JPH11211821A - Snow and ice accretion removing device of radar antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To start the device at a necessary time against rain fall and snow accretion and stop it at an unnecessary time by setting a windshield wiper to be on, and automatically making a snow and ice accretion removing means to be in the on state when open air temperature is specific temperature or lower. SOLUTION: An antenna wiper 1 is provided as a snow and ice acretion removing means, and when a windshield wiper driving motor 3 is in the on state and the open air temperature detected by a temperature sensor 4 is (t) deg.C or lower, the driving motor 5 of the antenna wiper 1 is made in the on state. A windshield wiper control circuit 8 controls the wiper 2 driving motor 3 by the operation input of a wiper switch 7. In the open air temperature (t) deg.C, when the temperature near to the ground is 0 deg.C or lower, or even when it is 0 deg.C or over but the cold exists up in the air, it may snow, and because attenuation of electric wave due to snow accretion is larger in the case of wet snow, it is desirable to be set at about 4 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an automotive radar device. The present invention relates to an inter-vehicle distance adjusting device which is mounted on a vehicle body and measures or adjusts or warns an inter-vehicle distance from a preceding vehicle, an automatic steering device which identifies and tracks a lane on a road, and a radio radar device used for other purposes. About. In particular, the present invention relates to an improvement for preventing a fall in radar sensitivity due to snow or ice adhering to a radar antenna in winter.

[0002]

2. Description of the Related Art An automotive radar system has a frequency of several tens of GHz.
The frequency is allocated so as to utilize the electromagnetic wave, and a device that can be supplied at low cost, is mechanically robust, and can operate stably has been studied. Research has been conducted on a structure in which a small round or square antenna with a width of about several centimeters is embedded in a bumper for an automobile, emits electromagnetic waves in front of the vehicle, and receives reflected waves of the electromagnetic waves.

As a prior art, Japanese Unexamined Utility Model Publication No. 3-130748 and Japanese Unexamined Utility Model Application Publication No.
The technique disclosed in Japanese Patent No. 28759 is known. Further, as a technique for preventing a vehicular lamp from becoming dirty, there is known a technique disclosed in Japanese Patent Application Laid-Open No. 3-27046 and others.

[0004]

SUMMARY OF THE INVENTION The inventors of the present invention have conducted many and long-term tests on a vehicle equipped with an automotive radar device. From the results, it was found that the sensitivity of the radar device suddenly decreased when snow fell and snowflakes adhered to the antenna. In the case of rainfall, the sensitivity did not decrease so much, but it was found that the sensitivity of the radar device suddenly decreased when the temperature dropped and the antenna surface was frozen.

[0005] In order to remove raindrops or snow accumulation on the antenna surface, a mechanical wiper device, a washer using water or antifreeze, or an electric heater may be used to prevent snow and icing by heating. However, all of these consume power due to operation, and it is desirable to use them only as short as possible, even if equipped. In particular, a mechanical wiper device or the like may be an obstacle to transmission of electromagnetic waves, and the life of the device itself may be shortened by prolonged use.

SUMMARY OF THE INVENTION The present invention has been made in such a background, and it is possible to activate the radar antenna when it is necessary for rainfall and snowfall and to stop it when it is unnecessary when snowfall occurs. An object is to provide an icing removal device.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for automatically removing snow or ice from a radar antenna provided in an inter-vehicle distance adjusting device, an automatic steering device, or a wireless radar device used for other purposes. It is characterized by.

That is, the present invention provides a windshield
When the wiper is on and the outside air temperature is t ° C. (for example, 0
(Selected from the range of ° C. to 4 ° C.) or less.

The driver is looking out of the windshield glass and activates the wiper device when rainwater adheres to the windshield glass and visibility becomes poor. The radar device has a relatively small decrease in sensitivity when rainwater occurs, but has a large effect when snow accretion occurs. When the windshield wiper is operating and the outside air temperature is equal to or lower than t ° C., the control circuit automatically operates the snow / icing removing means assuming that ice or snow has adhered to the antenna surface. This removes ice and snowflakes attached to the radar antenna and improves the electromagnetic wave transmission characteristics on the antenna surface.

When the outside temperature rises to a temperature higher than t ° C., even if the windshield wiper is operating, it is assumed that water droplets are attached to the antenna surface, and snow is automatically attached. The driving of the icing removal means is stopped.

[0011] The snow accretion removing means driven by the control circuit includes an antenna wiper for mechanically wiping the antenna surface to remove snow accretion, and an antenna for discharging attached snowflakes by spraying water or antifreeze. A washer or an antenna heater that flows out snowflakes attached to the antenna surface by heating can be used.

