From Sideguard Assist to passenger compartment monitoring.
Particularly in city traffic, dangers are sometimes unpredictable. Therefore all the more important that measures be taken to prevent an accident. Mercedes-Benz has equipped the Citaro urban bus with many safety features which help in mastering critical driving situations.
Every Citaro is equipped with turning assistant Sideguard Assist 2, Frontguard Assist, Traffic Sign Assist and Tyre Pressure Monitoring (TPM) as standard. The optional braking assistant Preventive Brake Assist 2 warns of stationary and moving obstacles – including pedestrians and cyclists – and initiates partial braking if necessary to avoid an accident. The Citaro can also be equipped with MirrorCam, which provides better visibility to the rear and side than conventional mirrors.
The best basis for driving safety is a driver who is fully focused on traffic conditions. This is why special attention was given to the ergonomic driver's work area. In the Citaro, the driver has comfortable access to all controls and a perfect view of all the instruments. Further convenience is provided by the automatic transmission and the standard reversing camera. The Opticool windscreen and the separately controlled air conditioning system ensure that the driver is still able to concentrate even when it is hot outside.
Depending on the vehicle, the images are displayed on 7" and 15" monitors. The two high-resolution displays show the different fields of vision. The photodiodes integrated in the monitors detect the incident light and adjust the brightness of the respective monitor individually. To make it easier for the driver to evaluate the images, the 15" variants have three different guide lines. Together with the permanently calibrated vehicle end line, the distance line assists the driver in assessing approaching objects. The Overtaking Assist overlay is activated from a speed of 10 km/h with flashing, in order to safely assist overtaking or turning. In addition, the display for Blind Spot Assist is installed in the monitor.
The modern MirrorCam system provides a clear and full view of the road traffic. Equipped with high-resolution cameras, the driving safety is improved and the risk of accidents is minimised. The extended field of vision enables the driver to see pedestrians, cyclists and other road users in the surrounding area. This eliminates the blind spot when turning right.
High beam assistant.
The function can be activated or deactivated. It is active from a speed of approximately 20 mph (35 km/h) and is automatically deactivated below a speed of approximately 15 mph (27 km/h). The function adapts to the illumination/brightness of the surroundings (no automatic switching on if there is sufficient street lighting).
The high beam assistant automatically switches the high beam on or off depending on traffic, so that optimum illumination of the road is always ensured. In this way, it contributes to greater safety through improved lighting conditions and optimized illumination, and increases driving comfort and safety.
Traffic Sign Assist (TSA).
The innovative Traffic Sign Assist offers maximum safety and comfort on the road. Thanks to GPS and camera support, the vehicle speed is constantly compared with the current traffic regulations.
The system is designed to provide dedicated and appropriate feedback if the permitted speed is exceeded. Thanks to the state-of-the-art instrument cluster, the driver receives both visual and audible signals that immediately draw attention to the speed.
The 360° camera system consists of four cameras that capture the immediate vehicle environment and generate an indirect all-round view. The associated 10" screen is located on the A-pillar above the cockpit. This system allows pedestrians, cyclists and obstacles to be seen even in areas that are otherwise not visible to the driver. In this way, the system increases road safety, as collision hazards can be detected and, at best, prevented.
The views from the 360° camera are available up to a speed of approx. 20 mph (30 km/h) when driving forwards and always when reversing.
Risk of accidents due to objects protruding into the traffic area above the cameras, e.g. protruding roofs, exterior mirrors of your own and other buses, etc. The cameras cannot detect these objects. Particularly in the 360° view, the impression of a free environment can be created even though objects above the mounted cameras protrude into the turning space.
Electronic Stability Program (ESP®).
The Electronic Stability Program (ESP®) is an active system for increasing driving safety and driving stability. It makes a noticeable contribution to reducing the risk of skidding during cornering or evasive manoeuvres. This is achieved by specifically controlling the braking forces on each individual wheel in situations where the driving dynamics are critical, for example, if the bus is driven at the limit when cornering. At the same time the engine output is reduced. A possible "breaking-loose" of the bus is thereby prevented by the finely metered braking - within the limits of the physical possibilities.
ESP® monitors, among other things, the lateral acceleration of the bus. If, on long bends – such as motorway exits – or during rapid lane changes, the bus reaches a critical driving situation, the vehicle speed is automatically reduced until driving stability is achieved again.
Anti-lock Braking System (ABS).
The Anti-lock Braking System (ABS) supports driving stability during critical braking operations and ensures that the vehicle remains steerable. The braking forces acting on the individual wheels are distributed by the ABS so that even in an emergency braking situation no wheel is blocked for any length of time, and the steerability of the bus is largely maintained.
The control unit of the brake electronics records the current wheel speed via the pole wheels and wheel sensors. When braking, the system controls the brake pressure at the individual wheel brake cylinders via the control valves. During emergency braking and braking with locking wheels, the system opens and closes the control valves of the wheel brake cylinders fully automatically at very short intervals, thus preventing locking and keeping the vehicle steerable.
