Collision Avoidance and Parking Assist Systems: Description and Operation
66 05 04 (119)
Park Distance Control
E70, E87, E90, E91, E92, E93, R56
Introduction
Park Distance Control (PDC) is an item of special equipment. Park Distance Control (i.e.: parking aid) assists the driver when he is parking and manoeuvring in tight spaces. This means that even small parking spaces can be used. At the same time, parking damage is reduced.
PDC uses ultrasonic sensors to measure the distance to objects within the effective range.
> - E70 (system supplier Valeo)
[System overview]
> - E87, E90, E91, E92, E93 (system supplier Bosch)
> - R56 (system supplier Bosch)
PDC is available in the following versions:
- Option 507: Park Distance Control (PDC), rear
- Option 508: Park Distance Control (PDC), front and rear
The PDC button in the centre console switch cluster is only provided with option 508.
Compared to earlier systems, PDC has the following new features:
- Modified ultrasonic sensor with decoupling element on sensor housing
- Increased range for ultrasonic sensor: 2.5 metres front and rear
- Good detection of obstacles while remaining insensitive to echo pulses from the ground
The driver is warned of an object that could cause a collision as follows:
- Acoustic warning via (depends on equipment fitted):
> - E70
- Mid-range loudspeakers with Multimedia Platform (CHAMP), Multi-audio system controller (M-ASK) or Car Communication Computer (CCC)
> - E87, E90, E91, E92, E93
- 2 acoustic generators (1 front, 1 rear) with radio without audio system
- Mid-range loudspeaker with BMW "Professional" radio, multi-audio system controller or Car Communication Computer
> - R56
- 1 acoustic generators (rear) with Radio Wave
- Mid-range loudspeaker with Radio Wave CD, Radio Boost CD or Car Communication Computer
- Visual warning by PDC image with multi-audio system controller and Car Communication Computer
The visual warning function in particular enables PDC to provide assistance for drivers who are hard of hearing or have restricted mobility.
The visual warning has additional benefits if the noise level inside the vehicle is very high (e.g. loud music).
Important: The driver remains responsible at all times
PDC is not a substitute for the driver's personal judgement with respect to obstacles.
The ultrasonic sensors also have a "blind spot". In this blind spot, objects can no longer be detected.
The detection of objects can test the physical limits of ultrasonic measurements if the ultrasonic waves are reflected either poorly or not at all (e.g. due to trailer tow bars or narrow objects).
Objects close to the ground can suddenly "disappear", before a continuous tone sounds (e.g. a high kerbstone).
Loud noises outside and inside the vehicle can drown out the PDC signal tone.
It therefore remains the driver's responsibility to watch for obstacles, even in vehicles with PDC.
Brief description of components
PDC consists of the following components:
- Ultrasonic sensors
> - E70
8 ultrasonic sensors with option 508: Park Distance Control (PDC), front and rear
> - E87, E90, E91, E92, E93
4 ultrasonic sensors with option 507: Park Distance Control (PDC), rear
8 ultrasonic sensors with option 508: Park Distance Control (PDC), front and rear
> - R56
4 ultrasonic sensors with option 507: Park Distance Control (PDC), rear
There are 4 ultrasonic sensors in each of the front and rear bumpers.
The ultrasonic sensors emit ultrasonic pulses. These ultrasonic pulses are reflected by obstacles (echo pulses).
The ultrasonic sensors receive and amplify these echo pulses. The amplified echo pulses are then converted into a digital signal. Each ultrasonic sensor has its own electronics, its own power supply and its own data connection to the PDC control unit.
Important: Measuring range of ultrasonic sensors
The measuring range of the ultrasonic sensors is between approx. 25 centimetres and a maximum of approx. 250 centimetres. A continuous warning tone sounds when the distance is less than about 25 centimetres.
Dirty sensors, moisture, ice and snow can also cause the continuous warning tone to sound.
