LEMON Manuals: Even more car manuals for everyone
Home >> Mercedes Benz >> 2015 >> ML400 >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Throttle Control, Speed Control Systems - 166 Chassis >> Basic Knowledge >> DISTRONIC PLUS with Steer Assist and stop & go pilot function - GF30.30-P-0017GN

DISTRONIC PLUS with Steer Assist and stop & go pilot function - GF30.30-P-0017GN

MODEL 166 as of model year 2016 with CODE 266 (DISTRONIC PLUS with Steer Assist and Stop & Go Pilot) 

MODEL 292 with CODE 266 (DISTRONIC PLUS with Steer Assist and Stop & Go Pilot) 

Fig 1: DISTRONIC PLUS With Steer Assist And Stop Block Diagram - Except Model 166.063
G10076558Courtesy of MERCEDES-BENZ USA

Block diagram, except model 166.063 

Fig 2: DISTRONIC PLUS With Steer Assist And Stop Block Diagram - Model 166.063
G10076559Courtesy of MERCEDES-BENZ USA

Block diagram, model 166.063 

Function requirements, general 

IMPORTANT At a speed of 0 to 60 km/h, Stop & Go Pilot orients itself towards the vehicle in front while taking into account lane markings, e.g. during the traffic jam vehicle following function and at a speed of 60 to 130 km/h using lane markings as a guideline (or using the vehicle in front as a substitute if lane markings are not available). At a speed of 130 to 200 km/h, Steer Assist orients itself towards the lane markings detected (left and right). If these conditions are not present, Steer Assist and Stop & Go Pilot offer no support.

IMPORTANT Object recording (e.g. vehicle ahead) via the radar sensor system is based on the radar measuring procedure.

The front long range radar sensor and the front bumper radar sensors run a contamination and function test after each engine start to ensure that they are functioning correctly. The function test requires an object to be located in the respective detection area (this object is used as a reference value) and the vehicle must have moved. DISTRONIC PLUS cannot be activated if a malfunction is established or if there are no objects (for the function test) in the detection range. The radar sensors control unit (with CODE 23P (Driving assistance package plus)) receives the signals from the front bumper radar sensors via radar CAN 1 and sends them via chassis FlexRay to the front long range radar sensor. The front long range radar sensor evaluates them in combination with its own signals and, when all the radar sensors are functioning correctly, sends the "Radar sensor system operational" status via the chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving assistance package plus)).

DISTRONIC PLUS with Steer Assist and Stop & Go Pilot function, general 

The DISTRONIC PLUS automatically controls the speed and the distance to a vehicle driving immediately ahead in accordance with the driver's request by braking when necessary and accelerating again if possible. The distance and speed control is carried out by the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). In order to do this, the radar sensors control unit (with CODE 23P (Driving assistance package plus)) actively intervenes in the engine management or the brake system.

In stop and go traffic the DISTRONIC PLUS brakes vehicle automatically (if necessary through to a standstill). Once the traffic situation again allows this, the DISTRONIC PLUS accelerates the vehicle automatically up to the set target speed and therefore frees up the driver from these tiring routine tasks (e.g. frequent starting off and braking in stop-and-go or convoy driving traffic).

IMPORTANT If the vehicle was at a standstill for more than = 1.5 s, automatic acceleration does not occur. The driver must confirm the start-off request (by actuating the accelerator pedal or using the cruise control lever).

If the DISTRONIC PLUS recognizes that strong braking is necessary (e.g. weaving in traffic, a stationary obstacle), the DISTRONIC warning lamp in the instrument cluster lights up and an intermittent alarm tone sounds. Both require the driver to proceed with increased caution and to possibly also brake himself. If the driver reacts to the acoustic warning and brakes, he or she will be assisted in this by the Brake Assist system. This calculates the required brake force amplification according to the situation. A threatening accident can be prevented under certain circumstances or at least one can mitigate its consequences. However if the driver fails to respond to the acoustic warning, the PRE-SAFE ® brake initiates (in addition to the visual and acoustic warnings) an automated partial and then emergency braking.

