JP2007008238A - Vehicle control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle control apparatus capable of preventing a driver from feeling a sense of discomfort due to changes in the traveling state of a vehicle when performing control for preventing or suppressing the vibration of a brake or the generation of foreign sound. <P>SOLUTION: The vehicle control apparatus provided with a braking torque setting means for setting the braking torque of respective wheels by controlling a braking apparatus independently of driver's operation and a vibration detection means (step S101) for detecting the vibration of the braking apparatus to suppress vibration when the vibration of the braking apparatus is detected is also provided with: a driving torque setting means for setting the driving torque of respective wheels by controlling the output of a power source independently of driver's operation; a traveling state detection means (step S102) for detecting the traveling state of the vehicle; and a vibration suppressing means (steps S104, S105) for changing at least one of the braking torque and the driving torque on the basis of the traveling state when the vibration of the braking apparatus is detected. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vehicle control device that controls a braking force and a driving force of a vehicle.

  Conventionally, in a vehicle, as a device for controlling a braking force, a wheel cylinder is operated based on an occupant's brake operation or independently of a brake operation, and a friction member such as a brake pad or a brake shoe is integrated with a wheel. A braking device (braking device) that applies braking torque to the wheels by being pressed against a rotating member such as a rotating brake disk or a brake drum is provided.

  In a state where the vehicle is braked and stopped by such a braking device, a braking torque larger than the driving torque of the vehicle is applied to the wheels. For example, a vehicle equipped with an automatic transmission is braked by an occupant's brake operation when a travel range in which power is transmitted by a transmission such as a D (drive) range is selected as a shift position of the automatic transmission. In the stopped state, braking torque greater than so-called creep torque, that is, driving torque that can drive the vehicle at a very low speed on a flat ground, is applied to the wheels.

  When the vehicle is started from this stop state, the brake operation by the occupant is gradually released (for example, the depression of the brake pedal is gradually released), and the braking torque is gradually reduced accordingly. Then, the braking torque and the creep torque, that is, the driving torque become substantially equal, and the vehicle starts to start when the braking torque falls below the driving torque. At this time, in the vicinity where the braking torque and the driving torque are substantially equal, the braking torque slightly fluctuates with respect to the driving torque, so that the friction member and the rotating member of the braking device are in a slip / engaged state. When a so-called stick-slip phenomenon occurs repeatedly, and as a result, vibration (brake vibration) in the components of the braking device increases and abnormal noise (so-called goo noise, brake noise, or brake noise) is generated due to the brake vibration. There is. In order to prevent or suppress the occurrence of brake vibration or abnormal noise in such a braking device, the brake fluid pressure for the vehicle is controlled so as to change the distribution of the brake fluid pressure on the front and rear wheels when a brake squeal is detected. An invention relating to a control device is described in Patent Document 1.

  The vehicle brake hydraulic pressure control device described in Patent Document 1 is configured so that when the brake squeal is detected by the means for detecting the brake squeal, the front wheel brake fluid is not changed without changing the total braking force of the front and rear wheels. The distribution of the brake fluid pressure of the front and rear wheels is changed so as to reduce the pressure and increase the fluid pressure of the rear wheel brake. Therefore, it is said that brake noise can be suppressed while ensuring an appropriate deceleration.

  Further, Patent Document 2 describes the occurrence of brake squeal in each wheel based on the brake pedal depression amount and depression speed for the purpose of preventing the occurrence of brake squeal without complicating the brake system and increasing the cost. When the possibility is detected and it is determined that a brake squeal is likely to occur on any of the wheels, the distribution of the braking force of each wheel is changed so that the total braking force of all the wheels does not change substantially. An invention relating to a braking force control device for a vehicle configured to be described is described.

Furthermore, in Patent Document 3, the brake squeal state of all wheels is constantly monitored for the purpose of preventing brake noise by changing the distribution of brake fluid pressure for all wheels to the most efficient fluid pressure distribution. When brake noise is detected on one of the left and right wheels, the brake fluid pressure on that wheel is reduced and the corresponding brake fluid pressure on the opposite wheel is reduced without changing the total braking force. An invention relating to a brake noise prevention device configured to increase pressure according to the above is described.
JP-A-9-2221013 Japanese Patent Laid-Open No. 10-305768 JP 2000-177552 A

  Each of the inventions described in the above Patent Documents 1 to 3 is intended to prevent or suppress brake vibration as described above, and when occurrence of brake vibration or abnormal noise is detected, For example, by reducing the braking torque of the front wheels and increasing the braking torque of the rear wheels, or by reducing the braking torque of one of the left and right wheels in which brake vibration is detected, the braking torque of the opposite wheel is reduced. By increasing the brake vibration or abnormal noise is reduced. That is, when brake vibration or abnormal noise is detected, the brake vibration or abnormal noise is suppressed by controlling only the braking torque of the wheels.

  However, the braking operation of the vehicle is performed in various vehicle traveling states. For example, when the braking operation is performed while the vehicle is traveling, the above-described brake vibration or abnormal noise is generated. If the braking torque increase / decrease control is performed without considering the running state of the vehicle and the behavior of the driving torque, for example, the braking torque increases during acceleration and the vehicle decelerates. Or a change in the driving state unintended by the occupant, such as the braking torque decreasing during deceleration and the vehicle accelerating, or the braking torque changing during constant speed driving and the vehicle speed fluctuating. Sometimes caused the passengers to feel uncomfortable.