During emergency braking and braking with locking wheels, the system opens and closes the control valves of the wheel brake cylinders fully automatically at very short intervals, thus preventing locking and keeping the vehicle steerable.
Sideguard Assist 2.
Sideguard Assist 2 is a safety assistance system that supports the driver in critical situations when turning right or turning left when visibility is possibly restricted. The system is designed to help detect moving obstacles within the system limits, and warns the driver so as to avoid critical situations or reduce the consequences of accidents when turning off or changing lanes.
The side areas of the vehicle are constantly monitored. As a result, vehicles, pedestrians or cyclists who may be in the blind spot are detected on both the front passenger side and the driver’s side. The radar system precisely detects the movements and warns the driver of possible collisions. The intuitive user interface and clear warnings allow the driver to drive safely and relaxed.
Preventive Brake Assist 2.
With Preventive Brake Assist 2, Daimler Buses offers the second generation of Active Brake Assist. The system warns of collisions with moving pedestrians and cyclists as well as stationary and moving objects. In the event of a serious risk of collision, the driver is alerted by a visual and acoustic warning and partial braking is initiated automatically.
Warning cascade and braking intervention are specifically designed for use in urban traffic. In the event of an impending collision with pedestrians or cyclists as well as with moving or stationary objects, Preventive Brake Assist 2 issues a warning. The driver is warned both visually by a flashing red triangle in the central display and acoustically, and simultaneously initiates partial braking. This braking intervention is maintained either until the driver intervenes, the situation is no longer critical, or the bus comes to a stop.
Thanks to the interaction of front radar, short-range radar and the front camera, the area up to 250 metres in front of the bus is constantly scanned. This assistance is ensured up to a speed of 60 km/h. In snow, rain, fog, heavy spray, glare/dazzling conditions, direct sunlight or constantly changing light conditions, the system range and detection of vehicles and people may be impaired.
The cornering light function.
The cornering light function provides even more safety through better visibility conditions at night-time when cornering at intersections and roundabouts and when manoeuvring in forward driving and backing up.
The cornering light function is activated automatically at speeds of up to approx. 35 km/h if the main headlamps are on, the turn indicator is actuated or the steering wheel is turned. One of the two front fog lamps then cuts in to illuminate an area on the side in front of the vehicle that is not being illuminated by the main headlamps.
The intelligent electronic system switches the cornering lights on or off progressively in the same way as a dimmer switch. This gives the driver's eyes a chance to adapt to the change in light.
The unique ATC articulation limiter system in the Citaro G.
Safe, manoeuvrable and stable. The Citaro G has the same highly developed assistance systems and a body just as stable as any other Citaro. It can also be manoeuvred safely on narrow roads. Its front and rear section are connected to a unique jack-knife control system (ATC) by a proven low-floor articulation. This guarantees high stability and manoeuvrability. The driver can even manoeuvre it comfortably in reverse gear. This is aided by the independent suspension on the front axle.
It makes the Citaro G one of the most manoeuvrable vehicles in its class — with ride comfort almost comparable to that of a coach.
ATC (Articulation Turntable Controller): stabilises articulated buses in critical driving situations almost like ESP®.
Both agile and robust. The Articulation Turntable Controller (ATC) developed by Mercedes-Benz is a sophisticated anti-jackknife system for articulated buses. This swivel joint and its control system form one of the core components of the vehicle.
The otherwise usual high damping of the joint leads to a strong tendency to understeer in curves and increased tire wear on the front axle, this vehicle’s joint runs freely under normal running conditions and is attenuated only by the friction of the elements.
Tyre Pressure Monitoring (TPM).*
The wireless tyre pressure monitoring with indication in the multifunctional display is an electronic safety system that permanently monitors the air pressure of all tyres. Tyre pressure losses are displayed within the system limits.
The right tyre pressure contributes to driving safety and significantly reduced fuel consumption. Even a tyre pressure set 0.5 bar too low can increase fuel consumption by up to 5%. The wheel electronics are positioned on the valve on the inside of the rim. The sensors record the data relevant to the tyre pressure and transmit it to the display instrument.
The tyre pressure is recorded both when the vehicle is stationary and when it is moving. Caution! A sudden loss of pressure, for example due to the penetration of a foreign body, is not immediately indicated by the tyre pressure monitoring system. Damage to the tyres that does not lead to acute pressure loss is also not detected by the monitoring system. Here, visual inspection by the driver is and remains essential.
Passenger compartment monitoring.
Installed video monitoring cameras can monitor events in the bus. A video monitoring system can not only improve the perceived safety for the bus driver and passengers, it can also deter hooligans committing acts of vandalism in the vehicle and record acts of violence.
The data is transmitted to the monitor in the bus driver's workstation. The bus driver can then better discern and assess certain situations and events occurring in the passenger compartment and if necessary react to any threat.
The vehicle is labelled with pictograms to inform passengers that the vehicle is video-monitored. Together with the video monitoring, they increase the perceived safety for your driver and the passengers and thereby enhance the attractiveness of public transport. The video monitoring system is optional equipment.
For more information on the functioning of the video monitoring and data storage, contact our bus sales advisor.