This paper focuses on the 3-axis MEMS gyroscope, 3-axis MEMS accelerometer study spatial orientation. In order to avoid the influence of the environment on the positioning of the text based on physical principles established sports model, combining coordinate transformation method, the microcontroller STM32 platform with integrated 3-axis MEMS gyroscope, 3-axis MEMS accelerometer chip MPU60x0 designed a new space positioning system, and using I2C protocol to transfer information. The system is highly integrated, simple circuit, small size, low power consumption, easy expansion, easy maintenance, etc., can be used as an adjunct to a wireless network based positioning, improve positioning accuracy, precision can also be positioned relatively low areas applications.

1. International Journal of Research in Engineering and Science (IJRES)
ISSN (Online): 2320-9364, ISSN (Print): 2320-9356
www.ijres.org Volume 3 Issue 11 ǁ November. 2015 ǁ PP.18-21
www.ijres.org 18 | Page
Design and Implementation of Spatial Localization Based on Six
－axis MEMS Sensor
WU Xiang1
, QIAN Li2
1,2(College of Mechanical Engineering, Shanghai University of Engineering Science, China)
PROJRCT NUMBER: 15KY0104
2,Correspondence author. Email: ql0327@163.com
Abstract: This paper focuses on the 3-axis MEMS gyroscope, 3-axis MEMS accelerometer study spatial
orientation. In order to avoid the influence of the environment on the positioning of the text based on physical
principles established sports model, combining coordinate transformation method, the microcontroller STM32
platform with integrated 3-axis MEMS gyroscope, 3-axis MEMS accelerometer chip MPU60x0 designed a new
space positioning system, and using I2
C protocol to transfer information. The system is highly integrated, simple
circuit, small size, low power consumption, easy expansion, easy maintenance, etc., can be used as an adjunct to
a wireless network based positioning, improve positioning accuracy, precision can also be positioned relatively
low areas applications.
Key words: accelerometer, gyro, space positioning, low power consumption, displacement, orbit.
I. INTRODUCTION
Using positioning technology, we can know the position of an object in a frame of reference. In real life, the
most commonly used positioning system, such as the use of satellite global positioning system or the use of base
transceiver stations for mobile phones to provide location-basedservices.[1]
However, to achieve indoor
positioning system there are still many restrictions, such as GPSpositioning entirely dependent on satellite signals,
so this technique can not be used inside buildings. On the other hand, the base station can be used to seamlessly
connect the phone to locate indoor, but the precision is very small, typically about 100 m to 35km.[2]
Therefore, the
limitation that they can not be achieved in indoor positioning.
When the user needs to know the location of the target in a building, indoor positioning becomes very
important. As firefighters need to understand their position in the building in order to better for the rescue effort.
Another method of indoor positioning is pedestrian dead reckoning. [3-4]
PDR technology is the use of a known
position as the starting position, by using an acceleration sensor for sensing a pedestrian steps, each step has a
displacement Correspondingly, real-time location estimation latest pedestrians.In previous studies it has been
done a number of related studies, they use a special sensor module, it can be installed in the helmet, attached to
the foot, or the use of inexpensive sensors are integrated in the smart phone and place to trouser pocket.
In view of this, the paper presents a new spatial positioning system. The system is based on MEMS sensors,
by collecting information on the target acceleration and angle generated in the course of the campaign, in the
host computer for information processing and trajectory calculations, based on signal strength indicator out of
position, so that the external environment has no effect on measurement accuracy and limitations to achieve
three-dimensional positioning.

2. Design and Implementation of Spatial Localization Based on Six－axis MEMS Sensor
www.ijres.org 19 | Page
II. POSITIONING SYSTEM HARDWARE DESIGN
2.1 THE OVERALL SYSTEM ARCHITECTURE
Use sensor senses acceleration and angular information, to achieve the target location, and calculate the
trajectory. The hardware system is highly integrated, low power consumption, easy to expand the features of
convenient data transfer and can achieve a broader application to lay a foundation for future expansion.
Overall system architecture shown in FIG 1.
MEMS triaxial
accelerometer
MEMS triaxial
accelerometer
Filterand AD
STM32 RS232
PC Information Processing
FIG 1 System block diagram
2.2 Hardware Design
MPU6050 is an integrated 3-axis MEMS gyroscope, 3-axis MEMS accelerometer, MPU6050 support SPI
and I2C two means of communication, in order to save I / O port, STM32 development board I2C connected.
I2C connection circuit shown in FIG 2.
FIG 2 I2
C connection circuit diagram
III. SENSOR IS POSITIONED TO ACHIEVE
3.1 DEAD RECKONING THEORY
Dead reckoning on the premise that know the initial position of the target, and the target can sense
acceleration in real time. Assuming that the initial position at the origin, then simply perceive real-time
acceleration goals.
Since the sampling data is discrete, so MEMS sensor sampling interval is t , after iterations can be
obtained:
Wherein the speed determined by the following formula iteration:
)1(
4
][]1[
]1[
2
][]1[
]1[][
2






