed of the regulator cut valve 65 so that the regulator cut valve 65 is closed more slowly than the master cut valve 64. In this case, for example, the brake ECU 70 may execute current smoothing control on both the master cut valve 64 and the regulator cut valve 65. The annealing time of the second current profile of the regulator cut valve 65 may be set longer than the annealing time of the master cut valve 64. The annealing time of the first current profile of the regulator cut valve 65 may be set equal to the annealing time of the master cut valve 64. In this way, the control responsiveness of the regulator cut valve 65 is normally made equal to that of the master cut valve 64, while the regulator cut valve 65 can be gently closed when priority is given to reducing operating noise. .

  In the current profile selection processing shown in FIG. 5, the first current profile is a current profile that is adjusted so that the regulator cut valve 65 is closed within the valve closing time that meets the required specification of the brake response. . The second current profile is a current profile that is adjusted so as to reduce the operation sound when the regulator cut valve 65 is closed as compared with the first current profile. The first current profile may be, for example, the current profile shown in FIG. The second current profile may be, for example, the current profile shown in FIG. Each of the first current profile and the second current profile is preset and stored in the brake ECU 70.

  Each of the first current profile and the second current profile may include a variable parameter that is changed according to the vehicle environment including the detection result of the detection system described above, for example. This variable parameter includes, for example, the above-described annealing current and annealing time. Each of the first current profile and the second current profile may be a current profile shown in FIG.

  If the brake ECU 70 determines that the brake response is allowed to be relaxed from the required specification, the brake ECU 70 selects the second current profile and supplies the control current according to the second current profile to the regulator cut valve 65. To do. On the other hand, when the brake ECU 70 determines that the brake responsiveness satisfying the required specifications should be realized, the brake ECU 70 selects the first current profile and supplies the control current according to the first current profile to the regulator cut valve 65. In other words, the brake ECU 70 normally supplies a control current according to the first current profile, and only when it is determined that a decrease in control responsiveness is permitted, the brake current is changed according to the second current profile instead of the first current profile. Supply.

  The process shown in FIG. 5 is started when the brake ECU 70 detects the occurrence of a braking request. For example, when the operation of the brake pedal 24 by the driver is detected, the brake ECU 70 starts the process shown in FIG. The brake ECU 70 executes this processing periodically (for example, at the calculation cycle of the brake ECU 70) during braking, for example. The brake ECU 70 may repeatedly execute this process until at least the regulator cut valve 65 is confirmed to be closed.

  When this process is started, the brake ECU 70 determines whether or not the vehicle is stopped (S10). The brake ECU 70 determines whether the vehicle is stopped based on the output of the vehicle speed sensor 81, for example. It should be prioritized to achieve high brake responsiveness when the vehicle is moving, but high brake responsiveness is not necessarily required when the vehicle is stopped.

  Therefore, if the brake ECU 70 determines that the vehicle is stopped (Yes in S10), the brake ECU 70 selects the second current profile described above (S12). In this case, the brake ECU 70 determines that a decrease in the control response of the regulator cut valve 65 is allowed. In this case, the brake ECU 70 gives a control current to the regulator cut valve 65 according to the selected second current profile.

  On the other hand, if the brake ECU 70 determines that the vehicle is moving (No in S10), the brake ECU 70 selects the first current profile (S14). In this case, the brake ECU 70 determines that the regulator cut valve 65 should be closed with normal control responsiveness. In the present embodiment, the annealing current value of the first current profile is a variable parameter that is adjusted using the detection result of the detection system. Therefore, the brake ECU 70 adjusts the smoothing current of the first current profile based on the input from each sensor of the detection system (see FIG. 4) (S16). The annealing current adjustment process will be described later with reference to FIG. Then, the brake ECU 70 supplies a control current to the regulator cut valve 65 according to the first current profile.

  When the current profile to be applied to the regulator cut valve 65 is selected as described above, the current profile selection process shown in FIG. 5 ends. The brake ECU 70 performs the current profile selection process again at the next execution timing. Therefore, for example, when the vehicle starts moving after the second current profile is selected in the first current profile selection process, the first current profile is selected in the second current profile selection process. That is, when the vehicle starts moving after the second current profile is selected, the brake ECU 70 switches from the second current profile to the first current profile. As described above, when the vehicle moves during the current smoothing control, the control is switched to the normal control, so that the brake response is ensured.

