JP2011073664A - Vehicular brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a sense of incongruity during deceleration, which is produced when a low skilled driver brakes. <P>SOLUTION: This vehicular brake device includes a reduced speed computing part 11 for sequentially computing a target value for a speed reduction from a brake-starting owned vehicle speed as the speed of an owned vehicle detected by a vehicle speed sensor 5 at starting braking operation, on the basis of the stroke of a brake pedal 2 sequentially detected by a stroke sensor 6, and a required deceleration computing part 13 for sequentially computing a required deceleration as a necessary deceleration for actualizing a target speed, on the basis of the target speed as the difference between the brake-starting owned vehicle speed and the target value for the speed reduction and a current owned vehicle speed as the current speed of the owned vehicle sequentially detected by the vehicle speed sensor 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a brake-by-wire vehicle brake device.

  2. Description of the Related Art Conventionally, brake devices that generate deceleration and decelerate a vehicle are known. For example, a brake device generally used in a vehicle is a hydraulic brake device that connects a brake pedal and a wheel brake using the hydraulic pressure of the brake oil, and mechanically transmits a signal from the brake pedal to the wheel brake. By doing so, the vehicle is decelerated by generating a deceleration corresponding to the pedal position of the brake pedal.

  In recent years, part or all of the connection between the brake pedal and the wheel brake is electrically performed instead of mechanically, and part or all of the signal transmission from the brake pedal to the wheel brake is performed by an electrical signal. 2. Description of the Related Art Brake-by-wire brake devices that generate braking force or deceleration using pedal stroke and pedal reaction force of a brake pedal operated by a driver as input information have been known.

  The brake-by-wire brake device is characterized in that a part of or all of the signal transmission from the brake pedal to the wheel brake is performed by an electric signal, so that free braking force and deceleration can be generated by electronic control. However, the conventional brake-by-wire type brake device aims to maintain the same feeling as that of the hydraulic brake device, and has not been able to make full use of this feature that a free braking force can be generated.

  On the other hand, for example, in Patent Document 1, an invalid pedaling force and hysteresis are provided in the relationship between the pedaling force and the vehicle output or the vehicle output command, and the relationship between the pedaling force and the vehicle output or the vehicle output command in the stepping and releasing operations. A technique is disclosed that can generate deceleration or braking force in consideration of fluctuation characteristics of pedal force by making the vehicle output or vehicle output command with respect to the pedal force have a certain gradient even in holding operation. ing.

  Further, for example, in Patent Document 2, when a pedaling force detected by a pedaling force detector that calculates a pedaling force based on an operation amount of a pedal and detects a pedaling force is equal to or more than the calculated pedaling force, based on the detected pedaling force. When the braking force is determined and the pedaling force detected by the pedaling force detector is smaller than the calculated pedaling force, the braking force is determined based on the calculated pedaling force, so that even when the pedal operation timing or speed changes. A technique that enables a stable braking force to be generated is disclosed.

  Further, for example, in Patent Document 3, in a panic braking situation where the driver hesitates to step on the pedal with the maximum force, the brake pressure booster is adjusted electronically to increase the boosting action, thereby increasing the normal braking force. There is disclosed a technique for securing a high deceleration by realizing a wheel cylinder pressure larger than a wheel cylinder pressure applied to the wheel cylinder in pedal depression force.

JP 2006-281810 A JP 2008-2222027 A JP 7-89432 A

  When braking by a driver with low driving skill, the speed change immediately before stopping the vehicle is too steep and the vehicle body pitches when the wheel stops rotating. Often ends up becoming. On the other hand, the technique disclosed in Patent Document 1 is intended to output a vehicle output in consideration of the pedaling force variation characteristics, and is a deceleration according to the pedaling force by electronic control. It only changes the generation gain. Further, the technique disclosed in Patent Document 2 is intended to generate a stable braking force even when the pedal operation timing, speed, or the like changes. The deceleration is merely determined by a graph (map) showing the relationship. Furthermore, the technique disclosed in Patent Document 3 is intended to ensure a high deceleration in a panic braking situation, and doubles the brake pressure booster when a certain brake pedal depression force is exerted. The force action is only increased by electronic control.

  As described above, the conventional technology is not intended to reduce the uncomfortable feeling caused by the brake operation by the driver with the low driving skill, and therefore reduces the uncomfortable feeling during the deceleration caused by the brake operation by the driver with the low driving skill. Had the problem of being difficult.

  The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide a brake-by-wire brake that makes it possible to further reduce discomfort during deceleration caused by a brake operation by a driver with low driving skill. To provide an apparatus.

  According to the vehicle brake device of the first aspect, based on either the stroke amount of the brake pedal or the pedaling force on the brake pedal, the vehicle speed from the vehicle operation start point (that is, the vehicle speed at the start of the brake) is determined. Calculate the target value for the speed drop. And since the target speed which is the difference of the own vehicle speed at the time of a brake start and the target value for the said speed fall can be obtained, the deceleration control based on a target speed is attained.

  In addition, when a driver with a high driving skill decelerates to a target speed, the driver should imagine what kind of deceleration should be generated in order to smoothly decelerate, and make it proportional to the imaged deceleration. Since the brake operation is performed, it is possible to smoothly decelerate to the target speed. On the other hand, when a driver with low driving skill decelerates to the target speed, he / she performs a constant brake operation until the target speed is reached, and then returns the brake pedal when the target speed is reached or until the target speed is reached. Since the brake operation amount is gradually increased and the brake pedal is returned when the target speed is reached, it is not possible to smoothly decelerate to the target speed.

  According to the configuration of the first aspect, since the target speed is sequentially obtained, it is also possible to sequentially obtain the required deceleration, which is a deceleration necessary to match the current host vehicle speed with the target speed. According to the configuration of claim 1, since it is possible to sequentially decelerate at a deceleration according to the required deceleration, the driver can achieve the target even if the driver does not delicately operate the brake pedal. It is possible to smoothly decelerate to the speed to be performed. Therefore, according to the structure of Claim 1, even if it is a driver with a low driving technique, it becomes possible to smoothly decelerate to a target speed. Therefore, according to the configuration of the first aspect, it is possible to further reduce the uncomfortable feeling during deceleration caused by the brake operation by the driver with low driving skill.

  Further, according to the vehicle brake device of the second aspect, the required deceleration required for adjusting the current vehicle speed to the target speed can be obtained. Therefore, the deceleration according to the required deceleration is performed by the brake by wire. Thus, the driver can smoothly decelerate to a target speed without performing a delicate operation of the brake pedal.

  Furthermore, according to the configuration of claim 2, the required deceleration required for realizing the target speed determined based on either the stroke amount of the brake pedal once operated by the driver or the pedaling force on the brake pedal is output. Therefore, even if the road surface gradient changes suddenly or gently toward the downhill, the target speed can be maintained. Specifically, when the road gradient changes downward and acceleration occurs, and the vehicle speed exceeds the target speed, the brakes will be decelerated according to the required deceleration required to achieve the target speed. , You can continue to maintain the target speed.

  Therefore, according to the above configuration, the driver can easily continue to maintain the target speed without adjusting the increase / decrease of the deceleration by increasing / decreasing the brake pedal according to the road gradient. Become. For example, according to the above configuration, the target speed on the flat road can be maintained even if the brake pedal enters a downward slope while keeping the operation amount of the brake pedal constant.

  According to the vehicle brake device of the third aspect, part of the signal transmission from the brake pedal to the wheel brake is performed by an electrical signal, and part of the signal transmission is reduced by a hydraulic pressure corresponding to the pedaling force on the brake pedal. Since it is performed via the hydraulic unit that generates the speed, it is possible to perform deceleration according to the required deceleration by brake-by-wire. Therefore, even with the configuration of claim 3, it is possible to further reduce the uncomfortable feeling during deceleration caused by the brake operation by the driver with low driving skill.

  According to the fourth aspect of the present invention, the hydraulic unit is prohibited from operating from the initial position of the brake pedal to a predetermined stroke, so that signal transmission from the brake pedal to the wheel brake is performed by an electrical signal. Thus, at least from the initial position of the brake pedal to a predetermined stroke, the same effect as that of the structure of claim 3 can be expected.

  Furthermore, according to the configuration of claim 4, if the driver depresses the brake pedal strongly in an emergency and the brake pedal becomes a stroke area after a predetermined stroke, the deceleration is reduced by the hydraulic pressure corresponding to the depression force of the brake pedal. Emergency braking is possible by the generated hydraulic unit.

  Further, when the driver depresses the brake pedal continuously from the initial position, a transition is made from the initial position to a predetermined stroke after the predetermined stroke. At this time, according to the configuration of the fourth aspect, after the predetermined stroke, the required deceleration is output when the required deceleration is larger than the deceleration generated by the hydraulic pressure corresponding to the depression force on the brake pedal, If the required deceleration is not larger than the deceleration generated by the hydraulic pressure corresponding to the pedaling force on the brake pedal, the vehicle will decelerate at the deceleration generated by the hydraulic pressure. There is no speed discontinuity, and continuous deceleration increases are possible.

