JP2000043694A - Braking control device for coupled vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To execute both the yaw moment control and the automatic deceleration control while unstable behavior peculiar to a coupled vehicle is inhibited by operating a first and a second controlled variables to control the yaw motion and automatic deceleration according to the detected traveling condition of the vehicle separately from a driver's braking operation to automatically generate required braking force in a tractor and a trailer wheel. SOLUTION: From the processing results of various sensor signals, operation blocks 84, 86 evaluate the traveling condition, and when a tractor is in the state of oversteering, the target air pressure P1... the increase and decrease pressure of an object wheel is operated according to the required braking force to the controlled wheel from the magnitude of the required yaw moment. With the operation, when the car speed of the tractor and the required decelerating speed of transverse accelerating speed exceed designated thresholds, the operation block 86 operates the target air pressure P1 for obtaining the required decelerating speed, valve control signals ST, SR are formed by a signal forming block 8, and the required braking force is generated in each object wheel. Thus during the behavior control in turning, pushing force from the trailer can be restrained to secure the operation of control for yaw motion and automatic deceleration and its effectiveness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking control device for a connected vehicle suitable for a behavior control technique for stabilizing the behavior of a vehicle when turning.

[0002]

[Related Background Art] For example, Japanese Patent Application Laid-Open No. 3-276852
In Japanese Patent Application Publication No. JP-A-2002-115, there is disclosed a turning control device for causing an actual yaw rate during turning to follow a target yaw rate as a vehicle behavior control technique. On the other hand, Japanese Patent Laying-Open No. 3-42360 discloses a turning behavior control device that automatically activates a brake so that a vehicle speed during turning does not exceed a tire grip limit.

The former turning control device is a technique for generating a yaw moment in a vehicle by giving a braking force difference between left and right controlled wheels, and the control is effective only within a grip limit of a tire. Conceivable. On the other hand, the latter turning behavior control device is a technology for automatically decelerating the vehicle speed at the time of turning to recover the tire grip, and does not actively correct the yaw motion of the vehicle.

[0004] Therefore, if these known turning control devices and turning behavior control devices are applied to one vehicle, and automatic deceleration control is performed to execute yaw motion control while securing the tire grip at the time of turning, it is safer. It is thought that a very favorable behavior control technique can be obtained from a viewpoint.

[0005]

However, in the case of a connected vehicle in which a tractor is used to pull a trailer, it is necessary to consider the unstable behavior of the connected vehicle, which is unique to the connected vehicle, in applying the above-described behavior control technology. Therefore, there are the following problems in the method of controlling the braking force on the trailer wheels.

That is, when both the yaw motion control and the automatic deceleration control are performed on the connected vehicle in parallel, for example, for a tractor wheel, the braking force of each wheel is controlled by a control amount obtained by adding the control amounts of both. Is preferred. In contrast,
For the trailer wheels, it is conceivable that only the automatic deceleration control is performed with priority from the viewpoint of securing the tire grip. However, when the vehicle speed is sufficiently reduced during the actual turning and the automatic deceleration control is terminated, the braking force associated with the yaw motion control remains on the tractor wheels, whereas the braking force is exerted on the trailer wheels at all. Disappears. In such a situation, the pushing force (so-called thrust) applied from the trailer to the tractor suddenly increases during the turn,
The jackknife phenomenon may be caused.

On the other hand, if the braking force is generated with the total control amount for the trailer wheels in order to avoid the above-mentioned problem, the control amount becomes excessively large when the trailer is empty, for example, which tends to cause locking of the wheels. It destabilizes the behavior of the vehicle.

The present invention has been made based on the above-described circumstances, and an object of the present invention is to control both yaw motion control and automatic deceleration control rationally while suppressing unstable behavior peculiar to a connected vehicle. An object of the present invention is to provide a brake control device for a connected vehicle that can function.

[0009]

SUMMARY OF THE INVENTION The above object is achieved by the present invention.
The vehicle is provided with independent braking means which operates independently of the driver's braking operation and control means for controlling the operation. Further, the traveling state of the vehicle is detected by the traveling state detecting means, and information of the detection signal is evaluated by the control means to determine first and second control amounts for executing the yaw motion control and the automatic deceleration control of the vehicle, respectively. Calculate. The control means controls the operation of the independent braking means according to the first and second control amounts, and automatically generates the required braking force on the tractor and the trailer wheel, respectively.

[0010] The control means selects and uses the higher required braking force among the first and second control amounts calculated for the trailer wheel.

