JP4158778B2 - Hydroplaning state judgment device - Google Patents

Description

  The present invention relates to a hydroplaning state determination device.

  A technique for detecting the occurrence of hydroplaning from wheel speed and road surface condition is disclosed (for example, Patent Document 1). In this technology, a ground speed sensor attached at a position immediately before the front wheel also functions as a road surface condition detection sensor. The road surface state detection sensor determines that the traveling surface is in a wet asphalt state when the sensor signal strength of the ultrasonic receiver is equal to or less than a predetermined value. When the road surface state has a smoothness greater than or equal to a predetermined value and the wheel speed difference between the driven wheel and the drive wheel is equal to or greater than a predetermined value, it is determined that the hydroplaning has occurred.

Japanese Patent Laid-Open No. 7-110335

  Hydroplaning is an action or state in which water acts as a wedge to lift a wheel when traveling at high speed on a road covered with water. Hydroplaning is a very slippery phenomenon in which the wheel cannot remove water when traveling at high speed on a road surface where water has accumulated, and the contact between the wheel and the road surface is interrupted by the hydrodynamic pressure of the generated water.

  In the conventional technique, since the road surface state detection sensor is attached immediately before the front wheel, it cannot be accurately determined whether or not the contact between the wheel and the road surface is cut off.

  The invention according to claim 1 is a transmission function for transmitting a transmission wave, a reception function for receiving a reflected wave of the transmission wave transmitted by the transmission function, and a transmission surface transmitted from the transmission function for a road surface behind a wheel. And a hydroplaning state determination function for determining a hydroplaning occurrence state by receiving a reflected wave from a road surface of the transmission wave with the reception function.

  According to a second aspect of the present invention, in the hydroplaning state determination device according to the first aspect, the hydroplaning state determination function generates hydroplaning when a reflected wave signal received by the reception function is smaller than a predetermined threshold value. It is characterized in that it is determined.

  According to a third aspect of the present invention, in the method for attaching the hydroplaning state determination device according to any one of the first to second aspects to a vehicle, a transmission wave transmitted from the transmission function according to a driving system of the vehicle is different from behind the wheel. It is attached so that it may transmit to.

  According to a fourth aspect of the present invention, in the method for attaching the hydroplaning state determination device according to any one of the first to second aspects to a vehicle, the transmission function and the reception function are attached to a muffler or the vicinity thereof.

  The invention according to claim 5 is a transmission function for transmitting a transmission wave, a reception function for receiving a reflected wave of the transmission wave transmitted by the transmission function, and hydroplaning based on the reflected wave received by the reception function. A vehicle having a hydroplaning state determination function for determining an occurrence state, a vehicle body speed measurement function for measuring a vehicle body speed based on a reflected wave received by the reception function, and a wheel speed measurement function for measuring a wheel speed The wheel speed measured by the wheel speed measuring function and the vehicle body speed measuring function when the hydroplaning state determining function determines that hydroplaning has occurred. Control is performed so that the difference between the measured vehicle speed and the vehicle speed becomes small.

  The invention according to claim 6 is a transmission function for transmitting a transmission wave, a reception function for receiving a reflected wave of the transmission wave transmitted by the transmission function, and hydroplaning based on the reflected wave received by the reception function. All wheels having a hydroplaning state determination function for determining an occurrence state, a vehicle body speed measurement function for measuring a vehicle body speed based on a reflected wave received by the reception function, and a wheel speed measurement function for measuring a wheel speed A control device for controlling the speed of a wheel of a driving vehicle, and when it is determined that hydroplaning of the vehicle is occurring, each wheel speed measured by the wheel speed measurement function and the vehicle body speed measurement function Control is performed so that the difference between the measured vehicle speed and the vehicle speed becomes small.

  The invention according to claim 7 is a transmission function for transmitting a transmission wave, a reception function for receiving a reflected wave of the transmission wave transmitted by the transmission function, and hydroplaning based on the reflected wave received by the reception function. A hydroplaning state determination function for determining an occurrence state, a vehicle body speed measurement function for measuring a vehicle body speed based on a reflected wave received by the reception function, a wheel speed measurement function for measuring a wheel speed, and a preceding vehicle; An inter-vehicle distance control device for a vehicle having an inter-vehicle distance measuring function for measuring an inter-vehicle distance, wherein the inter-vehicle distance from the preceding vehicle is determined according to a hydroplaning occurrence state determined by the hydroplaning state determining function. It is characterized by changing.

