JP3751752B2 - Brake control device - Google Patents

Description

[0001]
[Technical field to which the invention belongs]
The present invention relates to a brake control device that controls a braking force.
[0002]
[Prior art]
An example of a brake control device including (1) an actuator that operates a brake and (2) an actuator control device that controls the braking force by controlling the actuator is disclosed in Japanese Patent Laid-Open No. 4-278882. Are listed. In the brake control device described in this publication, a control gain for controlling the actuator is determined according to the vehicle speed. When the vehicle speed is high, the control gain is made larger than when the vehicle speed is low. As a result, the response of the brake when the vehicle speed is high can be improved.
However, in the brake control device described in the above publication, as long as the vehicle speed is the same, the control gain is the same in both normal control and non-normal control. Therefore, if the control gain is set to a value suitable for normal control, problems such as a response delay will occur during non-normal control. If the control gain is set to a value suitable for non-normal control, hunting will occur during normal control. There was a problem.
[0003]
[Problems to be Solved by the Invention, Solution, Action and Effect]
Against the background of the above circumstances, an object of the present invention is to obtain a brake control device that can satisfactorily perform brake control both during normal control and during non-normal control. The above-mentioned subject is solved by having a brake control device of the composition of each following mode. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating understanding of the possibility of the combination of features described in each section, and the technical features described in this specification and the combinations thereof are interpreted as being limited to the following. Should not.
(1) an actuator for operating a brake;
And an actuator controller that controls the braking force by controlling the actuator.See
The actuator controller is
Normal braking control means for electrically controlling the actuator based on a brake operation related amount related to an operation amount of a brake operation member during normal braking;
By electrically controlling the actuator, anti-lock control for controlling braking slip to be in an appropriate state, traction control for controlling driving slip to be in an appropriate state, and turning state to be in an appropriate state Non-normal control means for performing at least one of vehicle stability control for controlling
Control gain determining means for making a control gain when controlling the actuator larger than that during control by the normal braking time control means during the at least one control by the non-normal control means;
Brake control device comprising:(Claim 1).
In the brake control device described in this section, the control gain during non-normal control (hereinafter abbreviated as a non-normal control gain) is greater than the control gain during normal control (hereinafter abbreviated as normal control gain). Is increased. Therefore, for example, the normal control gain can be set to a magnitude that can suppress control hunting, and the non-normal control gain can be set to a magnitude that provides high responsiveness.
The normal control is control when normal braking is performed. This is so-called normal braking control, which is control when the brake operation member is operated in a normal state (at a normal operation speed).During normal braking, the actuator is controlled based on the brake operation related amount. For example, control that obtains a braking force corresponding to the braking operation force, that is, braking effect control is performed. Even if a booster is not provided, the brake operation force can be boosted and the brake force corresponding to the operation force can be output as in the case where the booster is provided. This can be referred to as booster control. The brake operation related amount includes the brake operation amount itself such as the operation force of the brake operation member, the operation stroke, etc., and the amount that can be estimated, that is, the master cylinder hydraulic pressure that changes in accordance with the brake operation amount. This corresponds to the amount of change in brake operation amount, the amount of brake operation, the amount of change in brake operation amount, etc.
Non-normal control is control other than normal control.Anti-lock control for controlling the braking slip to be in an appropriate state, traction control for controlling the driving slip in an appropriate state, and vehicle stability control for controlling the turning state to be in an appropriate state. At least one is supposed to be done. Compared to normal control for non-normal controlHigh responsiveness is required. Non-normal control can also be referred to as safety control, preventive safety control, high response demand control, and the like.
The brake described in this section may be operated by hydraulic pressure or may be operated by an electric driving force. For example, in a friction braking device in which a brake is operated by pressing a friction member against a brake rotating body that rotates with a wheel, even if the friction member is pressed by hydraulic pressure, it is pressed by an electric driving force. May be. When the friction member is pressed by hydraulic pressure, the brake cylinder corresponds to the actuator, and a hydraulic control valve device that can control the hydraulic pressure of the brake cylinder and a computer that controls the hydraulic pressure control valve device, etc.Electrically control the actuatorAn actuator control device is configured. In addition, when the friction member is pressed by an electric driving force, the electric motor that moves the friction member corresponds to the actuator, and a command is given to the drive circuit that can control the operating state of the electric motor and the drive circuit. Depending on the computer supplied, Electrically controlling the actuatorAn actuator control device is configured.
