Geely Emgrand X7. Manual part — 509

11.3.3 System work principle

11.3.3.1 Schematic diagram of navigation system

NL11-2020b

11.3.3.2 GPS system-A-GPS

A GPS is used to locate a user on the
earth. Each GPS satellite revolves
around the earth for two circles each
day, so signals from more than 4 GPS
satellites can be received from
anywhere on the earth. By using these
signals, the computer can calculate the
exact coordinates (longitude and
latitude) of the user on the earth. After
the receiver receives these signals, the
current three-dimensional position,
three-dimensional direction and the
motion speed and time and the like are
obtained through calculation. The GPS
receiver usually employs
pseudo-range measurement, carrier
phase measurement, satellite radio
interferometry, doppler measurement,
etc.

x

y

z

(x1、y1、z1)

(x2、y2、z2)

(x3、y3、z3)

(x4、y4、z4)

NL11-2021b

Antenna unit

Front amplifier

Frequency converter

Speed sensor

Speed signal

Receiver unit

Measure, calculation

Inspection, correction

Gyroscope sensor

Detect calculation direction

changed

Map matching correction

Map database

Figure out vehicle

position data of front

vehicle

Microprocessor

Monitor

Audio output

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11.3.3.3 Self-discipline

When the vehicle is driven in underground tunnels, high-rise buildings, highways and other cover
materials and can not receive the GPS satellite signal, the system can automatically enter into
autonomous navigation. At this time, the vehicle speed sensor measures the vehicle speed from the
forward speed and calculates the vehicle speed through the microprocessor.

Calculate the forward distance of the vehicle. Gyro sensor is used for directly detecting the change
and traveling state forward. For example, when the vehicle traveling in groove-like mountain path,
annular disc-shaped bridge and in-situ sliding district of trail, all these curve distance and the
longitude and latitude of satellite navigation produce error; thus, the position of the vehicle only
can be detected by the detection of a gyro sensor and the calculation of a microprocessor.
However, its positioning precision is far below that of GPS (Global Positioning System).

11.3.3.4 Map matching technology

The electronic map distinguished by
the microprocessor is the nodded data.

NL11-2022b

Both the vehicle position coordination data and the forward direction detected by GPS satellite
navigation and autonomous navigation device are different from the actual travel route traces
certainly. In order to correct the errors of the both with the unification of the route on the map, a
map matching technique needs to be used; at this time, the microprocessor performs relevant
real-time matching and automatic correction on the vehicle driving route and the road error on the
electronic map. Vehicle arterial traffic, road map and urban traffic map are reserved into the map
database. Before driving, the driver inputs the city, street and place name to go into the processor
through an input interface; the processor determines the orientation of the place to go according to
the actual measurement data, such as speed sensor, gyroscope sensor and the like and by virtue of
the signal of the satellite as well as marks the best route of the place to go according to the
attribute of the current route planning. The driver can observe the map of area where the vehicle is
and the position of the vehicle on the map on the screen at any time through the display screen in
the vehicle in the driving process. The display screen can further display the rest distance to the
destination. Meanwhile, the relevant information is output via audio and prompts the driver via
voice.

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11.3.4 Part position

11.3.4.1 Component position

MUTE

PHONE

MEDIA

SEEK

SEEK

SET

micro

RADIO

NAV

MIC

4

6

2

1

5

5

1

3

3

NL11-2023b

1. Front door high -pitch speaker

2. Main host of navigation.

3. Front

door

loudspeaker.

4. Functional

instrument

5. Steering wheel wire control switch

6. GPS

antenna

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11.3.5 Electrical schematic diagram

11.3.5.1 Diagnostic schematic diagram

NL11-2024b

GPSantenna

Radio antenna

Combination

instrument

Park brake

switch

Steering wheel

switch

Speed signal

Stop signal

Remotecontrol signal

Navigation

main

machine

Speaker

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