Active safety technology enriches Nissan's new X-Trail technology

At the Frankfurt Motor Show that ended in September, Nissan launched a new generation of X-Trail models. Compared with the previous generation of models, the new generation of models has richer technical reserves, especially in active safety and human-computer interaction systems.

Born on a new platform

The new generation of X-Trail is based on Nissan's CMF platform (Common Module Family). Using this newly developed production platform, the cost of parts for the new X-Trail can be reduced by about 20%, mainly due to the increased commonality of the same parts in its models. Of course, not only Nissan, but also Renault will use this platform to develop and produce new models. According to the confirmed news, the two brands will have 14 models using the CMF platform. Nissan hopes to gradually reduce production costs in this way to compete with Volkswagen Group, PSA Group and others.

The CMF platform is divided into four parts according to different body structures: engine compartment, passenger compartment, front chassis and rear chassis. In addition, the CMF system also includes electronic systems. Nissan engineers combine these components in various ways, and each component can be adjusted according to the needs of different models. In fact, Nissan has already started the platform modular production method very early. The Infiniti G35, FX and Nissan GT-R models we are familiar with are all from the FM platform.

Forward collision warning + lane departure warning system is a highlight

Nissan's new X-Trail is equipped with the LDW (Lane Departure Warning) lane departure warning system and the FCW (Forward Collision Warning) forward collision warning. We are not unfamiliar with these two functions. We have also learned about them in the previous article "The Secret Behind the Central Rearview Mirror". However, most of the systems we have come into contact with before use photoelectric sensors (Volvo) and stereo cameras (Subaru) to achieve the monitoring function in front of the car, while the new X-Trail uses a ranging sensor called a monocular camera. In comparison, the anti-collision system based on such sensors is easier to miniaturize, and of course, the cost can also be lower.

The system includes a camera, a display unit and a controller. The monocular camera behind the central rearview mirror can monitor vehicles and pedestrians about 60 meters in front of the car in real time. When a collision with an obstacle in front is detected, the system will issue an alarm through the display unit in the dashboard within 2.7 seconds before the collision. In addition, the controller analyzes the received signals such as vehicle speed (captures the turn signal on signal to determine whether to activate the lane departure warning) and cooperates with the ABS control unit to brake, so as to avoid collision or reduce the impact force during collision.

This anti-collision system, which uses a camera with CMOS chip imaging (black and white images) for monitoring, has certain functional limitations. It can identify vehicles, pedestrians and bicycles during the day, but it cannot identify pedestrians or bicycles at night.

As mentioned above, this device also supports lane departure warning function, the camera determines the vehicle's trajectory by identifying the white line of the lane. This function is turned on when the vehicle speed exceeds 55 km/h. If the vehicle is found to deviate from the lane without turning on the turn signal, the system will issue a warning to remind the driver to pay attention to driving safety.

Human-computer interaction system

The new generation X-Trail is the first Nissan model equipped with the NissanConnect in-vehicle information system, which includes a 7-inch touch screen installed on the center console. The system can connect to the mobile phone via Bluetooth and share information. The built-in navigation system of NissanConnect is a new generation system developed in cooperation with Google. In addition to providing conventional navigation, points of interest and other services to the driver, it can also present more information to the driver.

Driver Assistance Systems

The new generation of X-Trail also adds an active control system that can improve driving stability. In daily driving, the combination of Active Ride Control and Active Engine Brake systems can filter out some driver's inadvertent biased actions, and reduce the pitch of the vehicle body during driving by controlling the engine power, thereby improving ride comfort. In addition, when the vehicle turns and decelerates, the active engine brake system can cooperate with the CVT gearbox to adjust the transmission gear ratio, so that the driver can brake more easily.

Other driver assistance features

In addition to the above functions, the new generation X-Trail is also equipped with an automatic parking system that supports parallel parking and parking in a garage. The radar probes distributed around the vehicle body can monitor the surrounding conditions of the vehicle in all directions. This function can also be used when the vehicle is backed out of the parking space. When it detects that there are vehicles or pedestrians approaching the vehicle, an alarm will be sounded inside the vehicle to remind the driver to pay attention to the surrounding conditions of the vehicle. It can be said that the addition of these functions has made great contributions to both driving safety and convenience.

    Powertrain

    In terms of power system, the new generation X-Trail also uses a 2.5-liter naturally aspirated engine. However, according to official information, the engine has improved its efficiency by reducing internal losses and streamlining its internal structure while maintaining the same displacement. Ultimately, the maximum power of this 2.5-liter engine is 172 horsepower and the maximum torque is 237 Nm. In addition, a 2.0-liter naturally aspirated engine is still available.

    In terms of gearbox, it is also matched with a CVT gearbox provided by Jatco. According to Nissan's deployment in powertrain, the new X-Trail should use the CVT8 gearbox that can be used for larger power output. The current Teana's gearbox is also a CVT8 model. Compared with the current X-Trail's gearbox, the new gearbox has a higher transmission efficiency.

    By reducing the friction between the drive wheel and the pulley and using a smaller oil pump, the energy consumed by internal friction was reduced by about 40%. Combined with peripheral adjustments, the overall transmission efficiency was improved by 12%.

    Compared with the previous generation model, although the new X-Trail has a larger body size, the rational application of materials and aerodynamic design combined with the above-mentioned optimization of the power system have improved the fuel economy of the whole vehicle by 18%.

    Four-wheel drive system

    The new generation X-Trail's four-wheel drive system also provides models with three modes: automatic, front-wheel drive and lock. In automatic mode, the system will constantly monitor the throttle opening, engine speed and torque to make advance judgments on the status of the wheels. When the front and rear wheels are found to have a tendency to slip, the power between the front and rear axles will be adjusted. When driving at low speeds under complex road conditions, the driver can select the four-wheel drive mode as lock through the knob on the center console. In this way, the front and rear wheels can distribute power in a 50:50 ratio, and then combined with the braking of the VDC system (ESC dynamic stability control system) to lock the wheels, so as to help the vehicle pass through complex road conditions smoothly.

    Editor's summary:

    The new generation of X-Trail, with a more modern appearance and a stronger sense of technology, is obviously weakening its relatively tough side, and is more focused on urban use in terms of technology. The new generation of Nissan X-Trail models produced using the CMF platform have richer technical aspects than the current models, especially in terms of active safety technology. The anti-collision and lane keeping functions achieved by relying on a single-lens camera are relatively rare in products of the same level (currently, the high-end models of Kuga have this function), but it is still unknown how it will be installed in domestic models in the future. The NissanConnect in-vehicle information system is a very mainstream configuration in the future. By connecting with a mobile phone, it can not only expand the functions of the system but also import the information in the mobile phone. This synchronization of information enhances the entertainment of the in-vehicle information system.

    There have been reports that Nissan X-Trail and Qashqai will be merged in the future, but from the information we have obtained, these two SUV models will still be positioned differently for different markets, but in terms of power, Qashqai is equipped with a 1.2T engine with a power of 113 horsepower, and a 1.5-liter direct injection engine is also available. If nothing unexpected happens, the new X-Trail will appear in front of us first, and we may be able to see it at the upcoming Guangzhou Auto Show.