nt
nana
tnv
t
nvnv
nsns

3. Design and Implementation of Spatial Localization Based on Six－axis MEMS Sensor
www.ijres.org 20 | Page
Therefore, when the rotation sensor node, the system simply subtracting the measured acceleration g on the
shaft of the component, and then obtained by iteration node trajectory in space.
3.2 REMOVAL DIRECTION OF GRAVITY ACCLERATION COMPONENT
Moving targets, the sensor will rotate, then the sensor X, Y, Z axis no longer coincides with the target
location coordinates of space objects OXYZ, sensor coordinate system X, Y, Z-axis direction component will be
the acceleration of gravity g.
To solve this problem, the system for recording space by the posture sensor gyroscope g calculated by the
coordinate transformation components. [4]
Let sensor location coordinates OX1Y1Z1 and space coordinates OXYZ angle vector ω as: ω = φ + θ + γ,
then along the coordinate system OX1Y1Z1 projection (ωx, ωy, ωz) have the following relationship:
Can be obtained from the above equation:
Where, ωx, ωy, ωz that can be measured by a gyroscope. By solving this Euler differential equation can be
obtained numerical parameters φ, θ and γ's. Therefore, in the coordinate system OX1Y1Z1 g component (gx, gy,
gz) as follows:
Table 1 triaxial accelerometer and a triaxial accelerometer data
Xg/(deg/s) Yg/(deg/s) Zg/(deg/s) Xa/(m/s2
) Ya/(m/s2
) Za/(m/s2
)
-14 -35 -14 -1132 -5734 13486
-13 -34 -14 -1138 -5752 13480
-14 -35 -15 -1132 -5748 13504
-14 -34 -15 -1140 -5738 13512
-14 -34 -14 -1152 -5746 13488
-14 -35 -14 --1136 -5734 13484
)1(
2
][]1[
]1[][ 

 nt
nana
nvnv



















































 






























 




























0sincoscos
10sin
0coscossin
0
0
0
0
cos0sin
010
sin0cos
0
0
cossin0
sincos0
001
cos0sin
010
sin0cos
z
y
x

































z
y
x










cossincossinsin
cossin0sincos
cos0sin
cos
1


































gg
g
g
z
y
x
0
0
coscoscossincoscossinsinsincoscossin
sincoscossincos
cossincossinsinsincossinsinsincoscos




4. Design and Implementation of Spatial Localization Based on Six－axis MEMS Sensor
www.ijres.org 21 | Page
-14 -35 -14 -1140 -5756 13484
-14 -34 -14 -1140 -5734 13498
-14 -35 -14 -1132 -5748 -13504
IV. CONCLUSION
Table 1 collected data triaxial accelerometer and triaxial angular variation data, through iteration, you can
get the target displacement sensor coordinate system along each axis and the current instantaneous speed.
According to vector addition, data can be integrated 3-axis from the PC, you can get track targets.
3-axis MEMS sensor can output a three-dimensional acceleration nodes ][],[],[ nanana zyx can calculate the
instantaneous velocity and displacement nodes X, Y, Z axis can be obtained by the vector addition of nodes
trajectory. The design of the localization algorithm based sensor devices are installed in the carriage of the body,
the motion information is not dependent on the external environment perception, and affect the accuracy of less
susceptible to environmental interference, is an autonomous positioning system. The design is based MEMS
sensors can be combined with other positioning systems, assisted positioning, such as addressing individual use
WiFi location positioning or circumstances exist base jumping positioning process. [5-6]
In addition, an important
value in relatively low positioning accuracy requirements in the field.
REFERENCES
[1.] Li Tianwen. GPS Principles and Applications [M]. Beijing: Science Press, 2003.(in Chinese)
[2.] Dulya B.GSM-positioning-outdoorpositioning: technolo-gies, characteristics, and limitations [EB / OL]. [2013－09]. http://
www.ks.uni-freiburg.de /.
[3.] Lei Fang, Antsaklis P J, Montestruque LA, et al. Design of awireless assisted pedestrian dead reckoning system-the Nav-Mote
experience [J]. IEEE Transactions on Instrumentation and Measurement, 2005, 54(6): 2342-2358. (in Chinese)
[4.] Xu Rui, Sunyong Rong, Chen Wu, et al. Pedestrian navigation algorithm based on robust filtering [J]. Systems Engineering and
Electronics, 2010, 32 (7): 1506-1508. (in Chinese)
[5.] Li Wenzhong, section towards Yu Zigbee2007 / Pro Stack experiment and practice [M] Beijing: Beijing University of
Aeronautics and Astronautics Press, 2010. (in Chinese)
[6.] Su Sanqing MEMS-based acceleration sensor space trajectory tracking system design and implementation [D] Wuhan: Huazhong
University of Science and Technology, 2009. (in Chinese)