  The present invention has been made paying attention to the above technical problem, and when the control for preventing or suppressing the occurrence of brake vibration or abnormal noise is performed, the traveling state of the vehicle changes and the passenger feels uncomfortable. It is an object of the present invention to provide a vehicle control device that can avoid the occurrence of the problem.

  In order to achieve the above object, the invention of claim 1 is directed to a braking torque setting means for setting the braking torque of each wheel by controlling the braking device independently of an occupant's operation, and detecting the vibration of the braking device. And a vibration detecting means for controlling the braking torque setting means to suppress the vibration when the vibration is detected by the vibration detecting means. A drive torque setting means for controlling the output of the power source to set the drive torque of each wheel; a running state detecting means for detecting the running state of the vehicle; and when the vibration is detected by the vibration detecting means, Based on the running state detected by the running state detecting means, the braking torque set by the braking torque setting means and the driving torque set by the driving torque setting means A control apparatus characterized by comprising a vibration suppression means for changing at least one of.

  According to a second aspect of the present invention, in the first aspect of the invention, the traveling state detecting means includes a traveling direction detecting means for detecting a traveling direction of the vehicle, and the vibration suppressing means includes the vibration detecting means and the vibration detecting means. A control device comprising: means for reducing the driving torque when the vibration is detected and the vehicle is moving backward by the traveling direction detection means.

  According to a third aspect of the present invention, in the first aspect of the invention, the running state detecting means includes acceleration detecting means for detecting longitudinal acceleration of the vehicle, and the vibration suppressing means includes the vibration detecting means and the acceleration. When the vibration is detected and the vehicle is being accelerated, the braking torque is reduced by the detecting means, and the vibration is detected and the vehicle is being decelerated. And a means for reducing the braking torque and the driving torque when the vibration is detected and the vehicle is detected to be traveling at a constant speed, respectively. It is a control device.

  According to the first aspect of the present invention, when vibration of the braking device due to a so-called stick-slip phenomenon occurs in the vicinity where the braking torque output to each wheel and the driving torque are substantially equal when the vehicle is braked, the vibration is generated. Is detected, and the traveling state of the vehicle at that time is detected. Based on the detected running state, at least one of the braking torque setting value and the driving torque setting value of each wheel is changed, and the vibration state of the braking device is changed. Is less likely to increase, that is, stick slip is unlikely to occur, and vibration of the braking device is suppressed. Therefore, even when the brake is operated during driving and vibration occurs in the braking device, either the braking torque setting value of each wheel or the driving torque setting value, or both of them, The vibration is suppressed by appropriately changing according to the traveling state at the time. As a result, when the control for suppressing the vibration of the braking device is executed, it is possible to prevent or suppress the occurrence of a change in the traveling state that is not intended by the occupant and causing the occupant to feel uncomfortable.

  According to the invention of claim 2, when vibration is generated in the braking device when the vehicle is braked, the vibration is detected and the traveling direction of the vehicle is detected as the traveling state of the vehicle. When it is detected that the vehicle is moving backward, the braking torque is not changed, and only the driving torque is reduced, thereby suppressing the vibration of the braking device. Therefore, to ensure the safety of the driving operation by avoiding that the braking torque is reduced and the vehicle is accelerated against the occupant's intention when the vehicle is moving backward, which is not easy as compared with the case of moving forward. Can do.

  According to the invention of claim 3, when vibration is generated in the braking device when the vehicle is braked, the vibration is detected and the longitudinal acceleration of the vehicle is detected as the running state of the vehicle. When it is detected that the vehicle is accelerating, the braking torque is reduced. When it is detected that the vehicle is decelerating, the driving torque is reduced, and the vehicle is traveling at a constant speed. When it is detected that the vehicle is in the middle, the braking torque and the driving torque are reduced in cooperation with each other, thereby suppressing the vibration of the braking device. For this reason, when the braking device is actuated during driving and vibration is generated in the braking device, and the control for suppressing the vibration is executed, for example, the vehicle is decelerating because the driving torque is reduced while the vehicle is accelerating. The vehicle speed is reduced because the braking torque is reduced and the vehicle is accelerating because it is decelerating, or the braking torque and the driving torque are controlled independently while the vehicle is running at a constant speed. Can be avoided. As a result, when the control for suppressing the vibration of the braking device is executed, it is possible to prevent or suppress the occurrence of a change in the traveling state that is not intended by the occupant and causing the occupant to feel uncomfortable.

  Next, an embodiment of the present invention will be described with reference to the drawings. First, a vehicle drive system to which the present invention is applied is shown in FIG. FIG. 5 shows an example in which the vehicle Ve to which the present invention is applied is, for example, an FR (front engine / rear drive) type two-wheel drive vehicle Ve. In the vehicle Ve shown in FIG. 5, a transmission 2 for shifting the rotational output of the power source 1 is disposed on the output side of the power source 1, and the transmission 2 is transmitted from the transmission 2 to the output side of the transmission 2. A drive shaft 5 that transmits the drive force to the drive wheels 3 and 4 is provided.

  As the power source 1, for example, at least one of an internal combustion engine or an electric motor can be used. As the internal combustion engine, for example, an internal combustion engine having a mechanism capable of electrically controlling an output such as an electronic throttle valve is preferably used. Is done. As the electric motor, for example, a motor generator having a power running function for converting electric energy into kinetic energy and a regeneration function for converting kinetic energy into electric energy can be used. In this embodiment, the case where an engine 1 such as a gasoline engine, a diesel engine, or a natural gas engine having an electronic throttle valve 1a is used as the power source 1 will be described.