Note: Cleaning the ultrasonic sensors
To make sure the system remains fully operational, keep the ultrasonic sensors clean and free from ice. Do not clean by spraying high-pressure washers directly at the ultrasonic sensors. When cleaning, always maintain a minimum distance of at least 10 centimetres.
Note: Make sure the decoupling element on ultrasonic sensor is correctly located.
The respective decoupling element must be correctly located. Otherwise, transmission and reception will be impaired.
- PDC button
> E70, E87, E90, E91, E92, E93
The PDC button is integrated in the centre console switch cluster (no control unit). The signal from the PDC button is read by the IHKA (or IHKR/IHR control unit) control unit. In turn, the IHKA control unit sends a signal on the K-CAN.
The PDC button is used to manually switch the Park Distance Control system on and off. When the PDC is switched on, the function LED in the PDC button lights up.
If a fault develops in the PDC, the function LED in the PDC button flashes.
- PDC control unit
The PDC control unit controls the ultrasonic sensors for transmitting ultrasonic pulses. The PDC control unit also receives the digital signals from the individual ultrasonic sensors. From the individual digital signals, the PDC control unit calculates the minimum distance between the ultrasonic sensor and the object.
When an object is detected, an acoustic warning and a visual warning are given.
> - E70
> - E87, E90, E91, E92, E93
> - R56
The PDC control unit is connected to various other control units via the bus system:
- RAD2, CHAMP, M-ASK or CCC: BMW "Professional" radio, Multimedia Platform, multi-audio system controller or Car Communication Computer
> E70, E87, E90, E91, E92, E93
Depending on the equipment fitted, the audio master emits acoustic PDC warnings via the mid-range loudspeaker.
- Radio Wave CD, Radio Boost CD or CCC: Radio Wave CD, Radio Boost CD or Car Communication Computer
> R56
Depending on the equipment fitted, the audio master emits acoustic PDC warnings via the mid-range loudspeaker.
- CID: Central Information Display
> E70, E87, E90, E91, E92, E93
The visual PDC warnings are given in the Central Information Display (CID).
In addition, information regarding a Check-Control message that may be present is shown.
- KOMBI: Instrument cluster
> E70, E87, E90, E91, E92, E93
A current Check-Control message is indicated by a symbol in the LCD display in the instrument cluster. Moreover, the instrument cluster also provides the exterior temperature and the kilometre reading for the PDC control unit.
The PDC control unit is then able to correct the calculated distance with a factor corresponding to the outside temperature.
- KOMBI and CID: Instrument cluster and Central Information Display
> R56
The instrument cluster has two section. The instrument cluster itself is in the middle of the dashboard. The auxiliary instrument is on the steering column.
The KOMBI and the CID are both control units. These control units are plugged into one another an installed together in the dashboard.
All equipment versions are connected to the auxiliary instrument via a K-bus.
The auxiliary instrument is the gateway to the K-CAN.
A current Check-Control message is indicated by a symbol in the LCD display in the auxiliary instrument.
The instrument cluster provides the exterior temperature and the kilometre reading for the PDC control unit. The PDC control unit is then able to correct the calculated distance with a factor corresponding to the outside temperature.
- EGS: Electronic transmission control
On vehicles with automatic transmission, the electronic transmission control (ESG) supplies the signal that reverse gear is engaged.
The PDC control unit activates PDC after a short delay (approx. 1 second).
This prevents PDC from being unexpectedly activated on vehicles with automatic transmission, fro example when the selector lever is moved from "P" to "N" via "R".
- DSC: Dynamic Stability Control
The DSC control unit supplies the PDC with information about the road speed and distance travelled.
- FRM: Footwell module
On vehicles with manual transmission, the footwell module (FRM) supplies the signal that reverse gear is engaged.
- CAS: Car access system
The CAS control unit supplies the PDC with the terminal status (e.g. terminal 15).
- AHM: Trailer module
The trailer module (AHM) sends a signal indicating whether the vehicle is towing a trailer or if a rear carrier rack is fitted. If a trailer or rear carrier rack is recognised, the acoustic and visual warnings for the rear bumper are deactivated.