The control gain is not limited to the proportional gain, but widely means “the ratio of the output signal to the input signal”. Therefore, “increasing the control gain” includes not only increasing the proportional gain when P control (proportional control) is performed in feedback control, but also I control (integral control), D control (differential control). When the P · I control, P · D control, P · I · D control, or the like, which is a combination of these, is performed, the ratio of the output signal to the input signal is widely increased. Further, not only the feedback control but also a large ratio between these signals is applicable in the feedforward control. In any case, if the ratio of the output signal to the input signal is increased, the change in the input signal is sensitively reflected and the responsiveness is improved.
(2) The actuator is a brake cylinder that operates a brake by hydraulic pressure, and the actuator control device controls the brake cylinder by electrically controlling the brake hydraulic pressure supplied to the brake cylinder. The actuator control device includes a control gain determining means for increasing a control gain when controlling the brake fluid pressure during non-normal control than during normal control. (1) The brake fluid pressure control device according to item.
(3)The actuator control device includes one of a high pressure source and a low pressure source;SaidAn electromagnetic hydraulic pressure control valve that is provided between the brake cylinder and has an opening area determined based on a hydraulic pressure difference between the front and rear of the brake cylinder and an applied voltage, and that controls the applied voltage.SaidA solenoid valve control means for controlling the brake fluid pressure(2) TermThe brake control device described in 1.
In the electromagnetic hydraulic pressure control valve, when the front and rear hydraulic pressure differences are the same, the opening area is increased when the applied voltage is large compared to when the applied voltage is small. When the opening area is large, the hydraulic fluid flow rate is larger than when the opening area is small, so that the speed of change of the braking force is increased and the response is increased. The control gain increases.
(4)The electromagnetic hydraulic control valve includes a valve seat, a valve element provided so as to be able to approach and separate from the valve seat, and a biasing means for biasing the valve element in a direction to approach the valve seat; A seating valve including an electromagnetic driving force applying device that applies an electromagnetic driving force according to the applied voltage in a direction opposite to the biasing force by the biasing unit to the valve element;(3)The brake control device according to item.
A differential pressure acting force, an urging force, and an electromagnetic driving force according to the hydraulic pressure difference between the front and rear act on the seating valve. If the resultant force of these three forces acts in the direction that separates the valve element from the valve seat, the valve element is separated from the valve seat, and the flow of hydraulic fluid is allowed from the opening between the valve element and the valve seat. Is done. If the electromagnetic driving force is increased when the hydraulic pressure difference is the same, the opening area is increased and the working fluid flow rate is increased. Increasing the electromagnetic driving force itself or causing the electromagnetic driving force to increase corresponds to increasing the control gain.
(5) The aboveUnusual control meansIs controlled based on the amount of brake operation when emergency braking is performed by the driver.HandIncluding steps(1) Term or (Four) Any of the termsThe brake control device described.
In the brake control device described in this section, it is detected by a brake operation speed detection device that detects an operation speed of a brake operation member such as a brake pedal, that the brake operation member is operated at an operation speed equal to or higher than a set operation speed. Alternatively, emergency braking is performed based on, for example, detection by the master cylinder hydraulic pressure increase gradient detection device that the increase gradient of the brake hydraulic pressure is equal to or higher than the set increase gradient, and the brake operation amount and brake operation speed at that time are determined. The actuator is controlled based on a brake operation related amount such as a brake fluid pressure increase gradient or a predetermined control pattern, and the braking force is increased. In this sense,Unusual control meansIt can also be called emergency braking control means, emergency brake assist control means, or the like.
(6) The aboveUnusual control meansIs for performing two or more of the anti-lock control, the traction control, and the vehicle stability control, and the control gain determining means includesUnusual control meansMeans for determining said control gain to a different value for said two or more controls during control by(1) Term or (Five) Any of the termsA brake control device according to claim 2.
(7) The actuator control device includes feedback control means for controlling the actuator based on a deviation between a target brake force and an actual brake force, according to any one of (1) to (6). Brake control device.
