JPH09207746A - Method of controlling brake of connection of vehicles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the offset of loading position and the influence of inclinations and projections of road surface by comparing the car body speed of a self-traveling vehicle with the wheel speed of a vehicle to be connected, and controlling the brake force of the wheel of the vehicle to be connected. SOLUTION: The brake pressure of a vehicle to be connected in start of braking is increased with a fixed gradient regardless of the operating quantity of a brake valve until a main device is operated. Therefore, the wheel speed Vw:slip of the vehicle to be connected starts lowering, and when it becomes under a first threshold Vw:slip 1, the brake pressure is transferred to the held state. When the wheel speed Vw:slip is further reduced under a second threshold Vw: slip 2, pressure reduction is started. Thereafter, the wheel speed Vw:slip is restored, and when the wheel deceleration and acceleration Vw:g is smaller than a second threshold Vw:g2 of wheel deceleration and acceleration, the brake pressure is laid in the held state. Further, when the wheel speed Vw:slip is restored and raised over a second threshold Vw:slip 3 of wheel speed, the increase in the brake pressure is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for controlling a brake of a connected vehicle for controlling a braking force of a self-propelled vehicle (truck / tractor) and a connected vehicle (trailer / semi-trailer) in a towed state. Yes, in more detail, in order to prevent an error in detection of the axle load sensor due to the deviation of the load on the connected vehicle, the inclination of the road surface, the inclination of the vehicle caused by the protrusion, or the like, the wheel speed of the connected vehicle is It is possible to control the braking force on the connected vehicle side so that the slip ratio becomes constant with respect to the wheel speed, and thereby perform the braking force control with the braking force distribution appropriately corresponding to the change in the load capacity. The present invention relates to a brake control method and its device.

[0002]

2. Description of the Related Art In a connected vehicle composed of a self-propelled vehicle and a connected vehicle, a self-propelled vehicle (tractor) and a connected vehicle (semi-trailer) are connected by a connecting device (coupler),
If you need to apply the brakes while driving, operate the brake pedal on the driver's seat (tractor side),
The same air pressure is transmitted from the same air pressure source to the tractor side and the trailer side, whereby the brake is applied.

However, in the case of such a brake system, it takes some time from when the driver operates the brake pedal to when the air pressure reaches the brake device on the connected vehicle side, so the service brake (main brake). However, there is a problem in that the vehicle stability deteriorates. Therefore, recently, in order to eliminate such inconvenience,
Instead of an electric signal according to the amount of depression of the brake valve, instead of the conventional service brake mechanism by air pressure transmission, the pressure in the brake cylinder is adjusted by the modulator installed near each wheel so that the pressure value corresponds to the electric signal. Electronically controlled brakes for controlling have been proposed. Note that this type of brake is also equipped with the function of an anti-lock / traction control system.

The outline of the configuration of the electronically controlled brake will be described with reference to FIG. In the figure, reference numeral 1 is a brake valve that outputs a signal corresponding to the stroke of the brake pedal, and a stroke sensor of the brake pedal is built in the brake valve. Reference numeral 2 is a modulator incorporating a sub ECU and a pressure sensor, 3 is a brake chamber, and this brake chamber 3 has a function equivalent to that of a conventional wheel cylinder. 4 is a dual relay valve that proportionally controls pressure according to input pressure, 5 is a parking brake valve, 6 is a wheel speed sensor (vehicle speed sensor), 7 is an electronic control unit (ECU) mounted on the tractor side, and 8 is Signal converter (CAN adapter) that converts input / output signals, 9 is a vehicle height sensor that detects the load on the tractor side, 11 is an additional sensor (such as a temperature sensor), 12 is a traction control servomotor, and 13 is fuel control Governor with electronic timer to execute 1
4 is an exhaust brake valve mainly operated manually, 15 is a retarder controller (fluid type retarder switch), 1
6 is a retarder main body, 17 is an emergency valve which is mainly operated manually, 18 is an electronic control unit (ECU) mounted on the trailer side, 19 is a trailer side vehicle height sensor (load sensor) for detecting a load. ).

