JP2002067915A - Braking force control device for combination vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a braking force to wheels of a towed vehicle in a dummy ABS-controlled way for preventing a trailer swing phenomenon even if the towed vehicle connected with a tow car is not provided with ABS. SOLUTION: When the towed vehicle is not provided with ABS, the tow car comprises means STEP3-STEP5 to control a braking pressure or its signal pressure for the towed vehicle on the basis of a detected load of the towed vehicle and an estimate of road surface friction coefficient. In STEP3-STEP5, a braking force gain on the basis of and corresponding to a data map (Fig. 3) is determined from the detected load of the towed vehicle and the estimate of road surface friction coefficient and a braking force frequency on the basis of and corresponding to a data map (Fig. 4) is determined from the estimate of road surface friction coefficient for regulating the braking pressure or its signal pressure according to braking amount with the braking force gain as a multiplier to give intermittently the regulated pressure to the towed vehicle by the braking force frequency.

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 connected vehicle.

[0002]

2. Description of the Related Art Even in a connected vehicle, there is a tendency that an ABS (antilock brake system) is equipped on a towed vehicle. The ABS prevents wheel lock even in the towed vehicle, so that abnormal vehicle behavior (trailer swing phenomenon or jackknife phenomenon) due to this can be prevented. Note that Japanese Patent Application Laid-Open No. 7-75977 discloses an ABS control method.

[0003]

Existing towed vehicles not equipped with ABS are still in heavy use, and when such towed vehicles are connected to the towed vehicle, the amount of brake operation from the towed vehicle is reduced. Is supplied to the towed vehicle, and the braking force based on this is applied to each wheel of the towed vehicle. Become.

The present invention provides a means effective in preventing the trailer swing phenomenon even when the towed vehicle connected to the towable vehicle does not have the ABS in a situation where the towed vehicle without the ABS is still frequently used. With the goal.

[0005]

According to a first aspect of the present invention, there is provided a braking force control device for a connected vehicle, wherein a brake pressure corresponding to a brake operation amount or a signal pressure thereof is supplied from a towing vehicle to a towed vehicle. Means for detecting the load of the tow vehicle, means for detecting the presence or absence of ABS of the tow vehicle connected to the tow vehicle, and when the tow vehicle has no ABS, the tow vehicle based on the detected load of the tow vehicle Means for controlling the brake pressure or the signal pressure thereof to the towing vehicle.

According to a second aspect of the present invention, there is provided a braking force control device for a coupled vehicle, wherein a means for supplying a brake pressure or a signal pressure corresponding to the brake operation amount from the towing vehicle to a towed vehicle, and a means for estimating a road surface friction coefficient. Means for detecting the presence / absence of ABS of the towed vehicle connected to the towed vehicle;
When there is no vehicle, a means for controlling a brake pressure or a signal pressure of the towed vehicle based on the estimated value of the road surface friction coefficient is provided in the towed vehicle.

According to a third aspect of the present invention, there is provided a braking force control device for a connected vehicle, wherein a means for supplying a brake pressure or a signal pressure corresponding to a brake operation amount from the tow vehicle to the tow vehicle, and detecting a load on the tow vehicle. Means for estimating the coefficient of road surface friction, means for detecting the presence or absence of ABS of the tow vehicle connected to the tow vehicle, and the detected load and road surface friction of the tow vehicle when the tow vehicle has no ABS. Means for controlling the brake pressure on the towed vehicle or the signal pressure thereof based on the estimated value of the coefficient on the towed vehicle.

According to a fourth aspect of the present invention, in the braking force control device for a connected vehicle, the means for controlling the brake pressure on the towed vehicle or the signal pressure thereof uses the detected load of the towed vehicle and the estimated value of the road surface friction coefficient. Means for obtaining a braking force gain corresponding to these based on the data map, means for obtaining a corresponding braking force frequency based on the data map from the estimated value of the road surface friction coefficient, and a method for determining whether the towed vehicle has no ABS. Means for adjusting the brake pressure or its signal pressure according to the brake operation amount using the braking force gain as a multiplier, and means for intermittently supplying the adjusted pressure to the towed vehicle at the braking force frequency. And

[0009]

According to the first aspect of the present invention, when the tow vehicle connected to the tow vehicle has no ABS, the brake pressure or the signal pressure corresponding to the brake operation amount is supplied from the tow vehicle to the tow vehicle as it is. Rather, since the control is performed based on the detected load of the towed vehicle, the braking force is appropriately applied to each wheel of the towed vehicle, so that the possibility of the occurrence of wheel lock is reduced.

