JPH1163211A - Braking control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deceleration feeling corresponding to expectation of a driver when an acceleration operation is stopped by determining a target deceleration ratio, determining a stage of a transmission based on that, performing engine braking, and when shortage occurs, compensating it by a braking means. SOLUTION: When a driver stops operating an accelerator pedal 5 so as to decelerate a car preparing the curved road in front of the car, a target deceleration ratio determination means 6 determines the target deceleration ratio based on the assumed approaching speed defined by the present speed, distance to the curved road and the condition of the curved road. Based on the target deceleration ratio, a shifting stage determination means 12 determines the stage of an automatic transmission 11 which attains desirable engine braking effect with the deceleration ratio almost of the target one, while not exceeding the target deceleration ratio. When shortage occurs, it is compensated by deceleration obtained by braking a brake actuator. It is thus possible to secure a deceleration ratio corresponding to a condition of curved road and expectation of a driver.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking force control device for a vehicle for realizing information on the surroundings of the vehicle and deceleration that meets the driver's expectations.

[0002]

2. Description of the Related Art As a conventional technique, there is, for example, the one shown in FIG. 13 (see Japanese Patent Application Laid-Open No. 5-302666, Japanese Patent Application Laid-Open No. 61-249841, Japanese Patent Publication No. 63-47940, etc.).

The accelerator opening degree sensor 101, accelerator opening degree change detecting means 102, accelerator opening degree change rate measuring means 103, and accelerator opening degree change rate determining means 104
, Gear position holding means 105, automatic transmission 106
Shift speed detecting means 107 and the highest speed shift speed determining means 10
8 is provided.

In this device, when the accelerator return speed exceeds a fixed fixed value, the automatic transmission 106
By holding the current gear position, the engine braking effect is enhanced when the driver suddenly returns to the accelerator in an attempt to decelerate, for example, when the vehicle suddenly cuts ahead or when following the preceding vehicle, That is.

[0005]

However, in such a conventional apparatus, since the simple control of activating or not activating the engine brake according to the operation speed of the accelerator is required, the driver's expectation is not necessarily obtained. It cannot be said that the feeling of deceleration has been obtained. Also, in the case of a stepped automatic transmission, since the gear ratio must be selected from several fixed values, the deceleration is too strong or too weak, and it is not possible to realize a good deceleration feeling. The situation also existed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a braking force control device capable of obtaining a feeling of deceleration expected by a driver when an accelerator is off.

[0007]

According to a first aspect of the present invention, as shown in FIG. 14, regardless of the driver's brake pedal operation,
In a vehicle having braking means capable of generating a braking force, a vehicle surrounding information detecting means for detecting surrounding information of the vehicle, a driver intention detecting means for detecting a driver's intention, and an output from these detecting means Target deceleration determining means for determining a target deceleration of the vehicle in accordance with the target speed, and shift speed determining means for determining a shift speed of the transmission in accordance with the target deceleration determined by the target deceleration determining means. Target engine brake auxiliary braking force determining means for determining a braking force for compensating for a deceleration that is insufficient with engine braking, based on the target deceleration and the deceleration by the engine brake obtained at the gear position determined by the gear position determining means. And brake control means for adjusting the braking force by driving the brake means according to the result determined by the target engine brake auxiliary braking force determination means. Obtain.

[0008] In a second aspect based on the first aspect, an accelerator operation detecting means for detecting a driver's accelerator operation is provided as the driver intention detecting means.

According to a third aspect, in the first aspect, a turn signal operation detecting means for detecting a turn signal operation is provided as the vehicle surrounding information detecting means.

In a fourth aspect based on the first aspect, the vehicle surrounding information detecting means includes a curved road detecting means for detecting a curved road from position information and map information of the vehicle obtained from the navigation system.

In a fifth aspect based on the first aspect, an intersection detecting means for detecting an intersection is provided as the vehicle surrounding information detecting means.