  FIG. 6 is a flowchart for explaining an example of variable parameter adjustment processing of the current profile. FIG. 6 shows an example of a process for adjusting the annealing current of the first profile. It is possible to adjust the annealing current of the second profile in the same manner, and it is also possible to adjust the annealing times of the first and second profiles in the same manner.

  The smoothing current adjustment process shown in FIG. 6 is executed by the brake ECU 70 after the first current profile is selected as shown in FIG. 5 (S16 in FIG. 5). First, the brake ECU 70 performs the annealing current adjustment based on the vehicle speed (S20). The brake ECU 70 calculates a current addition amount corresponding to the vehicle speed and adds the current addition amount to the initial value of the smoothing current to adjust the smoothing current based on the vehicle speed. The initial value of the annealing current may be equal to the annealing current value of the second current profile, for example. During high-speed driving, it is difficult for the driver to sense the control valve operating sound due to the driving sound. Therefore, the smoothing current value may be increased as the vehicle speed increases, and control valve responsiveness during high-speed traveling may be prioritized over operating noise reduction.

The brake ECU 70 obtains a smoothing current adjustment value A1 based on the vehicle speed, for example, by the following equation.
A1 = A0 + (Az−A0) α
Here, A0 is an initial value of the annealing current, Az is a target starting current of the control valve, and α is a coefficient of 0 or more and 1 or less. The amount of current addition corresponding to the coefficient α is added to the initial value A0, and an adjusted smoothed current value A1 is obtained.

The coefficient α varies according to the vehicle speed, for example, as in the following equation.
α = 1− (X−V) / X
Here, V is a vehicle speed and X is a reference upper limit speed. The coefficient α = 0 when the vehicle speed V = 0, and the coefficient α = 1 when the vehicle speed V = X, and the coefficient α increases linearly from 0 to 1 as the vehicle speed V increases from zero to X. When the vehicle speed V exceeds the reference upper limit speed X, the coefficient α is set to 1. In this way, the smoothing current value can be increased as the vehicle speed increases.

  After the smoothing current adjustment based on the vehicle speed, the brake ECU 70 performs the smoothing current adjustment based on the environmental sound (S22). The brake ECU 70 calculates the current addition amount based on the environmental sound using the input from the detection system, and adds the initial value of the annealing current to adjust the smoothing current based on the environmental sound. Here, the initial value of the annealing current may be, for example, the annealing current adjustment value A1 based on the vehicle speed. When the environmental sound is loud, it is difficult for the driver to sense the control valve operating sound. Therefore, the smoothing current value may be increased as the environmental sound is increased, and the control valve response and the brake response may be prioritized over the operation noise reduction.

The brake ECU 70 obtains a smoothing current adjustment value A2 based on the environmental sound, for example, by the following equation.
A2 = A1 + β · S
Here, the coefficient β is a weighting coefficient, and S is an amount representing the magnitude of the environmental sound. The product β · S of both represents the amount of current addition based on the environmental sound. A quantity S representing the magnitude of the environmental sound is calculated by the brake ECU 70 based on the output of the detection system.

The amount S representing the loudness of the environmental sound is calculated as follows using, for example, the output volume level Sa of the speaker 88, the window open / closed degree Sb, the blinker lighting state Sc, and the rainfall Sd.
S = a · Sa + b · Sb + c · Sc + d · Sd
Here, coefficients a, b, c, and d are weighting coefficients.

  The speaker output volume level Sa is, for example, Sa = 0 when the volume level is below a predetermined threshold (for example, when there is no sound), Sa = 1 when the volume level exceeds the predetermined threshold, and linear interpolation is performed in the meantime. Good. The window opening / closing degree Sb may be calculated by obtaining the opening / closing degree of an individual window from the output of the window opening / closing switch 83 and summing or averaging the obtained opening / closing degrees of the windows. The degree of opening / closing of each window may be 0 when the window is completely closed, 1 when the window is fully open, and linear interpolation between them. The blinker lighting state Sc is obtained from the output of the blinker sensor 82. For example, Sc = 1 is set during lighting, and Sc = 0 is set during lighting off. The rainfall amount Sd is obtained from the output of the raindrop sensor 85. Sd = 0 may be set when the rainfall falls below a predetermined threshold, Sd = 1 may be set when the rainfall exceeds the predetermined threshold, and linear interpolation may be performed during that time. In this way, the value S increases as the environmental sound increases, and the annealing current value can be increased.