In the brake control device described in this section, feedback control is performed, and the actual braking force is controlled to almost the target braking force. The target braking force is determined based on the brake operation-related amount at the time of normal braking during normal control, and determined based on the non-normal driving state of the vehicle during non-normal control, or emergency braking. It may be determined based on a brake operation related amount at the time.
[0004]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a brake device including a brake fluid pressure control device as a brake control device according to an embodiment of the present invention will be described with reference to the drawings.
In FIG. 2, 10 is a brake pedal as a brake operation member, and 12 is a master cylinder. The master cylinder 12 is of a tandem type having two hydraulic chambers, and brake cylinders 18 and 20 of left and right front wheels 16 and 17 as drive wheels are connected to one hydraulic chamber via a fluid passage 14. The other hydraulic pressure chamber is connected to brake cylinders 26 and 28 of left and right rear wheels 23 and 24 via a fluid passage 22. This brake device is a front and rear pipe.
The brake device is provided with a hydraulic pressure source 30 different from the master cylinder 12. The hydraulic pressure source 30 pressurizes and stores the hydraulic fluid in the master reservoir 32, and includes a pump 34, a motor 36 that drives the pump 34, an accumulator 38, check valves 40 and 42, a pressure switch 44, and the like. The hydraulic fluid in the master reservoir 32 is pumped up and pressurized by the pump 34 and stored in the accumulator 38. When the hydraulic pressure in the accumulator 38 becomes lower than the set pressure, this is detected by the pressure switch 44 and the motor 36 is driven.
[0005]
An electromagnetic opening / closing valve 50 is provided upstream of the branch position in the middle of the liquid passage 14, and an electromagnetic opening / closing valve 52 is provided between the two brake cylinders 18, 20. Similarly, an electromagnetic opening / closing valve 54 is provided upstream of the branch position of the liquid passage 22, and an electromagnetic opening / closing valve 56 is provided between the two brake cylinders 26, 28.
The electromagnetic on-off valves 50 and 54 are used to connect or shut off the brake cylinder to the master cylinder 12, and are in a communicating state during non-braking, but are switched to a shut-off state during normal braking. The electromagnetic open / close valves 52 and 56 are used to connect and shut off the two brake cylinders. When the hydraulic pressures of the two brake cylinders can be controlled in common, they are kept in communication. When controlling, it is switched to the shut-off state. Since these electromagnetic open / close valves 50 to 56 are normally open valves, they are returned to the communication state when an electric system including the hydraulic pressure source 30 fails, and all the brake cylinders and the master cylinder 12 are made to communicate with each other. In addition, the two brake cylinders on the rear wheel side are communicated with each other, and the hydraulic pressure is the same.
[0006]
The brake cylinders 18 and 20 are connected to the hydraulic pressure source 30 via a fluid passage 60, and brake cylinders 26 and 28 are connected via a fluid passage 62. Electromagnetic on-off valves 64 and 66 are provided upstream of the branch positions in the middle of the liquid passages 60 and 62, respectively. The electromagnetic on-off valves 64 and 66 are normally closed when the hydraulic pressure of the brake cylinder is controlled by using the hydraulic pressure of the hydraulic pressure source 30, but otherwise the closed state is maintained. It is a valve. Since the electric system including the hydraulic pressure source 30 is returned to the shut-off state when the electric system is broken, it is avoided that the hydraulic pressure of the brake cylinder is returned to the master reservoir 32 via the fluid passages 60 and 62.
[0007]
Linear valve devices 70 to 76 are provided between each of the brake cylinders 18, 20, 26, 28, the hydraulic pressure source 30, and the master reservoir 32. Since the structures of these linear valve devices 70 to 76 are the same, only the linear valve device 70 will be described, and description of the other components will be omitted.
[0008]
As shown in FIG. 3, the linear valve device 70 includes a pressure increasing linear valve 80 as a pressure increasing control valve and a pressure reducing linear valve 82 as a pressure reducing control valve. The pressure-increasing linear valve 80 is provided in the middle of the liquid passage 60, and the pressure-reducing linear valve 82 is provided in the middle of the liquid passage 86 that connects the brake cylinder 18 and the master reservoir 32.
