Method for operating a radar sensor system in a motor vehicle

Patent metadata

Field	Value
Publication number	US-11747465-B2
Application number	US-201816960884-A
Country	US
Kind code	B2
Filing date	Nov 22, 2018
Priority date	Jan 29, 2018
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

A method for operating a radar sensor system including multiple radar sensors operating independently of one another in a motor vehicle, wherein the radar sensors are synchronized with one another with respect to their transmission times and transmission frequencies in such a way that two radar signals whose frequency separation is smaller than a certain minimum frequency separation are at no point in time transmitted simultaneously.

First claim

What is claimed is:

1. A method for operating a radar sensor system including a first radar sensor and a second radar sensor operating in a motor vehicle, the method comprising the following step:
operating the first radar sensor to transmit radar signals with a first frequency ramp;
operating the second radar sensor to transmit radar signals with a second frequency ramp, wherein:
the transmission of at least part of the first frequency ramp overlaps in time with the transmission of at least part of the second frequency ramp so that there are a plurality of frequency pairs that each has a respective one of the frequencies of the first frequency ramp and a respective one of the frequencies of the second frequency ramp that are transmitted simultaneously;
a frequency separation between the simultaneously transmitted frequencies of the first and second frequency ramps changes, during the radar signal transmissions, between different ones of the pairs; and
each of at least one of the frequencies of the first frequency ramp has less than a predefined threshold frequency separation from one or more of the frequencies of the second frequency ramp; and

synchronizing the first and second radar sensors with each other with respect to their transmission times and their ramp frequencies to ensure that, for each of the at least one of the frequencies of the first frequency ramp, the respective frequency does not occur simultaneously with any of the one or more of the frequencies of the second frequency ramp that is within the predefined threshold frequency separation from the respective frequency of the first ramp;
wherein, for the synchronization, the radar signals having the first and second frequency ramps are output so that the radar signals have at least one of the following features (a)-(d):
(a) the second frequency ramp is repeated intermittently with respective interruptions between pairs of immediately time adjacent instances of the second frequency ramp, and the first frequency ramp is output so that each instance of a lowest frequency of the first frequency ramp occurs during a respective one of the interruptions;
(b) the second frequency ramp is sawtooth wave shaped so that, for each instance of a highest frequency of the second frequency ramp, an immediately following one of the frequencies of the second frequency ramp is a respective instance of the lowest frequency of the second frequency ramp, and, for each of at least one instance of a highest frequency of the first frequency ramp, the first frequency ramp gradually lowers towards a respective instance of a lowest frequency of the first frequency ramp;
(c) the second frequency ramp is repeated multiple time during a single instance of the first frequency ramp; and
(d) each instance of the lowest frequency of the second frequency ramp occurs when a frequency of the first frequency ramp is higher than the lowest frequency of the first frequency ramp.

2. The method as recited in claim 1 , further comprising the following step:
providing a shared clock signal to the radar sensors, the radar sensors being synchronized with one another based on the shared clock signal.

3. The method as recited in claim 2 , wherein a bus system present in the motor vehicle is used to provide the shared clock signal to the radar sensors.

4. The method as recited in claim 3 , wherein the shared clock signal in each of the radar sensors is constructed based on data traffic taking place on the bus system.

5. The method as recited in claim 1 , wherein, for the synchronization, the radar signals having the first and second frequency ramps are output so that the second frequency ramp is repeated intermittently with the interruptions, and the first frequency ramp is output so that each instance of the lowest frequency of the first frequency ramp occurs during the respective one of the interruptions.

6. The method as recited in claim 5 , wherein the first frequency ramp is repeated continuously so that at least two immediately time adjacent instances of the first frequency ramp occur without interruption between them.

7. The method as recited in claim 5 , wherein a frequency rate of change of the second frequency ramp is higher than a frequency rate of change of the first frequency ramp.

8. The method as recited in claim 1 , wherein, for the synchronization, the radar signals having the first and second frequency ramps are output so that the second frequency ramp is sawtooth wave shaped so that, for each instance of the highest frequency of the second frequency ramp, the immediately following one of the frequencies of the second frequency ramp is the respective instance of the lowest frequency of the second frequency ramp, and, for each of the at least one instance of the highest frequency of the first frequency ramp, the first frequency ramp gradually lowers towards the respective instance of the lowest frequency of the first frequency ramp.

9. The method as recited in claim 8 , wherein a frequency rate of change of the second frequency ramp is higher than a frequency rate of change of the first frequency ramp.

10. The method as recited in claim 1 , wherein, for the synchronization, the radar signals having the first and second frequency ramps are output so that the second frequency ramp is repeated multiple time during the single instance of the first frequency ramp.

11. The method as recited in claim 10 , wherein a frequency rate of change of the second frequency ramp is higher than a frequency rate of change of the first frequency ramp.

12. The method as recited in claim 1 , wherein, for the synchronization, the radar signals having the first and second frequency ramps are output so that each instance of the lowest frequency of the second frequency ramp occurs when the frequency of the first frequency ramp is higher than the lowest frequency of the first frequency ramp.

13. The method as recited in claim 12 , wherein a frequency rate of change of the second frequency ramp is higher than a frequency rate of change of the first frequency ramp.

14. A radar sensor system, comprising:
a first radar sensor and a second radar sensor operating in a motor vehicle;
wherein:
the system is configured to:
operate the first radar sensor to transmit radar signals with a first frequency ramp;
operate the second radar sensor to transmit radar signals with a second frequency ramp;

the transmission of at least part of the first frequency ramp overlaps in time with the transmission of at least part of the second frequency ramp so that there are a plurality of frequency pairs that each has a respective one of the frequencies of the first frequency ramp and a respective one of the frequencies of the second frequency ramp that are transmitted simultaneously;
a frequency separation between the simultaneously transmitted frequencies of the first and second frequency ramps changes, during the radar signal transmissions, between different ones of the pairs;
each of at least one of the frequencies of the first frequency ramp has less than a predefined threshold frequency separation from one or more of the frequencies of the second frequency ramp; and

the system is configured to synchronize the first and second radar sensors with each other with respect to their transmission times and their ramp frequencies to ensure that, for each of the at least one of the frequencies of the first frequency ramp, the respective frequency does not occur simultaneously with any of the one or more of the frequencies of the second frequency ramp that is within the predefined threshold frequency separation from the respective frequency of the f

Assignees

• Bosch Gmbh Robert

Inventors

• Mayer Marcel
• Schoor Michael

Classifications

• G01S13/87 Primary

  Combinations of radar systems, e.g. primary radar and secondary radar · CPC title

• G01S7/023

  Interference mitigation, e.g. reducing or avoiding non-intentional interference with other HF-transmitters, base station transmitters for mobile communication or other radar systems, e.g. using electro-magnetic interference [EMI] reduction techniques (auxiliary means for detecting or identifying radar signals or the like G01S7/021; means for anti-jamming G01S7/36) · CPC title

• G01S7/0232

  Avoidance by frequency multiplex · CPC title

• G01S7/0235

  Avoidance by time multiplex · CPC title

• G01S7/35

  Details of non-pulse systems · CPC title