  Furthermore, the brake ECU 70 performs the smoothing current adjustment based on the driver's abnormal noise sensitivity (S24). The brake ECU 70 quantifies the driver's movement measured by the detection system as the driver's abnormal noise sensitivity. The brake ECU 70 calculates a current addition amount based on the driver's abnormal noise sensitivity and adds it to the initial value of the smoothed current. Thus, the smoothing current adjustment based on the driver's abnormal noise sensitivity is performed. Here, the initial value of the annealing current may be, for example, the annealing current adjustment value A2 based on the environmental sound. When the driver is performing a driving operation, the driver becomes insensitive to abnormal noise, and the driver is less likely to detect the control valve operating sound. Therefore, the smoothing current value may be increased so that the driver's sensitivity to abnormal noise is poor, and control valve response and therefore brake response may be prioritized over operating noise reduction.

The brake ECU 70 obtains the smoothing current adjustment value A3 based on the driver's abnormal noise sensitivity using, for example, the following equation.
A3 = A2 + γ · F
Here, the coefficient γ is a weighting coefficient, and F is an amount representing the driver's noise sensitivity. The product γ · F of both represents the amount of current addition based on the driver's noise sensitivity.

  The amount F representing the driver's noise sensitivity is calculated by the brake ECU 70 based on the output of the detection system. The amount F representing the driver's abnormal noise sensitivity is quantified so that the value becomes larger as the driver is less sensitive to abnormal noise, and the value becomes smaller as the driver is more sensitive to abnormal noise. Here, it is assumed that the driver is less sensitive to abnormal noise as the driver's operation amount or its change speed is larger, and the driver's abnormal sound sensitivity is digitized based on the driver's operation amount or its change speed.

The amount F representing the driver's noise sensitivity is calculated as follows using, for example, the driver's speech volume level Fa, the driver's steering speed Fb, and the driver's braking operation speed Fc.
F = a · Fa + b · Fb + c · Fc
Here, the coefficients a, b, and c are weighting coefficients. These weighting coefficients may naturally be different from the coefficients used when obtaining the quantity S representing the magnitude of the environmental sound.

  For example, the speech volume level Fa may be set to Fa = 0 when the volume level falls below a predetermined threshold (for example, when there is no sound), Fa = 1 when the volume level exceeds the predetermined threshold, and linear interpolation may be performed during that time. . The steering speed Fb is obtained from the steering angular speed detected by the steering sensor 86, for example. The steering speed Fb may be Fb = 0 when the steering angular speed is lower than a predetermined threshold, Fb = 1 when the steering angular speed is higher than the predetermined threshold, and linear interpolation may be performed during that time. The braking operation speed Fc is obtained from outputs of the pedal depression force sensor 26 and the stroke sensor 25. If it is determined that the driver is suddenly stepping on the brake pedal 24, Fc = 1, and if it is determined that the driver is not suddenly stepping, Fc = 0. In this way, the smoothing current value can be increased as the driver's sensitivity to abnormal noise becomes worse.

  In this way, the brake ECU 70 increases the smoothed current value when it is difficult for the driver to sense the operation sound using the detection result of the detection system. As a result, control valve response and brake response can be enhanced. In addition, instead of increasing the annealing current value, or increasing the annealing current value, the detection time of the detection system may be used to increase the annealing time.

  This raising process is also expressed as follows, for example. The detection system may include a first sensor and a second sensor having a measurement object different from the first sensor. The control unit may adjust the initial current of the first current profile based on the measurement result of the first sensor, and increase the adjusted initial current based on the measurement result of the second sensor. Thus, the control valve can be opened and closed more quickly by increasing the initial current.

  In FIG. 6, the smoothing current is adjusted in the order of the adjustment based on the vehicle speed, the adjustment based on the environmental sound, and the adjustment based on the noise sensitivity, but may be adjusted in a different order. In this case, as described above, the adjusted annealing current values may be sequentially raised. In FIG. 6, the three-step annealing current adjustment is performed, but one or two of the adjustments may be omitted.

  FIG. 7 is a diagram illustrating an example of the first current profile and the second current profile. In the first current profile shown in FIG. 7, the annealing current is adjusted by the above-described annealing current adjustment processing. The second current profile shown in FIG. 7 is, for example, the operating noise reduction current profile shown in FIG. In FIG. 7, the first current profile is indicated by a solid line, and the second current profile is indicated by a broken line.

  In the first current profile, energization is started as the brake is turned on, and the adjusted annealing current A3 described above is applied. Thereafter, the control current is linearly increased to the target activation current Az until the opening / closing operation completion time T1. The time T1 is a required time allowed for the opening / closing operation in the normal control, and is set based on the control response required for the control valve. After time T1, energization of the target starting current Az is continued during braking.