In accordance with the first aspect of the present invention, the control means controls the operation of the independent braking means in accordance with the first and second control amounts, so that the yaw motion control and the automatic deceleration control of the vehicle can be performed in parallel. Can be done. At this time, for the trailer wheel, a control amount to be used is selected from the first and second control amounts in accordance with the principle of select high (selection height). Only one of the controls is preferentially performed.

According to a second aspect of the present invention, the control means in the brake control device for a connected vehicle includes:
And the second control amount are used. In this case, a required braking force for executing both yaw motion control and automatic deceleration control is generated at each wheel of the tractor.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, a tractor 1 of an articulated vehicle is provided with an air brake system using an air tank 2, 4, 6 as an operating pressure source. The brake system includes front and rear service brakes. Routes 8 and 10, service brake route 12 for trailer and independent brake route 1
4,16,18.

More specifically, the front service brake path 8 extracts the air pressure of the air tank 2 through the brake valve 20 and supplies the air pressure to the front brake path 24 via the double check valve 22. The rear service brake path 10 is connected to the relay valve 2
The air pressure of the air tank 4 is taken out through 6 and the air pressure is supplied to the rear brake path 30 via the double check valve 28. The relay valve 26 receives a signal pressure from the brake valve 20 through a pilot pressure path 32.

Further, a service brake path 1 for a trailer
2 is an air tank 6 through a dual relay valve 34.
Is supplied to the brake hose 38 via the double check valve 36. The brake hose 38 is connected to a brake coupling of a trailer (not shown). The relay valve 34 receives a signal pressure from the brake valve 20 via the pilot pressure paths 40 and 42.

On the other hand, the independent brake path 14 takes out the air pressure of the air tank 2 through the air supply valve 44 and supplies the air pressure to the front brake path 24 via the double check valve 22. Each of the independent brake paths 16 extracts the air pressure of the air tank 4 through the air supply valve 46 and supplies the air pressure to the rear brake path 30 via the double check valve 28.

The independent brake path 18 is connected to the air supply valve 4.
The air pressure of the air tank 6 is taken out through 8, and the air pressure is supplied to the brake hose 38 via the double check valve 36. The above-described air supply valves 44, 46, 4
Each of the reference numerals 8 comprises a solenoid on-off valve.

The above-described front brake path 24 and rear brake path 30 are connected to the brake chamber 50, respectively.
The front and rear brake paths 24, 30 are respectively connected to the pressure regulating valve 5 as shown in FIG.
2, 54 are interposed. A pressure adjusting valve 56 is also interposed between the outlet port of the double check valve 36 and the brake hose 38. Each of these pressure regulating valves 52, 54, 56 is composed of a solenoid switching valve, and each of the pressure regulating valves 52, 54, 56 has a normal position for ventilating the inserted path, and
The position between an operation position where the downstream pressure connected to the brake chamber 50 is released to the atmosphere and an operation position where the supply air pressure from each of the air tanks 2, 4, and 6 is shut off and the pressure in the brake chamber 50 is maintained. Can be switched.

The tractor 1 has respective air supply valves 44, 46, 48
And an electronic control unit (ECU) 58 for controlling the operation of each pressure regulating valve 52, 54, 56,
Individual air supply valves 44, 46, 48 and pressure regulating valves 52, 5
The ECUs 4 and 56 are electrically connected to the ECU 58.

The above-described independent brake paths 14, 16, 1
8. Air supply valves 44, 46, 48 and pressure regulating valves 52, 5
Independent brake systems including 4, 56
In other words, an independent braking means that operates independently of the depression of the brake pedal, the operation of the trailer brake, or the like is formed, and the operation is controlled by the ECU 58. This independent brake system adjusts the magnitude of the braking force generated on the tractor wheels (FR, FL, RR, RL) by adjusting the brake air pressure for each wheel of the tractor 1 with its operation. In addition, the braking force of the trailer wheel can be adjusted separately from the tractor wheel.

The tractor 1 is equipped with a plurality of sensors as means for detecting its running state and outputting a signal. Specifically, a steering angle sensor 60, a wheel speed sensor 62, a yaw rate sensor 64 , Longitudinal acceleration sensor 6
6 and a lateral acceleration sensor 68 are provided.