IMPORTANT If the DISTRONIC PLUS is switched off, the situation directly in front of the vehicle is still detected and evaluated. In dangerous situations warnings are given, as described above, or there is autonomous braking.

The Steer Assist supports the driver in maintaining directional stability. Here the Steering Assistant is oriented over the whole vehicle speed range on the traffic lane markings and also for lower speeds on the vehicles driving immediately ahead, for example for subsequent dangers in a traffic jam. The vehicle stays in its lane and unintentional movement towards the lane markings is prevented. The Steer Assist does not relieve the driver of his/her task of keeping the vehicle in the lane. It serves more to relieve the load and therefore to facilitate the resultant increase in comfort. Assistance is also only provided within defined limits, i.e. no assistance can be provided for large steering angles at slow speeds, e.g. caused by driving on roads going over passes.

The Steer Assist is designed to be so sensitive that it recognizes whether the driver has his hands on the steering wheel. If not, the Steer Assist outputs a warning. The Steer Assist is integrated in the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). The course of the road in front of the vehicle and the vehicles ahead are recorded by the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) and the radar sensor system. The steering movements that are requested are carried out by the electric steering.

The following subfunctions in the DISTRONIC PLUS are described in the separate "Cruise control (CC) Function" subfunction:

Operation:

The DISTRONIC PLUS is operated via the CRUISE CONTROL lever. The steering column tube module control unit directly reads in the control signals of the cruise control lever and sends them via the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). The menu settings in the instrument cluster can be used to switch the distance display on and off.

Design of the cruise control lever 

Fig 3: Identifying Cruise Control Lever Adjustment Position
G10076560Courtesy of MERCEDES-BENZ USA

IMPORTANT If the SPEEDTRONIC LED (without code 494 (USA version)) lights up, the DISTRONIC PLUS is deactivated and the function variable SPEEDTRONIC (without code 494 (USA version)) preselected. Actuation of the SPEEDTRONIC LED takes place by the switchover logic integrated in the steering column tube module control unit.

IMPORTANT The distance to the vehicle driving immediately ahead is displayed in the multifunction display for t = 5 s after actuation of the CC lever. Through selection of the "DISTRONIC PLUS" operating level in the "Assistance" menu, the distance graphic is shown permanently. Display of the assist graphic can be switched on or off independently of the activity of the automatic distance control. The distance to the vehicle driving immediately ahead can be switched on or off via the DISTRONIC control in seven stages between about. t = 1.0 and 2.0 s. If a distance of t = 2.0 s is set for example, the vehicle driving immediately ahead will be followed at a temporal distance of t = 2.0 s. This physical gap thus increases with increasing speed.

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) evaluates the following input factors, among other information: 

Signal "Engine running" or "Drivetrain operational":

Parking brake status

The Electronic Stability Program control unit sends the status of the parking brake over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Engaged gear range:

Driver request via the cruise control lever:

The driver request over the CC lever are directly read in by the steering column tube module control unit. The steering column tube module control unit sends the control signals of the cruise control lever over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Vehicle speed/direction of travel/acceleration

The vehicle speed is calculated from the wheel speed. The direction of travel is defined by the wheel rotation direction, the acceleration by the increase in the wheel rotation speed. The Electronic Stability Program control unit sends the wheel speed signals over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) (Steer Assist only) and radar sensors control unit (with CODE 23P (Driving assistance package)).

ESP® status:

The Electronic Stability Program control unit sends the status of the ESP® via chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving assistance package plus)) and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving assistance package plus)).

"Steer Assist" status (Steer Assist only):

The Steer Assist can be switched on or off in the "Assistance" menu of the instrument cluster. The status of the Steer Assist is sent by the instrument cluster over the chassis CAN 2, electronic ignition lock control unit, chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

IMPORTANT Successful activation or deactivation is shown by the status indication in the instrument cluster.