  As the transmission 2, various transmissions such as a manual transmission, an automatic transmission, or a continuously variable transmission can be used. The drive shaft 5 is connected to the left and right rear wheel drive shafts 7 and 8 via the rear differential 6. The rear wheel drive shafts 7 and 8 have wheels (drive wheels) 3 serving as left and right rear wheels. , 4 are connected. The wheels 9 and 10 that are the left and right front wheels are provided as non-driving wheels 9 and 10 that themselves do not generate a driving force.

  The output torque of the engine 1 is transmitted to the drive wheels 3 and 4 through the power transmission system formed by each mechanism. Here, the operation of the electronic throttle valve 1a that controls the output torque of the engine 1 is controlled by the electronic control device 100 described later. That is, the electronic control device 100 controls the operation of the electronic throttle valve 1a to increase / decrease the output of the engine 1 and to increase / decrease the drive torque output to the drive wheels 3, 4. Therefore, by controlling the operation of the electronic throttle valve 1a based on the signal output from the electronic control device 100, for example, the driving torque of the driving wheels 3 and 4 is independent of the occupant's operation such as the depression of the accelerator pedal. Can be controlled.

  Each wheel 3, 4, 9, 10 is provided with a braking device 11 respectively. Further, in the hydraulic system of the hydraulic fluid that connects the wheel cylinder 12 constituting the braking device 11 and the master cylinder 13, the hydraulic pressure in the wheel cylinder 12 is increased or decreased independently of the driver's brake operation, A brake actuator 14 for controlling the braking torque applied to each of the wheels 3, 4, 9, 10 is provided.

  FIG. 6 schematically shows the configuration of the brake actuator 14. The brake actuator 14 is configured to be able to independently control the hydraulic pressure for each braking device 11 of each wheel 3, 4, 9, 10 and FIG. The structure of the brake actuator 14 regarding one wheel among 3, 4, 9, and 10 is shown typically. Accordingly, the other wheels have the same configuration.

  The hydraulic system constituting the brake actuator 14 is provided with a hydraulic pump 21 that is rotationally driven by a motor 20. The hydraulic pump 21 functions as a hydraulic pressure source when controlling the braking force, and the discharge port 21 a of the hydraulic pump 21 is connected to a pipe between the shut-off valve 23 and the holding valve 24 via a pipeline 22. It is connected to the path 25. A check valve 26 is provided on the discharge port 21 a side of the hydraulic pump 21 to block the flow of hydraulic fluid in the direction opposite to the discharge direction of the hydraulic pump 21.

  On the other hand, the suction port 21b of the hydraulic pump 21 is connected to the reservoir 28 via a conduit 27, and the flow of hydraulic fluid in the direction opposite to the suction direction of the hydraulic pump 21 is blocked in the conduit 27. Check valves 29 and 30 are provided. The pipe line 27 between the check valves 29 and 30 is connected to the reservoir tank 32 through the pipe line 31, and the hydraulic fluid in the reservoir tank 32 is supplied to the hydraulic pump 21 through the pipe line 27. It is configured to be inhaled. A suction valve 33 of a normally closed type (a type that opens when energized) is provided in the middle of the pipe 31 to open and close the pipe 31.

  The pipe 25 connecting the master cylinder 13 and the wheel cylinder 12 is provided with a normally open type (a type that closes when energized) shut-off valve 23, and hydraulic pressure control of the hydraulic fluid is executed. At this time, the valve 25 is closed, and the conduit 25 between the master cylinder 13 and the wheel cylinder 12 is shut off. Further, a normally open type holding valve 24 is provided in the pipe line 25 closer to the wheel cylinder 12 than the shutoff valve 23, and when the holding valve 24 is closed, the holding valve 24 and the wheel cylinder 12 are closed. The hydraulic system on the side is closed, that is, the hydraulic pressure of the hydraulic system on the wheel cylinder 12 side is maintained from the holding valve 24.

  The conduit 25 between the holding valve 24 and the wheel cylinder 12 is connected to the reservoir 28 by a conduit 34. The pipe 34 is provided with a normally closed pressure reducing valve 35. The pressure reducing valve 35 is constituted by an electromagnetic valve such as a linear solenoid valve or a duty solenoid valve, for example, and the communication state of the pipe line 34 can be changed according to the duty ratio by driving the pressure reducing valve 35 with a duty ratio. .

  Therefore, by controlling the open / close state of the pressure reducing valve 35, the communication state of the pipe line 34 can be changed, and the hydraulic pressure (brake hydraulic pressure) of the hydraulic system on the wheel cylinder 12 side from the holding valve 24 can be changed. . For example, from the state in which the brake fluid pressure is maintained, that is, in the state in which the braking torque applied to each of the wheels 3, 4, 9, and 10 is retained, the brake fluid pressure is reduced and each wheel 3, 4, When the braking torque of 9, 10 is reduced, the brake fluid pressure in the wheel cylinder 12 is controlled by controlling the duty ratio of the pressure reducing valve 35 driven by the duty ratio, so that the wheels 3, 4, 9, The braking torque reduction state of 10 can be appropriately controlled.

  As described above, the operation of the brake actuator 14 constituted by the hydraulic pump 21 and various valve devices is controlled by the electronic control device 100. That is, the operation of the brake actuator 14 is controlled by the electronic control device 100, and the hydraulic pressure in the wheel cylinder 12 of the braking device 11 is controlled to increase or decrease. Therefore, based on the signal output from the electronic control unit 100, the braking device 11 provided on each wheel 3, 4, 9, 10 is controlled, that is, added to each wheel 3, 4, 9, 10. Each braking torque can be controlled and the value of the braking torque can be set. In other words, by controlling the operation of the brake actuator 14 based on the signal output from the electronic control device 100, each wheel 3, 4, 9, 10 braking torques can be controlled.

