Nissan Serena teardown (1): ProPILOT autonomous driving technology
A wide-range of features including the latest driving support system and visibility aids
|The Nissan Serena being torn down|
A teardown analysis of the Nissan Serena was conducted in January 2017 as part of the benchmarking activities of the Hiroshima Industrial Promotion Organization. The fifth generation Serena (model C27: released in 2016) has been praised for its pursuit of advanced functionality and the implementation of the ProPILOT autonomous technology for driving in a single highway lane. As a result, the model was awarded the 2017 RJC Car of the Year award.
While an increasing number of European and U.S. luxury vehicles are equipped with driving support technology including for steering systems, Nissan chose to implement ProPILOT in its mass-produced family minivan first. Moreover, even though the vehicle boasts a wide-range of features for a minivan, the price has been set at less than JPY 3 million.
This report will cover the driver support systems starting from the all-new ProPILOT technology, and then focusing on the Smart Rearview Mirror, Around View Monitor, and parking assist systems. Future reports will cover equipment that was carefully optimized based on the utility of minivans, and Nissan's efforts to reduce the vehicle's costs in order to provide it at a low price despite its many features.
Previous teardown reports:
(1) 1.4L turbo-gasoline engine (Oct. 2016)
Teardown of Toyota's Flagship Sedan
(Part 1) 2.5-liter V6 engine "4GR-FSE" (May 2016)
(Part 2) Chassis technology for high-end rear-wheel drive cars common to Toyota and Lexus vehicles (Jun. 2016)
(Part 3) High-rigidity body structure for crash safety, handling stability, and quietness (Sep. 2016)
(Part 4) Teardown of Toyota’s Flagship Sedan: Photo gallery (Oct. 2016)
4th-Generation Toyota Prius Teardown
(Part 1) Powertrain units miniaturized and lightened to achieve 40km/liter fuel economy (Feb. 2016)
(Part 2) New TNGA platform enhances dynamic performance; advanced aerodynamics and chassis technologies (Mar. 2016)
(Part 3) Body structure based on TNGA, sound insulating, absorbing and damping technologies (Apr. 2016)
Photo gallery (132 parts): Photographs of TNGA parts/components and a list of parts suppliers (May 2016)
ProPILOT autonomous driving technology
Nissan's autonomous driving technology combined with Mobileye's image analysis technology Source: Nissan Motor
Serena's ProPILOT autonomously controls acceleration, braking, and steering in single lanes on highways. The system's forward monitoring camera recognizes the lane lines on both sides of the vehicle as well as preceding vehicles, and controls the vehicle so it stays in the center of the lane while maintaining inter-vehicular distance. If there are no vehicles ahead, the system maintains the predetermined vehicle speed. If there is a vehicle ahead, the system will follow and stop in accordance with it. The equipment that recognizes preceding vehicles and white lines is a combination of technology developed by Nissan and Mobileye. This system autonomously controls acceleration, braking, and steering, and falls under level 2 autonomy as designated by the Japanese Cabinet Office's strategic innovation promotion program (SIP) promotion committee and the U.S.'s National Highway Traffic Safety Administration (NHTSA). It controls the vehicle under specific conditions, but the driver is required to constantly monitor the situation, and is responsible for handling emergencies.
System configuration of the ProPILOT featured on the Nissan Serena Source: Nissan Motor
The highlight of this system is the single-lens camera equipped on the front window, which recognizes lanes, preceding vehicles, and pedestrians, and does not use millimeter wave or laser radars. Other OEMs that commercialize similar level 2 systems, such as Mercedes-Benz, BMW, Audi, and Volkswagen use millimeter wave radars or laser radars with cameras. Nissan is the first automaker to achieve level 2 autonomous driving with only a camera, a technology developed with an aim for releasing family cars such as the Serena at affordable prices.
The vehicle provided for this teardown investigation was a grade X vehicle, priced at JPY 2,489,400 that featured the additional Safety Pack B option, priced at JPY 243,000. Consumers can purchase a Serena featuring ProPILOT for a total of JPY 2,732,400. The Safety Pack B not only features ProPILOT, but also includes lane departure prevention (LDP), emergency assist for pedal misapplication, Intelligent Parking Assist, detection of signs indicating when entry is prohibited, Around View Monitor, swerving alarm, front and rear sonar, SRS curtain airbag and side airbag system, Smart Rearview Mirror, electric parking brake, auto brake hold, and door mirrors with heaters. Additionally, emergency braking and lane departure warning (LDW) come as standard features, making it so most driver support systems, safety features, and convenient features are equipped at a reasonable price.
Information recognized by the camera is processed by the ADAS ECU, which gives commands to each driving operation system unit. Depending on the command, the ECM controls the engine and transmission, the VDC unit controls the brake, and the steering ECU attached to the EPS controls steering.
