JPH08119083A - Ascent starting auxiliary device - Google Patents

Abstract

PURPOSE: To automatically sense an abnormal condition in a vehicle speed sensor by providing a means, which carries out control as if a vehicle is in a traveling condition even though a vehicle speed display indicates 0 when vibration beyond the predetermined amplitude is detected within the predetermined time in a sensor input, in a control circuit. CONSTITUTION: As a road surface is rough, a vehicle body is vibrated according to travel of a vehicle even though vehicle wheels are not rotated. When a vehicle speed is zero, an output from an inclination sensor or an acceleration sensor 6 is taken into, and it is determined whether the present output from the inclination sensor or the acceleration sensor 6 exceeds the predetermined value or not. When the output of the inclination sensor or the acceleration sensor 6 exceeds the predetermined value, movement of the vehicle is assumed, and transmission of a control signal to a solenoid valve 9 is prohibited, and then, auxiliary operation is stopped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a vehicle driving assistance device. The present invention temporarily holds the braking pressure even when the brake pedal is released when the vehicle speed reaches zero due to the application of a braking pressure above a predetermined level, and the clutch is disengaged. And a slope start assist device that automatically releases the temporarily held braking pressure at a set value. INDUSTRIAL APPLICABILITY The present invention is applied to an automobile equipped with a clutch and a manual shift transmission, and is not applied to an automatic vehicle having no clutch pedal.

[0002]

2. Description of the Related Art A driving operation for starting a slope on a vehicle that is stopped in the middle of a slope in an uphill direction is performed by depressing a clutch pedal with the brake pedal depressed to shift the transmission to a start gear (or a reverse gear). When the clutch is in the half-clutch state, the brake pedal is released and the accelerator pedal is depressed, while the clutch pedal is set and the clutch pedal is gently pulled in the shallower step.
The slope start assist device is a driving assist device that automatically executes this. In other words, when the vehicle decelerates when the vehicle decelerates and the vehicle speed reaches zero or almost zero, if the clutch pedal is depressed beyond a predetermined value at this time, the hill-start assist device brakes even if the brake pedal is released. Controlled to automatically hold pressure. Further, when the clutch pedal, on which the transmission has been set and depressed, is released to the set release point, the holding state of the braking pressure is automatically released.

This device takes an electromagnetic valve that holds the braking pressure according to the control even when the brake pedal is released, and a solenoid valve that takes in vehicle speed information, braking pressure information and clutch pedal stroke information. And a program control circuit for controlling. In a vehicle equipped with this device, even if the driver releases the brake pedal while the side brake is not applied, the vehicle is held in a stopped state, so that the driving operation for starting a slope as described above can be performed smoothly. It can be carried out. In addition, when driving on a road in a traffic jam, keep pressing the brake pedal for a long time,
Since it is not necessary to repeatedly operate the side brakes, fatigue of the driver can be reduced.

Such a slope starting assist device is disclosed in Japanese Patent Laid-Open No.
No. 4,789,56. This device has come into widespread use in freight vehicles whose operating conditions change depending on the weight of the vehicle.

As described above, in the above-described hill-start assisting device, when a vehicle stopped on a hill is started,
When the clutch pedal is slowly released, and the stroke of the clutch pedal reaches a preset release point, the braking pressure held is automatically released.

Accelerometers or gradient sensors have come to be used in such devices. In this system, a sensor for detecting the acceleration in the traveling direction of the automobile is provided, and the output information of the acceleration sensor is used by the control device of the hill start assisting device for acquisition control. For example, when the information of the vehicle speed sensor outputs zero vehicle speed, when the deceleration acceleration is detected by the acceleration sensor, the vehicle travels on a slippery road surface and the wheels stop rotating and slip. Is in a state. In such a case, it is preferable to prohibit the holding of the braking pressure and let the driver decide the driving operation.

The acceleration sensor in the traveling direction can be used as a gradient sensor. That is, when the vehicle stops on a downhill, the acceleration sensor displays the acceleration in the front direction. When the vehicle stops on a downhill, the acceleration sensor displays the acceleration in the backward direction.

The following control can be performed by using the acceleration sensor. That is, when the vehicle is stopped by stepping on the brake, when the vehicle stops in the middle of the downhill and then the vehicle is started in the forward state,
There is no need for auxiliary movements by the slope start assist device. Also,
When the vehicle is stopped by stepping on the brakes and the vehicle stops in the middle of the uphill and then the vehicle is started in the backward state, the assisting operation by the slope start assist device is unnecessary.

