Bosch FR5CUEC User manual

Chassis Systems Control
Leonberg
20 December 2021
Page 1 of 15
From
XC-DA/ESR1
Robert Binder
User Manual ITA
Model: FR5CUEC
Content
1Description of FR5CUEC parts ..........................................................................................2
2Explanation of CW Radar function .....................................................................................3
3Operating principal of the FR5CUEC .................................................................................5
4National Statements ..........................................................................................................6
4.1.1 European Union...................................................................................................6
4.1.2 United Kingdom ...................................................................................................6
4.1.3 Canada................................................................................................................6
4.1.4 United States.......................................................................................................6
5User information ................................................................................................................7
5.1 Principle......................................................................................................................7
5.2 Features and mechanical design................................................................................8
5.3 Areas of app
li c at i on ...................................................................................................8
6Vehicle Integration...........................................................................................................10
6.1 Radar Cone ..............................................................................................................10
6.2 Fascia design guidelines ..........................................................................................11
6.3 Installation hints........................................................................................................12
7Technical Data.................................................................................................................15

Chassis Systems Control
Leonberg
20 December 2021
Page 2 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
1Description of FR5CUEC parts
Figure 1: FR5CUEC expanded view
Radome
Absorber
PCB
Heat dissipation
pads
Connectors
Lower part of housing

Chassis Systems Control
Leonberg
20 December 2021
Page 3 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
2Explanation of CW Radar function
Continuous-wave radar is a type of radar system where a known stable frequency
continuous-wave radio energy is transmitted and then received from any reflecting objects.
Continuous-wave (CW) radar uses Doppler, which renders the radar immune to interference
from large stationary objects and slow moving clutter.
Maximum distance in a continuous-wave radar is determined by the overall bandwidth and
transmitter power. This bandwidth is determined by two factors.
•Transmit energy density (watts per Hertz)
•Receiver filter size (bandwidth divided by the total number of filters)
Frequency-modulated continuous-wave radar (FM-CW) – also called continuous-wave
frequency-modulated (CWFM) radar – is a short-range measuring radar set capable of
determining distance. This increases reliability by providing distance measurement along with
speed measurement, which is essential when there is more than one source of reflection arriving
at the radar antenna. This kind of radar is often used as "radar altimeter" to measure the exact
height during the landing procedure of aircraft. It is also used as early-warning radar, wave radar,
and proximity sensors. Doppler shift is not always required for detection when FM is used.
In this system the transmitted signal of a known stable frequency continuous wave varies up
and down in frequency over a fixed period of time by a modulating signal. Frequency difference
between the receive signal and the transmit signal increases with delay, and hence with
distance. This smears out, or blurs, the Doppler signal. Echoes from a target are then mixed
with the transmitted signal to produce a beat signal which will give the distance of the target after
demodulation.
A variety of modulations is possible, the transmitter frequency can slew up and down as follows :
•Sine wave, like air raid siren
•Sawtooth wave, like the chirp from a bird
•Triangle wave, like police siren in the United States
•Square wave, like police siren in the United Kingdom
Range demodulation is limited to 1/4 wavelength of the transmit modulation. Instrumented range
for 100 Hz FM would be 500 km. That limit depends upon the type of modulation and
demodulation.

Chassis Systems Control
Leonberg
20 December 2021
Page 4 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
Sawtooth modulation is the most used in FM-CW radars where range is desired for objects that
lack rotating parts. Range information is mixed with the Doppler velocity using this technique.
Modulation can be turned off on alternate scans to identify velocity using unmodulated carrier
frequency shift. This allows range and velocity to be found with one radar set. Triangle wave
modulation can be used to achieve the same goal.
As shown in the figure the received waveform (green) is simply a delayed replica of the
transmitted waveform (red). The transmitted frequency is used to down-convert the receive
signal to baseband, and the amount of frequency shift between the transmit signal and the
reflected signal increases with time delay (distance). The time delay is thus a measure of the
range; a small frequency spread is produced by nearby reflections, a larger frequency spread
corresponds with more time delay and a longer range.
Ranging with an FM-CW radar system: if the error caused by a possible Doppler frequency
can be ignored and the transmitter's power is linearly frequency modulated, then the time
delay is proportional to the difference of the transmitted and the received signal at any
time
References for chapter 2 of this document:
https://en.wikipedia.org/wiki/Continuous-wave_radar
This work is released under CC-BY-SA: http://creativecommons.org/licenses/by-sa/3.0/

