JPH10325863A - Scanning radar equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide scanning radar equipment without needing mechanical precision on a rotation part for scanning a radar sensor and without enlarging burden of a motor. SOLUTION: A radar sensor part 2 is rotated at a constant angular velocity, when a desired angle is obtained, it is detected and measuring is performed without being stationary. In addition, the detection means of the angle is simplified by detecting that the radar sensor part 2 directs a prescribed angle in elapsed time. Furthermore, it is detected that the radar sensor part 2 directs the prescribed angle by a signal from a potentiometer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle radar scanning apparatus. In particular, the present invention relates to a scanning device that continuously performs a scanning operation without stopping and sequentially measures at a desired angle.

[0002]

2. Description of the Related Art When scanning a radar, in a conventional mechanical scan radar, a radar sensor is rotated by a turntable to obtain information on a desired angle, an angle at that time is detected, and this is monitored on a monitor. Each time the desired angle is reached, the sensor is stopped and measurement is performed.

FIG. 1 is a diagram showing an outline of the configuration of a mechanical scan radar device. In FIG. 1, reference numeral 1 denotes a synchronizing signal generation unit, 2 denotes a radar sensor unit, 3 denotes a rotating unit including a turntable for rotating the radar sensor 2 for scanning, and 4 denotes a signal for processing a detection signal input from the radar sensor 2. It is a processing unit. Reference numeral 5 denotes a rotation control unit for turning the rotation unit 3 in a desired direction, and a rotation angle detection unit 6 for detecting a rotation angle of the rotation unit 3.
, The radar sensor 2 is directed in a desired angle direction, and the distance and the relative speed between the radar sensor 2 and an object existing in the direction are measured.

Here, the rotation control unit 5 obtains a detection signal from the rotation angle detection unit 6 of the rotation unit 3 of the radar sensor unit 2, monitors this on a monitor, and monitors the rotation unit 3 every time the rotation angle reaches a desired angle.
Was stopped, the radar sensor unit 2 was stopped, and a signal was sent to the signal processing unit 4 to perform measurement. Note that the rotation control unit 5 also sends a signal to another system via the input interface 7.

FIG. 2 is a diagram for explaining a scanning operation by a conventional mechanical scan radar device. FIG.
, The transmission signal is radiated forward from the radar sensor unit 2. The radar sensor section 2 is rotated by a rotating section 3 (FIG. 1). The rotating section 3 is rotated every time a desired angle (θ1, θ2, θ3,..., Θn in the figure) is reached.
Is stopped, the radar sensor unit 2 is stopped, and the measurement is performed.

[0006]

In a conventional mechanical scan radar apparatus, a radar sensor section is rotated by a rotating section, an angle at that time is detected, and this is monitored by a monitor. The measurement is performed by stopping the rotating part and stopping the sensor. However, since the rotating portion is a mechanical type, it takes a long time to stop. In addition, in order to stably and surely stop at a desired angle, mechanical accuracy must be increased.

[0007] Also, in the rotation operation, first, the rotating part is moved, stopped at a desired angle, and measured. And
The rotating, stationary, and measuring operations are repeated, such as moving the rotating unit to the next angle, stopping at a desired angle, and measuring, so that the load on the motor that rotates the rotating unit increases. Accordingly, it is an object of the present invention to provide a scan radar apparatus which does not require a high degree of mechanical accuracy for a rotating unit to scan a radar sensor and does not increase the load on a motor.

[0008]

Therefore, according to the present invention, the measurement is performed by stopping the rotating unit and performing the measurement in a state where the radar sensor unit is stationary, but by rotating the radar sensor unit at a constant angular velocity. Detect this when facing the desired angle,
The measurement is performed without stopping.

Further, the angle detecting means can be simplified by detecting that the radar sensor section is oriented at a predetermined angle with the passage of time. Further, it is configured to detect that the radar sensor section is oriented at a predetermined angle by a signal from the potentiometer.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a diagram for explaining a scanning operation by a scan radar device according to the present invention.
The basic components of the scan radar device performing the following operation are substantially the same as those of the scan radar device shown in FIG. 1, and therefore, the configuration of FIG. 1 will be used in the following description.