[0009]

Such a hill start assist device holds the brake pressure when the brake is depressed and the vehicle speed becomes substantially zero. If the brake pressure is maintained before the vehicle speed reaches zero, slip between the wheels and the road surface will occur. The fact that the vehicle speed has become substantially zero is observed from the output of the vehicle speed sensor. The vehicle speed sensor generates a pulse signal that accompanies the rotation of the wheel at regular intervals,
The vehicle speed is calculated by counting this pulse signal every unit time. When an abnormality occurs in the circuit of this pulse signal, the pulse does not arrive and the vehicle speed is mistakenly recognized as substantially zero. Further, when the vehicle is traveling on a slippery road surface, the rotation of the wheels may stop due to a small brake pressure, and the vehicle may slip on the road surface as it is.

The present invention has been made against such a background, and when there is an abnormality in the vehicle speed sensor, or when there is substantially no vehicle rotation speed information even if the vehicle speed sensor does not show information about wheel rotation, it is possible to detect it. It is an object to provide a device that can automatically sense. SUMMARY OF THE INVENTION It is an object of the present invention to provide a slope start assist device that can automatically prohibit the operation of the vehicle when the vehicle speed is available.

[0011]

SUMMARY OF THE INVENTION The present invention is characterized by controlling a hill start assisting operation on the assumption that the vehicle is not completely stopped when the vehicle is being vibrated.

That is, a solenoid valve that holds braking pressure according to control even when the brake pedal is released, and a control circuit that controls the solenoid valve by taking in vehicle speed information, braking pressure information, and clutch pedal stroke information And the control circuit applies a braking pressure to the solenoid valve when the vehicle speed display becomes zero at a braking pressure equal to or higher than a predetermined value and the stroke of the clutch pedal is greater than the predetermined value, or when the transmission is in the neutral position. In a slope start assist device having a control means for holding and holding the brake pressure holding state of the solenoid valve when the transmission is set and the stroke of the clutch pedal becomes smaller than the set release point,
The control circuit includes means for controlling the vehicle as being in a traveling state even when the vehicle speed display is zero when a vibration exceeding a predetermined amplitude is detected in the sensor input within a predetermined time. .

The sensor input is preferably an input from any one or more of a gradient sensor, an acceleration sensor and a vehicle height sensor.

[0014]

When the vehicle is moving on the road, the vehicle body vibrates back and forth, left and right, or up and down with the ups and downs of the road surface regardless of whether the wheels are rotating or not. The vibration of the vehicle body is detected by a gradient sensor, an acceleration sensor, or a vehicle height sensor. On the other hand, the rotation of the wheels is detected by a vehicle speed sensor that counts pulses generated according to the rotation of the wheels. Whether or not the vehicle is moving on the road, the pulses cease to occur when the wheels stop spinning. Further, when an abnormality such as a wire breakage occurs in the vehicle speed sensor, the wheel rotation information is not detected.

Therefore, a gradient sensor or an acceleration sensor,
Alternatively, by taking one of the output signals of the vehicle height sensor, it is determined whether or not the output signal shows vibration exceeding a predetermined amplitude within a predetermined time. Even if the output information of 1 indicates 0, it is possible to determine that the vehicle is in a running state, and therefore the execution of the slope start assist operation is prohibited.

When zero is shown as the output information of the vehicle speed sensor, if it is due to the abnormality of the vehicle speed sensor, there is no output even if the wheels are rotating, so it is automatically abnormal. Is detected and an alarm is issued to notify. Further, the gradient sensor, the acceleration sensor, or the vehicle height sensor outputs the detection output even when the vehicle stops on a slope, but in this case, the vehicle is not traveling (moving) on the road surface, and therefore the output signal is Since it is not output for a long time and its amplitude is less than a predetermined value, it is possible to clearly discriminate whether it is an output signal due to vehicle running or a signal due to stopping on a slope.

Thus, when there is an abnormality in the vehicle speed sensor, or when there is substantially no vehicle speed information due to slippage even if the vehicle speed sensor does not show information about wheel rotation, it is automatically sensed to assist in starting the slope. The operation can be prohibited.

[0018]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of the present invention.

In the embodiment of the present invention, the vehicle speed sensor 1 for detecting the vehicle speed, the clutch stroke sensor 2 for detecting the stroke of the clutch, the stop lamp switch 3 for detecting the braking state by the service brake, and the braking by the parking brake. A parking brake switch 4 for detecting a state, a gear-in switch 5 for detecting a state in which a transmission is started to a starting gear, a gradient sensor or an acceleration sensor 6 for detecting a gradient and vibration of a vehicle, and a vehicle height. A vehicle height sensor 7, a solenoid valve 9 that adjusts the brake valve 12 according to a control signal to maintain a brake pressure even when the brake pedal 11 is released, and a gradient sensor or an acceleration sensor 6 while the brake pressure is maintained. Output on a downhill that exceeds a specified value and when a failure occurs Comprises an alarm device 14 for generating a program control circuit 10 for the control the uptake solenoid valve 9 outputs from the sensors and the switches, and an input unit 13 for performing an operation input to the program control circuit 10. The alarm device 14 is provided with an alarm buzzer 14a that sounds an alarm by sound and an alarm lamp 14b that lights up to generate an alarm.