Chassis Systems Control
Leonberg
20 December 2021
Page 5 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
3Operating principal of the FR5CUEC
The radar sensor’s main task is to detect
o b j e c t s
and measure their speed and position relative
to
t he movement of the vehicle in which it is mounted.
To do this, the FR5CUEC senses targets by emitting many short frequency modulated waves
using the transmit antennas while receiving waves reflected by targets using the receive
antennas.
Distance and relative speed are determined via beat frequency (due to travelling time of the
waves) and phase differences between ramps (due to change of distance in short time). By
using the antenna diagramm the angles of departure and arrival of the radar waves can be
determined.
Using the Bosch chirp sequence radar modulation, the FR5CUEC allows unambiguous
determination of relative speed in a single measurement cycle. Therefore, no complex object
models are needed for ambiguity resolution.
The radar reflections (strength, distance and relative speed, angular direction, and derived
values) are basis for building a comprehensive model of the sensed environment.

Chassis Systems Control
Leonberg
20 December 2021
Page 6 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
4National Statements
4.1.1 Exposure information (all countries)
This device should be installed and operated with minimum distance of 20 cm between the
front of device and human body.
4.1.2 United Kingdom
This device should be installed and operated with minimum distance of 20 cm between the
front of device and human body.
4.1.3 Canada
This device complies with Industry Canada license-exempt RSS standard(s). Operation is
subject to the following two conditions:
(1) this device must not cause interference, and
(2) this device must accept any interference, including interference that may cause undesired
operation of the device.
This equipment complies with the IC radiation exposure limits for an uncontrolled environment.
This equipment should be installed and operated with a minimum distance of 20 cm between
the radiation source and your body.
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio
exempts de licence. L'exploitation est autorisée aux deux conditions suivantes:
(1) l'appareil ne doit pas produire de brouillage, et
(2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le
brouillage est susceptible d'en compromettre le fonctionnement.
Cet équipement est conforme aux limites d'exposition aux rayonnements IC établies pour un
Environnement non contrôlé. Cet équipement doit être installé et utilisé avec un minimum de
20 cm de distance entre la source de rayonnement et votre corps.
4.1.4 United States
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) this device may not cause harmful interference, and
(2) this device must accept any interference received, including interference that may
cause undesired operation.

Chassis Systems Control
Leonberg
20 December 2021
Page 7 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
Changes or modifications made to this equipment not expressly approved by Robert Bosch
GmbH may void the FCC authorization to operate this equipment.
This equipment has been tested and found to comply with the limits for a Class A digital
device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio frequency energy and, if
not installed and used in accordance with the instruction manual, may cause harmful
interference to radio communications. Operation of this equipment in a residential area is likely
to cause harmful interference in which case the user will be required to correct the interference
at his own expense.
Radiofrequency radiation exposure Information:
This equipment complies with FCC radiation exposure limits set forth for an uncontrolled
environment. This equipment should be installed and operated with minimum distance of 20
cm between the radiator and your body.
This transmitter must not be co-located or operating in conjunction with any other antenna or
transmitter.
5User information
5.1 Principle
The FR5CUEC radar sensor and control unit (SCU) contains a FMCW radar transceiver
operating in the globally harmonized frequency range of 76.0 - 77.0 GHz. It senses targets by
emitting many short frequency modulated waves using the transmit antennas while receiving
waves reflected by targets using the receive antennas. Distance and relative speed are
determined via beat frequency (due to travelling time of the waves) and phase differences
between ramps (due to change of distance in short time). By using the antenna diagram the
angles of departure and arrival of the radar waves can be determined.
Using the Bosch chirp sequence radar modulation, the FR5CUEC allows unambiguous
determination of relative speed in a single measurement cycle. Therefore, no complex object
models are needed for ambiguity resolution.
The radar reflections (strength, distance and relative speed, angular direction, and derived
values) are basis for building a comprehensive model of the sensed environment.