  The invention according to claim 8 is a transmission function for transmitting a transmission wave, a reception function for receiving a reflected wave of the transmission wave transmitted by the transmission function, and hydroplaning based on the reflected wave received by the reception function. A hydroplaning state determination function for determining an occurrence state, a vehicle body speed measurement function for measuring a vehicle body speed based on a reflected wave received by the reception function, a wheel speed measurement function for measuring a wheel speed, and other vehicles The vehicle has a vehicle-to-vehicle communication function for communicating data of the vehicle, and transmits a hydroplaning occurrence state determined by the vehicle-to-vehicle communication function to the other vehicle. Receiving the determined hydroplaning occurrence state, and changing the inter-vehicle distance from the preceding vehicle according to the received hydroplaning occurrence state from another vehicle That.

  The present invention accurately determines the occurrence of hydroplaning from the road surface after the wheels have passed. By using the determined hydroplaning occurrence state, the vehicle can be safely driven even on a wet road.

  Hereinafter, the hydroplaning state determination apparatus according to the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 shows the configuration of the hydroplaning state determination device. The hydroplaning state determination device 101 includes a transceiver 102 and a hydroplaning state determination unit 103. The transceiver 102 radiates a transmission wave (any type of electromagnetic wave, sound wave, light, laser, etc., as long as it is used as a transmission wave) 108 from the transmission antenna 104 toward the road surface 105, and the road surface of the transmission wave 108 The reflected wave 106 from 105 is received by the receiving antenna 107. Then, a signal corresponding to the smoothness of the road surface 105 is output from the received reflected wave 106. The hydroplaning state determination unit 103 determines the occurrence state of hydroplaning based on a signal output from the transceiver 102. The hydroplaning state determination device 101 may have a configuration in which the transceiver 102 and the hydroplaning state determination unit 103 are housed in different housings.

  Hydroplaning is an action or state in which water acts as a wedge to lift a wheel when traveling at high speed on a road covered with water. Hydroplaning is a very slippery phenomenon in which the wheel cannot remove water when traveling at high speed on a road surface where water has accumulated, and the contact between the wheel and the road surface is interrupted by the hydrodynamic pressure of the generated water.

  In a state where hydroplaning is not generated while traveling on a wet road, the wheel 109 discharges water between the road surface 105 and the unevenness of the road surface 105 after the wheel 109 has passed appears on the water surface. When hydroplaning occurs, the wheel 109 cannot discharge water between the road surface 105 and the water 110 before passing through the wheel 109 remains on the road surface 105 even after the wheel 109 passes. Therefore, is the hydroplaning generated by radiating the transmission wave from the transmitter / receiver 102 toward the road surface 105 after the wheel 109 passes and receiving the reflected wave 106 to detect the smoothness of the road surface 105? Judge whether or not. By transmitting the transmission wave 108 to the rear of the wheel 109, it can be determined whether or not the wheel 109 has drained water from the road surface 105. Therefore, it is possible to accurately determine whether hydroplaning has occurred. There is an effect that can be done.

FIG. 2 shows a method for determining the occurrence of hydroplaning. When the signal from the transmitter / receiver 102 is Fourier-transformed while traveling on a wet road, a frequency spectrum as shown in FIG. 2A is obtained when hydroplaning is not occurring. From the frequency spectrum, a peak of the signal intensity S1 corresponding to the smoothness of the road surface 105 occurs at the frequency fv corresponding to the speed of the vehicle body. If the signal intensity S1 is greater than the no hydroplaning threshold 201 for determining whether or not hydroplaning has occurred, it is determined that hydroplaning has not occurred since the unevenness of the road surface 105 is visible. Further, the vehicle body speed can be measured by converting the frequency fv corresponding to the vehicle body speed into a speed. FIG. 2B shows a case where the water pool on the road surface 105 before the wheel 109 passes becomes deeper than in FIG. The signal from the transmitter / receiver 102 is Fourier-transformed, and the peak of the signal intensity S2 corresponding to the road surface smoothness is obtained from the frequency spectrum at the frequency fv corresponding to the vehicle speed. When the signal strength S2 is smaller than the no hydroplaning threshold 201 and larger than the hydroplaning threshold 202 for determining whether or not hydroplaning has occurred, the unevenness of the road surface 105 is partially covered with water, so that the hydroplaning is performed. It is determined that it is likely to occur. FIG.2 (c) is a case where the water pool of the road surface 105 before the wheel 109 passes becomes deeper than FIG.2 (b). When the signal from the transmitter / receiver 102 is Fourier-transformed and the peak signal intensity is smaller than the hydroplaning threshold 202 or the peak cannot be detected, water accumulates on the road surface 105 after the wheel 109 passes, and the road surface 105 is uneven. Since it is not visible, it is determined that hydroplaning has occurred.