In the above-described air brake system, each brake chamber 50 is provided with a brake air pressure sensor 70 for detecting a brake air pressure. In addition,
The brake valve 20 is provided with a depressed air pressure sensor 72 for detecting an outlet air pressure corresponding to the depressed amount of the brake pedal, and the pressure adjusting valve 56 is provided with a trailer-side brake path (not shown). (Not shown) is provided with a trailer air pressure sensor 74 for detecting the outlet air pressure to be supplied toward the outlet. The relay valve 26 (with LSV) is provided with an air pressure sensor 76 for detecting the outlet air pressure.

Referring to FIG. 2, there is shown a connection diagram showing an electrical connection state for the ECU 58 to control the operation of the air brake system of the tractor 1. As illustrated, each of the various sensors described above is electrically connected to the ECU 58, and outputs a detection signal to the ECU 58.

Referring to FIG. 3, there is shown a control block diagram of the braking control device. As illustrated, sensor signals output from various sensors are input to processing blocks 80 and 82 in the ECU 58. In these processing blocks 80 and 82, calculation of the vehicle motion state quantity and determination of the driving operation of the driver are performed, and the calculation result A and the determination result B are output. These calculation and determination results A and B represent the traveling state information of the vehicle, and specifically include information such as the front wheel steering angle δ, the vehicle speed V, the actual yaw rate γ of the tractor 1, the longitudinal acceleration Gx, and the lateral acceleration Gy. Have been.

The ECU 58 has a function of evaluating the running state information and controlling the operation of the above-described air brake system based on the evaluation result. It is programmed in blocks 84 and 86.

In the operation block 84, when the yaw motion of the tractor 1 is evaluated as a result of the turning of the vehicle and it is recognized that the yaw motion needs to be positively corrected, the yaw motion is corrected based on a known yaw rate feedback control law. One control amount is calculated. Specifically, a required restoring or turning yaw moment of the tractor 1 is obtained based on the yaw rate deviation, and a wheel to be controlled for adding the required yaw moment is selected. Then, it calculates the target air pressure P ₁ for each controlled wheel the size of the required yaw moment.

On the other hand, the arithmetic block 86 evaluates information such as the vehicle speed V and the lateral acceleration Gy. As a result, a known automatic deceleration control law is used so that the vehicle speed V and the lateral acceleration Gy do not exceed predetermined allowable values during turning. Is used to calculate the second control amount. Specifically, calculated deceleration necessary to limit the vehicle speed V and the lateral acceleration Gy to the allowable value or less, for calculating a target air pressure P ₂ from the magnitude of the determined deceleration. The permissible values of the vehicle speed V and the lateral acceleration Gy are, for example, a limit vehicle speed and a limit lateral acceleration that do not cause a drift-out, spin, rollover, or the like of the vehicle during a turn, and include a vehicle specification and a road surface friction coefficient. It varies according to the change.

The calculated target air pressures P ₁ and P ₂ (target air pressures for each wheel) are input to the next signal forming block 88. In the signal forming block 88, each of the above-described air supply valves 44, 46, 48 and each of the pressure adjustment valves 52, 54, 5
6 to form a valve actuation signal. Here, the signal forming block 88 has an adding circuit 90 and a selecting circuit 92, and the above-described target air pressures P ₁ and P ₂ are input to these adding and selecting circuits 90 and 92, respectively.

The addition circuit 90 adds two inputs (target air pressures P ₁ and P ₂ ) to obtain a total air pressure (= P ₁ + P ₂ ), and based on the obtained total air pressure, a valve actuation signal S
Form _T. On the other hand, in the selection circuit 92, as a result of comparing the _two target air pressures P ₁ and P ₂ , the valve operation signal S is determined based on the higher target air pressure, that is, the higher target air pressure required by the control. Form _R.

The valve operation signals S _T and S _R are output as control signals for the independent brake system for the tractor wheels and the independent brake system for the trailer wheels, respectively, as shown in the figure. Of these, the valve actuation signal _ST is actually
58 supplies the air supply valves 44 and 46 and the pressure adjustment valves 52 and 54, and the valve operation signal S _R is supplied from the ECU 58 to the air supply valve 48 and the pressure adjustment valve 56.

[0031] In the independent brake system of the tractor wheels, the above-mentioned valve actuation signal S fed on the basis of the _T valves 44, 46 open and separate pressure control valve with air pressure is supplied to the brake passage 14 and 16 52 and 54 Is driven, and the brake air pressure adjusted to the above-described total air pressure is supplied into the brake chamber 50 of the wheel to be controlled.