  According to the vehicle brake device of the fifth aspect, the hydraulic unit limiting means is connected in series to the hydraulic unit so that the pedaling force on the brake pedal after a predetermined stroke can be mechanically transmitted to the hydraulic unit. Therefore, even if there is a failure or malfunction in the mechanism that performs signal transmission from the brake pedal to the wheel brake using an electrical signal, the brake pedal will It becomes a stroke area after the stroke, and it becomes possible to mechanically transmit the depression force to the brake pedal to the hydraulic unit. Therefore, according to the configuration of claim 5, even when there is a failure or malfunction in the mechanism that performs signal transmission from the brake pedal to the wheel brake by an electric signal, the vehicle can be braked by the hydraulic unit. Safety is further improved.

  According to the vehicle brake device of the sixth aspect, the value of the required deceleration output from the required deceleration calculating means is greater than the deceleration generated by the hydraulic pressure in the hydraulic unit corresponding to the depression force on the brake pedal. When it becomes larger, signal transmission from the brake pedal to the wheel brake is performed by an electric signal. Therefore, according to the above configuration, when at least the value of the required deceleration output from the required deceleration calculating means is greater than the deceleration generated by the hydraulic pressure in the hydraulic unit according to the pedaling force on the brake pedal. Can be expected to have an effect of further reducing the uncomfortable feeling during deceleration caused by a brake operation by a driver with low driving skill.

  On the other hand, when the driver depresses the brake pedal strongly in an emergency, the deceleration generated by the fluid pressure in the fluid pressure unit corresponding to the depression force on the brake pedal is greater than the requested deceleration output from the requested deceleration calculation means. In this case, the emergency braking can be performed by the hydraulic unit that generates the deceleration by the hydraulic pressure corresponding to the depression force of the brake pedal.

  According to the vehicle brake device of the seventh aspect, the calculation of the required deceleration is performed by a simple mathematical expression (Equation (1)) for obtaining the required deceleration necessary for adjusting the current host vehicle speed to the target speed. Therefore, it is possible to more easily realize a brake-by-wire vehicular brake device that makes it possible to further reduce the uncomfortable feeling during deceleration caused by a brake operation by a driver with low driving skill.

  Further, according to the vehicle brake device of the eighth aspect, a simple mathematical expression ((2) for obtaining the required deceleration required to match the current host vehicle speed with the target speed that reaches the target value of the speed decrease after t seconds. Since the required deceleration can be calculated with the formula ()), the brake-by-wire vehicle brake device that makes it possible to further reduce the uncomfortable feeling during deceleration caused by the brake operation by a driver with low driving skills is easier. Can be realized.

  Further, according to the configuration of claim 9, when the target speed becomes a negative value, the target speed is set to 0, and the required deceleration is calculated by the formula shown in the formula (2). The requested deceleration output due to the difference from the current vehicle speed converges to zero. Therefore, according to the above configuration, when the vehicle is stopped, the vehicle is smoothly decelerated toward the vehicle speed 0, and the cuckling brake at the time of stopping can be satisfactorily eliminated.

  According to the vehicle brake device of claim 10, when the driver completely returns the brake pedal and the stroke returns to the initial position, the output of the requested deceleration from the requested deceleration calculating means is stopped. The driver can obtain the same feeling as the brake device.

1 is a block diagram illustrating an example of a schematic configuration of a vehicle brake device 100. FIG. 2 is a block diagram illustrating an example of a schematic configuration of a control device 1. FIG. (A)-(c) is a figure explaining an action limiting mechanism. It is a figure explaining an example of the difference between the brake operation of a driver with high driving skill and the brake operation of a driver with low driving skill. It is a figure explaining an example of brake operation of a driver with low driving technology. It is a figure explaining an example of brake operation of a driver with high driving technology. It is a figure which shows an example of the relationship between the stroke amount of the brake pedal 2, the time change of the present own vehicle speed and target speed, and the time change of request | requirement deceleration. It is a figure which shows an example of the relationship between the stroke amount of the brake pedal 2, the time change of the present own vehicle speed and target speed, and the time change of request | requirement deceleration. It is a figure explaining an example of the method of determination of target speed. It is a figure which shows an example of the relationship between the stroke amount of the brake pedal 2, the time change of the present own vehicle speed and target speed, and the time change of request | requirement deceleration. (A)-(c) is a figure explaining the relationship between the brake pedal 2 and the hydraulic unit 3 in the modification 1. FIG. It is a figure which shows an example of the relationship between the stroke amount of the brake pedal 2, the time change of the present own vehicle speed and target speed, and the time change of deceleration. It is a figure which shows an example of the relationship between the time change of the stroke amount of the brake pedal 2, when the brake pedal 2 is stepped on, the present vehicle speed and the target speed, and the time change of the deceleration. It is a figure which shows an example of the relationship between the time change of the stroke amount of the brake pedal 2, when the brake pedal 2 is stepped on, the present vehicle speed and the target speed, and the time change of the deceleration. It is a figure which shows an example of the relationship between the time variation | change_quantity of the stroke amount of the brake pedal 2, when the brake pedal 2 depresses, the present vehicle speed and target speed, and the time change of deceleration. It is a figure which shows an example of the relationship between the time variation | change_quantity of the stroke amount of the brake pedal 2, when the brake pedal 2 depresses, the present vehicle speed and target speed, and the time change of deceleration. It is a figure explaining an example of the method of determination of the target speed when there is a stepping-up operation or stepping-back operation of the brake pedal. It is a figure which shows an example of the relationship between the time change of the stroke amount of the brake pedal 2 in case a vehicle stops, the present own vehicle speed and target speed, and the time change of deceleration. It is a figure which shows an example of a structure in case the rotation resistance at the time of the electric power generation of an electric motor is utilized as a braking force of a vehicle.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an example of a schematic configuration of a vehicle brake device 100 to which the present invention is applied. A vehicle brake device 100 shown in FIG. 1 is mounted on a vehicle, and includes a brake pedal 2, a hydraulic unit 3, a wheel brake 4, a vehicle speed sensor 5, a stroke sensor 6, a brake actuator 7, and a control device 1. I have. Hereinafter, a vehicle equipped with the vehicle brake device 100 is referred to as a host vehicle.

  The brake pedal 2 is a pedal that the user steps on when operating the brake. The hydraulic unit 3 converts the pedaling force on the brake pedal 2 into a hydraulic pressure such as a hydraulic pressure and transmits the hydraulic pressure to the wheel brake 4. For example, the hydraulic unit 3 includes a booster (boost device) 31 and a master cylinder 32. The boosting force applied to the brake pedal 2 is amplified by the booster 31 and transmitted to the master cylinder 32, and the hydraulic pressure corresponding to the transmitted pedaling force is transmitted. It is generated in the brake fluid of the master cylinder 32 and transmitted to the wheel brake 4.

  In the present embodiment, the vehicular brake device 100 has a mechanism that prevents the hydraulic unit 3 from operating from the initial position of the brake pedal 2 to a predetermined stroke (hereinafter referred to as an operation limiting mechanism). It shall be provided. The details of the operation limiting mechanism will be described later.

  The wheel brake 4 is a brake provided on the wheel of the host vehicle, such as a disc brake or a drum brake, and brakes the host vehicle. For example, when the wheel brake 4 is a disc brake, the brake pad incorporated in the disc caliper is pressed against the disc rotor rotating together with the wheel by the hydraulic pressure transmitted from the hydraulic unit 3 to brake the vehicle. I do. When the wheel brake 4 is a drum brake, the vehicle is braked by pressing the brake shoe against the inside of the cylindrical drum that rotates together with the wheel by the hydraulic pressure transmitted from the hydraulic unit 3.

  Furthermore, the wheel brake 4 can also perform braking by the action of a brake actuator 7 described later. The configuration in which braking is performed by the action of the brake actuator 7 may be a configuration in which braking is performed by operating a disk caliper or a brake shoe by the hydraulic pressure from the pump motor of the brake actuator 7. A configuration may be adopted in which braking is performed by operating a disk caliper or a brake shoe by driving a motor.

