Black box with volatile memory caching

1. An apparatus comprising:

a volatile memory module configured to store vehicle data;

a collision-detector module configured to identify a collision event of a vehicle;

a refrigeration module coupled to the collision-detection module and thermally coupled to the volatile memory module, wherein the refrigeration module is configured to lower a temperature of the volatile memory module in response to receiving an indication from the collision-detector module that the collision event has occurred and in response to receiving energy from an energy-storage module; and

a controller coupled to the refrigeration module and the collision-detector module, wherein the controller is configured to initiate lowering the temperature of the volatile memory module in response to receiving an indication from the collision-detector module that the collision event has occurred.

2. The apparatus of claim 1 , further comprising a non-volatile memory module, wherein the vehicle data stored in the non-volatile memory module comprises uncompressed sensor or navigation decision data.

3. The apparatus of claim 1 , wherein the refrigeration module comprises a barrier separating a chamber containing a first material and a chamber containing a second material, wherein:

the barrier separating the chambers is removed in response to receiving the indication from the crash detector module that the collision has occurred; and

the first and second materials have a reaction causing a temperature to drop once the first and second materials are mixed.

4. The apparatus of claim 3 , wherein the materials comprise water and ammonium salt, water and ammonium chloride, water and ammonium nitrate, water and potassium chloride, barium hydroxide octahydrate crystals and dry ammonium chloride, or thionyl chloride (SOCl 2 ) and cobalt(II) sulfate heptahydrate.

5. The apparatus of claim 1 , wherein the refrigeration module is a thermoelectric refrigerator.

6. The apparatus of claim 5 , wherein the vehicle data comprises computational logs, intermediate computation results, object detection results, speed information, or sensor status information.

7. The apparatus of claim 1 , wherein the volatile memory module is configured to receive sensor data and vehicle information from one or more processing units.

8. The apparatus of claim 1 , wherein the vehicle data comprises video or images from infrared cameras or optical cameras, light detection and ranging (LiDAR) imaging data, radar data, global positioning system (GPS), inertial measurement unit data, or accelerometer data.

9. The apparatus of claim 1 , wherein the volatile memory module, refrigeration module, collision-detector module, and controller are housed in a black box enclosure.

10. The apparatus of claim 1 , wherein vehicle data comprises uncompressed image data from one or more optical cameras or imaging data from one or more LiDAR receivers.

11. The apparatus of claim 1 , further comprising the energy storage device and a non-volatile memory module, wherein the energy storage device is configured to store an amount of power sufficient to write data stored in the volatile memory module on the non-volatile memory module.

12. The apparatus of claim 1 , further comprising a non-volatile memory module, wherein the vehicle data is written on the non-volatile memory only when the collision event has occurred.

13. The apparatus of claim 1 , wherein a storage capacity of the volatile memory module is sufficient to store at least 30 seconds of imaging and LiDAR data gathered by one or more sensors of the vehicle.

14. A method comprising, by a computing device:

receiving an indication from a crash-detector module that a collision event of a vehicle has occurred;

transmitting a signal to refrigeration module initiating lowering a temperature of a volatile memory of a volatile memory module in response to receiving the indication from the crash-detector module that the collision event has occurred, wherein the refrigeration module is configured to lower the temperature of the volatile memory in response to receiving energy from an energy-storage module.

15. The method claim 14 , wherein the signal transmitted to the refrigeration module initiates a mixing of water with ammonium salts for lowering the temperature of the volatile memory module.

16. The method of claim 14 , further comprising transmitting a signal to a bus controller initiating a transfer of vehicle data stored in the volatile memory module to non-volatile memory of a non-volatile memory module in response to receiving the indication from the crash-detector module that the collision event has occurred.

17. One or more computer-readable non-transitory storage media embodying software that is operable when executed to cause one or more processors to perform operations comprising:

receive an indication from a crash-detector module that a collision event of a vehicle has occurred;

transmit a signal to refrigeration module initiating lowering a temperature of a volatile memory of a volatile memory module in response to receiving the indication from the crash-detector module that the collision event has occurred, wherein the refrigeration module is configured to lower the temperature of the volatile memory in response to receiving energy from an energy-storage module.

18. The media of claim 17 , wherein the software is further operable to transmit a signal to a bus controller initiating a transfer of vehicle data stored in a volatile memory module to non-volatile memory of a non-volatile memory module in response to receiving the indication from the crash-detector module that the collision event has occurred.

19. The media of claim 17 , wherein the signal transmitted to the refrigeration module initiates a mixing of water with ammonium salts for lowering the temperature of the volatile memory module.

20. The apparatus of claim 1 , further comprising a heat sink, heat pipe, or heat spreader in thermal contact with the volatile memory of volatile memory module.