Further, the program control circuit 10 controls the solenoid valve 9 when the vehicle speed display becomes zero at a braking pressure equal to or higher than a predetermined value and the stroke of the clutch pedal is larger than the predetermined value, or when the transmission is in the neutral position. Control means for holding the braking pressure, releasing the braking pressure holding state of the solenoid valve 9 when the transmission is set and the stroke of the clutch pedal becomes smaller than the set release point, the gradient sensor or acceleration sensor 6, the vehicle When a vibration exceeding a predetermined amplitude is detected within a predetermined time by an input of any one or more of the high sensors 7, the vehicle is controlled to be traveling even if the vehicle speed display is zero. State confirmation means is provided.

FIG. 2 is a block diagram showing the construction of the vehicle traveling confirmation means in the embodiment of the present invention. The detection output (voltage value V) from the vehicle height sensor 7 is taken into the vehicle travel confirmation means, and is sampled at regular time intervals t during a predetermined time T according to the clock signal from the clock signal generation circuit 10a. A sampling circuit 10b, a differentiating circuit 10c for performing a differential operation of a sampled value (voltage value V) for each time t with respect to time, and a positive and negative predetermined value (+ V ₀ , -V ₀ ) for the differentially operated _value . And a comparison circuit 10d that outputs the comparison result.

Next, the operation of detecting the traveling state of the vehicle in the embodiment of the present invention thus constructed will be described. FIG.
3 is a flowchart showing a flow of a vehicle traveling state detecting operation in the embodiment of the present invention.

The program control circuit 10 includes a vehicle speed sensor 1
The detection output is taken from and it is determined whether the vehicle speed is zero. If the vehicle speed is zero, the timer is set to the time T (for example, 0.1 to 0.1).
Set to a constant value of 1 sec). With this timer set, the sampling circuit 10b of the vehicle travel confirmation means outputs the detection output (voltage value V) from the vehicle speed sensor 1 at the time interval t according to the clock signal from the clock signal generation circuit 10a.
Sampling is performed every (for example, 20 msec).

This sampled value is differentiated (dV / d) by the differentiating circuit 10c until the set time expires.
t) and the result is sent to the comparison circuit 10d. In the comparison circuit 10d, the differentially calculated value V is set to a predetermined positive and negative predetermined amplitude (determination reference value + V ₀ , −).
Whether exceeds the V range _{0) (-V 0 <V <} +
V ₀ ) is determined. If the amplitude exceeds the predetermined amplitude, it means that the vehicle is in a slip state and is moving on the road surface even if the vehicle speed is displayed as zero. Therefore, the control signal to the solenoid valve 9 is immediately sent. Is prohibited and the hill start assist operation is stopped. If the amplitude does not exceed the predetermined amplitude, it is determined that the vehicle has stopped traveling due to braking, and a control signal to the solenoid valve 9 is generated to execute the slope start assisting operation.

If the vehicle is moving on the road surface when the vehicle speed is zero, it means that the vehicle is in a slip state. Whether the vehicle is moving or not is determined by the gradient sensor or the acceleration sensor 6, or the vehicle height. It can be detected by the sensor 7. That is, since the road surface has undulations, if the vehicle travels (moves) even when the wheels are not rotating, the vehicle body vibrates accordingly. This vibration is detected by the gradient sensor, the acceleration sensor 6, or the vehicle height sensor 7.

The vibration in such a state continuously vibrates with an amplitude different from that when the vehicle is stopped. Therefore,
If the predetermined amplitude is set empirically or experimentally, when the vibration exceeds the predetermined amplitude for a predetermined time, it can be detected that the vehicle is in a running state.
If the vehicle is on a slope and is completely stopped, the gradient sensor, the acceleration sensor 6, or the vehicle height sensor 7 shows a detection value according to the gradient. In this case, the vehicle is on the road surface. Since the vehicle is not traveling (moving), the detected value is within the range of the predetermined amplitude, and it can be assumed that the vehicle is completely stopped by braking.

When the vehicle speed sensor 1 has an abnormality, the detection signal does not reach the program control circuit 10 regardless of whether the vehicle is stopped or running, so it is confirmed that it is abnormal. To be done.

Here, the brake holding operation and the brake releasing operation performed by the slope start assisting device in the embodiment of the present invention will be described. FIG. 4 is a flow chart showing the flow of the brake holding operation in the embodiment of the present invention, and FIG. 5 is a flow chart showing the flow of the brake release operation in the embodiment of the present invention. In this example, it is assumed that the control is performed by the output of the gradient sensor.