In a sixth aspect based on the first aspect, the vehicle surrounding information detecting means includes an obstacle detecting means for detecting an obstacle in front of the surroundings.

According to a seventh aspect based on the first aspect, there is provided a weather condition detecting means for detecting a weather condition, and a target deceleration changing means for changing a target deceleration according to the detection result.

In an eighth aspect based on the first aspect, a target value smoothing means for smoothing a change in the rise of the target deceleration is provided.

[0015]

According to the first invention, when deceleration is required by the detection of the vehicle surrounding information detecting means and the driver's intention detecting means, the target deceleration is determined according to these detections. Based on the above, the gear position of the transmission is determined and braking by the engine brake is performed, and the shortage of the engine brake is compensated for by braking by the brake means, and deceleration is performed. Therefore, it is possible to obtain a deceleration that matches the surroundings of the vehicle and the driver's expectations, thereby improving drivability.

According to the second aspect, it is possible to obtain a feeling of deceleration and deceleration suitable for the driver's accelerator operation.

According to the third aspect, the deceleration control expected by the driver can be performed when making a right turn or a left turn.

According to the fourth aspect, in the case of a curved road, the vehicle can enter the curved road at a reduced speed to an appropriate speed and travel.

According to the fifth aspect, in the case of an intersection, the speed can be reduced to an appropriate speed.

According to the sixth aspect, deceleration control that meets the driver's expectation can be performed with respect to the obstacle ahead in the vicinity.

According to the seventh aspect, stable deceleration control can be performed for road conditions such as sunny, rain, snow, and the like.

According to the eighth aspect, a smooth deceleration feeling without deceleration shock can be realized.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of the entire system according to the first embodiment.

The curve road detecting means 1 as the vehicle surrounding information detecting means detects the position of the vehicle, the distance to the curve road ahead of the vehicle, and the information on the curve road from the vehicle position information and map information obtained from the navigation system 2. Detect the radius of curvature.

The accelerator operation detecting means 3 as a driver intention detecting means uses a position sensor using a variable resistor as the stroke sensor 4, for example, and determines the position of the accelerator pedal 5 and the time of the position of the accelerator pedal 5. Detects the accelerator operation speed required from the dynamic change.

The deceleration target value determining means 6 as the target deceleration determining means detects the driver's intention to decelerate based on the detection result of the curve road detecting means 1 and the detection result of the accelerator operation detecting means 3, The target deceleration is set according to a predetermined logic.

The engine controller 7 controls the engine 8 based on the engine speed, the throttle opening TVO, and the like.

The engine operating state detecting means 9 detects the engine output torque from the detected engine speed and the throttle opening TVO by using the entire performance map of the engine shown in FIG. 2 which is measured and stored in advance.

The automatic transmission controller 10 determines a shift speed according to a shift map defined by the throttle opening TVO and the detected vehicle speed, and controls a clutch and a brake in the automatic transmission 11 via a corresponding solenoid valve or the like. Then, the shift is being executed.

The gear position determining means 12 includes an engine output torque (minus torque) obtained from the entire performance map of the engine operating state detecting means 9, a final gear ratio and a tire radius stored in the automatic transmission controller 10 in advance. From the specifications such as the vehicle weight, the deceleration obtained at the shift speed at that time or the deceleration obtained at the shift speed when shifting to a lower speed side is estimated. Then, the estimated deceleration estimated to be obtained at each shift speed is compared with the target deceleration set by the deceleration target value determination means 6, and the deceleration closest to the target deceleration is not exceeded within the target deceleration. The gear position at which deceleration is estimated to be obtained is determined.

Of course, when calculating the deceleration, the characteristics of a starting element such as a torque converter installed between the engine and the automatic transmission 11 are also taken into consideration. For example, in the case of a torque converter, its characteristics are represented by a performance curve shown in FIG. When the lock-up clutch is off,
By using this performance curve to calculate the speed ratio, which is the ratio of the torque converter input shaft rotation speed to the torque converter output shaft rotation speed, the engine output torque obtained from the full engine performance map can be used as the torque converter input torque. Then, the output torque of the torque converter can be obtained. When the lockup clutch is on, the torque converter output torque matches the engine output torque.