  The vehicle speed sensor 5 is a sensor that sequentially detects the speed of the host vehicle by detecting a signal corresponding to the rotational speed of the wheel of the host vehicle. Therefore, the vehicle speed sensor 5 corresponds to the vehicle speed detection means in the claims. The stroke sensor 6 is a sensor that detects the depression amount of the brake pedal 2 by the driver of the host vehicle by detecting the stroke position of the brake pedal 2. Therefore, the stroke sensor 6 corresponds to the pedal-related amount detection means in the claims. In the present embodiment, the configuration in which the stroke sensor 6 is used as a sensor for detecting the depression amount of the brake pedal 2 is shown, but the present invention is not necessarily limited thereto. For example, as a sensor for detecting the depression amount of the brake pedal 2, a sensor other than the stroke sensor 6 such as an optical sensor for detecting the depression amount of the brake pedal 2 by detecting the distance between the brake pedal 2 and the floor may be used. Good.

  The brake actuator 7 causes the wheel brake 4 to perform braking in accordance with an instruction from the control device 1. The brake actuator 7 may be provided with a pump motor so that braking by the wheel brake 4 is performed by the hydraulic pressure from the pump motor as described above, or the wheel brake 4 is driven by driving the motor. It is also possible to perform braking.

  The control device 1 is configured as a normal computer, and includes a well-known CPU, ROM, RAM, I / O, and a bus line (all not shown) for connecting these configurations. The control device 1 executes processing related to deceleration of the host vehicle based on various signals (that is, various information) input from the vehicle speed sensor 5 and the stroke sensor 6.

  Next, a schematic configuration of the control device 1 will be described with reference to FIG. FIG. 2 is a block diagram illustrating an example of a schematic configuration of the control device 1. As shown in FIG. 2, the control device 1 includes a decrease speed calculation unit 11, a target speed calculation unit 12, a required deceleration calculation unit 13, an output determination unit 14, and a deceleration control unit 15.

  Based on the sensor signal input from the stroke sensor 6 and the sensor signal input from the vehicle speed sensor 5, the decrease speed calculation unit 11 determines the speed of the host vehicle at the start of the brake operation (hereinafter referred to as the host vehicle speed at the start of the brake). ) Sequentially calculates the target value for the current speed drop from). Therefore, the reduction speed calculation unit 11 corresponds to a reduction speed calculation means in the claims. Specifically, based on the stroke amount detected by the stroke sensor 6 and the vehicle speed at the start of braking detected by the vehicle speed sensor 5, a predetermined mathematical formula that satisfies the linear relationship between the stroke amount and the value of the speed reduction is obtained. By calculating, for example, a target value for a speed decrease from the vehicle speed at the start of braking corresponding to the stroke amount of the brake pedal 2 corresponding to the stroke amount is calculated. The determination of the brake operation start time may be configured such that, for example, the reduction speed calculation unit 11 determines the time when the stroke sensor 6 starts detecting a stroke amount larger than 0 as the brake operation start time. Then, the speed reduction unit 11 may handle the speed of the host vehicle detected by the vehicle speed sensor 5 at the start of the brake operation as the host vehicle speed at the start of the brake. Further, the speed from the vehicle speed at the start of the brake corresponding to the stroke amount of the brake pedal 2 corresponding to the stroke amount by using, for example, a map or a table in which the stroke amount and the value for the speed decrease are associated with each other. It is good also as a structure which calculates the target value of a fall part.

  In the present embodiment, from the vehicle speed at the start of braking according to the stroke amount of the brake pedal 2 based on the stroke amount detected by the stroke sensor 6 and the vehicle speed at the start of braking detected by the vehicle speed sensor 5. Although the configuration for calculating the target value for the speed decrease is shown, it is not necessarily limited thereto. For example, on the basis of the pedaling force detected by the pedaling force sensor that detects the pedaling force on the brake pedal 2 from the driver and the vehicle speed at the start of braking detected by the vehicle speed sensor 5, It is good also as a structure which calculates the target value for the speed fall from a vehicle speed. In this case, the pedal force sensor corresponds to the pedal-related amount detection means in the claims.

  In the present embodiment, a configuration is shown in which the target value for the speed decrease from the vehicle speed at the start of the brake is calculated based on the stroke amount, the pedal effort and the vehicle speed at the start of the brake. Not exclusively. For example, the target value for the speed decrease from the vehicle speed at the start of the brake may be calculated by calculating the target value for the speed decrease as a simple change amount based on the stroke amount and the pedal effort. In this case, the sensor signal from the vehicle speed sensor 5 is input to the target speed calculation unit 12 instead of the reduction speed calculation unit 11, and the speed of the host vehicle detected by the vehicle speed sensor 5 at the start of the brake operation is set at the start of braking. What is necessary is just to set it as the structure which the below-mentioned target speed calculating part 12 handles as the own vehicle speed.

  The target speed calculation unit 12 calculates the difference between the vehicle speed at the start of braking used for the processing in the reduction speed calculation unit 11 and the target value for the speed reduction calculated by the reduction speed calculation unit 11, and the difference is set as the target. Calculate sequentially as speed. Based on the target speed calculated by the target speed calculation unit 12 and the current speed of the host vehicle detected by the vehicle speed sensor 5 (hereinafter referred to as the current host vehicle speed), the required deceleration calculation unit 13 The deceleration required to realize the speed (hereinafter referred to as the required deceleration) is sequentially calculated from the following equation (1). Therefore, the required deceleration calculating unit 13 corresponds to the required deceleration calculating means. In equation (1), the constant Ta is a divisor for converting the difference between the target speed and the current host vehicle speed into the required deceleration, and is set as appropriate. Although the constant is represented as Ta here, it may be represented as Td. Further, in the equation (1), the target value for the current speed reduction is expressed as Vt, the own vehicle speed at the start of braking is expressed as Vs, the current own vehicle speed is expressed as Vs0, and the required deceleration is expressed as G. Note that Vt = f (stroke amount of the brake pedal 2), that is, Vt is a variable that changes according to the stroke amount of the brake pedal 2. Further, when the target value for the current speed reduction is calculated based on the pedaling force instead of the stroke amount, Vt = f (the pedaling force on the brake pedal 2).

  In the present embodiment, the required deceleration calculation unit 13 calculates the required deceleration by subtracting the current host vehicle speed from the target speed calculated by the target speed calculation unit 12 and dividing by the constant Ta. However, this is not necessarily the case. For example, the target speed calculation unit 12 is not provided, and the requested deceleration calculation unit 13 subtracts the current vehicle speed detected by the vehicle speed sensor 5 from the vehicle speed at the start of braking used for the processing in the decrease speed calculation unit 11. After that, the requested deceleration may be calculated by further subtracting the target value for the current speed decrease calculated by the decrease speed calculation unit 11 and dividing by the constant Ta.

  Based on the sensor signal of the stroke sensor 6, the output determination unit 14 determines whether the stroke position of the brake pedal 2 is in a stroke region from the initial position of the brake pedal 2 to a predetermined stroke, or in a stroke region after the predetermined stroke. Determine if there is. When it is determined that the stroke position is in the stroke region from the initial position of the brake pedal 2 to a predetermined stroke, the requested deceleration calculated by the requested deceleration calculating unit 13 is output to the deceleration control unit 15.

  On the other hand, when it is determined that the stroke position is in a stroke area after a predetermined stroke, the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3 (that is, by the hydraulic pressure corresponding to the pedaling force on the brake pedal). The output determination unit 14 estimates the generated deceleration), and compares the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3 with the requested deceleration calculated by the requested deceleration calculation unit 13. When the required deceleration is larger than the deceleration generated by the braking by the wheel brake 4 via the hydraulic unit 3 (that is, the deceleration generated by the braking by the wheel brake 4 via the hydraulic unit 3). When the absolute value of the requested deceleration is greater than the absolute value of the required deceleration), the requested deceleration calculated by the requested deceleration calculating unit 13 is output to the deceleration control unit 15. Therefore, the output determination part 14 is equivalent to the output determination means of a claim. If the requested deceleration is not larger than the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3, the requested deceleration calculated by the requested deceleration calculating unit 13 is controlled to be reduced. Does not output to unit 15. When the stroke position is after a predetermined stroke and the requested deceleration calculated by the requested deceleration calculation unit 13 is not output to the deceleration control unit 15, braking by the wheel brake 4 via the hydraulic unit 3 is performed. The host vehicle is decelerated due to the deceleration generated in step (b).

  Note that the estimation by the output determination unit 14 of the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3 occurs, for example, by braking by the wheel brake 4 via the stroke amount and pedaling force and the hydraulic unit 3. What is necessary is just to make it the structure performed by using the map which matched previously the deceleration to perform.

  The deceleration control unit 15 sends a control signal for causing the brake actuator 7 to perform a drive that generates a deceleration according to the requested deceleration output from the requested deceleration calculating unit 13. When the brake actuator 7 is driven in accordance with this control signal, a braking force corresponding to the required deceleration calculated by the required deceleration calculating unit 13 is generated, and a deceleration corresponding to the braking force is generated. The host vehicle is decelerated until

  Note that when the stroke position is in the stroke region from the initial position of the brake pedal 2 to a predetermined stroke, the hydraulic unit 3 is restricted from being operated by the operation restriction mechanism as described above. The deceleration by the wheel brake 4 via the pressure unit 3 does not occur, and the deceleration according to the requested deceleration calculated by the requested deceleration calculating unit 13 is performed via the deceleration control unit 15.