Status of the electric power steering (only Steer Assist)

Information about the status of the electric power steering is sent by the electrical power steering control unit through the chassis CAN 2, electronic ignition lock control unit, chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Object detection by the front bumper radar sensors:

The front bumper radar sensors operate according to the short impulse principle and have a maximum range of s = 30 m. The front bumper radar sensors register objects in the short range area and send the data via the radar CAN 1 to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Object detection by the front long range radar sensor:

The front long range radar sensor monitors the area in front of the ∠ = 18°. vehicle up to a distance of s = 200 m within a corridor of Objects up to a distance of s = 0 to 60 m are detected in a corridor of ∠ = 60°.

The front long range radar sensor operates according to the pulse modulated Doppler radar concept, which enables the distances and speeds of individual objects (e.g. vehicles) to be measured independently of each other.

Object detection by the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) (Steer Assist only): The stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) consists of two high-resolution mono cameras and an integrated control unit. The laterally offset location of the two mono cameras creates a difference in perspective (parallax displacement) between the left and right optical path. The distance to the object ahead and other variables such as the height thereof are calculated on the basis of the differences between the image data.

The stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) records vehicles in the same lane under the following conditions:

IMPORTANT The conditions listed here merely represent the system constraints for calculating the function. The hardware installed is capable of detecting larger areas.

Stereo multifunction camera object detection (with CODE 23P (Driving Assistance package Plus)) 

Fig 4: Overview Of Stereo Multifunction Camera Object Detection
G10076561Courtesy of MERCEDES-BENZ USA

The integrated control unit evaluates image data from the two mono cameras, processes it and sends corresponding data over the chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). The radar sensors control unit (with CODE 23P (Driving assistance package Plus)) compares the image data with the signals from the radar sensor system.

Lane data (Steer Assist only):

The stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) records pictures of the lane markings on the road with a fixed sampling rate. The integrated control unit calculates a lane from the picture sequences and the measurements resulting from the pictures of the road markings. The stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) sends the lane data over the chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Stereo multifunction camera lane detection (with CODE 23P (Driving Assistance package Plus)) 

Fig 5: Overview Of Stereo Multifunction Camera Lane Detection
G10076562Courtesy of MERCEDES-BENZ USA

IMPORTANT Detailed information about lane detection is contained in the separate subfunction "Active Lane Keeping Assist function". Steering torque of driver and wheel angle (Hands-Off Detection status) (Steer Assist only):

The electric power steering torque sensor records the steering torque applied by the driver and the wheel angle. The electrical power steering control unit directly reads in the signals of the electric power steering torque sensor and sends them over the chassis CAN 2, electronic ignition lock control unit, chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). On the basis of these values, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) determines whether and at which time intervals the driver is making steering movements (hands-off detection).

GPS signals/signals for traffic assessment:

The COMAND controller unit evaluates the GPS data received utilizing further information for the traffic assessment and sends corresponding information over the interior CAN, electronic ignition lock control unit and chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Engine drive torque:

Braking torque:

Information about the braking torque currently applied is sent by the Electronic Stability Program control unit over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). Tire pressure monitoring status (with CODE 475 (Tire pressure monitoring) or CODE 477 (Tire pressure loss warning) (Steer Assist only)):

Vehicles with CODE 475 (Tire pressure monitor):

The tire pressure monitor control unit (with CODE 475 (Tire pressure monitor)) sends information about the respective tire pressure over the chassis CAN 2, electronic ignition lock control unit, chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Vehicles with code 477 (Tire pressure loss warning):

The tire pressure is determined using the rolling circumference. The tire pressure loss warning (RDW) system is functionally integrated in the Electronic Stability Program control unit. The Electronic Stability Program control unit sends information about the tire pressure over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