The pressure increasing linear valve 80 includes a seating valve 90 and an electromagnetic urging device 94. The seating valve 90 includes a valve body 100, a valve seat 102, an electromagnetically biased body 104 that moves integrally with the valve body 100, and an electromagnetically biased body 104 in a direction in which the valve body 100 is seated on the valve seat 102. And a spring 106 for urging the power. The electromagnetic urging device 94 includes a solenoid 110, a resin holding member 112 that holds the solenoid 110, a first magnetic path forming body 114, and a second magnetic path forming body 116. When a voltage is applied across the windings of the solenoid 110, a current flows through the windings of the solenoid 110 and a magnetic field is formed. If the voltage applied to the winding of the solenoid 110 is changed, the magnetic force (hereinafter referred to as electromagnetic driving force) acting between the electromagnetic biased body 104 and the second magnetic path forming body 116 changes. .
A fitting protrusion 120 is formed on the end surface of the electromagnetic biased body 104 on the second magnetic path forming body 116 side, and the end surface of the second magnetic path forming body 116 on the electromagnetic biased body 104 side is formed. A fitting hole 122 is formed for fitting with the fitting protrusion 120 in a state of being relatively movable in the axial direction. The spring 106 is attached to the fitting hole 122.
[0009]
When a voltage is applied to the solenoid 110, the magnetic path passing through the solenoid 110, the first magnetic path forming body 114, the electromagnetic biased body 104, the second magnetic path forming body 116, the first magnetic path forming body 114, and the solenoid 110. However, the magnetic resistance of the magnetic path between the electromagnetic biased body 104 and the second magnetic path forming body 116 is in the axial direction between the electromagnetic biased body 104 and the second magnetic path forming body 116. It changes depending on the relative position. Specifically, if the axial relative position of the electromagnetic biased body 104 and the second magnetic path forming body 116 changes, the fitting protrusion 120 of the electromagnetic biased body 104 and the second magnetic path forming body The areas of the cylindrical surfaces facing each other with a small distance from the fitting hole 122 of 116 (the portion of the outer peripheral surface of the fitting protrusion 120 and the inner peripheral surface of the fitting hole 122 facing each other) change. If the electromagnetically biased body 104 and the second magnetic path forming body 116 are simply opposed to each other with a minute gap between the end faces, the electromagnetic biased body 104 and the second magnetic path forming body 116 are opposed to each other. As the distance in the axial direction decreases, that is, with an approach, the magnetic resistance decreases at an accelerated rate, and the magnetic force acting between them increases at an accelerated rate. On the other hand, in this pressure-increasing linear valve 80, the area of the cylindrical surface of the fitting protrusion 120 and the fitting hole 122 as the electromagnetically biased body 104 and the second magnetic path forming body 116 approach each other. And the magnetic flux passing through this cylindrical surface increases, while the magnetic flux passing through the air gap between the end face of the electromagnetic biased body 104 and the end face of the second magnetic path forming body 116 decreases. As a result, if the voltage applied to the solenoid 110 is constant, the electromagnetic driving force that urges the electromagnetic biased body 204 in the direction of the second magnetic path forming body 116 will cause the electromagnetic biased body 104 and the second magnetic biasing body 116 to move. It is almost constant regardless of the relative movement in the axial direction with respect to the path forming body 116. On the other hand, the urging force that urges the electromagnetically biased body 104 by the spring 106 in the direction away from the second magnetic path forming body 116 is accompanied by the approach between the electromagnetic biased body 104 and the second magnetic path forming body 116. Increase. Therefore, in a state where the biasing force based on the hydraulic pressure difference is not applied to the valve element 100, the movement of the electromagnetic biased body 104 in the direction of the second magnetic path forming body 116 causes the biasing force and the electromagnetic driving force of the spring 106 to move. Will stop when they become equal.
[0010]
The magnitude of the electromagnetic driving force acting in the direction in which the electromagnetically biased body 104 approaches the second magnetic path forming body 116 increases with the magnitude of the voltage applied to the winding of the solenoid 110 and applies them. The relationship between the voltage and the electromagnetic driving force can be known in advance. When the applied voltage is increased, the electromagnetic driving force is increased, the force for pressing the valve element 100 against the valve seat 102 is reduced, and the valve element 100 is easily separated from the valve seat 102. The biasing force due to the differential pressure of the hydraulic fluid acting on the valve body 100 is the force acting on the electromagnetic biased body 104 (the resultant force of the electromagnetic driving force and the biasing force of the spring 106. When the force is greater than the urging force, they are separated from each other. When the applied voltage is increased, even if the differential pressure is small, the pressure-increasing linear valve 80 can be opened, and the valve opening pressure is reduced.