  As illustrated, the adjusted annealing current A3 may be larger than the actual starting current At. In this case, when the brake is turned on, the control current exceeds the actual starting current At and the open / close state of the control valve is changed. In contrast to this, the adjusted annealing current may be smaller than the actual starting current At. In this case, the open / close state of the control valve is changed while the control current is linearly increased to the target activation current Az until the open / close operation completion time T1. In any case, the open / close state of the control valve is changed by the open / close operation completion time T1. Thus, when the first current profile is selected, the open / close state of the control valve is changed by time T1, and the required brake response is realized in preference to the reduction of the operating noise.

  As described above, according to the present embodiment, in order to close the regulator cut valve 65 at the time of braking on, the first current profile giving priority to brake response is usually selected. When the brake response may be lowered, the second current profile giving priority to the reduction of the operating noise is selected. As a result, the driver's discomfort can be reduced by reducing the operating noise when the regulator cut valve 65 is closed while minimizing the influence on the brake response.

  In the first current profile, the annealing time is set based on the required responsiveness, and the annealing current value is raised from the initial value by the vehicle speed, the vehicle environmental sound, and the driver noise sensitivity. . For this reason, the regulator cut valve 65 is closed by the end of the smoothing time at the latest, and a good brake response is realized. Further, the braking response can be further increased by raising the annealing current value. On the other hand, when the vehicle speed, the vehicle environment sound, and the driver noise sensitivity are relatively small, the amount of increase in the smoothing current is also small. In this case, if the annealing current value is smaller than the actual starting current of the control valve, the control valve is opened and closed when the current is increased with a relatively small current increase gradient, so the opening / closing operation noise is small. Become. Thus, not only a good brake response is realized, but also a reduction in operating noise is realized according to the situation.

  In the second current profile, the annealing time is set longer than that in the first current profile. For this reason, the second current profile has a smaller current increase gradient than the first current profile, and the operation noise can be reduced during opening and closing. In addition, applying an annealing current as the energization starts contributes to reducing the current increase gradient to the target starting current. Since the second current profile is selected while the vehicle is stopped, the second current profile can be adjusted to a current profile that gives maximum consideration to the reduction of operating noise.

  By the way, the brake ECU 70 may adjust the operation timing of the brake pump 36 by using the environmental sound and the driver abnormal noise sensitivity described above. FIG. 8 is a flowchart for explaining an example of the adjustment process of the operation timing of the brake pump 36. This process can be executed independently of the control valve opening / closing control described above.

  The process shown in FIG. 8 is started, for example, when the vehicle is started and is repeated periodically. When the process is started, the brake ECU 70 determines whether or not the accumulator pressure Pacc is smaller than a predetermined pressure (S30). This predetermined pressure may be an accumulator lower limit pressure set as a value at which the operation of the brake pump 36 should be started, or may be a value set by adding a predetermined margin to the accumulator lower limit pressure. . By allowing the brake pump 36 to operate when the accumulator pressure becomes lower than the value set by adding a predetermined margin to the lower limit pressure of the accumulator, the accumulator pressure is applied with a margin before the accumulator pressure becomes sufficiently low. This is preferable in that the pressure can be maintained within a predetermined range.

  If it is determined that the accumulator pressure is greater than the predetermined pressure that is the determination criterion (No in S30), the brake ECU 70 ends the process. In this case, the accumulator pressure is sufficiently high and it is not necessary to operate the brake pump 36.

  On the other hand, when it is determined that the accumulator pressure is smaller than the predetermined pressure (Yes in S30), the brake ECU 70 calculates the driver pump sound tolerance R. The pump sound tolerance R is calculated using, for example, the above-described vehicle speed, environmental sound, and driver's abnormal noise sensitivity.

The pump sound tolerance R is calculated by the following equation, for example.
R = e · F + f · S + g · V
Here, e, f, and g are weighting factors, F is the driver's abnormal noise sensitivity, S is the environmental sound of the vehicle, and V is the vehicle speed.

  When this operation timing adjustment processing is executed together with the above-described operation valve opening / closing control processing, if the driver's abnormal noise sensitivity F, vehicle environmental sound S, and vehicle speed V acquired in the operation valve opening / closing control processing are used. Good. When only the operation timing adjustment process is executed, the driver's abnormal noise sensitivity F, the vehicle environmental sound S, and the vehicle speed V may be calculated, for example, by the above-described method.