On the other hand, in the independent brake system for the trailer wheels, the air supply valve 48 is opened based on the valve operation signal S _R to supply air pressure to the independent brake path 18 and to drive the pressure adjusting valve 56 to set the target air pressure. The brake air pressure adjusted to the higher one of the pressures P ₁ and P ₂ is applied to the brake hose 38.
To the brake chamber of the trailer wheel. The driving of the pressure adjusting valves 52, 54, 56 described above is accurately performed by switching their positions at regular intervals.

By controlling the independent brake systems as described above, the required braking force is generated on the tractor wheel and the trailer wheel, respectively, and as a result, the vehicle behavior is observed as a state quantity. The vehicle behavior is detected by various sensors in the form of various state variables, and the processing blocks 80, 8
2 is fed back.

Hereinafter, a procedure for controlling the behavior of the connected vehicle executed according to the control system having the configuration shown in FIG. 3 will be described in detail.

Now, sensor signals from various sensors are processed in processing blocks 80 and 82, and calculation and determination results A and
When B is obtained, the operation blocks 84 and 86 evaluate the running state information included in the results A and B, respectively.

As shown in FIG. 4, when the actual turning circle of the tractor 1 is in the direction shown by the solid arrow in the figure and it is evaluated that the tractor 1 tends to oversteer with respect to the target turning circle shown by the broken arrow. In the calculation block 84, the right front wheel FR outside the turning circle and the left rear wheel RL inside the turning circle are selected as the control target wheels. Then, from the magnitude of the above-mentioned required yaw moment calculates a target air pressure P ₁ on the basis of a requested braking force for obtaining a braking force difference to be applied to between the wheels. In this case, the target air pressure P ₁ of the tractor wheels is only one of the control object wheels, in particular the right front wheel
Pressure increase amount for FR (corresponds to + _BY described later), left rear wheel RL
Pressure reduction amount (corresponding to the later-described -B _Y) means respectively for. Also, the target air pressure P ₁ for the trailer wheel
Is set to a value smaller than, for example, the tractor wheel.

In parallel with the above-mentioned evaluation, when it is evaluated that the required deceleration for limiting the vehicle speed V and the lateral acceleration Gy of the tractor 1 to the allowable values or less respectively exceeds a predetermined threshold, the operation block 86 in, for calculating a target air pressure P ₂ based on the required braking force for obtaining the required deceleration.
The target air pressure P ₂ for the trailer wheels is set to a value larger than, for example, the tractor wheels.

[0038] In the signal forming block 88, the valve control signal S _T, as described above, S _R is formed. At this time, if the direction of the required braking force of the automatic deceleration control than the yaw moment control is high, the valve control signal S _R is formed on the basis of the target air pressure P _2.

Then, as a result of the ECU 58 outputting the valve control signals S _T and S _R to operate the respective independent braking systems, the ECU 58 requests the tractor wheel and the trailer wheel according to the magnitudes of the target air pressures P ₁ and P ₂ , respectively. A braking force is generated.

[0040] In this case, the required braking force B _X automatic deceleration control as shown in FIG. 4, it is generated in all the tractor wheels and the trailer wheels. On the other hand, the required braking force _BY of the yaw moment control is generated only on each wheel to be controlled, and the braking force of the right front wheel FR is the sum of the two required braking forces (B _X + B _Y ). And the braking force of the left rear wheel RL is a magnitude (B _X -B _Y ) obtained by subtracting one from the required braking force.

In the state shown in FIG. 4, due to the braking force difference between the right front wheel FR and the left rear wheel RL due to the yaw moment control, the restored yaw moment M is set so that the actual turning circle of the tractor 1 matches the target turning circle. appear. Further, the vehicle speed V is decreased by the braking force B _X accompanying the automatic deceleration control, the lateral acceleration Gy is also reduced.

[0042] In the state of FIG. 4, is reduced sufficiently vehicle speed V and the lateral acceleration Gy is, the end determination of the automatic deceleration control is satisfied, the output of the target air pressure P ₂ is eliminated from the calculation block 86 in the block diagram of FIG. 3 (P ₂ = 0). in this case,
Valve control signal S _T In the adding circuit 90 simply based on only the target air pressure P ₁ is formed. Incidentally, since there is no subtraction original target air pressure P ₂ for the rear left wheel RL, not selected as the controlled wheel.

On the other hand, the selecting circuit 92, the target air pressure P ₁ is selected in accordance with the principles of the select-high, the valve control signal S _R on the basis of the target air pressure P ₁ is formed.