In the second aspect, when the towed vehicle connected to the tow vehicle has no ABS, the brake pressure or the signal pressure corresponding to the brake operation amount is supplied from the towed vehicle to the towed vehicle as it is. Instead, the control is performed based on the estimated value of the road surface friction coefficient, so that the braking force is appropriately applied to each wheel of the towed vehicle, so that the possibility of the occurrence of wheel lock is reduced.

In the third aspect, when the towed vehicle connected to the tow vehicle has no ABS, the brake pressure or the signal pressure corresponding to the brake operation amount is supplied from the towed vehicle to the towed vehicle as it is. Instead, the vehicle is controlled based on the detected load of the towed vehicle and the estimated value of the road surface friction coefficient, so that the braking force is appropriately applied to each wheel of the towed vehicle, thereby reducing the possibility of wheel lock. Become.

In the fourth invention, when the towed vehicle connected to the towed vehicle has no ABS, the braking force gain and the estimated value of the road surface friction coefficient are obtained from the detected load of the towed vehicle and the estimated value of the road surface friction coefficient. A braking force frequency is required. The brake pressure or its signal pressure according to the brake operation amount is not supplied directly from the towing vehicle to the towed vehicle, but the braking force gain is adjusted to a multiplier, and the adjusted pressure is intermittently applied to the towed vehicle at the braking force frequency Supplied. Therefore, since the braking force acts on each wheel of the towed vehicle in a pseudo ABS control manner, the possibility of the occurrence of wheel lock is reduced.

[0013]

FIG. 1 shows the overall schematic structure of a connected vehicle. Reference numerals 10 to 13 denote brake chambers for generating a braking force on wheels of a towing vehicle 20, and reference numerals 14 and 15 denote towing vehicles 30. A braking chamber for generating a braking force on the wheels of the vehicle; 4, a braking force modulator interposed in a brake circuit of the towing vehicle 20 (air piping connecting each of the brake chambers 10 to 13 to a pressure supply source of the towing vehicle); Towed car 3
0 shows a relay valve interposed in a brake circuit of No. 0 (an air pipe connecting each brake chamber 14 and 15 to a pressure supply source of a towed vehicle).

A front portion of the towed vehicle 30 is connected to a rear portion of the towed vehicle 30 via a fifth wheel coupler. Various connectors (for piping and wiring) are provided between the towing vehicle 20 and the towing vehicle 30, and the braking force modulator 4 of the towing vehicle 20 includes the towing vehicle 3.
0 relay valve 6 is connected. Then, the output of the braking force modulator 4 (each brake chamber 1 of the towing vehicle 30)
The control unit 5 controls the brake pressure to 0 to 13 and the signal pressure to the relay valve 6 of the towed vehicle 30), and various detection means necessary for the control are provided.

7 is a means 7 (brake opening sensor) for detecting the pedal depression angle (brake operation amount) of the brake pedal, 8 is a means 8 (steering angle sensor) for detecting the steering angle of the steering wheel, and 1 is a towing vehicle 20 Means 1 (lateral G sensor) for detecting the lateral acceleration, means 2 (load sensor) for detecting the load of the towed vehicle 30 acting on the coupler, and 3 means the electrical connection of the towed vehicle 30 to the connector of the towed vehicle 20. This is a means for detecting whether or not the wiring is connected (for the towed vehicle 30 connected to the towed vehicle 20, whether or not there is ABS equipment). Although not shown, towing vehicle 2
Means for detecting each wheel speed (tire rotation speed) of 0 is provided.