  The brake ECU 70 determines whether or not the calculated pump sound tolerance R is larger than a predetermined value serving as a determination criterion (S34). This determination reference value can be determined experimentally as appropriate, for example, taking into account the discomfort that the pump operating sound gives to the driver. When it is determined that the pump sound tolerance R exceeds the reference (Yes in S34), the brake ECU 70 operates the brake pump 36 (S36). When it is determined that the pump sound tolerance R does not satisfy the standard (No in S34), the brake ECU 70 ends the process.

  Thus, according to this pump operation timing adjustment process, when the accumulator pressure becomes low, the brake pump 36 is operated on condition that the driver's pump sound tolerance R is higher than the reference. For this reason, the discomfort which a pump operation sound gives to a driver | operator can be reduced.

It is a figure which shows an example of the control current profile which concerns on one Embodiment of this invention. It is a figure which shows an example of the control current profile which concerns on one Embodiment of this invention. It is a distribution diagram showing a brake control device concerning one embodiment of the present invention. It is a figure showing typically composition of a control system concerning one embodiment of the present invention. It is a flowchart for demonstrating the control processing which concerns on one Embodiment of this invention. It is a flowchart for demonstrating an example of the process which concerns on one Embodiment of this invention. It is a figure which shows an example of the 1st current profile and 2nd current profile which concern on one Embodiment of this invention. It is a flowchart for demonstrating an example of the brake pump operation timing adjustment process which concerns on one Embodiment of this invention.

Explanation of symbols

  20 brake control device, 23 wheel cylinder, 27 master cylinder unit, 31 hydraulic booster, 32 master cylinder, 33 regulator, 34 reservoir, 60 separation valve, 64 master cut valve, 65 regulator cut valve, 66 pressure increase linear control valve, 67 pressure-reducing linear control valve, 70 brake ECU, 71 regulator pressure sensor, 72 accumulator pressure sensor, 73 control pressure sensor.

Claims (5)

A detection system including at least one sensor provided in association with the vehicle;
An electromagnetic control valve provided in a hydraulic circuit for controlling a braking force applied to the vehicle;
The electromagnetic control is performed by applying a control current according to a first current profile that is connected to the detection system so as to be able to receive an output from the detection system and is guaranteed to open and close the electromagnetic control valve with a required control response. A control unit for opening and closing the valve,
The control unit determines whether or not a decrease in control responsiveness of the electromagnetic control valve is allowed based on an output from the detection system, and when determining that a decrease in control responsiveness is allowed, Providing a control current to the electromagnetic control valve according to a second current profile adjusted to reduce operating noise of the electromagnetic control valve from the first current profile;
The second current profile is regulated such that an initial current applied at the start of energization of the electromagnetic control valve is adjusted to be smaller than the first current profile, and the open / close state of the electromagnetic control valve is guaranteed to be changed. The time required to reach the starting current is adjusted to be longer than the first current profile,
The brake control device according to claim 1, wherein the initial current of the second current profile is adjusted to a magnitude that ensures that the open / close state of the electromagnetic control valve is not changed. The detection system includes at least one sensor that detects a driver's movement;
The control unit acquires a driver's sensitivity to the operation sound of the electromagnetic control valve based on a detection result of the detection system, and adjusts the first current profile according to the acquired sensitivity. The brake control device according to claim 1. The detection system includes at least one sensor that detects environmental sound of the vehicle;
The said control part acquires the environmental sound of a vehicle based on the detection result of the said detection system, and adjusts a said 1st electric current profile according to the acquired environmental sound. Brake control device. An accumulator that stores high-pressure hydraulic fluid supplied to the hydraulic circuit, and a pump that pressurizes the hydraulic fluid of the accumulator in response to a control command from the control unit,
The detection system includes at least one sensor that detects a driver's movement;
The control unit determines whether or not the driver's sensitivity to the operation sound of the electromagnetic control valve is worse than a reference based on the detection result of the detection system, and operates the pump when it is determined that the sensitivity is poor The brake control device according to any one of claims 1 to 3, wherein An accumulator that stores high-pressure hydraulic fluid supplied to the hydraulic circuit, and a pump that pressurizes the hydraulic fluid of the accumulator in response to a control command from the control unit,
The detection system includes at least one sensor that detects environmental sound of the vehicle;
The control unit determines whether the environmental sound of the vehicle is in a state exceeding a reference based on a detection result of the detection system, and operates the pump when it is determined that the reference sound exceeds the reference. The brake control device according to any one of claims 1 to 3.

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