Further, when the hydraulic pressure difference is the same, the opening area is larger when the applied voltage is large than when the applied voltage is small, and the flow rate of the flowing working fluid is large. The change speed of the braking force increases, and the responsiveness increases.
[0011]
The pressure reducing linear valve 82 is basically the same as the pressure increasing linear valve 80, and when the applied voltage is increased, the valve opening pressure of the pressure reducing linear valve 82 is reduced. In the pressure-reducing linear valve 82, as will be described later, the biasing force of the spring 124 is larger than that of the spring 106 of the pressure-increasing linear valve 80, and is larger than the value corresponding to the maximum brake cylinder hydraulic pressure. This is to prevent backflow of hydraulic fluid from the brake cylinder to the master reservoir 32. Of the configuration of the pressure-reducing linear valve 82, the same components as those of the pressure-increasing linear valve 80 are denoted by the same reference numerals, and description thereof is omitted.
[0012]
The brake device is provided with pressure sensors 140 to 146 that detect the hydraulic pressure of the brake cylinders 18, 20, 26, and 28 and a pressure sensor 148 that detects the hydraulic pressure of the master cylinder 12. In the present embodiment, the operation force of the driver's brake pedal 10 is acquired by detecting the hydraulic pressure of the master cylinder 12, and the master cylinder hydraulic pressure corresponds to the brake operation related amount. Become. Further, a stroke simulator 150 is provided on the upstream side of the electromagnetic opening / closing valve 50 in the liquid passage 14, and when the electromagnetic opening / closing valves 50 and 54 are both closed, the stroke of the brake pedal 10 becomes almost zero. Is avoided. A pressure increasing valve 154 is provided on the upstream side of the electromagnetic opening / closing valve 54 in the liquid passage 22. The pressure increasing valve 154 is a mechanical type in which the hydraulic pressure of the hydraulic pressure source 30 is a pilot pressure. When the hydraulic pressure of the hydraulic pressure source 30 decreases, the pressure increasing valve 154 is switched from the non-intensified state to the increased pressure state. The hydraulic pressure in the master cylinder 12 is increased and transmitted to the wheel cylinders 26 and 28. Further, a brake switch 160 is provided, and it is detected that the brake pedal 10 is depressed. Further, wheel speed sensors 162 to 168 for detecting the rotational speeds of the wheels 16, 17, 23, and 24 are provided, and a braking slip state, a driving slip state, and the like are acquired based on these output signals. Further, a steering sensor 170 for detecting the rotation angle of a steering wheel (not shown) is provided, and a yaw rate sensor 171 for detecting the yaw rate of the vehicle is provided.
[0013]
The brake device is provided with brake fluid pressure control means 172 mainly composed of a computer. The pressure sensors 140 to 146, the brake switch 160, the wheel speed sensors 162 to 168, the steering sensor 170, the yaw rate sensor 171 and the pressure switch 44 are connected to the input portion of the brake fluid pressure control means 172, and the output portion is connected. Are connected to the linear valve devices 70 to 76, solenoids of the electromagnetic on-off valves 50 to 56, 64 and 66, the motor 36, and the like via a drive circuit (not shown). The ROM stores a large number of programs and data such as the linear valve control program represented by the flowchart of FIG.
[0014]
The operation of the brake device configured as described above will be described.
At the time of non-braking, the electromagnetic on-off valves 50 to 56, 64, 66, etc. are in the state shown in FIG. Each brake cylinder 18, 20, 26, 28 is communicated with the master cylinder 12 and is disconnected from the hydraulic pressure source 30.