The engine brake auxiliary amount determining means 13 as the target engine brake auxiliary braking force determining means calculates the difference between the target deceleration and the deceleration by the engine brake obtained at the speed determined by the speed determining means 12. Calculated as the engine brake assist amount.

The brake controller 14 obtains a target hydraulic pressure value from the engine brake auxiliary amount calculated by the engine brake auxiliary amount determining means 13 by using the relationship between the brake hydraulic pressure and the generated braking force stored in advance. Then, the brake unit 15 is controlled so as to reach the target hydraulic pressure value.

As the automatic transmission 11, for example, the one shown in FIG. 4 is used. This automatic transmission 11 comprises a four-stage transmission composed of two sets of single pinion type planetary gears 20 and 21, four clutches 22 to 25, two brakes 26 and 27, and two one-way clutches 28 and 29. doing.

The first speed state can be achieved by operating the forward clutch 22, the forward one-way clutch 28, and the low one-way clutch 29. Further, if the overrun clutch 23 is engaged in place of the forward one-way clutch 28 and the low & reverse brake 26 is engaged in place of the low one-way clutch 29, the engine brake is activated in the first speed state.

To shift to the second speed state, the band brake 27 may be engaged from the first speed state. To apply the engine brake, the overrun clutch 23
To conclude.

To shift to the third speed state, the band brake 27 is released from the second speed state, and the high clutch 24 is simultaneously engaged. Also in this case, if the overrun clutch 23 is engaged, the engine brake will be effective.

To shift to the fourth speed state, the band brake 27 is engaged again from the third speed state.

As described above, by engaging and disengaging the friction element, it is possible to shift to an arbitrary gear and generate an engine brake.

The system configuration of the brake means 15 is as shown in FIG. The broken line indicates the connection of the electric system, and the solid line indicates the connection of the hydraulic system. In this system, a brake pedal 40 for generating pressure, a booster 41, and a master cylinder 42 are provided in order to match the operation feeling with the normal brake.

In a normal brake operation, when the brake pedal 40 is depressed, the master cylinder pressure is detected by the pressure sensor 43, and the amount of depression of the brake pedal 40 is detected by the stroke sensor 44. The target hydraulic pressure value is determined from the value. The brake actuators 50 to 53 installed on the wheels 45 to 48 are controlled by the brake controller 14 so as to generate a pressure according to a target value, and generate a desired braking force.

On the other hand, the engine brake assist amount determining means 1
3, when the engine brake assist amount is commanded, that is, the deceleration due to the engine brake obtained at the speed determined by the speed determining means 12 is subtracted from the target deceleration from the deceleration target value determining means 6. The brake controller 50 controls the brake actuators 50 to 53 so that the brake controller 14 generates a pressure according to the target value, with the hydraulic pressure value necessary to realize the deceleration for one minute as the target hydraulic pressure value.

Incidentally, 54 to 57 are pressure sensors for detecting each brake pressure.

As the brake actuators 50 to 53, for example, those shown in FIG. 6 are used. The brake operation unit 38 is provided with a brake pedal 4 operated by the driver with his / her feet.
0, a booster 41 that amplifies the pedaling force applied to the pedal 40,
The master cylinder 42 is configured to compress the brake fluid in response to the amplified pedaling force and generate a brake pressure. The master cylinder pressure sensor 43 detects the pressure (M / C pressure) of the master cylinder 42. The hydraulic line 60 shown by a solid line guides brake fluid and transmits pressure.
The wheel cylinder 61 receives the brake pressure generated by the master cylinder 42 and brakes the disk.

