Radar apparatus and radar system for a vehicle

Abstract

A radar apparatus including units for transmitting and receiving an electric wave to detect a target, a unit for detecting wave interference caused by surroundings, a unit for controlling the modulation state of the transmitted wave, a communication unit for acquiring modulation state information being used by the other radar apparatuses, and a unit for selecting such a modulation state as to avoid interference with the modulation state information when the wave interference detecting unit detects the wave interference.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B show an arrangement of radar apparatuses in a vehicle radar system in accordance with an embodiment of the present invention and also a block diagram of the system;

FIG. 2 is a diagram for explaining a relation among a plurality of radar apparatuses;

FIG. 3 is a diagram for explaining how frequency is used before interference occurrence;

FIG. 4 is a diagram for explaining how frequency is used after the interference occurrence;

FIG. 5 shows an example 1 of setting frequency allocation;

FIG. 6 shows an example 2 of setting the frequency allocation;

FIG. 7 is a diagram for explaining an example of communication;

FIG. 8 shows an example 1 of a means for detecting wave interference;

FIG. 9 is a main flow chart for explaining the operation of the present invention;

FIG. 10 is a block diagram for explaining another embodiment of the present invention;

FIG. 11 is an example 2 of the unit for detecting wave interference;

FIG. 12 is a block diagram of a radar apparatus for controlling turning ON/OFF of wave transmission;

FIG. 13 shows a status transition diagram of a wave transmission determining unit;

FIG. 14 is a flow chart for explaining the operation of the wave transmission determining unit;

FIGS. 15A and 15B are timing charts for explaining a wave transmission/reception cycle of a pulse modulation radar apparatus; and

FIGS. 16A, 16B, and 16C show examples of setting priorities of radio wave radar apparatuses.

Claims

1. A radar apparatus comprising: means for transmitting and receiving an electric wave to detect a target;means for detecting wave interference caused by surroundings;means for controlling a modulation state of the transmitted wave;communication means for acquiring modulation state information being used by the other radar apparatuses: and means for selecting such a modulation state as to avoid interference with the modulation state information when the wave interference detecting means detects the wave interference.

2. A radar system for a vehicle including a plurality of radar apparatuses mounted on the vehicle, each of the radar apparatuses comprising: means for transmitting and receiving an electric wave to detect the presence or absence of a target;means for detecting wave interference caused by surroundings; andmeans for controlling a modulation state of the transmitted wave, the system further comprising:means for allocating different modulation state ranges to the respective radar apparatuses; andmeans, when the wave interference detecting means detects the wave interference, for selecting modulation states in the range of the transmitted wave to avoid the interference.

3. A radar apparatus according to claim 1, wherein the modulation state includes one or more of a carrier frequency, a modulation type, an orientation of polarization plane of the wave, a transmission cycle, and a modulation code.

4. A radar apparatus according to claim 1, wherein the wave interference detecting means processes a received signal of the wave for determination.

5. A radar apparatus according to claim 1, wherein the modulation state selecting means selects the same modulation state for the radar apparatuses different in mounting direction by an angle of 90 degrees or more.

6. A radar apparatus according to claim 1, wherein a random factor is included in the modulation state selecting means.

7. A radar apparatus according to claim 1, wherein the wave interference detecting means determines the presence of the wave interference with use of the modulation state information of the other radar apparatuses.

8. A radar apparatus according to claim 1, comprising: identification means for identifying a priority of the radar apparatus; andmeans for determining change of the modulation state according to an identified result.

9. A radar system for a vehicle including a plurality of the radar apparatuses set forth in claim 8, comprising: means, when the usable modulation state becomes insufficient, for stopping functions of the radar apparatuses in an increasing order of the priority.

10. A radar system according to claim 2, wherein the modulation state allocating means allocates modulation states more than those of the other radar apparatuses to the specific radar apparatus.

11. A radar apparatus according to claim 1, wherein one or more of the wave interference detecting means, the communication means, and the modulation state selecting means are provided outside the radar apparatus.

12. A radar apparatus according to claim 1, comprising means for acquiring a usable range of the modulation state, and wherein a limitation is applied to the means for selecting the modulation state according to the acquired range.