When the brake pedal 10 is depressed in a normal state, normal braking control is performed. In the normal braking control, the hydraulic pressure of the brake cylinder is controlled so as to obtain a deceleration corresponding to the operating force of the brake operating member. The electromagnetic on-off valves 50 and 54 are switched to the shut-off state, and the electromagnetic on-off valves 64 and 66 are switched to the communication state, so that the electromagnetic on-off valves 52 and 56 are kept in the communication state. The hydraulic pressure of the hydraulic pressure source 30 is controlled and transmitted to the brake cylinders 18, 20, 26, and 28 by the linear valve devices 70 to 76, but the hydraulic pressure of the brake cylinders 18, 20, 26, and 28 is almost the same. Controlled to the same size.
[0015]
In the present embodiment, feedback control is performed, and the applied voltage of the linear valve devices 70 to 76 is determined so that the difference between the target hydraulic pressure and the actual hydraulic pressure becomes small. Target hydraulic pressure PH^*However, by the execution of the normal braking control program, the vehicle deceleration according to the operating force of the driver's brake pedal 10, that is, the vehicle deceleration corresponding to the hydraulic pressure of the master cylinder 12 is determined. The actual fluid pressure PH is detected by the pressure sensors 140-146. This target hydraulic pressure PH^*ΔP (= PH) between the actual hydraulic pressure PH and^*-PH) is the input signal and the applied voltage is the output signal. P · I · D control is performed on the deviation ΔP, and the deviation ΔP and the applied voltage P_EThe transfer function G (s) between
G (s) = K_C(1 + sT_D+ 1 / sT_I)
Represented by Where s is a Laplace operator and T_D, T_IIs the time constant of differentiation and integration, and K_CIs a control gain during normal control (hereinafter referred to as normal control gain).
[0016]
When the operating force of the brake pedal 10 is excessive with respect to the friction coefficient of the road surface, antilock control is performed. In the anti-lock control, the hydraulic pressure of the brake cylinder is controlled so that the braking slip state of each wheel 16, 17, 23, 24 is maintained in an appropriate state. Since anti-lock control is performed for each wheel, the hydraulic pressures of the brake cylinders 18, 20, 26, and 28 are controlled independently, and the electromagnetic on-off valves 52 and 56 are switched to the shut-off state.
Target hydraulic pressure PH during anti-lock control^*Is determined by the execution of the anti-lock control program so that the braking slip state is maintained in an appropriate state as described above. As with normal braking, the target hydraulic pressure PH^*ΔP (= PH) between the actual hydraulic pressure PH and^*-PH), the applied voltage P of the linear valve device 70-76_EIs determined. Deviation ΔP and applied voltage P_EThe transfer function G (s) between
G (s) = K_A(1 + sT_D+ 1 / ST_I)
Represented by Where K_AIs a control gain during anti-lock control (hereinafter referred to as anti-lock control gain).
In this embodiment, anti-lock control gain K_AIs the normal control gain K_CMade bigger. This is to improve responsiveness during anti-lock control and to prevent hunting during normal control.
[0017]
If the driving slip state becomes excessive with respect to the friction coefficient of the road surface, traction control is performed. In the traction control, the hydraulic pressures of the brake cylinders 18 and 20 of the front wheels 16 and 17 that are drive wheels are controlled so that the drive slip state is maintained in an appropriate state. In this embodiment, the electromagnetic on-off valve 50 on the front wheel side is switched to the shut-off state, the electromagnetic on-off valve 64 is switched to the communicating state, the electromagnetic on-off valve 54 on the rear wheel side is kept in the communicating state, and the electromagnetic on-off valve 66 is kept in the shut-off state. Be drunk.
Target hydraulic pressure PH of brake cylinders 18 and 20^*Is determined by execution of the traction control program. Similar to the case of anti-lock control, the target hydraulic pressure PH^*ΔP (= PH) between the actual hydraulic pressure PH and^*-PH), P, I, and D control is performed, whereby the applied voltage P_EIs determined.
Deviation ΔP and applied voltage P_EThe transfer function G (s) between
G (s) = K_T(1 + sT_D+ 1 / ST_I)
Represented by Where traction control gain K_TIs the normal control gain K during normal braking._CGreater value.
The brake cylinders 26 and 28 on the rear wheel side are disconnected from the hydraulic pressure source 30 and communicated with the master cylinder 12. Therefore, when the brake pedal 10 is depressed during control, the hydraulic fluid in the master cylinder 12 is discharged. It is supplied immediately, and it is avoided that the braking effect is delayed.