  Here, the operation limiting mechanism will be described with reference to FIGS. 3 (a) to 3 (c). Fig.3 (a)-FIG.3 (c) are the figures explaining an action | operation limitation mechanism. The brake pedal 2 is provided with a tension spring 91 that returns the brake pedal 2 to the initial position. Further, as shown in FIG. 3A, a push rod 92 is provided between the hydraulic pressure unit 3 including the booster (boost device) 31 and the master cylinder 32 and the brake pedal 2. The push rod 92 is divided into two parts in the axial direction, and one of the divided parts is connected to the brake pedal 2 and the other part is arranged so as to contact the booster 31 of the hydraulic unit 3. ing. Further, the push rod 92 is provided with a stopper 93 at each end portion of each of the two divided members. Further, when the brake pedal 2 is in the initial position, the push rod 92 is provided such that a predetermined interval is provided between the stoppers 93 of the respective members described above, as shown in FIG. Further, the predetermined interval is set at the end of each member as shown in FIG. 3B when the user performs a brake operation on the brake pedal 2 and the stroke position reaches the predetermined stroke. The provided stoppers 93 are adjusted so as to engage with each other. Note that the predetermined stroke referred to here is a value that can be arbitrarily set.

  Then, after the stroke position becomes a predetermined stroke or later, as shown in FIG. 3C, the opposing stoppers 93 provided at the end portions of the respective members continue to be engaged with each other, and the brake pedal 2 is not engaged. Since the pedal effort can be transmitted to the booster 31 of the hydraulic unit 3 via the push rod 92, the deceleration by the wheel brake 4 via the hydraulic unit 3 can be generated. In this way, the push rod 92 and the stopper 93 prohibit the operation of the hydraulic unit 3 from the initial position of the brake pedal 2 to a predetermined stroke, and the operation that permits the operation of the hydraulic unit 3 after the predetermined stroke. Acts as a limiting mechanism. Therefore, the push rod 92 and the stopper 93 correspond to the hydraulic unit limiting means in the claims.

  As shown in FIGS. 3 (a) to 3 (c), the operation restriction mechanism can mechanically transmit the pedaling force on the brake pedal 2 after a predetermined stroke to the hydraulic unit 3. It is preferable that the brake pedal 2 and the hydraulic unit 3 are arranged in series. According to this, even when there is a failure or malfunction in a mechanism that performs signal transmission from the brake pedal 2 to the wheel brake 4 by an electric signal, the driver depresses the brake pedal 2 for a predetermined stroke or more, so that the brake pedal 2 Is a stroke area after a predetermined stroke, and the pedaling force on the brake pedal 2 can be mechanically transmitted to the hydraulic unit 3. Therefore, according to the above configuration, even when there is a failure or malfunction in the mechanism that performs signal transmission from the brake pedal 2 to the wheel brake 4 by an electrical signal, the hydraulic unit 3 can brake the vehicle. And safety is further improved.

  In the present embodiment, the tension spring 91 that is generally provided in the brake pedal 2 is used, and when the brake pedal 2 is in the initial position, a predetermined interval is provided between the stoppers 93 of the respective members described above. Although the configuration in which the space is made empty is shown, it is not necessarily limited thereto. For example, a configuration may be adopted in which a predetermined interval is provided between the stoppers 93 of the respective members described above by providing a spring between the stoppers 93 of the respective members described above.

  According to the configuration of the vehicle brake device 100 of the present embodiment, the speed of the host vehicle at the start of the brake operation (that is, at the start of the brake) based on either the stroke amount of the brake pedal 2 or the pedaling force on the brake pedal 2. The target value for the speed drop from the vehicle speed is calculated. Then, the target speed, which is the difference between the vehicle speed at the start of braking and the target value for the speed reduction, is obtained, and the deceleration required to match the current vehicle speed to the target speed (that is, the requested deceleration) is calculated. Therefore, it is possible to adjust to the target speed without delicate operation of the brake pedal 2 by performing the deceleration according to the required deceleration by the brake-by-wire.

  Further, according to the above configuration, since it becomes possible to sequentially decelerate at a deceleration according to the requested deceleration, which is a deceleration necessary to match the current vehicle speed to the target speed, the driver can Even if the brake pedal 2 is not delicately operated, the driver can smoothly decelerate to the target speed. Therefore, according to the above configuration, even a driver with low driving skill can smoothly decelerate to a target speed. Therefore, according to the above configuration, it is possible to further reduce the uncomfortable feeling during deceleration caused by the brake operation by the driver with low driving skill.

  Further, according to the above configuration, the required deceleration required to realize the target speed determined based on either the stroke amount of the brake pedal 2 once operated by the driver or the pedaling force on the brake pedal 2 is output. Therefore, even if the road surface gradient changes suddenly or gently toward the downhill, the target speed can be maintained. Specifically, when the road gradient changes downward and acceleration occurs, and the vehicle speed exceeds the target speed, the brakes will be decelerated according to the required deceleration required to achieve the target speed. , You can continue to maintain the target speed.

  Therefore, according to the above configuration, the driver can easily maintain the target speed without adjusting the increase / decrease of the deceleration by increasing / decreasing the brake pedal according to the road gradient. For example, even if the amount of operation of the brake pedal 2 is kept constant and the vehicle enters a downward slope from a flat road, the effect of maintaining the target speed on the flat road can be obtained.

  Further, according to the above configuration, the required deceleration can be calculated with a simple mathematical formula for obtaining the required deceleration required to match the current host vehicle speed with the target speed shown in the equation (1). Therefore, it is possible to more easily realize a brake-by-wire vehicular brake device that makes it possible to further reduce the uncomfortable feeling during deceleration caused by a brake operation by a driver with low driving skill.

  Furthermore, according to the above configuration, since the operation of the hydraulic unit 3 is prohibited from the initial position of the brake pedal 2 to a predetermined stroke, signal transmission from the brake pedal 2 to the wheel brake 4 is performed by an electrical signal. Even at least from the initial position of the brake pedal 2 to a predetermined stroke, even a driver with low driving skill can expect the effect of being able to smoothly decelerate in the same manner as a driver with high driving skill.

  Further, according to the above configuration, after the predetermined stroke, when the required deceleration is larger than the deceleration generated by the braking by the wheel brake 4 via the hydraulic unit 3, the required deceleration is output. If the required deceleration is not larger than the deceleration generated by the braking by the wheel brake 4 via the pressure unit 3, the vehicle is decelerated at the deceleration generated by the hydraulic pressure. The discontinuity of the deceleration does not occur, and the continuous deceleration can be increased.

  Here, the effect in this invention is demonstrated concretely using FIGS. 4-8. FIG. 4 is a diagram illustrating an example of a difference between a brake operation of a driver with a high driving skill and a brake operation of a driver with a low driving skill. FIG. 5 is a diagram illustrating an example of a brake operation of a driver with a low driving skill, and FIG. 6 is a diagram illustrating an example of a brake operation of a driver with a high driving skill. 4 to 6, the graph A represents time variation of the stroke amount, the graph B represents time variation of the current vehicle speed, and the graph C represents time variation of the deceleration. The vertical axis of the A graph represents the stroke amount, the vertical axis of the B graph represents the speed, and the vertical axis of the C graph represents the deceleration. Further, the horizontal axis of the graphs A to C represents time. Also, the solid lines in the graphs A to C in FIG. 4 represent the amount of change in the brake operation of a driver with high driving skill, and the thick broken line represents the amount of change in the brake operation of a driver with low driving skill.

  Note that the brake operation of the driver with low driving skill when the vehicle stops and the brake operation of the driver with high driving skill when the vehicle stops are the same as the example shown in FIGS.

  7 and 8 are diagrams showing an example of the relationship between the stroke amount of the brake pedal 2, the time change of the current host vehicle speed and the target speed, and the time change of the requested deceleration. The D graph in FIG. 7 and the G graph in FIG. 8 are the time variations of the stroke amount, the E graph in FIG. 7 and the H graph in FIG. 8 are the time variations of the target speed and the current host vehicle speed. The graph of F in FIG. 7 and the graph of I in FIG. 8 represent the change over time of the required deceleration. In addition, the vertical axis of the D graph and the G graph represents the stroke amount, the vertical axis of the E graph and the H graph represents the speed, and the vertical axis of the F graph and the I graph represents the deceleration. Represents. Further, the horizontal axis of the graphs D to I represents time. In addition, the solid line of the graph of E represents the target speed, and the alternate long and short dash line represents the current vehicle speed. The thick solid line in the G graph represents the target speed during panic braking, and the alternate long and short dash line represents the current vehicle speed during panic braking. The thin solid line in the G graph represents the target speed during normal operation, and the thin broken line represents the normal speed. It represents the current vehicle speed when driving.