The operation of the snow accretion and icing means is performed in accordance with the operation speed of the windshield wiper according to an operation pattern programmed in advance. The operation frequency can be arbitrarily set by a program. For example, they can be linked at the same speed as the windshield wiper, or can be operated at a speed higher or lower than the speed of the windshield wiper.

As described above, when the outside air temperature when the windshield wiper is operating is detected, and the outside air temperature indicates a value at which there is a possibility of freezing, the snow and ice removal means is automatically activated. When the temperature is exceeded, the device is automatically stopped, so that the driver can perform a driving operation without being conscious of driving or stopping the device. When operation of the device is continued when it is no longer necessary to remove snow and ice, it may affect transmission and reception of electromagnetic waves, use antifreeze liquid wastefully, or shorten the life of the device. Can be prevented.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

[0015]

Next, an embodiment of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a configuration of a main part of a first embodiment of the present invention.

In the first embodiment of the present invention, an antenna wiper 1 is provided as a means for removing snow and icing, and a windshield
When the windshield / wiper drive motor 3 for driving the wiper 2 is in the ON state and the outside air temperature detected by the temperature sensor 4 is equal to or lower than t ° C., the antenna wiper 1
And a windshield / wiper control circuit 8 for controlling the windshield / wiper drive motor 3 by an operation input of the wiper switch 7. .

Further, a windshield washer 9 for removing dirt from the windshield glass is provided. Sprays water or antifreeze onto the windshield glass.

FIG. 2 is a diagram showing an example of the external shape of the wiper switch and the washer switch according to the first embodiment of the present invention.

Wiper switch 7 for windshield
And the washer switch 10 is formed integrally with one lever, and is disposed below the steering wheel. The wiper switch 7 is in the off state when the lever is at the uppermost position, and is sequentially moved downward, so that the intermittent operation (INT), low speed operation (LOW) and high speed operation (HI) instruction signals are transmitted to the windshield. -Output to the wiper control circuit 8 and the control circuit 6. The wiper switch 7 is provided with an intermittent time adjusting knob 12, and when the lever is at the intermittent (INT) position, turning the intermittent time adjusting knob 12 adjusts the intermittent time within a range of 2 to 11 seconds. Can be.

FIG. 3 is a perspective view showing a state in which the antenna wiper according to the first embodiment of the present invention is mounted on a radar device, and FIG. 4 is a front view thereof. In FIG. 4, the antenna wiper driving motor 5 is omitted.

The antenna wiper 1 is attached to a dome 21 in which an antenna element of a radar device 20 is housed, and is shown in FIG.
The wiper blade 1a is rotated while the wiper blade 1a is in contact with the surface of the lens 22 by the antenna wiper drive motor 5 shown in FIG. An antenna wiper driving motor 5 for driving the antenna wiper 1 is arranged outside the figure, and is connected to a shaft of the antenna wiper 1 by a link, a belt, or a gear.

Outside air temperature at which the antenna wiper 1 is driven t.degree.
If the temperature near the ground is 0 ° C or lower, snow may occur, and if there is strong cold air above the ground, snow may occur even at 0 ° C or higher. It is desirable to set the temperature to about 4 ° C. in accordance with the operating conditions shown in FIG.

Here, a radar device according to the present invention will be described. FIG. 6 is a block diagram showing a configuration example of a radar device according to the present invention.

The radar device 20 is mounted on a vehicle and transmits a transmission antenna element 23a for transmitting an electromagnetic wave in the traveling direction, a reception antenna element 23b for receiving a reflected wave from an obstacle, and a transmission material formed of a dielectric material. A dome 21 is provided over the antenna element 23a and the receiving antenna element 23b.

The incident angle θ of the transmission wave and the reception wave with respect to the surface of the dome 21 is set to be substantially equal to the Brewster's angle, and the thickness T of the dome 21 near the passage of the electromagnetic wave is determined by the guide wavelength of the electromagnetic wave in the dielectric material. When λg is set, 0.5 × nλg (where n is a natural number) is set, and the dome 21 is formed in a box structure with a dielectric material. The transmitting antenna element 23a and the receiving antenna element 23b are mounted inside the box structure, and the box structure has a mounting tool 24 having a mounting hole for mounting on a vehicle body.
Is provided.

An attenuator 31 and a mixer 32 are connected to the transmitting antenna element 23a, and an oscillator 33 is connected to the attenuator 31. Also, the receiving antenna element 2
A mixer 32 is connected to 3bb, and an amplifier 34 is connected to the mixer 32.