In the electronically controlled brake having the above structure,
When the brake pedal is operated, a signal corresponding to the amount of depression of the brake pedal is output from the brake valve 1 and input to the electronic control unit (ECU) 7 on the self-propelled vehicle (tractor) side. The electronic control unit 7 executes the calculation of the braking pressure according to the input signal and the signal such as the load, and outputs the result to the modulator 2 having the tractor side sub ECU and the pressure sensor. The modulator 2 supplies a predetermined pressure to the brake chamber 3 on the tractor side by monitoring a built-in pressure sensor to execute braking. On the side of the connected vehicle (trailer) side, the trailer side electronic control unit 18 executes a predetermined calculation based on the signal from the electronic control unit 7 and the signal from the trailer vehicle height sensor 19 etc. Is output to the modulator 2 having a built-in valve to supply a predetermined pressure to the brake chamber 3 as in the tractor side to execute braking.

While performing the above-mentioned normal brake control, the electronic control unit naturally performs antilock control according to a conventionally known antilock control program based on a signal from a wheel speed sensor, etc. Therefore, traction control is performed. Traction control is
The wheel speed sensor 6 or the like detects the slip state of the wheel and supplies a predetermined pressure to the brake chamber 3 by a signal from each modulator 2 and, if necessary, a signal from an electronic control unit 7 via a signal converter 8. The output state of the engine is controlled by controlling the traction control servomotor 12 or the governor 13 with an electronic timer.

Further, in a system different from the one described above, auxiliary deceleration means provided on the side of the self-propelled vehicle in response to a command from the electronic control unit 7 mainly by operating a manual switch or in combination with engine braking or the like, For example, the exhaust brake 14,
The fluid retarders 15 and 16 can be operated to apply a braking force to the self-propelled vehicle. In this case, the service brake (main brake) that operates by operating the brake pedal.
Separately, the braking force works on the side of the self-propelled vehicle. Since the programs for executing the anti-lock control and the traction control and the structures of the exhaust brake and the fluid retarder are well known in the art, detailed description thereof will be omitted here. Further, the electronic control unit and the ECU incorporated in the modulator can be integrated into one unit if necessary.

[0008]

However, the following problems have been clarified in the electronically controlled brake having the above configuration. That is, in the connected vehicle equipped with the electronically controlled brake, the electronic control devices 7 and 18 of the self-propelled vehicle and the connected vehicle respectively receive electronic signals based on the signals from the pressure sensors and vehicle height sensors 9 and 19 of the respective vehicles. A predetermined calculation is executed by the control devices 7 and 18, and the result is the sub-E
Since a predetermined pressure is supplied to the brake chamber 3 by outputting it to the modulator 2 having a built-in CU and a pressure sensor to execute braking, for example, the above-mentioned vehicle height sensor uses a load sensor installed on the axle. If it is of a type that detects the axial load,
If the load is uneven or the vehicle body is tilted due to road surface inclination or protrusions, the load detection error will increase due to these effects, and proper braking force distribution corresponding to the load capacity can be obtained. Will be difficult. Further, in order to ensure the stability of the vehicle when braking with the connected vehicle, it is effective to prevent the jack knife phenomenon by controlling the braking force of the connected vehicle to be slightly higher than the braking force of the self-propelled vehicle. However, it is difficult to execute such braking force distribution control.

Therefore, in the present invention, the brake cylinder pressure of the vehicle to be connected is determined by the load amount (axial load) with a large detection error.
Instead of calculating and controlling based on, the braking force is controlled so that the wheel speed of the connected vehicle becomes a constant slip ratio with respect to the wheel speed of the self-propelled vehicle, and it appropriately responds to changes in the load capacity. This enables brake control with the appropriate braking force distribution. More specifically, at least one threshold value is determined based on the pseudo vehicle speed of the self-propelled vehicle, the threshold value is compared with the wheel speed of the connected vehicle, and the braking force on the connected vehicle side is determined. Execute control.

According to the present invention, since the coupled vehicle can always perform the brake control based on the average wheel speed of the self-propelled vehicle during the normal braking, the detection error of the sensor due to the deviation of the load is eliminated. In any situation, it is possible to generate a slightly higher braking force than the self-propelled vehicle side, and it is possible to reliably avoid the jack knife phenomenon. The braking force control of the connected vehicle according to the present invention is released when the self-propelled vehicle starts the anti-lock control. In this case, the braking force control of the connected vehicle is set to the pseudo vehicle body speed of the connected vehicle. The standard anti-lock control is performed.