  When the driver with high driving skill decelerates to the target speed, he / she imagines what kind of deceleration should be generated in order to smoothly decelerate, and operates the brakes in proportion to the imaged deceleration. Therefore, as shown in the graph B in FIG. 4 and FIG. 6, it is possible to smoothly decelerate to the target speed. On the other hand, when the driver with low driving skill decelerates to the target speed, the driver performs a constant brake operation until the target speed is reached, and returns the brake pedal 2 when the target speed is reached. As shown in the middle graph A, the brake operation amount is gradually increased until the target speed is reached, and the brake pedal 2 is returned when the target speed is reached. As shown in FIG. 2, the vehicle cannot be smoothly decelerated to the target speed, and a so-called cuckling brake is generated. Specifically, a driver with low driving skill can imagine only a change in speed, not a change in deceleration to decelerate to a target speed, so it is possible to perform a flexible brake operation in accordance with a road surface disturbance such as a slope. It is not possible to smoothly decelerate to the target speed.

  On the other hand, according to the configuration of the vehicle brake device 100 of the present embodiment, the brake operation amount is gradually increased until the driver with low driving skill reaches the target speed as shown in the graph of D in FIG. Even when the brake operation is performed by increasing the braking force, the control device 1 electronically controls the brake actuator 7 to adjust the braking force at the wheel brake 4 and automatically reduce the deceleration to the target speed. adjust. Specifically, according to the equation shown in equation (1), the host vehicle is decelerated by increasing the required deceleration as the current host vehicle speed becomes higher than the target speed (as the current host vehicle speed becomes faster than the target speed). Then, adjust so that the current vehicle speed approaches the target speed. Therefore, according to the configuration of the vehicle brake device 100, even in the case of a driver's braking operation with a low driving skill, as shown in the graph F of FIG. A change in deceleration similar to the time change is realized, and as shown in the graph of E in FIG. 7, the speed of the own vehicle similar to the time change of the current own vehicle speed in the brake operation of the driver with high driving skill is shown. Change can be realized. Therefore, according to the configuration of the vehicle brake device 100, even a driver with low driving skill can smoothly decelerate in the same manner as a driver with high driving skill.

  Even when the control device 1 electronically controls the brake actuator 7 to adjust the braking force at the wheel brake 4 and automatically adjust the deceleration so as to reach the target speed, the brake is braked by the panic brake. When the pedal 2 is depressed greatly in a short time and the target speed becomes 0 km / h or less, as shown in the graph H in FIG. 8, the own vehicle stops when the current vehicle speed becomes 0 km / h. To do. Therefore, according to the configuration of the vehicle brake device 100, when an emergency stop is required as in a panic brake, as shown in the graph H and the graph I in FIG. Emergency stop is given priority over deceleration, and safety can be ensured.

  In the above-described embodiment, the configuration in which the required deceleration calculation unit 13 calculates the required deceleration from the equation (1) is shown, but the present invention is not necessarily limited thereto. For example, the required deceleration calculation unit 13 may be configured to calculate the required deceleration from equation (2) described below. In equation (2), the constant Ta is a divisor for converting the difference between the target speed after t seconds, which is a predetermined time after the present, and the current host vehicle speed into the required deceleration, and is set as appropriate. It is what is done. Here, as an example, the constant is represented as Ta, but it may be represented as Td. In addition, the target speed after t seconds referred to here indicates a target speed that reaches the target value of the speed decrease after t seconds from the present time. In the equation (2), the target speed t seconds after the present is represented as Vt (t), the current host vehicle speed is represented as Vs0, and the requested deceleration is represented as G. Vt (t) is a variable that changes according to the stroke amount of the brake pedal 2. Further, when the target value for the current speed reduction is calculated based on the pedaling force instead of the stroke amount, Vt (t) is a variable that changes according to the pedaling force on the brake pedal 2. Note that “after t seconds” is a value that can be arbitrarily set, for example, 3 seconds.

  In addition, what is necessary is just to set it as the structure which estimates and calculates in the required deceleration calculating part 13 about the target speed after t second. Here, the method for determining the target speed will be described with reference to FIG. FIG. 9 is a diagram illustrating an example of a method for determining a target speed. In addition, the graph of M of FIG. 9 represents the relationship between stroke amount and the target value for speed reduction, and the graph of N represents the time change of the target speed. The vertical axis of the M and N graphs represents the speed, the horizontal axis of the M graph represents the stroke amount (S) of the brake pedal 2, and the horizontal axis of the N graph represents time. .

  For example, the decrease speed calculation unit 11 uses a mathematical formula, a map, or the like that is set such that the target value for the speed decrease linearly decreases as the stroke amount increases (that is, the speed decrease increases linearly). As shown in the graph of M in FIG. 9, the target value for the speed decrease corresponding to the stroke amount of the brake pedal 2 is calculated linearly.

  Then, the required deceleration calculation unit 13 determines a target speed that reaches the target value for the speed decrease after t seconds from the current time, based on the target value for the speed decrease calculated by the decrease speed calculation unit 11. For example, as shown in the graph N of FIG. 9, the current vehicle speed (the vehicle speed at the start of braking in the example of FIG. 9) from the current time to the target value for the speed reduction is reached while changing linearly over the t seconds from the current time. A target speed is determined by using a mathematical formula, a map, or the like. As a specific example, for example, the target speed may be calculated from equation (3). In equation (3), the target speed is expressed as Vt (t), the current vehicle speed is expressed as Vs0, the vehicle speed at the start of braking is expressed as Vs, and the target value for the speed reduction is expressed as Vt. Further, the target speed for each elapsed time is calculated by the equation (3). The transition time t can be set to an arbitrary value. For example, a value of about several seconds such as 3 seconds may be set.

  In addition, although the structure which determines the target speed which reaches | attains while changing linearly from the present own vehicle speed to the target value for speed reduction over t seconds from now is shown as an example, it is not necessarily limited to this. For example, the target speed may be determined so as to reach the target value for the speed reduction from the current vehicle speed over a period of t seconds while changing in a curvilinear manner, or may be reached while changing stepwise. The structure which determines target speed may be sufficient. Also in this case, the configuration may be realized by using a mathematical formula, a map, or the like corresponding to each. The same applies to the target speed in the following description.

  Further, as the target speed after t seconds, the target speed after t seconds from the present time, which is the difference between the vehicle speed at the start of braking and the target value of the speed decrease after t seconds that is a predetermined time after the current time, is used. It is good also as a structure. In this case, the requested deceleration calculation unit 13 adds the predetermined coefficient to the current target speed, or subtracts a constant speed, for example, so that the target speed after t seconds from the present time. It is good also as a structure which estimates and calculates. Further, the target speed after t seconds may be estimated and calculated by subtracting the target value corresponding to the reduced speed after t seconds calculated by the lowering speed calculation unit 11 from the own vehicle speed at the start of braking. Good. In this case, the lowering speed calculation unit 11 uses a table or map in which the stroke amount and the target value for the predicted lowering speed after t seconds are associated with each other based on the stroke amount. It is good also as composition which presumes and computes a target value for reduction speed, and it is a predetermined quantity which meets linear relation between stroke quantity and the value of speed reduction predicted after t seconds based on stroke quantity It is good also as a structure which estimates and calculates the target value for the fall speed after t second by calculating a numerical formula. The configuration for calculating the required deceleration from the equation (1) uses the real-time target speed to calculate, but this configuration is different in that the target speed t seconds after the estimated current is used. The configuration is the same except for.

  Here, the effect by the above structure is demonstrated using FIG. FIG. 10 is a diagram illustrating an example of the relationship between the stroke amount of the brake pedal 2, changes over time in the current host vehicle speed and target speed, and changes over time in the requested deceleration. The graph of J in FIG. 10 is the time change of the stroke amount, the graph of K in FIG. 10 is the time change of the target speed and the current vehicle speed after t seconds from the present, and the graph of L in FIG. It represents the time change of deceleration. The vertical axis of the J graph represents the stroke amount, the vertical axis of the K graph represents the speed, and the vertical axis of the L graph represents the deceleration. Further, the horizontal axis of the graphs J to L represents time. The solid line in the graph of K represents the target speed t seconds after the present, and the alternate long and short dash line represents the current vehicle speed.