3 and 9 show an example of attachment of the hydroplaning state determination unit 103 to the vehicle body. FIG. 3 is an example of attachment when the drive system is rear wheel drive, and FIG. 9 is an example of attachment when front wheel drive is used. Since the hydroplaning state determination device 101 may not be able to radiate a transmission wave toward the road surface or receive a reflected wave from the road surface if it becomes dirty, it needs to be installed in a place where it is difficult to get dirty. When the driving method is rear wheel driving, the rear wheel 109b, which is the driving wheel, has more mud splash than the front wheel 109a of the driven wheel, so the hydroplaning state determination device 101 is attached behind the front wheel 109a. If the hydroplaning state determination device 101 is attached behind the front wheel mudguard 301, the influence of mud splashing can be further reduced. By doing so, it can prevent that the hydroplaning state determination apparatus 101 becomes dirty by the mud splash of a wheel. In the case of front wheel drive, as shown in FIG. 9A, the hydroplaning state determination device 101 is attached behind the rear wheel 109b that is a driven wheel. If it is installed behind the rear wheel mudguard 901, the influence of mud splashing can be further reduced. Moreover, if snow adheres to the hydroplaning state determination apparatus 101, there is a case where a transmitted wave cannot be emitted toward the road surface or a reflected wave from the road surface cannot be received. As shown in FIG. 9B, by attaching the hydroplaning state determination device 101 to the muffler 902 and warming the hydroplaning state determination device 101, even if snow adheres to the hydroplaning state determination device 101, the attached snow is melted. I can do it. Further, the hydroplaning state determination device 101 may be attached in the vicinity of the muffler 902. Also in this case, the snow adhering to the hydroplaning state determination device 101 can be melted, and the influence of vibration of the muffler 902 can be reduced. When the driving method is front-rear wheel driving, the front wheel 109a slips ahead of the rear wheel 109b, so the hydroplaning state determination device 101 is attached behind the front wheel 109a. By doing so, the occurrence state of hydroplaning can be determined quickly. Alternatively, the direction of the rear wheel 109b does not change even when the steering wheel is turned off, and mud splashes fly in a certain direction. Therefore, the hydroplaning state determination device 101 may be attached behind the rear wheel 109b. By doing so, the hydroplaning state determination apparatus 101 can be attached to a place where mud splash and snow are difficult to adhere.

  FIG. 4 shows a first embodiment of a hydroplaning control apparatus provided with the hydroplaning state determination apparatus 101 of the present invention. If the hydroplaning state determination unit 103 determines that hydroplaning has occurred, the hydroplaning control device 401 causes the wheel speed to approach the vehicle speed if the vehicle speed measurement unit 402 measures the vehicle speed. The throttle 404 or the brake 405 is controlled. When the vehicle speed cannot be measured by the vehicle speed measuring unit 402, the throttle 404 or the brake 405 is controlled so as to approach the vehicle speed before the vehicle speed cannot be measured. Further, the reaction force of the steering wheel 406 is increased to make it difficult for the driver to operate the steering wheel. By doing so, the vehicle can be driven stably.

FIG. 5 shows a second embodiment of a hydroplaning control apparatus provided with the hydroplaning state determination apparatus 101 of the present invention. The vehicle of the second embodiment is front and rear wheel drive that includes an engine and a motor as power sources. One of the front wheels or the rear wheels transmits the output from the engine to the road surface, and the other transmits the output from the motor to the road surface. The hydroplaning control device 501 controls the throttle 404 or the brake 405 to control the engine if the hydroplaning state determination unit 103 determines that hydroplaning is occurring and the vehicle speed measurement unit 402 measures the vehicle speed. The wheel speed based on the output is brought close to the vehicle body speed, and the motor 502 is controlled to bring the wheel speed based on the output of the motor 502 close to the vehicle body speed. When the vehicle speed cannot be measured, the throttle 404 or the brake 405 and the motor 502 are controlled so that the wheel speed approaches the vehicle speed before the vehicle speed cannot be measured. Further, the reaction force of the steering wheel 406 is increased to make it difficult for the driver to operate the steering wheel. By doing so, the vehicle can be driven stably.