In FIG. 3, a transmission signal is radiated forward from the radar sensor unit 2. The radar sensor section 2 is rotated by a rotating section 3 (FIG. 1). When the scanning is started, the rotating unit 3 rotates, and the radar sensor unit 2 (FIG. 1) facing an arbitrary angle is stopped at the initial setting angle θ0. Next, in the acceleration part a from the initial setting angle θ0 to the measurement start angle θ1, the radar sensor unit 2
Is increased to the scan speed. Then, after reaching the angle θ1, the desired angle θ1,
Measurements are sequentially performed at θ2, θ3,..., θn. Note that these angles θ0, θ1, θ2, θ3, ---
, Θn represent angles from a reference angle when a specific angle of the radar sensor unit 2 is used as a reference. In the present invention, instead of measuring at the desired angles θ1, θ2, θ3,..., Θn in a state where the rotating unit 3 is stopped and the radar sensor unit 2 is stationary, the rotating unit 3 performs measurement during the measurement period b. The radar sensor 2 rotates at a constant angular velocity from θ1 to θn, and the desired angle θ1, θ2, θ3,.
Measure at n.

FIG. 4 is a graph showing the angular velocity of the rotating unit in the scanning operation by the scan radar apparatus of the present invention, that is, the rotational angular velocity ω of the scan of the radar sensor unit 2 and the change of the rotational angle θ with respect to time. At time 0, the rotational angular velocity ω of the radar sensor unit 2 is 0 because the radar sensor unit 2 is stopped at the initially set angle θ0 (FIG. 3). Next, from the initial setting angle θ0 to the measurement start angle θ1, the rotational angular velocity ω is accelerated from 0 to ω0, and at time t1, the rotational angular velocity becomes ω0. From the measurement start angle .theta.1 to the final measurement angle .theta.n, the radar sensor unit 2 rotates at a constant angular velocity .omega.0 without standing still and obtains the desired angles .theta.1, .theta.2.
, .Theta.3,..., .Theta.n, and ends the measurement at time tn. The radar sensor 2 decelerates from the final measurement angle θn to the rotation end angle θm, and the rotation angular velocity ω becomes 0 at tm.

FIGS. 5 and 6 are diagrams for explaining an embodiment of control for causing the scan radar apparatus of the present invention to perform the above-described scan operation. Note that the following embodiment will be described by taking an FM-CW radar as an example, but can be applied to other types of radar such as a pulse radar. In FIG. 5, a detection synchronization signal generation unit 1 of the sensor integrates a synchronization signal such as a pulse signal sent from the microcomputer 4 or the like, and generates an FM modulation signal which is a modulation signal of a triangular wave. This FM
The modulation signal is input to a voltage controlled oscillator (VCO) in the radar sensor unit 2 and modulates the frequency of the VCO. FM
The modulated transmission signal is radiated to the outside via the transmission antenna 21 of the radar sensor unit 2, and a part of the transmission signal is branched into a local signal. On the other hand, the transmission signal reflected by the preceding vehicle or the like is transmitted to the receiving antenna 2 of the radar sensor unit 2.
2 and mixed with the local signal to obtain a radar signal. The radar signal is processed by a signal processing unit of the microcomputer 4 to obtain an inter-vehicle distance to a preceding vehicle, a relative speed, and the like.

In the embodiment of the present invention shown in FIG. 5, the rotation angle θ of the radar sensor unit 2 is detected as follows. First, from the rotating unit 3 (FIG. 1) of the radar sensor unit 2, the measurement start angle θ1 in FIG. 3 and a constant rotational angular velocity ω when the radar sensor unit 2 scans from θ1 to θn.
0 is input to the timing signal generator 8. On the other hand, an FM modulation signal, which is a modulation signal of a triangular wave, is input as a detection synchronization signal A of the sensor from the detection synchronization signal generation unit 1 of the sensor. The detection synchronization signal A of this sensor is used for detecting the elapsed time t. From these signals, that is, the measurement start angle θ1, the rotational angular velocity ω0, and the elapsed time t, a desired angle θ can be detected by the following equation.