  Even if the driver with low driving skill increases the amount of brake operation until the target speed is reached, as shown in the graph J in FIG. In accordance with the equation shown in equation (2), the required deceleration becomes higher as the current vehicle speed becomes larger than the target speed after t seconds from the present time (as the current vehicle speed becomes faster than the target speed after t seconds from the present time). By increasing the vehicle speed, the host vehicle is decelerated and adjusted so that the current host vehicle speed approaches the target speed t seconds after the present time. Therefore, according to the above configuration, even when the brake operation is performed by a driver with a low driving skill, as shown by the graph L in FIG. As shown in the graph of K in FIG. 10, a change in the speed of the own vehicle similar to the time change of the current own vehicle speed in the brake operation of a driver with a high driving skill is realized. be able to. Thus, even with the above configuration, a driver with low driving skill can smoothly decelerate in the same manner as a driver with high driving skill.

  In the above-described embodiment, the required deceleration output from the required deceleration calculation unit 13 is supplied to the deceleration control unit 15 from the initial position of the brake pedal 2 to a predetermined stroke by providing the aforementioned operation restriction mechanism. In addition to the output, when the required deceleration calculated by the required deceleration calculation unit 13 is greater than the deceleration generated by the hydraulic pressure corresponding to the depression force on the brake pedal 2 after a predetermined stroke, the required deceleration Although the structure which outputs this to the deceleration control part 15 was shown, it does not necessarily restrict to this. For example, the above-described operation restriction mechanism is not provided, and the required deceleration output from the required deceleration calculation unit 13 and the deceleration generated by the braking by the wheel brake 4 via the hydraulic unit 3 (that is, the pedaling force on the brake pedal) (Deceleration generated by the corresponding hydraulic pressure) and a deceleration with a larger value may be output to the deceleration control unit 15 (hereinafter, modified example 1). Below, this modification 1 is demonstrated using figures. For convenience of explanation, members having the same functions as those shown in the drawings used in the description of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  First, the relationship between the brake pedal 2 and the hydraulic unit 3 in Modification 1 will be described with reference to FIGS. 11 (a) to 11 (c). FIG. 11A to FIG. 11C are diagrams illustrating the relationship between the brake pedal 2 and the hydraulic unit 3. FIG. 11A shows an example when the brake pedal 2 is in the initial position, and FIG. 11C shows an example when the brake pedal 2 is stepped on. FIG. 11B shows an example in which the brake pedal 2 is between the state of FIG. 11A and the state of FIG. Further, the push rod 92 in FIG. 11 is not divided in the axial direction unlike the above-described embodiment, and the pedaling force on the brake pedal 2 can be directly transmitted to the hydraulic unit 3. Further, the rotary encoder type stroke sensor 6 is provided in parallel with the hydraulic unit 3.

  In the first modification, unlike the above-described embodiment, as shown in FIG. 10A to FIG. 10C, after the initial position of the brake pedal 2, the pedaling force on the brake pedal 2 is hydraulically applied by the push rod 92. It can be communicated to unit 3.

  Subsequently, processing in the control device 1 will be described. Here, based on the target value for the speed reduction calculated by the reduction speed calculation unit 11, the required deceleration calculation unit 13 sets the target speed (which is described above) to become the target value for the speed reduction after t seconds. The target speed after t seconds) is determined. The method for determining the target speed is the same as described above.

  And when the said target speed becomes a value more than 0, the required deceleration calculating part 13 calculates a required deceleration from (2) Formula based on the said target speed and the present own vehicle speed. . If the target speed is smaller than 0, the target speed is set to 0, and the required deceleration is calculated from equation (2) based on the target speed and the current vehicle speed. Then, the obtained requested deceleration is output to the output determination unit 14.

  Subsequently, in the output determination unit 14 of Modification 1, the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3 and the required deceleration calculation unit 13 are calculated regardless of the stroke position of the brake pedal 2. Compare with the requested deceleration. As for the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3 (that is, the deceleration generated by the hydraulic pressure corresponding to the pedaling force on the brake pedal), the output determination is performed as in the above-described embodiment. Assume that the unit 14 estimates.

  If the requested deceleration is greater than the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3, the requested deceleration calculated by the requested deceleration calculating unit 13 is used as the deceleration control unit 15. Output to. On the other hand, if the requested deceleration is not larger than the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3, the requested deceleration calculated by the requested deceleration calculating unit 13 is controlled to be reduced. Does not output to unit 15. If the requested deceleration calculated by the requested deceleration calculation unit 13 is not output to the deceleration control unit 15, the deceleration of the host vehicle is caused by the deceleration generated by braking by the wheel brake 4 via the hydraulic unit 3. Will be done.

  According to the above configuration, when the value of the required deceleration output from the required deceleration calculation unit 13 is larger than the deceleration generated by the hydraulic pressure in the hydraulic pressure unit 3 corresponding to the depression force on the brake pedal 2. The signal transmission from the brake pedal 2 to the wheel brake 4 is performed by an electric signal. Therefore, according to the above configuration, at least the value of the required deceleration output from the required deceleration calculating unit 13 is larger than the deceleration generated by the hydraulic pressure in the hydraulic pressure unit 3 corresponding to the depression force on the brake pedal 2. In such a case, an effect of further reducing the uncomfortable feeling during deceleration caused by the brake operation by the driver with low driving skill can be expected.

  On the other hand, when the driver depresses the brake pedal 2 in an emergency, a deceleration generated by the hydraulic pressure in the hydraulic unit 3 corresponding to the depression force on the brake pedal 2 is output from the required deceleration calculation unit 13. When the speed is greater than the speed, emergency braking is possible by the hydraulic unit 3 that generates a deceleration by the hydraulic pressure corresponding to the depression force of the brake pedal 2.

  Here, the effect by the structure of the vehicle brake device 100 of the modification 1 is demonstrated concretely using FIG. FIG. 12 is a diagram illustrating an example of the relationship between the stroke amount of the brake pedal 2, the temporal change in the current host vehicle speed and target speed, and the temporal change in deceleration. 12 is a time change of the stroke amount, a graph E of FIG. 12 is a time change of the target speed and the current vehicle speed, and a graph of O in FIG. 12 is the required deceleration calculating unit 13. Required deceleration value (G_cont in the figure), deceleration generated by the hydraulic pressure in the hydraulic unit 3 (G_dri in the figure), and actual vehicle deceleration (G_out in the figure) It represents a change. The vertical axis of the D graph represents the stroke amount, the vertical axis of the E graph represents the speed, and the vertical axis of the O graph represents the deceleration. Further, the horizontal axis of the graphs of D, E, and O represents time. Note that the solid line of the graph of E represents the target speed, the dashed line represents the current vehicle speed, the thick solid line of the graph of O represents G_out, the thin solid line represents G_cont, and the dashed line represents G_out.

  According to the configuration of the vehicle brake device 100 of the first modification, a driver with low driving skill increases the brake operation amount at a time toward the target speed as shown in the graph of D in FIG. Even if the control device 1 performs, the control device 1 electronically controls the brake actuator 7 to adjust the braking force of the wheel brake 4 and decelerate so as to reach the target speed over a predetermined time t seconds. Adjust automatically. Specifically, when the value of G_cont is larger than the value of G_dri, the vehicle is moved by increasing the required deceleration as the current vehicle speed becomes larger than the target speed according to the equation shown in equation (2). Decelerate and adjust the current vehicle speed to approach the target speed. Therefore, according to the configuration of the vehicle brake device 100 of the first modification example, even if the brake operation is performed by a driver with a low driving skill, as shown in the graph O in FIG. As shown in the graph of E in FIG. 12, the time change of the current own vehicle speed in the brake operation of a driver with high driving skill is realized (see FIG. 6). It is possible to realize a change in the speed of the own vehicle similar to). Therefore, according to the configuration of the vehicle brake device 100 of the first modification, even a driver with a low driving skill can smoothly decelerate in the same manner as a driver with a high driving skill.

  12 shows an example in which the stroke amount is changed at once, unlike the example in FIG. 5 in which the stroke amount is gradually changed, but the stroke amount is gradually changed in the same manner as in the example in FIG. Even so, the same effect can be obtained by the configuration of the vehicle brake device 100 of the first modification.

  Moreover, the case where there is a stepping-up operation or a stepping-back operation of the brake pedal 2 will be described with reference to FIGS. FIG. 13 and FIG. 14 show the relationship between the stroke amount of the brake pedal 2 when the brake pedal 2 is further depressed, the time change of the current host vehicle speed and the target speed, and the time change of the deceleration. It is a figure which shows an example. FIG. 15 and FIG. 16 show the relationship between the stroke amount of the brake pedal 2 when the brake pedal 2 is stepped back, the time change of the current host vehicle speed and the target speed, and the time change of the deceleration. It is a figure which shows an example. Further, FIG. 17 is a diagram for explaining an example of a method for determining the target speed when there is an operation of increasing the brake pedal 2 or an operation of returning the brake pedal 2.

