REAR MOUNTED RADAR FOR AUTONOMOUS VEHICLES
Methods, systems, apparatus for mitigating adverse effects of road vibrations on radars mounted on a vehicle include an apparatus used for mounting a radar on a rear side of the vehicle. The apparatus includes a base plate, a bracket, one or more fasteners, and one or more washers. The washers may include a vibration dampener material that dampens horizontal and vertical vibration force.
1 . An apparatus for vehicular radar installation, comprising:
a base plate comprising a top surface and a bottom surface, the base plate comprising one or more through-holes;
a bracket having a horizontal portion and a vertical portion that is perpendicular to the horizontal portion wherein the horizontal portion comprises one or more through-holes that align with corresponding one of more through-holes of the base plate;
one or more fasteners extending through the one or more through-holes of the horizontal portion and the one or more through-holes of the base plates configured to rigidly couple the base plate with the bracket; and
one or more washers having base portions having base portion openings and cylindrical portions surrounding the base portion openings and extending in a vertical direction,
wherein cross-sections of the cylindrical portions allow the cylindrical portions to be inserted into the one or more through-holes of the horizontal portion of the bracket and further allow insertion of the one or more fasteners through the cylindrical portions and the one or more openings of the base plate such that the base portions of the one or more washers provide a separation between the bottom surface of the base plate and a top surface of the horizontal portion of the bracket.
2 . The apparatus of claim 1 , wherein the one or more washers comprise a vibration dampener material that dampens vibrations between the base plate and the bracket along the vertical direction and dampens vibrations between the base plate and the bracket along a plane of the base plate.
3 . The apparatus of claim 1 , wherein the cylindrical portions of the one or more washers completely surround the base portion openings.
4 . The apparatus of claim 1 , wherein the vertical portion of the bracket comprises a receptacle mechanism that is configured to securely affix a radar housing to the bracket.
5 . The apparatus of claim 4 , wherein the receptacle mechanism comprises one or more through holes in the bracket through which one or more fasteners are passed and secure using one or more screws, and wherein a second vibration dampener material is inserted in a first gap between the vertical portion of the bracket and the radar housing and a second gap between the one or more screws and the bracket.
6 . The apparatus of claim 1 , wherein the vertical portion of the bracket comprises a planar plate.
7 . The apparatus of claim 1 , wherein the vertical portion of the bracket comprises multiple strips that are spaced apart from each other.
8 . The apparatus of claim 2 , wherein the vibration dampener material is configured to attenuate vibrations having a peak frequency between 1.2 KHz and 1.8 KHz and a bandwidth between 300 to 500 Hz.
9 . The apparatus of claim 5 , wherein the second vibration dampener material comprises a same material as the vibration dampener material.
10 . The apparatus of claim 5 , wherein the vibration dampener material and the second vibration dampener material are configured to mitigate vibrations having a duration between 20 millisecond and 1 second.
11 . A method of controlling operation of a vehicle, comprising:
monitoring, by a processor on a vehicle, status reports from one or more radar units disposed on the vehicle;
transmitting, upon receiving a status report from a radar unit of the one or more radar unit that the radar unit has experienced a disturbance, a reset request to a controller of the one or more radar units, wherein a power to the radar unit is turned off for a pre-determined time period due to the reset request; and
determining, at a time after the pre-determined time period, whether the radar unit has successfully power cycled and is operating as expected.
12 . The method of claim 11 , wherein the one or more radar units comprise at least 5 radar units.
13 . The method of claim 11 , wherein the status report indicates that the radar unit has experienced a vibrational disturbance.
14 . The method of claim 11 , wherein the processor sends the reset request to the controller over a controller area network interface.
15 . The method of claim 11 , wherein the reset request specifies the pre-determined time period.
16 . The method of claim 11 , wherein the pre-determined time period is pre-configured for the controller based on a thermal cooling characteristic of the radar unit.
17 . The method of claim 11 , wherein the reset request is an N-bit message wherein N is a number of the one or more radar units.
18 . A radar controller system, comprising:
one or more radar units disposed on a vehicle, wherein at least one radar unit is affixed to a rear of the vehicle using the apparatus recited in claim 1 .
19 . A vehicle controller unit, comprising:
a controller disposed on a vehicle, the control being configured to control power to one or more radar units, the controller being communicatively coupled via a controller area network with a processor on the vehicle, the controller configured to:
receive a reset request from the processor;
power cycle radar units from the one or more radar units identified in the reset request,
wherein the power cycling a particular radar unit comprises turning off power to the particular radar unit for a duration that allowed the particular radar unit to cool down below a threshold prior to being powered on.
20 . The vehicle controller unit of claim 19 ,
wherein the one or more radar units comprise at least 5 radar units; and
wherein the duration is between 0.2 to 1.5 seconds.