  FIG. 6 shows a third embodiment of the hydroplaning control apparatus provided with the hydroplaning state determination apparatus 101 of the present invention. The vehicle of the third embodiment is a front-rear wheel drive in which front wheels and rear wheels are connected via a power distribution device, and power of the front wheels and rear wheels is distributed by the power distribution device. If the hydroplaning state determination unit 103 determines that hydroplaning has occurred and the vehicle body speed measurement unit 402 measures the vehicle body speed, the hydroplaning control device 601 controls the throttle 404 or brake 405, and the power distribution device 602. Control the wheel speed of the front and rear wheels closer to the vehicle speed. When the vehicle speed cannot be measured, the throttle 404 or the brake 405 and the power distribution device 602 are controlled so that the wheel speed approaches the vehicle speed before the vehicle speed cannot be measured. Further, the reaction force of the steering wheel 406 is increased to make it difficult for the driver to operate the steering wheel. By doing so, the vehicle can be driven stably.

  FIG. 7 shows an embodiment of an inter-vehicle distance control device provided with the hydroplaning state determination device 101 of the present invention. The inter-vehicle distance control device 701 controls the throttle 404 or the brake 405 to accelerate and decelerate the own vehicle based on the inter-vehicle distance from the preceding vehicle measured by the inter-vehicle distance measuring unit 702. If the hydroplaning state determination unit 103 determines that hydroplaning is likely to occur, the inter-vehicle distance is increased as compared with the case where hydroplaning is not occurring. Even if the preceding vehicle accelerates, the own vehicle does not accelerate. Further, the inter-vehicle distance control is canceled and the driver returns to the state where the driving operation is performed. By doing so, a collision with a preceding vehicle can be prevented.

  FIG. 8 shows an embodiment in which the hydroplaning state determination device of the present invention is provided and vehicle group traveling is performed. Vehicles 801a, 801b, and 801c are controlled by the vehicle group control devices 803a, 803b, and 803c based on the inter-vehicle distance measurement unit, wheel speed measurement unit, vehicle body speed measurement unit, and hydroplaning state determination unit. Run. If the hydroplaning state determination device 101a of a vehicle (for example, 801a) in the vehicle group determines that hydroplaning is likely to occur during vehicle group traveling, the vehicle-to-vehicle communication unit 802a is likely to generate hydroplaning. Send that. When the vehicle (for example, 801b, 801c) in the vehicle group receives that the hydroplaning is likely to occur by the inter-vehicle communication units 802b, 802c, the vehicle travels with a wider inter-vehicle distance from the preceding vehicle. Or even if the preceding vehicle accelerates, it does not accelerate itself. By doing so, a collision with a preceding vehicle can be prevented.

The structure of a hydroplaning state determination apparatus is shown. A method for determining the occurrence of hydroplaning will be described. The example of attachment of the hydroplaning state determination apparatus of a rear-wheel drive vehicle is shown. 1 shows a first embodiment of a hydroplaning control apparatus. 2 shows a second embodiment of the hydroplaning control apparatus. 3 shows a third embodiment of the hydroplaning control apparatus. An embodiment of an inter-vehicle distance control device will be shown. The Example which performs vehicle group driving | running is shown. The example of attachment of the hydroplaning state determination apparatus of a front-wheel drive vehicle and a front-and-rear wheel drive vehicle is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Hydroplaning state determination apparatus, 102 ... Transceiver, 103 ... Hydroplaning state determination part, 104 ... Transmission antenna, 105 ... Road surface, 106 ... Reflected wave, 107 ... Reception antenna, 108 ... Transmission wave, 109 ... Wheel, 109a ... front wheel, 109b ... rear wheel,
110, 111 ... water, fv ... frequency according to the speed of the vehicle body, 201 ... threshold without hydroplaning, 202 ... threshold with hydroplaning, 301 ... mudguard for front wheels, 401,
501, 601 ... Hydroplaning control device, 402 ... Body speed measurement unit, 403 ... Wheel speed measurement unit, 404 ... Throttle, 405 ... Brake, 406 ... Steering, 502 ... Motor, 602 ... Power distribution device, 701 ... Inter-vehicle distance control Device, 702: Inter-vehicle distance measurement unit, 801a, 801b, 801c ... Vehicle, 802a, 802b, 802c ... Inter-vehicle communication unit, 901 ... Rear wheel mudguard.