Chassis Systems Control
Leonberg
20 December 2021
Page 8 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
5.2 Features and mechanical design
The high level of integration of the sensor and control unit functionalities, along with the
compact design and space-saving planar antenna, mean that the system can be easily
integrated into vehicles. The FR5CUEC can be concealed in the bumper or fitted in the radiator
grill of the vehicle, with minimal impact on the design or cooling air flow.
The FR5CUEC is equipped with a function for self-calibration. Once the sensor has been fitted
in the vehicle, it automatically searches for reference points during the first journey, and then
uses these reference points to calculate the sensor axis deviation from the dynamic driving
axis. The system software then compensates for this deviation. While the system is “learning”
this reference information, certain functions may be deactivated or restricted. In order to
achieve maximum performance on delivery, the system must be calibrated during the final
stages of series production using a defined reference point. Time-consuming and expensive
mechanical sensor calibration processes are not required.
Thanks to the robust sensor design, which does not have any mechanical moving parts and
features a high tolerance for vibration, the FR5CUEC can be used across all vehicle segments.
Radom heating is available as an option for the FR5CUEC – guaranteeing high sensor
availability, even in poor weather conditions, such as snow and ice.
5.3 Areas of a pp li c at i on
The FR5CUEC is the foundation on which a range o
f sa f e t y and driver assistance functions
can be implemented. The FR5CUEC can be used for the following functions:
Predictive emergency braking system
With the FR5CUEC, vehicle manufacturers can meet the requirements for the automatic
emergency braking systems “AEB City” and Interurban” as outlined in the Euro NCAP
assessment scheme.
With its predictive emergency braking system, Bosch is helping to prevent rear-end collisions
and reduce the severity of accidents. The system becomes active as soon as the vehicle is
started, and supports the driver at all speeds – both day and night.
If the predictive emergency braking system determines that the distance to the preceding
vehicle is becoming critical short at a vehicle speed above 5km/h, it prepares the braking
system for potential emergency braking. If the driver does not react to the hazardous situation,
the system warns the driver via an audible and/or visual signal, followed by a short but
noticeable brake jerk.
The system then initiates partial braking to reduce the speed and give the driver valuable time
to react. As soon as the driver presses the brake pedal, the system provides braking support.
To do this, the system continuously calculates the degree of vehicle deceleration required to

Chassis Systems Control
Leonberg
20 December 2021
Page 9 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
avoid the collision. If the system detects that the driver has failed to apply sufficient brake force,
it increases the braking pressure to the required level so that the driver can attempt to bring
the vehicle to a standstill before a collision occurs.
If the driver fails to react to the immediate risk of collision, and the predictive emergency
braking system detects that a rear-end-collision is unavoidable, it can – working conjunction
with a video camera – automatically initiate full braking. As a result, the vehicle is traveling at
significantly reduced speed when the collusion occurs, reducing the severity of the crash for
the passengers of both vehicles.
If the predictive emergency braking system detects that the distance to a moving or stationary
vehicle in front is becoming critically short at a vehicle speed below 30km/h (18mph), it
prepares the braking system for a potential emergency braking procedure. If the driver fails to
react to the critical situation, the system can automatically initiate full braking in an attempt to
prevent the collision. If the rear-end collision is unavoidable, this action can at least minimize
the severity of the collision, reducing the risk of injury to the passengers of both vehicles.
Heading distance indicator
This function measures the distance from the vehicle ahead and, depending on the speed at
which the vehicle is travelling, warns the driver when the safe distance from the vehicle in front
is not being maintained. The function does not intervene independently, but instead informs
the driver of the distance from the vehicle in front via a visual and/or audible signal.
Sensor data fusion
The FR5CUEC can utilize sensor data fusion without the need for additional hardware. Sensor
data fusion combines the benefits of different sensors and measuring principles in the most
effective way possible, providing data that individual sensors working in isolation are unable to
generate. Fusion of multiple sensors increases the measurement range, reliability and
accuracy.
Video sensors, such as the multi-purpose camera or the stereo video camera from Bosch, are
the ideal supplement to radar technology. Using powerful software algorithms, the fusion of
sensor data generates an extremely detailed “image”, which forms the basis for a powerful
interpretation of the vehicle`s surroundings.
Sensor fusion enables the implementation of additional assistance and safety functions, such
as pedestrian protection (“AEB Pedestrian”). The function for predictive pedestrian protection
meets the safety requirements as specified by Euro NCAP.
It continually monitors, in combination with a video camera, the area in front of the vehicle in
order to detect impending collisions with pedestrians who are in the path of the vehicle or
moving toward it in a way that is likely to present a risk. If the function detects that pedestrians

