KR20150108681A - Radar device for vehicle and control method of it - Google Patents

Abstract

The radar device for a vehicle of the present invention comprises: a modulating unit for modulating a radar transmission signal into a certain frequency; a transmission circuit for outputting the modulated signal to a transmission antenna; a receiving circuit for receiving a reflected radio wave, which is a radar radio wave outputted by the transmission antenna and reflected by an object; a demodulating unit for demodulating the reflected radio wave received into a radar receiving signal; a signal processing unit for outputting the radar transmission signal to the modulating unit at a certain cycle, and receiving the radar receiving signal from the demodulating unit to perform signal processing for determining the position of the object; a temperature determining unit for determining the temperature; and a motion control unit for controlling the motion frequency of the signal processing unit according to the temperature determined.

Description

Technical Field [0001] The present invention relates to a radar device,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus and a control method for detecting a position of a moving object and measuring a speed thereof, and more particularly, to a method for controlling a temperature of a radar apparatus for a vehicle.

Vehicle radar devices / systems are being used to detect and track the location of moving and stationary objects, such as other vehicles on the road.

Radar systems used for vehicle operation are typically CW (Continuous Wave) radar and Frequency Modulation Continuous Wave (FMCW) radar.

CW radar is a radar that transmits and receives sinusoidal waves using a duplexer that uses the same antenna at the same time as a transmitter and a receiver.

To overcome this disadvantage, FMCW radar is used to transmit and receive sinusoidal waves through frequency variable.

The FMCW radar has the advantage of measuring the distance between the target and the radar by emitting an electromagnetic wave to the target, measuring the beat frequency by mixing the reflection echo from the target with a part of the transmission frequency.

In this case, the frequency of the echoes received at the FMCW radar has a different value from the frequency of the signal that the transmitter is emitting, depending on the speed of the moving object.

That is, the speed of the moving object can be known by the frequency difference, and the distance to the moving object is measured by the difference between the transmission time and the reception time.

In the car, CW radar and FMCW radar are used simultaneously or alternately.

On the other hand, a vehicle radar apparatus / system generates a considerable amount of heat by driving a fast signal processing processor, a microwave oscillation circuit, and the like. In addition, signal processing processors and the like of a radar apparatus / system for a vehicle may malfunction at a temperature exceeding the number limit.

However, even if the radar for the vehicle is temporarily malfunctioning, it may become a serious risk to the safe operation of the vehicle.

Japanese Patent Application Laid-Open No. 10-2011-0114795

An object of the present invention is to provide a vehicular radar apparatus and a control method thereof that can prevent overheating.

Alternatively, the present invention is intended to provide a radar apparatus for a vehicle and a control method thereof that can secure the safety of vehicle operation.

According to an aspect of the present invention, there is provided a radar apparatus for a vehicle, comprising: a modulator for modulating a radar transmission signal at a predetermined frequency; A transmitting circuit for outputting the modulated signal to a transmitting antenna; A receiving circuit for receiving a reflected radio wave reflected by an object, the radar wave radiated from the transmitting antenna; A demodulator for demodulating the received reflected wave into a radar received signal; A signal processor for outputting the radar transmission signal to the modulator at a predetermined cycle, receiving a radar reception signal from the demodulator, and performing signal processing for determining an object position; A temperature judging unit for judging a temperature; And an operation control unit for controlling an operation frequency of the signal processing unit according to the determined temperature.

Here, the operation control unit may control the period for outputting the radar transmission signal to the modulator to be longer as the determined temperature is higher.

Here, the operation control unit may control a period in which the modulating unit and the demodulating unit operate in accordance with a period of outputting the radar transmission signal to the modulating unit.

Here, the radar transmission signal has a pulse shape, and the operation time of the modulator is controlled according to the pulse, and the signal processor can control the width or the frequency of the pulse according to the control of the operation controller.

The modulator modulates the frequency of the radar transmission signal into a signal having a frequency multiplied by a predetermined reference frequency and adjusts a time for the signal processing unit to output the radar transmission signal under the control of the operation control unit .

Here, the operation control unit may adjust the frequency of the reference clock of the signal processing unit.