A radar device housing 25 is mechanically coupled to the dome 21 by a fixing screw via a packing. The output from the amplifier 34 is input into the radar device housing 25 to perform A / D conversion. A / D converter 35 and current value determination circuit 36 for determining the current value, and FFT circuit 37 for receiving the output of A / D converter 35 and performing fast Fourier transform
And a computer device 38 which receives the outputs of the FFT circuit 37 and the current value determination circuit 36 and calculates the following distance.
And an oscillator output control circuit 39 for sending a control signal to the attenuator 31 and the amplifier 34 under the control of the computer device 38.

A back cover is fixed to the rear end opening of the radar device housing 25 by a mounting screw via a packing, and the inside is sealed.

An indicator 40 provided with an inter-vehicle distance alarm lamp 41 and a dirt alarm lamp 42 is provided in the driver's seat, and is turned on according to the alarm output of the computer device 38 to generate an alarm.

The radar device configured as described above has the structure shown in FIG.
As shown in (2), the bumper is fixed in the traveling direction of the vehicle by using a mounting tool 24.

Next, the operation of the first embodiment of the present invention will be described. FIG. 8 is a flowchart showing the flow of the operation for removing snow accretion and icing in the first embodiment of the present invention.

The control circuit 6 determines whether or not the output from the wiper switch 7 indicates "ON". If "ON" is not indicated, the windshield wiper 2 is not in operation, and the operation of the antenna wiper drive motor 5 is stopped.

If the wiper switch 7 indicates "ON", since the windshield wiper 2 is operating, the output of the temperature sensor 4 is taken and it is determined whether or not the outside air temperature t is 4 ° C. or less. judge. If the outside air temperature t is 4 ° C. or less, power is supplied to the antenna wiper drive motor 5 to operate the antenna wiper 1.

The antenna wiper 1 has a windshield
If the wiper 2 is in the operating state and the outside temperature t is 4 ° C. or less, the operation is continued in conjunction with the windshield wiper 2. The interlocking operation is performed according to the number of operations programmed in advance.

FIG. 9A is an operation chart when the windshield wiper and the antenna wiper operate at the same speed in the first embodiment of the present invention, and FIG. 9B is an operation chart when the windshield wiper and the antenna wiper operate at different speeds. . According to this example, the antenna wiper 1 operates at a preset number of times,
The intermittent operation is performed when the wiper switch 7 is set to intermittent (INT), the low-speed operation is performed when the wiper switch 7 is set to low (LOW), and the high-speed operation is performed when the wiper switch 7 is set to high (HI).

The operation of the antenna wiper 1 is as follows.
When the switch 7 is set to intermittent (INT), it can be set to operate at low speed, and when it is set to the low (LOW) position, it can be set to operate at high speed.
Intermittent operation can be performed when the wiper switch 7 is set to low speed (LOW), and low speed operation can be performed when the wiper switch 7 is set to high speed (HI).

(Second Embodiment) FIG. 10 is a block diagram showing a configuration of a main part of a second embodiment of the present invention.

In the second embodiment of the present invention, an antenna washer 13 and an antenna washer driving motor 14 are provided instead of the antenna wiper 1 and the antenna wiper driving motor 5 in the first embodiment, and the control circuit 6 includes a windshield wiper. 2 includes a means for driving the antenna washer driving motor 14 to operate the antenna washer 13 when the output of the temperature sensor 4 is equal to or lower than t ° C. Other configurations are the same as in the first embodiment.

FIG. 11 is a front view showing a state where the antenna washer of the second embodiment of the present invention is mounted on a radar device. The antenna washer 13 is attached to the dome 21 in which the antenna element of the radar device 20 is housed, and the injection nozzle 1 is driven by an antenna washer driving motor 14 (not shown).
Antifreeze is sprayed from 3a onto the surface of the lens 22.

FIG. 12 is an operation chart showing an example of the interlocking operation between the windshield wiper and the antenna washer in the second embodiment of the present invention.

In this example, when the wiper switch 7 is set to intermittent (INT), the injection interval is extended to perform eight injections per minute, and when the wiper switch 7 is set to high speed (HI), the injection is performed. An example is shown in which the interval is shortened and 12 injections are performed per minute. The injection interval is fixedly set at the time of shipment, but can be set to an arbitrary interval by adding a variable switch.