  FIG. 7 schematically shows the configuration of the electronic control device 100. The electronic control device 100 includes a wheel speed sensor 101 that detects the rotation speed (number of rotations and rotation direction) of each wheel 3, 4, 9, and 10, a shift position sensor 102 that detects the shift position of the shift lever, and a brake pedal. 36, a brake pedal sensor 103 that detects a depression amount (depression angle) or depression pressure, an accelerator pedal sensor 104 that detects an depression amount (depression angle) or depression pressure or depression time of an accelerator pedal (not shown), and the engine 1 The throttle valve sensor 105 for detecting the throttle opening of the electronic throttle valve 1a provided in the vehicle, the drive torque sensor 106 for detecting the drive torque of each wheel 3, 4, 9, 10 and the longitudinal acceleration of the vehicle Ve are detected. Longitudinal acceleration sensor 107, Various sensors such as a brake fluid pressure sensor 108 for detecting the brake fluid pressure acting on the wheel cylinder 12 and a vibration sensor 109 for detecting the vibration generated in each brake device 11 are provided, and output signals of these sensors are provided. Is input to the electronic control unit 100.

  Various types of data are stored in the electronic control device 100, and the electronic throttle valve 1a and the brake are transmitted from the electronic control device 100 based on the signal input to the electronic control device 100 and the stored data. A signal for controlling the actuator 14 is output.

  Here, the rotational speed and direction of the wheels 3, 4, 9, and 10 detected by the wheel speed sensor 101, the shift position detected by the shift position sensor 102, or the longitudinal acceleration sensor 107, respectively. The running state of the vehicle Ve can be detected by performing arithmetic processing with the electronic control device 100 based on the detected value such as the longitudinal acceleration of the vehicle Ve. Therefore, the electronic control device 100, the wheel speed sensor 101, the shift position sensor 102, the longitudinal acceleration sensor 107, and the like function as the traveling state detection means in the present invention.

  Among these, in particular, the electronic control unit 100 is based on detected values such as the rotation direction of each wheel 3, 4, 9, 10 detected by the wheel speed sensor 101 or the shift position detected by the shift position sensor 102. By calculating, it is possible to detect the traveling direction of the vehicle Ve. Therefore, the electronic control device 100, the wheel speed sensor 101, the shift position sensor 102, and the like function as traveling direction detection means in the traveling state detection means of the present invention. Further, electronic control is performed based on detected values such as the rotational speed and rotational direction of the wheels 3, 4, 9, and 10 detected by the wheel speed sensor 101, or the longitudinal acceleration of the vehicle Ve detected by the longitudinal acceleration sensor 107, respectively. By performing arithmetic processing with the apparatus 100, the longitudinal acceleration state of the vehicle Ve can be detected. Therefore, the electronic control device 100, the wheel speed sensor 101, the longitudinal acceleration sensor 107, and the like function as longitudinal acceleration detection means in the traveling state detection means of the present invention.

  Further, the rotation speed and rotation direction of each wheel 3, 4, 9, 10 detected by the wheel speed sensor 101, or the brake fluid pressure or vibration acting on each wheel cylinder 12 detected by the brake fluid pressure sensor 108, respectively. A brake vibration generated in each braking device 11 can be detected by performing arithmetic processing in the electronic control device 100 based on a detection value such as vibration generated in each braking device 11 detected by the sensor 109. Therefore, the electronic control device 100, the wheel speed sensor 101, the brake fluid pressure sensor 108, the vibration sensor 109, and the like function as vibration detection means in the present invention.

  Furthermore, to each of the braking devices 11 constituted by the wheel cylinders 12, the master cylinders 13, the brake actuators 14 and the hydraulic systems connecting them, and the braking devices 11 of the wheels 3, 4, 9, 10 described above. The electronic control device 100 that outputs a control signal and controls and sets the braking torque applied to each of the wheels 3, 4, 9, and 10 functions as the braking torque setting means in the present invention. Further, the electronic throttle valve 1a of the engine 1, the electronic control device 100 that controls and sets the driving torque to be applied to the driving wheels 3 and 4 by outputting a control signal to the electronic throttle valve 1a, etc. It functions as a torque setting means.

  As described above, the present invention provides a vehicle in which brake vibration or abnormal noise is generated in the braking device 11 during braking of the vehicle Ve, and control is performed to prevent or suppress the occurrence of the brake vibration or abnormal noise. An object of the present invention is to prevent or suppress the passenger from feeling uncomfortable due to a change in the traveling state of Ve against the passenger's intention. For this purpose, the control device of the present invention performs the following control. It is configured.