A method of controlling a radar for a vehicle according to another aspect of the present invention includes: measuring a temperature; Determining a radar wave transmission period of the vehicle radar according to the measured temperature; Outputting a radar wave from a transmission antenna at the determined transmission period; Receiving a reflected radio wave reflected from an object by the radar wave outputted from the transmission antenna; And performing signal processing for determining the position of the object using the received reflected radio wave.

Here, in the step of determining the radar wave transmission period, the higher the determined temperature, the longer the radar wave transmission period can be set.

The radar apparatus for a vehicle and the control method thereof according to the present invention according to the above-described configuration have an advantage that overheat of the radar apparatus can be prevented.

Alternatively, the present invention has an advantage that safety of vehicle operation can be secured even in a situation where there is concern about overheating.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram illustrating a radar transmission environment of a vehicle according to an embodiment of the present invention; FIG.
2 is a block diagram showing a radar apparatus according to an embodiment of the present invention;
3 is a block diagram showing an embodiment of the modulator and the transmission circuit of Fig.
Fig. 4 is a block diagram showing another embodiment of the modulator and the transmission circuit of Fig. 2; Fig.
Fig. 5 is a block diagram showing still another embodiment of the modulator and the transmission circuit of Fig. 2; Fig.
Fig. 6 is a block diagram showing another embodiment of the modulator and the transmission circuit of Fig. 2; Fig.
FIG. 7 is a flowchart showing a method of controlling a radar for a vehicle, which is performed in the radar apparatus of FIG. 2;
8A and 8B are conceptual diagrams showing modulation aspects in a radar wave in a modulation section at a cycle determined by the temperature of the laser device, according to the idea of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood that the present invention is not intended to be limited to the specific embodiments but includes all changes, equivalents, and alternatives included in the spirit and scope of the present invention.

In describing the present invention, the terms first, second, etc. may be used to describe various elements, but the elements may not be limited by terms. Terms are for the sole purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being connected or connected to another element, it may be directly connected or connected to the other element, but it may be understood that other elements may be present in between . On the other hand, when it is mentioned that an element is directly connected to or directly connected to another element, it can be understood that there is no other element in between.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions may include plural expressions unless the context clearly dictates otherwise.

It is to be understood that the term " comprising, " or " comprising " as used herein is intended to specify the presence of stated features, integers, But do not preclude the presence or addition of steps, operations, elements, components, or combinations thereof.

Also, unless otherwise defined, all terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs . Terms such as those defined in commonly used dictionaries can be interpreted as having a meaning consistent with the meaning in the context of the related art and, unless explicitly defined herein, are interpreted in an ideal or overly formal sense .

In addition, the following embodiments are provided so as to explain the invention more clearly to those skilled in the art. The shapes and sizes of the elements in the drawings may be exaggerated for clarity.

1 is a configuration diagram illustrating a radar transmission environment of a vehicle according to an embodiment of the present invention.

Referring to FIG. 1, a car 101 according to an embodiment of the present invention transmits a radar transmission signal 501 forward and transmits a signal reflected from a moving object 601 or a fixed object 701 to a car 101 ). ≪ / RTI >

The moving object 601 can move at a low speed, a constant velocity and a high speed with respect to the speed of the car 101. At this time, the reflected signal has a delay time relative to the radar transmission signal 501 and a frequency deviation exists due to the Doppler effect do. The car 101 measures the delay time and the frequency deviation to determine the position and the speed of the moving object 601. [

The signal reflected by the fixed object 701 is mixed with the signal reflected from the moving object 601 and is received by the subcarrier 101. In the subcarrier 101, the signal reflected from the moving object 601 is fixed The signal reflected from the object 701 is removed.

Incidentally, among the respective components constituting the radar apparatus of the vehicle, there is a risk of malfunction of the radar device when the temperature of the radar apparatus is increased due to the heat generation of the elements including the high calorific value.