IMPORTANT Information about tire pressure monitoring can be found in the separate function description titled, "Tire pressure monitor function" (with CODE 475 (Tire pressure monitor)) or "Tire pressure loss warning (RDW) function" (with CODE 477 (Tire pressure loss warning)). Status of trailer recognition (with CODE 550 (Trailer hitch) (Steer Assist only)) (except model 166.063):

If a trailer is detected, the trailer recognition control unit (with CODE 550 (Trailer hitch)) sends the "trailer detected" status over the interior CAN, electronic ignition lock control unit and chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Acceleration/yaw rate:

The acceleration/yaw rate is detected by the yaw rate sensor for lateral and longitudinal acceleration. The turn rate sensor for lateral and longitudinal acceleration sends corresponding values over the vehicle dynamics CAN, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) (Steer Assist only) and radar sensors control unit (with CODE 23P (Driving Assistance package Plus)). With active Steer Assist and traffic jam vehicle following function, the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) calculates the exact position of the vehicle driving immediately ahead based on these values.

Transmission mode status:

The driver can influence the acceleration behavior of the vehicle through selection of the transmission mode via the transmission mode control. The transmission modes control panel directly reads in the status of the transmission mode control and sends it:

Steering wheel angle:

The steering angle is recorded by the steering wheel angle sensor. The steering column tube module control unit directly reads in the signals of the steering wheel angle sensor and sends information about the steering wheel angle over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Set the turn signal indicator at the combination switch (e.g. overtaking request of the driver):

The steering column tube module control unit directly reads in the position of the combination switch and sends it via the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) (Steer Assist only) and radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

Accelerator pedal position:

Brake pedal position:

The Electronic Stability Program control unit sends the status of the brake pedal over the chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)).

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) outputs the following initial parameters (requirements): 

Status of DISTRONIC PLUS with Steer Assist and Stop & Go Pilot (Steer Assist only):

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) sends the status of the DISTRONIC PLUS over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)) and chassis CAN 1, electronic ignition lock control unit, and chassis CAN 2 to the electrical power steering control unit.

Raise/reduce engine torque:

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) sends the "increase engine torque" or "decrease engine torque" request over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis CAN 1 to the Electronic Stability Program control unit. The Electronic Stability Program control unit evaluates this request as well as further driving dynamics requests and sends them in accordance with their relevance:

The CDI control unit or the ME-SFI [ME] control unit implements this request.

Engage targeted gear (downshift or upshift):

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) sends the "Engage targeted gear" request over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis CAN 1 to the Electronic Stability Program control unit. The Electronic Stability Program control unit evaluates this request as well as further driving dynamics requests and sends them in accordance with their relevance:

This request is however to be understood as a switching recommendation. Downshifting or upshifting of the automatic transmission takes place autonomously by the fully integrated transmission control unit, dependent on the current operating condition

Raise/reduce braking torque:

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) sends the "Increase braking torque" or "Decrease braking torque" request over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis CAN 1 to the Electronic Stability Program control unit. The Electronic Stability Program control unit reacts by directly actuating the traction system hydraulic unit, which reacts by increasing or decreasing the braking torque according to the brake torque.

Steering requests (Steer Assist only):

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) uses such variables as the steering torque of the driver, lateral acceleration, vehicle speed, and the object and lane data of the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) to calculate the additive toothed rack force and sends corresponding steering requests over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), chassis CAN 1, electronic ignition lock control unit, and chassis CAN 2 to the electrical power steering control unit. The electrical power steering control unit checks the incoming steering requests for plausibility and actuates the electric power steering actuator motor accordingly.

The additive toothed rack force is only available up to a certain threshold value dependent on the above-mentioned variables and thereby limits the characteristic of the power steering.

Emit warning tones, system or warning messages

The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) sends the requests for outputting acoustic warnings, system and warning messages over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), chassis CAN 1, electronic ignition lock control unit, and chassis CAN 2 to the instrument cluster, which issues the corresponding system and warning messages over the multifunction display and directly actuates the instrument cluster's warning buzzer.