(First control example)
FIG. 1 is a flowchart for explaining a first control example of the brake vibration prevention control by the control device of the present invention. The routine shown in this flowchart is repeatedly executed every predetermined short time. In FIG. 1, first, it is determined whether or not a brake vibration of a predetermined value α or more has been detected in each braking device 11 (step S101). The predetermined value α is a threshold value set in advance for identifying vibrations at a level that can be recognized by the occupant. The brake vibration is the braking of the wheels 3, 4, 9, 10 as described above. Vibration generated in each part of each braking device 11 when a so-called stick-slip phenomenon occurs due to a slight fluctuation of the braking torque with respect to the driving torque in a state where the torque and the driving torque are substantially balanced with each other. Or the abnormal noise caused by the vibration. Therefore, this brake vibration is, for example, the behavior of the detected value of the rotational speed of each wheel 3, 4, 9, 10 detected by the wheel speed sensor 101, or each wheel cylinder 12 detected by the brake hydraulic pressure sensor 108. Can be detected or estimated based on the behavior of the detected value of the brake fluid pressure acting on the vehicle or the behavior of the detected value of the longitudinal acceleration of the vehicle Ve detected by the longitudinal acceleration sensor 107, respectively. Alternatively, it can be detected by a vibration sensor 109 or a noise sensor (not shown) installed at a predetermined position of each braking device 11.

  If no brake vibration greater than the predetermined value α is detected in any of the braking devices 11 of the wheels 3, 4, 9, and 10, and if a negative determination is made in this step S101, the subsequent control is not executed. The routine is once terminated. On the other hand, when a positive determination is made in step S101 by detecting a brake vibration of a predetermined value α or more in at least one braking device 11 of each of the wheels 3, 4, 9, 10 (for example, When the brake vibration is detected by the vibration sensor 109, the vibration amplitude greater than or equal to the predetermined value α is detected, or when the brake fluid pressure sensor 108 detects the variation of the brake fluid pressure to detect the brake vibration. If the amplitude of the brake fluid pressure fluctuation equal to or greater than the value α is detected), the process proceeds to step S102, and the wheel (vibrating wheel) in which the brake vibration greater than the predetermined value α is detected in the braking device 11 is specified.

  Next, the braking torque and driving torque of each wheel 3, 4, 9, 10 are detected (step S103). Among these, the braking torque of each wheel 3, 4, 9, 10 is calculated based on the brake fluid pressure of each wheel cylinder 12 of each wheel 3, 4, 9, 10 detected by the brake fluid pressure sensor 108, for example. Can do. Further, the drive torques of the wheels 3, 4, 9, and 10 can be calculated based on the detection values of the drive torque sensors 106 provided on the wheels 3, 4, 9, and 10, respectively.

  Further, the braking torque of the vibrating wheel set to suppress the brake vibration in the vibrating wheel is calculated, and distributed to other wheels other than the vibrating wheel based on the set value of the braking torque of the vibrating wheel. The set value (distributed value) of the braking torque to be applied and the driving torque output to the driving wheels 3 and 4 are calculated (step S104). Specifically, first, in order to suppress the brake vibration of the vibrating wheel, the set value of the braking torque of the vibrating wheel is lowered. Then, in consideration of the decrease in the braking torque of the vibrating wheel, that is, even if the braking torque of the vibrating wheel is reduced, the traveling state of the vehicle Ve is not changed and distributed to other wheels other than the vibrating wheel. The braking torque setting value and the driving torque setting value output to the driving wheels 3 and 4 are calculated.

  Subsequently, based on the braking torque setting values of the wheels 3, 4, 9, and 10 calculated in step S104 and the driving torque setting values of the driving wheels 3 and 4, the wheels 3, 4, and 9 are set. , 10 and the driving torque of the driving wheels 3 and 4 are output (step S105). That is, control for suppressing brake vibration is executed.

  Then, it is determined whether or not the brake vibration is suppressed to a desired level, for example, a level smaller than the predetermined value α by executing the brake vibration suppression control (step S106). If the brake vibration has not yet been suppressed to the desired level, and a negative determination is made in step S106, the process returns to the above-described step S102, and the subsequent control is repeatedly executed. On the other hand, if the determination in step S106 is affirmative because the brake vibration has been suppressed to a desired level, this routine is temporarily terminated.

(Second control example)
FIG. 2 is a flowchart for explaining a second control example of the brake vibration prevention control by the control device of the present invention. Like the first control example shown in FIG. The routine is repeatedly executed every predetermined short time. In FIG. 2, first, it is determined whether or not brake vibrations of a predetermined value α or more have been detected in each braking device 11 (step S201).

  If no brake vibration greater than the predetermined value α is detected in any of the braking devices 11 of the wheels 3, 4, 9, and 10, and if a negative determination is made in step S201, the subsequent control is not executed. The routine is once terminated. On the other hand, when a positive determination is made in step S201 by detecting a brake vibration of a predetermined value α or more in at least one braking device 11 of each of the wheels 3, 4, 9, and 10, Then, the process proceeds to step S202, and the wheel (vibrating wheel) in which the braking vibration of the braking device 11 having a predetermined value α or more is detected is specified.

  Subsequently, the braking torque of the specified vibration wheel is reduced, that is, the brake fluid pressure of the wheel cylinder 12 of the vibration wheel is reduced (step S203). In addition, vibrations in the braking device 11 of other wheels other than the vibration wheels are required, and there is a wheel (margin wheel) in which no vibration is generated in the braking device 11 or only a level of vibration smaller than the predetermined value β is generated. It is identified (step S204). Here, the predetermined value β is a threshold value set in advance to identify a vibration at a level that cannot be recognized by the occupant, and may be a value equivalent to the predetermined value α, or may be a predetermined value. It can also be set to a value smaller than α.

  In addition, the brake fluid pressure equivalent to the pressure reduced in step S203 is lowered in step S203, that is, a set value for allocating to the other wheels other than the vibration wheels so that the acceleration / deceleration of the vehicle Ve does not change greatly. The set value for allocating the braking torque equivalent to that to the other wheels to the wheels other than the vibrating wheel is calculated, and the braking torques of the wheels 3, 4, 9, 10 are output based on the set value of the braking torque. (Step S205). That is, control for suppressing brake vibration is executed.