First, in the brake holding operation, as shown in FIG. 4, the program control circuit 10 takes in the output from the stop lamp switch 3 and determines whether or not the brake is depressed. If the brake pedal is not depressed, it means that the vehicle is not stopped by the braking operation. Therefore, the sending of the control signal to the solenoid valve 9 is prohibited and the assisting operation for starting the slope is stopped. When the brake is depressed, the output from the vehicle speed sensor 1 is fetched to determine whether the vehicle speed is zero. If the vehicle speed is not zero, the vehicle is running, so the sending of the control signal to the solenoid valve 9 is prohibited and the auxiliary operation for starting the slope is stopped.

When the vehicle speed is zero, the output from the gradient sensor or acceleration sensor 6 is fetched, and it is determined whether or not the current output of the gradient sensor or acceleration sensor 6 exceeds the set predetermined value S. When the output of the gradient sensor or the acceleration sensor 6 exceeds the predetermined value S, it is assumed that the vehicle is moving, and the sending of the control signal to the solenoid valve 9 is prohibited and the auxiliary operation is stopped. If the predetermined value S is not exceeded, a control signal is sent to the solenoid valve 9 as if the vehicle is stopped, the solenoid valve 9 is driven and the brake valve 12 is operated, and an auxiliary operation for starting a slope is executed.

Next, the brake release operation will be described. Whether or not the output from the clutch stroke sensor 2 and the gear-in switch 5 is taken in and the clutch is depressed to set the gear to the forward start position (low or second) or the reverse position when the vehicle is in the brake holding state on a slope. To determine.

When the clutch is stepped on and the gear is set to the starting state, it is determined from the output of the clutch stroke sensor 2 whether or not the stroke is equal to or less than a predetermined stroke set in advance. When the stroke is equal to or less than the predetermined stroke, it is assumed that the vehicle is started, and the sending of the control signal to the solenoid valve 9 is prohibited and the brake is released. When the gear is not set to the start state or the amount of depression of the clutch is equal to or greater than the predetermined stroke, the control signal is continuously sent to the solenoid valve 9 to maintain the brake holding state.

The brake release position (the value of the clutch pedal depressing stroke) can be set arbitrarily in accordance with the driver's preference and changes due to clutch wear. The value of the set stroke of the clutch pedal is held until it is reset. If the depression stroke of the clutch pedal exceeds the set reference value, the starting assist operation is continued.

[0034]

As described above, according to the present invention, it is possible to clearly distinguish whether the vehicle is traveling with the wheels locked by braking and whether the vehicle is completely stopped. If the sensor is abnormal, or if the wheel is locked due to braking on a slippery road and the rotation speed is not displayed but the actual vehicle speed is indicated, the condition is automatically detected. Then, there is an effect that the slope start assist operation can be immediately prohibited.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a main part of an embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of a traveling state confirmation means in the embodiment of the present invention.

FIG. 3 is a flowchart showing a flow of a vehicle traveling state detection operation in the embodiment of the present invention.

FIG. 4 is a flowchart showing a flow of a brake holding operation in the embodiment of the present invention.

FIG. 5 is a flowchart showing a flow of a brake releasing operation in the embodiment of the present invention.

[Explanation of symbols]

 1 Vehicle speed sensor 2 Clutch stroke sensor 3 Stop lamp switch 4 Parking brake switch 5 Gear-in switch 6 Gradient sensor or acceleration sensor 7 Vehicle height sensor 9 Solenoid valve 10 Program control circuit 10a Clock signal generation circuit 10b Sampling circuit 10c Differentiation circuit 10d Comparing circuit 11 Brake pedal 12 Brake valve 13 Input unit 14 Alarm device 14a Alarm buzzer 14b Alarm lamp

Claims (2)

[Claims] 1. A solenoid valve for holding a braking pressure according to control even if the brake pedal is released, and a control circuit for controlling the solenoid valve by taking in vehicle speed information, braking pressure information and clutch pedal stroke information. The control circuit provides a braking pressure to the solenoid valve when the vehicle speed display becomes zero at a braking pressure equal to or higher than a predetermined value and the stroke of the clutch pedal is larger than the predetermined value, or when the transmission is in the neutral position. In a slope start assist device having a control means for holding the transmission and releasing the braking pressure holding state of the solenoid valve when the transmission is set and the stroke of the clutch pedal becomes smaller than the set release point, the control circuit is , If a vibration exceeding a predetermined amplitude is detected in the sensor input within a predetermined time, the vehicle is in the running state even if the vehicle speed display is zero. Hill-start assist, characterized in that it comprises means for controlling as a thing. 2. The slope start assist device according to claim 1, wherein the sensor input is an input from at least one of a gradient sensor, an acceleration sensor, and a vehicle height sensor.