System functions
PDC incorporates the following functions:
- Acoustic warnings
- Visual warning with multi-audio system controller and Car Communication Computer
- Check Control
- System limits
Acoustic warnings
The acoustic warnings are emitted by:
> - E70
- Mid-range loudspeaker with CHAMP, M-ASK or CCC
If an object is detected by 2 ultrasonic sensors, the loudspeaker closest to the object is actuated.
The mid-range loudspeakers can be actuated.
(depending on the model concerned, the mid-range loudspeakers in the left/right front doors or left/right rear doors are actuated, for example)
If an object is detected by the central ultrasonic sensors, the mid-range loudspeakers on the left and right-hand sides are actuated together.
> - E87, E90, E91, E92, E93
- 2 acoustic generators (1 front, 1 rear) with radio without audio system
The PDC control unit directly actuates the acoustic generators (front/rear in vehicle interior). Within the acoustic generator, the control signal is transformed to approx. 48 volts. This voltage excites a piezo-ceramic element that together with the resonator (housing) generates a warning tone.
Up to 09/2006, the tone is in the frequency range of approximately 1 kHz.
From 09/2006 the tone is in the frequency range of approximately 1.5 kHz (front) or 1.0 kHz (rear).
- Mid-range loudspeaker with RAD 2, M-ASK or CCC
If an object is detected by 2 ultrasonic sensors, the loudspeaker closest to the object is actuated.
The mid-range loudspeakers can be actuated.
(e.g. the mid-range loudspeakers in the front doors, left/right, in the rear shelf, left/right, in the rear doors, left/right, in the rear shelf, left/right or in the rear side trim, left/right are actuated, depending on the vehicle model.)
If an object is detected by the central ultrasonic sensors, the mid-range loudspeakers on the left and right-hand sides are actuated together.
> - R56
- 1 acoustic generator (rear) with Radio Wave
The PDC control unit directly actuates the acoustic generators (in rear of vehicle interior). Within the acoustic generator, the control signal is transformed to approx. 48 volts. This voltage excites a piezo-ceramic element that together with the resonator (housing) generates a warning tone. The tone is in the frequency range of approximately 1 kHz.
- Mid-range loudspeakers with Radio Wave CD, Radio Boost CD or CCC
If an object is detected by 2 ultrasonic sensors, the loudspeaker closest to the object is actuated. The mid-range loudspeaker on the left/right can be actuated.
If an object is detected by the central ultrasonic sensors, the mid-range loudspeakers on the left and right-hand sides are actuated together.
The distance to the object determines the tone sequence for the acoustic warning (the smaller the distance, the faster the tone sequence).
A distance of less than approx. 25 centimetres is indicated by a continuous tone. The continuous tone is emitted alternately from the front and the rear.
If the vehicle moves away from the object, the warning tone will be cancelled when the distance increases by more than 10 centimetres.
Effective range for acoustic warnings:
- approx. 60 centimetres for the ultrasonic sensors at the two corners of the front bumper
- approx. 70 centimetres for the two middle ultrasonic sensors in the front bumper
- approx. 60 centimetres for the ultrasonic sensors at the two corners of the rear bumper
- approx. 150 centimetres for the two middle ultrasonic sensors in the rear bumper
Optical warning with multimedia platform or multi audio system controller or Car Communication Computer
The visual PDC warnings are given in the Central Information Display (CID). This is subject to the PDC display in the CID being active.
The visual warnings are given earlier than the acoustic warnings.
The effective range is approx. 2.5 metres at the front and rear.
The graphic display is shown on the CID. The PDC control unit supplies the distance between the ultrasonic sensor and the object detected via the K-CAN.
The PDC display on the CID is an overhead view of the vehicle with the effective range of the ultrasonic sensors.