The description of the situations takes place, as an example, in the following chronological sequence:

IMPORTANT Longitudinal and lateral regulation is active for the aforementioned descriptions of DISTRONIC PLUS. This means that the driver is supported in all situations referenced during acceleration, braking, and steering. The primary regulation is highlighted in the following situations for a better understanding.

Reactivate DISTRONIC PLUS and drive off automatically 

The following options are available for reactivating DISTRONIC PLUS:

Drive off from standstill without a vehicle in detection range of the radar sensor system

If there is no stationary/moving vehicle in the detection range, the DISTRONIC PLUS function is active but the vehicle does not start off automatically. To initiate the drive-off procedure, the driver has to either briefly press the accelerator pedal or operate the Resume from memory switch on the CRUISE CONTROL lever to call up the last selected set speed (set speed 30 km/h (mph)).

Automated drive-off from standstill with a vehicle in detection range of the radar sensor system

If a stationary or moving vehicle is in the detection range of the radar sensor system, the vehicle follows the vehicle immediately ahead (the vehicle accelerates up to the set speed defined) as long as the driver has briefly operated the accelerator pedal beforehand or used the Resume from memory switch on the cruise control lever to call up the last selected set speed.

IMPORTANT For vehicles at a standstill a specified distance limit exists beyond which a stationary vehicle is no longer displayed.

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Display on the instrument cluster

The brake application takes place by means of hydraulic pressure controlling in the wheel brake cylinder by the traction system hydraulic unit according to the current vehicle status. To do this the Electronic Stability Program control unit assesses various variables such as the required braking torque.

IMPORTANT In model 166.063, the kinetic energy is converted into electrical energy via a generator (regenerative braking) within defined limits. If the requested braking torque exceeds the deceleration through recuperation (for example in a case of a emergency braking), the Electronic Stability Program control unit additionally actuates the traction system hydraulic unit and therefore the service brake. The driver must press on the brake pedal accordingly if he or she sees that the instigated measures are not adequate to avoid a possible collision.

IMPORTANT If the driver does not intervene, an additional intervention by the brake system is made by the PRE-SAFE ® brake. Detailed information about autonomous braking is available in the partial function "PRE-SAFE® brake function".

If the vehicle driving immediately ahead accelerates again, the engine torque is increased and the vehicle also accelerates. The increase in engine torque is dependent on the ascent or the descent involved, among other things.

The maximum (positive) acceleration is dependent on the selected transmission mode. The driver can influence the vehicle's acceleration behavior by selecting the transmission mode using the transmission mode button.

The driver furthermore has the option of operating the accelerator pedal to accelerate the vehicle (e.g. when overtaking). The automatic acceleration is put out of action until the driver uses the accelerator pedal. The multifunction display shows the message "DISTRONIC passive". If the automatic distance control requires a higher acceleration than the driver prescribes, the driver request is overlaid by the request for automatic distance control and the "DISTRONIC passive" message goes off.

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Change of driving lane (overtaking) 

When overtaking above a speed of v = 70 km/h the vehicle is also automatically accelerated. To do this the driver must initiate the overtaking maneuver by setting the turn signal. Provided that the automatic distance control is activated, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) recognizes the intention of the driver to overtake and accelerates the vehicle while taking account of the distance to the vehicle driving immediately ahead.

When approaching a slowly moving vehicle and therefore an active automatic intervention by the brake system, this is then reduced insofar as the driver initiates the overtaking procedure by operating the turn signal indicator. If required, the vehicle is additionally accelerated. If there is no vehicle in the detection range of the radar sensors after the overtaking procedure, the automatic distance control changes over to automatic speed control. If a vehicle driving immediately ahead is subsequently detected as a target object after the overtaking procedure the automatic speed control function changes over again into the automatic distance control function.