(Desired angle θ) = (measurement start angle θ1) +
(Rotation angular velocity ω 0) × (elapsed time t) In FIG. 5, when the timing signal generator 8 detects that the radar sensor unit 2 has reached the desired angle θ, it generates a timing signal B and outputs it to the microcomputer 4. Then, measurement is performed by radar at that angle. In FIG. 6, a detection synchronization signal generator 1 of the sensor integrates a synchronization signal such as a pulse signal sent from the microcomputer 4 or the like, and generates an FM modulation signal that is a triangular wave modulation signal. The FM modulation signal is input to a voltage controlled oscillator (VCO) in the radar sensor unit 2 and modulates the frequency of the VCO. The FM-modulated transmission signal is radiated to the outside via the transmission antenna 21 of the radar sensor unit 2, and a part of the transmission signal is branched into a local signal. On the other hand, a transmission signal reflected by a preceding vehicle or the like is received via the reception antenna 22 of the radar sensor unit 2 and mixed with the local signal to obtain a radar signal. The radar signal is processed by a signal processing unit of the microcomputer 4 to obtain an inter-vehicle distance to a preceding vehicle, a relative speed, and the like.

In the embodiment of the present invention shown in FIG. 6, the rotation angle .theta. Of the radar sensor unit 2 is detected by detecting a rotation signal from the rotation unit 3 by a rotation signal detection unit 9, and an A / D converter 10
A / D converted and input to the microcomputer 4. The rotation signal of the radar sensor unit 2 is detected as a voltage signal by, for example, a potentiometer attached to the rotation unit of the turntable 3 and A / D converted to obtain a rotation angle θ of the rotation unit 3. The microcomputer 4 receives a signal from the A / D converter 10 and generates an angle synchronizing signal C when the radar sensor unit 2 faces a desired angle, and outputs it to the synchronizing signal generator 11. Synchronous signal generator 1
1, the FM modulation signal is continuously input as a detection synchronization signal A of the sensor, and the synchronization signal A0 is output to the microcomputer 4 at the moment when the radar sensor unit 2 turns to a desired angle. This synchronizing signal A0 is a signal corresponding to one period from the start point of the first cycle after the generation of the angle synchronizing signal C (the trough or top of the triangular wave in FIG. 6) in the detection synchronizing signal A of the sensor. is there. Then, of the radar detection signals D, the radar detection signal D0 received while the synchronization signal A0 is being output is fetched, and measurement is performed based on this signal to obtain a measurement value at a desired angle.

In the embodiment of FIG. 6, the desired angle is determined in advance. However, the desired angle is not determined in advance, and the predetermined timing of the detection synchronization signal A of the sensor is set to the desired angle. The radar data may be sequentially measured by the radar sensor unit 2 when facing, and angle information may be added to the measurement data. FIG.
FIG. 5 is a diagram illustrating a flowchart of an embodiment of control of a scan operation according to the present invention. These controls are performed by the microcomputer 4 shown in FIGS.

When the scanning operation by the radar sensor is started (S1), first, the radar sensor unit 2 facing an arbitrary angle is turned to the initial setting angle θ0 and stopped, and thereafter, the measurement starting angle is changed from the initial setting angle θ0. Up to θ1,
The rotation speed of the rotating unit is accelerated at a predetermined acceleration so that the radar sensor unit 2 reaches the scan speed (S2). Next, it is determined whether the acceleration time has elapsed, that is, whether the rotation has been performed from the initially set angle θ0 to the measurement start angle θ1 (S3).
If it is s, the measurement at the first point, that is, the measurement at the measurement start angle θ1 is performed (S4). If No in S3, that is, if the acceleration time has not elapsed, the process returns to S3 again, and the same judgment is performed. After measuring the first point in S4, it is determined whether or not a predetermined time has elapsed, that is, whether or not the rotation has been performed from the measurement start angle θ1 to the next measurement angle θ2 (S5). If No, it is determined again whether a predetermined time has elapsed (S5). If yes, measure the second point,
That is, the measurement at the measurement angle θ2 is performed (S6), the analysis of the second signal is performed, and the distance and the relative speed are calculated (S7). At the same time, the angle of the second signal is calculated, and it is determined at what point the measurement data is. The same operation is repeated until the measurement at the n-th point, and it is determined whether the required number of measurements has been completed (S8). If No, the process returns to S5. If Yes, the process ends (S9), and returns to S2 as necessary.