[0011]

Therefore, the technical solution adopted by the present invention is a connected vehicle in which a self-propelled vehicle equipped with an antilock control device and a coupled vehicle equipped with the antilock control device are connected to each other. Therefore, when the self-propelled vehicle is in non-antilock control, the vehicle speed of the self-propelled vehicle and the wheel speed of the connected vehicle are compared, and the braking force of the wheel of the connected vehicle is controlled based on the result. A method for controlling a brake of a connected vehicle, comprising:

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, in addition to the antilock control means, the wheel speed of the vehicle to be connected is automatically controlled in the controller of the vehicle to be connected. It is characterized in that a brake control means for controlling the braking force is provided so that the slip ratio becomes constant with respect to the wheel speed of the traveling vehicle. This brake control means will be described below.

FIG. 1 is a diagram showing the relationship between wheel speed and brake pressure on the side of a vehicle to which the present invention is applied, and FIG. 2 shows that the wheel speed of the vehicle to be connected is constant with respect to the wheel speed of the vehicle. It is a flow chart for controlling brake pressure so that it may become a slip rate. In addition, the self-propelled vehicle and the connected vehicle are equipped with an anti-lock control device capable of performing independent anti-lock control as in the conventional case,
Further, since the entire structure of the electronically controlled brake of the connected vehicle is the same as the electronically controlled brake described in the conventional example, the description of the entire structure thereof will be omitted here.

First, an outline of the braking force control on the connected vehicle side according to the present invention will be described with reference to FIG. In the figure, VV
w is the pseudo vehicle speed of the self-propelled vehicle, Vw: slip1, V
w: slip2, Vw: slip3 are the first, second, and third threshold values of the wheel speed, and Vw: slip is the wheel speed (slip rate) of the connected vehicle, and the threshold values are all It is set based on the vehicle body speed VVw of the self-propelled vehicle. By the way, normally, the above-mentioned respective threshold values used when executing the braking force control are based on the pseudo vehicle body speed of the vehicle having the wheels to be controlled (for example, when executing the braking force control on the self-propelled vehicle side). It is usually set based on the pseudo vehicle body speed of the self-propelled vehicle, and when executing the braking force control on the connected vehicle side, based on the pseudo vehicle body speed of the connected vehicle). However, in the present invention,
In order to control the braking force on the connected vehicle side, the braking force control is executed using a threshold value obtained based on the pseudo vehicle body speed on the self-propelled vehicle side.

The state of the brake control will be described with reference to FIG. 1. The brake pressure of the connected vehicle at the start of braking is applied at a constant gradient regardless of the depression amount of the brake valve until the operation of this device. As a result, the wheel speed Vw: slip on the connected vehicle side starts to decrease as shown in the figure. When the wheel speed Vw: slip falls below the first threshold value Vw: slip1 (that is, when Vw: slip> the first threshold value Vw: slip1), the brake pressure shifts to the holding state, and the wheel speed Vw: slip is further increased. When the pressure decreases and falls below the second threshold value Vw: slip2 (that is, when Vw: slip> second threshold value Vw: slip2), the pressure reduction is started. After that, the wheel speed Vw: sli
When p is recovered and the wheel deceleration Vw: g on the connected vehicle side becomes smaller than the second threshold value Vw: g2 of the wheel deceleration, the brake pressure enters the holding state, and the wheel speed Vw:
The slip is recovered and the second threshold value Vw: sl of the wheel speed is obtained.
When ip3 is exceeded (that is, Vw: slip <third threshold value Vw: slip3), pressurization of the brake pressure is disclosed.

As described above, in this example, the braking force control is executed by using the threshold value obtained based on the pseudo vehicle body speed of the self-propelled vehicle in order to control the braking force of the connected vehicle side. Therefore, when the braking force control is executed, the influence of the uneven loading position, the inclination of the road surface, the protrusion, etc. is eliminated, and a braking force slightly higher than that of the self-propelled vehicle side is generated in any situation. Therefore, the jack knife phenomenon can be surely avoided.