  Then, it is determined whether or not the amount of change in the longitudinal acceleration of the vehicle Ve due to execution of the brake vibration suppression control as described above is smaller than a predetermined value δ (step S206). The predetermined value δ here is used to identify the amount of change in the longitudinal acceleration at a level at which the occupant feels uncomfortable when the longitudinal acceleration of the vehicle Ve changes due to execution of control for suppressing brake vibration. It is a preset threshold value.

  Therefore, if the amount of change in the longitudinal acceleration of the vehicle Ve due to the execution of the brake vibration suppression control exceeds the predetermined value δ, if a negative determination is made in step S206, the appropriate brake vibration suppression is performed again. In order to execute the control, the process returns to step S204 described above, and the subsequent control is repeatedly executed.

  On the other hand, when the amount of change in the longitudinal acceleration of the vehicle Ve due to execution of the brake vibration suppression control is smaller than the predetermined value δ, if the determination in step S206 is affirmative, step S207 is performed. It is determined whether or not the brake vibration is suppressed to a desired level (for example, a level smaller than the predetermined value α) by executing the brake vibration suppression control. If a negative determination is made in step S207 because the brake vibration has not yet been suppressed to the desired level, the process returns to step S202 described above, and the subsequent control is repeatedly executed. On the other hand, if the determination in step S207 is affirmative because the brake vibration has been suppressed to the desired level, this routine is temporarily terminated.

(Third control example)
FIG. 3 is a flowchart for explaining a third control example of the brake vibration prevention control by the control device of the present invention, and is shown in this flowchart as in the first and second control examples. The routine is repeatedly executed every predetermined short time. In FIG. 3, first, it is determined whether or not brake vibrations of a predetermined value α or more are detected in each braking device 11 (step S301).

  If no brake vibration of a predetermined value α or more is detected in any braking device 11 of each wheel 3, 4, 9, 10 and the determination is negative in this step S301, the subsequent control is not executed. The routine is once terminated. On the other hand, when a positive determination is made in step S301 by detecting a brake vibration of a predetermined value α or more in at least one braking device 11 of each of the wheels 3, 4, 9, and 10, Then, the process proceeds to step S302, and the wheel (vibrating wheel) in which the braking vibration of the braking device 11 having a predetermined value α or more is detected is specified.

  Subsequently, it is determined whether or not the longitudinal acceleration of the vehicle Ve is greater than “0”, that is, whether or not the vehicle Ve is accelerating (step S303). If the vehicle Ve has a longitudinal acceleration greater than “0”, that is, if the vehicle Ve is accelerating, affirmative determination is made in step S303, the process proceeds to step S304 to suppress brake vibration. The braking torque of the vibrating wheel is reduced. At this time, the driving torque is not reduced. Therefore, even when brake vibration suppression control is executed during acceleration of the vehicle Ve, the driving torque is not reduced. In this case, the longitudinal acceleration of the vehicle Ve changes to the deceleration side and the occupant It is possible to avoid giving a sense of incongruity.

  On the other hand, if a negative determination is made in step S303 because the longitudinal acceleration of the vehicle Ve is “0” or less, the process proceeds to step S305, and whether or not the longitudinal acceleration of the vehicle Ve is “0”. That is, it is determined whether or not the vehicle Ve is traveling at a constant speed. If the negative determination is made in step S305 because the longitudinal acceleration of the vehicle Ve is not “0”, that is, the longitudinal acceleration of the vehicle Ve is smaller than “0”, that is, the vehicle Ve is decelerating, Proceeding to step S306, the driving torque of the vibrating wheel is reduced. At this time, the braking torque of the vibrating wheel is not reduced. Therefore, even when the brake vibration suppression control is executed during deceleration of the vehicle Ve, the braking torque is not reduced. In this case, the longitudinal acceleration of the vehicle Ve changes to the acceleration side and the occupant It is possible to avoid giving a sense of incongruity.

  On the other hand, if the longitudinal acceleration of the vehicle Ve is “0”, that is, if the vehicle Ve is traveling at a constant speed and the determination is affirmative in step S305, the process proceeds to step S307, and the vibrating wheel The braking torque and the driving torque are reduced. At this time, the braking torque and the driving torque are reduced in a coordinated manner so that longitudinal acceleration does not occur in the vehicle Ve. Therefore, even when brake vibration suppression control is executed while the vehicle Ve is traveling at a constant speed, no new longitudinal acceleration occurs in the vehicle Ve. In this case, the vehicle speed of the vehicle Ve changes. It can be avoided that the passenger feels uncomfortable.

  As described above, when the braking torque of the vibrating wheel is reduced in step S304, or when the driving torque of the vibrating wheel is reduced in step S306, or the braking torque and driving torque of the vibrating wheel are reduced in step S307. When it is lowered, the process proceeds to step S308, and it is determined whether or not the brake vibration is suppressed to a desired level (for example, a level smaller than the predetermined value α) by executing the control for suppressing the brake vibration. Is done. If a negative determination is made in step S308 because the brake vibration has not yet been suppressed to a desired level, the process returns to step S302 described above, and the subsequent control is repeatedly executed. On the other hand, if the determination in step S308 is affirmative because the brake vibration has been suppressed to the desired level, this routine is temporarily terminated.