The cut valve 62 serves to shut off the master cylinder 42 and the control cylinder 63 by an electric operation and to seal the fluid pressure to the control cylinder 63 side. The solenoid valve 62a, the plunger 62b, the return spring 62c, It is composed of a valve seat 62d, a port 62e, and a port 62f.

The cylinder 63a of the control cylinder 63 has a cut valve 62 and a port 63e connected to the wheel cylinder 61 at the left end, so that the control piston 63b can slide inside. The control piston 63b includes a seal 63c and divides the inside of the cylinder 63a into left and right rooms. When the control piston 63b slides left and right, the volume of the chamber 63d connected to the cut valve 62 and the wheel cylinder 61 changes. The rod 63f transmits the thrust generated by the thrust generator 64 to the control piston 63b.

The spring housing 65 comprises a spring 65a which is preloaded in a mounted state, and a movable spring seat 65b.

The thrust generator 64 includes a control piston 63b
To generate tension and compression forces. The electric motor 64a generates a torque when a current flows. Generally, the torque is proportional to the applied current, so that the torque can be controlled by controlling the current. The pinion 64b transmits the torque generated by the electric motor 64a to the gear 64c, and the gear 64c transmits the torque to the ball screw nut 64d.
The ball screw nut 64d fits the ball with the ball screw shaft 64e, and converts rotational motion and linear motion to each other. The ball screw shaft 64e generates a thrust according to the torque applied to the ball screw nut 64d and transmits the thrust to the rod 63f.
The spline nut 64f and the spline tube 64g are provided so that the ball screw shaft 64e can move left and right, but cannot rotate.

The outline of the operation of the brake means 15 will be described. At the time of non-braking, the control piston 63b is at the neutral position in the figure, and even if the brake pedal 40 is depressed, the control piston 63b is prevented from retreating by the preloaded spring 65a.

At the time of pressure reduction control, the cut valve 62 is closed, and the pressure is reduced by moving the control piston 63b in a direction of increasing the volume of the cylinder 63a on the side communicating with the wheel cylinder 61 (rightward in the figure). This control piston 63b
Is performed by generating the thrust on the control piston 63b by the force of the electric motor 64a via the gear 64c and the ball screw nut 64d.

On the other hand, at the time of pressure increase control, the cut valve 62 is closed, and the pressure is increased by moving the control piston 63b in the direction of reducing the volume in the cylinder 63a (to the left in the figure).

During these controls, the wheel cylinder pressure (W
/ C pressure) and the current of the electric motor 64a as the driving means of the control piston 63b are as shown in FIG. First,
At the time of pressure reduction control, even if the current is increased, the control piston 63b
The control piston 63b does not move until the combined force of the thrust force and the pressure sealed in the cylinder 63a overcomes the force of the spring 65a. When the current increases to a point where the resultant force exceeds the force of the spring 65a, the control piston 63b compresses the spring 65a to reduce the pressure.

On the other hand, during the pressure increase control, the control piston 63b does not move unless the current increases until the piston thrust exceeds the force of the sealing pressure. When the current is increased and the thrust exceeds the sealing pressure, the control piston 63b moves to increase the pressure. Based on the relationship of FIG. 7, a current value corresponding to a desired pressure is commanded to the electric motor 64a to control the pressure.

Hereinafter, the flow of the brake control will be described with reference to the flowcharts of FIGS.

In step 500, it is detected whether or not there is a curved road ahead of the vehicle. In this case, a road image ahead of the vehicle is cut out from the map information around the vehicle possessed by the navigation system 2, and it is determined whether there is a road in the traveling direction. If there is a road in the traveling direction, the alignment of the road is straight, and if there is no road, it can be estimated that there is a curved road (intersections such as T-shaped intersections can be distinguished from the map information). If it is determined that there is a curved road, the process proceeds to step 510.
If it is determined that the road is not a curved road, the process exits this subroutine.

