Dissecting Subaru Eyesight Stereo Cameras
Hello. I regularly come across very interesting devices from modern cars. Today I want to tell the respected public about the Subaru's Eyesight stereo camera I got. The device itself was removed from a car recalled in Japan and shipped to Novosibirsk.
Eyesight is a serial ADAS (Advanced Driver Assistance System) installed on Subaru cars. The camera is developed and manufactured by Hitachi. The tasks of the system are typical for all ADAS, namely:
Unlike systems from other manufacturers (for example: MobilEye, BOSH), Eyesight has a number of interesting differences. For example, the design of the pupil \ lens hood.
This is what the typical ADAS camera design looks like:
The characteristic surface under the lens is protection against glare. A very important element.
And this is what Subaru’s “eye” looks like:
It seems that the glare protection is not as good as in the previous version, but it is not. Why, I will explain below.
And of course, as you can see, this ADAS is a stereoscopic system; I came across such a solution only on a Mercedes car, but there are generally 3 “eyes”.
The camera assembly is quite large, 40 cm long, 7 wide, has a significant weight, and is assembled on a thick aluminum frame. Camera lenses are protected by plastic caps.
Inside there are three processors with strapping, RAM and FLASH-memory, power supply and Image-sensor boards.
1. SUBARU HITACHI MB8AA4561 Apparently, this is some kind of customized ASIC based on a typical SuperH processor core. No information could be found.
2. Renesas R8A77850 Again, the system on a chip based on the Super-H4 architecture, judging by the bits of the information found, belongs to the R-Car family and has a hardware image recognition accelerator.
3. R5F7253 And again SuperH, a simpler family SH2A-FPU. Apparently it performs the function of a peripheral controller and provides communication through two CAN-Bus channels.
1. Winbond RAM W9751g6kb 515Mbits DDR2 in the amount of four pieces. Total RAM: 256Mbyte
2. Macrinix FLASH MX29GL128 16Mbyte - one chip
The switching power supply is assembled on two chips TPS65251 and one SPF3009. CAN physical interface standard. Two 500kbit / s channels through TLE6250 transceivers.
I have already said that the Eyesight glare protection is implemented in an interesting way. Not like everyone else. The window in the protective cap of the lens is covered with a polarized film. This protects the sensor from glare, although it reduces the light transmission of the system.
Actually the lens itself, a pupil diameter of 11 mm.
Image-sensor is not recognized. As a rule, in ADAS systems this is a specialized sensor with an extended dynamic range, for stable operation at different levels of illumination.
In addition, the camera has an interface resembling the layout of an HDMI or LDWS board, but when the camera is turned on, it is silent.
Ultimately, it would be interesting to connect this system to a native car and explore its work using the CAN analyzer. After that, most likely, it would be possible to reveal a lot of interesting details of the system.
Here is the final video of the analysis:
References:
Briefly about what is Eyesight
Eyesight is a serial ADAS (Advanced Driver Assistance System) installed on Subaru cars. The camera is developed and manufactured by Hitachi. The tasks of the system are typical for all ADAS, namely:
- 1. Estimation of the distance to the vehicle ahead and initiation of braking in the absence of the driver’s response
- 2. Adaptive cruise control
- 3. Warning of the exit of the strip
- 4. The system is able to recognize pedestrians, motorcyclists and cyclists.
Unlike systems from other manufacturers (for example: MobilEye, BOSH), Eyesight has a number of interesting differences. For example, the design of the pupil \ lens hood.
This is what the typical ADAS camera design looks like:
The characteristic surface under the lens is protection against glare. A very important element.
And this is what Subaru’s “eye” looks like:
It seems that the glare protection is not as good as in the previous version, but it is not. Why, I will explain below.
And of course, as you can see, this ADAS is a stereoscopic system; I came across such a solution only on a Mercedes car, but there are generally 3 “eyes”.
So, we proceed to the analysis
The camera assembly is quite large, 40 cm long, 7 wide, has a significant weight, and is assembled on a thick aluminum frame. Camera lenses are protected by plastic caps.
Inside there are three processors with strapping, RAM and FLASH-memory, power supply and Image-sensor boards.
Processors
1. SUBARU HITACHI MB8AA4561 Apparently, this is some kind of customized ASIC based on a typical SuperH processor core. No information could be found.
2. Renesas R8A77850 Again, the system on a chip based on the Super-H4 architecture, judging by the bits of the information found, belongs to the R-Car family and has a hardware image recognition accelerator.
3. R5F7253 And again SuperH, a simpler family SH2A-FPU. Apparently it performs the function of a peripheral controller and provides communication through two CAN-Bus channels.
Memory
1. Winbond RAM W9751g6kb 515Mbits DDR2 in the amount of four pieces. Total RAM: 256Mbyte
2. Macrinix FLASH MX29GL128 16Mbyte - one chip
Food, connection with the car
The switching power supply is assembled on two chips TPS65251 and one SPF3009. CAN physical interface standard. Two 500kbit / s channels through TLE6250 transceivers.
Optical part
I have already said that the Eyesight glare protection is implemented in an interesting way. Not like everyone else. The window in the protective cap of the lens is covered with a polarized film. This protects the sensor from glare, although it reduces the light transmission of the system.
Actually the lens itself, a pupil diameter of 11 mm.
Image-sensor is not recognized. As a rule, in ADAS systems this is a specialized sensor with an extended dynamic range, for stable operation at different levels of illumination.
In addition, the camera has an interface resembling the layout of an HDMI or LDWS board, but when the camera is turned on, it is silent.
Ultimately, it would be interesting to connect this system to a native car and explore its work using the CAN analyzer. After that, most likely, it would be possible to reveal a lot of interesting details of the system.
Here is the final video of the analysis:
References:
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