  13 to 16, the graph of D in the stroke amount changes with time, the graph of P in FIGS. 13 and 15 shows the change in time of the target velocity, and the graph of Q in FIGS. 14 and 16 shows the target velocity and It represents the change over time of the current vehicle speed. 13 and 15 are generated by the required deceleration values (G_cont1, G_cont2, G_cont3 in the figure) output from the required deceleration calculating unit 13 and the hydraulic pressure in the hydraulic unit 3. Represents the time change of the deceleration (G_dri in the figure). Furthermore, the graph of T in FIG. 14 and FIG. 16 represents the time change of the actual vehicle deceleration (G_out in the figure). Further, the graph M in FIG. 17 represents the relationship between the stroke amount and the target value for the speed reduction, and the graph N represents the time change of the target speed.

  Further, the vertical axis of the D graph represents the stroke amount, the vertical axis of the P and Q graphs represents the speed, and the vertical axis of the R and T graphs represents the deceleration. Furthermore, the horizontal axis of the graphs of D, P to R, and T represents time. The vertical axis of the M and N graphs represents the speed, the horizontal axis of the M graph represents the stroke amount (S) of the brake pedal 2, and the horizontal axis of the N graph represents time. .

  Note that the solid line in the graph of P is the target speed for the first brake operation (Vt (t) 1 in the figure), and the dotted line is the target speed for the stepping-up operation or stepping-back operation (Vt in FIG. 13). (T) 2, Vt (t) 3) in FIG. 15, the solid line of the Q graph represents the target speed, and the alternate long and short dash line represents the current vehicle speed. The thin solid line of the R graph represents G_cont1, the dotted line represents G_cont2 or G_cont3, the alternate long and short dash line represents G_out, and the thick solid line of the T graph represents G_out. Furthermore, point A in the graph of M is the stroke amount before starting the brake operation, point B is the stroke amount at the time of the first brake operation, point C is the stroke amount when the stepping operation is increased, and point D is the stroke amount when the stepping back operation is performed. Represents. Further, the solid line of the N graph indicates the target speed (Vt (t) 1) for the first brake operation, the dotted line indicates the target speed (Vt (t) 2) for the stepping-in operation, and the broken line indicates the stepping-back operation. Represents the target speed (Vt (t) 3). Furthermore, the point X in the graph of N represents the time when the brake operation amount is changed.

  First, based on the stroke amount at the time of the first brake operation (see point B in FIG. 17), the target value for speed reduction (Vt1 in FIGS. 13 to 16) is calculated by the speed reduction calculation unit 11. Subsequently, a target speed (Vt (t) 1) that reaches Vt1 over t seconds from the vehicle speed at the start of braking is determined. Then, when the value of G_cont1 becomes larger than the value of G_dri, the required deceleration G_cont1 is set as the current host vehicle speed becomes higher than the target speed (Vt (t) 1) according to the equation shown in equation (2). By increasing the speed, the host vehicle is decelerated and the adjustment is continued so that the current host vehicle speed approaches the target speed (Vt (t) 1).

  Here, if there is an additional operation of the brake pedal 2 before reaching the target value (Vt1) for the speed reduction (see point X in FIG. 17), a new stroke amount (in FIG. 17) Based on the point C), the reduction speed calculation unit 11 calculates a new target value for the speed reduction (Vt2 in FIGS. 13 and 14). Then, a target speed (Vt (t) 2) that reaches Vt2 over t seconds from the current own vehicle speed at the time when the brake pedal 2 is further depressed is determined (see the graph of N in FIG. 17).

  According to the above configuration, when the value of G_cont2 becomes larger than the value of G_dri even after the brake pedal 2 is further depressed, a new target speed ( As the current host vehicle speed becomes larger than Vt (t) 2), the host vehicle is decelerated by increasing the required deceleration G_cont2 so that the current host vehicle speed approaches the target speed (Vt (t) 2). It will be. Therefore, even after the brake pedal 2 is further depressed, as shown in the graph of T in FIG. 14, the speed of the own vehicle is similar to the time change of the current own vehicle speed in the brake operation of a driver with high driving skill. Can be realized.

  In addition, even when the brake pedal 2 is depressed again before reaching the target value (Vt1) for the speed reduction (see point X in FIG. 17), a new stroke amount (point in FIG. 17) is also obtained. The target value (Vt3 in FIGS. 15 and 16) for the new speed reduction is calculated by the speed reduction calculation unit 11 based on D). Then, a target speed (Vt (t) 3) that reaches Vt3 over t seconds from the current host vehicle speed when the brake pedal 2 is stepped back is determined.

  According to the above configuration, when the value of G_cont3 becomes larger than the value of G_dri even after the brake pedal 2 is depressed, the new target speed ( As the current host vehicle speed becomes larger than Vt (t) 3), the host vehicle is decelerated by increasing the required deceleration G_cont3 so that the current host vehicle speed approaches the target speed (Vt (t) 3). It will be. Therefore, even after the brake pedal 2 is depressed, the speed of the host vehicle is similar to the time change of the current host vehicle speed in the brake operation of a driver with high driving skill, as shown in the graph of T in FIG. Can be realized.

  As described above, according to the present invention, smooth deceleration to the speed intended by the driver can be achieved even when the brake pedal operation amount is increased or decreased by the driver and the brake operation amount is changed. Is possible.

  Next, the case where the vehicle stops will be described with reference to FIG. FIG. 18 is a diagram illustrating an example of the relationship between the stroke amount of the brake pedal 2 when the vehicle stops, the temporal change in the current host vehicle speed and the target speed, and the temporal change in deceleration. In addition, the graph of D in FIG. 18 represents the time change of the stroke amount, and the graph of U represents the time change of the target speed and the current host vehicle speed. Further, the graph of O in FIG. 18 shows the required deceleration value (G_cont in the figure) output from the required deceleration calculating unit 13 and the deceleration generated by the hydraulic pressure in the hydraulic unit 3 (G_dri in the figure). ), And shows the change over time of actual vehicle deceleration (G_out in the figure).

  Furthermore, the vertical axis of the graph of D represents the stroke amount, the vertical axis of the graph of U represents the speed, and the vertical axis of the graph of O represents the deceleration. Further, the horizontal axis of the graphs of D, U, and O represents time. The solid line in the graph of E represents the output value of the target speed, the broken line represents the calculated value of the target speed, and the alternate long and short dash line represents the current host vehicle speed. In the graph of O, the thick solid line represents G_out, the thin solid line represents G_cont, and the alternate long and short dash line represents G_out.

  In the vehicle brake device 100, the target value for the speed reduction is calculated by the reduction speed calculation unit 11 based on the stroke amount at the time of the brake operation. There is a case where the value is larger than the value of the speed decrease from the vehicle speed to the vehicle speed 0. Here, since the target speed is determined so as to reach the target value corresponding to the speed decrease over t seconds from the vehicle speed at the start of braking, the calculated value of the target speed is indicated by a broken line in the graph of U in FIG. As shown in the part surrounded by the ellipse, there is a case where the value is smaller than 0. However, in the vehicle brake device 100 of the first modification, when the target speed becomes a value smaller than 0, the target deceleration is calculated from the equation (2) with the target speed set to 0. The requested deceleration output due to the difference from the current vehicle speed converges to zero. Therefore, according to the above configuration, as shown in the graph of O of FIG. 18, the vehicle is smoothly decelerated toward the vehicle speed 0 when stopped, and as shown in the graph of C of FIG. 5 even when stopped. Cuckling brakes are eliminated satisfactorily.

  The vehicle brake device 100 may be configured to stop the output of the requested deceleration from the requested deceleration calculation unit 13 to the deceleration control unit 15 when the stroke of the brake pedal 2 returns to the initial position. In this case, for example, the requested deceleration calculated by the requested deceleration calculating unit 13 may be stopped when the output determining unit 14 does not output it to the deceleration control unit 15. Therefore, the output determination unit 14 corresponds to the requested deceleration output stop unit in the claims.

  According to the above configuration, when the driver completely returns the brake pedal 2 and the stroke returns to the initial position, output of the requested deceleration from the requested deceleration calculating unit 13 to the deceleration control unit 15 is stopped. The driver can obtain the same feeling as the hydraulic brake device.

  In the above-described embodiment, the configuration in which the vehicle brake device 100 is mounted on a vehicle using an internal combustion engine as a driving force source is shown. However, the present invention is not necessarily limited thereto, and the vehicle is not limited to this. The vehicle brake device 100 may be mounted on a vehicle using an electric motor (motor) as a driving force source.

  In addition, when the vehicle brake device 100 is mounted on a vehicle that uses an electric motor as a driving force source, the rotation resistance during power generation of the electric motor may be used as the braking force of the vehicle. Hereinafter, this embodiment will be described with reference to the drawings. FIG. 19 is a diagram illustrating an example of a configuration in the case where the rotation resistance during power generation of the electric motor is used as the braking force of the vehicle. For convenience of explanation, members having the same functions as those shown in the drawings used in the description of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. Here, an example in the case of application to HV is shown. Here, it is assumed that the hydraulic unit 3 also performs braking by the wheel brake 4 via the brake actuator 7.