Claims (8)

A transmission function for transmitting a transmission wave;
A reception function for receiving a reflected wave of a transmission wave transmitted by the transmission function;
A transmission wave transmitted from the transmission function is transmitted to the road surface behind the wheel, a reflected wave from the road surface of the transmission wave is received by the reception function, and a hydroplaning state determination function for determining a hydroplaning occurrence state; A hydroplaning state determination device characterized by comprising: In the hydroplaning state determination apparatus according to claim 1,
The hydroplaning state determination function determines that hydroplaning has occurred when a reflected wave signal received by the reception function is smaller than a predetermined threshold value. In the method of attaching the hydroplaning state determination device according to claim 1 or 2 to a vehicle,
A mounting method for a hydroplaning state determination device, wherein a transmission wave transmitted from the transmission function is transmitted behind different wheels in accordance with a driving method of the vehicle. In the method of attaching the hydroplaning state determination device according to claim 1 or 2 to a vehicle,
A method for attaching a hydroplaning state determination device, wherein the transmission function and the reception function are attached to a muffler or the vicinity thereof. A transmission function for transmitting a transmission wave;
A reception function for receiving a reflected wave of a transmission wave transmitted by the transmission function;
A hydroplaning state determination function for determining a hydroplaning occurrence state based on the reflected wave received by the reception function;
A vehicle body speed measurement function for measuring the vehicle body speed based on the reflected wave received by the reception function;
Of a vehicle having a wheel speed measuring function for measuring the speed of the wheel,
A control device for controlling the speed of the wheel,
When the hydroplaning state determination function determines that hydroplaning has occurred, the difference between the wheel speed measured by the wheel speed measurement function and the vehicle speed measured by the vehicle body speed measurement function is reduced. Hydroplaning control device characterized by controlling. A transmission function for transmitting a transmission wave;
A reception function for receiving a reflected wave of a transmission wave transmitted by the transmission function;
A hydroplaning state determination function for determining a hydroplaning occurrence state based on the reflected wave received by the reception function;
A vehicle body speed measurement function for measuring the vehicle body speed based on the reflected wave received by the reception function;
Of an all-wheel drive vehicle having a wheel speed measuring function for measuring a wheel speed,
A control device for controlling the speed of the wheel,
If it is determined that hydroplaning of the vehicle has occurred, control is performed so that the difference between the wheel speed measured by the wheel speed measurement function and the vehicle speed measured by the vehicle body speed measurement function is reduced. Features hydroplaning control device. A transmission function for transmitting a transmission wave;
A reception function for receiving a reflected wave of a transmission wave transmitted by the transmission function;
A hydroplaning state determination function for determining a hydroplaning occurrence state based on the reflected wave received by the reception function;
A vehicle body speed measurement function for measuring the vehicle body speed based on the reflected wave received by the reception function;
Wheel speed measurement function that measures the speed of the wheel,
Of a vehicle having an inter-vehicle distance measuring function for measuring an inter-vehicle distance with a preceding vehicle,
An inter-vehicle distance control device,
An inter-vehicle distance control device that changes an inter-vehicle distance from the preceding vehicle according to a hydroplaning occurrence state determined by the hydroplaning state determination function. A transmission function for transmitting a transmission wave;
A reception function for receiving a reflected wave of a transmission wave transmitted by the transmission function;
A hydroplaning state determination function for determining a hydroplaning occurrence state based on the reflected wave received by the reception function;
A vehicle body speed measurement function for measuring the vehicle body speed based on the reflected wave received by the reception function;
Wheel speed measurement function that measures the speed of the wheel,
A travel control device for a vehicle having a vehicle-to-vehicle communication function for communicating data with other vehicles,
The hydroplaning occurrence state determined by the inter-vehicle communication function is transmitted to another vehicle, the hydroplaning occurrence state determined by the other vehicle is received, and the received hydroplaning occurrence state from the other vehicle is received. Accordingly, the travel control device is characterized by changing the inter-vehicle distance from the preceding vehicle.

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