The overtaking maneuver is broken off in the following situations:

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Initial parameters:

Convoy driving 

IMPORTANT The convoy driving function is only available in selected Western European countries with the appropriate legislation (overtaking on right prohibited at speeds in excess of v = 80 km/h, as well as overtaking speed limit relative to the convoy of a max. v = 20 km/h). DISTRONIC PLUS with Steer Assist and Stop & Go Pilot generally prevents illegal takeovers on the right-hand side; a special scenario is described here. If a convoy forms in the left-hand lane due to the current traffic situation that could theoretically be overtaken in the right-hand lane, this is detected by DISTRONIC PLUS. A convoy overtaking maneuver in the right-hand lane (relative overtaking speed to convoy ≤ 20 km/h, maximum overtaking speed v = 85 km/h) is only initiated if the following requirements have been met:

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Initial parameters:

Additional function requirements for Steer Assist power steering 

Power steering Steer Assist 

The Steer Assist supports the driver in maintaining directional stability (lateral guidance). By means of targeted steering intervention it keeps the vehicle on course and prevents it from unintentionally deviating from the road. For example, if no lane markings are detected in urban traffic or in a freeway traffic jam because of the proximity to the vehicle in front, the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)) evaluates object-related data of the vehicle in front.

If the electrical power steering control unit detects zero or insufficient torque at the steering wheel for t > 10 s ("Hands-Off Detection"), it sends corresponding information over the chassis CAN 2, electronic ignition lock control unit, chassis CAN 1, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), and chassis FlexRay to the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) and a message (gray icon with red hands) over the chassis CAN 2 to the instrument cluster. A message is shown on the multifunction display.

If the driver does not react to the message within t = 5 s, an additional acoustic message is issued over the warning buzzer in the instrument cluster. The radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) sends the request to output an acoustic warning over the chassis FlexRay, chassis gateway control unit (with CODE 23P (Driving Assistance package Plus)), chassis CAN 1, electronic ignition lock control unit, and chassis CAN 2 to the instrument cluster. The instrument cluster directly actuates its warning buzzer and the volume of active audio sources is reduced simultaneously. In this case, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) renders the Steer Assist passive. The "Hands-Off Detection" is suppressed by the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) at vehicle speeds of v < 10 km/h (intelligent Hands-Off-Detection). The status of the Steer Assist is continuously shown to the driver on the multifunction display of the instrument cluster. A message (optical and acoustic) is also always issued if there is a concrete danger situation recognized.

The following traffic situations lead to object guidance being aborted or Steer Assist being rendered passive:

DISTRONIC PLUS is thereby deactivated. The driver is notified of this by emission of an intermittent tone over the warning buzzer in the instrument cluster, and a warning indicator in the instrument cluster's multifunction display. The driver can subsequently reactivate the DISTRONIC PLUS.

Fig 6: Identifying Steer Assist
G10076563Courtesy of MERCEDES-BENZ USA

IMPORTANT The icons for the system status and for steering readiness appear in the upper area of the multifunction display.

IMPORTANT The power steering of the Steer Assist system is reduced as speed increases when the vehicle is driven on narrow streets or with a limited field of view of the stereo multifunction camera (with CODE 23P (Driving Assistance package Plus)).

IMPORTANT More detailed information about the electric power steering assistance can be found in the separate function description "Electric power steering (ES)".

Automatic speed control 

If the vehicle is in active distance control and the vehicle driving immediately ahead accelerates above v = 200 km/h or removes itself from the detection area of the radar sensor system, the automatic distance control switches over into automatic speed control.

IMPORTANT Detailed information about automatic speed control can be found in the separate function description "CC (TPM) function".

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Initial parameters:

Passing over roundabouts, T intersections and freeway exit lane 

If the vehicle driving immediately ahead leaves the detection area of the radar sensor system in one of the above-mentioned traffic situations, then the current speed is maintained:

If, after this, no vehicle is detected driving immediately ahead, the vehicle accelerates or decelerates to the established set speed.

IMPORTANT Since traffic situations are subject to alteration, the digital map data has to be regularly updated.