2 is a block diagram illustrating a radar apparatus according to an embodiment of the present invention. The illustrated radar apparatus 200 includes a modulator 230 for modulating a radar transmission signal to a predetermined frequency; A transmission circuit 220 for outputting the modulated signal to a transmission antenna; A receiving circuit (250) for receiving a reflected radio wave reflected from an object, the radar wave outputted from the transmitting antenna; A demodulator 260 for demodulating the received reflected wave into a radar received signal; A signal processor 270 for outputting the radar transmission signal to the modulator at predetermined intervals, receiving a radar reception signal from the demodulator, and performing signal processing for determining an object position; A temperature determination unit (290) for determining a temperature; And an operation control unit 280 for controlling the operation speed of the signal processing unit according to the determined temperature.

The transmission circuit 220 feeds a current for generating a radio wave to a transmission (TX) antenna 210 constituting a radar. The transmission circuit 220 uses the signal output from the modulation unit 230 to feed the current And amplification for ensuring transmission power can be performed.

The modulator 230 may include a frequency multiplier, a switching device, and the like for generating the modulated signal.

The TX antenna 210 and the RX antenna 240 may be implemented as radar antennas. For example, the TX antenna 210 and the RX antenna 240 may each be an array antenna including unit antenna elements. In this case, some unit antenna elements may overlap.

The receiving circuit 250 and the demodulation unit 260 may have a structure used in a general radar system and are not related to the concept of the present invention.

The signal processing unit 270 and the operation control unit 280 may be partial SW and / or HW modules in one single chip, depending on the implementation. In particular, when using a recent high performance multifunctional DSP chip, the signal processing unit 270 and the operation control unit 280 can be easily implemented as an internal SW module.

The signal processing unit 270 can detect and track an object using radar waves in the radar device. That is, when the receiving antenna 240 receives the reflected radio wave reflected from the object to be detected / tracked by the radar wave emitted from the transmitting antenna 210, the receiving antenna 240 analyzes the received signal from the receiving antenna 240 Thereby performing detection and / or tracking of the object.

The operation control unit 280 adjusts the operation frequency (i.e., frequency) of the radar device according to the temperature of the radar device according to the idea of the present invention. That is, the higher the temperature, the smaller the frequency of operation of the radar device (that is, the frequency is lower), thereby preventing the radar device from overheating. For example, the higher the temperature, the longer the period of outputting the radar transmission signal to the modulator.

To this end, the operation control unit 280 may receive the temperature information of the radar device from the temperature determination unit 290. The temperature determination unit 290 may include a temperature sensor (e.g., a thermistor) provided in the radar device.

The operation control unit 280 may control at least one of the modulation unit 230, the signal processing unit 270 and the demodulation unit 260 so as to be executed according to the adjusted operation frequency. However, since the demodulating unit 260 does not have a high specific gravity during a period in which no signal is received from the RX antenna, the demodulating unit 260 operates passively according to the reception of the reflected radio waves. Therefore, the demodulation unit 260 can not be subjected to the operation frequency adjustment alone, and may be excluded from the operation frequency adjustment subject in some cases.

FIG. 3 shows an embodiment of the modulator and the transmission circuit of FIG. 2. FIG. The illustrated structure can adjust the radar wave emission frequency according to the operation frequency determined according to the idea of the present invention by using a variable oscillator. In the illustrated structure, the modulating unit includes a variable oscillator 231 for oscillating a signal of a predetermined frequency in accordance with the control signal C1 output from the operation control unit 280 of FIG. 2, and the transmitting circuit amplifies the oscillated signal An amplifier 221 may be included. When the radar apparatus is a CW system, the predetermined frequency is a fixed frequency, and in the case of an FMCW system, the predetermined frequency can also be determined by the control signal C1.

Fig. 4 shows another embodiment of the modulator and the transmission circuit of Fig. 2. Fig. The illustrated structure modulates a square wave clock (which may be a clock having a waveform of another type such as an impulse or a triangle wave) oscillating at a frequency according to the operation frequency determined according to the idea of the present invention by multiplying the reference frequency signal. In the illustrated structure, the modulating unit includes a reference oscillator 203 for generating the reference frequency signal; And a frequency multiplier 232 for generating a signal obtained by multiplying the reference frequency signal by the square wave clock. In addition, the transmitting circuit may include an amplifier 221 for amplifying the oscillated signal. 2 includes a DSP oscillator 207 including a clock oscillator 207 for generating a square wave clock adjusted in accordance with the control signal C2 output from the operation control unit 280 272). The oscillation time interval and the stop time interval are repeated in the predetermined period T2 of the square wave clock. In order to realize the idea of the present invention, the predetermined period T2 may be determined according to the control signal C2. The radar device having the structure shown in FIG. 4 may be a CW-type radar device or an FMCW-type radar device. In the latter case, the oscillation frequency of the rectangular wave clock may also be determined according to the control signal C2 have.

