Method and system for calibration of sensor signals in a vehicle
View Patent ↗A method for calibrating sensor signals in networks in a vehicle, wherein a number of sensors are arranged in the vehicle including one or more cameras, one or more LIDAR, and one or more radar units each communicating with a electronic control unit over a network, the electronic control unit communicating with vehicle elements including braking system and steerings system. The method includes receiving incoming signals from sensors at a calibration unit, wherein the incoming signals contain information of a detected object or signal, determining a delay for each received signal relative to a predetermined master clock time; and determining one calibration time for all the received signals based on the determined delays relative the predetermined master clock time.
1. A method implemented in an electronic control unit for calibrating sensor signals in networks in a vehicle, a number of sensors being arranged in the vehicle including at least one camera, at least one LIDAR, and at least one radar unit each communicating with an electronic control unit over a network, the electronic control unit including processing circuitry configured for communicating with vehicle elements including a braking system and a steering system, the method comprising:
receiving incoming signals from at least one sensor at the electronic control unit, the incoming signals containing information of one of a detected object and a signal;
determining a delay for each signal of the received incoming signals relative to a predetermined master clock time;
determining one calibration time for all the received incoming signals based on the determined delays relative to each other;
modifying at least one signal of the received incoming signals from sensors based on the determined one calibration time; and
causing an instruction to be transmitted to at least one of the braking system and the steering system, the instruction being generated based on the at least one modified signal.
2. The method according to claim 1 , further including selecting a system clock time of one of the electronic control unit and the network as the predetermined master clock time.
3. The method according to claim 2 , further including:
selecting a sensor as master origin in a graphical representation of sensor positions, wherein the graphical representation is determined based on received incoming signals from the sensors;
determining coordinates for each other sensor in the graphical representation relative said master origin; and
off-setting each other sensor coordinates in the graphical representation to obtain a minimum deviation between the master origin and respective sensor coordinates, wherein at least one of calibrated sensor positions and time can be provided.
4. The method according to claim 1 , further including selecting a sensor clock time as the predetermined master clock time.
5. The method according to claim 1 , further including:
selecting a sensor as master origin in a graphical representation of sensor positions, wherein the graphical representation is determined based on the received incoming signals from the sensors;
determining coordinates for each other sensor in the graphical representation relative to the master origin; and
off-setting each other sensor coordinates in the graphical representation to obtain a minimum deviation between the master origin and respective sensor coordinates, wherein at least one of calibrated sensor positions and time can be provided.
6. The method according to claim 1 , wherein determining one calibration time for all the received signals is based on one of:
a weighted average of the different delays;
a median value of the different delays; and
a selected time corresponding to the predetermined master clock time and a delay being lower than the maximum delay and higher than the minimum delay.
7. The method according to claim 1 , further including:
sending at least one light signal to at least one sensor from a calibration signal emitting unit at a predetermined distance from said sensor;
sending a first network signal to the processing circuitry from the calibration signal emitting unit one of simultaneously and at a predetermined delay;
receiving a second network signal from the at least one sensor that the light signal has been detected;
determining the difference between the first and respective second network signals in the processing circuitry; and
determining a calibration time for the respective sensor based on the determined difference.
8. The method according to claim 7 , wherein the predetermined distance can be varied.
9. A system for calibrating sensor signals in networks in a vehicle, a number of sensors being arranged in the vehicle including at least one camera, at least one LIDAR, and at least one radar unit each communicating with an electronic control unit over a network, the electronic control unit communicating with vehicle elements including a braking system and a steering system, the electronic control unit comprising processing circuitry, the processing circuitry being configured to:
receive incoming signals from the number of sensors, the incoming signals containing information of one of a detected object and a signal;
determine a delay for each signal of the received incoming signals relative to a predetermined master clock time;
determine one calibration time for all the received incoming signals based on the determined delays relative to each other;
modify at least one signal of the received incoming signals from sensors based on the determined one calibration time; and
cause an instruction to be transmitted to at least one of the braking system and the steering system, the instruction being generated based on the at least one modified signal.
10. The system according to claim 9 , wherein the processing circuitry is further configured to select a system clock time of one of the electronic control unit and the network as the predetermined master clock time.
11. The system according to claim 9 , wherein a sensor clock time is selected as the predetermined master clock time.
12. The system according to claim 9 , wherein the processing circuitry is:
one of configured to select and configured to receive an instruction to select a sensor as master origin in a graphical representation of sensor positions, the graphical representation being determined based on received incoming signals from the number of sensors;
determine coordinates for each other sensor in the graphical representation relative to the master origin; and
off-set each other sensor coordinates in the graphical representation to obtain a minimum deviation between the master origin and respective sensor coordinates, wherein at least one of calibrated sensor positions and time can be provided.
13. The system according to claim 9 , wherein determining one calibration time for all the received signals is based on one of:
a weighted average of the different delays;
a median value of the different delays; and
a selected time corresponding to the predetermined master clock time and a delay being lower than the maximum delay and higher than the minimum delay.