(Fourth control example)
FIG. 4 is a flowchart for explaining a fourth control example of the brake vibration prevention control by the control device of the present invention. This flowchart is similar to the first, second, and third control examples described above. The routine indicated by is repeatedly executed every predetermined short time. In FIG. 4, first, it is determined whether or not brake vibrations of a predetermined value α or more are detected in each braking device 11 (step S401).

  If no brake vibration of a predetermined value α or more is detected in any braking device 11 of each wheel 3, 4, 9, 10 and the determination is negative in this step S401, the subsequent control is not executed. The routine is once terminated. On the other hand, when a positive determination is made in step S401 by detecting a brake vibration of a predetermined value α or more in at least one braking device 11 of each of the wheels 3, 4, 9, and 10, Then, the process proceeds to step S402, and the wheel (vibrating wheel) in which the braking vibration of the braking device 11 having a predetermined value α or more is detected is specified.

  Subsequently, it is determined whether or not the vehicle speed of the vehicle Ve is greater than “0”, that is, whether or not the vehicle Ve is traveling forward (step S403). If the vehicle speed of the vehicle Ve is greater than “0”, that is, if the vehicle Ve is traveling forward, affirmative determination is made in step S403, the process proceeds to step S404 to suppress brake vibration. In addition, it is permitted to control the braking torque and driving torque of the vibrating wheel. Then, brake vibration suppression control such as control for changing the braking torque, control for changing the driving torque, or control for changing the braking torque and the driving torque in a coordinated manner is executed (step S405).

  On the other hand, if the vehicle speed of the vehicle Ve is “0” or less, and a negative determination is made in step S403, the process proceeds to step S406, where the vehicle body speed of the vehicle Ve is smaller than “0”. Whether or not the vehicle Ve is traveling backward is determined. When the vehicle body speed of the vehicle Ve is not smaller than “0”, that is, when the vehicle body acceleration of the vehicle Ve is “0”, that is, when the vehicle Ve is stopped, a negative determination is made in step S406. Does not execute the subsequent control, and terminates this routine once.

  On the other hand, if the vehicle speed of the vehicle Ve is smaller than “0”, that is, if the vehicle Ve is traveling backward, affirmative determination is made in step S406, the process proceeds to step S407 to suppress brake vibration. In order to do so, it is allowed to reduce the driving torque of the vibrating wheel. In other words, when brake vibration suppression control is executed during reverse travel of the vehicle Ve, it is prohibited to control the braking torque of the vibrating wheel and increase the driving torque of the vibrating wheel. Only a reduction in torque is allowed. In general, the driving operation of the vehicle Ve is not easier during backward traveling than when traveling forward, but when brake vibration suppression control is executed during backward traveling of the vehicle Ve as described above. Because it is only allowed to reduce the driving torque of the vibrating wheel, for example, the braking torque is reduced against the occupant's intention and the vehicle is accelerated, thereby improving the safety of the occupant's driving operation. Can be made.

  Then, as described above, when the braking torque and the driving torque of the vibrating wheel are controlled in step S405 or the driving torque of the vibrating wheel is reduced in step S408 in order to suppress the brake vibration, step S409 is performed. It is determined whether or not the brake vibration is suppressed to a desired level (for example, a level smaller than the predetermined value α) as a result of execution of the brake vibration suppression control. If the brake vibration is not yet suppressed to the desired level and a negative determination is made in step S409, the process returns to the above-described step S402, and the subsequent control is repeatedly executed. On the other hand, if the determination in step S409 is affirmative because the brake vibration has been suppressed to the desired level, this routine is temporarily terminated.

  As described above, when the control by the control device of the present invention is executed, when the vehicle Ve is braked, the braking torque output to each of the wheels 3, 4, 9, and 10 is substantially equal to the driving torque. When a brake vibration of the braking device 11 due to a so-called stick-slip phenomenon occurs in the vicinity, the brake vibration is detected and a vibration wheel in which the brake vibration is generated is specified. Then, based on the traveling state of the vehicle Ve at that time, either one or both of the setting value of the braking torque and the setting value of the driving torque of each of the wheels 3, 4, 9, and 10 are changed, and the braking device 11 is changed. Brake vibration is suppressed. Therefore, even when the brake is operated during traveling and vibration is generated in the braking device 11, the set value of the braking torque and the set value of the driving torque of each wheel 3, 4, 9, 10 are The vibration is suppressed by appropriately changing according to the traveling state of the vehicle Ve. As a result, when the brake vibration suppression control is executed, it is possible to prevent or suppress the occurrence of a change in the traveling state that is not intended by the occupant and causing the occupant to feel uncomfortable.

  Further, when the brake vibration is generated, the brake vibration is detected, and the longitudinal acceleration of the vehicle Ve is detected as the traveling state of the vehicle Ve. When it is detected that the vehicle Ve is accelerating, the braking torque of the vibrating wheel is reduced, and when it is detected that the vehicle Ve is decelerating, the driving torque of the braking wheel is reduced, and When it is detected that the vehicle Ve is traveling at a constant speed, the braking vibration and the driving torque of the vibrating wheel are reduced in cooperation with each other, thereby suppressing the brake vibration. For this reason, when brake vibration is generated during traveling and the suppression control of the brake vibration is executed, for example, the vehicle Ve is decelerated due to a decrease in driving torque even during acceleration, or the vehicle Ve is decelerating. However, the vehicle torque of the vehicle Ve fluctuates due to the braking torque being lowered and the vehicle Ve accelerating, or the braking torque and the driving torque being independently controlled while the vehicle is running at a constant speed. Can be avoided. As a result, when the brake vibration suppression control is executed, it is possible to prevent or suppress the occurrence of a change in the traveling state that is not intended by the occupant and causing the occupant to feel uncomfortable.