Fig. 5 shows another embodiment of the modulator and the transmission circuit of Fig. 2. Fig. The illustrated structure performs modulation by PWM control by using a pulse having an operation frequency determined according to the idea of the present invention whether an oscillation signal having a predetermined frequency is outputted or not.

In the illustrated structure, the modulator includes a reference oscillator 204 for generating the oscillation signal of the predetermined frequency; And a switch 233 for switching output of the oscillation signal of the reference oscillator 204 according to a predetermined PWM pulse. In addition, the transmitting circuit may include an amplifier 221 for amplifying the oscillated signal. The switch 233 may be turned on at a high or low interval of the PWM pulse.

2 includes a DSP oscillator 208 including a clock oscillator 208 for generating the PWM pulses that are adjusted in accordance with the control signal C3 output from the operation control unit 280. In addition, (273). The PWM pulse has a predetermined period T3. In order to realize the idea of the present invention, the predetermined period T3 may be determined according to the control signal C3. The radar device having the structure shown in Fig. 5 is advantageously a CW type radar device. The reference oscillator 204 may be replaced with a variable oscillator to implement a radar device of the FMCW scheme in the illustrated structure.

Fig. 6 shows another embodiment of the modulator and the transmission circuit of Fig. 2. Fig. The illustrated structure implements the idea of the present invention by controlling the operation clock of a device for generating PWM pulses in a structure in which the output of an oscillation signal having a predetermined frequency is PWM controlled and modulated.

In the illustrated structure, the modulator includes a reference oscillator 204 for generating the oscillation signal of the predetermined frequency; And a switch 233 for switching output of the oscillation signal of the reference oscillator 204 according to a predetermined PWM pulse. In addition, the transmitting circuit may include an amplifier 221 for amplifying the oscillated signal. The switch 233 may be turned on at a high or low interval of the PWM pulse.

2 may be a chip element 274 including a clock oscillator 208 for generating the PWM pulse. The chip device 274 operates in accordance with a reference clock in the same manner as a general chip device. The frequency of a reference clock input to the chip device 274 is controlled by a control signal C4). ≪ / RTI > Accordingly, when the frequency of the reference clock is lowered, the frequency of the PWM pulse also becomes lower (T4 becomes longer), and accordingly, the frequency of outputting the oscillation signal becomes lower. In order to keep the switch 233 in the ON state constant even if the duty of the PWM pulse is changed, a delay unit (not shown) which operates in the falling edge or rising edge of the PWM pulse and maintains the ON signal for a fixed delay time (Not shown).

The radar apparatus having the structure shown in Fig. 6 is advantageously a CW type radar apparatus. The reference oscillator 204 may be replaced with a variable oscillator to implement a radar device of the FMCW scheme in the illustrated structure.

7 is a flowchart showing a method of controlling a radar for a vehicle, which is performed in the radar apparatus of FIG.

The control method for the vehicle radar shown in the figure includes: a step (S110) of measuring the temperature of the radar device; Determining a radar wave transmission period of the vehicle radar according to the measured temperature (S120); Outputting a radar wave at a transmission antenna at the determined transmission period (S140); A step (S160) of receiving a reflected radio wave reflected by an object, the radar wave outputted from the transmission antenna; And performing signal processing for determining the position of the object using the received reflected wave (S180).

The step S110 is for checking the degree to which the radar device is heated by the heating elements constituting the radar device. If the radar device is overheated, a radar malfunction may be a risk to vehicle safety operation. Although the radar apparatus is provided with a predetermined cooling apparatus, there is a possibility that the radar apparatus is overheated regardless of the cooling apparatus due to an increase in outside air temperature or overheating of the vehicle itself. For example, the step S110 may be performed in such a manner as to calculate the operating temperature of the radar device from the output value of the thermistor attached to the substrate of the radar device.