In step 510, a signal from the stroke sensor 4 installed on the accelerator pedal 5 is detected, and it is determined whether or not the accelerator pedal 5 has changed from the on state to the off state. If it is determined that the accelerator pedal 5 has changed from the on state to the off state, the process proceeds to step 520. If it is determined that the accelerator pedal 5 has not changed from the on state to the off state, the process exits this subroutine.

In step 520, it is determined whether a flag indicating that the engine brake control is being performed is set. If not, step 5
Proceed to 30. If set, the process proceeds to step 670.

At step 530, a flag indicating that the engine brake control is being performed is set.

In step 540, the operation speed of the accelerator pedal 5 is determined by calculation. This is obtained from the time change of the signal from the stroke sensor 4 of the accelerator pedal 5.

At step 550, the radius of curvature of the curved road in the vehicle traveling direction is calculated using the map information of the navigation system 2. As a specific method, for example, a node (node) representing a road is followed, a change in direction between adjacent nodes is obtained, a local maximum value is searched from a vehicle position, and each of the nodes on both sides thereof is searched. By obtaining a straight line passing through the midpoint and perpendicular to each node, and calculating the distance between the intersection and the midpoint of one of the nodes, the radius of curvature of the curved road ahead of the vehicle can be obtained.

At step 560, the position of the entrance of the curved road in the vehicle traveling direction is detected using the map information of the navigation system 2. Specifically,
For example, the first node whose direction differs from the vehicle traveling direction by a predetermined angle or more may be detected, and the coordinates of the end on the vehicle side may be set as the curve road entrance point.

In step 570, the passing speed on the curved road is determined as the assumed approach speed from the radius of curvature obtained in step 550. This can be determined by searching a map in which a passing speed on a curved road is determined in advance. Of course, the map can be learned and rewritten to make the speed suitable for each driver. Further, it is possible to estimate that the driver's intention to decelerate is higher as the off-operation speed of the accelerator pedal 5 is higher, so that the assumed approach speed on a curved road can be reduced.

In step 580, the position of the vehicle is detected using the own vehicle position detection function of the navigation system 2.

At step 590, the vehicle speed is detected using the signal from the vehicle speed sensor.

In step 600, a target deceleration is obtained. The target deceleration is calculated by calculating the distance between the own vehicle position and the curve road entrance position, calculating the speed that must be decelerated from the vehicle speed and the assumed approach speed, and calculating the required deceleration based on the calculated deceleration. Deceleration.

In step 610, the current gear position is detected and set as the assumed gear position.

In step 620, a minus torque generated when the engine brake is applied at the assumed gear position is calculated with reference to the full engine performance map, and calculated from the known gear ratio, tire radius, vehicle weight, and the like. Calculate the deceleration that occurs.

In step 630, the deceleration obtained in step 620 is compared with the target deceleration. If the target deceleration is larger, the process proceeds to step 640. If the target deceleration is smaller, the process proceeds to step 650.

In step 640, the assumed shift speed is set to a lower speed (a shift speed at which the engine brake becomes larger).

In step 650, the speed at the time of engine braking is set to one speed higher than the assumed speed (speed at which engine braking becomes smaller).

In step 660, the automatic transmission 11 is controlled so as to control the clutch and brake of the automatic transmission 11 in order to shift to the gear position determined in step 650.
Control each solenoid valve.

At step 670, the brake actuator 5 is adjusted to adjust the deceleration (target deceleration-deceleration due to engine braking at the determined gear position) for the lack.
Output control commands for 0 to 53. In other words, the electric motors 64a and the cut valves 62 of the brake actuators 50 to 53 are controlled so that the hydraulic pressure value realizes the deceleration for the insufficient amount.

As shown in FIGS. 10A and 10B, it is presumed that the driver's intention to decelerate is greater as the off-operation speed of the accelerator pedal 5 is larger, and the target deceleration (deceleration target value) is set. You may make it large.

