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 

2035

 

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. 

2036

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

 

2037

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 

2038