When the brake pedal is depressed, the control unit 5 controls the braking force modulator 4 for each of the brake chambers 10 to 13 based on the respective wheel speeds (detected values) of the towing vehicle 20 so that locking does not occur for each wheel. The output of the braking force modulator 4 to the relay valve 6 is controlled such that the signal pressure corresponding to the brake operation amount is supplied to the towed vehicle 30. The towed vehicle 3
When the pressure supply source 0 is not mounted, the brake force modulator 4 supplies a brake pressure to the towed vehicle 30 to the relay valve 6 according to the brake operation amount.

In the towed vehicle 30, upon receiving a signal pressure from the braking force modulator 4, the relay valve 6 supplies a corresponding brake pressure from the pressure supply source to each of the brake chambers 14,15. When the ABS is provided, the controller controls the brake pressure from the relay valve 6 to each of the brake chambers 14 and 15 based on each wheel speed of the towed vehicle 30 so as not to lock each wheel. is there.

In the case shown, the towed vehicle 30 is not equipped with an ABS. For this reason, in the control unit 5 of the towing vehicle 20, although not shown, in order to prevent a trailer swing particularly at the time of turning, the vehicle body speed (the average value of each wheel speed of the towing vehicle 20) and the lateral acceleration (detected value) Means for estimating the road surface friction coefficient from the steering angle (detected value), and obtaining the braking force gain from the load (detected value) of the towed vehicle 30 and the estimated value of the road surface friction coefficient based on a data map as shown in FIG. Means for obtaining a braking force frequency from an estimated value of the road surface friction coefficient based on a data map as shown in FIG. 4; and when ABS of the towed vehicle is absent, a signal pressure corresponding to a brake operation amount is set as a control force gain as a multiplier. Means is provided for controlling the output of the braking force modulator 4 to the relay valve 6 so as to adjust and supply the adjustment pressure intermittently at the braking force frequency.

The road surface friction coefficient is obtained by detecting data of a certain period of the vehicle body speed, the steering angle and the lateral acceleration (a very short time from the transition to turning to the start of the ABS control for the towing vehicle 20). Based on these data, these data are input to the coordinate axes as shown in FIG. 2, and the time-series changes are compared with preset reference data, so that the road surface friction coefficient of the closest reference data is selected as the estimated value. is there.

FIG. 5 is a flow chart for explaining the control contents relating to the output of the braking force modulator 4 for the relay valve 6. In step 1, the steering angle, the lateral acceleration and the vehicle speed are detected for a certain period of time. In step 2, based on the detected data, the road surface friction coefficient is estimated from the comparison with the reference data as described above (see FIG. 2,
reference). In step 3, it is determined (detected) whether the towed vehicle 30 connected to the towed vehicle 20 has no ABS equipment.

When the determination in step 3 is no (when the towed vehicle 30 has ABS), the process jumps to END. The control modulator 4 supplies a signal pressure corresponding to the brake operation amount to the relay valve 6 of the towed vehicle 30 based on a command from the control unit 5. When the determination in step 3 is yes (when the towed vehicle 30 has no ABS), step 4 and step 5 are sequentially processed.

In step 4, the load of the towed vehicle 30 is detected. In step 5, the braking force gain is obtained from the load (detected value) of the towed vehicle 30 and the estimated value of the road surface friction coefficient, and the braking force frequency (frequency at which the braking force is applied to the wheels) is obtained from the estimated value of the road surface friction coefficient. (See FIGS. 3 and 4). Then, the braking force gain is used as a multiplier to adjust the signal pressure according to the brake operation amount, and the adjusted pressure is supplied to the towed vehicle 30 at the braking force frequency.
The braking force modulator 4 is controlled.

With this configuration, when the towed vehicle 30 connected to the towable vehicle 20 has an ABS, when the towed vehicle 30 receives a signal pressure from the braking force modulator 4 according to the brake operation amount, The brake pressure from the relay valve 6 to each of the brake chambers 14 and 15 is controlled by the controller of the towed vehicle 30 based on each wheel speed of the towed vehicle 30 so as not to cause locking for each wheel.