[0019]

According to the present invention, the measurement is not performed in a state where the rotating unit stops at a predetermined desired angle and the radar sensor unit is stationary, but the rotating unit rotates at a constant angular velocity, and the radar sensor unit performs the measurement. Since the measurement is performed at a desired angle without standing still, the rotating section does not require a high degree of mechanical accuracy, and the load on the motor for rotating is reduced, and the design is simplified.

Further, since it is detected by a lapse of time that the radar sensor has turned to a predetermined angle, the means for detecting the angle can be simplified. Furthermore, if the passage of time is measured using the detection synchronization signal of the sensor, synchronization with the detection signal of the sensor can be easily obtained, and the configuration of the timing signal generator can be simplified. Also, when detecting that the radar sensor is oriented at a predetermined angle by a signal from the potentiometer,
Even if the rotation of the motor is not constant or even if an axis shift occurs, the measurement can be performed at a correct angle. Then, by continuously outputting the detection synchronization signal of the sensor in advance, the operation of the sensor is stabilized.

Further, the predetermined timing of the detection synchronization signal of the sensor is set to a desired angle without previously determining the desired angle,
If the measurement is performed sequentially, the synchronization circuit can be simplified.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a mechanical scan radar device.

FIG. 2 is a diagram for explaining a conventional scanning operation performed by a mechanical scan radar device.

FIG. 3 is a diagram for explaining a scan operation according to the present invention.

FIG. 4 is a graph showing a change in a rotational angular velocity and a rotational angle of a radar sensor unit with time in a scanning operation by the scan radar apparatus of the present invention.

FIG. 5 is a diagram for describing an embodiment of control for causing a scan operation to be performed by the scan radar device of the present invention.

FIG. 6 is a diagram for explaining another embodiment of control for causing a scan operation to be performed by the scan radar device of the present invention.

FIG. 7 is a diagram showing a flowchart of an embodiment of control of a scan operation according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Synchronization signal generation part 2 ... Radar sensor part 3 ... Rotation part 4 ... Signal processing part 5 ... Rotation control part 6 ... Rotation angle detection part 7 ... Input / output interface 8 ... Timing signal generator 9 ... Rotation signal detection part 10 ... A / D converter 11: Synchronous signal generator

Claims (7)

[Claims] 1. A radar sensor unit, a signal processing unit that calculates predetermined data based on a signal from the radar sensor unit, a rotation unit that rotates the radar sensor unit, and a rotation control unit that directs the rotation unit in a desired direction. In a vehicle-mounted radar device comprising: a means for detecting that the radar sensor unit is oriented at a desired angle, the radar unit rotates the radar sensor unit at a constant angular velocity without standing still, A scan radar device that measures sequentially when facing an angle. 2. The means for detecting that the radar sensor unit is oriented at a desired angle is provided by measuring the time elapsed from a position of a predetermined reference angle by detecting that the radar sensor unit is oriented at a desired angle. The scan radar device according to claim 1, which detects. 3. The means for detecting that the radar sensor unit is oriented at a desired angle, detects that the radar sensor unit is oriented at a desired angle by using a radar sensor detection synchronization signal at a position at a predetermined reference angle. The scan radar device according to claim 1, wherein the detection is performed by measuring a time elapsed from the scan radar. 4. The means for detecting that the radar sensor section is oriented at a desired angle is configured to detect that the radar sensor section is oriented at a desired angle by a rotation angle detecting means provided in a rotating section. Item 2. The scan radar device according to item 1. 5. The scan radar apparatus according to claim 4, wherein said rotation angle detecting means comprises a potentiometer and an A / D converter. 6. A detection synchronization signal of a radar sensor and an angle synchronization signal generated when the radar sensor unit is oriented at a desired angle are inputted, and the first detection synchronization signal of the radar sensor after the generation of the angle synchronization signal is inputted. A synchronizing signal generator for generating a synchronizing signal corresponding to one cycle from the start point of the cycle, and performing measurement based on a radar detection signal received while the synchronizing signal is output among the radar detection signals; The scan radar apparatus according to claim 4, wherein the scan radar apparatus performs the scan radar. 7. A predetermined angle of a detection synchronization signal of a radar sensor is set to a desired angle without previously determining a desired angle.
2. The scan radar device according to claim 1, wherein the measurement is performed sequentially.