In the case of the second embodiment constructed as described above, the control circuit 6 controls the antenna washer driving motor when the windshield wiper 2 is on and the outside air temperature is t.degree. By driving the antenna washer 13 to drive the antenna washer 13, antifreeze is sprayed from the spray nozzle 13 a to the lens 22 on the surface of the radar antenna to remove attached snowflakes.

(Third Embodiment) FIG. 13 is a block diagram showing a configuration of a main part of a third embodiment of the present invention.

In the third embodiment of the present invention, an antenna heater 15 is provided instead of the antenna wiper 1 and the antenna wiper driving motor 5 in the first embodiment, and the control circuit 6
Means for energizing the antenna heater 15 when the windshield wiper 2 is on and the output of the temperature sensor 4 indicates a temperature of t ° C. or less is included. Other configurations are the same as in the first embodiment.

FIGS. 14A, 14B and 14C are front views showing examples of the arrangement of the heater wires of the antenna heater according to the third embodiment of the present invention. A heater wire 15a is arranged on the antenna heater 15, and is attached to the surface of the radar antenna. Antenna heater 1 other than the arrangement example shown in FIG.
5 can also be used.

Also in the case of the third embodiment, the control circuit 6
When the windshield wiper is on and the outside air temperature is lower than or equal to t ° C., the antenna heater 15 is energized to melt and remove snowflakes attached to the lens 22.

FIG. 15 is an operation chart showing an example of the interlocking operation of the windshield wiper and the antenna heater in the third embodiment of the present invention.

Here, the wiper switch 7 is intermittent (I
NT), the antenna heater 15 is set to 1
An example is shown in which power is supplied at intervals of 0 seconds "on" and 5 seconds "off", and continuous power is supplied when the wiper switch 7 is set to low speed (LOW) or high speed (HI). The energization of the antenna heater 15 can be set variously by changing the program.

(Fourth Embodiment) FIG. 16 is a block diagram showing a configuration of a main part of a fourth embodiment of the present invention.

In the fourth embodiment of the present invention, the antenna washer 1 and the antenna wiper driving motor 5 of the first embodiment, the antenna washer 13 and the antenna washer driving motor 14 of the second embodiment are provided, and the control circuit 6 When the windshield wiper 2 is in the ON state and the output of the temperature sensor 4 is lower than t ° C., the antenna wiper drive motor 5 and the antenna washer drive motor 14 are driven, and the antenna wiper 1 and the antenna washer 13 are driven. Means for operating is included.
Other configurations are the same as in the first embodiment.

FIG. 17 is a front view showing a state where the antenna wiper and the antenna washer of the fourth embodiment of the present invention are mounted on a radar device. In this figure, the antenna wiper drive motor 5 and the antenna washer drive motor 14 are omitted.

In the case of the fourth embodiment, when the windshield wiper 2 is in the ON state, the control circuit 6 takes in the output from the temperature sensor 4 and if the outside air temperature indicates t.degree. The antenna wiper drive motor 5 and the antenna washer drive motor 14 are driven to operate the antenna wiper 1 to wipe the surface of the lens 22, and the antenna washer 13 is operated to spray antifreeze and remove snowflakes attached to the lens 22. I do.

FIG. 18A is an operation chart when the windshield wiper, the antenna wiper and the antenna washer operate at the same speed in the fourth embodiment of the present invention, and FIG. 18B shows the operation when the windshield wiper operates at different speeds. It is a chart.

In the pattern shown in FIG. 18A, when the wiper switch 7 is set to intermittent (INT), the antenna wiper 1 performs an intermittent operation in synchronization with the windshield wiper 2, and the antenna washer operates. Inject antifreeze at a rate of 4 times a minute. Wiper switch 7
Is set to low speed (LOW) or high speed (HI), the antenna wiper 1 continuously operates in synchronization with the windshield wiper 2, and the antenna washer 1
No. 3 injects antifreeze at a rate of 6 times per minute.

In the pattern shown in FIG.
The antenna wiper 1 has the wiper switch 7 intermittent (IN
When set to T), the intermittent operation is performed with a smaller number of operations than the number of operations of the windshield wiper 2, and the antenna washer 13 injects the antifreeze at a rate of twice a minute. Wiper switch 7 is low speed (LOW)
Alternatively, when high speed (HI) is set, the antenna wiper 1 performs continuous operation with a smaller number of operations than the number of times of operation of the windshield wiper 2, and the antenna washer 13 injects antifreeze at a rate of four times per minute. I do.

(Fifth Embodiment) In the fifth embodiment of the present invention, an air nozzle and an open / close valve are provided instead of the antenna washer 13 and the antenna washer driving motor 14 of the second embodiment of the present invention. When the above-described operating conditions are satisfied, compressed air is blown out from the air nozzle to remove the adhesion of snowflakes.