  Further, when the brake vibration is generated, the brake vibration is detected, and the traveling direction of the vehicle Ve is detected as the traveling state of the vehicle Ve. When it is detected that the vehicle Ve is traveling backward, changing the braking torque is prohibited, and only the drive torque is allowed to be reduced, and the brake vibration suppression control is executed. For this reason, during reverse travel where the driving operation is not easy compared to forward travel, the braking torque is reduced and the vehicle Ve is accelerated against the occupant's intention, thereby improving the safety of the drive operation. Can be secured.

  Here, the relationship between the above-described specific example and the present invention will be briefly described. The functional means of the above-described steps S101, S201, S301, and S401 correspond to the vibration detecting means of the present invention, and steps S102, S103, The functional means of S202, S204, S206, S302, S303, S305, S402, S403, and S406 correspond to the traveling state detecting means of the present invention. Of these, the functional means of steps S403 and S406 correspond to the traveling direction detection means of the present invention, and the functional means of steps S303 and S305 correspond to the acceleration detection means of the present invention. The functional means of steps S104, S105, S203 to S205, S304, S306, S307, S404, S405, S407, and S408 correspond to the vibration suppressing means of the present invention.

  The present invention is not limited to the above specific example. In the specific example, the vehicle to which the present invention is applied is an FR type two-wheel drive vehicle, but the vehicle is not a FR type vehicle. It may be a four-wheel drive vehicle.

  Further, in the above specific example, as a device for setting the braking torque of each wheel by controlling the braking device independently of the occupant's operation, the hole cylinder is set by the hydraulic pressure of the hydraulic fluid as shown in FIG. Although an example of a brake actuator that controls the braking torque applied to each wheel by operating is shown, for example, an actuator that operates to apply braking torque to the wheel by an electric servo motor may be used. Any mechanism that controls the braking force applied to the wheels may be used separately from the operation of the occupant such as the depression of the brake pedal or independently of the operation of the occupant.

  In the above specific example, the operation of the electronic throttle valve (throttle opening) is controlled as a device for setting the driving torque of each wheel by controlling the output of the power source independently of the occupant's operation. Although an example of an engine provided with an electronic throttle valve that controls the output torque of each wheel by controlling the output of the engine by means of, is not limited to this, for example, the output of the engine is controlled by controlling the fuel injection amount The engine may include an electronically controlled fuel injection device that controls the driving torque of each wheel. Further, it may be a motor or a motor generator that controls the output torque by controlling the amount of power supplied to control the driving torque of each wheel.

It is a flowchart for demonstrating the 1st control example by the control apparatus of this invention. It is a flowchart for demonstrating the 2nd control example by the control apparatus of this invention. It is a flowchart for demonstrating the 3rd control example by the control apparatus of this invention. It is a flowchart for demonstrating the 4th example of control by the control apparatus of this invention. It is a conceptual diagram which shows typically the power train and control system of the two-wheel drive vehicle which can apply the control apparatus of this invention. It is a conceptual diagram which shows typically the hydraulic system regarding the braking force control of one wheel among the structures of the brake actuator used for the control apparatus of this invention. It is a block diagram which shows roughly the control system used for the control apparatus of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Power source (engine), 1a ... Electronic throttle valve, 2 ... Transmission, 3, 4, 9, 10 ... Wheel, 12 ... Wheel cylinder, 13 ... Master cylinder, 14 ... Brake actuator, 36 ... Brake pedal, 100 DESCRIPTION OF SYMBOLS ... Electronic control device 101 ... Wheel speed sensor 102 ... Shift position sensor 103 ... Brake pedal sensor 104 ... Accelerator pedal sensor 105 ... Throttle valve sensor 106 ... Driving torque sensor 107 ... Longitudinal acceleration sensor 108 ... Brake Fluid pressure sensor 109 ... Vibration sensor Ve ... Vehicle.

Claims (3)

Brake torque setting means for setting the braking torque of each wheel by controlling the braking device independently of the occupant's operation, and vibration detection means for detecting the vibration of the braking device, wherein the vibration is detected by the vibration detection means. In a vehicle control device that suppresses the vibration by controlling the braking torque setting means when detected,
Driving torque setting means for setting the driving torque of each wheel by controlling the output of the power source independently of the operation of the occupant;
Traveling state detecting means for detecting the traveling state of the vehicle;
When the vibration is detected by the vibration detecting unit, the braking torque set by the braking torque setting unit and the driving torque setting unit are set based on the traveling state detected by the traveling state detecting unit. A vehicle control device comprising vibration suppression means for changing at least one of the drive torque. The traveling state detection unit includes a traveling direction detection unit that detects a traveling direction of the vehicle,
The vibration suppression means includes means for reducing the driving torque when the vibration is detected and the vehicle is moving backward when the vibration detection means and the traveling direction detection means are detected. The vehicle control device according to claim 1, characterized in that: The running state detection means includes acceleration detection means for detecting longitudinal acceleration of the vehicle,
The vibration suppressing means reduces the braking torque and detects the vibration when the vibration detecting means and the acceleration detecting means detect the vibration and detect that the vehicle is accelerating. And when it is detected that the vehicle is decelerating, the drive torque is reduced, and when the vibration is detected and the vehicle is detected to be traveling at a constant speed, the braking torque and the drive are reduced. The vehicle control device according to claim 1, further comprising means for reducing torque.

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