[0018]
Further, when the turning state exceeds the set state, vehicle stability control is performed. Spin based on steering wheel steering angle, actual yaw rate of the vehicle, etc.Trend valueDrift outTrend valueWhen these values exceed the set values, the spin tendency and the drift-out tendency are considered to be excessive, respectively, and the spin suppression control and the drift-out suppression control are performed. For example, if the spin tendency becomes stronger during the left turn, the braking force of the turning outer wheel (right wheel) is made larger than the braking force of the turning inner wheel (left wheel), and a moment in the right turning direction is applied. When the drift-out tendency becomes stronger, the braking force of the turning inner wheel (left wheel) is made larger than that of the turning outer wheel (right wheel), and a moment in the left turning direction is applied.
[0019]
If the spin tendency becomes excessive during the left turn, the right brake force is increased on the front wheel side. The electromagnetic on-off valves 50 and 64 are both kept in communication, and the electromagnetic on-off valve 52 provided between the brake cylinders 18 and 20 is switched to the shut-off state. The brake cylinder 18 of the left front wheel 16 is in communication with the master cylinder 12, and the hydraulic pressure of the brake cylinder 20 of the right front wheel 17 is controlled. Target hydraulic pressure PH^*Is determined to be a magnitude that gives a moment that can suppress the spin tendency by executing the vehicle stability control program. Similarly, P · I · D control is performed with respect to the deviation ΔP between the target hydraulic pressure and the actual hydraulic pressure, whereby the applied voltage P_EIs determined. Gain K for vehicle stability control_VIs the normal control gain K_CGreater value.
During the spin suppression control, as in the case of the traction control, the brake cylinders 26 and 28 on the rear wheel, which are non-control wheels, are kept in communication with the master cylinder 12, so that the braking effect is maintained. Delays can be avoided.
[0020]
When the drift-out tendency becomes excessive during the left turn, the brakes on both wheels on the drive wheel side are increased and the brake force on the left side on the non-drive wheel side is increased. On the rear wheel side, the hydraulic pressure of the brake cylinder 26 is controlled while the electromagnetic on-off valves 54 and 66 are kept in communication and the electromagnetic on-off valve 56 is kept in a shut-off state.
[0021]
Further, when the operation speed of the brake pedal 10 is higher than the set speed, emergency brake assist control is performed. Target hydraulic pressure PH in this case^*Is determined according to the operating force by executing the emergency brake assist control program. Control gain (brake assist control gain) K during brake assist control_FThe normal control gain K_CGreater value.
[0022]
In the flowchart of FIG. 4, at step 10 (hereinafter abbreviated as S10; the same applies to other steps), any one of antilock control, traction control, vehicle stability control, and emergency brake assist control is controlled. It is determined whether it is medium or not. Whether or not the anti-lock control is being performed is determined based on whether or not the anti-lock control flag is set. The antilock control flag is a flag that is kept in the set state during control and kept in the reset state during non-control by execution of the antilock control program. Hereinafter, similarly, whether or not traction control is being performed, whether or not vehicle stability control is being performed, and whether or not emergency brake assist control is being performed is determined based on the set state of these control flags. If no control is performed, it is determined in S20 whether or not braking is being performed based on the state of the brake switch 160. When braking, the control gain is the normal control gain K in S30._CTo be determined. By executing the normal braking control program, the target hydraulic pressure PH^*Is determined based on the master cylinder hydraulic pressure.^*And the normal control gain K between the actual pressure PH and the deviation ΔP_CBased on the applied voltage P in S40._EIs determined and applied to the linear valve devices 70-76.
On the other hand, for example, when the antilock control is being performed, the control gain is the normal control gain K in S50._CLarger anti-lock control gain K_ATo be determined. In S60, the target hydraulic pressure PH determined by the execution of the anti-lock control program^*Deviation P between the actual hydraulic pressure and the anti-lock control gain K_ABased on the applied voltage P_EIs determined and applied to the linear valve devices 70-78.