  The electric motor 40 is an electric motor used as a driving force source of the vehicle. The battery 41 is, for example, a nickel metal hydride battery or a lithium ion battery, and the electric motor 40 is connected to the battery 41 via an inverter 42.

  The inverter 42 supplies the electric power of the battery 41 to the electric motor 40 and causes the electric motor 40 to generate a driving force. Further, the inverter 42 generates electric power with the electric motor 40 and charges the battery 41 with the generated electric power. When electric power is generated by the electric motor 40, for example, the electric motor 40 is rotated by the rotational power of the drive wheels. When the electric motor 40 is rotated by the rotational power of the drive wheels, a braking force corresponding to the generated electric power is generated.

  The hybrid ECU 43 determines the power distribution ratio between the engine and the electric motor 40 using the operation amount and vehicle speed input to the accelerator pedal by the driver and the power distribution ratio determination map stored in advance. Further, the hybrid ECU 43 instructs the inverter 42 to perform regenerative braking, or calculates the deceleration due to regenerative braking based on the rotational speed of the electric motor 40, the input voltage of the inverter 42, and the like.

  The brake ECU 44 is assumed to include the control device 1. The brake ECU 44 outputs the required deceleration calculated by the required deceleration calculation unit 13 of the control device 1 to the deceleration control unit 15 in the case where the rotational resistance during power generation of the electric motor 40 can be used as the braking force of the vehicle. In this case, arbitration is performed by subtracting the deceleration due to regenerative braking calculated by the hybrid ECU 43 from the requested deceleration calculated by the requested deceleration calculating unit 13 and outputting the result to the deceleration control unit 15. For example, the output determination unit 14 may be configured to subtract the deceleration due to regenerative braking calculated by the hybrid ECU 43 from the required deceleration calculated by the required deceleration calculation unit 13 and output the result to the deceleration control unit 15.

  And the deceleration control part 15 sends the control signal according to the deceleration obtained by arbitration to the brake actuator 7, and the braking force according to the deceleration obtained by arbitration is generated. According to the above configuration, even in a vehicle such as EV or HV that can use the rotational resistance during power generation of the electric motor 40 as the braking force of the vehicle, it is possible to smoothly decelerate without causing the driver to feel uncomfortable. .

  Moreover, although the structure provided with the control apparatus 1 in brake ECU44 was shown here, it does not necessarily restrict to this. For example, the function of the control device 1 may be provided separately for each of the brake ECU 44 and the hybrid ECU 43.

  Here, the configuration in which the electric motor used as the driving force source of the vehicle such as EV or HV is the electric motor 40 is shown, but the present invention is not limited to this, and the alternator of the vehicle using the internal combustion engine as the driving power source is the electric motor 40. It is good also as a structure used as.

  In the above-described embodiment, part of the signal transmission from the brake pedal 2 to the wheel brake 4 is performed by an electrical signal via the control device 1 and the brake actuator 7, and the signal transmission from the brake pedal 2 to the wheel brake 4 is performed. Is configured through a hydraulic unit 3 that generates hydraulic pressure corresponding to the pedaling force applied to the brake pedal 2 (that is, when signal transmission from the brake pedal 2 to the wheel brake 4 is performed by an electrical signal, and from the brake pedal 2 to the wheel brake. 4 shows a configuration in which it is possible to select the case where the signal transmission to 4 is performed via the hydraulic unit 3 that generates the hydraulic pressure according to the depression force applied to the brake pedal 2). For example, the signal transmission from the brake pedal 2 to the wheel brake 4 may be performed without using the hydraulic unit 3, or the signal transmission from the brake pedal 2 to the wheel brake 4 may be performed by an electrical signal. Also good. That is, it is only necessary that the signal transmission from the brake pedal 2 to the wheel brake 4 can be performed by an electric signal.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments can be appropriately combined. Such embodiments are also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Control apparatus, 2 Brake pedal, 3 Hydraulic unit, 4 Wheel brake, 5 Vehicle speed sensor (vehicle speed detection means), 6 Stroke sensor (Pedal related quantity detection means), 7 Brake actuator, 11 Deceleration speed calculation part (deceleration speed calculation) Means), 12 target speed calculation unit, 13 required deceleration calculation unit (required deceleration calculation unit), 14 output determination unit (output determination unit), 15 deceleration control unit, 31 booster, 32 master cylinder, 40 electric motor, 41 battery , 42 inverter, 43 hybrid ECU, 44 brake ECU, 91 tension spring, 92 push rod (hydraulic pressure unit restricting means), 93 stopper (hydraulic pressure unit restricting means), 100 brake device for vehicle

Claims (10)

A brake-by-wire vehicle brake device mounted on a vehicle and performing at least part of signal transmission from a brake pedal to a wheel brake by an electric signal,
Pedal-related amount detection means for detecting either the stroke amount of the brake pedal or the pedaling force on the brake pedal;
Vehicle speed detection means for sequentially detecting the speed of the vehicle;
Based on the input, either the stroke amount or the pedaling force sequentially detected by the pedal-related amount detection means, the speed from the vehicle speed at the start of the brake, which is the speed of the vehicle at the start of the brake operation. A reduction speed calculating means for sequentially calculating a target value for the decrease, and
A vehicle brake device characterized by sequentially obtaining a target speed based on the vehicle speed at the start of the brake and the target value for the speed reduction. In claim 1,
Based on the target speed obtained sequentially and the current host vehicle speed, which is the current vehicle speed sequentially detected by the vehicle speed detecting means, a required reduction that is a deceleration required to realize the target speed. The apparatus further comprises required deceleration calculating means for sequentially calculating the speed. In claim 2,
A part of signal transmission from a brake pedal to a wheel brake is performed by an electrical signal, and the signal transmission is performed via a hydraulic unit that generates hydraulic pressure in accordance with a pedaling force with respect to the brake pedal. Brake device. In claim 3,
Hydraulic unit restriction means for prohibiting operation of the hydraulic unit from the initial position of the brake pedal to a predetermined stroke, and permitting operation of the hydraulic unit after the predetermined stroke;
From the initial position of the brake pedal to a predetermined stroke, the required deceleration output from the required deceleration calculating means is output, and after the predetermined stroke, it is generated by a hydraulic pressure corresponding to the pedaling force on the brake pedal. An output determining means for outputting the required deceleration calculated by the required deceleration calculating means when the required deceleration calculated by the required deceleration calculating means is greater than the deceleration; A vehicle brake device. In claim 4,
The hydraulic pressure unit limiting means is provided in series with the hydraulic pressure unit so as to be able to mechanically transmit a pedaling force on the brake pedal after the predetermined stroke to the hydraulic pressure unit. Brake device. In claim 3,
The required deceleration output from the required deceleration calculation means is compared with the deceleration generated by the hydraulic pressure in the hydraulic pressure unit according to the depression force on the brake pedal, and the larger deceleration is output. The vehicle brake device further includes an output determination means. In any one of Claims 2-6,
The target speed is a current target speed which is a difference between the vehicle speed at the start of the brake and a target value for the current speed reduction,
The required deceleration calculating means calculates the required deceleration from equation (1).
Vt: Target value for current speed drop [m / s]
Vs: Vehicle speed at start of brake [m / s]
Vs0: Current vehicle speed [m / s]
G: Required deceleration (≤0)
Ta: A divisor for converting the difference between the current target speed and the current vehicle speed into the required deceleration In any one of Claims 2-6,
The requested deceleration calculation means sequentially obtains a target speed that reaches the target value for the speed decrease after t seconds from the present, based on the target value for the speed decrease sequentially calculated by the decrease speed calculation means, A vehicle brake device characterized in that the required deceleration is calculated from equation (2) based on the target speed and the current host vehicle speed.
Vt (t): target speed [m / s] that reaches the target value for the speed decrease after t seconds from the present time
Vs0: Current vehicle speed [m / s]
G: Required deceleration (≤0)
Ta: A divisor for converting the difference between the target speed that reaches the target value of the speed decrease after t seconds from the present time and the current host vehicle speed into the required deceleration In claim 8,
The requested deceleration calculation means includes
When the target speed is 0 or more, the required deceleration is calculated from the equation (2) based on the target speed and the current host vehicle speed,
If the target speed is smaller than 0, the target speed is set to 0, and the required deceleration is calculated from the equation (2) based on the target speed and the current host vehicle speed. A brake device for a vehicle. In claims 2-9,
A vehicular brake device further comprising requested deceleration output stopping means for stopping output of requested deceleration from the requested deceleration calculating means when the stroke of the brake pedal returns to the initial position.