With such a configuration, there is a curved road ahead in the traveling direction of the vehicle, so that the vehicle speed is reduced.
When the driver releases the accelerator pedal 5, a target deceleration is determined based on an assumed approach speed determined by a current vehicle speed, a distance to a curved road, a situation of a curved road, and the like, and a target deceleration is determined based on the target deceleration. The gear position of the automatic transmission 11 is controlled so that the engine brake with the deceleration closest to the target deceleration can be obtained within a range not exceeding the deceleration, and the shortfall is compensated for by the braking of the brake actuators 50 to 53, Deceleration takes place. Therefore, when the vehicle reaches the entrance of the curved road, the vehicle speed is smoothly reduced to the estimated approach speed.

That is, the assumed approach speed and the target deceleration are appropriately determined for the curved road, and the deceleration is performed by using both the engine brake and the brake actuator.

Accordingly, the deceleration that matches the conditions of the curved road and the driver's expectations is secured, and the drivability is improved.

An intersection detecting means for detecting an intersection based on map information or the like obtained from the navigation system 2 is provided. When there is an intersection ahead of the vehicle in the traveling direction, the current vehicle speed, the distance to the intersection, the accelerator pedal 5 It is also possible to determine the target deceleration based on the operation state, the OFF operation speed, and the like, and perform the deceleration control as described above.

Hereinafter, the second to sixth embodiments will be described.

The second embodiment is directed to an obstacle in front (vehicle in front), and as a vehicle surrounding information detecting means,
An obstacle detection device including a radar device using light, radio waves, ultrasonic waves, and the like, an imaging device for photographing the front of the vehicle and an image processing device is used.

The obstacle detecting device detects the distance to the front obstacle, and detects the relative speed with respect to the front obstacle from a temporal change of the distance.

The deceleration target value determination means detects the driver's intention based on the detection result of the obstacle detection device and the detection result of the accelerator pedal operation detection means, and performs the target deceleration according to a predetermined logic. To determine. in this case,
The target deceleration is increased as the distance to the obstacle in front is shorter, or as the relative speed is greater (as the approaching speed is faster).

Note that, based on the target deceleration, the automatic transmission 11
And the brake actuators 50 to 53 are controlled in the same manner as in the first embodiment.

Therefore, the target deceleration is appropriately determined for the preceding vehicle, and the deceleration that meets the driver's expectation is secured.

The third embodiment relates to road regulation, and is provided with road regulation detecting means for detecting information from a signpost or the like installed on the side of the road as vehicle surrounding information detecting means.

The road regulation detecting means detects the operation state of the traffic light in front of the traveling direction and road regulation such as a stop sign.

The deceleration target value determination means detects the driver's intention based on the detection result of the road regulation detection means, the position of the own vehicle by the navigation system, and the detection result of the accelerator pedal operation detection means, and determines in advance. The target deceleration is determined according to the provided logic. In this case, if the road regulation detecting means detects a situation in which the vehicle must decelerate or stop, and if the accelerator pedal operation detecting means detects the driver's intention to decelerate, the shorter the distance to the regulation point, the higher the vehicle speed. Is larger, the target deceleration is increased.

Note that, based on the target deceleration, the automatic transmission 11
And the brake actuators 50 to 53 are controlled in the same manner as in the first embodiment.

In this way, a target deceleration appropriate for road regulation is obtained, and a deceleration that meets the driver's expectation is secured.

In the fourth embodiment, turn signal operation detecting means for detecting a driver's turn signal operation is provided as vehicle surrounding information detecting means.

The deceleration target value determining means detects the driver's intention based on the detection result of the turn signal operation detecting means, the vehicle speed, and the detection result of the accelerator pedal operation detecting means, and determines the target deceleration. In this case, if the driver's intention to decelerate is detected by the accelerator pedal operation detecting means after the turn signal operation is detected by the turn signal operation detecting means, the target deceleration is increased as the vehicle speed increases.

Note that, based on the target deceleration, the automatic transmission 11
And the brake actuators 50 to 53 are controlled in the same manner as in the first embodiment.