Similarly, when traction control, vehicle stability control, and emergency brake assist control are being performed, the control gain is determined to be larger than the normal control gain in S50 and 60, and the applied voltage is determined accordingly. The The antilock control gain, the traction control gain, the vehicle stability control gain, and the emergency brake assist control gain may be collectively referred to, or each may be referred to as a non-normal control gain.
[0023]
Thus, in this embodiment, as shown in FIG. 1, the linear valve devices 70 to 76 are controlled by the linear valve control means 176. In the linear valve control means 176, the applied voltage to be applied to the linear valve devices 70 to 76 is determined based on the deviation between the target hydraulic pressure and the actual hydraulic pressure and the control gain. It is determined according to the execution of the hour control program, antilock control program, traction control program, vehicle stability control program, and emergency brake assist control program.
In this embodiment, an actuator is constituted by the brake cylinders 18, 20, 26, 28, etc., and the linear valve control programs of the linear valve devices 70 to 76 and the brake hydraulic pressure control means 172 are stored and executed by the portions to be executed. A control device is configured. Further, in the actuator control device, a control gain determining unit is configured by a portion that stores and executes S10, S30, and 50 of the brake fluid pressure control unit 172.
Further, a normal braking time control program of the brake fluid pressure control means 172 is stored and executed, and the normal braking time control means 178 is configured to include an antilock control program, a traction control program, a vehicle stability control program, an emergency time. The non-normal control means 180 is configured by a part that stores and executes a brake assist control program or the like. The non-normal control unit 180 includes an anti-lock control unit 190, a traction control unit 192, a vehicle stability control unit 194, an emergency brake assist control unit 196, and the like.
[0024]
In the above embodiment, the control gain is commonly provided in the P / I / D control. However, the control gain may be separately provided in each of the P control, the I control, and the D control. It is sufficient to increase at least one of the control gains. Alternatively, in the feedforward control, when the ratio of the output signal to the input signal is increased, this corresponds to increasing the control gain described in this specification. Further, the present invention can be applied not only to P / I / D control but also to other control such as P control and P / I control. Furthermore, the control mode in vehicle stability control, the mode in emergency brake assist control, and the like are not limited to those in the above embodiment. In emergency brake assist control, the target hydraulic pressure may be determined based not only on the brake operation amount but also on the operation speed and the like. Further, in the brake control device in the above embodiment, the antilock control, the traction control, the vehicle stability control, and the emergency brake assist control can be executed, but it is not necessary to perform all of these,Anti-lock control, traction control, vehicle stability controlIf at least one of the controls can be executedYes.
[0025]
Furthermore, the structure of the actuator is not limited to that in the above-described embodiment, and may be another structure, for example, may include a plurality of electromagnetic on-off valves. Further, the present invention is not limited to a hydraulic brake device, but can be applied to an electrically operated brake device. The present invention can be implemented in various modifications and improvements based on the above.
[Brief description of the drawings]
FIG. 1 is a diagram conceptually showing a brake control apparatus according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of a brake device including the brake control device.
FIG. 3 is a partial cross-sectional view of the entire linear valve device included in the brake control device.
FIG. 4 is a flowchart showing a part of a linear valve device control program stored in a ROM of the brake control device.
[Explanation of symbols]
18, 20, 26, 28 Brake cylinder
70-76 linear valve device
140-148 Pressure sensor
172 Brake fluid pressure control means
176 Linear valve control means
178 Control means during normal braking
180 Unusual control means

Claims (2)

An actuator for operating the brake;
By controlling the actuator, viewed contains an actuator control device for controlling the braking force,
The actuator controller is
Normal braking control means for electrically controlling the actuator based on a brake operation related amount related to an operation amount of a brake operation member during normal braking;
By electrically controlling the actuator, anti-lock control for controlling braking slip to be in an appropriate state, traction control for controlling driving slip to be in an appropriate state, and turning state to be in an appropriate state Non-normal control means for performing at least one of vehicle stability control for controlling
Brake control comprising: control gain determining means for making a control gain when controlling the actuator larger than that during control by the normal braking time control means during the at least one control by the non-normal control means apparatus. The non-normal control means performs two or more controls among the anti-lock control, the traction control, and the vehicle stability control, and the control gain determining means is controlled during the control by the non-normal control means. The brake control device according to claim 1, further comprising means for determining the control gain to be a different value for the two or more controls.

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