Next, a flow chart for executing the control of this example will be described with reference to FIG. When this program is started, first, at step S0, it is judged whether or not the anti-lock control condition is satisfied for the vehicle.
When the anti-lock control condition is not satisfied, the pseudo vehicle body speed VVw of the self-propelled vehicle (the highest wheel speed of the plurality of wheel speeds of the self-propelled vehicle, and its deceleration / acceleration is a constant value (step S1). For example, the speed limited to 1G] and the wheel speed Vw: slip of the connected vehicle are calculated, and the process proceeds to step S2 to determine whether the self-propelled vehicle is decelerating. When the self-propelled vehicle is decelerating, it is determined in step S3 whether or not the connected vehicle is executing the braking force control, and when it is not executing the braking force control, the process proceeds to step S4 to be connected. Starts applying the vehicle brake pressure. Further, in step S5, the slip ratio (Vw: slip) of each wheel of the connected vehicle with respect to the pseudo vehicle body speed VVw of the self-propelled vehicle is calculated, and step S5
6, the deceleration of each wheel speed of the connected vehicle (Vw:
g) is calculated.

Next, in step S7, it is judged whether or not the brake pressure of the connected vehicle is being reduced (step S4).
If the pressurization is started in step S4, the determination of No is naturally made in this step.) If the brake pressure of the connected vehicle is not reduced, in step S8 the previously obtained Vw: slip is determined. Is the first threshold Vw: s
It is determined whether or not it is larger than lip1, and if it is larger, the process proceeds to step S9 to hold the brake pressure of the wheels of the connected vehicle. That is, referring to FIG. 1, step S
The series of judgments from 7 to step S9 means that the point A in FIG. 1 is judged.

In step S10, it is determined whether the wheel speed of the connected vehicle is accelerating. If not, the process proceeds to step S11, in which the wheel deceleration Vw: g is the first wheel deceleration. It is determined whether the threshold value Vw is larger than g1. That is, in this step, the pressure reducing condition at the time of sudden deceleration is judged in order to judge whether or not the sudden braking is applied. If it is determined in step S11 that rapid deceleration is being performed, the process proceeds to step S12 to start depressurizing the connected vehicle.

Then, in step S13, the wheel deceleration Vw: g of the connected vehicle is compared with the second threshold value Vw: g2 of the wheel deceleration, and the wheel deceleration Vw: g is the second threshold value Vw: g2. If it is larger than step S14,
And the wheel speed Vw: slip reaches the third threshold value Vw: s.
It is determined whether it is smaller than lip3. That is, in steps S13 and S14, the wheel deceleration Vw: g is larger than the second threshold value Vw: g2 (specifically, the state indicated by the dotted line in FIG. 1). In this state, the wheel speed Vw: g2 is further increased. slip is the third threshold value Vw: slip3
It is determined whether or not the value exceeds the point (whether or not point D in the figure is exceeded).

In step S14, the wheel speed Vw: s
If it is determined that lip is smaller than the third threshold value Vw: slip3 (exceeding point D in the figure), the process proceeds to step S15, the brake pressure of the connected vehicle is increased, and the process proceeds to step S16 to end the determination or return. Becomes In step S11, it is determined that the wheel speed of the connected vehicle is not accelerating and the wheel deceleration Vw: g on the connected vehicle side is smaller than the wheel deceleration threshold value Vw: g1 (that is, not sudden braking). Then, the process proceeds to step S18, where the wheel speed Vw: slip of the connected vehicle is the second threshold value Vw: sl.
It is determined whether it is larger than ip2. Wheel speed Vw:
When slip is larger than the second threshold value Vw: slip2, the process proceeds to step S12, the brake pressure of the connected vehicle is reduced, and the control from step S13 is executed. When the wheel speed Vw: slip is smaller than the second threshold value Vw: slip2 in step S18,
In step S14, the timing of brake pressurization is determined.

If it is determined in step S14 that the wheel speed Vw: slip is smaller than the third threshold value Vw: slip3 (point D in the figure has not been exceeded), the program proceeds to step S16 and this program is executed again. repeat. On the other hand, when the self-propelled vehicle is not decelerating in step S2 (that is, when it is determined that the connected vehicle is in the non-braking state), naturally, step S17 is performed.
Then, the brake pressure control of the connected vehicle is ended, and then the process proceeds to step S16 to end the determination or return.