When the towed vehicle 30 has no ABS as shown, the signal pressure corresponding to the brake operation amount is equal to the towed vehicle 30.
Instead of being supplied as is, the braking force gain is adjusted to a multiplier, and the adjusted pressure is intermittently supplied at the braking force frequency.
Since it works in a manner controlled by the S control, the occurrence of wheel lock can be avoided. Therefore, even when the towed vehicle 30 connected to the towable vehicle 20 has no ABS, appropriate braking characteristics can be obtained, and abnormal vehicle behavior (such as a trailer swing phenomenon) can be prevented.

In this embodiment, the control unit 5 controls the output of the braking force modulator 4 to the towed vehicle 30 from the load (detected value) of the towed vehicle and the estimated value of the road surface friction coefficient. However, at least one of the braking force gain and the braking force frequency is obtained from only the load (detected value) of the towed vehicle 30 or only the estimated value of the road surface friction coefficient, and based on this, the relay valve 6 is transmitted to the relay valve 6. The signal pressure corresponding to the brake operation amount is supplied to the relay valve 6 as it is, and the possibility of wheel lock is greatly reduced.

The road surface friction coefficient may be estimated from the relationship between the braking force acting on the wheels of the towing vehicle 20 and the deceleration of the rotation of the wheels (change in the slip ratio). Alternatively, the weather condition such as temperature and raindrops may be detected, and the road surface friction coefficient may be selected according to the road surface condition (for example, a frozen road, a wet road, or a dry road).

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an embodiment of the present invention.

FIG. 2 is a characteristic diagram of a road surface friction coefficient.

FIG. 3 is a characteristic diagram of a braking force gain.

FIG. 4 is a characteristic diagram of a braking force frequency.

FIG. 5 is a flowchart illustrating control contents of a control unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lateral G sensor 2 Load sensor 3 Detecting means related to the presence or absence of ABS 4 Braking force modulator 5 Control unit 6 Relay valve 7 Brake opening sensor 8 Steering angle sensor 10-13, 14, 15 Brake chamber

Claims (4)

[Claims] 1. A means for supplying a brake pressure or a signal pressure corresponding to a brake operation amount from a tow vehicle to a tow vehicle, a means for detecting a load of the tow vehicle, and a tow vehicle connected to the tow vehicle Means for detecting the presence or absence of ABS, and
Means for controlling the brake pressure or the signal pressure of the detected towed vehicle based on the detected load of the towed vehicle when there is no BS, and a braking force control device for a connected vehicle, comprising: . 2. A means for supplying a brake pressure or a signal pressure corresponding to a brake operation amount from a tow vehicle to a tow vehicle, a means for estimating a road surface friction coefficient, and an ABS of the tow vehicle connected to the tow vehicle. Means for detecting the presence or absence of
A means for controlling a brake pressure or a signal pressure applied to the towed vehicle based on an estimated value of the road surface friction coefficient when there is no S, the braking force control device for a coupled vehicle, comprising: . A means for supplying a brake pressure or a signal pressure corresponding to the brake operation amount from the towing vehicle to the towed vehicle; a means for detecting a load on the towed vehicle; a means for estimating a road surface friction coefficient; Means for detecting the presence or absence of the ABS of the towed vehicle connected to the towed vehicle, and braking to the towed vehicle based on the detected load of the towed vehicle and the estimated value of the road surface friction coefficient when the towed vehicle has no ABS And a means for controlling the pressure or a signal pressure thereof, provided on the towing vehicle. And means for controlling a brake pressure or a signal pressure applied to the towed vehicle based on a data map based on a detected load of the towed vehicle and an estimated value of a road surface friction coefficient based on a data map. Means for obtaining a braking force frequency corresponding to the estimated value of the road surface friction coefficient based on the data map, and a brake in accordance with the amount of brake operation using the braking force gain as a multiplier when the towed vehicle has no ABS. 4. A system according to claim 3, further comprising means for adjusting the pressure or the signal pressure thereof, and means for intermittently supplying the adjusted pressure to the towed vehicle at a braking force frequency. Power control device.