According to the idea of the present invention, the operation frequency of the radar device is set to be low in case of overheating in step S120. Steps S120 and S140 may be performed according to various structures, as shown in FIGS.

Although the steps S140 and S160 are repeatedly performed in one cycle of the transmission period defined in the step S120, the process of performing the processes in succession may be performed continuously for several transmission periods .

Steps S140 and S160, which are performed for each period of the transmission period, may be similar to the transmission and reception of radar waves performed in a general vehicle radar.

The step S180 may be similar to the process of determining / tracking the position of an object using a received radar reflection wave performed in a general vehicle radar.

8A and 8B are conceptual diagrams showing modulation aspects in a radar wave in a modulation section at a cycle determined by the temperature of the laser apparatus, according to the idea of the present invention. For example, if it is determined in step S120 of FIG. 7 that the operation temperature is the general operation temperature, step S140 is performed in a cycle of FIG. 8A, and if it is determined in step S120 of FIG. 7 that the operation temperature is high, Step S140 may be performed. In the illustrated control mode, the measured temperature of the radar device is simply divided into the general operation temperature and the high temperature operation temperature (divided into two stages) and the radar operation frequency (cycle) is doubled in the case of the high temperature operation temperature. Accordingly, when operating at a high temperature, the operation occupancy rate of the components of the radar apparatus, particularly, the processors can be reduced, thereby effectively preventing overheating.

In other implementations, the radar operation frequency can be divided into three or more stages, or three or more radar operation frequencies, or continuous values, and the radar operation frequency can be selected from successive values.

It should be noted that the above-described embodiments are intended to be illustrative, not limiting. In addition, it will be understood by those of ordinary skill in the art that various embodiments are possible within the scope of the technical idea of the present invention.

200: Radar device
220: transmitting circuit
230: Modulation section
250: receiving circuit
260: Demodulator
270: Signal processor
280:
290: Temperature judging unit

Claims (8)

A modulator for modulating the radar transmission signal at a predetermined frequency;
A transmitting circuit for outputting the modulated signal to a transmitting antenna;
A receiving circuit for receiving a reflected radio wave reflected by an object, the radar wave radiated from the transmitting antenna;
A demodulator for demodulating the received reflected wave into a radar received signal;
A signal processor for outputting the radar transmission signal to the modulator at a predetermined cycle, receiving a radar reception signal from the demodulator, and performing signal processing for determining an object position;
A temperature judging unit for judging a temperature; And
An operation control unit for controlling an operation frequency of the signal processing unit according to the determined temperature,
And a radar device for a vehicle.
The method according to claim 1,
The operation control unit,
And controls the period for outputting the radar transmission signal to the modulator to be longer as the determined temperature is higher.
3. The method of claim 2,
The operation control unit,
And controls a period in which the modulating unit and the demodulating unit operate according to a period of outputting the radar transmission signal to the modulating unit.
The method according to claim 1,
The radar transmission signal has a pulse shape,
According to the pulse, the operation time of the modulator is adjusted,
And the signal processing unit controls the width or frequency of the pulse according to the control of the operation control unit.
The method according to claim 1,
Wherein the modulator modulates the frequency of the radar transmission signal into a signal having a frequency multiplied by a predetermined reference frequency,
And controls the time when the signal processing unit outputs the radar transmission signal under the control of the operation control unit.
The method according to claim 1,
Wherein the operation control unit adjusts the frequency of the reference clock of the signal processing unit.
Measuring a temperature;
Determining a radar wave transmission period of the vehicle radar according to the measured temperature;
Outputting a radar wave from a transmission antenna at the determined transmission period;
Receiving a reflected radio wave reflected from an object by the radar wave outputted from the transmission antenna; And
Performing signal processing for determining the position of the object using the received reflected wave;
And controlling the radar.
8. The method of claim 7,
Wherein the step of determining the radar wave transmission period sets the radar wave transmission period to be longer as the determined temperature is higher.

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