In step S3, if the connected vehicle is executing brake pressure control while the self-propelled vehicle is in the decelerating state, it is not necessary to increase the brake pressure of the connected vehicle, and therefore the process directly proceeds to step S5. The control after step S5 is executed. If the brake pressure of the connected vehicle is being reduced in step S7, step S13
Then, in step S13, the wheel deceleration Vw: g on the connected vehicle side is the second threshold value Vw: g2 of the wheel deceleration.
If it is smaller than step S9, the process proceeds to step S9 and step S9.
The control thereafter is executed, and if it is larger, the control after step S14 described above is executed. In step S10, when the wheel speed of the connected vehicle is accelerating,
The control after step S14 is executed. That is, the timing of brake pressurization is determined in step S14.

As described above, in this program, it is first determined whether or not the self-propelled vehicle satisfies the antilock control condition, and then the braking force control on the coupled vehicle side is performed to determine the pseudo vehicle body speed on the self-propelled vehicle side. Since it is executed by using the threshold value calculated based on the above, the influence of uneven loading position, inclination of road surface, protrusion, etc. is eliminated when the braking force control is executed, and it does It is possible to generate a braking force slightly higher than that on the running vehicle side, and it is possible to reliably avoid the jack knife phenomenon.

In the braking force control on the self-propelled vehicle side while the braking force control on the connected vehicle side is being executed, the brake pressure is calculated by detecting the depression amount of the brake valve and the axial load as in the conventional case. Then run. Further, in the present embodiment, as described above, the jack knife phenomenon of the connected vehicle can be reliably avoided, but in the present embodiment, braking of the connected vehicle is independently performed for each vehicle by using a so-called electronic control device. As a matter of course, the present invention can be applied to any type as long as it is a system for performing control. Alternatively, the vehicle speed of the self-propelled vehicle may be directly detected, and the wheel speed of the connected vehicle may be compared to control the brake of the connected vehicle.

[0026]

As described above in detail, conventionally, when executing the braking force control, the threshold value obtained based on the pseudo vehicle body speed of the vehicle having the wheels to be controlled is used. On the other hand, in the present invention, the braking force control on the connected vehicle side is executed using the threshold value obtained based on the pseudo vehicle body speed on the self-propelled vehicle side. It is possible to eliminate the effects of position deviation, road surface inclination, protrusions, etc., and to perform highly accurate brake control, and to generate a slightly higher braking force than the self-propelled vehicle side in any situation. It is possible to achieve an excellent effect that the jack knife phenomenon can be surely avoided.

[Brief description of drawings]

FIG. 1 is a relationship diagram of wheel speed and brake pressure in brake control according to an embodiment of the present invention.

FIG. 2 is a control flowchart diagram according to the embodiment of the present invention.

FIG. 3 is an overall configuration diagram of a braking force control device for a coupled vehicle.

[Explanation of symbols]

1 Brake valve 2 Modulator with built-in sub ECU and pressure sensor 3 Brake chamber 4 Dual relay valve 5 Parking brake valve 6 Wheel speed sensor (vehicle speed sensor) 7 Electronic control unit (EC) installed on the tractor side
U) 8 Signal converter for converting input / output signals (CAN adapter) 9 Vehicle height sensor for detecting loading load on tractor side 11 Additional sensor (temperature sensor etc.) 12 Traction control servo motor 13 Electronic timer for executing fuel control Governor 14 Exhaust brake valve mainly operated by hand 15 Retarder controller (Fluid type retarder switch) 16 Retarder body 17 Emergency valve 18 Electronic control unit mounted on the trailer side (EC
U) 19 Trailer side vehicle height sensor

Claims (2)

[Claims] 1. A connected vehicle in which a self-propelled vehicle having an antilock control device and a coupled vehicle having an antilock control device are coupled to each other, and the self-propelled vehicle is in non-antilock control,
A brake control method for a connected vehicle, characterized in that a vehicle speed of a self-propelled vehicle and a wheel speed of a connected vehicle are compared with each other, and a braking force of a wheel of the connected vehicle is controlled based on the result. 2. The brake control method for a combined vehicle according to claim 1, wherein the vehicle body speed is a pseudo vehicle body speed calculated from a plurality of wheel speeds of the self-propelled vehicle.