The front camera is attached to the top of the front windshield together with the rearview mirror. The camera also detects preceding vehicles and pedestrians, as well as the distance between them and the vehicle. The camera's control circuit is made by Panasonic and integrated in the main body. It consists of a small circuit board installed on an imaging element attached to the rear of the camera, as well as a main control circuit board. The main circuit board features a chip produced by Mobileye, a leading image processing technology manufacturer. Mobileye's vehicle detection technology is capable of accurately recognizing automobiles, trucks, and motorcycles thanks to an original algorithm, and forms the core of the ProPILOT system.
|The front camera not only detects vehicles, but also pedestrians, and is also used for purposes other than the ProPILOT system.|
Information obtained by the front camera is not only used for ProPILOT, but also for emergency braking, LDW, LDP, and detection of signs that indicate when entry is prohibited. Separate from ProPILOT, which operates the steering gear and keeps the vehicle in the center of the lane, the LDP system controls the vehicle's brakes when it detects that it is departing from a lane.
|ADAS control unit case and circuit board (Hitachi Automotive Systems)|
Information detected by the front camera unit is sent to the ADAS control unit, which in turn sends commands to each component. The ADAS control unit is split into two control units, with the main unit (pictured above) being supplied by Hitachi Automotive Systems. The control unit analyzes the conditions detected by the camera and sends commands to the acceleration, steering, and braking units.
|2nd ADAS control unit case and circuit board (made by Panasonic)|
The 2nd ADAS control unit controls emergency assist for pedal misapplication, LDW, LDP, and detection of signs that indicate entry is prohibited. Additionally, it also controls driver assist buzzers during emergency braking, ProPILOT, LDW, and LDP. The control unit is made by Panasonic.
|Steering column EPS||EPS motor (Nidec)|
|EPS control unit case and circuit board (NSK)|
The EPS control unit controls the steering angle according to commands from the ADAS control unit. The Serena has a column EPS, and a Nidec-made motor attached to the steering column drives the steering rack gear through the column shaft and intermediate shaft. The EPS control unit is supplied by NSK.
|ABS actuator control unit (Hitachi Automotive Systems)|
The ABS control unit regulates braking in accordance with commands from the ADAS control unit. The control unit, which is integrated with the ABS actuator, is attached to the dash panel in the engine room, and is made by Hitachi Automotive Systems.
|Engine ECU and radio wave protection case||Engine ECU connecting terminal|
The engine ECU controls the engine in accordance with commands from the ADAS control unit. The engine ECU is attached to the front of the front wheel housing and is covered in a steel case, which seems to have been done to protect the unit from radio interference. The supplier of the unit is Hitachi Automotive Systems.
Smart Rearview Mirror
|Smart Rearview Mirror attached||Smart Rearview Mirror components|
|Smart Rearview Mirror circuit board|
The Serena features a Smart Rearview Mirror, which can act as a regular rearview mirror, but also displays images from the rear camera via a LCD behind the half-mirror. The rear camera is attached to the rear windshield and helps drivers see to the rear when there are passengers in the second and third rows and the view would be obstructed with a regular rearview mirror. An LCD and circuit board made by Panasonic are integrated with the mirror.
|Rear camera and imaging element circuit||Rear camera and the back of the imaging element circuit|
|Rear camera imaging element circuit board||Rear camera case and coaxial cable|
The rear camera is attached on the inside of the rear windshield on the back door, and is supplied by Panasonic. A single coaxial cable connects to the rear camera and powers it.
Around View Monitor
In addition to the ProPILOT front and rear cameras for the Smart Rearview Mirror, the Serena features three cameras for the Around View Monitor for a total of five. The ProPILOT front camera is attached to the front windshield screen, but the front camera for the Around View Monitor is installed inside the Nissan emblem on the front grill. The ProPILOT front camera requires advanced image recognition technology for precision, whereas the Around View Monitor camera only requires images to be shown on the display, and possesses different functions. Moreover, the ProPILOT and Around View Monitor are available in different option packages, which may be the reason for their being two separate front cameras. As for the rear camera, it is also used by the Smart Rearview Mirror and Around View Monitor because of its similar performance and function requirements. The Serena's Around View Monitor is mounted in its own display in the instrument panel.
Intelligent Parking Assist
The Serena's driver support system features an autonomous parking function as a factory-installed option, called Intelligent Parking Assist. The system uses a total of eight sonar sensors; four on the front and four on the back, as well as the Around View Monitor camera to provide parking assistance. When drivers set a parking space in the Around View Monitor screen, the system automatically steers the wheel to provide parking assistance, and these actions can be observed via the Around View Monitor.
The Serena's Intelligent Parking Assist Source: Nissan Motor
|Sonar sensors attached to the front bumper
(Four on each of the front and rear bumpers)
Front bumper rear
In the garage-parking mode (parking at a right angle with the road), the system can be set to have the vehicle park so the door mirrors are slightly in front of the parking space without requiring any corrections. In parallel parking mode (parking spaces facing the same direction as the road), the system can be set so that the vehicle parks with the front wheels stopping at the edge of the parking space and without requiring any corrections.
Keyword: Nissan, Serena, teardown, ProPILOT, autonomous driving, Mobileye
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