[0044] In this case, as shown in FIG. 5, for the tractor wheels only required braking force B _Y occurs right front wheel FR, all the trailer wheels are required braking force B _Y with the yaw moment control occurs . Therefore, the trailer wheels do not suddenly enter the no-brake state after the automatic deceleration control ends, and as a result, the pushing force from the trailer is suppressed.

According to the coupled vehicle braking control apparatus of the above-described embodiment, when both the yaw moment control and the automatic deceleration control are operated in parallel, the control with the higher required braking force is given priority to the trailer wheels. Run. At this time,
In the situation where only one of the automatic deceleration controls is completed as described above, the required braking force _BY accompanying the yaw moment control is immediately generated on the trailer wheels, so that the occurrence of the jack knife phenomenon or the like during these controls is suppressed. can do.

Further, in the above-described embodiment, the case where the required braking force on the trailer wheel is higher in the automatic deceleration control than in the yaw moment control is described. Generates a required braking force _{BY for} yaw moment control. Therefore, after the end of the automatic deceleration control, the required braking force _BY for the yaw moment control is continuously generated in FIG.

When the driver is performing the braking operation in FIG. 5, it goes without saying that the left rear wheel RL of the tractor 1 is selected as the control target wheel as in FIG. In this case, braking force caused by the braking operation of the rear left wheel RL is subtracted according to the pressure reduction amount of the target air pressure P _1.

In addition, the specific configurations of the air brake system and the sensors in FIG. 1 can be variously changed, and the specific configuration of the control system for controlling the behavior is limited to the example of FIG. It is not something to be done.

[0049]

As described above, according to the brake control apparatus for a connected vehicle according to the first aspect, the pushing force from the trailer is effectively suppressed during the behavior control during turning, and the yaw motion control and the automatic deceleration are performed. Accurate operation of the control and its effectiveness can be ensured.

Further, since the braking force applied to the trailer wheels is limited to the range of the required braking force associated with the yaw motion control or the automatic deceleration control, the braking force becomes extremely large and the trailer wheels are locked. I won't let you.

According to the brake control device for a connected vehicle according to the second aspect, in addition to the effect of the first aspect, the yaw motion control and the automatic deceleration control can be both efficiently achieved, and the turning performance and the turning stability of the connected vehicle can be improved. Properties can be dramatically improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a tractor equipped with a braking control device according to one embodiment.

FIG. 2 is a conceptual diagram showing a connection relationship between an ECU, sensors, and a solenoid valve.

FIG. 3 is a block diagram showing a configuration of a control system in the braking control device.

FIG. 4 is a diagram showing a state of generation of a braking force on each wheel when yaw moment control and automatic deceleration control are executed.

FIG. 5 is a diagram showing a state of generation of a braking force after the automatic deceleration control is ended from the state of FIG. 4;

[Explanation of symbols]

 1 Tractor 14, 16, 18 Independent brake path (independent braking means) 44, 46, 48 Air supply valve (independent braking means) 52, 54, 56 Pressure regulating valve (independent braking means) 58 ECU (control means) 60 Steering angle Sensor (running state detecting means) 62 Wheel speed sensor (running state detecting means) 64 Yaw rate sensor (running state detecting means) 66 Longitudinal acceleration sensor (running state detecting means) 68 Lateral acceleration sensor (running state detecting means)

Continued on front page F term (reference) 3D045 AA04 BB40 EE21 FF42 GG10 GG25 GG26 GG27 3D046 AA04 BB21 BB31 BB32 HH08 HH21 HH22 HH25 HH26 HH46

Claims (2)

[Claims] 1. A connected vehicle having a tractor and a trailer connected to the tractor and towed, detecting a running state of the vehicle and outputting a detection signal, and a braking operation by a driver. Independent braking means that operates independently of each other to generate a braking force on each of the tractor wheel and the trailer wheel, and that the braking force on each of the tractor wheel and the trailer wheel is adjustable. A detection signal output from the traveling state detecting means is evaluated, a first control amount of a required braking force is calculated based on the evaluation result to control the yaw motion of the vehicle, and a vehicle speed during turning is calculated based on the evaluation result. And a second control amount of the required braking force is calculated so as to limit at least one of the vehicle lateral acceleration to a predetermined allowable value or less, and the calculated first and second control amounts are calculated. Control means for controlling the operation of the independent braking means according to the amount to generate the required braking force on each of the tractor wheel and the trailer wheel, the control means comprising:
And selecting and using the one of the second control amount having the higher required braking force. 2. The braking control apparatus for a connected vehicle according to claim 1, wherein the control means adds and uses the first and second control amounts for each of the tractor wheels. .