Chassis Systems Control
Leonberg
20 December 2021
Page 10 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
are at risk, it can actively trigger application of the brakes in order to considerably reduce the
risk and the consequences of the collision, or to prevent the accident altogether.
Sensor data fusion can also be used to significantly improve the performance of the comfort
functions. Thanks to the high degree of lateral measuring accuracy of a video camera, the
ACC function is able, for example, to detect vehicles merging at an earlier stage, and therefore
respond in a more dynamic manner. The system also ensures that vehicles in front are
assigned to the correct lanes, which further enhances ACC functionality, especially when
cornering.
6Vehicle Integration
This chapter describes the requirements for all parts mounted in front or around the sensor,
like painted bumper, unpainted cover and emblem/radome, regarding RF integration at 77 GHz
with FR5CUEC radar sensors.
The radar sensor performance should be influenced as low as possible by the installation
behind a fascia. Therefore the two-way radar loss by the fascia should be as low as possible
and the reflection attenuation must fulfill the requirements listed below.
Vertical misalignment will cause additional attenuation reducing the maximum range.
Horizontal misalignment will cause reduced detection at higher azimuth angles.
Ghost target detection caused by interference signals of multiple reflection at fascia and
metallic parts of the vehicle must be avoided. A simulation can be offered to evaluate the risk
and the need of using absorber material to suppress this unwanted signal. Because the
threshold of detection is very low, a high attenuation is required. Plastic material can only
achieve high enough attenuation, if carbon black is added.
Scope of FR5CU vehicle integration
The FR5CUEC requires the installation in the front center of the vehicle. The normal vector of
the sensor shall be directed in driving direction.
6.1 Radar Cone
Radar Cone for FR5CU

Chassis Systems Control
Leonberg
20 December 2021
Page 11 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
The radar cone describes the zone where the fascia has to be optimized. Any parts of the vehicle
inside the radar cone may influence the radar performance. Cables, brackets, bars etc. should
not touch the radar cone. The fascia in this zone may not have bends and edges as well as
changes in thickness or material or painting.
Based on the footprint on the top side of the radar PCB the cone is characterized by a vertical
and a horizontal opening angle. The footprint is centered regarding to the sensor housing. A
CAD model of the radar cone is available. The footprint for radar cone has the following
dimensions: (W x H) 95 mm x 84 mm
Radar cone definition for covered installation FR5CU:
The horizontal opening angle depends on the angle range that is evaluated by the sensor in
azimuth and elevation.
Radar cone:
•±75° in horizontal direction (not including misalignment)
•±25° in vertical direction (not including misalignment)
6.2 Fascia design guidelines
Material
Material with low dielectric constant (εr) and low dielectric loss factor tanδat 77 GHz should be
used. Recommended are materials based on polypropylene (PP) and polymethyl methacrylate
(PMMA), while materials like polycarbonate (PC) and acrylonitrile butadiene styrene (ABS) are
still ok. The material shall be homogenous, compounds including glass fiber, carbon fiber or
metal particles are not recommended.
The fascia shall be designed for radar transparency. The thickness shall be a multiple of the
half wavelength (in the material) to minimize the influence of the fascia. The quality criteria of
radar transparency is the reflection coefficient of the radome/fascia. Tolerances of the overall
thickness and the dielectric constant of the used material influence the amount of reflection at
the radome/fascia. Additional influence occurs due to curvature of the fascia. Therefore the
radius has to be as large as possible. With sharp edges the negative influence will increase
significantly. Not allowed are ribs, structures and steps changing the thickness of the
radome/fascia.
Painting
The layer structure of the painting, typically made of three painting layers consisting of primer,
base coating and clear coating, will increase the effective permittivity value εr,eff and dielectric
loss factor tanδof the painted plate used as fascia.