The distance to objects detected is shown in the colours of traffic lights:
- Distance between 200 (250) and 101 centimetres: green
- Distance between 100 an 51 centimetres: yellow
- Distance less than 50 centimetres: Red
The PDC display appears as soon as the PDC is switched on (manually or automatically). The PDC display overrides other displays in the CID. When the PDC is switched off again, the previous display automatically appears again in the Central Information Display.
Check Control
If a fault should develop in the PDC, the function LED in the PDC button will flash with a frequency of 2 Hz.
In this situation, PDC cannot be switched on.
At the same time, a Check-Control message is displayed in the following form
- Symbol in the LCD display in the instrument cluster
- The following text appears in the status line of the Central Information Display:
"PDC failure!"
In the menu "BMW Service", the following text can be called up in the submenu "Check-Control messages":
"Park Distance Control
No acoustic warning available for Park Distance Control PDC.
Have the problem checked by BMW Service as soon as possible."
If a fault memory entry is recorded, the kilometre reading and the outside temperature are recorded along with the type of fault.
System limits
Important: The driver remains responsible at all times
PDC is not a substitute for the driver's personal judgement with respect to obstacles.
The ultrasonic sensors also have a "blind spot". In this blind spot, objects can no longer be detected.
The detection of objects can test the physical limits of ultrasonic measurements if the ultrasonic waves are reflected either poorly or not at all (e.g. due to trailer tow bars or narrow objects).
Objects close to the ground can suddenly "disappear", before a continuous tone sounds (e.g. a high kerbstone).
Loud noises outside and inside the vehicle can drown out the PDC signal tone.
It therefore remains the driver's responsibility to watch for obstacles, even in vehicles with PDC.
During operation, the following system functions, which require explanation, can occur due to the limits of the functional range (for the driver):
- Under the following conditions, it could happen that the PDC gives a warning, even though there is no obstacle within the effective range:
- Ultrasonic sensor incorrectly located in its bracket
- Heavy rainfall
- Ultrasonic sensors covered in snow
- Exhaust gases
- Echo pulses caused by ground, e.g. extremely coarse road surface or high grass
- Very smooth walls in large, enclosed, rectangular spaces, e.g. in underground car parks (interference from previously reflected echo pulses)
- Protective cap for trailer coupling ball head incorrectly seated or objects being transported protruding into the effective range of the ultrasonic sensors.
- Under the following conditions, the PDC may not recognise an obstacle that is present:
- Objects close to the ground (no reflection)
- Objects with corners and sharp edges (no reflection)
- If you drive alongside a wall for more than 3 seconds, the acoustic warning will be deactivated. Here, the distance must be greater than the effective range for the continuous tone (approx. 25 centimetres). As soon as the distance drops below 25 centimetres, the continuous tone will sound again.
- If the vehicle approaches an object too fast
- Starting up and moving away too quickly while PDC is starting
Conditions for switching on and off
PDC is switched on under the following conditions:
- PDC button pressed (PDC switched on manually), option 508 only
- Reverse gear engaged (PDC switched on automatically)
PDC is switched off under the following conditions:
- Reverse gear disengaged, option 507 only
- PDC button pressed (PDC switched off manually), option 508 only
- Ignition switched off (PDC switched off automatically
- After driving approx. 50 metres
- After exceeding a speed of 30 km/h
When towing a trailer or driving with a rear carrier rack, the acoustic and visual warnings for the rear bumper are deactivated by the trailer module (AHM).
The trailer or rear carrier rack must be electrically connected.
Operation
The visual warning (PDC display) is switched on in the Central Information Display (CID) as follows:
- "Settings (i)" menu
- "Vehicle settings" menu
- "PDC" menu
- Activate "Display on"
Notes for service staff
The following information is available for service staff:
- General note:
- Diagnosis: ---
- Encoding/programming: ---
Japanese national version
So long as reverse gear is engaged, an acoustic signal (reversing gong) is given via the acoustic generator or the mid-range loudspeaker.
The reversing gong is deactivated immediately if the PDC detects an object in the effective range and emits its own acoustic warning.
Subject to change.