In this way, a deceleration that meets the driver's expectation when making a right or left turn is ensured.

In the fifth embodiment, a weather condition detecting means is provided in each of the above embodiments, and the target deceleration is corrected according to the detection result.

As the weather condition detecting means, for example, means for detecting the operation of the wiper to detect rain, or adding a temperature sensor to detect the operation of the wiper and to judge it as snow when the outside air temperature is low. Conceivable. Alternatively, the weather information may be directly received from a signpost on the roadside, a leaked cable, or the like, or the driver may input a switch from preset options (sunny, rain, snow, etc.).

In this manner, the vehicle can be decelerated in a stable state with respect to the road surface state.

FIG. 11 shows a sixth embodiment. This is because, when controlling to the target deceleration determined by the deceleration target value determining means 6, the target deceleration is applied to a low-pass filter (reference model) 70, and transient deceleration until the target deceleration is reached. This is to smooth the change in speed. That is, the target value smoothing means 70 for smoothing the change of the rise of the target deceleration is provided.

In this manner, the temporal change of the control command value for the brake actuator becomes smooth,
Since there is no deceleration shock due to the rapid rise of the deceleration, the driver does not feel uncomfortable or the driving performance does not deteriorate.

An automatic transmission 1 in the case where a low-pass filter 70 is applied to this target deceleration to smoothly change the control command value over time with respect to the brake actuator.
FIG. 12 shows how the braking force by the engine brake and the auxiliary braking force by the brake actuator change with time according to the change of the shift speed of FIG. In this case, the speed of the automatic transmission 11 that can obtain the deceleration closest to the target deceleration within a range not exceeding the target deceleration is set to the second speed with respect to the target deceleration determined by the deceleration target value determining means 6. I do.

When the low-pass filter is not used, the speed is immediately changed to the second speed on the basis of the target deceleration, and the insufficient deceleration is compensated by the control of the brake actuator. I'm standing up. For this reason, the driver may feel this as a deceleration shock, which may cause discomfort.

On the other hand, when the low-pass filter 70 is used, as the target deceleration gradually increases, first the control command value to the brake actuator gradually increases. The deceleration gradually increases and reaches a level equal to the deceleration generated by the third-speed engine braking. At this stage, a shift command is issued to the automatic transmission 11 and the gear is shifted to the third speed. At the same time, the command value to the brake actuator temporarily decreases, and only the braking by the engine brake is performed. Thereafter, the command value to the brake actuator gradually increases again, and the deceleration generated by braking of the brake actuator gradually increases. Then, the speed reaches a level equal to the deceleration generated by the braking by the second speed engine brake. At this stage, a shift command is issued to the automatic transmission 11 to shift to the second speed, and at the same time, the command value to the brake actuator temporarily decreases, and only the braking by the engine brake is performed. From here, the command value to the brake actuator gradually increases, and reaches a final target value.

As described above, by controlling the automatic transmission 11 and the brake actuator, a smooth deceleration feeling without any unpleasant deceleration shock can be realized.

In this case, of course, according to the driver's operation speed of the accelerator pedal 5, the distance to a curved road or an intersection, the distance to an obstacle, the relative speed, and the like, the rising characteristic of the low-pass filter 70 ( For example, the time constant of the primary filter, the attenuation coefficient of the secondary filter, etc.) are changed, and the characteristics of the transient change of the deceleration are changed according to the driving environment, the traffic condition, the personality of the driver, and the like. Can also.

In each embodiment, the description has been made on the assumption that the brake actuator which can generate the braking force independently of the operation of the brake pedal is used independently of the four wheels, but the master cylinder is used for one channel (one actuator). A drive device or a drive device that independently drives front and rear brake actuators on two channels may be used. Further, the wheels to be braked by the brake actuator which can generate the braking force irrespective of the operation of the brake pedal may be provided only on the non-drive wheel side.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an entire system according to a first embodiment.