Chassis Systems Control
Leonberg
20 December 2021
Page 12 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
Fascia Classification (FR5CUEC)
The two-way radar loss caused by fascia should be as low as possible. High losses decrease
the sensor performance regarding range and angle estimation. Therefore it is recommended
to achieve a two-way radar loss below 3 dB.
Surface Properties of the fascia
The surfaces of the fascia shall not exceed an average roughness height of 20 µm
(corresponding to ISO 1302 class N10; VDI 3400 class 45).
6.3 Installation hints
To enable the full performance of the radar sensor, it is recommended to use the following
installation hints and guidelines for the RF integration of the sensor.
Maximum angle between radar cone and fascia
The angle αbetween the radar beam inside the radar cone and the fascia may not be larger
than 70° anywhere inside the radar cone.
Figure: Maximum angle between fascia and radar cone
Minimum distance between sensor and fascia

Chassis Systems Control
Leonberg
20 December 2021
Page 13 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
The minimum distance between the sensor radome and the fascia or any other part of the
vehicle may not be smaller than 5 mm tbc.
This is valid for fascia parts fulfilling the following requirements.
Figure: Minimum distance above sensor radome
Curvature of fascia for FR5CU
Curvature of the fascia may influence the radar performance, especially with low vertical tilt
angles. The minimum radius of the curvature shall be according to the following rules:
Fascia thickness up to 4 mm:
R > 500 mm, no significant influence expected
R < 500 mm, significant influence possible, has to be evaluated
R < 300 mm, significant influence expected, not recommended
Fascia thickness up to 8 mm:
R > 900 mm, no significant influence expected
R < 900 mm, significant influence possible, has to be evaluated
R < 700 mm, significant influence expected, not recommended
Reflection from outside the radar cone
Reflections from structures located outside the radar cone have to be avoided.
Furthermore interference signals picked up by the sensor antennas should be avoided by
keeping a minimum distance (d) of 5 mm to 10 mm for parts in front of the sensor.
Even with compliance to the radar cone, reflections at parts outside the radar cone may disturb
the received signal. Reflections at parts causing an interference signal to the receiving antenna
and reflections at parts getting to the receiving antenna after a second reflection at the fascia
(multipath reflection).
Closed surfaces of brackets and masks made of metal or high reflecting material need a tilt
angle being arranged that the reflection is not received by the receiving antennas of the sensor.

Chassis Systems Control
Leonberg
20 December 2021
Page 14 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
Multipath reflection
Incident RF waves are reflected between components (e.g. the sensor itself, the sensor
bracket or an absorber cone) and the sensor cover. The sensor performance can be
deteriorated if the reflections hit the sensor. As acountermeasure, the surface tilt angles of
these components and their locations have to be choosen in a way that reflections do not reach
the sensor.
References for Chapter 5 of this document:
FR5CU - Technical Customer Documentation.doc

Chassis Systems Control
Leonberg
20 December 2021
Page 15 of 15
Model
Document
Dept.
FR5CUEC
User Manual ITA
XC-DA/ESR1
7Technical Data
Frequency Band: 76 - 77 GHz
Transmit Power (EIRP pk): 37.79 dBm
Transmit Power (EIRP avg): 21.89 dBm