[0058]

As described above, according to the present invention, during the operation of the windshield wiper, when the temperature of the radar antenna falls below the outside temperature at which rain turns into snow and water drops may freeze. The icing removal device is automatically driven, and when the outside air temperature rises above that temperature, the device is automatically stopped, so that the driver can perform driving operations without being aware of driving or stopping the device. it can. Further, it is possible to prevent the operation of the apparatus from being continued when it becomes unnecessary to remove snow and ice and prevent the transmission of electromagnetic waves from the radar apparatus, and prevent the life of the apparatus from being shortened.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing an example of an external shape of a wiper switch and a washer switch according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a state in which the antenna wiper according to the first embodiment of the present invention is attached to a radar device.

FIG. 4 is a front view showing a state where the antenna wiper according to the first embodiment of the present invention is attached to a radar device.

FIG. 5 is a view for explaining setting of an antenna wiper operating temperature in the first embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration example of a radar device according to the first embodiment of the present invention.

FIG. 7 is a perspective view showing a state in which the radar device according to the first embodiment of the present invention is mounted on a vehicle.

FIG. 8 is a flowchart showing a flow of a snow accretion removal operation in the first embodiment of the present invention.

9A is an operation chart when the windshield wiper and the antenna wiper operate at the same speed in the first embodiment of the present invention, and FIG. 9B is an operation chart when the windshield wiper and the antenna wiper operate at different speeds.

FIG. 10 is a block diagram showing a configuration of a main part of a second embodiment of the present invention.

FIG. 11 is a front view showing a state in which the antenna washer according to the second embodiment of the present invention is attached to a radar device.

FIG. 12 is an operation chart showing an example of an interlocking operation between a windshield wiper and an antenna washer in a second embodiment of the present invention.

FIG. 13 is a block diagram showing a configuration of a main part of a third embodiment of the present invention.

FIGS. 14 (a), (b) and (c) are front views showing examples of arrangement of heater wires of an antenna heater in the embodiment of the present invention.

FIG. 15 is an operation chart showing an example of an interlocking operation of the windshield wiper and the antenna heater in the third embodiment of the present invention.

FIG. 16 is a block diagram showing a configuration of a main part of a fourth embodiment of the present invention.

FIG. 17 is a front view showing a state where an antenna wiper and an antenna washer according to a fourth embodiment of the present invention are mounted on a radar device.

FIG. 18A is an operation chart when the windshield wiper, the antenna wiper, and the antenna washer operate at the same speed in the fourth embodiment of the present invention;
(B) is an operation chart when operating at different speeds.

[Explanation of symbols]

 Reference Signs List 1 antenna wiper 1a wiper blade 2 windshield wiper 3 windshield wiper drive motor 4 temperature sensor 5 antenna wiper drive motor 6 control circuit 7 wiper switch 8 windshield wiper control circuit 9 windshield washer 10 washer switch DESCRIPTION OF SYMBOLS 11 Windshield / washer drive motor 12 Intermittent time adjustment knob 13 Antenna washer 13a Injection nozzle 14 Antenna washer drive motor 15 Antenna heater 15a Heater wire 20 Radar device 21 Dome 22 Lens 23a Transmitting antenna element 23b Receiving antenna element 24 Mounting device 25 Radar device Casing 31 Attenuator 32 Mixer 33 Oscillator 34 Amplifier 35 A / D converter 36 Current value judgment circuit 37 FFT circuit 38 Computer device 39 Oscillator output control circuit 40 Display 41 Inter-vehicle distance alarm lamp 42 Dirt alarm lamp

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI G01S 7/03 G01S 7/03 D H01Q 1/02 H01Q 1/02 1/22 1/22 A

Claims (5)

[Claims] 1. A control circuit for automatically turning on a snow and ice removing means when a windshield wiper is on and an outside air temperature is not more than t ° C. Snow and ice removal equipment for radar antennas. 2. An apparatus for removing snow and ice from a radar antenna according to claim 1, wherein said means for removing snow and ice is an antenna wiper. 3. The apparatus according to claim 1, wherein said means for removing icing and ice is an antenna washer. 4. The apparatus for removing snow and ice of a radar antenna according to claim 1, wherein said means for removing snow and ice is an antenna heater. 5. The apparatus for removing snow and ice from a radar antenna according to claim 1, further comprising means for controlling the operation frequency of said means for removing snow and ice according to the operation speed of said windshield wiper.