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Initial parameters:

Automated Stop Vehicle 

For an active DISTRONIC PLUS the vehicle will follow the vehicle driving immediately ahead to standstill. Deceleration here is through regenerative braking (in model 166.063) or the service brake. The service brake also secures a stationary vehicle against rolling away. After a defined time period the electric parking brake is also activated (standstill control safety strategy).

IMPORTANT

Going back into a lane/person in the front regulation 

If the vehicle driving immediately ahead turns off and there is another vehicle in front, the system only switches over to the new target vehicle if it is moving. The system does not operate for stationary objects unless a preceding vehicle is tracked to a standstill. If while driving a vehicle turns in front within the safe distance to the vehicle driving immediately ahead, the distance to this new vehicle is regulated. If the vehicle is in automatic speed control and a vehicle tuns onto the lane driven in this vehicle is registered as the vehicle driving immediately ahead. If the distance to the moving in vehicle is below the value which was programmed, the DISTRONIC PLUS function brakes the vehicle. If the requested brake power is not sufficient, a visual and an acoustic warning is issued, and the driver has to press the brake pedal. If the driver fails to respond, PRE-SAFE ® brake initiates (in addition to the visual and acoustic warnings) an automated partial and then emergency braking.

IMPORTANT The negative acceleration (deceleration) is restricted to 50% (approx. a = 5.0 m/s 2) of the maximum brake power.

DISTRONIC PLUS is thereby deactivated. The driver is notified of this by emission of an intermittent tone over the warning buzzer in the instrument cluster, and a warning indicator in the instrument cluster's multifunction display. The driver can subsequently reactivate the DISTRONIC PLUS.

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Initial parameters:

Securing the vehicle using the DISTRONIC PLUS function (standstill control) does not replace securing the vehicle for parking.

Technical implementation 

To do this, the radar sensors control unit (with CODE 23P (Driving Assistance package Plus)) receives and sends the following information or requests:

Input factors:

Initial parameters:

The following traffic situations show the limits of DISTRONIC PLUS:

Obstacles and stationary vehicles

The DISTRONIC PLUS does not brake for obstacles or stationary vehicles which were not previously registered as the target object. If, for example, the detected vehicle turns off and there is an obstacle or a stationary vehicle behind it, no automatic intervention by the brake system occurs.

Fig 7: Overview Of Traffic Situations (Obstacles And Stationary Vehicles)
G07300324Courtesy of MERCEDES-BENZ USA

Curves, curved entrances and exits:

The DISTRONIC PLUS can only provides limited detection of vehicles in curves. One's own vehicle can then brake unexpectedly or late.

Fig 8: Overview Of Traffic Situations (Curves, Curved Entrances And Exits)
G07300325Courtesy of MERCEDES-BENZ USA

Vehicles moving across in front of one's own vehicle:

DISTRONIC PLUS may detect vehicles in cross traffic by mistake.

For an activated distance control the vehicle can start off unintended, (e g. at a traffic light with cross-traffic).

Fig 9: Overview Of Traffic Situations (Vehicles Moving Across In Front Of One's Own Vehicle)
G07300326Courtesy of MERCEDES-BENZ USA

Lane change by other vehicles:

The DISTRONIC PLUS does not yet detect the vehicle moving into the lane. The distance to the vehicle moving into the lane becomes too small.

Fig 10: Overview Of Traffic Situations (Displaced Driving Style)
G10050075Courtesy of MERCEDES-BENZ USA

Narrow vehicles:

DISTRONIC PLUS does not detect the vehicle in front at the edge of the carriageway because of its narrow width. The distance to the vehicle in front becomes too small.

Fig 11: Overview Of Traffic Situations (Narrow Vehicles)
G10050077Courtesy of MERCEDES-BENZ USA
Electrical function schematic for DISTRONIC PLUS with Steer Assist and Stop & Go Pilot PE30.30-P-2066-97NBA 
Overview of system components for driver assistance systems GF54.00-P-9998GN
scientia non olet · About LEMON Manuals