FIG. 2 is a characteristic diagram showing performance characteristics of an engine.

FIG. 3 is a characteristic diagram showing performance characteristics of a torque converter.

FIG. 4 is a sectional view of the configuration of the automatic transmission.

FIG. 5 is a configuration diagram of a system of a brake unit.

FIG. 6 is a configuration sectional view of a brake actuator.

FIG. 7 is a characteristic diagram of a brake actuator.

FIG. 8 is a flowchart showing control contents.

FIG. 9 is a flowchart showing control contents.

FIG. 10 is a characteristic diagram showing a setting example of a target deceleration.

FIG. 11 is a configuration diagram of an entire system according to a sixth embodiment.

FIG. 12 is an operation characteristic diagram thereof.

FIG. 13 is a system configuration diagram of a conventional example.

FIG. 14 is a configuration diagram of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Curved road detecting means 2 Navigation system 3 Accelerator operation detecting means 4 Stroke sensor 5 Accelerator pedal 6 Deceleration target value determining means 7 Engine controller 8 Engine 9 Engine operating state detecting means 10 Automatic transmission controller 11 Automatic transmission 12 Gear stage determination Means 13 Engine brake auxiliary amount determining means 14 Brake controller 15 Brake means 20, 21 Single pinion type planetary gear 22 to 25 Clutch 26, 27 Brake 28, 29 One-way clutch 38 Brake operation unit 40 Brake pedal 41 Booster 42 Master cylinder 43 Pressure sensor 44 Stroke sensor 45-48 Wheel 50-53 Brake actuator 54-57 Pressure sensor 60 Hydraulic piping 61 Wheel cylinder 62 Cut valve 6 a solenoid coil 62b, the plunger 62e, f port 63 control cylinder 63a cylinder 63b control piston 63e port 64 thrust generator 64a electric motor 64e ball screw shaft 65a spring 65b movable spring seat 70 low-pass filter

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI // F16H 59:18 59:48 59:52 59:54 59:60 59:62 59:66 63:12

Claims (8)

[Claims] 1. A vehicle having a brake means capable of generating a braking force irrespective of a driver's operation of a brake pedal, comprising: vehicle surrounding information detecting means for detecting surrounding information of the vehicle; A driver intention detecting means for detecting, a target deceleration determining means for determining a target deceleration of the vehicle in accordance with an output from the detecting means, and a target deceleration determined by the target deceleration determining means. Speed determining means for determining the speed of the transmission, and the target deceleration and the deceleration by the engine brake obtained at the speed determined by the speed determining means.
A target engine brake auxiliary braking force determining means for determining a braking force for compensating for a deceleration which is insufficient in the engine brake; and a braking force by driving the brake means in accordance with a result determined by the target engine brake auxiliary braking force determining means. And a brake control means for adjusting the braking force. 2. The vehicle braking force control device according to claim 1, further comprising: accelerator operation detecting means for detecting a driver's accelerator operation as the driver intention detecting means. 3. The braking force control device for a vehicle according to claim 1, further comprising a turn signal operation detecting means for detecting a turn signal operation as the vehicle surrounding information detecting means. 4. The braking force control device for a vehicle according to claim 1, further comprising a curved road detecting unit that detects a curved road from vehicle position information and map information obtained from a navigation system, as the vehicle surrounding information detecting unit. 5. The vehicle braking force control device according to claim 1, further comprising an intersection detection unit that detects an intersection as the vehicle surrounding information detection unit. 6. The vehicle braking force control device according to claim 1, further comprising an obstacle detecting means for detecting an obstacle in front of the surroundings as the vehicle surrounding information detecting means. 7. The vehicle braking force control device according to claim 1, further comprising weather condition detecting means for detecting a weather condition, and target deceleration changing means for changing a target deceleration according to the detection result. 8. The vehicle braking force control device according to claim 1, further comprising target value smoothing means for smoothing a change in the rise of the target deceleration.